Erosion-corrosion(EC)-induced damage is a primary contributor to premature failures in hydraulic transport structures involving sudden changes in flow patterns,especially the hydraulic pipeline(tee,reducer,pipe bend,e...Erosion-corrosion(EC)-induced damage is a primary contributor to premature failures in hydraulic transport structures involving sudden changes in flow patterns,especially the hydraulic pipeline(tee,reducer,pipe bend,etc.),pumps,and valves.A comprehensive exploration of EC behavior of steels subjected to high tensile stress was provided,as most engineering structures are operated under high stress.The stress-accelerated erosion(SAE)and stress-accelerated corrosion(SAC)behaviors of highly stressed steel and their synergistic effect were mainly focused.SAE,SAC,and their synergistic mechanisms,existing debate,and possible reasons,as well as available analytic models with their advantages and limitations,are thoroughly discussed.The multiphysics simulation methods for modeling EC interactions with both static and cyclic stresses are also summarized,and EC mitigation strategies,especially the bionics-based strategies,were also summarized in detail.展开更多
Background:Clear cell renal carcinoma(ccRCC),the leading histological subtype of RCC,lacks any targeted therapy options.Although some studies have shown that early growth response factor 1(EGR1)has a significant role ...Background:Clear cell renal carcinoma(ccRCC),the leading histological subtype of RCC,lacks any targeted therapy options.Although some studies have shown that early growth response factor 1(EGR1)has a significant role in cancer development and progression,its role and underlying mechanisms in ccRCC remain poorly understood.Methods:The Cancer Genome Atlas(TCGA)database was utilized to examine the expression of EGR1 in ccRCC.The expression of EGR1 in 55 ccRCC tissues was evaluated using immunohistochemistry.The link between EGR1 expression and clinicopathological variables was examined through an analysis.Gain-of-function assays were employed to investigate EGR1’s biological functions in ccRCC cells,involving proliferation,colony formation,invasion assays,and tumorigenesis in nude mice.In order to assess the protein expression of mitogen-activated protein kinase 15(MAPK15),E-cadherin,matrix metalloproteinase-9/-2(MMP-9 and MMP-2),Western blot technique was applied.Results:The results revealed a decrease in EGR1 expression in ccRCC tissues.This decrease was strongly linked to TNM stage,lymphatic metastasis,tumor size,histological grade,and unfavorable prognosis in ccRCC patients.It has been demonstrated that overexpressing EGR1 inhibits the growth of xenograft tumors in vivo and inhibits cell colony formation,motility,and invasion in vitro.Furthermore,EGR1 can prevent the development and movement of ccRCC cells by controlling the expression of MMP-2,MMP-9,E-cadherin,and MAPK15.Conclusions:The EGR1/MAPK15 axis may represent a promising target for drug development,with EGR1 serving as a possible target for ccRCC therapy.展开更多
Matrix metalloproteinase 2(MMP2) has been shown to play an important role in several steps of cancer development.The-1306C/T polymorphism of the MMP2 gene displays a strikingly lower promoter activity than the T allel...Matrix metalloproteinase 2(MMP2) has been shown to play an important role in several steps of cancer development.The-1306C/T polymorphism of the MMP2 gene displays a strikingly lower promoter activity than the T allele,and the CC genotype in the MMP2 promoter has been reported to associate with the development of several cancers.To assess the contribution of the MMP2-1306C/T polymorphism to the risk of nasopharyngeal carcinoma(NPC),we conducted a case-control study and analyzed MMP2 genotypes in 370 patients with NPC and 390 frequency-matched controls using real-time PCR-based TaqMan allele analysis.We found that subjects with the CC genotype had an increased risk(OR = 1.55,95% CI = 1.05-2.27) of developing NPC compared to those with the CT or TT genotypes.Furthermore,we found that the risk of NPC was markedly increased in subjects who were smokers(OR = 15.04,95% CI = 6.65-33.99),heavy smokers who smoked ≥20 pack-years(OR = 18.66,95% CI = 7.67-45.38),or young(<60 years) at diagnosis(OR = 1.52,95% CI = 1.01-2.29).Our results provide molecular epidemiological evidence that the MMP2-1306C/T promoter polymorphism is associated with NPC risk,and this association is especially noteworthy in heavy smokers.展开更多
This observational study included 21 patients at remarkably high risk of ovarian hyperstimulation syndrome(OHSS),characterized by more than 30 follicles measuring≥11 mm in diameter on trigger day and/or pre-trigger p...This observational study included 21 patients at remarkably high risk of ovarian hyperstimulation syndrome(OHSS),characterized by more than 30 follicles measuring≥11 mm in diameter on trigger day and/or pre-trigger peak estradiol exceeding 10 000 pg/mL.which was also the feature of women with established severe early OHSS followed by gonadotrophin-releasing hormone agonist(GnRHa)trigger and freeze-all policy that previously have been reported.All patients received a second dose of GnRHa 12 h after the first GnRHa trigger combined with administration of GnRH antagonist at 0.25 mg/day for a period of 3 days from the day of oocyte retrieval onwards.The in vitro fertilization(IVF)outcomes may be preferable compared with a bolus of GnRHa trigger and none of the included patients developed moderate-to-severe OHSS.Moreover,patients'symptoms,reproductive honnone levels and ultrasound findings were improved significantly.This new strategy seems to be efficacious and could be a further supplement of GnRHa trigger with or without applying freeze-all strategy to completely prevent early-onset moderate to severe OHSS,especially for the patients characterized by≥30 follicles measuring≥11 mm in diameter on trigger day and/or pre-trigger peak estradiol exceeding 10 000 pg/mL.Further studies should be performed to compare this regimen with conventional methods of OHSS prevention.展开更多
Introduction: The rearrangement of the anaplastic lymphoma kinase(ALK) gene accounts for approximately 1%–6% of lung adenocarcinoma cases and deines a molecular subgroup of tumors characterized by clinical sensitivit...Introduction: The rearrangement of the anaplastic lymphoma kinase(ALK) gene accounts for approximately 1%–6% of lung adenocarcinoma cases and deines a molecular subgroup of tumors characterized by clinical sensitivity to ALK inhibitors such as crizotinib. This study aimed to identify the relationship between ALK rearrangement and the clinico?pathologic characteristics of non?small cell lung cancer(NSCLC) and to analyze the therapeutic responses of crizotinib and conventional chemotherapy to ALK rearrangement in NSCLC patients.Methods: A total of 487 lung cancer patients who underwent testing for ALK rearrangement in our department were included in this study. ALK rearrangement was examined by using fluorescence in situ hybridization(FISH) assay.Results: Among the 487 patients, 44(9.0%) were diagnosed with ALK rearrangement by using FISH assay. In 123 patients with adenocarcinoma who were non?smokers and of a young age(≤58 years old), the frequency of ALK rearrangement was 20.3%(25/123). Short overall survival(OS) was associated with non?adenocarcinoma tumor type(P = 0.006), poorly diferentiated tumors(P al growth factor rece= 0.001), advanced?stage tumors(P < 0.001), smoking history(P ptor(EGFR)(P = 0.008), and wild?type epidermrter time to cancer p= 0.008). Moreover, patients with poorly diferentiated and advanced?stage tumors had a shorogression compared with those with well diferentiated(P = 0.023) and early?stage tumors(P = 0.001), respectively.Conclusions: ALK?rearranged NSCLC tends to occur in younger individuals who are either non?smokers or light smokers with adenocarcinoma. Patients with ALK rearrangement might beneit from ALK inhibitor therapy.展开更多
In this work, cobalt nanoparticles were syn- thesized by chemical reduction procedure. After the hydrophilic functionalization, Co/polypyrrole （PPy） nanocomposites were prepared by in situ polymerization of pyrrole ...In this work, cobalt nanoparticles were syn- thesized by chemical reduction procedure. After the hydrophilic functionalization, Co/polypyrrole （PPy） nanocomposites were prepared by in situ polymerization of pyrrole in aqueous dispersion of Co nanoparticles. The Co/ PPy nanocomposites show good electromagnetic properties with both magnetic loss and dielectric loss to electromag- netic wave. The electromagnetic wave absorbing band- width （reflection loss 〈-10 dB） for Co/PPy （20 wt%） is above 5.5 GHz at a thickness of 2 mm, and with a maximum reflection loss （around -20.02 dB） at 14.77 GHz. This magnetic nanoparticles/conducting polymer nanocomposites are great potential candidates for electromagnetic wave absorbent, because of their wide-absorbing frequency, strong absorption, good compatibility, low density, and controllable absorbing properties.展开更多
Endometrial receptivity is an important factor that influences embryo implantation.Thus,it is important to identify an applicable approach to improve endometrial receptivity in women undergoing assisted reproductive t...Endometrial receptivity is an important factor that influences embryo implantation.Thus,it is important to identify an applicable approach to improve endometrial receptivity in women undergoing assisted reproductive technology.Recently,growing evidence has indicated that intrauterine platelet-rich plasma(PRP)infusion is an effective method to obtain a satisfactory reproductive outcome by increasing endometrial thickness and improving endometrial receptivity.Therefore,the present review aims to outline the possible mechanisms of PRP on endometrial receptivity and summarize the present literature on the effects of PRP therapy in improving endometrial receptivity.展开更多
Topoisomerase III （topo III）, a type IA topoisomerase, is widespread in hyperthermophilic archaea. In order to interrogate the in vivo role of archaeal topo III, we constructed and characterized a topo III gene dele...Topoisomerase III （topo III）, a type IA topoisomerase, is widespread in hyperthermophilic archaea. In order to interrogate the in vivo role of archaeal topo III, we constructed and characterized a topo III gene deletion mutant of Sulfolobus islandicus. The mutant was ,viable but grew more slowly than the wild-type strain, especially in a nutrient-poor medium. Flow cytometry analysis revealed changes of the mutant in growth cycle characteristics including an increase in proportion of cells containing either more than two genome equivalents or less than one genome equivalent in exponentially-growing cultures. As shown by fluorescence microscopy, a fraction of mutant cells in the cultures were drastically enlarged, and at least some of the enlarged cells were apparently capable of resuming cell division. The mutant also shows a different tran- scriptional profile from that of the wild-type strain. Our results suggest that the enzyme may serve roles in chromosomal segregation and control of the level of supercoiling in the cell.展开更多
This paper investigates fast time-varying channel estimation in LTE-R communication systems. The Basis Expansion Model （BEM） is adopted to fit the fast time-varying channel in a high-speed railway com- munication sc...This paper investigates fast time-varying channel estimation in LTE-R communication systems. The Basis Expansion Model （BEM） is adopted to fit the fast time-varying channel in a high-speed railway com- munication scenario. The channel impulse response is modeled as the sum of basis functions multiplied by different coefficients. The optimal coefficients are obtained by theoretical analysis. Simulation results show that a Generalized Complex-Exponential BEM （GCE-BEM） outperforms a Complex-Exponential BEM （CE-BEM） and a polynomial BEM in terms of Mean Squared Error （MSE）. Besides, the MSE of the CE- BEM decreases gradually as the number of basis functions increases. The GCE-BEM has a satisfactory performance with the serious fading channel.展开更多
The shift from skotomorphogenesis to photomorphogenesis,a developmental transition in seed plants,in-volves dramatic proteomic changes.Lysine acetylation(Lys-Ac)is an evolutionarily conserved and recog-nized post-tran...The shift from skotomorphogenesis to photomorphogenesis,a developmental transition in seed plants,in-volves dramatic proteomic changes.Lysine acetylation(Lys-Ac)is an evolutionarily conserved and recog-nized post-translational modification that plays a crucial role in plant development.However,its role in seedling deetiolation remains unclear.In this study,we conducted a comparative lysine acetylomic anal-ysis of etiolated Arabidopsis seedlings before and after red(R)light irradiation,uncovering that exposure to R light mainly led to protein lysine deacetylation during seedling deetiolation.Phytochrome A(phyA),a unique far-red(FR)light photoreceptor,was deacetylated at lysine 65(K65)when etiolated seedlings were moved to light.This residue is a critical ubiquitination site that regulates phyA stability.Moreover,K65 deacetylation facilitates phyA ubiquitination and 26s proteasome-mediated degradation,and is required for the function of phyA in FR light signaling and seedling photomorphogenesis.Furthermore,we identified a plant-specific lysine deacetylase HDT2 that interacts with and deacetylates phyA in the nu-cleus to promote its ubiquitination and degradation during seedling deetiolation.Genetic analysis revealed that HDT2 is critical for phyA-mediated photomorphogenic growth.Taken together,these findings reveal that lysine deacetylation of phyA by HDT2 plays a crucial role in modulating phyA turnover in response to light,suggesting that Lys-Ac might be central to the reprogramming of plants for photomorphogenic growth.展开更多
Seed germination represents a critical step in the life cycle of plants. The far-red/red light photoreceptor phytochrome B (phyB) plays a dominant role in promoting germination by modulating gibberellin (GA) and absci...Seed germination represents a critical step in the life cycle of plants. The far-red/red light photoreceptor phytochrome B (phyB) plays a dominant role in promoting germination by modulating gibberellin (GA) and abscisic acid (ABA) metabolism, although the underlying mechanism remains poorly understood. In this study, we identified BREVIPEDICELLUS (BP)/KNAT1, a KNOX transcription factor that acts downstream of phyB and activates light-initiated seed germination in Arabidopsis thaliana. BP undergoes ubiquitination and is degraded through the 26S proteasome pathway. phyB directly interacts with BP and stabilizes BP protein by decreasing its ubiquitination in imbibed seeds. A genome-wide transcriptomic analysis revealed that BP and phyB co-regulate the expression of genes associated with ABA biosynthesis, signal transduction, seed dormancy, and cell wall organization. BP suppresses the expression of two key ABA biosynthetic genes, NCED6 and NCED9, thus lowering ABA levels in imbibed seeds under phyB-activated conditions. BP directly binds to NCED6 and NCED9 and represses their expression by increasing the levels of H3K27me3, a repressive histone modification marker. Genetic analysis demonstrated that NCED6/NCED9 acts epistatic to BP in phyB-dependent germination. Overall, this study reveals a transcriptional module consisting of phyB-BP-NCED6/9, which transfers light signals that inhibit ABA biosynthesis, thereby promoting light-induced germination.展开更多
Uninterrupted,efficient power supplies have posed a significant hurdle to the ubiquitous adoption of wearable devices,despite their potential for revolutionizing human‒machine interactions.This challenge is further co...Uninterrupted,efficient power supplies have posed a significant hurdle to the ubiquitous adoption of wearable devices,despite their potential for revolutionizing human‒machine interactions.This challenge is further compounded by the requirement of these devices to supply dependable energy for data-intensive sensing and transmission.Traditional thermoelectric solutions fail to deliver satisfactory performance under conditions of extremely low voltages.Here,we present a novel solution of a wearable thermoelectric generator integrated with an energy management system,which is capable of powering sensors and Bluetooth by harnessing body heat.Distinct from previous works,our innovation lies in its ability to consistently operate even with a minimal temperature difference(i.e.,4 K)between the human skin and the ambient environment,ensuring reliable data transmission within a time as short as 1.6 s.Furthermore,our system can recharge utilizing body heat under ultralow voltage conditions(30 mV).Our developed system provides a novel pathway for the continuous,reliable monitoring of self-contained wearable devices without depending on batteries.展开更多
基金This project was supported by National Natural Science Foundation of China(Nos.52301339 and U2005216)the Natural Science Foundation of Fujian Province(Nos.2021J05004 and 2020J01010)+1 种基金State Key Laboratory of Hydraulic Engineering Intelligent Construction and Operation opening Fund(HESS-2402)the Fundamental Research Funds for the Central Universities(20720240038).
文摘Erosion-corrosion(EC)-induced damage is a primary contributor to premature failures in hydraulic transport structures involving sudden changes in flow patterns,especially the hydraulic pipeline(tee,reducer,pipe bend,etc.),pumps,and valves.A comprehensive exploration of EC behavior of steels subjected to high tensile stress was provided,as most engineering structures are operated under high stress.The stress-accelerated erosion(SAE)and stress-accelerated corrosion(SAC)behaviors of highly stressed steel and their synergistic effect were mainly focused.SAE,SAC,and their synergistic mechanisms,existing debate,and possible reasons,as well as available analytic models with their advantages and limitations,are thoroughly discussed.The multiphysics simulation methods for modeling EC interactions with both static and cyclic stresses are also summarized,and EC mitigation strategies,especially the bionics-based strategies,were also summarized in detail.
基金supported by grants from the Shenzhen Basic Research Project(JCYJ20210324125803008)the Shenzhen Longhua District Science and Innovation Bureau Fund for Medical Institutions(2022143).
文摘Background:Clear cell renal carcinoma(ccRCC),the leading histological subtype of RCC,lacks any targeted therapy options.Although some studies have shown that early growth response factor 1(EGR1)has a significant role in cancer development and progression,its role and underlying mechanisms in ccRCC remain poorly understood.Methods:The Cancer Genome Atlas(TCGA)database was utilized to examine the expression of EGR1 in ccRCC.The expression of EGR1 in 55 ccRCC tissues was evaluated using immunohistochemistry.The link between EGR1 expression and clinicopathological variables was examined through an analysis.Gain-of-function assays were employed to investigate EGR1’s biological functions in ccRCC cells,involving proliferation,colony formation,invasion assays,and tumorigenesis in nude mice.In order to assess the protein expression of mitogen-activated protein kinase 15(MAPK15),E-cadherin,matrix metalloproteinase-9/-2(MMP-9 and MMP-2),Western blot technique was applied.Results:The results revealed a decrease in EGR1 expression in ccRCC tissues.This decrease was strongly linked to TNM stage,lymphatic metastasis,tumor size,histological grade,and unfavorable prognosis in ccRCC patients.It has been demonstrated that overexpressing EGR1 inhibits the growth of xenograft tumors in vivo and inhibits cell colony formation,motility,and invasion in vitro.Furthermore,EGR1 can prevent the development and movement of ccRCC cells by controlling the expression of MMP-2,MMP-9,E-cadherin,and MAPK15.Conclusions:The EGR1/MAPK15 axis may represent a promising target for drug development,with EGR1 serving as a possible target for ccRCC therapy.
基金supported in part by grants from the Chinese State Key Basic Research Project (No.2011CB504805)National High Technology Research and Development Program of China (863 Program) (No.20060102A4002)a grant of 985 Project from Ministry of Education of P. R. China
文摘Matrix metalloproteinase 2(MMP2) has been shown to play an important role in several steps of cancer development.The-1306C/T polymorphism of the MMP2 gene displays a strikingly lower promoter activity than the T allele,and the CC genotype in the MMP2 promoter has been reported to associate with the development of several cancers.To assess the contribution of the MMP2-1306C/T polymorphism to the risk of nasopharyngeal carcinoma(NPC),we conducted a case-control study and analyzed MMP2 genotypes in 370 patients with NPC and 390 frequency-matched controls using real-time PCR-based TaqMan allele analysis.We found that subjects with the CC genotype had an increased risk(OR = 1.55,95% CI = 1.05-2.27) of developing NPC compared to those with the CT or TT genotypes.Furthermore,we found that the risk of NPC was markedly increased in subjects who were smokers(OR = 15.04,95% CI = 6.65-33.99),heavy smokers who smoked ≥20 pack-years(OR = 18.66,95% CI = 7.67-45.38),or young(<60 years) at diagnosis(OR = 1.52,95% CI = 1.01-2.29).Our results provide molecular epidemiological evidence that the MMP2-1306C/T promoter polymorphism is associated with NPC risk,and this association is especially noteworthy in heavy smokers.
基金the National Natural Science Foundation of China(No.81401177)Guangdong Province Natural Science Foundation(No.2015A030313286)Milstein Medical Asian American Partnership Foundation Fellowship Award in Reproductive Medicine,Nanfang Hospital High-level Project Matching Funds(No.G2014005).
文摘This observational study included 21 patients at remarkably high risk of ovarian hyperstimulation syndrome(OHSS),characterized by more than 30 follicles measuring≥11 mm in diameter on trigger day and/or pre-trigger peak estradiol exceeding 10 000 pg/mL.which was also the feature of women with established severe early OHSS followed by gonadotrophin-releasing hormone agonist(GnRHa)trigger and freeze-all policy that previously have been reported.All patients received a second dose of GnRHa 12 h after the first GnRHa trigger combined with administration of GnRH antagonist at 0.25 mg/day for a period of 3 days from the day of oocyte retrieval onwards.The in vitro fertilization(IVF)outcomes may be preferable compared with a bolus of GnRHa trigger and none of the included patients developed moderate-to-severe OHSS.Moreover,patients'symptoms,reproductive honnone levels and ultrasound findings were improved significantly.This new strategy seems to be efficacious and could be a further supplement of GnRHa trigger with or without applying freeze-all strategy to completely prevent early-onset moderate to severe OHSS,especially for the patients characterized by≥30 follicles measuring≥11 mm in diameter on trigger day and/or pre-trigger peak estradiol exceeding 10 000 pg/mL.Further studies should be performed to compare this regimen with conventional methods of OHSS prevention.
基金supported in part by grants from the National High Technology Research and Development Program of China(863 Program)(No.2012AA02A502)a State Key Laboratory Grant at Sun Yat?sen University Cancer Center
文摘Introduction: The rearrangement of the anaplastic lymphoma kinase(ALK) gene accounts for approximately 1%–6% of lung adenocarcinoma cases and deines a molecular subgroup of tumors characterized by clinical sensitivity to ALK inhibitors such as crizotinib. This study aimed to identify the relationship between ALK rearrangement and the clinico?pathologic characteristics of non?small cell lung cancer(NSCLC) and to analyze the therapeutic responses of crizotinib and conventional chemotherapy to ALK rearrangement in NSCLC patients.Methods: A total of 487 lung cancer patients who underwent testing for ALK rearrangement in our department were included in this study. ALK rearrangement was examined by using fluorescence in situ hybridization(FISH) assay.Results: Among the 487 patients, 44(9.0%) were diagnosed with ALK rearrangement by using FISH assay. In 123 patients with adenocarcinoma who were non?smokers and of a young age(≤58 years old), the frequency of ALK rearrangement was 20.3%(25/123). Short overall survival(OS) was associated with non?adenocarcinoma tumor type(P = 0.006), poorly diferentiated tumors(P al growth factor rece= 0.001), advanced?stage tumors(P < 0.001), smoking history(P ptor(EGFR)(P = 0.008), and wild?type epidermrter time to cancer p= 0.008). Moreover, patients with poorly diferentiated and advanced?stage tumors had a shorogression compared with those with well diferentiated(P = 0.023) and early?stage tumors(P = 0.001), respectively.Conclusions: ALK?rearranged NSCLC tends to occur in younger individuals who are either non?smokers or light smokers with adenocarcinoma. Patients with ALK rearrangement might beneit from ALK inhibitor therapy.
基金financially supported by the National Natural Science Foundation of China(Nos.51101013 and 51371055)the Fundamental Research Funds for the Central Universities(Nos.FRF-TP-12-038A and FRF-TP-14-012A2)
文摘In this work, cobalt nanoparticles were syn- thesized by chemical reduction procedure. After the hydrophilic functionalization, Co/polypyrrole （PPy） nanocomposites were prepared by in situ polymerization of pyrrole in aqueous dispersion of Co nanoparticles. The Co/ PPy nanocomposites show good electromagnetic properties with both magnetic loss and dielectric loss to electromag- netic wave. The electromagnetic wave absorbing band- width （reflection loss 〈-10 dB） for Co/PPy （20 wt%） is above 5.5 GHz at a thickness of 2 mm, and with a maximum reflection loss （around -20.02 dB） at 14.77 GHz. This magnetic nanoparticles/conducting polymer nanocomposites are great potential candidates for electromagnetic wave absorbent, because of their wide-absorbing frequency, strong absorption, good compatibility, low density, and controllable absorbing properties.
基金the Guangdong Medical Science and Technology Research Foundation(No.A2021345).
文摘Endometrial receptivity is an important factor that influences embryo implantation.Thus,it is important to identify an applicable approach to improve endometrial receptivity in women undergoing assisted reproductive technology.Recently,growing evidence has indicated that intrauterine platelet-rich plasma(PRP)infusion is an effective method to obtain a satisfactory reproductive outcome by increasing endometrial thickness and improving endometrial receptivity.Therefore,the present review aims to outline the possible mechanisms of PRP on endometrial receptivity and summarize the present literature on the effects of PRP therapy in improving endometrial receptivity.
基金supported by the National Natural Science Foundation of China(Nos.30921065,30730003 and 30870058) to L.Huangthe Danish Research Council for Technology and Production(No.274-07-0116)
文摘Topoisomerase III （topo III）, a type IA topoisomerase, is widespread in hyperthermophilic archaea. In order to interrogate the in vivo role of archaeal topo III, we constructed and characterized a topo III gene deletion mutant of Sulfolobus islandicus. The mutant was ,viable but grew more slowly than the wild-type strain, especially in a nutrient-poor medium. Flow cytometry analysis revealed changes of the mutant in growth cycle characteristics including an increase in proportion of cells containing either more than two genome equivalents or less than one genome equivalent in exponentially-growing cultures. As shown by fluorescence microscopy, a fraction of mutant cells in the cultures were drastically enlarged, and at least some of the enlarged cells were apparently capable of resuming cell division. The mutant also shows a different tran- scriptional profile from that of the wild-type strain. Our results suggest that the enzyme may serve roles in chromosomal segregation and control of the level of supercoiling in the cell.
文摘This paper investigates fast time-varying channel estimation in LTE-R communication systems. The Basis Expansion Model （BEM） is adopted to fit the fast time-varying channel in a high-speed railway com- munication scenario. The channel impulse response is modeled as the sum of basis functions multiplied by different coefficients. The optimal coefficients are obtained by theoretical analysis. Simulation results show that a Generalized Complex-Exponential BEM （GCE-BEM） outperforms a Complex-Exponential BEM （CE-BEM） and a polynomial BEM in terms of Mean Squared Error （MSE）. Besides, the MSE of the CE- BEM decreases gradually as the number of basis functions increases. The GCE-BEM has a satisfactory performance with the serious fading channel.
基金supported by grants from the National Natural Science Foundation of China(32371326 and 32070551)the Science and Technology Projects in Guangzhou(E3330900-01)the Youth Innovation PromotionAssociation,CAs(201860).
文摘The shift from skotomorphogenesis to photomorphogenesis,a developmental transition in seed plants,in-volves dramatic proteomic changes.Lysine acetylation(Lys-Ac)is an evolutionarily conserved and recog-nized post-translational modification that plays a crucial role in plant development.However,its role in seedling deetiolation remains unclear.In this study,we conducted a comparative lysine acetylomic anal-ysis of etiolated Arabidopsis seedlings before and after red(R)light irradiation,uncovering that exposure to R light mainly led to protein lysine deacetylation during seedling deetiolation.Phytochrome A(phyA),a unique far-red(FR)light photoreceptor,was deacetylated at lysine 65(K65)when etiolated seedlings were moved to light.This residue is a critical ubiquitination site that regulates phyA stability.Moreover,K65 deacetylation facilitates phyA ubiquitination and 26s proteasome-mediated degradation,and is required for the function of phyA in FR light signaling and seedling photomorphogenesis.Furthermore,we identified a plant-specific lysine deacetylase HDT2 that interacts with and deacetylates phyA in the nu-cleus to promote its ubiquitination and degradation during seedling deetiolation.Genetic analysis revealed that HDT2 is critical for phyA-mediated photomorphogenic growth.Taken together,these findings reveal that lysine deacetylation of phyA by HDT2 plays a crucial role in modulating phyA turnover in response to light,suggesting that Lys-Ac might be central to the reprogramming of plants for photomorphogenic growth.
基金supported by grants from the National Natural Science Foundation of China(Nos.32571474 and 31801091)the Tianshan Talent in Science and Technology Innovation Team(No.2024TSYCTD0010)the Youth Innovation Promotion Association,Chinese Academy of Sciences(No.201860).
文摘Seed germination represents a critical step in the life cycle of plants. The far-red/red light photoreceptor phytochrome B (phyB) plays a dominant role in promoting germination by modulating gibberellin (GA) and abscisic acid (ABA) metabolism, although the underlying mechanism remains poorly understood. In this study, we identified BREVIPEDICELLUS (BP)/KNAT1, a KNOX transcription factor that acts downstream of phyB and activates light-initiated seed germination in Arabidopsis thaliana. BP undergoes ubiquitination and is degraded through the 26S proteasome pathway. phyB directly interacts with BP and stabilizes BP protein by decreasing its ubiquitination in imbibed seeds. A genome-wide transcriptomic analysis revealed that BP and phyB co-regulate the expression of genes associated with ABA biosynthesis, signal transduction, seed dormancy, and cell wall organization. BP suppresses the expression of two key ABA biosynthetic genes, NCED6 and NCED9, thus lowering ABA levels in imbibed seeds under phyB-activated conditions. BP directly binds to NCED6 and NCED9 and represses their expression by increasing the levels of H3K27me3, a repressive histone modification marker. Genetic analysis demonstrated that NCED6/NCED9 acts epistatic to BP in phyB-dependent germination. Overall, this study reveals a transcriptional module consisting of phyB-BP-NCED6/9, which transfers light signals that inhibit ABA biosynthesis, thereby promoting light-induced germination.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.52008343 and 12202276)the Fundamental Research Funds for Central Universities(Grant No.SWU-KT22020。
文摘Uninterrupted,efficient power supplies have posed a significant hurdle to the ubiquitous adoption of wearable devices,despite their potential for revolutionizing human‒machine interactions.This challenge is further compounded by the requirement of these devices to supply dependable energy for data-intensive sensing and transmission.Traditional thermoelectric solutions fail to deliver satisfactory performance under conditions of extremely low voltages.Here,we present a novel solution of a wearable thermoelectric generator integrated with an energy management system,which is capable of powering sensors and Bluetooth by harnessing body heat.Distinct from previous works,our innovation lies in its ability to consistently operate even with a minimal temperature difference(i.e.,4 K)between the human skin and the ambient environment,ensuring reliable data transmission within a time as short as 1.6 s.Furthermore,our system can recharge utilizing body heat under ultralow voltage conditions(30 mV).Our developed system provides a novel pathway for the continuous,reliable monitoring of self-contained wearable devices without depending on batteries.
