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.

Doped nanocrystalline ZnO powders for non-linear resistor applications by spray pyrolysis method.

Homogeneous and doped nanocrystalline ZnO powders (30-200 nm) were synthesized by spray pyrolysis technique. The spray pyrolysed powders were calcined in the temperature range of 500-750 degrees C. Formation of insulating pyrochlore phase started from 700 degrees C during the calcination itself. The calcined powders were compacted and sintered at different temperatures ranging from 900-1200 degrees C for 0.5-4 h. The densification behavior was found to be dependent on calcination temperature of the nanopowder. The resulting discs were found to have density (5.34-5.62 g/cc) in the range of 96-99% of theoretical density. The breakdown voltage value obtained for the nanopowder based non-linear resistor is 10.3 kV/cm with low leakage current density of 0.7 microA/cm2 and coefficient of nonlinearity as high as 193. The activation energy for grain growth of the doped ZnO nanopowder powders is 449.4 +/- 15 kJ/mol.

The role of Lin28b in myeloid and mast cell differentiation and mast cell malignancy.

Mast cells (MCs) are critical components of the innate immune system and important for host defense, allergy, autoimmunity, tissue regeneration and tumor progression. Dysregulated MC development leads to systemic mastocytosis (SM), a clinically variable but often devastating family of hematologic disorders. Here we report that induced expression of Lin28, a heterochronic gene and pluripotency factor implicated in driving a fetal hematopoietic program, caused MC accumulation in adult mice in target organs such as the skin and peritoneal cavity. In vitro assays revealed a skewing of myeloid commitment in LIN28B-expressing hematopoietic progenitors, with increased levels of LIN28B in common myeloid and basophil-MC progenitors altering gene expression patterns to favor cell fate choices that enhanced MC specification. In addition, LIN28B-induced MCs appeared phenotypically and functionally immature, and in vitro assays suggested a slowing of MC terminal differentiation in the context of LIN28B upregulation. Finally, interrogation of human MC leukemia samples revealed upregulation of LIN28B in abnormal MCs from patients with SM. This work identifies Lin28 as a novel regulator of innate immune function and a new protein of interest in MC disease.

Development and biologic evaluation of a kit for preformed chelate technetium-99m radiolabeling of an antibody Fab fragment using a diamide dimercaptide chelating agent.

A kit has been developed for 99mTc antibody radiolabeling via defined chemistry using an N2S2 diamide dimercaptide bifunctional chelating agent and the performed chelate method. The process involved efficient transchelation of 99mTc from gluconate to 2,3,5,6-tetrafluorophenyl 4,5-bis-S-(1-ethoxyethyl) mercaptoacetamidopentanoate as an active ester ligand and subsequent conjugation to antibody lysine amine functional groups. The use of the ethoxyethyl group for sulfur protection allowed optimum yields of 99mTc N2S2 chelate formation with complete retention of the active ester. Subsequent addition of antibody Fab fragment gave 99mTc chelate conjugates indistinguishable from the stepwise in situ esterification and purification of the 99mTc N2S2 complex followed by conjugation as previously shown to give stable 99mTc antibody fragments with retained immunoreactivity and tumor-targeting properties.

Microbiologic spectrum and susceptibility of isolates: part I. Postoperative endophthalmitis. Endophthalmitis Research Group.

PURPOSE: To present the microbial spectrum and susceptibilities of isolates in postoperative endophthalmitis. METHOD: Isolates from 206 eyes of 206 patients who underwent vitrectomy for postoperative endophthalmitis were examined. RESULTS: One-hundred twelve (54.4%) of 206 vitreous samples were culture positive and 14 (12.5%) of 112 culture-positive cases were polymicrobial, yielding a total of 126 isolates. Isolates included 59 (46.8%) gram-positive cocci, eight (6.3%) gram-positive bacilli, 33 (26.2%) gram-negative organisms, five (4.0%) Actino-mycetes-related organisms, and 21 (16.7%) fungi. Susceptibilities to amikacin, ceftazidime, chloramphenicol, cefazolin, ciprofloxacin, gentamicin, and vancomycin are reported. CONCLUSIONS: This is the largest, single-center, prospective series on microbial susceptibilities in postoperative endophthalmitis. We report a high prevalence of gram-negative species and fungi, suggesting that empiric therapy should include coverage for gram-negative pathogens and for fungal pathogens in appropriate settings.

Microbiologic spectrum and susceptibility of isolates: part II. Posttraumatic endophthalmitis. Endophthalmitis Research Group.

PURPOSE: To present the microbial spectrum and susceptibilities of isolates in posttraumatic endophthalmitis. METHOD: Isolates from 182 eyes of 182 patients who underwent vitrectomy for posttraumatic endophthalmitis were examined. RESULTS: One hundred thirteen (62.1%) of 182 vitreous samples were culture-positive, and 23 (20.4%) of 113 culture-positive cases were polymicrobial, including three (2.7%) trimicrobial cases, yielding a total of 139 isolates. Isolates included 63 (45.3%) gram-positive cocci, 24 (17.3%) gram-positive bacilli, 25 (18.0%) gram-negative organisms, seven (5.0%) Actinomycetes-related organisms, and 20 (14.4%) fungi. Susceptibilities to amikacin, ceftazidime, chloramphenicol, cefazolin, ciprofloxacin, gentamicin, and vancomycin are reported. CONCLUSIONS: This study represents a large series on microbial spectrum and susceptibilities in posttraumatic endophthalmitis. We report a high prevalence of gram-positive bacilli species and polymicrobial infections containing gram-negative species, underscoring the importance of broad-spectrum, combination antibiotics in the empiric treatment of posttraumatic endophthalmitis.

Effect of DDT on adipose tissue lipolysis in rat.

The effect of acute (600 mg/kg body wt) and chronic (15 mg/kg body wt/day for 45 days) 1,1,1-trichloro-2,2-bis (p-chlorophenyl)ethane (DDT) treatments of albino rats on the lipolytic activity of the adipose tissue was studied. There was no effect on the rate of glycerol release on incubation of isolated epididymal fat pads of the treated animals when compared to that of controls. Similarly, in vitro addition of DDT (10-4M) (35.4 ppm) to the fat pads did not alter their lipolytic response. Noradrenaline (NA) stimulated lipolysis, in fat pads, was also unaffected by in vitro addition of DDT. Basal as well as NA or caffeine stimulated lipolysis in isolated fat cells also remained unchanged in the presence of DDT over a range of concentrations from 10-8 M to 10-4 M.

Effect of DDT on adipose tissue lipolysis in rat.

The effect of acute (600 mg/kg body wt) and chronic (15 mg/kg body wt/day for 45 days) DDT treatments of albino rats on the lipolytic activity of the adipose tissue was studied. There was no effect on the rate of glycerol release on incubation of isolated epididymal fat pads of the treated animals when compared to that of controls. Similarly, in vitro addition of DDT (10(-4) M) to the fat pads did not alter their lipolytic response. Noradrenaline stimulated lipolysis, in fat pads, was also unaffected by in vitro addition of DDT. Basal as well as noradrenaline or caffeine stimulated lipolysis in isolated fat cells also remained unchanged in the presence of DDT over a range of concentrations from 10(-8) M to 10(-4) M.

Synthesis and spectroscopic and fungicidal characterization of hydroxamic acids and their metal chelates.

Hydroxamic acid chelates of the type ML2, ML2', and ML2" where M = Cu(II), Ni(II) or Co(II) and L = N,2'-diphenylacetohydroxamic acid (N,2'-DPAHA), L' = 2,2'-diphenylacetohydroxamic acid (2,2'-DPAHA), and L" = 2-phenylacetohydroxamic acid (2-PAHA) have been isolated and characterized on the basis of elemental analysis and infrared and magnetic data. These metal chelates were screened for their fungicidal activity. The testing against fungi has been carried out by slide germination technique against Alternaria alternata and by inhibition zone technique against Fusarium oxysporum and Aspergillus flavus. The fungicidal activity of chelates and their parent ligand has been compared with the commercial fungicide, Dithane M-45, screened under similar conditions.

Gradient liquid chromatography of leucine-enkephalin peptide and its metabolites with electrochemical detection using highly boron-doped diamond electrode.

Boron-doped diamond thin film (BDD) electrodes have been used to study the oxidation reactions and to detect leucine-enkephalinamide (LEA) and its metabolites, tyrosine (T), tyrosyl-alanine (TA), tyrosyl-alanine-glycine (TAG) and leucine-enkephalin (LE) using cyclic voltammetry (CV), flow-injection analysis (FIA), and gradient liquid chromatography (LC) with amperometric detection. At diamond electrodes, well-defined and highly reproducible cyclic voltammograms were obtained with signal-to-background (S/B) ratios 5-10 times higher than those observed for glassy carbon (GC) electrodes. The analytical peaks of LC for LEA and its metabolites were well resolved. No deactivation of BDD electrodes was found after several experiments with standard as well as plasma samples, indicating high stability of the electrode. Calibration curves were linear over a wide range from 0.06 to 30 microM with regression coefficients of 0.999 for all compounds. The limits of detection obtained based on a signal-to-noise ratio of 3:1 were 3, 2.2, 2.7, 20 and 11 nM for T, TA, TAG, LE and LEA, respectively. These values were at least one order lower than those obtained at GC electrodes, which has given limits of detection of 22.88, 20.64, 89.57, 116.04 and 75.67 for T, TA, TAG, LE and LEA, respectively. Application of this method to real samples was demonstrated and validated using rabbit serum samples. This work shows the promising use of conducting diamond as an amperometric detector in gradient LC, especially for the analysis of enkephalinamide and its metabolites.

Acute exposure of rhesus monkeys to DDT: effect on carbohydrate metabolism.

The administration of a single oral dose of DDT (150 mg/kg body wt.) to rhesus monkey elevated the hepatic glycogen and glycogen synthase activity but depressed the glycogen phosphorylase activity. A decrease in adenylate cyclase, both basal as well as fluoride and norepinephrine stimulated activity, was observed in liver of DDT-treated animals as compared to controls. Gluconeogenic enzymes did not record any significant change in the liver.

Effect of a single oral dose of DDT on lipid metabolism in rat.

A single oral dose of 1,1,1-trichloro-2-2-bis (p-chlorophenyl)ethane (DDT) (600 mg/kg body weight) was given to rats and the levels of various lipids in adipose tissue, liver and plasma were studied. No alteration was observed in the levels of various lipid classes in these tissues except for a decrease in the phospholipid and triglyceride fractions in liver. Lipoprotein lipase activity of post-heparin plasma (protamine-sensitive and -resistant) was significantly decreased, whereas in liver and adipose tissue, the activity of this enzyme remained unchanged.

Comparative evaluation of zinc sulfadiazine and silver sulfadiazine in burn wound infection.

One percent silver sulfadiazine has been commonly used as a topical antimicrobial agent after a burn injury. Incidence of burn wound colonization by Staphylococcus aureus in patients treated with silver sulfadiazine has spurred research for other agents. A topical preparation that contains zinc and sulfadiazine (Zad-G) was evaluated for in vitro antibacterial spectrum and in vivo efficacy. Muscle biopsy specimens of rats treated with Zad-G appear to have fewer colonies of S. aureus than groups treated with silver sulfadiazine. Topical therapy with Zad-G for patients with burns was comfortable, reduced wound infection, and was comparable to therapy with silver sulfadiazine. A topical Zad-G preparation that contains zinc sulfadiazine appears to be an effective alternative to silver sulfadiazine in the treatment of burn wounds.

CSF orbitorrhoea with tension pneumocephalus.

A seventy eight year old man sustained penetrating injury to right orbit about 15 years ago. Later he developed right orbital infection leading to phthisis bulbi. Two months before admission he developed CSF leak from the right orbit, tension pneumocephalous and meningitis. A rare case of CSF orbitorrhoea is reported here along with the discussion on mechanisms and management.