1,861 research outputs found

    Experimental exploration of ErB2_2 and SHAP analysis on a machine-learned model of magnetocaloric materials for materials design

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    Stimulated by a recent report of a giant magnetocaloric effect in HoB2_2 found via machine-learning predictions, we have explored the magnetocaloric properties of a related compound ErB2_2, that has remained the last ferromagnetic material among the rare-earth diboride (REB2_2) family with unreported magnetic entropy change |{\Delta}SM|. The evaluated ΔSM|\Delta S_M| at field change of 5 T in ErB2_2 turned out to be as high as 26.1 (J kg1^{-1} K1^{-1}) around the ferromagnetic transition (TC{T_C}) of 14 K. In this series, HoB2_2 is found to be the material with the largest ΔSM|\Delta S_M| as the model predicted, while the predicted values showed a deviation with a systematic error compared to the experimental values. Through a coalition analysis using SHAP, we explore how this rare-earth dependence and the deviation in the prediction are deduced in the model. We further discuss how SHAP analysis can be useful in clarifying favorable combinations of constituent atoms through the machine-learned model with compositional descriptors. This analysis helps us to perform materials design with aid of machine learning of materials data.Comment: 9 pages, 10 figures. Accepted manuscript. Published by Taylor & Francis in STAM:Methods, available at https://doi.org/10.1080/27660400.2023.221747

    Avaliação da presença de anticorpos IgG anti-Schistosoma mansoni no soro de pacientes com esquistossomose mansônica crônica, antes e após tratamento específico

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    The circumoval precipitin test (COPT), enzyme-linked immunosorbent assay (ELISA) and the immunoblotting anti-adult worm antigen (AWA) and soluble egg antigen (SEA) tests were applied to 17 chronically schistosome-infected patients for the detection of anti-Schistosoma mansoni antibodies before and on four occasions after oxamniquine administration over a period of six months. Compared to a control group, schistosomiasis patients showed high levels of IgG antibodies in AWA and SEA-ELISA. A decrease in IgG levels was observed six months after treatment, although negative reactions were not obtained. Significant decreases in IgG1, IgG3 and, mainly, IgG4, but not anti-SEA IgG2 levels were observed six months after treatment, again without negativity. Analysis of anti-AWA IgG antibodies by immunoblotting before treatment showed a 31 kDa strand in 14 patients (82%) which disappeared in three cases up to six months after treatment; furthermore, anti-SEA IgG antibodies showed the same band in nine patients (53%) before treatment, which disappeared in only four cases up to six months after treatment.Em 17 pacientes com infecção crônica por Schistosoma mansoni utilizaram-se os testes de reação periovular, imunoenzimático (ELISA) e imunoblotting, empregando-se antígenos obtidos a partir de vermes adultos (AWA) ou de ovos de S. mansoni (SEA), para detecção de anticorpos anti-S. mansoni, antes e em quatro ocasiões após tratamento com oxamniquine. Quando cotejados a grupo controle os pacientes esquistossomóticos revelaram altos níveis séricos de anticorpos IgG nos testes ELISA (anti-AWA e anti-SEA), não se observando, porém, negativação até seis meses após tratamento específico. Encontrou-se, entretanto, decréscimo significativo, sem negativação, dos níveis de IgG1, IgG3 e, principalmente, IgG4, quando se utilizou antígeno solúvel obtido a partir de ovos de S. mansoni (SEA), seis meses após administração de oxamniquine. O mesmo não foi observado no caso de anticorpos da subclasse IgG2. Nos imunoblottings efetuados com o emprego de antígeno de verme adulto (AWA), antes do tratamento com oxamniquine, evidenciou-se a presença de banda com 31 kDa em 14 (82%) dos 17 pacientes estudados, observando-se seu desaparecimento em três pacientes examinados seis meses após tratamento específico. Quando se utilizou antígeno obtido a partir de ovos de S. mansoni (SEA) a mesma banda foi evidenciada em nove pacientes, desaparecendo em quatro casos, após o tratamento

    Neural networks for a quick access to a digital twin of scanning physical properties measurements

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    For performing successful measurements within limited experimental time, efficient use of preliminary data plays a crucial role. This work shows that a simple feedforward type neural networks approach for learning preliminary experimental data can provide quick access to simulate the experiment within the learned range. The approach is especially beneficial for physical properties measurements with scanning on multiple axes, where derivative or integration of data are required to obtain the objective quantity. Due to its simplicity, the learning process is fast enough for the users to perform learning and simulation on-the-fly by using a combination of open-source optimization techniques and deep-learning libraries. Here such a tool for augmenting the experimental data is proposed, aiming to help researchers to decide the most suitable experimental conditions before performing costly experiments in real. Furthermore, this tool can also be used from the perspective of taking advantage of reutilizing and repurposing previously published data, accelerating data-driven exploration of functional materials.Comment: 19 pages, 5 figures + 7 pages of Supporting Informatio

    ABORTO RETENIDO CON FETOS TORACOPAGOS

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    Se presenta el caso de una paciente que consulta por síntomas de aborto, detectándose aborto retenido de 9 semanas con fetos toracopagos, que se confirma con el examen macroscópico luego de la evacuación uterin

    Analysis of Long-Lived Slepton NLSP in GMSB model at Linear Collider

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    We performed an analysis on the detection of a long-lived slepton at a linear collider with s=500\sqrt{s}=500 GeV. In GMSB models a long-lived NLSP is predicted for large value of the supersymmetry breaking scale F\sqrt{F}. Furthermore in a large portion of the parameter space this particle is a stau. Such heavy charged particles will leave a track in the tracking volume and hit the muonic detector. In order to disentangle this signal from the muon background, we explore kinematics and particle identification tools: time of flight device, dE/dX and Cerenkov devices. We show that a linear collider will be able to detect long-lived staus with masses up to the kinematical limit of the machine. We also present our estimation of the sensitivity to the stau lifetime.Comment: Minor changes, Ref. 10 fixed. 12 pages, RevTex, 4 eps figure

    The double-edged sword effect of warming on the soil predatory mite Cosmolaelaps brevistilis (Karg, 1978) (Mesostigmata: Laelapidae)

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    In this study we used the average annual temperature in Brazil and four warming predictions to propose a maximum thermal threshold for the predatory mite Cosmolaelaps brevistilis (Karg, 1978) (Mesostigmata: Laelapidae) as an experimental model. Then, we evaluated the effects of warming on the biological parameters of C. brevistilis for conservation biological control. We observed higher rates of oviposition and predation of the prey Tyrophagus putrescentiae (Schrank, 1781) (Astigmatina: Acaridae) under warmer conditions at 75 ± 10% RH. The highest rates of prey consumption and oviposition were observed at 28°C compared to the others tested (22, 24, and 26°C). However, the egg viability of C. brevistilis was reduced at the same temperature. Therefore, temperature increases both positive and negative effects on the biological parameters of C. brevistilis which are important for the ecological interactions that are essential for biological control programs

    Protection of rat renal vitamin E levels by ischemic-preconditioning

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    BACKGROUND: During renal transplantation, the kidney remains without blood flow for a period of time. The following reperfusion of this ischemic kidney causes functional and structural injury. Formation of oxygen-derived free radicals (OFR) and subsequent lipid peroxidation (LP) has been implicated as the causative factors of these injuries. Vitamin E is known to be the main endogenous antioxidant that stabilizes cell membranes by interfering with LP. The present study was designed to examine the role of ischemic-preconditioning (repeated brief periods of ischemia, IPC) in prevention of renal injury caused by ischemia-reperfusion (IR) in rats. METHODS: IPC included sequential clamping of the right renal artery for 5 min and release of the clamp for another 5 min for a 3 cycles. IR was induced by 30 min ischemia followed by 10 min reperfusion. Four groups of male rats were used: Control, IPC, IR and IPC-IR. Vitamin E, an endogenous antioxidant and as an index of LP, was measured by HPLC and UV detection in renal venous plasma and tissue. Renal function was assessed by serum creatinine and BUN levels. Renal damage was assessed in sections stained with Haematoxylin and Eosin. RESULTS: In the IR group, there was a significant decrease in vitamin E in plasma and tissue compared to a control group (p,0.05). In the IPC-IR group, vitamin E concentration was significantly higher than in the IR group (p,0.01). The results showed that 30 min ischemia in the IR group significantly (p,0.05) reduced renal function demonstrated by an increase in serum creatinine levels as compared with the control group. These results in the IPC group also showed a significant difference with the IR group but no significant difference in serum BUN and creatinine between IR and IPC-IR group were detected. Histological evaluation showed no structural damage in the IPC group and an improvement in the IPC-IR group compared to IR alone. CONCLUSIONS: In this study, IPC preserved vitamin E levels, but it could not markedly improve renal function in the early phase (1–2 h) of reperfusion. IPC may be a useful method for antioxidant preservation in organ transplantation

    The Role of MMP7 and Its Cross-Talk with the FAS/FASL System during the Acquisition of Chemoresistance to Oxaliplatin

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    Background: The efficacy of oxaliplatin in cancer chemotherapy is limited by the development of drug resistance. MMP7 has been related to the loss of tumor cell response to cytotoxic agents although the exact mechanism is not fully understood. Moreover, MMP7 is an independent prognosis factor for survival in patients with colorectal cancer. The aim of the present study was to analyze the role of MMP7 and its cross-talk with the Fas/FasL system during the acquisition of oxaliplatin resistance in colon cancer cells. Principal Findings: For this purpose we have developed three different oxaliplatin-resistant cell lines (RHT29, RHCT116 p53+/+, RHCT116 p53−/−) from the parental HT29, HCT116 p53+/+ and HCT116 p53−/− colon cancer cells. MMP7 basal expression was higher in the resistant compared to the parental cell lines. MMP7 was also upregulated by oxaliplatin in both HT29 (p53 mutant) and RHCT116 p53−/− but not in the RHCT116 p53+/+. Inhibition of MMP by 1,10-phenantroline monohydrate or siRNA of MMP7 restores cell sensitivity to oxaliplatin-induced apoptosis in both HT29 and RHCT116 p53−/− but not in the RHCT116 p53+/+. Some of these effects are caused by alterations in Fas receptor. Fas is upregulated by oxaliplatin in colon cancer cells, however the RHT29 cells treated with oxaliplatin showed a 3.8-fold lower Fas expression at the cell surface than the HT29 cells. Decrease of Fas at the plasma membrane seems to be caused by MMP7 since its inhibition restores Fas levels. Moreover, functional analysis of Fas demonstrates that this receptor was less potent in inducing apoptosis in RHT29 cells and that its activation induces MAPK signaling in resistant cells. Conclusions: Taking together, these results suggest that MMP7 is related to the acquisition of oxaliplatin-resistance and that its inhibition restores drug sensitivity by increasing Fas receptor. Furthermore, Fas undergoes a change in its functionality in oxaliplatin-resistant cells inducing survival pathways instead of apoptotic signals
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