CdS-sensitized TiO2 nanocorals: hydrothermal synthesis, characterization, application.

Cadmium sulfide (CdS) nanoparticle-sensitized titanium oxide nanocorals (TNC) were synthesized using a two-step deposition process. The TiO(2) nanocorals were grown on the conducting glass substrates (FTO) using A hydrothermal process and CdS nanoparticles were loaded on TNC using successive ionic layer adsorption and reaction (SILAR) method. The TiO(2), CdS and TiO(2)-CdS samples were characterized by optical absorption, X-ray diffraction (XRD), FT-Raman, FT-IR, scanning electron microscopy (SEM) and contact angle. Further, their photoelectrochemical (PEC) performance was tested in NaOH, Na(2)S-NaOH-S and Na(2)S electrolytes, respectively. When CdS nanoparticles are coated on TNCs, the optical absorption is found to be enhanced and band edge is red-shifted towards visible region. The TiO(2)-CdS sample exhibits improved photoelectrochemical (PEC) performance with maximum short circuit current of (J(sc)) 1.04 mA cm(-2). After applying these TiO(2)-CdS electrodes in photovoltaic cells, the photocurrent was found to be enhanced by 2.7 and 32.5 times, as compared with those of bare CdS and TiO(2) nanocorals films electrodes respectively. Also, the power conversion efficiency of TiO(2)-CdS electrodes is 0.72%, which is enhanced by about 16 and 29 times for TiO(2), CdS samples.

Probable Mechanism(s) of Antifungal Activity of SJA-95, a Heptaene Polyene Antibiotic.

A new strain, streptomyces sp. S. 24 was isolated from a soil sample collected from Japan. The strain produced heptaene polyene antibiotic, SJA-95, in submerged culture and found to elicit promising antifungal activity against yeasts, filamentous fungi and clinical isolates, both in vitro and in vivo. Experimental studies were carried out using biological methods to understand the probable mechanism(s) of antifungal activity of SJA-95. Our experimental findings suggest that SJA-95 binds more avidly to ergosterol, the sterol in fungal cell membranes, than to cholesterol found in mammalian cell membranes. Such preferential binding of SJA-95 to ergosterol might help to establish its usefulness as a chemotherapeutic agent with lesser adverse reactions.

Anti-inflammatory activity of Butea monosperma flowers.

Methanolic extract of Butea monosperma flowers (MEBM) was studied for anti-inflammatory activity against carrageenin induced paw edema and cotton pellet granuloma in albino rats. In carrageenin induced paw edema, MEBM at oral doses of 600 mg/kg and 800 mg/kg, dose-dependently inhibited the paw edema. In cotton pellet induced granuloma, MEBM at the same doses was found to significantly inhibit granuloma tissue formation, including significant reduction in levels of serum lysosomal enzymes (SGOT, SGPT and ALP) and lipid peroxides as compared to control.

Assimilatory nitrate reductase: lysine 741 participates in pyridine nucleotide binding via charge complementarity.

Assimilatory NADH:nitrate reductase (EC 1.6.6.1), a complex Mo-pterin-, cytochrome b557-, and FAD-containing protein, catalyzes the regulated and rate-limiting step in the utilization of inorganic nitrogen by high plants. With a recombinant, histidine-tagged form of the spinach nitrate reductase flavin domain, site-directed mutagenesis has been utilized to examine the role of lysine 741 in binding the reducing substrate, NADH. Seven individual mutants, corresponding to K741R, K741H, K741A, K741E, K741M, K741Q, and K741P, have been engineered and six of the resulting proteins purified to homogeneity. With the exception of K741P, all the mutants were obtained as functional flavoproteins which retained FAD as the sole prosthetic group and exhibited spectroscopic properties comparable to those of the wild-type domain, indicating that the amino acid substitutions had no effect on FAD binding. In contrast, all the mutants were found to have altered NADH:ferricyanide reductase (NADH:FR) activity with mutations affecting both kcat and K(NADH)m, which decreased and increased, respectively. At pH 7.0, kcat decreased in the order WT > K741R > K741A > K741H > K741E > K741M > K741Q while K(NADH)m increased in the same order. The most efficient mutant, K741R, retained 80% of the wild-type NADH:FR activity, while in contrast the most inefficient mutant, K741Q, retained only 18% of the wild-type NADH:FR activity together with a 118-fold increased K(NADH)m. pH studies of K741H revealed that both kcat and K(NADH)m were pH-dependent, with enhanced activity observed at acidic pH. These results indicated that retention of a positively charged side chain at position 741 in the spinach nitrate reductase primary sequence is important for the efficient binding and subsequent oxidation of NADH and that the positively charged side chain enhances nucleotide binding via charge complementarity with the negatively charged pyrophosphate moiety.

Ovarian torsion: diagnosis by color Doppler ultrasonography.

BACKGROUND: Ovarian torsion, although a rare gynecologic emergency, is a threat to women of all ages. Traditionally, ultrasonography and laparoscopy facilitated early diagnosis and treatment of this condition. This case report highlights the usefulness of color Doppler ultrasonography in the diagnosis of ovarian torsion. CASE: A 25-year-old patient who conceived after ovulation induction was treated conservatively for mild ovarian hyperstimulation and threatened abortion. She subsequently underwent selective first-trimester multifetal reduction and was admitted and treated for suspected pelvic infection. On the 17th post-procedure morning, ovarian torsion was diagnosed using color Doppler ultrasonography. CONCLUSION: Because gynecologists face serious management dilemmas when confronted with ovarian torsion, this technique of using color Doppler ultrasonography should provide a highly specific finding in complete ovarian torsion, aiding the clinician in prompt diagnosis and treatment.

Selective reduction of multifetal pregnancies in the first trimester using colour Doppler ultrasonography.

In pregnancies with multiple gestation, an adverse outcome is directly proportional to the number of fetuses within the uterus, primarily because of an increased predisposition to premature delivery. Although there is a good deal of information about multifetal reduction in triplets and quadruplets and even quintuplets, there is very little on sextuplets, and virtually nothing on septuplets. Among the different techniques proposed for selective termination, two approaches have been more widely adopted: transcervical aspiration and transabdominal needling of the embryo using grey scale ultrasonography, but as yet there is no report on multifetal reduction using colour Doppler ultrasound. A method for selective termination of multiple pregnancy using transabdominal colour Doppler ultrasonography has been described here for the first time in a case of septuplets.