Search

Since 2016, the corn seed industry has gradually passed the stage of overcapacity, and the area and output of seed production have shown a trend of first decline and second rise. The ratio of seed supply and demand reached a record low after the 2022 sales season. The seed production situation showed the characteristics of concentrated distribution of seed production bases, polarization of variety demand, and continuous increase in seed sales prices and production costs. In 2023, the supply of corn seeds is sufficient, and a few high-quality varieties are in short supply, with slight differences in different regions. From the current situation and domestic development, it is expected that the market value of corn seeds will remain above CNY 30 billion in the future; the supply-demand relationship of seeds will remain stable in the benign development range; the variety selection will shift from supply-oriented to demand-oriented; the seed market price will continue to increase; industry mergers and reorganizations will accelerate, and concentration will gradually increase.

The carbon nanotube (CNT)-polyetherimide (PEI) was successfully grafted onto the surface of carbon fibers (CF) through chemical grafting method for constructing a CF-g-CNT reinforcing phase. Results show the construction of CF-g-CNT fiber can effectively improve the interface, impact resistance and bending properties of the composites. Considering the effect of strengthening phase on the mechanical properties of composites, the interfacial shear strength, impact strength, flexural modulus and flexural strength of CF-g-CNT/BMI composites respectively increase by 48.8%, 10.8%, 5.2% and 14.6%, companed with those of CF/BMI. In addition, the interfacial shear strength, impact strength, flexural modulus and flexural strength of CF-g-CNT/BMI-PEI-CNT composites are 56.9%, 27.1%, 12.5% and 16.1% higher than those of CF/BMI-PEI-CNT, respectively. The interfacial shear strength, impact strength, flexural modulus and flexural strength of CF-g-CNT/BMI-PEI-CNT composites increase by 57.7%, 33.7%, 20.0% and 23.7% compared with CF/BMI. The CNT-PEI in CF-g-CNT can effectively change the interface composition and change the expansion path of horizontal stress or vertical stress at the interface, which is beneficial to disperse the stress concentration as well as improve the mechanical properties of the composites.

The aim of this study is to explore a novel classification and investigate the clinical significance of hepatocellular carcinoma (HCC) cells. We analyzed integrated single-cell RNA sequencing and bulk RNA-seq data obtained from HCC samples. Cell trajectory analysis divided HCC cells into three subgroups with different differentiation states: state 1 was closely related to phosphoric ester hydrolase activity, state 2 was involved in eukaryotic initiation factor 4E binding, translation regulator activity and ribosome, and state 3 was associated with oxidoreductase activity and metabolism. Three molecular classes based on HCC differentiation-related genes (HDRGs) from HCC samples were identified, which revealed immune checkpoint gene expression and overall survival (OS) of HCC patients. Moreover, a prognostic risk scoring (RS) model was generated based on eight HDRGs, and the results showed that the OS of the high-risk group was worse than that of the low-risk group. Further, potential therapeutic drugs were screened out based on eight prognostic RS-HDRGs. This study highlights the importance of HCC cell differentiation in immunotherapy, clinical prognosis, and potential molecular-targeted drugs for HCC patients, and proposes a direction for the development of individualized treatments for HCC.

The Manas River Basin is located in the inland arid area of China. It has a unique natural environment that contains a mountain, oasis, and desert complex ecosystem. Changes in land use type have had significant impacts on the social, economic, and ecological environment in the basin. Based on the remote sensing interpretation data of land use types from 1980 to 2020 in the Manas River Basin, using ArcGIS 10.2 and Fragstats 4.2 and other software to study the temporal and spatial evolution of land use, landscape pattern, and ecological service value (ESV) in the Manas River Basin, several key results were obtained. (1) Unused land accounted for the largest proportion of the total area at about 44%, and the smallest proportion was construction land at 1%, the construction land and farmland areas increased significantly to 82.16 and 34.87%, while the woodland and grassland area decreased to 15.06 and 14.34%, respectively. (2) Between 1980 and 2020, the inflows and outflows of the quantitative transfer tracks for farmland, grassland, and unused land were highly dominant, but the frequent conversion among various types of land led to the transfer tracks becoming more diversified. (3) From 1980 to 2020 the complexity and fragmentation of landscape in the basin decreased, and the heterogeneity, differences, and connectivity of the landscape increased. (4) The ESV of the Manas River Basin had a tendency to initially decrease and then increase, which increased from 237.27 × 108 yuan in 1980 to 238.10 × 108 yuan in 2020. The above research results can not only provide a basis for the ecological improvement of the Manas River Basin but also provide a reference for the study of other basins/regions in arid areas.

In this paper, the chain structure of magnetorheological fluid (MRF) magnetic particles was studied and analyzed, the mechanical model of MRF with different diameter ferromagnetic particles was established, silicone oil-based MRF with different particle volume fractions was prepared, the shear properties of the MRF were tested, and the theoretical and experimental data were compared. The experimental results show that the shear stress is stable with the increase of shear strain rate under the action of the magnetic field, and it has a shear thinning effect. The shear stress increases linearly with the increase of particle volume fraction. The shear stress increases with the increase of magnetic induction intensity. After data analysis and in the case of control variables, the average error of improved theoretical data and experimental data is lower than that of previous theoretical data and experimental data, which verifies that the improved theory (mechanical model) has a certain accuracy.

Endothelial-mesenchymal transition (EndMT) is a differentiation process in which endothelial cells lose their own characteristics and acquire mesenchymal-like characteristics, which contributes to the formation and development of atherosclerotic plaques. Until now, there is still a lack of effective measures to treat atherosclerosis (AS), so there is an urgent need to understand the underlying mechanisms of AS. In addition, although various studies have shown that EndMT is involved in the pathological stages of cardiovascular diseases, such as myocardial fibrosis, myocardial hypertrophy, and hypertension, the specific molecular mechanisms driving EndMT are still in the exploratory stage. In this review, we review the role of histone modifications (methylation, demethylation and acetylation, deacetylation) on EndMT in cardiovascular disease, aiming to target histone-modifying enzymes to guide cardiovascular disease therapy.

By utilising data from official sources, a statistical analysis was made on the elevator accidents that occurred in China during the period 2002 to 2019 on five aspects namely elevator type, occurrence stage, casualty’s identity, accident type and accident causes. The main purpose is to use the frequency and correlation among related factors to evaluate crucial causes, and to prevent similar accidents among technicians and users. Based on the statistical results and discussion, some proposals were put forward to the management of the responsible authorities for accident investigation and prevention of similar elevator accidents in the future.

Dental bonding technology and materials have been used widely in dentistry because of their excellent properties. The development of novel bonding technology and materials is constantly being performed to improve the effect of dental bonding restorations. Observation and analysis of the dental bonding interface is one of the most important methods for laboratory evaluation of bonding efficiency. This paper aims to review the methods of observation and analysis of dental bonding interfaces to provide a reference for the selection of evaluation methods in dental bonding research. The features of 6 methods, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), confocal laser scanning microscopy (CLSM), Raman spectroscopy (RS), optical coherence tomography (OCT) and atomic force microscopy (AFM), were described and summarized. Among these methods, SEM and TEM are used most often in the analysis of fine structures; CLSM and OCT are used for the acquisition of characteristic image signals, such as microleakage and exogenous and endogenous fluorescence; and RS and AFM can test chemical composition and mechanical properties.

The purpose of this study is to suggest the physicians using olanzapine to strengthen the recognition and treatment of restless leg syndrome （RLS） in clinical practice. In this paper， one patient with schizophrenia suffered from RLS during olanzapine administration， which was characterized by unpleasant sensory disturbances in bilateral lower extremity at night， intense urges to move legs， and inability to sleep. After taking gabapentin， the above symptoms were significantly improved.

Rice (Oryza sativa) production is damaged to a great extent by sheath blight disease (ShB). However, the defense mechanism in rice against this disease is largely unknown. Previous transcriptome analysis identified a significantly induced eukaryotic protein phosphatase 2A catalytic subunit 1 (PP2A-1) after the inoculation of Rhizoctonia solani. Five genes encoding PP2A exist in rice genome, and these five genes are ubiquitously expressed in different tissues and stages. Inoculation of R. solani showed that the genome edited pp2a-1 mutants using the CRISPR/Cas9 were more susceptible to ShB than the wild-type control, but other PP2A gene mutants exhibited similar response to ShB compared to wild-type plants. In parallel, PP2A-1 expression level was higher in the activation tagging line, and PP2A-1 overexpression inhibited plant height and promoted the resistance to ShB. PP2A-1-GFP was localized in the cytoplasm and nucleus. In addition, R. solani-dependent induction kinetics of pathogen-related genes PBZ1 and PR1b was lower in pp2a-1 mutants but higher in PP2A-1 activation line compared to those in the wild-type. In conclusion, our analysis shows that PP2A-1 is a member of protein phosphatase, which regulates rice resistance to ShB. This result broadens the understanding of the defense mechanism against ShB and provides a potential target for rice breeding for disease resistance.

The intelligent auxiliary decision-making (IADM) is emerging as a feasible solution for air traffic control (ATC) to reduce undesirable conflicts in shared airspace; meanwhile, unmanned aerial vehicles (UAVs) can be operated with enhanced efficiency and safety using IADM. This paper presents the conflict risk framework of the MAV\UAV flight that improves flight safety of MAVs and UAVs in shared airspace. This is accomplished by focusing on two steps: First, determine the minimum safety communication interval between the UAV and controller; second, build a conflict risk model to detect which decision mechanism will minimize risk. Our approach provides a standard model to start with to improve IADM and allow engineers to focus on the operational purpose of MAV/UAV. Results show that our work presented here is practical and straightforward, and it brings an evident engineering application prospect.

The current experience-dominated structural design process separates the structural design from CAE analysis in the development of a new wind turbine gearbox,which leads to a quite long-term development cycle and the redundancy of structural materials.Consequently,a new structural design process is presented based on topological optimization theory and combined with CAE.Through a secondary development for Hyperworks with C# and TCL / TK language,a new process automatic system characterized by lightweight structure for the structural design of wind turbine gearboxes is developed.The operability of the system is testified by the instance of designing a planet carrier.The case indicates that the process automatic system can lead designers to finish the lightweight-oriented structural design for wind turbine gearbox parts,and the pre and post processing efficiency can increase by 90% than the current process,and the development cycle of new products of wind turbine gearbox is shorten enormously.

Due to the long service life of a quayside container crane in an enterprise, there is slight corrosion on the surface of metal structure, which has potential safety hazard. In order to master the technical condition of the metal structure of the crane, the stress distribution and change information of the crane are obtained by dynamic and static stress testing and non-destructive testing. According to the analysis and test results, the safety assessment of the whole machine is completed and reasonable management suggestions are put forward.

The Xujiawan monzogranitic intrusion is located at the junction of the Tongbai-Tongcheng fault and the Tancheng-Lujiang fault in North Huaiyang tectonic belt. The rocks intruded into the Neoproterozoic metamorphic rocks as stocks. In this study, major and trace element contents of the rocks are determined by Atomic Absorption Spectrometer and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). Results show that these rocks have high contents of SiO2 and Al2O3 and are alkali-rich and peraluminous with low Mg# values. They are rich in large ion lithophile elements such as Rb and Ba, but are poor in Sr. They are rich in high field strength elements such as Y, Th, Nb, Hf, U, but are poor in Ta, P, Ti. In general, these rocks are deplete in HFSE but enriched in LILE. They have high LaN/YbN and LREE/HREE ratios and have weak Ce anomalies. Major and trace elements indicate that these rocks belong to peraluminous A-type granite. LA-ICP-MS Zircon U-Pb dating of Xujiawan monzogranite yield ages of 128.0 0.9 Ma to 129.6 1.4 Ma, indicating that these intrusions were produced by the early Cretaceous magmatism. Xujiawan monzogranite may have formed in a post-collisional extensional setting. The magma may be derived from the mantle and contaminated by the continental crust.

The modularization and serialization design idea is introduced into the method to research the design method of yaw reducer of wind power transmission system,a new configuration programs- NGW compound NGWN（ Ⅰ） is proposed,serialization basic planetary gear transmission modules are formed,the parts reusability and interchangeability of yawing reducer are enhanced. According to the definition of modular design approach,the yawing reducer planetary transmission mechanism is divided into NGW type and NGWN（ Ⅰ）type two planetary modules. The tooth number optimization model is built for both modules respectively,the same type and function but different transmission ratio planetary planets modules are formed,there are 28 species NGW modules and 9 species NGWN（ Ⅰ） modules. By the definition of serialization design method,the standard series modulus are given,the gear module series are formed. Finally,the wind power yaw reducer rapid design process is established based on planetary modules. The reference to design yaw planetary reducer in wind power transmission system is provided.

When the interference fit connection structure being applied load,its contact surface can produce small relative slip amplitude.When the relative slip amplitude is in a certain range,the fretting fatigue life would be shortened.In order to evaluate the rationality of the joint of planet carrier interference fit connection structure,the condition of interference fit fretting slip is analyzed by using Workbench.Since Workbench cannot directly get the fretting slip amplitude of certain direction or loading step,therefore a method for extracting slip vector magnitude is proposed to analyze the slip amplitude of a certain direction or loading step.The results show that,in the loading stage,the fretting slip of back-end interference contact area is in critical value range,the fretting fatigue life is shorter.The analysis results provide a reference for structural design improvement.

Improving the load sharing property of multiple planets is not only one of the effective methods to improve the large megawatt wind turbine gearbox power density,but also is the key to the design of wind turbine gearbox. Taking the latest research and development of 8 megawatt wind offshore wind power gearbox as the research object,and the rigid flexible coupling dynamics model with a gearbox of new configuration and initial parameters is established by using the ADAMS. The real dynamics analysis of functional virtual prototype is carried out to research the bearing property of planet gears and pinions,and then conduct its contained load sharing design. The load sharing of each planetary wheel and pinion is analyzed by fitting data of the extracting gear meshing force simulation data,and take center external gear in ordinary gear train and the internal ring gear in the differential gear train floating as design scheme in order to improve the system load characteristics,the results show that the performance of the load sharing is effectively improved. This study laid the foundation for the detailed structure design of high power density megawatt wind power gearbox.

Objective To investigate the occupational exposure and its risk fatctors among the medical staff of stomatological department and, in order to improve the occupational protection and reduce the risk for occupational exposure.Methods The occupational exposures that occurred in 44 medical staff from Jan 2013 to Dec 2015 were investigated, and the occupation, exposure sources, types of exposures, exposure link were analyzed.Results Among the 44 medical staff of oral department with occupational exposure, doctors accounted for 54.5%, nurses 34.1%. There were 39 medical staff with sharps injuries and 3 medical staff with mucous membrane exposure. The major expose reason is cleaning medical instruments or equipment at the end of medical treatment, accounting for 43.2%(19 cases). Needle stick injures in operation is the second major reason, accounting for 34.1%(15 cases). All the subjects with occupational exposures have received appropriate treatment, and the follow-up showed that none of the medical staff were infected due to the occupational exposure.Conclusion The major expose reason is cleaning medical instruments or equipment at the end of medical treatment. It is crucial to intensify the training of medical staff of stomatological department in the knowledge of occupational exposure, implement the standard of preventive measures, and standarize the operation procedures so as to reduce the risk of occupational exposure.

【Abstract】Objective: To study the epidemiologic characteristics of traffic injuries among people over 60 years old in the Nan’an district (urban) and Jiangjin district (rural) of Chongqing, and to discuss the corresponding strategies for its prevention and cure. Methods: Records of traffic injuries in people over 60 years old registered by the traffic police between 2000 and 2006 in Nan’an district and Jiangjin district were collected in the Database of Road Traffic Accidents and Traffic Injuries. Epidemiologic characteristics of traffic injuries among the aged people were analyzed and compared. Results: Between the year 2000 and 2006, the average annual incidence of traffic injuries and mortality rate in the aged people in Nan’an district were 124.62/100 000 and 13.85/ 100 000 respectively, higher than that in Jiangjin district (27.49/ 100 000, 7.13/100 000, P

On the basis of introducing the limitations of the double-star positioning system,the precision rubidium clock was put forward to be the internal clock of the RDSS receiver.If the receiver could measure the pseudo-ranges from the user to the satellites,with the help of barometer,the RDSS could be integrated with the strap-down inertial navigation system based on pseudo-range.The simulation result shows that the output navigation parameters of the integrated sys-tem have the characteristic of low error,which offers one new way to develop our country’s RDSS.

Abstract.: It has been known that oxidative stress plays an important role in the development of diabetic nephropathy (DN). The antioxidative effects of Astragalus saponin I (AS I) were studied in vitro and in vivo. In the presence of high glucose and H2O2, the total antioxidative capability, catalase, reduced glutathione, and superoxide dismutase level of rat mesangial cells were significantly decreased, and transforming growth factor β1 (TGF-β1) mRNA level, collagen IV, and laminin level were significantly increased. When compared with those in the high glucose group, these 4 indexes of cells incubated in 2.0 and/or 20 µmol/L of AS I were significantly enhanced, and levels of TGF-β1 mRNA, collagen IV and laminin were statistically decreased. By flowcytomery, percentages of S phase of cells incubated in high glucose and H2O2 were lowered, while those in AS I were increased. Furthermore, the physical behaviors of rats treated with 12 mg/kg of AS I restored with vigor and weight gaining, while the level of HbAlC was significantly reduced. Thus, AS I has antioxidative effects and is a potential compound worth further study because it may prevent the development of DN. Keywords:: Astragalus saponin I, diabetic nephropathy, antioxidative, mesangial cell