Flame retardant and superoleophilic polydopamine/chitosan-graft (g)-octanal coated polyurethane foam for separation oil/water mixtures

The discharge of crude petroleum oils and their derivatives poses serious environmental challenges, which can be mitigated through oil/water separation. In this study, polyurethane (PU)/polydopamine (PDA)/chitosan-graft (g)-octanal foam was prepared by immersing of PU foam in PDA and chitosan-g-octanal solutions. The fabricated PU foam exhibited thermal stability, flame retardancy, and hydrophobicity/superoleophilicity. The coated PU foam can selectively absorb heavy and light oils from dynamic and static oil/water mixtures. The maximum sorption capacity for olive oil was found to be as high as 41.48 g/g. PU/PDA/chitosan-g-octanal foam also demonstrated excellent flame retardancy and the ability to quickly extinguish fire, as confirmed by the limiting oxygen index (LOI) test.

Biosynthesis of Calcite Nanocrystal by a Novel Polyextremophile Bhargavaea cecembensis-Related Strain Isolated from Sandy Soil

Urease-producing bacteria are abundant in soils, which can precipitate calcium carbonate nanocrystals by enzymatic hydrolysis of urea in the presence of calcium ions. This process is known as microbially induced calcium carbonate precipitation (MICP), and it has received much attention in recent years as an eco-friendly technology. Therefore, the purpose of the present study was to isolate local extremophile bacterial strains capable of producing calcium carbonate. Among a total of 44 isolated urease-producing strains from sandy soils, one strain with a high level of urease activity (8.16 U/ml) and production of a large amount of calcium carbonate (410 mg/100 ml) was selected for further investigation. 16S rRNA gene sequencing showed that this strain had 99.66% sequence identity to Bhargavaea cecembensis. The SEM-EDX and XRD analyses indicated that irregular vaterite and aggregated nanocalcite were the dominant polymorphs produced by this strain. The size of these nanocalcite crystals ranged between 25 and 42 nm. The selected strain showed high levels of tolerance to different conditions of temperature, pH, and salinity. This strain grows at high temperatures up to 50 °C, alkaline pH (9-11), and high concentrations of NaCl (20-25% w/v). Flow cytometry analysis demonstrated 96% cell viability of the isolated strain after desiccation stress. Bhargavaea was first reported in 2009 as a new genus, and it belongs to the Firmicutes. So far, there has been no report on its MICP potential. The present study is the first one to report nanocrystal calcium carbonate precipitation in polyextremophile Bhargavaea cecembensis, which makes it a suitable candidate for bio-cementation under extreme circumstances.

Evaluating the Radiosensitization Effect of Hydroxyapatite Nanoparticles on Human Breast Adenocarcinoma Cell Line and Fibroblast

Background:

Nanohydroxyapatite (nHAP) exhibit anti-proliferative effects on various cancer cells. However, to date, there are only a few studies on the radiosensitization effect of nHAP. The present study aimed to investigate the possible enhancement of the radiosensitization effect of nHAP on human breast adenocarcinoma cancer (MCF-7) and fibroblast.

Methods:

nHAP was extracted from fish scales using the thermal alkaline method and characterized at Babol University of Medical Sciences (Babol, Iran) in 2017. The anti-proliferative and the radiosensitization effects of nHAP were investigated by 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-Diphenyltetrazolium Bromide (MTT), clonogenic assay, and apoptosis assay. MCF-7 cells and fibroblasts were incubated with different concentrations of nHAP and at different periods. The MTT solution was added and the absorbance was measured at 570 nm. The MCF-7 cells were exposed to 0, 1.5, 3.5, and 5 Gy X-ray irradiation and incubated for 10-14 days. The data were compared using the one-way analysis of variance (ANOVA) followed by the post hoc tests (Tukey’s method).

Results:

The results showed that nHAP significantly inhibited the growth of MCF-7 cells compared with controls (P<0.001), but the difference was not statistically significant for fibroblasts (P=0.686 at 400 µg/mL at 72 hours). After 48 hours, the proliferation of MCF-7 cells and fibroblasts was inhibited by about 81% and 34% at 400 µg/mL concentration, respectively. The radiosensitization enhancement factor for MCF-7 cells and fibroblasts at a dose of 3.5 Gy and 100 μg/mL concentration were 1.87 and 1.3, respectively.

Conclusion:

nHAP can be considered as a breast cancer radiosensitization agent with limited damage to the surrounding healthy tissue.

Synthesis of anticorrosion nanohybrid films based on bioinspired dopamine, L-cys/CNT@PDA through self-assembly on 304 stainless steel in 3.5% NaCl

Nanohybrid films containing multiwalled carbon nanotubes (MWCNTs) were successfully coated on 304-stainless steel (304ss) for anti-corrosion use. The nanocompositewas made by a self-assembly of poly (dopamine), wrapped with MWCNTs (CNT@PDA) through a mussel inspired method. In order to enhance the corrosion protection, an inner layer of L-cysteine, an adhesive amino acid to 304ss surface through thiol (-SH) functional group were constructed through a dip-coating process. Potentiodynamic polarization measurements and electrochemical impedance spectroscopy revealed that the double nano-layer could act as a noble anticorrosive coating in 3.5% NaCl, which was assigned to the hydrophobicity, robustness, and dense double layer coating.

Preparation and characterization of marine mineralized ASC nanocomposites through biomineralization

Mineralized collagen provides new solutions in the manufacture of porous scaffolds for tissue engineering. In this research, the use of biomimetic mineralization, the process of mineralization of acid soluble collagen (ASC) type I extracted from white fish (Rutilus frisii kutum) scales, in a body simulated fluid (SBF) in the presence and absence of an anionic surfactant, sodium dodecyl benzene sulphonate (SDBS) was thoroughly investigated. The formation of β-tricalcium phosphate (β-TCP) nanocrystals in mineralized nanocomposites was detected by XRD, TGA, and FT-IR techniques. The denaturation temperature (T_d) of mineralized ASC was determined at 42.87 °C without surfactant, and at 70.2 °C with surfactant using DSC technique, which indicated a higher thermal stability of ASC without the SDBS surfactant. TEM images illustrated that the formation of β-TCP crystals on collagen nano-fibrils was in an irregular form in the absence of surfactant while it was more regular and in the form of rectangular sheets in the presence of surfactant. The results of UV/Vis spectrophotometer for turbidity measurements during the initial step of biomineralization revealed that SDBS while accelerating the self-assembly process of collagen nano-fibrills, delayed the process of nucleation and the growth of calcium phosphate nanocrystals by increasing the kinetic energy barrier.

Application of FT-IR spectroscopy on breast cancer serum analysis

Breast cancer is regarded as the most malignant tumor among women throughout the world. Therefore, early detection and proper diagnostic methods have been known to help save women's lives. Fourier Transform Infrared (FT-IR) spectroscopy, coupled with PCA-LDA analysis, is a new technique to investigate the characteristics of serum in breast cancer. In this study, 43 breast cancer and 43 healthy serum samples were collected, and the FT-IR spectra were recorded for each one. Then, PCA analysis and linear discriminant analysis (LDA) were used to analyze the spectral data. The results showed that there were differences between the spectra of the two groups. Discriminating wavenumbers were associated with several spectral differences over the 950-1200cm^-1(sugar), 1190-1350cm^-1 (collagen), 1475-1710cm^-1 (protein), 1710-1760cm^-1 (ester), 2800-3000cm^-1 (stretching motions of -CH₂ & -CH₃), and 3090-3700cm^-1 (NH stretching) regions. PCA-LDA performance on serum IR could recognize changes between the control and the breast cancer cases. The diagnostic accuracy, sensitivity, and specificity of PCA-LDA analysis for 3000-3600cm^-1 (NH stretching) were found to be 83%, 84%, 74% for the control and 80%, 76%, 72% for the breast cancer cases, respectively. The results showed that the major spectral differences between the two groups were related to the differences in protein conformation in serum samples. It can be concluded that FT-IR spectroscopy, together with multivariate data analysis, is able to discriminate between breast cancer and healthy serum samples.

A novel metabolite (1,3-benzenediol, 5-hexyl) production by Exophiala spinifera strain FM through dibenzothiophene desulfurization

Sulfur dioxide which is released from petroleum oil combustion causes pollution over the atmosphere and the soil. Biodesulfurization can be used as a complementary method of hydrodesulfurization, the common method of petroleum desulfurization in refineries. Many studies have been carried out to develop biological desulfurization of dibenzothiophene (DBT) with bacterial biocatalysts. However, fungi are capable to metabolize a wide range of aromatic hydrocarbons through cytochrome P450 and their extracellular enzymes. The aim of the present work was isolation and identification of fungi biocatalysts capable for DBT utilization as sulfur source and production of novel metabolites. DBT consumption and the related produced metabolites were analyzed by HPLC and GC-MS respectively. One of the isolated fungi that could utilize DBT as sole sulfur source was identified by both traditional and molecular experiments and registered in NCBI as Exophiala spinifera FM strain (accession no. KC952672). This strain could desulfurize 99 % of DBT (0.3 mM) as sulfur source by co-metabolism reaction with other carbon sources through the same pathway as 4S and produced 2-hydroxy biphenyl (2-HBP) during 7 days of incubation at 30 °C and 180 rpm shaking. However, the isolate was able to transform 2-HBP to 1,3-benzenediol, 5-hexyl. While biphenyl compounds are toxic to leaving cells, biotransformation of them can reduce their toxicity and the fungi will be more tolerant to the final product. These data are the first report about the desulfurization of DBT comparable to 4S-pathway and production of innovative metabolite by E. spinifera FM strain.

The use of antibacterial activity of ZnO nanoparticles in the treatment of municipal wastewater

Nanotechnology holds great potential in advanced water and wastewater treatment to improve treatment efficiency. Zinc oxide nanoparticles (ZnO NPs) have received considerable attention due to their unique antibacterial activities toward various microorganisms that are commonly found in the environment. In the present study, ZnO NPs were synthesized through both mechano-chemical and sol-gel methods. The synthesized ZnO NPs were characterized through X-ray diffraction and transmission electron microscopy techniques. Then, their antibacterial activities against separated wastewater bacteria were evaluated by determining the zone inhibitor, the minimum inhibitory concentration, and the minimum bactericidal concentration. The results were compared with those obtained from wastewater after chlorine disinfection and ultraviolet (UV) disinfection. These studies demonstrated that the antibacterial activity of ZnO NPs depends on the type and the strain of bacteria. They have also demonstrated that the activity increases as the concentration of ZnO NPs increases. Overall, the experimental results suggest that ZnO NPs can potentially be an antibacterial reagent to treat wastewater. They can particularly be applied as a complementary method with UV disinfection. Thus, they can be developed as antibacterial agents to improve wastewater quality.

Density functional theory study of nitrogen-14 nuclear quadrupole coupling parameters of L-histidine: hydrogen-bonded system

The calculations of nitrogen-14 nuclear quadrupole parameters, nuclear quadrupole coupling constant, χ, and asymmetry parameter, η, of L-His were done in two distinct environments: one as a free fully optimized molecule, an isolated molecule with the geometrical parameters taken from X-ray, and the other in the orthorhombic and monoclinic solid states. The most probable interacting molecules with the central molecule in the crystalline phase were considered in the hexameric clusters to include hydrogen-bonding effects in the calculations. The computations were performed with PW91P86/6-31++G** and B3LYP6-31++G** methods using the Gaussian 98 program. The good agreement between the nitrogen-14 quadrupole parameters of the free His and imidazole molecules with their microwave available data demonstrates that the applied level of theory and the 6-31++G** basis set are suitable to obtain reliable electric field gradient values. In the solid state, the shifts of quadrupole coupling parameters from the monomer to the solid phase are reasonably well reproduced for the amino and imino sites of imidazole ring in a hexameric cluster. That implies the fact that the hexameric cluster worked effectively to generate the results which are compatible with the experiment. The quadrupole coupling constant values of -N(+) H(3) group are in fair agreement with the experiment. This discrepancy is due to the absences of vibrational effects and the rotation of -N(+) H(3) group around N-C(α) bond.

Density functional theory investigation of hydrogen bonding effects on the oxygen, nitrogen and hydrogen electric field gradient and chemical shielding tensors of anhydrous chitosan crystalline structure

A systematic computational investigation was carried out to characterize the 17O, 14N and 2H electric field gradient, EFG, as well as 17O, 15N, 13C and 1H chemical shielding tensors in the anhydrous chitosan crystalline structure. To include the hydrogen-bonding effects in the calculations, the most probable interacting molecules with the target molecule in the crystalline phase were considered through a hexameric cluster. The computations were performed with the B3LYP method and 6-311++G(d,p) and 6-31++G(d,p) standard basis sets using the Gaussian 98 suite of programs. Calculated EFG and chemical shielding tensors were used to evaluate the 17O, 14N and 2H nuclear quadrupole resonance, NQR, and 17O, 15N, 13C and 1H nuclear magnetic resonance, NMR, parameters in the hexameric cluster, which are in good agreement with the available experimental data. The difference between the calculated NQR and NMR parameters of the monomer and hexamer cluster shows how much hydrogen bonding interactions affect the EFG and chemical shielding tensors of each nucleus. These results indicate that both O(3)-H(33)...O(5-3) and N-H(22)...O(6-4) hydrogen bonding have a major influence on NQR and NMR parameters. Also, the quantum chemical calculations indicate that the intra- and intermolecular hydrogen bonding interactions play an essential role in determining the relative orientation of EFG and chemical shielding principal components in the molecular frame axes.

Urinary ascites due to retroperitoneal fibrosis: a case report

Urinary ascites in adults is usually secondary to iatrogenic or traumatic injuries. A case of a 69-year-old male with abdominal pain and decreased renal function is described. Ultrasound showed bilateral hydronephrosis and ascites. Computed tomography revealed retroperitoneal fibrosis complicated by a rupture at the right ureteropelvic junction and urine extravasation in the perirenal and intraperitoneal spaces. Delayed scans showed leaking of contrast media from the anterior perirenal space to the peritoneal cavity. The urinary ascites resolved using a double-J stent.

A Systematic Investigation of Hydrogen-Bonding Effects on the 17O, 14N, and 2H Nuclear Quadrupole Resonance Parameters of Anhydrous and Monohydrated Cytosine Crystalline Structures: A Density Functional Theory Study

A systematic computational study was carried out to characterize the 17O, 14N, and 2H nuclear quadrupole resonance (NQR) parameters in the anhydrous and monohydrated cytosine crystalline structures. To include the hydrogen-bonding effects in the calculations, the most probable interacting molecules with the central molecule in the crystalline phase were considered in the pentameric clusters of both structures. To calculate the parameters, couples of the methods B3LYP and B3PW91 and the basis sets 6-311++G** and CC-pVTZ were employed. The mentioned methods calculated reliable values of 17O, 14N, and 2H NQR tensors in the pentameric clusters, which are in good agreements with the experiment. The different influences of various hydrogen-bonding interactions types, N-H...N, N-H...O, and O-H...O, were observed on the 17O, 14N, and 2H NQR tensors. Lower values of quadrupole coupling constants and higher values of asymmetry parameters in the crystalline monohydrated cytosine indicate the presence of stronger hydrogen-bonding interactions in the monohydrated form rather than that of crystalline anhydrous cytosine.

Stereoselective esterase from Pseudomonas putida IFO12996 reveals alpha/beta hydrolase folds for D-beta-acetylthioisobutyric acid synthesis

Esterase (EST) from Pseudomonas putida IFO12996 catalyzes the stereoselective hydrolysis of methyl dl-beta-acetylthioisobutyrate (dl-MATI) to produce d-beta-acetylthioisobutyric acid (DAT), serving as a key intermediate for the synthesis of angiotensin-converting enzyme inhibitors. The EST gene was cloned and expressed in Escherichia coli; the recombinant protein is a non-disulfide-linked homotrimer with a monomer molecular weight of 33,000 in both solution and crystalline states, indicating that these ESTs function as trimers. EST hydrolyzed dl-MATI to produce DAT with a degree of conversion of 49.5% and an enantiomeric excess value of 97.2% at an optimum pH of about 8 to 10 and an optimum temperature of about 57 to 67 degrees C. The crystal structure of EST has been determined by X-ray diffraction to a resolution of 1.6 A, confirming that EST is a member of the alpha/beta hydrolase fold superfamily of enzymes and includes a catalytic triad of Ser97, Asp227, and His256. The active site is located approximately in the middle of the molecule at the end of a pocket approximately 12 A deep. EST can hydrolyze the methyl ester group without affecting the acetylthiol ester moiety in dl-MATI. The examination of substrate specificity of EST toward other linear esters revealed that the enzyme showed specific activity toward methyl esters and that it recognized the configuration at C-2.

A Study on the Intermolecular Hydrogen Bonds of α-Glycylglycine in Its Actual Crystalline Phase Using ab Initio Calculated 14N and 2H Nuclear Quadrupole Coupling Constants

alpha-Glycylglycine in its actual crystalline phase is studied by ab initio calculated nuclear quadrupole coupling constants. These physical quantities are computed for 2H and 14N in the hydrogen bonds. The type of hydrogen bond is the N-H...O type. The computations are performed with the RHF and B3LYP methods and 6-31++G** and 6-311++G** basis sets using the Gaussian 98 program. Values of the calculated nuclear quadrupole coupling constants are shown in Tables 1-3. The aim of this work is the study of 2H and 14N quadrupole coupling constants which contribute in the CON2H...O=CN2H type of hydrogen bond. The computed nuclear quadrupole coupling constants of 2H nuclei meet the related experimental values. In addition, the computed chi value of 14N belonging to the -CO-14NH- group agrees well with values obtained experimentally. However, there are some discrepancies between calculated 14N chi values of the N+H3 residue and experiments. Also, the values of these physical parameters are calculated for >C2H2 of alpha-glycylglycine in its crystalline phase. Calculations for these parameters are carried out in a single molecule using X-ray diffraction coordinates, too.

Samario 153 in the Treatment of Bones Pain Caused by Metastatic PCa

Treatment options in patients with prostate cancer (PCa) localized to the bones include the use of drugs making an attempt to improve their quality of life. In addition new therapies based on drugs with strong bone tropism have been developed. Samario 153 (Sm 153) is a radio-active compound that linked to a particular bifosfanate drug (EDTA) is able to reach and to bind to the bony-tessue carrying out its therapeutic effects. In this report we have analyzed the efficacy and the safety of a single treatment with Sm 153 in patients with metastatic bones spread of PCa causing a painful symptomatology.

Glomerular diseases in Iranian children: clinico-pathological correlations

Glomerular disease constitutes an important part of renal disease. The purpose of this study was to describe and correlate the types of glomerular diseases reported in native kidney biopsy specimens and their clinical presentations in Iranian children. The medical records and pathological diagnoses of patients with glomerular disease whose native kidney biopsy specimens were received by our hospital during a 10-year period were reviewed. In each patient, pathological diagnosis, clinical presentation, age at onset of disease, gender, and presence of nephrotic proteinuria, hematuria, and hypertension, were determined. Minimal-change disease was the most frequent glomerular disease and nephrotic syndrome was the most frequent clinical presentation encountered. For each disease, correlations between the clinical presentation and pathological diagnosis were made. This study describes various glomerular diseases encountered in Iranian children, with their respective clinical presentations.

Isolated profound thrombocytopenia associated with clopidogrel

Clopidogrel is a new oral antiplatelet agent with a structure and mechanism of action similar to ticlopidine; they both block the adenosine diphosphate receptor. Because of better side-effect profile and simpler dosing regime, clopidogrel has largely replaced ticlopidine. In fact, the excellent safety and tolerability profile of clopidogrel compares favorably with that of aspirin as documented in the CAPRIE (Clopidogrel versus Aspirin in Patients at Risk of Ischemic Events) study. After marketing, several cases of clopidogrel-associated thrombotic thrombocytopenic purpura (TTP) were reported. We report our experience with a case of isolated profound thrombocytopenia without evidence of TTP after clopidogrel administration with prompt recovery of platelet counts upon discontinuation of clopidogrel and treatment with intravenous immunoglobulin.

Acute profound thrombocytopenia without bleeding complications after abciximab administration

Abciximab (c7E3) is the Fab fragment of the chimeric monoclonal antibody directed against glycoprotein IIb/IIIa found on the surface of platelets. It is the first FDA-approved platelet receptor glycoprotein inhibitor. Severe thrombocytopenia (defined as platelet count < 50 x 109/L) on first administration is a rare complication, occurring in only 1.6% of patients in the EPIC (Evaluation of 7E3 for the Prevention of Ischemic Complications) study. Bleeding complications were the rule in these thrombocytopenic patients as reported by EPIC investigators, Kereiakes et al. and Berkowitz et al. Platelet transfusions are required to reverse the bleeding diathesis. Intravenous IgG has not reportedly been helpful in reversing thrombocytopenia, and experience with corticosteroids is not reported in the literature. We report a case of acute profound thrombocytopenia following abciximab administration treated with platelet transfusion augmented by intravenous corticosteroids, in whom there was no bleeding complication.

[Bourneville's syndrome: diagnostic and urologic implications]

Angiomyolipoma is a rare tumor frequently associated with tuberous sclerosis and it has a higher incidence of bilateral renal involvement in this case. Patients effected by Bourneville's Syndrome are often more symptomatic than patients with angiomyolipoma only, however it is necessary to examine the renal conditions in all of them because of the high risk for severe hemorrhage. Diagnostic evaluation is based on radiological findings as Ultrasonography and Computed Tomography. We present a case of bilateral and symptomatic angiomyolipoma is a young woman with Bourneville's Syndrome.

Primary nephrotic syndrome in Iran: clinicopathological study of 310 cases

Three hundred and ten children with primary nephrotic syndrome were studied since 1972. 190 patients are classified as nephrosis (61%); including minimal glomerular lesions (22.9%), diffuse mesangial proliferation (6.77%) and focal and segmental sclerosis (31.6%). Corticoresponsivity was limited: 53.75% with a higher success rate in minimal glomerular lesions: 74% versus 38% of diffuse mesangial proliferation and 42.5% focal and segmental sclerosis. Immunosuppressive drugs were used for 96 patients corticodependent or resistant. They were more effective in dependent than resistant cases 94% versus 38%. A total of 149 cases were followed (mean: 3.9 years). In the last evaluation 67% were in remission, 8.10% in chronic renal failure and 24.8% with other abnormalities.