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1.
Nat Commun ; 15(1): 3774, 2024 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-38710680

RESUMEN

Structural distortions and imperfections are a crucial aspect of materials science, on the macroscopic scale providing strength, but also enhancing corrosion and reducing electrical and thermal conductivity. At the nanometre scale, multi-atom imperfections, such as atomic chains and crystalline domain walls have conversely been proposed as a route to topological superconductivity, whose most prominent characteristic is the emergence of Majorana Fermions that can be used for error-free quantum computing. Here, we shed more light on the nature of purported domain walls in Fe(Se,Te) that may host 1D dispersing Majorana modes. We show that the displacement shift of the atomic lattice at these line-defects results from sub-surface impurities that warp the topmost layer(s). Using the electric field between the tip and sample, we manage to reposition the sub-surface impurities, directly visualizing the displacement shift and the underlying defect-free lattice. These results, combined with observations of a completely different type of 1D defect where superconductivity remains fully gapped, highlight the topologically trivial nature of 1D defects in Fe(Se,Te).

2.
Proc Natl Acad Sci U S A ; 121(1): e2303423120, 2024 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-38150501

RESUMEN

The ability to efficiently control charge and spin in the cuprate high-temperature superconductors is crucial for fundamental research and underpins technological development. Here, we explore the tunability of magnetism, superconductivity, and crystal structure in the stripe phase of the cuprate La[Formula: see text]Ba[Formula: see text]CuO[Formula: see text], with [Formula: see text] = 0.115 and 0.135, by employing temperature-dependent (down to 400 mK) muon-spin rotation and AC susceptibility, as well as X-ray scattering experiments under compressive uniaxial stress in the CuO[Formula: see text] plane. A sixfold increase of the three-dimensional (3D) superconducting critical temperature [Formula: see text] and a full recovery of the 3D phase coherence is observed in both samples with the application of extremely low uniaxial stress of [Formula: see text]0.1 GPa. This finding demonstrates the removal of the well-known 1/8-anomaly of cuprates by uniaxial stress. On the other hand, the spin-stripe order temperature as well as the magnetic fraction at 400 mK show only a modest decrease under stress. Moreover, the onset temperatures of 3D superconductivity and spin-stripe order are very similar in the large stress regime. However, strain produces an inhomogeneous suppression of the spin-stripe order at elevated temperatures. Namely, a substantial decrease of the magnetic volume fraction and a full suppression of the low-temperature tetragonal structure is found under stress, which is a necessary condition for the development of the 3D superconducting phase with optimal [Formula: see text]. Our results evidence a remarkable cooperation between the long-range static spin-stripe order and the underlying crystalline order with the three-dimensional fully coherent superconductivity. Overall, these results suggest that the stripe- and the SC order may have a common physical mechanism.

3.
Artículo en Chino | MEDLINE | ID: mdl-37899567

RESUMEN

Extensive burns can cause nonnegligible acute and chronic damage to central nervous system of patients. The damage of central nervous system may have a profound impact on patients, including neurobehavioral changes such as post-traumatic stress disorder, depression, anxiety, and sleep disorder. These changes may persist after injury, greatly affecting patients' integration into society and return to work. This paper systematically reviewed the clinical manifestations, pathogenesis, and current intervention methods of mental disorders in patients with extensive burns, aiming to provide a basis for further understanding, prevention, and treatment of patients with mental disorders after burns.


Asunto(s)
Quemaduras , Trastornos por Estrés Postraumático , Humanos , Ansiedad , Trastornos por Estrés Postraumático/etiología , Trastornos por Estrés Postraumático/prevención & control , Trastornos de Ansiedad/complicaciones , Quemaduras/complicaciones , Quemaduras/terapia , Quemaduras/patología
4.
J Hosp Infect ; 139: 44-55, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37406860

RESUMEN

Multi-drug-resistant organisms (MDROs) have become a global threat to human health. Prior bed occupancy with MDRO infection/colonization is an exposure factor that is closely associated with the MDRO acquisition rates in subsequent bed patients in intensive care units (ICUs). A meta-analysis was conducted to investigate the risk of MDRO acquisition from prior bed occupants in the ICU. PubMed, Cochrane Library, Web of Science, and Embase databases and reference lists were searched for articles published up to December 2021. The Newcastle-Ottawa scale was used for quality assessment. The risk measure was calculated as the odds ratio (OR) and corresponding 95% confidence interval (CI), and the heterogeneity was tested using I2 method and Q test. Eight articles were analysed using a random-effects model. Of the 8147 patients exposed to prior bed occupants infected or colonized with MDROs, 421 had acquired MDROs. The control group consisted of 55,933 patients without exposure factors, of which 1768 had been infected/colonized with MDROs. The pooled acquisition OR for MDROs was 1.80 (95% CI: 1.42, 2.29), P<0.00001. Subgroup analysis based on multi-drug-resistant Gram-positive and Gram-negative organisms was conducted using a fixed-effects model. The results significantly varied between the groups. Heterogeneity was partially explained by the MDRO type. In conclusion, exposure of bed occupants to infected/colonized MDROs significantly increased the risk of MDRO acquisition in subsequent bed occupants.


Asunto(s)
Infección Hospitalaria , Humanos , Infección Hospitalaria/epidemiología , Infección Hospitalaria/prevención & control , Enterococcus , Unidades de Cuidados Intensivos , Farmacorresistencia Bacteriana Múltiple
6.
Artículo en Chino | MEDLINE | ID: mdl-37006143

RESUMEN

Objective: To investigate the level of psychosocial factors in workplace and their health effects among workers in a natural gas field. Methods: A prospective and open cohort of natural gas field workers was established to study the level of workplace psychosocial factors and their health effects, with a follow-up every 5 years. In October 2018, a cluster sampling method was used to conduct a baseline survey of 1737 workers in a natural gas field, including a questionnaire survey on demographic characteristics, workplace psychosocial factors and mental health outcomes, physiological indicators such as height and weight, and biochemical indicators such as blood routine, urine routine, liver function and kidney function. The baseline data of the workers were statistically described and analyzed. The psychosocial factors and mental health outcomes were divided into high and low groups according to the mean score, and the physiological and biochemical indicators were divided into normal and abnormal groups according to the reference range of normal values. Results: The age of 1737 natural gas field workers was (41.8±8.0) years old, and the length of service was (21.0±9.7) years. There were 1470 male workers (84.6%). There were 773 (44.5%) high school (technical secondary school) and 827 (47.6%) college (junior college) graduates, 1490 (85.8%) married (including remarriage after divorce), 641 (36.9%) smokers and 835 (48.1%) drinkers. Among the psychosocial factors, the detection rates of high levels of resilience, self-efficacy, colleague support and positive emotion were all higher than 50%. Among the mental health outcomes evaluation indexes, the detection rates of high levels of sleep disorder, job satisfaction and daily stress were 41.82% (716/1712), 57.25% (960/1677) and 45.87% (794/1731), respectively. The detection rate of depressive symptoms was 22.77% (383/1682). The abnormal rates of body mass index (BMI), triglyceride and low density lipoprotein were 46.74% (810/1733), 36.50% (634/1737) and 27.98% (486/1737), respectively. The abnormal rates of systolic blood pressure, diastolic blood pressure, uric acid, total cholesterol and blood glucose were 21.64% (375/1733), 21.41% (371/1733), 20.67% (359/1737), 20.55% (357/1737) and 19.17% (333/1737), respectively. The prevalence rates of hypertension and diabetes were 11.23% (195/1737) and 3.45% (60/1737), respectively. Conclusion: The detection rates of high level psychosocial factors in natural gas field workers are high, and their effects on physical and mental health remain to be verified. The establishment of a cohort study of the levels and health effects of psychosocial factors provides an important resource for confirming the causal relationship between workplace psychosocial factors and health.


Asunto(s)
Gas Natural , Yacimiento de Petróleo y Gas , Humanos , Masculino , Adulto , Persona de Mediana Edad , Estudios de Cohortes , Estudios Prospectivos , Lugar de Trabajo/psicología , Encuestas y Cuestionarios
7.
Nat Commun ; 13(1): 7418, 2022 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-36456570

RESUMEN

The quantum limit (QL) of an electron liquid, realised at strong magnetic fields, has long been proposed to host a wealth of strongly correlated states of matter. Electronic states in the QL are, for example, quasi-one dimensional (1D), which implies perfectly nested Fermi surfaces prone to instabilities. Whereas the QL typically requires unreachably strong magnetic fields, the topological semimetal ZrTe5 has been shown to reach the QL at fields of only a few Tesla. Here, we characterize the QL of ZrTe5 at fields up to 64 T by a combination of electrical-transport and ultrasound measurements. We find that the Zeeman effect in ZrTe5 enables an efficient tuning of the 1D Landau band structure with magnetic field. This results in a Lifshitz transition to a 1D Weyl regime in which perfect charge neutrality can be achieved. Since no instability-driven phase transitions destabilise the 1D electron liquid for the investigated field strengths and temperatures, our analysis establishes ZrTe5 as a thoroughly understood platform for potentially inducing more exotic interaction-driven phases at lower temperatures.

8.
Nat Commun ; 13(1): 7193, 2022 Nov 23.
Artículo en Inglés | MEDLINE | ID: mdl-36424384

RESUMEN

The dynamics of a nuclear open quantum system could be revealed in the correlations between the breakup fragments of halo nuclei. The breakup mechanism of a proton halo nuclear system is of particular interest as the Coulomb polarization may play an important role, which, however, remains an open question. Here we use a highly efficient silicon detector array and measure the correlations between the breakup fragments of 8B incident on 120Sn at near-barrier energies. The energy and angular correlations can be explained by a fully quantum mechanical method based on the state-of-the-art continuum discretized coupled channel calculations. The results indicate that, compared to the neutron halo nucleus 6He, 8B presents distinctive reaction dynamics: the dominance of the elastic breakup. This breakup occurs mainly via the short-lived continuum states, almost exhausts the 7Be yield, indicating the effect of Coulomb polarization on the proton halo state. The correlation information reveals that the prompt breakup mechanism dominates, occurring predominantly on the outgoing trajectory. We also show that, as a large environment, the continuum of 8B breakup may not significantly influence elastic scattering and complete fusion.

9.
Science ; 377(6611): 1218-1222, 2022 09 09.
Artículo en Inglés | MEDLINE | ID: mdl-36074835

RESUMEN

Incorporating relativistic physics into quantum tunneling can lead to exotic behavior such as perfect transmission through Klein tunneling. Here, we probed the tunneling properties of spin-momentum-locked relativistic fermions by designing and implementing a tunneling geometry that uses nanowires of the topological Kondo insulator candidate samarium hexaboride. The nanowires are attached to the end of scanning tunneling microscope tips and used to image the bicollinear stripe spin order in the antiferromagnet Fe1.03Te with a Neel temperature of about 50 kelvin. The antiferromagnetic stripes become invisible above 10 kelvin concomitant with the suppression of the topological surface states in the tip. We further demonstrate that the direction of spin polarization is tied to the tunneling direction. Our technique establishes samarium hexaboride nanowires as ideal conduits for spin-polarized currents.

10.
Proc Natl Acad Sci U S A ; 119(39): e2211670119, 2022 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-36126100

RESUMEN

The interplay between charge order and superconductivity remains one of the central themes of research in quantum materials. In the case of cuprates, the coupling between striped charge fluctuations and local electromagnetic fields is especially important, as it affects transport properties, coherence, and dimensionality of superconducting correlations. Here, we study the emission of coherent terahertz radiation in single-layer cuprates of the La2-xBaxCuO4 family, for which this effect is expected to be forbidden by symmetry. We find that emission vanishes for compounds in which the stripes are quasi-static but is activated when c-axis inversion symmetry is broken by incommensurate or fluctuating charge stripes, such as in La1.905Ba0.095CuO4 and in La1.845Ba0.155CuO4. In this case, terahertz radiation is emitted by surface Josephson plasmons, which are generally dark modes, but couple to free space electromagnetic radiation because of the stripe modulation.

11.
Zhonghua Yu Fang Yi Xue Za Zhi ; 56(8): 1087-1094, 2022 Aug 06.
Artículo en Chino | MEDLINE | ID: mdl-35922236

RESUMEN

Objective: To explore the relationship between DNA methylation and occupational noise-induced hearing loss. Methods: A case-control study was conducted. People with hearing loss induced by occupational noise were recruited as the case group and those with normal hearing but still exposed to occupational noise were recruited as the control group. A total of 60 participants were included, of which 30 participants were in the case group and 30 in the control group. The methylation level was detected by 850k genome-wide DNA methylation chip technology. The significance of differential methylated position (DMP) was tested by R-packet 'Champ'. The differential methylated region (DMR) was analyzed by using Champ's Bumphunter algorithm. Cluster profiler was used to analyze the gene list for GO and KEGG pathway enrichment. Results: There was significant difference between two groups in binaural high-frequency average hearing threshold (P<0.05), but there was no significant difference in age, smoking, drinking, hypertension, physical exercise and cumulative noise exposure. The results of DMP and DMR analysis showed that 713875 sites were detected in the case group and the control group, and 439 methylation sites with significant difference, accounting for 0.06%; 650 regions were detected, and 72 methylation regions with significant differences, accounting for 11.08%. Compared with the control group, the results of GO enrichment analysis showed that the case group had statistically significant differences in four pathways: axogenesis of projection neurons in the central nervous system, neuronal development in the central nervous system, axogenesis of neurons in the central nervous system and neuronal differentiation in the central nervous system. KEGG enrichment analysis showed that there were significant differences in sphingolipid metabolism, aldosterone synthesis and secretion, primary bile acid biosynthesis pathway between the case group and the control group. Conclusion: The occurrence of occupational noise-induced hearing loss may be related to the regulation of gene expression related to axogenesis of projection neurons in the central nervous system, development of neurons in the central nervous system, axogenesis of neurons in the central nervous system, differentiation of neurons in the central nervous system, sphingolipid metabolism, aldosterone synthesis and secretion, primary bile acid biosynthesis and gene methylation related to metabolism.


Asunto(s)
Pérdida Auditiva Provocada por Ruido , Ruido en el Ambiente de Trabajo , Enfermedades Profesionales , Exposición Profesional , Aldosterona , Ácidos y Sales Biliares , Estudios de Casos y Controles , Metilación de ADN , Pérdida Auditiva Provocada por Ruido/epidemiología , Pérdida Auditiva Provocada por Ruido/genética , Humanos , Ruido en el Ambiente de Trabajo/efectos adversos , Esfingolípidos
12.
Artículo en Chino | MEDLINE | ID: mdl-34488263

RESUMEN

Objective: To explore the occurrence level of depressive symptoms and it's influencing factors among gas field workers. Methods: In October 2018, a cross-sectional study was conducted in 1726 gas field workers from a gas field by using cluster sampling method. Questionaire was used to evaluate the individual factors, depressive symptoms, occupational stress factors and stress regulatory factors. The correlation between depressive symptoms and occupational stress was analyzed. Multivariate logistic regression was used to analyze the influencing factors of depressive symptoms. Results: The depressive symptoms score of gas field workers was 12.00 (7.00, 19.00) point. Correlation analysis revealed that depressive symptoms score was positively related to sleep disorders (r=0.598) , effort (r=0.186) , daily tension (r=0.478) , negative affectivity (r=0.565) , social support (r=0.446) and monotony of work (r=0.484) (P<0.01) . And it was negatively related to reward (r=-0.386) , work stability (r=-0.294) , promotion opportunities (r=-0.258) , positive affectivity (r= -0.310) , self-efficacy (r=-0.312) , contral strategy (r=-0.268) , support strategy (r=-0.209) and job satisfaction (r=-0.398) (P<0.01) . Multivariate logistic regression analysis revealed that sleep disorder, high negative affectivity, low support from colleagues, low support from family, high monotony of work and high daily tension were the risk factors for depressive symptoms of gas field worker (OR=3.423, 95%CI: 2.644-4.397; OR=2.847, 95%CI: 2.200-3.683; OR=1.646, 95%CI: 1.215-2.116; OR=1.496, 95%CI: 1.164-1.923; OR=1.578, 95%CI: 1.227-2.303; OR=1.903, 95%CI: 1.480-2.440; P<0.01) . High work stability, high self-efficacy and high job satisfaction were protective factors for depressive symptoms of gas field workers (OR=0.752, 95%CI: 0.591-0.958; OR=0.590, 95%CI: 0.465-0.749; OR=0.718, 95%CI: 0.516-0.999; P<0.05) . Conclusion: Occupational stress factors have a great influence on the depressive symptoms of gas field workers. Increased work stability, self-efficacy and job satisfaction could reduce the risk of depressive symptoms.


Asunto(s)
Depresión , Estrés Laboral , Estudios Transversales , Depresión/epidemiología , Humanos , Satisfacción en el Trabajo , Estrés Laboral/epidemiología , Yacimiento de Petróleo y Gas , Estrés Psicológico , Encuestas y Cuestionarios
13.
Zhonghua Zhong Liu Za Zhi ; 43(8): 821-826, 2021 Aug 23.
Artículo en Chino | MEDLINE | ID: mdl-34407585

RESUMEN

Objective: To analyze the expression pattern, mechanism and clinical significance of melanoma-associated antigen-C2 (MAGE-C2) in tumor-free breast specimens, breast benign disease specimens and breast cancer specimens. Methods: Reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry were used to investigate the expressions of MAGE-C2 in 60 tumor-free breast specimens, 60 breast benign disease specimens and 60 breast cancer specimens. The correlation of MAGE-C2 expression with clinicopathological parameters and prognosis of breast cancer patients were analyzed. The expression of MAGE-C2 was also detected by RT-PCR in breast cancer cell MCF-7 and MDA-MB-231 treated with DNA methylase inhibitor 5-aza-2'-deoxycytidine (5-aza-CdR) and histone deacetylase inhibitor trichostatin A (TSA). Results: The positive expression rates of MAGE-C2 mRNA and protein were 61.7% (37/60) and 58.3% (35/60) in breast cancer specimens, respectively, while negative expressed in breast and begin disease specimens. MAGE-C2 protein expression was associated with tumor grade, histological type and blood vessel invasion of breast cancer patients (P<0.05). The incidence of recurrence-free survival of patients with positive MAGE-C2 expression were lower than that of patients with negative MAGE-C2 expression (P<0.05). Multivariate Cox regression analysis showed that the clinical stage (P<0.01), lymph node metastasis (P<0.05) and MAGE-C2 expression (P<0.05) were the independent prognostic factors of breast cancer patients. The MAGE-C2 mRNA was not observed in the control and TSA treated breast cancer cells while upregulated in the 5-aza-CdR treated cells. Besides, 5-aza-CdR combined with TSA further enhanced MAGE-C2 mRNA level in breast cancer cells (P<0.05). Conclusions: MAGE-C2 is one of the tumor-specific antigen and its expression is related with the poor prognosis of breast cancer patients. DNA methylation and histone acetylation may be an important regulation mechanism of MAGE-C2 gene expression.


Asunto(s)
Neoplasias de la Mama , Melanoma , Azacitidina/farmacología , Neoplasias de la Mama/genética , Decitabina/farmacología , Femenino , Inhibidores de Histona Desacetilasas/farmacología , Humanos
14.
J Physiol Pharmacol ; 72(1)2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34272350

RESUMEN

To determine whether curcumin (Cur) can treat mice with experimentally-induced colitis by regulating follicular helper T cells (Tfh) and follicular regulatory T cells (Tfr) by inhibiting interleukin (IL)-21. In this study, 40 male C57BL/6 mice were randomly grouped into four groups, i.e., normal, trinitrobenzene sulfonic acid (TNBS), TNBS + curcumin, and TNBS + anti-IL-21. Mice with experimental colitis were induced by 100 mg/kg TNBS. The mice in the TNBS + Cur group were treated with 100 mg/kg curcumin for seven days, and mice in the TNBS + anti-IL-21 group were treated with anti-IL-21 (150 µg/mouse) once per week, intraperitoneally, starting on the second day after establishing the experimental colitis model. On day eight, the therapeutic effect of curcumin was evaluated by colon mucosa damage index (CMDI), histological examination, and disease activity index (DAI). Furthermore, the number of CD4 + CXCR5 + PD-1 + Tfh and CD4 + CXCR5 + FoxP3 + Tfr cells were measured by flow cytometry. The mRNA and protein expression of IL-21, Bcl-6, FOXP3, ICOS, and PD-1 in colonic mucosa was detected by reverse transcription polymerase chain reaction and the Western blot technique. Compared with the TNBS group, the DAI, CMDI, histological score, the number of CD4 + CXCR5 + PD-1 + Tfh cells, the expression of IL-21, Bcl-6, ICOS, and PD-1 were significantly decreased in the TNBS + curcumin group and TNBS + anti-IL-21 group; body weight, number of CD4 + CXCR5 + FoxP3 + Tfr cells, and the expression of FoxP3 were observably elevated in the TNBS + curcumin group (all P < 0.05). Curcumin may have a potential therapeutic effect on mice with colitis treated experimentally through regulation of the balance of Tfh and Tfr cells via inhibiting the synthesis of IL-21.


Asunto(s)
Colitis/tratamiento farmacológico , Curcumina/farmacología , Interleucinas/metabolismo , Mucosa Intestinal/efectos de los fármacos , Animales , Colitis/fisiopatología , Modelos Animales de Enfermedad , Citometría de Flujo , Mucosa Intestinal/patología , Masculino , Ratones , Ratones Endogámicos C57BL , ARN Mensajero/metabolismo , Células T Auxiliares Foliculares/metabolismo , Linfocitos T Reguladores/metabolismo , Ácido Trinitrobencenosulfónico
15.
Nat Commun ; 12(1): 3197, 2021 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-34045452

RESUMEN

The quantum Hall effect (QHE) is traditionally considered to be a purely two-dimensional (2D) phenomenon. Recently, however, a three-dimensional (3D) version of the QHE was reported in the Dirac semimetal ZrTe5. It was proposed to arise from a magnetic-field-driven Fermi surface instability, transforming the original 3D electron system into a stack of 2D sheets. Here, we report thermodynamic, spectroscopic, thermoelectric and charge transport measurements on such ZrTe5 samples. The measured properties: magnetization, ultrasound propagation, scanning tunneling spectroscopy, and Raman spectroscopy, show no signatures of a Fermi surface instability, consistent with in-field single crystal X-ray diffraction. Instead, a direct comparison of the experimental data with linear response calculations based on an effective 3D Dirac Hamiltonian suggests that the quasi-quantization of the observed Hall response emerges from the interplay of the intrinsic properties of the ZrTe5 electronic structure and its Dirac-type semi-metallic character.

16.
Nat Commun ; 12(1): 597, 2021 Jan 26.
Artículo en Inglés | MEDLINE | ID: mdl-33500415

RESUMEN

In strongly correlated systems the strength of Coulomb interactions between electrons, relative to their kinetic energy, plays a central role in determining their emergent quantum mechanical phases. We perform resonant x-ray scattering on Bi2Sr2CaCu2O8+δ, a prototypical cuprate superconductor, to probe electronic correlations within the CuO2 plane. We discover a dynamic quasi-circular pattern in the x-y scattering plane with a radius that matches the wave vector magnitude of the well-known static charge order. Along with doping- and temperature-dependent measurements, our experiments reveal a picture of charge order competing with superconductivity where short-range domains along x and y can dynamically rotate into any other in-plane direction. This quasi-circular spectrum, a hallmark of Brazovskii-type fluctuations, has immediate consequences to our understanding of rotational and translational symmetry breaking in the cuprates. We discuss how the combination of short- and long-range Coulomb interactions results in an effective non-monotonic potential that may determine the quasi-circular pattern.

17.
Nat Commun ; 12(1): 406, 2021 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-33462222

RESUMEN

A quantum spin Hall (QSH) insulator hosts topological states at the one-dimensional (1D) edge, along which backscattering by nonmagnetic impurities is strictly prohibited. Its 3D analogue, a weak topological insulator (WTI), possesses similar quasi-1D topological states confined at side surfaces. The enhanced confinement could provide a route for dissipationless current and better advantages for applications relative to strong topological insulators (STIs). However, the topological side surface is usually not cleavable and is thus hard to observe. Here, we visualize the topological states of the WTI candidate ZrTe5 by spin and angle-resolved photoemission spectroscopy (ARPES): a quasi-1D band with spin-momentum locking was revealed on the side surface. We further demonstrate that the bulk band gap is controlled by external strain, realizing a more stable WTI state or an ideal Dirac semimetal (DS) state. The highly directional spin-current and the tunable band gap in ZrTe5 will provide an excellent platform for applications.

18.
Nat Mater ; 20(3): 329-334, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33462464

RESUMEN

Dissipationless currents from topologically protected states are promising for disorder-tolerant electronics and quantum computation. Here, we photogenerate giant anisotropic terahertz nonlinear currents with vanishing scattering, driven by laser-induced coherent phonons of broken inversion symmetry in a centrosymmetric Dirac material ZrTe5. Our work suggests that this phononic terahertz symmetry switching leads to formation of Weyl points, whose chirality manifests in a transverse, helicity-dependent current, orthogonal to the dynamical inversion symmetry breaking axis, via circular photogalvanic effect. The temperature-dependent topological photocurrent exhibits several distinct features: Berry curvature dominance, particle-hole reversal near conical points and chirality protection that is responsible for an exceptional ballistic transport length of ~10 µm. These results, together with first-principles modelling, indicate two pairs of Weyl points dynamically created by B1u phonons of broken inversion symmetry. Such phononic terahertz control breaks ground for coherent manipulation of Weyl nodes and robust quantum transport without application of static electric or magnetic fields.

19.
Zhonghua Wei Chang Wai Ke Za Zhi ; 23(12): 1177-1181, 2020 Dec 25.
Artículo en Chino | MEDLINE | ID: mdl-33353273

RESUMEN

Objective: To investigate the safety and feasibility of transgluteal percutaneous drainage using double catheterization cannula in the treatment of deep pelvic abscess. Methods: A retrospective analysis of the clinical data of patients who underwent transgluteal percutaneous drainage using double catheterization cannula with deep pelvic abscesses admitted to the Jinling Hospital from May 2017 to September 2020 was conducted. Seven patients were enrolled, including 5 males and 2 females, who aged 26-74 (median 53.0) years old, and all of them had digestive fistula. One male patient was punctured again due to the tube falling off, and a total of 7 patients underwent 8 times of transgluteal percutaneous drainage, all under the guidance of CT. The puncture and drainage steps of the double catheterization cannula group are as follows: (1) Locate the puncture point under CT in the lateral position; (2) Place the trocar into the abscess cavity; (3) Confirm that the trocar is located in the abscess cavity under CT; (4) Pull out the inner core and insert into the double catheterization cannula through the operating hole; (5) Confirmthat the double catheterization cannula is located in the abscess cavity under CT; (6) The double catheterization cannula is properly fixed to prevent it from falling off. The white blood cells, C-reactive protein (CRP), procalcitonin, and interleukin-6 (IL-6) of all patients before the drainage and 1 days, 3 days, and 5 days after the drainage were collected, as well as the bacterial culture results of the drainage fluid. The changes of various infection biomarkers before and after the drainage were compared. Results: All 7 patients were cured. No complications such as hemorrhage and severe pain were observed. The average time with drainage tube was 60.8 (18-126) days. Five patients finally underwent gastrointestinal reconstruction surgery due to gastrointestinal fistula. The median serum interleukin-6 of patients before drainage, 1 day, 3 days and 5 days after drainage were 181.6 (113.0, 405.4) µg/L, 122.2 (55.8, 226.0) µg/L, 59.2 (29.0,203.5) µg/L and 64.1 (30.0,88.4) µg/L, respectively.The level of serum interleukin-6 at 3 days and 5 days after drainage was significantly lower than before drainage (F=3.586, P=0.026). Although the white blood cell count, C-reactive protein, and procalcitonin decreased gradually after drainage compared with before drainage, the difference was not statistically significant (all P>0.05). Conclusion: Transgluteal percutaneous drainage with double catheterization cannula is simple and effective, and can be used for the treatment of deep pelvic abscess.


Asunto(s)
Absceso , Fístula del Sistema Digestivo/complicaciones , Drenaje/métodos , Infección Pélvica/cirugía , Absceso/etiología , Absceso/cirugía , Adulto , Anciano , Nalgas/cirugía , Cateterismo/métodos , Fístula del Sistema Digestivo/cirugía , Estudios de Factibilidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Infección Pélvica/etiología , Pelvis/cirugía , Estudios Retrospectivos , Cirugía Asistida por Computador , Tomografía Computarizada por Rayos X/métodos , Resultado del Tratamiento
20.
Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi ; 38(11): 819-822, 2020 Nov 20.
Artículo en Chino | MEDLINE | ID: mdl-33287473

RESUMEN

Objective: To investigate the level of social support and its correlation with occupational stress among gas production workers in the field. Methods: In October 2018, the cluster sampling method was used to perform a cross-sectional survey for 1726 gas production workers in the field, and related data of these workers were collected, including age, education level, marital status, level of social support, and related factors for occupational stress. A Spearman's rank correlation analysis was used to investigate the correlation between social support and occupational stress, and the levels of occupational stress-related factors were compared between the groups with different social support scores. Results: The gas production workers in the field had a median (25th percentile, 75th percentile) social support score of 24.00 (19.00, 28.00) , and there was a significant difference in social support score between the workers with different posts or work shifts (P<0.01) . Social support score was positively correlated with effort, daily stress, negative emotion, and job routinization (P<0.05) and was negatively correlated with job satisfaction, reward, working stability, and promotion opportunity (P<0.05) . The group with a high social support score had significantly higher scores of effort, job routinization, sleep disorders, and daily stress than the other two groups (P<0.01) , and the group with a low social support score had significantly higher scores of reward, self-efficacy, positive affection, and job satisfaction than the other two groups (P<0.01) . Conclusion: High-level social support plays an important role in alleviating occupational stress and protecting mental health among gas production workers in the field.


Asunto(s)
Estrés Laboral , Estrés Psicológico , Estudios Transversales , Humanos , Apoyo Social , Encuestas y Cuestionarios
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