Electrochemical cycling of hydrogen,carbon,and nitrogen-containing molecules is of great importance to tackling energy and environmental crises and composes a central piece of the net-zero emissions scenario.Obtaining...Electrochemical cycling of hydrogen,carbon,and nitrogen-containing molecules is of great importance to tackling energy and environmental crises and composes a central piece of the net-zero emissions scenario.Obtaining an in-depth understanding of interfacial processes with molecular-level information is a cornerstone to developing more advanced electrocatalysts and electrochemical interfaces and further improving reaction efficiencies to meet industrial requirements.Among various in situ characterization techniques that can probe the interfacial processes,attenuated total reflection infrared spectroscopy(ATR-IR)has gained considerable attention most recently.A systematic review of its applications is expected to stimulate further efforts in studying the above-mentioned electrochemical reactions.Herein,we summarize the basic principles of in situ ATR-IR and its applications in understanding mechanisms of electrochemical hydrogen,carbon,and nitrogen cycling reactions,including identification of key reaction intermediates and pathways,deciphering the impacts of interfacial environments,and revealing the structure-to-performance relationship on electrocatalysts.Outlooks on challenges and opportunities faced by ATR-IR in further studying these reactions are also provided.展开更多
Objective:This paper aims to investigate the efficacy of desogestrel in the treatment of endometriosis.Methods:In this study,61 patients with endometriosis in our hospital from January 2023 to December 2023 were selec...Objective:This paper aims to investigate the efficacy of desogestrel in the treatment of endometriosis.Methods:In this study,61 patients with endometriosis in our hospital from January 2023 to December 2023 were selected and divided using the random sampling method.All the patients were treated with desogestrel and the pain symptom scores and HDL-C(high-density lipoprotein cholesterol)levels of the patients were compared before and after the treatment.The treatment effects and adverse effects during the administration of the drug were closely observed.Results:After the patients were treated with desogestrel,the effective rate of treatment was as high as 98.36%,and the incidence of adverse reactions during treatment was 6.55%.Compared with the pre-treatment period,the scores of various pain symptoms were significantly reduced and the HDL-C level was improved after treatment,with P<0.05.Conclusion:Desogestrel showed significant efficacy in the treatment of endometriosis,effectively relieving patients’pain while elevating HDL-C levels.In addition,the incidence of adverse reactions to this drug is relatively low,which is worth utilizing.展开更多
The objective of this paper is to investigate the effects of initial particle gradation and rock content on the crushing behavior(i.e.grain size before and after crushing) of weathered phyllite fills.Compaction tests ...The objective of this paper is to investigate the effects of initial particle gradation and rock content on the crushing behavior(i.e.grain size before and after crushing) of weathered phyllite fills.Compaction tests were conducted on weathered phyllite fills with rock contents of 35%,45%,55%,65% and 75%(by weight).First,the particle size distributions(PSDs) were observed before and after compaction,and then the particle breakage of weathered phyllite fills was analyzed by fractal dimension.Relative fractal dimension was proposed to evaluate the effects of initial rock content and initial gradation on the particle breakage.It was found that the fractal dimension method can well characterize the crushing behaviors of the weathered phyllite fills.The finer the fills were,the more they were compacted.That is,after the first compaction,the relative fractal dimension of the weathered phyllite fills increased as the rock content increased,reaching the values of 0.013,0.016,0.024,0.037 and 0.08,respectively.After the second compaction,these relative fractal dimension values,dominated by the initial particle gradation,became 0.059,0.072,0.052,0.095 and 0.118,respectively.In conclusion,the weathered phyllite fills with 55% rock content exhibited the least breakage and were most suitable for filling the subgrade.Findings in this paper will provide significant guidance for the construction of weathered phyllite filling subgrade in future projects.展开更多
MADS-box transcription factors show highly diverse regulatory functions in a wide variety of organisms. In this study, we characterized a MADS-box gene (BpMADS12) from the white birch (Betula platyphylla Suk). Thi...MADS-box transcription factors show highly diverse regulatory functions in a wide variety of organisms. In this study, we characterized a MADS-box gene (BpMADS12) from the white birch (Betula platyphylla Suk). This gene is a member of the suppressor of overexpression of CO 1/tomato MADS 3 class of MADS-box genes. We generated lines overexpressing BpMADS12 and found that these had higher levels of lignin compared to that observed in nontransgenic lines. Transcriptome anal- ysis revealed numerous changes in gene expression patterns. In total, 8794 differentially expressed genes were identified, including 5006 upregulated unigenes and 3788 downregulated unigenes in BpMADS-overexpression lines. Differentially expressed genes involved in the pathways for lignin and brassinosteroid biosynthesis were significantly enriched and may have contributed to phenotypic changes. The results from a quantitative RT-PCR analysis were consistent those obtained with the transcriptome analysis.Our transcriptome analysis, in combination with measure- ment of lignin level, indicated that BpMADS12 promotes lignin synthesis through regulation of key enzymes in response to brassinosteroid signaling. These results suggest that this MADS-box protein is crucial to all subsequent structural events and provide a good foundation for studies aiming to elucidate the developmental mechanisms underlying formation of wood.展开更多
With the fast development of Qingdao's economy, the energy consumption is increasing significantly. In this paper, based on the energy statistic data in Qingdao area from 2010 to 2015,energy consumption structure ...With the fast development of Qingdao's economy, the energy consumption is increasing significantly. In this paper, based on the energy statistic data in Qingdao area from 2010 to 2015,energy consumption structure was analyzed, indicating the existence of single energy structure;that is, coal, petroleum, and natural gas are dominant in the area. Thus, some issues between energy supply and demand have been brought. To solve present problem, we put forward to formulate the development strategy of energy, including energy savings, the exploitation of petroleum and natural gas resources, the development and utilization of renewable energy sources, and energy policy. It is worthy of mentioning that, according to the geological investigation, the shale gas may be abundant in Qingdao area and the gas resource amount estimated is huge. This is our first finding, important for developing unconventional energy and adjusting the energy structure in Qingdao in the future. Therefore, we suggest that Qingdao government should take action to develop local new energy resources for satisfying the energy demand.展开更多
Objective: To study the possibility of mismatch repair gene hMSH2 as a marker to predict the occurrence of gastric carcinoma. Methods: Immunohistochemical method was used to detect hMSH2 protein expressions of gastric...Objective: To study the possibility of mismatch repair gene hMSH2 as a marker to predict the occurrence of gastric carcinoma. Methods: Immunohistochemical method was used to detect hMSH2 protein expressions of gastric carci- nomas (carcinoma group) and their surrounding epithelia (surrounding epithelium group) in patients and the epithelia (normal epithelium group) in persons without carcinoma. Results: The positive rates of hMSH2 protein expression in nucleus of carcinoma, surrounding epithelium and normal epithelium groups were 44.94% (71/158), 28.48% (45/158) and 11.76% (4/34), respectively (P=0.000); the positive rates of hMSH2 protein expression in plasma of the 3 groups were 37.97% (60/158), 27.85% (44/158) and 23.53% (8/34), respectively (P=0.084); the positive rates of hMSH2 protein expression in both nucleus and plasma of the 3 groups were 20.89% (33/158), 17.72% (28/158) and 2.94% (1/34), respectively (P=0.045). Although the difference of positive rates between carcinoma and surrounding epithelium groups was not significant (P=0.476), both of them were higher than that of normal epithelium group (P=0.018). Conclusion: Our findings show that the detection of hMSH2 protein expression in gastric epithelia may help to predict and diagnose gastric carcinoma.展开更多
Background:China’s accelerating development and increasingly important role in global health engagement create a great demand for global health professionals including international consulting experts.This study repo...Background:China’s accelerating development and increasingly important role in global health engagement create a great demand for global health professionals including international consulting experts.This study reported the detailed development and evaluation of an international consulting training for global health workforce.Methods:Based on Kirkpatrick’s model,a mixed-methods approach was used to evaluate the effectiveness of the training.Quantitative and qualitative data on participants’reaction,learning,and application of the learned knowledge and skills were collected by a training evaluation survey at the ending of training and a follow-up interview in three months after the training.Results:Thirty-six participants attended the training and 34 of them completed quantitative investigation.The training satisfaction evaluations were positive,for which participants rated the training program highly and over 90%of them agreed with the usefulness of the training.About knowledge and skills change,participants showed improved consulting knowledge and skills from pre-to post-training(P<0.001).A total of 23 participants accepted follow-up interview,and most participants applied knowledge and skills learned from the training in their daily work or study.However,only 30.4%of participants applied their learning in the consulting program.The largest barrier of application was the lack of consulting opportunities.In addition,almost all the participants reported that they would be glad to attend more training courses in the future.Conclusion:The international consulting training program was well-received,and was feasible to improve the consulting service competence of global health professionals.According to participants’feedback,it is essential to develop and expand consulting training in the field of global health.展开更多
Thin-walled metal parts with functional micro-featured surface have broad application prospects in the fields of resistance reduction,noise reduction,etc.In this study,a novel micro-rolling&incremental sheet formi...Thin-walled metal parts with functional micro-featured surface have broad application prospects in the fields of resistance reduction,noise reduction,etc.In this study,a novel micro-rolling&incremental sheet forming hybrid process(μR-ISF)is proposed to fabricate thin-walled metal parts with microgroove arrays.An analytical model which relates the rolling force and microgroove depth in the micro-rolling stage was first established.Then,the formation mechanism of microgroove morphology during both micro-rolling stage and macro-shape forming stage are investigated.After the micro-grooved sheet being incrementally formed,a significant reduction(between 21%to nearly 60%)is occurred in the depth of both transverse and longitudinal grooves compared to the flat sheet.Meanwhile,the width of transverse grooves decreases slightly by about 10%on average,while the width of longitudinal microgrooves increases significantly by more than 30%on average.After micro-rolling,85°{102}tensile twins appear on the micro-grooved sheet and the percentage of 65°{112}compressive twins increases.After incremental forming,the percentage of low-angle grain boundaries and the density of geometrically necessary dislocations in the formed part increase significantly,and the grain size distribution becomes more uniform.The present work provides a new strategy for the fabrication of 3D metal thin-walled components with surface micro-features.展开更多
The synovium,a thin layer of tissue that is adjacent to the joints and secretes synovial fluid,undergoes changes in aging that contribute to intense shoulder pain and other joint diseases.However,the mechanism underly...The synovium,a thin layer of tissue that is adjacent to the joints and secretes synovial fluid,undergoes changes in aging that contribute to intense shoulder pain and other joint diseases.However,the mechanism underlying human synovial aging remains poorly characterized.Here,we generated a comprehensive transcriptomic profile of synovial cells present in the subacromial synovium from young and aged individuals.By delineating aging-related transcriptomic changes across different cell types and their associated regulatory networks,we identified two subsets of mesenchymal stromal cells(MSCs)in human synovium,which are lining and sublining MSCs,and found that angiogenesis and fibrosis-associated genes were upregulated whereas genes associated with cell adhesion and cartilage development were downregulated in aged MSCs.Moreover,the specific cell-cell communications in aged synovium mirrors that of aging-related inflammation and tissue remodeling,including vascular hyperplasia and tissue fibrosis.In particular,we identified forkhead box O1(FOXO1)as one of the major regulons for aging differentially expressed genes(DEGs)in synovial MSCs,and validated its downregulation in both lining and sublining MSC populations of the aged synovium.In human FOXO1-depleted MSCs derived from human embryonic stem cells,we recapitulated the senescent phenotype observed in the subacromial synovium of aged donors.These data indicate an important role of FOXO1 in the regulation of human synovial aging.Overall,our study improves our understanding of synovial aging during joint degeneration,thereby informing the development of novel intervention strategies aimed at rejuvenating the aged joint.展开更多
The mitogen-activated protein kinases(MAPK) pathway, often known as the RAS-RAFMEK-ERK signal cascade, functions to transmit upstream signals to its downstream effectors to regulate physiological process such as cell ...The mitogen-activated protein kinases(MAPK) pathway, often known as the RAS-RAFMEK-ERK signal cascade, functions to transmit upstream signals to its downstream effectors to regulate physiological process such as cell proliferation, differentiation, survival and death. As the most frequently mutated signaling pathway in human cancer, targeting the MAPK pathway has long been considered a promising strategy for cancer therapy. Substantial efforts in the past decades have led to the clinical success of BRAF and MEK inhibitors. However, the clinical benefits of these inhibitors are compromised by the frequently occurring acquired resistance due to cancer heterogeneity and genomic instability. This review briefly introduces the key protein kinases involved in this pathway as well as their activation mechanisms. We also generalize the correlations between mutations of MAPK members and human cancers, followed by a summarization of progress made on the development of small molecule MAPK kinases inhibitors. In particular, this review highlights the potential advantages of ERK inhibitors in overcoming resistance to upstream targets and proposes that targeting ERK kinase may hold a promising prospect for cancer therapy.展开更多
Vectorial optical fields(VOFs)exhibiting arbitrarily designed wavefronts and polarization distributions are highly desired in photonics.However,current methods to generate them either require complicated setups or exh...Vectorial optical fields(VOFs)exhibiting arbitrarily designed wavefronts and polarization distributions are highly desired in photonics.However,current methods to generate them either require complicated setups or exhibit limited functionalities,which is unfavorable for integration-optics applications.Here,we propose a generic approach to efficiently generate arbitrary VOFs based on metasurfaces exhibiting full-motrix yet inhomogeneous Jones-matrix distributions.We illustrate our strategy with analytical calculations on a model system and an experimental demonstration of a meta-device that can simultaneously deflect light and manipulate its polarization.Based on these benchmark results,we next experimentally demonstrate the generation of a far-field VOF exhibiting both a vortex wavefront and an inhomogeneous polarization distribution.Finally,we design/fabricate a meta-device and experimentally demonstrate that it can generate a complex near-field VOF-a cylindrically polarized surface plasmon wave possessing orbital angular momentum-with an efficiency of-34%.Our results establish an efficient and ultracompact platform for generating arbitrary predesigned VOFs in both the near-and far-fields,which may find many applications in optical manipulation and communications.展开更多
Although metasurfaces have shown great potential for manipulating light,most previously realized meta-devices suffer from uncontrolled angular dispersions,making them unfavorable for many applications.Here,we propose ...Although metasurfaces have shown great potential for manipulating light,most previously realized meta-devices suffer from uncontrolled angular dispersions,making them unfavorable for many applications.Here,we propose a general strategy to realize optical metasurfaces with desired angular dispersions based on carefully controlling both the near-field couplings between meta-atoms and the radiation pattern of a single meta-atom.Utilizing such a strategy,we experimentally demonstrate a series of optical meta-devices with predesigned angular dispersions,including two incident-angle-insensitive absorbers,one incident-angle-selective absorber,and one multifunctional meta-polarizer whose functionality changes from a perfect mirror to a half-waveplate as the excitation angle varies.Finally,we design a gradient meta-device using meta-atom arrays with purposely controlled angular dispersions and numerically demonstrate that it can exhibit distinct wavefront-control functionalities when illuminated at different incident angles.Our findings establish a new platform for achieving angle-multiplexed functional meta-devices,significantly expanding the wave-manipulation capabilities of optical metasurfaces.展开更多
Dear Editor, The retina is a light-sensitive highly-organized tissue,which is vulnerable to aging and age-related retinal diseases.Specifically,progressive retinal degeneration leads to visual function deterioration a...Dear Editor, The retina is a light-sensitive highly-organized tissue,which is vulnerable to aging and age-related retinal diseases.Specifically,progressive retinal degeneration leads to visual function deterioration and vision impairment in the elderly(Lin et al.,2016).In diseases such as age-related macular degeneration(AMD),retinitis pigmentosa(RP)and diabetic retinopathy(DR),pathological process lacking effective treatments profoundly and negatively impact on the quality of life in the elderly(Lin et al.,2016;Chen et al.,2019).Thus,an in-depth molecular assessment of the mechanisms driv-ing retinal aging is of urgent scientific and medical importance.展开更多
The Lingshan Island scientific drill confirms that two episodes(Laiyang period and Qingshan period) of rifting developed in the central Sulu orogenic belt(SOB) in Late Mesozoic. With a set of methods including fieldwo...The Lingshan Island scientific drill confirms that two episodes(Laiyang period and Qingshan period) of rifting developed in the central Sulu orogenic belt(SOB) in Late Mesozoic. With a set of methods including fieldwork, drilling, core logging, zircon U-Pb dating and whole rock geochemistry applied, the age, the depositional sequence and the deep dynamic mechanisms of rift evolution were unraveled. The stratigraphic sequence of the Laiyang-Qingshan Groups on Lingshan Island was composed of two different rifting sequences:(1) Laiyang Group(147–125 Ma), which consists of deep-water gravity flow deposits with interlayers of intermediate volcanic rocks;and(2) Lower Qingshan Group(125–119 Ma), which unconformably overlies the former sequence and contains subaerial volcanic deposits and terrestrial deposits. The tectonic environment changed during the evolution of these two episodes of rifting: the rift was in a NNW-SSE extensional environment in the Laiyang period and showed the typical passive rifting character that “lithospheric extension and rifting preceded volcanism”. The passive rifting period was ended by a short WNW-ESE compression at about 125 Ma. After that, the tectonic environment transferred to a strong NW-SE extensional environment and the rifting evolved into a volcanic arc basin in the Qingshan period. The igneous rocks are shoshonitic to high-K calc-alkaline trachyandesites to trachytes with a few intercalated lamprophyres and a rhyolite.The geochemical characteristics of the igneous rocks indicate that they are mantle-derived melts with a metasomatized mantle source and/or crustal contamination. In addition, an increased thinning of the lithosphere happened during the rifting episodes.The low-angle subduction of the Paleo-Pacific plate in the Jurassic weakened the thickened SOB lithospheric mantle. The rollback of the subducting plate started in late Jurassic to early Cretaceous, and the SOB lithospheric mantle was delaminated synchronously because of the gravity collapse. Thus, this caused passive rifting in the Laiyang period. Thereafter, the rollback and trench retreat of the high-angle subducting Paleo-Pacific plate would have achieved its climax, resulting in the strong regional extension. Passive rifting was ended by the crustal uplift caused by asthenospheric upwelling beneath the rift. The lower crust was heated by the upwelling asthenosphere and partially melted to form felsic melts, which were emplaced upwards and erupted explosively. The rift evolved into a volcanic arc basin in the Qingshan period and showed some characteristics of active rifting. Above all, a passive rifting in the Laiyang period and a volcanic arc basin in the Qingshan period developed successively in the Lingshan Island area(the central SOB). This records the transfer of the study area from the Paleo-Tethys tectonic domain to the circum-Pacific tectonic domain. The delamination of SOB lithospheric mantle and the upwelling of asthenospheric material were the deep dynamic mechanisms driving the development and evolution of two rift episodes. Additionally, the rift development was controlled remotely by the subduction of the Paleo-Pacific plate.展开更多
The hepatitis B virus(HBV) is a global public health challenge due to its highly contagious nature. It is estimated that almost 300 million people live with chronic HBV infection annually. Although nucleoside analogs ...The hepatitis B virus(HBV) is a global public health challenge due to its highly contagious nature. It is estimated that almost 300 million people live with chronic HBV infection annually. Although nucleoside analogs markedly reduce the risk of liver disease progression, the analogs do not fully eradicate the virus. As such, new treatment options and drugs are urgently needed. Psoralen is a nourishing monomer of Chinese herb and is known to inhibit virus replication and inactivate viruses. In this study, we evaluated the potential of psoralen as an anti-HBV agent.Quantitative PCR and Southern blot analysis revealed that psoralen inhibited HBV replication in Hep G2.2.15 cells in a concentration-dependent manner. Moreover, psoralen was also active against the 3TC/ETV-dual-resistant HBV mutant. Further investigations revealed that psoralen suppressed both HBV RNA transcription and core protein expression. The transcription factor FOXO1, a known target for PGC1α co-activation, binds to HBV precore/core promoter enhancer II region and activates HBV RNA transcription. Co-immunoprecipitation showed that psoralen suppressed the expression of FOXO1, thereby decreasing the binding of FOXO1 co-activator PGC1αto the HBV promoter. Overall, our results demonstrate that psoralen suppresses HBV RNA transcription by downregulating the expression of FOXO1 resulting in a reduction of HBV replication.展开更多
Probiotic fermented fruit juice could improve intestinal health with better sensory attributes.The effects of fermentation conditions on flavor quality of fermented bayberry juice were compared through microbial viabi...Probiotic fermented fruit juice could improve intestinal health with better sensory attributes.The effects of fermentation conditions on flavor quality of fermented bayberry juice were compared through microbial viability and sensory evaluation.Fermentation by combined Streptococcus thermophilus(ST)and Lactobaillus acidophilus(L A)resulted in higher microbial viability and sensory evaluation scores.The fermentation con-ditions were optimized by orthogonal experimental design and Technique for Order Preference by Similarity to an Ildeal Solution analysis(ST and LA in a mass ratio of 3:1;0.6%(mass concentration)inoculation;fermentation time,48 h,at 37℃;10%(mass concentration)added sucrose).Fermentation under these conditions decreased the anthocyanin content of the juice,maintained the total phenolic content,and slightly de-creased the antioxidant capacity.Fermentation reduced aroma volatiles from 42 in fresh juice to 33,as determined by gas chromatography-mass spectrometry-olfactometry(GC-MS-O),the aldehyde content decreased and the alcohol content increased.Lactic acid fermented bayberry juice by ST and LA produced a beverage with desirable consumer attributes,combining the health benefits of fresh juice and probiotics.展开更多
The geological units in Shandong Province, North China are important parts of the North China Craton and offer important insights into their crustal evolutionary history. This paper presents 611 sets of Nd isotopic da...The geological units in Shandong Province, North China are important parts of the North China Craton and offer important insights into their crustal evolutionary history. This paper presents 611 sets of Nd isotopic data of Archean–Mesozoic rocks from Shandong including the Luxi, Jiaobei, and Sulu terranes, which provides important constraints for crustal growth and reactivation. Nd-depleted mantle model ages(TDM) of Archean rocks with positive εNd(t) values showed that ca. 2.9 and 2.8–2.7 Ga were the most important periods of crustal growth in the Jiaobei and Luxi terranes, respectively, while the period of ca. 2.6–2.5 Ga in the Jiaobei terrane likely indicates a coherent event of crustal growth and reworking. During the Proterozoic, multi-stage rifting and collisional orogenic events possibly led to the reworking of Archean crust in the source region. The Nd isotopic data of the Paleoproterozoic and Neoproterozoic rocks from Sulu indicated significant reworking of older crust with juvenile magmatic input. Crustal reactivation occurred during the Mesozoic. The younger TDM ages of the Mesozoic rocks with low negative εNd(t) values indicate that a juvenile crustal/mantle component was added to the ancient basement. The reactivation reflectes significant crust-mantle interaction via the mechanism of crustal subduction and mantle-derived magma underplating, or possibly asthenospheric upwelling. In addition, the crustal correlation between Shandong and Korea(including the Gyeonggi massif, Ogcheon belt, and Yeongnam massif) is established in this study. The TDM age distribution provides evidence favoring the affinity relationship between the Gyeonggi massif and Ogcheon belt of South Korea and the Jiaobei and Sulu terranes of Shandong, while the Yeongnam massif is more correlated with the South China Block.展开更多
Chlorpyrifos is one of the most extensively used insecticides in China. The distribution and residues of chlorpyrifos in a paddy environment were characterized under field and laboratory conditions. The half-lives of ...Chlorpyrifos is one of the most extensively used insecticides in China. The distribution and residues of chlorpyrifos in a paddy environment were characterized under field and laboratory conditions. The half-lives of chlorpyrifos in the two conditions were 0.9–3.8 days(field) and 2.8–10.3 days(laboratory), respectively. The initial distribution of chlorpyrifos followed the increasing order of water 〈 straw 〈 soil, and soil was characterized as the major absorber. The ultimate residues in rice grain were below the maximum residue limit(MRL) with a harvest interval of 14 days. The chronic exposure for chlorpyrifos was rather low compared to the acceptable daily intake(ADI = 0.01 mg/kg bw) due to rice consumption. The chronic exposure risk from chlorpyrifos in rice grain was 5.90% and 1.30% ADI from field and laboratory results respectively. Concerning the acute dietary exposure,intake estimated for the highest chlorpyrifos level did not exceed the acute reference dose(ARf D = 0.1 mg/kg bw). The estimated short-term intakes(ESTIs) were 0.78% and 0.25% of the ARf D for chlorpyrifos. The results showed that the use of chlorpyrifos in rice paddies was fairly safe for consumption of rice grain by consumers.展开更多
Dear Editor,Stem cells,including pluripotent stem cells and adult stem cells,possess the remarkable capability of being able to selfrenew while at the same time having potential to differentiate into different cell li...Dear Editor,Stem cells,including pluripotent stem cells and adult stem cells,possess the remarkable capability of being able to selfrenew while at the same time having potential to differentiate into different cell lineages and functionally distinct cell types.Human embryonic stem cells(hESCs)can differentiate into all adult stem cell types,including human mesenchymal stem cells(hMSCs)and human neural stem cells(hNSCs),but can also give rise to all terminally differentiated cell types(Wang et al.,2021a).Through the continuous replenishment of differentiated cells,stem cells support tissue homeostasis and respond to tissue injuries.Given the promising applications of stem cells in cell therapy and regenerative medicine,insights into molecular events underlying stem cell maintenance,self-renewal ability and pluripotency,continue to garner strong interest(Shan et al.,2021).Although metabolic pathways have been implicated in the reciprocal regulations of stem cell self-renewal and differentiation as well as organ homeostatic maintenance(Garcia-Prat et al.,2017),central aspects of how metabolic requirements differ and are regulated across the various types of human stem cells in our body remain enigmatic.展开更多
A crawler system provides much larger ground contact,leading to excellent terrain adaptability.Due to its structural characteristics,high‐frequency vibration proportional to the vehicle speed is generated during the ...A crawler system provides much larger ground contact,leading to excellent terrain adaptability.Due to its structural characteristics,high‐frequency vibration proportional to the vehicle speed is generated during the driving process.This is a result of the polygon and rolling effects between the track and the wheels.A field test of a tracked vehicle is performed to monitor movement signals of the chassis and a rocker arm.Their corresponding power spectral density distributions confirm the correctness of the frequency‐calculation equation.Then,a novel elastic track tensioning device with a damper is designed as a cushion between the idler and the chassis.Depending on its geometry,the equivalent damping coefficient for a dynamic model is evaluated.Subsequently,the damping is altered in response to different operating conditions by a hybrid damping fuzzy semiactive control system.The controller accounts for both chassis and track vibration.Based on the transfer matrix method for multibody systems,a dynamical model of the track system is developed.Control performances are evaluated using two numerical simulations of obstacle crossing and off‐road driving operations.Results indicate that the proposed semiactive tensioner is substantially better than the conventional one.This paper provides a novel feasible scheme for vibration reduction of tracked vehicles.展开更多
基金supported by the Start-up Research Fund of Southeast University(RF1028623256)。
文摘Electrochemical cycling of hydrogen,carbon,and nitrogen-containing molecules is of great importance to tackling energy and environmental crises and composes a central piece of the net-zero emissions scenario.Obtaining an in-depth understanding of interfacial processes with molecular-level information is a cornerstone to developing more advanced electrocatalysts and electrochemical interfaces and further improving reaction efficiencies to meet industrial requirements.Among various in situ characterization techniques that can probe the interfacial processes,attenuated total reflection infrared spectroscopy(ATR-IR)has gained considerable attention most recently.A systematic review of its applications is expected to stimulate further efforts in studying the above-mentioned electrochemical reactions.Herein,we summarize the basic principles of in situ ATR-IR and its applications in understanding mechanisms of electrochemical hydrogen,carbon,and nitrogen cycling reactions,including identification of key reaction intermediates and pathways,deciphering the impacts of interfacial environments,and revealing the structure-to-performance relationship on electrocatalysts.Outlooks on challenges and opportunities faced by ATR-IR in further studying these reactions are also provided.
文摘Objective:This paper aims to investigate the efficacy of desogestrel in the treatment of endometriosis.Methods:In this study,61 patients with endometriosis in our hospital from January 2023 to December 2023 were selected and divided using the random sampling method.All the patients were treated with desogestrel and the pain symptom scores and HDL-C(high-density lipoprotein cholesterol)levels of the patients were compared before and after the treatment.The treatment effects and adverse effects during the administration of the drug were closely observed.Results:After the patients were treated with desogestrel,the effective rate of treatment was as high as 98.36%,and the incidence of adverse reactions during treatment was 6.55%.Compared with the pre-treatment period,the scores of various pain symptoms were significantly reduced and the HDL-C level was improved after treatment,with P<0.05.Conclusion:Desogestrel showed significant efficacy in the treatment of endometriosis,effectively relieving patients’pain while elevating HDL-C levels.In addition,the incidence of adverse reactions to this drug is relatively low,which is worth utilizing.
基金supported by the National Natural Science Foundation of China(Grant Nos.51378072 and 51878064)the Special Fund for Basic Scientific Research of the Central College of Chang’an University(Grant No.300102218408)the financial support provided by the China Association of Science and Technology(Grant No.2017CASTQNJL048)for visiting the University of Alberta。
文摘The objective of this paper is to investigate the effects of initial particle gradation and rock content on the crushing behavior(i.e.grain size before and after crushing) of weathered phyllite fills.Compaction tests were conducted on weathered phyllite fills with rock contents of 35%,45%,55%,65% and 75%(by weight).First,the particle size distributions(PSDs) were observed before and after compaction,and then the particle breakage of weathered phyllite fills was analyzed by fractal dimension.Relative fractal dimension was proposed to evaluate the effects of initial rock content and initial gradation on the particle breakage.It was found that the fractal dimension method can well characterize the crushing behaviors of the weathered phyllite fills.The finer the fills were,the more they were compacted.That is,after the first compaction,the relative fractal dimension of the weathered phyllite fills increased as the rock content increased,reaching the values of 0.013,0.016,0.024,0.037 and 0.08,respectively.After the second compaction,these relative fractal dimension values,dominated by the initial particle gradation,became 0.059,0.072,0.052,0.095 and 0.118,respectively.In conclusion,the weathered phyllite fills with 55% rock content exhibited the least breakage and were most suitable for filling the subgrade.Findings in this paper will provide significant guidance for the construction of weathered phyllite filling subgrade in future projects.
基金financially supported by the National Science and Technology Program of China during the 12th Five-Year Plan Period(No.2013AA102704)the National Natural Science Foundation of China(NO:31200510)
文摘MADS-box transcription factors show highly diverse regulatory functions in a wide variety of organisms. In this study, we characterized a MADS-box gene (BpMADS12) from the white birch (Betula platyphylla Suk). This gene is a member of the suppressor of overexpression of CO 1/tomato MADS 3 class of MADS-box genes. We generated lines overexpressing BpMADS12 and found that these had higher levels of lignin compared to that observed in nontransgenic lines. Transcriptome anal- ysis revealed numerous changes in gene expression patterns. In total, 8794 differentially expressed genes were identified, including 5006 upregulated unigenes and 3788 downregulated unigenes in BpMADS-overexpression lines. Differentially expressed genes involved in the pathways for lignin and brassinosteroid biosynthesis were significantly enriched and may have contributed to phenotypic changes. The results from a quantitative RT-PCR analysis were consistent those obtained with the transcriptome analysis.Our transcriptome analysis, in combination with measure- ment of lignin level, indicated that BpMADS12 promotes lignin synthesis through regulation of key enzymes in response to brassinosteroid signaling. These results suggest that this MADS-box protein is crucial to all subsequent structural events and provide a good foundation for studies aiming to elucidate the developmental mechanisms underlying formation of wood.
基金supported by Fundamental Research Funds for the Central Universities:[Grant Number 15CX05070A]
文摘With the fast development of Qingdao's economy, the energy consumption is increasing significantly. In this paper, based on the energy statistic data in Qingdao area from 2010 to 2015,energy consumption structure was analyzed, indicating the existence of single energy structure;that is, coal, petroleum, and natural gas are dominant in the area. Thus, some issues between energy supply and demand have been brought. To solve present problem, we put forward to formulate the development strategy of energy, including energy savings, the exploitation of petroleum and natural gas resources, the development and utilization of renewable energy sources, and energy policy. It is worthy of mentioning that, according to the geological investigation, the shale gas may be abundant in Qingdao area and the gas resource amount estimated is huge. This is our first finding, important for developing unconventional energy and adjusting the energy structure in Qingdao in the future. Therefore, we suggest that Qingdao government should take action to develop local new energy resources for satisfying the energy demand.
基金Supported by a grant from Chinese Scientific Academy Creative Foundation (No. DICPkaaaabc).
文摘Objective: To study the possibility of mismatch repair gene hMSH2 as a marker to predict the occurrence of gastric carcinoma. Methods: Immunohistochemical method was used to detect hMSH2 protein expressions of gastric carci- nomas (carcinoma group) and their surrounding epithelia (surrounding epithelium group) in patients and the epithelia (normal epithelium group) in persons without carcinoma. Results: The positive rates of hMSH2 protein expression in nucleus of carcinoma, surrounding epithelium and normal epithelium groups were 44.94% (71/158), 28.48% (45/158) and 11.76% (4/34), respectively (P=0.000); the positive rates of hMSH2 protein expression in plasma of the 3 groups were 37.97% (60/158), 27.85% (44/158) and 23.53% (8/34), respectively (P=0.084); the positive rates of hMSH2 protein expression in both nucleus and plasma of the 3 groups were 20.89% (33/158), 17.72% (28/158) and 2.94% (1/34), respectively (P=0.045). Although the difference of positive rates between carcinoma and surrounding epithelium groups was not significant (P=0.476), both of them were higher than that of normal epithelium group (P=0.018). Conclusion: Our findings show that the detection of hMSH2 protein expression in gastric epithelia may help to predict and diagnose gastric carcinoma.
基金funded by the China-UK Global Health Support Program(No.GHSP-CS-OP3-V04).
文摘Background:China’s accelerating development and increasingly important role in global health engagement create a great demand for global health professionals including international consulting experts.This study reported the detailed development and evaluation of an international consulting training for global health workforce.Methods:Based on Kirkpatrick’s model,a mixed-methods approach was used to evaluate the effectiveness of the training.Quantitative and qualitative data on participants’reaction,learning,and application of the learned knowledge and skills were collected by a training evaluation survey at the ending of training and a follow-up interview in three months after the training.Results:Thirty-six participants attended the training and 34 of them completed quantitative investigation.The training satisfaction evaluations were positive,for which participants rated the training program highly and over 90%of them agreed with the usefulness of the training.About knowledge and skills change,participants showed improved consulting knowledge and skills from pre-to post-training(P<0.001).A total of 23 participants accepted follow-up interview,and most participants applied knowledge and skills learned from the training in their daily work or study.However,only 30.4%of participants applied their learning in the consulting program.The largest barrier of application was the lack of consulting opportunities.In addition,almost all the participants reported that they would be glad to attend more training courses in the future.Conclusion:The international consulting training program was well-received,and was feasible to improve the consulting service competence of global health professionals.According to participants’feedback,it is essential to develop and expand consulting training in the field of global health.
基金This work is supported by the National Natural Science Foundation of China(Nos.51975328,52275348)Taishan Scholar Project of Shandong Province(No.tsqn202306006)Youth Innovation Technology Support Program of Shandong Provincial Universities(No.2022KJ041).
文摘Thin-walled metal parts with functional micro-featured surface have broad application prospects in the fields of resistance reduction,noise reduction,etc.In this study,a novel micro-rolling&incremental sheet forming hybrid process(μR-ISF)is proposed to fabricate thin-walled metal parts with microgroove arrays.An analytical model which relates the rolling force and microgroove depth in the micro-rolling stage was first established.Then,the formation mechanism of microgroove morphology during both micro-rolling stage and macro-shape forming stage are investigated.After the micro-grooved sheet being incrementally formed,a significant reduction(between 21%to nearly 60%)is occurred in the depth of both transverse and longitudinal grooves compared to the flat sheet.Meanwhile,the width of transverse grooves decreases slightly by about 10%on average,while the width of longitudinal microgrooves increases significantly by more than 30%on average.After micro-rolling,85°{102}tensile twins appear on the micro-grooved sheet and the percentage of 65°{112}compressive twins increases.After incremental forming,the percentage of low-angle grain boundaries and the density of geometrically necessary dislocations in the formed part increase significantly,and the grain size distribution becomes more uniform.The present work provides a new strategy for the fabrication of 3D metal thin-walled components with surface micro-features.
基金supported by the National Natural Science Foundation of China(92149301,81921006,82125011)the National Key Research and Development Program of China(2022YFA1103700,2022YFA1103800,2020YFA0804000,2020YFA0112200,2021YFF1201000,the STI2030-Major Projects-2021ZD0202400)+8 种基金the National Natural Science Foundation of China(92168201,91949209,92049304,92049116,32121001,82192863,82122024,82071588,32000500,82271600)CAS Project for Young Scientists in Basic Research(YSBR-076,YSBR-012)the Project for Technology Development of Beijing-affiliated Medical Research Institutes(11000023T000002036310)Youth Innovation Promotion Association of CAS(E1CAZW0401,2023092,2022083)the Informatization Plan of Chinese Academy of Sciences(CAS-WX2021SF-0301,CAS-WX2022SDC-XK14,CAS-WX2021SF-0101)New Cornerstone Science Foundation through the XPLORER PRIZE(2021-1045)Excellent Young Talents Program of Capital Medical University(12300927)Excellent Young Talents Training Program for the Construction of Beijing Municipal University Teacher Team(BPHR202203105)Young Elite Scientists Sponsorship Program by CAST(2021QNRC001).
文摘The synovium,a thin layer of tissue that is adjacent to the joints and secretes synovial fluid,undergoes changes in aging that contribute to intense shoulder pain and other joint diseases.However,the mechanism underlying human synovial aging remains poorly characterized.Here,we generated a comprehensive transcriptomic profile of synovial cells present in the subacromial synovium from young and aged individuals.By delineating aging-related transcriptomic changes across different cell types and their associated regulatory networks,we identified two subsets of mesenchymal stromal cells(MSCs)in human synovium,which are lining and sublining MSCs,and found that angiogenesis and fibrosis-associated genes were upregulated whereas genes associated with cell adhesion and cartilage development were downregulated in aged MSCs.Moreover,the specific cell-cell communications in aged synovium mirrors that of aging-related inflammation and tissue remodeling,including vascular hyperplasia and tissue fibrosis.In particular,we identified forkhead box O1(FOXO1)as one of the major regulons for aging differentially expressed genes(DEGs)in synovial MSCs,and validated its downregulation in both lining and sublining MSC populations of the aged synovium.In human FOXO1-depleted MSCs derived from human embryonic stem cells,we recapitulated the senescent phenotype observed in the subacromial synovium of aged donors.These data indicate an important role of FOXO1 in the regulation of human synovial aging.Overall,our study improves our understanding of synovial aging during joint degeneration,thereby informing the development of novel intervention strategies aimed at rejuvenating the aged joint.
文摘The mitogen-activated protein kinases(MAPK) pathway, often known as the RAS-RAFMEK-ERK signal cascade, functions to transmit upstream signals to its downstream effectors to regulate physiological process such as cell proliferation, differentiation, survival and death. As the most frequently mutated signaling pathway in human cancer, targeting the MAPK pathway has long been considered a promising strategy for cancer therapy. Substantial efforts in the past decades have led to the clinical success of BRAF and MEK inhibitors. However, the clinical benefits of these inhibitors are compromised by the frequently occurring acquired resistance due to cancer heterogeneity and genomic instability. This review briefly introduces the key protein kinases involved in this pathway as well as their activation mechanisms. We also generalize the correlations between mutations of MAPK members and human cancers, followed by a summarization of progress made on the development of small molecule MAPK kinases inhibitors. In particular, this review highlights the potential advantages of ERK inhibitors in overcoming resistance to upstream targets and proposes that targeting ERK kinase may hold a promising prospect for cancer therapy.
基金the National Key Research and Development Program of China(Nos.2017YFA0303504,2017YFA0700201 and 2020YFA0710100)National Natural Science Foundation of China(Nos.11734007,91850101,11674068,11874118 and 62005197)+1 种基金Natural Science Foundation of Shanghai(Nos.18ZR1403400 and 20JC1414601)Fudan University-CIOMP Joint Fund(No.FC2018-006).L.Zhou and Q.He acknowledge technical support from the Fudan Nanofabrication Laboratory for sample fabrication.
文摘Vectorial optical fields(VOFs)exhibiting arbitrarily designed wavefronts and polarization distributions are highly desired in photonics.However,current methods to generate them either require complicated setups or exhibit limited functionalities,which is unfavorable for integration-optics applications.Here,we propose a generic approach to efficiently generate arbitrary VOFs based on metasurfaces exhibiting full-motrix yet inhomogeneous Jones-matrix distributions.We illustrate our strategy with analytical calculations on a model system and an experimental demonstration of a meta-device that can simultaneously deflect light and manipulate its polarization.Based on these benchmark results,we next experimentally demonstrate the generation of a far-field VOF exhibiting both a vortex wavefront and an inhomogeneous polarization distribution.Finally,we design/fabricate a meta-device and experimentally demonstrate that it can generate a complex near-field VOF-a cylindrically polarized surface plasmon wave possessing orbital angular momentum-with an efficiency of-34%.Our results establish an efficient and ultracompact platform for generating arbitrary predesigned VOFs in both the near-and far-fields,which may find many applications in optical manipulation and communications.
基金funded by the National Natural Science Foundation of China(Nos.91850101,11734007,11674068,and 11874118)the National Key Research and Development Program of China(Nos.2017YFA0303504 and 2017YFA0700201)+2 种基金the Natural Science Foundation of Shanghai(No.18ZR1403400)the Fudan University-CIOMP Joint Fund(No.FC2018-006)the technical support from the Fudan Nanofabrication Laboratory for sample fabrication.
文摘Although metasurfaces have shown great potential for manipulating light,most previously realized meta-devices suffer from uncontrolled angular dispersions,making them unfavorable for many applications.Here,we propose a general strategy to realize optical metasurfaces with desired angular dispersions based on carefully controlling both the near-field couplings between meta-atoms and the radiation pattern of a single meta-atom.Utilizing such a strategy,we experimentally demonstrate a series of optical meta-devices with predesigned angular dispersions,including two incident-angle-insensitive absorbers,one incident-angle-selective absorber,and one multifunctional meta-polarizer whose functionality changes from a perfect mirror to a half-waveplate as the excitation angle varies.Finally,we design a gradient meta-device using meta-atom arrays with purposely controlled angular dispersions and numerically demonstrate that it can exhibit distinct wavefront-control functionalities when illuminated at different incident angles.Our findings establish a new platform for achieving angle-multiplexed functional meta-devices,significantly expanding the wave-manipulation capabilities of optical metasurfaces.
文摘Dear Editor, The retina is a light-sensitive highly-organized tissue,which is vulnerable to aging and age-related retinal diseases.Specifically,progressive retinal degeneration leads to visual function deterioration and vision impairment in the elderly(Lin et al.,2016).In diseases such as age-related macular degeneration(AMD),retinitis pigmentosa(RP)and diabetic retinopathy(DR),pathological process lacking effective treatments profoundly and negatively impact on the quality of life in the elderly(Lin et al.,2016;Chen et al.,2019).Thus,an in-depth molecular assessment of the mechanisms driv-ing retinal aging is of urgent scientific and medical importance.
基金supported by the Key R&D Plan of Shandong Province (Grant No. 2017CXGC1608)the Project of Department of Science and Technology of Sinopec (Grant No. P20028)+1 种基金the Shandong Natural Science Foundation Youth Fund Project (Grant No. ZR2020QD026)the Fundamental Research Funds for the Central Universities (Grant Nos. 18CX06019A, 19CX05004A)。
文摘The Lingshan Island scientific drill confirms that two episodes(Laiyang period and Qingshan period) of rifting developed in the central Sulu orogenic belt(SOB) in Late Mesozoic. With a set of methods including fieldwork, drilling, core logging, zircon U-Pb dating and whole rock geochemistry applied, the age, the depositional sequence and the deep dynamic mechanisms of rift evolution were unraveled. The stratigraphic sequence of the Laiyang-Qingshan Groups on Lingshan Island was composed of two different rifting sequences:(1) Laiyang Group(147–125 Ma), which consists of deep-water gravity flow deposits with interlayers of intermediate volcanic rocks;and(2) Lower Qingshan Group(125–119 Ma), which unconformably overlies the former sequence and contains subaerial volcanic deposits and terrestrial deposits. The tectonic environment changed during the evolution of these two episodes of rifting: the rift was in a NNW-SSE extensional environment in the Laiyang period and showed the typical passive rifting character that “lithospheric extension and rifting preceded volcanism”. The passive rifting period was ended by a short WNW-ESE compression at about 125 Ma. After that, the tectonic environment transferred to a strong NW-SE extensional environment and the rifting evolved into a volcanic arc basin in the Qingshan period. The igneous rocks are shoshonitic to high-K calc-alkaline trachyandesites to trachytes with a few intercalated lamprophyres and a rhyolite.The geochemical characteristics of the igneous rocks indicate that they are mantle-derived melts with a metasomatized mantle source and/or crustal contamination. In addition, an increased thinning of the lithosphere happened during the rifting episodes.The low-angle subduction of the Paleo-Pacific plate in the Jurassic weakened the thickened SOB lithospheric mantle. The rollback of the subducting plate started in late Jurassic to early Cretaceous, and the SOB lithospheric mantle was delaminated synchronously because of the gravity collapse. Thus, this caused passive rifting in the Laiyang period. Thereafter, the rollback and trench retreat of the high-angle subducting Paleo-Pacific plate would have achieved its climax, resulting in the strong regional extension. Passive rifting was ended by the crustal uplift caused by asthenospheric upwelling beneath the rift. The lower crust was heated by the upwelling asthenosphere and partially melted to form felsic melts, which were emplaced upwards and erupted explosively. The rift evolved into a volcanic arc basin in the Qingshan period and showed some characteristics of active rifting. Above all, a passive rifting in the Laiyang period and a volcanic arc basin in the Qingshan period developed successively in the Lingshan Island area(the central SOB). This records the transfer of the study area from the Paleo-Tethys tectonic domain to the circum-Pacific tectonic domain. The delamination of SOB lithospheric mantle and the upwelling of asthenospheric material were the deep dynamic mechanisms driving the development and evolution of two rift episodes. Additionally, the rift development was controlled remotely by the subduction of the Paleo-Pacific plate.
基金supported by the National Science Fund (82104240)Shanghai Science and Technology Innovation Project (20S11906200)self-deployed scientific research projects (State Key Laboratory of Drug Research) (SIMM1903ZZ-03)。
文摘The hepatitis B virus(HBV) is a global public health challenge due to its highly contagious nature. It is estimated that almost 300 million people live with chronic HBV infection annually. Although nucleoside analogs markedly reduce the risk of liver disease progression, the analogs do not fully eradicate the virus. As such, new treatment options and drugs are urgently needed. Psoralen is a nourishing monomer of Chinese herb and is known to inhibit virus replication and inactivate viruses. In this study, we evaluated the potential of psoralen as an anti-HBV agent.Quantitative PCR and Southern blot analysis revealed that psoralen inhibited HBV replication in Hep G2.2.15 cells in a concentration-dependent manner. Moreover, psoralen was also active against the 3TC/ETV-dual-resistant HBV mutant. Further investigations revealed that psoralen suppressed both HBV RNA transcription and core protein expression. The transcription factor FOXO1, a known target for PGC1α co-activation, binds to HBV precore/core promoter enhancer II region and activates HBV RNA transcription. Co-immunoprecipitation showed that psoralen suppressed the expression of FOXO1, thereby decreasing the binding of FOXO1 co-activator PGC1αto the HBV promoter. Overall, our results demonstrate that psoralen suppresses HBV RNA transcription by downregulating the expression of FOXO1 resulting in a reduction of HBV replication.
基金the Natural Science Foundation of Zhejiang province of China(LGN20C200019)the Major Science and Technology Projects of Agricultural of Ningbo(2019C10033)+1 种基金the Experimental Technology Research project of Zhejiang University(SYB202122)the Fundamental Research Funds for the Central Universities(No.226-2022-00045),China.
文摘Probiotic fermented fruit juice could improve intestinal health with better sensory attributes.The effects of fermentation conditions on flavor quality of fermented bayberry juice were compared through microbial viability and sensory evaluation.Fermentation by combined Streptococcus thermophilus(ST)and Lactobaillus acidophilus(L A)resulted in higher microbial viability and sensory evaluation scores.The fermentation con-ditions were optimized by orthogonal experimental design and Technique for Order Preference by Similarity to an Ildeal Solution analysis(ST and LA in a mass ratio of 3:1;0.6%(mass concentration)inoculation;fermentation time,48 h,at 37℃;10%(mass concentration)added sucrose).Fermentation under these conditions decreased the anthocyanin content of the juice,maintained the total phenolic content,and slightly de-creased the antioxidant capacity.Fermentation reduced aroma volatiles from 42 in fresh juice to 33,as determined by gas chromatography-mass spectrometry-olfactometry(GC-MS-O),the aldehyde content decreased and the alcohol content increased.Lactic acid fermented bayberry juice by ST and LA produced a beverage with desirable consumer attributes,combining the health benefits of fresh juice and probiotics.
基金supported by a scientific and technological innovation project of Shandong Province(No.2017CXGC1608)
文摘The geological units in Shandong Province, North China are important parts of the North China Craton and offer important insights into their crustal evolutionary history. This paper presents 611 sets of Nd isotopic data of Archean–Mesozoic rocks from Shandong including the Luxi, Jiaobei, and Sulu terranes, which provides important constraints for crustal growth and reactivation. Nd-depleted mantle model ages(TDM) of Archean rocks with positive εNd(t) values showed that ca. 2.9 and 2.8–2.7 Ga were the most important periods of crustal growth in the Jiaobei and Luxi terranes, respectively, while the period of ca. 2.6–2.5 Ga in the Jiaobei terrane likely indicates a coherent event of crustal growth and reworking. During the Proterozoic, multi-stage rifting and collisional orogenic events possibly led to the reworking of Archean crust in the source region. The Nd isotopic data of the Paleoproterozoic and Neoproterozoic rocks from Sulu indicated significant reworking of older crust with juvenile magmatic input. Crustal reactivation occurred during the Mesozoic. The younger TDM ages of the Mesozoic rocks with low negative εNd(t) values indicate that a juvenile crustal/mantle component was added to the ancient basement. The reactivation reflectes significant crust-mantle interaction via the mechanism of crustal subduction and mantle-derived magma underplating, or possibly asthenospheric upwelling. In addition, the crustal correlation between Shandong and Korea(including the Gyeonggi massif, Ogcheon belt, and Yeongnam massif) is established in this study. The TDM age distribution provides evidence favoring the affinity relationship between the Gyeonggi massif and Ogcheon belt of South Korea and the Jiaobei and Sulu terranes of Shandong, while the Yeongnam massif is more correlated with the South China Block.
基金supported by the National Natural Science Foundation of China (No. 31101458)
文摘Chlorpyrifos is one of the most extensively used insecticides in China. The distribution and residues of chlorpyrifos in a paddy environment were characterized under field and laboratory conditions. The half-lives of chlorpyrifos in the two conditions were 0.9–3.8 days(field) and 2.8–10.3 days(laboratory), respectively. The initial distribution of chlorpyrifos followed the increasing order of water 〈 straw 〈 soil, and soil was characterized as the major absorber. The ultimate residues in rice grain were below the maximum residue limit(MRL) with a harvest interval of 14 days. The chronic exposure for chlorpyrifos was rather low compared to the acceptable daily intake(ADI = 0.01 mg/kg bw) due to rice consumption. The chronic exposure risk from chlorpyrifos in rice grain was 5.90% and 1.30% ADI from field and laboratory results respectively. Concerning the acute dietary exposure,intake estimated for the highest chlorpyrifos level did not exceed the acute reference dose(ARf D = 0.1 mg/kg bw). The estimated short-term intakes(ESTIs) were 0.78% and 0.25% of the ARf D for chlorpyrifos. The results showed that the use of chlorpyrifos in rice paddies was fairly safe for consumption of rice grain by consumers.
基金the National Key Research and Development Program of China(2018YFA0107203)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA16010000)+10 种基金the National Key Research and Development Program of China(2020YFA0804000,2018YFC2000100,2020YFA0112201,2017YFA0103304,2017YFA0102802,2020YFA0113400,2019YFA0110100)the National Natural Science Foundation of China(Grant Nos.81901433,81921006,81625009,91749202,81861168034,91949209,92049304,81822018,92049116,82071588,32000500,81922027,81870228,82125011,82122024,32100937,92149301,92168201)the Key Research Program of the Chinese Academy of Sciences(KFZD-SW-221)the Program of Beijing Municipal Science and Technology Commission(Z191100001519005)the Program of the Beijing Natural Science Foundation(Z190019,JQ20031)K.C.Wong Education Foundation(GJTD-2019-06,GJTD-2019-08)Beijing Hospitals Authority Youth Programme(QML20200802)Youth Innovation Promotion Association of CAS(2021078,E1CAZW0401)the 14th Five-year Network Security and Informatization Plan of Chinese Academy of Sciences(WX145XQ07-18)the Non-profit Central Research Institute Fund of Chinese Academy of Medical Sciences(2020-JKCS-011)the State Key Laboratory of Stem Cell and Reproductive Biology,the State Key Laboratory of Membrane Biology,and the Milky Way Research Foundation(MWRF).
文摘Dear Editor,Stem cells,including pluripotent stem cells and adult stem cells,possess the remarkable capability of being able to selfrenew while at the same time having potential to differentiate into different cell lineages and functionally distinct cell types.Human embryonic stem cells(hESCs)can differentiate into all adult stem cell types,including human mesenchymal stem cells(hMSCs)and human neural stem cells(hNSCs),but can also give rise to all terminally differentiated cell types(Wang et al.,2021a).Through the continuous replenishment of differentiated cells,stem cells support tissue homeostasis and respond to tissue injuries.Given the promising applications of stem cells in cell therapy and regenerative medicine,insights into molecular events underlying stem cell maintenance,self-renewal ability and pluripotency,continue to garner strong interest(Shan et al.,2021).Although metabolic pathways have been implicated in the reciprocal regulations of stem cell self-renewal and differentiation as well as organ homeostatic maintenance(Garcia-Prat et al.,2017),central aspects of how metabolic requirements differ and are regulated across the various types of human stem cells in our body remain enigmatic.
基金supported by the Natural Science Foundation of Jiangsu Province(No.BK20190438)the Natural Science Foundation of Jiangsu Province(No.BK20210321).
文摘A crawler system provides much larger ground contact,leading to excellent terrain adaptability.Due to its structural characteristics,high‐frequency vibration proportional to the vehicle speed is generated during the driving process.This is a result of the polygon and rolling effects between the track and the wheels.A field test of a tracked vehicle is performed to monitor movement signals of the chassis and a rocker arm.Their corresponding power spectral density distributions confirm the correctness of the frequency‐calculation equation.Then,a novel elastic track tensioning device with a damper is designed as a cushion between the idler and the chassis.Depending on its geometry,the equivalent damping coefficient for a dynamic model is evaluated.Subsequently,the damping is altered in response to different operating conditions by a hybrid damping fuzzy semiactive control system.The controller accounts for both chassis and track vibration.Based on the transfer matrix method for multibody systems,a dynamical model of the track system is developed.Control performances are evaluated using two numerical simulations of obstacle crossing and off‐road driving operations.Results indicate that the proposed semiactive tensioner is substantially better than the conventional one.This paper provides a novel feasible scheme for vibration reduction of tracked vehicles.