Influence of RE (Pr3+, Er3+, Nd3+) doping on structural, vibrational and enhanced persistent photocatalytic properties of ZnO nanostructures

Rare earth (RE- Pr, Er and Nd) doped ZnO nanostructures were prepared through simple wet chemical precipitation route. The RE doping induced interesting morphological transition from spherical to flower like structures were analyzed. The X-ray diffraction (XRD) measurements revealed that the prepared materials were of highly crystalline in nature and RE dopant ions did not altered the crystal structure of ZnO. The microstrain of ZnO was altered with respect to the nature of dopants. In the case of the Pr doped ZnO, X-ray photoelectron spectroscopy (XPS) analysis confirmed that the dopant (Pr) ions successfully substituted in the ZnO lattice. Raman spectra revealed RE doping induced lower energy side shift and variation in intensity of the peaks related to the characteristic phonon modes of ZnO. In the case of Nd doped ZnO nanostructures, dopant induced suppression in classical Raman modes and evolution of multiphonon related modes were identified. Optical diffuse reflectance spectral (DRS) measurements, along with the characteristic excitonic band of ZnO, other bands associated to the transitions of 4f energy levels related to the RE ions were observed. The partially filled 4f orbitals led to the enhanced photocatalytic activity in RE doped ZnO nanostructures. The observed enhanced photocatalytic activity in RE doped ZnO when compared to bare ZnO was discussed. The decolorization efficiency of MB ensued the following order 96 > 94 > 86 > 78% for ZnErO, ZnNdO, ZnPrO and ZnO, respectively.

Conformational analysis, molecular structure, spectroscopic, NBO, reactivity descriptors, wavefunction and molecular docking investigations of 5,6-dimethoxy-1-indanone: A potential anti Alzheimer's agent

The objective of the present study is focused to elucidate the structure of potential anti-Alzheimer's compound 5,6-Dimethoxy-1-indanone (5,6-DMI) and study its binding interaction towards the active site by molecular docking studies. The structural and various spectroscopic tools are used to understand the various interaction behaviors of the title compound. The theoretical calculation of 5,6-DMI molecule is computed by Gaussian 09W software with Density functional B3LYP and CAM-B3LYP method utilizing 6-311G(d,p) as basis set. The Natural Bond Orbital (NBO) analysis has been performed to find all possible transition was correlate with electronic transition. The Non covalent interaction of 5,6-DMI molecule was examined by adopt Reduced Density Gradient (RDG) analysis and colour filled ELF diagram. Molecular docking results suggest that 5,6-DMI may exhibit inhibitory activity against apoE protein and may act as potential against Alzheimer's disease.

A study of Factors Affecting Dialysis Recovery Time in Haemodialysis Patients in India

Background:

Patients on maintenance haemodialysis (MHD) often complain of fatigue and tiredness following haemodialysis sessions leading to poor compliance with the dialysis schedule. There is limited Indian data on dialysis recovery time (DRT). The present study was designed to assess the factors affecting DRT in our haemodialysis population.

Methods:

We recorded self-reported patient recovery times of 120 patients who satisfied the inclusion criteria, over three consecutive dialysis sessions by asking the question, 'How long does it take to recover from a dialysis session'? Data recorded included patient factors like age, sex, co-morbidities, Charlson comorbidity index score (CCI), dialysis vintage, duration of kidney disease, interdialytic weight gain (IDWG), treatment factors like ultrafiltration rate (UFR), SpKt/V, blood pump speed, dialysate sodium, session length, pre and post HD blood pressure and laboratory parameters. Health-related quality of life (HRQoL) was assessed with the KDQOL-SF v. 1.3 questionnaire. Results from the SF-36 score were summarised into the physical composite score (PCS), mental composite score (MCS) and kidney disease composite score (KDCS).

Results:

The mean age of the study population was 50.6 ± 12.6 years. Among the 120 patients, 77 (64.2%) were males. Thirty-nine patients (32.5%) were diabetic and 95 (79.1%) patients were hypertensive. The mean dialysis vintage of the study population was 26.1 ± 18.6 months, 41 (34.2%) patients reported DRT <2 h; 48 (40%) reported DRT between 2–6 h and 31 (25.8%) reported DRT >6 h. On multivariate regression analysis, higher IDWG, CCI score and UFR were associated with prolonged DRT. Reported DRT also inversely correlated with PCS (r = - 0.66), MCS (r = - 0.65) and KDCS (r = - 0.59) scores which was statistically significant.

Conclusion:

The present study showed that higher CCI scores, IDWG and UFR were associated with prolonged DRT in Indian haemodialysis patients and patients with longer recovery time had poor HRQoL. Interventions to reduce DRT need to be assessed in further trials in Indian MHD patients.

Post Renal Transplant Collapsing Glomerulopathy is Associated with Poor Outcomes

Introduction:

Collapsing glomerulopathy (CG) is a distinct morphologic pattern of proliferative renal parenchymal injury. It differ from focal segmental glomerulosclerosis (FSGS) by clinicopathologic pattern and its adverse outcome. The clinical significance of CG in renal allograft biopsies is not yet clear due to scant data and less occurrence of CG in renal transplant recipients. We conducted this single-center retrospective study to evaluate the prevalence, clinicopathological features, and outcome of post renal transplant CG.

Subjects and Methods:

We studied 127 renal allograft biopsies performed over a period of 45 months (Jan 2015–Oct 2018). A diagnosis of CG was made if at least one glomerulus demonstrated global or segmental collapse of the glomerular capillary walls, associated marked hyperplasia, and hypertrophy of the overlying visceral epithelial cells. We analyzed clinical, biochemical, and pathological characteristics and its impact on renal allograft outcome. Statistical analysis was performed and continuous variables were expressed as means ± standard deviation (SD) or medians (interquartile range and noncontinuous data were expressed in percentage and numerical values.

Results:

The prevalence of CG was 5.3% (7/127) of allograft biopsies. Out of the seven patients, six patients had undergone live donor transplant and one patient had undergone deceased donor renal transplant. The native kidney disease was unknown in these patients except one (IgA nephropathy). The median duration of diagnosis for CG was 17 months after transplantation (range 5–132months). Presenting symptoms were pedal edema and hypertension in 71.4% (5) patients each. All patients had proteinuria of more than 1 gm and renal allograft dysfunction and median serum creatinine of 3.05 mg/dl (1.5–4.8 mg/dl). All patients received standard triple immunosuppression. Over a period of 2–20 months, 57.14% (4) patients developed a graft failure and 43% (3) of the other patients had functioning grafts with serum creatinine of 1.5–4.2 mg/dl.

Conclusions:

CG presents with moderate to severe proteinuria and may lead to rapid graft dysfunction and subsequent graft failure in most of the patients.

2,4-Dimorpholino-4-yl-6-(4-nitrophenoxy)-[1,3,5]-triazine: Structural and spectroscopic study using experimental and DFT method

2,4-Dimorpholino-4-yl-6-(4-nitrophenoxy)-[1,3,5]-triazine (DMNT) was synthesized and the molecular structure and vibrational frequencies were studied by density functional theory (DFT) method. The functional used was Becke’s three parameter exchange functional combined with the Lee-Yang-Parr correlation (B3LYP) and the standard basis set was 6-31G(d) for all atoms. The Fourier Transform-Infra Red (FT-IR) and FT-Raman spectra of DMNT were recorded and complete assignments of the observed vibrational frequencies are done. The assignments were confirmed by isotopic labelling. The structural parameters, harmonic vibrational frequencies, IR intensities and Raman intensities of DMNT in the ground-state were also computed. Non-linear optical behaviour of DMNT was analysed by examining the properties like electric dipole moment, polarizability and hyperpolarizability. Molecular properties such as ionization potential, electro-negativity, chemical potential and chemical hardness were obtained from molecular orbital analysis. Hyper conjugative interaction and charge delocalization taking place in DMNT was confirmed by Natural bond analysis studies. UV-Vis spectrum of DMNT was also recorded to understand the electronic properties.

Graphical Abstract:

Heart disease prediction using stacked ensemble technique

Heart diseases are one of the crucial diseases that may cause fatality in both men and women. About 12 million deaths occur across the world due to heart diseases. With the advancement in information technology, it is possible for the Healthcare industry to store enormous volume of data containing millions of patient’s medical information along with their treatment details. If utilized in an efficient manner, this information helps the doctors to diagnose the diseases in a precise manner. Data mining algorithms are employed to analyse huge data sets and to discover unseen patterns. Data mining plays an essential role in medical diagnosis. Doctors bank on different computer models which uses data mining algorithms to prefigure different kinds of diseases in patients. So, the need is to design a methodical data mining algorithm that helps for better forecast of diseases. The main goal of this work is to create an ensemble of algorithms which results in better accuracy. The ensemble is constructed by making use of stacking ensemble technique, which comprises of two categorization algorithms namely Naïve Bayes and Artificial Neural Network. The Cleveland heart disease data set acquired from UCI machine learning repository containing 14 attributes and 303 instances is given as input to these algorithms. From our experimental analysis it is evident that the proposed ensemble scheme results in a better accuracy.

An ingenious non-spherical mesoporous silica nanoparticle cargo with curcumin induces mitochondria-mediated apoptosis in breast cancer (MCF-7) cells

Curcumin delivery to cancer cells is challenging due to its hydrophobic nature, low bio distribution and low availability. Many nano vehicles suffer from low stability and toxicity, and hence the prerequisite of a non-toxic nano vehicle with effective drug delivery is still being delved. The present study investigates the delivery efficiency of curcumin with non-spherical mesoporous silica nanoparticles (MSNAs). Their mechanism of drug delivery and signalling proteins activated to induce apoptosis was further explored in MCF-7 cells. A non-spherical MSN was synthesised, functionalised with PEI (MSNAP) and analysed its intracellular behaviour. Our result indicates that MSNAP was non-toxic until 20 µg/mL and likely localizes in cytoplasmic vesicles. On contrast, well-known MCM-41P induced autophagosome formation, indicating cellular toxicity. Curcumin was loaded on MSNAP and its effectiveness in inducing cell death was studied in MCF-7 and in MCF-7R cells. Curcumin loading on MSNAP induces better cell death with 30 µM curcumin, better than unbounded curcumin. Western blot analysis suggest, curcumin induce apoptosis through the activation of caspase 9, 6, 12, PARP, CHOP and PTEN. The cell survival protein Akt1 was downregulated by curcumin with and without the nanostructure. Interestingly, cleaved caspase 9 was activated in higher amount in nano-conjugated curcumin compared to the free curcumin. But other ER resident protein like IRE1α, PERK and GRP78 were downregulated indicating curcumin disturbs ER homeostasis. Further, electron microscopic analysis reveled that nanocurcumin induced apoptosis by disrupting mitochondria and nucleus. Our results with doxorubicin resistant MCF-7 cell lines confirm nanodelivery of doxorubicin and curcumin sensitised cells effectively at lesser concentration. Further docking studies of curcumin indicate it interacts with the apoptotic proteins through hydrogen bonding formation and with higher binding energy.

Environment dependent enhanced photoluminescence and Boolean logic gates like behavior of Bi2O3 and Ag:Bi2O3 nanostructures

In the evolution of nanotechnology research for smart and precise sensor fabrication, here we report the implementation of simple logic gate operations performing by luminescent nanostructures in biomolecule environment based on photoluminescence (PL) technique. This present work deals with the luminescence property of α-Bi₂O₃ and Ag modified α-Bi₂O₃ nanostructures for d-glucose and Bovine serum albumin (BSA) sensing applications. These nanostructures are prepared by simple co-precipitation method and their morphology are examined using transmission electron microscope (TEM). We explore the PL characteristics of the prepared nanostructures and observe their change in PL intensity in the presence of d-glucose and BSA molecules. Enhancement in PL intensity is observed in the presence of d-glucose and BSA. Based on the PL response of prepared nanostructures in the biomolecule environment, we demonstrate biophotonic logic gates including YES, PASS 0, OR and INHIBIT gates.

Insights on the involvement of (-)-epigallocatechin gallate in ER stress-mediated apoptosis in age-related macular degeneration

Endoplasmic reticulum (ER) stress-mediated apoptosis is a well-known factor in the pathogenesis of age-related macular degeneration (AMD). ER stress leads to accumulation of misfolded proteins, which in turn activates unfolded protein response (UPR) of the cell for its survival. The prolonged UPR of ER stress promotes cell death; however, the transition between adaptation and ER stress-induced apoptosis has not been clearly understood. Hence, the present study investigates the regulatory effect of (-)-epigallocatechin gallate (EGCG) on ER stress-induced by hydrogen peroxide (H₂O₂) and disturbance of calcium homeostasis by thapsigargin (TG) in mouse retinal pigment epithelial (MRPE) cells. The oxidant molecules influenced MRPE cells showed an increased level of intracellular calcium [Ca²⁺]_i in ER and transferred to mitochondria through ER-mitochondrial tether site then increased ROS production. EGCG restores [Ca²⁺]_i homeostasis by decreasing ROS production through inhibition of prohibitin1 which regulate ER-mitochondrial tether site and inhibit apoptosis. Effect of EGCG on ER stress-mediated apoptosis was elucidated by exploring the UPR signalling pathways. EGCG downregulated GRP78, CHOP, PERK, ERO1α, IRE1α, cleaved PARP, cleaved caspase 3, caspase 12 and upregulated expression of calnexinin MRPE cells. In addition to this, inhibition of apoptosis by EGCG was also confirmed with expression of proteins Akt, PTEN and GSK3β. MRPE cells with EGCG upregulates phosphorylation of Akt at ser473 and phospho ser380 of PTEN, but phosphorylation at ser9 of GSK3β was inhibited. Further, constitutively active (myristoylated) CA-Akt transfected in MRPE cells had an increased Akt activity in EGCG influenced cells. These findings strongly suggest that antioxidant molecules inhibit cell death through the proper balancing of [Ca²⁺]_i and ROS production in order to maintain UPR of ER in MRPE cells. Thus, modulation of UPR signalling may provide a potential target for the therapeutic approaches of AMD.

HR-TEM and FT-Raman dataset of the caffeine interacted Phe-Phe peptide nanotube for possible sensing applications

Sensing ability of caffeine interaction with Phe-Phe annotates (PNTs), is presented (Govindhan et al., 2017; Karthikeyan et al., 2014; Tavagnacco et al., 2013; Kennedy et al., 2011; Wang et al., 2017) [1–5] in this data set. Investigation of synthesized caffeine carrying peptide nanotubes are carried out by FT-Raman spectral analysis and high resolution transmission electron microscopy (HR-TEM). Particle size of the caffeine loaded PNTs is < 40 nm. The FT-Raman spectrum signals are enhanced in the region of 400–1700 cm⁻¹. These data are ideal tool for the applications like biosensing and drug delivery research (DDS).

Optimization of treatment modality in elderly end-stage renal disease population: Peritoneal dialysis versus transplant

Despite kidney transplantation (KT) being considered as the best treatment modality for end-stage renal disease (ESRD), patient and graft survival in the elderly population is poorer than younger individuals. Many authors argue that prolonged life expectancy outweighs the risk of remaining on dialysis, but few studies had compared the treatment modalities, especially with peritoneal dialysis (PD). A retrospective study was conducted at a tertiary care institute to compare outcome of elderly ESRD patients, who received KT with those continued on PD; and to evaluate the predictors of patient survival. Patient survival at 1 year was (76.2% vs. 91.1%); 5 years (53.7% vs. 21.8%); and 10 years (35.6% vs. 0.00%) among KT and PD population, respectively. Infection was the most common cause of death among KT group (35 [41.2%] vs. 34 [28.2%]) while cardiovascular mortality in PD group (55 [46.2%] vs. 7 [8.2%]). Technique survival at 1, 5, and 10 years in PD group was 92.8%, 58.5%, and 0%, respectively. Similarly, graft survival at 1, 5, and 10 years in KT group was 98.7%, 90.2%, and 90.2%, respectively. Multivariate analysis showed body mass index (BMI) (hazard ratio [HR] 0.88, 95% confidence interval [CI] 0.82–0.93, p < 0.001), and albumin (HR 0.55, 95% CI 0.37–0.80, p = 0.002) were significant predictors of survival. In the 1^st year, patient survival was better in PD than KT, but after adjustment for BMI and albumin, both short-term and long-term survival in elderly KT group was better than that of PD. Hence, elderly ESRD patients should not be barred from KT just because of age.

Maternal Risk Factors and Periodontal Disease: A Cross-sectional Study among Postpartum Mothers in Tamil Nadu

Background and Aim

It is inconclusive that periodontitis is an independent risk factor for adverse pregnancy outcomes. This study aims to investigate the association between maternal periodontitis and preterm and/or low birth weight babies.

Settings and Design

This was a prospective cross-sectional study. After prior informed consent, 3500 postpartum mothers were selected from various hospitals in Tamil Nadu and categorized into the following groups: group-1 - Normal term normal birth weight (n = 1100); Group-2 - Preterm normal birth weight (n = 400); Group-3 - preterm low birth weight (PTLBW) (n = 1000); and Group-4 - Normal term low birth weight (n = 1000). Periodontal examination was done, and risk factors were ascertained by means of questionnaire and medical records.

Statistical Analysis

Comparison between case groups and control groups were done, odds ratio (OR) was calculated, and statistical significance were assessed by Chi-square tests. To control for the possible confounders, all variables with P < 0.05 were selected and entered into multivariate regression model, and OR and 95% confidence limits were again estimated. SPSS-15 software was used.

Results

Periodontitis was diagnosed in 54.8%, 52.3%, 53.8%, 59.4%, respectively. On comparison between the groups, none of periodontal parameters showed significant association except for the crude association observed in Group-4 for mild periodontitis (OR - 1.561; P = 0.000) and PTLBW.

Conclusion

Periodontitis is not a significant independent risk factor, and obstetric factors contribute a major risk for preterm and/or low birth weight babies.

Polyethylenimine-modified curcumin-loaded mesoporus silica nanoparticle (MCM-41) induces cell death in MCF-7 cell line

Breast cancer accounts for the first highest mortality rate in India and second in world. Though current treatment strategies are effectively killing cancer cells, they also end in causing severe side effects and drug resistance. Curcumin is a nutraceutical with multipotent activity but its insolubility in water limits its therapeutic potential as an anti-cancer drug. The hydrophilicity of curcumin could be increased by nanoformulation or changing its functional groups. In this study, curcumin is loaded on mesoporous silica nanoparticle and its anti-cancer activity is elucidated with MCF-7 cell death. Structural characteristics of Mobil Composition of Matter - 41(MCM-41) as determined by high-resolution transmission electron microscopy (HR-TEM) shows that MCM-41 size ranges from 100 to 200 nm diameters with pore size 2-10 nm for drug adsorption. The authors found 80-90% of curcumin is loaded on MCM-41 and curcumin is released efficiently at pH 3.0. The 50 µM curcumin-loaded MCM-41 induced 50% mortality of MCF-7 cells. Altogether, their results suggested that increased curcumin loading and sustained release from MCM-41 effectively decreased cell survival of MCF-7 cells in vitro.

Förster resonance energy transfer and excited state life time reduction of rhodamine 6G with NiO nanorods in PVP films

In the present study, we report the preparation of NiO nanorods (NNR) and its Förster resonant energy transfer (FRET) behaviour with rhodamine 6G (R6G) in a Polyvinyl pyrrolidone (PVP) polymer matrix. The prepared nanocomposite polymer (NCP) films contain PVP and R6G whose concentrations are kept constant and different concentrations of NNR. Spectral overlap between the absorption and fluorescence spectrum of R6G and NNR shows the possibility of FRET phenomena to be occurring in the prepared NCP films. Steady state and time resolved fluorescence measurements are carried out at two excitation wavelengths (330 and 510nm) to study the energy transfer process between R6G and NNR in the PVP host. The obtained results show that the energy transfer is from R6G (serves as a donor) to NNR (functions as an acceptor). Calculated radiative efficiencies, donor-acceptor distances and average lifetime also confirm the energy transfer from R6G to NNR.

Surfactant assisted control on optical, fluorescence and phonon lifetime in α-Bi2O3 microrods

We report preparation of pure and surfactant added α-Bi2O3 microrods through simple chemical method at moderate temperature. Cetyltrimethyl ammonium bromide (CTAB) is used as a surfactant. X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier Transform Infrared (FTIR) spectroscopy, Raman spectroscopy, UV-Vis absorption and photoluminescence (PL) measurements were carried out to understand the effect of surfactant (CTAB) on structural, phonon and optical properties of the prepared material. It is observed that the crystallite size, optical band gap and the structural defects (oxygen vacancies) decreases due to the effect of surfactant. Raman spectral studies exhibit various phonon modes of Bi2O3 and also decrease in the FWHM of the phonon modes is observed after the addition of CTAB.

Role of ZnS Nanoparticles on Endoplasmic Reticulum Stress-mediated Apoptosis in Retinal Pigment Epithelial Cells

Age-related macular degeneration (AMD) is the leading cause for irreversible visual impairment affecting 30-50 million individuals every year. Oxidative stress and endoplasmic reticulum stress have been identified as crucial factors for the pathogenesis of AMD. Current treatments do not focus on underlying stimuli responsible for the disease like AMD. Zinc is an important trace metal in retina and its deficiency leads to AMD. Recent studies on zinc sulphide nanoparticles (ZnS-NPs) are gaining attention in the field of physical and biological research. In this present study, in investigating the role of ZnS-NPs on hydrogen peroxide and thapsigargin-treated primary mice retinal pigment epithelial (MRPE) cells, we synthesized ZnS-NPs and characterized using atomic force microscope (AFM) and SEM-EDX. The ZnS-NPs abrogate the primary MRPE cell death through inhibition of oxidative stress-induced reactive oxygen species production and cell permeability. Oxidant molecules hydrogen peroxide and thapsigargin alter unfolded protein response such as glucose-regulated protein 78 (GRP78) and C/EBP homology protein (CHOP) expressions, whereas ZnS-NPs-pre-treated primary MRPE cells downregulated the overexpression of such proteins. The expressions of apoptotic proteins caspase 12 and cleaved caspase 9 and caspase 3 were also significantly controlled in ZnS-NPs-treated primary MRPE cells when comparing with thapsigargin- and hydrogen peroxide-treated cells. From these results, ZnS-NPs stabilize reactive oxygen species elevation, when subjected to hydrogen peroxide- and thapsigargin-mediated oxidant injury and helps in maintaining normal homeostasis through regulating endoplasmic reticulum (ER) stress response proteins which is the lead cause for apoptosis-mediated pathogenesis of AMD.

Enhanced blue light emission in transparent ZnO:PVA nanocomposite free standing polymer films

ZnO:PVA nanocomposite films were prepared and their fluorescence and time resolved photoluminescence properties were discussed. X-ray diffraction and infrared spectroscopy results confirmed the ZnO:PVA interaction. Optical absorption spectra showed two bands at 280 and 367nm which were ascribed to PVA and excitonic absorption band, respectively. Fluorescence spectra showed that the blue emission of ZnO was enhanced about tenfold through chemical interface electron transfer. The electron transfer from ZnO to PVA and its decay dynamics were experimentally analyzed through time resolved fluorescence measurements. The study revealed that the excited electrons found pathway through PVA to ground state which was slower than the pure ZnO nanoparticles.

Optical and surface band bending mediated fluorescence sensing properties of MoS2 quantum dots

Band bending assisted fluorescence sensing of glucose and bovine serum albumin using MoS₂ quantum dots.

Crown lengthening procedure in the management of amelogenesis imperfecta

Full mouth rehabilitation includes a promising treatment planning and execution thus fulfilling esthetic, occlusal, and functional parameters maintaining the harmony of the stomatognathic system. Crown lengthening procedures have become an integral component of the esthetic armamentarium and are utilized with increasing frequency to enhance the appearance of restorations placed in the esthetic zone. Crown lengthening plays a role to create healthy relationship of the gingiva and bone levels so as to gain access to more of the tooth which can be restored, if it is badly worn, decayed or fractured, below the gum line. This paper highlights the full mouth crown lengthening procedure performed on a patient with amelogenesis imperfecta.

Evaluation of transcription factor that regulates T helper 17 and regulatory T cells function in periodontal health and disease

Background:

The differentiation of naοve T helper (Th) cells towards Th17 and regulatory T cells (Treg) is regulated by the transcription factors retinoic acid related orphan receptor gamma transcription (RORYt) and Forkhead box p3 (Foxp3), respectively. An imbalance in the activity of these transcription factors could result in the dysregulation of Th17/Treg response.

Materials and Methods:

Total RNA was isolated from gingival tissue obtained from 10 patients, each from periodontally healthy and diseased groups. The gene expression of RORYt and Foxp3 was measured by real-time reverse transcription polymerization chain reaction using total RNA isolates from gingival tissues group when compared to the healthy group, while Foxp3 demonstrated a 6.68 ± 0.03 fold decrease of expression in diseased group when compared to healthy group.

Conclusion:

Our results indicate a functional imbalance in the Th17/Treg response in periodontal disease group when compared to the periodontally healthy group.

Enhanced ultraviolet fluorescence in surface modified ZnO nanostructures: Effect of PANI

ZnO:polyaniline nanocomposite (ZnO:PANI) films were prepared and their steady state fluorescence and time resolved photoluminescence properties were discussed. X-ray diffraction and infrared spectroscopy analyses confirmed the interaction and formation of ZnO:PANI composite films. Optical absorption spectrum of pure PANI showed two bands at 325 and 625 nm which were ascribed to π→π(∗) transition in the benzoid and exciton formation in the quinoid rings, respectively. Pure ZnO nanoparticles exhibited a band at 369 nm was due to their exciton absorption and the composite films showed a broad band in the visible region and small intensity band at the UV region. Fluorescence spectra showed that the ultra violet emission of ZnO was enhanced about tenfold due to the electron transfer from PANI to ZnO nanoparticles and the suppression of visible emission was attributed to the surface passivation effect. The transfer of electron from PANI to ZnO and its decay dynamics were experimentally analyzed through time resolved fluorescence measurements.

Molecular structure, spectroscopic (FT-IR, FT-Raman), NBO analysis of N,N'-diphenyl-6-piperidin-1-yl-[1,3,5]-triazine-2,4-diamine

In the present work, we have synthesized and reported a combined experimental and theoretical study on the molecular structure, vibrational spectra and HOMO-LUMO analysis of N,N'-diphenyl-6-piperidin-1-yl-[1,3,5]-triazine-2,4-diamine (C20N6H22). The FT-IR and FT-Raman spectra of N,N'-diphenyl-6-piperidin-1-yl-[1,3,5]-triazine-2,4-diamine were recorded. The molecular geometry, harmonic vibrational wavenumbers and bonding features of the title molecule in the ground-state have been calculated by using the density functional B3LYP method with 6-31G(d) as basis set. Non-linear optical (NLO) behavior of the N,N'-diphenyl-6-piperidin-1-yl-[1,3,5]-triazine-2,4-diamine was investigated by determining the electric dipole moment μ, polarizability α, and hyperpolarizability β using the above mentioned basis set. The molecular properties such as ionization potential, electro-negativity, chemical potential, electrophilicity have been deduced from HOMO-LUMO analysis employing the same basis set. The calculated HOMO and LUMO energies showed that charge transfer occurs within the molecule. Stability of the molecule arising from hyper conjugative interaction and charge delocalization has been analyzed using natural bond orbital (NBO) analysis. Finally, the calculation results were applied to simulate infrared and Raman spectra of the title compound which showed good agreement with the observed spectra.

Enhanced multi-phonon Raman scattering and nonlinear optical power limiting in ZnO:Au nanostructures

Enhanced Raman scattering and nonlinear optical power limiting in ZnO:Au nanostructures is demonstrated.

Experimental and first-principles investigation of the adsorption and entrapping of guanine with SiO2 clusters of sol–gel silicate material for understanding DNA photodamage

A sol–gel silicate matrix containing entrapped guanine was prepared. The SiO₂ matrix provides UVA protection by reducing the light penetration to the entrapped guanine molecules.

Surface enhanced vibrational spectroscopy and first-principles study of l-cysteine adsorption on noble trimetallic Au/Pt@Rh clusters

First-principles study of l-cysteine adsorption on noble trimetallic Au/Pt@Rh clusters has been discussed in the light of SEIRS and theoretical surface complex calculation.

Spectroscopic and fiber optic ethanol sensing properties Gd doped ZnO nanoparticles

We report the structural, optical and gas sensing properties of prepared pure and Gd doped ZnO nanoparticles through solgel method at moderate temperature. Structural studies are carried out by X-ray diffraction method confirms hexagonal wurtzite structure and doping induced changes in lattice parameters is observed. Optical absorption spectral studies shows red shift in the absorption peak corresponds to band-gap from 3.42 eV to 3.05 eV and broad absorption in the visible range after Gd doping is observed. Scanning electron microscopic studies shows increase in particle size where the particle diameters increase from few nm to micrometers after Gd doping. The clad modified ethanol fiber-optic sensor studies for ethanol sensing exhibits best sensitivity for the 3% Gd doped ZnO nanoparticles and the sensitivity get lowered incase of higher percentage of Gd doped ZnO sample.

Experimental and first-principles study of guanine adsorption on ZnO clusters

Electronic structure for interaction of guanine with Zn₂O₂ cluster and the most preferred N1-site to form a stable G–Zn₂O₂ model.

Vibrational spectra, molecular structure, natural bond orbital, first order hyperpolarizability, TD-DFT and thermodynamic analysis of 4-amino-3-hydroxy-1-naphthalenesulfonic acid by DFT approach

Vibrational spectral analysis of 4-amino-3-hydroxy-1-naphthalenesulfonicacid (4A3HNSA) molecule were carried out using FT-IR and FT-Raman spectroscopic techniques. The equilibrium geometry, harmonic vibrational wavenumbers, various bonding features have been computed using density functional B3LYP method with 6-31G(d,p) as basis set. The Non-Linear Optical (NLO) behavior of 4A3HNSA has been studied by determination of the electric dipole moment (μ) and hyperpolarizability β using HF/6-31G(d,p) method. Stability of the molecule arising from hyperconjugative interactions, charge delocalization have been analyzed using natural bond orbital (NBO) analysis. The results show that charge in electron density (ED) in σ(*) and π(*) antibonding orbitals and second order delocalization energies (E2) confirms the occurrence of Intramolecular Charge Transfer (ICT) within the molecule. The energy and oscillator strength calculated by Time-Dependent Density Functional Theory (TD-DFT) complements with the experimental findings. The simulated spectra satisfactorily coincide with the experimental spectra.

Optical properties of annealing induced post growth ZnO:ZnFe2O4 nanocomposites

The effects of annealing on structural and optical properties of Fe doped ZnO nanoparticles have been investigated. XRD analysis reveals that prepared particles are in hexagonal wurtzite structure and formation of secondary phases which are related to the ZnFe2O4 phases. FTIR analysis confirms the wurtzite structure and the presence of Zn-O and Fe-O bonds. UV-visible measurements show free exciton absorption band appeared at 363 nm and red shifted for annealed samples. Room temperature photoluminescence spectrum of the as prepared Fe doped ZnO nanoparticles shows three bands which belongs to the near band edge emission (NBE) at 375 nm, blue emission at 450 nm and green emission at 556 nm. Annealed samples exhibit suppression of green emission band and red shift in the NBE emission band. This is attributed to the decrease in the oxygen vacancies and combined effects of size and exchange interaction between the conduction band electrons of ZnO and localised 3d electrons of the substitutional Fe ions, respectively.