The recent Zika virus （ZIKV） epidemic in Latin America coincided with a marked increase in microcephaly in newborns. However, the causal link between maternal ZIKV infection and malformation of the ...fetal brain has not been firmly established. Here we show a vertical transmission of ZIKV in mice and a marked effect on fetal brain development. We found that intraperitoneal （i.p.） injection of a contemporary ZIKV strain in pregnant mice led to the infection of radial gila cells （RGs） of dorsal ventricular zone of the fetuses, the primary neural progenitors responsi- ble for cortex development, and caused a marked reduction of these cortex founder cells in the fetuses. Interestingly, the infected fetal mice exhibited a reduced cavity of lateral ventricles and a discernable decrease in surface areas of the cortex. This study thus supports l;he conclusion that vertically transmitted ZIKV affects fetal brain development and provides a valuable animal model for the evaluation of potential therapeutic or preventative strategies.
Biomimetic assembly of high-quality nanosheets into nacre-like structures can produce macroscopic films with favorable mechanical and optical performances due to the intrinsic properties and high ...level of ordering of the nanoscale building blocks. Natural ground mica is abundant and exhibits great application potential. However, large size and low aspect ratio greatly limit its biomimetic assembly. Moreover, exfoliation of ground mica into high-quality nanosheets remains a significant challenge. Here, we report that large-scale exfoliation of ground mica into mono- or few-layered mica nanosheets with a production rate of ~1.0 g h
can be successfully achieved. The mica nanosheets are then assembled into strong biomimetic polymeric mica film that inherits the high electric insulation, excellent visible transmittance, and unique ultraviolet-shielding properties of natural mica. Its overall performance is superior to that of natural sheet mica and other biomimetic films, making the polymeric mica film a suitable substrate for flexible and transparent devices.
Summary
Background
Finite nucleos(t)ide analogue (NUC) therapy has been proposed as an alternative treatment strategy for chronic hepatitis B (CHB).
Aim
To quantify the incidence of severe hepatitis ...flares following NUC cessation in everyday clinical practice.
Methods
This population‐based cohort study enrolled 10,192 patients (male 71.7%, median age 50.9 years, cirrhosis 10.7%) who had received first‐line NUCs for at least 1 year before discontinuing treatment. The primary outcome was severe flare with hepatic decompensation. We used competing risk analyses to assess event incidences and associated risk factors.
Results
During a median follow‐up of 2.2 years, 132 patients developed severe flares with hepatic decompensation, yielding a 4‐year cumulative incidence of 1.8% (95% confidence interval CI, 1.5%–2.2%). Significant risk factors were cirrhosis (adjusted sub‐distributional hazard ratio aSHR, 2.74; 95% CI, 1.82–4.12), manifestations of portal hypertension (aSHR, 2.46; 95% CI, 1.45–4.18), age (aSHR, 1.21 per 10 years; 95% CI, 1.03–1.42) and male sex (aSHR, 1.58; 95% CI, 1.04–2.38). In patients without cirrhosis or portal hypertension (n = 8863), the 4‐year cumulative incidence of severe withdrawal flares stood at 1.3% (95% CI, 1.0%–1.7%). For those patients with available data confirming adherence to the standard stopping rules (n = 1274), the incidence was 1.1% (95% CI, 0.6%–2.0%).
Conclusions
Severe flares with hepatic decompensation were observed in 1%–2% of patients with CHB after stopping NUC therapy in daily practice. Risk factors included older age, cirrhosis, portal hypertension and male sex. Our findings argue against NUC cessation as part of routine clinical care.
A nationwide population‐based cohort study revealed that severe hepatitis flares complicated with hepatic decompensation occurred in 1–2% of patients with chronic hepatitis B after discontinuing nucleos(t)ide analogue therapy.
Perovskite solar cells (PSCs) have received great attention due to their outstanding performance and their low processing costs. To boost their performance, one approach is to reinforce the built‐in ...electric field (BEF) to promote oriented carrier transport. The BEF is maximized by reinforcing the work function difference between cathode and anode (Δμ1) and increasing the work function difference between lower and upper surfaces of perovskite film (Δμ2) via introduction of electric dipole molecules, denoted as PTFCN and CF3BACl. The synergistic reinforcement of BEF improves charge transport and collection, and realizes markedly high photovoltaic performances with the best power conversion efficiency (PCE) up to 21.5%, a growth of 15.6% as compared to the control device, which is higher than the superposition of improvements achieved by either raising Δμ1 or Δμ2. Importantly, dual‐functional CF3BACl not only supplies dipole effect for tuning the surface potential of perovskite but offers hydrophobic trifluoride group toward the long‐term stable unencapsulated PSCs retaining more than 95% PCE after storing 2000 h under ambient conditions. This work demonstrates the synergistic effect of Δμ1 and Δμ2, providing an effective strategy for the further development of PSC in terms of photovoltaic conversion and stability.
The built‐in electric field of a perovskite solar cell is reinforced by introducing electric dipole molecules, and the oriented charge transfer and collection are significantly improved. An efficiency of 21.5% is demonstrated and the average stability of the NMFL device retains 95% of the power conversion efficiency after storing over 2000 h under ambient conditions.
The existence of spontaneous magnetization in low dimensional magnetic systems has attracted intensive studies since the early 60s and research remains very active even now. Only recently, magnetic ...van der Waals (vdW) systems down to a few layers have been broadly discussed for their magnetic order ground states at finite temperature. The naturally inherited layered structure of the vdW magnetic systems possessing onsite magnetic anisotropy from band electrons can suppress the long‐range fluctuations. This provides an excellent vehicle to study the transition of magnetism to 2D limits both theoretically and experimentally. Here the current status of 2D vdW magnetic system and its potential applications are briefly summarized and discussed.
Recently, magnetic van der Waals (vdW) systems down to the single layer limit have been studied intensively. Herein, the current status of 2D vdW magnetic systems is summarized from both a theoretical and an experimental point of view. The fundamental physics of 2D magnetism are discussed, along with the future outlook and potential applications of 2D vdW magnetic systems.
Silicon nanostructure-based solar cells have lately intrigued intensive interest because of their promising potential in next-generation solar energy conversion devices. Herein, we report a silicon ...nanowire (SiNW) array/carbon quantum dot (CQD) core–shell heterojunction photovoltaic device by directly coating Ag-assisted chemical-etched SiNW arrays with CQDs. The heterojunction with a barrier height of 0.75 eV exhibited excellent rectifying behavior with a rectification ratio of 103 at ±0.8 V in the dark and power conversion efficiency (PCE) as high as 9.10% under AM 1.5G irradiation. It is believed that such a high PCE comes from the improved optical absorption as well as the optimized carrier transfer and collection capability. Furthermore, the heterojunction could function as a high-performance self-driven visible light photodetector operating in a wide switching wavelength with good stability, high sensitivity, and fast response speed. It is expected that the present SiNW array/CQD core–shell heterojunction device could find potential applications in future high-performance optoelectronic devices.
Primary lung cancer is one of the most common malignant tumors in China. Approximately 60% of lung cancer patients have distant metastasis at the initial diagnosis, so it is necessary to find new ...tumor markers for early diagnosis and individualized treatment. Tumor markers contribute to the early diagnosis of lung cancer and play important roles in early detection and treatment, as well as in precision medicine, efficacy monitoring, and prognosis prediction. The pathological diagnosis of lung cancer in small biopsy specimens determines whether there are tumor cells in the biopsy and tumor type. Because biopsy is traumatic and the compliance of patients with multiple biopsies is poor, liquid biopsy has become a hot research direction. Liquid biopsies are advantageous because they are nontraumatic, easy to obtain, reflect the overall state of the tumor, and allow for real-time monitoring. At present, liquid biopsies mainly include circulating tumor cells, circulating tumor DNA, exosomes, microRNA, circulating RNA, tumor platelets, and tumor endothelial cells. This review introduces the research progress and clinical application prospect of liquid biopsy technology for lung cancer.
Manipulation of magnetization by electric‐current‐induced spin–orbit torque (SOT) is of great importance for spintronic applications because of its merits in energy‐efficient and high‐speed ...operation. An ideal material for SOT applications should possess high charge‐spin conversion efficiency and high electrical conductivity. Recently, transition metal dichalcogenides (TMDs) emerge as intriguing platforms for SOT study because of their controllability in spin–orbit coupling, conductivity, and energy band topology. Although TMDs show great potentials in SOT applications, the present study is restricted to the mechanically exfoliated samples with small sizes and relatively low conductivities. Here, a manufacturable recipe is developed to fabricate large‐area thin films of PtTe2, a type‐II Dirac semimetal, to study their capability of generating SOT. Large SOT efficiency together with high conductivity results in a giant spin Hall conductivity of PtTe2 thin films, which is the largest value among the presently reported TMDs. It is further demonstrated that the SOT from PtTe2 layer can switch a perpendicularly magnetized CoTb layer efficiently. This work paves the way for employing PtTe2‐like TMDs for wafer‐scale spintronic device applications.
PtTe2, a layered type‐II Dirac semimetal, is successfully synthesized in a scalable and controllable manner. High spin–orbit torque and large spin Hall conductivity are found in these PtTe2 thin films, which manifest the potential of PtTe2 thin film for energy‐efficient magnetization switching. The experiments establish a primary basis for further research on similar systems for high‐performance spintronic devices.
Zika virus (ZIKV) has become a threat to global health since the outbreak in Brazil in 2015. Although ZIKV is generally considered an Aedes-transmitted pathogen, new evidence has shown that parts of ...the virus closely resemble Culex-transmitted viruses. Therefore, it is important to evaluate the competence of Culex species for ZIKV to understand their potential as vectors. In this study, female Culex pipiens quinquefasciatus were orally exposed to ZIKV. Mosquito midguts, salivary glands and ovaries were tested for ZIKV to measure infection and dissemination at 2, 4, 6, 8, 12, 16 and 18 days post exposure (pe). In addition, saliva was collected from mosquitoes after infection and infant mice were bitten by infected mosquitoes to measure the transmission ability of Cx. p. quinquefasciatus. The results showed that the peak time of virus appearance in the salivary glands was day 8 pe, with 90% infection rate and an estimated virus titer of 3.92±0.49 lg RNA copies/mL. Eight of the nine infant mice had positive brains after being bitten by infected mosquitoes, which meant that Cx. p. quinquefasciatus could be infected with and transmit ZIKV following oral infection. These laboratory results clearly demonstrate the potential role of Cx. p. quinquefasciatus as a vector of ZIKV in China. Because there are quite different vector management strategies required to control Aedes (Stegomyia) species and Cx. p. quinquefasciatus, an integrated approach may be required should a Zika epidemic occur.
Near infrared light photodiodes have been attracting increasing research interest due to their wide application in various fields. In this study, the fabrication of a new n‐type GaAs nanocone ...(GaAsNCs) array/monolayer graphene (MLG) Schottky junction is reported for NIR light detection. The NIR photodetector (NIRPD) shows obvious rectifying behavior with a turn‐on voltage of 0.6 V. Further device analysis reveals that the photovoltaic NIRPDs are highly sensitive to 850 nm light illumination, with a fast response speed and good spectral selectivity at zero bias voltage. It is also revealed that the NIRPD is capable of monitoring high‐switching frequency optical signals (∼2000 Hz) with a high relative balance. Theoretical simulations based on finite difference time domain (FDTD) analysis finds that the high device performance is partially associated with the optical property, which can trap most incident photons in an efficient way. It is expected that such a self‐driven NIRPD will have potential application in future optoelectronic devices.
A new Schottky junction near‐infrared light photodetector is fabricated by coating a GaAs nanocone array with a monolayer graphene film, which shows high sensitivity to near‐infrared light irradiation, with good reproducibility, excellent selectivity, and rapid response speed.
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