Fish, like many other animals, have two major cell lineages, namely the germline and soma. The germ-soma separation is one of the earliest events of embryonic development. Germ cells can be specifically labeled and is...Fish, like many other animals, have two major cell lineages, namely the germline and soma. The germ-soma separation is one of the earliest events of embryonic development. Germ cells can be specifically labeled and isolated for culture and transplan-tation, providing tools for reproduction of endangered species in close relatives, such as surrogate production of trout in salmon. Haploid cell cultures, such as medaka haploid embryonic stem cells have recently been obtained, which are capable of mimicking sperm to produce fertile offspring, upon nuclear being directly transferred into normal eggs. Such fish originated from a mosaic oocyte that had a haploid meiotic nucleus and a transplanted haploid mitotic cell culture nucleus. The first semi-cloned fish is Holly. Here we review the current status and future directions of understanding and manipulating fish germ cells in basic research and reproductive technology.展开更多
Small bowel vascular lesions, including angioectasia (AE), Dieulafoy’s lesion (DL) and arteriovenous malformation (AVM), are the most common causes of obscure gastrointestinal bleeding. Since AE are considered to be ...Small bowel vascular lesions, including angioectasia (AE), Dieulafoy’s lesion (DL) and arteriovenous malformation (AVM), are the most common causes of obscure gastrointestinal bleeding. Since AE are considered to be venous lesions, they usually manifest as a chronic, well-compensated condition. Subsequent to video capsule endoscopy, deep enteroscopy can be applied to control active bleeding or to improve anemia necessitating blood transfusion. Despite the initial treatment efficacy of argon plasma coagulation (APC), many patients experience re-bleeding, probably because of recurrent or missed AEs. Pharmacological treatments can be considered for patients who have not responded well to other types of treatment or in whom endoscopy is contraindicated. Meanwhile, a conservative approach with iron supplementation remains an option for patients with mild anemia. DL and AVM are considered to be arterial lesions;therefore, these lesions frequently cause acute life-threatening hemorrhage. Mechanical hemostasis using endoclips is recommended to treat DLs, considering the high re-bleeding rate after primary APC cauterization. Meanwhile, most small bowel AVMs are large and susceptible to re-bleeding therefore, they usually require surgical resection. To achieve optimal diagnostic and therapeutic approaches for each type of small bowel lesion, the differences in their epidemiology, pathology and clinical presentation must be understood.展开更多
目的观察血液样本处理方式对大鼠血液生化指标检测结果的影响。方法取体重180~220 g的SPF级Wistar大鼠40只,雌雄各半,禁食不禁水12 h后,用3%戊巴比妥钠麻醉后取全血和肝素抗凝血各3 m L。将每种血样分别置于3个1.5 m L的离心管和肝素抗...目的观察血液样本处理方式对大鼠血液生化指标检测结果的影响。方法取体重180~220 g的SPF级Wistar大鼠40只,雌雄各半,禁食不禁水12 h后,用3%戊巴比妥钠麻醉后取全血和肝素抗凝血各3 m L。将每种血样分别置于3个1.5 m L的离心管和肝素抗凝管中各1 m L,并分别在室温放置1 h、2 h、4 h后进行离心,测定血糖、血脂、蛋白、肝功能、肾功能、心肌酶等指标。结果血液样本类型和采集后离心前的放置时间对Wistar大鼠的血清或血浆TC、TG、TP、ALB、ALT、ALP、BUN和CREA等指标均无明显影响（P〉0.05）。但血浆的GLU值显著高于血清（P〈0.05,P〈0.01）,并随着采集后离心前放置时间的延长持续下降。血清AST和CK、LDH值则均显著高于血浆（P〈0.05,P〈0.01）,且随采集后离心前放置的延长呈现持续显著的上升（P〈0.05,P〈0.01）。而采集后离心前放置时间对Wistar大鼠血浆AST和CK、LDH值均无明显影响（P〉0.05）。结论血液样本类型对血脂、蛋白和肾功能指标无明显影响,但对GLU、AST、CK、LDH等检测结果有一定影响。采集后离心前的放置时间延长可导致血清血浆GLU下降,血清AST、CK、LDH升高,但对血浆AST、CK、LDH指标无明显影响。展开更多
In many metazoan species, germ cell formation requires the germ plasm, a specialized cytoplasm which often con-tains electron dense structures. Genes required for germ cell formation in Drosophila have been isolated p...In many metazoan species, germ cell formation requires the germ plasm, a specialized cytoplasm which often con-tains electron dense structures. Genes required for germ cell formation in Drosophila have been isolated predominantlyin screens for maternal-effect mutations. One such gene is tudor (tud); without proper tud function germ cell formationdoes not occur. Unlike other genes involved in Drosophila germ cell specification tud is dispensable for other somaticfunctions such as abdominal patterning. It is not known how TUD contributes at a molecular level to germ cell forma-tion but in tud mutants, polar granule formation is severely compromised, and mitochondrially encoded ribosomal RNAsdo not localize to the polar granule. TUD is composed of 11 repeats of the protein motif called the Tudor domain. Thereare similar proteins to TUD in the germ line of other metazoan species including mice. Probable vertebrate orthologuesof Drosophila genes involved in germ cell specification will be discussed.展开更多
We report a feasible method to realize tun able surface plasm on-polarit on(SPP)res onance in orga nic light-emitt ing devices(OLEDs)by emplo ying corrugated Ag-Al alloy electrodes.The excited SPP res onance in duced ...We report a feasible method to realize tun able surface plasm on-polarit on(SPP)res onance in orga nic light-emitt ing devices(OLEDs)by emplo ying corrugated Ag-Al alloy electrodes.The excited SPP res onance in duced by the periodic corrugations can be precisely tuned based on the composition ratios of the Ag-Al alloy electrodes.With an appropriate composition ratio of the corrugated alloy electrode,the photons trapped in SPP modes are recovered and extracted effectively.The 25%in creaseme nt in luminance and 21%enhan ceme nt in curre nt efficie ncy have bee n achieved by using the corrugated Ag-Al alloy electrodes in OLEDs.展开更多
When quantum emitters and plasmonic nanoparticles are in close vicinity,the energy exchange,termed as plasmon-exciton coupling,can make the absorption and emission behavior of the hybrid structure very different from ...When quantum emitters and plasmonic nanoparticles are in close vicinity,the energy exchange,termed as plasmon-exciton coupling,can make the absorption and emission behavior of the hybrid structure very different from those of the two constituents alone.The coupling strength between the two constituents highly depends on how the hybrid structure is constructed.As a result,a diverse range of coupling effect arise including plasmon induced fluorescence quenching/enhancing (weak coupling),Fano interference (intermediate coupling),Rabi-splitting and lasing (strong coupling).The emergence of different coupling behavior can be controlled by the different combinations of quantum emitters and plasmonic nanoparticles as well as the spatial arrangement of the individual components.Colloidal assembly/synthesis methods are essentially delicate strategies that can build the hybrid nanostructures with nanometer precision and allow for large-scale processing.In this review,we discuss the theoretical models that apply to different coupling behaviors,the optical properties of the hybrid systems,and the advancement of colloidal methods to manipulate the plasmon-exciton in the hybrid structures.We also provide perspectives on the challenges and future directions of the research in coupled plasmon-exciton nanosystems.展开更多
基金supported by the Biomedical Research Council of Singapore (Grant Nos. R-05-1-21-19-404, R-08-1-21-19-585 and SBIC-SSCC C-002-2007)the Ministry of Education of Singapore (Grant No. R-154-000-285-112)+1 种基金the National University of Singapore (Grant No. R-154-000-153-720)the National Key Basic Research Program of China (Grant Nos. 2004CB117406 and 2010CB126301)
文摘Fish, like many other animals, have two major cell lineages, namely the germline and soma. The germ-soma separation is one of the earliest events of embryonic development. Germ cells can be specifically labeled and isolated for culture and transplan-tation, providing tools for reproduction of endangered species in close relatives, such as surrogate production of trout in salmon. Haploid cell cultures, such as medaka haploid embryonic stem cells have recently been obtained, which are capable of mimicking sperm to produce fertile offspring, upon nuclear being directly transferred into normal eggs. Such fish originated from a mosaic oocyte that had a haploid meiotic nucleus and a transplanted haploid mitotic cell culture nucleus. The first semi-cloned fish is Holly. Here we review the current status and future directions of understanding and manipulating fish germ cells in basic research and reproductive technology.
文摘Small bowel vascular lesions, including angioectasia (AE), Dieulafoy’s lesion (DL) and arteriovenous malformation (AVM), are the most common causes of obscure gastrointestinal bleeding. Since AE are considered to be venous lesions, they usually manifest as a chronic, well-compensated condition. Subsequent to video capsule endoscopy, deep enteroscopy can be applied to control active bleeding or to improve anemia necessitating blood transfusion. Despite the initial treatment efficacy of argon plasma coagulation (APC), many patients experience re-bleeding, probably because of recurrent or missed AEs. Pharmacological treatments can be considered for patients who have not responded well to other types of treatment or in whom endoscopy is contraindicated. Meanwhile, a conservative approach with iron supplementation remains an option for patients with mild anemia. DL and AVM are considered to be arterial lesions;therefore, these lesions frequently cause acute life-threatening hemorrhage. Mechanical hemostasis using endoclips is recommended to treat DLs, considering the high re-bleeding rate after primary APC cauterization. Meanwhile, most small bowel AVMs are large and susceptible to re-bleeding therefore, they usually require surgical resection. To achieve optimal diagnostic and therapeutic approaches for each type of small bowel lesion, the differences in their epidemiology, pathology and clinical presentation must be understood.
文摘目的观察血液样本处理方式对大鼠血液生化指标检测结果的影响。方法取体重180~220 g的SPF级Wistar大鼠40只,雌雄各半,禁食不禁水12 h后,用3%戊巴比妥钠麻醉后取全血和肝素抗凝血各3 m L。将每种血样分别置于3个1.5 m L的离心管和肝素抗凝管中各1 m L,并分别在室温放置1 h、2 h、4 h后进行离心,测定血糖、血脂、蛋白、肝功能、肾功能、心肌酶等指标。结果血液样本类型和采集后离心前的放置时间对Wistar大鼠的血清或血浆TC、TG、TP、ALB、ALT、ALP、BUN和CREA等指标均无明显影响（P〉0.05）。但血浆的GLU值显著高于血清（P〈0.05,P〈0.01）,并随着采集后离心前放置时间的延长持续下降。血清AST和CK、LDH值则均显著高于血浆（P〈0.05,P〈0.01）,且随采集后离心前放置的延长呈现持续显著的上升（P〈0.05,P〈0.01）。而采集后离心前放置时间对Wistar大鼠血浆AST和CK、LDH值均无明显影响（P〉0.05）。结论血液样本类型对血脂、蛋白和肾功能指标无明显影响,但对GLU、AST、CK、LDH等检测结果有一定影响。采集后离心前的放置时间延长可导致血清血浆GLU下降,血清AST、CK、LDH升高,但对血浆AST、CK、LDH指标无明显影响。
文摘In many metazoan species, germ cell formation requires the germ plasm, a specialized cytoplasm which often con-tains electron dense structures. Genes required for germ cell formation in Drosophila have been isolated predominantlyin screens for maternal-effect mutations. One such gene is tudor (tud); without proper tud function germ cell formationdoes not occur. Unlike other genes involved in Drosophila germ cell specification tud is dispensable for other somaticfunctions such as abdominal patterning. It is not known how TUD contributes at a molecular level to germ cell forma-tion but in tud mutants, polar granule formation is severely compromised, and mitochondrially encoded ribosomal RNAsdo not localize to the polar granule. TUD is composed of 11 repeats of the protein motif called the Tudor domain. Thereare similar proteins to TUD in the germ line of other metazoan species including mice. Probable vertebrate orthologuesof Drosophila genes involved in germ cell specification will be discussed.
基金This work was supported by the National Key Research and Development Program of China and the National Natural Science Foundation of China(NSFC)under Grants No.2020YFA0715000 and No.61825402.
文摘We report a feasible method to realize tun able surface plasm on-polarit on(SPP)res onance in orga nic light-emitt ing devices(OLEDs)by emplo ying corrugated Ag-Al alloy electrodes.The excited SPP res onance in duced by the periodic corrugations can be precisely tuned based on the composition ratios of the Ag-Al alloy electrodes.With an appropriate composition ratio of the corrugated alloy electrode,the photons trapped in SPP modes are recovered and extracted effectively.The 25%in creaseme nt in luminance and 21%enhan ceme nt in curre nt efficie ncy have bee n achieved by using the corrugated Ag-Al alloy electrodes in OLEDs.
文摘When quantum emitters and plasmonic nanoparticles are in close vicinity,the energy exchange,termed as plasmon-exciton coupling,can make the absorption and emission behavior of the hybrid structure very different from those of the two constituents alone.The coupling strength between the two constituents highly depends on how the hybrid structure is constructed.As a result,a diverse range of coupling effect arise including plasmon induced fluorescence quenching/enhancing (weak coupling),Fano interference (intermediate coupling),Rabi-splitting and lasing (strong coupling).The emergence of different coupling behavior can be controlled by the different combinations of quantum emitters and plasmonic nanoparticles as well as the spatial arrangement of the individual components.Colloidal assembly/synthesis methods are essentially delicate strategies that can build the hybrid nanostructures with nanometer precision and allow for large-scale processing.In this review,we discuss the theoretical models that apply to different coupling behaviors,the optical properties of the hybrid systems,and the advancement of colloidal methods to manipulate the plasmon-exciton in the hybrid structures.We also provide perspectives on the challenges and future directions of the research in coupled plasmon-exciton nanosystems.
