One of the main bottleneck issues for room-temperature antiferromagnetic spintronic devices is the small signal read-out owing to the limited anisotropic magnetoresistance in antiferromagnets. ...However, this could be overcome by either utilizing the Berry-curvature-induced anomalous Hall resistance in noncollinear antiferromagnets or establishing tunnel junction devices based on effective manipulation of antiferromagnetic spins. In this work, we demonstrate the giant piezoelectric strain control of the spin structure and the anomalous Hall resistance in a noncollinear antiferromagnetic metal - D019 hexagonal Mn3Ga. Furthermore, we built tunnel junction devices with a diameter of 200 nm to amplify the maximum tunneling resistance ratio to more than 10% at room-temperature, which thus implies significant potential of noncollinear antiferromagnets for large signal-output and high-density antiferromagnetic spintronic device applications.
Non-collinear antiferromagnetic materials have received dramatically increasing attention in the field of spintronics as their exotic topological features such as the Berry-curvature-induced ...anomalous Hall effect and possible magnetic Weyl states could be utilized in future topological antiferromagnetic spintronic devices. In this work, we report the successful integration of the antiferromagnetic metal Mn3Sn thin films onto ferroelectric oxide PMN-PT. By optimizing growth, we realized the large anomalous Hall effect with small switching magnetic fields of several tens mT fully comparable to those of bulk Mn3Sn single crystals, anisotropic magnetoresistance and negative parallel magnetoresistance in Mn3Sn thin films with antiferromagnetic order, which are similar to the signatures of the Weyl state in bulk Mn3Sn single crystals. More importantly, we found that the anomalous Hall effect in antiferromagnetic Mn3Sn thin films can be manipulated by electric fields applied onto the ferroelectric materials, thus demonstrating the feasibility of Mn3Sn-based topological spintronic devices operated in an ultralow power manner.
Hepatitis C virus (HCV) induces a high rate of chronic infection via dysregulation of host immunity. We have previously shown that T-cell immunoglobulin and mucin domain protein-3 (Tim-3) is ...up-regulated on monocyte/macrophages (M/Mφ) during chronic HCV infection; little is known, however, about the transcription factor that controls its expression in these cells. In this study, we investigated the role of transcription factor, T-box expressed in T cells (T-bet), in Tim-3 expression in M/Mφ in the setting of HCV infection. We demonstrate that T-bet is constitutively expressed in resting CD14+ M/Mφ in the peripheral blood. M/Mφ from chronically HCV-infected individuals exhibit a significant increase in T-bet expression that positively correlates with an increased level of Tim-3 expression. Up-regulation of T-bet is also observed in CD14+ M/Mφ incubated with HCV+ Huh7.5 cells, as well as in primary M/Mφ or monocytic THP-1 cells exposed to HCV core protein in vitro, which is reversible by blocking HCV core/gC1qR interactions. Moreover, the HCV core-induced up-regulation of T-bet and Tim-3 expression in M/Mφ can be abrogated by incubating the cells with SP600125 – an inhibitor for the c-Jun N-terminal kinase (JNK) signalling pathway. Importantly, silencing T-bet gene expression decreases Tim-3 expression and enhances interleukin-12 secretion as well as signal transducer and activator of transcription 1 phosphorylation. These data suggest that T-bet, induced by the HCV core/gC1qR interaction, enhances Tim-3 expression via the JNK pathway, leading to dampened M/Mφ function during HCV infection. These findings reveal a novel mechanism for Tim-3 regulation via T-bet during HCV infection, providing new targets to combat this global epidemic viral disease.
The traditional corneal cryopreservation technique was improved. We carried out an experimental study that rabbit corneas were cryopreserved by using polyvinylpyrolidone (PVP) as cryoprotective agent ...and dimethylsulfoxide (DMSO) as the control. The endothelia of cryopreserved corneas were evaluated by scanning and transmission electron microscopy and vital staining. The study shows that PVP is an excellent extracellular cryoprotective agent and has the characteristic of low toxicity or not toxicity to corneal endothelia. PVP is able to enhance the cryoprotective action of DMSO when combined with DMSO. The changes of the ultrastructure of endothelial cells are able to reflect the endothelial viability.
T cells have a crucial role in viral clearance and vaccine response; however, the mechanisms regulating their responses to viral infections or vaccinations remain elusive. In this study, we ...investigated T-cell homeostasis, apoptosis, DNA damage, and repair machineries in a large cohort of subjects with hepatitis C virus (HCV) infection. We found that naive CD4 T cells in chronically HCV-infected individuals (HCV T cells) were significantly reduced compared with age-matched healthy subjects. In addition, HCV T cells were prone to apoptosis and DNA damage, as evidenced by increased 8-oxoguanine expression and γH2AX/53BP1-formed DNA damage foci—hallmarks of DNA damage responses. Mechanistically, the activation of DNA repair enzyme ataxia telangiectasia mutated (ATM) was dampened in HCV T cells. ATM activation was also diminished in healthy T cells exposed to ATM inhibitor or to HCV (core protein) that inhibits the phosphoinositide 3 kinase pathway, mimicking the biological effects in HCV T cells. Importantly, ectopic expression of ATM was sufficient to repair the DNA damage, survival deficit, and cell dysfunctions in HCV T cells. Our results demonstrate that insufficient DNA repair enzyme ATM leads to increased DNA damage and renders HCV T cells prone to apoptotic death, which contribute to the loss of naive T cells in HCV infection. Our study reveals a novel mechanism for T-cell dysregulation and viral persistence, providing a new strategy to improve immunotherapy and vaccine responses against human viral diseases.
TS201.4; 单宁类化合物是覆盆子的主要活性成分,具有降血糖、降血脂、抗炎、延缓衰老及预防心脑血管疾病等功能.本实验从覆盆子中提取富集单宁,通过体外模拟消化模型探究覆盆子单宁富集组分消化前后单宁含量及抗氧化活性、α-葡萄糖苷酶抑制活性变化,通过体外厌氧发酵模型分析模拟消化对其肠道菌群调节作用的影响,最后采用超高效液相色谱-四极杆飞行时间串联质谱法(ultra-high performance ...liquid chromatography-quadrupole time of flight-tandem mass spectrometry,UPLC-ESI-QTOF-MS/MS)比较体外消化和酵解产物中单宁组成及其代谢产物含量变化情况.结果表明,在胃、肠消化过程中水解单宁含量均呈先增加后降低趋势,胃肠消化提升了覆盆子单宁富集组分的1,1-二苯基-2-三硝基苯肼自由基清除能力(半抑制质量浓度为29.15～39.65 ug/mL),但对2,2'-联氮基-双(3-乙基苯并噻唑啉-6-磺酸)阳离子自由基清除能力无显著性影响(P＞0.05),经肠道模拟消化后,样品的a-葡萄糖苷酶抑制能力提升了7.16～7.86倍.体外结肠发酵实验结果表明,覆盆子单宁显著增加了粪球菌属(Coprococcus)、丁酸弧菌(Anaerostipes)、瘤胃球菌属(Ruminococcus)、粪便杆菌属(Faecalibaterium)等有益菌的相对丰度,胃肠模拟消化降低其对双歧杆菌等有益菌的改善效果.UPLC-ESI-QTOF-MS/MS分析结果表明,胃、肠消化过程中,单宁代谢物含量均呈现先下降后上升的趋势,结肠发酵后样品中的尿石素A和尿石素B含量明显下降,而尿石素C和尿石素D未检测到.本研究可为覆盆子单宁稳态递送体系的构建,提高其体内的生物利用率提供理论依据.
