Optoelectronic properties of triphenylamine based dyes for solar cell applications. A DFT study

Indexación: Scopus.GSM thanks to the Department of Chemistry at the Universidad Andres Bello, Concepcion, Chile. LHMH gratefully acknowledges financial support from CONACYT (Projects CB2015-257823) and to the Universidad Autónoma del Estado de Hidalgo.Dye-sensitized solar cells (DSSCs) based on triphenylamine (TPA) as a donor group linked with the acceptor cyanoacrylic acid electron acceptor by 2,2'-bithiophene as π-bridged (D-π-A) has been investigated by Density Functional Theory (DFT) at the B3LYP/6-311G(d,p) level of theory, to establish the conformational orientation of cyanoacrylic acid group as well as evaluate the effect of planarizing the 2,2'-bithiophene unit in position 3 and 3' by electron withdrawing or donor groups on the electronic structure properties of ground and doping(n,p) states. Also, the Time Dependent Density Functional Theory (TD-DFT) at the CPCM-TD-CAM-B3LYP//CAM-B3LYP/6-311G(d,p) level of theory were selected to modulate the electronic absorption spectra and charge-transfer capabilities of the molecules analyzed in the present work. The results indicate that adding an auxiliary donor or withdrawing group to the 2,2'-bithiophene in the (D-π-A) arrangement allow to modify the LUMO's energy of the dyes, while the HOMO's energy is slightly affected. © 2018 Sociedade Brasileira de Quimica. All rights reserved.http://quimicanova.sbq.org.br/imagebank/pdf/AR20170232.pd

Temperature dependence of J–V and C–V characteristics of n-InAs/p-GaAs heterojunctions prepared by flash evaporation technique and liquid phase epitaxy

In this work, n-type of InAs films have been successfully fabricated on p-GaAs monocrystalline substrates by both flash evaporation technique and liquid phase epitaxy. The elemental composition of the prepared films has been confirmed by energy dispersive X-ray (EDX) spectroscopy. The morphology of the films has been characterized by scanning electron microscopy (SEM). The current transport mechanisms of n-InAs/p-GaAs heterojunctions in the temperature range 300-400 K have been investigated. Temperature-dependent dark current density-voltage (J–V) studies under forward and reverse bias have been carried out for this purpose. In the temperature range studied, the dark current contribution in the low bias range is believed to be due to the generation-recombination of minority carriers in the space-charge region. A change in the preparation technique does not seem to have altered the dark current conduction mechanism. Capacitance-voltage (C–V) at various temperatures has been measured to identify the junction type as well as determination of the important junction parameters

Increased platelet reactivity in idiopathic pulmonary fibrosis is mediated by a plasma factor

Introduction Idiopathic Pulmonary Fibrosis (IPF) is a progressive, incurable fibrotic interstitial lung disease with a prognosis worse than many cancers. Its pathogenesis is poorly understood. Activated platelets can release pro-fibrotic mediators that have the potential to contribute to lung fibrosis. We determine platelet reactivity in subjects with IPF compared to age-matched controls. Methods Whole blood flow cytometry was used to measure platelet-monocyte aggregate formation, platelet P-selectin expression and platelet fibrinogen binding at basal levels and following stimulation with platelet agonists. A plasma swap approach was used to assess the effect of IPF plasma on control platelets. Results Subjects with IPF showed greater platelet reactivity than controls. Platelet P-selectin expression was significantly greater in IPF patients than controls following stimulation with 0.1 µM ADP (1.9% positive ±0.5 (mean ± SEM) versus 0.7%±0.1; p = 0.03), 1 µM ADP (9.8%±1.3 versus 3.3%±0.8; p<0.01) and 10 µM ADP (41.3%±4.2 versus 22.5%±2.6; p<0.01). Platelet fibrinogen binding was also increased, and platelet activation resulted in increased platelet-monocyte aggregate formation in IPF patients. Re-suspension of control platelets in plasma taken from subjects with IPF resulted in increased platelet activation compared to control plasma. Conclusions IPF patients exhibit increased platelet reactivity compared with controls. This hyperactivity may result from the plasma environment since control platelets exhibit increased activation when exposed to IPF plasma

PHARMACEUTICAL AND BIOPHARMACEUTICAL ASPECTS OF QUANTUM DOTS-AN OVERVIEW

In the twenty-first century, nanotechnology has become cutting-edge technology. It is interdisciplinary and multidisciplinary, covering numerous fields such as medicine, engineering, biology, physics, material sciences, and chemistry. The present work aims to cover the optical properties, method of preparations, surface modifications, bio-conjugation, characterization, stability, and cytotoxicity of quantum dots (QDs). Articles were reviewed in English literature reporting the pharmaceutical and bio-pharmaceutical aspects of QDs which were indexed in Scopus, web of science, google scholar and PubMed without applying the year of publication criterion. One significant value of utilizing nanotechnology is that one can alter and control the properties in a genuinely unsurprising way to address explicit applications' issues. In science and biomedicine, the usage of functional nanomaterials has been broadly investigated and has become one of the quick-moving and stimulating research directions. Different types of nanomaterial (silicon nanowires, QDs, carbon nanotubes, nanoparticles of gold/silver) were extensively utilized for biological purposes. Nanomedicine shows numerous advantages in the natural characteristics of targeted drug delivery and therapeutics. For instance, protection of drugs against degradation, improvement in the drug's stability, prolonged circulation time, deceased side effects, and enhanced distribution in tissues. The present review article deals with the quantum dots, their optical properties, method of preparations, surface modifications, bio-conjugation, characterization, stability, and cytotoxicity of quantum dots. The review also discusses various biomedical applications of QDs. The QDs-based bio-nanotechnology will always be in the growing list of unique applications, with progress being made in specialized nanoparticle development, the detection of elegant conjugation methods, and the discovery of new targeting ligands

Gender Bias in Collaborative Medical Decision Making: Emergent Evidence DRAFT

The article of record as published may be found at https://doi.org/10.1097/ACM.0000000000003590Online ahead of print.This initial, exploratory study on gender bias in collaborative medical decision making examined the degree to which physicians' reliance on a team member's patient care advice differs as a function of the gender of the advice giver. In 2018, 283 anesthesiologists read a brief, online clinical vignette and were randomly assigned to receive treatment advice from 1 of 8 possible sources (physician or nurse; man or woman; experienced or inexperienced). They then indicated their treatment decision, as well as the degree to which they relied upon the advice given.The results revealed two patterns consistent with gender bias in participants' advice taking. First, when treatment advice was delivered by an inexperienced physician, participants reported replying significantly more on the advice of a man versus a woman, F(1,61) = 4.24, P = .04. Second, participants' reliance on the advice of the woman physician was a function of her experience, F(1,62) = 6.96, P = .01, whereas reliance on the advice of the man physician was not, F(1,60) = 0.21, P = .65.These findings suggest women physicians, relative to men, may encounter additional hurdles to performing their jobs, especially at early stages in their careers. These hurdles are rooted in psychological biases of others, rather than objective features of cases or treatment settings. Cultural stereotypes may shape physicians' information use and decision-making processes (and hinder collaboration), even in contexts that appear to have little to do social category membership. The authors recommend institutions adopt policies and practices encouraging equal attention to advice, regardless of the source, to help ensure advice taking is a function of information quality rather than the attributes of the advice giver. Such policies and practices may help surface and implement diverse expert perspectives in collaborative medical decision making, promoting better and more effective patient care.Internal funding reported.Internal funding reported

Pralidoxime in Acute Organophosphorus Insecticide Poisoning-A Randomised Controlled Trial

Background: Poisoning with organophosphorus (OP) insecticides is a major global public health problem, causing an estimated 200,000 deaths each year. Although the World Health Organization recommends use of pralidoxime, this antidote's effectiveness remains unclear. We aimed to determine whether the addition of pralidoxime chloride to atropine and supportive care offers benefit. Methods and Findings: We performed a double-blind randomised placebo-controlled trial of pralidoxime chloride (2 g loading dose over 20 min, followed by a constant infusion of 0.5 g/h for up to 7 d) versus saline in patients with organophosphorus insecticide self-poisoning. Mortality was the primary outcome; secondary outcomes included intubation, duration of intubation, and time to death. We measured baseline markers of exposure and pharmacodynamic markers of response to aid interpretation of clinical outcomes. Two hundred thirty-five patients were randomised to receive pralidoxime (121) or saline placebo (114). Pralidoxime produced substantial and moderate red cell acetylcholinesterase reactivation in patients poisoned by diethyl and dimethyl compounds, respectively. Mortality was nonsignificantly higher in patients receiving pralidoxime: 30/121 (24.8%) receiving pralidoxime died, compared with 18/114 (15.8%) receiving placebo (adjusted hazard ratio HR] 1.69, 95% confidence interval CI] 0.88-3.26, p = 0.12). Incorporating the baseline amount of acetylcholinesterase already aged and plasma OP concentration into the analysis increased the HR for patients receiving pralidoxime compared to placebo, further decreasing the likelihood that pralidoxime is beneficial. The need for intubation was similar in both groups (pralidoxime 26/121 21.5%], placebo 24/114 21.1%], adjusted HR 1.27 95% CI 0.71-2.29]). To reduce confounding due to ingestion of different insecticides, we further analysed patients with confirmed chlorpyrifos or dimethoate poisoning alone, finding no evidence of benefit. Conclusions: Despite clear reactivation of red cell acetylcholinesterase in diethyl organophosphorus pesticide poisoned patients, we found no evidence that this regimen improves survival or reduces need for intubation in patients with organophosphorus insecticide poisoning. The reason for this failure to benefit patients was not apparent. Further studies of different dose regimens or different oximes are required

Outcomes of resection for rectal cancer in India: The impact of the double stapling technique

BACKGROUND: The introduction of circular staplers into colorectal surgery has revolutionized anastomotic techniques stretching the limits of sphincter preservation. Data on the double-stapling technique (DST) has been widely published in the West where the incidence of colorectal cancer is high. However studies using this technique and their results, in the Indian scenario, as well as the rest of Asia, have been few and far between. AIM: To evaluate the feasibility of the DST in Indian patients with low rectal cancers and assess its impact on anastomotic leak rates, covering colostomy rates, level of resection and morbidity in patients undergoing low anterior resection (LAR). METHODS: A comparative analysis was performed between retrospectively acquired data on 78 patients (mean age 53.2 ± 13.5 years) undergoing LAR with the single-stapling technique (SST) (between January 1999 and December 2001) and prospective data acquired on 138 LARs (mean age 50.3 ± 13.9 years) performed using the DST (between January 2003 – December 2005). RESULTS: A total of 77 out of 78 patients in the SST group had Astler Coller B and C disease while the number was 132/138 in the DST group. The mean distance of the tumor from anal verge was 7.6 cm (2.5–15 cm) and 8.0 cm (4–15 cm) in the DST and SST groups, respectively. In the DST group, there were 5 (3.6%) anastomotic failures and 62 (45%) covering stomas compared to 7 (8.9%) anastomotic failures and 51 (65.4%) covering stomas in the SST group. The anastomotic leak rate, though objectively lower in the DST group, did not attain statistical significance (p = 0.12). Covering stoma rates were significantly lower in DST group (p = 0.006). There was 1 death in the DST group due to cardiac causes (unrelated to the anastomosis) and no mortality in the SST group. The LAR and abdominoperineal resection (APR) rates were 40% and 60%, respectively, during 1999–2001. In 2005, these rates were 55% and 45%, respectively. CONCLUSION: This study, perhaps the first from India, demonstrates the feasibility of the DST in a country where the incidence of colorectal cancer is increasing. Since the age at presentation is at least a decade younger than the Western world, consideration of sphincter preservation assumes greater significance. The observed improvement of surgical outcomes with DST needs further studies to significantly prove these findings in a population where the tumors at presentation are predominantly Astler Coller Stage B and C

Role of Spinophilin in Group I Metabotropic Glutamate Receptor Endocytosis, Signaling, and Synaptic Plasticity

Activation of Group I metabotropic glutamate receptors (mGluRs) activates signaling cascades, resulting in calcium release from intracellular stores, ERK1/2 activation, and long term changes in synaptic activity that are implicated in learning, memory, and neurodegenerative diseases. As such, elucidating the molecular mechanisms underlying Group I mGluR signaling is important for understanding physiological responses initiated by the activation of these receptors. In the current study, we identify the multifunctional scaffolding protein spinophilin as a novel Group I mGluR-interacting protein. We demonstrate that spinophilin interacts with the C-terminal tail and second intracellular loop of Group I mGluRs. Furthermore, we show that interaction of spinophilin with Group I mGluRs attenuates receptor endocytosis and phosphorylation of ERK1/2, an effect that is dependent upon the interaction of spinophilin with the C-terminal PDZ binding motif encoded by Group I mGluRs. Spinophilin knock-out results in enhanced mGluR5 endocytosis as well as increased ERK1/2, AKT, and Ca2+ signaling in primary cortical neurons. In addition, the loss of spinophilin expression results in impaired mGluR5-stimulated LTD. Our results indicate that spinophilin plays an important role in regulating the activity of Group I mGluRs as well as their influence on synaptic activity

An 8-mm diameter fibre robot positioner for massive spectroscopy surveys

Massive spectroscopic survey are becoming trendy in astrophysics and cosmology, as they can address new fundamental knowledge such as understanding the formation of the Milky Way and probing the nature of the mysterious dark energy. To enable massive spectroscopic surveys, new technology has been developed to place thousands of optical fibres at a given position on a focal plane. This technology needs to be: (1) accurate, with micrometer positional accuracy; (2) fast to minimize overhead; (3) robust to minimize failure; and (4) low cost. In this paper, we present the development, properties, and performance of a new single 8-mm in diameter fibre positioner robot, using two 4-mm DC-brushless gearmotors, that allows us to achieve accuracies up to 0.07arcsec (5 μm). This device has been developed in the context of the Dark Energy Spectroscopic Instrument.