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Background To develop an effective model of predicting fatal outcomes in the severe coronavirus disease 2019 (COVID-19) patients. Methods Between February 20, 2020 and April 4, 2020, consecutive confirmed 2541 COVID-19 patients from three designated hospitals were enrolled in this study. All patients received chest computed tomography (CT) and serological examinations at admission. Laboratory tests included routine blood tests, liver function, renal function, coagulation profile, C-reactive protein (CRP), procalcitonin (PCT), interleukin-6 (IL-6), and arterial blood gas. The SaO2 was measured using pulse oxygen saturation in room air at resting status. Independent high-risk factors associated with death were analyzed using Cox proportional hazard model. A prognostic nomogram was constructed to predict the survival of severe COVID-19 patients. Results There were 124 severe patients in the training cohort, and there were 71 and 76 severe patients in the two independent validation cohorts, respectively. Multivariate Cox analysis indicated that age ≥ 70 years (HR = 1.184, 95% CI 1.061–1.321), panting (breathing rate ≥ 30/min) (HR = 3.300, 95% CI 2.509–6.286), lymphocyte count 9/L (HR = 2.283, 95% CI 1.779–3.267), and interleukin-6 (IL-6) > 10 pg/ml (HR = 3.029, 95% CI 1.567–7.116) were independent high-risk factors associated with fatal outcome. We developed the nomogram for identifying survival of severe COVID-19 patients in the training cohort (AUC = 0.900, 95% CI 0.841–0.960, sensitivity 95.5%, specificity 77.5%); in validation cohort 1 (AUC = 0.811, 95% CI 0.763–0.961, sensitivity 77.3%, specificity 73.5%); in validation cohort 2 (AUC = 0.862, 95% CI 0.698–0.924, sensitivity 92.9%, specificity 64.5%). The calibration curve for probability of death indicated a good consistence between prediction by the nomogram and the actual observation. The prognosis of severe COVID-19 patients with high levels of IL-6 receiving tocilizumab were better than that of those patients without tocilizumab both in the training and validation cohorts, but without difference (P = 0.105 for training cohort, P = 0.133 for validation cohort 1, and P = 0.210 for validation cohort 2). Conclusions This nomogram could help clinicians to identify severe patients who have high risk of death, and to develop more appropriate treatment strategies to reduce the mortality of severe patients. Tocilizumab may improve the prognosis of severe COVID-19 patients with high levels of IL-6.

This paper describes a new species of Cymbella from an alpine lake in the Hengduan Mountains, southwestern China. The detailed morphological description of the new species, named Cymbella xiaojinensis sp. nov. is presented, based on light and scanning electron microscopy. The main features of C. xiaojinensis are characterized by strongly dorsiventral, triangular valves with a strongly reverse-lateral raphe system positioned near the proximal ends and an asymmetrical, larger central area, occupying approximately 1/2 of the width with the valve. Most morphological characteristics of the new species are similar to C. shudunensis, C. terrafuegiana, C. pamirensis, and C. gravida, but differ in details of size, valve shape, striae density, central area, and number of stigmata.

The versatility and flexibility of organic photoelectric materials endow organic photovoltaic cells fine function modulation and huge commercial potential. In this work, a new noncovalent fused-ring small molecule acceptor (SMA) BID-4F has been synthesized for high-efficient organic solar cells (OSCs). BID-4F consists of a diflurobenzothiadiazole (DFBT) core, ladder-like indacenodithiophene (IDT) spacers, and dicyanoindanone electron-withdrawing end groups, which are supposed to be conformationally interlocked by noncovalent interactions, leading to good molecular planarity. In addition, compact solid state stacking was revealed by UV–vis–NIR absorption spectrum. The optimized PM6:BID-4F based device delivers an eminent power conversion efficiency (PCE) of 12.30% with a high open-circuit voltage (Voc) of 0.92 V and a high fill factor (FF) of 74.3%. Most importantly, the PCE and FF are among one of the highest values reported for the OSCs based on the unfused-ring SMAs. Overall, our work demonstrates that the unfused ring central framework with high molecular planarity through noncovalent interactions provides a good strategy to construct highly efficient SMAs.

In this paper, we calculate the vector, axial-vector and tensor form factors of $$P\rightarrow T$$ P → T transition within the standard light-front (SLF) and covariant light-front (CLF) quark models (QMs). The self-consistency and Lorentz covariance of CLF QM with two types of correspondence schemes are investigated. The zero-mode effects and the spurious $$\omega $$ ω -dependent contributions to the form factors of $$P\rightarrow T$$ P → T transition are analyzed. Employing a self-consistent CLF QM, we present our numerical predictions for the vector, axial-vector and tensor form factors of $$c\rightarrow (q,s)$$ c → ( q , s ) ($$q=u,d$$ q = u , d ) induced $$D \rightarrow (a_2,K^*_2)$$ D → ( a 2 , K 2 ∗ ) , $$D_s \rightarrow (K^*_2,f'_{2})$$ D s → ( K 2 ∗ , f 2 ′ ) , $$\eta _c(1S) \rightarrow (D^*_2,D^*_{s2})$$ η c ( 1 S ) → ( D 2 ∗ , D s 2 ∗ ) , $$ B_c \rightarrow (B^*_2,B^*_{s2})$$ B c → ( B 2 ∗ , B s 2 ∗ ) transitions and $$b\rightarrow (q,s,c)$$ b → ( q , s , c ) induced $$B \rightarrow (a_2,K^*_2,D^*_2)$$ B → ( a 2 , K 2 ∗ , D 2 ∗ ) , $$B_s \rightarrow (K^*_2,f'_2,D^*_{s2})$$ B s → ( K 2 ∗ , f 2 ′ , D s 2 ∗ ) , $$B_c \rightarrow (D^*_2,D^*_{s2},\chi _{c2}(1P))$$ B c → ( D 2 ∗ , D s 2 ∗ , χ c 2 ( 1 P ) ) , $$\eta _b(1S) \rightarrow (B^*_2,B^*_{s2})$$ η b ( 1 S ) → ( B 2 ∗ , B s 2 ∗ ) transitions. Finally, in order to test the obtained form factors, the semileptonic $$B\rightarrow {\bar{D}}_2^*(2460)\ell ^+\nu _\ell $$ B → D ¯ 2 ∗ ( 2460 ) ℓ + ν ℓ ($$\ell =e,\mu $$ ℓ = e , μ ) and $${\bar{D}}_2^*(2460)\tau ^+\nu _{\tau }$$ D ¯ 2 ∗ ( 2460 ) τ + ν τ decays are studied. It is expected that our results for the form factors of $$P\rightarrow T$$ P → T transition can be applied further to the relevant phenomenological studies of meson decays.

The method to fluorinate the terminal group has achieved remarkable success and been widely used to fine-tune the intrinsic properties of organic acceptor materials. Referring to chlorination, however, it gets less attention and remains ambiguous effect on organic photovoltaic (OPV) cells. Herein, a new non-fullerene acceptor named Y19 was reported with benzotriazole as the electron-deficient core and 2Cl-ICs as the strong electron-withdrawing end groups. Y19 exhibits a wide film absorption band from 600 nm to 948 nm and low LUMO (the lowest unoccupied molecular orbital) energy level of −3.95 eV Photovoltaic devices based on PM6:Y19 show high-power conversion efficiency (PCE) of 12.76 % with high open-circuit voltage (Voc) of 0.84 V, short-circuit current density (Jsc) of 22.38 mA/cm2 and fill factor (FF) of 68.18 %. Broad external quantum efficiency (EQE) response of over 60 % in the range of 480–860 nm can be obtained. This study demonstrates that chlorination, as a low-cost molecular design strategy, has its own superiorities to improve device performance and promote the potential application in OPV.

In this paper, we investigate the tree-dominated B¯u,d,s,c∗⟶Vℓ−ν¯ℓ (V=Du,d∗,Ds∗,J/ψ and ℓ=e,μ,τ) decays in the Standard Model with the relevant form factors obtained in the light-front quark model. These decays involve much more helicity states relative to the corresponding B¯∗⟶Pℓ−ν¯ℓ and B¯⟶Vℓ−ν¯ℓ decays, and moreover, the contribution of longitudinal polarization mode (V meson) is relatively small, ~30%, compared with the corresponding B meson decays. We have also computed the branching fraction, lepton spin asymmetry, forward-backward asymmetry, and ratio RV∗L≡BB¯∗⟶Vτ−ν¯τ/BB¯∗⟶Vℓ′−ν¯ℓ′ℓ′=e,μ. Numerically, the branching fractions of B¯∗⟶Vℓ′−ν¯ℓ′ decays are at the level of O10−7 and are hopeful to be observed by LHC and Belle-II experiments. The ratios RD∗,Ds∗,J/ψ∗L have relatively small theoretical uncertainties and are close to each other, RD∗∗L≃RDs∗∗L≃RJ/ψ∗L≃0.26,0.270.27,0.29, which are a bit different from the predictions in some previous works. The future measurements are expected to make tests on these predictions.

We propose three different methods to determine the optimal number of hidden nodes based on $L_{1}$ regularization for a multilayer perceptron network. The first two methods, respectively, use a set of multiplier functions and multipliers for the hidden-layer nodes and implement the $L_{1}$ regularization on those, while the third method equipped with the same multipliers uses a smoothing approximation of the $L_{1}$ regularization. Each of these methods begins with a given number of hidden nodes, then the network is trained to obtain an optimal architecture discarding redundant hidden nodes using the multiplier functions or multipliers. A simple and generic method, namely, the matrix-based convergence proving method (MCPM), is introduced to prove the weak and strong convergence of the presented smoothing algorithms. The performance of the three pruning methods has been tested on 11 different classification datasets. The results demonstrate the efficient pruning abilities and competitive generalization by the proposed methods. The theoretical results are also validated by the results.

Additional file 1: Table S1. Comparison of 16S sequencing data volume between the two groups. Table S2 Enrichment table of metabolism pathway.

A major limitation of fuzzy or neuro-fuzzy systems is their failure to deal with high-dimensional datasets. This happens primarily due to the use of T-norm, particularly, product or minimum (or a softer version of it). Thus, there are hardly any work dealing with datasets with dimensions more than hundred or so. Here, we propose a neuro-fuzzy framework that can handle datasets with dimensions even more than 7000! In this context, we propose an adaptive softmin (Ada-softmin) which effectively overcomes the drawbacks of ``numeric underflow" and ``fake minimum" that arise for existing fuzzy systems while dealing with high-dimensional problems. We call it an Adaptive Takagi-Sugeno-Kang (AdaTSK) fuzzy system. We then equip the AdaTSK system to perform feature selection and rule extraction in an integrated manner. In this context, a novel gate function is introduced and embedded only in the consequent parts, which can determine the useful features and rules, in two successive phases of learning. Unlike conventional fuzzy rule bases, we design an enhanced fuzzy rule base (En-FRB), which maintains adequate rules but does not grow the number of rules exponentially with dimension that typically happens for fuzzy neural networks. The integrated Feature Selection and Rule Extraction AdaTSK (FSRE-AdaTSK) system consists of three sequential phases: (i) feature selection, (ii) rule extraction, and (iii) fine tuning. The effectiveness of the FSRE-AdaTSK is demonstrated on 19 datasets of which five are in more than 2000 dimension including two with dimension greater than 7000. This may be the first time fuzzy systems are realized for classification involving more than 7000 input features.

Additional file 2: Fig. S1. 16S sequencing results of gut microbiota and gut microbiome composition at phylum level. Fig. S2 Quality control of LC-MS/MS (a-c: positive ion, d-f: negative ion). Fig. S3 BPH may induce variation in intestinal metabolites. Fig. S4 BPH leads to changes in metabolic pathways. Fig. S5 Association of intestinal differential metabolites with gut microbiota.

The high-frequency signal generator MAX038 is particularly suitable for RF signal sources of electromagnetic nondestructive testing, but the lack of finite element simulation model impedes the application of MAX038 in physical field simulation analysis. In this paper, we study the internal structure and principle of MAX038, divide its equivalent circuit architecture into different function modules, and then create and package its simulation model with modularization method. Based on the MAX038 simulation model, the RF excitation signal generator is designed and fabricated by using MSP430 processor, and an optimized detection algorithm is proposed to verify the simulation model. The test results of the MAX038 model and RF signal generator show that the MAX038 model proposed in this paper matches the real chip performance, it can also meet the requirements of simulation analysis for the parameter coupling relationship between electromagnetic field and defects.

The wear degree of twist drill affects significantly the quality and efficiency of small-deep hole drilling. A monitoring method for tool wear degree based on the signals of sound and current is proposed in this paper, and five kinds of tools with different wear grades are analyzed by using this method. The statistical characteristics of the sound and the current in the time-frequency and psycho-acoustic domains are used to extract the features of drill bits in the proposed method, and the whale optimization algorithm (WOA) is used to optimize features. Finally, the five classifications of twist drill wear degree are realized by K-Nearest Neighbors (KNN). The experimental results show that the combination of the sound and the current can accurately achieve the classification of tool wear, and the recognition accuracy can reach 100%, which can also meet the monitoring requirements of small-deep hole drilling.

Model identification is divided into two parts: structure identification and parameter identification, and the parameter identification is actually an optimization process. For improving the optimization performance, in this paper, we firstly present a novel conjugate gradient descent method with a modified Armijo-type line search technique to train a Takagi-Sugeno fuzzy neural network model. Numerical simulations are implemented to demonstrate the efficiency of the proposed algorithm. According to the experimental comparisons that are evaluated over 15 classification and 3 regression problems, the advantages of the given method are superior to its another two counterparts. To complement the simulation results and help in establishing a robust fuzzy neural network model, we strictly prove two deterministic convergent behaviors of the presented algorithm, i.e., weak and strong convergence results. They indicate the gradient of the target function with respect to network weights converges to zero and the parameter sequence approaches a fixed optimal point, respectively.

Receptor-like cytoplasmic kinase subfamily VII (RLCK-VII) proteins are the central immune kinases in plant pattern-recognition receptor (PRR) complexes, and they orchestrate a complex array of defense responses against bacterial and fungal pathogens. However, the role of RLCK-VII in plant-oomycete pathogen interactions has not been established. Phytophthora capsici is a notorious oomycete pathogen that infects many agriculturally important vegetables. Here, we report the identification of RXLR25, an RXLR effector that is required for the virulence of P. capsici. In planta expression of RXLR25 significantly enhanced plants' susceptibility to Phytophthora pathogens. Microbial pattern-induced immune activation in Arabidopsis was severely impaired by RXLR25. We further showed that RXLR25 interacts with RLCK-VII proteins. Using nine rlck-vii high-order mutants, we observed that RLCK-VII-6 and RLCK-VII-8 members are required for resistance to P. capsici. The RLCK-VII-6 members are specifically required for Phytophthora culture filtrate (CF)-induced immune responses. RXLR25 directly targets RLCK-VII proteins such as BIK1, PBL8, and PBL17 and inhibits pattern-induced phosphorylation of RLCK-VIIs to suppress downstream immune responses. This study identified a key virulence factor for P. capsici, and the results revealed the importance of RLCK-VII proteins in plant-oomycete interactions.

espanolAntecedentes: a diferencia de la estimulacion ventricular derecha tradicional, la estimulacion del area de la rama izquierda del haz (LBBAP) se logra con una implantacion mas profunda del electrodo y mas intentos. Sin embargo, el dano miocardico no esta claro en LBBAP. Objetivo: El objetivo del estudio fue observar el cambio de la troponina T y explorar posibles factores asociados a un mayor dano miocardico en BRI. Metodos: Los pacientes con indicacion de implante de marcapasos fueron sometidos a intentos de BRI mediante el metodo del tabique transventricular. Los niveles de troponina T se determinaron antes de la operacion, 12 hy 1 semana despues de la operacion. Se registraron y analizaron parametros intraoperatorios y de seguimiento. Resultados: En total, se logro LBBAP exitoso en 126 pacientes. Los niveles de troponina T aumentaron significativamente a las 12 h despues de la operacion en comparacion con los anteriores a la operacion (96,45 ± 11,07 [69,06] frente a 16,59 ± 1,84 [11,92] ng / L, p Conclusiones: El dano miocardico de LBBAP fue clinicamente significativo. El numero de intentos fue un factor independiente relacionado con el dano miocardico. EnglishBackground: Different from the traditional right ventricular pacing, the left bundle branch area pacing (LBBAP) is accomplished with deeper lead implantation and more attempts. However, myocardial damage is unclear in LBBAP. Objective: The objective of the study was to observe the change of troponin T and explore possible factors associated with greater myocardial damage in LBBAP. Methods: Patients with an indication for pacemaker implantation underwent attempts for LBBAP by transventricular septal method. Levels of troponin T were determined before operation, 12 h and 1 week after the operation. Parameters of intraoperation and follow-up were recorded and analyzed. Results: In total, successful LBBAP was achieved in 126 patients. The levels of troponin T increased significantly at 12 h after the operation compared with those before operation (96.45 ± 11.07 [69.06] vs. 16.59 ± 1.84 [11.92] ng/L, p Conclusions: Myocardial damage of LBBAP was clinically significant. The number of attempts was an independent factor related to the myocardial damage.

Development of stable and efficient non-noble metal based electrocatalysts for oxygen evolution reaction (OER) in acidic media is of great importance for proton exchange membrane based water electrolysis, which is indispensable for green hydrogen production. Herein, iron-doped, carbon-coated Co3O4 nanocomposite derived from a cobalt metal-organic framework, is grown in-situ on fluorine-doped tin oxide (FTO) glass (Fe-Co3O4@C/FTO) as an efficient and a stable binder-free electrode for acidic OER. Fe doping enhances both catalytic efficiency and stability of carbon coated Co3O4 toward acidic OER, through inducing small primary particle sizes and suitably modulated electronic structure of Co3O4, and better catalyst/substrate adhesion. Fe-Co3O4@C/FTO exhibits impressive electrocatalytic performances in 0.5 M H2SO4, with a low overpotential of 396 mV at 10 mA cm−2 and a small Tafel slope of 68.6 mV dec−1. Its electrochemical performances remain stable for over 50 h at 10 mA cm−2, making it a promising non-noble metal based electrocatalyst for acidic OER.

Acoustic manipulation is one of the well-known technologies of particle control and a top research in acoustic field. Calculation of acoustic radiation force on a particle nearby boundaries is one of the critical tasks, as it approximates realistic applications. Nevertheless, it is quite difficult to solve the problem by theoretical method when the boundary conditions are intricate. In this study, we present a finite element method numerical model for the acoustic radiation force exerting on a rigid cylindrical particle immersed in fluid near a rigid corner. The effects of the boundaries on acoustic radiation force of a rigid cylinder are analyzed with particular emphasis on the non-dimensional frequency and the distance from the center of cylinder to each boundary. The results reveal that these parameters play important roles in acoustic manipulation for particle-nearby complicated rigid boundaries. This study verifies the feasibility of numerical analysis on the issue of acoustic radiation force calculation close to complex boundaries, which may provide a new idea on analyzing the acoustic particle manipulation in confined space.