背景:骨代谢紊乱会引起骨相关疾病的发生,而叉头框转录因子O3可以通过调节氧化应激、自噬水平等来影响骨组织细胞增殖、分化与凋亡,调控骨代谢过程。目的:系统性分析叉头框转录因子O3调控骨代谢及其在骨科疾病中作用机制的相关研究文献...背景:骨代谢紊乱会引起骨相关疾病的发生,而叉头框转录因子O3可以通过调节氧化应激、自噬水平等来影响骨组织细胞增殖、分化与凋亡,调控骨代谢过程。目的:系统性分析叉头框转录因子O3调控骨代谢及其在骨科疾病中作用机制的相关研究文献,为后续以叉头框转录因子O3为靶点治疗骨疾病的研究提供参考。方法:以“(SU=FoxO3a OR SU=Foxo3 OR SU=Forkhead box O3 OR SU=叉头框转录因子O3)AND SU=骨”为检索句在中国知网进行检索,以“主题:(“FoxO3a”)OR主题:(“Foxo3”)OR主题:(“Forkhead box O3”)OR主题:(“叉头框转录因子O3”)AND主题:(“骨”)”为检索句在万方医学数据库进行检索;以“((FoxO3a)OR(Foxo3)OR(Forkhead box O3))AND((bone)OR(Skeleton))”为检索句在PubMed数据库进行检索,排除陈旧、重复、质量较差以及不相关的文献,最终纳入56篇文献进行综述分析。结果与结论:①叉头框转录因子O3与骨髓间充质干细胞:叉头框转录因子O3能够促进成骨谱系的形成,还可通过激活自噬促进早期成骨分化。同时,叉头框转录因子O3在骨髓间充质干细胞中体现抗氧化特性,保护细胞免受氧化应激诱导的衰老。②叉头框转录因子O3与成骨细胞:叉头框转录因子O3在成骨细胞中能通过干扰Wnt/β-连环蛋白通路抑制成骨,同时能激活抗氧化酶保护成熟成骨细胞。叉头框转录因子O3能促进成骨祖细胞的增殖,并通过激活自噬促进成骨分化。③叉头框转录因子O3与破骨细胞:叉头框转录因子O3表达可抵抗氧化应激和激活自噬抑制破骨细胞生成。④叉头框转录因子O3与骨细胞:叉头框转录因子O3可通过抗氧化作用保护骨细胞,还可通过抑制p16和p53信号通路和抑制衰老相关分泌表型来减少骨流失。⑤叉头框转录因子O3与软骨细胞:叉头框转录因子O3在骨关节炎中对软骨细胞起到保护作用,抑制软骨细胞分解或凋亡,促进软骨细胞外基质合成,可抑制软骨细胞肥大;然而,叉头框转录因子O3与Runt相关转录因子1在软骨细胞中高度共表达却会促进软骨祖细胞的早期软骨形成和终末肥大。⑥叉头框转录因子O3通过参与氧化应激抵抗与调控自噬等过程影响骨代谢,参与多类骨相关疾病的病理进程。展开更多
为探究稻茬小麦深施肥“一基一追”机艺融合技术的增产增效减排机制,2021—2024年在长江下游南通稻茬麦区开展大田试验。试验采用缓释掺混肥料(SRF,N∶P_(2)O_(5)∶K_(2)O=26∶12∶12)和普通尿素(U,46%N),结合自主研发的2BFGK-12(6)260...为探究稻茬小麦深施肥“一基一追”机艺融合技术的增产增效减排机制,2021—2024年在长江下游南通稻茬麦区开展大田试验。试验采用缓释掺混肥料(SRF,N∶P_(2)O_(5)∶K_(2)O=26∶12∶12)和普通尿素(U,46%N),结合自主研发的2BFGK-12(6)260全秸秆茬地洁区旋耕智能施肥播种机和3ZF-4(200)中耕追肥机,设置7种施肥模式(30 cm+15 cm宽窄行种植):以尿素4次分施(N 240 kg hm^(-2),基肥∶分蘖肥∶拔节肥∶孕穗肥=5∶1∶2∶2,窄行基施,追肥全田撒施)为对照(CK);减氮15%(N 204 kg hm^(-2))条件下设置6种处理:M_(1)(100%SRF窄行基施);M_(2)(60%SRF窄行基施+40%U拔节期窄行撒施);M_(3)(60%SRF窄行基施+40%U返青期宽行条施);M_(4)(60%SRF窄行基施+40%SRF返青期窄行撒施);M_(5)(60%SRF窄行基施+40%SRF返青期宽行条施);M_(4+5)(60%SRF窄行基施+20%SRF返青期宽行条施+20%SRF返青期窄行撒施)。研究比较不同施肥模式对小麦产量效益、根系形态生理、氮素利用效率及N_(2)O排放的影响。结果表明,与CK相比,M_(2)~M_(5)处理提高了小麦产量(4.0%~19.0%)和经济效益(13.7%~35.7%),其中M_(4)和M_(5)处理表现最优,分别增产14.1%和19.0%,经济效益提升34.5%和35.7%。这些处理明显改善了根系特性(根干重密度增加9.7%~111.8%,根系活力和氧化力分别提高6.8%~52.0%和4.2%~44.2%),降低N_(2)O累积排放量22.6%~34.5%,提高0~20 cm土层硝态氮含量11.2%~40.0%。在氮素利用方面,M_(2)~M_(5)处理均提高了籽粒氮素积累量、花后氮素积累量及其对籽粒氮素的贡献率,氮肥利用效率指标(包括偏生产力、农学效率和表观利用率)分别显著提升了22.4%~40.0%、29.7%~74.3%和9.41~18.77个百分点。值得注意的是,M_(4)和M_(5)处理表现出最优的综合效益:N_(2)O累积排放量降幅最大(分别达27.0%和34.5%),氮肥表观利用率2季均维持在43.0%以上(均值分别为43.5%和46.8%),同时在生育后期保持较高的根系活性和耕层无机氮含量。相比之下,M_(1)处理虽然实现了最大的N_(2)O减排效果(降幅35.9%),但导致减产10.4%和经济效益下降10.8%,且氮肥利用效率呈现不稳定的年际变化特征。而优化处理M_(4+5)进一步改善了根系形态生理特性,并提高氮肥表观利用率和籽粒氮素积累量。综上,减氮15%条件下(N 204 kg hm^(-2)),缓混肥2次施用处理(M_(4)和M_(5))能实现产量、经济效益、氮肥利用效率和N_(2)O减排的协同提高,并以追肥深施处理(M_(5))效应更强。本研究为稻茬小麦缓释肥减氮优化高效应用提供重要理论依据。展开更多
We study a novel replication mechanism to ensure service continuity against multiple simultaneous server failures.In this mechanism,each item represents a computing task and is replicated intoξ+1 servers for some int...We study a novel replication mechanism to ensure service continuity against multiple simultaneous server failures.In this mechanism,each item represents a computing task and is replicated intoξ+1 servers for some integerξ≥1,with workloads specified by the amount of required resources.If one or more servers fail,the affected workloads can be redirected to other servers that host replicas associated with the same item,such that the service is not interrupted by the failure of up toξservers.This requires that any feasible assignment algorithm must reserve some capacity in each server to accommodate the workload redirected from potential failed servers without overloading,and determining the optimal method for reserving capacity becomes a key issue.Unlike existing algorithms that assume that no two servers share replicas of more than one item,we first formulate capacity reservation for a general arbitrary scenario.Due to the combinatorial nature of this problem,finding the optimal solution is difficult.To this end,we propose a Generalized and Simple Calculating Reserved Capacity(GSCRC)algorithm,with a time complexity only related to the number of items packed in the server.In conjunction with GSCRC,we propose a robust replica packing algorithm with capacity optimization(RobustPack),which aims to minimize the number of servers hosting replicas and tolerate multiple server failures.Through theoretical analysis and experimental evaluations,we show that the RobustPack algorithm can achieve better performance.展开更多
Titanium plates with a Ti−O solid solution surface-hardened layer were cold roll-bonded with 304 stainless steel plates with high work hardening rates.The evolution and mechanisms affecting the interfacial bonding str...Titanium plates with a Ti−O solid solution surface-hardened layer were cold roll-bonded with 304 stainless steel plates with high work hardening rates.The evolution and mechanisms affecting the interfacial bonding strength in titanium/stainless steel laminated composites were investigated.Results indicate that the hardened layer reduces the interfacial bonding strength from over 261 MPa to less than 204 MPa.During the cold roll-bonding process,the hardened layer fractures,leading to the formation of multi-scale cracks that are difficult for the stainless steel to fill.This not only hinders the development of an interlocking interface but also leads to the presence of numerous microcracks and hardened blocks along the nearly straight interface,consequently weakening the interfacial bonding strength.In metals with high work hardening rates,the conventional approach of enhancing interface interlocking and improving interfacial bonding strength by using a surface-hardened layer becomes less effective.展开更多
This study investigates the distinct impacts of eastern Pacific(EP)and central Pacific(CP)El Niño events on winter shortwave solar radiation(SSR)in southern China,revealing different spatial distributions and und...This study investigates the distinct impacts of eastern Pacific(EP)and central Pacific(CP)El Niño events on winter shortwave solar radiation(SSR)in southern China,revealing different spatial distributions and underlying mechanisms.The results show that,during the developing winter of EP El Niño,significant SSR reductions occur in southwestern China and the east coast of southern China due to a strong,zonally extended Northwest Pacific anticyclone that transports moisture from the tropical Northwest Pacific and North Indian Ocean,while the northeast of southern China experiences a weak increase in SSR.In contrast,during the developing winter of CP El Niño,SSR decreases in the east of southern China with a significant decrease in the lower basin of the Yangtze River but an increase in the west of southern China with a remarkable increase in eastern Yunnan.The pronounced east-west dipole pattern in SSR anomalies is driven by a meridionally elongated Northwest Pacific anticyclone,which enhances northward moisture transport to the east of southern China while leaving western areas drier.Further research reveals that distinct moisture anomalies during the developing winter of EP and CP events result in divergent SSR distributions across southern China,primarily through modulating the total cloud cover.These findings highlight the critical need to differentiate between El Niño types when predicting medium and long-term variability of radiation in southern China.展开更多
文摘背景:骨代谢紊乱会引起骨相关疾病的发生,而叉头框转录因子O3可以通过调节氧化应激、自噬水平等来影响骨组织细胞增殖、分化与凋亡,调控骨代谢过程。目的:系统性分析叉头框转录因子O3调控骨代谢及其在骨科疾病中作用机制的相关研究文献,为后续以叉头框转录因子O3为靶点治疗骨疾病的研究提供参考。方法:以“(SU=FoxO3a OR SU=Foxo3 OR SU=Forkhead box O3 OR SU=叉头框转录因子O3)AND SU=骨”为检索句在中国知网进行检索,以“主题:(“FoxO3a”)OR主题:(“Foxo3”)OR主题:(“Forkhead box O3”)OR主题:(“叉头框转录因子O3”)AND主题:(“骨”)”为检索句在万方医学数据库进行检索;以“((FoxO3a)OR(Foxo3)OR(Forkhead box O3))AND((bone)OR(Skeleton))”为检索句在PubMed数据库进行检索,排除陈旧、重复、质量较差以及不相关的文献,最终纳入56篇文献进行综述分析。结果与结论:①叉头框转录因子O3与骨髓间充质干细胞:叉头框转录因子O3能够促进成骨谱系的形成,还可通过激活自噬促进早期成骨分化。同时,叉头框转录因子O3在骨髓间充质干细胞中体现抗氧化特性,保护细胞免受氧化应激诱导的衰老。②叉头框转录因子O3与成骨细胞:叉头框转录因子O3在成骨细胞中能通过干扰Wnt/β-连环蛋白通路抑制成骨,同时能激活抗氧化酶保护成熟成骨细胞。叉头框转录因子O3能促进成骨祖细胞的增殖,并通过激活自噬促进成骨分化。③叉头框转录因子O3与破骨细胞:叉头框转录因子O3表达可抵抗氧化应激和激活自噬抑制破骨细胞生成。④叉头框转录因子O3与骨细胞:叉头框转录因子O3可通过抗氧化作用保护骨细胞,还可通过抑制p16和p53信号通路和抑制衰老相关分泌表型来减少骨流失。⑤叉头框转录因子O3与软骨细胞:叉头框转录因子O3在骨关节炎中对软骨细胞起到保护作用,抑制软骨细胞分解或凋亡,促进软骨细胞外基质合成,可抑制软骨细胞肥大;然而,叉头框转录因子O3与Runt相关转录因子1在软骨细胞中高度共表达却会促进软骨祖细胞的早期软骨形成和终末肥大。⑥叉头框转录因子O3通过参与氧化应激抵抗与调控自噬等过程影响骨代谢,参与多类骨相关疾病的病理进程。
文摘为探究稻茬小麦深施肥“一基一追”机艺融合技术的增产增效减排机制,2021—2024年在长江下游南通稻茬麦区开展大田试验。试验采用缓释掺混肥料(SRF,N∶P_(2)O_(5)∶K_(2)O=26∶12∶12)和普通尿素(U,46%N),结合自主研发的2BFGK-12(6)260全秸秆茬地洁区旋耕智能施肥播种机和3ZF-4(200)中耕追肥机,设置7种施肥模式(30 cm+15 cm宽窄行种植):以尿素4次分施(N 240 kg hm^(-2),基肥∶分蘖肥∶拔节肥∶孕穗肥=5∶1∶2∶2,窄行基施,追肥全田撒施)为对照(CK);减氮15%(N 204 kg hm^(-2))条件下设置6种处理:M_(1)(100%SRF窄行基施);M_(2)(60%SRF窄行基施+40%U拔节期窄行撒施);M_(3)(60%SRF窄行基施+40%U返青期宽行条施);M_(4)(60%SRF窄行基施+40%SRF返青期窄行撒施);M_(5)(60%SRF窄行基施+40%SRF返青期宽行条施);M_(4+5)(60%SRF窄行基施+20%SRF返青期宽行条施+20%SRF返青期窄行撒施)。研究比较不同施肥模式对小麦产量效益、根系形态生理、氮素利用效率及N_(2)O排放的影响。结果表明,与CK相比,M_(2)~M_(5)处理提高了小麦产量(4.0%~19.0%)和经济效益(13.7%~35.7%),其中M_(4)和M_(5)处理表现最优,分别增产14.1%和19.0%,经济效益提升34.5%和35.7%。这些处理明显改善了根系特性(根干重密度增加9.7%~111.8%,根系活力和氧化力分别提高6.8%~52.0%和4.2%~44.2%),降低N_(2)O累积排放量22.6%~34.5%,提高0~20 cm土层硝态氮含量11.2%~40.0%。在氮素利用方面,M_(2)~M_(5)处理均提高了籽粒氮素积累量、花后氮素积累量及其对籽粒氮素的贡献率,氮肥利用效率指标(包括偏生产力、农学效率和表观利用率)分别显著提升了22.4%~40.0%、29.7%~74.3%和9.41~18.77个百分点。值得注意的是,M_(4)和M_(5)处理表现出最优的综合效益:N_(2)O累积排放量降幅最大(分别达27.0%和34.5%),氮肥表观利用率2季均维持在43.0%以上(均值分别为43.5%和46.8%),同时在生育后期保持较高的根系活性和耕层无机氮含量。相比之下,M_(1)处理虽然实现了最大的N_(2)O减排效果(降幅35.9%),但导致减产10.4%和经济效益下降10.8%,且氮肥利用效率呈现不稳定的年际变化特征。而优化处理M_(4+5)进一步改善了根系形态生理特性,并提高氮肥表观利用率和籽粒氮素积累量。综上,减氮15%条件下(N 204 kg hm^(-2)),缓混肥2次施用处理(M_(4)和M_(5))能实现产量、经济效益、氮肥利用效率和N_(2)O减排的协同提高,并以追肥深施处理(M_(5))效应更强。本研究为稻茬小麦缓释肥减氮优化高效应用提供重要理论依据。
基金supported in part by the National Key R&D Program of China under No.2023YFB2703800the National Science Foundation of China under Grants U22B2027,62172297,62102262,61902276 and 62272311+3 种基金Tianjin Intelligent Manufacturing Special Fund Project under Grants 20211097the China Guangxi Science and Technology Plan Project(Guangxi Science and Technology Base and Talent Special Project)under Grant AD23026096(Application Number 2022AC20001)Henan Provincial Natural Science Foundation of China under Grant 622RC616CCF-Nsfocus Kunpeng Fund Project under Grants CCF-NSFOCUS202207。
文摘We study a novel replication mechanism to ensure service continuity against multiple simultaneous server failures.In this mechanism,each item represents a computing task and is replicated intoξ+1 servers for some integerξ≥1,with workloads specified by the amount of required resources.If one or more servers fail,the affected workloads can be redirected to other servers that host replicas associated with the same item,such that the service is not interrupted by the failure of up toξservers.This requires that any feasible assignment algorithm must reserve some capacity in each server to accommodate the workload redirected from potential failed servers without overloading,and determining the optimal method for reserving capacity becomes a key issue.Unlike existing algorithms that assume that no two servers share replicas of more than one item,we first formulate capacity reservation for a general arbitrary scenario.Due to the combinatorial nature of this problem,finding the optimal solution is difficult.To this end,we propose a Generalized and Simple Calculating Reserved Capacity(GSCRC)algorithm,with a time complexity only related to the number of items packed in the server.In conjunction with GSCRC,we propose a robust replica packing algorithm with capacity optimization(RobustPack),which aims to minimize the number of servers hosting replicas and tolerate multiple server failures.Through theoretical analysis and experimental evaluations,we show that the RobustPack algorithm can achieve better performance.
基金supported by the National Key R&D Program of China (No. 2018YFA0707300)the National Natural Science Foundation of China (No. 52374376)the Introduction Plan for High end Foreign Experts, China (No. G2023105001L)。
文摘Titanium plates with a Ti−O solid solution surface-hardened layer were cold roll-bonded with 304 stainless steel plates with high work hardening rates.The evolution and mechanisms affecting the interfacial bonding strength in titanium/stainless steel laminated composites were investigated.Results indicate that the hardened layer reduces the interfacial bonding strength from over 261 MPa to less than 204 MPa.During the cold roll-bonding process,the hardened layer fractures,leading to the formation of multi-scale cracks that are difficult for the stainless steel to fill.This not only hinders the development of an interlocking interface but also leads to the presence of numerous microcracks and hardened blocks along the nearly straight interface,consequently weakening the interfacial bonding strength.In metals with high work hardening rates,the conventional approach of enhancing interface interlocking and improving interfacial bonding strength by using a surface-hardened layer becomes less effective.
基金funded by a Project from China Southern Power Grid Company Ltd.(Nos.ZBKJXM20232481 and ZBKJXM20232482)。
文摘This study investigates the distinct impacts of eastern Pacific(EP)and central Pacific(CP)El Niño events on winter shortwave solar radiation(SSR)in southern China,revealing different spatial distributions and underlying mechanisms.The results show that,during the developing winter of EP El Niño,significant SSR reductions occur in southwestern China and the east coast of southern China due to a strong,zonally extended Northwest Pacific anticyclone that transports moisture from the tropical Northwest Pacific and North Indian Ocean,while the northeast of southern China experiences a weak increase in SSR.In contrast,during the developing winter of CP El Niño,SSR decreases in the east of southern China with a significant decrease in the lower basin of the Yangtze River but an increase in the west of southern China with a remarkable increase in eastern Yunnan.The pronounced east-west dipole pattern in SSR anomalies is driven by a meridionally elongated Northwest Pacific anticyclone,which enhances northward moisture transport to the east of southern China while leaving western areas drier.Further research reveals that distinct moisture anomalies during the developing winter of EP and CP events result in divergent SSR distributions across southern China,primarily through modulating the total cloud cover.These findings highlight the critical need to differentiate between El Niño types when predicting medium and long-term variability of radiation in southern China.
文摘硫酸软骨素A(chondroitin sulfate A,CSA)是关节软骨修复中不可或缺的重要成分。CSA由软骨素4-O-磺基转移酶-1(chondroitin 4-O-sulfotransferase-1,C4ST-1)催化软骨素中N-乙酰氨基半乳糖胺(N-acetylgalactosamine,GalNAc)4号位羟基磺酸化合成。然而,由于C4ST-1酶活性较低,其催化能力受限,进而阻碍了CSA的工业化生产进程。为此,该研究旨在通过结合重组菌构建和培养基优化提升C4ST-1酶活性。首先在筛选确定了以毕赤酵母GS115为底盘细胞的基础上,进一步优化了以OST1-α分泌信号肽和SUMO Pro 3促溶标签的组合方式进行C4ST-1分泌表达,经摇瓶发酵C4ST-1最高酶活性为1889.2 U/L。鉴于前期研究发现无机盐对C4ST-1酶活性的抑制以及现有培养基成本较高问题,该研究通过优化培养基组分,发现不添加昂贵成分酵母无氨基氮源(yeast nitrogen base without amino acids,YNB)时,C4ST-1酶活性较原培养基提高68.4%。此外,结合碳源、其他氮源以及生物素的筛选与优化使C4ST-1酶活性进一步提高。最终,在5L发酵罐补料分批发酵72 h时,获得最高酶活性为5040.7 U/L。该研究不仅为CSA规模化生产奠定了基础,也将为其他糖胺聚糖(如肝素、硫酸皮肤素)合成所需的磺基转移酶发酵生产提供借鉴。
