The 12 May 2008 Wenchuan earthquake （Ms=8.0） struck on the Longmen Shan foreland thrust zone. The event took place within the context of long-term uplift of the Longmen Shan range as a result of the extensive eastwa...The 12 May 2008 Wenchuan earthquake （Ms=8.0） struck on the Longmen Shan foreland thrust zone. The event took place within the context of long-term uplift of the Longmen Shan range as a result of the extensive eastward-extrusion of crustal materials from the Tibetan plateau against the rheologically strong crust of the Sichuan Basin. The Longmen Shan range is charac- terized by a Pre-Sinian crystalline complex constrained by the Maoxian-Wenchuan-Kangding ductile detach- ment at the western margin and the Yingxiu-Beichuan- Luding ductile thrust at the eastern margin. The Long- men Shan uplift was initiated by intracontinental sub- duction between the Songpan-Ganzi terrane and the Yangtze block during the Pre-Cenozoic. The uplift rate was increased considerably by the collision between the Indian and Eurasian plates since -50 Ma. The Wenchuan earthquake resulted in two major NE-strik- ing coseismic ruptures （i.e., the -275 km long Yingxiu- Beichuan-Qingchuan fault and the -100 km long Anx- ian-Guanxian fault）. Field investigations combined with focal solutions and seismic reflection profiles suggest that the coseismic ruptures are steeply dipping close-to- pure reverse or right reverse oblique slip faults in the -15 km thick upper crust. These faults are unfavorably oriented for frictional slip in the horizontally compres- sional regime, so that they need a long recurrence interval to accumulate the tectonic stress and fluid pres- sure to critically high levels for the formation of strong earthquakes at a given locality. It is also found that all the large earthquakes （Ms〉7.0） occurred in the fault zones across which the horizontal movement velocities measured by the GPS are markedly low （〈3 mm/yr）. The faults, which constitute the northeastern fronts of the enlarging Tibetan plateau against the strong Sichuan Basin, Ala Shan and Ordos blocks, are very destructive, although their average recurrence intervals are generally long.展开更多
Dear Editor,Genome editing technologies enable precise modifications of DNA sequences in vivo and offer great promise for crop improvement. CRISPR/Cas9 （Clustered Regularly Interspaced Short Palindromic Repeats/CRISP...Dear Editor,Genome editing technologies enable precise modifications of DNA sequences in vivo and offer great promise for crop improvement. CRISPR/Cas9 （Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR-associated Cas9） has revolution- ized genome editing because of its simplicity and versatility （Cong et al., 2013）.展开更多
Chinese medicine （CM） is the most typical conventional therapy compared with any other traditional or alternative medicine systems. The active components of CMs are either primary or secondary metabolites generated ...Chinese medicine （CM） is the most typical conventional therapy compared with any other traditional or alternative medicine systems. The active components of CMs are either primary or secondary metabolites generated by metabolic and biosynthetic enzymes in plants, protecting the plants from environmental stress. The characteristics of these metabolites are diverse, complicated and unique. In this paper, current approaches for quality assessment were extensively reviewed, a new concept of quality marker （Q-marker） was then proposed for CM quality assessment. Additionally, definition of the Q-marker, as well as the relevant methods, were discussed, on the basis of the biosynthetic pathways of secondary metabolites and source of biological active components. Study design of Q-marker is complex system for quality assessment and production process control of CM products with transitivity and traceability. Therefore, the system with characteristics of transmission and traceability is expected to be established for regulation of quality. Upon the concept which the transitivity and traceability in the quality assessment and production process control covered the entire process, such as raw materials, decoction slices, processing, extraction and production can be further enhanced. The transitivity and traceability will inevitably require close attention to ＂who, what, where, when, and why＂ details at each stage of Q-markers of CM production form raw materials to patent product. The establishing quality standards are enablers of many and various transitivity and traceability solutions, not a solution in them. It means that the transitivity and traceability system is readily link between products and across borders in quality. According to the thinking mode and methods of investigation on quality assessment of CM product, we focus on the entire process, in terms of safety and effectiveness and quality control. The standard preparation of CM or CM decoction is not only the basis for study of Q-marker, but also the展开更多
An important tectonic inversion took place in eastern North China Block(NCB) during Mesozoic, which caused a great lithosphere thinning, reconstruction of basin-range series, powerful interaction between mantle and cr...An important tectonic inversion took place in eastern North China Block(NCB) during Mesozoic, which caused a great lithosphere thinning, reconstruction of basin-range series, powerful interaction between mantle and crust, a vast granitic intrusion and volcanism, and large-scale metallogenic explosion. The time range of the Mesozoic tectonic regime inversion in the eastern North China Block is one of the key issues to understand mechanism of tectonic regime inversion. Our updated results for recognizing the time range are mainly obtained from the following aspects: structural analyses along northern and southern margins of the NCB and within the NCB for revealing tectonic inversion from compression to extension and structural striking from ~EW to NNE; geothermic analyses of the eastern sedimental basins for a great change of thermal history and regime; basin analysis for basin inversion from compression to extension and basin migration from ~EW to NNE; petrological and geochemical studies of volcanic rocks and lowermost crust xenoliths for recognizing peak period of mantle upwelling and intense interaction between mantle and crust, and main metallogenic epoch. All the studies of the above give the same time range from~150-140 Ma to ~110-100Ma, peaking at ~120 Ma.展开更多
Background and Aims:Hepatitis B surface antigen(HBsAg)loss is seldom achieved with nucleos(t)ide analog(NA)therapy in chronic hepatitis B patients but may be enhanced by switching to finite pegylated-interferon(Peg-IF...Background and Aims:Hepatitis B surface antigen(HBsAg)loss is seldom achieved with nucleos(t)ide analog(NA)therapy in chronic hepatitis B patients but may be enhanced by switching to finite pegylated-interferon(Peg-IFN)alfa-2a.We assessed HBsAg loss with 48-and 96-week Peg-IFN alfa-2a in chronic hepatitis B patients with partial response to a previous NA.Methods:Hepatitis B e antigen(HBeAg)-positive patients who achieved HBeAg loss and hepatitis B virus DNA<200 IU/mL with previous adefovir,lamivudine or entecavir treatment were randomized 1:1 to receive Peg-IFN alfa-2a for 48(n=153)or 96 weeks(n=150).The primary endpoint of this study was HBsAg loss at end of treatment.The ClinicalTrials.gov identifier is NCT01464281.Results:At the end of 48 and 96 weeks'treatment,14.4%(22/153)and 20.7%(31/150)of patients,respectively,who switched from NA to Peg-IFN alfa-2a cleared HBsAg.Rates were similar irrespective of prior NA or baseline HBeAg seroconversion.Among those who cleared HBsAg by the end of 48 and 96 weeks'treatment,77.8%(14/18)and 71.4%(20/28),respectively,sustained HBsAg loss for a further 48 weeks.Baseline HBsAg<1500 IU/mL and week 24 HBsAg<200 IU/mL were associated with the highest rates of HBsAg loss at the end of both 48-and 96-week treatment(51.4%and 58.7%,respectively).Importantly,extending treatment from 48 to 96 weeks enabled 48.3%(14/29)more patients to achieve HBsAg loss.Conclusions:Patients on long-term NA who are unlikely to meet therapeutic goals can achieve high rates of HBsAg loss by switching to Peg-IFN alfa-2a.HBsAg loss rates may be improved for some patients by extending treatment from 48 to 96 weeks,although the differences in our study cohort were not statistically significant.Baseline and on-treatment HBsAg may predict HBsAg loss with Peg-IFN alfa-2a.展开更多
Zircon is the most useful mineral for studies in U-Pb geochronology and Hf and O isotope geochemistry.Matrix effect is a major problem of the microbeam techniques such as SIMS and LA-(MC)-ICPMS.Therefore,external stan...Zircon is the most useful mineral for studies in U-Pb geochronology and Hf and O isotope geochemistry.Matrix effect is a major problem of the microbeam techniques such as SIMS and LA-(MC)-ICPMS.Therefore,external standardization using well-characterized natural zircon standards is fundamental for accurate microbeam measurements.While the isotopic geochronology and geochemistry laboratories equipped with microbeam analytical facilities have been increasingly established in China during the past decade,applications of the isotopic microanalysis are still limited due to shortage of available standards.We report here the Qinghu zircon as a potential new working reference for microbeam analysis of zircon U-Pb age and O-Hf isotopes.This zircon was separated from the Qinghu quartz monzonite from the western Nanling Range,Southeast China.It is fairly homogeneous in U-Pb age and Hf and O isotopes in terms of large amounts of mircobeam measurements by LA-MC-ICPMS and SIMS at the scales of 20–60 m.SIMS measurements yield consistent206Pb/238U age within analytical uncertainties with that obtained by ID-TIMS.Precise determinations of O isotopes by IRMS and Hf isotopes by solution MC-ICPMS are in good agreement with the statistical mean of microbeam measurements.We recommend U-Pb age of=159.5±0.2 Ma(2SE),18O=5.4‰±0.2‰(2SD)and176Hf/177Hf=0.283002±0.000004(2SD)as the best reference values for the Qinghu zircon.展开更多
Objective: The purposes of this study were to identify risk factors for cervical lymph node metastasis and to examine the association between BRAF^(V600E) status and clinical features in papillary thyroid microcarcino...Objective: The purposes of this study were to identify risk factors for cervical lymph node metastasis and to examine the association between BRAF^(V600E) status and clinical features in papillary thyroid microcarcinoma(PTMC).Methods: A total of 1,587 patients with PTMC, treated in Tianjin Medical University Cancer Institute and Hospital from January2011 to March 2013, underwent retrospective analysis. We reviewed and analyzed factors including clinical results, pathology records, ultrasound results, and BRAF^(V600E) status.Results: Multivariate logistic regression analyses demonstrated that gender(male) [odds ratio(OR) = 1.845, P = 0.000], age(< 45 years)(OR = 1.606, P = 0.000), tumor size(> 6 mm)(OR = 2.137, P = 0.000), bilateralism(OR = 2.011, P = 0.000) and extrathyroidal extension(OR = 1.555, P = 0.001) served as independent predictors of central lymph node metastasis(CLNM).Moreover, CLNM(OR = 29.354, P = 0.000) served as an independent predictor of lateral lymph node metastasis(LLNM). Among patients with a solitary primary tumor, those with tumor location in the lower third of the thyroid lobe or the isthmus were more likely to experience CLNM(P < 0.05). Univariate analyses indicated that CLNM, LLNM, extrathyroidal extension, and multifocality were not significantly associated with BRAF^(V600E) mutation.Conclusions: The present study suggested that prophylactic neck dissection of the central compartment should be considered in patients with PTMC, particularly in men with tumor size greater than 6 mm, age less than 45 years, extrathyroidal extension, and tumor bilaterality. Among patients with PTMC, BRAF^(V600E) mutation is not significantly associated with prognostic factors. For a better understanding of surgical management of PTMC and the risk factors, we recommend multicenter research and long-term follow-up.展开更多
AIM: To explore the role of psychological factors in gastroesophageal reflux disease(GERD) and their effect on quality of life(Qo L) of GERD patients.METHODS: A total of 279 consecutive patients with typical symptoms ...AIM: To explore the role of psychological factors in gastroesophageal reflux disease(GERD) and their effect on quality of life(Qo L) of GERD patients.METHODS: A total of 279 consecutive patients with typical symptoms and 100 healthy controls were enrolled in the study.All of the participants wereevaluated with the Zung Self-Rating Anxiety Scale(ZSAS), the Zung Self-Rating Depression Scale(ZSDS) and the SF-36 questionnaire.The scores for anxiety, depression and Qo L of the two groups were analyzed.The correlation between psychological factors and Qo L was also analyzed.RESULTS: Compared with healthy controls(34.70 ± 8.00), the scores of ZSAS in the non-erosive reflux disease( N E R D) group(48.27±10.34) and the reflux esophagitis(RE) group(45.38 ± 10.27) were significantly higher(P < 0.001).The mean ZSAS score of the NERD group was significantly higher than that of the RE group(P = 0.01).Compared with healthy controls(37.61 ± 8.44), the mean ZSDS scores were significantly higher in the NERD group(49.65 ± 11.09, P < 0.001) and the RE group(46.76 ± 11.83, P < 0.001).All dimensions of the SF-36 form were negatively correlated with the SAS and SDS scores in patients with NERD and RE(P < 0.05).According to the S F- 3 6 form, vitality, mentalhealth and social functioning were significantly correlated with symptoms of depression in patients with NERD and RE.General health was obviously affected by symptoms of depression in patients with NERD(P < 0.05).CONCLUSION: Anxiety and depression may play an important role in the occurrence of GERD and especially that of NERD.The Qo L of patients with GERD is reduced by anxiety and depression.展开更多
Higher strength is always the goal pursued by researchers for the structural materials,especially for the lightweight magnesium(Mg)alloys which generally have relatively low strength at present.From this aspect,the pr...Higher strength is always the goal pursued by researchers for the structural materials,especially for the lightweight magnesium(Mg)alloys which generally have relatively low strength at present.From this aspect,the present paper reviews the recent reports of a kind of Mg alloys,i.e.Mg-RE(RE:rare earths,mainly Gd or Y)casting and wrought alloys,which have been able to achieve high strength compared with common or commercial Mg alloys,from the viewpoint and content of the alloy system,alloying constitution,preparation process,tensile strength and each of the main strengthening mechanisms.This review of recent research and developments in high-strength Mg-RE alloys is beneficial for the further design of Mg alloys with higher strength as well as excellent comprehensive performance.展开更多
Background Understanding the characteristics of Chinese dialysis patients and the current practice trends is the first step to evaluate the association between practice pattern and outcome in these populations. In the...Background Understanding the characteristics of Chinese dialysis patients and the current practice trends is the first step to evaluate the association between practice pattern and outcome in these populations. In the present study, we evaluated the status of medical treatment and characteristic features of chronic dialysis patients in China. Methods Through a clustering sampling, we selected 9 centers from the largest dialysis facilities in 6 cities around China. All adult undergoing dialysis in the selected units were screened. A total of 2388 （1775 on hemodialysis （HD） and 613 on peritoneal dialysis （PD）） patients were finally enrolled. All data were collected at enrollment on the bases of review of medical records. Results In this cohort, 1313 （55.0%） were male. The mean age was 54 years old. The median time for dialysis was 26 months （12-51 months）. Seventy-five percent of patients were on HD and 25.0% on PD. Among PD patients, about 21% patients did not receive dialysis adequacy. For HD patients, about 14.0% of them did not achieve dialysis adequacy when the target of kt/V was set as 1.2. Only 44.7% of patients achieved blood pressure target of 140/90 mmHg. About 60% of patients did not reach the hemoglobin target of 110 g/L even though 85.0% of them were treated with erythropoietin. In addition, 48.5% of the patients had uncontrolled mineral metabolism revealed by the high calcium-phosphate product. Compared with HD patients, higher level of serum glucose, triglyceride, and total and low density lipoprotein cholesterol were more common in PD patients. Conclusions This observational study suggests that many Chinese dialysis patients did not achieve the therapeutic target, particularly in blood pressure control, anemia correction, and mineral balance. PD patients were more likely to suffer metabolic disturbance.展开更多
Tea plant is an important economic crop,which is used to produce the world's oldest and most widely consumed tea beverages.Here,we present a high-quality reference genome assembly of the tea plant(Camellia sinensi...Tea plant is an important economic crop,which is used to produce the world's oldest and most widely consumed tea beverages.Here,we present a high-quality reference genome assembly of the tea plant(Camellia sinensis var.sinensis)consisting of 15 pseudo-chromosomes.LTR retrotransposons(LTR-RTs)account for 70.38%of the genome,and we present evidence that LTR-RTS play critical roles in genome size expansion and the transcriptional diversification of tea plant genes through preferential insertion in promoter regions and introns.Genes,particularly those coding for terpene biosynthesis pro-teins,associated with tea aroma and stress resistance were significantly amplified through recent tandem duplications and exist as gene clusters in tea plant genome.Phylogenetic analysis of the sequences of 81 tea plant accessions with diverse origins revealed three well-differentiated tea plant populations,support-ing the proposition for the southwest origin of the Chinese cultivated tea plant and its later spread to western Asia through introduction.Domestication and modern breeding left significant signatures on hundreds of genes in the tea plant genome,particularly those associated with tea quality and stress resis-tance.The genomic sequences of the reported reference and resequenced tea plant accessions provide valuable resources for future functional genomics study and molecular breeding of improved cul-tivars of tea plants.展开更多
Bckground Stem cells, which have the ability to differentiate into insulin-producing cells （IPCs）, would provide a potentially unlimited source of islet cells for transplantation and alleviate the major limitations ...Bckground Stem cells, which have the ability to differentiate into insulin-producing cells （IPCs）, would provide a potentially unlimited source of islet cells for transplantation and alleviate the major limitations of availability and allogeneic rejection. Therefore, the utilization of stem cells is becoming the most promising therapy for diabetes mellitus （DM）. Here, we studied the differentiation capacity of the diabetic patient＇s bone marrow-derived mesenchymal stem cells （MSCs） and tested the feasibility of using MSCs for β-cell replacement. Methods Bone marrow-derived MSCs were obtained from 10 DM patients （5 type 1 DM and 5 type 2 DM） and induced to IPCs under a three-stage protocol. Representative cell surface antigen expression profiles of MSCs were analysed by flow cytometric analysis. Reverse transcription-polymerase chain reaction （RT-PCR） was performed to detect multiple genes related to pancreatic β-cell development and function. The identity of the IPCs was illustrated by the analysis of morphology, ditizone staining and immunocytochemistry. Release of insulin by these cells was confirmed by immunoradioassay. Results Flow cytometric analysis of MSCs at passage 3 showed that these cells expressed high levels of CD29 （98.28%）, CD44 （99.56%） and CD106 （98.34%）. Typical islet-like cell clusters were observed at the end of the protocol （18 days）. Ditizone staining and immunohistochemistry for insulin were both positive. These differentiated cells at stage 2 （10 days） expressed nestin, pancreatic duodenal homeobox-1 （PDX-1）, Neurogenin3, Pax4, insulin, glucagon, but at stage 3 （18 days） we observed the high expression of PDX-1, insulin, glucagon. Insulin was secreted by these cells in response to different concentrations of glucose stimulation in a regulated manner （P〈0.05）. Conclusions Bone marrow-derived MSCs from DM patients can differentiate into functional IPCs under certain conditions in vitro. Using diabetic patient＇s own bone marrow-deriv展开更多
Recent evidence indicates that mesenchymal stem cells （MSC） possess immunosuppressive properties both in vitro and in vivo. We previously demonstrated the functional abnormality of bone marrow derived MSC in patient...Recent evidence indicates that mesenchymal stem cells （MSC） possess immunosuppressive properties both in vitro and in vivo. We previously demonstrated the functional abnormality of bone marrow derived MSC in patients with systemic lupus erythematosus （SLE）. In this study, we aimed to investigate whether transplantation of human bone marrow derived MSC affects the autoimmune pathogenesis in MRL/Ipr mice. We found that human MSC from healthy donors reduced the proliferation of T lymphocytes from MRL/Ipr mice in a dose-dependent fashion. Two weeks after in vivo transfer of MSC, we detected significantly reduced serum levels of anti ds-DNA antibodies and 24 hour proteinuria in MRL/Ipr mice as compared with control groups without MSC transplantation. Moreover, flow cytometric analysis revealed markedly reduced number of CD4＋ T cells while increased Thl subpopulation in MSC group and MSC ＋ CTX group when compared with controls. Histopathological examination showed significantly reduced renal pathology in MSC-treated mice. Immunohistochemical studies further revealed reduced expression of TGF-~, FN, VEGF and the deposition of complement C3 in renal tissue after MSC and MSC ＋ CTX treatment. Taken together, we have demonstrated that transplantation of human MSC can significantly inhibit the autoimmune progression in MRL/Ipr mice. Cellular ＆ Molecular Immunology. 2008;5（6）：417-424.展开更多
Achieving both high yield and high nitrogen use efficiency （NUE） simultaneously has become a major challenge with increased global demand for food, depletion of natural resources, and deterioration of environment. A...Achieving both high yield and high nitrogen use efficiency （NUE） simultaneously has become a major challenge with increased global demand for food, depletion of natural resources, and deterioration of environment. As the greatest consumers of N fertilizer in the world, Chinese farmers have overused N, and there has been poor synchrony between crop N demand and N supply because of limited understanding of the N uptake-yield relationship. To address this problem, this study evaluated the total and dynamic N requirement for different yield ranges of two major crops （maize and wheat）, and suggested improvements to N management strategies. Whole-plant N aboveground uptake requirement per grain yield （Nreq） initially deceased with grain yield improvement and then stagnated, and yet most farmers still believed that more fertilizer and higher grain yield were synonymous. When maize yield increased from 〈 7.5 to 〉 12.0 Mg ha-I, Nreq decreased from 19.8 to 17.0 kg Mg-1 grain. For wheat, it decreased from 27.1 kg Mg-1 grain for grain yield 〈 4.5 Mg ha-1 to 22.7 kg Mg-1 grain for yield 〉 9.0 Mg ha-1. Meanwhile, the percentage of dry matter and N accumulation in the middle-late growing season increased significantly with grain yield, which indicated that N fertilization should be concentrated in the middle-late stage to match crop demand while farmers often applied the majority of N fertilizer either before sowing or during early growth stages. We accordingly developed an integrated soil-crop system management strategy that simultaneously increases both grain yield and NUE.展开更多
Stable and safe operation of power grids is an important guarantee for economy development.Support Vector Machine(SVM)based stability analysis method is a significant method started in the last century.However,the SVM...Stable and safe operation of power grids is an important guarantee for economy development.Support Vector Machine(SVM)based stability analysis method is a significant method started in the last century.However,the SVM method has several drawbacks,e.g.low accuracy around the hyperplane and heavy computational burden when dealing with large amount of data.To tackle the above problems of the SVM model,the algorithm proposed in this paper is optimized from three aspects.Firstly,the gray area of the SVM model is judged by the probability output and the corresponding samples are processed.Therefore the clustering of the samples in the gray area is improved.The problem of low accuracy in the training of the SVM model in the gray area is improved,while the size of the sample is reduced and the efficiency is improved.Finally,by adjusting the model of the penalty factor in the SVM model after the clustering of the samples,the number of samples with unstable states being misjudged as stable is reduced.Test results on the IEEE 118-bus test system verify the proposed method.展开更多
A novel integrated guidance and autopilot design method is proposed for homing missiles based on the adaptive block dynamic surface control approach. The fully integrated guidance and autopilot model is established by...A novel integrated guidance and autopilot design method is proposed for homing missiles based on the adaptive block dynamic surface control approach. The fully integrated guidance and autopilot model is established by combining the nonlinear missile dynamics with the nonlinear dynamics describing the pursuit situation of a missile and a target in the three-dimensional space. The integrated guidance and autopilot design problem is further converted to a state regulation problem of a time-varying nonlinear system with matched and unmatched uncertainties. A new and simple adaptive block dynamic surface control algorithm is proposed to address such a state regulation problem. The stability of the closed-loop system is proven based on the Lyapunov theory. The six degrees of freedom （6DOF） nonlinear numerical simulation results show that the proposed integrated guidance and autopilot algorithm can ensure the accuracy of target interception and the robust stability of the closed-loop system with respect to the uncertainties in the missile dynamics.展开更多
The seed germination and seedling growth of pakchoi （Brassica campestris ssp. chinensis var. communis Tsen et Lee cv. Hanxiao） were not significantly inhibited until the concentration of NaCl was increased to 150 mm...The seed germination and seedling growth of pakchoi （Brassica campestris ssp. chinensis var. communis Tsen et Lee cv. Hanxiao） were not significantly inhibited until the concentration of NaCl was increased to 150 mmol/L. Treatment of pakchoi seeds with exogenous 5-aminolevulinic acid （ALA）, at concentrations ranging from 0.01 to 10.00 mg/L, promoted seed germination when seeds were stressed by salinity, whereas levulinic acid （LA）, an inhibitor of ALA dehydrase, significantly inhibited seed germination and seedling growth, suggesting that metabolism of ALA into porphyrin compounds was necessary for seed germination and seedling growth. Determination of respiratory rate during seed germination showed that ALA increased seed respiration under both normal conditions and salt stress. Furthermore, salt stress decreased levels of endogenous ALA, as well as heme, in etiolated seedlings. More salt-tolerant cultivars of pakchoi contained higher relative levels of endogenous ALA and heme under conditions of salt stress. These results indicate that salt stress may inhibit the biosynthesis of endogenous ALA and then heme, which is necessary for seed germination, and treatment of seeds with exogenous ALA prior to germination may be associated with the biosynthesis of heme.展开更多
Network pharmacology is a powerful tool to reflect the pharmacologically active effects,mechanism of action and toxic activity of traditional Chinese medicines(TCMs).The ingredients of TCMs,associated with quality con...Network pharmacology is a powerful tool to reflect the pharmacologically active effects,mechanism of action and toxic activity of traditional Chinese medicines(TCMs).The ingredients of TCMs,associated with quality control of TCM products,are those fundamental chemicals that exhibit biological activities.A great amount of effort has been made by scientists in that field in order to improve the quality of TCMs,though the approaches to determine their quality and the TCM theory and compatibility rules remain ambiguous.Now some methods and technologies must be applied to predict and explore the quality marker(Q-marker)for quality control,as well as to clarify the factors affecting the quality of TCM,which may give new insight into rational ground of establishment of appropriate quality control and assessment system.In this review paper,authors focus on the prediction of quality markers of TCMs by network pharmacology based on three aspects:(1)from network medicine to network pharmacology,(2)complex network system of traditional Chinese medicine,and(3)predicting TCM quality markers based on network pharmacology.Authors proposed the research pattern on network pharmacology based on biological and medical networks,and further TCM network pharmacology based on substantial basis of TCM formulae,and the idea of"effect-ingredient-target-fingerprint"to predict and recognize the TCM Qmarker was the ultimate goal.In addition,authors yet noted how to make full use of the advantages of network toxicology to provide new ideas for the toxicity study of complex TCM systems and the prediction of TCM toxicity markers.展开更多
文摘The 12 May 2008 Wenchuan earthquake （Ms=8.0） struck on the Longmen Shan foreland thrust zone. The event took place within the context of long-term uplift of the Longmen Shan range as a result of the extensive eastward-extrusion of crustal materials from the Tibetan plateau against the rheologically strong crust of the Sichuan Basin. The Longmen Shan range is charac- terized by a Pre-Sinian crystalline complex constrained by the Maoxian-Wenchuan-Kangding ductile detach- ment at the western margin and the Yingxiu-Beichuan- Luding ductile thrust at the eastern margin. The Long- men Shan uplift was initiated by intracontinental sub- duction between the Songpan-Ganzi terrane and the Yangtze block during the Pre-Cenozoic. The uplift rate was increased considerably by the collision between the Indian and Eurasian plates since -50 Ma. The Wenchuan earthquake resulted in two major NE-strik- ing coseismic ruptures （i.e., the -275 km long Yingxiu- Beichuan-Qingchuan fault and the -100 km long Anx- ian-Guanxian fault）. Field investigations combined with focal solutions and seismic reflection profiles suggest that the coseismic ruptures are steeply dipping close-to- pure reverse or right reverse oblique slip faults in the -15 km thick upper crust. These faults are unfavorably oriented for frictional slip in the horizontally compres- sional regime, so that they need a long recurrence interval to accumulate the tectonic stress and fluid pres- sure to critically high levels for the formation of strong earthquakes at a given locality. It is also found that all the large earthquakes （Ms〉7.0） occurred in the fault zones across which the horizontal movement velocities measured by the GPS are markedly low （〈3 mm/yr）. The faults, which constitute the northeastern fronts of the enlarging Tibetan plateau against the strong Sichuan Basin, Ala Shan and Ordos blocks, are very destructive, although their average recurrence intervals are generally long.
文摘Dear Editor,Genome editing technologies enable precise modifications of DNA sequences in vivo and offer great promise for crop improvement. CRISPR/Cas9 （Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR-associated Cas9） has revolution- ized genome editing because of its simplicity and versatility （Cong et al., 2013）.
基金National Natural Science Fundantion of China(No.81430096)
文摘Chinese medicine （CM） is the most typical conventional therapy compared with any other traditional or alternative medicine systems. The active components of CMs are either primary or secondary metabolites generated by metabolic and biosynthetic enzymes in plants, protecting the plants from environmental stress. The characteristics of these metabolites are diverse, complicated and unique. In this paper, current approaches for quality assessment were extensively reviewed, a new concept of quality marker （Q-marker） was then proposed for CM quality assessment. Additionally, definition of the Q-marker, as well as the relevant methods, were discussed, on the basis of the biosynthetic pathways of secondary metabolites and source of biological active components. Study design of Q-marker is complex system for quality assessment and production process control of CM products with transitivity and traceability. Therefore, the system with characteristics of transmission and traceability is expected to be established for regulation of quality. Upon the concept which the transitivity and traceability in the quality assessment and production process control covered the entire process, such as raw materials, decoction slices, processing, extraction and production can be further enhanced. The transitivity and traceability will inevitably require close attention to ＂who, what, where, when, and why＂ details at each stage of Q-markers of CM production form raw materials to patent product. The establishing quality standards are enablers of many and various transitivity and traceability solutions, not a solution in them. It means that the transitivity and traceability system is readily link between products and across borders in quality. According to the thinking mode and methods of investigation on quality assessment of CM product, we focus on the entire process, in terms of safety and effectiveness and quality control. The standard preparation of CM or CM decoction is not only the basis for study of Q-marker, but also the
基金This work was jointly supported by the Chinese Academy of Sciences (Grant No. KZCX1-07) the Ministry of Science and Technology of China (Grant No. G1999402307)the National Natural Science Foundation of China (Grant. No. 40234050).
文摘An important tectonic inversion took place in eastern North China Block(NCB) during Mesozoic, which caused a great lithosphere thinning, reconstruction of basin-range series, powerful interaction between mantle and crust, a vast granitic intrusion and volcanism, and large-scale metallogenic explosion. The time range of the Mesozoic tectonic regime inversion in the eastern North China Block is one of the key issues to understand mechanism of tectonic regime inversion. Our updated results for recognizing the time range are mainly obtained from the following aspects: structural analyses along northern and southern margins of the NCB and within the NCB for revealing tectonic inversion from compression to extension and structural striking from ~EW to NNE; geothermic analyses of the eastern sedimental basins for a great change of thermal history and regime; basin analysis for basin inversion from compression to extension and basin migration from ~EW to NNE; petrological and geochemical studies of volcanic rocks and lowermost crust xenoliths for recognizing peak period of mantle upwelling and intense interaction between mantle and crust, and main metallogenic epoch. All the studies of the above give the same time range from~150-140 Ma to ~110-100Ma, peaking at ~120 Ma.
基金The authors would like to thank the patients and their families for their contribution to this studyThis study was supported by the National Science and Technology Major Project of China(2008ZX10002-006,2012ZX10002007001,2017ZX10202203-007,2017ZX10202203-008)+2 种基金the National Natural Science Foundation of China(81171561,30972584)This study was also supported in part by Shanghai Roche Pharmaceuticals LtdWriting assistance was provided by Stefanie Chuah,from Mudskipper Business Ltd,funded by F Hoffmann-La Roche
文摘Background and Aims:Hepatitis B surface antigen(HBsAg)loss is seldom achieved with nucleos(t)ide analog(NA)therapy in chronic hepatitis B patients but may be enhanced by switching to finite pegylated-interferon(Peg-IFN)alfa-2a.We assessed HBsAg loss with 48-and 96-week Peg-IFN alfa-2a in chronic hepatitis B patients with partial response to a previous NA.Methods:Hepatitis B e antigen(HBeAg)-positive patients who achieved HBeAg loss and hepatitis B virus DNA<200 IU/mL with previous adefovir,lamivudine or entecavir treatment were randomized 1:1 to receive Peg-IFN alfa-2a for 48(n=153)or 96 weeks(n=150).The primary endpoint of this study was HBsAg loss at end of treatment.The ClinicalTrials.gov identifier is NCT01464281.Results:At the end of 48 and 96 weeks'treatment,14.4%(22/153)and 20.7%(31/150)of patients,respectively,who switched from NA to Peg-IFN alfa-2a cleared HBsAg.Rates were similar irrespective of prior NA or baseline HBeAg seroconversion.Among those who cleared HBsAg by the end of 48 and 96 weeks'treatment,77.8%(14/18)and 71.4%(20/28),respectively,sustained HBsAg loss for a further 48 weeks.Baseline HBsAg<1500 IU/mL and week 24 HBsAg<200 IU/mL were associated with the highest rates of HBsAg loss at the end of both 48-and 96-week treatment(51.4%and 58.7%,respectively).Importantly,extending treatment from 48 to 96 weeks enabled 48.3%(14/29)more patients to achieve HBsAg loss.Conclusions:Patients on long-term NA who are unlikely to meet therapeutic goals can achieve high rates of HBsAg loss by switching to Peg-IFN alfa-2a.HBsAg loss rates may be improved for some patients by extending treatment from 48 to 96 weeks,although the differences in our study cohort were not statistically significant.Baseline and on-treatment HBsAg may predict HBsAg loss with Peg-IFN alfa-2a.
基金supported by the State Key Laboratory of Lithospheric Evolution and the Ministry of Science and Technology of China(2007AA06Z126)
文摘Zircon is the most useful mineral for studies in U-Pb geochronology and Hf and O isotope geochemistry.Matrix effect is a major problem of the microbeam techniques such as SIMS and LA-(MC)-ICPMS.Therefore,external standardization using well-characterized natural zircon standards is fundamental for accurate microbeam measurements.While the isotopic geochronology and geochemistry laboratories equipped with microbeam analytical facilities have been increasingly established in China during the past decade,applications of the isotopic microanalysis are still limited due to shortage of available standards.We report here the Qinghu zircon as a potential new working reference for microbeam analysis of zircon U-Pb age and O-Hf isotopes.This zircon was separated from the Qinghu quartz monzonite from the western Nanling Range,Southeast China.It is fairly homogeneous in U-Pb age and Hf and O isotopes in terms of large amounts of mircobeam measurements by LA-MC-ICPMS and SIMS at the scales of 20–60 m.SIMS measurements yield consistent206Pb/238U age within analytical uncertainties with that obtained by ID-TIMS.Precise determinations of O isotopes by IRMS and Hf isotopes by solution MC-ICPMS are in good agreement with the statistical mean of microbeam measurements.We recommend U-Pb age of=159.5±0.2 Ma(2SE),18O=5.4‰±0.2‰(2SD)and176Hf/177Hf=0.283002±0.000004(2SD)as the best reference values for the Qinghu zircon.
基金supported by grants from the National Natural Science Foundation of China (Grant No. 81402392, 81472580, 81502322)Tianjin Municipal Science and technology project (Grant No. 15JCQNJC12800 and 17YFZCSY00690)
文摘Objective: The purposes of this study were to identify risk factors for cervical lymph node metastasis and to examine the association between BRAF^(V600E) status and clinical features in papillary thyroid microcarcinoma(PTMC).Methods: A total of 1,587 patients with PTMC, treated in Tianjin Medical University Cancer Institute and Hospital from January2011 to March 2013, underwent retrospective analysis. We reviewed and analyzed factors including clinical results, pathology records, ultrasound results, and BRAF^(V600E) status.Results: Multivariate logistic regression analyses demonstrated that gender(male) [odds ratio(OR) = 1.845, P = 0.000], age(< 45 years)(OR = 1.606, P = 0.000), tumor size(> 6 mm)(OR = 2.137, P = 0.000), bilateralism(OR = 2.011, P = 0.000) and extrathyroidal extension(OR = 1.555, P = 0.001) served as independent predictors of central lymph node metastasis(CLNM).Moreover, CLNM(OR = 29.354, P = 0.000) served as an independent predictor of lateral lymph node metastasis(LLNM). Among patients with a solitary primary tumor, those with tumor location in the lower third of the thyroid lobe or the isthmus were more likely to experience CLNM(P < 0.05). Univariate analyses indicated that CLNM, LLNM, extrathyroidal extension, and multifocality were not significantly associated with BRAF^(V600E) mutation.Conclusions: The present study suggested that prophylactic neck dissection of the central compartment should be considered in patients with PTMC, particularly in men with tumor size greater than 6 mm, age less than 45 years, extrathyroidal extension, and tumor bilaterality. Among patients with PTMC, BRAF^(V600E) mutation is not significantly associated with prognostic factors. For a better understanding of surgical management of PTMC and the risk factors, we recommend multicenter research and long-term follow-up.
文摘AIM: To explore the role of psychological factors in gastroesophageal reflux disease(GERD) and their effect on quality of life(Qo L) of GERD patients.METHODS: A total of 279 consecutive patients with typical symptoms and 100 healthy controls were enrolled in the study.All of the participants wereevaluated with the Zung Self-Rating Anxiety Scale(ZSAS), the Zung Self-Rating Depression Scale(ZSDS) and the SF-36 questionnaire.The scores for anxiety, depression and Qo L of the two groups were analyzed.The correlation between psychological factors and Qo L was also analyzed.RESULTS: Compared with healthy controls(34.70 ± 8.00), the scores of ZSAS in the non-erosive reflux disease( N E R D) group(48.27±10.34) and the reflux esophagitis(RE) group(45.38 ± 10.27) were significantly higher(P < 0.001).The mean ZSAS score of the NERD group was significantly higher than that of the RE group(P = 0.01).Compared with healthy controls(37.61 ± 8.44), the mean ZSDS scores were significantly higher in the NERD group(49.65 ± 11.09, P < 0.001) and the RE group(46.76 ± 11.83, P < 0.001).All dimensions of the SF-36 form were negatively correlated with the SAS and SDS scores in patients with NERD and RE(P < 0.05).According to the S F- 3 6 form, vitality, mentalhealth and social functioning were significantly correlated with symptoms of depression in patients with NERD and RE.General health was obviously affected by symptoms of depression in patients with NERD(P < 0.05).CONCLUSION: Anxiety and depression may play an important role in the occurrence of GERD and especially that of NERD.The Qo L of patients with GERD is reduced by anxiety and depression.
基金supported by Natural Science Foundation of Heilongjiang Province of China(E2017030,ZD2017010)National Natural Science Foundation of China(51671063,51771060,51871069)+1 种基金Fundamental Research Funds for the Central Universities(HEUCFM181002)Foundation of State Key Laboratory of Rare Earth Resources Utilization(RERU2018017).
文摘Higher strength is always the goal pursued by researchers for the structural materials,especially for the lightweight magnesium(Mg)alloys which generally have relatively low strength at present.From this aspect,the present paper reviews the recent reports of a kind of Mg alloys,i.e.Mg-RE(RE:rare earths,mainly Gd or Y)casting and wrought alloys,which have been able to achieve high strength compared with common or commercial Mg alloys,from the viewpoint and content of the alloy system,alloying constitution,preparation process,tensile strength and each of the main strengthening mechanisms.This review of recent research and developments in high-strength Mg-RE alloys is beneficial for the further design of Mg alloys with higher strength as well as excellent comprehensive performance.
基金This work was supported by the grants from the National 973 Program （No. 2012CB517703 and No. 2011CB504005）, the National Natural Science Foundation of China （No. U0932002）, and the Public Welfare and Health Sector Research Project （No. 201002010）.
文摘Background Understanding the characteristics of Chinese dialysis patients and the current practice trends is the first step to evaluate the association between practice pattern and outcome in these populations. In the present study, we evaluated the status of medical treatment and characteristic features of chronic dialysis patients in China. Methods Through a clustering sampling, we selected 9 centers from the largest dialysis facilities in 6 cities around China. All adult undergoing dialysis in the selected units were screened. A total of 2388 （1775 on hemodialysis （HD） and 613 on peritoneal dialysis （PD）） patients were finally enrolled. All data were collected at enrollment on the bases of review of medical records. Results In this cohort, 1313 （55.0%） were male. The mean age was 54 years old. The median time for dialysis was 26 months （12-51 months）. Seventy-five percent of patients were on HD and 25.0% on PD. Among PD patients, about 21% patients did not receive dialysis adequacy. For HD patients, about 14.0% of them did not achieve dialysis adequacy when the target of kt/V was set as 1.2. Only 44.7% of patients achieved blood pressure target of 140/90 mmHg. About 60% of patients did not reach the hemoglobin target of 110 g/L even though 85.0% of them were treated with erythropoietin. In addition, 48.5% of the patients had uncontrolled mineral metabolism revealed by the high calcium-phosphate product. Compared with HD patients, higher level of serum glucose, triglyceride, and total and low density lipoprotein cholesterol were more common in PD patients. Conclusions This observational study suggests that many Chinese dialysis patients did not achieve the therapeutic target, particularly in blood pressure control, anemia correction, and mineral balance. PD patients were more likely to suffer metabolic disturbance.
基金This work was supported by the National Key Research and Development Program of China(2018YFD1000601 and 2019YFD1001601)the National Natural Science Foundation of China(31800180)+2 种基金the Natural Science Foundation of Anhui Province of China(1908085MC75)the China Postdoctoral Science Foundation(2017M621992)and the special funds for tea germplasm garden construction(2060502 and 201834040003).
文摘Tea plant is an important economic crop,which is used to produce the world's oldest and most widely consumed tea beverages.Here,we present a high-quality reference genome assembly of the tea plant(Camellia sinensis var.sinensis)consisting of 15 pseudo-chromosomes.LTR retrotransposons(LTR-RTs)account for 70.38%of the genome,and we present evidence that LTR-RTS play critical roles in genome size expansion and the transcriptional diversification of tea plant genes through preferential insertion in promoter regions and introns.Genes,particularly those coding for terpene biosynthesis pro-teins,associated with tea aroma and stress resistance were significantly amplified through recent tandem duplications and exist as gene clusters in tea plant genome.Phylogenetic analysis of the sequences of 81 tea plant accessions with diverse origins revealed three well-differentiated tea plant populations,support-ing the proposition for the southwest origin of the Chinese cultivated tea plant and its later spread to western Asia through introduction.Domestication and modern breeding left significant signatures on hundreds of genes in the tea plant genome,particularly those associated with tea quality and stress resis-tance.The genomic sequences of the reported reference and resequenced tea plant accessions provide valuable resources for future functional genomics study and molecular breeding of improved cul-tivars of tea plants.
文摘Bckground Stem cells, which have the ability to differentiate into insulin-producing cells （IPCs）, would provide a potentially unlimited source of islet cells for transplantation and alleviate the major limitations of availability and allogeneic rejection. Therefore, the utilization of stem cells is becoming the most promising therapy for diabetes mellitus （DM）. Here, we studied the differentiation capacity of the diabetic patient＇s bone marrow-derived mesenchymal stem cells （MSCs） and tested the feasibility of using MSCs for β-cell replacement. Methods Bone marrow-derived MSCs were obtained from 10 DM patients （5 type 1 DM and 5 type 2 DM） and induced to IPCs under a three-stage protocol. Representative cell surface antigen expression profiles of MSCs were analysed by flow cytometric analysis. Reverse transcription-polymerase chain reaction （RT-PCR） was performed to detect multiple genes related to pancreatic β-cell development and function. The identity of the IPCs was illustrated by the analysis of morphology, ditizone staining and immunocytochemistry. Release of insulin by these cells was confirmed by immunoradioassay. Results Flow cytometric analysis of MSCs at passage 3 showed that these cells expressed high levels of CD29 （98.28%）, CD44 （99.56%） and CD106 （98.34%）. Typical islet-like cell clusters were observed at the end of the protocol （18 days）. Ditizone staining and immunohistochemistry for insulin were both positive. These differentiated cells at stage 2 （10 days） expressed nestin, pancreatic duodenal homeobox-1 （PDX-1）, Neurogenin3, Pax4, insulin, glucagon, but at stage 3 （18 days） we observed the high expression of PDX-1, insulin, glucagon. Insulin was secreted by these cells in response to different concentrations of glucose stimulation in a regulated manner （P〈0.05）. Conclusions Bone marrow-derived MSCs from DM patients can differentiate into functional IPCs under certain conditions in vitro. Using diabetic patient＇s own bone marrow-deriv
基金supported by grants from the National Natural Science Foundation of China (No. 30772014)the Chinese Education Ministry Fundation (No. 20050315001)Jiangsu Province 135 Talent Foundation (No. RC2007002)
文摘Recent evidence indicates that mesenchymal stem cells （MSC） possess immunosuppressive properties both in vitro and in vivo. We previously demonstrated the functional abnormality of bone marrow derived MSC in patients with systemic lupus erythematosus （SLE）. In this study, we aimed to investigate whether transplantation of human bone marrow derived MSC affects the autoimmune pathogenesis in MRL/Ipr mice. We found that human MSC from healthy donors reduced the proliferation of T lymphocytes from MRL/Ipr mice in a dose-dependent fashion. Two weeks after in vivo transfer of MSC, we detected significantly reduced serum levels of anti ds-DNA antibodies and 24 hour proteinuria in MRL/Ipr mice as compared with control groups without MSC transplantation. Moreover, flow cytometric analysis revealed markedly reduced number of CD4＋ T cells while increased Thl subpopulation in MSC group and MSC ＋ CTX group when compared with controls. Histopathological examination showed significantly reduced renal pathology in MSC-treated mice. Immunohistochemical studies further revealed reduced expression of TGF-~, FN, VEGF and the deposition of complement C3 in renal tissue after MSC and MSC ＋ CTX treatment. Taken together, we have demonstrated that transplantation of human MSC can significantly inhibit the autoimmune progression in MRL/Ipr mice. Cellular ＆ Molecular Immunology. 2008;5（6）：417-424.
基金supported by the National Basic Research Program(973 Program) of China(No.2015CB150402)the National Maize Production System in China(No.CARS-02-24)+1 种基金the Special Fund for Agroscientific Research in the Public Interest of China (No.201103003)the Innovative Group Grant of the NSFC,China(No.31421092)
文摘Achieving both high yield and high nitrogen use efficiency （NUE） simultaneously has become a major challenge with increased global demand for food, depletion of natural resources, and deterioration of environment. As the greatest consumers of N fertilizer in the world, Chinese farmers have overused N, and there has been poor synchrony between crop N demand and N supply because of limited understanding of the N uptake-yield relationship. To address this problem, this study evaluated the total and dynamic N requirement for different yield ranges of two major crops （maize and wheat）, and suggested improvements to N management strategies. Whole-plant N aboveground uptake requirement per grain yield （Nreq） initially deceased with grain yield improvement and then stagnated, and yet most farmers still believed that more fertilizer and higher grain yield were synonymous. When maize yield increased from 〈 7.5 to 〉 12.0 Mg ha-I, Nreq decreased from 19.8 to 17.0 kg Mg-1 grain. For wheat, it decreased from 27.1 kg Mg-1 grain for grain yield 〈 4.5 Mg ha-1 to 22.7 kg Mg-1 grain for yield 〉 9.0 Mg ha-1. Meanwhile, the percentage of dry matter and N accumulation in the middle-late growing season increased significantly with grain yield, which indicated that N fertilization should be concentrated in the middle-late stage to match crop demand while farmers often applied the majority of N fertilizer either before sowing or during early growth stages. We accordingly developed an integrated soil-crop system management strategy that simultaneously increases both grain yield and NUE.
基金This work was supported by China’s National key research and development program 2017YFB0902201National Natural Science Foundation of China under Grant 51777104Science and Technology Project of the State Grid Corporation of China.
文摘Stable and safe operation of power grids is an important guarantee for economy development.Support Vector Machine(SVM)based stability analysis method is a significant method started in the last century.However,the SVM method has several drawbacks,e.g.low accuracy around the hyperplane and heavy computational burden when dealing with large amount of data.To tackle the above problems of the SVM model,the algorithm proposed in this paper is optimized from three aspects.Firstly,the gray area of the SVM model is judged by the probability output and the corresponding samples are processed.Therefore the clustering of the samples in the gray area is improved.The problem of low accuracy in the training of the SVM model in the gray area is improved,while the size of the sample is reduced and the efficiency is improved.Finally,by adjusting the model of the penalty factor in the SVM model after the clustering of the samples,the number of samples with unstable states being misjudged as stable is reduced.Test results on the IEEE 118-bus test system verify the proposed method.
基金the Fundamental Research Funds for the Central Universities(No.HIT.NSRIF.2013039)the National Natural Science Foundation of China(Nos.61203125 and 61021002)
文摘A novel integrated guidance and autopilot design method is proposed for homing missiles based on the adaptive block dynamic surface control approach. The fully integrated guidance and autopilot model is established by combining the nonlinear missile dynamics with the nonlinear dynamics describing the pursuit situation of a missile and a target in the three-dimensional space. The integrated guidance and autopilot design problem is further converted to a state regulation problem of a time-varying nonlinear system with matched and unmatched uncertainties. A new and simple adaptive block dynamic surface control algorithm is proposed to address such a state regulation problem. The stability of the closed-loop system is proven based on the Lyapunov theory. The six degrees of freedom （6DOF） nonlinear numerical simulation results show that the proposed integrated guidance and autopilot algorithm can ensure the accuracy of target interception and the robust stability of the closed-loop system with respect to the uncertainties in the missile dynamics.
基金the Overseas Scholarship Foundation of the Chinese Education Department，国家自然科学基金
文摘The seed germination and seedling growth of pakchoi （Brassica campestris ssp. chinensis var. communis Tsen et Lee cv. Hanxiao） were not significantly inhibited until the concentration of NaCl was increased to 150 mmol/L. Treatment of pakchoi seeds with exogenous 5-aminolevulinic acid （ALA）, at concentrations ranging from 0.01 to 10.00 mg/L, promoted seed germination when seeds were stressed by salinity, whereas levulinic acid （LA）, an inhibitor of ALA dehydrase, significantly inhibited seed germination and seedling growth, suggesting that metabolism of ALA into porphyrin compounds was necessary for seed germination and seedling growth. Determination of respiratory rate during seed germination showed that ALA increased seed respiration under both normal conditions and salt stress. Furthermore, salt stress decreased levels of endogenous ALA, as well as heme, in etiolated seedlings. More salt-tolerant cultivars of pakchoi contained higher relative levels of endogenous ALA and heme under conditions of salt stress. These results indicate that salt stress may inhibit the biosynthesis of endogenous ALA and then heme, which is necessary for seed germination, and treatment of seeds with exogenous ALA prior to germination may be associated with the biosynthesis of heme.
基金supported by National Nature Science Foundation for Key Projects(No.81430096)National New Drug Innovation(No.2017ZX09301062.)Tianjin Science and Technology Plan Project(No.19YFSLQY00110).
文摘Network pharmacology is a powerful tool to reflect the pharmacologically active effects,mechanism of action and toxic activity of traditional Chinese medicines(TCMs).The ingredients of TCMs,associated with quality control of TCM products,are those fundamental chemicals that exhibit biological activities.A great amount of effort has been made by scientists in that field in order to improve the quality of TCMs,though the approaches to determine their quality and the TCM theory and compatibility rules remain ambiguous.Now some methods and technologies must be applied to predict and explore the quality marker(Q-marker)for quality control,as well as to clarify the factors affecting the quality of TCM,which may give new insight into rational ground of establishment of appropriate quality control and assessment system.In this review paper,authors focus on the prediction of quality markers of TCMs by network pharmacology based on three aspects:(1)from network medicine to network pharmacology,(2)complex network system of traditional Chinese medicine,and(3)predicting TCM quality markers based on network pharmacology.Authors proposed the research pattern on network pharmacology based on biological and medical networks,and further TCM network pharmacology based on substantial basis of TCM formulae,and the idea of"effect-ingredient-target-fingerprint"to predict and recognize the TCM Qmarker was the ultimate goal.In addition,authors yet noted how to make full use of the advantages of network toxicology to provide new ideas for the toxicity study of complex TCM systems and the prediction of TCM toxicity markers.
