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1.
Front Aging Neurosci ; 14: 833365, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35401157

RESUMO

Objectives: We evaluated the effects of long-term/recurrent use of antibiotics in childhood on developing cognitive impairment in middle and old age from UK Biobank Database. Methods: UK Biobank recruited participants aged 37-73 years. Cognitive impairment was ascertained by fluid intelligence questionnaire. Primary outcome was the occurrence of cognitive impairment in middle and old age. Multivariate logistic regression models were used to explore the relationship between long-term/recurrent use of antibiotics and cognitive impairment. Results: Over 3.8-10.8 years' follow-up, 4,781 of the 35,921 participants developed cognitive impairment. The odds of cognitive impairment in middle and old age among long-term/recurrent use of antibiotics in childhood were increased by 18% compared with their counterparts (adjusted odd ratio 1.18, 95% confidence interval 1.08-1.29, p < 0.01). The effect of long-term/recurrent use of antibiotics in childhood on cognitive impairment was homogeneous across different categories of various subgroup variables such as sex, age, APOE4, ethnic groups, income before tax, smoking status, alcohol status, BMI, hypertension and diabetes but the effect of long-term/recurrent use of antibiotics in childhood was modified by the educational qualification (p-value for interaction <0.05). Conclusion: Long-term/recurrent use of antibiotics in childhood may increase the risk of cognitive impairment in middle and old age.

2.
J Clin Monit Comput ; 2021 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-34743260

RESUMO

The change in maternal hemodynamics during cesarean section has not been well studied. Continuous transthoracic echocardiography can monitor cardiac function continuously. This study aimed to evaluate the effectiveness of maternal hemodynamic parameters monitoring during cesarean section using continuous transthoracic echocardiography. In this prospective, observational study, women with an uncomplicated singleton pregnancy scheduled for elective cesarean section at term under combined spinal-epidural anesthesia were enrolled. Maternal hemodynamic parameters were assessed by continuous transthoracic echocardiography at 11 pre-set time points. The image quality of continuous transthoracic echocardiography was evaluated before measurement was performed. Totally, one hundred parturients were recruited, and transthoracic echocardiography images with sufficient quality for further analysis were obtained in 72 women. Following anesthesia, maternal heart rate decreased by 11.18% and cardiac output decreased by 7.82%, but stroke volume remained stable. After delivery of the neonate and placenta, stroke volume and cardiac output increased by 21.09% and 22.33%, respectively. End-diastolic volume also increased significantly after delivery of the neonate, but end-systolic volume was unchanged. Following delivery of the neonate, fractional shortening increased till the end of the cesarean section while total peripheral resistance decreased significantly. In conclusion, continuous transthoracic echocardiographic monitoring revealed that there were significant changes in hemodynamic parameters during cesarean section after delivery of the newborn and placenta, which warranted further investigation.

3.
J Card Surg ; 36(12): 4792-4795, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34647368

RESUMO

BACKGROUND: Myxoma is the most common tumor of the heart that can cause embolism, obstruction, and cardiac failure, but rarely causes chylothorax. We herein report a case of chylothorax caused by left atrial myxoma, which responded to diuretic therapy and was subsequently cured by resecting cardiac myxoma. CASE PRESENTATION: This is a case of a 63-year-old male with symptoms of cardiac insufficiency who was diagnosed with a left atrial myxoma. The patient also had a massive pleural effusion on the right side, which was diagnosed as chylothorax by Sudan III staining and the content of triglyceride. The pleural effusion disappeared and the symptoms of heart failure were relieved after draining the effusion with a fine thoracic drainage tube, but pleural effusion and cardiac insufficiency symptoms relapsed soon. Although diuretic treatment can improve the symptoms and reduced the amount of chylous fluid preoperatively, the chylous pleural effusion was eventually cured by surgical removal of the tumor, and no recurrence of the tumor and chylothorax was found in the 6-month follow-up. CONCLUSIONS: Chylothorax is rare comorbidity of cardiac myxoma. Large myxoma can cause congestive heart failure and lead to disfunction of chylous reflux, resulting in chylothorax, which can be cured by resection of the primary tumor.


Assuntos
Quilotórax , Neoplasias Cardíacas , Mixoma , Derrame Pleural , Quilotórax/etiologia , Quilotórax/cirurgia , Neoplasias Cardíacas/complicações , Neoplasias Cardíacas/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Mixoma/complicações , Mixoma/cirurgia , Recidiva Local de Neoplasia
4.
Nano Lett ; 21(16): 6800-6806, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34369798

RESUMO

Ionic liquid gating has proved to be effective in inducing emergent quantum phenomena such as superconductivity, ferromagnetism, and topological states. The electrostatic doping at two-dimensional interfaces relies on ionic motion, which thus is operated at sufficiently high temperature. Here, we report the in situ tuning of quantum phases by shining light on an ionic liquid-gated interface at cryogenic temperatures. The light illumination enables flexible switching of the quantum transition in monolayer WS2 from an insulator to a superconductor. In contrast to the prevailing picture of photoinduced carriers, we find that in the presence of a strong interfacial electric field conducting electrons could escape from the surface confinement by absorbing photons, mimicking the field emission. Such an optical tuning tool in conjunction with ionic liquid gating greatly facilitates continuous modulation of carrier densities and hence electronic phases, which would help to unveil novel quantum phenomena and device functionality in various materials.

5.
Iran J Public Health ; 50(1): 11-23, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34178760

RESUMO

BACKGROUND: Vascular dementia (VD), as the second-largest type of dementia, is a serious stage of vascular cognitive impairment. It is significant to conduct retrospective epidemiological studies to characterize further the disease for public health. This study estimated the prevalence of VD among the population aged 18 yr and older in China. METHODS: Epidemiological investigations on VD published in journals and covering the period from 1999 to 2019 were identified manually and online by using Chinese databases (such as Chinese BioMedical Literature Database, Chinese National Knowledge Infrastructure database, Chinese science-technology databases, and the Chinese Wan-fang and Chongqing VIP database) and English databases (such as PubMed, Elsevier Science Bibliographic Databases and Cochrane library). Studies were included if the diagnostic criteria for VD are clear and the quality of the included literature was evaluated using the quality evaluation criteria of epidemiological research methods. A random-effects model was employed according to the statistical test of homogeneity. RESULTS: Twenty-six studies met the inclusion criteria, including 100,923 subjects and 977 VD patients. The pooled prevalence of VD was 0.96% (95% [confidence interval, CI] 0.63%∼2.1%). The prevalence of VD increased with increasing age. There was a higher prevalence of VD in the northeast China population, in urban areas and males. CONCLUSION: We stratified the included studies based on age, location, gender, and geographical distribution for prevalence. The prevalence of VD has slowly risen since 1999. It is obviously different between the North & South and urban &rural districts. While there are many benefits of systematic reviews, the methods presented have inherent limitations.

6.
Nano Lett ; 21(5): 2026-2032, 2021 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-33606545

RESUMO

Topological materials that possess spin-momentum locked surface states provide an ideal platform to manipulate the quantum spin states by electrical means. However, an antisymmetric magnetoresistance (MR) superimposed on the spin-polarized transport signals is usually observed in the spin potentiometric measurements of topological materials, rendering more power loss and reduced signal-to-noise ratio. Here we reveal the mechanism of surface-bulk interaction for the observed antisymmetric linear MR in the spin transport of Dirac semimetal Cd3As2 nanoplates. The antisymmetric linear MR can be eliminated through sample surface modifications. As a consequence, clean signals of charge current induced spin-polarized transport are observed, robust up to room temperature. The purification of spin signals can be attributed to the isolation of surface and bulk transport channels via forming a charge depletion layer with surface modifications. This surface engineering strategy should be valuable for high-performance spintronic devices on topological materials.

7.
Phys Rev Lett ; 126(2): 027001, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33512215

RESUMO

We report the topological transition by gate control in a Cd_{3}As_{2} Dirac semimetal nanowire Josephson junction with diameter of about 64 nm. In the electron branch, the quantum confinement effect enforces the surface band into a series of gapped subbands and thus nontopological states. In the hole branch, however, because the hole mean free path is smaller than the nanowire perimeter, the quantum confinement effect is inoperative and the topological property maintained. The superconductivity is enhanced by gate tuning from electron to hole conduction, manifested by a larger critical supercurrent and a larger critical magnetic field, which is attributed to the topological transition from gapped surface subbands to a gapless surface band. The gate-controlled topological transition of superconductivity should be valuable for manipulation of Majorana zero modes, providing a platform for future compatible and scalable design of topological qubits.

8.
Phys Rev Lett ; 124(15): 156601, 2020 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-32357024

RESUMO

The notion of topological phases has been extended to higher-order and has been generalized to different dimensions. As a paradigm, Cd_{3}As_{2} is predicted to be a higher-order topological semimetal, possessing three-dimensional bulk Dirac fermions, two-dimensional Fermi arcs, and one-dimensional hinge states. These topological states have different characteristic length scales in electronic transport, allowing one to distinguish their properties when changing sample size. Here, we report an anomalous dimensional reduction of supercurrent transport by increasing the size of Dirac semimetal Cd_{3}As_{2}-based Josephson junctions. An evolution of the supercurrent quantum interferences from a standard Fraunhofer pattern to a superconducting quantum interference device (SQUID)-like one is observed when the junction channel length is increased. The SQUID-like interference pattern indicates the supercurrent flowing through the 1D hinges. The identification of 1D hinge states should be valuable for deeper understanding of the higher-order topological phase in a 3D Dirac semimetal.

9.
ACS Nano ; 14(4): 3755-3778, 2020 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-32286783

RESUMO

Characterized by bulk Dirac or Weyl cones and surface Fermi-arc states, topological semimetals have sparked enormous research interest in recent years. The nanostructures, with large surface-to-volume ratio and easy field-effect gating, provide ideal platforms to detect and manipulate the topological quantum states. Exotic physical properties originating from these topological states endow topological semimetals attractive for future topological electronics (topotronics). For example, the linear energy dispersion relation is promising for broadband infrared photodetectors, the spin-momentum locking nature of topological surface states is valuable for spintronics, and the topological superconductivity is highly desirable for fault-tolerant qubits. For real-life applications, topological semimetals in the form of nanostructures are necessary in terms of convenient fabrication and integration. Here, we review the recent progresses in topological semimetal nanostructures and start with the quantum transport properties. Then topological semimetal-based electronic devices are introduced. Finally, we discuss several important aspects that should receive great effort in the future, including controllable synthesis, manipulation of quantum states, topological field effect transistors, spintronic applications, and topological quantum computation.

10.
Phys Rev Lett ; 124(11): 116802, 2020 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-32242698

RESUMO

The exotic topological surface states of Dirac or Weyl semimetals, namely Fermi arcs, are predicted to be spin polarized, while their spin polarization nature is still not revealed by transport measurements. Here, we report the spin-polarized transport in a Dirac semimetal Cd_{3}As_{2} nanowire employing the ferromagnetic electrodes for spin detection. The spin-up and spin-down states can be changed by reversing the current polarity, showing the spin-momentum locking property. Moreover, the nonlocal measurements show a high fidelity of the spin signals, indicating the topological protection nature of the spin transport. As tuning the Fermi level away from the Dirac point by gate voltages, the spin signals gradually decrease and finally are turned off, which is consistent with the fact that the Fermi arc surface state has the maximum ratio near the Dirac point and disappears above the Lifshitz transition point. Our results should be valuable for revealing the transport properties of the spin-polarized Fermi arc surface states in topological semimetals.

11.
Nat Commun ; 11(1): 1150, 2020 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-32123180

RESUMO

One prominent hallmark of topological semimetals is the existence of unusual topological surface states known as Fermi arcs. Nevertheless, the Fermi-arc superconductivity remains elusive. Here, we report the critical current oscillations from surface Fermi arcs in Nb-Dirac semimetal Cd3As2-Nb Josephson junctions. The supercurrent from bulk states are suppressed under an in-plane magnetic field ~0.1 T, while the supercurrent from the topological surface states survives up to 0.5 T. Contrary to the minimum normal-state conductance, the Fermi-arc carried supercurrent shows a maximum critical value near the Dirac point, which is consistent with the fact that the Fermi arcs have maximum density of state at the Dirac point. Moreover, the critical current exhibits periodic oscillations with a parallel magnetic field, which is well understood by considering the in-plane orbital effect from the surface states. Our results suggest the Dirac semimetal combined with superconductivity should be promising for topological quantum devices.

12.
ACS Omega ; 5(8): 4133-4138, 2020 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-32149242

RESUMO

We report on a high-brightness ultraviolet (UV) nanoscale light source. The light emission diodes are constructed with graphene/ZnO nanowire/p-GaN vertical junctions, which exhibit strong UV electroluminescence (EL) emissions centered at a wavelength of 397 nm at one end of the ZnO nanowire. Compared to the horizontal heterojunction, the vertical junction based on the ZnO nanowire increases the interface area of the heterojunction along with a high-quality interface, thus making the device robust under a large excitation current. In this structure, transparent flexible graphene is used as the top electrode, which can effectively improve performance by increasing the carrier injection area. Moreover, by analyzing the relationship between the integrated light intensity and applied bias, a superlinear dependency with a slope of 3.99 is observed, which means high electrical-to-optical conversion efficiency. Three electron-hole irradiation recombination processes are distinguished according to the EL emission spectra.

13.
ACS Nano ; 13(12): 14262-14273, 2019 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-31790198

RESUMO

Two-dimensional (2D) layered semiconductors have recently emerged as attractive building blocks for next-generation low-power nonvolatile memories. However, challenges remain in the controllable fabrication of bipolar resistive switching circuit components from these materials. Here, the experimental realization of lateral memtransistors from monolayer single-crystal molybdenum disulfide (MoS2) utilizing a focused helium ion beam is reported. Site-specific irradiation with the focused probe of a helium ion microscope creates a nanometer-scale defect-rich region, bisecting the MoS2 lattice. The reversible drift of these defects in the applied electric field modulates the resistance of the channel, enabling versatile memristive functionality. The device can reliably retain its resistance ratios and set/reset biases for 1180 switching cycles. Long-term potentiation and depression with sharp habituation are demonstrated. This work establishes the feasibility of ion irradiation for controllable fabrication of 2D memristive devices with promising key performance parameters, such as low power consumption. The applicability of these devices for synaptic emulation may address the demands of future neuromorphic architectures.

14.
Phys Rev Lett ; 122(3): 036602, 2019 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-30735405

RESUMO

The quantum Hall effect (QHE) in a 3D Dirac semimetal thin film is attributed to either the quantum confinement induced bulk subbands or the Weyl orbits that connect the opposite surfaces via bulk Weyl nodes. However, it is still unknown whether the QHE based on the Weyl orbit can survive as the bulk Weyl nodes are gapped. Moreover, there are closed Fermi loops rather than open Fermi arcs on the Dirac semimetal surface, which can also host the QHE. Here we report the QHE in the 3D Dirac semimetal Cd_{3}As_{2} nanoplate by tuning the gate voltage under a fixed 30 T magnetic field. The quantized Hall plateaus at odd filling factors are observed as a magnetic field along the [001] crystal direction, indicating a Berry's phase π from the topological surface states. Furthermore, even filling factors are observed when the magnetic field is along the [112] direction, indicating the C_{4} rotational symmetry breaking and a topological phase transition. The results shed light on the understanding of QHE in 3D Cd_{3}As_{2}.

15.
Transl Cancer Res ; 8(4): 1258-1267, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35116868

RESUMO

BACKGROUND: The purpose of this study was to perform a systematic review of the interventions for advanced non-small cell lung cancer (NSCLC) including chemotherapy alone and chemotherapy plus COX-2 inhibitors to identify and discuss the cause of any variation across studies and to explore the best currently available evidence. METHODS: The literature was comprehensively searched to identify relevant meta-analyses, and the Jadad decision algorithm was used to select the best evidence from the included meta-analyses. Quality assessment of the meta-analyses was performed using the Quality of Reporting (QUOROM) checklist and the Oxman-Guyatt quality index. RESULTS: Five meta-analyses were selected for inclusion in this study. Three were published prior to 2018 and had Oxman-Guyatt scores of 5. Only one study had the highest QUOROM and Oxman-Guyatt scores, and that study concluded that first-line treatment with chemotherapy plus COX-2 inhibitors was superior to chemotherapy alone in terms of the overall response rate (ORR). However, no significant difference in clinical benefit, progression-free survival (PFS), overall survival (OS), or 1-year survival rate was found. In addition, toxicities of the drugs had some influence on patients with heart disease. CONCLUSIONS: The Jadad algorithm identified the optimal current meta-analysis. COX-2 inhibitors increased the ORR when combined with chemotherapy, but did not improve the survival indices. In addition, they may increase the risk of cardiovascular events and hematological toxicities in NSCLC patients.

16.
Phys Rev Lett ; 121(23): 237701, 2018 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-30576175

RESUMO

The combination of superconductivity and surface states in Dirac semimetal can produce a 4π-periodic supercurrent in a Josephson junction configuration, which can be revealed by the missing of odd Shapiro steps (especially the n=1 step). However, the suppression of the n=1 step is also anticipated in the high-power oscillatory regime of the ordinary 2π-periodic Josephson effect, which is irrelevant to the 4π-periodic supercurrent. Here, in order to identify the origin of the suppressed n=1 step, we perform the measurements of radio frequency irradiation on Nb-Dirac semimetal Cd_{3}As_{2} nanowire-Nb junctions with continuous power dependence at various frequencies. Besides the n=1 step suppression, we uncover a residual supercurrent of first node at the n=0 step, which provides a direct and predominant signature of the 4π-periodic supercurrent. Furthermore, by tuning the gate voltage, we can modulate the surface and bulk state contribution and the visibility of the n=1 step. Our results provide deep insights to explore the topological superconductivity in Dirac semimetals.

17.
Nat Commun ; 9(1): 5168, 2018 12 05.
Artigo em Inglês | MEDLINE | ID: mdl-30518867

RESUMO

Lateral graphene p-n junctions are important since they constitute the core components in a variety of electronic/photonic systems. However, formation of lateral graphene p-n junctions with a controllable doping levels is still a great challenge due to the monolayer feature of graphene. Herein, by performing selective ion implantation and in situ growth by dynamic chemical vapor deposition, direct formation of seamless lateral graphene p-n junctions with spatial control and tunable doping is demonstrated. Uniform lattice substitution with heteroatoms is achieved in both the boron-doped and nitrogen-doped regions and photoelectrical assessment reveals that the seamless lateral p-n junctions exhibit a distinct photocurrent response under ambient conditions. As ion implantation is a standard technique in microelectronics, our study suggests a simple and effective strategy for mass production of graphene p-n junctions with batch capability and spatial controllability, which can be readily integrated into the production of graphene-based electronics and photonics.

18.
Adv Mater ; : e1707547, 2018 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-29995347

RESUMO

Dirac semimetal is an emerging class of quantum matters, ranging from 2D category, such as, graphene and surface states of topological insulator to 3D category, for instance, Cd3 As2 and Na3 Bi. As 3D Dirac semimetals typically possess Fermi-arc surface states, the 2D-3D Dirac van der Waals heterostructures should be promising for future electronics. Here, graphene-Cd3 As2 heterostructures are fabricated through direct layer-by-layer stacking. The electronic coupling results in a notable interlayer charge transfer, which enables us to modulate the Fermi level of graphene through Cd3 As2 . A planar graphene p-n-p junction is achieved by selective modification, which demonstrates quantized conductance plateaus. Moreover, compared with the bare graphene device, the graphene-Cd3 As2 hybrid device presents large nonlocal signals near the Dirac point due to the charge transfer from the spin-polarized surface states in the adjacent Cd3 As2 . The results enrich the family of van der Waals heterostructure and should inspire more studies on the application of Dirac/Weyl semimetals in spintronics.

19.
Phys Rev Lett ; 120(25): 257701, 2018 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-29979085

RESUMO

Dirac semimetals possess Fermi-arc surface states, which will be a set of discrete surface subbands in a nanowire due to the quantum confinement effect. Here, we report a tunable Fano effect induced by the interference between the discrete surface states and continuous bulk states of a Dirac semimetal Cd_{3}As_{2} nanowire. The discrete surface bands lead to a zero bias peak in conductance as the Femi level is tuned to across the surface subbands. The Fano resonance results in an asymmetric line shape in the differential conductance dI/dV spectrum. Furthermore, the Fano interference would introduce an additional phase into the Weyl orbits and lead to a modification of the oscillation frequency. The results are valuable for further understanding the exotic quantum transport properties of topological semimetals.

20.
J Phys Chem Lett ; 9(14): 4045-4052, 2018 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-29976067

RESUMO

Liquid-cell electron microscopy (LC-EM) provides a unique approach for in situ imaging of morphology changes of nanocrystals in liquids under electron beam irradiation. However, nanoscale real-time imaging of chemical and physical reaction processes in liquids under optical stimulus is still challenging. Here, we report direct observation of photomorphic reaction dynamics of gold nanoparticles (AuNPs) in water by liquid-cell four-dimensional electron microscopy (4D-EM) with high spatiotemporal resolution. The photoinduced agglomeration, coalescence, and fusion dynamics of AuNPs at different temperatures are studied. At low laser fluences, the AuNPs show a continuous aggregation in several seconds, and the aggregate size decreases with increasing fluence. At higher fluences close to the melting threshold of AuNPs, the aggregates further coalesced into nanoplates. While at fluences far above the melting threshold, the aggregates fully fuse into bigger NPs, which is completed within tens of nanoseconds. This liquid-cell 4D-EM would also permit study of other numerical physical and chemical reaction processes in their native environments.

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