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Mercury (Hg) is detrimental to human health, but its impact on lipid biomarkers remains a subject of controversy. This study sought to delineate a clear link between blood Hg and lipid biomarkers correlated with cardiovascular disease (CVD), including total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides (TG), in hypertensive adults in the USA. Methods: This cross-sectional research gathered data from a total of 4415 participants sourced from the National Health and Nutrition Examination Survey (NHANES). The Holm-Bonferroni stepdown procedure was utilized to control the type I error rate in multiple comparisons. We employed multivariable linear regression models to assess the correlation between blood Hg and lipid biomarkers. Subsequently, subgroup analyses were conducted, categorized by both gender and race. Additionally, we used smooth curve fittings and generalized additive models to confirm the presence of non-linear relationships. When non-linearity was detected, we applied a recursive algorithm to calculate the inflection points. Finally, we established a weighted two-piecewise linear regression model to illustrate the associations on either side of the inflection point. Results: In our multivariable linear regression models, clear associations emerged. Specifically, positive correlations were observed between blood mercury and TC (β = 0.025; 95% CI 0.009 to 0.041; corrected P = 0.011), LDL-C (β = 0.022; 95% CI 0.007 to 0.036; corrected P = 0.012), and HDL-C (β = 0.007; 95% CI 0.001 to 0.013; corrected P = 0.058). However, there was no significant correlation with TG (β = − 0.007; 95% CI − 0.018 to 0.004; corrected P = 0.526). Notably, it has been demonstrated that distinct inverted U-shaped and U-shaped curves exist when stratified by gender in our analysis. Conclusions: Blood Hg exhibited a positive correlation with TC, LDL-C, and HDL-C in hypertensive adults in the USA. Nonetheless, no significant association was observed with TG. [ABSTRACT FROM AUTHOR]

Synthetic aperture radar (SAR) is crucial for military reconnaissance and remote sensing, but image quality can be affected by various factors, impacting target detection performance. Thus, pre-evaluation of SAR image quality is essential to filter out poor-quality images, optimize resource allocation, and enhance detection accuracy and efficiency. This paper proposes a comprehensive SAR image quality evaluation method combining objective and subjective approaches. Specifically, the processes encompassing the generation of a series of disturbed SAR images on the SAR ship detection dataset (SSDD), the calculation of various objective quality indicators for those images, and the assignment of a subjective quality label to each image through subjective evaluation. Based on the dataset constructed by the above evaluation methods, the IHHO-XGBoost model was developed. This model uses an improved harris hawk optimization (IHHO) algorithm to optimize extreme gradient boosting (XGBoost) hyperparameters. The IHHO algorithm effectively alleviates the problem of getting trapped in local optima by improving the escape energy calculation strategy and integrating the average difference evolution mechanism while maintaining the diversity of the population, showing significant advantages over the traditional HHO algorithm. Comparative experiments demonstrate the model's superiority in SAR image quality evaluation. This study validates the scientificity and practicability of the proposed method, offering new tools for SAR image quality research. [ABSTRACT FROM AUTHOR]

During space flight, prolonged weightlessness stress exerts a range of detrimental impacts on the physiology and psychology of astronauts. These manifestations encompass depressive symptoms, anxiety, and impairments in both short-term memory and motor functions, albeit the precise underlying mechanisms remain elusive. Recent studies have revealed that hindlimb unloading (HU) animal models, which simulate space weightlessness, exhibited a disorder in memory and motor function associated with endogenous formaldehyde (FA) accumulation in the hippocampus and cerebellum, disruption of brain extracellular space (ECS), and blockage of interstitial fluid (ISF) drainage. Notably, the impairment of the blood-brain barrier (BBB) caused by space weightlessness elicits the infiltration of albumin and hemoglobin from the blood vessels into the brain ECS. However, excessive FA has the potential to form cross-links between these two proteins and amyloid-beta (Aβ), thereby obstructing ECS and inducing neuron death. Moreover, FA can inhibit N-methyl-D-aspartate (NMDA) currents by crosslinking NR1 and NR2B subunits, thus impairing memory. Additionally, FA has the ability to modulate the levels of certain microRNAs (miRNAs) such as miRNA-29b, which can affect the expression of aquaporin-4 (AQP4) so as to regulate ECS structure and ISF drainage. Especially, the accumulation of FA may inactivate the ataxia telangiectasia-mutated (ATM) protein kinase by forming cross-linking, a process that is associated with ataxia. Hence, this review presents that weightlessness stress-derived FA may potentially serve as a crucial catalyst in the deterioration of memory and motor abilities in the context of microgravity. [ABSTRACT FROM AUTHOR]

Because the fabrication of three-dimensional (3D) microelectrodes is quite challenging, microelectrodes with a simple cross-section are usually used in micro-electro-discharge machining (micro-EDM) to perform layer-by-layer scanning machining for machining 3D microstructures. In this study, we used pure copper powder as the raw material to prepare 3D queue microelectrodes through selective laser melting (SLM). The influences of laser power and laser scanning speed on the densification rate of the 3D microelectrodes were investigated. Moreover, the effects of the temperature and temperature holding time on the conductivity and EDM performance of the 3D microelectrodes during heat treatment were also analyzed. In order to improve the geometric accuracy of the 3D microstructure, 3D microstructures were subjected to micro-EDM with 3D queue microelectrodes: the first microelectrode was used for rough machining and the remaining microelectrodes were used for fine machining. In addition, to ensure a high surface quality of the 3D microstructure, multiple EDM were conducted to eliminate unmelted copper powder and layer defects on the surface of the 3D queue microelectrode. Finally, by applying the 3D queue microelectrodes in micro-EDM, a 3D microstructure with a height error of 1 µm and surface roughness of 1.685 µm was obtained after three repeated discharges. [ABSTRACT FROM AUTHOR]

Polymer dielectrics possessing the superiorities of easy processing and high power density are widely used in pulsed power and power electronics. However, the low energy storage density (Ue) of polymer dielectrics limits their application in the modern electronic industries. In this work, we present the sea-island structure multilayered composites based on polymethylmethacrylate (PMMA) matrix and polyvinylidene fluoride (PVDF) nanoparticles, which is constructed by the solution blending with typical solubility differences method and the layer-by-layer solution casting method. The PVDF/PMMA composite incorporated with high PVDF content is placed in the middle of the sandwich-structured composite as a non-traditional intermediate polarization layer. The PVDF/PMMA composite with low PVDF loading is placed in the outer layer to improve the insulating property of the composite. The results show that the PVDF/PMMA composites with inner and outer PVDF volume content of 30% and 10%, respectively, obtained an excellent dielectric constant value (εr ~ 4.35), which is 45% higher than that of PMMA (εr ~ 3). Meanwhile, the maximum Ue (~ 4.95 J cm−3) of the PVDF/PMMA composites at an electric field of 422.48 MV m−1 was obtained, which is 207% higher than that of PMMA (Ue ~ 1.61 J cm−3). The improved energy storage capability could be attributed to the introduction of highly polarizing particles, the increased number of heterogeneous interfaces, and the multilayered construction of composite. This work provides a strategy for the preparation of advanced all-organic dielectrics with a higher discharge energy density. [ABSTRACT FROM AUTHOR]

Background: The clinical value and molecular characteristics of tumor differentiation in oral squamous cell carcinoma (OSCC) remain unclear. There is a lack of a related molecular classification prediction system based on pathological images for precision medicine. Methods: Integration of epidemiology, genomics, experiments, and deep learning to clarify the clinical value and molecular characteristics, and develop a novel OSCC molecular classification prediction system. Results: Large-scale epidemiology data (n = 118,817) demonstrated OSCC differentiation was a significant prognosis indicator (p < 0.001), and well-differentiated OSCC was more chemo-resistant than poorly differentiated OSCC. These results were confirmed in the TCGA database and in vitro. Furthermore, we found chemo-resistant related pathways and cell cycle-related pathways were up-regulated in well- and poorly differentiated OSCC, respectively. Based on the characteristics of OSCC differentiation, a molecular grade of OSCC was obtained and combined with pathological images to establish a novel prediction system through deep learning, named ShuffleNetV2-based Molecular Grade of OSCC (SMGO). Importantly, our independent multi-center cohort of OSCC (n = 340) confirmed the high accuracy of SMGO. Conclusions: OSCC differentiation was a significant indicator of prognosis and chemotherapy selection. Importantly, SMGO could be an indispensable reference for OSCC differentiation and assist the decision-making of chemotherapy. [ABSTRACT FROM AUTHOR]

The influence mechanism of tensile load on the conductivity of thin films is a key issue in evaluating the conductivity of engineering structural thin films under complex loading conditions. How to reveal the correlation mechanisms of different physical quantities of metal films, and to predict the variation of film resistance with tensile load is a very critical and challenging problem. In this paper, a multiscale model of film resistance under tensile neching is established to describe the mechanical behavior, resistivity, and resistance of metal films under tensile load. The results show that the tensile load has a significant effect on the resistivity and conductivity of the film. This provides a reference for the evaluation and optimization of the conductivity of thin films with complex engineering structures. [ABSTRACT FROM AUTHOR]

Objective: To compare the predictive performance of the current clinical prediction models for predicting intravesical recurrence (IVR) after radical nephroureterectomy (RNU) in patients with upper tract urothelial carcinoma (UTUC). Methods: We retrospectively analysed upper tract urothelial carcinoma patients who underwent radical nephroureterectomy in our centre from January 2009 to December 2019. We used the propensity score matching (PSM) method to adjust the confounders between the IVR and non-IVR groups. Additionally, Xylinas' reduce model and full model, Zhang's model, and Ishioka's risk stratification model were used to retrospectively calculate predictions for each patient. Receiver operating characteristic (ROC) curves were generated, and the areas under the curves (AUCs) were compared to identify the method with the highest predictive value. Results: We included 217 patients with a median follow-up of 41 months, of which 57 had IVR. After PSM analysis, 52 pairs of well-matched patients were included in the comparative study. No significant difference was found in clinical indicators besides hydronephrosis. The model comparison showed that the AUCs of the reduced Xylinas' model for 12 months, 24 months, and 36 months were 0.69, 0.73, and 0.74, respectively, and those of the full Xylinas' model were 0.72, 0.75, and 0.74, respectively. The AUC of Zhang's model for 12 months, 24 months, and 36 months was 0.63, 0.71, and 0.71, respectively, the performance of Ishioka's model is that the AUC of 12 months, 24 months and 36 months was 0.66, 0.71, and 0.74, respectively. Conclusion: The external verification results of the four models show that more comprehensive data and a larger sample size of patients are needed to strengthen the models' derivation and updating procedure, to better apply them to different populations. [ABSTRACT FROM AUTHOR]

Volumetric measurement for the non-cavitating tip vortex in the near field of an elliptical hydrofoil is conducted using tomographic particle image velocimetry, which provides a fully three-dimensional diagnose of the vortex formation and development. The wandering motion and flow properties of the near-field tip vortex under different incident angles and Reynolds numbers are investigated in detail. Unlike in the far field, the wandering motion in the near field is mainly subject to the local flow unsteadiness rather than the flow condition. By the "re-centered" post-processing, the deviations introduced by the wandering motion can be technically corrected, and more accurate vortex properties can be thus obtained. In the near field, a turning point of the vortex center trajectory is detected, the position of which is basically independent of the flow condition. By investigating the local flow properties, it is found that this turning point is the position where the tip vortex completely leaves the trailing edge of hydrofoil and enters the wake region. At this turning point, the external supply to the vortex core starts to be restricted, and the vortex circulation reaches a rather constant value. Further according to the local flow properties, the development process of the near-field tip vortex can be divided into three stages: vortex-attached stage, vortex-lifting stage and vortex-detached stage, which are found to be closely relevant to the hydrofoil configuration. [ABSTRACT FROM AUTHOR]

Oryza coarctata (2n = 4X = 48, KKLL) is an allotetraploid, undomesticated relative of rice and the only species in the genus Oryza with tolerance to high salinity and submergence. Therefore, it contains important stress and tolerance genes/factors for rice. The initial draft genome published was limited by data and technical restrictions, leading to an incomplete and highly fragmented assembly. This study reports a new, highly contiguous chromosome-level genome assembly and annotation of O. coarctata. PacBio high-quality HiFi reads generated 460 contigs with a total length of 573.4 Mb and an N50 of 23.1 Mb, which were assembled into scaffolds with Hi-C data, anchoring 96.99% of the assembly onto 24 chromosomes. The genome assembly comprises 45,571 genes, and repetitive content contributes 25.5% of the genome. This study provides the novel identification of the KK and LL genome types of the genus Oryza, leading to valuable insights into rice genome evolution. The chromosome-level genome assembly of O. coarctata is a valuable resource for rice research and molecular breeding. [ABSTRACT FROM AUTHOR]

The influence mechanism of cyclic loading on the stiffness, thermal resistance, and electrical resistance of rough contact surfaces is a key issue in evaluating the interface contact performance of engineering structures under complex loading conditions. How to characterize this random contact process and reveal the correlation mechanism of different physical quantities at the contact interface, and to predict the changes of interface contact stiffness, thermal resistance and electrical resistance with cyclic load is a very critical and challenging problem. In this paper, a probabilistic characterization method for the random contact process is proposed. Then, based on this method, theoretical models are established to describe the mechanical behavior, thermal and electrical contact resistance of the rough contact surface under cyclic loading. The results show that the cyclic load has a significant effect on the thermal and electrical contact resistance. The stiffness, thermal insulation capacity, and electrical conductivity of the interface are closely related to the number of cyclic loads, which provides a reference for the evaluation of interface performance and life prediction of engineering structures in complex environments. [ABSTRACT FROM AUTHOR]

The plane geometry design of the cable-net structure is the basis for the form-finding and structural design. The loop-free single-layer cable-net structure is a new cable-net scheme, but due to its special and complex shape, it is difficult to determine its plane geometry according to architectural requirements. In this paper, the moving support node method is proposed, which can quickly get the plane geometry of a loop-free single-layer cable-net structure. The form-finding is proceeded based on the existing small elastic modulus method. There are two constraints when using the moving support node method. One is that the projection of all cables is straight line, and the other is that the distance between the two cables of each support node and the inner boundary of the target is equal. The aim is to minimize the sum of the distances from all cables to the inner boundary of the target. Using the plane geometry control parameters and the plane coordinates of the support nodes as decision variables, the plane geometry closest to the target inner and outer boundaries is get through optimization analysis. According to the derivation of the formula, the plane projection shape of a loop-free single-layer cable-net structure is mainly related to three parameters, including the number of supports, the difference between the node numbers of the supports at both ends of each cable, and the target curve equations of the inner and outer boundaries. Finally, taking the roof structure of Linyi Olympic Stadium as an instance, the feasibility of the plane geometry design method of the loop-free single-layer cable-net structures based on the moving support node method is verified. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to establish and validate nomograms to predict the probability of intravesical recurrence (IVR) after radical nephroureterectomy (RNU) for upper urinary tract epithelial carcinoma (UTUC). Methods: Clinical data of 528 patients with UTUC after RNU were collected from two medical centers between 2009 and 2020. We used the least absolute shrinkage and selection operator (LASSO) regression to select variables for multivariable Cox regression analysis in the training cohort and included independent risk factors into nomogram models predicting IVR-free survival (IVRFS). Another center was applied as the external cohort to validate the predictive accuracy and discriminative ability of the nomogram by performing area under the receiver operating curve (AUC), consistency index (C-index), and calibration curve. Results: History of bladder cancer, tumor size, preoperative urine cytology, postoperative instillation, Ki-67, and platelet-to-lymphocyte ratio (PLR) were identified as independent risk factors for IVR. The prognosis model including these predictors demonstrated excellent discriminatory performance in both the training cohort (C-index, 0.814) and external validation cohort (C-index, 0.748). The calibration plots of the nomogram revealed good consistency in both cohorts. Finally, patients could be classified into two risk groups based on scores obtained from the nomogram, with significant differences in IVRFS. Conclusion: Our study provided a reliable nomogram for predicting the probability of IVR in patients with UTUC after RNU. Risk stratification based on this model may assist urologists make optimal clinical decisions on the management of UTUC. [ABSTRACT FROM AUTHOR]

The correction notice in the Biological Trace Element Research journal addresses an error in the published version of an article on the association between blood mercury and lipid biomarkers in US hypertensive adults. The study found significant positive links between blood mercury levels and total cholesterol, LDL cholesterol, and HDL cholesterol in hypertensive adults in the USA. The research suggests that blood mercury may impact various pathophysiological mechanisms related to cardiovascular disease risk, potentially contributing to the development of cardiovascular disease in conjunction with other blood lipid biomarkers. The correction notice provides insights into the mechanisms through which mercury may affect lipid metabolism and emphasizes the importance of adhering to health guidelines and modifying lifestyle and dietary habits to lower blood mercury levels and blood lipid biomarker levels. [Extracted from the article]

Purpose: This study aimed to explore the value of cytoreductive nephrectomy (CN) and develop nomograms to predict the prognosis of metastatic renal cell carcinoma (mRCC) patients with receiving radiology therapy or/and chemotherapy (RT/&CT). Methods: Clinical data of patients with mRCC between 2010 and 2015 were collected from the Surveillance, Epidemiology, and End Results (SEER) database. Prognostic nomograms were constructed to predict the overall survival (OS) and cancer-specific survival (CSS) probability for 1-, 3-, and 5- years in patients with mRCC. A series of validation methods were used to validate the accuracy and reliability of the model, including area under the receiver operating curve (AUC), consistency index (C-index), calibration curve, and decision curve analysis (DCA). Results: 1394 patients were enrolled in this study. All patients were randomly divided into the training cohort (n = 976) and the validation cohort (n = 418). In the training cohort, multivariate Cox regression analysis suggested that pathology grade, histology type, T stage, N stage, surgery, and distant metastasis were independent risk factors for OS and CSS. The AUC and C-index were both over 0.65 in both cohorts, indicating that the nomograms for OS and CSS had satisfactory discriminative power. The calibration curves revealed that the predictive nomograms had a good consistency between the observed and the predicted survival. Conclusion: This study provided evidence that mRCC patients underwent RT/&CT could gain survival benefits from CN. The prognostic nomogram constructed in our study is reliable and practical, may help guide clinical strategies in the treatment of mRCC. [ABSTRACT FROM AUTHOR]

Background: In previous observational studies, food-derived antioxidant vitamins have been suggested to be associated with breast cancer. However, the findings were inconsistent and the causal relationship could not be clearly elucidated. To confirm the potential causal relationship between food-derived antioxidants (retinol, carotene, vitamin C and vitamin E) and the risk of breast cancer, we conducted a two-sample Mendelian randomization (MR) study. Methods: The instrumental variables (IVs) as proxies of genetic liability to food-derived antioxidant vitamins were obtained from the UK Biobank Database. We extracted breast cancer data (122,977 cases and 105,974 controls) from the Breast Cancer Consortium (BCAC). In addition, we studied estrogen expression status categorically, including estrogen receptor positive (ER+) breast cancer (69,501 cases and 105,974 controls) and versus estrogen receptor (ER−) negative breast cancer (21,468 cases and 105,974 controls). We performed two-sample Mendelian randomization study, and inverse variance–weighted (IVW) test was regarded as main analysis. Sensitivity analyses were further conducted to assess heterogeneity and horizontal pleiotropy. Results: The results of IVW showed that among the four food-derived antioxidants, only vitamin E had protective effect on the risk of overall breast cancer (OR = 0.837, 95% CI 0.757–0.926, P = 0.001) and ER+ breast cancer (OR = 0.823, 95% CI 0.693–0.977, P = 0.026). However, we found no association between food-derived vitamin E and ER− breast cancer. Conclusions: Our study suggested food-derived vitamin E can decrease the risk of breast cancer overall and ER+ breast cancer, and the robustness of our results was confirmed by sensitivity analyses. [ABSTRACT FROM AUTHOR]

Purpose: To explore the predictive value of preoperative magnetic resonance imaging structural and diffusion indices of the spinal trigeminal tract (SpTV) on the results of microvascular decompression (MVD) in patients with trigeminal neuralgia (TN). Methods: This retrospective study included patients diagnosed with TN and treated with MVD in the Jining First People's Hospital between January 2020 and January 2021. The patients were divided into good and poor results groups according to postoperative pain relief. Logistic regression analysis was performed to explore independent risk factors for poor results of MVD, and their predictive value was examined using receiver operating characteristic (ROC) curves. Results: A total of 97 TN cases were included, 24 cases with a poor result and 73 with a good result. They were comparable in demographic characteristics. Fractional anisotropy (FA) was lower (P < 0.001), and radial diffusivity (RD) was higher (P < 0.001) in the poor result group compared to the good result group. Patients in the good result group showed a higher proportion of grade 3 neurovascular contact (NVC) (39.7% vs. 16.7%, P = 0.001) and a lower RD (P < 0.001). The multivariate analysis showed that the RD of SpTV (OR = 0.000016, 95% CI: 0.000–0.004, P < 0.001) and NVC (OR = 8.07, 95% CI: 1.67–38.93, P = 0.009) were independently associated with poor results. The area under the curve (AUC) of RD and NVC were 0.848 and 0.710, and their combination achieved an AUC of 0.880. Conclusion: NVC and RD of SpTV are independent risk factors for poor results after MVD surgery, and combining the NVC and RD might achieve relatively high predictive value for poor results. [ABSTRACT FROM AUTHOR]

The Lower Wuerhe Formation in Mahu 1 well area of Junggar Basin is rich in oil and gas resources, which are rich in zeolite cements. In this paper, based on core observation and scanning electron microscope data, we clarified that there are four types of zeolite minerals, mainly turbidite, followed by zeolite, and occasionally zeolite and clinoptilolite. Based on the data of X-ray diffraction, physical properties and thin sections, there are two genetic modes of zeolite minerals in this area: cementation and volcanic erosion. For the first time, the prediction model of zeolite content was established by the method of multiple regression, and the plane distribution map of the content of turbidized zeolite in the target strata in the study area was established. The study found that zeolite mainly distributed in the conglomerate size in fine conglomerate and small conglomerate, and the microfacies mainly distributed in the front zone of fan delta. [ABSTRACT FROM AUTHOR]

Aiming at the obstacle avoidance trajectory problem of robotic manipulators in operation space, a combinatorial optimisation solution of the obstacle avoidance path and near time-optimal trajectory planning is proposed. The robotic manipulator and the obstacles are modelled by a swept sphere volume (SSV) envelope and a capsule envelope, respectively. Based on the target offset and the target preference expansion strategy in the repulsion field, an improved RRT* algorithm is adopted to avoid collision to realise obstacle-free path planning at the end-effector level in Cartesian space and the link level in joint space. The thresholds of velocity, acceleration and jerk are set as constraints, and the interval time between nodes is optimised as position information of the improved whale optimisation algorithm. Near time-optimal trajectory planning of robotic manipulators with motion constraints is further completed. The IWOA obtains a high-quality initial population by covering the search space, and the population is updated by the thermal memory (TM) to improve individual quality. Thermal exchange optimisation (TEO) is applied to enhance the exploitation performance of IWOA, and the hierarchical structure strategy is introduced to explore potential optimal solutions. The simulation results show that the method limits the jerk of the robotic manipulator, ensures smooth movement and has higher obstacle avoidance ability and work efficiency than previous methods. [ABSTRACT FROM AUTHOR]

Objectives: To retrospectively evaluate the diagnostic value of MRI for the uterotubal junctional pregnancies during the first trimester. Methods: This retrospective study involved 59 patients (January 2016 to July 2021) with a preoperative imaging diagnosis of uterotubal junctional pregnancy. Using operative and pathological reports as the reference standard, we identified 22 patients with upper-lateral intracavitary (angular) pregnancy and 37 patients with interstitial pregnancy. Two senior radiologists, blinded to the patients' information, reviewed the MRI images and determined each MRI feature based on the original interpretation criteria. Any disagreement was resolved by discussion to achieve a consensus. The sensitivity and specificity of each MRI feature were calculated according to the reference standard. Results: The endometrial thickness in the upper-lateral intracavitary pregnancy group was larger than in the interstitial group (p = 0.001). The cutoff value of the endometrial thickness was 11.5 mm with a sensitivity, specificity, and area under the curve that were 77.3%, 64.9%, and 0.743, respectively. Two key features to diagnose upper-lateral intracavitary pregnancy were "medial free edge" and "medial free edge plus above-cutoff endometrial thickness." The sensitivity and specificity of the medial free edge were 100% and 94.9%, respectively. The sensitivity and specificity of the medial free edge plus above-cutoff endometrial thickness were 77.3% and 100%, respectively. The key feature to diagnose interstitial pregnancy was an "intact lateral junctional zone," of which the sensitivity and specificity were 94.6% and 100%, respectively. Conclusions: MRI can be used to differentiate the upper-lateral intracavitary pregnancy and interstitial pregnancy during the first trimester. Key Points: • We demonstrated MRI diagnostic criteria for the interstitial pregnancy and upper-lateral intracavitary pregnancy. • MRI might be used to identify the complex interstitial pregnancies, those with a gestational sac protruding into the uterine cavity. [ABSTRACT FROM AUTHOR]

With the rapid development of civil aviation industry and the continuous improvement in passenger demand, higher requirements have been put forward for safety and comfort in the design process of civil aircraft. In order to develop a special ergonomic simulation experimental system for civil aircraft cabin seats, from the perspective of "human", this paper comprehensively considers the impact on civil aircraft cabin seats environment on human physiology and psychology, and puts forward an evaluation method of civil aircraft cabin ergonomic simulation experimental system based on passengers' perception of key design features. Based on the principles of ergonomics, the connection between key design features of seat comfort and the requirements of user preference is comprehensively considered, a simulation experimental system based on comfort evaluation is constructed using subjective and objective evaluation methods. Moreover, according to the experimental requirements of the simulation experimental system and the characteristics of seat structure, an ergonomic simulation experimental system for civil aircraft cabin is developed. The final experimental results prove the practicability and validity of the simulation experiment system designed. [ABSTRACT FROM AUTHOR]

The dielectric capacitors with high energy storage capability are demand for power electronic devices to keep pace with the development of the modern electronic and electrical industry. Although polymer-based dielectric composites showing the superiorities of ease processing, self-healing and low cost have a great potential in various applications, their energy storage capability is still severely limited by the negative coupling effect between dielectric permittivity and breakdown strength. In this study, we present a two-dimensional graphene oxide@silica core–shell nanoplatelets (GO@SiO2) constructed through the classical Stöber method. Moreover, a series of polyvinylidene fluoride (PVDF)/GO@SiO2/PVDF sandwich-structured composites were assembled layer-by-layer and obtained through combining the spray coating and solution casting procedures. The GO@SiO2 nanoplatelets were closely aligned and orientated along the direction that perpendicular to the electric field, forming the non-traditional inorganic middle layer. The thickness of the middle layer is dependent on the GO@SiO2 loading fraction, which directly influenced the overall dielectric and electrical performances of the sandwich-structured composites. An enhanced breakdown strength (~ 253 MV m−1) and discharged density (~ 5.19 J cm−3) can be obtained from the PVDF/GO@SiO2/PVDF composite filled with the GO@SiO2 loading fraction as small as 1.37 wt%, which are 23.4% and 161% higher than those of neat PVDF (~ 1.99 J cm−3 at 205 MV m−1), respectively. The improved energy storage capability could be attributed to the synergetic contribution of highly insulating SiO2 shell, the additional core–shell interfacial interaction, the orientation that perpendicular to electric field and the multilayered construction of composite. Thus, this research provides a promising approach for the design of advanced composites with an improved dielectric energy storage property. [ABSTRACT FROM AUTHOR]

Micro-stepped holes have been widely used in the fields of micro motor, precision mold, medical device, and so on. YG8 cemented carbide is widely used for machining micro-stepped hole because of its high hardness and good wear resistance. However, it is difficult to realize high-quality machining of micro-stepped holes on YG8 cemented carbide by turning and milling. Micro-EDM has no macroscopic cutting force and is not limited by material hardness, so it is the mainstream technology for machining microstructures on superhard materials. To address the above problems, the paper proposed to adopt micro-EDM to process the micro-stepped hole by using a micro milling cutter. Firstly, micro-EDM was carried out on YG8 cemented carbide with a high-speed rotating micro milling cutter to obtain the basic micro-hole structure. In the process of micro-EDM, the length of micro milling cutter was reduced due to wear. Secondly, micro-EDM was performed on the YG8 cemented carbide using the micro milling cutter with wear in length as the tool electrode, which was made to shake around the central axis of the basic micro-hole, so that a secondary basic micro-hole was machined on the basic micro-hole and a micro-stepped hole was formed. In the process of machining the secondary basic micro-hole, micro milling cutter with no wear would produce a secondary basic micro-hole with the same depth as the basic micro-hole, and no micro-stepped hole would be formed. In this paper, the wear of micro milling cutter in the length direction was transformed into a favorable factor. With the micro milling cutter shaking, a micro-stepped hole was obtained using the same micro milling cutter in different stages of EDM. Through a large number of machining experiments, the main process parameters were optimized and the experimental results were analyzed in this paper. Finally, the micro-EDM of YG8 cemented carbide was carried out with a micro milling cutter with a diameter of 400 µm at 2000 RPM rotational speed n, 90 V machining voltage V, and 0.5 duty ratio R, and a micro-stepped hole with good quality was obtained. [ABSTRACT FROM AUTHOR]

The parameter analysis of satellite tracking, telemetry, and command signal is necessary for space situational awareness. Unified S-Band (USB) waveforms are widely used in space missions. As a crucial parameter of the USB waveform, the modulation index influences the power distribution and spectrum characteristics of the waveform. This paper proposes two novel blind estimation methods of the modulation index based on spectral analysis. The equations for estimating the modulation index are constructed by the relation between the spectral characteristics and the Fourier transform of signal. The theoretical analysis of the estimation error of the methods is derived. The factors that influence the estimation error are investigated by Monte Carlo simulation, and an actual Geostationary Earth Orbit satellite signal is used to verify the methods. The proposed methods have lower complexity than existing methods, while also providing more than 10 times accuracy improvement at low signal-to-noise ratios. Suggestions for the application of the proposed methods to different scenarios are also provided. [ABSTRACT FROM AUTHOR]

It is of great significance to study the effects of precipitation events on carbon exchange in the ecosystem for an accurate understanding of the carbon cycle. However, the response of net ecosystem CO2 exchange (NEE) in the desert to precipitation events is elusive. In this study, the NEE in response to precipitation events of varying intensities in the Badain Jaran Desert (BJD) in China was continuously monitored using the eddy covariance (EC) technique. The following results were obtained: (1) The BJD ecosystem was a net CO2 sink throughout the study period, with NEE values of -113.4, -130.7, and -175.4 g C m-2a-1 in 2016, 2018, and 2019, respectively. The total precipitation yielded a higher carbon sequestration capacity in 2019 than in the other two years. In addition, the intensity, time, and frequency of precipitation had significant impacts on CO2; (2) the threshold value of the NEE response to precipitation was ~1.4 mm, indicating the extreme sensitivity of the BJD to precipitation events; (3) the variations in the NEE response to precipitation events conformed to a dual exponential model. The analytical results of the model indicate that precipitation intensity was positively correlated with the carbon sequestration capacity of the desert. The model revealed that the greater the precipitation intensity, the longer it takes the NEE to reach the maximum, and the lengthier the duration of the residual effects. With an increase in the total precipitation and frequency of extreme precipitation events under warm and humidification climates, the carbon sequestration capacity of the BJD will likely be enhanced. The results of this study are of great significance for revealing the carbon cycle mechanism of the desert ecosystem. [ABSTRACT FROM AUTHOR]

Biologically derived and biologically inspired fibers with outstanding mechanical properties have found attractive technical applications across diverse fields. Despite recent advances, few fibers can simultaneously possess high-extensibility and self-recovery properties especially under wet conditions. Here, we report protein-based fibers made from recombinant scallop byssal proteins with outstanding extensibility and self-recovery properties. We initially investigated the mechanical properties of the native byssal thread taken from scallop Chlamys farreri and reveal its high extensibility (327 ± 32%) that outperforms most natural biological fibers. Combining transcriptome and proteomics, we select the most abundant scallop byssal protein type 5-2 (Sbp5-2) in the thread region, and produce a recombinant protein consisting of 7 tandem repeat motifs (rTRM7) of the Sbp5-2 protein. Applying an organic solvent-enabled drawing process, we produce bio-inspired extensible rTRM7 fiber with high-extensibility (234 ± 35%) and self-recovery capability in wet condition, recapitulating the hierarchical structure and mechanical properties of the native scallop byssal thread. We further show that the mechanical properties of rTRM7 fiber are highly regulated by hydrogen bonding and intermolecular crosslinking formed through disulfide bond and metal-carboxyl coordination. With its outstanding mechanical properties, rTRM7 fiber can also be seamlessly integrated with graphene to create motion sensors and electrophysiological signal transmission electrode. Bio-inspired materials are an intense area of study as researchers try to adapt biomaterials for other applications. Here, the authors report on the processing of protein materials derived from the byssal thread of scallops to create high-extensibility materials with self-recovery under wet conditions. [ABSTRACT FROM AUTHOR]

We tackle the online 3D bin packing problem (3D-BPP), a challenging yet practically useful variant of the classical bin packing problem. In this problem, the items are delivered to the agent without informing the full sequence information. The agent must directly pack these items into the target bin stably without changing their arrival order, and no further adjustment is permitted. Online 3D-BPP can be naturally formulated as a Markov decision process (MDP). We adopt deep reinforcement learning, in particular, the on-policy actor-critic framework, to solve this MDP with constrained action space. To learn a practically feasible packing policy, we propose three critical designs. First, we propose an online analysis of packing stability based on a novel stacking tree. It attains a high analysis accuracy while reducing the computational complexity from O(N2) to O(N log N), making it especially suited for reinforcement learning training. Second, we propose a decoupled packing policy learning for different dimensions of placement which enables high-resolution spatial discretization and hence high packing precision. Third, we introduce a reward function that dictates the robot to place items in a far-to-near order and therefore simplifies the collision avoidance in movement planning of the robotic arm. Furthermore, we provide a comprehensive discussion on several key implemental issues. The extensive evaluation demonstrates that our learned policy outperforms the state-of-the-art methods significantly and is practically usable for real-world applications. [ABSTRACT FROM AUTHOR]

Aiming at the problem of complex path planning in the processing of curved surface workpieces of body-in-white, a hybrid path planning method based on a memetic algorithm is proposed. The method is divided into two parts: welding sequence planning and welding path planning between weld points. By establishing the kinematic model of a spot welding robot based on the pipper criterion and z-y-z Euler angle solution method, the motion constraints of path optimization are analyzed. Under the framework of the memetic algorithm, the improved A-star algorithm with redundant node deletion and a post-smoothing process is used to obtain the smooth collision-free optimal path set between weld points and to construct the objective function of travelling all weld points with the shortest path length and highest smoothness. The multiobjective elitist-simulated annealing genetic algorithm (MESAGA) is used to achieve the welding sequence planning of all weld points. The variable neighborhood search method improves the mutation operator; the elitist strategy is introduced to improve the probability of elitist individual crossover and mutation operation, and a simulated annealing algorithm is used to jump out of local search to obtain the global optimal solution. According to the motion constraints, the joint space path is obtained by the optimal path in Cartesian space. Simulation analysis results demonstrate that the hybrid path planning method based on the memetic algorithm can effectively optimize the path of spot welding robots and lay the foundation for control and trajectory planning during welding processes. [ABSTRACT FROM AUTHOR]

Titanium alloy has been widely applied in industrial fields because of its excellent material properties. Electrical discharge machining (EDM) is commonly technology for processing titanium alloy. When titanium alloy was processed by EDM, a recast layer was inevitably be produced on its surface, which can adversely affect the surface quality and working life. Focus on the above problem, this paper proposed to add B4C powders into the spark oil and cooperate with the tool electrode sloshing for powder mixed electrical discharge machining (PMEDM) of titanium alloy, which can reduce the thickness of the recast layer and thereby improve the quality of the machined surface. Firstly, B4C powders were mixed in the spark oil and the PMEDM of the titanium alloy was carried out. In this step, the thickness of recast layer was preliminarily reduced and the quality of machined surface was improved. Secondly, when the PMEDM of the titanium alloy was nearly completed, the tool electrode sloshed along the machine tool spindle within the EDM gap. Combining PMEDM with the tool electrode sloshing, the recast layer on the machined surface was further eliminated and the quality of machined surface was further improved. By adding 3000 mesh B4C powders into the spark oil, the paper carried out the PMEDM of titanium alloy combining with the tool electrode sloshing. Under the action of appropriate process parameters, the micro-groove structure with surface roughness Ra of 0.205 μm was obtained in the titanium alloy and the recast layer on the machined surface was almost invisible. [ABSTRACT FROM AUTHOR]

Ti-6Al-4V alloy has been widely used in industrial fields. Electrical discharge machining (EDM) is a commonly used technology for machining Ti-6Al-4V alloy. During EDM of Ti-6Al-4V alloy, the thermal and physical characteristics of tool electrode have an important influence on processing characteristics. In order to study the influence of different electrode materials on the processing characteristics of Ti-6Al-4V alloy, brass electrode, copper tungsten electrode, and tungsten electrode were used to perform EDM of Ti-6Al-4V alloy. In this paper, electrodes with V-groove array structures were designed to carry out powder mixed electrical discharge machining (PMEDM) of Ti-6Al-4V alloy, and the machining results were evaluated based on four indicators: microstructures morphology, tool electrode wear (TEW), material removal rate (MRR), and recast layer thickness (RLT). The processing results show that copper tungsten electrode is recommended to machine Ti-6Al-4V alloy because it has the highest reproduction rate (75.2%), a smaller TEW (139 μm), the highest MRR (255.39 mm3/min), and a thinner RLT (3.35 μm). [ABSTRACT FROM AUTHOR]

To promote the development and application of ultra-thin heat dissipation devices, Cu/grapheme (GR) composite foils with hierarchical microscale structure were prepared by ultrasonic-assisted composite electrodeposition, and chemical etching and plasma oxidation treatment were applied to obtain superhydrophilic. The study found that the hierarchical multi-scale structure on the mold electrode surface can be replicated on the foil surface. Ultrasonic refines the grains and reduces the internal defects, while an increase in the GR content not only further refines the grains but also makes the microstructure multi-directional. The combined effect of ultrasonic and GR significantly improves the microhardness of the foils up to 125 HV0.01. Without any surface treatment, the contact angle (CA) of foil gradually increased with the introduction of ultrasonic and GR, the wettability developed towards hydrophobic, and the highest CA reached 98.43°. Chemical etching can change the submicron-scale structure of the foil surface, and then make the wettability towards to hydrophilic, but not enough to reach the superhydrophilic state. After plasma oxidation treatment, a large number of nanoscale CuO and Cu2O particles are generated on the surface of the chemical etching foils, which not only further enriches the multi-scale structure, but also improves the surface energy. As a result, the wettability of foil surface is further improved, showing a superhydrophilic state, and the CA is less than 5°. Moreover, with the introduction of ultrasonic and the increase of GR content, the hydrophily of the foil surface also tends to improve, and the minimum CA can reach 1.89°. [ABSTRACT FROM AUTHOR]

Let X be a minimal projective threefold of general type over C with only Gorenstein quotient singularities, and let Aut Q (X) be the subgroup of automorphisms acting trivially on H ∗ (X , Q) . In this paper, we show that if X is of maximal Albanese dimension, then | Aut Q (X) | ≤ 6 . Moreover, if X is nonsingular and K X is ample, then | Aut Q (X) | ≤ 5 . Seeking for higher-dimensional examples of varieties with nontrivial Aut Q (X) , we concern d-folds X isogenous to an unmixed product of curves. If d = 3 , we show that Aut Q (X) is a 2-elementray abelian group whose order is at most 4 under some conditions on their minimal realizations. Moreover, each of the possible groups can be realized. If d ≥ 3 , we give a sufficient condition for Aut Q (X) being trivial. Curiously, there exist examples of projective threefolds X with terminal singularities and maximal Albanese dimension whose Aut Q (X) can have an arbitrarily large order. [ABSTRACT FROM AUTHOR]

During duration spaceflight, or after their return to earth, astronauts have often suffered from gait instability and cerebellar ataxia. Here, we use a mouse model of hindlimb unloading (HU) to explore a mechanism of how reduced hindlimb burden may contribute to motor deficits. The results showed that these mice which have experienced HU for 2 weeks exhibit a rapid accumulation of formaldehyde in the gastrocnemius muscle and fastigial nucleus of cerebellum. The activation of semicarbazide-sensitive amine oxidase and sarcosine dehydrogenase induced by HU-stress contributed to formaldehyde generation and loss of the abilities to maintain balance and coordinate motor activities. Further, knockout of formaldehyde dehydrogenase (FDH-/-) in mice caused formaldehyde accumulation in the muscle and cerebellum that was associated with motor deficits. Remarkably, formaldehyde injection into the gastrocnemius muscle led to gait instability; especially, microinfusion of formaldehyde into the fastigial nucleus directly induced the same symptoms as HU-induced acute ataxia. Hence, excessive formaldehyde damages motor functions of the muscle and cerebellum. Dandan Yao et al. demonstrated that accumulation of formaldehyde in the cerebellum and skeletal muscle contributed toward motor deficits in a mouse model of hindlimb unloading. Their results collectively suggest that scavenging formaldehyde may be a useful treatment to limit motor dysfunction following limb offloading conditions. [ABSTRACT FROM AUTHOR]

This study aims to investigate the combined effects of temperature and precipitation on the hydrological processes in a watershed with intensive agricultural land uses during the spring snowmelt period. Temperature, precipitation, soil moisture, frozen soil depth, and discharge were monitored during the freezing and thawing periods in 2014, 2015, and 2016 within the 75 km2 agricultural Heidingzi watershed in northeast China. The results indicated that high autumn rainfall and early precipitation, as well as the corresponding temperature rise, during the stable freezing period, increased the amount of surface water stored in the ice form before the spring runoff. These conditions produced a prolonged and increasing runoff event, and the highest runoff ratio of the ice melt runoff process during the thawing period in 2014. However, low autumn rainfall, dispersed precipitation, and negligible temperature rises during the stable freezing period in 2014–2015 led to a significant but short-term snowmelt runoff during the thawing period in 2015. Because of similar precipitation conditions as in 2014–2015 and a temperature rise event during the freezing period in 2015–2016, the runoff during the thawing period in 2016 was a combination of snow and ice melt; the runoff ratio during the early- and late-melt stages in the maize-dominated drainage region (DR) was the highest with the lowest precipitation. Additionally, the early low rainfall during the thawing period in 2014 increased the direct runoff ratios by 2–13 times for the entire watershed, DRM, and DRP-M, as early rainfall resulted in small soil thaw depth and low water storage. Different land use activities in the agricultural watershed supported the spatial and temporal differences and uncertainties in the spring snow or ice melt runoff generation process. Moreover, snowmelt simulation models can rarely distinguish between ice and snowmelt during spring runoff generation processes, probably leading to high uncertainty in simulating spring runoff response to climate change in seasonal freezing areas. This study reveals the characteristics and causes of snow and ice melt runoff processes in agricultural watersheds that experience seasonal freezing and provides a new perspective for improving the modeling of water generation processes. [ABSTRACT FROM AUTHOR]

In inertial confinement fusion, quantitative and high-spatial resolution ( < 10 μ m) measurements of the X-rays self-emitted by the hotspot are critical for studying the physical processes of the implosion stagnation stage. Herein, the 8 ± 0.39-keV monochromatic X-ray distribution from the entire hotspot is quantitatively observed in 5- μ m spatial resolution using a Kirkpatrick–Baez microscope, with impacts from the responses of the diagnosis system removed, for the first time, in implosion experiments at the 100 kJ laser facility in China. Two-dimensional calculations along with 2.5% P2 drive asymmetry and 0.3 ablator self-emission are congruent with the experimental results, especially for the photon number distribution, hotspot profile, and neutron yield. Theoretical calculations enabled a better understanding of the experimental results. Furthermore, the origins of the 17.81% contour profile of the deuterium-deuterium hotspot and the accurate Gaussian source approximation of the core emission area in the implosion capsule are clarified in detail. This work is significant for quantitatively exploring the physical conditions of the hotspot and updating the theoretical model of capsule implosion. [ABSTRACT FROM AUTHOR]

Ti-containing porous materials are extensively studied in liquid-phase oxidative desulfurization (ODS) to obtain low-sulphur fuel, these materials displayed excellent ODS performance co-operating with organic oxidants but relatively poor ability with H2O2, which is a green and cheap oxidant widely used in industrial process. To overcome this challenge, we reported a H2O2 compatible ODS catalyst Ti-MIL-101 by treating MIL-101 with TiCl4 in dehydrated CH2Cl2. The results of N2-absorption, UV–vis, IR and XPS indicated that Ti species were mainly confined in mesopore cages of MIL-101 in the form of isolated and oligomeric octahedral Ti which were grafted to Cr centres of MIL-101 by Cl bridge. Moreover, wettability studies further suggested this catalyst possessed good affinity with water-based substance. As a result, Ti-MIL-101 exhibited efficient ODS ability in the oxidative reaction of DBT with H2O2 compared with that with organic oxidant. In model fuel, sulphur content was reduced to less than 10 ppmw from 1000 ppmw within 30 min at 333 K and the corresponding TOF value over Ti-MIL-101 reached 16.8 h−1. This outstanding catalytic ability might be the result of the synergy between the distinct active Ti species and the good surface affinity of Ti-MIL-101. Ti-containing metal–organic frameworks were prepared for oxidative desulfurization of obstinate sulphur compounds with H2O2. This catalyst displayed highly efficient activity in ODS of DBT. The sulphur content was reduced from 1000 ppmw to less than 10 ppmw in 30 min, corresponding TOF number reached 16.8 h−1. This outstanding catalytic result could be attributed to the superior affinity between catalyst and oxidant. [ABSTRACT FROM AUTHOR]

Microbial contamination in drinking water has become an important threat to human health. There is thus an urgent need to develop antibacterial materials to treat drinking water. Here, porous silver-loaded biochar (C–Ag) was prepared using corn straw as the substrate and silver as the antibacterial agent. C–Ag was then uniformly distributed in polyvinyl alcohol gel beads of eluted calcium carbonate to prepare p-PVA/C–Ag antibacterial composite. The polymer composites were tested by FT-IR, XRD, SEM and TG-DSC. The results showed that C–Ag was more evenly distributed in the PVA gel spheres. Antibacterial experiments showed that p-PVA/C–Ag greatly inhibited Escherichia coli. Practical application tests revealed that p-PVA/C–Ag showed high and sustained bactericidal inhibition and reusability. Generally, p-PVA/C–Ag composite shows high potential to be applied to drinking water treatment. [ABSTRACT FROM AUTHOR]

The worldwide emergence and spread of antimicrobial resistance is accelerated by irrational administration and use of empiric antibiotics. A key point to the crisis is a lack of rapid diagnostic protocols for antimicrobial susceptibility testing (AST), which is crucial for a timely and rational antibiotic prescription. Here, a recombinant bacteriophage tail fiber protein (TFP) was functionalized on magnetic particles to specifically capture Pseudomonas aeruginosa, while fluorescein isothiocyanate-labeled-magainin II was utilized as the indicator. For solving the magnetic particles' blocking effects, a reverse assaying protocol based on TFP recognition was developed to investigate the feasibility of detection and AST of P. aeruginosa. P. aeruginosa can be rapidly, sensitively and specifically detected within 1.5 h with a linear range of 1.0 × 102 to 1.0 × 106 colony forming units (CFU)⋅mL−1 and a detection limit of 3.3 × 10 CFU⋅mL−1. Subsequently, AST results, which were consistent with broth dilution results, can be obtained within 3.5 h. Due to the high specificity of the TFP, AST can actually be conducted without the need for bacterial isolation and identification. Based on the proof-of-principle work, the detection and AST of other pathogens can be extended by expressing the TFPs of their bacteriophages. [ABSTRACT FROM AUTHOR]

Introduction: Considering the controversial relationship between blood lipid levels and osteopenia and osteoporosis (OP), we performed this meta-analysis. Materials and methods: Using specific keywords and related words, we searched PubMed, Embase, and Cochrane Library databases. The Newcastle–Ottawa Scale form was used to evaluate the quality of the literature. According to the inclusion and exclusion criteria, we systematically screened the literature to extract relevant information and data. ReVman 5.3 and Stata 13.0 software were used for statistical analysis. Results were expressed as the mean difference (MD) and 95% confidence interval (95% CI). The heterogeneity test was conducted according to I2 and Q tests. Egger's test was used to quantitatively evaluate publication bias. Results: This analysis involved 12 studies (12,395 subjects). The quality of the literature was acceptable. Among subjects who were not taking lipid-lowering drugs, total cholesterol (TC) (MD = 0.11 mmol/L, 95%CI: − 0.03, 0.25; I2 = 21%; P = 0.36), triglycerides (TG) (MD = − 0.01 mmol/L, 95%CI: − 0.09, 0.07; I2 = 6%; P = 0.34), and low-density lipoprotein cholesterol (LDL-C) (MD = 0.10 mmol/L, 95%CI: 0.00, 0.19; I2 = 0%; P = 0.74) in the osteopenia were not significantly increased/decreased. There were no significant differences in LDL-C (MD = 0.02 mmol/L, 95%CI: − 0.09, 0.13; I2 = 0%; P = 0.74) in postmenopausal women in osteopenia. TG (MD = − 0.04 mmol/L, 95%CI: − 0.14,0.07; I2 = 49%; P = 0.07) was unchanged in the osteoporosis (OP) group in subjects without taking lipid-lowering drugs. HDL-C was elevated in OP group (MD = 0.05 mmol/L, 95%CI: 0.03, 0.07; I2 = 31%; P = 0.15) but not in osteopenia group (MD = 0.01 mmol/L, 95%CI: − 0.01, 0.02; I2 = 38%; P = 0.14) in all subjects. Conclusion: HDL-C was elevated in patients with OP. [ABSTRACT FROM AUTHOR]

Bees are vitally important in natural and agricultural ecosystems, providing key pollination services to wild plants and crops. Increasing reports of regional declines of bee populations have attracted intense attention worldwide. Challenges to bee health are multifactorial and include poor nutrition, heat stress, agrochemicals, and pathogens. The impact of heat stress is a relatively minor factor in current bee declines compared with agrochemicals and pathogens. However, heat stress has adverse impacts on foraging activity, pollination services, task-related physiology, immunocompetence, reproductive capacity, growth, and development of bees, and these adverse impacts are variable in different bee species. Heat stress–related damage to bees receives extra attention when it is accompanied by climate change. Heat-tolerance mechanisms are key enablers for bee survival under high-temperature stress conditions, and we now understand that both behavior and molecular regulation strongly impact the ability of bees to reduce damage from heat stress. In this review, we summarize and synthesize previous findings about the detrimental effects of heat stress to bees and discuss the strategies bees use to cope with heat stress. Bee species mentioned here are mainly honeybees, bumblebees, and stingless bees, with a focus on the honeybee Apis mellifera. [ABSTRACT FROM AUTHOR]

Printed circuit board (PCB) can provide assembly support and electrical connection for components in electronic systems. The machining of micro-holes in PCB is a necessary process and key step for its application in electronic components. Therefore, micro-holes are the key structures of PCB. At present, high-speed drilling based on micro-bit is the key supporting technology for machining PCB micro-holes. However, when the copper foil layer in PCB is machined by this technology, the micro-holes are prone to defects such as hole mouth burr and hole nail head, which could seriously affect the performance of PCB. Focusing on the above problems, this paper proposed to use micro electro-discharge machining (micro-EDM) for assisted machining of PCB micro-holes. With this method, the copper foil layer in PCB was machined by micro-EDM, so as to remove hole mouth burr and hole nail head. The paper detailedly studied the influence of micro-EDM voltage, pulse width and pulse interval on hole mouth burr and hole nail head. Finally, under the effects of 10,000 rpm rotational speed, 40 V voltage, 80 ns pulse width and 160 ns pulse interval, the micro-bit with diameter of 200 μm was used to carry out micro-EDM-assisted machining of the copper foil in PCB. From the machining results, it can be found that the hole mouth burr and the hole nail head were basically eliminated and PCB micro-holes with good quality were obtained by the proposed method. [ABSTRACT FROM AUTHOR]

Thermal-sprayed aluminum (Al) coatings are widely used for corrosion protection in marine environments. The corrosive nature of seawater and the synergy with marine microbes make for aggressive service environments for Al coatings. In this study, Al coatings were deposited on 316L stainless steel (316L SS) substrates by using wire arc spraying. Chlorella vulgaris, a typical marine fouling algae, was used to investigate the effects of biofilm adhesion on the electrochemical behavior of wire arc-sprayed Al coatings in artificial seawater environment. Electrochemical measurements via dynamic potential polarization curves and electrochemical impedance spectroscopy were used to monitor the corrosion behavior after attachment of microbes on Al coatings and bare, uncoated 316L SS. Analysis of the corrosion products was conducted using scanning electron microscope and energy-dispersive spectrum. The results showed that the Chlorella vulgaris biofilm slowed the corrosion of the Al coatings. This suggested that Chlorella vulgaris biofilm was a critical contributing factor to the corrosion behavior of the Al coatings. Moreover, a mechanism was suggested to illustrate the corrosion behavior of Al coatings in the presence of Chlorella vulgaris. [ABSTRACT FROM AUTHOR]

As predominant pollinators, honeybees are important for crop production and terrestrial ecosystems. Recently, various environmental stresses have led to large declines in honeybee populations in many regions. The ability of honeybees to respond to these stresses is critical for their survival. However, the details of the stress defense mechanisms of honeybees have remained elusive. Here, we found that the Nuclear Factor Y (NF-Y) family (containing NF-YA, NF-YB, and NF-YC) is a novel stress mediator family that regulates honeybee environmental stress resistance. NF-YA localized in the nucleus, NF-YB accumulated in the cytoplasm, and NF-YC presented in both the nucleus and cytoplasm. NF-YC interacted with NF-YA and NF-YB in vitro and in vivo, and the nuclear import of NF-YB relied on its interaction with NF-YC. We further found that the expression of NF-Y was induced under multiple stress conditions. In addition, NF-Y regulated many stress responses and antioxidant genes at the transcriptome-wide level, and knockdown of NF-Y repressed the expression of stress-inducible genes, particularly LOC108003540 and LOC107994062, under adverse circumstances. Silencing NF-Y lowered honeybee stress resistance by reducing total antioxidant capacity and enhancing oxidative impairment. Collectively, these results indicate that NF-Y plays important roles in stress responses. Our study sheds light on the underlying defense mechanisms of honeybees under environmental stress. [ABSTRACT FROM AUTHOR]

Interfacial solar-thermal water evaporation (STWE) shows considerable potential in terms of harvesting freshwater from the ocean; thereinto, the design of an efficient floatable material with low-cost and salt deposition resistance is always one of the most concerned issues. In this work, we prepared an economical Janus complex for STWE by assembling commercial carbon nanotubes and porous cotton fiber paper, functionalized by silanization and combination of polyelectrolyte. Because of the synergy of efficient photothermal conversion, localized hot layer and fast transmission of water and vapor, the Janus complex displayed a superior evaporation rate of 3.443 kg m−2 h−1 under 5 suns (5 kW m−2) in saltwater. Moreover, almost no salt was detected in the used Janus complex, and the salt deposition was rejected at the source due to the strong ionic strength of polyelectrolyte. These results indicated that the Janus complex has potential applications for water purification. [ABSTRACT FROM AUTHOR]

In this study, the vibration characteristics of gearbox considering the eccentricity error and the friction excitation of helical gear pair were evaluated theoretically and experimentally. A geometric model of a single-stage helical gear pair with eccentricity error was established to obtain the calculation formula of the length of the dynamic contact line and the friction excitation. The multi-degree-of-freedom dynamic model of the transmission system was established considering the influences of tooth friction, support stiffness and damping, meshing stiffness and damping, static error, and dynamic tooth backlash. Then, the dynamic meshing forces of the system were obtained and applied to the gearbox for vibration response analysis using mode superposition method. A correlation test rig was developed to measure vibration under different operating conditions for verifying the correctness of the simulation models. Comparison between simulation and test was performed to demonstrate the accuracy of the proposed model in predicting vibrations. Results showed that eccentricity greatly influenced the overall vibration characteristics. The relative error between measurement and prediction can be significantly reduced by considering the eccentricity error in the dynamic model of transmission system. [ABSTRACT FROM AUTHOR]