Development and validation of a structured feedback questionnaire from postgraduates on various elements of postgraduate medical curriculum.

BACKGROUND: Medical Council of India, introduced the Post Graduate (PG) curriculum as 'Competency Based Medical Education' (CBME). Feedback from the end users is a vital step in curriculum evaluation. Therefore, the primary objective of this study was to develop and validate a Structured Feedback Questionnaire (SFQ) for postgraduates, encompassing all the components of the PG-CBME curriculum. METHODS: SFQ was developed with 23 Likert based questions and four open ended questions. Content validation was done by Lawshe method. After getting institutional ethics clearance and informed consent, SFQ was administered to 121 final year PGs (response rate 100%). We performed Principal component analysis (PCA), Structural equation modeling (SEM), Chi squared test (χ2/df); goodness-of-fit index (GFI); adjusted GFI; comparative fit index (CFI) and root mean square error of approximation (RMSEA). Cronbach's alpha was done for estimating the internal consistency. RESULTS: The validation resulted in a three-factor model comprising of "curriculum" (42.1%), "assessment" (28%), and "support" (18.5%). Chi squared test (χ2/df ratio) < 2, CFI (0.78), GFI (0.72) and RMSEA (0.09) indicated superior goodness of fit for the three-factor model for the sample data. All the extracted factors had good internal consistency of ≥0.9. CONCLUSION: We believe that this 23 item SFQ is a valid and reliable tool which can be utilized for curriculum evaluation and thereby formulating recommendations to modify the existing curriculum wherever required, facilitating enriched program outcomes.

Structurally modified bacteriorhodopsin as an efficient bio-sensitizer for solar cell applications.

Structurally modified bacteriorhodopsin (BR) was prepared by simple surfactant treatment using Cetyl trimethylammonium bromide (cationic; CTAB), Sodium dodecyl sulphate (anionic; SDS) and Triton X-100 (nonionic; TX-100). In the UV-visible absorption spectrum, the characteristic absorption band of native BR at 560 nm is hyperchromically (CTAB, due to induced aggregation), bathochromically (SDS, BR solubilisation and partial unfolding) and hypsochromically (TX-100, BR monomerizes) shifted after chemical treatment and the structural modifications were further confirmed by Raman spectra. Theoretical calculations based on optical absorption support an enhancement of BR optical and electrical conductivity via structural modification. Bio-sensitized solar cells (BSSCs) with structurally altered BR as sensitizer were fabricated and their photovoltaic performance was measured. We obtained the maximum short-circuit photocurrent and photoelectric conversion efficiency with TX-100-treated BR (0.93 mA cm-2, 0.47%), with a quasi-Fermi level and a 124-ms lifetime of photogenerated electrons in TX-100-treated BR-sensitized BSSCs, two times higher than that observed in BSSCs with native BR. A single-diode equivalent circuit model reveals favorable BSSC parameters such as high reverse saturation current (I0 = 55 nA), low series resistance (Rs = 22.9 Ω) and high shunt resistance (Rsh = 3765.5 Ω) with TX-100-treated BR-based BSSCs. As TX-100 does not alter the BR carboxyl terminus during its monomerization, maximum anchoring to the BSSC occurs which results in enhanced photocurrent generation. Thus, monomerized BR-sensitized BSSCs with their excellent photovoltaic parameters suggest the possibility of replacing native BR with TX-100 BR and this opens up the possibility of reduced cost manufacture of bio-sensitized solar cells.

Risk factors and epidemiologic predictors of blood stream infections with New Delhi Metallo-b-lactamase (NDM-1) producing Enterobacteriaceae.

Carbapenem-resistant Enterobacteriaceae conferred by New Delhi metallo-b-lactamase (NDM-1) resistance mechanism are endemic in India and Southeast Asia. An understanding of risk factors for NDM-1 infections is necessary to guide prevention strategies. We performed a retrospective case-control study of patients admitted at Christian Medical College Hospital, Vellore, India between May 2010 and August 2014 with Klebsiella pneumoniae blood stream infection (BSI). We compared patients with BSI caused by NDM-1 producing strains to two control groups: BSI with other multidrug resistant (MDR) strains and BSI with pan-susceptible strains. The study groups were assessed for risk factors for the outcomes: (1) infection with any MDR strain compared to pan-susceptible; and, (2) infection with NDM-1 strain as compared with other MDR and (3) Mortality. A total of 101 patients with BSI with NDM-1 producing Klebsiella pneumoniae were matched to two groups of controls: 112 with non-NDM-1 MDR strains and 101 with pan-susceptible strains. Medical (OR 10.4) and neonatal (OR 0.7) ICU admission, central venous catheter placement (CVC, OR 7.4) predicted MDR BSI. Prior carbapenem use (OR 8.4) and CVC (OR 4.8) predicted acquisition of an NDM-1 strain. Significant predictors for mortality included ICU stay (OR 3.0), mechanical ventilation (OR 3.2), female gender (OR 2.2), diabetes (OR 0.4). CVC placement, prior carbapenem use and ICU admission were significantly associated with BSI with NDM-1 producing and other MDR strains.

Tunable photovoltaic performance of preferentially oriented rutile TiO2 nanorod photoanode based dye sensitized solar cells with quasi-state electrolyte.

Photoanodes made of highly oriented TiO2 nanorod (NR) arrays with different aspect ratios were synthesized via a one-step hydrothermal technique. Preferentially oriented single crystalline rutile TiO2 was confirmed by the single peak in an XRD pattern (2θ = 63°, (0 0 2)). FESEM images evidenced the growth of an array of NRss having different geometries with respect to reaction time and solution refreshment rate. The length, diameter and aspect ratio of the NRs increased with reaction time as 4 h (1.98 µm, 121 nm, 15.32), 8 h (4 µm, 185 nm, 22.70), 12 h (5.6 µm, 242 nm, 27.24) and 16 h (8 µm, 254 nm, 38.02), respectively. Unlike a conventional dye-sensitized solar cell (DSSC) with a liquid electrolyte, DSSCs were fabricated here using one-dimensional rutile TiO2 NR based photoanodes, N719 dye and a quasi-state electrolyte. The charge transport properties were investigated using current-voltage curves and fitted using the one-diode model. Interestingly the photovoltaic performance of the DSSCs increased exponentially with the length of the NR and was attributed to a higher surface to volume ratio, more dye anchoring, and channelized electron transport. The higher photovoltaic performance (Jsc = 5.99 mA cm-2, Voc = 750 mV, η = 3.08%) was observed with photoanodes (16 h) made with the longer, densely packed TiO2 NRs (8 µm, 254 nm).

Update on: Shigella new serogroups/serotypes and their antimicrobial resistance.

Shigellosis represents a major burden of disease in developing countries. A low infectious dose allows the disease to be spread effectively. Although shigellosis is mostly a self-limiting disease, antibiotics are recommended to reduce deaths, disease symptoms and organism-shedding time. However, in India, antimicrobial resistance among the genus Shigella is more common than among any other enteric bacteria. Notably, new serotypes or subserotypes in Shigella are reported from various parts of the world. Identification of new subserotypes of Shigella spp. is becoming a major issue as these strains are nontypeable by conventional serotyping. The commercially available antisera may not cover all possible epitopes of the O lipopolysaccharide antigen of Shigella serotypes. Therefore, molecular methods which most closely approach the resolution of full serotyping are necessary to identify such strains. In addition, the knowledge of a prevalent serotype in various geographic regions may assist in formulating strategies such as the development of a vaccine to prevent infection especially when the immunity to disease is serotype specific, and to understand the disease burden caused by new Shigella serotypes.

Strengthening the laboratory diagnosis of pathogenic Corynebacterium species in the Vaccine era.

Over the last three decades, successful implementation of the diphtheria vaccination in the developed and developing countries has reduced the infections caused by the toxigenic strains of Corynebacterium diphtheriae, but a concomitant increase in the invasive infections due to the nontoxigenic strains was seen. In addition, the recent reports on the emergence of nontoxigenic toxin gene-bearing strains, having the potential to revert back to toxigenic form poses a significant threat to human beings. Besides infections caused by C. diphtheriae, the emergence of the respiratory, cutaneous and invasive infections by related pathogenic Corynebacterium species like C. ulcerans and C. pseudotuberculosis, complicate the diagnosis and management of infection. These observations together with the widespread prevalence of diphtheria in the vaccine era, necessitates the strengthening of the epidemiological surveillance and laboratory diagnosis of the pathogen. This review provides the overview of the advantages and limitations of different molecular methods and the role of MALDI-TOF in the laboratory diagnosis of Diphtheria. The contribution of next generation sequencing technology and different genotyping techniques in understanding the pathogenicity, transmission dynamics and epidemiology of the C. diphtheriae is discussed.

Results from the Survey of Antibiotic Resistance (SOAR) 2012-14 in Thailand, India, South Korea and Singapore.

OBJECTIVES: To provide susceptibility data for community-acquired respiratory tract isolates of Streptococcus pneumoniae, Streptococcus pyogenes, Haemophilus influenzae and Moraxella catarrhalis collected in 2012-14 from four Asian countries. METHODS: MICs were determined using Etest(®) for all antibiotics except erythromycin, which was evaluated by disc diffusion. Susceptibility was assessed using CLSI, EUCAST and pharmacokinetic/pharmacodynamic (PK/PD) breakpoints. For macrolide/clindamycin interpretation, breakpoints were adjusted for incubation in CO2 where available. RESULTS: Susceptibility of S. pneumoniae was generally lower in South Korea than in other countries. Penicillin susceptibility assessed using CLSI oral or EUCAST breakpoints ranged from 21.2% in South Korea to 63.8% in Singapore. In contrast, susceptibility using CLSI intravenous breakpoints was much higher, at 79% in South Korea and ∼95% or higher elsewhere. Macrolide susceptibility was ∼20% in South Korea and ∼50%-60% elsewhere. Among S. pyogenes isolates (India only), erythromycin susceptibility (∼20%) was lowest of the antibiotics tested. In H. influenzae antibiotic susceptibility was high except for ampicillin, where susceptibility ranged from 16.7% in South Korea to 91.1% in India. South Korea also had a high percentage (18.1%) of ß-lactamase-negative ampicillin-resistant isolates. Amoxicillin/clavulanic acid susceptibility for each pathogen (PK/PD high dose) was between 93% and 100% in all countries except for H. influenzae in South Korea (62.5%). CONCLUSIONS: Use of EUCAST versus CLSI breakpoints had profound differences for cefaclor, cefuroxime and ofloxacin, with EUCAST showing lower susceptibility. There was considerable variability in susceptibility among countries in the same region. Thus, continued surveillance is necessary to track future changes in antibiotic resistance.

Salivary and serum level of CYFRA 21-1 in oral precancer and oral squamous cell carcinoma.

BACKGROUND: CYFRA 21-1, a constituent of the intermediate filament proteins of epithelial cells, is known to be increased in many cancers. This study was designed to estimate the levels of salivary and serum CYFRA 21-1 in patients with oral precancer and oral squamous cell carcinoma (OSCC) and compare them with healthy controls. MATERIALS AND METHODS: Each group comprised of 100 subjects. Saliva and blood samples were collected from patients with OSCC, premalignant subjects, and normal healthy subjects. Serum and salivary CYFRA 21-1 levels were measured by enzyme-linked immunosorbent assay. Appropriate statistical tests were employed to assess diagnostic potency of CYFRA 21-1. RESULTS: We found a significant increase in CYFRA 21-1 level in OSCC compared with PML and healthy subjects. Salivary CYFRA 21-1 levels in OSCC was threefold higher when compared to serum levels. PML group showed increased salivary CYFRA 21-1 when compared to control subjects, but it was significantly lower compared with OSCC. Receiver operator characteristic curve analysis showed salivary CYFRA 21-1 to have superior sensitivity in detecting OSCC compared with serum CYFRA 21-1. CONCLUSIONS: The outcome of this study suggests that salivary CYFRA 21-1 can be utilized as a biomarker in early detection of oral cancer.

Fabrication of visible-light-driven N-doped ordered mesoporous TiO2 photocatalysts and their photocatalytic applications.

Herein we report a facile method for the synthesis of N-doped crystalline mesoporous titanium dioxide (NMT) with ordered structure. Structural characterization and HR-TEM studies revealed that NMT exhibits pure anatase phase with highly crystalline ordered mesoporous structure in NMT. The N2 isotherms are of type IV with an H1 hysteresis loop and a pronounced capillary condensation step at high relative pressure for NMT, suggesting the presence of well-ordered mesoporous structure. The reflectance spectrum of NMT shows stronger absorption in the visible region above 400 nm, owing to the substitution of the lattice oxygen by nitrogen. XPS results proved the doping of nitrogen in to oxygen in TiO2 lattice, which confirmed by the presence of peak at 401 eV for N1s. The efficiency of photocatalyst was evaluated by the degradation of Rhodamine-B and antibacterial activity against E. coli under visible-light irradiation. N-doped mesoporous TiO2 shows superior photocatalytic and anti-bacterial activity compared to pure TiO2 under visible-light irradiation. The enhanced photocatalytic activity of NMT is attributed to synergistic effect of NMT that is N-doping and well ordered crystalline mesoporous structure with high surface area of NMT. These findings suggest that N-doped mesoporous TiO2 has potential application in many areas such as degradation of hazardous pollutants, anti-bacterial agents, fuel cells, battery electrode, sensors, opto electronic devices, photo active self-cleaning surfaces.

Association of parent-reported timing of first tooth emergence and ECC: a secondary analysis of a case-control study.

PURPOSE: Tooth eruption is a dynamic process. Appearance of any part of the cusp through gingiva may be a clinical marker of eruption. Early childhood caries (ECC) is a public health problem globally. This study aimed to assess the relationship between parent-reported timing of first tooth emergence and ECC in toddlers. METHODS: This study is a secondary data analysis of 627 toddlers involved in a case-control study on sleep-time feeding practises in children. The children were categorised into four groups based on the parent-reported timing of first primary tooth emergence (G1-when the first primary tooth emerged before 6 months of age, G2-between 7 and 9 months; G3-10 to 12 months and G4-when the first primary tooth emerged after 12 months of age). Univariate binary logistic regression analysis was performed to evaluate the association between timing of first tooth emergence and ECC. RESULTS: The mean age of the children was 24.4 ± 7.3 months (cases, that is children with ECC-25.4 ± 6.9 months, controls, that is children without ECC-23.6 ± 7.5 months). Of 60 children, whose first tooth erupted before 6 months of age, 35 (12%) were cases compared to 25(8%) controls. Amongst the cases, boys had more caries than girls (p < 0.05). Of the anterior teeth, 22% of the emerged teeth were decayed in the first group, followed by 19%, 16% and 10% in the second, third and fourth groups, respectively (p < 0.05). Analysis of the posterior teeth showed a lower percentage of decayed teeth with delayed emergence of the first primary tooth (p < 0.05). Children whose teeth emerged before 6 months of age had an odds ratio of 3.5 (95% CI 1.49, 8.42) (p = 0.004). CONCLUSION: This study concluded that the early emergence of the first primary tooth, as reported by the parent, was associated with an increased risk of developing ECC.

Visible-light active mesoporous ce incorporated TiO2 for the degradation of 4-chlorophenol in aqueous solution.

Efficient visible-light active mesoporous Ce incorporated TiO2 nanoparticles have been prepared by sol-gel method using Pluranic P123 as the structure directing agent. Low angle XRD and BET analysis revealed the mesoporous nature of the nanoparticles. The incorporation of Ce4+ into TiO2 and Ti4+ into CeO2 is evident from the slight shift in their respective XRD patterns. XPS results exhibited +4 oxidation state for Ce and Ti ions. UV-DRS analysis of Ce incorporated TiO2 demonstrated red shift in the absorbance spectrum of TiO2, which is mainly due to the formation of Ce impurity states below the conduction band edge of TiO2. The photocatalytic activity of mesoporous Ce incorporated TiO2 nanoparticles has been evaluated in the degradation of 4-chlorophenol in aqueous solution under solar light illumination. Pure mesoporous TiO2 showed poor visible-light activity due to its small absorption of sun light. Mesoporous Ce incorporated TiO2 photocatalysts exhibited the highest photocatalytic activity compared to pristine mesoporous TiO2 and CeO2. The incorporation of Ce4+ in TiO2 played a major role in the enhancement of photocatalytic activity under sun light.

Response Surface Methodology Analysis of Energy Harvesting System over Pathway Tiles.

This paper presents an experimental analysis of the optimization of PZT-based tiles for energy harvesting. The hardware (actual experiment), PZT-based tiles, were developed using 6 × 6 piezoelectric (PZT-lead zirconate titanate) sensors of 40 mm in diameter on a hard cardboard sheet (300 × 300 mm2). Our experimental analysis of the designed tiles obtained an optimized power of 3.626 mW (85 kg or 0.83 kN using 36 sensors) for one footstep and 0.9 mW for 30 footsteps at high tapping frequency. Theoretical analysis was conducted with software (Design-Expert) using the response surface methodology (RSM) for optimized PZT tiles, obtaining a power of 6784.155 mW at 150 kg or 1.47 kN weight using 34 sensors. This software helped to formulate the mathematical equation for the most suitable PZT tile model for power optimization. It used the quadratic model to provide adjusted and predicted R2 values of 0.9916 and 0.9650, respectively. The values were less than 0.2 apart, which indicates a high correlation between the actual and predicted values. The outcome of the various experiments can help with the selection of input factors for optimized power during pavement design.

No evidence of resistance to itraconazole in a prospective real-world trial of dermatomycosis in India.

BACKGROUND: The prevalence of superficial fungal infections in India is believed to have increased substantially in the past decade. We evaluated the treatment outcomes and risk factors associated with clinical response to a treatment course of itraconazole for the management of dermatomycosis in India. METHODS: In this real-world, prospective pilot study (August 2019 to March 2020), adult participants (18-60 years), diagnosed with T. cruris or T. corporis, received itraconazole 200 mg/day (any formulation) orally for 7 days, and were followed for an additional 7 days. RESULTS: The study was terminated early due to the COVID-19 pandemic. Of 40 enrolled participants (mean [SD] age, 35.5 [12.73] years; {62.5%}] male; 37 received itraconazole and 20 (50%) completed the study. The median (range) Clinical Evaluation Tool Signs and Symptoms total score at baseline was 5.5 (2-10). Clinical response of "healed" or "markedly improved" based on the Investigator Global Evaluation Tool at day 7 (primary objective) was 42.9% (12/28; 95% CI: 24.53%, 61.19%). Itraconazole minimum inhibitory concentration for identified microorganisms, T. mentagrophytes species complex (91.7%) and T. rubrum (8.3%), was within the susceptibility range (0.015-0.25 mcg/mL). At day 14, 8/13 (61.5%) participants achieved a mycological response, 2/13 participants (15.4%) had a mycological failure and 90% showed a clinical response. CONCLUSION: COVID-19 pandemic affected patient recruitment and follow-up, so the findings call for a careful interpretation. Nevertheless, this real-world study reconfirmed the clinical efficacy and microbial susceptibility to itraconazole for the fungi causing dermatophytosis in India. TRIAL REGISTRATION: Trial registration number: Clinicaltrials.gov NCT03923010.

Evaluation of workshop on teaching skills for medical postgraduates (Ramachandra Annual Postgraduate Teaching Skills).

BACKGROUND: Postgraduate medical curriculum is usually devoted to developing competencies in the specialty concerned, patient care, and submitting dissertations. The need to impart teaching skills during postgraduation has gone unnoticed, hence Ramachandra Annual Postgraduate Teaching Skills (RAPTS), a teaching skills workshop, was conceptualized and implemented as postgraduate students serve as tutors/residents in the department to teach undergraduate medical students. This study is aimed to evaluate the effectiveness of the teaching skills workshop for postgraduates. MATERIALS AND METHODS: One hundred and seventy-eight postgraduate students of pre- and paraclinical department underwent the training in medical education principles and participated in the feedback. RAPTS Workshop was implemented as per the six-step approach. The learning was evaluated through a pre- and posttest scores. Student feedback was also obtained on the process overall objectives and contents of the workshop. Force-field analysis was performed. RESULTS: There was a significant learning by the postgraduates on various medical education principles as evidenced by significant improvement in the posttest scores (P < 0.05). Feedback regarding the general aspects of the workshop showed that 92% of the participants felt that the contents of the workshop suited their learning. Eighty-four percent of the participants opined that the presentations of the sessions were good and 91% felt that time management was good. Force-field analysis indicated that the factors favoring teaching skills workshop were higher. CONCLUSION: This study has highlighted the importance of including teaching methodology training in the postgraduate curriculum that helps in grooming the future teachers in the right direction, in the right time. Competencies related to teaching skills based on medical education principles can be included in the postgraduate curriculum.

Studies on evaluation of surfactant coupled sonication pretreatment on Ulva fasciata (marine macroalgae) for enhanced biohydrogen production.

Biohydrogen production from marine macroalgal biomass by advanced pre-treatment strategies is considered a clean energy technology. The present study focuses on investigating the effects of sonication pre-treatment (SP) and saponin coupled sonic pre-treatment (SSP) on Ulva fasciata for enhancing the production of biohydrogen. The SP and SSP were optimized to improve the hydrolysis process during digestion. The optimized time and sonication power were found respectively as 30 min and 200 W. A high concentration of biopolymer release was noticed in SSP than SP at optimized conditions. The surfactant dosage in SSP was optimized at 0.0036 g/g TS. The effect of SSP process was assessed by estimation of COD (Chemical Oxygen Demand) and SCOD (Soluble Chemical Oxygen Demand) release. The study revealed that, at a specific energy of 36,000 KJ/Kg TS, the SCOD release was higher in SSP (1900 mg/L) than SP (1050 mg/L). The SSP process could improve the COD solubilization to 15 % more than the SP. Carbohydrate and protein release are also more in SSP than SP. The use of biosurfactants significantly reduced the energy utilization in the hydrolysis process. The SSP pre-treated Ulva fasciata biomass has yielded a higher biohydrogen of 91.7 mL/g COD which is higher compared to SP (40.5 mL/g COD) and Control (9 mL/g COD).

Magnetically recyclable CoFe2O4/ZnO nanocatalysts for the efficient catalytic degradation of Acid Blue 113 under ambient conditions.

CoFe2O4/ZnO magnetic nanocatalysts were synthesized using a low-frequency ultrasound-assisted technique to enhance the optical, morphological, magnetic and catalytic properties of ZnO. The as-synthesized nanocatalysts were characterized by XRD, Raman, TEM, DR-UV-Vis and VSM analyses in order to confirm the expected modifications of the resulting nanocatalysts. The Raman spectral analysis revealed substitutional Zn2+ in the CoFe2O4/ZnO nanocatalyst. The as-synthesized material was tested for its catalytic activity in the degradation of Acid Blue (AB113), a known textile pollutant. The CoFe2O4 and CoFe2O4/ZnO nanocatalysts revealed the efficient catalytic degradation of AB113 in ambient conditions. The nanocatalyst dosage and the initial concentration of AB113 were varied by fixing one parameter as constant in order to determine the maximum catalytic efficiency with the minimum catalyst loading for AB113 degradation. The CoFe2O4/ZnO nanocatalyst demonstrated 10-fold enhanced mineralization of AB113 compared to the individual bare nanocatalysts, which could be achieved within 3 hours of catalytic degradation of AB113. The magnetic CoFe2O4/ZnO nanocatalyst was found to be stable for six consecutive recycles of AB113 degradation, which indicates that the catalytic efficiency of the nanocatalyst was retained after various numbers of cycles.

First report of Burkholderia pseudomallei ST412 and ST734 clones harbouring blaOXA-57 but susceptible to imipenem in India.

Melioidosis caused by Burkholderia pseudomallei has become an important clinical threat, especially in Northern Australia and Southeast Asia. However, the genome information on this pathogen is limited. B. pseudomallei isolates identified from bloodstream infections from inpatients were subjected to whole-genome sequencing by IonTorrent PGM and MinION Oxford Nanopore sequencing technologies. Highly accurate complete genomes of two strains, VB3253 and VB2514, were obtained by a hybrid genome assembly method using both short and long DNA reads. Both isolates carried blaPenI and carbapenemase-encoding blaOXA-57 genes, although the isolates were susceptible to imipenem by E-test method with MIC 1 µg/mL. Multiple IS family transposases specific for all non-fermenting Gram-negative bacteria (NFGNBs)-especially IS3 and IS5, which facilitate mobilization of extended-spectrum ß-lactamase (ESBL) and carbapenemase genes-were carried in these genomes. This further adds to the complexity of gene transmission. These IS families were identified only upon hybrid genome assembly and would otherwise be missed.

Ultrasmall Plasmonic Nanoparticles Decorated Hierarchical Mesoporous TiO2 as an Efficient Photocatalyst for Photocatalytic Degradation of Textile Dyes.

Hierarchical mesoporous TiO2 was synthesized via a solvothermal technique. The sonochemical method was adopted to decorate plasmonic nanoparticles (NPs) (Ag, Au) on the pores of mesoporous TiO2. The crystallinity, structure, and morphology were determined to understand the physicochemical nature of the nanocomposites. The catalytic efficiency of the plasmonic nanocatalysts was tested for the azo dyes (congo red, methyl orange, acid orange 10, and remazol red) under solar and visible light irradiations. The generation of hydroxyl radicals was also studied using terephthalic acid as a probe molecule. An attempt was made to understand the influence of size, work function and Fermi level of the metal NPs toward the efficiency of the photocatalyst. The efficiency of the nanocomposites was found to be in the order of P25 < mesoporous TiO2 < mesoporous Ag-TiO2 < mesoporous Au-TiO2 nanospheres under both direct solar light and visible light irradiation. The results indicated that the adsorption of dye, anatase phase, and surface plasmon resonance of NPs favored the effective degradation of dyes in aqueous solution. Further, the efficiency of the catalyst was also tested for xanthene (rose bengal), rhodamine (rhodamine B, rhodamine 6G), and thiazine (methylene blue) dyes. Both TiO2 and NPs (Ag & Au) possess a huge potential as an eco-friendly photocatalyst for wastewater treatment.

Economical synthesis of silver nanoparticles using leaf extract of Acalypha hispida and its application in the detection of Mn(II) ions.

This study was focused on the synthesis of silver nanoparticles using Acalypha hispida leaf extract and the characterization of the particles using UV-Vis spectroscopy, XRD, FT-IR, and TEM. The results showed the formation of silver nanoparticles, crystalline in nature, with an average size of 20-50 nm. The leaf extract components were analyzed with GC-MS and exhibited a high content of Phytol (40.52%), n-Hexadecanoic acid (9.67%), 1,2,3-Benzenetriol (7.04%), α-d-Mannofuranoside methyl (6.22%), and d-Allose (4.45%). The optimization and statistical investigation of reaction parameters were studied and maximum yield with suitable properties of silver nanoparticles was obtained at leaf extract volume (0.5 mL), the concentration of silver nitrate (1.75 mM), and reaction temperature (50 °C). The method of detecting Mn2+ ions using the colloidal silver nanoparticles was discussed. The minimum and maximum detection limit were found to be 50 and 200 µM of Mn(II) ions, respectively. Thus, the obtained results encourage the use of economical synthesis of silver nanoparticles in the development of nanosensors to detect the pollutants present in industrial effluents.