Tensile Behaviors and Strain Hardening Mechanisms in a High-Mn Steel with Heterogeneous Microstructure.

Heterogeneous structures with both heterogeneous grain structure and dual phases have been designed and obtained in a high-Mn microband-induced plasticity (MBIP) steel. The heterogeneous structures show better synergy of strength and ductility as compared to the homogeneous structures. Higher contribution of hetero-deformation induced hardening to the overall strain hardening was observed and higher density of geometrically necessary dislocations were found to be induced at various domain boundaries in the heterogeneous structures, resulting in higher extra strain hardening for the observed better tensile properties as compared to the homogeneous structures. MBIP effect is found to be still effective in the coarse austenite grains of heterogeneous structures, while the typical Taylor lattice structure and the formation of microband are not observed in the ultra-fine austenite grains of heterogeneous structures, indicating that decreasing grain size might inhibit the occurrence of microbands. High density of dislocation is also observed in the interiors of BCC grains, indicating that both phases are deformable and can accommodate plastic deformation. It is interesting to note that the deformation mechanisms are highly dependent on the phase and grain size for the present MBIP steel with heterogeneous structures.

Effects of Berberine on Atherosclerosis.

Atherosclerosis is an epidemic across the globe[A1], and its morbidity and mortality remain high, involving various complications and poor prognoses. In atherosclerosis, endothelial cells (ECs) dysfunction, vascular smooth muscle cells (VSMCs) migration and proliferation, foam cell formation, and inflammatory cell recruitment contribute to disease progression. Vascular stem cells (VSCs) also play a critical role in the cardiovascular system. Important data showed that the simultaneous increase of proliferation and apoptosis of VSMCs is the main cause of graft vein stenosis, suggesting that inhibition of VSMCs proliferation and apoptosis simultaneously is an important strategy for the treatment of atherosclerotic stenosis. Complementary and alternative medicine use among patients with cardiovascular disease (CVD) is growing. Berberine is an extract of Chinese traditional herbs that is known for its antimicrobial and anti-inflammatory effects in the digestive system. Its underlying anti-CVD mechanisms are currently attracting interest, and its pharmacological actions, such as antioxidation, regulation of neurotransmitters and enzymes, and cholesterol-lowering effects, have been substantiated. Recent studying found that berberine could inhibit both the proliferation and apoptosis of VSMCs induced by mechanical stretch stress simultaneously, which suggests that berberine might be an excellent drug to treat atherosclerosis. This review will focus on the recent progress of the effect of berberine on vascular cells, especially VSMCs, to provide important data and a new perspective for the application of berberine in anti-atherosclerosis.

Axially chiral 1,4-dihydropyridine derivatives: aggregation-induced emission in exciplexes and application as viscosity probes.

By combining the fluorophores of axially chiral 1,1'-binaphthol (BINOL) and 1,4-dihydropyridine derivatives, axially chiral 1,4-dihydropyridine derivatives ((R)-/(S)-2) with aggregation-induced emission (AIE) in exciplexes were designed and synthesized. (R)-/(S)-2 emitted low fluorescence in THF solutions of their locally excited states; however, they emitted red-shifted fluorescence in the aggregate state upon exciplex formation. Moreover, (R)-/(S)-2 showed linear and multi-exponential relationships between their local excited and exciplex fluorescence intensities and the viscosity of the medium, which allowed us to determine the viscosities of different mixed solvents. In addition, as an axially chiral viscosity probe, (R)-/(S)-2 show excellent CD signals and have potential applications in the fields of chiral recognition and fluorescence imaging, which will broaden the new family of AIE fluorophores. To the best of our knowledge, there are few reports of axially chiral intramolecular exciplex-mediated AIE molecules.

Mortality and associated factors of patients with extensive drug-resistant tuberculosis: an emerging public health crisis in China.

BACKGROUND: Limited treatment options of extensive drug-resistant tuberculosis (XDR-TB) have led to its high mortality worldwide. Relevant data about mortality of XDR-TB patients in literature are limited and likely underestimate the real situation in China, since the majority of patients with XDR-TB are lost to follow-up after discharge from TB hospitals. In this study, we sought to investigate the mortality and associated risk factors of Human Immunodeficiency Virus (HIV)-negative patients with XDR-TB in China. METHODS: All patients who were diagnosed with XDR-TB for the first time in four TB care centers across China between March 2013 and February 2015 were consecutively enrolled. Active tracking through contacting patients or family members by phone or home visit was conducted to obtain patients' survival information by February 2017. Multivariable Cox regression models were used to evaluate factors associated with mortality. RESULTS: Among 67 patients enrolled, the mean age was 48.7 (Standard Deviation [SD] = 16.7) years, and 51 (76%) were men. Fourteen patients (21%) were treatment naïve at diagnosis indicating primary transmission. 58 (86.8%) patients remained positive for sputum smear or culture when discharged. During a median follow-up period of 32 months, 20 deaths occurred, with an overall mortality of 128 per 1000 person-years. Among patients who were dead, the median survival was 5.4 months (interquartile range [IQR]: 2.2-17.8). Seventeen (85%) of them died at home, among whom the median interval from discharge to death was 8.4 months (IQR: 2.0-18.2). In Cox proportional hazards regression models, body mass index (BMI) < 18.5 kg/m2 (adjusted hazard ratio [aHR] = 4.5, 95% confidence interval [CI]: 1.3-15.7), smoking (aHR = 4.7, 95%CI:1.7-13.2), or a clinically significant comorbidity including heart, lung, liver, or renal disorders or auto-immune diseases (aHR = 3.5, 95%CI: 1.3-9.4), were factors independently associated with increased mortality. CONCLUSION: Our study suggested an alarming situation of XDR-TB patients in China with a sizable proportion of newly transmitted cases, a high mortality rate, and a long period in community. This observation calls for urgent actions to improve XDR-TB case management in China, including providing regimens with high chances of cure and palliative care, and enhanced infection control measures.

Genetic characterization of novel fowl aviadenovirus 4 isolates from outbreaks of hepatitis-hydropericardium syndrome in broiler chickens in China.

Since May 2015, severe outbreaks of hepatitis-hydropericardium syndrome (HHS) associated with infections of fowl aviadenovirus (FAdV) have emerged in broiler chickens in several Chinese provinces. To identify the genotype and gain a better understanding of the genetic properties of the FAdV strains responsible for the recent HHS outbreaks in China, the complete genome sequences of five isolates from outbreaks of HHS in broiler chickens in five provinces were determined. The results demonstrated that a novel fowl aviadenovirus 4 (FAdV-4) genotype was epidemic in China. To investigate the molecular characteristics of these Chinese FAdV-4 isolates, their genome contents were compared with those of reported pathogenic and non-pathogenic FAdV-4 strains. The comparative analysis revealed that the novel Chinese FAdV-4 isolates contain various genomic deletions and multiple distinct amino-acid mutations in their major structural genes. Two additional putative genetic virulence markers in the fiber 2 gene were identified. These findings confirmed some of the genetic differences between the pathogenic and non-pathogenic FAdV-4 isolates. The data presented in this report will enhance the current understanding of the molecular epidemiology and genetic diversity of FAdV-4 isolates in China and will provide additional insight into the critical factors that determine the pathogenicity of FAdV-4 strains. Finally, the emergence of this novel and highly pathogenic FAdV-4 genotype emphasizes that preventive measures against FAdV-4 infections on poultry farms should be implemented in China.

Impaired NK cells' activity and increased numbers of CD4 + CD25+ regulatory T cells in multidrug-resistant Mycobacterium tuberculosis patients.

Multidrug-resistant tuberculosis (MDR-TB) often causes persistent infection and chemotherapy failure, which brings heavy burden of society and family. Many immune cell subsets and regulatory mechanisms may operate throughout the various stages of infection. The presence of regulatory T cells (Tregs) is thought to be an important mechanism that TB successfully evades the immune system. Tregs play a central role in the prevention of autoimmunity and in the control of immune responses. The role of Tregs in MDR-TB infection and persistence is inadequately documented. The current study was designed to determine whether CD4 + CD25+ regulatory T cells may modulate innate immunity (such as NK cells) against human tuberculosis. Our results indicated that the numbers of CD4 + CD25+ Treg cells increased in MDR-TB patients' blood, and the cytokine production of IL-10 increased from MDR-patients compared with healthy subjects, along with the lower activity and low CD69 expression of NK cells in patients. These results suggested that immunity to MDR-TB patients induced circulating CD4 + CD25+ T regulatory cells expansion, which may be related to the persistence of Mycobacterium tuberculosis (M. tb) infection, and to the balance between effectors immune responses and suppression immune responses.