Objective To investigate the serum lipid profiles of patients with localized osteosarcoma around the knee joint before and after neoadjuvant chemotherapy.Methods After retrospectively screening the data of 742 patient...Objective To investigate the serum lipid profiles of patients with localized osteosarcoma around the knee joint before and after neoadjuvant chemotherapy.Methods After retrospectively screening the data of 742 patients between January 2007 and July 2020,50 patients aged 13 to 39 years with Enneking stage II disease were included in the study.Serum lipid levels,including total cholesterol(TC),triglycerides(TG),high-density lipoprotein cholesterol(HDL-C),low-density lipoprotein cholesterol(LDL-C),lipoprotein-α[Lp(a)],and apolipoprotein A1,B,and E(ApoA1,ApoB,and ApoE),and clinicopathological characteristics were collected before and after neoadjuvant chemotherapy.Results The mean levels of TC,TG,and ApoB were significantly increased following neoadjuvant chemotherapy(16%,38%,and 20%,respectively,vs.pretreatment values;P<0.01).The mean levels of LDL-C and ApoE were also 19%and 16%higher,respectively(P<0.05).No correlation was found between the pretreatment lipid profile and the histologic response to chemotherapy.An increase in Lp(a)was strongly correlated with the Ki-67 index(R=0.31,P=0.023).Moreover,a trend toward longer disease-free survival(DFS)was observed in patients with decreased TG and increased LDL-C following chemotherapy,although this difference was not statistically significant(P=0.23 and P=0.24,respectively).Conclusion Significant elevations in serum lipids were observed after neoadjuvant chemotherapy in patients with localized osteosarcoma.There was no prognostic significance of pretreatment serum lipid levels on histologic response to neoadjuvant chemotherapy.The scale of increase in serum Lp(a)might have a potential prognostic role in osteosarcoma.Patients with increased LDL-C or reduced TG after chemotherapy seem to exhibit a trend toward favorable DFS.展开更多
BACKGROUND Pancreatic adenocarcinoma,a malignancy that arises in the cells of the pancreas,is a devastating disease with unclear etiology and often poor prognosis.Locally advanced pancreatic cancer,a stage where the t...BACKGROUND Pancreatic adenocarcinoma,a malignancy that arises in the cells of the pancreas,is a devastating disease with unclear etiology and often poor prognosis.Locally advanced pancreatic cancer,a stage where the tumor has grown significantly but has not yet spread to distant organs,presents unique challenges in treatment.This article aims to discuss the current strategies,challenges,and future directions in the management of locally advanced pancreatic adenocarcinoma(LAPC).AIM To investigate the feasibility and efficacy of programmed cell death 1(PD-1)inhibitor sintilimab plus concurrent chemoradiotherapy for LAPC.METHODS Eligible patients had LAPC,an Eastern cooperative oncology group performance status of 0 or 1,adequate organ and marrow functions,and no prior anticancer therapy.In the observation group,participants received intravenous sintilimab 200 mg once every 3 wk,and received concurrent chemoradiotherapy(concurrent conventional fractionated radiotherapy with doses planning target volume 50.4 Gy and gross tumor volume 60 Gy in 28 fractions and oral S-140 mg/m2 twice daily on days 1-14 of a 21-d cycle and intravenous gemcitabine 1000 mg/m2 on days 1 and 8 of a 21-d cycle for eight cycles until disease progression,death,or unacceptable toxicity).In the control group,participants only received concurrent chemoradiotherapy.From April 2020 to November 2021,64 participants were finally enrolled with 34 in the observation group and 30 in the control group.RESULTS Thirty-four patients completed the scheduled course of chemoradiotherapy,while 32(94.1%)received sintilimab plus concurrent chemoradiotherapy with 2 patients discontinuing sintilimab in the observation group.Thirty patients completed the scheduled course of chemoradiotherapy in the control group.Based on the Response Evaluation Criteria in Solid Tumors guidelines,the analysis of the observation group revealed that a partial response was observed in 11 patients(32.4%),stable disease was evident in 19 patients(55.9%),and 4 patients(11.8%)experienced progressive disease;a partial response was observed in 6(20.0%)patients,stable disease in 18(60%),and progressive disease in 6(20%)in the control group.The major toxic effects were leukopenia and nausea.The incidence of severe adverse events(AEs)(grade 3 or 4)was 26.5%(9/34)in the observation group and 23.3%(7/30)in the control group.There were no treatment-related deaths.The observation group demonstrated a significantly longer median overall survival(22.1 mo compared to 15.8 mo)(P<0.05)and progression-free survival(12.2 mo vs 10.1 mo)(P<0.05)in comparison to the control group.The occurrence of severe AEs did not exhibit a statistically significant difference between the observation group and the control group(P>0.05).CONCLUSION Sintilimab plus concurrent chemoradiotherapy was effective and safe for LAPC patients,and warrants further investigation.展开更多
BACKGROUND Polyether ether ketone(PEEK)is a high-performance medical polymer,and there are some clinical cases of PEEK prosthesis implantation.However,application of 3D-printed injection-molded PEEK lunate prosthesis ...BACKGROUND Polyether ether ketone(PEEK)is a high-performance medical polymer,and there are some clinical cases of PEEK prosthesis implantation.However,application of 3D-printed injection-molded PEEK lunate prosthesis for treatment of stage Ⅲ Kienböck’s disease has not been reported.This study’s purpose was to analyze the clinical efficacy of 3D-printed injection-molded PEEK lunate prosthesis in the treatment of stage Ⅲ Kienböck’s disease and thus provide a good therapeutic choice for Kienböck’s disease.CASE SUMMARY We report a patient with stage Ⅲ Kienböck’s disease.With the healthy lunate bone as reference,3D lunate reconstruction was performed using a mirroring technique.A PEEK lunate prosthesis was prepared by 3D printing and injection molding,and then it was inserted into the original anatomical position after removing the necrotic lunate bone.Wrist pain and function,anatomical suitability of the lunate prosthesis,and complications were evaluated and analyzed postoperatively.At the last visit(one year after surgery),the range of motion,grasp force,visual analog scale score and Cooney score of the affected wrist were significantly improved,and postoperative X-ray examination indicated that the lunate prosthesis had good anatomical suitability for adjacent bony structures.CONCLUSION The 3D-printed injection-molded PEEK lunate prosthesis demonstrated definite efficacy in treating stage Ⅲ Kienböck’s disease.展开更多
Brassicaceae represents an important plant family from both a scientific and economic perspective.However,genomic features related to the early diversification of this family have not been fully characterized,especial...Brassicaceae represents an important plant family from both a scientific and economic perspective.However,genomic features related to the early diversification of this family have not been fully characterized,especially upon the uplift of the Tibetan Plateau,which was followed by increasing aridity in the Asian interior,intensifying monsoons in Eastern Asia,and significantly fluctuating daily temperatures.Here,we reveal the genomic architecture that accompanied early Brassicaceae diversification by analyzing two high-quality chromosome-level genomes for Meniocus linifolius(Arabodae;clade D)and Tetracme quadricornis(Hesperodae;clade E),together with genomes representing all major Brassicaceae clades and the basal Aethionemeae.We reconstructed an ancestral core Brassicaceae karyotype(CBK)containing 9 pseudochromosomes with 65 conserved syntenic genomic blocks and identified 9702 conserved genes in Brassicaceae.We detected pervasive conflicting phylogenomic signals accompanied by widespread ancient hybridization events,which correlate well with the early divergence of core Brassicaceae.We identified a successive Brassicaceae-specific expansion of the class I TREHALOSE-6-PHOSPHATE SYNTHASE 1(TPS1)gene family,which encodes enzymes with essential regulatory roles in flowering time and embryo development.The TPS1s were mainly randomly amplified,followed by expression divergence.Our results provide fresh insights into historical genomic features coupled with Brassicaceae evolution and offer a potential model for broad-scale studies of adaptive radiation under an ever-changing environment.展开更多
AIM:To investigate the short-term benefits of laparoscopic radical gastrectomy(LARG)and open radical gastrectomy(ORG)in patients with gastric cancer.METHODS:A total of 400 patients with gastric cancer aged≤65 years w...AIM:To investigate the short-term benefits of laparoscopic radical gastrectomy(LARG)and open radical gastrectomy(ORG)in patients with gastric cancer.METHODS:A total of 400 patients with gastric cancer aged≤65 years who were treated at General Hospital of Lanzhou Military Region were enrolled.Among these,200 patients underwent LARG between October2008 and August 2012(LARG group);and 200 patients underwent ORG between March 2000 and September2008(ORG group).The short-term therapeutic benefits between the two groups were analyzed.RESULTS:The LARG procedure offered significantly better benefits to the patients compared to the ORG procedure,including less intraoperative blood loss(103.1±19.5 mL vs 163.0±32.9 mL,P【0.0001),shorter postoperative hospital stay(6.8±1.2 d vs 9.5±1.6 d,P【0.0001),less frequent occurrence of postoperative complications(6.5%vs 13.5%,P=0.02),shorter time to mobilization(1.0±0.3 vs 3.3±0.4 d,P【0.0001),shorter time to bowel opening(3.3±0.7 d vs 4.5±0.7 d,P【0.0001),and shorter time to normal diet(3.0±0.4 vs d 3.8±0.5 d,P【0.0001).However,LARG required a longer time to complete than the ORG procedure(192.3±20.9 min vs 180.0±26.9 min,P【0.0001).CONCLUSION:Compared to ORG,LARG is safer,more effective,and less invasive for treating gastric cancer,with better short-term efficacy.展开更多
Salvia is the largest genus of Lamiaceae,with almost 1000 species,and has been divided into 11 subgenera.Salvia subg.Glutinaria,native to East Asia,is particularly important because of its potential medicinal value.Ho...Salvia is the largest genus of Lamiaceae,with almost 1000 species,and has been divided into 11 subgenera.Salvia subg.Glutinaria,native to East Asia,is particularly important because of its potential medicinal value.However,the interspecific relationships of this subgenus have not been resolved and the plastomes of Salvia have rarely been studied.In the current study,we compared plastid genome structure and organization of 19 species of Salvia(14 newly sequenced and 5 previously published).Our comparative analysis showed that all Salvia plastomes examined have a quadripartite structure typical of most angiosperms and contain an identical set of 114 unique genes(80 protein-coding genes,4 rRNA genes,and 30 tRNA genes).The plastome structure of all Salvia species is highly conserved like other Lamiaceae plastomes.Gene content,gene order,and GC content were highly similar in these plastomes.The inverted repeats/single copy region(IR/SC)boundaries of Salvia are highly conserved,and IR contraction only occurred in two species(Salvia mekongensis and S.rosmarinus).In Salvia,sequence divergence was higher in non-coding regions than in coding regions.We found that using large single copy(LSC)and small single copy regions(SSC)with exclusion of the rapidly evolving sites produced the highest resolution in phylogenetic analysis of Salvia,suggesting that using suitable informative sites to build trees is more conducive in phylogenetic research.This study assembled a powerful matrix data set for studying the phylogeny of Salvia,resolving the interspecific relationship of Salvia subg.Glutinaria.The newly sequenced plastid genomes will also enrich the plastome database of Salvia,providing the scientific basis for the development and utilization of germplasm resources of this large and important genus.展开更多
We demonstrate that the transport of hot carriers may result in the phenomenon where an oscillated output current appears at the waveforms in a high-power photoconductive semiconductor switch(PCSS) working at long pul...We demonstrate that the transport of hot carriers may result in the phenomenon where an oscillated output current appears at the waveforms in a high-power photoconductive semiconductor switch(PCSS) working at long pulse width when the laser disappears or the electric field changes. The variational laser and electric field will affect the scattering rates of hot carriers and crystal lattice in high-power PCSS, and the drift velocity of hot carriers and also the on-state resistance will be changed. The present result is important for reducing the on-state resistance and improving the output characteristics of high-power Si/Ga As PCSS.展开更多
The advances accelerated by next-generation sequencing and long-read sequencing technologies continue to provide an impetus for plant phylogenetic study.In the past decade,a large number of phylogenetic studies adopti...The advances accelerated by next-generation sequencing and long-read sequencing technologies continue to provide an impetus for plant phylogenetic study.In the past decade,a large number of phylogenetic studies adopting hundreds to thousands of genes across a wealth of clades have emerged and ushered plant phylogenetics and evolution into a new era.In the meantime,a roadmap for researchers when making decisions across different approaches for their phylogenomic research design is imminent.This review focuses on the utility of genomic data(from organelle genomes,to both reduced representation sequencing and whole-genome sequencing) in phylogenetic and evolutionary investigations,describes the baseline methodology of experimental and analytical procedures,and summarizes recent progress in flowering plant phylogenomics at the ordinal,familial,tribal,and lower levels.We also discuss the challenges,such as the adverse impact on orthology inference and phylogenetic reconstruction raised from systematic errors,and underlying biological factors,such as whole-genome duplication,hybridization/introgression,and incomplete lineage sorting,together suggesting that a bifurcating tree may not be the best model for the tree of life.Finally,we discuss promising avenues for future plant phylogenomic studies.展开更多
Most species in the genus Tacca （Dioscoreaceae） feature green to black purple, conspicuous inflorescence involucral bracts with variable shapes, motile filiform appendages （bracteoles）, and diverse types of inflor...Most species in the genus Tacca （Dioscoreaceae） feature green to black purple, conspicuous inflorescence involucral bracts with variable shapes, motile filiform appendages （bracteoles）, and diverse types of inflorescence morphology. To infer the evolution of these inflorescence traits, we reconstructed the molecular phylogeny of the genus, using DNA sequences from one nuclear, one mitochondrial, and three plastid loci （Internal Transcribed Spacer （ITS）, atpA, rbcL, trnL-F, and trnH-psbA）. Involucres and bracteoles characters were mapped onto the phylogeny to analyze the sequence of inflorescence trait evolution. In all analyses, species with showy involucres and bracteoles formed the most derived clade, while ancestral Tacca had small and plain involucres and short bracteoles, namely less conspicuous inflorescence structures. Two of the species with the most elaborate inflorescence morphologies （T. chantrieri in southeast China and T. integrifolia in Tibet）, are predominantly self-pollinated, indicating that these conspicuous floral displays have other functions rather than pollinator attraction. We hypothesize that the motile bracteoles and involucres may facilitate selfing; display photosynthesis in the dim understory, and protect flowers from herbivory.展开更多
基金supported by China Medicine Education Association(CMEA)(No.2020KTS012)the National Natural Science Foundation of China(NSFC)(No.82002962 and No.81900189).
文摘Objective To investigate the serum lipid profiles of patients with localized osteosarcoma around the knee joint before and after neoadjuvant chemotherapy.Methods After retrospectively screening the data of 742 patients between January 2007 and July 2020,50 patients aged 13 to 39 years with Enneking stage II disease were included in the study.Serum lipid levels,including total cholesterol(TC),triglycerides(TG),high-density lipoprotein cholesterol(HDL-C),low-density lipoprotein cholesterol(LDL-C),lipoprotein-α[Lp(a)],and apolipoprotein A1,B,and E(ApoA1,ApoB,and ApoE),and clinicopathological characteristics were collected before and after neoadjuvant chemotherapy.Results The mean levels of TC,TG,and ApoB were significantly increased following neoadjuvant chemotherapy(16%,38%,and 20%,respectively,vs.pretreatment values;P<0.01).The mean levels of LDL-C and ApoE were also 19%and 16%higher,respectively(P<0.05).No correlation was found between the pretreatment lipid profile and the histologic response to chemotherapy.An increase in Lp(a)was strongly correlated with the Ki-67 index(R=0.31,P=0.023).Moreover,a trend toward longer disease-free survival(DFS)was observed in patients with decreased TG and increased LDL-C following chemotherapy,although this difference was not statistically significant(P=0.23 and P=0.24,respectively).Conclusion Significant elevations in serum lipids were observed after neoadjuvant chemotherapy in patients with localized osteosarcoma.There was no prognostic significance of pretreatment serum lipid levels on histologic response to neoadjuvant chemotherapy.The scale of increase in serum Lp(a)might have a potential prognostic role in osteosarcoma.Patients with increased LDL-C or reduced TG after chemotherapy seem to exhibit a trend toward favorable DFS.
文摘BACKGROUND Pancreatic adenocarcinoma,a malignancy that arises in the cells of the pancreas,is a devastating disease with unclear etiology and often poor prognosis.Locally advanced pancreatic cancer,a stage where the tumor has grown significantly but has not yet spread to distant organs,presents unique challenges in treatment.This article aims to discuss the current strategies,challenges,and future directions in the management of locally advanced pancreatic adenocarcinoma(LAPC).AIM To investigate the feasibility and efficacy of programmed cell death 1(PD-1)inhibitor sintilimab plus concurrent chemoradiotherapy for LAPC.METHODS Eligible patients had LAPC,an Eastern cooperative oncology group performance status of 0 or 1,adequate organ and marrow functions,and no prior anticancer therapy.In the observation group,participants received intravenous sintilimab 200 mg once every 3 wk,and received concurrent chemoradiotherapy(concurrent conventional fractionated radiotherapy with doses planning target volume 50.4 Gy and gross tumor volume 60 Gy in 28 fractions and oral S-140 mg/m2 twice daily on days 1-14 of a 21-d cycle and intravenous gemcitabine 1000 mg/m2 on days 1 and 8 of a 21-d cycle for eight cycles until disease progression,death,or unacceptable toxicity).In the control group,participants only received concurrent chemoradiotherapy.From April 2020 to November 2021,64 participants were finally enrolled with 34 in the observation group and 30 in the control group.RESULTS Thirty-four patients completed the scheduled course of chemoradiotherapy,while 32(94.1%)received sintilimab plus concurrent chemoradiotherapy with 2 patients discontinuing sintilimab in the observation group.Thirty patients completed the scheduled course of chemoradiotherapy in the control group.Based on the Response Evaluation Criteria in Solid Tumors guidelines,the analysis of the observation group revealed that a partial response was observed in 11 patients(32.4%),stable disease was evident in 19 patients(55.9%),and 4 patients(11.8%)experienced progressive disease;a partial response was observed in 6(20.0%)patients,stable disease in 18(60%),and progressive disease in 6(20%)in the control group.The major toxic effects were leukopenia and nausea.The incidence of severe adverse events(AEs)(grade 3 or 4)was 26.5%(9/34)in the observation group and 23.3%(7/30)in the control group.There were no treatment-related deaths.The observation group demonstrated a significantly longer median overall survival(22.1 mo compared to 15.8 mo)(P<0.05)and progression-free survival(12.2 mo vs 10.1 mo)(P<0.05)in comparison to the control group.The occurrence of severe AEs did not exhibit a statistically significant difference between the observation group and the control group(P>0.05).CONCLUSION Sintilimab plus concurrent chemoradiotherapy was effective and safe for LAPC patients,and warrants further investigation.
基金Supported by Chongqing Science and Health Combined Medical Discipline,No.2020MSXM012。
文摘BACKGROUND Polyether ether ketone(PEEK)is a high-performance medical polymer,and there are some clinical cases of PEEK prosthesis implantation.However,application of 3D-printed injection-molded PEEK lunate prosthesis for treatment of stage Ⅲ Kienböck’s disease has not been reported.This study’s purpose was to analyze the clinical efficacy of 3D-printed injection-molded PEEK lunate prosthesis in the treatment of stage Ⅲ Kienböck’s disease and thus provide a good therapeutic choice for Kienböck’s disease.CASE SUMMARY We report a patient with stage Ⅲ Kienböck’s disease.With the healthy lunate bone as reference,3D lunate reconstruction was performed using a mirroring technique.A PEEK lunate prosthesis was prepared by 3D printing and injection molding,and then it was inserted into the original anatomical position after removing the necrotic lunate bone.Wrist pain and function,anatomical suitability of the lunate prosthesis,and complications were evaluated and analyzed postoperatively.At the last visit(one year after surgery),the range of motion,grasp force,visual analog scale score and Cooney score of the affected wrist were significantly improved,and postoperative X-ray examination indicated that the lunate prosthesis had good anatomical suitability for adjacent bony structures.CONCLUSION The 3D-printed injection-molded PEEK lunate prosthesis demonstrated definite efficacy in treating stage Ⅲ Kienböck’s disease.
基金supported by the Priority Research Program of the Chinese Academy of Sciences(CAS)(Grant No.XDA0440000 and XDB31000000).
文摘Brassicaceae represents an important plant family from both a scientific and economic perspective.However,genomic features related to the early diversification of this family have not been fully characterized,especially upon the uplift of the Tibetan Plateau,which was followed by increasing aridity in the Asian interior,intensifying monsoons in Eastern Asia,and significantly fluctuating daily temperatures.Here,we reveal the genomic architecture that accompanied early Brassicaceae diversification by analyzing two high-quality chromosome-level genomes for Meniocus linifolius(Arabodae;clade D)and Tetracme quadricornis(Hesperodae;clade E),together with genomes representing all major Brassicaceae clades and the basal Aethionemeae.We reconstructed an ancestral core Brassicaceae karyotype(CBK)containing 9 pseudochromosomes with 65 conserved syntenic genomic blocks and identified 9702 conserved genes in Brassicaceae.We detected pervasive conflicting phylogenomic signals accompanied by widespread ancient hybridization events,which correlate well with the early divergence of core Brassicaceae.We identified a successive Brassicaceae-specific expansion of the class I TREHALOSE-6-PHOSPHATE SYNTHASE 1(TPS1)gene family,which encodes enzymes with essential regulatory roles in flowering time and embryo development.The TPS1s were mainly randomly amplified,followed by expression divergence.Our results provide fresh insights into historical genomic features coupled with Brassicaceae evolution and offer a potential model for broad-scale studies of adaptive radiation under an ever-changing environment.
文摘AIM:To investigate the short-term benefits of laparoscopic radical gastrectomy(LARG)and open radical gastrectomy(ORG)in patients with gastric cancer.METHODS:A total of 400 patients with gastric cancer aged≤65 years who were treated at General Hospital of Lanzhou Military Region were enrolled.Among these,200 patients underwent LARG between October2008 and August 2012(LARG group);and 200 patients underwent ORG between March 2000 and September2008(ORG group).The short-term therapeutic benefits between the two groups were analyzed.RESULTS:The LARG procedure offered significantly better benefits to the patients compared to the ORG procedure,including less intraoperative blood loss(103.1±19.5 mL vs 163.0±32.9 mL,P【0.0001),shorter postoperative hospital stay(6.8±1.2 d vs 9.5±1.6 d,P【0.0001),less frequent occurrence of postoperative complications(6.5%vs 13.5%,P=0.02),shorter time to mobilization(1.0±0.3 vs 3.3±0.4 d,P【0.0001),shorter time to bowel opening(3.3±0.7 d vs 4.5±0.7 d,P【0.0001),and shorter time to normal diet(3.0±0.4 vs d 3.8±0.5 d,P【0.0001).However,LARG required a longer time to complete than the ORG procedure(192.3±20.9 min vs 180.0±26.9 min,P【0.0001).CONCLUSION:Compared to ORG,LARG is safer,more effective,and less invasive for treating gastric cancer,with better short-term efficacy.
基金supported by the Large-scale Scientific Facilities of the Chinese Academy of Sciences(Grant No:2017eLSFGBOWSe02)。
文摘Salvia is the largest genus of Lamiaceae,with almost 1000 species,and has been divided into 11 subgenera.Salvia subg.Glutinaria,native to East Asia,is particularly important because of its potential medicinal value.However,the interspecific relationships of this subgenus have not been resolved and the plastomes of Salvia have rarely been studied.In the current study,we compared plastid genome structure and organization of 19 species of Salvia(14 newly sequenced and 5 previously published).Our comparative analysis showed that all Salvia plastomes examined have a quadripartite structure typical of most angiosperms and contain an identical set of 114 unique genes(80 protein-coding genes,4 rRNA genes,and 30 tRNA genes).The plastome structure of all Salvia species is highly conserved like other Lamiaceae plastomes.Gene content,gene order,and GC content were highly similar in these plastomes.The inverted repeats/single copy region(IR/SC)boundaries of Salvia are highly conserved,and IR contraction only occurred in two species(Salvia mekongensis and S.rosmarinus).In Salvia,sequence divergence was higher in non-coding regions than in coding regions.We found that using large single copy(LSC)and small single copy regions(SSC)with exclusion of the rapidly evolving sites produced the highest resolution in phylogenetic analysis of Salvia,suggesting that using suitable informative sites to build trees is more conducive in phylogenetic research.This study assembled a powerful matrix data set for studying the phylogeny of Salvia,resolving the interspecific relationship of Salvia subg.Glutinaria.The newly sequenced plastid genomes will also enrich the plastome database of Salvia,providing the scientific basis for the development and utilization of germplasm resources of this large and important genus.
基金Supported by the Rector’s Fund of China Academy of Engineering Physics(Grant No.YZJJLX2016002)the National Natural Science Foundation of China(Grant Nos.61504127 and U1530128).
文摘We demonstrate that the transport of hot carriers may result in the phenomenon where an oscillated output current appears at the waveforms in a high-power photoconductive semiconductor switch(PCSS) working at long pulse width when the laser disappears or the electric field changes. The variational laser and electric field will affect the scattering rates of hot carriers and crystal lattice in high-power PCSS, and the drift velocity of hot carriers and also the on-state resistance will be changed. The present result is important for reducing the on-state resistance and improving the output characteristics of high-power Si/Ga As PCSS.
基金supported by the Priority Research Program of the Chinese Academy of Sciences (CAS) (Grant No.XDB31000000)Large-scale Scientific Facilities of the CAS (Grant No.2017LSF-GBOWS-2)。
文摘The advances accelerated by next-generation sequencing and long-read sequencing technologies continue to provide an impetus for plant phylogenetic study.In the past decade,a large number of phylogenetic studies adopting hundreds to thousands of genes across a wealth of clades have emerged and ushered plant phylogenetics and evolution into a new era.In the meantime,a roadmap for researchers when making decisions across different approaches for their phylogenomic research design is imminent.This review focuses on the utility of genomic data(from organelle genomes,to both reduced representation sequencing and whole-genome sequencing) in phylogenetic and evolutionary investigations,describes the baseline methodology of experimental and analytical procedures,and summarizes recent progress in flowering plant phylogenomics at the ordinal,familial,tribal,and lower levels.We also discuss the challenges,such as the adverse impact on orthology inference and phylogenetic reconstruction raised from systematic errors,and underlying biological factors,such as whole-genome duplication,hybridization/introgression,and incomplete lineage sorting,together suggesting that a bifurcating tree may not be the best model for the tree of life.Finally,we discuss promising avenues for future plant phylogenomic studies.
基金funded by the Key Project of the Chinese Academy of Science (KSCX2-YW-Z-0904)National Natural Science Foundation of China (30670131)+1 种基金Yunnan Provincial Natural Science Foundation (2006C0055M)to Ling ZhangLaboratory equipment for phylogenetic analyses was provided by the State Key Basic Research and Development Plan of China (973, 2008GA001) to De-Zhu Li
文摘Most species in the genus Tacca （Dioscoreaceae） feature green to black purple, conspicuous inflorescence involucral bracts with variable shapes, motile filiform appendages （bracteoles）, and diverse types of inflorescence morphology. To infer the evolution of these inflorescence traits, we reconstructed the molecular phylogeny of the genus, using DNA sequences from one nuclear, one mitochondrial, and three plastid loci （Internal Transcribed Spacer （ITS）, atpA, rbcL, trnL-F, and trnH-psbA）. Involucres and bracteoles characters were mapped onto the phylogeny to analyze the sequence of inflorescence trait evolution. In all analyses, species with showy involucres and bracteoles formed the most derived clade, while ancestral Tacca had small and plain involucres and short bracteoles, namely less conspicuous inflorescence structures. Two of the species with the most elaborate inflorescence morphologies （T. chantrieri in southeast China and T. integrifolia in Tibet）, are predominantly self-pollinated, indicating that these conspicuous floral displays have other functions rather than pollinator attraction. We hypothesize that the motile bracteoles and involucres may facilitate selfing; display photosynthesis in the dim understory, and protect flowers from herbivory.
