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We observed bacterial or fungal co-infections in COVID-19 patients admitted between March 1 – April 18, 2020 (152/4267, 3.6%). Mortality was 57%; 74% were intubated; 51% with bacteremia had central venous catheters. Time to culture positivity was 6-7 days; 79% received preceding antibiotics. Metallo-beta-lactamase-producing E. cloacae co-infections occurred in 5 patients.
A one-dimensional steady-state model for stimulated Raman backscatter (SRS) and stimulated Brillouin backscatter (SBS) processes in laser-irradiated plasmas is presented. Based on a novel “predictor-corrector” method, the model is capable to deal with broadband scattered light and inhomogeneous plasmas, exhibiting robustness and high efficiency. Influences of the electron density and temperature on the linear gains of both SRS and SBS are investigated, which indicates that the SRS gain is more sensitive to the electron density and temperature than that of the SBS. For the low-density case, the SBS dominates the scattering process, while the SRS exhibits much higher reflectivity in the high-density case. The nonlinear saturation mechanisms and competition between SRS and SBS are included in our model by a phenomenological method. The typical anti-correlation between SRS and SBS versus electron density is reproduced in the model. Calculations of the reflectivities are qualitatively in agreement with the typical results of experiments and simulations.
The novel coronavirus (COVID-19) pandemic has spread over 213 countries and territories. We sought to describe the clinical features of fatalities in patients with severe COVID-19 in an internet-based retrospective cohort study through retrieving the clinical information of 100 COVID-19 deaths from non-duplicating incidental reports in Chinese provincial and other governmental websites between January 23 and March 10, 2020. About 6 of 10 COVID-19 deaths were males (64.0%). The average age was 70.7±13.5 years, and 84% of patients were elderly (over age 60 y). The mean duration from admission to diagnosis was 2.2±3.8 days (median: 1). The mean duration from diagnosis to death was 9.9±7.0 days (median: 9). About 3 of 4 cases (76.0%) were complicated by 1 or more chronic diseases, including hypertension (41.0%), diabetes (29.0%) and coronary heart disease (27.0%), respiratory disorders (23.0%) and cerebrovascular disease (12.0%). Fever (46.0%), cough (33.0%), shortness of breath (9.0%) were the most common first symptoms. Multiple organ failure (67.9%), circulatory failure (20.2%) and respiratory failure (11.9%) are the top three direct causes of death. COVID-19 deaths are mainly elderly and patients with chronic diseases especially cardiovascular disorders and diabetes. Multiple organ failure is the most common direct cause of death.
Significant uncertainty remains regarding the exact timing and nature of subduction events during the closure of the Tethyan seas in what is now NW Iran. This study thus presents new geochemical compositions and U–Pb ages for a suite of volcanic rocks emplaced during Cenozoic volcanism in the west Alborz Magmatic Assemblage, which is commonly regarded as the back-arc of the Neotethyan magmatism in Central Iran. The subalkali basalts and andesites are dated to 57 ± 1.2 Ma, and are likely derived from a supra-subduction mantle wedge. Later, trachytic A-type rocks erupted from ~42 to 25 Ma during an anorogenic (extensional) stage triggered by slab retreat and associated asthenospheric mantle influx. A-type melts were at least partly concurrent with lithospheric mantle magmatism implied by eruption of subalkali basalts–andesites around 26–24 Ma. Next, Amp-Bt trachybasaltic volcanism with high-Nb basaltic affinity at ~19 Ma likely records slab deepening and slab partial melting, which reacted with the mantle wedge to produce the source material for the high-Nb basalts. Sr–Nd isotopic ratios for SE Ahar mafic as well as A-type rocks imply rather enriched mantle source(s). Some crustal contamination is implied by the presence of inherited zircons dominated by those derived from Neoproterozoic–Cambrian basement rocks and Carboniferous magmatism. Rhyolitic rocks with adakitic affinity probably mark the final volcanism in the study area. The adakitic rocks show crustal signatures such as high K and Th, probably formed as a consequence of higher temperature gradients, at crustal levels, imposed by both slab and mantle partial melts.
Sample geometry effects on mechanical strengths of gold micro-cantilevers are evaluated by a micro-bending test. Six micro-cantilevers with the same length of 50 μm are prepared, and the width and the thickness are varied to examine individual effects on the yield stress. The yield stress increases from 428 to 519 MPa when the thickness decreases from 11.1 to 6.0 μm. No obvious dependency is observed when varying the width. The results reveal that the thickness and the width each has a different influence on the yield stresses of micro-cantilevers evaluated by the bending test, which is the sample geometry effect.
In late December 2019, patients of atypical pneumonia due to an unidentified microbial agent were reported in Wuhan, Hubei Province, China. Subsequently, a novel coronavirus was identified as the causative pathogen which was named SARS-CoV-2. As of 12 February 2020, more than 44 000 cases of SARS-CoV-2 infection have been confirmed in China and continue to expand. Provinces, municipalities and autonomous regions of China have launched first-level response to major public health emergencies one after another from 23 January 2020, which means restricting movement of people among provinces, municipalities and autonomous regions. The aim of this study was to explore the correlation between the migration scale index and the number of confirmed coronavirus disease 2019 (COVID-19) cases and to depict the effect of restricting population movement. In this study, Excel 2010 was used to demonstrate the temporal distribution at the day level and SPSS 23.0 was used to analyse the correlation between the migration scale index and the number of confirmed COVID-19 cases. We found that since 23 January 2020, Wuhan migration scale index has dropped significantly and since 26 January 2020, Hubei province migration scale index has dropped significantly. New confirmed COVID-19 cases per day in China except for Wuhan gradually increased since 24 January 2020, and showed a downward trend from 6 February 2020. New confirmed COVID-19 cases per day in China except for Hubei province gradually increased since 24 January 2020, and maintained at a high level from 24 January 2020 to 4 February 2020, then showed a downward trend. Wuhan migration scale index from 9 January to 22 January, 10 January to 23 January and 11 January to 24 January was correlated with the number of new confirmed COVID-19 cases per day in China except for Wuhan from 22 January to 4 February. Hubei province migration scale index from 10 January to 23 January and 11 January to 24 January was correlated with the number of new confirmed COVID-19 cases per day in China except for Hubei province from 22 January to 4 February. Our findings suggested that people who left Wuhan from 9 January to 22 January, and those who left Hubei province from 10 January to 24 January, led to the outbreak in the rest of China. The ‘Wuhan lockdown’ and the launching of the first-level response to this major public health emergency may have had a good effect on controlling the COVID-19 epidemic. Although new COVID-19 cases continued to be confirmed in China outside Wuhan and Hubei provinces, in our opinion, these are second-generation cases.
Patients with COVID-19 may present with respiratory syndromes indistinguishable from those caused by common viruses. Early isolation and containment is challenging. Although screening all patients with respiratory symptoms for COVID-19 has been recommended, the practicality of such an effort has yet to be assessed.
Over a 6-week period during a SARS-CoV-2 outbreak, our institution introduced a “respiratory surveillance ward” (RSW) to segregate all patients with respiratory symptoms in designated areas, where appropriate personal protective equipment (PPE) could be utilized until SARS-CoV-2 testing was done. Patients could be transferred when SARS-CoV-2 tests were negative on 2 consecutive occasions, 24 hours apart.
Over the study period, 1,178 patients were admitted to the RSWs. The mean length-of-stay (LOS) was 1.89 days (SD, 1.23). Among confirmed cases of pneumonia admitted to the RSW, 5 of 310 patients (1.61%) tested positive for SARS-CoV-2. This finding was comparable to the pickup rate from our isolation ward. In total, 126 HCWs were potentially exposed to these cases; however, only 3 (2.38%) required quarantine because most used appropriate PPE. In addition, 13 inpatients overlapped with the index cases during their stay in the RSW; of these 13 exposed inpatients, 1 patient subsequently developed COVID-19 after exposure. No patient–HCW transmission was detected despite intensive surveillance.
Our institution successfully utilized the strategy of an RSW over a 6-week period to contain a cluster of COVID-19 cases and to prevent patient–HCW transmission. However, this method was resource-intensive in terms of testing and bed capacity.
We conduct Eulerian–Lagrangian simulations to study double-diffusive sedimentation in stratified flows. The results show the pattern of double-diffusive sedimentation and the transition to the pattern of Rayleigh–Taylor instability when the size of particles increases. In cases of double-diffusive sedimentation, our simulation results show little variation in the temperature-to-particle flux ratio among cases with various particle sizes and initial concentrations, which is consistent with previous theoretical derivations and experimental observations. The energy budget is analysed to show that the settling enhancement is a result of the thermal effect combined with shear dissipation and that the thermal contribution decreases as the size increases. Based on the balance of the energy budget, velocity scaling was derived for the quasi-steady state in the thermally controlled region, which can be used to characterize the plumes’ final velocity of double-diffusive sedimentation. Moreover, adopting some values from the simulation results yields a velocity criterion with which to distinguish different sedimentation patterns. Finally, we investigate changes in the particle-laden plumes below the region of the apparent temperature gradient at which secondary instabilities occur in the form of significant horizontal flow motion. We show that the resulting initial shift of the dominant modes can be approximated with the existing theoretical analysis of collective instabilities for salt fingers. A simple scaling argument for the change in the total cross-sectional area of particle-laden plumes is presented, which is then used to scale the resulting enhanced sedimentation.
Situated between the North China Craton to the east and the Tarim Craton to the west, the northern Alxa area in westernmost Inner Mongolia in China occupies a key location for interpreting the late-stage tectonic evolution of the southern Central Asian Orogenic Belt. New LA-ICP-MS zircon U–Pb dating results reveal 282.2 ± 3.9 Ma gabbros and 216.3 ± 3.2 Ma granites from the Yagan metamorphic core complex in northern Alxa, NW China. The gabbros are characterized by low contents of Si, Na, K, Ti and P and high contents of Mg, Ca, Al and Fe. These gabbros have arc geochemical signatures with relative enrichments in large ion lithophile elements and depletions in high field strength elements, as well as negative εNd(t) (−0.91 to −0.54) and positive εHf(t) (2.59 to 6.37) values. These features indicate that a depleted mantle magma source metasomatized by subduction fluids/melts and contaminated by crustal materials was involved in the processes of magma migration and emplacement. The granites show high-K calc-alkaline and metaluminous to weakly peraluminous affinities, similar to A-type granites. They have positive εNd(t) (1.55 to 1.99) and εHf(t) (5.03 to 7.64) values. These features suggest that the granites were derived from the mixing of mantle and crustal sources and formed in a postcollisional tectonic setting. Considering previous studies, we infer that the final closure of the Palaeo-Asian Ocean in the central part of the southern Central Asian Orogenic Belt occurred in late Permian to Early–Middle Triassic times.
This study aimed to describe outcomes in four women aged 28–34 years with central cytoplasmic granulation (CCG) of the oocytes who underwent in vitro fertilization/intracytoplasmic sperm injection (ICSI) using gonadotrophin-releasing hormone (GnRH) agonist to replace human chorionic gonadotrophin (hCG) as a trigger of final oocyte maturation. The initial ICSI procedure showed that all four women had CCG of the ooplasm and poor quality embryos. Subsequent ICSI used an antagonist protocol with a GnRH agonist trigger replacing the agonist protocol, plus hCG triggered ovulation. Ooplasm and embryo quality were improved in all four patients. All four became pregnant and gave birth to live infants. This study provides GnRH agonist triggering that may improve ooplasm granularity and embryo quality.
The isolation of male and female gametes is an effective method to study the fertilization mechanisms of higher plants. An osmotic shock method was used to rupture pollen grains of Allium tuberosum Roxb and release the pollen contents, including generative cells, which were mass collected. The pollinated styles were cut following 3 h of in vivo growth, and cultured in medium for 6–8 h, during which time pollen tubes grew out of the cut end of the style. After pollen tubes were transferred into a solution containing 6% mannitol, tubes burst and released pairs of sperm cells. Ovules of A. tuberosum were incubated in an enzyme solution for 30 min, and then dissected to remove the integuments. Following transfer to a dissecting solution free of enzymes, each nucellus was cut in the middle, and squeezed gently on the micropylar end, resulting in the liberation of the egg, zygote and proembryo from ovules at selected stages. These cells can be used to explore fertilization and embryonic development using molecular biological methods for each cell type and development stage.
The aim of this study was to analyze the profile of chest injuries, oxygen therapy for respiratory failure, and the outcomes of victims after the Jiangsu tornado, which occurred on June 23, 2016 in Yancheng City, Jiangsu Province, China.
The clinical records of 144 patients referred to Yancheng City No.1 People’s Hospital from June 23 through June 25 were retrospectively investigated. Of those patients, 68 (47.2%) sustained major chest injuries. The demographic details, trauma history, details of injuries and Abbreviated Injury Scores (AIS), therapy for respiratory failure, surgical procedures, length of intensive care unit (ICU) and hospital stay, and mortality were analyzed.
Of the 68 patients, 41 (60.3%) were female and 27 (39.7%) were male. The average age of the injured patients was 57.1 years. Forty-six patients (67.6%) suffered from polytrauma. The mean thoracic AIS of the victims was calculated as 2.85 (SD = 0.76). Rib fracture was the most common chest injury, noted in 56 patients (82.4%). Pulmonary contusion was the next most frequent injury, occurring in 12 patients (17.7%). Ten patients with severe chest trauma were admitted to ICU. The median ICU stay was 11.7 (SD = 8.5) days. Five patients required intubation and ventilation, one patient was treated with noninvasive positive pressure ventilation (NPPV), and four patients were treated with high-flow nasal cannula (HFNC). Three patients died during hospitalization. The hospital mortality was 4.41%.
Chest trauma was a common type of injury after tornado. The most frequent thoracic injuries were rib fractures and pulmonary contusion. Severe chest trauma is usually associated with a high incidence of respiratory support requirements and a long length of stay in the ICU. Early initiation of appropriate oxygen therapy was vital to restoring normal respiratory function and saving lives. Going forward, HFNC might be an effective and well-tolerated therapeutic addition to the management of acute respiratory failure in chest trauma.
Uranium–35 wt.% zirconium (U–35 wt.% Zr) alloy was annealed for 1 h and 24 h at 650 °C and characterized to understand the early-stage microstructure evolution. Dendritic microstructure with fine (∼300 nm in length) α-U precipitates clustered between dendrite branches were observed in the 1-h annealed sample. After 24-h annealing at 650 °C, the α-U precipitates coarsened, and the dendritic microstructure disappeared because of microstructure homogenization. Furthermore, microchemical homogenization observed with energy-dispersive X-ray spectroscopy analysis suggests that α-U precipitates are approaching thermodynamic equilibrium in the 24-h annealed sample. The findings from this study have potential impacts on the manufacturing and computer modeling of metallic nuclear fuel.
B vitamins (including folate, vitamin B2, vitamin B6 and vitamin B12) and methionine are essential for methylation reactions, nucleotide synthesis, DNA stability and DNA repair. However, epidemiological evidence among Chinese populations is limited. The objective of this study was to evaluate B vitamins and methionine in relation to colorectal cancer risk in a Chinese population. A case–control study was conducted from July 2010 to April 2019. A total of 2502 patients with colorectal cancer were recruited along with 2538 age- (5-year interval) and sex-matched controls. Dietary data were collected using a validated FFQ. Multivariable logistic regression was used to assess OR and 95 % CI. The intake of folate, vitamin B2, vitamin B6 and vitamin B12 was inversely associated with colorectal cancer risk. The multivariable OR for the highest quartile v. the lowest quartile were 0·62 (95 % CI 0·51, 0·74; Ptrend < 0·001) for folate, 0·46 (95 % CI 0·38, 0·55; Ptrend < 0·001) for vitamin B2, 0·55 (95 % CI 0·46, 0·76; Ptrend < 0·001) for vitamin B6 and 0·72 (95 % CI 0·60, 0·86; Ptrend < 0·001) for vitamin B12. No statistically significant association was found between methionine intake and colorectal cancer risk. Stratified analysis by sex showed that the inverse associations between vitamin B12 and methionine intake and colorectal cancer risk were found only among women. This study indicated that higher intake of folate, vitamin B2, vitamin B6 and vitamin B12 was associated with decreased risk of colorectal cancer in a Chinese population.
Transmission of varicella occurs frequently in schools and households. We investigated the characteristics of varicella cases derived from within-household transmission and the modes of varicella transmission between school and household settings in Shanghai, China, from 2009 to 2018. Within-household transmission occurred in 278 households, of which 134 transmission events were between children. Sixty-one household varicella transmission events may be attributed to isolation procedures for infected students during school outbreaks, and 7.6% of school outbreaks were caused by schoolchildren cases derived from within-household transmission. The frequency of ‘school-household-school’ transmission adds an additional layer of complexity to the control of school varicella outbreaks. Administration of varicella vaccine as post-exposure prophylaxis after exposure is considered to be an effective measure to control varicella spread within households and schools.
The authors propose an alternative route to circumvent the limitation of neutron flux using the recent deep learning super-resolution technique. The feasibility of accelerating data collection has been demonstrated by using small-angle neutron scattering (SANS) data collected from the EQ-SANS instrument at Spallation Neutron Source (SNS). Data collection time can be reduced by increasing the size of binning of the detector pixels at the sacrifice of resolution. High-resolution scattering data is then reconstructed by using a deep learning-based super-resolution method. This will allow users to make critical decisions at a much earlier stage of data collection, which can accelerate the overall experimental workflow.