Biocompatible CuInS2 Nanoparticles as Potential Antimicrobial, Antioxidant, and Cytotoxic Agents.

A simple hydrothermal route is employed to synthesize pure copper indium disulfide (CIS) and CIS nanoparticles (NPs) mediated by various natural plant extracts. The plant extracts used to mediate are Azadirachta indica (neem), Ocimum sanctum (basil), Cocos nucifera (coconut), Aloe vera (aloe), and Curcuma longa (turmeric). The tetragonal unit cell structure of as-synthesized NPs is confirmed by X-ray diffraction. The analysis by energy-dispersive X-rays shows that all the samples are near-stoichiometric. The morphologies of the NPs are confirmed by high-resolution scanning and transmission modes of electron microscopy. The thermal stability of the synthesized NPs is determined by thermogravimetric analysis. The optical energy band gap is determined from the absorption spectra using Tauc's equation. The antimicrobial activity analysis and the estimation of the minimum inhibitory concentration (MIC) value of the samples are performed for Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris, Enterobacter aerogenes, and Staphylococcus aureus pathogens. It shows that the aloe-mediated CIS NPs possess a broad inhibitory spectrum. The best inhibitory effect is observed against S. aureus, whereas the least effect was exhibited against P. vulgaris. The least MIC value is found for aloe-mediated CIS NPs (0.300 mg/mL) against S. aureus, P. aeruginosa, and E. aerogenes, along with basil-mediated NPs against E. coli. The antioxidant activity study showed that the IC50 value to inhibit the scavenging activity is maximum for the control (vitamin C) and minimum for pure CIS NPs. The in vivo cytotoxicity study using brine shrimp eggs shows that the pure CIS NPs are more lethal to brine shrimp than the natural extract-mediated CIS NPs. The in vitro cytotoxicity study using the human lung carcinoma cell line (A549) shows that the IC50 value of turmeric extract-mediated CIS NPs is minimum (15.62 ± 1.58 µg/mL). This observation reveals that turmeric extract-mediated CIS NPs are the most potent in terms of cytotoxicity toward the A549 cell line.

Study of the sign change of exchange bias across the spin reorientation transition in Co(Cr1-x Fe x )2O4 (x = 0.00-0.125).

We present the evolution of novel phenomena of magnetic compensation effect, exchange bias (EB) effect and the field induced anomalies in '[Formula: see text]' substituted multiferroic compound [Formula: see text]. A few percent of '[Formula: see text]' substitution for '[Formula: see text]' in [Formula: see text] results in the reversal of field cooled magnetization under low applied fields below compensation temperature T comp. Further, increase in the field leads to the spin reorientation transition (T SR). Signature of EB in a narrow temperature window in the vicinity of T SR and its sign change across T SR is observed. Magnitude of EB depends on the amount of compensation and rigidity of the spin reorientation. We also notice the appearance of positive EB below the lock-in transition (T L). Presence of unidirectional anisotropy developed in the commensurate spin-spiral below T L could be responsible for the appearance of EB below T L.

Trans-catheter closure of patent ductus arteriosus-What is the best device?

BACKGROUND: Over the past three decades, transcatheter occlusion of patent ductus arteriosus (PDA) has evolved to be the procedure of choice. Gianturco and Flipper coils are the most commonly used coils in the United States for closure of small and moderate size PDAs. For larger PDAs, interventionalists in the United States commonly use the Amplatzer Duct Occluder (ADO) and those in Europe use the ADO or the Nit-Occlud Coils (NOC). A comparison between Gianturco coils, Flipper coils, ADO, and NOC has never been made. OBJECTIVE: To compare the success and complication rate associated with the four different devices used for transcatheter closure of PDA. Success was defined as complete closure of PDA with absence of a residual shunt (R.S.) at six months follow-up. METHODS: Two institutions collaborated in combining their data to evaluate the results of transcatheter closure of PDA. RESULTS: Totally, 546 patients underwent successful PDA occlusion at both institutions. Gianturco and Flipper coils were used in 120 (22%) and 119 (22%) patients respectively. A total of 152 (28%) patients received ADO and 155 (28%) patients received NOC. Immediate R.S. were noted in 226 (41.4%) patients in the entire study group with the NOC group having the highest percentage of R.S. (80/155, 51.6%, P = 0.004). Of the 484 patients with follow-up echocardiograms at 6 months, 35 (7.2%) patients had persistent R.S. The NOC (3/143, 2.1%) and ADO (5/150, 3.3%) groups had the least R.S. at six months follow-up. CONCLUSION: Per our definition of success, the Nit-Occlud coils and the Amplatzer duct-occluder devices had significantly higher success rate for PDA occlusion versus the coils. © 2010 Wiley-Liss, Inc.

Transport and magnetotransport studies on Sol-Gel grown nanostructured La0.7Pb0.3MnO3 manganites.

Sol-Gel synthesis offers relatively inexpensive scale processing of mixed oxide materials with a good control over the stoichiometry and morphology which helps to tailor the required materials on atomic scale to suit specific applications. Nanophasic polycrystalline samples of La0.7Pb0.3MnO3 (LPMO) manganites having perovskite type structure synthesized by novel Sol-Gel technique using acetate precursor route were sintered at various temperatures in the range 950-1150 degrees C for studying the effect of grain size modifications on their structural, transport and magnetotransport properties. X-ray diffraction (XRD) studies show that the samples exhibit rhombohedral structure crystallizing in space group R-3C. Microstructural investigations using Scanning Electronic Microscopy (SEM), Atomic Force Microscopy (AFM) and Lateral Force Microscopy (LFM) measurements reveal the observation of secondary grain growth behavior starting in the sample sintered at 1000 degrees C. The d.c. four probe resistivity measurements with and without applied magnetic field in the temperature range of 2-380 K, show the effect of secondary grain growth on the magnetoresistance (MR) behavior of LPMO manganites. The microstructural studies show the atomic scale engineering at nanoscale which is reflected in the improvement of surface to volume ratio (D(-1)) which in turn modifies the physical properties of samples under investigation. All the samples exhibit resistivity minima at approximately 30 K which can be explained in terms of e-e interaction at 0 Tesla field. There is a correlation between the parameters derived from e-e scattering model and the secondary grain growth present in the samples. The results of the microstructural and MR measurements on the nanostructured LPMO manganites have been discussed in detail.

Simple and precise thermoelectric power measurement setup for different environments.

We report here on a simple but precise thermoelectric power measurement setup that can be adapted for different environments. This setup has been extensively used for cryogen-free environment to measure a variety of samples. It is made simple to load and hold the sample between two copper blocks by a spring-shaft arrangement. The usable range of measurements is a few microV/K to a few hundreds of microV/K. The salient features of the setup in achieving good precision both in natural warm-up/cooldown and controlled measurements are (i) the continuous DeltaT control across the sample by a chromel-AuFe(0.07%) thermocouple and (ii) the measurements of emf generated across the sample and the thermocouple using a nanovoltmeter and a scanner system. The versatile nature of the setup is further demonstrated by employing it in a magnetic field environment up to 140 kOe. The precision achieved using this system is highlighted for a few systems of current interest.

Regional variations in fibre growth dynamics of myotomal and caudal fin muscles in relation to body size of a freshwater teleost, Barbus sarana (Cuv. & Val.).

The growth of red fibres in anterior and middle myotomal regions of B. sarana was mainly by hyperplasia in smaller size classes. In higher size classes, growth by hyperplasia was greater in posterior myotomal region compared to the other two myotomal regions. The growth of pink fibres in anterior myotomal regions was mainly by hypertrophy. The middle and posterior myotomal regions showed fibre growth by hyperplasia. The growth dynamics of white fibres revealed more or less similar pattern in all three myotomal regions against the somatic development. White fibres grew by hyperplasia up to 8 cm F.L. size classes and thereafter by hypertrophy. However, in > 12 cm F.L. size classes, the mean diameter of white fibres did not increase significantly. Similar pattern of growth was found in the white fibres of caudal fin muscle. It is interesting to note that the hyperplasia was mostly completed in the white fibres of the smallest fish studies, whereas, it continued to quite larger fish size in red and pink fibres. Thus, hyperplasia and hypertrophy may be responsible for growth in all fibre types in all myotomal regions in relation to somatic development in this small and medium growing species.