62 research outputs found
Seven Steps Towards the Classical World
Classical physics is about real objects, like apples falling from trees,
whose motion is governed by Newtonian laws. In standard Quantum Mechanics only
the wave function or the results of measurements exist, and to answer the
question of how the classical world can be part of the quantum world is a
rather formidable task. However, this is not the case for Bohmian mechanics,
which, like classical mechanics, is a theory about real objects. In Bohmian
terms, the problem of the classical limit becomes very simple: when do the
Bohmian trajectories look Newtonian?Comment: 16 pages, LaTeX, uses latexsy
Development of Humanized Mouse Model for Organ Transplantation
Purpose of Study: Solid organ transplantation has been a life-saving procedure for thousands of patients worldwide. Recent advances on improving donor-screening diagnostics have aimed at identification of the most compatible donor for the transplant recipient to maximize allograft survival. Current standards of donor selection relies on HLA typing and in vitro mixed lymphocyte reaction (MLR) which do not take into account the in vivo environment and recipient’s adaptive immune response. Humanized mouse models are an appealing alternative that permits personalized investigation of the immunocompatibility of potential donor tissues for the recipient human immune system without putting patients at risk. By utilizing genomics, molecular and cellular analyses of allogeneic immune response we analyze the efficiency of our novel humanized mouse model to assess the donor-recipient compatibility and determine that it to be significantly more sensitive than conventional screening methods.
Methods Used: Human Leukocyte Antigen (HLA) typing and MLR for histocompatibility. Special strain of immunodeficient mice, NSG mice, subjected to irradiation (2Gy) and i.v injection of 8×10 peripheral blood mononuclear cells (PBMCs) from transplant recipients. For allogeneic immune response, humanized mice received 3×10 PBMCs from unrelated donors (UD) or related donors(RD). Whole genome transcriptome analysis and Real-Time PCR (RT-PCR) Transplant Rejection Array was used.
Summary of Results: Humanized mice demonstrated that allogeneic UD challenge induced significant splenomegaly with infiltration of activated cytotoxic human CD8+ CD25+ T cells expressing Perforin, Granzyme B and Interferon gamma (IFN-γ). Amongst the RDs, RD1 showed minimal allogeneic response while RD2 promoted higher cytotoxic CD8+ T cells infiltration, indicating that RD1 has better immunocompatibility with the recipient than RD2. However, MLR and HLA typing had failed to differentiate the 2 RDs showing them to have equal immunocompatibility with the recipient.
Conclusions: NSG-PBMC humanized mouse model was able to identify the related donor exhibiting minimal allogeneic response to the recipient. This model is significantly more immunologically sensitive than conventional MLR and HLA typing for selection of an immunocompatible donor for the transplant recipient
Macroscopic coherence of a single exciton state in a polydiacetylene organic quantum wire
We show that a single exciton state in an individual ordered conjugated
polymer chain exhibits macroscopic quantum spatial coherence reaching tens of
microns, limited by the chain length. The spatial coherence of the k=0 exciton
state is demonstrated by selecting two spatially separated emitting regions of
the chain and observing their interference.Comment: 12 pages with 2 figure
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A Randomized Trial to Assess the Impact of a Package of Diagnostic Tools and Diagnostic Algorithm on Antibiotic Prescriptions for the Management of Febrile Illnesses Among Children and Adolescents in Primary Health Facilities in Burkina Faso.
BACKGROUND: Low- and middle-income countries face significant challenges in differentiating bacterial from viral causes of febrile illnesses, leading to inappropriate use of antibiotics. This trial aimed to evaluate the impact of an intervention package comprising diagnostic tests, a diagnostic algorithm, and a training-and-communication package on antibiotic prescriptions and clinical outcomes. METHODS: Patients aged 6 months to 18 years with fever or history of fever within the past 7 days with no focus, or a suspected respiratory tract infection, arriving at 2 health facilities were randomized to either the intervention package or standard practice. The primary outcomes were the proportions of patients who recovered at day 7 (D7) and patients prescribed antibiotics at day 0. RESULTS: Of 1718 patients randomized, 1681 (97.8%; intervention: 844; control: 837) completed follow-up: 99.5% recovered at D7 in the intervention arm versus 100% in standard practice (P = .135). Antibiotics were prescribed to 40.6% of patients in the intervention group versus 57.5% in the control arm (risk ratio: 29.3%; 95% CI: 21.8-36.0%; risk difference [RD]: -16.8%; 95% CI: -21.7% to -12.0%; P < .001), which translates to 1 additional antibiotic prescription saved every 6 (95% CI: 5-8) consultations. This reduction was significant regardless of test results for malaria, but was greater in patients without malaria (RD: -46.0%; -54.7% to -37.4%; P < .001), those with a respiratory diagnosis (RD: -38.2%; -43.8% to -32.6%; P < .001), and in children 6-59 months old (RD: -20.4%; -26.0% to -14.9%; P < .001). Except for the period July-September, the reduction was consistent across the other quarters (P < .001). CONCLUSIONS: The implementation of the package can reduce inappropriate antibiotic prescription without compromising clinical outcomes. CLINICAL TRIALS REGISTRATION: clinicaltrials.gov; NCT04081051
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Advancing Access to Diagnostic Tools Essential for Universal Health Coverage and Antimicrobial Resistance Prevention: An Overview of Trials in Sub-Saharan Africa.
We introduce the Antimicrobial Resistance Diagnostic Use Accelerator program, and the articles in this Supplement, which cover the program in 3 sub-Saharan Africa countries
Kinetic characterization, antioxidant and in vitro toxicity potential evaluation of the extract M116 from Bacillus amyloliquefaciens, a Cuban southern coastmarine microorganism
Abstract
Context: Marine ecosystems are sources of bioactive compounds. Thirty-eight microorganism strains from the Cuban platform were screened, which allowed us to identify an extract from Bacillus amyloliquefaciens, strain CBM-116, as a source for obtaining bioproducts with biomedical applications.
Aims: To physiologically characterize the culture of Bacillus amyloliquefaciens (CBM-116 strain) and to evaluate the antioxidant and toxic potentialities in vitro of the M116 extract obtained from CBM-116.
Methods: The growth and metabolite production of the culture were evaluated at a sieve scale. The chemical composition of the M116 extract obtained from the fermented CBM-116 culture was qualitatively characterized. The extract antioxidant activity was measured by DPPH• and FRAP assays, while cytotoxicity was evaluated in MDCK, J774, CT26, 4T1, MCF-7, A549 cell lines and in Caulobacter crescentus, as well as the effects on genetic material by SOS colorimetric and Rifampicin Resistance, in the last model.
Results: Grow kinetic parameters of CBM-116 showed the formation of protein metabolites, while the extract revealed antioxidant capacity, which was evidenced by its iron-reducing capacity. M116 was not cytotoxic up to 2000 μg/mL in C. crescentus; however, it induced mutagenicity and primary damage to the DNA of the bacteria. The extract significantly inhibited cell viability of CT26, 4T1, MCF-7, A549 cells after 48 hours’ exposure. Mean inhibitory concentration (IC50) was calculated for CT26 and 4T1 cells with values of 384 and 488 µg/mL, respectively, in the MTT assay. In the neutral red assay, the values were 478.6 and 398 µg/mL, respectively. Meanwhile, the selectivity index showed values above 2 for both assays. MDCK and J774 cells were not affected.
Conclusions: The M116 extract obtained from B. amyloliquefaciens showed bioactive properties with potential application for developing new anti-tumor agents
Erratum to: Scaling up strategies of the chronic respiratory disease programme of the European Innovation Partnership on Active and Healthy Ageing (Action Plan B3: Area 5).
[This corrects the article DOI: 10.1186/s13601-016-0116-9.]
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