Search

The quantitative characterization of coal structure is one of the hot topics in coal reservoir research. To finely characterize the spatial distribution of coal structure and identify the main controlling factors for its differential distribution, through observation and measurement of coal cores, quantitative characterization of coal structure using geological intensity factors, and statistics of logging response of different coal structures, a quantitative characterization model of coal structure based on logging curves was constructed. The spatial distribution of coal structure was predicted, and the influence characteristics of sedimentation, structure, in-situ stress, and micro-mechanical properties on coal structure were explored. The research results indicate that density, gamma-ray, interval transit time, and caliper loggings are sensitive to the coal structure, and the use of logging multiple regression method can significantly improve the accuracy of coal structure identification. The coals in the study area are mainly composed of primary-fragmented coals, followed by cataclastic coals, with a small amount of primary and cataclastic-granulated coals developed. The coal structure of the entire study area can be divided into four categories and seven small areas. The sedimentary environment can affect the coal structure by controlling the thickness of coal seam development. The thickness of coal seams developed in tidal channels, sand flats, mud flats, delta plains, and lagoon environments gradually increases, but there is no obvious relationship between coal structure and coal seam thickness. However, the ash content is positively correlated with the integrity of coal structure, and studying the changes in ash content in different sedimentary environments is the key to revealing the control characteristics of sedimentary environments on coal structure. The average structural curvature of primary structured coals, primary- fragmented structured coals, and cataclastic coals are 8.4×10−6, 18.7×10−6, 25.7×10−6 m−1, respectively. Where faults develop, the coal structure is characterized by cataclastic coals. As the burial depth increases, the in-situ stress increases, and the integrity of the coal structures are enhanced. Based on this, the in-situ stress state further differentiates the coal structures. In the shallow extensional and compression transition zone, the coal structure is mainly fragmented and fragmented; In the deep compression state, the primary fragmented structure is dominant; The proportion of fractured structures in the deep compression and extension transition zone has increased. The micro mechanical properties of coal are controlled by the composition of coal matrix and micro pore structure. The mechanical strength of inorganic components of coal is higher than that of organic components of coal, and the pore size of inorganic components is smaller than that of organic components. The higher the content of inorganic components, the higher the mechanical strength of coal, and the more complete the coal structure. This research achievement provides reference for coal seam drilling construction, fracturing transformation, and reservoir evaluation.

The external combustion hot blast stove is widely used in the steelmaking industry due to the advantage of providing a large amount of high-temperature and stable hot blast for blast furnaces. To research the thermal efficiency and stability of external combustion hot blast stoves, the non-equilibrium porous medium model coupled with transient thermal analysis is used to discuss the characteristics of two types of external combustion hot blast stoves during the cyclic operation process. In this paper, a comparison of the numerical data and in situ data during one cycle to ensure the accuracy of the calculation, which of the results showed that the temperature maximum relative error value is within 3%. The numerical results displayed that the velocity and temperature distribution of fluid are mainly affected by pressure, flow rate, cycle time, and geometric structure, where the hot blast temperature is affected by the cycle time but the distribution of velocity and relative pressure are affected by the height of hot blast branch. It can be concluded that the flow field and the structure of type A hot blast stove are more stable than that of type B by comparing the results of two types of hot blast stoves.

The accurate detection and classification of invisible weld defects is very important to ensure the quality of welding products. A magneto-optical (MO) imaging detection system excited by a rotating magnetic field is proposed for feature extraction and detection classification of invisible natural weld defects. A finite element analysis (FEA) model of multidirectional natural weld cracks is developed to study the distribution of rotating magnetic fields at different transient times, and the distribution of leakage magnetic field for four types of invisible defects is analyzed. The correctness of the finite element model is verified by MO imaging test of multidirectional natural weld defects. The grayscale values and texture features of MO images can reflect the leakage magnetic field characteristics of weld defects. The MO imaging detection system excited by a rotating magnetic field is used to obtain MO images of defects such as non-penetration, pit, subsurface crack, surface crack, and no defect for weld defect diagnosis. The principal component analysis (PCA) method and the Tamura method are used to extract the grayscale values and texture features of natural weld defect’s MO images, respectively. Using backpropagation (BP) neural network as the weak classifier, a strong classification model of BP-Adaboost weld defects is established by the Adaboost algorithm. Experimental results show that the recognition accuracy of the PCA + Tamura- BP-Adaboos model is higher than that of the PCA + Tamura-BP model, and its overall recognition rate reaches 97.8%, and the detection and classification of multidirectional natural weld defects can be realized.

ObjectiveTo analyse whether the accumulation of early adverse experiences among individuals of different generations has an impact on disabilities and evaluate the cumulative effects of disadvantages in rural older adults in China.MethodsA Binary Logit Model was used to analyse the life course effects of the disability dilemma among rural older adults.ResultsRegarding Activities of Daily Life (ADLs), there was no significant difference between older adults that experienced 1 adverse events and the control group. The probability of older adults experiencing difficulties in 2, 3, 4, or more types of ADLs was 1.486 times, 2.173 times, and 3.048 times higher than that of the control group, respectively. Regarding Instrumental Activities of Daily Life (IADLs), there was no significant difference between the population that experienced 1 or 2 adverse events and the control group. The probability of experiencing difficulties in 3, 4, or more types of IADLs was 1.527 times and 1.937 times higher than that of the control group, respectively. Early adverse events had a cumulative disadvantageous effect on disability in older adults. The longer the duration of adverse experiences, the higher the risk of disability in old age. Education had a significant mitigating effect on health risks.ConclusionPay attention to early factors in the life course, strengthen the promotion of health prevention concepts, and pay attention to the moderating and relieving effects of education on health. We should also gradually improve the rural disability care system and family health security capabilities in China’s rural areas.

Altered glycosylation profiles have been correlated with potential drug targets in various diseases, including Alzheimer’s disease (AD). In this area, the linkage between bisecting N-acetylglucosamine (GlcNAc), a product of N-acetylglucosaminyltransferase III (GnT-III), and AD has been recognized, however, our understanding of the cause and the causative role of this aberrant glycosylation in AD are far from completion. Moreover, the effects and mechanisms of glycosylation-targeting interventions on memory and cognition, and novel targeting strategies are worth further study. Here, we showed the characteristic amyloid pathology-induced and age-related changes of GnT-III, and identified transcription factor 7-like 2 as the key transcription factor responsible for the abnormal expression of GnT-III in AD. Upregulation of GnT-III aggravated cognitive dysfunction and Alzheimer-like pathologies. In contrast, loss of GnT-III could improve cognition and alleviate pathologies. Furthermore, we found that an increase in bisecting GlcNAc modified ICAM-1 resulted in impairment of microglial responses, and genetic inactivation of GnT-III protected against AD mechanistically by blocking the aberrant glycosylation of ICAM-1 and subsequently modulating microglial responses, including microglial motility, phagocytosis ability, homeostatic/reactive state and neuroinflammation. Moreover, by target-based screening of GnT-III inhibitors from FDA-approved drug library, we identified two compounds, regorafenib and dihydroergocristine mesylate, showing pharmacological potential leading to modulation of aberrant glycosylation and microglial responses, and rescue of memory and cognition deficits.

The dynamic characteristics of rubber isolation pad (abbreviated as RIP) after service under the high temperature thermal oxygen aging and the variable preloads have preload dependence and thermal oxygen aging dependence, which is a crucial problem for matching the vibration isolation system of air conditioner compressor to reveal the dynamic characteristic mechanism of the RIP with different preloads and thermal oxygen aging conditions. The Peck model is first introduced to characterize the thermal oxygen aging factor, the fractional derivative Kelvin-Voigt thermal oxygen aging-perturbation model (FDKVTPM) and the Coulomb frictional thermal oxygen aging-perturbation model (CFTPM) are established to describe the frequency dependence and the amplitude dependence, respectively. The thermal oxygen aging-dynamic characteristic model of the RIP is built by considering the influence of variable preloads, the model parameters under different preloads are further identified, the validity of the model was examined by the experimental data. The concepts of the stiffness transition point (STP) and the stiffness transition frequency (STF) are innovatively proposed to better describe softening effect of the RIP under variable preload and variable amplitude working conditions. The results show that the static stiffness of RIP increases by 20.7%, the dynamic stiffness increases by 9.3%, and the loss factor decreases by 35% after thermal oxygen aging under different preload conditions, which can lay a theoretical foundation for in-depth study of the stiffness matching and optimization of air conditioner compressor with the RIP.

The surface defects of automobile door seals are mainly detected manually at present, which is costly and has low efficiency. Therefore, a deep learning automatic detection algorithm of automobile door seals is studied in this paper. At first, the defects are classified and the data set is made according to the geometric characteristics of the defects. While enhancing the data set, the K-means clustering algorithm is used to cluster the target annotation frame in the data set, and the anchor that matches with the surface defect size of the seal is obtained. Finally, in view of the characteristics of large variation range of defect size, the target detection algorithm YOLOV3 is selected as the basic framework. Meanwhile, considering the high proportion of small and medium-sized targets in defects, the output scale is introduced at 4 times of the sampling position of YOLOV3 backbone network. In order to further enhance the correlation between the extracted features and the channel, spatial position and coordinate position, the feature fusion and attention mechanism module is constructed. The test results show that the mean of the average precision is improved by 4.81% compared with YOLOV3.

Abstract Background China has one of the world’s largest internal migrant populations. The Chinese Hukou system is a unique household registration system that limits internal migrants in their access to basic urban public services, such as public health insurance and social assistance of their host city. In the case of female internal migrants, this may lead to high-risk pregnancies. The objective of this study is to assess the relationship between internal migrant status (Hukou) and the likelihood of high-risk pregnancies that occur in one large municipal-level obstetrics hospital in Shanghai, China. Methods Medical records data from the Shanghai First Maternity and Infant Hospital from January 1, 2013, to May 31, 2018, were used to analyze 133,358 live births for Shanghai natives (n = 83,872) and internal migrant women (n = 49,486). A propensity score matching approach was used in conjunction with logistic regression analysis to identify the role of internal migrant status (Hukou) on the likelihood of high-risk pregnancies. Results A greater likelihood of high-risk pregnancies were found among internal migrant women who moved from other parts of China to Shanghai. This effect was more obvious for women who gave birth for the first time and internal migrant women who were employed. Conclusion The results show the effects of internal migrant status (Hukou) and the elevated likelihood of high-risk pregnancies among internal migrant women relative to their urban counterparts in Shanghai even after accounting for self-selection by employing the propensity score matching method. China’s unique Hukou household registration system limits access to public services for internal migrant women and accordingly may account for the elevated likelihood of high-risk pregnancies.

The aim of this study was to investigate the antioxidative and neuroprotective activities of total flavonoids from sea buckthorn (Hippophae rhamnoides L.) (TFH). Results indicated that TFH possessed DPPH radicals, hydroxyl radicals and superoxide anions scavenging activities. The neuroprotective potential was assessed with acetylcholinesterase (AChE) and monoamine oxidase A (MAO-A). The inhibition rates of AChE and MAO-A by 50 μg/ml TFH were 75.85 and 51.22%, respectively. The in vivo antioxidative and neuroprotective potential of TFH were explored in Caenorhabditis elegans. In the longevity assay, TFH (50 μg/ml) significantly increased the lifespan of wild-type C. elegans (29.40%). In the hydrogen peroxide-induced oxidative stress challenge, the antioxidant capacity of TFH-treated wild-type C. elegans was significantly enhanced. The C. elegans mutant strain CL4176 was used to study the neuroprotective effect of TFH in vivo. Results showed that TFH significantly delayed paralysis in C. elegans CL4176. Our study suggested total flavonoids from sea buckthorn (Hippophae rhamnoides L.) had the potential as an antioxidative and neuroprotective agent to extend aging and treat neurodegenerative diseases.

Achieving online inspection and recognition of laser welding quality is essential for intelligent industrial manufacturing. The weld penetration status is an important indicator for assessing the welding quality, and the optical signal is the most common changing feature in the laser welding process. This paper proposes a new method based on a photoelectric signal and neural network for laser welding penetration status identification. A laser welding experimental system platform based on a photoelectric sensor is built, the laser welding experimental material is DC01 mild steel, and the photoelectric signal in the laser welding process is collected. The collected signal is then processed, and features are extracted using wavelet packet transform and probability density analyses. The mapping relationship between the signal features and weld penetration status is investigated. A deep learning convolutional neural network (CNN)-based weld penetration status recognition model is constructed, with multiple eigenvalue vectors as input, and the model training and recognition results are analyzed and compared. The experimental results show that the photoelectric signal features are highly correlated with the weld penetration status, and the constructed CNN weld penetration status recognition model has an accuracy of up to 98.5% on the test set, demonstrating excellent performance in identifying the quality of the laser welding. This study provides the basis for the online inspection and intelligent identification of laser welding quality.

In the field of genetic code expansion (GCE), improvements in the efficiency of noncanonical amino acid (ncAA) incorporation have received continuous attention. By analyzing the reported gene sequences of giant virus species, we noticed some sequence differences at the tRNA binding interface. On the basis of the structural and activity differences between Methanococcus jannaschii Tyrosyl-tRNA Synthetase (MjTyrRS) and mimivirus Tyrosyl-tRNA Synthetase (MVTyrRS), we found that the size of the anticodon-recognized loop of MjTyrRS influences its suppression activity regarding triplet and specific quadruplet codons. Therefore, three MjTyrRS mutants with loop minimization were designed. The suppression of wild-type MjTyrRS loop-minimized mutants increased by 1.8–4.3-fold, and the MjTyrRS variants enhanced the activity of the incorporation of ncAAs by 15–150% through loop minimization. In addition, for specific quadruplet codons, the loop minimization of MjTyrRS also improves the suppression efficiency. These results suggest that loop minimization of MjTyrRS may provide a general strategy for the efficient synthesis of ncAAs-containing proteins.

NB-IoT,which is the key technology of the Internet of things,has received widespread attention from global operators.Firstly,the commercial technologies of NB-IoT was outlined,then the research status of NB-IoT enhancement technology was introduced in detail from the aspects of mobile IoT enhancement technology,positioning enhancement technology,mobility enhancement technology and intelligent network optimization technology,and finally,future evolution of NB-IoT technology was introduced.

Previously we have reported a specific hydrolysate form of silk fibroin named SFH and in vitro beneficial effects of SFH on neuron, however, evidence in vivo for the specific neuroprotective function of SFH on AD is urgently needed and our understanding for mechanism underlying SFH function is far from completion. In this study, we report here the amelioration of neurodegenerative changes in Aβ25-35-induced rat models of AD by SFH. We found that SFH in vivo significantly attenuated impairment of spatial learning and memory, prevented neuronal damages and decreased multisite tau hyperphosphorylation induced by Aβ25-35. In vivo and in vitro results also further indicated that the beneficial effect of SFH on AD may be due to its interference with microglia-mediated neuroinflammation. SFH can inhibit abnormal activation of microglial and expressions of proinflammatory mediators in Aβ25-35-induced rat and rat primary microglia models can be inhibited by SFH via MAPKs /NF-κB signaling pathway.

The influence mechanism of thermal oxygen aging on the dynamic characteristic of the rubber isolation pad (RIP) is usually ignored in studies. However, the ambient temperature of the RIP could reach up to 70°C in general, and even 108°C under some extreme conditions, which will lead to accelerated thermal oxygen aging and a decline in the mechanical performance for the RIP. In the meantime, the thermal oxygen aging will result in excessive vibration and even a damaged external air conditioner. Therefore, the research on the influence mechanism of rubber thermal oxygen aging on the dynamic performances of the RIP is crucial to the mechanical characteristic matching of the RIP. Considering the effect of the thermal oxygen aging on the dynamic characteristic, a novel model of thermal oxygen aging-dynamic characteristic of the RIP is established by adopting the Peck model, the hyperelastic model, the fractional derivative model, and the smooth Coulomb friction model (SCFM) in this paper. A test rig of the static and dynamic characteristics of the RIP is built, and an identification method of model parameters is developed based on the MTS831 elastomer test system as well which of the thermal oxygen aging-dynamic characteristic model is verified by the experimental data. The result is shown that the maximum growth rate of the static stiffness and the dynamic stiffness is 20.7% and 4.5%, respectively, and the maximum decrease rate of the loss factor is 10.6% as the thermal oxygen aging hardness of the RIP increases by 5HA. The amplitude-dependent, frequency-dependent, and thermal oxygen aging-dependent performances of the RIP are effectively characterized by the thermal oxygen aging-dynamic characteristic model. Moreover, a theoretical foundation is provided for the evolution law of the dynamic characteristic of the RIP after the service with the thermal oxygen aging condition in this research.

Pectin is the most studied compound. However, recently, more attention has been paid to the health care of pectin oligosaccharides, especially the potential of prebiotics. In order to obtain lower molecular weight molecules with improved bioactivities, the pectin (ALP2) was partially degraded by acid and enzymatic hydrolysis. The molecular weights of acid hydrolyzed fragment (ALP2-A) and enzymatic hydrolyzed fragment (ALP2-E) were 2.4 × 104 Da and 5.8 × 103 Da, respectively. ALP2-A was composed of rhamnose and galacturonic acid while ALP2-E contained rhamnose, glucuronic acid, galacturonic acid, galactose, and arabinose. Rheological experiments showed that ALP2-A and ALP2-E solutions had lower viscosity than that of ALP2 solution, exhibited shear-thinning behavior and belonged to pseudoplastic fluids. ALP2-A could alleviate the constipation symptoms of mice while ALP2-A and ALP2-E had better intestinal flora regulation activity than that of ALP2. Therefore, the results indicated that ALP2-A and ALP2-E could be recommended as potential prebiotic or functional food that could benefit the host by regulating human gut microbiota.

Objective: The bias towards males at birth has resulted in a major imbalance in the Chinese sex ratio that is often attributed to China’s one-child policy. Relaxation of the one-child policy has the potential to reduce the imbalance in the sex ratio away from males. In this study, we assessed whether the bias towards males in the child sex ratio was reduced as a result of the two-child policy in China. Medical records data from one large municipal-level obstetrics hospital in Shanghai, East China. Design: Matching and difference-in-differences (MDID) techniques were used to investigate the effect of the two-child policy on the imbalance in the sex ratio at birth after matching for pregnancy status and socioeconomic factors. Results: Analyzing 133,358 live births suggest that the relaxation of the one-child policy had a small, but statistically significant effect in reducing the imbalance in the male to female sex ratio at birth. Conclusion: The results demonstrate that relaxation of the one-child policy reduced the imbalance in the male to female sex ratio at birth from 1.10 to 1.05 over the study period at one of the major obstetrics and gynecology hospitals in China.

A laser welding technology for the dissimilar materials 316L stainless steel (316L ss) and polylactic acid (PLA) was investigated to analyze the process parameters, which have a large influence on the joint quality. Orthogonal tests, single-factor tests, response surface method (RSM), and Box–Behnken design (BBD) were utilized to optimize the experimental design. A metallographic microscopy analysis was conducted to classify the joint morphology into two categories: effective and ineffective. The effective area ratio was established as an effective judgment method for the joint mechanical properties. Mathematical relations between the process parameters and the mechanical properties of the joints were investigated and the process parameters were optimized and validated. The test values were in excellent agreement with the actual values, thus demonstrating the reliability of the proposed model.

Metal–polymer hybrid structures have been widely used in research into their lightweight automotive applications, because of their excellent comprehensive properties. As an efficient technology for automatic connection of dissimilar materials, laser joining has great application potential and development value in the field of lightweight automotive design. However, due to the physical and chemical differences between metals and polymers, the formation quality of the hybrid joint is seriously affected by defects, low bonding strength, and poor morphology. Meanwhile, it is difficult to meet the demands for lightweight automobiles by considering only bonding strength as the target for forming quality. Therefore, the technological characteristics of metal–polymer hybrid structures for use in lightweight automotive applications are analyzed, the advantages and problems of laser-joining technology are discussed, and the characterization indexes and regulation measures of forming quality in laser joining are summarized. This paper which provides reference and guidance for reliable forming, intelligent development, and lightweight application of laser joining for polymer–metal hybrid structures.

Abstract Background Despite extensive research concerning the impact of health insurance on the advancement of infant health in developed countries, few studies have adjusted their results for potential confounding due to adverse selection in insurance coverage, wherein those who anticipate a need for health services tend to be the ones that acquire insurance. The presence of compulsory health insurance in China, such as the Urban Employee Basic Medical Insurance (UEBMI) scheme may provide an opportunity to estimate the effect of health insurance on infant health, by reducing the endogeneity problem into insurance due to the adverse selection. The objective is to assess the relationship between UEBMI and infant health outcomes in one sizeable municipal-level obstetrics hospital in Shanghai, East China. Methods Medical records data from the Shanghai First Maternity and Infant Hospital from January 1, 2013 to April 30, 2019 were used to form an analysis dataset of 160,429 live births which was comprised of Shanghai residents with UEBMI coverage (n = 101,153) and women without any insurance coverage (n = 59,276). A propensity score matching approach using conjoint quantile regression and probit regression models was used to eliminate latent endogeneity of UEBMI coverage in order to garner robust results. Further analysis stratified by maternal migrant status was conducted to further assess the sensitivity of the findings to distinct patient subgroups. Results The UEBMI scheme was shown to be associated with improvements in infant birth outcomes. The scheme was associated with: an increase in birth weight of about 30 g (p

In this research, an auxiliary illumination visual sensor system, an ultraviolet/visible (UVV) band visual sensor system (with a wavelength less than 780 nm), a spectrometer, and a photodiode are employed to capture insights into the high-power disc laser welding process. The features of the visible optical light signal and the reflected laser light signal are extracted by decomposing the original signal captured by the photodiode via the wavelet packet decomposition (WPD) method. The captured signals of the spectrometer mainly have a wavelength of 400–900 nm, and are divided into 25 sub-bands to extract the spectrum features by statistical methods. The features of the plume and spatters are acquired by images captured by the UVV visual sensor system, and the features of the keyhole are extracted from images captured by the auxiliary illumination visual sensor system. Based on these real-time quantized features of the welding process, a deep belief network (DBN) is established to monitor the welding status. A genetic algorithm is applied to optimize the parameters of the proposed DBN model. The established DBN model shows higher accuracy and robustness in monitoring welding status in comparison with a traditional back-propagation neural network (BPNN) model. The effectiveness and generalization ability of the proposed DBN are validated by three additional experiments with different welding parameters. Keywords: Online monitoring, Multiple sensors, Wavelet packet decomposition, Deep belief network

Welding status determines the post-weld quality and is crucial to high-power disk laser welding. A low-cost monitoring system based on two photodiodes is developed to monitor the real-time welding statuses in this paper. A deep learning architecture based on stacked autoencoder (SAE) is proposed to automatically learn more representative features of welding statuses from the raw signal features captured by the visible light photodiode and the reflected laser light photodiode without any manual operations. The maximum correntropy loss function is applied to improve the learning ability of the proposed SAE method. Furthermore, a genetic algorithm is applied to optimize the key parameters of the proposed SAE method. The proposed SAE is applied to the high-power disk laser welding experiments and shows better performance in welding status monitoring than the standard AE framework and the conventional SVM and BP method. Additional experiments with different welding parameters validate the effectiveness and robustness of our proposed SAE method.

During laser-metal inert gas (MIG) hybrid welding, a large amount of welding status information is generated in droplet transfer, keyhole and molten pool. In this paper, austenitic stainless steel was adopted as an experimental object, with a dual high-speed camera system used to obtain real-time images of droplet transfer, keyhole and molten pool in a laser-MIG hybrid welding process. The changing regulation of a keyhole in three different penetration states (i.e., non-penetration, partial penetration and normal penetration) was analyzed by extracting the morphological characteristics of a keyhole shape, and combining the droplet transition information and the shape of the weld pool. Experimental results show that the proposed method could effectively reflect the variation characteristics of the keyhole, and the correlation among the keyhole characteristics, the droplet transfer information, the weld pool shape and the welding status, and provide a new perspective for online detection of the laser-MIG welding quality.

Using the traditional magneto-optical detection methods, micro-weld defects parallel with the magnetic field direction may be overlooked. In order to overcome this, a non-destructive testing method based on magneto-optical imaging under a vertical combined magnetic field (VCMF) is proposed. To demonstrate this, the experimental results of the magneto-optical imaging of weld defects excited by a vertical combined magnetic field (VCMF) or parallel combined magnetic field (PCMF) are compared with those of traditional magnetic fields (constant magnetic field (CMF), alternating magnetic field (AMF), and rotating magnetic field (RMF)). It is found that the magneto-optical imaging under a VCMF can accurately detect weld defects of any shape and distribution. In addition, the center difference method is used to eliminate the influence of noise on the defect contour extraction of magneto-optical images, and the active contour of weld defects in the magneto-optical images is extracted. The results show that many noises can be identifiedby the robustness of the level set method, operating in low-pass filtering, so that much information that is usually lost can be retained.

Junlian coalfield is one of the main targets for coalbed methane (CBM) exploration and development in the southwest China. Based on field geological survey, core observation, gas content statistics, coal maceral composition, vitrinite reflectance (RO), proximate analysis and trace element test, lithological types, lithofacies, sedimentary environment, and structural analysis, this research established the sequence stratigraphy frame, revealed the plane distribution characteristics of sedimentary facies, and defined CBM accumulation mode. The results show that six rock types were identified and further subdivided into twenty lithofacies types. Four types of sedimentary systems such as alluvial plains, delta, lagoon-tidal flat, and carbonate platform were summarized according to their combination characteristics. Additionally, 12-14 fourth-order sequences and three third-order sequences CSI, CSII, and CSIII were divided, and a sequence stratigraphic framework of the Lopingian coal-bearing series was established. Among them, the features of third-order sequence CSIII paleogeography from west to east are alluvial plains, deltas, lagoon-tidal flats, and limited carbonate platforms. Thick coal seams are mainly developed in the sedimentary environment of tidal flats, delta plains, and floodplains behind banks. Closely related to coal seam thickness, gas contents of Lopingian coal seams are generally higher than 8 m3/t, except the low level in northwest and partial denudation areas. CBM accumulation is significantly controlled by the fold structure, and the hydraulic plugging effect makes the syncline core favorable for CBM accumulation. Furthermore, favorable geostress conditions enable the secondary anticline to become a favorable area for CBM accumulation when the sealing conditions are better. This research will provide a theoretical guide for the exploration and development of CBM in the study area.

The fiber laser butt welding of AISI 304L and Q235 low-carbon steel is performed in this study. An integrated heat source combined with an asymmetric double-ellipsoidal heat source and a cylindrical heat source is designed to perform the numerical simulation of the laser butt welding process. With the established numerical simulation model, the formation of the welded joint is studied by investigating the thermal process. The effects of the laser power and laser beam offset to the sides of the center of the welding gap on the welded joint shape and strength are experimentally investigated, and the optimum laser power and laser beam offset are determined via tensile strength and hardness tests of the weldment. The numerical simulation results based on the asymmetric heat source agree well with the experimental results and are applied to investigate the mechanisms for forming different welded joint shapes in AISI 304L and Q235 steels. The different thermal conductivity and melting temperatures of the two dissimilar metals result in the different shapes of the welded joint.

Systemic lupus erythematosus (SLE) is an autoimmune disease that is mainly caused by excessive accumulation of autoantibodies that target autoantibodies such as nucleic acids. T helper (Th) cell have been associated with the development of SLE. Typically, different subsets of Th cells secrete various cytokines to regulate the disease progression. IL-12 and IL-23 participate in the differentiation and activation of multiple Th cell subsets, including Th1, Th2, Th9, Th17, regulatory T (Treg) and follicular helper T (Tfh) cells. Because of the signature p40 subunit shared by IL-12 and IL-23, blocking IL-12/IL-23 signaling may interfere the differentiation of Th cell and directly inhibit the secretion of proinflammatory cytokines. In this study, we examined the effects of anti−IL-12/23 p40 antibody on chronic graft-versus-host disease with lupus nephritis, and found that the therapeutic effectiveness was mediated through the inhibition of Tfh cell in mice. Moreover, anti−IL-12/23 p40 antibody inhibited human Tfh cell differentiation in vitro. These results strongly suggest that Tfh cell contribute to the pathogenesis of SLE, and the neutralization of IL-12/IL-23 signaling during Tfh cell differentiation may be critical for the treatment of SLE.

This paper proposes an approach for analyzing the microstructure evolution of laser welding seam by magneto-optical imaging (MOI). The Faraday magneto-optical effect and magnetic domain theory are used to account for the MOI mechanism. The influence of laser welding on the welded joint was inspected by the analysis of color, grayscale and brightness of magneto-optical images. The relation between the brightness of magneto-optical image and grain size of microstructure is discussed as well, and the characteristics of magneto-optical images of weld microstructure were compared with those of scanning electron microscope (SEM) images. Experimental results show that three regions, including the weld zone (WZ), the heat-affected zone (HAZ), and the base metal (BM) are distributed in the magneto-optical image of the welded joint. The MOI method can investigate the microstructure evolution of welded joints and provide a theory and experimental basis for detecting weld defects.

PEG modification is a common clinical strategy for prolonging the half-life of therapeutic proteins or polypeptides. In a previous work, we have successfully synthesized PEG-modified Exendin-4 (PE) by conjugating a 20 kDa PEG to the C-terminal of Exendin-4. Then, we introduced an integrative characterization for PE to evaluate its hypoglycemic activity and pharmacokinetic properties. The normoglycemic efficacies and therapeutic activity of PE were investigated in db/db mice. The hypoglycemic time after single administration of PE on db/db mice was prolonged from 8.4 h to 54.9 h. In multiple treatment with PE, the fasting blood glucose in various PE dosages (50, 150, and 250 nmol/kg) were remarkably reduced, and the glycosylated hemoglobin level was decreased to 2.0%. When the in vivo single- and multiple-dose pharmacokinetics of PE were examined in Sprague–Dawley rats, the half-life was prolonged to 31.7 h, and no accumulation effect was observed. Overall, this study provided a novel promising therapeutic approach to improving glucose-controlling ability and extending half-life without accumulation in vivo for long-acting treatment of type-2 diabetes. Keywords: GLP-1 mimetic, PEGylation, db/db mice, Pharmacodynamics, Pharmacokinetics

Silk fibroin (SF) has been widely used as biomedical materials and the hydrolysate form of SF (SFH) has shown many activities. The purpose of the current study was to explore the neuroprotective effects of SFH against Aβ25–35-induced cytotoxicity in SH-SY5Y cells and primary hippocampal neurons and the possible mechanism. The results showed that SFH could improve the viabilities of SH-SY5Y and primary hippocampal neurons injured by Aβ25–35. The lowered mitochondrial membrane potential and increased cell apoptosis induced by Aβ25–35 were recovered after SFH treatment. Further study indicated that the beneficial effects of SFH were likely due to its interference with reactive oxygen species (ROS). SFH inhibited the phosphorylation of Ser/Thr protein phosphatase 2A (PP2A) by suppressing Aβ25–35-induced ROS, and then suppressed the activation of MAPKs and tau hyperphosphorylation, and protected SH-SY5Y cells and primary neurons from Aβ25–35-induced damages. SFH has the potential to be a nutraceutical for AD intervention.

Room-temperature ferromagnetism was obtained in SrSn0.5Co0.5O3 (SSCO) epitaxial film on SrTiO3 substrate by pulsed laser deposition, and the effects of oxygen pressure (PO2) on the microstructure, optical and magnetic properties were examined. An interesting hybrid epitaxial film embedded with polycrystalline SSCO and SrCoOx nanoparticles was observed. The increase of PO2 relaxed the film/substrate compressive strain, promoted the growth of crystallites and reduced the optical band gap (from 2.43 to 1.68 eV). The SSCO film deposited at 0.1 Pa exhibited good ferromagnetism at 100–300 K, while the ferromagnetism in the film with higher and lower oxygen pressure (1 Pa and 10−4 Pa) was weak.

Abstract The “Hu Line” and its demographic implications have attracted world-wide attention since the line was developed 80 years. Using GIS, this paper conducts a statistical analysis and systematic investigation on the stability and spatial of China’s minority population growth on both sides of “Hu Line” by constructing the spatial database of China’s census data from 1953 to 2010 and initiating a new method for identifying the spatial patterns of population growth. Major findings are as follows: (1) Spatial distribution of the minority population in China is not balanced, showing a significant spatial clustering; (2) The minority population is widely distributed across China, spreading to East China and all over the country; (3) The distribution pattern of China’s minority population is characterized by extraordinary stability, with the ratio of south-east half to north-west half standing roughly at 75:25 from 1953 to 2010. We can thus say that the “Hu Line” is also a mutant line of China’s minority population.

The activity and function of proteins can be improved by incorporation of non-canonical amino acids (ncAAs). To avoid the tedious synthesis of a large number of chiral phenylalanine derivatives, we synthesized the corresponding phenylpyruvic acid precursors. Escherichia coli strain DH10B and strain C321.ΔA.expΔPBAD were selected as hosts for phenylpyruvic acid bioconversion and genetic code expansion using the MmPylRS/pyltRNACUA system. The concentrations of keto acids, PLP and amino donors were optimized in the process. Eight keto acids that can be biotransformed and their coupled genetic code expansions were identified. Finally, the genetic encoded ncAAs were tested for incorporation into fluorescent proteins with keto acids.

Laser welding experiments involving amorphous thermoplastic polymer (PMMA) and 304 austenitic stainless steel plates were conducted to explore the influence of laser welding process parameters on plastic–metal joints. A high-speed camera was applied to record the dynamics of the molten pool and the formation of bubbles to reveal the bonding mechanisms of the hybrid joints. The influence of process parameters on the joints was analyzed using temperature measurements performed with thermocouples. The microstructure morphology of joints was observed using SEM. The mechanical characterization of the hybrid joints was carried out to understand the effect of the welding conditions on the weld morphology, flaws and shear stress. Different interface temperatures resulted in two types of bubbles and led to different weld morphology characteristics. A stable hybrid joint with the best shear stress was produced with a laser line energy of 20.16 J/mm2, a temperature of 305 °C and small bubbles. The shear stress of the effective joint under the maximum mechanical resistance was 4.17 MPa. The chemical bonds (M-O, M-C) and mechanical anchoring that formed on the steel’s surface contributed to the joint bonding. Range analysis provided guidance for identifying the impact of individual factors in the shear stress for the laser welding of plastic–metal.

We assess the association between maternal migrant status and health outcomes in China, which has one of the world’s largest migrant populations. Health records from the Shanghai First Maternity and Infant Hospital from January 1, 2013, to June 30, 2017, were used to analyze 104 681 live births for Shanghai native-born and migrant women based on International Classification of Diseases, Tenth Revision diagnosis codes and demographic data. Regression analysis including propensity score matching was conducted to investigate the association between maternal migrant status and adverse infant birth outcomes (fetal disease, congenital malformation, neonatal disease) and maternal health after controlling for pregnancy status and socioeconomic factors. The results demonstrate that migrant women had statistically significant increased odds (9.1%-10%, P < .001) of having infants with adverse health outcomes compared with their urban counterparts and that migrant mothers have less likelihood of pregnancy complications and gestational diabetes mellitus. Our results show the mixed effects of migration on infant and maternal health may be a possible outcome of China’s Hukou system that often represents an important barrier in accessing prenatal health care by migrant women. Current reforms that improve access to prenatal health care services for migrant women may enhance the health outcomes of their infants.

Single B cell antibody technology is a method for isolating antigen-specific B cells from human peripheral blood and obtaining antibody genes in developing antibody drugs. However, owing to immune tolerance to autoantigen, human autoantigen-specific B cells are difficult to acquire by conventional single B cell technology. In this study, we constructed a nitrated T-cell epitope named NitraTh by incorporating p-nitrophenylalanine into a universal T helper epitope. NitraTh had enhanced ability to activate CD4+ T cells and can be recognized by CD4+ T cells with different HLA class II haplotypes. This NitraTh can also break immune tolerance to autoantigens, such as human epidermal growth factor receptor 2 (HER2) and cannabinoid receptor 1, and induce strong specific IgM+ B cell responses in vitro. HER2-NitraTh vaccine can also stimulate the generation of HER2-specific IgG+ B cells in human immune system mice, which was established by cotransplanting lymphocytes and autologous dendritic cells in immunodeficient mice. We obtained 30 fully human IgG antibody genes by sorting single B cells from the human immune system mice immunized with HER2-NitraTh vaccine. The analysis of antibody genes showed that sorted B cells underwent the extensive somatic mutation of the antibody genes. We randomly selected eight genes for cloning, six of which expressed antibodies that can bind to HER2. Hence, we provided a convenient and effective method in acquiring fully human antibody genes against self-proteins, which can be used in developing therapeutic antibody drugs.

Although research on microbial biogeography has made great progress in the past decade, distributions of terrestrial microbial communities in extreme environments such as Antarctica are not well understood. In addition, knowledge of whether and how historical contingencies affect microbial distributions at small spatial scales is lacking. Here, we analyzed soil-borne microbial (bacterial, archaeal, and fungal) communities in 12 quadrat plots around the Fildes Region of King George Island, maritime Antarctica, and the communities were divided into two groups according to the soil elemental compositions and environmental attributes of Holocene raised beach and Tertiary volcanic stratigraphy. Prokaryotic communities of the two groups were well separated; the prokaryotic data were primarily correlated with soil elemental compositions and were secondly correlated with environmental attributes (e.g., soil pH, total organic carbon, NO3-, and vegetation coverage; Pearson test, r = 0.59 vs. 0.52, both P < 0.01). The relatively high abundance of P, S, Cl, and Br in Group 1 (Holocene raised beach site) was likely due to landform uplift. Lithophile-elements (Si, Al, Ca, Sr, Ti, V, and Fe) correlated with prokaryotic communities in Group 2 may have originated from weathering of Tertiary volcanic rock. No significant correlations were found between the fungal community distribution and both the soil elemental composition and environmental attributes in this study; however, Monte Carlo tests revealed that elements Sr and Ti, soil pH, sampling altitude, and moss and lichen species numbers had significant impacts on fungal communities. The elements and nutrients accumulated during the formation of different landforms influenced the development of soils, plant growth, and microbial communities, and this resulted in small-scale spatially heterogeneous biological distributions. These findings provide new evidence that geological evolutionary processes in the Fildes Region were crucial to its microbial community development, and the results highlight that microbial distribution patterns are the legacies of historical events at this small spatial scale. Based on this study, the ice-free regions in maritime Antarctica represent suitable research sites for studying the influence of geomorphological features on microbial distributions, and we envision the possibility of a site-specific landform assignment through the analysis of the soil prokaryotic community structure.

Interleukin (IL)-23 is considered an effective therapeutic target for the treatment of psoriasis because of the crucial role of the IL-23/IL-17 axis in the pathogenesis of psoriasis, and it has recently been reported to be involved in ILC3 cell differentiation. In this study, we report that eukaryotically expressed rhIL23R-CHR/Fc, as an endogenous extracellular receptor analogue, could be a natural antagonist in an imiquimod (IMQ)-induced psoriasis-like mouse model, including the antagonizing effect of suppressed inflammation in the skin lesion, decreased production of pro-inflammatory cells, and reduced the expression of pro-inflammatory factors. The rhIL23R-CHR/Fc fusion protein inhibits both innate immune and adaptive immune-mediated inflammatory responses. These findings shed light on rhIL23R-CHR/Fc as a promising candidate therapy for the treatment of psoriasis.

In order to automatically evaluate the welding quality during high-power disk laser welding, a real-time monitoring system was developed. The images of laser-induced metal vapor during welding were captured and fifteen features were extracted. A feature selection method based on a sequential forward floating selection algorithm was employed to identify the optimal feature subset, and a support vector machine (SVM) classifier was built to recognize the welding quality. The experiment results demonstrated that this method had satisfactory performance, and could be applied in laser welding monitoring applications.

In order to improve the prediction ability of welding quality during high-power disk laser welding, a new approach was proposed and applied in the classification of the dynamic features of metal vapor plume. Six features were extracted through the color image processing method. Three features, including the area of plume, number of spatters, and horizontal coordinate of plume centroid, were selected based on the classification accuracy rates and Pearson product-moment correlation coefficients. A support vector machine model was adopted to classify the welding quality status into two categories, good or poor. The results demonstrated that the support vector machine model established according to the selected features had satisfactory prediction and generalization ability. The classification accuracy rate was higher than 90%, and the model could be applied in the prediction of welding quality during high-power disk laser welding.

Exendin-4 is a strong therapeutic candidate for the treatment of metabolic syndrome. Related receptor agonist drugs have been on the market since 2005. However, technical limitations and the pain caused by subcutaneous injection have severely limited patient compliance. The goal of the study is to investigate a biologically active exendin-4 analog could be administered orally. Using intraperitoneal glucose tolerance tests, we discovered that exendin4-cysteine administered by oral gavage had a distinct hypoglycemic effect in C57BL/6J mice. Using Rosetta Design and Amber, we designed and screened a series of exendin4-cysteine analogs to identify those that retained biological activity while resisting trypsin digestion. Trypsin Cleavage Site Mutated Exendin4-cysteine 1 (TSME-1), an analog whose bioactivity was similar to exendin-4 and was almost completely resistant to trypsin, was screened out. In addition, TSME-1 significantly normalized the blood glucose levels and the availability of TSME-1 was significantly higher than that of exendin-4 and exendin4-cysteine. Collectively orally administered TSME-1, a trypsin-resistant exendin-4 analog obtained by the system, is a strong candidate for future treatments of type 2 diabetes.

Glycopeptide from Ganoderma capense (Lloyd) Teng (GCGP) injection is widely used in kinds of immune disorders, but little is known about the molecular mechanisms of how GCGP could interfere with immune cell function. In the present study, we have found that GCGP had inflammatory modulation effects on macrophage cells to maintain NO production and iNOS expression at the normal level. Furthermore, western blot analysis showed that the underlying mechanism of immunomodulatory effect of GCGP involved NF-κB p65 translation, IκB phosphorylation, and degradation; NF-κB inhibitor assays also confirmed the results. In addition, competition study showed that GCGP could inhibit LPS from binding to macrophage cells. Our data indicates that GCGP, which may share the same receptor(s) expressed by macrophage cells with LPS, exerted immunomodulatory effect in a NF-κB-dependent signaling pathway in macrophages.

New Delhi metallo-β-lactamase-1 (NDM-1) has attracted extensive attention for its high catalytic activities of hydrolyzing almost all β-lactam antibiotics. NDM-1 shows relatively higher similarity to subclass B1 metallo-β-lactamases (MβLs), but its residue at position 229 is identical to that of B2/B3 MβLs, which is a Tyr instead of a B1-MβL-conserved Trp. To elucidate the possible role of Y229 in the bioactivity of NDM-1, we performed mutagenesis study and molecular dynamics (MD) simulations. Although residue Y229 is spatially distant from the active site and not contacting directly with the substrate or zinc ions, the Y229W mutant was found to have higher kcat and Km values than those of wild-type NDM-1, resulting in 1 ∼ 7 fold increases in k(cat) /K(m) values against tested antibiotics. In addition, our MD simulations illustrated the enhanced flexibility of Loop 2 upon Y229W mutation, which could increase the kinetics of both substrate entrance (kon) and product egress (koff). The enhanced flexibility of Loop 2 might allow the enzyme to adjust the geometry of its active site to accommodate substrates with different structures, broadening its substrate spectrum. This study indicated the possible role of the residue at position 229 in the evolution of NDM-1.

Various natural polysaccharides are capable of activating the immune system and therefore can be employed as biological response modifiers in anti-tumor therapy. We previously found a homogenous polysaccharide from the mycelium of marine fungus Phoma herbarum YS4108, named YCP, exhibiting strong in vivo antitumor ability via enhancement of the host immune responses. To further elucidate the role of YCP as a biological response modifier, the immunomodulating activities of YCP in B cells was investigated in the current study. We demonstrated that stimulation of YCP with murine splenic B cells resulted in cell proliferation and generation of IgM antibody response. Binding of YCP to B cells was a direct, saturable and reversible event and required TLR2 and TLR4 involvement. TLR2 and TLR4 defunctionalization by either antibody blocking or allele-specific mutation significantly impaired the B-cell proliferative and IgM responses to YCP. YCP interaction with TLR2 and TLR4 led to the activation of intracellular p38, ERK and JNK, as well as the translocation of transcriptional factor NF-κB into nucleus. Furthermore, specific inhibitors of p38, ERK, JNK and NF-κB could attenuate the ability of YCP to induce B cell proliferation and IgM production. Taken together, this study has indicated for the first time the immunostimulating properties of YCP on B cells through a receptor-mediated mechanism, which involves TLR2 and TLR4 and resultant activation of MAPK and NF-κB signaling pathways, thereby highlighting the role of YCP as an efficacious biological response modifier in oncologic immunotherapy.

Th17 cells have been reported to produce proinflammatory cytokines like Interleukin-17, IL-22, and regarded as important players in various inflammatory diseases. One of the IL-12 cytokine family cytokines, IL-23, composed of p19 and p40 subunit, is known for its potential to promote Th17 development and IL-17 producing, and the IL-23/IL-17 pathway is considered to be potential therapeutic target for autoimmune inflammation responses. Knockout mice deficient in either IL-23 or IL-17 related genes can suppress the allergic responses. Several IL-23 or IL-17 neutralizing agents are being evaluated in vitro or in vivo to disrupt the IL-23/IL-17 axis. Herein, we report that prokaryotically expressed soluble IL-23 receptor cytokine-binding homology region as an endogenous extracellular receptor analogue could be a natural antagonist against IL-23/IL-17 axis. We provide evidence that IL23R-CHR can bind to IL-23 in a dose-dependent manner in vitro, and block IL-23 signal by IL23R-CHR reducing the RORγt expression, which in turn lowers the expression of IL-17/IL-22, thus protecting naive CD4+ T cells against Th17 development. Together, this study indicates the importance of IL-23 pathway in Th17 development and the negative regulation of Th17 development by IL23R-CHR, and highlights the important roles of the soluble receptor extracellular region in the therapeutic strategy of neutralizing IL-23.