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A high speed train-track coupling system vertical dynamics model is established by considering the nonlinear wheel-rail contact, and the cross iteration method for solving the train-track nonlinear coupling system dynamics equations is proposed. Four kinds of track irregularities, i.e. the smooth track, the track random irregularity, the short-wave irregularity, and the combined track random irregularity and short-wavelength irregularity, on the vibration responses of the train and the track are analyzed with this model. The calculated results show that the vehicle and the bogie passing frequencies are the main excitation sources of the track vibration displacement and velocity, whereas the short-wave irregularity is the main excitation source of the track vibration acceleration. The track random irregularity, the short-wave irregularity and the sleeper spacing have great influence on the wheel-rail force, and the wheelset and the bogie vibration acceleration, while the car-body vibration acceleration is mainly affected by the track random irregularity. [ABSTRACT FROM AUTHOR]

Track irregularity is the main factor that affects the safety and comfort of high-speed railway. It is important to study the influence of the track irregularity on the safety service of high speed train–track coupling system. In this paper, a vehicle–track spatial nonlinear coupled system dynamics model is developed with FEM. The model includes vehicle subsystem and track subsystem, which are coupled by wheel–rail interface. The vehicle subsystem is a 31-DOF spatial vehicle model, and the track subsystem is a three-dimensional slab track model composed of the rail, rail pad and track slab. Considering wheel tread profile and rail head profile, the wheel–rail spatial contact geometry relationship is established, and the "Trace method" and the "Minimum distance method" are used to search for wheel–rail contact points. Considering the nonlinear contact between the wheel and the rail, a numerical approach is presented, where the "Trace method" is embedded into the algorithm for solving the vehicle–track nonlinear coupling dynamics equation by cross iteration, realizing searching the wheel–rail contact points and solving the vehicle–track nonlinear coupling equation simultaneously, which greatly improves the efficiency of numerical analysis. As application examples, the dynamic responses of a high speed train–track spatial nonlinear coupled system excited by the track V-shaped local profile irregularity and the track torsional irregularity are analyzed. The results show that the algorithm is effective in solving the vehicle–track spatial nonlinear coupled system dynamics problem, and the track irregularity has significant influence on the dynamic response of vehicle and track structure. [ABSTRACT FROM AUTHOR]

In order to assess the value of magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) in microscopic brain scans. Diffusion tensor imaging (DTI) and magnetic resonance spectroscopy (MRI) changes over time in patients with traumatic brain injury (TBI) show a relationship between recovery from coma and overall Glasgow prognostic parameters. The value of DTI combined with MRI in evaluating TBI has been investigated. 10 patients with TBI received 10 evaluations of magnetic resonance imaging, DTI and MRI scans. Thalamic plate nucleus, reticular nucleus, and retinal developmental activity were measured in normal controls and TBI coma (2-3 weeks) and mild (>4 weeks) patients. Anisotropy, mean diffusion coefficient, axial diffusion coefficient, and radial diffusion coefficient were measured using MRI together with acetylaspartic acid, choline, creatinine, and lactic acid. Independent control t-tests were conducted between controls and TBI patients, and 1-test paired between moderate and severe injuries, and regression and correlation were evaluated. Evaluated for all measures and treatments. DTI and MRI scores in TBI patients differed from normal controls. DTI and MRI can predict the prognosis of TBI patients better. The limitations of the thalamus-retinal activation system are gradually restored. axial diffusion coefficient and radial diffusion coefficient can be used to evaluate the reliability of comatose patients with TBI. DTI and MRI scans of the patient's brain can predict recovery and guide treatment in TBI coma patients. [ABSTRACT FROM AUTHOR]

With the rapid development of artificial intelligence, image processing technology has been more and more widely used. Image enhancement is an important part of image processing, and has become a research hotspot of theory and application of image processing technology. This article proposes a new method for underwater image enhancement to solve the problems of color distortion, low contrast and blurring in underwater images. The compensation factor is used to compensate the badly damaged color channels, and the compensation factor is constructed by the mean differences between the damaged color channels and the well-preserved color channel. Then, multi-scale convolution MSRCR technology is used to denoising and correct color distortion, in conclusion, CLAHS and global contrast stretching are used to improve the local and global contrast of the images. Qualitative and quantitative evaluations prove that the proposed method can solve the color cast effect and improve the contrast of underwater images. The images processed by our method have natural color, high contrast and high clarity. Similarly, our method can also achieve good results in underwater low light and underwater images captured by different camera scenes. [ABSTRACT FROM AUTHOR]

In order to study the dynamic response of bridge coupling caused by the overlapping of vehicle and railway dynamic loads, by using the time-domain samples of pavement irregularity compiled by MATLAB software and the secondary development function of ANSYS software, the vehicle, bridge, and train models are established in ANSYS software at the same time, and the train supported beam bridge coupling program is compiled with MATLAB software. The model considers the influence of initial conditions and vehicle speed on the system before entering the bridge, the interaction between the coupled large-scale highway and railway bridge system, and the influence of different adverse factors on the system. The influence of a vehicle or train on the bridge structure when the vehicle or train passes through the continuous steel truss bridge under different factors is calculated, respectively, and the displacement and acceleration limits of the bridge are evaluated in combination with the corresponding specifications. [ABSTRACT FROM AUTHOR]

Background: Non‐small‐cell lung cancer (NSCLC) is the primary cause of brain metastases (BM). This study aimed to investigate differences in clinical and magnetic resonance imaging (MRI) features of BM between anaplastic lymphoma kinase (ALK) gene fusion (ALK+) and ALK wild‐type (ALK‐) NSCLC, and to preliminarily assess the efficacy of radiotherapy for treating BM. Methods: A retrospective analysis included 101 epidermal growth factor receptor (EGFR)‐ NSCLC patients with BM: 41 with ALK gene fusion and 60 being ALK‐. The brain MRI and clinical features were compared between different ALK status using the multivariate analysis, and a nomogram was constructed to predict ALK gene fusion. Fifty‐six patients who did not undergo cerebral surgery and had complete pre‐ and post‐ treatment data were further divided based on whether they received radiotherapy. Log‐rank test was used to compare the short‐term effect of treatment between the two groups under different genotypes. Results: ALK+ BM exhibited decreased peritumoral brain edema size, lower peritumoral brain edema index (PBEI), and a more homogeneous contrast enhancement pattern compared to ALK‐ BM. Age (OR = 1.04; 95%CI: 1.02–1.06), time to BM (OR = 1.50; 95% CI: 1.04–2.14), PBEI (OR = 1.26; 95% CI: 0.97–1.62), smoking status (smoking index >400 vs. non‐smoking status: OR = 1.42; 95% CI: 0.99–2.04) and contrast enhancement pattern (OR = 1.89; 95% CI: 1.28–2.78) were associated with ALK gene fusion. A nomogram based on these variables demonstrated acceptable predictive efficiency (AUC = 0.844). In the ALK+ group, patients who received radiotherapy did not show increased disease control rate (DCR) or progression‐free survival (PFS). In contrast, in the ALK‐ group, those who received radiotherapy had improved objective response rate (ORR), DCR, and PFS compared to those who were only treated with systemic therapy. Conclusions: The clinical and MRI features of BM can indicate the status of ALK in NSCLC. In the ALK‐ group, patients who received radiotherapy showed higher ORR, DCR, and PFS compared to those who did not. [ABSTRACT FROM AUTHOR]

The influence of damping plates on structural vibration, noise and the contribution of the box girder bridge panels was analysed using the model test and numerical calculation methods. In this paper, a 1/10 scale box girder model test system was designed and constructed using a simply supported 32 m box girder from the Beijing–Shanghai high-speed railway as a prototype, and damping plates were laid on the box girder web side after the model was verified as being similar to the prototype by means of a series of model tests. The effects of the damping plates on the reduction of the structural vibration and noise were evaluated according to scaled model acoustic tests. In addition, the influence of the damping plates on the sound contribution of the panel was analysed based on the transient boundary element method. The study shows that the damping plates had an obvious vibration reducing effect on the concrete box girder, though their noise reduction properties were less than ideal. The vibration level reduction and time–history noise level reduction were kept within 10.2–29.5 dB and around 1.0 dB (A), respectively. The noise would decrease to its lowest value at 250 Hz – down to 4.0 dB. The damping plates were helpful in effectively reducing the sound power contribution and the sound pressure contribution of the concrete panel. At the peak frequencies of 17 Hz and 251 Hz, the sound power contributions of the panel on the damper side were reduced by 3.4 dB and 3.7 dB, respectively, compared with the normal side, while the sound pressure contributions on the panel decreased by 4.9 dB and 4.2 dB, respectively. [ABSTRACT FROM AUTHOR]

At present, the method of model testing is rarely used to study the low-frequency vibration problems of bridge structures, because it is difficult to keep the similarity between the bridge model and the prototype in model testing. Based on the similarity law of elastic force, a similarity model of a 32-m simply supported box girder bridge, a model bridge with a geometric similarity ratio of 10∶1 , was designed and manufactured in this paper. The validity of the similarity model was verified by modal testing and numerical simulation. Then, through the hammer test of the similarity model, the vibration transmission characteristics of the model box girder between the panels and along the longitudinal direction of the bridge were studied. Also, the influence of the bridge support on the box girder vibration and the vibration reduction effect of the bridge support were analyzed. The results showed that when the top plate of the box girder is excited, the vibration attenuation from the top plate to the bottom plate is the fastest, followed by the top plate to the web, and from the top plate to the wing plate is the slowest. In the frequency range of less than 45 Hz, the vibration of the top plate attenuates slowly along the longitudinal direction of the bridge; in the frequency range of 45–200 Hz, the vibration of the top plate attenuates rapidly from the middle span to the 1/4 span section of the bridge and attenuates slowly from the 1/4 span to the support section of the bridge. The vibration reduction effect of the elastic support on the bridge pier was related to support stiffness and vibration frequency; the general rule was that the smaller the support stiffness, the better the vibration reduction effect. In addition, the vibration reduction effect varied greatly with different vibration frequencies. [ABSTRACT FROM AUTHOR]

In order to predict more accurately the structural vibration and noise of elevated tracks induced by moving trains, a new prediction method based on the scaled model test is proposed in this paper. A 32-m simply supported box girder bridge used in the Beijing–Shanghai high-speed railway is selected as the prototype for designing and constructing a scaled model test with 10:1 geometric similarity ratio. Both experimental tests and finite element analyses were carried out to verify the similarity relationship between the model and prototype. The test result shows that the scaled model can predict the structural vibration and noise of the prototype, as long as the similarity constants between the prototype and scaled model are correctively determined. Furthermore, a standard finite element analysis model for the scaled model is built. Based on the sensitivity analysis, the model parameters for finite element analysis are updated by minimizing the errors between the measured and calculated modes. The computational results show that the updated model based on the local parameters partitioning works best, and the precision of the modal frequency calculated is noticeably improved after updating, with the average relative error reduced from 5.46% to 3.09%, and the difference of the peak values reduced from 0. 3 5 8 × 1 0 3 m/s2 to 0. 1 8 9 × 1 0 3 m/s2. The calculated dynamic response of the finite element model after updating is basically in line with experimental results, indicating that the updated model can better reflect the dynamic properties of the scaled box girder model. The updated finite element model is useful both for verification with the model test result and for reliable prediction of the dynamic characteristics of the prototype. [ABSTRACT FROM AUTHOR]

This paper examines the effects of extreme temperatures on mortality rates, using random year-to-year variation in temperature based on county-level panel data from China. The analysis finds a robust, U-shaped relationship between temperature and mortality rates, indicating that extremely cold or hot temperatures lead to excess deaths. The heat-related (cold-related) effect is 3.5 times (3.2 times) as large as previous findings that used U.S. data, and it is especially large for the elderly population, mainly due to excess deaths caused by cardiovascular diseases. Applying these results to climate change predictions from Hadley Centre Global Environmental Model shows that by 2061–2080 the annual mortality rate is likely to increase by 14.2% if global greenhouse gas emissions continue to rise throughout the 21st century, the estimated health cost of which is around 0.98 trillion Chinese Yuan per year. The paper also explores households' adaptation behaviors to extreme temperatures. It finds that although urban households adaptively increase energy consumption when they are exposed to cold temperatures and purchase more air conditioners on hot and cold days, rural households are unresponsive to temperature fluctuations. This finding implies that rural people may be more resource constrained and suffer more when extreme temperatures occur. [ABSTRACT FROM AUTHOR]

Based on the model similarity theory, this article deduces the model similarity relationship of the elevated railway box girder at the elastic stage and designs a 1/10 box girder scale model by adopting a 32 m simply-supported box girder bridge from the Beijing–Shanghai Railway as the prototype. It then verifies the validity of the model design and the dynamic similarity between the 1/10 model and the prototype through constraint mode and free mode experiments on the 1/10 scale model, together with transient finite element calculation. The dynamic calculation model is utilized here for the analysis of the errors occurring in the production of the model, and the effect of the model structure simplification on the box girder mode frequency and vibration response. Finally, the article studies the vibration transmissibility characteristics between the plates and along the longitudinal direction by means of model testing. It also discusses the effect of different bridge support stiffness on the box girder vibration. The results presented in this paper can provide a method for forecasting and evaluating the existing or plan-to-build high speed railway environment vibration. [ABSTRACT FROM AUTHOR]

We use a population survey of the Chinese adult population-2010 Chinese Family Panel Studies (CFPS) modeled after the Panel Study of Income Dynamics. We find that being the oldest child gives an education benefit to male and not female children who are often assigned supervisory roles for younger siblings. Most importantly, an increase in the fraction of female siblings leads to a significant increase in education of Chinese men and to a lesser extent Chinese women. This effect is concentrated among those with rural Hukou. In China, male children absorbed more education resources so that in a credit constrained family, increases in fraction of siblings who are sisters frees up resources for educating boys. This is less so for girls since their education was lower and additional resources would not be used for them. [ABSTRACT FROM AUTHOR]

A model for dynamic analyses of a steel spring floating slab track is developed with finite elements. Based on the model, modal analyses are performed with respect to the different kinds of the density, the thickness and the length of the floating slab as well as the isolator stiffness. To comprehensively understand the vibration reduction effects of the steel spring floating slab track, the harmonic response analyses are carried out, and the influence of varying parameters upon the vibration reduction rate is investigated. The results show that the stiffness and the damping of the isolator are the governing factors, whereas the stiffness and the damping of the rail pad are generally not important. The reasonable values for the steel spring floating slab track should meet the requirements of 50–120 MN/m and ≥30 kN·s/m for rail pad stiffness and damping, 5–10 MN/m and 50–100 kN·s/m for isolator stiffness and isolator damping, and 1.25 m for isolator spacing, in order to achieve the satisfactory effect of vibration reduction. [ABSTRACT FROM AUTHOR]

We examine the prevalence of depressive symptoms among the mid-aged and elderly in China and examine relationships between depression and current SES factors such as gender, age, education and income (per capita expenditures). In addition, we explore associations of depressive symptoms with measures of early childhood health, recent family deaths and current chronic health conditions. We use data from the China Health and Retirement Longitudinal Study (CHARLS) national baseline, fielded in 2011/12, which contains the ten question version of the Center for Epidemiologic Studies-Depression scale (CES-D) for 17,343 respondents aged 45 and older. We fill a major gap by using the CHARLS data to explore the general patterns of depression and risk factors among the Chinese elderly nationwide, which has never been possible before. We find that depressive symptoms are significantly associated with own education and per capita expenditure, and the associations are robust to the inclusion of highly disaggregated community fixed effects and to the addition of several other risk factors. Factors such as good general health during childhood are negatively associated with later depression. There exist strong gender differences, with females having higher depression scores. Being a recent widow or widower is associated with more depressive symptoms, as is having a series of chronic health problems, notably having moderate or severe pain, disability or problems with measures of physical functioning. Adding the chronic health problems to the specification greatly reduces the SES associations with depressive symptoms, suggesting that part of the pathways behind these associations are through these chronic health factors. [ABSTRACT FROM AUTHOR]

Slab tracks are widely used worldwide in high-speed railways. In order to investigate the dynamic behavior of the train and slab track coupling system, a new approach, based on conceptions of the vehicle element and track element, is developed with finite elements in a moving frame of reference. By discretizing the slab track subsystem into track elements that flow with the moving vehicle, the proposed method eliminates the need for keeping track of the vehicle position with respect to the track model. The governing equations are formulated in a coordinate system traveling at a constant velocity, and the associated stiffness matrix, mass matrix and damping matrix for the track element in a moving frame of reference are derived. The vehicle element is introduced to model a car with primary and secondary suspension systems, which has 26 degrees of freedom, where 10 degrees of freedom are used to describe the vertical movement of the car, and 16 degrees of freedom are associated with the rail displacements. In the numerical study, four cases of application examples are presented taking into consideration the effects of track roughness, train speed and track parameters. The numerical solutions compare favorably with the results obtained by alternative methods. The method is shown to work for varying train speed and track parameters, and has several advantages over the conventional finite element method in a fixed system of reference. [ABSTRACT FROM PUBLISHER]

This paper examines the impact of China's public long-term care insurance (LTCI) pilots on the well-being of older adults and their families. Using panel data from the Chinese Longitudinal Healthy Longevity Survey, we exploit the rollout of the LTCI pilots across different cities during 2015–2017 and identify the effect of LTCI using a difference-in-differences approach. We find that the implementation of LTCI has reduced the likelihood of older adults reporting unmet activity of daily living (ADL)–related need for care, the intensity of informal care, and the amounts of ADL-related care expenditures and out-of-pocket medical expenditures. LTCI coverage was also associated with an improvement in self-reported health and a reduction in one-year mortality risk of older adults with baseline need for care. From a policy perspective, these findings suggest that the introduction of LTCI may benefit all members of the household, both care recipient and caregivers, which has important implications for the development of LTCI in China and other middle-income and developing countries. • Study impacts of China's long-term care insurance (LTCI) on well-being of older adults. • We exploit the rollout of the LTCI pilots across different cities during 2015–2017. • LTCI reduced older adults' unmet activity of daily living (ADL)–related need for care. • LTCI reduced informal care intensity, ADL-related care expenses, and medical expenses. • LTCI was associated with better self-reported health and lower mortality risk. [ABSTRACT FROM AUTHOR]

Power capacitors are widely used in power transmission systems. During their operation, an electric force acting on the electrodes of the power capacitors actuates mechanical vibrations and radiates an audible noise. Considering a power capacitor as a general system, the frequency response with the electric force as the input and mechanical vibration as the output have been measured by engineers in recent years and used to evaluate the acoustic and mechanical features of products. Accidentally, it was found that the frequency of the capacitor vibration was not consistent with its excitation due to electro-mechanical coupling. This electro-mechanical coupling had not been considered in previous vibration models of power capacitors. Therefore, a new vibration model of power capacitors was built up in this paper and a so-called multi-frequency vibration characteristic was revealed. A theoretical analysis showed that the electric force and mechanical vibration of the power capacitors were coupled, which resulted in the multi-frequency vibration. The vibration frequency response was measured and the result was consistent with the vibration model proposed in this paper. Once the frequency of the electric force was near half the natural frequency of the power capacitor, a predominant multi-frequency vibration was triggered and the power capacitor was in a superharmonic resonance. [ABSTRACT FROM AUTHOR]

Abstract: Background: Hepatitis B virus-associated glomerulonephritis (HBV-GN) is a kind of immune complex-induced glomerulonephritis. The present study was designed to determine whether Hepatitis B virus (HBV) genotype is associated with glomerulonephritis in north-west Chinese children. Methods: A total of 296 HBV-infected patients were enrolled in this study. The serum of patients was subjected to DNA extraction and the HBV genotypes were determined by PCR. Results: The results showed that genotype C (49%) was predominant within the subjects, compared to HBV/B (38.5%), B/C recombinant (7.4%) and none B/C (5.1%). The serum tests showed that the changes of Complement 3 (C3) and alanine amino transferase (ALT) levels in the genotype C patients were significantly greater than those in the genotype B patients. The frequency of genotype C in HBV-GN patients was higher than that in non HBV-GN patients (χ2 value=30.239, P <0.001). But, it was not associated with renal dysfunction. Furthermore, The genotype C was associated with high HBV-DNA load (82.9% vs 17.1%, P <0.001), which is seen more frequently in the HBV-GN children (86.3% vs 13.3%, P =0.004). Conclusions: The genotype C may play a role in HBV-GN children, via favoring HBV replication. [Copyright &y& Elsevier]

• A wavenumber domain method is introduced. • Wheel-rail force identification by using wayside monitor data. • The regularization method is used solve the reverse problem. • FE model is adopted to analyze the accuracy. • Rail Corrugation is identified by WDM method. Wheel-rail vertical force is the main cause of service performance degradation of both vehicle components and track structures. In this paper, a Wavenumber Domain Method (WDM) was developed for identifying vertical wheel-rail force waveform from monitoring data of rail dynamic responses. A one-layer track model is used to derive the transfer equation from wheel-rail vertical forces to rail dynamic responses i.e. strains, displacements. The transfer equations can be solved by the regularization method. The influence of measurement error and parameter estimate error are investigated. A vehicle-track coupled finite element (FE) model is adopted to analyze the accuracy of the method, and the result shows that the WDM provides the identification of wheel-rail force accurately. Serious field tests were conducted on a metro line. Results demonstrate the accuracy and applicability of the proposed approach to identify wheel-rail forces. [ABSTRACT FROM AUTHOR]

Slab tracks are used worldwide in high-speed railways. The slab may be cast in situ, resulting in a continuous length of concrete, or it may be constructed in discrete precast sections laid end to end. According to structural characteristics of the China Railway Track System (CRTSII) slab track system, a model for dynamic analysis of vehicle-track-subgrade coupling system has been developed. Based on the model, a new type of slab track element is presented, and the associated stiffness matrix, mass matrix and damping matrix for the element are deduced. This element includes rail, rail fastening and pad, prefab slab, cement-asphalt mortar, hydraulically bonded layer, and subgrade. By means of the Lagrange equation, a numerical method for coupling the moving wheel and the rail with explicit formula is presented and the associated finite-element equation is formulated. As application examples, parameter studies on the track vibration of the slab track structure, such as stiffnesses and dampings resulting from the rail pad, CA mortar (cement-asphalt mortar) and subgrade, are investigated. To understand dynamic behavior of track transition from conventional ballast track to slab track, the effects of train speed and track stiffness on track vibration in the transition are evaluated. The obtained results show (1) reasonably chosen parameter values of the slab track structure and suitably specified stiffness of the transition will significantly improve the behavior of the track performance; (2) changing track stiffness in transition has an influence which increases with an increase of railspeed, on the vertical rail acceleration and the wheel/rail contact force; (3) smoothing of track stiffness in transition can reduce track vibration and improve the operational quality of the train. Countermeasures include long ties, additional rails, hot mix asphalt (HMA) underlayment, slab track approach, stone columns and piles to strengthen weak subgrade, rail seat pads, rubber tie mats, and other countermeasures. [ABSTRACT FROM AUTHOR]

Objective: We aimed to reveal the role of structural and functional alterations of cingulate gyrus in early cognitive impairment in Type 2 diabetes mellitus (T2DM) patients. Methods: Fifty‐six T2DM patients and 60 healthy controls (HCs) underwent a neuropsychological assessment and sagittal three‐dimensional T1‐weighted and resting‐state functional MRI. Differences in the cortical thickness of the cingulate cortex and the functional connectivity (FC) of the nine subregions of the cingulate gyrus and the whole brain were compared between T2DM patients and HCs. Correlation analysis was performed between cortex thickness and FC and the participants' clinical/cognitive variables. Results: The cortical thickness of the cingulate gyrus was not significantly different between T2DM patients and HCs. However, the T2DM patients showed significantly lower FC between the pregenual ACC (pACC) and the bilateral hippocampus, significantly higher FC between the pACC and bilateral lateral prefrontal cortex (LPFC) and left precentral gyrus, and significantly lower FC between the retrosplenial cortex (RSC) and right cerebellar Crus I. The FC between the pACC and the left hippocampus was negatively correlated with the FC between the pACC and LPFC (r = −0.306, p = 0.022). Interpretation: The pACC and the RSC show dysfunctional connectivity before the appearance of structural abnormalities in T2DM patients. Abnormal FC of the pACC with the bilateral hippocampus and LPFC may imply a neural compensatory mechanism for memory function. These findings provide valuable information and new directions for possible interventions for the T2DM‐related cognitive impairment. [ABSTRACT FROM AUTHOR]

As the most significant interannual variability in the climate system, El Niño-Southern Oscillation (ENSO) has critical effects on global weather and climate patterns. To simulate and predict ENSO, coupled general circulation models (CGCMs) have become a key tool. However, the accurate simulation of ENSO is still a challenge for CGCMs. The performance of El Niño simulations conducted through FIO-ESM v1.0 is examined based on the outputs of the Coupled Model Intercomparsion Project phase 5 (CMIP5) historical experiments. The results show that FIO-ESM v1.0 suffers from similar common problems to other CMIP5 models, including an eastward shift in the central locations of El Niño, adopting a regular period of roughly 3 years, addressing excessively high amplitude, spurious eastward propagation of El Niño events, and Aborted El Niño events. El Niño composite and mixed layer heat budget analyses indicate that these simulation biases are mainly associated with the mean state biases, including a warm Sea Surface Temperature (SST) bias for the central-eastern Pacific, a cold SST bias for the western and central Pacific, seasonal cycles of SST of the equatorial eastern Pacific, and weaker trade winds. Weaker SST-cloud-shortwave radiation feedback in La Niña events than in El Niño events is what creates spurious ENSO amplitude symmetry in the model. We suggest that the improvement of El Niño simulations may be realized by focusing on the mean state and SST-cloud-shortwave radiation feedback in the tropical region. Specifically, further incremental improvements in the mean state of the tropical Pacific should constitute the first step to realizing more accurate ENSO simulation. [ABSTRACT FROM AUTHOR]

[Display omitted] • The counties with high abandonment rates are close to 30%, while those with low rates are between 0 and 2%. • The abandoned farmland in Chongqing expanded from the northeast to the whole area. • Wild boar invasion has become the leading factor of farmland abandonment. • Ecological restoration and land abandonment are a vicious cycle of mutual causality. • A vicious cycle of farmland abandonment, mainly by wild boars, has emerged. Farmland abandonment reflects the decline of rural areas, resulting in a series of vicious chain reactions, hindering the promotion of the comprehensive rural revitalization strategy. From the perspective of ecological restoration, this paper integrated multi-source data such as Landsat, GF-1, and Google Earth images and household survey data, aiming to reveal the spatiotemporal pattern, attribution, and mechanism of farmland abandonment in typical mountainous areas over the past 20 years by employing spatial analysis and mathematical models and to promote comprehensive management of abandoned farmland. The results are as follows. (1) The scope of abandoned farmland in Chongqing has been expanding, with the abandoned area growing from 142,385.8 hm2 to 345,778.4 hm2 from 2000 to 2020, with the initially abandoned farmland mostly concentrated in the northeastern areas, such as Chengkou, with an abandonment rate of 21.8%, and thereafter, spreading in all directions; In the end, abandoned farmland was concentrated in northeastern and southeastern Chongqing, such as Wuxi and Youyang, with abandonment rates of approximately 25.1% and 20%, respectively. (2) The attribution of farmland abandonment mainly includes wild boar damage, labour shortage, and natural conditions, among which wild boar proliferation has become an important factor under the background of ecological restoration. (3) Ecological restoration has produced a counter-servicing effect of the ecosystem on human beings, forming a vicious circle in the mountainous countryside where ecological restoration continues to aggravate farmland abandonment. The contribution of this study is to investigate the pattern of farmland abandonment from both macroscopic and microscopic perspectives. At the same time, this paper explores the intrinsic mechanism between ecological restoration and farmland abandonment and proposes scientific countermeasures to break the vicious cycle of ecological restoration that continues to exacerbate farmland abandonment in mountainous areas. [ABSTRACT FROM AUTHOR]

The allelochemical para -hydroxybenzoic acid (pHBA) is a serious threat to poplars subjected to continuous cropping. In order to elucidate the responsive mechanisms of plants to pHBA stress, we here performed tandem mass tag-based quantitative proteomic analysis combined with physiological, transcriptional, and metabolic analyses by using H 2 O 2 treatment as a positive control. H 2 O 2 and O 2 •− levels and the activities of several antioxidant enzymes increased under pHBA stress. In total, 289 differentially expressed proteins were identified in the 84K poplar leaves under pHBA stress; among them, 161 and 128 proteins were upregulated and downregulated, respectively. The pHBA-responsive protein analysis showed that the antioxidant system, signal transduction, carbohydrate metabolism, biosynthesis of secondary metabolites, gene expression regulation, and many other biological processes were altered in poplars to cope with this stress. Overall, this study provides a new insight for the molecular mechanisms underlying pHBA stress in plants and may have potential application values in poplar genetic breeding for overcoming continuous cropping obstacles. • Allelochemical para -hydroxybenzoic acid induced the elevated levels of reactive oxygen species (H 2 O 2 and O 2 •−) in poplars. • 161 upregulated and 128 downregulated para -hydroxybenzoic acid responsive proteins were identified in poplars. • The cellular antioxidant system is required for poplar's response to para -hydroxybenzoic acid. • Signal transduction pathways were activated in poplars by para -hydroxybenzoic acid. • Gene expression regulation was altered in poplars to cope with para -hydroxybenzoic acid. [ABSTRACT FROM AUTHOR]

Background: The thalamus has been reported to be associated with pain modulation and processing. However, the functional changes that occur in the thalamus of vestibular migraine (VM) patients remain unknown. Methods: In total, 28 VM patients and 28 healthy controls who were matched for age and sex underwent resting-state functional magnetic resonance imaging. They also responded to standardized questionnaires aimed at assessing the clinical features associated with migraine and vertigo. Differences in the amplitude of low-frequency fluctuation (ALFF) were analyzed and brain regions with altered ALFF in the two groups were used for further analysis of whole-brain functional connectivity (FC). The relationship between clusters and clinical features was investigated by correlation analyses. Results: The ALFF in the thalamus was significantly decreased in the VM group versus the control group. In the VM group, the ALFF in the left thalamus negatively correlated with VM episode frequency. Furthermore, the left thalamus showed significantly weaker FC than both regions of the medial prefrontal cortex, both regions of the anterior cingulum cortex, the left superior/middle temporal gyrus, and the left temporal pole in the VM group. Conclusions: The thalamus plays an important role in VM patients and it is suggested that connectivity abnormalities of the thalamocortical region contribute to abnormal pain information processing and modulation, transmission, and multisensory integration in patients with VM. [ABSTRACT FROM AUTHOR]

Although disturbed functional connectivity is known to be a factor influencing cognitive impairment, the neuropathological mechanisms underlying the cognitive impairment caused by type 2 diabetes mellitus (T2DM) remain unclear. To characterize the neural mechanisms underlying T2DM-related brain damage, we explored the altered functional architecture patterns in different cognitive states in T2DM patients. Thirty-seven T2DM patients with normal cognitive function (DMCN), 40 T2DM patients with mild cognitive impairment (MCI) (DMCI), and 40 healthy controls underwent neuropsychological assessments and resting-state functional MRI examinations. Functional connectivity density (FCD) analysis was performed, and the relationship between abnormal FCD and clinical/cognitive variables was assessed. The regions showing abnormal FCD in T2DM patients were mainly located in the temporal lobe and cerebellum, but the abnormal functional architecture was more extensive in DMCI patients. Moreover, in comparison with the DMCN group, DMCI patients showed reduced long-range FCD in the left superior temporal gyrus (STG), which was correlated with the Rey auditory verbal learning test score in all T2DM patients. Thus, DMCI patients show functional architecture abnormalities in more brain regions involved in higher-level cognitive function (executive function and auditory memory function), and the left STG may be involved in the neuropathology of auditory memory in T2DM patients. These findings provide some new insights into understanding the neural mechanisms underlying T2DM-related cognitive impairment. [ABSTRACT FROM AUTHOR]

Background With the rapid population aging, the challenge to provide care for disabled older adults is becoming bigger. This study aims to develop the Disability Index (DI) to assess disability to indicate care needs, and we evaluated the reliability and validity of the DI among older adults aged 65–105. Methods A total of 12 559 older adults (54.0% women; mean age = 84.3; SD = 11.2) from 22 provinces in China were investigated in 2017–2018. We developed the 21-item DI covering 4 subdomains, including Activities of Daily Living (ADL), Instrumental Activities of Daily Living (IADL), physical performance, and cognitive function. Cronbach's alpha was used to determine internal consistency. The convergent and divergent validity were assessed by Spearman rank order correlation coefficients and Pearson correlation coefficients. The known-group validity was assessed by Mann–Whitney U tests. The concurrent validity was assessed by the area under the receiver operating characteristic curve (AUC). Results In the total sample, the internal consistency of the full DI and its subdomains were satisfactory with Cronbach's alpha ≥0.70; the convergent and divergent validity of the 4 subdomains were supported by all the alternative measures; the known-group validity of the full DI and its subdomains were supported by clear discriminative ability; and the concurrent validity of the full DI was supported with all the AUCs ≥0.70. The reliability and validity of the full DI and its subdomains were additionally supported by age subgroups and sex subgroups. Conclusions The DI is a reliable and valid instrument to assess disability status among older adults. [ABSTRACT FROM AUTHOR]

Tropical cyclone (TC) genesis over the western North Pacific (WNP) is analyzed using 23 CMIP5 (Coupled Model Intercomparison Project Phase 5) models and reanalysis datasets. The models are evaluated according to TC genesis potential index (GPI). The spatial and temporal variations of the GPI are first calculated using three atmospheric reanalysis datasets (ERA-Interim, NCEP/NCAR Reanalysis-1, and NCEP/DOE Reanalysis-2). Spatial distributions of July-October-mean TC frequency based on the GPI from ERA-interim are more consistent with observed ones derived from IBTrACS global TC data. So, the ERA-interim reanalysis dataset is used to examine the CMIP5 models in terms of reproducing GPI during the period 1982-2005. Although most models possess deficiencies in reproducing the spatial distribution of the GPI, their multimodel ensemble (MME) mean shows a reasonable climatological GPI pattern characterized by a high GPI zone along 20°N in the WNP. There was an upward trend of TC genesis frequency during 1982 to 1998, followed by a downward trend. Both MME results and reanalysis data can represent a robust increasing trend during 1982-1998, but the models cannot simulate the downward trend after 2000. Analysis based on future projection experiments shows that the GPI exhibits no significant change in the first half of the 21st century, and then starts to decrease at the end of the 21st century under the representative concentration pathway (RCP) 2.6 scenario. Under the RCP8.5 scenario, the GPI shows an increasing trend in the vicinity of 20°N, indicating more TCs could possibly be expected over the WNP under future global warming. [ABSTRACT FROM AUTHOR]

• The bp-MRI radiomics model was useful in distinguishing high-grade and low-grade bladder cancer. • For the 3 radiomic models, the predictive performance of the ADC combined with the T2WI model was better than that of the single-sequence model. • Radiomics model outperformed the traditional MRI model. To compare biparametric magnetic resonance imaging (bp-MRI) radiomics signatures and traditional MRI model for the preoperative prediction of bladder cancer (BCa) grade. This retrospective study included 255 consecutive patients with pathologically confirmed 113 low-grade and 142 high-grade BCa. The traditional MRI nomogram model was developed using univariate and multivariate logistic regression by the mean apparent diffusion coefficient (ADC), vesical imaging reporting and data system, tumor size, and the number of tumors. Volumes of interest were manually drawn on T 2 -weighted imaging (T 2 WI) and ADC maps by 2 radiologists. Using one-way analysis of variance, correlation, and least absolute shrinkage and selection operator methods to select features. Then, a logistic regression classifier was used to develop the radiomics signatures. Receiver operating characteristic (ROC) analysis was used to compare the diagnostic abilities of the radiomics and traditional MRI models by the DeLong test. Finally, decision curve analysis was performed by estimating the clinical usefulness of the 2 models. The area under the ROC curves (AUCs) of the traditional MRI model were 0.841 in the training cohort and 0.806 in the validation cohort. The AUCs of the 3 groups of radiomics model [ADC, T 2 WI, bp-MRI (ADC and T 2 WI)] were 0.888, 0.875, and 0.899 in the training cohort and 0.863, 0.805, and 0.867 in the validation cohort, respectively. The combined radiomics model achieved higher AUCs than the traditional MRI model. decision curve analysis indicated that the radiomics model had higher net benefits than the traditional MRI model. The bp-MRI radiomics model may help distinguish high-grade and low-grade BCa and outperforming the traditional MRI model. Multicenter validation is needed to acquire high-level evidence for its clinical application. [ABSTRACT FROM AUTHOR]

Rail corrugation remains a major problem in many railways and metros, leading to high noise and vibration levels as well as potential damage to the track and vehicle. A frequency domain simulation method is proposed for the evolution of the rail surface roughness, which can simulate the formation and development of rail corrugation in curves. A coupled vehicle-track dynamic model is established in the frequency domain to calculate the dynamic vertical and lateral wheel-rail contact forces and the associated vibration. The wheel-rail contact state is determined by using a multi-body dynamics model. The frictional-work wear model is used to calculate the roughness change caused by wheel-rail dynamic interaction. The method is verified by comparing the results with those of on-site testing on a 300 m radius curve of a metro line. It is shown that the main causes of rail corrugation are associated with the peaks in the vertical wheel-rail forces in the frequency domain, generated by the interaction between the wheel and rail. At short wavelengths the corrugation is associated with the wave reflections in the rail between adjacent axles. The phase relationship between the vertical wheel-rail force and the initial roughness has a strong influence on the roughness growth trend, leading to preferential growth in certain wavelength bands. The wheel-rail contact state and friction parameters affect the rate of development of the corrugation. Finally, a corrugation index is proposed to allow quick evaluation of the wavelength and growth rate of corrugation. • A frequency-domain approach models rail corrugation evolution in curves. • Accurate simulation the formation and development of P2-type, short pitch corrugation aligns well with experimental results. • Multi-wheelsets coupling, wheelset bending modes and wheel-rail force-roughness phase differences drive corrugation. • Proposed corrugation index to comprehensively evaluate the growth rate of wear in the frequency domain. [ABSTRACT FROM AUTHOR]

Background: There was no previous report on the three-dimensional simultaneous non-contrast angiography and intra-plaque hemorrhage (3D-SNAP) magnetic resonance imaging (MRI) sequence to diagnose intracranial artery dissection (IAD). Purpose: To improve the diagnostic accuracy and guide the clinical treatment for IAD by elucidating its pathological features using 3D-SNAP MRI. Material and Methods: From January 2015 to September 2018, 113 patients with suspected IAD were analyzed. They were divided into IAD and non-IAD groups according to the spontaneous coronary artery dissection (SCAD) criteria. All patients underwent 3D-SNAP, 3D-TOF, T2W imaging, 3D-PD, 3D-T1W-VISTA, and 3D-T1WCE) using 3.0-T MRI; clinical data were collected. The IAD imaging findings (intramural hematoma, double lumen, intimal flap, aneurysmal dilatation, stenosis, or occlusion) in every sequence were analyzed. Receiver operating characteristic (ROC) curve analysis was used to evaluate the diagnostic efficiency of each sequence. Results: There was a significant difference in the probability of intramural hematoma, relative signal intensity of intramural hematoma, double lumen, stenosis, or occlusion signs on 3D-TOF, T2W, 3D-PD, 3D-T1W-VISTA, 3D-SNAP, and 3D-T1WCE sequences (P <0.05). The 3D-SNAP and 3D-T1WCE sequences were most sensitive for diagnosing intramural hematoma and displaying double-lumen signs, respectively. The diagnostic efficiency of the 3D-SNAP sequence combined with 3D-T1WCE was the highest (area under the curve [AUC] 0.966). The AUC value of the 3D-SNAP sequence (AUC 0.897) was slightly inferior to that of 3D-T1W enhancement (AUC 0.903). Conclusion: 3D-SNAP MRI is a non-invasive and effective method and had the greatest potential among those methods tested for improving the diagnostic accuracy for IAD. [ABSTRACT FROM AUTHOR]

Based on the cellular automata (CA) method and the principle of wave superposition, this study examines a computational technique to analyze the sound radiation characteristics of arbitrary shape structures. The local evolution rule of the one-dimensional (1D) CA model of Y -function was derived from the acoustic wave equation in spherical coordinate, and the relationship between Y -function and sound pressure was used to calculate the sound pressure value. On this basis, the 1D CA model of sound propagation for pulsating sphere source was established, and the superimposed sound field of multiple sphere sources in two-dimensional (2D) space was analyzed. Furthermore, combined with the principle of the wave superposition, the acoustic radiation characteristics of a rectangular piston in three-dimensional (3D) space were discussed, and the feasibility of the proposed method was verified by experiments. Finally, by introducing the finite element method, the calculation method of noise radiated by the 3D structure under external loads was presented, and the radiated sound field of a simply supported beam under loads was analyzed. The results shown that the proposed method could avoid anisotropic updating of cell state variables in the traditional 2D CA model. Moreover, the modeling was simpler, the calculation accuracy and efficiency were also higher. The results calculated by the proposed method matched well with the analytical solutions, experimental results, and numerical results, which indicated the veracity of the calculation method. The proposed method can provide a novel way for noise calculation of engineering structures. [ABSTRACT FROM AUTHOR]

The apple target recognition algorithm is one of the core technologies of the apple picking robot. However, most of the existing apple detection algorithms cannot distinguish between the apples that are occluded by tree branches and occluded by other apples. The apples, grasping end-effector and mechanical picking arm of the robot are very likely to be damaged if the algorithm is directly applied to the picking robot. Based on this practical problem, in order to automatically recognize the graspable and ungraspable apples in an apple tree image, a light-weight apple targets detection method was proposed for picking robot using improved YOLOv5s. Firstly, BottleneckCSP module was improved designed to BottleneckCSP-2 module which was used to replace the BottleneckCSP module in backbone architecture of original YOLOv5s network. Secondly, SE module, which belonged to the visual attention mechanism network, was inserted to the proposed improved backbone network. Thirdly, the bonding fusion mode of feature maps, which were inputs to the target detection layer of medium size in the original YOLOv5s network, were improved. Finally, the initial anchor box size of the original network was improved. The experimental results indicated that the graspable apples, which were unoccluded or only occluded by tree leaves, and the ungraspable apples, which were occluded by tree branches or occluded by other fruits, could be identified effectively using the proposed improved network model in this study. Specifically, the recognition recall, precision, mAP and F1 were 91.48%, 83.83%, 86.75% and 87.49%, respectively. The average recognition time was 0.015 s per image. Contrasted with original YOLOv5s, YOLOv3, YOLOv4 and EfficientDet-D0 model, the mAP of the proposed improved YOLOv5s model increased by 5.05%, 14.95%, 4.74% and 6.75% respectively, the size of the model compressed by 9.29%, 94.6%, 94.8% and 15.3% respectively. The average recognition speeds per image of the proposed improved YOLOv5s model were 2.53, 1.13 and 3.53 times of EfficientDet-D0, YOLOv4 and YOLOv3 and model, respectively. The proposed method can provide technical support for the real-time accurate detection of multiple fruit targets for the apple picking robot. [ABSTRACT FROM AUTHOR]

Introduction: Previous voxel‐based morphometry (VBM) studies have revealed changes in brain structure in patients with vestibular migraine (VM); these findings have improved the present understanding of pathophysiology. Few other studies have assessed the association between structural changes and the severity of dizziness in VM. This study aimed to examine the structural changes and cortical morphometric features associated with migraine and vertigo attacks in patients with VM. Methods: Twenty patients with VM and 20 healthy normal volunteers were scanned on a 3‐tesla MRI scanner. The gray matter volume (GMV) was estimated using the automated Computational Anatomy Toolbox (CAT12). The relationship between clinical parameters and morphometric abnormalities was also analyzed in VM. Results: Compared with controls, VM patients have decreased GMV in the prefrontal cortex (PFC), posterior insula–operculum regions, inferior parietal gyrus, and supramarginal gyrus. Moreover, patient scores on the Dizziness Handicap Inventory (DHI) score showed a negative correlation with GMV in the posterior insula–operculum regions. Conclusion: These findings demonstrated abnormality in the central vestibular cortex and correlations between dizziness severity and GMV in core regions of the vestibular cortex of VM patients, suggesting a pathophysiological role of these core vestibular regions in VM patients. [ABSTRACT FROM AUTHOR]

Objectives: This meta-analysis was undertaken to review the diagnostic accuracy of PI-RADS V2 for prostate cancer (PCa) detection with multiparametric MR (mp-MR).Methods: A comprehensive literature search of electronic databases was performed by two observers independently. Inclusion criteria were original research using the PI-RADS V2 system in reporting prostate MRI. The methodological quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. Data necessary to complete 2 × 2 contingency tables were obtained from the included studies.Results: Thirteen studies (2,049 patients) were analysed. This is an initial meta-analysis of PI-RADs V2 and the overall diagnostic accuracy in diagnosing PCa was as follows: pooled sensitivity, 0.85 (0.78-0.91); pooled specificity, 0.71 (0.60-0.80); pooled positive likelihood ratio (LR+), 2.92 (2.09-4.09); pooled negative likelihood ratio (LR-), 0.21 (0.14-0.31); pooled diagnostic odds ratio (DOR), 14.08 (7.93-25.01), respectively. Positive predictive values ranged from 0.54 to 0.97 and negative predictive values ranged from 0.26 to 0.92.Conclusion: Currently available evidence indicates that PI-RADS V2 appears to have good diagnostic accuracy in patients with PCa lesions with high sensitivity and moderate specificity. However, no recommendation regarding the best threshold can be provided because of heterogeneity.Key Points: • PI-RADS V2 shows good diagnostic accuracy for PCa detection. • Initially pooled specificity of PI-RADS v2 remains moderate. • PCa detection is increased by experienced radiologists. • There is currently a high heterogeneity in prostate diagnostics with MRI. [ABSTRACT FROM AUTHOR]

Accelerating the energy transition of rural households in mountainous areas is an important step to improve energy poverty and mountain ecosystems and to help achieve carbon peaking and carbon neutrality. This paper explores the transformation of rural cooking energy in mountainous areas based on field investigation data from six villages in Chongqing. It systematically reveals the transformation process, driving factors and carbon emission changes in household cooking energy consumption in mountainous areas in the past 20 years by using mathematical statistics, multinomial logit models and the emission coefficient method. The results are as follows. (1) There has been a significant transition in the consumption of rural household cooking energy in mountainous areas. There has been a significant change in the proportion of different energy sources, including fuelwood (59.2%–1.9%), coal (16.5%–0%), gas (12.6%–15.5%), natural gas (6.8%–51.5%) and electricity (4.9%–31.1%). (2) The main driving factors of the household cooking energy transition in mountainous areas are income per capita, householder age, and householder education level. (3) The average annual household carbon emissions from rural household cooking energy decreased remarkably. The average annual household carbon emissions decreased from 6.80 t to 2.62 t in fuelwood (5.40–0.91 t), electricity (0.19–1.28 t) and natural gas (0.03–0.25 t) emissions during the study period. The contribution of this study is to investigate how the household cooking energy transition contributes to carbon peaking and carbon neutrality from a micro perspective. At the same time, this paper explores the mechanisms between the cooking energy transition and the ecological dividend of urbanization and proposes future reform initiatives for rural energy in mountainous areas to help achieve the goals of carbon peaking and carbon neutrality. [ABSTRACT FROM AUTHOR]

The box girder structure is widely used in engineering. The study of its dispersion characteristics is of great significance to clarify the mechanism of its vibration propagation and sound radiation. However, its dispersion analysis is currently relies mainly on the finite element method due to the relative complexity of the box girder structure model, and although FE-based methods are an effective means to simulate the dispersion characteristics of box girder structure, they are not as favorable or convenient as the analytical or semi-analytical methods to perform a deeper investigation of the parameters and mechanisms involved in this process. Therefore, this study develops a semi-analytical method based on the energy method to analyze the dispersion characteristics of the box girder structure, with the core idea being the use of virtual springs to simulate the Bloch boundary; this successfully corrects for the complications of constructing displacement functions that satisfy Bloch boundary conditions in the traditional energy method, and it can improve the calculation efficiency. Then, the box girder structure is simplified to a spatial plate coupling model, and its dispersion control equation is established using the variational principle. This paper studies the propagation characteristics of elastic waves in a box girder, and the accuracy of the method is verified by finite element simulation. • A semi-analytical method is developed to analyze the dispersion characteristics. • The Bloch boundary is simulated by virtual springs. • The box girder is simulated as a refinement spatial plate coupling model. [ABSTRACT FROM AUTHOR]

Objective The aim of this meta-analysis was to predict the grades of cerebral gliomas using quantitative apparent diffusion coefficient (ADC) values. Materials and methods A comprehensive search of the PubMed, EMBASE, Web of Science, and Cochrane Library databases was performed up to 8, 2016. The quality assessment of diagnostic accuracy studies (QUADAS 2) was used to evaluate the quality of studies. Statistical analyses included pooling of sensitivity and specificity, positive likelihood ratio (PLR), negative likelihood ratio' (NLR), diagnostic odds ratio (DOR), and diagnostic accuracy values of the included studies using the summary receiver operating characteristic (SROC). All analyses were conducted using STATA (version 12.0), RevMan (version 5.3), and Meta-Disc 1.4 software programs. Results Fifteen studies were analyzed and included a total of 821 patients and 821 lesions. In regards to the diagnostic accuracy of ADC maps, the pooled SEN, SPE, PLR, NLR, and DOR with 95%CIs were 0.85(95%CI: 0.80, 0.90)and 0.80 (95%CI: 0.71, 0.87),34.25(95%CI: 2.96, 6.09), 0.18(95%CI:0.13.0.25), and 23.14(95%CI: 14.73, 36.36), respectively. The SROC curve showed an AUC of 0.90. Deeks testing confirmed no significant publication bias in all studies. Conclusion Our findings indicate that quantitative ADC values have high accuracy in separating high-grade from low-grade cerebral gliomas. Further studies using a standardized methodology may help guide the use of ADC values for clinical decision-making. [ABSTRACT FROM AUTHOR]

Background: Magnetic resonance imaging (MRI) is increasingly being used to examine patients with suspected breast cancer. Purpose: To determine the diagnostic performance of combined dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and diffusion-weighted imaging (DWI) for breast cancer detection. Material and Methods: A comprehensive search of the PUBMED, EMBASE, Web of Science, and Cochrane Library databases was performed up to September 2014. Statistical analysis included pooling of sensitivity and specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and diagnostic accuracy using the summary receiver operating characteristic (SROC). All analyses were conducted using STATA (version 12.0), RevMan (version 5.2), and Meta-Disc 1.4 software programs. Results: Fourteen studies were analyzed, which included a total of 1140 patients with 1276 breast lesions. The pooled sensitivity and specificity of combined DCE-MRI and DWI were 91.6% and 85.5%, respectively. The pooled sensitivity and specificity of DWI-MRI were 86.0% and 75.6%, respectively. The pooled sensitivity and specificity of DCE-MRI were 93.2% and 71.1%. The area under the SROC curve (AUC-SROC) of combined DCE-MRI and DWI was 0.94, the DCE-MRI of 0.85. Deeks testing confirmed no significant publication bias in all studies. Conclusion: Combined DCE-MRI and DWI had superior diagnostic accuracy than either DCE-MRI or DWI alone for the diagnosis of breast cancer. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the ability of preoperative MRI-based radiomic features in predicting lymph node metastasis (LNM) in patients with cervical cancer.Methods: PubMed, Embase, Web of Science, Cochrane Library databases, and four Chinese databases were searched to identify relevant studies published up until October 22, 2021. Two reviewers screened all papers independently for eligibility. We included diagnostic accuracy studies that used radiomics-MRI for LNM in patients with cervical cancer, using histopathology as the reference standard.Quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies 2 and Radiomics Quality Score. Overall diagnostic odds ratio (DOR), sensitivity, specificity and area under the curve (AUC) were calculated to assess the prediction efficacy of MRI-based radiomic features in patients with cervical cancer. Spearman's correlation coefficient was calculated and subgroup analysis performed to investigate causes of heterogeneity.Results: Twelve studies comprising 793 female patients were included. The pooled DOR, sensitivity, specificity, and AUC of radiomics in detecting LNM were 12.08 [confidence interval (CI) 8.18, 17.85], 80% (72%, 87%), 76% (72%, 80%), and 0.83 (0.76, 0.89), respectively. The meta-analysis showed significant heterogeneity among the included studies. No threshold effect was detected. Subgroup analysis showed that multiple sequences, and radiomics combined with clinical factors, radiomics approach [DOR:15.49 (6.06, 39.62), 18.93 (8.46, 42.38), and 10.63 (6.23, 18.12), respectively] could slightly improve diagnostic performance compared with apparent diffusion coefficient-based radiomic features, T2 + dynamic contrast-enhanced MRI-based radiomic features, T2 images-based radiomic features, single radiomics, and human reading [DOR: 4.9 (1.91, 12.74), 7.63 (3.78, 15.38), 8.31 (3.05, 22.61), 16.10 (9.10, 28.47), and 6.46 (3.08, 13.56), respectively].Conclusion: Our meta-analysis showed that preoperative MRI-based radiomic features performs well in predicting LNM in patients with cervical cancer. This noninvasive and convenient tool may be used to facilitate preoperative identification of LNM. [ABSTRACT FROM AUTHOR]

• The Bloch periodic boundary is simulated by using a virtual spring. • A new band-gap solving method is proposed based on the energy functional variational principle. • The proposed method has the advantages of high computational efficiency and good applicability. Owing to the advantage in converting the boundary value problem of a differential equation into the extreme value problem of a functional, the energy method is widely applied in structural dynamic analysis. Recently, it has also been introduced to calculate the band gap of periodic structures. However, because of the relative complication in the boundary conditions of periodic structures, it is difficult to construct a displacement function using the traditional energy method such as Rayleigh-Ritz method for analysis. Besides, as the constructed displacement function contains wavenumber, when it is used to calculate the band gap by scanning the wavenumber, both the mass and stiffness matrices must be repeatedly calculated, leading to a large amount of calculation. In view of this, a new band-gap calculation method based on the basic framework of the energy method is proposed in this study. In this method, a virtual spring was introduced to simulate the boundary conditions of a periodic structure so that there is no need for a displacement function satisfying the boundary conditions. Thus, the boundary constraints were converted into the elastic potential energy of the spring. For each energy distribution, only the stiffness matrix corresponding to the periodic boundary elastic potential energy contains the wavenumber term and should be repeatedly calculated every time the wavenumber is scanned; the other stiffness and mass matrices require only one time of calculation. The amount of calculation is thus reduced. The results show that the method proposed in this study is precise, reliable, and has a higher calculation efficiency compared with the traditional energy method. The advantage of high calculation efficiency of this method is even more pronounced when the dimensionality of the mass and stiffness matrix or the number of scanning wavenumber increases. Moreover, the virtual spring is flexible, convenient, and widespread in application, thus it can be extended to analyze the band gap of periodic composite structures. [ABSTRACT FROM AUTHOR]

• Aims at gaining an understanding the grasping position and picking pattern of apple fruit during harvest. • Based on optimal grasping position, investigated four picking patterns by measuring the minimal grasping pressure. • Automatic dynamic analysis of mechanical systems, finite element method and response surface methodology were utilized. • There exists noticeable difference on required grasping pressure to pick a fruit between different robotic picking patterns. Operational efficiency is an important bottleneck in the industrialization of apple picking robots. The action planning of grasping and picking is key to improving the operational efficiency of picking robots. In this study, first, from the perspective of grip stability, the grasping positions of a three-finger end-effector were planned in two cases to determine an optimal three-finger grip posture: one that is parallel to the apple stem–calyx axis and the other being centripetal to the apple equatorial plane. Second, based on the gripping posture parallel to the apple stem-calyx axis, four picking patterns were designed: vertical pull, horizontal pull, vertical rotation, and rotation–horizontal pull. With the horizontal displacement, vertical displacement, and rotation angle as the main factors influencing the picking process, it was found through ABAQUS simulation software and the response surface analysis method that the rotation–horizontal pull pattern with the combination of horizontal displacement and rotation angle yields the minimum separation force for apple piking. With the three-fingered hand in the optimal grasping posture parallel to the stem–calyx, the four picking patterns were tested on a dedicated apple picking experimental device equipped with a grip force acquisition sensor, and the test results showed that the average three-finger grip force required for rotary tug-pull picking was the lowest (10.33 N). The proposed rotation–horizontal pull pattern with the three-finger grip posture was proven to be the best pattern for apple picking. The results of this study provide a theoretical basis for further research on apple picking robots. [ABSTRACT FROM AUTHOR]

• A vehicle-ballastless track coupled model with concrete cracks is proposed. • An iterative method is proposed to estimate the fatigue crack growth of concrete. • The fatigue crack growth process under different initial crack depths are discussed. This paper proposes a vehicle-ballastless track coupled model with consideration of concrete cracks in high-speed railways through finite element method. Cracked Euler beam elements are used to model the concrete slab and the supporting layer with through-transverse cracks. In addition, an iterative method is proposed to estimate the fatigue crack growth of concrete under long-term train dynamic load on the basis of the Forman model. The vehicle-ballastless track coupled model with concrete cracks is employed to obtain the crack-tip stress intensity factor (CTSIF) of concrete under the condition of initial crack depth. The CTSIF induced by a high-speed vehicle is adopted in the Forman model to calculate the crack growth rate. The crack depth is updated by the number of passing vehicles in each iteration step, which is determined by a crack growth increment threshold. The dynamic characteristics of the vehicle-ballastless track coupled system are re-calculated based on the updated crack depth. Then, the effects of the crack depth, the stiffness of CA mortar and subgrade on the CTSIF of the concrete slab and the supporting layer are investigated in detail. The fatigue crack propagation process and residual service life under different initial crack depths of the supporting layer are discussed. Some practical conclusions are drawn, which can provide some theoretical guidances for the routine maintenance of slab tracks. [ABSTRACT FROM AUTHOR]

In recent years, many agriculture-related problems have been evaluated with the integration of artificial intelligence techniques and remote sensing systems. The rapid and accurate identification of apple targets in an illuminated and unstructured natural orchard is still a key challenge for the picking robot's vision system. In this paper, by combining local image features and color information, we propose a pixel patch segmentation method based on gray-centered red–green–blue (RGB) color space to address this issue. Different from the existing methods, this method presents a novel color feature selection method that accounts for the influence of illumination and shadow in apple images. By exploring both color features and local variation in apple images, the proposed method could effectively distinguish the apple fruit pixels from other pixels. Compared with the classical segmentation methods and conventional clustering algorithms as well as the popular deep-learning segmentation algorithms, the proposed method can segment apple images more accurately and effectively. The proposed method was tested on 180 apple images. It offered an average accuracy rate of 99.26%, recall rate of 98.69%, false positive rate of 0.06%, and false negative rate of 1.44%. Experimental results demonstrate the outstanding performance of the proposed method. [ABSTRACT FROM AUTHOR]