Search

Abstract [Objective] The study aims to investigate the bamboo resources in Guizhou in order to supplement and enrich the existing bamboo materials, as well as to provide a basis for the planning and developing of bamboo industry. [Methods] Field investigation, specimen collection and identification, and information retrieval were conducted using a combination of “surface” and “point” methods to compile new distribution records of genera and species. [Results] One genus and six species of newly recorded bamboo plants were found in Guizhou Province. The new record genus was Schizostachyum . The six new record species were S. pseudolima McClure, Bambusa funghomii McClure, Yushania longshanensis D. Z. Li & X. Y. Ye, Y. polytricha Hsueh et Yi, Y. pauciramificans Yi, and Y. punctulata Yi. [Conclusion] The discovery of these new genera and species in Guizhou expands the distribution of bamboo plants and enriches their diversity in Guizhou

Abstract Gastroesophageal reflux disease (GERD) in the elderly is characterized by atypical symptoms, relatively severe esophageal injury, and more complications, and when GERD is treated, it is also necessary to fully consider the general health condition of the elderly patients. This consensus summarized the epidemiology, pathogenesis, clinical manifestations, and diagnosis and treatment characteristics of GERD in the elderly, and provided relevant recommendations, providing guidance for medical personnel to correctly understand and standardize the diagnosis and treatment of GERD in the elderly.

The identification and categorization of pills constitute critical tasks within a contemporary hospital, particularly for avoiding medication errors. Conventional approaches to visual recognition and classification predominantly rely on visible light imagery, proving inadequate for discerning white pills with similar visual characteristics. However, white pills exhibit distinctive infrared properties across various spectral bands. Building upon these observations, this paper introduces the MCIR-YOLO algorithm, a multi-band infrared image object detection system, which enhances the YOLOv5s model through multimodal fusion techniques. This study presents a novel dataset comprising IR images of white round pills captured across six channels, with peak wavelengths ranging from approximately 1400 nm to 1650 nm. Furthermore, a multimodal fusion strategy is proposed, facilitating multi-level feature integration across the six IR channels. This fusion technique exploits the scale features inherent to each IR modality, thereby enabling comprehensive information fusion across multiple modalities. Additionally, the model incorporates an auxiliary detection branch, independent of the backbone, which utilizes fused feature information to calculate a distinct loss, effectively mitigating overall loss. Attention mechanism modules are integrated after two distinct fusion points to enhance feature precision. Leveraging mean and scaling of IR features, these attention mechanisms significantly boost detection accuracy. Experimental results demonstrate that the improved model outperforms the baseline YOLOv5s model, particularly evident in a self-constructed dataset of white round pill IR images, where mAP0.5 increased by 5.47% and 7.96% for single-channel (peak at 1650 nm) and six-channel configurations, respectively. Notably, the utilization of the MCIR-YOLO model for six-channel recognition yields a substantial advantage of 12.05% over the best-performing single-channel IR image recognition.

Objective To explore and analyze the influencing factors of multi⁃disciplinary team (MDT) model in treatment of severe traumatic brain injury (sTBI) with severe multiple injuries, and to summarize the diagnosis and treatment experience. Methods Total 144 patients of sTBI with severe multiple injuries treated in a MDT model at The Affiliated Hospital of Guizhou Medical University from January 2016 to June 2021 were included. Glasgow Outcome Scale (GOS) was used to assess prognosis at discharge, univariate and multivariate stepwise Logistic regression analyses were used to screen for influencing factors postoperative prognosis. Results A total of 144 patients were divided into good prognosis group (n = 101) and poor prognosis group (n = 43) according to the GOS score at discharge. The poor prognosis group included hypertension (P = 0.003), diabetes (P = 0.004), smoking (P = 0.000), drinking (P = 0.000), traumatic shock (P = 0.009) and brain hernia formation (P = 0.000), combined chest injury (P = 0.046), abdominal injury (P = 0.000) and spinal injury (P = 0.009), the proportion of concurrent pulmonary infections (P = 0.031), multiple organ dysfunction syndrome (MODS, P = 0.004), ventilator ⁃ assisted ventilation (P = 0.005), and tracheostomy (P = 0.005) during treatment were higher than those in good prognosis group, while the proportion of Glasgow Coma Scale (GCS) score (P = 0.000) and brain contusion and laceration (P = 0.013) at admission were lower than those in good prognosis group. Logistic regression analysis showed diabetes (OR = 4.119, 95%CI: 2.632-5.832; P = 0.042), abdominal injury (OR = 1.183, 95%CI: 1.000-1.269; P = 0.006), low GCS score at admission (OR = 4.949, 95%CI: 1.609-15.218; P = 0.005), and MODS during treatment (OR = 4.642, 95%CI: 4.068-5.216; P = 0.008) were risk factors for poor prognosis of patients of sTBI with severe multiple injuries, while tracheotomy was a protective factor for good prognosis (OR = 0.223, 95%CI: 0.062-0.384; P = 0.007). Conclusions sTBI with severe multiple injuries is complicated and difficult to treat. Diabetes, combined with abdominal injury, low GCS score at admission, and MODS during treatment are risk factors for poor prognosis of patients of sTBI with severe multiple injuries under MDT.

The application of walnut protein is limited due to its poor water solubility and low yield. Five proteases, neutral protease, papain, bromelain, trypsin and protein glutaminase, were selected to carry out limited enzymatic hydrolysis reaction on walnut protein, and the modified walnut protein was applied to prepare the emulsion. The results showed that the solubility and emulsification of walnut protein were significantly improved after modification. Neutral protease modified protein (WP-Z) had the best emulsification and high stability. SDS-PAGE results showed that the macromolecular subunits of walnut protein were partially decomposed after limited enzymatic hydrolysis. After the modification, the particle size of the emulsion was reduced to 5~8 μm, and micro-volume of oil droplets was reduced. In addition, the dispersion was more uniform, and the emulsion index was greatly reduced, which did not exceed 10% in 30 days. By comprehensive analysis, the particle size of the emulsion prepared by WP-Z was moderate, which was more suitable for the preparation of emulsion.

Bone tissue engineering has emerged as a significant research area that provides promising novel tools for the preparation of biomimetic hydrogels applied in bone-related diseases (e.g., bone defects, cartilage damage, osteoarthritis, etc.). Herein, thermal sensitive polymers (e.g., PNIPAAm, Soluplus, etc.) were introduced into main chains to fabricate biomimetic hydrogels with injectability and compatibility for those bone defect need minimally invasive surgery. Mineral ions (e.g., calcium, copper, zinc, and magnesium), as an indispensable role in maintaining the balance of the organism, were linked with polymer chains to form functional hydrogels for accelerating bone regeneration. In the chemically triggered hydrogel section, advanced hydrogels crosslinked by different molecular agents (e.g., genipin, dopamine, caffeic acid, and tannic acid) possess many advantages, including extensive selectivity, rapid gel-forming capacity and tunable mechanical property. Additionally, photo crosslinking hydrogel with rapid response and mild condition can be triggered by different photoinitiators (e.g., I2959, LAP, eosin Y, riboflavin, etc.) under specific wavelength of light. Moreover, enzyme triggered hydrogels were also utilized in the tissue regeneration due to its rapid gel-forming capacity and excellent biocompatibility. Particularly, some key factors that can determine the therapy effect for bone tissue engineering were also mentioned. Finally, brief summaries and remaining issues on how to properly design clinical-oriented hydrogels were provided in this review.

This paper reviews the nutrition and utilization of rice bran and the future development of food grade rice bran. Rice bran has high nutritional value and rich biological activities. The utilization of rice bran fiber is mainly through modification. The combination of physical and enzymatic methods and supercritical CO2 treatment are beneficial to improve the soluble dietary fiber content and fiber extraction rate. The utilization of rice bran protein includes extraction and modification. The study of extraction of rice bran protein focuses on the combination of physical and enzymatic methods. Moreover, subcritical water, which is a new green extraction technology, has gradually become a research hotspot. The rice bran protein is mainly modified using enzymatic method to improve the function and biological activity of the protein. Therefore,studies on the development of food grade rice bran will be a trend in the future.

Under the background of global warming, climate extremes have become a crucial issue with distinct heterogeneity features in different regions. Hence, spatial–temporal changes in temperature and precipitation extremes in Guizhou Province were investigated utilizing daily maximums and minimums of temperature and daily precipitation data during 1960–2019 based on trend analysis. It was concluded that, firstly, all warm extremes but warm spell duration indicator (WSDI) are significantly enhanced, whereas for cold extremes, the monthly minimum value of daily minimum temperature (TNn) is significantly enhanced, while cool nights (TN10P), frost days (FD0), ice days (ID0), and cold spell duration indicator (CSDI) are significantly decreased. And all precipitation extremes but consecutive wet days (CWD) have no significant variational trend in Guizhou Province. Secondly, variational trends of temperature extremes are more prominent and robust in western Guizhou Province. Temperature and precipitation extremes show large differences from spring to winter. Thirdly, temperature extremes are closely correlated with strength, area, and the westernmost ridge point index of western Pacific subtropical high (WPSH), whereas precipitation extremes show no distinct correlation with WPSH. The WPSH has significantly strengthened and shifted westward in the past 60 years, leading to less total cloud cover and more downward solar wave flux reaching Earth’s surface, accordingly, exacerbating warm extremes and weakening cold extremes. These results will benefit understanding the heterogeneity of climate extremes at a regional scale.

C23H23BrO2, monoclinic, P21/c (no. 14), a = 24.193(4) Å, b = 5.8614(10) Å, c = 13.873(3) Å, β = 93.168(3)∘, V = 1964.3(6) Å3, Z = 4, Rgt(F) = 0.0316, wRref(F2) = 0.0915, T = 296(2) K.

Calcium phosphate (CaP) is the principal inorganic constituent of bone and teeth in vertebrates and has various applications in biomedical areas. Among various types of CaPs, amorphous calcium phosphate (ACP) is considered to have superior bioactivity and biodegradability. With regard to the instability of ACP, the phosphorus-containing molecules are usually adopted to solve this issue, but the specific roles of the molecules in the formation of nano-sized CaP have not been clearly clarified yet. Herein, alendronate, cyclophosphamide, zoledronate, and foscarnet are selected as the model molecules, and theoretical calculations were performed to elucidate the interaction between calcium ions and different model molecules. Subsequently, CaPs were prepared with the addition of the phosphorus-containing molecules. It is found that cyclophosphamide has limited influence on the generation of CaPs due to their weak interaction. During the co-precipitation process of Ca2+ and PO43-, the competitive relation among alendronate, zoledronate, and foscarnet plays critical roles in the produced inorganic-organic complex. Moreover, the biocompatibility of CaPs was also systematically evaluated. The DFT calculation provides a convincing strategy for predicting the structure of CaPs with various additives. This work is promising for designing CaP-based multifunctional drug delivery systems and tissue engineering materials.

Objective To summarize the sociodemographic information, injury data, treatment methods and prognosis of patients with traumatic brain injury (TBI) in Guizhou Province, and to explore the treatment ideas of TBI in this area. Methods A total of 1931 patients with TBI who were diagnosed and treated in Department of Neurosurgery, The Affiliated Hospital of Guizhou Medical University from January 2016 to December 2018 were recruited by self⁃designed data questionnaire. The clinical data included gender, age, occupation, area of injury, cause of injury, type of injury, location of injury, severity of injury, whether the midline deviated, location of hematoma, combined injury, whether pre⁃hospital first aid, whether surgical treatment, operation time window, postoperative complications and infection during hospitalization. Glasgow Outcome Scale (GOS) was used to evaluate the prognosis of patients. Results According to GOS score, there were 1488 cases (77.06%) with good recovery, 134 cases (6.94%) with mild disability, 101 cases (5.23%) with severe disability, 134 cases (6.94%) with vegetative survival and 74 cases (3.83%) with death. 1) Social demographic data: there were significant differences in GOS scores between different ages (F = 6.411, P = 0.000) and occupations (F = 5.446, P = 0.000). The prognosis of 46-55 years old patients was worse than that of 5-15 years old patients (t = 5.047, P = 0.000). The prognosis of self ⁃ employed workers was worse than that of preschool children (t = ⁃ 3.570, P = 0.021), students (t = ⁃ 5.050, P = 0.000) and cooks (t = ⁃ 3.763, P = 0.013). There was no significant difference in the prognosis between different genders (t = 0.123, P = 0.902). 2) Injury data: there were significant differences in the prognosis among different injury causes (F = 2.585, P = 0.017), injury sites (F = 5.314, P = 0.000) and injury severity (F = 238.321, P = 0.000). The prognosis of traffic injury was worse than that of strike injury (t = ⁃ 3.731, P = 0.004). The prognosis of basal ganglia injury was worse than that of cerebellar injury (t = ⁃ 3.340, P = 0.002). The prognosis of severe (t = 15.983, P = 0.000) and medium (t = 5.711, P = 0.000) patients was worse than that of mild, and severe patients was worse than that of the medium (t = 9.130, P = 0.000). The prognosis of no⁃Guiyang patients was worse than that of patients in Guiyang (t = ⁃ 2.231, P = 0.026). The prognosis of open injury patients was worse than that of closed injury patients (t = ⁃ 3.069, P = 0.002), subdural hematoma patients was worse than that of epidural hematoma patients (t = 4.559, P = 0.000), and the prognosis of patients with midline shift was worse than that of patients without midline shift (t = ⁃ 17.781, P = 0.000). The prognosis of patients with combined injury was worse than that of patients without combined injury (t = ⁃ 4.725, P = 0.000). 3) Treatment and complications: the prognosis of patients with pre⁃hospital first aid was worse than that without pre⁃hospital first aid (t = 4.343, P = 0.000). The prognosis of patients with surgical treatment was worse than that of patients with conservative treatment (t = ⁃ 5.506, P = 0.000). The prognosis of patients with postoperative complications was worse than that of patients without complications (t = ⁃ 15.845, P = 0.000), and the prognosis of patients with concurrent infection during hospitalization was worse than that of patients without infection (t = ⁃ 14.645, P = 0.000). While there was no significant difference in prognosis between CT examination time (t = ⁃ 1.942, P = 0.052) and operation time window (t = ⁃ 1.483, P = 0.140). Conclusions The disability rate of TBI in Guizhou Province is high. Strengthening the propaganda and education of traffic and production safety knowledge can prevent and reduce TBI. Strengthening the professional training of neurosurgeons in county⁃level hospitals can make TBI patients get timely, standardized and homogeneous treatment, and improve the prognosis. doi：10.3969/j.issn.1672⁃6731.2021.03.012

Guizhou Province is a typical representative karst region in China, with poverty and a fragile ecology, and knowledge of vegetation dynamics and its response to climate changes and human activities can provide basic information for ecological environmental resource management. Based on MOD13Q1 NDVI remote sensing products and meteorological data, spatial-temporal variations of NDVI in Guizhou Province from 2000 to 2021 were investigated using trend analysis, a coefficient of variation and the Hurst index. Simultaneously, the response to climate change and human activities was also explored using partial correlation and residual analysis. It was concluded that, firstly, the regional average NDVI in Guizhou Province displays a significant improving trend, with a rate of 0.056/10a from 2000 to 2021. NDVI in Guizhou Province displays notable spatial heterogeneity, with high values mainly concentrated in forests and woody savanna regions in eastern and northwestern Guizhou and low values distributed in croplands and rapid urban expansion regions in western and central Guizhou. In addition, the overall spatial distribution of NDVI displays an upward trend, and the area of extreme and light significant improvement accounts for 81.0% of Guizhou total area. Secondly, the NDVI variation in Guizhou Province is relatively stable and the area of lower-to-moderate fluctuation accounts for 90.1% of Guizhou total area; meanwhile, the future trend of NDVI variation in Guizhou is largely sustainable. Thirdly, the NDVI variations in Guizhou are more strongly influenced by air temperature than precipitation; meanwhile, compared to climatic factors, human activities have a stronger impact on vegetation dynamics in Guizhou Province. Fourthly, the trend, stability, sustainability and relationship with climatic factors and human activities of NDVI variations are varied among different vegetation types. These results will provide valuable information for ecosystem restoration and environment protection in Guizhou Province.

Graphical Abstract

There has been a rapid development of biomimetic platforms using cell membranes as nanocarriers to camouflage nanoparticles for enhancing bio-interfacial capabilities. Various sources of cell membranes have been explored for natural functions such as circulation and targeting effect. Biomedical applications of cell membranes-based delivery systems are expanding from cancer to multiple diseases. However, the natural properties of cell membranes are still far from achieving desired functions and effects as a nanocarrier platform for various diseases. To obtain multi-functionality and multitasking in complex biological systems, various functionalized modifications of cell membranes are being developed based on physical, chemical, and biological methods. Notably, many research opportunities have been initiated at the interface of multi-technologies and cell membranes, opening a promising frontier in therapeutic applications. Herein, the current exploration of natural cell membrane functionality, the design principles for engineered cell membrane-based delivery systems, and the disease applications are reviewed, with a special focus on the emerging strategies in engineering approaches.

The carbon fiber/epoxy resin composites with different stitch density were manufactured using modified lock stitching and vacuum assisted resin infusion (VARI) molding process. The influence of stitch space and stitch pitch on mechanical properties of the composites was investigated. The optimum stitch density was obtained. The results show that with increasing stitch space, both tensile and flexural properties enhance and interlaminar shear strength increases first and then decreases. With the increase of stitch pitch, both tensile and flexural properties exhibit an increasing trend. The stitched composites have the optimum integrated mechanical properties when the stitch density is 5 mm×8 mm. Their tensile strength, tensile modulus, flexural strength and flexural modulus reduce by 13.3%, 12.7%, 23.0% and 25.2%, respectively, whereas the interlaminar shear strength increases by 11.3% compared to the unstitched composites.

Chronic skeletal disorders (CSDs), including degenerative diseases such as osteoporosis (OP) and autoimmune disorders, have become a leading cause of disability in an ageing society, with natural drugs being indispensable therapeutic options. The clinical safety evaluation (CSE) of natural drugs in CSDs has been given priority and has been intensively studied. To provide fundamental evidence for the clinical application of natural drugs in the elderly population, clinical studies of natural drugs in CSDs included in this review were selected from CNKI, Web of Science, PubMed, Science Direct and Google Scholar since 2001. Seventeen randomized controlled trials (RCTs) met our inclusion criteria: four articles were on OP, seven on osteoarthritis (OA), four on rheumatoid arthritis (RA) and two on gout. Common natural drugs used for the treatment of OP include Epimedium brevicornu Maxim [Berberidaceae], Dipsacus asper Wall ex DC [Caprifoliaceae] root, and Phalaenopsis cornu-cervi (Breda) Blume & Rchb. f[ Orchidaceae], which have been linked to several mild adverse reactions, such as skin rash, gastric dysfunction, abnormal urine, constipation and irritability. The safety of Hedera helix L [Araliaceae] extract, Boswellia serrata Roxb [Burseraceae] extract and extract from perna canaliculus was evaluated in OA and upper abdominal pain, and unstable movements were obsrerved as major side effects. Adverse events, including pneumonia, vomiting, diarrhoea and upper respiratory tract infection, were reported when RA was treated with Tripterygium wilfordii, Hook. F [Celastraceae][TwHF] polyglycosides and quercetin (Capsella bursa-pastoris (L.) Medik [Brassicaceae]). The present review aimed to summarize the CSE results of natural drugs in CSDs and could provide evidence-based information for clinicians.

Abstract Background Salinity is one of the damaging abiotic stress factor. Proper management techniques have been proposed to considerably lower the intensity of salinity on crop growth and productivity. Therefore experiments were conducted to assess the role of improved nitrogen (N) supplementation on the growth and salinity stress tolerance in wheat by analyzing the antioxidants, osmolytes and secondary metabolites. Results Salinity (100 mM NaCl) stress imparted deleterious effects on the chlorophyll and carotenoid synthesis as well as the photosynthetic efficiency. N supplementation resulted in increased photosynthetic rate, stomatal conductance and internal CO2 concentration with effects being much obvious in seedlings treated with higher N dose. Under non-saline conditions at both N levels, protease and lipoxygenase activity reduced significantly reflecting in reduced oxidative damage. Such effects were accompanied by reduced generation of toxic radicals like hydrogen peroxide and superoxide, and lipid peroxidation in N supplemented seedlings. Antioxidant defence system was up-regulated under saline and non-saline growth conditions due to N supplementation leading to protection of major cellular processes like photosynthesis, membrane structure and function, and mineral assimilation. Increased osmolyte and secondary metabolite accumulation, and redox components in N supplemented plants regulated the ROS metabolism and NaCl tolerance by further strengthening the antioxidant mechanisms. Conclusions Findings of present study suggest that N availability regulated the salinity tolerance by reducing Na uptake and strengthening the key tolerance mechanisms.

C14H13ClN2O4, monoclinic, P21/n (no. 14), a = 9.7353(13) Å, b = 13.7790(18) Å, c = 10.5227(13) Å, β = 97.961(2)°, V = 1397.9(3) Å3, Z = 4, Rgt(F) = 0.0367, wRref(F2) = 0.1181, T = 296(2) K.

C26H18N2O9Sm, monoclinic P21/n (no. 14), a = 8.9665(3) Å, b = 9.3617(3) Å, c = 28.3925(9) Å, β = 95.134(3)°, V = 2373.76(12) Å3, Z = 4, Rgt(F) = 0.0317, wRref(F2) = 0.0637, T = 293(2) K.

The effects of chloride concentration and dissolved oxygen on the high-temperature electrochemical corrosion behaviors of 304 stainless steel sheets were investigated in simulated pressurized water reactor (PWR) primary water. The results of potentiodynamic polarization measurements reveal that the chloride ion mainly affects the second passivation region under high potential, but little effect under low potential. Oxide film chemical content analysis by X-ray photoelectron spectroscopy (XPS) shows that the second passivation properties are closely related to the Fe/Cr ratio of the oxide film. Electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM) results show that, when the chloride ion concentration increases, the oxide film resistance decreases, the size of oxide particles and the gap between oxide particles on the outer layer increases and the corrosion resistance decreases. Besides, with the increase of dissolved oxygen, the corrosion potential increases, the passive current density decreases, the passive potential region shrinks, and the oxide film resistance gradually increases.

C24H28O6N10Ni, monoclinic, P21/c (no. 14), a = 7.3274(4) Å, b = 15.6403(5) Å, c = 11.8035(6) Å, β = 106.966(5)°, V = 1293.85(10) Å3, Z = 2, Rgt(F) = 0.0397, wRref(F2) = 0.1002, T = 293(2) K.

C44H32N4O4Cl4Zn, triclinic, P1̅ (no. 2), a = 7.3158(2) Å, b = 13.6944(5) Å, c = 20.4081(6) Å, α = 82.930(3)°, β = 89.667(2)°, γ = 88.034(3)°, V = 2027.85(11) Å3, Z = 2, Rgt(F) = 0.0430, wRref(F2) = 0.1141, T = 293(2) K.

C52H40N2O9Pb, triclinic, P1̅ (no. 2), a = 10.3025(4) Å, b = 14.1740(9) Å, c = 16.0428(9) Å, α = 115.835(6)°, β = 97.680(4)°, γ = 90.493(4)°, V = 2083.7(2) Å3, Z = 2, Rgt(F) = 0.0342, wRref(F2) = 0.0612, T = 293(2) K.

The application of artificial intelligence in environmental design has entered a stage of rapid development, artificial intelligence in environmental design tools, methods, expression, as well as the expansion of design content, the richness of design language and other aspects have produced a wide range of changes. From the perspective of artificial intelligence in environmental design, this paper discusses the future trend and possible revolutionary changes of artificial intelligence in environmental design. This paper combs the application of artificial intelligence in environmental design, analyzes the design works with wide influence, and discusses the value and significance of artificial intelligence in applied environmental design, as well as its possible future development trend. The application of artificial intelligence in environmental design is a great change from design means to design content. From the interactive ability, virtual ability, to the integration of big data, all are new opportunities and challenges brought by the ability of artificial intelligence to environmental design. In response to such changes, environmental art design practitioners should establish a more systematic, three-dimensional and data-based design activity system and a broader design theory system.

The current blasting compaction faces technical difficulties brought by mud depth increment. The strength similarity theory provides theoretic support for deep mud blasting compaction, offering a large room for blasting parameters optimization. The author applied the strength similarity theory to engineering practice and introduced the deep mud soft foundation blasting compaction, blasting parameters selection, blasting safety and processing effect. According to detection results, the riprap settlement elevation and width can meet design requirements. The riprap bottom interface and bearing layer are well connected. Obvious mud layer is not found in the embankment core. It shows that the application of strength similarity theory achieves the satisfactory effect in the engineering practice.

Research progress of microwave curing on epoxy resin and its composites was summarized on the basis of introducing the principle of microwave curing technology and its advantages. The paper focused on the effect of microwave curing on the curing rate of epoxy resin and its composites as well as the mechanical and thermal properties of cured products. Two suitable composite systems for wave curing of powder-strengthened epoxy and fiber-strengthened epoxy and a few key technological problems for industrial application are introduced. The application prospect of microwave curing on epoxy resin and its composites was also presented.

At present, thermal simulation experiments on accumulating rules of shale gas mainly follow the conventional method, which uses powder samples as the simulation object and does not define the shale gas as retention gas. Moreover, the powder samples after simulation cannot be observed by Scanning Electron Microscopy (SEM), and thus the evolution rules of pore structure cannot be determined. A new thermal simulation experiment method for shale gas, which uses a quartz glass tube to package the sample, and the linear regression method to analysis the data has been established. The changes of gas content and microscopic pore characteristics in shale during different phases of evolution (Ro range of 0.596%-2.143%) were studied. Results show that the contents of vent gas and desorbed gas in mudstone and oil shale increase obviously in high-mature stage with temperature higher than 400℃. Combined with SEM analysis, it can be inferred that this trend may be caused by the increasing of inorganic pores and gas generated from organic matter. This method can provide change information of shale gas contents and pore characteristics during the thermal transformation, which is more suitable for the study on the shale gas exploration and development.

Background: L-proline is a natural, nontoxic cryoprotectant that helps cells and tissues to tolerate freezing in a variety of plants and animals. The use of L-proline in mammalian oocyte cryopreservation is rare. In this study, we explored the cryobiological characteristics of L-proline and evaluated its protective effect in mouse oocyte cryopreservation. Methods: The freezing property of L-proline was detected by Raman spectroscopy and osmometer. Mature oocytes obtained from 8-week-old B6D2F1 mice were vitrified in a solution consisting various concentration of L-proline with a reduced proportion of dimethyl sulfoxide (DMSO) and ethylene glycol (EG), comparing with the control group (15% DMSO and 15% EG without L-proline). The survival rate, 5-methylcytosine (5-mC) expression, fertilization rate, two-cell rate, and blastocyst rate in vitro were assessed by immunofluorescence and in vitro fertilization. Data were analyzed by Chi-square test. Results: L-proline can penetrate the oocyte membrane within 1 min. The osmotic pressure of 2.00 mol/L L-proline mixture is similar to that of the control group. The survival rate of the postthawed oocyte in 2.00 mol/L L-proline combining 7.5% DMSO and 10% EG is significantly higher than that of the control group. There is no difference of 5-mC expression between the L-proline combination groups and control. The fertilization rate, two-cell rate, and blastocyst rate in vitro from oocyte vitrified in 2.00 mol/L L-proline combining 7.5% DMSO and 10% EG solution are similar to that of control. Conclusions: It indicated that an appropriate concentration of L-proline can improve the cryopreservation efficiency of mouse oocytes with low concentrations of DMSO and EG, which may be applicable to human oocyte vitrification.

A new testing method based on direct current potential drop(DCPD) and pin loading tension(PLT) method was introduced for evaluating the fatigue crack growth rate of steam generator tubes. In analogy to compact tension(CT) specimens,a testing model was established by using thin-walled tube specimens,and the corresponding mechanical and electrical finite element analyses were made respectively,which determined the data acquisition plan based on DCPD method. Fatigue test was taken on nickel-based alloy 690 used for nuclear power steam generators,and the effects of applied load and temperature were discussed. The result was modeled with the Paris-Erdogan equation and accorded well with this model. Scanning electron microscopy(SEM) examination of the fatigue fracture surfaces revealed transgranular attack,and the transgranular regions of the fatigue fracture surfaces were covered with striation-like features.

Dinosaur egg fossils are important for exploring the survival and extinction of the dinosaurs. Current researches on dinosaur egg fossils are concentrated in their biology and burial features. In this study, Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) was used to determine trace element composition of twelve dinosaur eggshell fossils in the late Cretaceous from Xixia basin and their surrounding rocks, in order to the relationship between trace elements and the extinction of dinosaurs. Results show that the dinosaur eggshell fossils are depleted in organic elements such as C, N, P and S, and mainly consist of essential elements such as Ca, Al, Mg, Fe and K and other trace elements such as Sr, Mn, Ba, La, Zn, B, V, Co and Ir. Abnormal high Ir and Sr may be related to the extraterrestrial impact event causing the dramatic changes of the ecological environment. Element assemblages indicated that the climate during the late Cretaceous in this area might have been semiarid to arid. Abnormal high Ir and Sr in the environment probably have caused structure and pathological changes of those eggs within the dinosaurs. Thereby the dinosaur eggs could not be hatched, which probably resulted in the gradual demise of dinosaurs. This study provides an important basis for investigating the living environment of dinosaurs, causes of extinction and the late Cretaceous climate.

The stress corrosion cracking growth behavior of 316L stainless steel, which is used as nuclear auxiliary pipelines, was continuously monitored by a direct current potential drop method under a constant stress intensity factor K of 33 MPa·m1/2. By comparing the cracking behavior of this material at 200, 250, 280 and 325℃ in 2 mg·L-1 oxygenated water and deoxygenated water, we found that the crack growth rate is faster in the oxygenated water than in the deoxygenated water. Experimental results also show that there is a peak of the crack growth rate of this material in the deoxygenated water at 250℃, while the crack growth rate increases with the rise of temperature in the oxygenated water.

C100H60N12O16Cd4, monoclinic, I2/a (no. 15), a = 21.2654(5) Å, b = 11.1493(3) Å, c = 17.3039(4) Å, β = 97.774(2)°, V = 4064.96(18) Å3, Z = 2, Rgt(F) = 0.0213, wRref(F2) = 0.0559, T = 289.23(10) K.