Silver nanoparticles based spectroscopic sensing of eight metal ions in aqueous solutions.

Anthropogenic releases from different outlets of industry, municipal sewage and the road traffic can give rise to higher concentrations of heavy metals in food commodities which imposes a threat to human health and environment. A simple silver nanoparticle (Ag NPs) used for the sensing of heavy metal ions, Cd2+, Cu2+, Fe2+, Hg2+, Mn2+, Ni2+, Pb2+ and Zn2+ in aqueous solution is described qualitatively and quantitatively using spectroscopic tool. FE-SEM and TEM images confirmed that the particles are spherical in shape with an average diameter of 23.4 nm. Presence of heavy metal ions with Ag NPs gives, new peak at around 925, 898, 643, 665, 688, and 838 nm for Cd2+, Cu2+, Fe2+, Hg2+, Mn2+ and Zn2+ in addition to the peak found at 410 nm for Ag NPs. Further, the addition of Ni2+ and Pb2+ metal ion solution with Ag NPs increased the SPR band from 410 nm to 436 and 462 nm respectively. Citrate functionalized Ag NPs aggregate in solution in the presence of divalent metal ions by ions-template chelating process and are easily measurable changes in the UV-vis absorption spectrum of the particles. Further, studies also confirmed the interaction of Ag NPs with metal ions using FT-IR spectroscopy. The proposed method was found to be useful for simple UV-vis spectroscopic sensing of metal ions in aqueous solutions and real contaminated samples.

Dosimetric Comparison of Robotic and Linear Accelerator Multi-Leaf Collimator-Based Stereotactic Radiosurgery for Arteriovenous Malformation.

PURPOSE: To investigate the dosimetric comparison of different collimators which are used in robotic radiosurgery (cyberknife-CK) and linear accelerator (LINAC) for stereotactic radiosurgery (SRS) in arteriovenous malformation (AVM). MATERIALS AND METHODS: Twenty-five AVM patients were planned in CK using FIXED cone, IRIS collimator, and multi-leaf collimator (MLC) based in LINAC. Dosimetric comparison was performed using Paddick conformity index (CIPaddick) and International Commission on Radiation Units and measurements (ICRU) homogeneity index (HIICRU), gradient score (GS), normal brain dose received by 10cc (D10cc) and critical structure (brain stem, optic chiasma, optic nerves) doses. Paired sample t-test was used for statistical analysis. RESULTS: Mean treatment volume was 3.16cc (standard deviation ± 4.91cc). No significant deviation (P =0.45, 0.237 for FIXED vs. IRIS and FIXED vs. MLC, respectively) was found in target coverage. For CIPaddick, the mean difference (MD) between FIXED- and MLC-based plans was 0.16(P = 0.001); For HIICRU, difference between FIXED and IRIS was insignificant (0.5, P = 0.823); but, when FIXED versus MLC, the deviation was 7.99% (P = 0.002). In FIXED- and MLC-based plans, significant difference was found in GS70 and GS40 (P < 0.041 and 0.005, respectively). MD between FIXED- and MLC-based plans for normal brain for 5Gy, 10Gy, 12Gy, and 20Gy were 36.08cc (P = 0.009), 7.12cc (P = 0.000), 5.84cc (P = 0.000) and 1.56cc (P = 0.000), respectively. AVM volume <0.7cc should be treated with CK FIXED and >0.7cc were treated by using FIXED or IRIS collimators. AVM volume > 1.4cc can be treated by either LINAC MLC-based SRS or CK. CONCLUSION: Our study shows CK collimator (IRIS and FIXED) could be able to treat brain AVMs in any size. Linac MLC-based SRS has some limitations in terms of conformity and low-dose spillage, and advantages like reduced treatment time and MU.

Seaweed Sargassum wightii mediated preparation of zirconia (ZrO2) nanoparticles and their antibacterial activity against gram positive and gram negative bacteria.

In the present study, a facile and green combustion method has been optimized for the synthesis of zirconia (ZrO2) nanoparticles using marine brown alga (seaweed), Sargassum wightii (S. wightii). Structural, optical and photoluminescence properties of the prepared ZrO2 nanoparticles were studied using XRD, FTIR, HR-TEM, UV-vis and PL spectroscopy. The average grain size of the nanoparticles calculated from the XRD pattern was around 4.8 nm which exhibits tetragonal structure. TEM results showed that the synthesized nanoparticles were uniformly monodispersed without aggregation. Formation of zirconia nanoparticles were confirmed by FTIR studies. The PL spectra exhibit broad emission peaks at the interface of UV and visible regions which can be assigned to the ionized oxygen vacancy in the material. Antibacterial activity of the synthesized zirconia nanoparticles was studied against gram positive and gram negative bacterial strains using agar well diffusion method. The prepared zirconia nanoparticles show significant antibacterial effect against Bacillus subtilis, Escherichia coli and Salmonella typhi due to their large surface area by their nanosize.

Fly ash based Bacillus thuringiensis var. israelensis formulation for use against Culex quinquefasciatus, the vector of filariasis in natural ecosystems.

BACKGROUND & OBJECTIVES: Fly ash is produced in huge quantities by the various thermal power stations in India. This thermal waste has been employed as a carrier material in the preparation of a biopesticidal water dispersible powder (WDP) formulation for use against mosquitoes. In the present investigation, this newly developed fly ash based WDP formulation was evaluated in natural breeding habitats of mosquito. METHODS: Fly ash based WDP formulation of Bacillus thuringiensis var. israelensis (VCRC B17) was evaluated for its efficacy and residual activity in aquatic habitats supporting breeding of Culex quinquefasciatus, the vector of lymphatic filariasis in Neyveli Township, Neyveli Lignite Corporation, India for a period of one month. RESULTS: At an application rate of 10 kg/ha, the WDP was effective for five days regardless of the habitat, and provided 80-100% reduction in larval abundance of Cx. quinquefasciatus. INTERPRETATION & CONCLUSION: The study indicates that for continued control of immature density and prevention of adult emergence, a weekly application of this formulation is necessary. This study also showed that fly ash based formulations can be used for immediate control of mosquitoes in different types of habitats and has also brought out a new avenue for the utilization of coal ash.

Construction of single-chain variable fragment antibodies against MCF-7 breast cancer cells.

A phage display library of single chain variable fragment (scFv) against MCF-7 breast cancer cells was constructed from C3A8 hybridoma cells. RNA from the C3A8 was isolated, cDNA was constructed, and variable heavy and light immunoglobulin chain gene region were amplified using PCR. The variable heavy and light chain gene regions were combined with flexible linker, linked to a pCANTAB 5E phagemid vector and electrophoresed into supE strain of Escherichia coli TG1 cells. Forty-eight clones demonstrated positive binding activity to MCF-7 breast cancer cell membrane fragments and the strongest of 48 clones was selected for analysis. The anti-MCF-7 library evaluated by SfiI and NotI digests demonstrated that anti-MCF-7 scFv antibodies possess individual patterns that should be able to recognize distinct human breast cancer cells. The C3A8 scFv, with an apparent molecular weight of 32 kDa, showed high homology (99%) with single chain antibody against rice stripe virus protein P20. In summary, the anti MCF-7 scFv antibody can be used for pretargeting breast cancer for clinical diagnosis of patients; it also has potential for therapeutic applications.

Functionalization of gold nanoparticles as antidiabetic nanomaterial.

In the present investigation, functionalization of gold nanoparticles synthesized using propanoic acid 2-(3-acetoxy-4,4,14-trimethylandrost-8-en-17-yl) (PAT) an active biocomponent isolated from Cassia auriculata is studied in detail. On reaction of PAT with aqueous HAuCl4, rapid formation of stable gold nanoparticles was achieved. Formation of gold nanoparticles was confirmed by UV-vis spectroscopy, XRD, GC-MS,FTIR, TEM and SEM with EDAX. Gold nanoparticles mostly were monodisperse, spherical in shape and ranged in size 12-41 nm. Gold nanoparticles synthesised using PAT was administered to alloxan (150 mg/kg body weight) induced diabetic male albino rats at different doses (0.25, 0.5, 0.75 and 1.0mg/kg body weight) for 28 days. Plasma glucose level, cholesterol and triglyceride were significantly (p<0.001) reduced in experimental animals treated with gold nanoparticles at dosage of 0.5mg/kg body weight and plasma insulin increased significantly. The newly genre green gold nanoparticles exhibit remarkable protein tyrosine phosphatase 1B inhibitory activity.

Growth, thermal, dielectric and mechanical properties of L-phenylalanine-benzoic acid: a nonlinear optical single crystal.

An efficient amino acid family nonlinear optical single crystal L-phenylalanine-benzoic acid (LPB) was conveniently grown by slow evaporation technique at room temperature. The crystal system and the lattice parameters were analyzed by single crystal X-ray diffraction studies. The grown crystal has excellent transmission in the entire visible region and its lower cut-off wavelength was found to be 248 nm. The SHG efficiency of the grown crystal was found to be 1.6 times higher than that of KDP crystal. The Laser damage threshold value of LPB has been found to be 6.5 GW/cm(2). The sample was thermally stable up to 134°C. Microhardness, dielectric and AC/DC conductivity measurements were made along (001) plane and reported for the first time. Microhardness studies revealed that the sample belongs to hard nature. Frequency dependent dielectric constant was measured for different temperatures and found maximum dielectric constant of 14 for 363 K. Photoconductivity studies of LPB divulged its negative photoconducting nature.

Endothelin-1 and its receptors ET(A) and ET(B) in drug-induced gingival overgrowth.

BACKGROUND: The purpose of this study was to study the expression of endothelin-1 (ET-1) and its receptors ETA and ETB in normal human gingiva and cyclosporin-induced gingival fibroblasts. METHODS: Gingival samples were collected from eight normal healthy individuals, eight patients with periodontitis, and eight patients with cyclosporin A (CsA)-induced gingival overgrowth. Total RNA was extracted from tissue samples, and reverse transcriptase-polymerase chain reaction was performed for ET-1, ETA, and ETB. ET-1 protein was estimated from the tissues by enzyme-linked immunosorbent assay. The expression of ET-1 and its receptors was also examined in gingival fibroblast cells treated with CsA. RESULTS: ET-1 mRNA expression was significantly higher in patients with CsA-induced gingival overgrowth (P <0.001) than in patients with periodontitis and the controls. ETA mRNA was expressed more than the ETB in all examined samples. In human gingival fibroblasts, ET-1 expression was increased with CsA incorporation compared to controls (P <0.001). CONCLUSION: These results suggest that CsA can modulate the expression of ET-1 in gingival fibroblasts and CsA-induced gingival overgrowth.

Endothelin-1 and Its Receptors ETA and ETB in Drug-Induced Gingival Overgrowth.

BACKGROUND: The purpose of this study was to study the expression of endothelin-1 (ET-1) and its receptors ETA and ETB in normal human gingiva and cyclosporin-induced gingival fibroblasts. METHODS: Gingival samples were collected from eight normal healthy individuals, eight patients with periodontitis, and eight patients with cyclosporin A (CsA)-induced gingival overgrowth. Total RNA was extracted from tissue samples, and reverse transcriptase-polymerase chain reaction was performed for ET-1, ETA , and ETB . ET-1 protein was estimated from the tissues by enzyme-linked immunosorbent assay. The expression of ET-1 and its receptors was also examined in gingival fibroblast cells treated with CsA. RESULTS: ET-1 mRNA expression was significantly higher in patients with CsA-induced gingival overgrowth (P <0.001) than in patients with periodontitis and the controls. ETA mRNA was expressed more than the ETB in all examined samples. In human gingival fibroblasts, ET-1 expression was increased with CsA incorporation compared to controls (P <0.001). CONCLUSION: These results suggest that CsA can modulate the expression of ET-1 in gingival fibroblasts and CsA-induced gingival overgrowth.

Expression of Toll-like receptors 2 and 4 in gingivitis and chronic periodontitis.

Periodontal disease is the major cause of adult tooth loss and is commonly characterized by a chronic inflammation caused by infection by oral bacteria. Members of Toll-like receptor (TLR) family recognize conserved microbial structures, such as bacterial lipopolysaccharides, and activate signaling pathways that result in immune responses against microbial infections. The aim of the present study was to assess the mRNA expression of TLR-2 and TLR-4 in gingivitis and chronic periodontitis. Gingival tissue samples were collected from patients with chronic periodontitis, gingivitis, and healthy controls. Total RNA was extracted and RT-PCR was done for TLR-2 and TLR-4. The results showed that TLR-2 was significantly increased in gingivitis compared to TLR-4 expression and decreased in chronic periodontitis.