To develop a machine learning model and nomogram to predict the probability of persistent virus shedding (PVS) in hospitalized patients with coronavirus disease 2019 (COVID-19), the clinical symptoms and signs, laboratory parameters, cytokines, and immune cell data of 429 patients with nonsevere COVID-19 were retrospectively reviewed. Two models were developed using the Akaike information criterion (AIC). The performance of these two models was analyzed and compared by the receiver operating characteristic (ROC) curve, calibration curve, net reclassification index (NRI), and integrated discrimination improvement (IDI). The final model included the following independent predictors of PVS: sex, C-reactive protein (CRP) level, interleukin-6 (IL-6) level, the neutrophil-lymphocyte ratio (NLR), monocyte count (MC), albumin (ALB) level, and serum potassium level. The model performed well in both the internal validation (corrected C-statistic = 0.748, corrected Brier score = 0.201) and external validation datasets (corrected C-statistic = 0.793, corrected Brier score = 0.190). The internal calibration was very good (corrected slope = 0.910). The model developed in this study showed high discriminant performance in predicting PVS in nonsevere COVID-19 patients. Because of the availability and accessibility of the model, the nomogram designed in this study could provide a useful prognostic tool for clinicians and medical decision-makers.

The subduction model of the Neo-Tethys during the Early Cretaceous has always been a controversial topic, and the scarcity of Early Cretaceous magmatic rocks in the southern part of the Gangdese batholith is the main cause of this debate. To address this issue, this article presents new zircon U–Pb chronology, zircon Hf isotope, whole-rock geochemistry and Sr–Nd isotope data for the Early Cretaceous quartz diorite dykes with adakite affinity in Liuqiong, Gongga. Zircon U–Pb dating of three samples yielded ages of c. 141–137 Ma, indicating that the Liuqiong quartz diorite was emplaced in the Early Cretaceous. The whole-rock geochemical analysis shows that the Liuqiong quartz diorite is enriched in large-ion lithophile elements (LILEs) and light rare-earth elements (LREEs) and is depleted in high-field-strength elements (HFSEs), which are related to slab subduction. Additionally, the Liuqiong quartz diorite has high SiO2, Al2O3 and Sr contents, high Sr/Y ratios and low heavy rare-earth element (HREE) and Y contents, which are compatible with typical adakite signatures. The initial 87Sr/86Sr values of the Liuqiong adakite range from 0.705617 to 0.705853, and the whole-rock ϵNd(t) values vary between +5.78 and +6.24. The zircon ϵHf(t) values vary from +11.5 to +16.4. Our results show that the Liuqiong adakite magma was derived from partial melting of the Neo-Tethyan oceanic plate (mid-ocean ridge basalt (MORB) + sediment + fluid), with some degree of subsequent peridotite interaction within the overlying mantle wedge. Combining regional data, we favour the interpretation that the Neo-Tethyan oceanic crust was subducted at a low angle beneath the Gangdese during the Early Cretaceous.

We report on the generation of a mid-infrared (mid-IR) frequency comb with a maximum average output power of 250 mW and tunability in the 2.7–4.0 μm region. The approach is based on a single-stage difference frequency generation (DFG) starting from a compact Yb-doped fiber laser system. The repetition rate of the near-infrared (NIR) comb is locked at 75 MHz. The phase noise of the repetition rate in the offset-free mid-IR comb system is measured and analyzed. Except for the intrinsic of NIR comb, environmental noise at low frequency and quantum noise at high frequency from the amplifier chain and nonlinear spectral broadening are the main noise sources of broadening the linewidth of comb teeth, which limits the precision of mid-IR dual-comb spectroscopy.

In order to solve joint-angle drift problem of dual redundant manipulators at acceleration-level, an acceleration-level tri-criteria optimization motion planning (ALTC-OMP) scheme is proposed, which combines the minimum acceleration norm, repetitive motion planning, and infinity-norm acceleration minimization solutions via weighting factor. This scheme can resolve the joint-angle drift problem of dual redundant manipulators which will arise in single criteria or bi-criteria scheme. In addition, the proposed scheme considers joint-velocity joint-acceleration physical limits. The proposed scheme can not only guarantee joint-velocity and joint-acceleration within their physical limits, but also ensure that final joint-velocity and joint-acceleration are near to zero. This scheme is realized by dual redundant manipulators which consist of left and right manipulators. In order to ensure the coordinated operation of manipulators, two motion planning problems are reformulated as two general quadratic program (QP) problems and further unified into one standard QP problem, which is solved by a simplified linear-variational-inequalities-based primal-dual neural network at the acceleration-level. Computer-simulation results based on dual PUMA560 redundant manipulators further demonstrate the effectiveness and feasibility of the proposed ALTC-OMP scheme to resolve joint-angle drift problem arising in the dual redundant manipulators.

Geochronological, major and trace element, and Sr–Nd–Hf isotopic data are reported for the monzonitic rocks of the Fushan pluton in the Taihang Mountains, central North China Craton, in order to investigate their sources, petrogenesis and tectonic implications. Zircon U–Pb dating results reveal that the Fushan pluton was emplaced during the Early Cretaceous (∼126–124 Ma). The monzonites and quartz monzonites are mainly characterized by calc-alkaline and magnesian features and display light rare earth element (LREE) enrichment and flat heavy REE (HREE) patterns with slightly positive Eu anomalies. They have similar whole-rock initial 87Sr/86Sr ratios (0.70653–0.70819), εNd(t) values (−13.6 to −18.6) and zircon εHf(t) values (−21.8 to −17.3). The primary magma of the Fushan pluton was derived from the partial melting of a spinel-facies amphibole-bearing ancient enriched lithospheric mantle. The monzonitic rocks also have high Ba–Sr and low Y and Yb contents, with high Sr/Y and La/Yb ratios. These geochemical features of monzonitic rocks are not only inherited from the magma source but also significantly enhanced by crystal fractionation during magmatic evolution; e.g. hornblende fractionation increased the Ba–Sr concentrations and Sr/Y ratios. During the Early Cretaceous, the slab sinking and roll-back of the Palaeo-Pacific Plate could have created an ancient big mantle wedge beneath East Asia and induced a lithospheric extensional process in the central North China Craton within an intracontinental setting.

In this paper, an alternative lattice Boltzmann (LB)model for incompressible flows is proposed. By modifying directly the moments of the equilibrium distribution function (EDF), the continuous expression of the EDF in tensor Hermite polynomials is derived using the moment expansion and then discretizedwith the discrete velocity vectors of the D2Q9 lattice. The present model as well as its counterpart, the incompressible LB model proposed by Guo, reproduces the incompressible Navier-Stokes (N-S) equations for both steady and unsteady flows. Besides, an alternative pressure formula, which represents the pressure as the diagonal part of the stress tensor, is adopted in the present model. Furthermore, in order to enhance the stability of the present LB model, an additional relaxation time pertaining to the non-hydrodynamic mode is added to the BGK collision operator. The present LB model is validated by two benchmark tests: the cavity flow with different Reynolds number (Re) and the flow past an impulsively started cylinder at Re=40 and 550.

A well-dated palynological record spanning the interval ~ 40,500–7060 cal yr BP, retrieved from a peatland on the Leizhou Peninsula in south China, clearly shows regional vegetation and climate changes during the last glacial period. Pollen data showed that the study region was mainly covered by subtropical evergreen trees during Marine Isotope Stage 3 (MIS 3), indicating a subtropical climate with relatively high temperature and precipitation. During MIS 2, subtropical evergreen-deciduous forest with large areas of grassland occurred, implying cooler and drier conditions. Some tropical forest elements increased during the early Holocene, indicating a warm and wet trend. Several millennial-scale oscillations of the pollen records appeared to correlate with the cold anomalies in the North Atlantic region. Our records agree well with many records from other regions, but they are a bit different than that inferred from the neighboring Huguang Maar Lake. Furthermore, our results suggest that the vegetation surrounding Xialu peatland was strongly influenced by the migration of the intertropical convergence zone (ITCZ) and variability in the East Asian summer monsoon (EASM). Changes of atmospheric CO2 concentration (pCO2) levels may have also affected the long-term vegetation changes in the study region.

Geometric model of a lobed mixing exhaust system is created and its flow field is simulated by using the steady Reynolds Averaged Navier-Stokes (RANS) equations under the condition of different core flow inlet swirl angles. According to the numerical simulation results, due to the guidance effect of the lobe parallel side wall, the structure and vorticity of streamwise vortices change little near the lobe exit with inlet swirl angle, and it is the same with the thermal mixing efficiency. As the flow develops, although the inlet swirl angle has limited influence on the streamwise vorticity, it greatly affects the structure of streamwise vortices. It causes the thermal mixing efficiency to increase with the swirl angle. As for the total pressure recovery coefficient, it falls slightly when the inlet swirl strengthens. At the nozzle exit, the total pressure recovery coefficient of CFISA = 30° model is 0.5% lower than CFISA = 0° model. Moreover, as the inlet swirl strengthens, the thrust fall of lobed mixing exhaust system gradually accelerates, especially when the inlet swirl angle is over 15°.

Based on the Bayesian Inference (BI) method, the Mixture-Model approach is improved to combine all kinematic data, including the coordinative position($\vec{x}$), proper motion ($\vec{\mu}$) and radial velocity(v), to separate the motion of the cluster from field stars, as well as to determine the intrinsic kinematic status and dynamical effects of the cluster, such as the mass segregation, anisotropy etc.. Meanwhile, the membership probability of individual stars are estimated as by product results. This method has been testified by simulation of toy models and also successfully used for well studied open clusters, such as M67 and NGC188. It is expected to largely help the studies of open clusters while combine the coming GAIA data.

In current transparent Si based photovoltaic (PV) module fabrication, green or infrared laser is the most common used band frequency to wipe off the silicon and back contact layer in perpendicular direction of cells. However, this method would result in more power loss than calculation value due to the side effects during the process such as constructional damage of module and shunt effect. A new method is presented here which focus on wiping off more silicon layer by employing green pulsed laser(532 nm wavelength) along the parallel direction of Pattern2, and it shows higher efficiency and more attractive appearance.

The role of oxidative stress in skeletal health is unclear. The present study investigated whether a high dietary intake of antioxidant nutrients (vitamins C and E, β-carotene, animal-derived vitamin A, retinol equivalents, Zn and Se) is associated with a reduced risk of hip fracture in elderly Chinese. This 1:1 matched case–control study involved 726 elderly Chinese with hip fracture and 726 control subjects, recruited between June 2009 and May 2013. Face-to-face interviews were conducted to determine habitual dietary intakes of the above-mentioned seven nutrients based on a seventy-nine-item FFQ and information on various covariates, and an antioxidant score was calculated. After adjustment for potential covariates, dose-dependent inverse associations were observed between the dietary intake of vitamin C, vitamin E, β-carotene, and Se and antioxidant score and the risk of hip fracture (P for trend ≤ 0·005). The OR of hip fracture for the highest (v. lowest) quartile of intake were 0·39 (95 % CI 0·28, 0·56) for vitamin C, 0·23 (95 % CI 0·16, 0·33) for vitamin E, 0·51 (95 % CI 0·36, 0·73) for β-carotene, 0·43 (95 % CI 0·26, 0·70) for Se and 0·24 (95 % CI 0·17, 0·36) for the antioxidant score. A moderate-to-high dietary intake of retinol equivalents in quartiles 2–4 (v. 1) was found to be associated with a lower risk of hip fracture (OR range: 0·51–0·63, P< 0·05). No significant association was observed between dietary Zn or animal-derived vitamin A intake and hip fracture risk (P for trend >0·20). In conclusion, a higher dietary intake of vitamins C and E, β-carotene, and Se and a moderate-to-high dietary intake of retinol equivalents are associated with a lower risk of hip fracture in elderly Chinese.

Silicon is a very promising material for anodes of lithium ion batteries. It exhibits a high theoretical capacity of 3579 mAh/g. However, during the lithiation and de-lithiation, silicon materials experience up to a 300% volume change, leading to poor cyclability [1-2]. Research shows that reducing the silicon particle size can mitigate this problem. Carbon nanotubes (CNTs) function well as electrode materials in electrolytic cells because of their high electrical conductivity and surface area. In this work, we combine silicon nanoparticles (Si NPs) and CNTs as anode materials. Si NPs are generated using a plasma-enhanced chemical vapor deposition technique and their surface is modified with a 12-carbon long aliphatic chain to impart solubility in non-polar solvents. They are applied onto a nanotube-based layer using a wet-phase deposition technique. SEM and TEM analysis confirm that they form a conformal coating onto the nanotube surface. The CNTs - Si NPs composite active material is tested in half-cells where lithium foil acts as counter electrode. We have achieved an average of 810 mAh/g discharge capacity for composites with a CNTs to Si NPs weight ratio of 1:1. We expect to be able to increase the discharge capacity by increasing the Si NPs weight content.

Extended abstract of a paper presented at Microscopy and Microanalysis 2010 in Portland, Oregon, USA, August 1 – August 5, 2010.

This study reviews the results of the surgical management of 154 cases of ruptured aneurysm of the sinus of Valsalva. Of the patients0 73% were male, with an average age of 28 years. An associated ventricular septal defect was found in 40% and 23% had aortic valvar regurgitation. The aneurysms originated from the right coronary sinus in 79% and from the non-coronary sinus in the remainders. The aneurysms ruptured into the right ventricle in 73%, into the right atrium in 27% and into the left ventricle in less than 1%. Operative mortality was 4.5%. Long-term follow-up was achieved in 80% of patients, with a mean duration of 5.7 years and a range from two months to 29 years. Preoperative aortic regurgitation and preoperative functional class (NYHA III or IV) were both predictive of a worse long-term outcome. The optimal surgical approach was closure of the distal end of the fistula by direct suture together with reinforcement of the aortic sinus with a Dacron patch.