Buffer Layer Assisted Chemistry over Amorphous Solid Water: Oxide Thin Film or Metallic Nanoparticles Formation.

Novel procedures to grow pure thin metal oxide films are always welcome in view of their wide range of applications including photocatalysis, solar cells, sensors, and more. In this paper we present a unique way to grow pure nanofilms of metal oxides in vacuo at the temperature range 110-170 K. The reactive layer assisted deposition (RLAD) procedure for thin oxide films growth is based on the evaporation of a reactive metal element on top of a condensed layer of amorphous solid water (D2O-ASW). When applied to metals that do not react with the water layer, the process yields metal nanoclusters on the substrate. We observed that metal oxide films are formed if the redox potential is of -1.0 V or less, leading to deuterium molecules ejection to the gas phase (e.g., Ti and Al) while metals such as Zn, Fe, and Ag, with redox potentials more than -1.0 V, transform into nanoclusters, as revealed by SEM studies. We conclude that the redox potential ia a parameter that enables one to predict the nature and outcome of the ASW buffer layer assisted chemistry.

Comparison of haematological and biochemical changes between non-anaemic and anaemic primigravid women in a north Indian population to establish normative values.

Pregnancy is accompanied by several haemodynamic, biochemical and haematological changes, which may lead to severe problems, if they are not suitably addressed. The current study highlights the haematological and biochemical differences observed in anaemic (AP) and non-anaemic primigravida (NAP), in the 2nd trimester, in a north Indian population. There were significant differences (p < 0.05) in the body weight and body temperature of NAP compared with AP. A significant decrease (p < 0.001) in haematological parameters including haemoglobin, haematocrit, erythrocyte count, MCH and MCHC, was observed in AP; however, MCV was found to be significantly higher (p = 0.038). Many biochemical parameters viz. potassium, albumin, total protein and calcium levels were significantly reduced (p < 0.01) in AP, except alkaline phosphatase whose level was found significantly increased (p < 0.01). The findings of the study suggest that haematological and biochemical changes take place in anaemia during pregnancy. Further, the results obtained should be used for establishing normative values for similar populations.

Photocatalytic degradation of fluoroquinolone antibiotics using chitosan biopolymer functionalized copper oxide nanoparticles prepared by facile sonochemical method.

Photocatalytic degradation is an excellent method for removing pharmaceutical residues due to their simplicity, ecological benignity, high efficiency, and exceptional stability. Herein, we demonstrate the sonochemically synthesised chitosan biopolymer functionalized copper oxide nanoparticles as an efficient photocatalyst for the degradation of fluoroquinolone-based antibiotics. The X-ray diffraction Rietveld refinement revealed the formation of single-phase copper oxide (CuO) with a monoclinic structure. The presence of biopolymer functionalization was corroborated by Fourier Transform Infrared spectroscopy by observing the -NH2 and -OH functional groups. The high-resolution transmission electron microscopic images inferred that Chitosan functionalized copper oxide (C-CuO) particles are nano-sized with a smooth texture and aggregation-free particles. The strong absorbance and the broad photoluminescence emission in the ultraviolet-visible region confirm the suitability of CuO and C-CuO nanoparticles for photocatalytic applications. The catalytic activity was studied against fluoroquinolone-based antibiotics such as ciprofloxacin and norfloxacin under direct sunlight illumination. Interestingly, the C-CuO catalyst demonstrated 71.07 % (@140 min.) and 71.9 % (@60 min.) of degradation for ciprofloxacin and norfloxacin, respectively. The obtained photocatalytic activity of the prepared CuO and C-CuO catalysts was superior to the CuO particles prepared by the coprecipitation method (CC-CuO).

Factors predicting prolonged hospitalization after abdominal wall hernia repair - a prospective observational study.

Objectives: The aim of this study was to identify the factors predicting prolonged hospitalization following abdominal wall hernia repair. Material and Methods: This was a prospective observational study which included patients operated for elective and emergency abdominal wall hernias. Details of the patients including demographic profile, hernia characteristics, and perioperative factors were collected. Patients were followed up till discharge from the hospital to record the postoperative local and systemic complications. Patients who stayed for more than three days were considered as longer hospital stay. Analysis was performed to identify factors associated with the longer hospital stay. Results: A total of 200 consecutive patients of abdominal wall hernia were included over a period of two years. Female sex (p <0.05), obesity (p= 0.022), and smoking and alcohol consumption (0.002) led to a prolonged hospital stay. Patients with incisional hernias (p <0.05), American Society of Anesthesiologists (ASA) class of two or more (p= 0.002), complicated hernia (p= 0.007), emergency surgeries (p= 0.002), general anesthesia (p= 0.001), longer duration of surgery (>60 minutes, p <0.05), usage of drain (p <0.05), and surgical site infection (SSI, p= 0.001) were significantly associated with increased length of hospital stay. Whereas, age distribution, socio-economic status, co-morbidities, recurrent surgery, type of hernia repair and the level of surgeon did not affect the length of hospital stay. Conclusion: The risk factors associated with prolonged hospital stay in patients undergoing abdominal wall hernia repair were female sex, obesity, smoking and alcoholism, incisional hernia, complicated hernias, higher ASA class, and prolonged duration of surgeries.

A study of effect of hemodialysis on macular thickness in patients with end-stage renal disease.

PURPOSE: The purpose was to study the effect of hemodialysis (HD) on macular thickness in patients with diabetic retinopathy (DR) and end-stage renal disease. MATERIALS AND METHODS: In this prospective observational study, patients undergoing HD for diabetic nephropathy were recruited. None of the patients received treatment for DR per se during the study duration. Patients underwent ocular examination and optical coherence tomography before HD and were followed up on day 3 and day 30. At each visit, central subfield macular thickness (CSMT) and total macular volume (TMV) were measured and compared with baseline values using analysis of variance and post hoc test (Wilcoxon's matched-pairs signed-rank test). RESULTS: Thirty-one eyes of 19 patients were recruited in the study. The mean CSMT decreased from baseline value of 278.93 ± 45.01 µ to 239.81 ± 40.54 µ at the end of 30 days (P < 0.005). The mean TMV decreased from baseline value of 8.14 ± 0.68 mm3 to 7.80 ± 0.63 mm3 on day 30 (P < 0.005). CONCLUSION: There was a statistically significant reduction in CSMT and TMV after HD at 30 days as compared to baseline values. HD alone results in reduction of macular thickness over short term.

Adsorption of arsenic from aqueous solution on naturally available red soil.

In the present study arsenate and arsenite removal from naturally available red soil in and around Western Ghats of Maharashtra near Mumbai has been investigated. The parameters like adsorbent dose, operating pH, contact time, initial arsenite concentration, adsorbent particle size, etc. on the removal of arsenite and arsenate are examined. Kinetic study in centrifuge vessel reveals that uptake of As (III) ions is rapid in the first two hours and slows down thereafter. Maximum removal efficiency of As (III) achieved is 98% at an adsorbent dose of 45 g l(-1) with initial As (III) concentration of 1000 microg l(-1) in batch studies and 95% at 25 g l(-1) absorbent dose under the same conditions. Equilibrium time is almost independent of initial arsenite concentration. Equilibrium studies show that As (III) ions have high affinity towards red soil even at very low concentration of arsenite. In speciation study about 25% conversion to As (V) from As (III) is observed, with initial As (III) concentration of 1000 microg l(-1) and at 25 g l(-1) adsorbent dose. The results suggest that red soil could be used as effective filter medium for removal of arsenic from water.

Studies on sorption properties of pathogens on natural materials.

Presence of pathogens in high numbers in waste water is a cause of concern. Techno economic feasibility has restricted the conventional and non conventional treatment approaches for pathogen removal. Despite prolific use, carbon adsorption technology remains an expensive treatment process. The present study investigates the use of rice husk (RH), saw dust (SD), groundnut shells (GS) as natural agro-residues and partially weathered deccan trap basalt (PWDTB) for their sorption capacities and desorption pattern for two indicator organisms viz. Escherichia coli K12 and Staphylococcus aureus. Sorption experiments were carried out at flow-rate of 1.5 bed volumes per hour (bv hr(-1)) forcell suspension volume of 4, 8, 16 and 32 bed volumes. PWDTB have shown high sorption coefficient and log removal for E. coli K12 whereas GS have shown high sorption coefficient and log removal for S. aureus. PWDTB have shown maximum desorption constant and log retention for E. coli K12 whereas GS have shown maximum desorption constant and log retention for S. aureus during desorption experiment. Retention pattern suggest that adsorption is partially irreversible for almost all the materials used. It suggest that PWDTB in combination with RH and / GS could help in removal of pathogens from waste water.

Municipal wastewater treatment using novel constructed soil filter system.

The study gives a new approach for contaminant removal from municipal wastewater using constructed soil filter (CSF) and presents performance of two CSF units located in Mumbai, India. In this system, natural weathered rock is formulated which combines sedimentation, infiltration and biochemical processes to remove suspended solids and oxidisable organics and inorganics of the wastewater. Results show elevated dissolved oxygen (DO) levels, removal of COD (136-205 to 38-40 mg l(-1)) and BOD (80-125 to less than 12 mg l(-1)) suspended solids from 135-203 to 13-18 mg l(-1) and turbidity from 84-124 to 8-11 NTU, bacterial removal of 2.4-3.1 log order for Total coliform and Fecal coliform from site I which is almost 8 years old facility, and site II which is 3 years old. Estimated hydraulic retention time of 0.5-1.0 h, hydraulic loading of 0.036-0.047 m(3)m(-2)h(-1), no pretreatment, high DO levels in the effluent, no bio-sludge production, no mechanical aeration, low energy requirement (0.04 kW h m(-3)) and green aesthetic ambience are its unique features.

P2Y12 receptor-mediated potentiation of thrombin-induced thromboxane A2 generation in platelets occurs through regulation of Erk1/2 activation.

BACKGROUND: Thromboxane A2 (TXA2) is a positive feedback lipid mediator that is generated upon stimulation of platelets with various agonists. Aspirin works as an antithrombotic drug by blocking the generation of TXA2. The aim of this study was to evaluate the role of the purinergic P2Y receptors in thrombin-induced TXA2 generation. RESULTS: PAR1-activating peptide (SFLLRN), PAR4-activating peptide (AYPGKF), and thrombin, induced the activation of cytosolic phospholipase A2 (cPLA2), release of arachidonic acid (AA) from membrane-bound phospholipids, and subsequent TXA2 generation in human platelets. The actions of these agonists were significantly inhibited in the presence of the P2Y12 receptor antagonist, AR-C69931MX, but not the P2Y1 receptor antagonist, MRS2179. In addition, AYPGKF- and thrombin-induced TXA2 generation was significantly reduced in platelets from mice dosed with clopidogrel, confirming the results obtained with the human platelets. Also, Pearl mouse platelets that lack releasable nucleotides generated significantly less TXA2 when compared with the wild-type littermates in response to PAR stimulation. Inhibition of extracellular signal-regulated protein kinase 1/2 (Erk 1/2) activation using U0126, an inhibitor of MAP kinase kinase (MEK), suppressed PAR-mediated cPLA2 phosphorylation and TXA2 generation. Further, platelets that were pretreated with AR-C69931MX, as well as Pearl mouse platelets, displayed the reduced levels of Erk1/2 phosphorylation upon stimulation with the PAR agonists. CONCLUSIONS: Based on these findings, we conclude that thrombin-induced Erk1/2 activation is essential for PAR-mediated TXA2 generation, which is potentiated by the P2Y12 receptor-mediated signaling pathway but not the P2Y1 receptor-mediated signaling pathway. Finally, using selective inhibitors of Src kinases, we show that PAR-mediated Src activation precedes Erk1/2 activation.

Nucleotide receptor signaling in platelets.

Upon injury to a vessel wall the exposure of subendothelial collagen results in the activation of platelets. Platelet activation culminates in shape change, aggregation, release of granule contents and generation of lipid mediators. These secreted and generated mediators trigger a positive feedback mechanism potentiating the platelet activation induced by physiological agonists such as collagen and thrombin. Adenine nucleotides, adenosine diphosphate (ADP) and adenosine triphosphate (ATP), released from damaged cells and that are secreted from platelet-dense granules, contribute to the positive feedback mechanism by acting through nucleotide receptors on the platelet surface. ADP acts through two G protein-coupled receptors, the Gq-coupled P2Y1 receptor, and the Gi-coupled P2Y12 receptor. ATP, on the other hand, acts through the ligand-gated channel P2X1. Stimulation of platelets by ADP leads to shape change, aggregation and thromboxane A2 generation. ADP-induced dense granule release depends on generated thromboxane A2. Furthermore, costimulation of both P2Y1 and P2Y12 receptors is required for ADP-induced platelet aggregation. ATP stimulation of P2X1 is involved in platelet shape change and helps to amplify platelet responses mediated by agonists such as collagen. Activation of each of these nucleotide receptors results in unique signal transduction pathways that are important in the regulation of thrombosis and hemostasis.