Discovering knowledge from data is a quantum jump from quantity to quality, which is the characteristic and the spirit of the development of science. Symbolic regression (SR) is playing a greater role in the discovery of knowledge from data, specifically in this era of exponential data growth, because SRs are able to discover mathematical formulas from data. These formulas may provide scientifically meaningful models, especially when combined with domain knowledge. This article provides an overview of SR applications in the field of materials science and engineering. Integrating domain knowledge with SR is the key and a crucial approach, which allows gaining knowledge from data quickly, accurately, and scientifically. In the data-driven paradigm, SR allows for uncovering the underlying mechanisms of materials behavior, properties, and functions, in a wide range of areas from basic academic research to industrial applications, including experiments and computations, by providing explicit interpretable models from data, in comparison with other machine-learning “black-box” models. SR will be a powerful tool for rational and automatic materials development.

We investigated climate niches of grasses at regional scales and quantitatively reconstruct Asian monsoon precipitation at the sand-loess transitional zone in northern China. Our results provide direct evidence that certain grass lineages have been specialized in specific habitats: Pooideae grasses stand out and occupy a much cooler environment than all other subfamilies; Pooideae, Aristidoideae, and Chloridoieae occupy dry environments. Pooideae grasses occupy the coldest and driest environments compared to all other subfamilies, with a mean annual temperature (MAT) and precipitation (MAP) of ~13.6 to ~15.3°C and 224 to ~1674 mm, respectively, at a regional scale. We built a database for grasses and their corresponding climate parameters. Based on this database, past climate parameters at the margin of the Asian summer monsoon since ~70 ka were quantitatively reconstructed by phytolith assemblages. They show that this area was dominated by cold- and dry-adapted grasses since ~70 ka with a MAT and MAP of ~3.3 to ~11.0 °C and ~442 to ~900 mm, respectively, generally consistent with the results of phytolith-based transfer function reconstructions and with the results of previous nearby pollen-based quantitative reconstructions. With the improvement of the species-climate and ecosystem dataset, our database-based method is a promising quantitative reconstruction approach to past climatic change in the monsoon region.

Permian faunal affinity in the Lhasa Block plays a critical role in reconstructing its paleogeographic evolution. Cisuralian and Guadalupian faunas have been described from the Lhasa Block, but very few Lopingian (late Permian) brachiopods have been reported so far. In this paper, a new diverse brachiopod fauna consisting of 17 species of 17 genera and an unidentifiable Orthotetoidea is described from the uppermost part of the Xiala Formation at the Aduogabu section in the central part of the Lhasa Block. The age of this fauna can be assigned to the Changhsingian (late Lopingian) as indicated by the associated foraminifers Colaniella parva (Colani, 1924) and Reichelina pulchra Miklukho-Maklay, 1954. Characteristic brachiopods include Spinomarginifera chengyaoyenensis Huang, 1932, Haydenella wenganensis (Huang, 1932), and Araxathyris cf. dilatatus Shen, He, and Zhu, 1992. They also generally suggest a Changhsingian age. Paleobiogeographically, this fauna is uniformly composed of typical Tethyan elements represented by Spinomarginifera Huang, 1932 and Haydenella Reed, 1944, and some cosmopolitan elements, but no typical cold-water taxa of Gondwanan affinity. This is in contrast to the contemporaneous brachiopod faunas from the Tethys Himalayan region that are characterized by typical cold-water taxa of Gondwanan affinity, e.g., Costiferina indica (Waagen, 1884), Retimarginifera xizangensis Shen et al., 2000, Neospirifer (Quadrospina) tibetensis Ding, 1962. Thus, it is strongly indicative that the Lhasa Block had drifted into a relatively warm-water regime during the Changhsingian. An analysis of the paleobiogeographic change of brachiopods in the Lhasa Block throughout the entire Permian further suggests that the Lhasa Block probably had rifted away from the northern peri-Gondwanan margin between the latest Cisuralian and middle Guadalupian, that is, the Neotethys Ocean had opened before middle Guadalupian.

Fabrication and characterization of solution-processed, all-inorganic quantum dots (QDs) light-emitting diodes (QLEDs) incorporating colloidal CdSe/ZnS QDs are presented. Using a simple solvothermal process, Cu-doped NiO nanocrystals were fabricated and applied as a hole transport layer in all inorganic QLEDs. Cu-doped NiO nanocrystals are ascribed to bunsenite cubic structure. The transmittance of the film is more than 81%. The hole-only devices of Au/QDs/Cu–NiO/ITO structures showed that 5% mol Cu doped NiO film obtained the largest hole current. The resulting devices show pure QD electroluminescent emissions with a maximum electroluminescence brightness of 2258 cd/m2 after doping 5% mol Cu in NiO, which is almost 4-fold compared with that of intrinsic NiO due to the enhanced carrier concentration and conductivity. The current efficiency and EQE of the assembled all-inorganic QLED exhibited the maximum values of 1.18 cd/A and 1.223%, respectively.

There is a genuine need to shorten the development period for new materials with desired properties. In this work, machine learning (ML) was conducted on a dataset of the elastic moduli of 219 bulk-metallic glasses (BMGs) and another dataset of the critical casting diameters (Dmax) of 442 BMGs. The resulting ML model predicted the moduli and Dmax of BMGs in good agreement with most experimentally measured values, and the model even identified some errors reported in the literature. This work indicates the great potential of ML in design of advanced materials with target properties.

A 15-year-old teenager presented with a 2-month history of headache. Neurological examination was normal except for papilledema. Further lumbar puncture indicated intracranial hypertension (330 mm H2O). Brain magnetic resonance imaging (MRI) was normal but phase contrast-magnetic resonance venography (PC-MRV) (Figure 1(A)) suggested possible left transverse-sigmoid sinus thrombosis; subsequent contrast-enhanced 3D fat-saturated T1 volumetric isotropic turbo spin echo acquisition (VISTA) MRI (Figure 1(B)) confirmed the pathology. Hyper-coagulable panel results (including six steroid sex hormones, antithrombin III, protein C, protein S, lupus anticoagulant, and anticardiolipin antibodies) were all within normal range. In further examination, computed tomography (CT) venography images (Figure 1(C) and (D)) showed that the left jugular vein was compressed by the styloid process, consistent with Eagle syndrome.1 The patient who refused the recommended surgical treatment, however, chose anticoagulant therapy consisting of low-molecular weight heparin subcutaneous injection in addition to new oral anticoagulant. At 18-month follow-up, the patient reported no symptoms remained.

Cryptorchidism, characterized by the presence of one (unilateral) or both (bilateral) undescended testes, is a common male urogenital defect. Cryptorchidism can lead to male infertility, testicular cancer being the most extreme clinical symptom, as well as psychological issues of the inflicted individual. Despite this, both knowledge about the aetiology of cryptorchidism and the mechanism for cryptorchidism-induced male infertility remain limited. In this present study, by using an artificial cryptorchid mouse model, we investigated the effects of surgery-induced cryptorchidism on spermatogenic cells and seminiferous epithelial cycles. We found that surgery-induced cryptorchidism led to a reduced testicular weight, aberrant seminiferous epithelial cycles and impaired spermatogenesis characterized by degenerating spermatogenic cells. We also observed multinucleated giant cells after surgery-induced cryptorchidism. Transmission electron microscopy, terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) and western blot assays demonstrated cryptorchidism-induced apoptosis of spermatogenic cells. Moreover, we identified the occurrence of autophagy in germ cells after surgery-induced cryptorchidism. Interestingly, apoptosis and autophagy were synchronous, suggestive of their synergetic roles in promoting germ cell death. Our results provide novel insights into the cryptorchidism-induced male infertility, thereby contributing to the development of male contraceptive strategies as well as treatment options for male infertility caused by cryptorchidism.

The oxidation behavior of two percentages of TiB + TiC reinforced Ti–6Al–4V composites derived from Ti–B4C–C and Ti–TiB2–TiC systems was investigated at 873–1073 K for 320 h in air. The oxidation weight gain curves of the (TiB + TiC)/Ti–6Al–4V composites at 973 K basically obey parabolic law, while those at 873 and 1073 K mainly follow linear law and parabolic-linear law, respectively. The oxide layers of the composites are predominately found to be rutile TiO2, Al2O3, and the mixture of V2O3 and V2O5. The oxidation layers turn thinner with increasing the nominal volume fraction of reinforcements in the (TiB + TiC)/Ti–6Al–4V composites. Moreover, according to the calculation results of reaction index (n) and effective activation energy (Qeff) and the analyses of cross-sections of the oxidation layers, the oxidation resistance ability of the composites from Ti–TiB2–TiC system is higher than that from Ti–B4C–C system while employing the same sintering temperature and nominal volume fraction of reinforcement.

Hepatitis B constitutes a severe public health challenge in China. The Community-based Collaborative Innovation hepatitis B (CCI-HBV) project is a national epidemiological study of hepatitis B and has been conducting a comprehensive intervention in southern Zhejiang since 2009.

The comprehensive intervention in CCI-HBV areas includes the dynamic hepatitis B screening in local residents, the normalised treatment for hepatitis B infections and the upcoming full-aged hepatitis B vaccination. After two rounds of screening (each round taking for 4 years), the initial epidemiological baseline of hepatitis B in Qinggang was obtained, a coastal community in east China. By combining key data and system dynamics modelling, the regional hepatitis B epidemic in 20 years was predicted.

There were 1041 HBsAg positive cases out of 12 228 people in Round 1 indicating HBV prevalence of 8.5%. Of the 13 146 people tested in Round 2, 1171 people were HBsAg positive, with a prevalence of 8.9%. By comparing the two rounds of screening, the HBV incidence rate of 0.192 per 100 person-years was observed. By consulting electronic medical records, the HBV onset rate of 0.533 per 100 person-years was obtained. We generated a simulated model to replicate the real-world situation for the next two decades. To evaluate the effect of interventions on regional HBV prevalence, three comparative experiments were conducted.

In this study, the regional hepatitis B epidemic in 20 years was predicted and compared with HBV prevalence under different interventions. Owing to the existing challenges in research methodology, this study combined HBV field research and simulation to provide a system dynamics model with close-to-real key data to improve prediction accuracy. The simulation also provided a prompt guidance for the field implementation.

The finite element simulations show that non-equibiaxial residual stresses (RS) can shift the load–depth curve from the unstressed curve and cause elliptical remnant indentation in spherical indentation. Thus the relative load change between stressed and unstressed samples and the asymmetry of elliptical remnant indentation were employed as characteristic parameters to evaluate the magnitude and directionality of RS. Through theoretical and numerical analysis, the effects of RS on indentation load and remnant impression as well as the affect mechanism were systematically discussed. Finally, two equations which could provide foundations for establishing spherical indentation method to evaluate non-equibiaxial RS were obtained.

In this paper, we consider the existence of multiple solutions for the quasilinear Schrödinger equation

$$\left\{ {\matrix{ {-\Delta u-\Delta (\vert u \vert ^\alpha )\vert u \vert ^{\alpha -2}u = g(x,u) + \theta h(x,u),\;\;x\in \Omega } \hfill \cr {u = 0,\;\;x\in \partial \Omega ,} \hfill \cr } } \right.$$

This article investigates the statistical inference problem of whether a measurement equation is self-consistent in the logarithmic realized GARCH model (log-RealGARCH). First, we provide the sufficient and necessary conditions for the strict stationarity of both the log-RealGARCH model and the log-GARCH-X model. Under these conditions, strong consistency and asymptotic normality of the quasi-maximum likelihood estimators of these two models are obtained. Then, based on the asymptotic results, we propose a Hausman-type self-consistency test for diagnosing the suitability of the measurement equation in the log-RealGARCH model. Finally, the results of simulations and an empirical study are found to accord with the theoretical results.

This article investigates the impact of cross-level interplay between team members’ and their leaders’ goal orientations (learning, performance approach, and performance avoidance) on knowledge sharing using samples from design teams in two companies in China. Our results show that team leaders’ learning goal orientation plays a critical moderating role. Specifically, team leaders’ learning goal orientation strengthens the positive relationship between team members’ learning orientation and knowledge sharing; positively moderates the relationship between team members’ performance approach orientation and knowledge sharing; and weakens the negative relationship between team members’ performance avoidance orientation and knowledge sharing. Team leaders’ performance approach orientation demonstrates a positive moderating effect when there is congruence between the performance approach orientation of leaders and members. Finally, team leaders’ performance avoidance orientation negatively moderates the relationship between team members’ learning and performance approach orientation on knowledge sharing. This research enhances our understanding of the conditions under which knowledge sharing occurs among team members, using the lens of Trait Activation Theory.

Healthcare-associated infections (HAIs) are a major worldwide public-health problem, but less data are available on the long-term trends of HAIs and antimicrobial use in Eastern China. This study describes the prevalence and long-term trends of HAIs and antimicrobial use in a tertiary care teaching hospital in Hefei, Anhui, China from 2010 to 2017 based on annual point-prevalence surveys. A total of 12 505 inpatients were included; 600 HAIs were recorded in 533 patients, with an overall prevalence of 4.26% and a frequency of 4.80%. No evidence was found for an increasing or decreasing trend in prevalence of HAI over 8 years (trend χ2 = 2.15, P = 0.143). However, significant differences in prevalence of HAI were evident between the surveys (χ2 = 21.14, P < 0.001). The intensive care unit had the highest frequency of HAIs (24.36%) and respiratory tract infections accounted for 62.50% of all cases; Escherichia coli was the most common pathogen (16.67%). A 44.13% prevalence of antimicrobial use with a gradually decreasing trend over time was recorded. More attention should be paid to potential high-risk clinical departments and HAI types with further enhancement of rational antimicrobial use.