To determine distribution of severe acute respiratory syndrome coronavirus 2 in hospital wards in Wuhan, China, we tested air and surface samples. Contamination was greater in intensive care units ...than general wards. Virus was widely distributed on floors, computer mice, trash cans, and sickbed handrails and was detected in air ≈4 m from patients.
To promote the development of high energy Li–O2 batteries, it is important to design and construct a suitable and effective oxygen‐breathing cathode. Herein, activated cobalt‐nitrogen‐doped carbon ...nanotube/carbon nanofiber composites (Co‐N‐CNT/CNF) as the effective cathodes for Li–O2 batteries are prepared by in situ chemical vapor deposition (CVD). The unique architecture of these electrodes facilitates the rapid oxygen diffusion and electrolyte penetration. Meanwhile, the nitrogen‐doped carbon nanotube/carbon nanofiber (N‐CNT/CNF) and Co/CoNx serve as reaction sites to promote the formation/decomposition of discharge product. Li–O2 batteries with Co‐N‐CNT/CNF cathodes exhibit superior electrochemical performance in terms of a positive discharge plateau (2.81 V) and a low charge overpotential (0.61 V). Besides, Li–O2 batteries also present a high discharge capacity (11512.4 mAh g−1 at 100 mA g−1), and a long cycle life (130 cycles). Meanwhile, the Co‐N‐CNT/CNF cathode also has an excellent flexibility, thus the assembled flexible battery with Co‐N‐CNT/CNF can work normally and hold a wonderful capacity rate under various bending conditions.
Activated cobalt‐nitrogen‐doped carbon nanotube/carbon nanofiber composites (Co‐N‐CNT/CNF) cathodes are prepared via in situ chemical vapor deposition. The Li–O2 batteries with these cathodes exhibit great performances. Meanwhile, Co‐N‐CNT/CNF cathodes are flexible, based on which the assembled flexible battery exhibits great performances and flexibility under various bending conditions.
Segmentation of mobile laser point clouds of urban scenes into objects is an important step for post-processing (e.g., interpretation) of point clouds. Point clouds of urban scenes contain numerous ...objects with significant size variability, complex and incomplete structures, and holes or variable point densities, raising great challenges for the segmentation of mobile laser point clouds. This paper addresses these challenges by proposing a shape-based segmentation method. The proposed method first calculates the optimal neighborhood size of each point to derive the geometric features associated with it, and then classifies the point clouds according to geometric features using support vector machines (SVMs). Second, a set of rules are defined to segment the classified point clouds, and a similarity criterion for segments is proposed to overcome over-segmentation. Finally, the segmentation output is merged based on topological connectivity into a meaningful geometrical abstraction. The proposed method has been tested on point clouds of two urban scenes obtained by different mobile laser scanners. The results show that the proposed method segments large-scale mobile laser point clouds with good accuracy and computationally effective time cost, and that it segments pole-like objects particularly well.
Electrically driven molecular light emitters are considered to be one of the promising candidates as single-photon sources. However, it is yet to be demonstrated that electrically driven ...single-photon emission can indeed be generated from an isolated single molecule notwithstanding fluorescence quenching and technical challenges. Here, we report such electrically driven single-photon emission from a well-defined single molecule located inside a precisely controlled nanocavity in a scanning tunneling microscope. The effective quenching suppression and nanocavity plasmonic enhancement allow us to achieve intense and stable single-molecule electroluminescence. Second-order photon correlation measurements reveal an evident photon antibunching dip with the single-photon purity down to g
(0) = 0.09, unambiguously confirming the single-photon emission nature of the single-molecule electroluminescence. Furthermore, we demonstrate an ultrahigh-density array of identical single-photon emitters.Molecular emitters offer a promising solution for single-photon generation. Here, by exploiting electronic decoupling by an ultrathin dielectric spacer and emission enhancement by a resonant plasmonic nanocavity, the authors demonstrate electrically driven single-photon emission from a single molecule.
Since cancer stem cells (CSCs) were first identified in leukemia in 1994, they have been considered promising therapeutic targets for cancer therapy. These cells have self-renewal capacity and ...differentiation potential and contribute to multiple tumor malignancies, such as recurrence, metastasis, heterogeneity, multidrug resistance, and radiation resistance. The biological activities of CSCs are regulated by several pluripotent transcription factors, such as OCT4, Sox2, Nanog, KLF4, and MYC. In addition, many intracellular signaling pathways, such as Wnt, NF-κB (nuclear factor-κB), Notch, Hedgehog, JAK-STAT (Janus kinase/signal transducers and activators of transcription), PI3K/AKT/mTOR (phosphoinositide 3-kinase/AKT/mammalian target of rapamycin), TGF (transforming growth factor)/SMAD, and PPAR (peroxisome proliferator-activated receptor), as well as extracellular factors, such as vascular niches, hypoxia, tumor-associated macrophages, cancer-associated fibroblasts, cancer-associated mesenchymal stem cells, extracellular matrix, and exosomes, have been shown to be very important regulators of CSCs. Molecules, vaccines, antibodies, and CAR-T (chimeric antigen receptor T cell) cells have been developed to specifically target CSCs, and some of these factors are already undergoing clinical trials. This review summarizes the characterization and identification of CSCs, depicts major factors and pathways that regulate CSC development, and discusses potential targeted therapy for CSCs.
The coherent interaction between quantum emitters and photonic modes in cavities underlies many of the current strategies aiming at generating and controlling photonic quantum states. A plasmonic ...nanocavity provides a powerful solution for reducing the effective mode volumes down to nanometre scale, but spatial control at the atomic scale of the coupling with a single molecular emitter is challenging. Here we demonstrate sub-nanometre spatial control over the coherent coupling between a single molecule and a plasmonic nanocavity in close proximity by monitoring the evolution of Fano lineshapes and photonic Lamb shifts in tunnelling electron-induced luminescence spectra. The evolution of the Fano dips allows the determination of the effective interaction distance of ∼1 nm, coupling strengths reaching ∼15 meV and a giant self-interaction induced photonic Lamb shift of up to ∼3 meV. These results open new pathways to control quantum interference and field-matter interaction at the nanoscale.
Characterization of individual trees is essential for many applications in forest management and ecology. Previous studies relied on single tree detection from monochromatic wavelength airborne laser ...scanning (ALS) systems and they focused on the use of the geometric spatial information of the point clouds (i.e., X, Y, and Z coordinates). However, there is quite often a difficulty dealing with clumped trees when only the geometric spatial information is considered. The emergence of multispectral LiDAR sensors provides a new solution for individual tree structure acquisition. The aim of this paper is to investigate the performance of multispectral ALS data for delineating individual trees which are challenging by using the monochromatic wavelength ALS system. The proposed workflow utilizes the mean shift segmentation method on different feature spaces for crown isolation. In addition, both spatial domain and multispectral domain are used to refine the under-segmentation crown segments. Ten plots (2 sets of different structural complexity) located in the dense coniferous forest area in Tobermory, Ontario, Canada are selected as experiment data. Results show that the developed method correctly detects 88% and 82% of the dominant trees with and without multispectral information, respectively. Compared with segmentation using geometric spatial information solely, the main improvements are achieved for clumped tree segment with the distinguished multispectral features. This study demonstrates that multispectral airborne laser scanning data is more capable for individual tree delineation than monochromatic wavelength laser scanning data in dealing with forests with clumped crowns in dense forests.
Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease with an increasing case number and extensive geographical expansion, raising concerns locally and globally; ...however, the description of its clinical features needs to be addressed by large studies. We aimed to determine all the clinical features of SFTS in a large population of patients in an endemic area.
In this prospective observational study, data were collected on patients admitted to the People's Liberation Army Hospital in Xinyang, Henan Province, China, with laboratory-diagnosed SFTS. Demographic, clinical, laboratory, and treatment data were collected for each patient, and patients were followed up within 2 weeks after discharge or discontinuation of treatment. The association between each demographic, clinical, and laboratory variable with a fatal outcome was assessed. A clinical scoring model was designed for the early prediction of a fatal outcome, and the effect of treatment on outcome was analysed.
Between April 1, 2011, and Oct 31, 2017, 2096 patients with laboratory-confirmed SFTS were admitted. Mean age at admission was 61·4 years (SD 12·2) and 1239 (59%) patients were female. The case fatality rate (CFR) was 16·2% (95% CI 14·6–17·8). A higher risk was associated with being male (unadjusted odds ratio OR 1·45, 95% CI 1·15–1·83; p=0·002), older age (for a 10-year increase, unadjusted OR 1·82, 95% CI 1·62–2·04; p<0·0001), longer delay in admission (for every extra day taken before admission to hospital, unadjusted OR 1·18, 1·12–1·24; p<0·0001), presence of diarrhoea (adjusted OR 1·44, 1·12–1·87; p=0·005) or dyspnoea (adjusted OR 8·35, 5·97–11·69; p<0·0001), and development of haemorrhagic signs (adjusted OR 2·79, 95% CI 2·18–3·57; p<0·0001) or neurological symptoms (adjusted OR 30·26, 21·39–42·81; p<0·0001). Laboratory variables that were associated with death included abnormal concentrations of lactate dehydrogenase, aspartate aminotransferase, and blood urea nitrogen, and abnormal neutrophil percentage, which together with age and neurological symptoms were combined in the clinical scoring system. A total score of more than 8 was the optimal threshold to predict risk of death for patients who were evaluated within 6 days after symptom onset (area under the curve 0·879, 95% CI 0·855–0·902). For all participants, viraemia was a strong predictor of fatal outcome (all p<0·0001). Ribavirin therapy was effective in reducing CFR from 6·25% (15 of 240 participants) to 1·16% (two of 173 participants), but only in patients with a viral load below 1×106 copies per mL (hazard ratio 9·72, 95% CI 1·30–72·87; p=0·027).
The changing epidemiological features and high CFR of SFTS underscore the necessity of continued surveillance. Early prediction of fatal outcome can be attained by monitoring of clinical and laboratory data. Ribavirin should be applied early, with best results achieved before the viral load reaches 1 × 106 copies per mL.
National Natural Science Foundation of China.
Point clouds collected in urban scenes contain a huge number of points (e.g., billions), numerous objects with significant size variability, complex and incomplete structures, and variable point ...densities, raising great challenges for the automated extraction of urban objects in the field of photogrammetry, computer vision, and robotics. This paper addresses these challenges by proposing an automated method to extract urban objects robustly and efficiently. The proposed method generates multi-scale supervoxels from 3D point clouds using the point attributes (e.g., colors, intensities) and spatial distances between points, and then segments the supervoxels rather than individual points by combining graph based segmentation with multiple cues (e.g., principal direction, colors) of the supervoxels. The proposed method defines a set of rules for merging segments into meaningful units according to types of urban objects and forms the semantic knowledge of urban objects for the classification of objects. Finally, the proposed method extracts and classifies urban objects in a hierarchical order ranked by the saliency of the segments. Experiments show that the proposed method is efficient and robust for extracting buildings, streetlamps, trees, telegraph poles, traffic signs, cars, and enclosures from mobile laser scanning (MLS) point clouds, with an overall accuracy of 92.3%.
Patients with metastatic colorectal cancer (CRC) have limited effective and tolerable treatment options.
To evaluate the efficacy and safety of oral fruquintinib, a vascular endothelial growth factor ...receptor (VEGFR) inhibitor, as third-line or later therapy in patients with metastatic CRC.
FRESCO (Fruquintinib Efficacy and Safety in 3+ Line Colorectal Cancer Patients) was a randomized, double-blind, placebo-controlled, multicenter (28 hospitals in China), phase 3 clinical trial. From December 2014 to May 2016, screening took place among 519 patients aged 18 to 75 years who had metastatic CRC that progressed after at least 2 lines of chemotherapy but had not received VEGFR inhibitor therapy; 416 met the eligibility criteria and were stratified by prior anti-VEGF therapy and K-ras status. The final date of follow-up was January 17, 2017.
Patients were randomized in a 2:1 ratio to receive either fruquintinib, 5 mg (n = 278) or placebo (n = 138) orally, once daily for 21 days, followed by 7 days off in 28-day cycles, until disease progression, intolerable toxicity, or study withdrawal.
The primary end point was overall survival. Key secondary efficacy endpoints were progression-free survival (time from randomization to disease progression or death), objective response rate (confirmed complete or partial response), and disease control rate (complete or partial response, or stable disease recorded ≥8 weeks postrandomization). Duration of response was also assessed. Safety outcomes included treatment-emergent adverse events.
Of the 416 randomized patients (mean age, 54.6 years; 161 38.7% women), 404 (97.1%) completed the trial. Median overall survival was significantly prolonged with fruquintinib compared with placebo (9.3 months 95% CI, 8.2-10.5 vs 6.6 months 95% CI, 5.9-8.1); hazard ratio (HR) for death, 0.65 (95% CI, 0.51-0.83; P < .001). Median progression-free survival was also significantly increased with fruquintinib (3.7 months 95% CI, 3.7-4.6 vs 1.8 months 95% CI, 1.8-1.8 months); HR for progression or death, 0.26 (95% CI, 0.21 to 0.34; P < .001). Grades 3 and 4 treatment-emergent adverse events occurred in 61.2% (170) of patients who received fruquintinib and 19.7% (27) who received placebo. Serious adverse events were reported by 15.5% (43) of patients in the fruquintinib group and 5.8% (8) in the placebo group, with 14.4% (40) of fruquintinib-treated and 5.1% (7) of placebo-treated patients requiring hospitalization.
Among Chinese patients with metastatic CRC who had tumor progression following at least 2 prior chemotherapy regimens, oral fruquintinib compared with placebo resulted in a statistically significant increase in overall survival. Further research is needed to assess efficacy outside of China.
ClinicalTrials.gov Identifier: NCT02314819.
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