Chemical loss of volatile organic compounds (VOCs) is more important than the observed VOCs, which is the real actor of the chemical process in the atmosphere. The chemical loss of VOCs might impact ...on the identification of VOCs sources in ambient. For this reason, VOCs with 56 species were continuously measured in the urban area of Shanghai from 2009 to 2010, and based on the measurement the chemical loss of VOCs was calculated. According to the result, the initial VOCs in Shanghai urban was (34.8 ± 20.7) ppbv, higher than the observed one by ∼35%, including alkanes (∼38%), aromatics (∼36%), alkenes (∼17%), and acetylene (∼8%). The chemical reactivity of VOCs would be underestimated by ∼60% if the chemical loss were ignored. The chemical loss of VOCs showed a good agreement with Ox (O3 + NO2). C7–C8 aromatics and C3–C5 alkenes contributed ∼60% of consumed VOCs. Seven sources were identified and quantified from positive matrix factorization (PMF) analysis. Vehicular emissions were the largest anthropogenic source of VOCs in Shanghai urban, accounting for 27.6% of VOCs, followed by solvent usage (19.4%), chemical industry (13.2%), petrochemical industry (9.1%), and coal burning (∼5%). The contribution of biogenic emissions to total VOCs was 5.8%. Besides the five local anthropogenic sources and one biogenic source, the regional transportation was identified as one important source, contributing about 20% of VOCs in Shanghai urban. Sources apportionment results from PMF analysis based on the initial VOCs showed some differences from those based on observed data and might be more appropriate to be applied into the formulation of air pollution control measures.
•35% initial VOCs had been consumed during the transport from sources to the receptor.•Reactivity of VOCs was underestimated over 60% if the removal of VOCs was ignored.•C3–C5 alkenes and C8 aromatics contributed over 60% of the chemical loss of VOCs.•Seven sources of VOCs were identified and quantified in Shanghai urban.•The regional transportation contributed ∼20% of VOCs in Shanghai urban from PMF.
Growing interest in quantum computing for practical applications has led to a surge in the availability of programmable machines for executing quantum algorithms
. Present-day photonic quantum ...computers
have been limited either to non-deterministic operation, low photon numbers and rates, or fixed random gate sequences. Here we introduce a full-stack hardware-software system for executing many-photon quantum circuit operations using integrated nanophotonics: a programmable chip, operating at room temperature and interfaced with a fully automated control system. The system enables remote users to execute quantum algorithms that require up to eight modes of strongly squeezed vacuum initialized as two-mode squeezed states in single temporal modes, a fully general and programmable four-mode interferometer, and photon number-resolving readout on all outputs. Detection of multi-photon events with photon numbers and rates exceeding any previous programmable quantum optical demonstration is made possible by strong squeezing and high sampling rates. We verify the non-classicality of the device output, and use the platform to carry out proof-of-principle demonstrations of three quantum algorithms: Gaussian boson sampling, molecular vibronic spectra and graph similarity
. These demonstrations validate the platform as a launchpad for scaling photonic technologies for quantum information processing.
The infusion of coronavirus disease 2019 (COVID-19) patients with mesenchymal stem cells (MSCs) potentially improves clinical symptoms, but the underlying mechanism remains unclear. We conducted a ...randomized, single-blind, placebo-controlled (29 patients/group) phase II clinical trial to validate previous findings and explore the potential mechanisms. Patients treated with umbilical cord-derived MSCs exhibited a shorter hospital stay (P = 0.0198) and less time required for symptoms remission (P = 0.0194) than those who received placebo. Based on chest images, both severe and critical patients treated with MSCs showed improvement by day 7 (P = 0.0099) and day 21 (P = 0.0084). MSC-treated patients had fewer adverse events. MSC infusion reduced the levels of C-reactive protein, proinflammatory cytokines, and neutrophil extracellular traps (NETs) and promoted the maintenance of SARS-CoV-2-specific antibodies. To explore how MSCs modulate the immune system, we employed single-cell RNA sequencing analysis on peripheral blood. Our analysis identified a novel subpopulation of VNN2
hematopoietic stem/progenitor-like (HSPC-like) cells expressing CSF3R and PTPRE that were mobilized following MSC infusion. Genes encoding chemotaxis factors - CX3CR1 and L-selectin - were upregulated in various immune cells. MSC treatment also regulated B cell subsets and increased the expression of costimulatory CD28 in T cells in vivo and in vitro. In addition, an in vivo mouse study confirmed that MSCs suppressed NET release and reduced venous thrombosis by upregulating kindlin-3 signaling. Together, our results underscore the role of MSCs in improving COVID-19 patient outcomes via maintenance of immune homeostasis.
On the basis of the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC)‐measured fluctuations in the signal‐to‐noise ratio and excess phase of the GPS signal piercing ...through ionospheric sporadic E (Es) layers, the general morphologies of these layers are presented for the period from July 2006 to May 2011. It is found that the latitudinal variation in the Es layer occurrence is substantially geomagnetically controlled, most frequent in the summer hemisphere within the geomagnetic latitude region between 10° and 70° and very rare in the geomagnetic equatorial zone. Model simulations show that the summer maximum (winter minimum) in the Es layer occurrence is very likely attributed to the convergence of the Fe+ concentration flux driven by the neutral wind. In addition to seasonal and spatial distributions, the height‐time variations in the Es layer occurrence in the midlatitude (>30°) region in summer and spring are primarily dominated by the semidiurnal tides, which start to appear at local time around 6 and 18 h in the height range 110–120 km and gradually descend at a rate of about 0.9–1.6 km/h. In the low‐latitude (<30°) region, the diurnal tide dominates. The Horizontal Wind Model (HWM07) indicates that the height‐time distribution of Es layers at middle latitude (30°–60°) is highly coincident with the zonal neutral wind shear. However, Es layer occurrences in low‐latitude and equatorial regions do not correlate well with the zonal wind shear.
Key Points
Examination of Es layer summer maximum phenomenon
Global distribution of COSMIC‐retrieved Es layer
Es layer formation and wind shear mechanism
A nasopharyngeal carcinoma (NPC) mass screening trial using a combination of immunoglobulin A antibodies to Epstein-Barr virus capsid antigen and nuclear antigen-1 by enzyme-linked immunosorbent ...assay in addition to indirect mirror examination in the nasopharynx and/or lymphatic palpation (IMLP) was conducted in southern China. Cantonese aged 30-59 years residing in 2 cities randomly selected by cluster sampling, Sihui and Zhongshan, were invited to participate in this screening from May 2008 through May 2010. Participants were offered fiberoptic endoscopy examination and/or pathologic biopsy if their serologic tests reached our predefined level of high risk or if results from the physical examination indicated possible cancer (i.e., were IMLP positive). A total of 28,688 individuals were voluntarily screened in the initial round. The overall NPC detection rate was 0.14% (41/28,688) with an early diagnosis rate of 68.3% (28/41) during the first year of follow-up. Thirty-eight of 41 cases (92.7%) were detected among the high-risk group, and 7 of 41 cases (17.1%) were detected among the IMLP-positive group. The 2 Epstein-Barr virus serologic tests by enzyme-linked immunosorbent assay could be a feasible alternative for NPC screening in endemic areas. Further follow-up is needed to examine whether screening has an effect on decreasing mortality from NPC in these areas.
Silver staining, which exploits the special bioaffinity and the chromogenic reduction of silver ions, is an indispensable visualization method in biology. It is a most popular method for in‐gel ...protein detection. However, it is limited by run‐to‐run variability, background staining, inability for protein quantification, and limited compatibility with mass spectroscopic (MS) analysis; limitations that are largely attributed to the tricky chromogenic visualization. Herein, we reported a novel water‐soluble fluorogenic Ag+ probe, the sensing mechanism of which is based on an aggregation‐induced emission (AIE) process driven by tetrazolate‐Ag+ interactions. The fluorogenic sensing can substitute the chromogenic reaction, leading to a new fluorescence silver staining method. This new staining method offers sensitive detection of total proteins in polyacrylamide gels with a broad linear dynamic range and robust operations that rival the silver nitrate stain and the best fluorescent stains.
Fluorogenic development of silver: Reported is a fluorogenic Ag+ detection system accomplished by a spontaneous tetrazolate–Ag+ aggregation. This system can substitute the tricky chromogenic reduction step of the traditional silver staining methods with a fluorogenic detection step, leading to a sensitive and robust fluorescent visualization of total proteins.
ApKUPs are typical high-affinity potassium (K⁺) transporters of Alternanthera philoxeroides which are involved in its response to K⁺ starvation and abiotic stresses. In this study, the overexpression ...of ApKUP3 gene in rice resulted in enhanced K⁺ nutrition and drought tolerance of transgenic plants. Compared with wild-type (WT) plants, the transgenic plants showed a better growth performance and a strengthened K⁺ accumulation under different K⁺ supplies. The ApKUP3 overexpression in the rice plants also enhanced tolerance to a drought stress, as evidenced by a reduced leaf water loss and an increased total leaf chlorophyll content, stomatal conductance, net photosynthetic rate, and activities of superoxide dismutase, peroxidase, and ascorbate peroxidase (APX). Moreover, the transcription of genes involved in the antioxidation defense system were higher in the transgenic plants than in the WT plants upon the drought stress.
Linking topology in oligocarbazoles (see figure) has a strong influence on their electronic properties. 3(6),9′‐linked oligocarbazoles exhibit unusual suppression of electronic coupling between ...units, leading to localized excited states and very small reduction of triplet energies (compared to the monomer). Coupled with their excellent morphological stability, this makes them suitable as host materials for blue electrophosphorescence devices.
Objectives
Summarize the existing evidence regarding the prevalence and risk factors of frailty in stroke patients.
Design
A meta-analysis and systematic review.
Participants
Stroke patients in ...hospitals or communities.
Methods
We undertook a systematic review and meta-analysis using articles available in 8 databases, including PubMed, The Cochrane Library, Web of Science, Embase, Chinese Biomedical Database (CBM), China National Knowledge Infrastructure Database (CNKI), Wanfang Database, and Weipu Database (VIP) from January 1990 to April 2022. Studies were quality rated using the Newcastle-Ottawa Scale and Agency for Healthcare Research and Quality tool.
Results
A total of 24 studies involving 30,423 participants were identified. The prevalence of frailty and pre-frailty in stroke patients was 27% (95%CI: 0.23–0.31) and 47.9% (95%CI: 0.43–0.53). Female gender (OR = 1.76, 95%CI: 1.63–1.91), advanced age (MD = 6.73, 95%CI: 3.55–9.91), diabetes (OR = 1.34, 95%CI: 1.06–1.69), hyperlipidemia (OR = 1.46, 95%CI: 1.04–2.04), atrial fibrillation (OR = 1.36, 95%CI: 1.01–1.82), National Institutes of Stroke Scale (NIHSS) admission scores (MD = 2.27, 95%CI: 1.72–2.81) were risk factors of frailty in stroke patients.
Conclusions
Frailty was more prevalent in stroke patients. Female gender, advanced age, diabetes, hyperlipidemia, atrial fibrillation, and National Institutes of Stroke Scale (NIHSS) admission scores were identified as risk factors for frailty in stroke patients. In the future, medical staff should pay attention to the early screening of frailty in high-risk groups and provide information on its prevention.
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