The outbreak of a novel coronavirus (SARS‐CoV‐2) since December 2019 in Wuhan, the major transportation hub in central China, became an emergency of major international concern. While several ...etiological studies have begun to reveal the specific biological features of this virus, the epidemic characteristics need to be elucidated. Notably, a long incubation time was reported to be associated with SARS‐CoV‐2 infection, leading to adjustments in screening and control policies. To avoid the risk of virus spread, all potentially exposed subjects are required to be isolated for 14 days, which is the longest predicted incubation time. However, based on our analysis of a larger dataset available so far, we find there is no observable difference between the incubation time for SARS‐CoV‐2, severe acute respiratory syndrome coronavirus (SARS‐CoV), and middle east respiratory syndrome coronavirus (MERS‐CoV), highlighting the need for larger and well‐annotated datasets.
Highlights
It is unclear whether there are statistically significant differences in incubation times amongst SARS‐CoV‐2, SARS‐CoV and MERS‐CoV. However, this is because: 1) Limited available data challenges investigation of the current coronavirus outbreak. 2) Lack of annotation also makes it difficult to identify and consolidate the datasets. Thus, care should be taken when selecting datasets for comparative analysis with other viruses or outbreaks.
Inflammatory bowel disease (IBD) is a chronic, inflammatory, and autoimmune disorder. The pathogenesis of IBD is not yet clear. Studies have shown that the imbalance between T helper 17 (Th17) and ...regulatory T (Treg) cells, which differentiate from CD4+ T cells, contributes to IBD. Th17 cells promote tissue inflammation, and Treg cells suppress autoimmunity in IBD. Therefore, Th17/Treg cell balance is crucial. Some regulatory factors affecting the production and maintenance of these cells are also important for the proper regulation of the Th17/Treg balance; these factors include T cell receptor (TCR) signaling, costimulatory signals, cytokine signaling, bile acid metabolites, and the intestinal microbiota. This article focuses on our understanding of the function and role of the balance between Th17/Treg cells in IBD and these regulatory factors and their clinical significance in IBD.
Although lipopolysaccharides (LPS) have been used to establish animal models of memory loss akin to what is observed in Alzheimer's disease (AD), the exact mechanisms involved have not been ...substantiated. In this study, we established an animal model of learning and memory impairment induced by LPS and explored the biological processes and pathways involved. Mice were continuously intraperitoneally injected with LPS for 7 days. Learning- and memory-related behavioral performance and the pathological processes involved were assessed using the Morris water maze test and immunostaining, respectively. We detected comprehensive expression of C1q, C3, microglia, and their regulatory cytokines in the hippocampus. After 7 days of LPS administration, we were able to observe LPS-induced learning and memory impairment in the mice, which was attributed to neural impairment and synapse loss in the hippocampus. We elucidated that the immune system was activated, with the classical complement pathway and microglial phagocytosis being involved in the synapse loss. This study demonstrates that an LPS-injected mouse can serve as an early memory impairment model for studies on anti-AD drugs.
•We included 62 studies from 17 countries assessing psychological distress of COVID-19.•We found a high psychological burden among medical staff and the general public.•However, the psychological ...distress was significantly higher among patients.•We identified risk factors of psychological burdens to identify high-risk people.•Professional medical services should be allocated to high-risk population.•More self-help materials should be made available for people with milder impact.
The coronavirus disease 2019 (COVID-19) pandemic has caused enormous psychological impact worldwide. We conducted a systematic review and meta-analysis on the psychological and mental impact of COVID-19 among healthcare workers, the general population, and patients with higher COVID-19 risk published between 1 Nov 2019 to 25 May 2020. We conducted literature research using Embase, PubMed, Google scholar and WHO COVID-19 databases. Among the initial search of 9207 studies, 62 studies with 162,639 participants from 17 countries were included in the review. The pooled prevalence of anxiety and depression was 33% (95% confidence interval: 28%-38%) and 28% (23%-32%), respectively. The prevalence of anxiety and depression was the highest among patients with pre-existing conditions and COVID-19 infection (56% 39%-73% and 55% 48%-62%), and it was similar between healthcare workers and the general public. Studies from China, Italy, Turkey, Spain and Iran reported higher-than-pooled prevalence among healthcare workers and the general public. Common risk factors included being women, being nurses, having lower socioeconomic status, having high risks of contracting COVID-19, and social isolation. Protective factors included having sufficient medical resources, up-to-date and accurate information, and taking precautionary measures. In conclusion, psychological interventions targeting high-risk populations with heavy psychological distress are in urgent need.
The glutamatergic projection from the motor cortex to the subthalamic nucleus (STN) constitutes the cortico-basal ganglia circuit and plays a critical role in the control of movement. Emerging ...evidence shows that the cortico-STN pathway is susceptible to dopamine depletion. Specifically in Parkinson's disease (PD), abnormal electrophysiological activities were observed in the motor cortex and STN, while the STN serves as a key target of deep brain stimulation for PD therapy. However, direct morphological changes in the cortico-STN connectivity in response to PD progress are poorly understood at present. In the present study, we used a trans-synaptic anterograde tracing method with herpes simplex virus-green fluorescent protein (HSV-GFP) to monitor the cortico-STN connectivity in a rat model of PD. We found that the connectivity from the primary motor cortex (M1) to the STN was impaired in parkinsonian rats as manifested by a marked decrease in trans-synaptic infection of HSV-GFP from M1 neurons to STN neurons in unilateral 6-hydroxydopamine (6-OHDA)-lesioned rats. Ultrastructural analysis with electron microscopy revealed that excitatory synapses in the STN were also impaired in parkinsonian rats. Glutamatergic terminals identified by a specific marker (vesicular glutamate transporter 1) were reduced in the STN, while glutamatergic neurons showed an insignificant change in their total number in both the M1 and STN regions. These results indicate that the M1-STN glutamatergic connectivity is downregulated in parkinsonian rats. This downregulation is mediated probably via a mechanism involving the impairments of excitatory terminals and synapses in the STN.
•M1-STN anatomical connectivity is reduced by 73%–88% in parkinsonian rats.•Excitatory synapses are impaired in the STN of parkinsonian rats.•VGluT1 expression level is down-regulated in the STN of parkinsonian rats.
•A state-of-the-art review on particle methods for ocean/coastal engineering is presented.•The review is presented in three main categories of wave hydrodynamics, wave-structure interaction and ...wave-current-sediment interaction.•The review covers a wide range of engineering applications of particle methods as well as their numerical developments.•Future perspectives for extension/enhancement of particle methods are highlighted.
This paper aims at providing a state-of-the-art review on the applications of particle methods in hydrodynamics-related problems in ocean and coastal engineering. The problems are placed into three categories according to their physical characteristics, namely, wave hydrodynamics and corresponding mass (air, oil, etc.) transport, wave-structure interaction, and wave-current-sediment interaction. For the first category, particle-based simulations of wave generation, propagation, breaking, as well as the associated turbulence production and dissipation, air entrainment, and mass transport, are reviewed. For wave-structure interaction, extensive structural types are considered that include fixed and moving (floating) structures, rigid and deformable structures, impermeable and porous structures, etc. For the third category, the latest advances of particle methods in wave/current interaction with sediments, i.e., sediment transport and coastal morphological changes, are outlined. This article also reviews the latest developments of particle methods with respect to enhancement of numerical stability, accuracy, efficiency and consistency in order to handle the multi-physics and multi-scale problems emerging from coastal and ocean engineering practices. Finally, the future perspectives of extending particle methods to a wider range of ocean and coastal engineering applications are highlighted.
The basolateral amygdala (BLA) and ventral hippocampal CA1 (vCA1) are cellularly and functionally diverse along their anterior-posterior and superficial-deep axes. Here, we find that anterior BLA ...(aBLA) and posterior BLA (pBLA) innervate deep-layer calbindin1-negative (Calb1-) and superficial-layer calbindin1-positive neurons (Calb1+) in vCA1, respectively. Photostimulation of pBLA-vCA1 inputs has an anxiolytic effect in mice, promoting approach behaviours during conflict exploratory tasks. By contrast, stimulating aBLA-vCA1 inputs induces anxiety-like behaviour resulting in fewer approaches. During conflict stages of the elevated plus maze task vCA1
neurons are preferentially activated at the open-to-closed arm transition, and photostimulation of vCA1
neurons at decision-making zones promotes approach with fewer retreats. In the APP/PS1 mouse model of Alzheimer's disease, which shows anxiety-like behaviour, photostimulating the pBLA-vCA1
circuit ameliorates the anxiety in a Calb1-dependent manner. These findings suggest the pBLA-vCA1
circuit from heterogeneous BLA-vCA1 connections drives approach behaviour to reduce anxiety-like behaviour.
The catalyst was synthesized by a two-step calcination method. Advances of the in-situ growth allow intimate and enhanced the interfacial separation of charge carriers. At the same time, Co ...modification was introduced to regulate the adsorption energy of N2 and NH3 to achieve adsorption equilibrium. The obtained catalyst had high activity and stability in photocatalitic nitrogen fixation.
Display omitted
Modulation of the binding of the reactant or product species with catalysts is an effective approach to optimize the photocatalytic activity. Herein, we explored the relationship between the binding of reactant (N2) and product (NH3) with catalyst and the photocatalytic nitrogen fixation activity. The surface reactivity of nitrogen with water was tuned by introducing Co into the MXene@TiO2 catalysts, which the TiO2 nanoparticle derived from the in-situ growth on the surface of MXene nanosheets. Co modified adjusted the chemisorption equilibrium of the catalyst for reactant (N2) and product (NH3), thus promoted product desorption and efficiency of the active site. Remarkably, the optimal catalyst (MXene/TiO2/Co-0.5%) exhibited outstanding NH4+ production rate (110 μmol g−1 h−1) and excellent stability in pure water without any hole sacrificial agent under Ultraviolet–Visible (UV–vis) light in N2 and air ambient.
Electrocatalytic nitrogen reduction at ambient temperature is a green technology for artificial nitrogen fixation but greatly challenging with low yield and poor selectivity. Here, a nanoporous ...ordered intermetallic Pd3Bi prepared by converting chemically etched nanoporous PdBi2 exhibits efficient electrocatalytic nitrogen reduction under ambient conditions. The resulting nanoporous intermetallic Pd3Bi can achieve high activity and selectivity with an NH3 yield rate of 59.05 ± 2.27 µg h−1 mgcat−1 and a Faradaic efficiency of 21.52 ± 0.71% at −0.2 V versus the reversible hydrogen electrode in 0.05 m H2SO4 electrolyte, outperforming most of the reported catalysts in electrochemical nitrogen reduction reaction (NRR). Operando X‐ray absorption spectroscopy studies combined with density functional theory calculations reveal that strong coupling between the Pd–Bi sites bridges the electron‐transfer channel of intermetallic Pd3Bi, in which the Bi sites can absorb N2 molecules and lower the energy barrier of *N2 for N2 adsorption and activation. Meanwhile, the intermetallic Pd3Bi with bicontinuous nanoporous structure can accelerate the electron transport during the NRR process, thus improving the NRR performance.
Nanoporous ordered intermetallic Pd3Bi is prepared through electrochemical etching of PdBi2, and it can achieve extraordinary catalytic performance with high selectivity and excellent stability for electrochemical nitrogen reduction reaction (NRR) at ambient conditions. The intermetallic interaction between the Pd and neighboring Bi sites in nanoporous Pd3Bi can stabilize the transition state and lower the barrier for efficient NRR.
The multipotent mesenchymal stem/stromal cells (MSCs), initially discovered from bone marrow in 1976, have been identified in nearly all tissues of human body now. The multipotency of MSCs allows ...them to give rise to osteocytes, chondrocytes, adipocytes, and other lineages. Moreover, armed with the immunomodulation capacity and tumor-homing property, MSCs are of special relevance for cell-based therapies in the treatment of cancer. However, hampered by lack of knowledge about the controversial roles that MSC plays in the crosstalk with tumors, limited progress has been made with regard to translational medicine. Therefore, in this review, we discuss the prospects of MSC-associated anticancer strategies in light of therapeutic mechanisms and signal transduction pathways. In addition, the clinical trials designed to appraise the efficacy and safety of MSC-based anticancer therapies will be assessed according to published data.
PDF
