3,310 research outputs found

    On the local aspect of valleytronics

    Full text link
    Valley magnetic moments play a crucial role in valleytronics in 2D hexagonal materials. Traditionally, based on studies of quantum states in homogeneous bulks, it is widely believed that only materials with broken structural inversion symmetry can exhibit nonvanishing valley magnetic moments. Such constraint excludes from relevant applications those with inversion symmetry, as specifically exemplified by gapless monolayer graphene despite its technological advantage in routine growth and production. This work revisits valley-derived magnetic moments in a broad context covering inhomogeneous structures as well. It generalizes the notion of valley magnetic moment for a state from an integrated total quantity to the local field called "local valley magnetic moment" with space-varying distribution. In suitable inversion-symmetric structures with inhomogeneity, e.g., zigzag nanoribbons of gapless monolayer graphene, it is shown that the local moment of a state can be nonvanishing with sizable magnitude, while the corresponding total moment is subject to the broken symmetry constraint. Moreover, it is demonstrated that such local moment can interact with space-dependent electric and magnetic fields manifesting pronounced field effects and making possible a local valley control with external fields. Overall, a path to "local valleytronics" is illustrated which exploits local valley magnetic moments for device applications, relaxes the broken symmetry constraint on materials, and expands flexibility in the implementation of valleytronics

    Prevalence of Kaposi’s sarcoma-associated herpesvirus in Uygur and Han populations from the Urumqi and Kashgar regions of Xinjiang, China

    Get PDF
    Kaposi’s sarcoma-associated herpesvirus (KSHV) is the infectious etiologic agent associated with Kaposi’s sarcoma (KS), primary effusion lymphoma, and multicentric Castleman disease. It has been shown that high KSHV prevalence and high incidence of both classic KS and AIDSassociated KS are found mostly among people of Uygur ethnicity in Xinjiang, while people of Han ethnicity in Xinjiang have a higher KSHV seroprevalence than those of other Han populations in mainland China. However, it is still unclear why there is such geographical and population variation in KSHV distribution in China. In this work, we focused on the populations in the Kashgar region and Urumqi area, where a total of 1294 research subjects were randomly selected to investigate the potential correlation between KSHV prevalence and different ethnicities in endemic areas of Xinjiang, and to determine risk factors that may affect KSHV infection rates or KS incidence. We identified a high seroprevalence of KSHV and high peripheral blood DNA infection in the general Uygur and Han populations in both Urumqi and Kashgar regions of Xinjiang, and determined that advancing age, low education level, and stationary population status affect KSHV infection rates. Further, KSHV-positive Uygur participants were shown to have higher prevalence of neutralizing antibodies and neutralizing antibody titers than KSHV-positive Han participants

    Efficacy of a 6-Week Home-Based Online Supervised Exercise Program Conducted During COVID-19 in Patients With Post Percutaneous Coronary Intervention:A Single-Blind Randomized Controlled Trial

    Get PDF
    OBJECTIVE: The aim of this study was to assess the efficacy of a 6-week cardiac rehabilitation (CR) program designed for patients with coronary artery disease (CAD) after percutaneous coronary intervention (PCI) that involved an online supervised exercise program that they could access during COVID-19. METHODS: One hundred patients were randomly allocated into control group (CG) and supervision group (SG). CG accepted conventional health education with a home exercise program booklet delivered before discharge, SG had an additional home-based online supervised exercise program (HOSEP). Questionnaires, motor function and lipid profile were administered at baseline. Questionnaires included the Godin-Shephard Leisure-Time Physical Activity questionnaire (GSLTPAQ) and Bandura's Exercise Self-efficacy (ESE). Motor function included: 6-min walk test (6 MWT), timed up and go test (TUG), 30-s sit to stand (30-s STS), and Hand Grip Strength (HG). Lipid profile included: low-density lipoprotein (LDL), high-density lipoprotein (HDL), total cholesterol (TC) and triglycerides (TG). The questionnaires were re-administered after 2-weeks, all tests were re-evaluated after 6-weeks. RESULTS: the questionnaire results showed that scores on GSLTPAQ and ESE were significantly improved in the SG. The changes in GSLTPAQ scores from baseline to 2- and 6-weeks in the SG were significantly higher than in the CG (2-week: 6.9 ± 13.0 for SG and 0.2 ± 10.2 for CG, p = 0.005; 6-week: 9.4 ± 18.1 for SG and 0.2 ± 11.8 for CG, p = 0.003). in terms of motor function, both the CG and SG improved TUG and 6 MWT performance, with the 6 MWT improvement being significantly greater in the SG than CG (43.7 ± 39.2 m for SG and 16.6 ± 39.1 m for CG, p = 0.001). Improvement in the 30-s STS was significantly greater in the SG than CG (2.4 ± 3.6 repetitions for SG and 0.4 ± 3.5 repetitions for CG, p = 0.007). the lipid profile level significantly improved over baseline in both SG and CG after 6-week intervention, and these changes were not statistically different between groups. CONCLUSION: This pilot randomized control study demonstrated that a 6-week HOSEP, when added to education delivered pre-hospital discharge for CAD patients following PCI, was beneficial with respect to exercise self-efficacy, exercise behavior, motor function and lipid profile. Supervised exercise programs delivered online in addition to education providing effective and accessible CR during COVID-19

    Klinička primjena RT-PCR u otkrivanju DNK tuberkuloze u kombinaciji s TB-IGRA u dijagnostici plućne tuberkuloze s negativnim nalazom sputuma

    Get PDF
    The aim was to investigate detection of pulmonary alveolar lavage fluid tuberculosis DNA by real-time fluorescent polymerase chain reaction (RT-PCR) combined with clinical application of the sputum smear-negative pulmonary tuberculosis diagnosis with TB interferon-γ release assay (TB-IGRA). From October 2014 to October 2015, 632 outpatients and inpatients treated in our hospital were randomly selected, of which 459 patients as the research group managed with RT-PCR detection combined with TB-IGRA and 173 patients as the control group undergoing electronic bronchoscopy alveolar lavage fluid detection, with detection results statistically evaluated. The positive rate in the research group was 96.51%, i.e. significantly higher than that in the control group (66.47%), yielding a statistically significant difference (χ2=109.68, p=0.00). The true positive rate was 97.7% in the research group and 67.92% in the control group; the true positive rate was significantly higher in the research group patients as compared with the control group, yielding a statistically significant difference (χ2=112.04, p=0.00). The sensitivity and specificity, as well as Youden index were significantly higher in the research group as compared with the control group. In conclusion, TB DNA detection by RT-PCR combined with TB-IGRA is a very good method of diagnosing tuberculosis, and it can be implemented in clinical diagnosis of pulmonary tuberculosis.Cilj istraživanja bio je ispitati otkrivanje DNK tuberkuloze u plućnom alveolarnom ispirku pomoću lančane reakcije polimeraze u stvarnom vremenu s fluorescentnim bojama (RT-PCR) u kombinaciji s kliničkom primjenom dijagnostike plućne tuberkuloze s negativnim nalazom sputuma pomoću testa otpuštanja TB interferona-γ (TB-IGRA). Od listopada 2014. do listopada 2015. godine nasumce su odabrane 632 osobe bolnički i izvanbolnički liječene u našoj bolnici, od kojih je 459 uključeno u ispitnu skupinu podvrgnutu otkrivanju pomoću RT-PCR u kombinaciji s testom TB-IGRA, a 173 u kontrolnu skupinu podvrgnutu elektroničkom otkrivanju u bronhoskopskom alveolarnom ispirku; rezultati su statistički obrađeni. Stopa pozitivnih nalaza bila je 96,51% u ispitnoj skupini, odnosno značajno viša od one u kontrolnoj skupini (66,47%), uz statistički značajnu razliku (χ2=109,68; p=0,00). Stopa stvarno pozitivnih nalaza bila je 97,7% u ispitnoj skupini i 67,92% u kontrolnoj skupini, dakle značajno viša kod bolesnika ispitne skupine u usporedbi s kontrolnom skupinom, uz statistički značajnu razliku (χ2=112,04; p=0,00). Osjetljivost i specifičnost, kao i Youdenov indeks bili su značajno viši u ispitnoj skupini u usporedbi s kontrolnom skupinom. U zaključku, otkrivanje TB DNK pomoću RT-PCR u kombinaciji s TB-IGRA vrlo je dobra metoda za dijagnosticiranje tuberkuloze, koja se može primjenjivati u kliničkoj dijagnostici plućne tuberkuloze

    Identification of Magnetic Interactions and High-field Quantum Spin Liquid in α\alpha-RuCl3_3

    Full text link
    The frustrated magnet α\alpha-RuCl3_3 constitutes a fascinating quantum material platform that harbors the intriguing Kitaev physics. However, a consensus on its intricate spin interactions and field-induced quantum phases has not been reached yet. Here we exploit multiple state-of-the-art many-body methods and determine the microscopic spin model that quantitatively explains major observations in α\alpha-RuCl3_3, including the zigzag order, double-peak specific heat, magnetic anisotropy, and the characteristic M-star dynamical spin structure, etc. According to our model simulations, the in-plane field drives the system into the polarized phase at about 7 T and a thermal fractionalization occurs at finite temperature, reconciling observations in different experiments. Under out-of-plane fields, the zigzag order is suppressed at 35 T, above which, and below a polarization field of 100 T level, there emerges a field-induced quantum spin liquid. The fractional entropy and algebraic low-temperature specific heat unveil the nature of a gapless spin liquid, which can be explored in high-field measurements on α\alpha-RuCl3_3.Comment: To appear in Nature Communications (12 pages, 6 figures, and 5 Supplementary Notes

    Expression of Endoplasmic Reticulum Stress-Related Factors in the Retinas of Diabetic Rats

    Get PDF
    Recent reports show that ER stress plays an important role in diabetic retinopathy (DR), but ER stress is a complicated process involving a network of signaling pathways and hundreds of factors, What factors involved in DR are not yet understood. We selected 89 ER stress factors from more than 200, A rat diabetes model was established by intraperitoneal injection of streptozotocin (STZ). The expression of 89 ER stress-related factors was found in the retinas of diabetic rats, at both 1- and 3-months after development of diabetes, by quantitative real-time polymerase chain reaction arrays. There were significant changes in expression levels of 13 and 12 ER stress-related factors in the diabetic rat retinas in the first and third month after the development of diabetes, Based on the array results, homocysteine- inducible, endoplasmic reticulum stress-inducible, ubiquitin-like domain member 1(HERP), and synoviolin(HRD1) were studied further by immunofluorescence and Western blot. Immunofluorescence and Western blot analyses showed that the expression of HERP was reduced in the retinas of diabetic rats in first and third month. The expression of Hrd1 did not change significantly in the retinas of diabetic rats in the first month but was reduced in the third month
    corecore