445 research outputs found

    Reaction control system integrated systems performance analysis - LM computer program user's manual

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    Reaction control system integrated systems performance analysis LM computer program - users manua

    Randomized clinical trial to evaluate the effect of fecal microbiota transplant for initial Clostridium difficile infection in intestinal microbiome

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    Objective The aim of this study was to evaluate the impact of fecal donor-unrelated donor mix (FMT-FURM) transplantation as first-line therapy for C. difficile infection (CDI) in intestinal microbiome. Methods We designed an open, two-arm pilot study with oral vancomycin (250mg every 6 h for 10–14 days) or FMT-FURM as treatments for the first CDI episode in hospitalized adult patients in Hospital Universitario “Dr. Jose Eleuterio Gonzalez”. Patients were randomized by a closed envelope method in a 1: 1 ratio to either oral vancomycin or FMT-FURM. CDI resolution was considered when there was a reduction on the Bristol scale of at least 2 points, a reduction of at least 50% in the number of bowel movements, absence of fever, and resolution of abdominal pain (at least two criteria). From each patient, a fecal sample was obtained at days 0, 3, and 7 after treatment. Specimens were cultured to isolate C. difficile, and isolates were characterized by PCR. Susceptibility testing of isolates was performed using the agar dilution method. Fecal samples and FMT-FURM were analyzed by 16S rRNA sequencing. Results We included 19 patients; 10 in the vancomycin arm and 9 in the FMT-FURM arm. However, one of the patients in the vancomycin arm and two patients in the FMT-FURM arm were eliminated. Symptoms resolved in 8/9 patients (88.9%) in the vancomycin group, while symptoms resolved in 4/7 patients (57.1%) after the first FMT-FURM dose (P = 0.26) and in 5/7 patients (71.4%) after the second dose (P = 0.55). During the study, no adverse effects attributable to FMT-FURM were observed in patients. Twelve isolates were recovered, most isolates carried tcdB, tcdA, cdtA, and cdtB, with an 18-bp deletion in tcdC. All isolates were resistant to ciprofloxacin and moxifloxacin but susceptible to metronidazole, linezolid, fidaxomicin, and tetracycline. In the FMT-FURM group, the bacterial composition was dominated by Firmicutes, Bacteroidetes, and Proteobacteria at all-time points and the microbiota were remarkably stable over time. The vancomycin group showed a very different pattern of the microbial composition when comparing to the FMT-FURM group over time. Conclusion The results of this preliminary study showed that FMT-FURM for initial CDI is associated with specific bacterial communities that do not resemble the donors’ sample.Peer reviewedFinal Published versio

    DEVELOPMENT OF A CONTINUOUS COUNTER-CURRENT HIGH EFFICIENCY GAS-SOLIDS CONTACTOR

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    Experimental conversions of UO/sub 3/ to UO /sub 2/ to UF/sub 4/ in batch fluidized bed pilot-scale contactor have demonstrated that conversion rates approaching those predicted from basic kinetic data are attainable. Further studies with fluidized beds in columns incorporating a very slight taper show that solids mixing with attendant product contamination is reduced by a factor of ten as a direct result of the taper. Experiments with tapered fluidlized beds made the design of continuous (as opposed to the step enrichment of a multistage contactor) countercurrent contactors practical. Design procedures, in generalized form, are presented. The procedures take into consideration heat transfer, mixing losses, reaction kinetics, and chemical equilibria. (auth

    Synergistic Antibacterial Effects of Metallic Nanoparticle Combinations

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    © The Author(s) 2019.Metallic nanoparticles have unique antimicrobial properties that make them suitable for use within medical and pharmaceutical devices to prevent the spread of infection in healthcare. The use of nanoparticles in healthcare is on the increase with silver being used in many devices. However, not all metallic nanoparticles can target and kill all disease-causing bacteria. To overcome this, a combination of several different metallic nanoparticles were used in this study to compare effects of multiple metallic nanoparticles when in combination than when used singly, as single elemental nanoparticles (SENPs), against two common hospital acquired pathogens (Staphylococcus aureus and Pseudomonas. aeruginosa). Flow cytometry LIVE/DEAD assay was used to determine rates of cell death within a bacterial population when exposed to the nanoparticles. Results were analysed using linear models to compare effectiveness of three different metallic nanoparticles, tungsten carbide (WC), silver (Ag) and copper (Cu), in combination and separately. Results show that when the nanoparticles are placed in combination (NPCs), antimicrobial effects significantly increase than when compared with SENPs (P < 0.01). This study demonstrates that certain metallic nanoparticles can be used in combination to improve the antimicrobial efficiency in destroying morphologically distinct pathogens within the healthcare and pharmaceutical industry.Peer reviewe

    Design and Implementation of Degenerate Microsatellite Primers for the Mammalian Clade

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    Microsatellites are popular genetic markers in molecular ecology, genetic mapping and forensics. Unfortunately, despite recent advances, the isolation of de novo polymorphic microsatellite loci often requires expensive and intensive groundwork. Primers developed for a focal species are commonly tested in a related, non-focal species of interest for the amplification of orthologous polymorphic loci; when successful, this approach significantly reduces cost and time of microsatellite development. However, transferability of polymorphic microsatellite loci decreases rapidly with increasing evolutionary distance, and this approach has shown its limits. Whole genome sequences represent an under-exploited resource to develop cross-species primers for microsatellites. Here we describe a three-step method that combines a novel in silico pipeline that we use to (1) identify conserved microsatellite loci from a multiple genome alignments, (2) design degenerate primer pairs, with (3) a simple PCR protocol used to implement these primers across species. Using this approach we developed a set of primers for the mammalian clade. We found 126,306 human microsatellites conserved in mammalian aligned sequences, and isolated 5,596 loci using criteria based on wide conservation. From a random subset of ∼1000 dinucleotide repeats, we designed degenerate primer pairs for 19 loci, of which five produced polymorphic fragments in up to 18 mammalian species, including the distinctly related marsupials and monotremes, groups that diverged from other mammals 120–160 million years ago. Using our method, many more cross-clade microsatellite loci can be harvested from the currently available genomic data, and this ability is set to improve exponentially as further genomes are sequenced

    Ethical issues relating to the banking of umbilical cord blood in Mexico

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    <p>Abstract</p> <p>Background</p> <p>Umbilical cord banks are a central component, as umbilical cord tissue providers, in both medical treatment and scientific research with stem cells. But, whereas the creation of umbilical cord banks is seen as successful practice, it is perceived as a risky style of play by others. This article examines and discusses the ethical, medical and legal considerations that arise from the operation of umbilical cord banks in Mexico.</p> <p>Discussion</p> <p>A number of experts have stated that the use of umbilical cord goes beyond the mere utilization of human tissues for the purpose of treatment. This tissue is also used in research studies: genetic studies, studies to evaluate the effectiveness of new antibiotics, studies to identify new proteins, etc. Meanwhile, others claim that the law and other norms for the functioning of cord banks are not consistent and are poorly defined. Some of these critics point out that the confidentiality of donor information is handled differently in different places. The fact that private cord banks offer their services as "biological insurance" in order to obtain informed consent by promising the parents that the tissue that will be stored insures the health of their child in the future raises the issue of whether the consent is freely given or given under coercion. Another consideration that must be made in relation to privately owned cord banks has to do with the ownership of the stored umbilical cord.</p> <p>Summary</p> <p>Conflicts between moral principles and economic interests (non-moral principles) cause dilemmas in the clinical practice of umbilical cord blood storage and use especially in privately owned banks. This article presents a reflection and some of the guidelines that must be followed by umbilical cord banks in order to deal with these conflicts. This reflection is based on the fundamental notions of ethics and public health and seeks to be a contribution towards the improvement of umbilical cord banks' performance.</p

    A quantitative description of the transition between intuitive altruism and rational deliberation in iterated Prisoner's Dilemma experiments

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    What is intuitive: pro-social or anti-social behaviour? To answer this fundamental question, recent studies analyse decision times in game theory experiments under the assumption that intuitive decisions are fast and that deliberation is slow. These analyses keep track of the average time taken to make decisions under different conditions. Lacking any knowledge of the underlying dynamics, such simplistic approach might however lead to erroneous interpretations. Here we model the cognitive basis of strategic cooperative decision making using the Drift Diffusion Model to discern between deliberation and intuition and describe the evolution of the decision making in iterated Prisoner's Dilemma experiments. We find that, although initially people's intuitive decision is to cooperate, rational deliberation quickly becomes dominant over an initial intuitive bias towards cooperation, which is fostered by positive interactions as much as frustrated by a negative one. However, this initial pro-social tendency is resilient, as after a pause it resets to the same initial value. These results illustrate the new insight that can be achieved thanks to a quantitative modelling of human behavior

    Long-term survival in patients with non-small cell lung cancer and synchronous brain metastasis treated with whole-brain radiotherapy and thoracic chemoradiation

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    <p>Abstract</p> <p>Background</p> <p>Brain metastases occur in 30-50% of Non-small cell lung cancer (NSCLC) patients and confer a worse prognosis and quality of life. These patients are usually treated with Whole-brain radiotherapy (WBRT) followed by systemic therapy. Few studies have evaluated the role of chemoradiotherapy to the primary tumor after WBRT as definitive treatment in the management of these patients.</p> <p>Methods</p> <p>We reviewed the outcome of 30 patients with primary NSCLC and brain metastasis at diagnosis without evidence of other metastatic sites. Patients were treated with WBRT and after induction chemotherapy with paclitaxel and cisplatin for two cycles. In the absence of progression, concurrent chemoradiotherapy for the primary tumor with weekly paclitaxel and carboplatin was indicated, with a total effective dose of 60 Gy. If disease progression was ruled out, four chemotherapy cycles followed.</p> <p>Results</p> <p>Median Progression-free survival (PFS) and Overall survival (OS) were 8.43 ± 1.5 and 31.8 ± 15.8 months, respectively. PFS was 39.5% at 1 year and 24.7% at 2 years. The 1- and 2-year OS rates were 71.1 and 60.2%, respectively. Three-year OS was significantly superior for patients with N0-N1 stage disease vs. N2-N3 (60 vs. 24%, respectively; Response rate [RR], 0.03; <it>p</it>= 0.038).</p> <p>Conclusions</p> <p>Patients with NSCLC and brain metastasis might benefit from treatment with WBRT and concurrent thoracic chemoradiotherapy. The subgroup of N0-N1 patients appears to achieve the greatest benefit. The result of this study warrants a prospective trial to confirm the benefit of this treatment.</p

    TRY plant trait database - enhanced coverage and open access

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    Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

    Nascentome Analysis Uncovers Futile Protein Synthesis in Escherichia coli

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    Although co-translational biological processes attract much attention, no general and easy method has been available to detect cellular nascent polypeptide chains, which we propose to call collectively a “nascentome.” We developed a method to selectively detect polypeptide portions of cellular polypeptidyl-tRNAs and used it to study the generality of the quality control reactions that rescue dead-end translation complexes. To detect nascent polypeptides, having their growing ends covalently attached to a tRNA, cellular extracts are separated by SDS-PAGE in two dimensions, first with the peptidyl-tRNA ester bonds preserved and subsequently after their in-gel cleavage. Pulse-labeled nascent polypeptides of Escherichia coli form a characteristic line below the main diagonal line, because each of them had contained a tRNA of nearly uniform size in the first-dimension electrophoresis but not in the second-dimension. The detection of nascent polypeptides, separately from any translation-completed polypeptides or degradation products thereof, allows us to follow their fates to gain deeper insights into protein biogenesis and quality control pathways. It was revealed that polypeptidyl-tRNAs were significantly stabilized in E. coli upon dysfunction of the tmRNA-ArfA ribosome-rescuing system, whose function had only been studied previously using model constructs. Our results suggest that E. coli cells are intrinsically producing aberrant translation products, which are normally eliminated by the ribosome-rescuing mechanisms
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