Study on the Fracture Extension Pattern of Shale Reservoir Fracturing under the Influence of Mineral Content.

This study aimed to investigate the effect of the microstructure of shale on fracture initiation and extension during hydraulic fracturing. The Longmaxi Formation shale reservoir in the Sichuan Basin was considered as the research object; its structure was modeled from a microscopic perspective, and a zero-thickness cohesive unit was embedded within the solid unit. Numerical simulations were performed to study the effect of mineral content on the microextension of the hydraulic fracture, extension behavior, and evolution law of shale. The results showed that changes in the mineral content resulted in changes in the forces between molecules within the minerals, which, in turn, affected the shale's brittleness. The percentages of brittle mineral content in the Long I, II, and III reservoir sections are 60.37, 47.60, and 53.56%, respectively. The fracture initiation pressures of the three reservoirs were 29.22, 31.42, and 30.22 MPa, respectively, and a linear correlation was found between the fracture initiation pressures and the brittle mineral contents of the reservoir sections. An increase in the reservoirs' percentage of brittle mineral content facilitated the fracture initiation, with a corresponding gradual decrease in the resistance to fracture initiation. The pore pressures of the fractures in the three reservoirs after fracture initiation were 0.90, 1.18, and 1.00 MPa, respectively. The larger the percentage of brittle minerals was, the lower was the fracture pore pressure. The greater the length, number, area, and width of the cracks were, the more likely they were to form longer and wider cracks. Hence, reservoirs with a high percentage of brittle minerals should be prioritized as the target formations for hydraulic fracturing operations. The results of this study reveal how the mineral content affects the extension of microscopic hydraulic fractures in shale reservoirs. As such, this work can provide a theoretical basis for rationally selecting a hydraulic fracturing operation layer in shale gas reservoirs.

Evaluating the therapeutic effects of NiaoDuQing particles on chronic kidney disease based on real world study.

BACKGROUND: NiaoDuQing Particle is the first Chinese herbal medicine approved by the China Food and Drug Administration for the treatment of chronic kidney disease. It has been used in clinical practice in China for over twenty years. However, there is limited literature reporting on the long-term therapeutic effects of NiaoDuQing Particles on chronic kidney disease patients. OBJECTIVE: This research aimed to comprehensively assess the therapeutic effect of NiaoDuQing Particles (NDQP) on chronic kidney disease patients based on clinical data analysis. METHODS: This study was carried out on a total of 148 participants diagnosed with different types of chronic kidney disease. Demographics information, chronic kidney disease classification and chronic kidney disease diganostic indicators were collected and analyzed before and after NiaoDuQing Particles treatment for 3, 6, 9, 12 and 18 months respectively. RESULTS: In all 148 patients, mean eGFR value was increased after NiaoDuQing Particles treatment for up to 18 months, and was statistically significant at month 3, 6, 9, 12 and 18 (P< 0.05). Mean uric acid value was decreased after NiaoDuQing Particles treatment for up to 18 months, and was statistically significant at month 3, 6, 9, 12 and 18 (P< 0.05). Mean urea nitrogen value was decreased after NiaoDuQing Particles treatment for up to 18 months and was statistically significant at month 3, 6, 9, 12 and 18 (P< 0.05). While mean creatinine value was decreased after NiaoDuQing Particles treatment for up to 18 months and was statistically significant at month 6 (P< 0.05). CONCLUSIONS: NiaoDuQing Particles could maintain the stable state of chronic kidney disease patients for up to 18 months especially in improving diagnostic indicators like eGFR, uric acid and urea nitrogen.

Pro-Inflammatory Diet as a Risk Factor for Stomach Cancer: Findings from a Multicenter Study in Central and Western China.

Purpose: We conducted a multicenter cross-sectional study in central and western China to explore the association between inflammatory diet and stomach cancer odds. Patients and Methods: Participants from five hospitals in the central and western regions were collected. All participants completed the questionnaire we provided before the gastroscopy examination, which includes inquiries about risk factors for stomach cancer and food frequency. All participants underwent gastroscopy, and a mucosal biopsy was confirmed pathologically. Pathological findings were classified as chronic gastritis group, precancerous lesions group and stomach cancer group. Dietary Inflammatory Index (DII) scores were calculated based on the frequency of food occurrences in the questionnaire, and finally SPSS was used to calculate the correlation between variables. Results: A total of 1162 patients were included in this study, including 668 cases of chronic gastritis, 411 cases of precancerous lesions, and 83 cases of cancer. A single factor analysis was conducted to examine the risk factors of stomach cancer, revealing a significant association between a pro-inflammatory diet and the stomach cancer odds (p value < 0.05). The results of binary classification analysis further confirmed that a pro-inflammatory diet is a risk factor for stomach cancer 【odds ratio (OR) =7.400)】. Moreover, correlation analysis demonstrated a positive correlation between the severity of gastric mucosal diseases and an inflammatory diet (including anti-inflammatory and pro-inflammatory diets) (rs=0.274, p-value < 0.001). Conclusion: Pro-Inflammatory diet is a risk factor for stomach cancer, and may accelerate the progression of stomach mucosal disease.

Characteristics of herbaceous plant community composition, niche and stability under different main-tenance measures at Sanxingdui City Wall, Sichuan, China.

To understand the distribution characteristics and restoration status of vegetation at Sanxingdui City Wall, we sampled five typical communities of the city wall at the Sanxingdui site and explored the stability and niche characteristics of herbaceous plant communities under different maintenance measures (natural regeneration, planting, abandoned field, shrub removal, and pruning) following the niche theory and the improved contribution law method. A total of 87 herbaceous species belonging to 73 genera and 31 families were recorded. Compositae and Gramineae were dominant, and perennial herbs were the majority. There were differences in the niche breadth of major herbaceous species under different maintenance measures. The niche breadth of annual plants was higher under natural regeneration and shrub removal, and that of perennial plants was higher under planting, abandoned field, and pruning measures. The niche overlap and similarity of herbaceous plants were higher under natural regene-ration, shrub removal and pruning measures, and were the lowest under planting measure. The importance values were positively correlated with the niche breadth, but the ranking was not completely consistent. Species with higher niche breadth usually had higher probability of niche overlap and higher niche similarity. Combined with the M-Godron's stability analysis, community stability was comparable among shrub removal, pruning, and natural regeneration measures whereas the abandoned field and planting showed lower community stability. We recommended the implementation of in situ conservation measures based on natural regeneration, supplemented by scientific artificial maintenance (shrub removal, pruning, etc.) when necessary, so as to achieve a stable species composition and promote the sustainable development and vegetation landscape restoration at Sanxingdui City Wall.

Identification of key immune-related genes in dilated cardiomyopathy using bioinformatics analysis.

Dilated cardiomyopathy (DCM) is characterized by the left ventricular dilatation and impaired myocardial systolic dysfunction with high mortality and morbidity. However, the underlying mechanisms remain elusive. We first identified the differentially expressed genes (DEGs) between the DCM and control group using two expression profiles from GSE3585 and GSE84796. Enrichment analysis was conducted to explore the potential mechanisms underlying DCM. A total of four algorithms, including key module of MCODE, degree, maximum neighborhood component (MNC), and maximal clique centrality (MCC), were used to identify the hub genes within Cytoscape. The correlation between hub genes and infiltrated immune cells was evaluated to determine potential immune-related genes. The expression analysis and diagnosis value analysis of potential immune-related genes were performed. Finally, the expression analysis with GSE57338 and relationship analysis with the comparative toxicogenomics database (CTD) were performed to identify the key immune-related genes in DCM. A total of 80 DEGs were screened for DCM. Enrichment analysis revealed that DEGs were involved in the immune-related pathological process. Immune infiltration analysis indicated a potentially abnormal immune response in DCM. Four up-regulated genes (COL1A2, COL3A1, CD53, and POSTN) were identified as potential immune-related genes. Finally, three genes (COL1A2, COL3A1, and POSTN) were determined as the key immune-related genes in DCM via expression analysis with a validation set (GSE57338) and relationship analysis with CTD. Our study suggested that the upregulated COL1A2, COL3A1, and POSTN might be the key immune-related genes for DCM. Further studies are needed to validate the underlying mechanisms.

Research on Gas Extraction and Cut Flow Technology for Lower Slice Pressure Relief Gas under Slice Mining of Extra-thick Coal Seam.

For extra-thick coal seams, slice mining is a safer mining method than top coal mining, which can effectively reduce the strong mine pressure behavior caused by mining. However, in the slice mining of high-gas and extra-thick coal seams, the gas in the lower slice flows into the goaf, which increases the gas control difficulty on the upper slice working face. It is easy to cause the gas transfinite at the upper corner in the upper slice and reduce the mining efficiency. Therefore, it is of a great significance to carry out the research on gas control technology in slice mining of the extra-thick coal seam. There are some problems in the gas control of slice mining, such as a single gas control method, low control efficiency, and unclear gas migration law. Therefore, it is necessary to study the gas migration law and propose a targeted prevention and control the technical scheme. In order to improve the gas control efficiency of the extra-thick coal seam, the evolution law of permeability of the lower slice is obtained under mining through experimental research. The liquid-solid coupling seepage-flow model for gas migration is established in the lower slice. Comsol Multiphysics software is used to study the migration law of pressure relief gas in the lower slice. Based on the gas migration law, the gas extraction and cut flow technology for the lower slice long borehole is proposed. Through this technology, the amount of gas flowing into the upper slice goaf and the gas content of the lower slice are reduced, and the drilling horizon is optimized. The research results show that the determination of the optimal drilling horizon of the lower slice needs to balance the amount of gas flowing into the goaf and the total amount of gas extraction. The range of 3-7 m horizon in the lower slice is appropriate to the boreholes arranged. When the borehole is located in the lower slice -3 m horizon, the 360 day gas emission quantity of goaf can be reduced to 51.2% of the nondrilled emission quantity, and the total extraction amount is 1143 m3. When the borehole is located in the lower slice -7 m horizon, the 360 day gas emission quantity of goaf can be reduced to 95.31% of the nondrilled emission quantity, and the total extraction amount is 1461 m3. Considering the gas emission capacity of the upper slice and ensuring that the total extraction volume of the lower slice is maximized and the boreholes in the lower slice are not damaged, the boreholes are located in the -6 m horizon of the lower slice.

Experimental Study on Hydraulic Fracturing of Bedding Shale Considering Anisotropy Effects.

The bedding plane formed by sedimentation makes shale anisotropic. To clarify the influence of bedding on the hydraulic fracturing of shale, the fracture characteristics of bedding shale were first clarified by conducting a hydraulic fracturing experiment on large-scale shale samples with different bedding angles. Subsequently, combined with the experimental results, based on the theory of elasticity, a new fracture initiation criterion for shale hydraulic fracturing considering its anisotropic characteristics was established. The influence of the bedding angle on the hydraulic fracture initiation pressure and initiation angle was analyzed. The results showed that the pump pressure curve during hydraulic fracturing can be divided into four stages: continuous pressurization, internal pressure drop, internal pressure attenuation, and internal pressure equilibrium stage. Corresponding to the four stages of the pump pressure curve, the evolution of hydraulic fracture has four processes: microfracture development, fracture initiation, fracture propagation, and fracture network equilibrium process. When the direction of the maximum principal stress is perpendicular to the bedding, a complex fracture network is easily formed. Depending on whether the bedding plane is open or not, the modes of interaction between the hydraulic fractures and bedding plane could be divided into eight types. Hydraulic fractures initiate in two ways: from the matrix and from natural fractures. During fracturing, with the increase in the bedding angle, the initiation pressure decreases gradually and the initiation angle decreases first and then increases. The knowledge gained in this study can provide data and theoretical support for drilling direction design and fracture pressure evaluation in the field of hydraulic fracturing.

Functional characterization and comparison of lycopene epsilon-cyclase genes in Nicotiana tabacum.

BACKGROUND: Lycopene epsilon-cyclase (ε-LCY) is a key enzyme in the carotenoid biosynthetic pathway (CBP) of higher plants. In previous work, we cloned two Ntε-LCY genes from allotetraploid tobacco (Nicotiana tabacum), Ntε-LCY2 and Ntε-LCY1, and demonstrated the overall effect of Ntε-LCY genes on carotenoid biosynthesis and stress resistance. However, their genetic and functional characteristics require further research in polyploid plants. RESULTS: Here, we used CRISPR/Cas9 to obtain Ntε-LCY2 and Ntε-LCY1 mutants in allotetraploid N.tabacum K326. Ntε-LCY2 and Ntε-LCY1 had similar promoter cis-acting elements, including light-responsive elements. The Ntε-LCY genes were expressed in roots, stems, leaves, flowers, and young fruit, and their highest expression levels were found in leaves. Ntε-LCY2 and Ntε-LCY1 genes responded differently to normal light and high light stress. Both the Ntε-LCY2 and the Ntε-LCY1 mutants had a more rapid leaf growth rate, especially ntε-lcy2-1. The expression levels of CBP genes were increased in the ntε-lcy mutants, and their total carotenoid content was higher. Under both normal light and high light stress, the ntε-lcy mutants had higher photosynthetic capacities and heat dissipation levels than the wild type, and this was especially true of ntε-lcy2-1. The reactive oxygen species content was lower in leaves of the ntε-lcy mutants. CONCLUSION: In summary, the expression patterns and biological functions of the Ntε-LCY genes Ntε-LCY1 and Ntε-LCY2 differed in several respects. The mutation of Ntε-LCY2 was associated with a greater increase in the content of chlorophyll and various carotenoid components, and it enhanced the stress resistance of tobacco plants under high light.

Experimental Study on the Effects of Pore Pressure and Slippage on the Permeability of a Fracture Network during Depressurization of Shale Gas Reservoir Production.

Hydraulic fracturing technology is an important technical means to increase shale gas production. The seepage channels formed in the hydraulic fractures during hydraulic fracturing can help increase reservoir permeability. Therefore, it is of significance to study the seepage law of the fracture network after reservoir hydraulic fracturing. In this study, hydraulic fracturing is used to fracture full-diameter shale cores, and three typical forms of hydraulic fracture networks are obtained. The characteristics of the fracture networks are analyzed by X-ray CT scanning. The effects of pore pressure and slippage on the permeability of the fracture networks are simulated by conducting experiments. The experimental results show that in the direction of gas seepage, hydraulic fractures completely penetrate the sample, and the greater the diameter and volume of the fracture, the better the hydraulic fracture conductivity. When the confining pressure remains unchanged at 50 MPa, the apparent permeability values of the hydraulic fractures with the worst and best fracture morphologies increase by 44.4 times and 2.8 times, respectively, with the decrease in the pore pressure from 30 to 2 MPa. The apparent permeability of the shale samples has a power function relationship with the pore pressure. The test results also show that the absolute permeability is positively correlated with the number of effective seepage channels in the hydraulic fractures and the number of hydraulic fractures, whereas the Klinkenberg coefficient is negatively correlated. Our research results can provide a basis for shale gas production model research and for on-site production capacity improvement. The qualitative understanding and scientific explanation of the effects of pore pressure and slippage on fracture network permeability in the process of depressurization of reservoir production have been realized.

Analysis of the Space-Time Synergy of Coal and Gas Co-mining.

The co-mining of coal and gas is the inevitable future direction of the mining of coal resources. Taking coal mining and gas extraction as the two subsystems of the coal and gas co-mining system, to reveal the mechanism of action between coal mining and gas extraction is the premise of orderly co-mining. On the basis of a similar simulation experiment of coal and gas co-mining, by obtaining the gas migration law during the mining process and collecting a large amount of data on the coal production and gas extraction, it is found that the two subsystems of coal extraction and gas extraction in the coal and gas co-mining system promote and restrict each other. The control parameters for coal mining and gas extraction that affect co-mining are identified. To coordinate the process connection between coal mining and gas extraction, the optimal synergistic relationship of co-mining should be found. The recovery rate and economic benefit of coal and gas resources are taken as the optimization objective function of coal and gas co-mining. Taking the safety production laws, regulations, and production technology-level restrictions of coal mining and gas drainage as constraints, by constituting a nonlinear model for the collaborative optimization of coal and gas co-mining, the method of determining the optimal advancing speed and optimal gas drainage volume of the working face is proposed. By optimizing variables, such as coal mining advancement, coal mining time, gas extraction time, and gas extraction volume, the co-mining of coal and gas is ensured to be safe and efficient, and the output of coal and gas resources is optimized. The time connection and the process succession of the two subsystems are attained. An overall orderly structure is formed between the coal mining system and the gas extraction system, and the mechanism of the cooperative co-mining of coal and gas is revealed. This research has important significance with regard to improving the basic theoretical system of coal and gas co-mining. The control variables of the co-mining working face in the Shaqu mine are optimized. After optimization, the profit is increased by 16.3%, and the gas extraction rate is increased by 2.6%. The drilling spacing is optimized according to the optimization results. The simulation shows that 7 m is the optimal drilling spacing of the working face.

The long-term efficacy and safety of combining ablation and left atrial appendage closure: A systematic review and meta-analysis.

BACKGROUND: Combined ablation and left atrial appendage closure (LAAC) is an alternative for atrial fibrillation patients with a high risk of stroke. However, the long-term outcomes of this combined procedure remain elusive. METHODS: PubMed, Embase, Cochrane Library, and Web of Science were systematically searched from the establishment of databases to 1 January 2021. Studies on the long-term (defined as a mean follow-up of approximately 12 months or longer) efficacy and safety outcomes of combined ablation and LAAC were included. RESULTS: A total of 16 studies comprising 1428 patients were enrolled. The pooled long-term freedom rate from atrial arrhythmia was 0.66 (95% confidence interval [CI]: 0.59-0.71), long-term successful rate sealing of LAAC was 1.00 (95% CI: 1.00-1.00), and ischemic stroke/transient ischemic attack/systemic embolism during follow-up was 0.01 (95% CI: 0.00-0.02). Meanwhile, of the periprocedural adverse events, phrenic nerve palsy, intracoronary air embolus, device embolization, and periprocedural death had a rate of 0.00 (95% CI: 0.00-0.00), procedure-related bleeding events of 0.03 (95% CI: 0.02-0.04), and pericardial effusion requiring or not requiring intervention of 0.00 (95% CI: 0.00-0.01). Moreover, for the long-term adverse events, device dislocation, intracranial bleeding, pericardial effusion requiring or not requiring intervention, and all-cause mortality had a rate of 0.00 (95% CI: 0.00-0.00), device embolization of 0.01 (95% CI: 0.00-0.01), and other bleeding events of 0.01 (95% CI: 0.00-0.03). CONCLUSION: This meta-analysis suggests that the combined atrial ablation and LAAC is an effective and safe strategy with long-term benefits.

Genome-wide identification of the BASS gene family in four Gossypium species and functional characterization of GhBASSs against salt stress.

Bile acid sodium symporter (BASS) family proteins encode a class of sodium/solute symporters. Even though the sodium transporting property of BASSs in mammals was well studied, their sodium transportability and functional roles in plant salt tolerance remained largely unknown. Here, BASS family members from 4 cotton species, as well as 30 other species were identified. Then, they were designated as members of BASS1 to BASS5 subfamilies according to their sequence similarity and phylogenetic relationships. There were 8, 11, 16 and 18 putative BASS genes in four cotton species. While whole-genome duplications (WGD) and segmental duplications rendered the expansion of the BASS gene family in cotton, BASS gene losses occurred in the tetraploid cotton during the evolution from diploids to allotetraploids. Concerning functional characterizations, the transcript profiling of GhBASSs revealed that they not only preferred tissue-specific expression but also were differently induced by various stressors and phytohormones. Gene silencing and overexpression experiments showed that GhBASS1 and GhBASS3 positively regulated, whereas GhBASS2, GhBASS4 and GhBASS5 negatively regulated plant salt tolerance. Taken together, BASS family genes have evolved before the divergence from the common ancestor of prokaryotes and eukaryotes, and GhBASSs are plastidial sodium-dependent metabolite co-transporters that can influence plant salt tolerance.

Experimental Study on the Thermal Effect during Gas Adsorption and Desorption on the Coal Surface.

The thermal effect of coal adsorption/desorption gas is very important for understanding the evolution of coal temperature and interaction between coal and gas during coal and gas outburst. The pressure difference between the high gas pressure area in front of the working face and the low gas pressure area near the coal wall may affect the adsorption/desorption thermal effect. In order to reveal the characteristics of the coal adsorption/desorption gas thermal effect at different pressure differences, a thermo-hydro-mechanical-coupled experimental system of coal and gas was designed. Taking no.3 coal from Xinjing Mine as the research object, the characteristics of the coal adsorption/desorption gas thermal effect under different pressure differences are studied by using the cycle-step experiment method. It is found that coal adsorbs gas to release heat, while coal desorbs gas to absorb heat. Also, the temperature variation and temperature accumulation caused by adsorption are greater than those caused by desorption. Under the same pressure difference, the temperature increase rate during the adsorption changes from large to small, and the temperature variation gradually decreases; the temperature decrease rate during the desorption changes from small to large, and the temperature variation gradually increases; desorption is the reverse process of adsorption. The relation between temperature variation and gas pressure is linear, and the increasing range of temperature variation gradually decreases with the increase of pressure difference. The relation between temperature accumulation and gas pressure conforms to an exponential function, and the decreasing range of temperature accumulation gradually decreases with the increase of pressure difference. The greater the pressure difference, the greater is the energy variation caused by the adsorption/desorption thermal effect. The experimental results of different pressure differences can reflect the characteristics of the coal adsorption/desorption gas thermal effect under different geological structures or outburst types.

Two Aquaporin Genes, GhPIP2;7 and GhTIP2;1, Positively Regulate the Tolerance of Upland Cotton to Salt and Osmotic Stresses.

Aquaporins (AQPs) facilitate the transport of water and small molecules across intrinsic membranes and play a critical role in abiotic stresses. In this study, 111, 54, and 56 candidate AQP genes were identified in Gossypium hirsutum (AD1), Gossypium arboreum (A2), and Gossypium raimondii (D5), respectively, and were further classified into five subfamilies, namely, plasma intrinsic protein (PIP), tonoplast intrinsic protein (TIP), nodulin 26-like intrinsic protein (NIP), small basic intrinsic protein (SIP), and uncategorized X intrinsic protein (XIP). Transcriptome analysis and quantitative real-time PCR (qRT-PCR) revealed some high-expression GhPIPs and GhTIPs (PIP and TIP genes in G. hirsutum, respectively) in drought and salt stresses. GhPIP2;7-silenced plants decreased in the chlorophyll content, superoxide dismutase (SOD) activity, and peroxidase (POD) activity comparing the mock control (empty-vector) under 400 mM NaCl treatment, which indicated a positive regulatory role of GhPIP2;7 in salt tolerance of cotton. The GhTIP2;1-silenced cotton plants were more sensitive to osmotic stress. GhTIP2;1-overexpressed plants exhibited less accumulation of H2O2 and malondialdehyde but higher proline content under osmotic stress. In summary, our study elucidates the positive regulatory roles of two GhAQPs (GhPIP2;7 and GhTIP2;1) in salt and osmotic stress responses, respectively, and provides a new gene resource for future research.

Bifidobacterium adolescentis and Lactobacillus rhamnosus alleviate non-alcoholic fatty liver disease induced by a high-fat, high-cholesterol diet through modulation of different gut microbiota-dependent pathways.

The incidence of non-alcoholic fatty liver disease (NAFLD) has increased year on year, and the increasing appreciation of the importance of gut microbiota provides novel therapeutic avenues for the treatment of NAFLD. To explore the similarities and differences between lactic acid bacteria (LAB) known to alleviate NAFLD, we selected three strains of Bifidobacterium adolescentis and three strains of Lactobacillus rhamnosus to administer to C57BL/6J mice on a high-fat, high-cholesterol diet (HFHCD) for 23 weeks. Subsequently, the effects of the LAB were evaluated through various measures. The six LAB strains were found to have varying degrees of efficacy in the prevention of NAFLD. We found that there were interspecific and intraspecific differences in the beneficial effects, mainly with respect to energy metabolism, lipid metabolism and short-chain fatty acid concentration. Three strains of B. adolescentis and one strain of L. rhamnosus were found to relieve NAFLD by increasing the concentration of short-chain fatty acids in the intestine of NAFLD mice. The other two strains of L. rhamnosus, LGG and L10-1, relieved NAFLD through different ways, LGG modulated energy metabolism and lipid metabolism, and L10-1 reduced liver inflammation. Examination of gut microbiota indicated that the six LAB strains could block the HFHCD-induced elevation of Firmicutes/Bacteroidetes and alter the dominant species within the gut. These results suggest that B. adolescentis and L. rhamnosus can inhibit the development of NAFLD by regulating gut microbiota, and their use is thus a promising therapeutic strategy.

Characterization of Ethyl Acetate and Trichloromethane Extracts from Phoebe zhennan Wood Residues and Application on the Preparation of UV Shielding Films.

In this work, ethyl acetate (EA) and trichloromethane (TR) extracts were extracted from Phoebe zhennan wood residues and the extracts were then applied to the preparation of UV shielding films (UV-SF). The results revealed that substances including olefins, phenols and alcohols were found in both EA and TR extracts, accounting for about 45% of all the detected substances. The two extracts had similar thermal stability and both had strong UV shielding ability. When the relative percentage of the extract is 1 wt% in solution, the extract solution almost blocked 100% of the UV-B (280-315 nm), and UV-A (315-400 nm). Two kinds of UV-SF were successfully prepared by adding the two extracts into polylactic acid (PLA) matrix. The UV-SF with the addition of 24 wt% of the extractive blocked 100% of the UV-B (280-315 nm) and more than 80% of the UV-A (315-400 nm). Moreover, the UV shielding performance of the UV-SF was still stable even after strong UV irradiation. Though the addition of extracts could somewhat decrease the thermal stability of the film, its effect on the end-use of the film was ignorable. EA extracts had less effect on the tensile properties of the films than TR extracts as the content of the extract reached 18%. The results of this study could provide fundamental information on the potential utilization of the extracts from Phoebe zhennan wood residues on the preparation of biobased UV shielding materials.

[Effects of slope position and aspect on structure and species diversity of shrub community in the Jiajin Mountains, Sichuan Province, China]. / å¡å‘å’Œå¡ä½å¯¹å››å·å¤¹é‡‘å±±çŒä¸›ç¾¤è½ç»“æž„ä¸Žç‰©ç§å¤šæ ·æ€§ç‰¹å¾çš„å½±å“.

We examined the impacts of slope direction and position on the community structure and species diversity of shrub community in Jiajin Mountains. The results showed that a total of 186 vascular plant species belonging to 50 families and 127 genera were recorded in the 24 sample plots. 32 species belonging to 14 families, 22 genera were recorded in the shrubs layer, with most species distributed at lower position of the shady slope. 154 species belonging to 43 families and 109 genera were recorded in the herbaceous layer, with the species number being the lowest on the shady slope. The average height of the shrub layer showed a decreasing order of sunny slope, semi-sunny slope, and shady slope, while an opposite order was observed for the average density. The average height of the herb layer was in the decreasing order of the shady slope, semi-sunny slope, sunny slope, whereas no significant changes were observed for the average density. The slope position had significant effect only on the average height of the herbaceous layer on the sunny slope. The overall level of species diversity in the shrub layer on the shady slope was relatively high, while that in the herbaceous layer was relatively high at the lower position of the sunny slope and at the middle position of the shady slope. Slope aspect had significant effect on species richness index, Shannon diversity index, Simpson dominance index, Pielou evenness index of shrub and herb layers except for Simpson index of herb layer. Slope position did not affect these indices. The interaction effect of slope aspect and position on the diversity index for herb layer was greater than that for the shrub layer. Results from redundancy analysis showed that species diversity was related to sin(aspect), cos(aspect), and community structure.

The Effect of rTMS over the Different Targets on Language Recovery in Stroke Patients with Global Aphasia: A Randomized Sham-Controlled Study.

OBJECTIVE: To evaluate and compare the effects of repetitive transcranial magnetic stimulation (rTMS) over the right pars triangularis of the posterior inferior frontal gyrus (pIFG) and the right posterior superior temporal gyrus (pSMG) in global aphasia following subacute stroke. METHODS: Fifty-four patients with subacute poststroke global aphasia were randomized to 15-day protocols of 20-minute inhibitory 1 Hz rTMS over either the right triangular part of the pIFG (the rTMS-b group) or the right pSTG (the rTMS-w group) or to sham stimulation, followed by 30 minutes of speech and language therapy. Language outcomes were assessed by aphasia quotient (AQ) scores obtained from the Chinese version of the Western Aphasia Battery (WAB) at baseline and immediately after 3 weeks (15 days) of experimental treatment. RESULTS: Forty-five patients completed the entire study. The primary outcome measures include the changes in WAB-AQ score, spontaneous speech, auditory comprehension, and repetition. These measures indicated significant main effect between the baseline of the rTMS-w, rTMS-b, and sham groups and immediately after stimulation (P<0.05). Compared with the sham group, the increases were significant for auditory comprehension, repetition, and AQ in the rTMS-w group (P<0.05), whereas the changes in repetition, spontaneous speech, and AQ tended to be higher in the rTMS-b group (P<0.05). CONCLUSIONS: Inhibitory rTMS targeting the right pIFG and pSTG can be an effective treatment for subacute stroke patients with global aphasia. The effect of rTMS may depend on the stimulation site. Low-frequency rTMS inhibited the right pSTG and significantly improved language recovery in terms of auditory comprehension and repetition, whereas LF-rTMS inhibited the right pIFG, leading to apparent changes in spontaneous speech and repetition.