AI tools are increasingly used in education,impacting teaching and learning across various disciplines.However,previous review articles and empirical studies have not systematically discussed the application of AI in ...AI tools are increasingly used in education,impacting teaching and learning across various disciplines.However,previous review articles and empirical studies have not systematically discussed the application of AI in higher education assessment,the impact on user acceptance during its application,and the future opportunities and challenges.This systematic review aims to understand the application of AI tools in assessment,factors that influence students'and educators'perceptions,and related challenges and opportunities.Analyzing 81 empirical studies through matrix coding and content analysis,the results show that AI tools are used in intelligent tutoring and personalized learning,giving automated assessment and feedback,virtual classroom and online collaboration,learning analytics and prediction,knowledge management and resource recommendation,and educational chat assistants.AI tools offer high-quality,real-time,personalized feedback,improving cognitive and metacognitive skills and fostering positive emotions.Despite the benefits,challenges such as security and privacy concerns,algorithmic bias,unreliable feedback,negative attitudes,insufficient abilities,academic integrity issues,and lack of proper guidance persist.To advance our understanding of AI as an assessment tool,we call for studies that explore ways to enhance teachers’and students’perceptions and refine guidelines to prevent academic dishonesty and ensure responsible AI use.展开更多
Background:Oral cancer is a common type of head and neck cancers.Knowing its epidemiologic characteristics is crucial to preventing,diagnosing,and treating this cancer.This study aimed to explore the epidemiologic cha...Background:Oral cancer is a common type of head and neck cancers.Knowing its epidemiologic characteristics is crucial to preventing,diagnosing,and treating this cancer.This study aimed to explore the epidemiologic characteristics of oral cancer in South China.Methods:We retrospectively analyzed data from 4097 oral cancer patients treated at the Sun Yat-sen University Cancer Center between 1960 and 2013.We compared the age of onset,sex ratio,pathologic type,and primary tumor location among three subcultural areas(Guangfu,Hakka,and Chaoshan) and between an economically developed region and a less-developed one in Guangdong.Results:Overall,oral cancer had a male-to-female ratio of approximately 2:1,and this ratio decreased over time.Oral cancer occurred mostly in patients of 45-64 years old(54.5%),and the percentage of older patients gradually increased over time.The most common tumor location was the tongue.Squamous cell carcinoma was the predominant pathologic type.The percentage of blood type O in oral cancer patients was lower than that in the healthy population.The male-to-female ratio in the Chaoshan area was higher than that in the Guangfu and Hakka areas,whereas the age of disease onset in Guangfu was higher than that in Hakka and Chaoshan.The male-to-female ratio was lower and the age of disease onset was higher in the economically developed region than in the less-developed region.Conclusion:The incidence of oral cancer in South China presents typical characteristics to which doctors should pay attention when diagnosing and treating oral cancer patients.展开更多
Pre-injection is a technique that involves injecting grout materials into the ground prior to excavation,with the aim of stabilizing the surrounding rock mass.This paper introduces an analytical closed-form model for ...Pre-injection is a technique that involves injecting grout materials into the ground prior to excavation,with the aim of stabilizing the surrounding rock mass.This paper introduces an analytical closed-form model for determining the ground reaction curve of tunnels in rock masses exhibiting elastic-brittleplastic behavior and adhering to the Mohr-Coulomb failure criterion.The model incorporates the reinforced region created by the pre-injection method.When the rock mass is reinforced through preinjection,plastic regions can form independently in both the natural and injected rock masses.This leads to six distinct modes of the problem.The analytical model presented in this paper considers three possible scenarios for the development of plastic regions.Each scenario comprises four stages,with each stage representing a different mode of the problem.While injecting the rock mass can enhance its strength and stiffness,it may also increase the brittleness of the injected rock mass and create stress concentrations within it,particularly when brittle grouts are used.As a result,this can elevate the risk of rockburst due to unstable failure.The results obtained from the model demonstrate that ductile grout performs exceptionally well in controlling tunnel convergence in rock masses,as it accommodates deformation without sudden failure,even in squeezing rock mass conditions.Conversely,the use of brittle grouts should be approached with caution,particularly in squeezing rock masses,due to their susceptibility to rockburst incidents.展开更多
Virtual maintenance,as an important means of industrial training and education,places strict requirements on the accuracy of participant pose perception and assessment of motion standardization.However,existing resear...Virtual maintenance,as an important means of industrial training and education,places strict requirements on the accuracy of participant pose perception and assessment of motion standardization.However,existing research mainly focuses on human pose estimation in general scenarios,lacking specialized solutions for maintenance scenarios.This paper proposes a virtual maintenance human pose estimation method based on multi-scale feature enhancement(VMHPE),which integrates adaptive input feature enhancement,multi-scale feature correction for improved expression of fine movements and complex poses,and multi-scale feature fusion to enhance keypoint localization accuracy.Meanwhile,this study constructs the first virtual maintenance-specific human keypoint dataset(VMHKP),which records standard action sequences of professional maintenance personnel in five typical maintenance tasks and provides a reliable benchmark for evaluating operator motion standardization.The dataset is publicly available at.Using high-precision keypoint prediction results,an action assessment system utilizing topological structure similarity was established.Experiments show that our method achieves significant performance improvements:average precision(AP)reaches 94.4%,an increase of 2.3 percentage points over baseline methods;average recall(AR)reaches 95.6%,an increase of 1.3 percentage points.This research establishes a scientific four-level evaluation standard based on comparative motion analysis and provides a reliable solution for standardizing industrial maintenance training.展开更多
Electrocatalytic carbon dioxide reduction(CO_(2)ER)driven by renewable energy sources to produce high-valueadded chemicals is a highly promising strategy for achieving a closed carbon cycle.Cu is the only highly activ...Electrocatalytic carbon dioxide reduction(CO_(2)ER)driven by renewable energy sources to produce high-valueadded chemicals is a highly promising strategy for achieving a closed carbon cycle.Cu is the only highly active catalyst capable of producing multi-carbon(C_(2)t)products through CO_(2)ER.However,due to the constraints of existing scaling relationships and competing hydrogen evolution reaction,it is still challenging to achieve high selectivity of a single desired product.In this work,high-entropy alloy(HEA)CuMoRuFeW surface skin on Cu nanorods was obtained by a one-pot co-reduction method.It is revealed that Fe could effectively facilitate the coreduction of Mo and W precursors and the formation of HEA surface on Cu nanorod.The Faradaic efficiency(FE)for ethylene and ethanol in CO_(2)ER reaches 49.5%and 20.4%,respectively,with a total FEC_(2)of 69.9%and current density of 250 mA cm^(-2)at-1.1 V vs.RHE.Theoretical calculations reveal that the Cu–W–Fe combination site is more active in CO_(2)activation and C–C coupling for C_(2)products than other sites.This work underscores the importance of HEA in overcoming the constraints of linear scaling relationships and improving the selectivity for C_(2)products in CO_(2)ER.展开更多
The uneven deposition and high reactivity of lithium-metal anode(LMA)lead to uncontrollable dendrite growth,low Coulombic efficiency,and safety concerns,hindering their commercialization.Here,a representative polar-ri...The uneven deposition and high reactivity of lithium-metal anode(LMA)lead to uncontrollable dendrite growth,low Coulombic efficiency,and safety concerns,hindering their commercialization.Here,a representative polar-rich-group triazine-based covalent organic framework(COF-TzDha)with a desolvation effect is designed as an interlayer for stable,dendrite-free LMA.The abundant triazine rings in COFTzDha as a donor effectively attract lithium ions,while the one-dimensional nanopore structure facilitates lithium-ion migration.The periodic arrangement of polar groups(-OH)in the backbone interacts with electrolyte components(DOL,DME,TFSI-)to form a hydrogen bonding network that slows solvent molecules transport.Therefore,COF-TzDha effectively desolvates lithium ions from the solvent sheath,promoting uniform lithium ion flux and Li plating/stripping.Theoretical calculations verify that COFTzDha with abundant adsorption sites and strong adsorption energy facilitates lithium ion desolvation.Consequently,the introduction of COF-TzDha obtains a high ion mobility(0.75).The Li|COF@PP|Li symmetric cell cycles stably for over 1200 h at 4 mA cm^(-2)/4.0 mA h cm^(-2).The Li|COF@PP|LiFePO_(4)full cell also displays highly stable cycling performance with 600 cycles(75.5%capacity retention,~100% Coulombic efficiency)at 1 C.This work verifies an effective strategy for inducing uniform Li deposition and achieving dendrite-free,stable LMA using a polar-rich-group COF interlayer with a desolvation effect.展开更多
Wastewater-based epidemiology has emerged as a transformative surveillance tool for estimating substance consumption and monitoring disease prevalence,particularly during the COVID-19 pandemic.It enables the populatio...Wastewater-based epidemiology has emerged as a transformative surveillance tool for estimating substance consumption and monitoring disease prevalence,particularly during the COVID-19 pandemic.It enables the population-level monitoring of illicit drug use,pathogen prevalence,and environmental pollutant exposure.In this perspective,we summarize the key challenges specific to the Chinese context:(1)Sampling inconsistencies,necessitating standardized 24-hour composite protocols with high-frequency autosamplers(≤15 min/event)to improve the representativeness of samples.展开更多
Porcine deltacoronavirus(PDCoV) is a newly identified virus that causes watery diarrhea in newborn piglets and results in significant economic losses to the pig industry. Since first reported in Hong Kong in 2012, PDC...Porcine deltacoronavirus(PDCoV) is a newly identified virus that causes watery diarrhea in newborn piglets and results in significant economic losses to the pig industry. Since first reported in Hong Kong in 2012, PDCoV has been subsequently detected in USA, South Korea, Thailand, and China's Mainland. Here we isolated a strain of PDCoV, named CHN-GD-2016,from the intestinal content of a diseased newborn piglet with severe diarrhea in a pig farm in Guangdong, China. PDCoV CHN-GD-2016 could be identified by immunofluorescence with PDCoV specific rabbit antisera, and typical crown-shaped particles with spiky surface projections of this PDCoV were observed with electron microscopy. Genomic analysis showed that the PDCoV CHN-GD-2016 was closely related to other Chinese PDCoV strains, with the highest sequence similarity with the strain CHN/Tianjin/2016. Importantly, inoculation of newborn piglets with 1×10~5 TCID_(50) of CHN-GD-2016 by oral feeding successfully reproduced clear clinical symptoms, including vomiting, dehydration, and severe diarrhea in piglets. In addition, the virus RNA in rectal swabs from 1 to 7 days post inoculation was detected, macroscopic and microscopic lesions in small intestine were observed, and viral antigen was also detected in the small intestines with immunohistochemical staining. Collectively, the data show in this study confirms that PDCoV is present in Guangdong,China and is highly pathogenic in newborn piglets.展开更多
A new diarylheptanoid, 3,5-dimethoxy1-17-hydroxyl-4, 11, 19-triketo-[7,0]meta-cyclophane, named as rubanone 1, was isolated from the bark of Myrica rubra along with four known compounds 2-5. Their structures were eluc...A new diarylheptanoid, 3,5-dimethoxy1-17-hydroxyl-4, 11, 19-triketo-[7,0]meta-cyclophane, named as rubanone 1, was isolated from the bark of Myrica rubra along with four known compounds 2-5. Their structures were elucidated by various spectroscopic methods including 2D-NMR techniques or comparison with authentic samples.展开更多
The toxicity of nano-materials has received increasing attention in recent years. Nevertheless, relatively few studies have focused on their oceanic distributions and toxicities. In this study, we assessed nano-ZnO to...The toxicity of nano-materials has received increasing attention in recent years. Nevertheless, relatively few studies have focused on their oceanic distributions and toxicities. In this study, we assessed nano-ZnO toxicity in marine organisms using the yellowstriped goby （Mugilogobius chulae）. The relative differences in nano-ZnO dissolution and dispersal in seawater and fresh water were also investigated. The effects of nano-ZnO on embryonic development, deformity, hatching, mortality, and histopathology were analyzed. In addition, the effects of the Zn2＋ concentration on M. chulae hatching and mortality were compared. The results showed that nano-ZnO had higher solubility in seawater than in fresh water. Nano-ZnO significantly inhibited hatching. By the fifth day of exposure, the LC50 of nano-ZnO was 45.40 mg/L, and the mortality rate spiked. Hatching inhibition and lethality were dose-dependent over a range of 1-25 mg/L nano-ZnO. Zn2＋ inhibited hatching and increased lethality, but its effects were weaker than those of nano-ZnO at the same concentrations. Nano-ZnO also induced spinal bending, oedema, hypoplasia, and other deformities in M. chulae embryos and larvae. Histopathology revealed vacuolar degeneration, hepatocyte and enterocyte enlargement, and morphological abnormalities of the vertebrae. Therefore, nano-ZnO caused malformations in M. chulae by affecting embryonic growth and development. We conclude that nano-ZnO toxicity in seawater was significantly positively correlated with the associated Zn2＋ concentration and sedimentary behaviour. The toxicity of nano-ZnO was cumulative and showed a critical point, beyond which embryonic and developmental toxicity in marine fish was observed.展开更多
The alkaline hydrogen evolution reaction(HER) on Pt-based catalysts is largely limited by the slow water dissociation kinetics. Pt-based single atom alloy catalysts(SAAC) with water dissociation sites have been demons...The alkaline hydrogen evolution reaction(HER) on Pt-based catalysts is largely limited by the slow water dissociation kinetics. Pt-based single atom alloy catalysts(SAAC) with water dissociation sites have been demonstrated as excellent alkaline HER catalysts. However, the regulation of their activity and stability at the atomic scale is still a great challenge. Herein, the kinetic and stability issues are successfully resolved via engineering the electronic structure of Pt-Co SAAC by Au-induced tensile strain. The atomic dispersion of Co into the Pt shell was confirmed by extended X-ray absorption fine structure and the electronic structure and catalytic HER performance was modulated by the tensile strain induced by the Pt shell thickness. An inverse volcano-type relation between HER activity and surface strain was found.Density functional theory(DFT) calculations reveal that the Au-induced tensile strain on Pt-Co shell can not only boost the adsorption and dissociation kinetics of water at Co site by upshifting the dband and promoting the electron transfer, but also downshift the d-band center of Pt in Pt-Co shell, leading to optimized H* adsorption/desorption. The champion catalyst provides an overpotential of only 14 m V at the current density of 10 mA cm^(-2). This work not only provides an effective strategy for the construction of single-atom alloy electrocatalysts for high performance toward alkaline HER but also sheds light on the understanding of the reaction mechanism at the atomic level.展开更多
Severe polysulfide shuttling and sluggish sulfur redox kinetics significantly decrease sulfur utilization and cycling stability in lithium-sulfur batteries(LSBs).Herein,we develop a hollow CoO/CoP-Box core-shell heter...Severe polysulfide shuttling and sluggish sulfur redox kinetics significantly decrease sulfur utilization and cycling stability in lithium-sulfur batteries(LSBs).Herein,we develop a hollow CoO/CoP-Box core-shell heterostructure as a model and multifunctional catalyst modified on separators to induce interfacial charge modulation and expose more active sites for promoting the adsorption and catalytic conversion ability of sulfur species.Theoretical and experimental findings verify that the in-situ formed core-shell hetero-interface induces the formation of P-Co-O binding and charge redistribution to activate surface O active sites for binding lithium polysulfides(LiPSs)via strong Li-O bonding,thus strongly adsorbing with Li PSs.Meanwhile,the strong Li-O bonding weakens the competing Li-S bonding in LiPSs or Li2S adsorbed on CoO/CoP-Box surface,plus the hollow heterostructure provides abundant active sites and fast electron/Li+transfer,so reducing Li2S nucleation/dissolution activation energy.As expected,LSBs with CoO/CoP-Box modified separator and traditional sulfur/carbon black cathode display a large initial capacity of 1240 mA h g^(-1)and a long cycling stability with 300 cycles(~60.1%capacity retention)at 0.5C.Impressively,the thick sulfur cathode(sulfur loading:5.2 mg cm^(-2))displays a high initial areal capacity of 6.9 mA h cm^(-2).This work verifies a deep mechanism understanding and an effective strategy to induce interfacial charge modulation and enhance active sites for designing efficient dual-directional Li-S catalysts via engineering hollow core-shell hetero-structure.展开更多
As a typical laser additive manufacturing technology,laser powder bed fusion(LPBF)has achieved demonstration applications in aerospace,biomedical and other fields.However,how to select process parameters quickly and r...As a typical laser additive manufacturing technology,laser powder bed fusion(LPBF)has achieved demonstration applications in aerospace,biomedical and other fields.However,how to select process parameters quickly and reasonably is still themain concern of LPBF production.In order to quantitatively analyze the influence of different process parameters(laser power,scanning speed,hatch space and layer thickness)on the LPBF process,the multilayer and multi-path forming process of LPBF was predicted based on the open-source discrete element method framework Yade and the open-source finite volume method framework OpenFOAM.Based on the design of experiments method,a four-factor three-level orthogonal test scheme was designed,and the porosity and surface roughness data of each calculation scheme were extracted.By analyzing the orthogonal test data,it was found that as the laser power increased,the porosity decreased,and as the scanning speed,hatch space,and layer thickness increased,the porosity increased.In addition,the influence of laser power and scanning speed on surface roughness showed a trend of decreasing first and then increasing,while the influence of scanning distance and layer thickness on surface roughness showed amonotonous increasing trend.The order of the influence of each process parameter on porosity was:scanning speed>laying thickness>laser power>hatch space,and the order of the influence of each process parameter on surface roughness was:hatch space>layer thickness>laser power>scanning speed.So the porosity of the part is most sensitive to scanning speed,and the surface roughness is the most sensitive to hatch space.The above conclusions are expected to provide process control basis for actual LPBF production of the 316L stainless steel alloy.展开更多
Natural rubber grafted maleic anhydride （NR-g-MAH） was synthesized by mixing maleic anhydride （MAH） and natural rubber （NR） in solid state in a torque rheometer using dicurnyl peroxide （DCP） as initiator. Then...Natural rubber grafted maleic anhydride （NR-g-MAH） was synthesized by mixing maleic anhydride （MAH） and natural rubber （NR） in solid state in a torque rheometer using dicurnyl peroxide （DCP） as initiator. Then the self-prepared NR-g-MAH was used as a compatibilizer in the natural rubber/short nylon fiber composites. Both the fimctionalization of NR with MAH and the reaction between the modified rubber and the nylon fiber were confirmed by Fourier transform infrared spectroscopy （FTIR）. Composites with different nylon short fiber loadings （0, 5, 10, 15 and 20 phr） were compounded on a two-roll mill, and the effects of the NR-g-MAH on the tensile and thermal properties, fiber-rubber interaction, as well as the morphology of the natural rubber/short nylon fiber composites were investigated. At equal fiber loading, the NR-g-MAH compatibilized NR/short nylon fiber composites showed improved tensile properties, especially the tensile modulus at 100% strain which was about 1.5 times that of the corresponding un-compatibilized ones. The equilibrium swelling tests proved that the incorporation of NR-g-MAH increased the interaction between the nylon fibers and the NR matrix. The crosslink density measured with NMR techniques showed that the NR-g-MAH compatiblized composites had lower total crosslink density. The glass transition temperatures of the compatibilized composites were about 1 K higher than that of the corresponding un-compabilized ones. Morphology analysis of the NR/short nylon fiber composites confirmed NR-g-MAH improved interfacial bonding between the NR matrix and the nylon fibers. All these results signified that the NR-g-MAH could act as a good compatilizer of NR/short nylon fiber composites and had a potential for wide use considering its easy to be prepared and compounded with the composites.展开更多
A reversed phase high performance liquid chromatography （HPLC） method was established for the simultaneous determination of 12, 13-dihydroxyeuparin and glycyrrhizic acid in Yanyanfang mixture. A Grace Apollo Cl8 col...A reversed phase high performance liquid chromatography （HPLC） method was established for the simultaneous determination of 12, 13-dihydroxyeuparin and glycyrrhizic acid in Yanyanfang mixture. A Grace Apollo Cl8 column （250 mm × 4.6 mm, 5 μm） was used as the stationary phase and the mobile phase was composed of acetonitrile and aqueous phosphoric acid （0.2%, v/v）. Gradient elution was carried out at the flow rate of 1.0 mL/min and the column temperature was 30 ℃. An ultraviolet （UV） detector was used with a selected wavelength of 240 nm. Calibration curves were linear within the concentration range of 4.6-45.75 μg/mL for 12, 13-dihydroxyeuparin （r〉0.9999） and 106.9-1068.9μg/mL for glycyrrhizic acid （r〉0.9999）, respectively. Recoveries were 102.18% for 12, 13-dihydroxyeuparin and 101.17% for glycyrrhizic acid. The method developed could be applied to the simultaneous determination of 12, 13- dihydroxyeuparin and glycyrrhizic acid in Yanyanfang mixture.展开更多
The research of superior water oxidation electrodes is essential for the green energy in the form of hydrogen by way of electrolytic water splitting, and still remains challenging. Based upon dealloying foam, Fe-Ni hy...The research of superior water oxidation electrodes is essential for the green energy in the form of hydrogen by way of electrolytic water splitting, and still remains challenging. Based upon dealloying foam, Fe-Ni hydroxide nanosheets network structure is designed on the surface of Fe-Ni alloy foam. The ratio of Ni/Fe elements was adjusted to realize the optimal catalytic activities for oxygen evolution reaction（OER） and hydrogen evolution reaction（HER）. The obtained electrode of Fe-Ni hydroxide nanosheets/Fe-Ni alloy foam-60% Fe（FN LDH/FNF-60, 60 is the percentage of Fe content） possess low overpotential of 261 mV to reach 10 mA/cm;, small Tafel slope（85.5 mV/dec）, and superior long-term stability（remaining 10 mA/cm;for over 14 h without attenuation） toward OER in 1.0 mol/L KOH.Moreover, an alkaline water electrolyzer is constructed with the FN LDH/FNF-60 as anode and Ni（OH）;/Fe-Ni alloy foam-25% Fe(Ni（OH）;/FNF-25) as cathode, which displays superior electrolytic performance（affording 10 mA/cm;at 1.62 V） and lasting durability.展开更多
Objective: To classify four new Sparassis strains(CLM1, CKM1, CKM2, and KJM1) using the internal transcribed spacer sequence and to elucidate their β-glucan content and mycelial growth.Methods: Two different microbio...Objective: To classify four new Sparassis strains(CLM1, CKM1, CKM2, and KJM1) using the internal transcribed spacer sequence and to elucidate their β-glucan content and mycelial growth.Methods: Two different microbiological media were used to determine growth rate. The β-glucan contents were analyzed using the Megazyme Mushroom and Yeast Beta-Glucan kit. To determine the genetic relationships, phylogenetic trees were constructed using ClustalX. Multiple sequence alignments were printed and shaded with the BOXSHADE 3.21 program. Results: In this study, four new Sparassis strains were isolated from the southern region of the Korea Peninsula. They were all classified into the Sparassis latifolia clade as a monophyletic group based on the internal transcribed spacer sequence. Mycelial growth rate of the CLM1 strain was highest in potato dextrose agar and potato dextrose agar larch. The β-glucan content of the CLM1 strain was highest at 29.5%(w/w). A high degree of sequence divergence was detected in the RNA polymerase second largest subunit II gene(RPB2) within Sparassis spp. tested. The putative amino acid sequences of the RPB2 had a distinct sequence. The nucleotide sequences of the RPB2's intron were also divergent among Sparassis spp., even though their nucleotide length was well conserved within Sparassis latifolia. Conclusions: These results indicate that the nucleotide sequences and the amino acid sequences of RPB2 can be used to identify individual Sparassis sp. The Sparassis strain CLM1 may be best for developing a remedy to prevent or treat cancer and other chronic diseases.展开更多
Beach rock,which forms at the intertidal zone,is a natural barrier to protect beach and island from wave erosion. The formation mechanism of beach rocks is significant in the study of surface carbonate diagenesis and ...Beach rock,which forms at the intertidal zone,is a natural barrier to protect beach and island from wave erosion. The formation mechanism of beach rocks is significant in the study of surface carbonate diagenesis and protection of island. Beach rocks in Qilian Islets and Cays were formed about 500–700 a BP,neither its composition nor sedimentary structure experienced intense post-reformation.Beach rocks in Qilian Islets and Cays are mainly composed of reef-building skeletal fragments and bioclasts without terrigenous sediments. This study focused on the types and morphologies of cements in beach rocks of Qilian Islets and Cays,and its cementation mechanisms and influencing factors. Biological activities,such as micritization caused by microbial activities and algae binding action,play an important role in the initial stage of bioclast transformation and promote the subsequent early marine and early meteoric cementation. Acicular aragonite induced by early marine cementation is well developed in beach rocks,especially in those samples from Medium Islet. Early meteoric cementation is not common as marine cementation,generally presenting granular and meniscus cements. The main factors affecting the formation and development of beach rocks in Qilian Islets and Cays include sediment source,hydrodynamic condition,climate,sea level change and anthropogenic impacts.展开更多
OBJECTIVE: To evaluate the effect and safety of Chinese herbal medicines on Helicobacter pylori(HP)-associated gastroduodenal ulcers.METHODS: All randomized controlled trials(RCTs)listed in the PubMed, EMBASE, Cochran...OBJECTIVE: To evaluate the effect and safety of Chinese herbal medicines on Helicobacter pylori(HP)-associated gastroduodenal ulcers.METHODS: All randomized controlled trials(RCTs)listed in the PubMed, EMBASE, Cochrane Library,China National Knowledge Infrastructure Database,WanFang, China Science and Technology Journal Database and SinoMed databases that were published in English or Chinese were searched, and the retrieval time range was from database inception to December 31, 2018. A comprehensive Meta-analysis of all publications was performed with RevMan 5.3 software, and the quality of the evidence report-ed in the results of Meta-analysis was analyzed with GRADE profiler software(version 3.6.1). Dichotomous data were analyzed by calculating odds ratios and 95% confidence intervals(CIs). Outcome measures included the HP clearance rate and percentage of adverse effects.RESULTS: Eight trials with 919 participants were included in this Meta-analysis. Compared with the effects of single drug therapy on HP-associated gastroduodenal ulcers, according to the statistical analysis, odds ratios for the HP clearance rate and percentage of adverse effects of Chinese herbal medicines administered as complementary medicines combined with drugs were 3.10 [95% CI(2.21, 4.36),P < 0.01] and 0.28 [95% CI(0.15, 0.52), P < 0.01], respectively, and the differences were statistically significant. According to the GRADE analysis, the quality of evidence for the HP clearance rate and percentage of adverse effects were both very low.CONCLUSION: Compared with using the drug therapy only, the combination of Chinese herbal medicines with the drug therapy more effectively eliminates HP and alleviates adverse reactions. However,the available studies were of low quality, and therefore more well-designed studies are required to further confirm the findings.展开更多
文摘AI tools are increasingly used in education,impacting teaching and learning across various disciplines.However,previous review articles and empirical studies have not systematically discussed the application of AI in higher education assessment,the impact on user acceptance during its application,and the future opportunities and challenges.This systematic review aims to understand the application of AI tools in assessment,factors that influence students'and educators'perceptions,and related challenges and opportunities.Analyzing 81 empirical studies through matrix coding and content analysis,the results show that AI tools are used in intelligent tutoring and personalized learning,giving automated assessment and feedback,virtual classroom and online collaboration,learning analytics and prediction,knowledge management and resource recommendation,and educational chat assistants.AI tools offer high-quality,real-time,personalized feedback,improving cognitive and metacognitive skills and fostering positive emotions.Despite the benefits,challenges such as security and privacy concerns,algorithmic bias,unreliable feedback,negative attitudes,insufficient abilities,academic integrity issues,and lack of proper guidance persist.To advance our understanding of AI as an assessment tool,we call for studies that explore ways to enhance teachers’and students’perceptions and refine guidelines to prevent academic dishonesty and ensure responsible AI use.
基金supported by grants from the National Natural Science Foundation of China(No.81172568)
文摘Background:Oral cancer is a common type of head and neck cancers.Knowing its epidemiologic characteristics is crucial to preventing,diagnosing,and treating this cancer.This study aimed to explore the epidemiologic characteristics of oral cancer in South China.Methods:We retrospectively analyzed data from 4097 oral cancer patients treated at the Sun Yat-sen University Cancer Center between 1960 and 2013.We compared the age of onset,sex ratio,pathologic type,and primary tumor location among three subcultural areas(Guangfu,Hakka,and Chaoshan) and between an economically developed region and a less-developed one in Guangdong.Results:Overall,oral cancer had a male-to-female ratio of approximately 2:1,and this ratio decreased over time.Oral cancer occurred mostly in patients of 45-64 years old(54.5%),and the percentage of older patients gradually increased over time.The most common tumor location was the tongue.Squamous cell carcinoma was the predominant pathologic type.The percentage of blood type O in oral cancer patients was lower than that in the healthy population.The male-to-female ratio in the Chaoshan area was higher than that in the Guangfu and Hakka areas,whereas the age of disease onset in Guangfu was higher than that in Hakka and Chaoshan.The male-to-female ratio was lower and the age of disease onset was higher in the economically developed region than in the less-developed region.Conclusion:The incidence of oral cancer in South China presents typical characteristics to which doctors should pay attention when diagnosing and treating oral cancer patients.
文摘Pre-injection is a technique that involves injecting grout materials into the ground prior to excavation,with the aim of stabilizing the surrounding rock mass.This paper introduces an analytical closed-form model for determining the ground reaction curve of tunnels in rock masses exhibiting elastic-brittleplastic behavior and adhering to the Mohr-Coulomb failure criterion.The model incorporates the reinforced region created by the pre-injection method.When the rock mass is reinforced through preinjection,plastic regions can form independently in both the natural and injected rock masses.This leads to six distinct modes of the problem.The analytical model presented in this paper considers three possible scenarios for the development of plastic regions.Each scenario comprises four stages,with each stage representing a different mode of the problem.While injecting the rock mass can enhance its strength and stiffness,it may also increase the brittleness of the injected rock mass and create stress concentrations within it,particularly when brittle grouts are used.As a result,this can elevate the risk of rockburst due to unstable failure.The results obtained from the model demonstrate that ductile grout performs exceptionally well in controlling tunnel convergence in rock masses,as it accommodates deformation without sudden failure,even in squeezing rock mass conditions.Conversely,the use of brittle grouts should be approached with caution,particularly in squeezing rock masses,due to their susceptibility to rockburst incidents.
基金funded by the Joint Development Project with Pharmapack Technologies Corporation:Open Multi-Person Collaborative Virtual Assembly/Disassembly Training and Virtual Engineering Visualization Platform,Grant Number 23HK0101.
文摘Virtual maintenance,as an important means of industrial training and education,places strict requirements on the accuracy of participant pose perception and assessment of motion standardization.However,existing research mainly focuses on human pose estimation in general scenarios,lacking specialized solutions for maintenance scenarios.This paper proposes a virtual maintenance human pose estimation method based on multi-scale feature enhancement(VMHPE),which integrates adaptive input feature enhancement,multi-scale feature correction for improved expression of fine movements and complex poses,and multi-scale feature fusion to enhance keypoint localization accuracy.Meanwhile,this study constructs the first virtual maintenance-specific human keypoint dataset(VMHKP),which records standard action sequences of professional maintenance personnel in five typical maintenance tasks and provides a reliable benchmark for evaluating operator motion standardization.The dataset is publicly available at.Using high-precision keypoint prediction results,an action assessment system utilizing topological structure similarity was established.Experiments show that our method achieves significant performance improvements:average precision(AP)reaches 94.4%,an increase of 2.3 percentage points over baseline methods;average recall(AR)reaches 95.6%,an increase of 1.3 percentage points.This research establishes a scientific four-level evaluation standard based on comparative motion analysis and provides a reliable solution for standardizing industrial maintenance training.
基金supported by the National Natural Science Foundation of China(No.22272059)the Natural Science Foundation of Guangdong Province(No.2024A1515010030)。
文摘Electrocatalytic carbon dioxide reduction(CO_(2)ER)driven by renewable energy sources to produce high-valueadded chemicals is a highly promising strategy for achieving a closed carbon cycle.Cu is the only highly active catalyst capable of producing multi-carbon(C_(2)t)products through CO_(2)ER.However,due to the constraints of existing scaling relationships and competing hydrogen evolution reaction,it is still challenging to achieve high selectivity of a single desired product.In this work,high-entropy alloy(HEA)CuMoRuFeW surface skin on Cu nanorods was obtained by a one-pot co-reduction method.It is revealed that Fe could effectively facilitate the coreduction of Mo and W precursors and the formation of HEA surface on Cu nanorod.The Faradaic efficiency(FE)for ethylene and ethanol in CO_(2)ER reaches 49.5%and 20.4%,respectively,with a total FEC_(2)of 69.9%and current density of 250 mA cm^(-2)at-1.1 V vs.RHE.Theoretical calculations reveal that the Cu–W–Fe combination site is more active in CO_(2)activation and C–C coupling for C_(2)products than other sites.This work underscores the importance of HEA in overcoming the constraints of linear scaling relationships and improving the selectivity for C_(2)products in CO_(2)ER.
基金supported by the National Natural Science Foundation of China(No.51972066)the Natural Science Foundation of Guangdong Province of China(No.2024A1515012499)。
文摘The uneven deposition and high reactivity of lithium-metal anode(LMA)lead to uncontrollable dendrite growth,low Coulombic efficiency,and safety concerns,hindering their commercialization.Here,a representative polar-rich-group triazine-based covalent organic framework(COF-TzDha)with a desolvation effect is designed as an interlayer for stable,dendrite-free LMA.The abundant triazine rings in COFTzDha as a donor effectively attract lithium ions,while the one-dimensional nanopore structure facilitates lithium-ion migration.The periodic arrangement of polar groups(-OH)in the backbone interacts with electrolyte components(DOL,DME,TFSI-)to form a hydrogen bonding network that slows solvent molecules transport.Therefore,COF-TzDha effectively desolvates lithium ions from the solvent sheath,promoting uniform lithium ion flux and Li plating/stripping.Theoretical calculations verify that COFTzDha with abundant adsorption sites and strong adsorption energy facilitates lithium ion desolvation.Consequently,the introduction of COF-TzDha obtains a high ion mobility(0.75).The Li|COF@PP|Li symmetric cell cycles stably for over 1200 h at 4 mA cm^(-2)/4.0 mA h cm^(-2).The Li|COF@PP|LiFePO_(4)full cell also displays highly stable cycling performance with 600 cycles(75.5%capacity retention,~100% Coulombic efficiency)at 1 C.This work verifies an effective strategy for inducing uniform Li deposition and achieving dendrite-free,stable LMA using a polar-rich-group COF interlayer with a desolvation effect.
基金supported by the National Natural Science Foundation of China(Grant no.42307534)Discovery Project(DP220101790)+1 种基金The University of Queensland ScholarshipAustralian Research Council Discovery Project(DP220101790).
文摘Wastewater-based epidemiology has emerged as a transformative surveillance tool for estimating substance consumption and monitoring disease prevalence,particularly during the COVID-19 pandemic.It enables the population-level monitoring of illicit drug use,pathogen prevalence,and environmental pollutant exposure.In this perspective,we summarize the key challenges specific to the Chinese context:(1)Sampling inconsistencies,necessitating standardized 24-hour composite protocols with high-frequency autosamplers(≤15 min/event)to improve the representativeness of samples.
基金supported by the National Key Research and Development Program (2016YFD0500101)
文摘Porcine deltacoronavirus(PDCoV) is a newly identified virus that causes watery diarrhea in newborn piglets and results in significant economic losses to the pig industry. Since first reported in Hong Kong in 2012, PDCoV has been subsequently detected in USA, South Korea, Thailand, and China's Mainland. Here we isolated a strain of PDCoV, named CHN-GD-2016,from the intestinal content of a diseased newborn piglet with severe diarrhea in a pig farm in Guangdong, China. PDCoV CHN-GD-2016 could be identified by immunofluorescence with PDCoV specific rabbit antisera, and typical crown-shaped particles with spiky surface projections of this PDCoV were observed with electron microscopy. Genomic analysis showed that the PDCoV CHN-GD-2016 was closely related to other Chinese PDCoV strains, with the highest sequence similarity with the strain CHN/Tianjin/2016. Importantly, inoculation of newborn piglets with 1×10~5 TCID_(50) of CHN-GD-2016 by oral feeding successfully reproduced clear clinical symptoms, including vomiting, dehydration, and severe diarrhea in piglets. In addition, the virus RNA in rectal swabs from 1 to 7 days post inoculation was detected, macroscopic and microscopic lesions in small intestine were observed, and viral antigen was also detected in the small intestines with immunohistochemical staining. Collectively, the data show in this study confirms that PDCoV is present in Guangdong,China and is highly pathogenic in newborn piglets.
文摘A new diarylheptanoid, 3,5-dimethoxy1-17-hydroxyl-4, 11, 19-triketo-[7,0]meta-cyclophane, named as rubanone 1, was isolated from the bark of Myrica rubra along with four known compounds 2-5. Their structures were elucidated by various spectroscopic methods including 2D-NMR techniques or comparison with authentic samples.
基金supported by the Science and Technology Programs of Guangdong Province(Nos.2015A020215031,2013B020600007,and 2012B050200002)supported by the National Key Technologies R&D Program of China(No.2015BAI09B05)
文摘The toxicity of nano-materials has received increasing attention in recent years. Nevertheless, relatively few studies have focused on their oceanic distributions and toxicities. In this study, we assessed nano-ZnO toxicity in marine organisms using the yellowstriped goby （Mugilogobius chulae）. The relative differences in nano-ZnO dissolution and dispersal in seawater and fresh water were also investigated. The effects of nano-ZnO on embryonic development, deformity, hatching, mortality, and histopathology were analyzed. In addition, the effects of the Zn2＋ concentration on M. chulae hatching and mortality were compared. The results showed that nano-ZnO had higher solubility in seawater than in fresh water. Nano-ZnO significantly inhibited hatching. By the fifth day of exposure, the LC50 of nano-ZnO was 45.40 mg/L, and the mortality rate spiked. Hatching inhibition and lethality were dose-dependent over a range of 1-25 mg/L nano-ZnO. Zn2＋ inhibited hatching and increased lethality, but its effects were weaker than those of nano-ZnO at the same concentrations. Nano-ZnO also induced spinal bending, oedema, hypoplasia, and other deformities in M. chulae embryos and larvae. Histopathology revealed vacuolar degeneration, hepatocyte and enterocyte enlargement, and morphological abnormalities of the vertebrae. Therefore, nano-ZnO caused malformations in M. chulae by affecting embryonic growth and development. We conclude that nano-ZnO toxicity in seawater was significantly positively correlated with the associated Zn2＋ concentration and sedimentary behaviour. The toxicity of nano-ZnO was cumulative and showed a critical point, beyond which embryonic and developmental toxicity in marine fish was observed.
基金supported by the National Natural Science Foundation of China (U2032151)the National Key R&D Program of China (2018YFB1502600)+1 种基金the Basic Research and Applied Basic Research Foundation of Guangzhou (B3210580)the Natural Science Foundation of Guangdong Province (B6211050)。
文摘The alkaline hydrogen evolution reaction(HER) on Pt-based catalysts is largely limited by the slow water dissociation kinetics. Pt-based single atom alloy catalysts(SAAC) with water dissociation sites have been demonstrated as excellent alkaline HER catalysts. However, the regulation of their activity and stability at the atomic scale is still a great challenge. Herein, the kinetic and stability issues are successfully resolved via engineering the electronic structure of Pt-Co SAAC by Au-induced tensile strain. The atomic dispersion of Co into the Pt shell was confirmed by extended X-ray absorption fine structure and the electronic structure and catalytic HER performance was modulated by the tensile strain induced by the Pt shell thickness. An inverse volcano-type relation between HER activity and surface strain was found.Density functional theory(DFT) calculations reveal that the Au-induced tensile strain on Pt-Co shell can not only boost the adsorption and dissociation kinetics of water at Co site by upshifting the dband and promoting the electron transfer, but also downshift the d-band center of Pt in Pt-Co shell, leading to optimized H* adsorption/desorption. The champion catalyst provides an overpotential of only 14 m V at the current density of 10 mA cm^(-2). This work not only provides an effective strategy for the construction of single-atom alloy electrocatalysts for high performance toward alkaline HER but also sheds light on the understanding of the reaction mechanism at the atomic level.
基金supported by the National Natural Science Foundation of China(51972066)the Natural Science Foundation of Guangdong Province of China(2021A1515011718)the Guangdong Province Universities and Colleges Pearl River Scholar Funded Scheme 2017。
文摘Severe polysulfide shuttling and sluggish sulfur redox kinetics significantly decrease sulfur utilization and cycling stability in lithium-sulfur batteries(LSBs).Herein,we develop a hollow CoO/CoP-Box core-shell heterostructure as a model and multifunctional catalyst modified on separators to induce interfacial charge modulation and expose more active sites for promoting the adsorption and catalytic conversion ability of sulfur species.Theoretical and experimental findings verify that the in-situ formed core-shell hetero-interface induces the formation of P-Co-O binding and charge redistribution to activate surface O active sites for binding lithium polysulfides(LiPSs)via strong Li-O bonding,thus strongly adsorbing with Li PSs.Meanwhile,the strong Li-O bonding weakens the competing Li-S bonding in LiPSs or Li2S adsorbed on CoO/CoP-Box surface,plus the hollow heterostructure provides abundant active sites and fast electron/Li+transfer,so reducing Li2S nucleation/dissolution activation energy.As expected,LSBs with CoO/CoP-Box modified separator and traditional sulfur/carbon black cathode display a large initial capacity of 1240 mA h g^(-1)and a long cycling stability with 300 cycles(~60.1%capacity retention)at 0.5C.Impressively,the thick sulfur cathode(sulfur loading:5.2 mg cm^(-2))displays a high initial areal capacity of 6.9 mA h cm^(-2).This work verifies a deep mechanism understanding and an effective strategy to induce interfacial charge modulation and enhance active sites for designing efficient dual-directional Li-S catalysts via engineering hollow core-shell hetero-structure.
基金supported by the Natural Science Foundation of Guangdong Province(No.2019A1515012040).
文摘As a typical laser additive manufacturing technology,laser powder bed fusion(LPBF)has achieved demonstration applications in aerospace,biomedical and other fields.However,how to select process parameters quickly and reasonably is still themain concern of LPBF production.In order to quantitatively analyze the influence of different process parameters(laser power,scanning speed,hatch space and layer thickness)on the LPBF process,the multilayer and multi-path forming process of LPBF was predicted based on the open-source discrete element method framework Yade and the open-source finite volume method framework OpenFOAM.Based on the design of experiments method,a four-factor three-level orthogonal test scheme was designed,and the porosity and surface roughness data of each calculation scheme were extracted.By analyzing the orthogonal test data,it was found that as the laser power increased,the porosity decreased,and as the scanning speed,hatch space,and layer thickness increased,the porosity increased.In addition,the influence of laser power and scanning speed on surface roughness showed a trend of decreasing first and then increasing,while the influence of scanning distance and layer thickness on surface roughness showed amonotonous increasing trend.The order of the influence of each process parameter on porosity was:scanning speed>laying thickness>laser power>hatch space,and the order of the influence of each process parameter on surface roughness was:hatch space>layer thickness>laser power>scanning speed.So the porosity of the part is most sensitive to scanning speed,and the surface roughness is the most sensitive to hatch space.The above conclusions are expected to provide process control basis for actual LPBF production of the 316L stainless steel alloy.
基金financially supported by the Joint Funds of the National Natural Science Foundation of China and Guangdong Province(No.U1134005)
文摘Natural rubber grafted maleic anhydride （NR-g-MAH） was synthesized by mixing maleic anhydride （MAH） and natural rubber （NR） in solid state in a torque rheometer using dicurnyl peroxide （DCP） as initiator. Then the self-prepared NR-g-MAH was used as a compatibilizer in the natural rubber/short nylon fiber composites. Both the fimctionalization of NR with MAH and the reaction between the modified rubber and the nylon fiber were confirmed by Fourier transform infrared spectroscopy （FTIR）. Composites with different nylon short fiber loadings （0, 5, 10, 15 and 20 phr） were compounded on a two-roll mill, and the effects of the NR-g-MAH on the tensile and thermal properties, fiber-rubber interaction, as well as the morphology of the natural rubber/short nylon fiber composites were investigated. At equal fiber loading, the NR-g-MAH compatibilized NR/short nylon fiber composites showed improved tensile properties, especially the tensile modulus at 100% strain which was about 1.5 times that of the corresponding un-compatibilized ones. The equilibrium swelling tests proved that the incorporation of NR-g-MAH increased the interaction between the nylon fibers and the NR matrix. The crosslink density measured with NMR techniques showed that the NR-g-MAH compatiblized composites had lower total crosslink density. The glass transition temperatures of the compatibilized composites were about 1 K higher than that of the corresponding un-compabilized ones. Morphology analysis of the NR/short nylon fiber composites confirmed NR-g-MAH improved interfacial bonding between the NR matrix and the nylon fibers. All these results signified that the NR-g-MAH could act as a good compatilizer of NR/short nylon fiber composites and had a potential for wide use considering its easy to be prepared and compounded with the composites.
基金supported by National Natural Science Foundation of China(No.21875048)Outstanding Youth Project of Guangdong Natural Science Foundation(No.2020B1515020028)+2 种基金Major Scientific Project of Guangdong University(No.2017KZDXM059)Yangcheng Scholars Research Project of Guangzhou(No.201831820)Science and Technology Research Project of Guangzhou(No.202002010007)。
基金supported by Guangdong Natural Product Reference Material Research & Development Central Lab,the First Affiliate Hospital of Sun Yat-sen University and the Industry-University-Research Cooperation Program from Science and Technology Department of Guangdong Province (No:2010B090400533)
文摘A reversed phase high performance liquid chromatography （HPLC） method was established for the simultaneous determination of 12, 13-dihydroxyeuparin and glycyrrhizic acid in Yanyanfang mixture. A Grace Apollo Cl8 column （250 mm × 4.6 mm, 5 μm） was used as the stationary phase and the mobile phase was composed of acetonitrile and aqueous phosphoric acid （0.2%, v/v）. Gradient elution was carried out at the flow rate of 1.0 mL/min and the column temperature was 30 ℃. An ultraviolet （UV） detector was used with a selected wavelength of 240 nm. Calibration curves were linear within the concentration range of 4.6-45.75 μg/mL for 12, 13-dihydroxyeuparin （r〉0.9999） and 106.9-1068.9μg/mL for glycyrrhizic acid （r〉0.9999）, respectively. Recoveries were 102.18% for 12, 13-dihydroxyeuparin and 101.17% for glycyrrhizic acid. The method developed could be applied to the simultaneous determination of 12, 13- dihydroxyeuparin and glycyrrhizic acid in Yanyanfang mixture.
基金supported by the Science and Technology Planning Project of Guangdong Province,China(No.2017B090916002)Tip-top Scientific and Technical Innovative Youth Talents of Guangdong Special Support Program(No.2016TQ03N541)+2 种基金Guangdong Natural Science Funds for Distinguished Young Scholar(No.2017B030306001)the National Natural Science Foundation of China(No.91745203)Guangdong Innovative and Entrepreneurial Research Team Program(No.2014ZT05N200)
文摘The research of superior water oxidation electrodes is essential for the green energy in the form of hydrogen by way of electrolytic water splitting, and still remains challenging. Based upon dealloying foam, Fe-Ni hydroxide nanosheets network structure is designed on the surface of Fe-Ni alloy foam. The ratio of Ni/Fe elements was adjusted to realize the optimal catalytic activities for oxygen evolution reaction（OER） and hydrogen evolution reaction（HER）. The obtained electrode of Fe-Ni hydroxide nanosheets/Fe-Ni alloy foam-60% Fe（FN LDH/FNF-60, 60 is the percentage of Fe content） possess low overpotential of 261 mV to reach 10 mA/cm;, small Tafel slope（85.5 mV/dec）, and superior long-term stability（remaining 10 mA/cm;for over 14 h without attenuation） toward OER in 1.0 mol/L KOH.Moreover, an alkaline water electrolyzer is constructed with the FN LDH/FNF-60 as anode and Ni（OH）;/Fe-Ni alloy foam-25% Fe(Ni（OH）;/FNF-25) as cathode, which displays superior electrolytic performance（affording 10 mA/cm;at 1.62 V） and lasting durability.
基金Supported by the Regional Technology Innovation Program(A001100501)funded by the Ministry of Knowledge Economy,Korea+1 种基金the Basic Science Research Program through the National Research Foundation of Koreafunded by the Ministry of Education,Science and Technology(NRF-2012R1A1A2006934)
文摘Objective: To classify four new Sparassis strains(CLM1, CKM1, CKM2, and KJM1) using the internal transcribed spacer sequence and to elucidate their β-glucan content and mycelial growth.Methods: Two different microbiological media were used to determine growth rate. The β-glucan contents were analyzed using the Megazyme Mushroom and Yeast Beta-Glucan kit. To determine the genetic relationships, phylogenetic trees were constructed using ClustalX. Multiple sequence alignments were printed and shaded with the BOXSHADE 3.21 program. Results: In this study, four new Sparassis strains were isolated from the southern region of the Korea Peninsula. They were all classified into the Sparassis latifolia clade as a monophyletic group based on the internal transcribed spacer sequence. Mycelial growth rate of the CLM1 strain was highest in potato dextrose agar and potato dextrose agar larch. The β-glucan content of the CLM1 strain was highest at 29.5%(w/w). A high degree of sequence divergence was detected in the RNA polymerase second largest subunit II gene(RPB2) within Sparassis spp. tested. The putative amino acid sequences of the RPB2 had a distinct sequence. The nucleotide sequences of the RPB2's intron were also divergent among Sparassis spp., even though their nucleotide length was well conserved within Sparassis latifolia. Conclusions: These results indicate that the nucleotide sequences and the amino acid sequences of RPB2 can be used to identify individual Sparassis sp. The Sparassis strain CLM1 may be best for developing a remedy to prevent or treat cancer and other chronic diseases.
基金supported by the National Natural Science Foundation of China (Nos. 41672107, 41372119, 41440040)supports provided by the Marine Environmental Observation and Research Station at the Xisha Islands, the South China Sea Institute of Oceanology, CAS during the fieldwork
文摘Beach rock,which forms at the intertidal zone,is a natural barrier to protect beach and island from wave erosion. The formation mechanism of beach rocks is significant in the study of surface carbonate diagenesis and protection of island. Beach rocks in Qilian Islets and Cays were formed about 500–700 a BP,neither its composition nor sedimentary structure experienced intense post-reformation.Beach rocks in Qilian Islets and Cays are mainly composed of reef-building skeletal fragments and bioclasts without terrigenous sediments. This study focused on the types and morphologies of cements in beach rocks of Qilian Islets and Cays,and its cementation mechanisms and influencing factors. Biological activities,such as micritization caused by microbial activities and algae binding action,play an important role in the initial stage of bioclast transformation and promote the subsequent early marine and early meteoric cementation. Acicular aragonite induced by early marine cementation is well developed in beach rocks,especially in those samples from Medium Islet. Early meteoric cementation is not common as marine cementation,generally presenting granular and meniscus cements. The main factors affecting the formation and development of beach rocks in Qilian Islets and Cays include sediment source,hydrodynamic condition,climate,sea level change and anthropogenic impacts.
文摘OBJECTIVE: To evaluate the effect and safety of Chinese herbal medicines on Helicobacter pylori(HP)-associated gastroduodenal ulcers.METHODS: All randomized controlled trials(RCTs)listed in the PubMed, EMBASE, Cochrane Library,China National Knowledge Infrastructure Database,WanFang, China Science and Technology Journal Database and SinoMed databases that were published in English or Chinese were searched, and the retrieval time range was from database inception to December 31, 2018. A comprehensive Meta-analysis of all publications was performed with RevMan 5.3 software, and the quality of the evidence report-ed in the results of Meta-analysis was analyzed with GRADE profiler software(version 3.6.1). Dichotomous data were analyzed by calculating odds ratios and 95% confidence intervals(CIs). Outcome measures included the HP clearance rate and percentage of adverse effects.RESULTS: Eight trials with 919 participants were included in this Meta-analysis. Compared with the effects of single drug therapy on HP-associated gastroduodenal ulcers, according to the statistical analysis, odds ratios for the HP clearance rate and percentage of adverse effects of Chinese herbal medicines administered as complementary medicines combined with drugs were 3.10 [95% CI(2.21, 4.36),P < 0.01] and 0.28 [95% CI(0.15, 0.52), P < 0.01], respectively, and the differences were statistically significant. According to the GRADE analysis, the quality of evidence for the HP clearance rate and percentage of adverse effects were both very low.CONCLUSION: Compared with using the drug therapy only, the combination of Chinese herbal medicines with the drug therapy more effectively eliminates HP and alleviates adverse reactions. However,the available studies were of low quality, and therefore more well-designed studies are required to further confirm the findings.
