T-cell senescence: A crucial player in autoimmune diseases.

Senescent T cells are proliferative disabled lymphocytes that lack antigen-specific responses. The development of T-cell senescence in autoimmune diseases contributes to immunological disorders and disease progression. Senescent T cells lack costimulatory markers with the reduction of T cell receptor repertoire and the uptake of natural killer cell receptors. Senescent T cells exert cytotoxic effects through the expression of perforin, granzymes, tumor necrosis factor, and other molecules without the antigen-presenting process. DNA damage accumulation, telomere damage, and limited DNA repair capacity are important features of senescent T cells. Impaired mitochondrial function and accumulation of reactive oxygen species contribute to T cell senescence. Alleviation of T-cell senescence could provide potential targets for the treatment of autoimmune diseases.

Development of diagnostic criteria and a prognostic score for hepatitis B virus-related acute-on-chronic liver failure.

OBJECTIVE: The definition of acute-on-chronic liver failure (ACLF) based on cirrhosis, irrespective of aetiology, remains controversial. This study aimed to clarify the clinicopathological characteristics of patients with hepatitis B virus-related ACLF (HBV-ACLF) in a prospective study and develop new diagnostic criteria and a prognostic score for such patients. DESIGN: The clinical data from 1322 hospitalised patients with acute decompensation of cirrhosis or severe liver injury due to chronic hepatitis B (CHB) at 13 liver centres in China were used to develop new diagnostic and prognostic criteria. RESULTS: Of the patients assessed using the Chronic Liver Failure Consortium criteria with the exception of cirrhosis, 391 patients with ACLF were identified: 92 with non-cirrhotic HBV-ACLF, 271 with cirrhotic HBV-ACLF and 28 with ACLF with cirrhosis caused by non-HBV aetiologies (non-HBV-ACLF). The short-term (28/90 days) mortality of the patients with HBV-ACLF were significantly higher than those of the patients with non-HBV-ACLF. Total bilirubin (TB) ≥12 mg/dL and an international normalised ratio (INR) ≥1.5 was proposed as an additional diagnostic indicator of HBV-ACLF, and 19.3% of patients with an HBV aetiology were additionally diagnosed with ACLF. The new prognostic score (0.741×INR+0.523×HBV-SOFA+0.026×age+0.003×TB) for short-term mortality was superior to five other scores based on both discovery and external validation studies. CONCLUSIONS: Regardless of the presence of cirrhosis, patients with CHB, TB ≥12 mg/dL and INR ≥1.5 should be diagnosed with ACLF. The new criteria diagnosed nearly 20% more patients with an HBV aetiology with ACLF, thus increasing their opportunity to receive timely intensive management.

MOF-Derived Porous Co/C Nanocomposites with Excellent Electromagnetic Wave Absorption Properties.

Composites incorporating ferromagnetic metal nanopartices into a highly porous carbon matrix are promising as electromagnetic wave absorption materials. Such special composite nanomaterials are potentially prepared by the thermal decomposition of metal-organic framework (MOF) materials under controlled atmospheres. In this study, using Co-based MOFs (Co-MOF, ZIF-67) as an example, the feasibility of this synthetic strategy was demonstrated by the successful fabrication of porous Co/C composite nanomaterials. The atmosphere and temperature for the thermal decomposition of MOF precursors were crucial factors for the formation of the ferromagnetic metal nanopartices and carbon matrix in the porous Co/C composites. Among the three Co/C composites obtained at different temperatures, Co/C-500 obtained at 500 °C exhibited the best performance for electromagnetic wave absorption. In particular, the maximum reflection loss (RL) of Co/C-500 reached -35.3 dB, and the effective absorption bandwidth (RL ≤ -10 dB) was 5.80 GHz (8.40 GHz-14.20 GHz) corresponding to an absorber thickness of 2.5 mm. Such excellent electromagnetic wave absorption properties are ascribed to the synergetic effects between the highly porous structure and multiple components, which significantly improved impedance matching.

MOF-templated synthesis of porous Co(3)O(4) concave nanocubes with high specific surface area and their gas sensing properties.

Porous metal oxides nanomaterials with controlled morphology have received great attention because of their promising applications in catalysis, energy storage and conversion, gas sensing, etc. In this paper, porous Co3O4 concave nanocubes with extremely high specific surface area (120.9 m(2)·g(-1)) were synthesized simply by calcining Co-based metal-organic framework (Co-MOF, ZIF-67) templates at the optimized temperature (300 °C), and the formation mechanism of such highly porous structures as well as the influence of the calcination temperature are well explained by taking into account thermal behavior and intrinsic structural features of the Co-MOF precursors. The gas-sensing properties of the as-synthesized porous Co3O4 concave nanocubes were systematically tested towards volatile organic compounds including ethanol, acetone, toluene, and benzene. Experimental results reveal that the porous Co3O4 concave nanocubes present the highest sensitivity to ethanol with fast response/recovery time (< 10 s) and a low detection limit (at least 10 ppm). Such outstanding gas sensing performance of the porous Co3O4 concave nanocubes benefits from their high porosity, large specific surface area, and remarkable capabilities of surface-adsorbed oxygen.