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Nanoparticles (NPs) are particles less than 100 nm in size. Silver nanoparticles have many important chemical and biological applications. These applications drag the attention of researchers for the production of silver nanoparticles. The objective of the study is to synthesize silver nanoparticles from the green method without using any hazardous chemicals. In the present study, Ocimum tenuiflorum (Tulsi) leaf extract was used to synthesize silver nanoparticles (Ag-NPs) from silver nitrate. Moreover, Tulsi leaf extract was also exploited, both traditionally and commercially, for their antibacterial potential which is essential oil components. The synthesis of Ag-NPs was visually deduced by a change in colour from light yellow to reddish-brown. UV-Visible Spectrometry, X-ray diffraction (XRD), and Transmission Electron Microscopic (TEM) analysis were then used to characterize synthesized nanoparticles. This study also determined the effect of temperature and effect of silver nitrate concentration on nanoparticle synthesis. Synthesized silver nanoparticles showed absorbance ‘peaks’ at 420 nm with UV-visible spectrometry. X-ray diffraction studies showed that the synthesized silver nanoparticles were crystalline. The mean crystallite size was estimated using the Debye-Scherrer equation. However, TEM showed that silver nanoparticles have spherical (40 nm) shape with a narrow size distribution. These synthesized nanoparticles were used to evaluate antimicrobial activity against the most common pathogens of nosocomial infections, MRSA, E. coli, Salmonella typhi, and Klebsiella pneumoniae (ESBL). O. tenuiflorum extract showed strong potential for the synthesis of silver nanoparticles from silver nitrate and the synthesized silver nanoparticles had efficient antimicrobial properties against different pathogens including drug-resistant pathogens in vitro. These synthesized nanoparticles showed maximum ‘zones’ of inhibition against MRSA among these four organisms.

Introduction: Periodontal diseases comprise a group of inflammatory diseases caused by bacteria that colonise the tooth surface and infect surrounding soft tissues, ultimately leading to tooth loss. Vitamin D, calcium, alkaline phosphatase, and parathyroid hormone have role in bone metabolism both in health or in disease. Objective: To compare serum Vitamin D, calcium, alkaline phosphatase, and parathyroid hormone levels in patients with generalised chronic periodontitis and healthy periodontium. Methods: A cross-sectional analytical study was done in 80 patients visiting Department of Dental Surgery from July to December 2019. Clinical parameters measured were plaque index, gingival index, clinical attachment level, and pocket depth in the healthy periodontium and generalised chronic periodontitis. Blood investigation for serum Vitamin D, calcium, alkaline phosphatase (ALP), and parathyroid hormone (PTH) level were done. Data was analysed in SPSS v.16. Results: Out of total 80 patients enrolled (mean age of 36.20±7.37 years), 40 (50%) patients had healthy periodontium and 40 (50%) had generalised chronic periodontitis. Mean levels of serum Vitamin D (P=0.006) and calcium (P=0.020) were significantly higher in chronic periodontitis patient compared to healthy controls while no significant intergroup differences were seen with respect to ALP (P=0.267) and PTH (P=0.351). Conclusion: No significant differences were found in the levels of ALP and PTH between generalised chronic periodontitis and healthy patients and higher levels of Vitamin D and calcium were seen in generalised chronic periodontitis patients as compared to healthy patients.

Adsorption property of graphene oxide (GO) towards cationic dyes such as methylene blue (MB) and rhodamine B (RhB) has been investigated experimentally. GO structure used in our study is decorated with experimentally observed oxygen functional groups (OFGs). Fast and effective adsorption of MB with GO in single and binary solute solution has been observed experimentally. In support of our experimental data and to understand the interaction of adsorbent (GO) and dye, density functional theory (DFT) calculation has been used for calculating individual binding energy of GO, GO/dye in aqueous medium. Further, study on dye interaction with GO reveals that adsorption was facilitated by presence of oxygen functional group through electrostatic interactions.

A low cost, non-explosive process for the synthesis of graphene oxide (GO) is demonstrated. Using suitable choice of reaction parameters including temperature and time, this recipe does not require expensive membranes for filtration of carbonaceous and metallic residues. A pre-cooling protocol is introduced to control the explosive nature of the highly exothermic reactions during the oxidation process. This alleviates the requirement for expensive membranes and completely eliminates the explosive nature of intermediate reaction steps when compared to existing methods. High quality of the synthesized GO is corroborated using a host of characterization techniques including X-ray diffraction, optical spectroscopy, X-ray photoemission spectroscopy and current-voltage characteristics. Simple reduction protocol using ultra-violet light is demonstrated for potential application in the area of photovoltaics. Using different reduction protocols together with the proposed inexpensive method, reduced GO samples with tunable conductance over a wide range of values is demonstrated. Density functional theory is employed to understand the structure of GO. We anticipate that this scalable approach will catalyze large scale applications of GO.

Water is the most precious gift of nature and is a valued natural resource for the existence of living beings. Management of this natural resource is thus of utmost importance. The present study was carried out to determine the presence of a few heavy metals viz, lead, chromium, copper and mercury in the various samples of Upper Lake, Bhopal. The samples were analyzed during both the pre-monsoon and the post-monsoon season. From the observations it was concluded that a general increase in the concentration was observed in the post monsoon season due to surface runoff coming into the lake water in the rainy season.

With the tremendous influx of people and consequent urban development, increased anthropogenic activities in the catchment, inflow of untreated sewage, nutrients and pesticides from urban and rural areas, the water quality of Upper Lake, Bhopal has deteriorated significantly. An attempt has been made to study various physico-chemical parameters, specifically nitrates and phosphates of five different sampling sites of Upper Lake and to study the effect of catchment area activities on these sites.

The current work is aimed to evaluate the degradation of triazo textile dye Acid Black 210 (AB210) by Providencia sp. SRS82 that degrade 100 mg/L dye within 90 min under optimum conditions and was also found tolerant to as high as 2000 ppm of dye AB210. Optimum conditions for decolourization and degradation of AB210 with the isolate were viz. temperature 30 °C, pH 8, NaCl concentration 2.5% (w/v) and initial cell load of 8 × 108 cells/mL under static condition. Induction of intracellular and extracellular lignin peroxidase, intracellular laccase and tyrosinase, azoreductase, and DCIP reductase indicated their contribution in the biodegradation of AB210. The products obtained from Providencia sp. SRS82 degradation was monitored through UV–Vis spectrophotometer and were characterized by FTIR, HPTLC, HPLC, GC/MS and LCMS. The proposed metabolic pathway for the biodegradation of AB210 is elucidated for the first time, which showed production of 4 molecules of benzene, one of naphthalene and 4-aminophenyl-N-(4-amino phenyl) benzene sulphonamide. Microbial toxicity and cytotoxicity studies revealed the comparatively less toxic nature of metabolites generated after degradation of AB210. Providencia sp. SRS82 was found competent to degrade actual effluent and diverse dyes that could be present in textile industry effluent showing usefulness of the organism for possible commercial application.

Commercial-grade limestone used in whitewashing which is a low-cost material has been used as a catalyst for the synthesis of fatty acid methyl esters. The catalyst was characterized by differential thermal analysis/thermogravimetric analysis, X-ray diffraction, and Fourier transform infrared spectroscopy for the study of its physicochemical nature. The catalyst was calcined at 900 °C for 2.5 h for the decomposition of calcium carbonate to calcium oxide. The catalyst was further activated by dissolving 1.5 wt% of catalyst in 30 ml methanol (7.5:1, methanol to used frying oil molar ratio) and stirred at 25 °C for 1 h on a magnetic stirrer. The transesterification reaction was performed using calcium oxide as a catalyst and then with the “activated calcium oxide.” The conversion obtained was 94.4 % with calcium oxide and was found to be lower for the “activated calcium oxide” (i.e., 87.36 %). The conversion increased to 96.8 % on increasing the catalyst amount to 2.0 wt% in 5 h. A high yield (>95 %) of fatty acid methyl esters was observed when either calcium oxide or “activated calcium oxide” was taken as catalyst. The catalytic activity of calcium oxide obtained from low-grade limestone has been found to be comparable with the laboratory-grade CaO.

Biodiesel has been synthesized from used frying oil at room temperature (35°C) using NaOH and CH3ONa as homogeneous catalyst and methanol as reactant. Glycerol has been obtained as a by-product which comprised of impurities such as unreacted methanol, inorganic metals, and traces of triglycerides. The inorganic materials present in glycerol were adsorbed on the surface of activated carbon derived from rice husk. Glycerol is then acidified with 1.2 M H2SO4 to form two layers. The upper layer comprised of free fatty acids, and the bottom layer comprised of a glycerol-rich layer. The bottom layer was decanted and neutralized with an aqueous solution of 10 M NaOH and heated at 110°C for 2.5 h to remove the residual water in the glycerol. Further extraction of glycerol with ethanol gives glycerol of high purity. For removal of ethanol from the glycerol, the solution was heated up to 80°C for 30 min. The purity of glycerol was verified by analysis on 13C-NMR. The upper free fatty acid layer is confirmed with the help of the treatment of this layer with base solution (NaOH) to give soap. Formation of soap is confirmed with the help of Fourier transform infrared spectroscopy.

In present communication, waste frying oil (WFO) has been used as a feedstock for biodiesel synthesis. WFO, procured from a local Indian restaurant possessed an acid value of 0.84 mg KOH/g, which is low enough for single step transesterification reaction. Biodiesel (fatty acid methyl esters) was washed after transesterification reaction and the yield got lowered substantially (from 96% to 86.36%) after water washing owing to loss of esters. 30:100 vol% (methanol to oil), 0.6 wt% NaOCH3, 60°C temperature and 600 rpm agitation in 1 h reaction time was found to be optimum for transesterification reaction. 1H NMR spectrum showed a high conversion (95.19%) of fatty acids in WFO to biodiesel in 2 h reaction time. Almost complete conversion (99.68%) was attained in 2 h reaction time. © 2011 Canadian Society for Chemical Engineering

Phosphorus (P) is one of the essential elements for all biological entities and an adequate supply of P in the early stages of plant growth is important for the proper growth and development of plants. Many microbes having phosphate solubilizing ability have been used as the soil inoculants to improve the uptake of phosphorus by plants. The use of pesticides is becoming very common in agriculture as plant protection measures. A potential inoculant organism must be tested thoroughly in lab under the conditions that will be experienced by the farmers. The major concern regarding the use of pesticides is that their use may adversely affect non target soil microflora and fauna. Phosphate solubilizing micro-organisms which are useful soil inhabiting microflora and of importance to soil fertility may be affected by some insecticides and herbicides. The isolate, Citrobacter freundii, used in present study is an efficient phosphate solubilizer and its effect on plants in presence as well as in absence of select pesticides was studied. Introduction Phosphate solubilizing microorganisms include bacteria and fungi which convert insoluble inorganic phosphatic compounds into soluble form. The use of pesticides is becoming very common in agriculture as plant protection measures and during storage of food grains. The use of organophosphorus and carbamate insecticides has been increasing whereas the use of chlorinated insecticides has decreased as these are very stable and persist in the environment for a long time (Vimal Ramani and H.H.Patel,2011). A potential inoculant organism must be tested under conditions that will be experienced by the farmers (Leggett et al., 1998). Although scientists continue to identify less persistent agrochemicals, microbiologists are concerned regarding their use, because some of these chemicals may adversely affect non-target soil microflora and fauna. Phosphate solubilizing micro-organisms which are useful soil inhabiting microflora and of importance to soil fertility may be affected by some insecticides and herbicides (Gaur, 1990). Raghu and Mac Rae (1967) found an increase in the population of anaerobic phosphorus solubilizers after treatment of soil with lindane. Effect of pesticides on microbial solubilization of rock phosphate in Pikovskaya medium was studied by Gaur (1990). Pseudomonas striata significantly augmented rock phosphate solubilization. Maximum phosphorus solubilization by the bacteria was obtained in the presence of carbofuran followed by oxyfluorfen at normal dosage. In a similar study the plant growth promoting traits of the strain Pseudomonas aeruginosa decreased consistently as the concentrations of each pesticide was increased from the recommended dose to the higher ones (Ahemad M,Khan MS,2011). Several studies have indicated augmented phosphate solubilization in presence of few pesticides and herbicides, while many other workers have reported significant decrease in phosphate solubi lization efficiency. In the present study attempt has been made to study the effect of various pesticides, which are used commonly by the farmers of this region of Madhya Pradesh on phosphate solubilizaton by C. freundii. Materials & Methods The culture Citrobacter freundii was maintained on Pikovskaya’s agar pH 7.2 at 4°C and sub cultured every month. Inoculum and Incubation Overnight grown culture of Citrobacter freundii in nutrient broth was harvested by centrifugation and resuspended in broth to have 1 O.D. mL-1at 660nm.Inoculum thus prepared was transferred under aseptic conditions to 100 mL Pikovskaya’s broth in 250 mL Erlenmeyer conical flasks. In one experimental set up the broth contained TCP 50 mg% equivalent to 114.5 mg P2O5 100 mL-1. To study the phosphate solubilization from URP (27.6 mg% P2O5), it was added equivalent to 50 mg P2O5 100 mL-1. The flasks were incubated at 28°C ± 2°C under static conditions with intermittent shaking at 12hr interval up to 7 and 15 days for TCP and URP respectively. Phosphate estimation Soluble phosphorus from the broth was estimated using chlorostannous reduced molybdophosphoric acid blue method as it is reported to be highly sensitive and satisfactory method. (Jackson M L,1973). Culture media Pikovskaya’s broth containing 50 mg % TCP and Modified Pikovskaya’s broth medium where TCP in Pikovskaya’s broth medium was replaced by URP equivalent to 50 mg % P2O5 was used. The required numbers of flasks with 100 ml of media mentioned above were sterilized. To each of these flasks the pesticides (malathion, chloropyriphos, dimethoate, monocrotophos, dicofol and phosphomidon) in the quantity of “recommended dose” as mentioned on the commercial packet and double the quantity of “recommended dose” (double dose) were added aseptically to separate flasks. The flasks containing Pikovskaya’s broth and modified pikovskaya’s broth without added pesticides were kept as control. Results and Discussions The effect of various pesticides on TCP solubilization by C. freundii is shown in Table 1. The results show significant decrease in phosphate solubilizing activity in presence of most of the pesticides under study. Maximum phosphate solubilizing activity was affected by both the single as well as double dose of the “recommended dose” of pesticides. However, in presence of pesticide phosphomidon, the organism shows

The composite membranes of multi‐walled carbon nanotube (MWCNT) and polymethylmethacrylate (PMMA) were prepared by solution cast method. The MWCNT was dispersing a very low concentration (0.1 wt %) in PMMA matrix. Alignment of MWCNT in PMMA matrix has been performed by inducing a DC electric field at different voltage parameter varying from 350 V/cm to 1250 V/cm. The MWCNT/PMMA composites were characterized by gas permeation and electrical measurement before and after electric field alignment. The effect of electric field alignment has been studied on gas permeation measurements for gas purification applications. These measurements indicate the enhancement in gas permeability due to the aligned of MWCNT in PMMA matix as compare to randomly dispersed MWCNT. I–V characteristics measurement also indicates that aligned MWCNT/PMMA composite membrane exhibits electron tunneling conductivity.

In the present work we have synthesized PANI by in‐situ chemical oxidative polymerization method. The chemiresistor type gas sensors have been fabricated by deposited tantalum and polyaniline composite thin film on to interdigited electrodes (IDE) configuration using sputtering ad spin coating techniques respectively. The composite thin film was irradiated using 150 MeV Au+7 at the fluence of 1×1011 ions/cm2. The pristine Ta/PANI composite sensor showed negligible sensing response which was further improved up to 1.42 ((i.e. %Sensitivity ≈30%) after SHI irradiation. The structural and morphological properties of composite sensing thin films have also been characterized by XRD and AFM measurement before and after SHI irradiation.