Directional massless Dirac fermions in a layered van der Waals material with one-dimensional long-range order.

One or a few layers of van der Waals (vdW) materials are promising for applications in nanoscale electronics. Established properties include high mobility in graphene, a large direct gap in monolayer MoS2, the quantum spin Hall effect in monolayer WTe2 and so on. These exciting properties arise from electron quantum confinement in the two-dimensional limit. Here, we use angle-resolved photoemission spectroscopy to reveal directional massless Dirac fermions due to one-dimensional confinement of carriers in the layered vdW material NbSi0.45Te2. The one-dimensional directional massless Dirac fermions are protected by non-symmorphic symmetry, and emerge from a stripe-like structural modulation with long-range translational symmetry only along the stripe direction as we show using scanning tunnelling microscopy. Our work not only provides a playground for investigating further the properties of directional massless Dirac fermions, but also introduces a unique component with one-dimensional long-range order for engineering nano-electronic devices based on heterostructures of vdW materials.

Genetic variants in adiponectin and blood pressure responses to dietary sodium or potassium interventions: a family-based association study.

Previous studies have shown that genetic factors might have an important role in blood pressure (BP) responses to dietary salt or potassium intake. The aim of this study was to assess the association of common genetic variants of the adiponectin gene with BP responses to controlled dietary sodium or potassium interventions. Subjects (n=334) from 124 families in rural areas of Northern China were recruited. After a 3-day baseline observation, participants sequentially maintained a 7-day low-sodium diet (NaCl, 3 g per day; or sodium, 51.3 mmol per day), followed by a 7-day high-sodium diet (NaCl, 18 g per day; or sodium, 307.8 mmol per day) and a 7-day high-sodium plus potassium supplementation intervention (KCl, 4.5 g per day; or potassium, 60 mmol per day). A total of seven single nucleotide polymorphisms (SNPs) in the adiponectin gene were selected as the study sites. After adjustment for multiple testing, the adiponectin SNP rs16861205 was significantly associated with the diastolic BP (DBP) response to low-salt intervention, and the DBP and mean arterial pressure (MAP) responses to high-salt intervention (P=0.028, 0.023 and 0.027, respectively). SNP rs822394 was associated with the DBP and MAP responses to low-salt intervention and the DBP response to high-salt intervention (P=0.023, 0.030 and 0.033 respectively). Meanwhile, significant association also existed between SNP rs16861194 and the systolic BP response to potassium supplementation intervention (P=0.026). In addition, SNP rs822394 was significantly associated with basal DBP after adjustment for multiple testing (P=0.033). Our study indicated that the genetic polymorphisms in the adiponectin gene are significantly associated with BP responses to dietary sodium and potassium intake.

Monitoring of extracellular pyruvate, lactate, and ascorbic acid during cerebral ischemia: a microdialysis study in awake gerbils.

In vivo microdialysis coupled with liquid chromatography was developed for the continuous monitoring of brain neurochemicals during cerebral ischemia in awake, free moving gerbils. The dead volume of the microdialysis system was estimated to be less than 30 microl. The detection limits of the present assay were 0.2 to 2.0 microM for analytes at a signal to noise ratio of five. To validate this assay, a focal cerebral ischemia was produced by occlusion of one common carotid artery for 60 min and then reperfusion for additional 3 h in awake gerbils. A microdialysis probe was inserted into the striatum of the gerbil. Dialysates were autoinjected and analyzed extracellular pyruvate, lactate, and ascorbic acid by liquid chromatography with a UV detector during cerebral ischemia. Significant changes of pyruvate and the lactate/pyruvate ratio were observed. Biphasic and dynamic changes in ascorbic acid and lactate were proposed to correlate a secondary damage. This assay can be used as a tool to study dynamic changes of brain neurochemicals in awake animals.

An evaluation on smoking-induced health costs in China (1988-1989).

A study on smoking-attributable health economic costs in China was conducted from 1988-1992, in which three major categories of chronic diseases, diseases of cancer, diseases of circulatory system, and diseases of respiratory system were included. A prevalence-based method which estimated the cumulative effect of cigarette smoking during the past 20-30 years was used. The results show that in 1989, the total smoking-attributable economic costs to health sectors in China were about 27.1 billion of Chinese Yuan, including about 7 billion Yuan in direct medical costs and 20 billion Yuan in indirect costs, which include indirect morbidity costs and indirect mortality costs. The relatively low direct costs reflected the low medical costs at hospitals in China at that time. And the high proportion of indirect costs relative to the total costs shows the high potential years of life lost due to cigarette smoking. The results also show the heavier health burden in urban areas than in rural areas, reflecting the worse situation in urban China at nowadays. But if considering that almost 80% of the Chinese are rural farmers with the higher smoking prevalence and relatively shorter history of manufactured cigarette smoking than their urban counterparts, the very frightful situation due to cigarette smoking would be for China in the next century.

Isolation of a strain of Hantaan virus from peritoneal exudate cells of a patient with hemorrhagic fever with renal syndrome.

A new strain of Hantaan virus (HTNV), GH716, was isolated from the peritoneal exudate cells (PEC) of a patient with severe hemorrhagic fever with renal syndrome (HFRS). The isolate was propagated in Vero E6 cells. At each passage the virus-infected cells were examined for HTNV with immunofluorescence technique using monoclonal antibodies (McAb) 25-1 and 84-1 against HTNV. From passage 5 on, fluorescent intensity tended to stabilize at (+++) and infectivity titer reached 10(5) TCID50/ml. Using 14 McAb to 76-118 and BI strains of HTNV, we found that strain GH716 was antigenically similar to strain 76-118 (Apodemus type) and different from strain R22 (Rattus type), suggesting that GH716 may fall into the Apodemus type of HTNV. This is the first isolation of an HTNV from human PEC collected on the tenth day of illness. The successful isolation of strain GH716 may provide an alternative source of obtaining HTNV during the later stages of HFRS.