1,116 research outputs found
Role of Nanolaminated Crystal Structure on the Radiation Damage Tolerance of Ti 3
Nanolaminated Ti3SiC2, a representative MAX phase,
shows excellent tolerance to radiation damage. In this paper, first-principles
calculations were used to investigate the mechanism of intrinsic point defects
in order to explain this outstanding property. Formation energies of intrinsic point
defects are calculated and compared; and the results establish a low-energy disorder
mechanism in Ti3SiC2. In addition, the migration energy
barriers of Si vacancy, Si interstitial, and TiSi antisite yield very low values: 0.9, 0.6, and 0.3 eV, respectively.
The intercalation of Si atomic plane between Ti3C2 nanotwinning
structures dominates the formation and migration of intrinsic native point defects
in Ti3SiC2. The present study also highlights a novel method
to improve radiation damage tolerance by developing nanoscale-layered structure which
can serve as a sink or rapid recovery channel for point defects
Building cloud-based healthcare data mining services
The linkage between healthcare service and cloud computing techniques has drawn much attention lately. Up to the present, most works focus on IT system migration and the management of distributed healthcare data rather than taking advantage of information hidden in the data. In this paper, we propose to explore healthcare data via cloud-based healthcare data mining services. Specifically, we propose a cloud-based healthcare data mining framework for healthcare data mining service development. Under such framework, we further develop a cloud-based healthcare data mining service to predict patients future length of stay in hospital
Tumor-Specific Human CD4+ Regulatory T Cells and Their Ligands Implications for Immunotherapy
AbstractRegulatory T cells play an important role in the maintenance of immunological self-tolerance by suppressing immune responses against autoimmune diseases and cancer. Little is known, however, about the nature of the physiological target antigens for CD4+ regulatory T (Treg) cells. Here we report the identification of the LAGE1 protein as a ligand for tumor-specific CD4+ Treg cell clones generated from the tumor-infiltrating lymphocytes (TILs) of cancer patients. Phenotypic and functional analyses demonstrated that they were antigen-specific CD4+ Treg cells expressing CD25 and GITR molecules and possessing suppressive activity on the proliferative response of naive CD4+ T cells to anti-CD3 antibody stimulation. Ligand-specific activation and cell-cell contact were required for TIL102 Treg cells to exert suppressive activity on CD4+ effector cells. These findings suggest that the presence of tumor-specific CD4+ Treg cells at tumor sites may have a profound effect on the inhibition of T cell responses against cancer
Increased co-expression of TIM-3 with TIGIT or 2B4 on CD8+ T cells is associated with poor prognosis in locally advanced nasopharyngeal carcinoma
The use of immune checkpoint inhibitors in malignant tumors improves patient outcomes. Because single-agent immune checkpoint blockade has a low objective response rate, it is meaningful to explore combined blockade of immune checkpoint receptors. We aimed to investigate the co-expression of TIM-3 with TIGIT or 2B4 on peripheral blood CD8+ T cells from patients with locally advanced nasopharyngeal carcinoma. The correlation between co-expression level and clinical characteristics and prognosis was studied to provide a basis for immunotherapy for nasopharyngeal carcinoma. Flow cytometry was used to detect TIM-3/TIGIT and TIM-3/2B4 co-expression on CD8+ T cells. The differences in co-expression between patients and healthy controls were analyzed. The correlation between co-expression of TIM-3/TIGIT or TIM-3/2B4 and the patient clinical characteristics and prognosis was examined. Also, the correlation between the TIM-3/TIGIT or 2B4 co-expression and other common inhibitory receptors was analyzed. We further validated our results using mRNA data from the Gene Expression Omnibus (GEO) database. TIM-3/TIGIT and TIM-3/2B4 co-expression was upregulated on peripheral blood CD8+ T cells from patients with nasopharyngeal carcinoma. They were both correlated with poor prognosis. There was a correlation between TIM-3/TIGIT co-expression and patient age and pathological stage, whereas TIM-3/2B4 co-expression correlated with age and sex. CD8+ T cells with elevated mRNA levels of TIM3/TIGIT and TIM3/2B4 also showed increased expression of multiple inhibitory receptors, indicating T cell exhaustion in locally advanced nasopharyngeal carcinoma. TIM-3/TIGIT or TIM-3/2B4 can be used as potential targets for combination immunotherapy in locally advanced nasopharyngeal carcinoma
The occurrence of early atrial fibrillation after cardiac valve operation and the establishment of a nomogram model
BackgroundPostoperative atrial fibrillation (POAF) is a common complication after cardiac surgery, which is associated with age and massive bleeding. However, whether thyroid hormone (TH) level can affect POAF remains controversial.AimTo investigate the occurrence and risk factors of POAF, in particular, the preoperative TH level of patients was introduced into this study as a variable for analysis, and a column graph prediction model of POAF was constructed.MethodsPatients who underwent valve surgery in Fujian Cardiac Medical Center from January 2019 to May 2022 were retrospectively analyzed and divided into POAF group and NO-POAF group. Baseline characteristics and relevant clinical data were collected from the two groups of patients. Independent risk factors for POAF were screened using univariate analysis and binary logistic regression analysis, and a column line graph prediction model was established based on the regression analysis results, and the diagnostic efficacy and calibration of the model were evaluated using the Receiver Operating Characteristic Curve (ROC) and calibration curve.ResultsA total of 2,340 patients underwent valve surgery, excluding 1,751 patients, a total of 589 patients were included, including 89 patients in POAF group and 500 patients in NO-POAF group. The total incidence of POAF was 15.1%. The results of the Logistics regression analysis showed that gender, age, leukocytes and TSH were risk factors of POAF. The area under the ROC curve of the nomogram prediction model for POAF was 0.747 (95% CI: 0.688–0.806, P < 0.001), with a sensitivity of 74.2% and specificity of 68%. Hosmer-Lemeshow test showed χ2 = 11.141, P = 0.194 > 0.05, the calibration curve was well fitted.ConclusionThe results of this study show that gender, age, leukocyte and TSH are risk factors of POAF, and the nomogram prediction model has a good prediction effect. Due to the limited sample size and included population, more studies are needed to validate this result
Phenothiazinen-Dimesitylarylborane-Based Thermally Activated Delayed Fluorescence: High-Performance Non-doped OLEDs With Reduced Efficiency Roll-Off at High Luminescence
We report a phenothiazinen-dimesitylarylborane thermally activated delayed fluorescence (TADF) molecule that exhibits high external quantum efficiency (EQE) in non-doped organic light-emitting diodes (OLEDs) at high luminescence. The non-doped device shows green electroluminescence with an emission peak of 540 nm and a maximum EQE of 19.66% obtained at a luminescence of ~170 cd m−2. The EQE is still as high as 17.31% at a high luminescence of 1,500 cd m−2 with small efficiency roll-off
SARS-CoV-2 mutations affect antigen processing by the proteasome to alter CD8+ T cell responses
Mutations within viral epitopes can result in escape from T cells, but the contribution of mutations in flanking regions of epitopes in SARS-CoV-2 has not been investigated. Focusing on two SARS-CoV-2 nucleoprotein CD8+ epitopes, we investigated the contribution of these flanking mutations to proteasomal processing and T cell activation. We found decreased NP9-17-B*27:05 CD8+ T cell responses to the NP-Q7K mutation, likely due to a lack of efficient epitope production by the proteasome, suggesting immune escape caused by this mutation. In contrast, NP-P6L and NP-D103 N/Y mutations flanking the NP9-17-B*27:05 and NP105-113-B*07:02 epitopes, respectively, increased CD8+ T cell responses associated with enhanced epitope production by the proteasome. Our results provide evidence that SARS-CoV-2 mutations outside the epitope could have a significant impact on proteasomal processing, either contributing to T cell escape or enhancement that may be exploited for future vaccine design
Determination of reference intervals of serum levels of human epididymis protein 4 (HE4) in Chinese women
The detailed numbers of subjects from different centers. (DOCX 17.3 kb
Early Virological and Immunological Events in Asymptomatic Epstein-Barr Virus Infection in African Children
Epstein-Barr virus (EBV) infection often occurs in early childhood and is asymptomatic. However, if delayed until adolescence, primary infection may manifest as acute infectious mononucleosis (AIM), a febrile illness characterised by global CD8+ T-cell lymphocytosis, much of it reflecting a huge expansion of activated EBV-specific CD8+ T-cells. While the events of AIM have been intensely studied, little is known about how these relate to asymptomatic primary infection. Here Gambian children (14–18 months old, an age at which many acquire the virus) were followed for the ensuing six months, monitoring circulating EBV loads, antibody status against virus capsid antigen (VCA) and both total and virus-specific CD8+ T-cell numbers. Many children were IgG anti-VCA-positive and, though no longer IgM-positive, still retained high virus loads comparable to AIM patients and had detectable EBV-specific T-cells, some still expressing activation markers. Virus loads and the frequency/activation status of specific T-cells decreased over time, consistent with resolution of a relatively recent primary infection. Six children with similarly high EBV loads were IgM anti-VCA-positive, indicating very recent infection. In three of these donors with HLA types allowing MHC-tetramer analysis, highly activated EBV-specific T-cells were detectable in the blood with one individual epitope response reaching 15% of all CD8+ T-cells. That response was culled and the cells lost activation markers over time, just as seen in AIM. However, unlike AIM, these events occurred without marked expansion of total CD8+ numbers. Thus asymptomatic EBV infection in children elicits a virus-specific CD8+ T-cell response that can control the infection without over-expansion; conversely, in AIM it appears the CD8 over-expansion, rather than virus load per se, is the cause of disease symptoms
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