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Ionita D, Cristea M, Sava I, Popescu MC, Dobromir M, Simionescu BC. Temperature-Controlled Chain Dynamics in Polyimide Doped with CoCl 2 Probed Using Dynamic Mechanical Analysis. Materials (Basel) 2024; 17:753. [PMID: 38591621 PMCID: PMC10856759 DOI: 10.3390/ma17030753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 01/26/2024] [Accepted: 01/31/2024] [Indexed: 04/10/2024]
Abstract
Cobalt(II) chloride (CoCl2) being in the vicinity of polyimide chains entails modifications in terms of the molecular dynamics, which are mainly governed by the possible presence of amic acid residual groups, by the transition-metal-type characteristics of cobalt and by the CoCl2 content. Polyimide was synthesized using poly(amic acid) according to the reaction of 2,2'-bis(3,4-dicarboxylphenyl)hexafluoropropane dianhydride (6FDA) with 3,3'-dimethyl-4,4'-diaminodiphenylmethane (MMDA) in N,N-dimethylacetamide. CoCl2 was added before the thermal imidization of the poly(amic acid). An experimental approach was designed to establish the interaction between the polyimide and CoCl2 and whether the interaction depends on the quantity of the salt. Evidence for the existence of residual amic acid groups was obtained using second derivative Fourier Transform Infrared Spectroscopy (FTIR) and with the help of 2D correlation spectroscopy (2D-COS). Moreover, FTIR, along with X-ray photoelectron spectroscopy (XPS), revealed the interaction between the polymer and CoCl2, primarily in the form of Co(II)-N coordinated bonds. Nevertheless, the coordination of cobalt with suitable atoms from the amic acid groups is not precluded. The results of dynamic mechanical analysis (DMA) featured a specific relaxation assigned to the presence of CoCl2 in the polymeric film and demonstrated that its (non)reinforcing effect depends on its content in the polyimide.
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Affiliation(s)
- Daniela Ionita
- “Petru Poni” Institute of Macromolecular Chemistry, Aleea Grigore Ghica Voda 41A, 700487 Iasi, Romania; (D.I.); (I.S.); (M.-C.P.); (B.C.S.)
| | - Mariana Cristea
- “Petru Poni” Institute of Macromolecular Chemistry, Aleea Grigore Ghica Voda 41A, 700487 Iasi, Romania; (D.I.); (I.S.); (M.-C.P.); (B.C.S.)
| | - Ion Sava
- “Petru Poni” Institute of Macromolecular Chemistry, Aleea Grigore Ghica Voda 41A, 700487 Iasi, Romania; (D.I.); (I.S.); (M.-C.P.); (B.C.S.)
| | - Maria-Cristina Popescu
- “Petru Poni” Institute of Macromolecular Chemistry, Aleea Grigore Ghica Voda 41A, 700487 Iasi, Romania; (D.I.); (I.S.); (M.-C.P.); (B.C.S.)
| | - Marius Dobromir
- Department of Exact and Natural Sciences, Institute of Interdisciplinary Research, “Alexandru Ioan Cuza” University of Iasi, Blvd. Carol I 11, 700506 Iasi, Romania;
| | - Bogdan C. Simionescu
- “Petru Poni” Institute of Macromolecular Chemistry, Aleea Grigore Ghica Voda 41A, 700487 Iasi, Romania; (D.I.); (I.S.); (M.-C.P.); (B.C.S.)
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Staszczak M, Urbański L, Cristea M, Ionita D, Pieczyska EA. Investigation of Shape Memory Polyurethane Properties in Cold Programming Process Towards Its Applications. Polymers (Basel) 2024; 16:219. [PMID: 38257020 PMCID: PMC10819366 DOI: 10.3390/polym16020219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 01/05/2024] [Accepted: 01/10/2024] [Indexed: 01/24/2024] Open
Abstract
Thermoresponsive shape memory polymers (SMPs) with the remarkable ability to remember a temporary shape and recover their original one using temperature have been gaining more and more attention in a wide range of applications. Traditionally, SMPs are investigated using a method named often "hot-programming", since they are heated above their glass transition temperature (Tg) and after that, reshaped and cooled below Tg to achieve and fix the desired configuration. Upon reheating, these materials return to their original shape. However, the heating of SMPs above their Tg during a thermomechanical cycle to trigger a change in their shape creates a temperature gradient within the material structure and causes significant thermal expansion of the polymer sample resulting in a reduction in its shape recovery property. These phenomena, in turn, limit the application fields of SMPs, in which fast actuation, dimensional stability and low thermal expansion coefficient are crucial. This paper aims at a comprehensive experimental investigation of thermoplastic polyurethane shape memory polymer (PU-SMP) using the cold programming approach, in which the deformation of the SMP into the programmed shape is conducted at temperatures below Tg. The PU-SMP glass transition temperature equals approximately 65 °C. Structural, mechanical and thermomechanical characterization was performed, and the results on the identification of functional properties of PU-SMPs in quite a large strain range beyond yield limit were obtained. The average shape fixity ratio of the PU-SMP at room temperature programming was found to be approximately 90%, while the average shape fixity ratio at 45 °C (Tg - 20 °C) was approximately 97%. Whereas, the average shape recovery ratio was 93% at room temperature programming and it was equal to approximately 90% at 45 °C. However, the results obtained using the traditional method, the so-called hot programming at 65 °C, indicate a higher shape fixity value of 98%, but a lower shape recovery of 90%. Thus, the obtained results confirmed good shape memory properties of the PU-SMPs at a large strain range at various temperatures. Furthermore, the experiments conducted at both temperatures below Tg demonstrated that cold programming can be successfully applied to PU-SMPs with a relatively high Tg. Knowledge of the PU-SMP shape memory and shape fixity properties, estimated without risk of material degradation, caused by heating above Tg, makes them attractive for various applications, e.g., in electronic components, aircraft or aerospace structures.
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Affiliation(s)
- Maria Staszczak
- Institute of Fundamental Technological Research, Polish Academy of Sciences, 02-106 Warsaw, Poland; (M.S.); (L.U.)
| | - Leszek Urbański
- Institute of Fundamental Technological Research, Polish Academy of Sciences, 02-106 Warsaw, Poland; (M.S.); (L.U.)
| | - Mariana Cristea
- “Petru Poni” Institute of Macromolecular Chemistry, 700487 Iasi, Romania; (M.C.); (D.I.)
| | - Daniela Ionita
- “Petru Poni” Institute of Macromolecular Chemistry, 700487 Iasi, Romania; (M.C.); (D.I.)
| | - Elżbieta Alicja Pieczyska
- Institute of Fundamental Technological Research, Polish Academy of Sciences, 02-106 Warsaw, Poland; (M.S.); (L.U.)
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Pelin IM, Popescu I, Calin M, Rebleanu D, Voicu G, Ionita D, Zaharia MM, Constantin M, Fundueanu G. Tri-Component Hydrogel as Template for Nanocrystalline Hydroxyapatite Deposition Using Alternate Soaking Method for Bone Tissue Engineering Applications. Gels 2023; 9:905. [PMID: 37998995 PMCID: PMC10671408 DOI: 10.3390/gels9110905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 11/08/2023] [Accepted: 11/15/2023] [Indexed: 11/25/2023] Open
Abstract
Composite hydrogels containing apatite-like particles can act as scaffolds for osteoblast proliferation, with applications in bone tissue engineering. In this respect, porous biocompatible hydrogels were obtained from chitosan, oxidized pullulan, and PVA in different ratios. The stability of the hydrogels was ensured both by covalent bonds between aldehyde groups of oxidized pullulan and free amino groups of chitosan, and by physical bonds formed during freeze-thaw cycles and lyophilization. The deposition of calcium phosphates was performed by alternate soaking of the porous hydrogels into solutions with calcium and phosphate ions, assuring a basic pH required for hydroxyapatite formation. The mineralized hydrogels were characterized using FTIR spectroscopy, scanning electron microscopy, X-ray diffraction, and thermogravimetric analysis, showing that inorganic particles containing between 80 and 92% hydroxyapatite were deposited in a high amount on the pore walls of the polymeric matrix. The composition of the organic matrix influenced the crystallization of calcium phosphates and the mechanical properties of the composite hydrogels. In vitro biological tests showed that mineralized hydrogels support the proliferation of MG-63 osteoblast-like cells to a greater extent compared to pristine hydrogels.
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Affiliation(s)
- Irina Mihaela Pelin
- “Petru Poni” Institute of Macromolecular Chemistry, Grigore Ghica Voda Alley 41A, 700487 Iasi, Romania; (I.M.P.); (D.I.); (M.-M.Z.); (G.F.)
| | - Irina Popescu
- “Petru Poni” Institute of Macromolecular Chemistry, Grigore Ghica Voda Alley 41A, 700487 Iasi, Romania; (I.M.P.); (D.I.); (M.-M.Z.); (G.F.)
| | - Manuela Calin
- Institute of Cellular Biology and Pathology “Nicolae Simionescu” of the Romanian Academy, 050568 Bucharest, Romania; (M.C.); (D.R.); (G.V.)
| | - Daniela Rebleanu
- Institute of Cellular Biology and Pathology “Nicolae Simionescu” of the Romanian Academy, 050568 Bucharest, Romania; (M.C.); (D.R.); (G.V.)
| | - Geanina Voicu
- Institute of Cellular Biology and Pathology “Nicolae Simionescu” of the Romanian Academy, 050568 Bucharest, Romania; (M.C.); (D.R.); (G.V.)
| | - Daniela Ionita
- “Petru Poni” Institute of Macromolecular Chemistry, Grigore Ghica Voda Alley 41A, 700487 Iasi, Romania; (I.M.P.); (D.I.); (M.-M.Z.); (G.F.)
| | - Marius-Mihai Zaharia
- “Petru Poni” Institute of Macromolecular Chemistry, Grigore Ghica Voda Alley 41A, 700487 Iasi, Romania; (I.M.P.); (D.I.); (M.-M.Z.); (G.F.)
| | - Marieta Constantin
- “Petru Poni” Institute of Macromolecular Chemistry, Grigore Ghica Voda Alley 41A, 700487 Iasi, Romania; (I.M.P.); (D.I.); (M.-M.Z.); (G.F.)
| | - Gheorghe Fundueanu
- “Petru Poni” Institute of Macromolecular Chemistry, Grigore Ghica Voda Alley 41A, 700487 Iasi, Romania; (I.M.P.); (D.I.); (M.-M.Z.); (G.F.)
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Raman B, McCracken C, Cassar MP, Moss AJ, Finnigan L, Samat AHA, Ogbole G, Tunnicliffe EM, Alfaro-Almagro F, Menke R, Xie C, Gleeson F, Lukaschuk E, Lamlum H, McGlynn K, Popescu IA, Sanders ZB, Saunders LC, Piechnik SK, Ferreira VM, Nikolaidou C, Rahman NM, Ho LP, Harris VC, Shikotra A, Singapuri A, Pfeffer P, Manisty C, Kon OM, Beggs M, O'Regan DP, Fuld J, Weir-McCall JR, Parekh D, Steeds R, Poinasamy K, Cuthbertson DJ, Kemp GJ, Semple MG, Horsley A, Miller CA, O'Brien C, Shah AM, Chiribiri A, Leavy OC, Richardson M, Elneima O, McAuley HJC, Sereno M, Saunders RM, Houchen-Wolloff L, Greening NJ, Bolton CE, Brown JS, Choudhury G, Diar Bakerly N, Easom N, Echevarria C, Marks M, Hurst JR, Jones MG, Wootton DG, Chalder T, Davies MJ, De Soyza A, Geddes JR, Greenhalf W, Howard LS, Jacob J, Man WDC, Openshaw PJM, Porter JC, Rowland MJ, Scott JT, Singh SJ, Thomas DC, Toshner M, Lewis KE, Heaney LG, Harrison EM, Kerr S, Docherty AB, Lone NI, Quint J, Sheikh A, Zheng B, Jenkins RG, Cox E, Francis S, Halling-Brown M, Chalmers JD, Greenwood JP, Plein S, Hughes PJC, Thompson AAR, Rowland-Jones SL, Wild JM, Kelly M, Treibel TA, Bandula S, Aul R, Miller K, Jezzard P, Smith S, Nichols TE, McCann GP, Evans RA, Wain LV, Brightling CE, Neubauer S, Baillie JK, Shaw A, Hairsine B, Kurasz C, Henson H, Armstrong L, Shenton L, Dobson H, Dell A, Lucey A, Price A, Storrie A, Pennington C, Price C, Mallison G, Willis G, Nassa H, Haworth J, Hoare M, Hawkings N, Fairbairn S, Young S, Walker S, Jarrold I, Sanderson A, David C, Chong-James K, Zongo O, James WY, Martineau A, King B, Armour C, McAulay D, Major E, McGinness J, McGarvey L, Magee N, Stone R, Drain S, Craig T, Bolger A, Haggar A, Lloyd A, Subbe C, Menzies D, Southern D, McIvor E, Roberts K, Manley R, Whitehead V, Saxon W, Bularga A, Mills NL, El-Taweel H, Dawson J, Robinson L, Saralaya D, Regan K, Storton K, Brear L, Amoils S, Bermperi A, Elmer A, Ribeiro C, Cruz I, Taylor J, Worsley J, Dempsey K, Watson L, Jose S, Marciniak S, Parkes M, McQueen A, Oliver C, Williams J, Paradowski K, Broad L, Knibbs L, Haynes M, Sabit R, Milligan L, Sampson C, Hancock A, Evenden C, Lynch C, Hancock K, Roche L, Rees M, Stroud N, Thomas-Woods T, Heller S, Robertson E, Young B, Wassall H, Babores M, Holland M, Keenan N, Shashaa S, Price C, Beranova E, Ramos H, Weston H, Deery J, Austin L, Solly R, Turney S, Cosier T, Hazelton T, Ralser M, Wilson A, Pearce L, Pugmire S, Stoker W, McCormick W, Dewar A, Arbane G, Kaltsakas G, Kerslake H, Rossdale J, Bisnauthsing K, Aguilar Jimenez LA, Martinez LM, Ostermann M, Magtoto MM, Hart N, Marino P, Betts S, Solano TS, Arias AM, Prabhu A, Reed A, Wrey Brown C, Griffin D, Bevan E, Martin J, Owen J, Alvarez Corral M, Williams N, Payne S, Storrar W, Layton A, Lawson C, Mills C, Featherstone J, Stephenson L, Burdett T, Ellis Y, Richards A, Wright C, Sykes DL, Brindle K, Drury K, Holdsworth L, Crooks MG, Atkin P, Flockton R, Thackray-Nocera S, Mohamed A, Taylor A, Perkins E, Ross G, McGuinness H, Tench H, Phipps J, Loosley R, Wolf-Roberts R, Coetzee S, Omar Z, Ross A, Card B, Carr C, King C, Wood C, Copeland D, Calvelo E, Chilvers ER, Russell E, Gordon H, Nunag JL, Schronce J, March K, Samuel K, Burden L, Evison L, McLeavey L, Orriss-Dib L, Tarusan L, Mariveles M, Roy M, Mohamed N, Simpson N, Yasmin N, Cullinan P, Daly P, Haq S, Moriera S, Fayzan T, Munawar U, Nwanguma U, Lingford-Hughes A, Altmann D, Johnston D, Mitchell J, Valabhji J, Price L, Molyneaux PL, Thwaites RS, Walsh S, Frankel A, Lightstone L, Wilkins M, Willicombe M, McAdoo S, Touyz R, Guerdette AM, Warwick K, Hewitt M, Reddy R, White S, McMahon A, Hoare A, Knighton A, Ramos A, Te A, Jolley CJ, Speranza F, Assefa-Kebede H, Peralta I, Breeze J, Shevket K, Powell N, Adeyemi O, Dulawan P, Adrego R, Byrne S, Patale S, Hayday A, Malim M, Pariante C, Sharpe C, Whitney J, Bramham K, Ismail K, Wessely S, Nicholson T, Ashworth A, Humphries A, Tan AL, Whittam B, Coupland C, Favager C, Peckham D, Wade E, Saalmink G, Clarke J, Glossop J, Murira J, Rangeley J, Woods J, Hall L, Dalton M, Window N, Beirne P, Hardy T, Coakley G, Turtle L, Berridge A, Cross A, Key AL, Rowe A, Allt AM, Mears C, Malein F, Madzamba G, Hardwick HE, Earley J, Hawkes J, Pratt J, Wyles J, Tripp KA, Hainey K, Allerton L, Lavelle-Langham L, Melling L, Wajero LO, Poll L, Noonan MJ, French N, Lewis-Burke N, Williams-Howard SA, Cooper S, Kaprowska S, Dobson SL, Marsh S, Highett V, Shaw V, Beadsworth M, Defres S, Watson E, Tiongson GF, Papineni P, Gurram S, Diwanji SN, Quaid S, Briggs A, Hastie C, Rogers N, Stensel D, Bishop L, McIvor K, Rivera-Ortega P, Al-Sheklly B, Avram C, Faluyi D, Blaikely J, Piper Hanley K, Radhakrishnan K, Buch M, Hanley NA, Odell N, Osbourne R, Stockdale S, Felton T, Gorsuch T, Hussell T, Kausar Z, Kabir T, McAllister-Williams H, Paddick S, Burn D, Ayoub A, Greenhalgh A, Sayer A, Young A, Price D, Burns G, MacGowan G, Fisher H, Tedd H, Simpson J, Jiwa K, Witham M, Hogarth P, West S, Wright S, McMahon MJ, Neill P, Dougherty A, Morrow A, Anderson D, Grieve D, Bayes H, Fallon K, Mangion K, Gilmour L, Basu N, Sykes R, Berry C, McInnes IB, Donaldson A, Sage EK, Barrett F, Welsh B, Bell M, Quigley J, Leitch K, Macliver L, Patel M, Hamil R, Deans A, Furniss J, Clohisey S, Elliott A, Solstice AR, Deas C, Tee C, Connell D, Sutherland D, George J, Mohammed S, Bunker J, Holmes K, Dipper A, Morley A, Arnold D, Adamali H, Welch H, Morrison L, Stadon L, Maskell N, Barratt S, Dunn S, Waterson S, Jayaraman B, Light T, Selby N, Hosseini A, Shaw K, Almeida P, Needham R, Thomas AK, Matthews L, Gupta A, Nikolaidis A, Dupont C, Bonnington J, Chrystal M, Greenhaff PL, Linford S, Prosper S, Jang W, Alamoudi A, Bloss A, Megson C, Nicoll D, Fraser E, Pacpaco E, Conneh F, Ogg G, McShane H, Koychev I, Chen J, Pimm J, Ainsworth M, Pavlides M, Sharpe M, Havinden-Williams M, Petousi N, Talbot N, Carter P, Kurupati P, Dong T, Peng Y, Burns A, Kanellakis N, Korszun A, Connolly B, Busby J, Peto T, Patel B, Nolan CM, Cristiano D, Walsh JA, Liyanage K, Gummadi M, Dormand N, Polgar O, George P, Barker RE, Patel S, Price L, Gibbons M, Matila D, Jarvis H, Lim L, Olaosebikan O, Ahmad S, Brill S, Mandal S, Laing C, Michael A, Reddy A, Johnson C, Baxendale H, Parfrey H, Mackie J, Newman J, Pack J, Parmar J, Paques K, Garner L, Harvey A, Summersgill C, Holgate D, Hardy E, Oxton J, Pendlebury J, McMorrow L, Mairs N, Majeed N, Dark P, Ugwuoke R, Knight S, Whittaker S, Strong-Sheldrake S, Matimba-Mupaya W, Chowienczyk P, Pattenadk D, Hurditch E, Chan F, Carborn H, Foot H, Bagshaw J, Hockridge J, Sidebottom J, Lee JH, Birchall K, Turner K, Haslam L, Holt L, Milner L, Begum M, Marshall M, Steele N, Tinker N, Ravencroft P, Butcher R, Misra S, Walker S, Coburn Z, Fairman A, Ford A, Holbourn A, Howell A, Lawrie A, Lye A, Mbuyisa A, Zawia A, Holroyd-Hind B, Thamu B, Clark C, Jarman C, Norman C, Roddis C, Foote D, Lee E, Ilyas F, Stephens G, Newell H, Turton H, Macharia I, Wilson I, Cole J, McNeill J, Meiring J, Rodger J, Watson J, Chapman K, Harrington K, Chetham L, Hesselden L, Nwafor L, Dixon M, Plowright M, Wade P, Gregory R, Lenagh R, Stimpson R, Megson S, Newman T, Cheng Y, Goodwin C, Heeley C, Sissons D, Sowter D, Gregory H, Wynter I, Hutchinson J, Kirk J, Bennett K, Slack K, Allsop L, Holloway L, Flynn M, Gill M, Greatorex M, Holmes M, Buckley P, Shelton S, Turner S, Sewell TA, Whitworth V, Lovegrove W, Tomlinson J, Warburton L, Painter S, Vickers C, Redwood D, Tilley J, Palmer S, Wainwright T, Breen G, Hotopf M, Dunleavy A, Teixeira J, Ali M, Mencias M, Msimanga N, Siddique S, Samakomva T, Tavoukjian V, Forton D, Ahmed R, Cook A, Thaivalappil F, Connor L, Rees T, McNarry M, Williams N, McCormick J, McIntosh J, Vere J, Coulding M, Kilroy S, Turner V, Butt AT, Savill H, Fraile E, Ugoji J, Landers G, Lota H, Portukhay S, Nasseri M, Daniels A, Hormis A, Ingham J, Zeidan L, Osborne L, Chablani M, Banerjee A, David A, Pakzad A, Rangelov B, Williams B, Denneny E, Willoughby J, Xu M, Mehta P, Batterham R, Bell R, Aslani S, Lilaonitkul W, Checkley A, Bang D, Basire D, Lomas D, Wall E, Plant H, Roy K, Heightman M, Lipman M, Merida Morillas M, Ahwireng N, Chambers RC, Jastrub R, Logan S, Hillman T, Botkai A, Casey A, Neal A, Newton-Cox A, Cooper B, Atkin C, McGee C, Welch C, Wilson D, Sapey E, Qureshi H, Hazeldine J, Lord JM, Nyaboko J, Short J, Stockley J, Dasgin J, Draxlbauer K, Isaacs K, Mcgee K, Yip KP, Ratcliffe L, Bates M, Ventura M, Ahmad Haider N, Gautam N, Baggott R, Holden S, Madathil S, Walder S, Yasmin S, Hiwot T, Jackson T, Soulsby T, Kamwa V, Peterkin Z, Suleiman Z, Chaudhuri N, Wheeler H, Djukanovic R, Samuel R, Sass T, Wallis T, Marshall B, Childs C, Marouzet E, Harvey M, Fletcher S, Dickens C, Beckett P, Nanda U, Daynes E, Charalambou A, Yousuf AJ, Lea A, Prickett A, Gooptu B, Hargadon B, Bourne C, Christie C, Edwardson C, Lee D, Baldry E, Stringer E, Woodhead F, Mills G, Arnold H, Aung H, Qureshi IN, Finch J, Skeemer J, Hadley K, Khunti K, Carr L, Ingram L, Aljaroof M, Bakali M, Bakau M, Baldwin M, Bourne M, Pareek M, Soares M, Tobin M, Armstrong N, Brunskill N, Goodman N, Cairns P, Haldar P, McCourt P, Dowling R, Russell R, Diver S, Edwards S, Glover S, Parker S, Siddiqui S, Ward TJC, Mcnally T, Thornton T, Yates T, Ibrahim W, Monteiro W, Thickett D, Wilkinson D, Broome M, McArdle P, Upthegrove R, Wraith D, Langenberg C, Summers C, Bullmore E, Heeney JL, Schwaeble W, Sudlow CL, Adeloye D, Newby DE, Rudan I, Shankar-Hari M, Thorpe M, Pius R, Walmsley S, McGovern A, Ballard C, Allan L, Dennis J, Cavanagh J, Petrie J, O'Donnell K, Spears M, Sattar N, MacDonald S, Guthrie E, Henderson M, Guillen Guio B, Zhao B, Lawson C, Overton C, Taylor C, Tong C, Mukaetova-Ladinska E, Turner E, Pearl JE, Sargant J, Wormleighton J, Bingham M, Sharma M, Steiner M, Samani N, Novotny P, Free R, Allen RJ, Finney S, Terry S, Brugha T, Plekhanova T, McArdle A, Vinson B, Spencer LG, Reynolds W, Ashworth M, Deakin B, Chinoy H, Abel K, Harvie M, Stanel S, Rostron A, Coleman C, Baguley D, Hufton E, Khan F, Hall I, Stewart I, Fabbri L, Wright L, Kitterick P, Morriss R, Johnson S, Bates A, Antoniades C, Clark D, Bhui K, Channon KM, Motohashi K, Sigfrid L, Husain M, Webster M, Fu X, Li X, Kingham L, Klenerman P, Miiler K, Carson G, Simons G, Huneke N, Calder PC, Baldwin D, Bain S, Lasserson D, Daines L, Bright E, Stern M, Crisp P, Dharmagunawardena R, Reddington A, Wight A, Bailey L, Ashish A, Robinson E, Cooper J, Broadley A, Turnbull A, Brookes C, Sarginson C, Ionita D, Redfearn H, Elliott K, Barman L, Griffiths L, Guy Z, Gill R, Nathu R, Harris E, Moss P, Finnigan J, Saunders K, Saunders P, Kon S, Kon SS, O'Brien L, Shah K, Shah P, Richardson E, Brown V, Brown M, Brown J, Brown J, Brown A, Brown A, Brown M, Choudhury N, Jones S, Jones H, Jones L, Jones I, Jones G, Jones H, Jones D, Davies F, Davies E, Davies K, Davies G, Davies GA, Howard K, Porter J, Rowland J, Rowland A, Scott K, Singh S, Singh C, Thomas S, Thomas C, Lewis V, Lewis J, Lewis D, Harrison P, Francis C, Francis R, Hughes RA, Hughes J, Hughes AD, Thompson T, Kelly S, Smith D, Smith N, Smith A, Smith J, Smith L, Smith S, Evans T, Evans RI, Evans D, Evans R, Evans H, Evans J. Multiorgan MRI findings after hospitalisation with COVID-19 in the UK (C-MORE): a prospective, multicentre, observational cohort study. Lancet Respir Med 2023; 11:1003-1019. [PMID: 37748493 PMCID: PMC7615263 DOI: 10.1016/s2213-2600(23)00262-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 06/16/2023] [Accepted: 06/30/2023] [Indexed: 09/27/2023]
Abstract
INTRODUCTION The multiorgan impact of moderate to severe coronavirus infections in the post-acute phase is still poorly understood. We aimed to evaluate the excess burden of multiorgan abnormalities after hospitalisation with COVID-19, evaluate their determinants, and explore associations with patient-related outcome measures. METHODS In a prospective, UK-wide, multicentre MRI follow-up study (C-MORE), adults (aged ≥18 years) discharged from hospital following COVID-19 who were included in Tier 2 of the Post-hospitalisation COVID-19 study (PHOSP-COVID) and contemporary controls with no evidence of previous COVID-19 (SARS-CoV-2 nucleocapsid antibody negative) underwent multiorgan MRI (lungs, heart, brain, liver, and kidneys) with quantitative and qualitative assessment of images and clinical adjudication when relevant. Individuals with end-stage renal failure or contraindications to MRI were excluded. Participants also underwent detailed recording of symptoms, and physiological and biochemical tests. The primary outcome was the excess burden of multiorgan abnormalities (two or more organs) relative to controls, with further adjustments for potential confounders. The C-MORE study is ongoing and is registered with ClinicalTrials.gov, NCT04510025. FINDINGS Of 2710 participants in Tier 2 of PHOSP-COVID, 531 were recruited across 13 UK-wide C-MORE sites. After exclusions, 259 C-MORE patients (mean age 57 years [SD 12]; 158 [61%] male and 101 [39%] female) who were discharged from hospital with PCR-confirmed or clinically diagnosed COVID-19 between March 1, 2020, and Nov 1, 2021, and 52 non-COVID-19 controls from the community (mean age 49 years [SD 14]; 30 [58%] male and 22 [42%] female) were included in the analysis. Patients were assessed at a median of 5·0 months (IQR 4·2-6·3) after hospital discharge. Compared with non-COVID-19 controls, patients were older, living with more obesity, and had more comorbidities. Multiorgan abnormalities on MRI were more frequent in patients than in controls (157 [61%] of 259 vs 14 [27%] of 52; p<0·0001) and independently associated with COVID-19 status (odds ratio [OR] 2·9 [95% CI 1·5-5·8]; padjusted=0·0023) after adjusting for relevant confounders. Compared with controls, patients were more likely to have MRI evidence of lung abnormalities (p=0·0001; parenchymal abnormalities), brain abnormalities (p<0·0001; more white matter hyperintensities and regional brain volume reduction), and kidney abnormalities (p=0·014; lower medullary T1 and loss of corticomedullary differentiation), whereas cardiac and liver MRI abnormalities were similar between patients and controls. Patients with multiorgan abnormalities were older (difference in mean age 7 years [95% CI 4-10]; mean age of 59·8 years [SD 11·7] with multiorgan abnormalities vs mean age of 52·8 years [11·9] without multiorgan abnormalities; p<0·0001), more likely to have three or more comorbidities (OR 2·47 [1·32-4·82]; padjusted=0·0059), and more likely to have a more severe acute infection (acute CRP >5mg/L, OR 3·55 [1·23-11·88]; padjusted=0·025) than those without multiorgan abnormalities. Presence of lung MRI abnormalities was associated with a two-fold higher risk of chest tightness, and multiorgan MRI abnormalities were associated with severe and very severe persistent physical and mental health impairment (PHOSP-COVID symptom clusters) after hospitalisation. INTERPRETATION After hospitalisation for COVID-19, people are at risk of multiorgan abnormalities in the medium term. Our findings emphasise the need for proactive multidisciplinary care pathways, with the potential for imaging to guide surveillance frequency and therapeutic stratification. FUNDING UK Research and Innovation and National Institute for Health Research.
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Ionita D, Cristea M, Gaina C, Silion M, Simionescu BC. Evidence through Thermal Analysis of Retro Diels-Alder Reaction in Model Networks Based on Anthracene Modified Polyester Resins. Polymers (Basel) 2023; 15:4028. [PMID: 37836077 PMCID: PMC10575195 DOI: 10.3390/polym15194028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 09/29/2023] [Accepted: 10/03/2023] [Indexed: 10/15/2023] Open
Abstract
The present work is focused on polyester resins obtained from the diglycidyl ether of bisphenol A and anthracene modified 5-maleimidoisophthalic acid. Because the maleimide-anthracene Diels-Alder (DA) adduct is stable at high temperatures, it is considered a good option for high performance polymers. However, the information related to the retroDA reaction for this type of adduct is sometimes incoherent. A detailed thermal study (conventional TGA, HiRes TGA, MTGA, DSC, MDSC) was performed in order to establish whether the rDA reaction can be revealed for this type of anthracene modified polyester resins. The TGA method confirmed the cleavage of the anthracene-maleimide DA adduct, while the DSC demonstrated the presence of anthracene in the system. At high temperatures, unprotected maleimide homopolymerizes and/or reacts with allyl groups according to the -ene reaction. Therefore, the thermal DA reaction is not displayed anymore upon the subsequent cooling, and the glass transition region is registered at a higher temperature range during the second heating. The use of sample-controlled thermal analysis (HiRes TGA) and MTGA improved the TGA result; however, it was not possible to separate the very complex degradation processes that are interconnected.
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Affiliation(s)
| | - Mariana Cristea
- “Petru Poni” Institute of Macromolecular Chemistry, Aleea Grigore Ghica 41A, 700487 Iasi, Romania; (D.I.); (C.G.); (M.S.); (B.C.S.)
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Ionita D, Cristea M, Cosmulescu SF, Predeanu G, Harabagiu V, Samoila P. Thermal and Viscoelastic Responses of Selected Lignocellulosic Wastes: Similarities and Differences. Polymers (Basel) 2023; 15:polym15092100. [PMID: 37177248 PMCID: PMC10181240 DOI: 10.3390/polym15092100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 04/21/2023] [Accepted: 04/24/2023] [Indexed: 05/15/2023] Open
Abstract
Woody lignocellulosic biomasses comprise the non-edible parts of fruit trees. In recent years, the exploitation of this biomass has been widening in order to mitigate environmental issues. At the same time, this waste could be transformed into a value-added product (active carbon by pyrolysis, isolation of nanocellulose, oils or proteins). For either valorization path, a complete thermo-mechanical characterization is required. A detailed thermo-mechanical study (TGA, DSC, DMA) was performed on two types of lignocellulosic wastes, with and without kernels: on one side, the walnut shells (WS) and the pistachio shells (PsS) and, in the second category, the apricot seeds (AS), the date seeds (DS), and the plum seeds (PS). The results of the sample-controlled thermal analyses (HiRes TGA) evidenced a better resolution of the degradation steps of WS. Kinetic studies conducted also by conventional TGA (Flynn-Wall-Ozawa) and modulated TGA (MTGA) allowed us to make comparative reasonings concerning the degradation of the investigated biomasses. The DMA results revealed the effect of water traces and oil kernels on relaxation and supported the atypical DSC endotherm emphasized in the freezing temperature domain.
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Affiliation(s)
- Daniela Ionita
- "Petru Poni" Institute of Macromolecular Chemistry, Aleea Grigore Ghica Voda 41A, 700487 Iasi, Romania
| | - Mariana Cristea
- "Petru Poni" Institute of Macromolecular Chemistry, Aleea Grigore Ghica Voda 41A, 700487 Iasi, Romania
| | | | - Georgeta Predeanu
- Research Center for Environmental Protection and Ecofriendly Technologies, University POLITEHNICA of Bucharest, Strada Gheorghe Polizu 1-7, 011061 Bucharest, Romania
| | - Valeria Harabagiu
- "Petru Poni" Institute of Macromolecular Chemistry, Aleea Grigore Ghica Voda 41A, 700487 Iasi, Romania
| | - Petrisor Samoila
- "Petru Poni" Institute of Macromolecular Chemistry, Aleea Grigore Ghica Voda 41A, 700487 Iasi, Romania
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Cleminte CI, Ionita D, Lisa C, Cristea M, Mamaligă I, Lisa G. Evaluation of the Sublimation Process of Some Purine Derivatives: Sublimation Rate, Activation Energy, Mass Transfer Coefficients and Phenomenological Models. Materials (Basel) 2022; 15:7376. [PMID: 36295442 PMCID: PMC9607597 DOI: 10.3390/ma15207376] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 10/14/2022] [Accepted: 10/18/2022] [Indexed: 06/16/2023]
Abstract
Caffeine and theophylline are compounds with important applications in the pharmaceutical industry and other fields of the chemical industry. These purine derivatives have simple chemical structures, therefore, the evaluation of their sublimation process contributes to the development of mass transfer analysis methods that can later be applied to other compounds with more complex structures. With the help of thermogravimetric analysis in isothermal conditions, the kinetic study of the sublimation of caffeine and theophylline, along with the evaluation of kinetic parameters (activation energy and the pre-exponential factor), was carried out. Global mass transfer coefficients were determined, which vary for caffeine between 53 × 10-8 and 631 × 10-8 mol/s·m2·Pa, and for theophylline between 68 × 10-8 and 441 × 10-8 mol/s·m2·Pa. The dimensionless equations of the form: Sh=a+b·Rec·Scd have been proposed, which allow the determination of individual mass transfer coefficients at temperatures between 130 and 160 °C for caffeine and between 170 and 200 °C for theophylline.
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Affiliation(s)
- Cerasela-Ionela Cleminte
- Faculty of Chemical Engineering and Environmental Protection “Cristofor Simionescu”, “Gheorghe Asachi” Technical University of Iasi-Romania, 73 D. Mangeron Street, 700050 Iasi, Romania
| | - Daniela Ionita
- “Petru Poni” Institute of Macromolecular Chemistry, Aleea Gr. Ghica Voda 41 A, 700487 Iasi, Romania
| | - Cătălin Lisa
- Faculty of Chemical Engineering and Environmental Protection “Cristofor Simionescu”, “Gheorghe Asachi” Technical University of Iasi-Romania, 73 D. Mangeron Street, 700050 Iasi, Romania
| | - Mariana Cristea
- “Petru Poni” Institute of Macromolecular Chemistry, Aleea Gr. Ghica Voda 41 A, 700487 Iasi, Romania
| | - Ioan Mamaligă
- Faculty of Chemical Engineering and Environmental Protection “Cristofor Simionescu”, “Gheorghe Asachi” Technical University of Iasi-Romania, 73 D. Mangeron Street, 700050 Iasi, Romania
| | - Gabriela Lisa
- Faculty of Chemical Engineering and Environmental Protection “Cristofor Simionescu”, “Gheorghe Asachi” Technical University of Iasi-Romania, 73 D. Mangeron Street, 700050 Iasi, Romania
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Evans RA, Leavy OC, Richardson M, Elneima O, McAuley HJC, Shikotra A, Singapuri A, Sereno M, Saunders RM, Harris VC, Houchen-Wolloff L, Aul R, Beirne P, Bolton CE, Brown JS, Choudhury G, Diar-Bakerly N, Easom N, Echevarria C, Fuld J, Hart N, Hurst J, Jones MG, Parekh D, Pfeffer P, Rahman NM, Rowland-Jones SL, Shah AM, Wootton DG, Chalder T, Davies MJ, De Soyza A, Geddes JR, Greenhalf W, Greening NJ, Heaney LG, Heller S, Howard LS, Jacob J, Jenkins RG, Lord JM, Man WDC, McCann GP, Neubauer S, Openshaw PJM, Porter JC, Rowland MJ, Scott JT, Semple MG, Singh SJ, Thomas DC, Toshner M, Lewis KE, Thwaites RS, Briggs A, Docherty AB, Kerr S, Lone NI, Quint J, Sheikh A, Thorpe M, Zheng B, Chalmers JD, Ho LP, Horsley A, Marks M, Poinasamy K, Raman B, Harrison EM, Wain LV, Brightling CE, Abel K, Adamali H, Adeloye D, Adeyemi O, Adrego R, Aguilar Jimenez LA, Ahmad S, Ahmad Haider N, Ahmed R, Ahwireng N, Ainsworth M, Al-Sheklly B, Alamoudi A, Ali M, Aljaroof M, All AM, Allan L, Allen RJ, Allerton L, Allsop L, Almeida P, Altmann D, Alvarez Corral M, Amoils S, Anderson D, Antoniades C, Arbane G, Arias A, Armour C, Armstrong L, Armstrong N, Arnold D, Arnold H, Ashish A, Ashworth A, Ashworth M, Aslani S, Assefa-Kebede H, Atkin C, Atkin P, Aung H, Austin L, Avram C, Ayoub A, Babores M, Baggott R, Bagshaw J, Baguley D, Bailey L, Baillie JK, Bain S, Bakali M, Bakau M, Baldry E, Baldwin D, Ballard C, Banerjee A, Bang B, Barker RE, Barman L, Barratt S, Barrett F, Basire D, Basu N, Bates M, Bates A, Batterham R, Baxendale H, Bayes H, Beadsworth M, Beckett P, Beggs M, Begum M, Bell D, Bell R, Bennett K, Beranova E, Bermperi A, Berridge A, Berry C, Betts S, Bevan E, Bhui K, Bingham M, Birchall K, Bishop L, Bisnauthsing K, Blaikely J, Bloss A, Bolger A, Bonnington J, Botkai A, Bourne C, Bourne M, Bramham K, Brear L, Breen G, Breeze J, Bright E, Brill S, Brindle K, Broad L, Broadley A, Brookes C, Broome M, Brown A, Brown A, Brown J, Brown J, Brown M, Brown M, Brown V, Brugha T, Brunskill N, Buch M, Buckley P, Bularga A, Bullmore E, Burden L, Burdett T, Burn D, Burns G, Burns A, Busby J, Butcher R, Butt A, Byrne S, Cairns P, Calder PC, Calvelo E, Carborn H, Card B, Carr C, Carr L, Carson G, Carter P, Casey A, Cassar M, Cavanagh J, Chablani M, Chambers RC, Chan F, Channon KM, Chapman K, Charalambou A, Chaudhuri N, Checkley A, Chen J, Cheng Y, Chetham L, Childs C, Chilvers ER, Chinoy H, Chiribiri A, Chong-James K, Choudhury N, Chowienczyk P, Christie C, Chrystal M, Clark D, Clark C, Clarke J, Clohisey S, Coakley G, Coburn Z, Coetzee S, Cole J, Coleman C, Conneh F, Connell D, Connolly B, Connor L, Cook A, Cooper B, Cooper J, Cooper S, Copeland D, Cosier T, Coulding M, Coupland C, Cox E, Craig T, Crisp P, Cristiano D, Crooks MG, Cross A, Cruz I, Cullinan P, Cuthbertson D, Daines L, Dalton M, Daly P, Daniels A, Dark P, Dasgin J, David A, David C, Davies E, Davies F, Davies G, Davies GA, Davies K, Dawson J, Daynes E, Deakin B, Deans A, Deas C, Deery J, Defres S, Dell A, Dempsey K, Denneny E, Dennis J, Dewar A, Dharmagunawardena R, Dickens C, Dipper A, Diver S, Diwanji SN, Dixon M, Djukanovic R, Dobson H, Dobson SL, Donaldson A, Dong T, Dormand N, Dougherty A, Dowling R, Drain S, Draxlbauer K, Drury K, Dulawan P, Dunleavy A, Dunn S, Earley J, Edwards S, Edwardson C, El-Taweel H, Elliott A, Elliott K, Ellis Y, Elmer A, Evans D, Evans H, Evans J, Evans R, Evans RI, Evans T, Evenden C, Evison L, Fabbri L, Fairbairn S, Fairman A, Fallon K, Faluyi D, Favager C, Fayzan T, Featherstone J, Felton T, Finch J, Finney S, Finnigan J, Finnigan L, Fisher H, Fletcher S, Flockton R, Flynn M, Foot H, Foote D, Ford A, Forton D, Fraile E, Francis C, Francis R, Francis S, Frankel A, Fraser E, Free R, French N, Fu X, Furniss J, Garner L, Gautam N, George J, George P, Gibbons M, Gill M, Gilmour L, Gleeson F, Glossop J, Glover S, Goodman N, Goodwin C, Gooptu B, Gordon H, Gorsuch T, Greatorex M, Greenhaff PL, Greenhalgh A, Greenwood J, Gregory H, Gregory R, Grieve D, Griffin D, Griffiths L, Guerdette AM, Guillen Guio B, Gummadi M, Gupta A, Gurram S, Guthrie E, Guy Z, H Henson H, Hadley K, Haggar A, Hainey K, Hairsine B, Haldar P, Hall I, Hall L, Halling-Brown M, Hamil R, Hancock A, Hancock K, Hanley NA, Haq S, Hardwick HE, Hardy E, Hardy T, Hargadon B, Harrington K, Harris E, Harrison P, Harvey A, Harvey M, Harvie M, Haslam L, Havinden-Williams M, Hawkes J, Hawkings N, Haworth J, Hayday A, Haynes M, Hazeldine J, Hazelton T, Heeley C, Heeney JL, Heightman M, Henderson M, Hesselden L, Hewitt M, Highett V, Hillman T, Hiwot T, Hoare A, Hoare M, Hockridge J, Hogarth P, Holbourn A, Holden S, Holdsworth L, Holgate D, Holland M, Holloway L, Holmes K, Holmes M, Holroyd-Hind B, Holt L, Hormis A, Hosseini A, Hotopf M, Howard K, Howell A, Hufton E, Hughes AD, Hughes J, Hughes R, Humphries A, Huneke N, Hurditch E, Husain M, Hussell T, Hutchinson J, Ibrahim W, Ilyas F, Ingham J, Ingram L, Ionita D, Isaacs K, Ismail K, Jackson T, James WY, Jarman C, Jarrold I, Jarvis H, Jastrub R, Jayaraman B, Jezzard P, Jiwa K, Johnson C, Johnson S, Johnston D, Jolley CJ, Jones D, Jones G, Jones H, Jones H, Jones I, Jones L, Jones S, Jose S, Kabir T, Kaltsakas G, Kamwa V, Kanellakis N, Kaprowska S, Kausar Z, Keenan N, Kelly S, Kemp G, Kerslake H, Key AL, Khan F, Khunti K, Kilroy S, King B, King C, Kingham L, Kirk J, Kitterick P, Klenerman P, Knibbs L, Knight S, Knighton A, Kon O, Kon S, Kon SS, Koprowska S, Korszun A, Koychev I, Kurasz C, Kurupati P, Laing C, Lamlum H, Landers G, Langenberg C, Lasserson D, Lavelle-Langham L, Lawrie A, Lawson C, Lawson C, Layton A, Lea A, Lee D, Lee JH, Lee E, Leitch K, Lenagh R, Lewis D, Lewis J, Lewis V, Lewis-Burke N, Li X, Light T, Lightstone L, Lilaonitkul W, Lim L, Linford S, Lingford-Hughes A, Lipman M, Liyanage K, Lloyd A, Logan S, Lomas D, Loosley R, Lota H, Lovegrove W, Lucey A, Lukaschuk E, Lye A, Lynch C, MacDonald S, MacGowan G, Macharia I, Mackie J, Macliver L, Madathil S, Madzamba G, Magee N, Magtoto MM, Mairs N, Majeed N, Major E, Malein F, Malim M, Mallison G, Mandal S, Mangion K, Manisty C, Manley R, March K, Marciniak S, Marino P, Mariveles M, Marouzet E, Marsh S, Marshall B, Marshall M, Martin J, Martineau A, Martinez LM, Maskell N, Matila D, Matimba-Mupaya W, Matthews L, Mbuyisa A, McAdoo S, Weir McCall J, McAllister-Williams H, McArdle A, McArdle P, McAulay D, McCormick J, McCormick W, McCourt P, McGarvey L, McGee C, Mcgee K, McGinness J, McGlynn K, McGovern A, McGuinness H, McInnes IB, McIntosh J, McIvor E, McIvor K, McLeavey L, McMahon A, McMahon MJ, McMorrow L, Mcnally T, McNarry M, McNeill J, McQueen A, McShane H, Mears C, Megson C, Megson S, Mehta P, Meiring J, Melling L, Mencias M, Menzies D, Merida Morillas M, Michael A, Milligan L, Miller C, Mills C, Mills NL, Milner L, Misra S, Mitchell J, Mohamed A, Mohamed N, Mohammed S, Molyneaux PL, Monteiro W, Moriera S, Morley A, Morrison L, Morriss R, Morrow A, Moss AJ, Moss P, Motohashi K, Msimanga N, Mukaetova-Ladinska E, Munawar U, Murira J, Nanda U, Nassa H, Nasseri M, Neal A, Needham R, Neill P, Newell H, Newman T, Newton-Cox A, Nicholson T, Nicoll D, Nolan CM, Noonan MJ, Norman C, Novotny P, Nunag J, Nwafor L, Nwanguma U, Nyaboko J, O'Donnell K, O'Brien C, O'Brien L, O'Regan D, Odell N, Ogg G, Olaosebikan O, Oliver C, Omar Z, Orriss-Dib L, Osborne L, Osbourne R, Ostermann M, Overton C, Owen J, Oxton J, Pack J, Pacpaco E, Paddick S, Painter S, Pakzad A, Palmer S, Papineni P, Paques K, Paradowski K, Pareek M, Parfrey H, Pariante C, Parker S, Parkes M, Parmar J, Patale S, Patel B, Patel M, Patel S, Pattenadk D, Pavlides M, Payne S, Pearce L, Pearl JE, Peckham D, Pendlebury J, Peng Y, Pennington C, Peralta I, Perkins E, Peterkin Z, Peto T, Petousi N, Petrie J, Phipps J, Pimm J, Piper Hanley K, Pius R, Plant H, Plein S, Plekhanova T, Plowright M, Polgar O, Poll L, Porter J, Portukhay S, Powell N, Prabhu A, Pratt J, Price A, Price C, Price C, Price D, Price L, Price L, Prickett A, Propescu J, Pugmire S, Quaid S, Quigley J, Qureshi H, Qureshi IN, Radhakrishnan K, Ralser M, Ramos A, Ramos H, Rangeley J, Rangelov B, Ratcliffe L, Ravencroft P, Reddington A, Reddy R, Redfearn H, Redwood D, Reed A, Rees M, Rees T, Regan K, Reynolds W, Ribeiro C, Richards A, Richardson E, Rivera-Ortega P, Roberts K, Robertson E, Robinson E, Robinson L, Roche L, Roddis C, Rodger J, Ross A, Ross G, Rossdale J, Rostron A, Rowe A, Rowland A, Rowland J, Roy K, Roy M, Rudan I, Russell R, Russell E, Saalmink G, Sabit R, Sage EK, Samakomva T, Samani N, Sampson C, Samuel K, Samuel R, Sanderson A, Sapey E, Saralaya D, Sargant J, Sarginson C, Sass T, Sattar N, Saunders K, Saunders P, Saunders LC, Savill H, Saxon W, Sayer A, Schronce J, Schwaeble W, Scott K, Selby N, Sewell TA, Shah K, Shah P, Shankar-Hari M, Sharma M, Sharpe C, Sharpe M, Shashaa S, Shaw A, Shaw K, Shaw V, Shelton S, Shenton L, Shevket K, Short J, Siddique S, Siddiqui S, Sidebottom J, Sigfrid L, Simons G, Simpson J, Simpson N, Singh C, Singh S, Sissons D, Skeemer J, Slack K, Smith A, Smith D, Smith S, Smith J, Smith L, Soares M, Solano TS, Solly R, Solstice AR, Soulsby T, Southern D, Sowter D, Spears M, Spencer LG, Speranza F, Stadon L, Stanel S, Steele N, Steiner M, Stensel D, Stephens G, Stephenson L, Stern M, Stewart I, Stimpson R, Stockdale S, Stockley J, Stoker W, Stone R, Storrar W, Storrie A, Storton K, Stringer E, Strong-Sheldrake S, Stroud N, Subbe C, Sudlow CL, Suleiman Z, Summers C, Summersgill C, Sutherland D, Sykes DL, Sykes R, Talbot N, Tan AL, Tarusan L, Tavoukjian V, Taylor A, Taylor C, Taylor J, Te A, Tedd H, Tee CJ, Teixeira J, Tench H, Terry S, Thackray-Nocera S, Thaivalappil F, Thamu B, Thickett D, Thomas C, Thomas S, Thomas AK, Thomas-Woods T, Thompson T, Thompson AAR, Thornton T, Tilley J, Tinker N, Tiongson GF, Tobin M, Tomlinson J, Tong C, Touyz R, Tripp KA, Tunnicliffe E, Turnbull A, Turner E, Turner S, Turner V, Turner K, Turney S, Turtle L, Turton H, Ugoji J, Ugwuoke R, Upthegrove R, Valabhji J, Ventura M, Vere J, Vickers C, Vinson B, Wade E, Wade P, Wainwright T, Wajero LO, Walder S, Walker S, Walker S, Wall E, Wallis T, Walmsley S, Walsh JA, Walsh S, Warburton L, Ward TJC, Warwick K, Wassall H, Waterson S, Watson E, Watson L, Watson J, Welch C, Welch H, Welsh B, Wessely S, West S, Weston H, Wheeler H, White S, Whitehead V, Whitney J, Whittaker S, Whittam B, Whitworth V, Wight A, Wild J, Wilkins M, Wilkinson D, Williams N, Williams N, Williams J, Williams-Howard SA, Willicombe M, Willis G, Willoughby J, Wilson A, Wilson D, Wilson I, Window N, Witham M, Wolf-Roberts R, Wood C, Woodhead F, Woods J, Wormleighton J, Worsley J, Wraith D, Wrey Brown C, Wright C, Wright L, Wright S, Wyles J, Wynter I, Xu M, Yasmin N, Yasmin S, Yates T, Yip KP, Young B, Young S, Young A, Yousuf AJ, Zawia A, Zeidan L, Zhao B, Zongo O. Clinical characteristics with inflammation profiling of long COVID and association with 1-year recovery following hospitalisation in the UK: a prospective observational study. Lancet Respir Med 2022; 10:761-775. [PMID: 35472304 PMCID: PMC9034855 DOI: 10.1016/s2213-2600(22)00127-8] [Citation(s) in RCA: 144] [Impact Index Per Article: 72.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 03/23/2022] [Accepted: 03/31/2022] [Indexed: 11/25/2022]
Abstract
BACKGROUND No effective pharmacological or non-pharmacological interventions exist for patients with long COVID. We aimed to describe recovery 1 year after hospital discharge for COVID-19, identify factors associated with patient-perceived recovery, and identify potential therapeutic targets by describing the underlying inflammatory profiles of the previously described recovery clusters at 5 months after hospital discharge. METHODS The Post-hospitalisation COVID-19 study (PHOSP-COVID) is a prospective, longitudinal cohort study recruiting adults (aged ≥18 years) discharged from hospital with COVID-19 across the UK. Recovery was assessed using patient-reported outcome measures, physical performance, and organ function at 5 months and 1 year after hospital discharge, and stratified by both patient-perceived recovery and recovery cluster. Hierarchical logistic regression modelling was performed for patient-perceived recovery at 1 year. Cluster analysis was done using the clustering large applications k-medoids approach using clinical outcomes at 5 months. Inflammatory protein profiling was analysed from plasma at the 5-month visit. This study is registered on the ISRCTN Registry, ISRCTN10980107, and recruitment is ongoing. FINDINGS 2320 participants discharged from hospital between March 7, 2020, and April 18, 2021, were assessed at 5 months after discharge and 807 (32·7%) participants completed both the 5-month and 1-year visits. 279 (35·6%) of these 807 patients were women and 505 (64·4%) were men, with a mean age of 58·7 (SD 12·5) years, and 224 (27·8%) had received invasive mechanical ventilation (WHO class 7-9). The proportion of patients reporting full recovery was unchanged between 5 months (501 [25·5%] of 1965) and 1 year (232 [28·9%] of 804). Factors associated with being less likely to report full recovery at 1 year were female sex (odds ratio 0·68 [95% CI 0·46-0·99]), obesity (0·50 [0·34-0·74]) and invasive mechanical ventilation (0·42 [0·23-0·76]). Cluster analysis (n=1636) corroborated the previously reported four clusters: very severe, severe, moderate with cognitive impairment, and mild, relating to the severity of physical health, mental health, and cognitive impairment at 5 months. We found increased inflammatory mediators of tissue damage and repair in both the very severe and the moderate with cognitive impairment clusters compared with the mild cluster, including IL-6 concentration, which was increased in both comparisons (n=626 participants). We found a substantial deficit in median EQ-5D-5L utility index from before COVID-19 (retrospective assessment; 0·88 [IQR 0·74-1·00]), at 5 months (0·74 [0·64-0·88]) to 1 year (0·75 [0·62-0·88]), with minimal improvements across all outcome measures at 1 year after discharge in the whole cohort and within each of the four clusters. INTERPRETATION The sequelae of a hospital admission with COVID-19 were substantial 1 year after discharge across a range of health domains, with the minority in our cohort feeling fully recovered. Patient-perceived health-related quality of life was reduced at 1 year compared with before hospital admission. Systematic inflammation and obesity are potential treatable traits that warrant further investigation in clinical trials. FUNDING UK Research and Innovation and National Institute for Health Research.
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Voicu ME, Demetrescu I, Dorobantu A, Enachescu M, Buica GO, Ionita D. Interaction of Mg Alloy with PLA Electrospun Nanofibers Coating in Understanding Changes of Corrosion, Wettability, and pH. Nanomaterials (Basel) 2022; 12:nano12081369. [PMID: 35458077 PMCID: PMC9027480 DOI: 10.3390/nano12081369] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 04/12/2022] [Accepted: 04/15/2022] [Indexed: 02/06/2023]
Abstract
A modified biodegradable magnesium alloy (AZ31, 96 wt% Mg, 3 wt% Al, and 1 wt% Zn) with polylactic acid (PLA) nanofibers was obtained by the electrospinning technique. The presence of PLA nanofibers was evidenced using Fourier transform infrared spectroscopy (FT-IR) and using an scanning electronic microscope (SEM) equipped with an energy dispersive X-ray spectroscopy (EDX) module. The degradation behavior of an uncoated Mg alloy and a Mg alloy coated with PLA was evaluated through hydrogen evolution, pH, and electrochemical measurements in simulated body fluid. Contact angle measurements showed a shift from hydrophilic towards the hydrophobic character of the alloy after its coating with PLA nanofibers. Furthermore, the electrochemical measurement results show that the Mg based alloy coated with PLA inhibits hydrogen evolution, thus being less prone to degradation. The aim of this research is not only to reduce the corrosion rate of Mg alloy and to improve its properties with the help of polylactic acid coating, but also to provide a study to understand the hydrophilic–hydrophobic balance of biodegradable magnesium based on surface energy investigations. Taking into account corrosion rate, wettability, and pH changes, an empiric model of the interaction of Mg alloy with PLA nanofibers is proposed.
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Affiliation(s)
- Manuela Elena Voicu
- Department of General Chemistry, Faculty of Applied Chemistry and Material Science, University Politehnica of Bucharest, 313 Splaiul Independentei, 060042 Bucharest, Romania; (M.E.V.); (I.D.)
| | - Ioana Demetrescu
- Department of General Chemistry, Faculty of Applied Chemistry and Material Science, University Politehnica of Bucharest, 313 Splaiul Independentei, 060042 Bucharest, Romania; (M.E.V.); (I.D.)
- Academy of Romanian Scientists, 3 Ilfov Street, 050044 Bucharest, Romania
| | - Andrei Dorobantu
- Center for Surface Science and Nanotechnology, University Politehnica of Bucharest, 060042 Bucharest, Romania;
| | - Marius Enachescu
- Academy of Romanian Scientists, 3 Ilfov Street, 050044 Bucharest, Romania
- Center for Surface Science and Nanotechnology, University Politehnica of Bucharest, 060042 Bucharest, Romania;
- Correspondence: (M.E.); (G.-O.B.); (D.I.)
| | - George-Octavian Buica
- Department of General Chemistry, Faculty of Applied Chemistry and Material Science, University Politehnica of Bucharest, 313 Splaiul Independentei, 060042 Bucharest, Romania; (M.E.V.); (I.D.)
- Correspondence: (M.E.); (G.-O.B.); (D.I.)
| | - Daniela Ionita
- Department of General Chemistry, Faculty of Applied Chemistry and Material Science, University Politehnica of Bucharest, 313 Splaiul Independentei, 060042 Bucharest, Romania; (M.E.V.); (I.D.)
- Correspondence: (M.E.); (G.-O.B.); (D.I.)
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Bele A, Yu L, Dascalu M, Timpu D, Sacarescu L, Varganici CD, Ionita D, Isac D, Vasiliu AL. Binary Silicone Elastomeric Systems with Stepwise Crosslinking as a Tool for Tuning Electromechanical Behavior. Polymers (Basel) 2022; 14:211. [PMID: 35012235 PMCID: PMC8747420 DOI: 10.3390/polym14010211] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 12/27/2021] [Accepted: 12/29/2021] [Indexed: 02/04/2023] Open
Abstract
Interpenetrating polymer networks (IPNs) represent an interesting approach for tuning the properties of silicone elastomers due to the possible synergism that may occur between the networks. A new approach is presented, which consists of mixing two silicone-based networks with different crosslinking pathways; the first network being cured by condensation route and the second network by UV curing. The networks were mixed in different ratios and the resulted samples yield good mechanical properties (improved elongations, up to 720%, and Young's modulus, 1 MPa), thermal properties (one glass transition temperature, ~-123 °C), good dielectric strength (~50 V/μm), and toughness (63 kJ/m3).
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Affiliation(s)
- Adrian Bele
- “Petru Poni” Institute of Macromolecular Chemistry, 700487 Iasi, Romania; (M.D.); (D.T.); (L.S.); (C.-D.V.); (D.I.); (D.I.); (A.-L.V.)
| | - Liyun Yu
- Danish Polymer Centre, Department of Chemical and Biochemical Engineering, Technical University of Denmark, 2800 Kongens Lyngby, Denmark;
| | - Mihaela Dascalu
- “Petru Poni” Institute of Macromolecular Chemistry, 700487 Iasi, Romania; (M.D.); (D.T.); (L.S.); (C.-D.V.); (D.I.); (D.I.); (A.-L.V.)
| | - Daniel Timpu
- “Petru Poni” Institute of Macromolecular Chemistry, 700487 Iasi, Romania; (M.D.); (D.T.); (L.S.); (C.-D.V.); (D.I.); (D.I.); (A.-L.V.)
| | - Liviu Sacarescu
- “Petru Poni” Institute of Macromolecular Chemistry, 700487 Iasi, Romania; (M.D.); (D.T.); (L.S.); (C.-D.V.); (D.I.); (D.I.); (A.-L.V.)
| | - Cristian-Dragos Varganici
- “Petru Poni” Institute of Macromolecular Chemistry, 700487 Iasi, Romania; (M.D.); (D.T.); (L.S.); (C.-D.V.); (D.I.); (D.I.); (A.-L.V.)
| | - Daniela Ionita
- “Petru Poni” Institute of Macromolecular Chemistry, 700487 Iasi, Romania; (M.D.); (D.T.); (L.S.); (C.-D.V.); (D.I.); (D.I.); (A.-L.V.)
| | - Dragos Isac
- “Petru Poni” Institute of Macromolecular Chemistry, 700487 Iasi, Romania; (M.D.); (D.T.); (L.S.); (C.-D.V.); (D.I.); (D.I.); (A.-L.V.)
| | - Ana-Lavinia Vasiliu
- “Petru Poni” Institute of Macromolecular Chemistry, 700487 Iasi, Romania; (M.D.); (D.T.); (L.S.); (C.-D.V.); (D.I.); (D.I.); (A.-L.V.)
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Dimonie D, Mathe S, Iftime MM, Ionita D, Trusca R, Iftimie S. Modulation of the PLLA Morphology through Racemic Nucleation to Reach Functional Properties Required by 3D Printed Durable Applications. Materials (Basel) 2021; 14:6650. [PMID: 34772174 PMCID: PMC8588124 DOI: 10.3390/ma14216650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 10/29/2021] [Accepted: 10/31/2021] [Indexed: 11/16/2022]
Abstract
This paper presents an alternative for enhancing the durability of poly (L-lactide) (PLLA) by racemic nucleation following stereo-complexation with a selected poly (D-lactide) (PLDA). The compounds are obtained by melt blending of a PLLA grade, previously designed for 3D printing but with a low heat deflection temperature and impact resistance, with grades of PLDA differing in their molecular weight (Mw), D-lactide content (DS) and concentration. Our method considered how to reveal the racemic nucleation caused by stereo-complexation and its influence on functional properties. The FTIR study we performed showed that, depending on Mw, DS and concentration of the stereo-complexer (PDLA) used, bigger or smaller spectral changes can occur. The stereo-complexation was confirmed by the DSC analysis and, for the selected compound, by the POM, SEM, AFM microscopies, functional property and shapeability as 3D printing filaments. All the obtained results sustain the idea that, if a PLLA with Mw of 4.5 × 104 g·mol-1 is modified with PDLA with a medium Mw of 11.6 × 104 g·mol-1, medium DS of 4% and 1% concentration, a racemic nucleation is possible. It produces a racemic polylactic acid (PDLLA) with improved durability and good shapeability as 3D printing filaments. These results are explicable if the dependence of the intermolecular interactions appears between the PLLA and stereo-complexer PDLA. To enlarge the durable applicability of racemic polylactic acid (PDLLA), future research should identify other parameters controling the PLA stereo-complexing as the intensifying the mobility of the macromolecules, the finding of the optimal recemic cristalization window.
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Affiliation(s)
- Doina Dimonie
- National Institute for Research and Development in Chemistry and Petrochemistry, 202 Splaiul Independentei, 060021 Bucharest, Romania;
| | - Silvia Mathe
- Doctoral School “Applied Chemistry and Materials Science”, Politehnica University of Bucharest, 1-7 Gheorghe Polizu, 011061 Bucharest, Romania
| | - Manuela Maria Iftime
- “Petru Poni” Institute of Macromolecular Chemistry, 41A Grigore Ghica Voda Alley, 700487 Iasi, Romania; (M.M.I.); (D.I.)
| | - Daniela Ionita
- “Petru Poni” Institute of Macromolecular Chemistry, 41A Grigore Ghica Voda Alley, 700487 Iasi, Romania; (M.M.I.); (D.I.)
| | - Roxana Trusca
- Department of Science and Engineering of Oxide Materials and Nanomaterials, Politehnica University of Bucharest, 1-7 Gheorghe Polizu, 011061 Bucharest, Romania;
| | - Sorina Iftimie
- Department of Electricity and Magnetism, Solid-State Physics, and Biophysics, Faculty of Physics, University of Bucharest, 405 Atomistilor, 077125 Magurele, Romania;
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Cristea M, Ionita D, Simionescu BC. Petru Poni - a Model of Leadership, Integrity and Tenacity. Rev Chim 2021. [DOI: 10.37358/rc.21.4.8451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The article recalls the big personality of Petru Poni, one of the Romanian pioneers of the research in chemistry. The evocation is realized from the perspective of his contribution in the development of education in the second part of the 19th century as it is reflected mainly in his memoirs �What I wanted to do�. The achievement of the objectives of his life did not have a smooth path. However, his willingness to learn, the choice of action instead of resemnation and the purpose to do something meaningful in his life brought him to accomplishment.
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Stoian AB, Demetrescu I, Ionita D. Nanotubes and nano pores with chitosan construct on TiZr serving as drug reservoir. Colloids Surf B Biointerfaces 2020; 185:110535. [DOI: 10.1016/j.colsurfb.2019.110535] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 09/25/2019] [Accepted: 09/27/2019] [Indexed: 01/12/2023]
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Abstract
By anodizing zirconium in phosphoric acid at various potentials, different structures were obtained on the surfaces of the samples. The morphologies and compositions of the obtained coatings were investigated using scanning electronic microscopy (SEM), X-rays analysis (XRD) and Raman spectroscopy and were found to be dependent on anodizing potential. Electrochemical tests were performed in order to establish the stability of the samples. The film delamination forces increased with the anodizing potential, confirming that the zirconium dioxide film formed during anodizing becomes more resistant at higher potentials.
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Badea MA, Balas M, Hermenean A, Ciceu A, Herman H, Ionita D, Dinischiotu A. Influence of Matrigel on Single- and Multiple-Spheroid Cultures in Breast Cancer Research. SLAS Discov 2019; 24:563-578. [PMID: 30897015 DOI: 10.1177/2472555219834698] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This study aimed to develop and compare single and multiple 3D models such as multicellular tumor spheroids and to investigate the influence of Matrigel on their morphological and functional behavior. MDA-MB-231 3D models were generated in the presence and absence of Matrigel and their key biological properties within 6 days of culture were monitored. Our results revealed the formation of well-defined 3D models in the presence of Matrigel, with a uniform morphology, increased diameter, good circularity, and increased expression of a proliferation marker (PCNA). In comparison, 3D models generated without Matrigel were characterized by an irregular border, reduced dimensions and circularity, and a decrease of PCNA expression. Similarities between the single and multiple 3D cultures were found in their viability, Nrf2 expression, and glutathione (GSH) content. The influence of Matrigel on MDA-MB-231 spheroids metabolism under hypoxic conditions was highlighted by released lactate dehydrogenase and nitric oxide, GSH levels and expression of Nrf2 and Hsp70 proteins. Based on the increased expression of PCNA and the development of the hypoxia process in the presence of extracellular matrix, our study showed that the addition of Matrigel improves the growing environment of tumor spheroids, making it closer to that of in vivo tumor conditions.
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Affiliation(s)
- Madalina Andreea Badea
- 1 Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Bucharest, Bucharest, Romania
| | - Mihaela Balas
- 1 Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Bucharest, Bucharest, Romania
| | - Anca Hermenean
- 2 Department of Histology, Faculty of Medicine, Vasile Goldis Western University of Arad, Arad, Romania.,3 Department of Experimental and Applied Biology, Institute of Life Sciences, Vasile Goldis Western University of Arad, Arad, Romania
| | - Alina Ciceu
- 3 Department of Experimental and Applied Biology, Institute of Life Sciences, Vasile Goldis Western University of Arad, Arad, Romania
| | - Hildegard Herman
- 3 Department of Experimental and Applied Biology, Institute of Life Sciences, Vasile Goldis Western University of Arad, Arad, Romania
| | - Daniela Ionita
- 4 Department of General Chemistry, Faculty of Applied Chemistry and Materials Science, Politehnica University of Bucharest, Bucharest, Romania
| | - Anca Dinischiotu
- 1 Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Bucharest, Bucharest, Romania
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Ionita D, Ungureanu C, Prodana M, Negru AM, Enachescu M. Hybrid Materials Based on Multi-walled Carbon Nanotubes with Antimicrobial Properties. Rev Chim 2018. [DOI: 10.37358/rc.18.10.6594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In the present paper were prepared four types of sample consisting of multi-walled carbon nanotubes functionalized with carboxyl groups (MWCNT-COOH being the reference sample) and further functionalized with ZnCl2, MgCl2, AgNO3 and CuCl2. The samples were submitted to scanning electron microscopy (SEM), Raman microscopy, scanning transmission electron microscopy (STEM), and determined the antimicrobial character.
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Demetrescu I, Dumitriu C, Totea G, Nica CI, Dinischiotu A, Ionita D. Zwitterionic Cysteine Drug Coating Influence in Functionalization of Implantable Ti50Zr Alloy for Antibacterial, Biocompatibility and Stability Properties. Pharmaceutics 2018; 10:E220. [PMID: 30413075 PMCID: PMC6321039 DOI: 10.3390/pharmaceutics10040220] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 11/02/2018] [Accepted: 11/06/2018] [Indexed: 01/06/2023] Open
Abstract
The present paper aims atincreasing the bioperformance of implantable Ti50Zr alloy using zwitterionic cysteine drug coating. Aspects such as stability, biocompatibility, and antibacterial effects were investigated with the help of various methods such as infrared spectroscopy (FT-IR), scanning electronic microscopy (SEM), electrochemical methods, contact angle determinations and cell response. The experimental data of zwitterionic cysteine coating indicate the existence of a hydration layer due to hydrophilic groups evidenced in FT-IR which is responsible for the decrease of contact angle and antibacterial capabilities. The electrochemical stability was evaluatedbased on Tafel plots and electrochemical impedance spectroscopy (EIS). The cell response to cysteine was determined with gingival fibroblasts measuring lactate dehydrogenase (LDH) activity, concentrations of nitric oxide (NO) and intracellular level of reactive oxygen species (ROS). All experimental results supported the increase of stability and better cells response of implantable Ti50Zr alloy coated with zwitterionic cysteine drug. The antibacterial index was measured against Staphylococcus aureus and Escherichia coli. It was demonstrated that the coating enhanced the production of intracellular ROS in time, which subsequently caused a significant increase in antibacterial index.
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Affiliation(s)
- Ioana Demetrescu
- Faculty of Applied Chemistry and Materials Science POLITEHNICAof Bucharest, Romania Str. Polizu1-7, 011061 Bucharest, Romania.
- Faculty of Biomedical Engineering POLITEHNICA of Bucharest, Romania Str. Polizu1-7, 011061 Bucharest, Romania.
- Academy of Romanian Scientists, Spaiul Independentei 54, 050094 Bucharest, Romania.
| | - Cristina Dumitriu
- Faculty of Applied Chemistry and Materials Science POLITEHNICAof Bucharest, Romania Str. Polizu1-7, 011061 Bucharest, Romania.
| | - Georgeta Totea
- Buftea, M. Burghele Hospital, Studiolului 5, 070000 Buftea, Romania.
| | - Cristina I Nica
- Department of Biochemistry and Molecular Biology, University of Bucharest, 91-95 Spl. Independentei, 050095 Bucharest, Romania.
| | - Anca Dinischiotu
- Department of Biochemistry and Molecular Biology, University of Bucharest, 91-95 Spl. Independentei, 050095 Bucharest, Romania.
| | - Daniela Ionita
- Faculty of Applied Chemistry and Materials Science POLITEHNICAof Bucharest, Romania Str. Polizu1-7, 011061 Bucharest, Romania.
- Faculty of Biomedical Engineering POLITEHNICA of Bucharest, Romania Str. Polizu1-7, 011061 Bucharest, Romania.
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Abstract
This study aims on antibacterial and corrosion characterization of a complex ceramic coating based on titania (TiO2) nanotubes, hydroxyapatite (HA) and single walled carbon nanotubes (SWCNTs), in physiological environment. Hybrid materials structure was identified by Fourier transformed infrared spectroscopy (FTIR) and their surface analysed by scanning electron microscopy (SEM) and contact angle analysis. The most hydrophilic sample was the one with TiO2-HA coating. The electrochemical behavior of materials has been investigated in Ringer solution performing potentiodiynamic polarization and electrochemical impedance spectroscopy. Antibacterial properties of coatings were determined by contact method using two types of strains, one of them Staphylococus aureus (S. aureus) is a positive gram bacteria and another one Pseudomonas aureoginosa (P. aureoginosa) a negative gram bacteria. The corrosion rates are in the perfect stable domain of corrosion resistance and no breakdown phenomena were observed. A range of stability in tested bioliquid has been established from electrochemical and ICP-MS measurements. TiO2-HA-SWCNTs coating has the best corrosion resistance and the best barrier properties for ions release. Antibacterial effect of TiO2-HA-SWCNTs coating seems to be synergistic being higher compared to TiO2 nanotubes and TiO2-HA coating.
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Gherghescu IA, Ionita D, Ciuca S, Dumitrescu RE. Thermal Parameters Influence Assessed by Electrochemical Impedance Spectroscopy on a Ni50Ti48Nb2 Shape Memory Alloy. Rev Chim 2018. [DOI: 10.37358/rc.18.1.6049] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
This paper presents some electrochemical impedance spectroscopy research results concerning the corrosion resistance of a shape memory Ni50Ti48Nb2 alloy. This one was previously studied by SEM and DSC [1,2] but some new research features had to be made clear in order to be able to explain its electrochemical corrosion behavior. The chemical composition Ni50Ti48Nb2 was chosen in order to obtain a shape memory alloy having a wider hysteresis than equiatomic NiTi, for the purpose of achieving a better thermomechanical stability. Cryogenic applications are aimed. After processing the cast ingot, two samples, S1 and S2, were further annealed at 800�C/12 h and, respectively, at 900�C/12h. Scanning electron micrographs together with the chemical elements mapping results were obtained. They were related to the previous results concerning the informations on the structure of the different phases found in this NiTiNb alloy: austenite, martensite and secondary phases, as well as some primary compounds [1,2]. Considering the size and shape of the complex precipitate particles of NiTiNb in the two differently heat treated samples, these were found responsible for some changes in the transformation temperatures [3] but the electrochemical corrosion behavior of the alloy seems to be influenced to a lesser extent by the heat treatments. Both samples exhibit good values of corrosion resistance, however S2 shows better values than S1. Thus lower transformation temperatures and a slightly better corrosion resistance make the Ni50Ti48Nb2 alloy annealed at 900�C/12h subsequently submitted to thermal cycling to be the right choice for producing couplings in the cryogenic industry.
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Andrei M, Dinischiotu A, Didilescu AC, Ionita D, Demetrescu I. Periodontal materials and cell biology for guided tissue and bone regeneration. Ann Anat 2017; 216:164-169. [PMID: 29289707 DOI: 10.1016/j.aanat.2017.11.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 10/07/2017] [Accepted: 11/15/2017] [Indexed: 02/06/2023]
Abstract
The present review is intended to find links between periodontal materials of the dentomaxillary apparatus and cell biology at the beginning of a century fraught with various forms of periodontal diseases and needing new treatment strategies. The manuscript has two different parts. The first describes the anatomy of tooth supporting structures, as well as related pathologies. The second part is related to cell and molecular biology in the context of periodontal regeneration.
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Affiliation(s)
- Mihai Andrei
- Division of Embryology, Faculty of Dental Medicine, "Carol Davila" University of Medicine and Pharmacy, Bucharest, Romania
| | - Anca Dinischiotu
- Department of Biochemistry and Molecular Biology, University of Bucharest, 91-95 Splaiul Independentei, Bucharest 050095, Romania
| | - Andreea Cristiana Didilescu
- Division of Embryology, Faculty of Dental Medicine, "Carol Davila" University of Medicine and Pharmacy, Bucharest, Romania
| | - Daniela Ionita
- Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest, 1-7 Polizu, 011061 Bucharest, Romania
| | - Ioana Demetrescu
- Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest, 1-7 Polizu, 011061 Bucharest, Romania; Academy of Romanian Scientist, Splaiul Independentei 54, 050094 Bucharest, Romania
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Martinof AM, Ionita D, Demetrescu I. Influence of Various Albumin Concentrations on the Corrosion Resistance of Zr-2.5%Nb Alloy. CHEM ENG COMMUN 2016. [DOI: 10.1080/00986445.2016.1225197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Anca Maria Martinof
- Faculty of Applied Chemistry and Materials Science, University “Politehnica” of Bucharest, Bucharest, Romania
| | - Daniela Ionita
- Faculty of Applied Chemistry and Materials Science, University “Politehnica” of Bucharest, Bucharest, Romania
| | - Ioana Demetrescu
- Faculty of Applied Chemistry and Materials Science, University “Politehnica” of Bucharest, Bucharest, Romania
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Bele A, Stiubianu G, Vlad S, Tugui C, Varganici CD, Matricala L, Ionita D, Timpu D, Cazacu M. Aging behavior of the silicone dielectric elastomers in a simulated marine environment. RSC Adv 2016. [DOI: 10.1039/c5ra22780a] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A series of silicone–barium titanate composites, designed as dielectric elastomer films to be used as active elements in wave energy conversion devices, were immersed in artificial sea water in pseudo-dynamic conditions to asses their aging behavior.
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Affiliation(s)
- A. Bele
- “Petru Poni” Institute of Macromolecular Chemistry
- 700487 Iasi
- Romania
| | - G. Stiubianu
- “Petru Poni” Institute of Macromolecular Chemistry
- 700487 Iasi
- Romania
| | - S. Vlad
- “Petru Poni” Institute of Macromolecular Chemistry
- 700487 Iasi
- Romania
| | - C. Tugui
- “Petru Poni” Institute of Macromolecular Chemistry
- 700487 Iasi
- Romania
| | - C. D. Varganici
- “Petru Poni” Institute of Macromolecular Chemistry
- 700487 Iasi
- Romania
| | - L. Matricala
- “Petru Poni” Institute of Macromolecular Chemistry
- 700487 Iasi
- Romania
| | - D. Ionita
- “Petru Poni” Institute of Macromolecular Chemistry
- 700487 Iasi
- Romania
| | - D. Timpu
- “Petru Poni” Institute of Macromolecular Chemistry
- 700487 Iasi
- Romania
| | - M. Cazacu
- “Petru Poni” Institute of Macromolecular Chemistry
- 700487 Iasi
- Romania
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23
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Abstract
The molecular dynamics of flax-reinforced ethylene–propylene–diene monomer (EPDM) composites, with increasing quantities of flax (EPDM0–EPDM20), was investigated by dynamic mechanical analysis. Multifrequency experiments were also performed in order to distinguish between the relaxation and the kinetic events. Also the time–temperature superposition was applied to the multifrequency results for obtaining the master curves. They were used to anticipate the behavior of the composites in time and to calculate the activation energies using the Williams–Landel–Ferry equation.
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Affiliation(s)
- Mariana Cristea
- “Petru Poni” Institute of Macromolecular Chemistry, Iasi, Romania
| | - Anton Airinei
- “Petru Poni” Institute of Macromolecular Chemistry, Iasi, Romania
| | - Daniela Ionita
- “Petru Poni” Institute of Macromolecular Chemistry, Iasi, Romania
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24
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Ionita D, Enescu D, Giuvelea S, Stoicescu S, Mitrache P. Optimal timing for burned hands in children. Ann Burns Fire Disasters 2015; 28:29-31. [PMID: 26668559 PMCID: PMC4665177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Accepted: 07/17/2014] [Indexed: 06/05/2023]
Abstract
Hand burns in children are frequent, severe, and require adequate treatment. A fundamental, though problematic aspect of this treatment is the assessment of the burn depth as this determines the surgical strategy. From a retrospective study of 369 hand burns admitted to our clinic, we were able to identify some patterns. A total of 14.91% required surgery, with varying etiology among these patients. Differences were also noticed in the number of days post-burn prior to surgical intervention. The patterns revealed by our results are reviewed in order to improve therapeutic strategy.
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Affiliation(s)
- D. Ionita
- Plastic Surgery Clinic of the emergency hospital for Children “Grigore Alexandrescu”, bucharest, Romania
| | - D. Enescu
- “Carol Davila” University of medicine and Pharmacy bucharest, Romania
- Plastic Surgery Clinic of the emergency hospital for Children “Grigore Alexandrescu”, bucharest, Romania
| | - S. Giuvelea
- Plastic Surgery Clinic of the emergency hospital for Children “Grigore Alexandrescu”, bucharest, Romania
| | - S. Stoicescu
- “Carol Davila” University of medicine and Pharmacy bucharest, Romania
- Plastic Surgery Clinic of the emergency hospital for Children “Grigore Alexandrescu”, bucharest, Romania
| | - P. Mitrache
- Plastic Surgery Clinic of the emergency hospital for Children “Grigore Alexandrescu”, bucharest, Romania
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25
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Ionita D, Gaina C, Cristea M, Banabic D. Tailoring the hard domain cohesiveness in polyurethanes by interplay between the functionality and the content of chain extender. RSC Adv 2015. [DOI: 10.1039/c5ra15190b] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Thermo-mechanical behavior of polyurethanes with diol/triol chain extension is reflected in a particular behavior in the glass transition and rubbery region and is ruled by the functionality and content of the chain extender.
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Affiliation(s)
- Daniela Ionita
- “Petru Poni” Institute of Macromolecular Chemistry
- Iasi
- Romania
- Technical University of Cluj-Napoca
- Cluj-Napoca
| | | | - Mariana Cristea
- “Petru Poni” Institute of Macromolecular Chemistry
- Iasi
- Romania
| | - Dorel Banabic
- Technical University of Cluj-Napoca
- Cluj-Napoca
- Romania
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26
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Racles C, Bele A, Dascalu M, Musteata VE, Varganici CD, Ionita D, Vlad S, Cazacu M, Dünki SJ, Opris DM. Polar–nonpolar interconnected elastic networks with increased permittivity and high breakdown fields for dielectric elastomer transducers. RSC Adv 2015. [DOI: 10.1039/c5ra06865g] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Polysiloxanes with polar cyano groups were cross-linked with PDMS by a hydrolysis–condensation process. Materials suitable for transducer applications with improved permittivity, good mechanical properties, and high breakdown fields were obtained.
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Affiliation(s)
- C. Racles
- Petru Poni Institute of Macromolecular Chemistry
- Iasi
- Romania
| | - A. Bele
- Petru Poni Institute of Macromolecular Chemistry
- Iasi
- Romania
| | - M. Dascalu
- Petru Poni Institute of Macromolecular Chemistry
- Iasi
- Romania
| | - V. E. Musteata
- Petru Poni Institute of Macromolecular Chemistry
- Iasi
- Romania
| | | | - D. Ionita
- Petru Poni Institute of Macromolecular Chemistry
- Iasi
- Romania
| | - S. Vlad
- Petru Poni Institute of Macromolecular Chemistry
- Iasi
- Romania
| | - M. Cazacu
- Petru Poni Institute of Macromolecular Chemistry
- Iasi
- Romania
| | - S. J. Dünki
- Empa
- Swiss Federal Laboratories for Materials Science and Technology
- Laboratory for Functional Polymers
- Dübendorf
- Switzerland
| | - D. M. Opris
- Empa
- Swiss Federal Laboratories for Materials Science and Technology
- Laboratory for Functional Polymers
- Dübendorf
- Switzerland
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27
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Mazare A, Dilea M, Ionita D, Demetrescu I. Electrochemical behavior in simulated body fluid of TiO2 nanotubes on TiAlNb alloy elaborated in various anodizing electrolyte. SURF INTERFACE ANAL 2014. [DOI: 10.1002/sia.5364] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Anca Mazare
- Faculty of Applied Chemistry and Materials Science; University Politehnica Bucharest; Polizu no 1-7 011061 Bucharest Romania
- Department of Materials Science and Engineering; University Erlangen-Nuremberg; WW4-LKO, Martensstrasse 7 D-91058 Erlangen Germany
| | - Mirela Dilea
- Faculty of Applied Chemistry and Materials Science; University Politehnica Bucharest; Polizu no 1-7 011061 Bucharest Romania
- Faculty of Biotechnical Systems Engineering; University Politehnica Bucharest; 313 Splaiul Independentei 060042 Bucharest Romania
| | - Daniela Ionita
- Faculty of Applied Chemistry and Materials Science; University Politehnica Bucharest; Polizu no 1-7 011061 Bucharest Romania
| | - Ioana Demetrescu
- Faculty of Applied Chemistry and Materials Science; University Politehnica Bucharest; Polizu no 1-7 011061 Bucharest Romania
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28
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Mazare A, Dilea M, Ionita D, Titorencu I, Trusca V, Vasile E. Changing bioperformance of TiO2 amorphous nanotubes as an effect of inducing crystallinity. Bioelectrochemistry 2012; 87:124-31. [DOI: 10.1016/j.bioelechem.2012.01.002] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Revised: 12/24/2011] [Accepted: 01/04/2012] [Indexed: 10/14/2022]
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29
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Gaina C, Ursache O, Gaina V, Buruiana E, Ionita D. Investigation on the thermal properties of new thermo-reversible networks based on poly(vinyl furfural) and multifunctional maleimide compounds. EXPRESS POLYM LETT 2012. [DOI: 10.3144/expresspolymlett.2012.14] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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30
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Ionita D, Grecu M, Ungureanu C, Demetrescu I. Antimicrobial activity of the surface coatings on TiAlZr implant biomaterial. J Biosci Bioeng 2011; 112:630-4. [DOI: 10.1016/j.jbiosc.2011.07.022] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Revised: 07/06/2011] [Accepted: 07/24/2011] [Indexed: 11/16/2022]
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31
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Cristea M, Ionita D, Hulubei C, Timpu D, Popovici D, Simionescu BC. Chain packing versus chain mobility in semialiphatic BTDA-based copolyimides. POLYMER 2011. [DOI: 10.1016/j.polymer.2011.02.026] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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32
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Demetrescu I, Popa MV, Vasilescu E, Drob P, Popescu B, Ionita D, Vasilescu C. Passive Layer Breakdown on Titanium in Doped and Undoped Artificial Saliva. ACTA ACUST UNITED AC 2011. [DOI: 10.1557/proc-781-z3.5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
AbstractThe aim of this work is to investigate the long term (3000 exposure hours) tendency of passive layers on titanium to breakdown in Tani-Zucchi and Carter-Brugirard artificial saliva undoped and doped with chloride and fluoride ions. The non-uniformity of the saliva pH (from 7.88 to 5.73 and extreme case 2.15) was simulated. The following techniques were used: potentiostatic, potentiodynamic and linear polarization, the monitoring of the open circuit potentials vs. exposure time and atomic force microscopy. The breakdown (pitting) potential at about +2.9 V and the re-passivation potential at +2.4 V in Tani-Zucchi artificial saliva were determined. So, the pitting protection potential is very noble and can not be reached in human body.
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33
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34
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35
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Cristea M, Ionita D, Simionescu BC. Dynamic Mechanical Analysis on Regenerated Cellulose. Rev Chim 2008. [DOI: 10.37358/rc.08.10.1975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Dynamical mechanical analysis was applied to two samples of cellulose (Cell 1 and Cell 2), obtained using the N-methylmorpholine-N-oxide blown technology in order to shed light on the secondary relaxations of cellulose. By tracking the storage modulus (E�), the loss modulus (E�) and loss factor (tand) vs. temperature it becomes possible to ascertain the dynamic molecular phenomena. A multiplex experiment (0.1, 0.5, 1, 5 and 10 Hz) was performed to calculate the apparent activation energy for the sub-glass transitions. Water and peculiarities of the fabrication process influence the dynamic mechanical behaviour of cellulose. To evidence the plasticizer/antiplasticizer role of water molecules four consecutive heating-isothermal-cooling cycles were accomplished.
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36
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Enescu D, Bratu T, Berechet-Comanescu P, Ionita D. An alternative for local treatment of superficial burns. Ann Burns Fire Disasters 2008; 21:138-40. [PMID: 21991126 PMCID: PMC3188165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 12/18/2007] [Indexed: 05/31/2023]
Abstract
There is a wide variety of local therapeutical methods for partial superficial burns. Burns require meticulous local treatment as part of the complex therapeutic protocol. Local treatment for burns is essential, influencing the patient's evolution and future. All local burn treatment methods are adapted in relation to the particular aspects of the burn lesion (patient's age, aetiology, localization, associated pathologies). Immerci H3 was clinically tested for partial superficial burns treatment and the results were favourable. Healing was more rapid and there was a decrease in mean hospital stay and treatment costs.
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Affiliation(s)
- D Enescu
- Children's Emergency Hospital, Grigore Plastic and Reconstructive Department, Bucharest, Rumania
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37
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Popescu R, Ionita D, Minculescu F. Influence of Composition, Concentration and Temperature of some Biological Liquids upon the Corrosion Behaviour of Titanum. Rev Chim 2008. [DOI: 10.37358/rc.08.1.1698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In order to investigate the corrosion behaviour of titan in aqueous solutions of lactic acid (1, 3 and 4% w) and albumin (2 and 10 % w) the cyclic polarization curves in potentiodynamic conditions were used. The corrosion parameters were estimated and their values were discussed as a function of acid lactic and albumin concentration and temperature. The stability of titan in investigated biological liquids was interpreted by involvment of the adsorption of either lactic acid or albumin onto the passive layer, a process which is favorised by moderate temperatures (as 370C � the human body temperature) as well as by low concentrations of lactic acid and albumin, respectively.
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38
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Popa MV, Vasilescu E, Drob P, Vasilescu C, Demetrescu I, Ionita D. Long-term assessment of the implant titanium material--artificial saliva interface. J Mater Sci Mater Med 2008; 19:1-9. [PMID: 17990081 DOI: 10.1007/s10856-007-3271-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2005] [Accepted: 08/23/2005] [Indexed: 05/25/2023]
Abstract
This paper studies the long-term (20,000 exposure hours) behavior of titanium and Ti-5Al-4V alloy-Carter-Brugirard saliva interface and the short-term (500 exposure hours) resistance of titanium and Ti-5Al-4V alloy-Tani&Zucchi saliva interface. Potentiodynamic polarization method was applied for the determination of the main electrochemical parameters. Linear polarization measurements for to obtain the corrosion rates were used. Monitoring of the open circuit potentials (E(oc)) for long-term have permitted to calculate the potential gradients due to the pH, DeltaE(oc)(pH) and to the saliva composition DeltaE(oc)(c) changes which can appear "in vivo" conditions and can generate local corrosion. Atomic force microscopy (AFM) has analyzed the surface roughness. Ion release was studied by atomic absorption spectroscopy (AAS). In Carter-Brugirard saliva both titanium and Ti-5Al-4V alloy present very stable passive films, long-term stability, "very good" resistance, low values of the open circuit potential gradients, which cannot generate local corrosion. In Tani&Zucchi artificial saliva, pitting corrosion and noble pitting protection potentials (which cannot be reached in oral cavity) were registered; titanium ion release is very low; surface roughness increase in time and in the presence of the fluoride ions, denoting some increase in the anodic activity.
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Affiliation(s)
- M V Popa
- Institute of Physical Chemistry I. G. Murgulescu, Spl. Independentei 202, P.O. Box 12-194, 060021 Bucharest, Romania
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39
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Popa MV, Demetrescu I, Suh SH, Vasilescu E, Drob P, Ionita D, Vasilescu C. Monitoring of titanium base alloys–biofluids interface. Bioelectrochemistry 2007; 71:126-34. [PMID: 17409027 DOI: 10.1016/j.bioelechem.2007.02.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2006] [Revised: 02/12/2007] [Accepted: 02/22/2007] [Indexed: 11/29/2022]
Abstract
Monitoring of the titanium, Ti-5Al-4V, Ti-6Al-4Fe implant materials--Ringer 1 and Ringer 2 solutions (of different pH values) interface for long term was studied in this work. In Ringer 1 solution (with high chloride ion content) all biomaterials present self-passivation. On Ti-6Al-4Fe alloy, the breakdown of the passive film was registered but at high pitting potential; pitting protection potential is very noble and can not be reached in human fluids. In Ringer 2 solution was obtained more electropositive corrosion potential values than in Ringer 1 solution; pitting corrosion of Ti-6Al-4Fe alloy is characterised by nobler breakdown and pitting protection potential values, therefore a better pitting corrosion resistance and tendency. Ion release increases in time, for the first 400-600 immersion hours and then tend to a constant level with very low values, non-dangerous for human body. All open circuit potentials oscillate around some electropositive values. The potential gradients calculated for extreme pH values have low values during 20,000 exposure hours and can not accelerate the corrosion. Atomic Force Microscopy images obtained after different exposure periods in Ringer 1 solution revealed that the roughness increased in time, suggesting a dynamic process at biomaterial-biofluid interface. X-ray Photoelectron spectra obtained after 2880 immersion hours in Ringer 2 solution show the existence of protective titanium dioxide TiO(2) and TiO and Ti(2)O(3) oxides both for titanium and Ti-5Al-4V alloy. Also, Al(2)O(3) oxide was detected.
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Affiliation(s)
- M V Popa
- Institute of Physical Chemistry "Ilie Murgulescu", Spl. Independentei 202, PO BOX 12-194, 060021 Bucharest, Romania
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40
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Manidakis G, Sifakis S, Froudarakis G, Relakis K, Mataliotakis I, Goumenu A, Manidaki A, Koumantakis E, Dracea L, Tomasu A, Ionita D, Puia S, Marinescu B. Adolescent versus mature gravida. Pregnancy and labor at the extremes of the reproductive age in different Balkan countries. Int J Gynaecol Obstet 2000. [DOI: 10.1016/s0020-7292(00)82751-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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41
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Manidakis G, Sifakis S, Froudarakis G, Angelakis E, Relakis K, Matalliotakis I, Goumenou A, Manidaki A, Koumantakis E, Dracea L, Tomasu A, Ionita D, Puia S, Marinescu B. Fetal, neonatal and maternal outcome related to adolescent pregnancy: Inter-university research in different Balkan countries. Int J Gynaecol Obstet 2000. [DOI: 10.1016/s0020-7292(00)82752-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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