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Research Progress on Application of Molecular Markers in Breeding of Camellia oleifera
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作者 Yimin HE jingjing cheng +4 位作者 Dayu YANG Jiancai SHEN Xiaofan MA Yali LI Ying ZHANG 《Agricultural Biotechnology》 2024年第3期1-4,10,共5页
Camellia oleifera is an important woody oil tree species unique to China.It is known as the world s four major woody oil crops along with olive,oil palm and coconut.It is known as the‘king of oil’because of its high... Camellia oleifera is an important woody oil tree species unique to China.It is known as the world s four major woody oil crops along with olive,oil palm and coconut.It is known as the‘king of oil’because of its high oil content.With the increase of people's attention to the yield of Camellia oleifera,its high yield has become the focus.In traditional breeding model,judgment is performed by phenotypic traits,but this method is single and easily affected by the environment,and can no longer meet the demand.In contrast,molecular marker breeding is not affected by the environment,and is stable and efficient and capable of accurately mapping target genes,so it has attracted much attention.In this paper,the research progress on C.oleifera germplasm resources diversity,DNA fingerprinting construction,genetic linkage map construction and QTL mapping was summarized,and the application of SSR molecular marker technique combined with association analysis in C.oleifera breeding in recent years was discussed,in order to provide new ideas for high-yield breeding of C.oleifera. 展开更多
关键词 Camellia oleifera DIVERSITY SSR molecular marker technology Correlation analysis
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Sulfur-mediated photodeposition synthesis of NiS cocatalyst for boosting H2-evolution performance of g-C3N4 photocatalyst 被引量:8
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作者 Min Wang jingjing cheng +3 位作者 Xuefei Wang Xuekun Hong Jiajie Fan Huogen Yu 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2021年第1期37-45,共9页
Modification of nickel sulfide cocatalysts is considered to be a promising approach for efficient enhancement of the photocatalytic hydrogen production performance of g-C3N4.Providing more NiS cocatalyst to function a... Modification of nickel sulfide cocatalysts is considered to be a promising approach for efficient enhancement of the photocatalytic hydrogen production performance of g-C3N4.Providing more NiS cocatalyst to function as active sites of g-C3N4 is still highly desirable.To realize this goal,in this work,a facile sulfur-mediated photodeposition approach was developed.Specifically,photogenerated electrons excited by visible light reduce the S molecules absorbed on g-C3N4 surface to S^2‒,and subsequently NiS cocatalyst is formed in situ on the g-C3N4 surface by a combination of Ni2+and S2‒due to their small solubility product constant(Ksp=3.2×10^‒19).This approach has several advantages.The NiS cocatalyst is clearly in situ deposited on the photogenerated electron transfer sites of g-C3N4,and thus provides more active sites for H2 production.In addition,this method utilizes solar energy with mild reaction conditions at room temperature.Consequently,the synthesized NiS/g-C3N4 photocatalyst achieves excellent hydrogen generation performance with the performance of the optimal sample(244μmol h^‒1 g^‒1)close to that of 1 wt%Pt/g-C3N4(316μmol h^‒1 g^‒1,a well-known excellent photocatalyst).More importantly,the present sulfur-mediated photodeposition route is versatile and facile and can be used to deposit various metal sulfides such as CoSx,CuSx and AgSx on the g-C3N4 surface,and all the resulting metal sulfide-modified g-C3N4 photocatalysts exhibit improved H2-production performance.Our study offers a novel insight for the synthesis of high-efficiency photocatalysts. 展开更多
关键词 g-C3N4 NIS Co-catalyst Sulfur-mediated photodeposition H2 Photocatalysis
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NS1结合蛋白通过转录抑制c-Myc增强食管鳞状细胞癌的放疗敏感性 被引量:2
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作者 Yuwen Wang jingjing cheng +10 位作者 Dan Xie Xiaofeng Ding Hailing Hou Xi Chen Puchun Er Furong Zhang Lujun Zhao Zhiyong Yuan Qingsong Pang Ping Wang Dong Qian 《癌症》 SCIE CAS CSCD 2019年第2期52-66,共15页
背景与目的基于顺铂的化疗联合放疗是晚期食管鳞状细胞癌(esophageal squamous cell carcinoma,ESCC)的标准疗法。NS1结合蛋白(NS1-binding protein,NS1-BP)是BTB-kelch蛋白家族中的一员,已被证明可通过抑制c-Myc进而抑制HeLa细胞增殖... 背景与目的基于顺铂的化疗联合放疗是晚期食管鳞状细胞癌(esophageal squamous cell carcinoma,ESCC)的标准疗法。NS1结合蛋白(NS1-binding protein,NS1-BP)是BTB-kelch蛋白家族中的一员,已被证明可通过抑制c-Myc进而抑制HeLa细胞增殖。在本研究中,我们检测NS1-BP表达在ESCC中的潜在作用,特别是其在ESCC放疗敏感性方面的作用。方法对于两组接受基于顺铂化疗且联合放疗的ESCC患者(研究组n=98;验证组n=46),采用免疫组化方法分别检测NS1-BP表达。使用正常食管黏膜组织块作为对照。我们也进行了一系列体外和体内实验来检测过表达NS1-BP对ESCC细胞各方面的潜在影响,尤其关注的是对电离辐射的敏感性方面的影响。结果在研究组中,59%(85/144)的ESCC样本观察到了NS1-BP下调。在研究组和验证组中,NS1-BP下调与放化疗抵抗和较短的疾病特异生存期(disease-specific survival,DSS)均具有相关性。体内和体外培养条件下过表达NS1-BP均能大幅度提高ECSS细胞对放疗的敏感性。NS1-BP也显著增强IR诱导的凋亡,阻断IR诱导的G2/M细胞周期阻滞和ATM/Chk1磷酸化。免疫沉淀反应显示NS1-BP可以与c-Myc启动子区相互作用从而抑制其转录。在ESCC组织中,c-Myc表达与NS1-BP水平负相关,与较短的疾病特异生存期相关。结论我们的研究结果显示了NS1-BP在ESCC放疗敏感性中的作用和重要性。以NS1-BP/c-Myc通路为靶标有望开发一种新的ESCC治疗策略。 展开更多
关键词 食管鳞状细胞癌 NS1-BP 预后标志物 放疗 C-MYC
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Albedo of Coastal Landfast Sea Ice in Prydz Bay,Antarctica:Observations and Parameterization 被引量:10
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作者 Qinghua YANG Jiping LIU +9 位作者 Matti LEPPRANTA Qizhen SUN Rongbin LI Lin ZHANG Thomas JUNG Ruibo LEI Zhanhai ZHANG Ming LI Jiechen ZHAO jingjing cheng 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2016年第5期535-543,共9页
The snow/sea-ice albedo was measured over coastal landfast sea ice in Prydz Bay, East Antarctica(off Zhongshan Station)during the austral spring and summer of 2010 and 2011. The variation of the observed albedo was ... The snow/sea-ice albedo was measured over coastal landfast sea ice in Prydz Bay, East Antarctica(off Zhongshan Station)during the austral spring and summer of 2010 and 2011. The variation of the observed albedo was a combination of a gradual seasonal transition from spring to summer and abrupt changes resulting from synoptic events, including snowfall, blowing snow, and overcast skies. The measured albedo ranged from 0.94 over thick fresh snow to 0.36 over melting sea ice. It was found that snow thickness was the most important factor influencing the albedo variation, while synoptic events and overcast skies could increase the albedo by about 0.18 and 0.06, respectively. The in-situ measured albedo and related physical parameters(e.g., snow thickness, ice thickness, surface temperature, and air temperature) were then used to evaluate four different snow/ice albedo parameterizations used in a variety of climate models. The parameterized albedos showed substantial discrepancies compared to the observed albedo, particularly during the summer melt period, even though more complex parameterizations yielded more realistic variations than simple ones. A modified parameterization was developed,which further considered synoptic events, cloud cover, and the local landfast sea-ice surface characteristics. The resulting parameterized albedo showed very good agreement with the observed albedo. 展开更多
关键词 Antarctic sea ice albedo observation parameterization
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Crystal Type Iof Azilsartan Polymorphs: Preparation and Analysis
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作者 Yuhua Ge Tingting Li jingjing cheng 《Journal of Crystallization Process and Technology》 2016年第1期1-10,共10页
Azilsartan (2-ethoxy-1-([2’-(5-oxo-4,5-dihydro-1,2,4-oxadiazol-3-yl)biphenyl-4-yl]methyl)-1H-benzimidazole-7-carboxylic acid) is a new angiotensin II receptor antagonist used in the treatment of hypertension. This pa... Azilsartan (2-ethoxy-1-([2’-(5-oxo-4,5-dihydro-1,2,4-oxadiazol-3-yl)biphenyl-4-yl]methyl)-1H-benzimidazole-7-carboxylic acid) is a new angiotensin II receptor antagonist used in the treatment of hypertension. This paper describes the preparation of type I crystal and its single crystal diffraction data, the comparison of the powder diffraction data for both type I and II crystals as well as their stability and solubility in methanol. 展开更多
关键词 Azilsartan Single Crystal Diffraction Powder Diffraction SOLUBILITY STABILITY
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A nanoplatform with oxygen self-supplying and heat-sensitizing capabilities enhances the efficacy of photodynamic therapy in eradicating multidrug-resistant biofilms 被引量:2
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作者 Haixin Zhang Yi Zou +7 位作者 Kunyan Lu Yan Wu Yuancheng Lin jingjing cheng Chunxia Liu Hong Chen Yanxia Zhang Qian Yu 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2024年第2期209-219,共11页
Bacterial biofilms,especially those caused by multidrug-resistant bacteria,have emerged as one of the greatest dangers to global public health.The acceleration of antimicrobial resistance to conventional an-tibiotics ... Bacterial biofilms,especially those caused by multidrug-resistant bacteria,have emerged as one of the greatest dangers to global public health.The acceleration of antimicrobial resistance to conventional an-tibiotics and the severe lack of new drugs necessitates the development of novel agents for biofilm eradication.Photodynamic therapy(PDT)is a promising non-antibiotic method for treating bacterial infections.However,its application in biofilm eradication is hampered by the hypoxic microenvironment of biofilms and the physical protection of extracellular polymeric substances.In this study,we develop a composite nanoplatform with oxygen(O_(2))self-supplying and heat-sensitizing capabilities to improve the PDT efficacy against biofilms.CaO_(2)/ICG@PDA nanoparticles(CIP NPs)are fabricated by combining calcium peroxide(CaO_(2))with the photosensitizer indocyanine green(ICG)via electrostatic interactions,followed by coating with polydopamine(PDA).The CIP NPs can gradually generate O_(2)in response to the acidic microenvironment of the biofilm,thereby alleviating its hypoxic state.Under near-infrared(NIR)irradiation,the nanoplatform converts O_(2)into a significant amount of singlet oxygen(^(1)O_(2))and heat to eradicate biofilm.The generated heat enhances the release of O_(2),accelerates the generation of^(1)O_(2)in PDT,increases cell membrane permeability,and increases bacterial sensitivity to^(1)O_(2).This nanoplatform significantly improves the efficacy of PDT in eradicating biofilm-dwelling bacteria without fostering drug resistance.Experiments on biofilm eradication demonstrate that this nanoplatform can eradicate over 99.9999%of methicillin-resistant Staphylococcus aureus(MRSA)biofilms under 5-min NIR irradiation.Notably,these integrated advantages enable the system to promote the healing of MRSA biofilm-infected wounds with negligible toxicity in vivo,indicating great promise for overcoming the obstacles associated with bacterial biofilm eradication. 展开更多
关键词 Bacterial biofilm Multidrug-resistant bacteria Photodynamic therapy Oxygen supplying Photothermal therapy
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Postnatal feeding with high-fat diet induces obesity and precocious puberty in C57BL/6J mouse pups: a novel model of obesity and puberty 被引量:7
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作者 Rahim Ullah Yan Su +10 位作者 Yi Shen Chunlu Li Xiaoqin Xu Jianwei Zhang Ke Huang Naveed Rauf Yang He jingjing cheng Huaping Qin Yu-Dong Zhou Junfen Fu 《Frontiers of Medicine》 SCIE CAS CSCD 2017年第2期266-276,共11页
Childhood obesity and obesity-related metabolic complications are induced by a high-fat postnatal diet. The lack of a suitable animal model, however, remains a considerable challenge in obesity studies. In the current... Childhood obesity and obesity-related metabolic complications are induced by a high-fat postnatal diet. The lack of a suitable animal model, however, remains a considerable challenge in obesity studies. In the current study, we provided high-fat diet (HFD) to dams during lactation and to pups after weaning. We also developed a novel model of C57BL/6J mouse pups with HFD-induced postnatal obesity. Results showed that feeding with HFD induces fat deposition and obesity in pups. Furthermore, HFD more potently increased the body weight (BW) of male than female pups. HFD-fed female pups were obese, underwent precocious puberty, and showed increased kisspeptin expression in the hypothalamus. However, parental obesity and precocious puberty exerted no synergistic effects on the HFD-induced postnatal weight gain and puberty onset of the pups. Interestingly, some HFD-fed litters with normal BW also exhibited precocious puberty. This finding suggested that diet composition but not BW triggers puberty onset. Our model suggests good construction validity of obesity and precocious puberty. Furthermore, our model can also be used to explore the mutual interactions between diet-induced postnatal childhood obesity and puberty. 展开更多
关键词 postnatal HFD feeding OBESITY KISSPEPTIN HPG axis precocious puberty
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Bacterial cellulose-based dressings with photothermal bactericidal activity and pro-angiogenic ability for infected wound healing 被引量:3
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作者 Yan Wu Dongxu Jia +9 位作者 Kunyan Lu Haixin Zhang Chunxia Liu Yuancheng Lin jingjing cheng Yi Zou Hu Xu Hong Chen Yanxia Zhang Qian Yu 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2023年第29期76-85,共10页
For most traditional wound dressings,it is challenging to simultaneously eliminate bacteria and promote angiogenesis to accelerate the healing process of bacteria-infected wounds.In this work,we develop a multifunctio... For most traditional wound dressings,it is challenging to simultaneously eliminate bacteria and promote angiogenesis to accelerate the healing process of bacteria-infected wounds.In this work,we develop a multifunctional dressing based on bacterial cellulose(BC)deposited with a tannic acid/Cu^(2+)ion/Mg^(2+)ion(TCM)complex film.Overall,the TCM complex exhibits robust interfacial adhesion to modify BC and good photothermal properties to effectively eradicate bacteria in the wound area under near-infrared(NIR)irradiation.The individual components of the TCM complex have several advantageous features for wound healing,such as antibacterial ability and negligible cytotoxicity;in particular,the released Cu^(2+)and Mg^(2+)ions are favorable for the proliferation,migration,and tube formation of endothelial cells in vitro.The results of in vivo experiments demonstrated that with the assistance of NIR irradiation,this composite dressing is more effective than traditional gauze or pristine BC dressing in promotion of angiogenesis and collagen deposition without causing remarkable inflammation,thereby accelerating the healing process of bacteria-infected full-thickness skin wounds.This work thus provides a simple and facile way to fabricate multifunctional BC-based dressings that could be potentially used for treating infected wounds. 展开更多
关键词 Bacterial cellulose Metal-phenolic network Photothermal therapy Antibacterial Angiogenesis Wound dressing
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NS1-binding protein radiosensitizes esophageal squamous cell carcinoma by transcriptionally suppressing c-Myc 被引量:4
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作者 Yuwen Wang jingjing cheng +10 位作者 Dan Xie Xiaofeng Ding Hailing Hou Xi Chen Puchun Er Furong Zhang Lujun Zhao Zhiyong Yuan Qingsong Pang Ping Wang Dong Qian 《Cancer Communications》 SCIE 2018年第1期352-365,共14页
Background:Cisplatin-based chemotherapy with concurrent radiotherapy is a standard treatment for advanced esophageal squamous cell carcinoma(ESCC).NS1-binding protein(NS1-BP),a member of the BTB-kelch protein fam-ily,... Background:Cisplatin-based chemotherapy with concurrent radiotherapy is a standard treatment for advanced esophageal squamous cell carcinoma(ESCC).NS1-binding protein(NS1-BP),a member of the BTB-kelch protein fam-ily,has been shown to inhibit the proliferation of Hela cells by suppressing c-Myc.In the present study,we examined the potential function role of NS1-BP expression in ESCC,and particularly,the sensitivity of ESCC to radiotherapy.Methods:NS1-BP expression was examined using immunohistochemistry in two cohorts(n=98 for the training cohort;n=46 for independent validation cohort)of ESCC patients receiving cisplatin-based chemotherapy and con-current radiotherapy.Normal esophageal mucosal tissue blocks were used as a control.We also conducted a series of in vitro and in vivo experiments to examine the potential effects of over-expressing NS1-BP on ESCC cells,and particu-larly their sensitivity to ionizing irradiation.Results:In the training cohort,NS1-BP downregulation was observed in 59%(85/144)of the ESCC specimens.NS1-BP downregulation was associated with chemoradiotherapeutic resistance and shorter disease-specific survival(DSS)in both the training and validation cohorts.Over-expressing NS1-BP in cultured ESCC cells substantially increased the cellular response to irradiation both in vitro and in vivo.NS1-BP also significantly enhanced IR-induced apoptosis,and abrogated IR-induced G2/M cell-cycle arrest and ATM/Chk1 phosphorylation.Immunoprecipitation assays indicated that NS1-BP could interact with c-Myc promoter regions to inhibit its transcription.In ESCC tissues,c-Myc expression was inversely correlated with NS1-BP levels,and was associated with a shorter DSS.Conclusions:Our findings highlight the role and importance of NS1-BP in radiosensitivity of ESCC.Targeting the NS1-BP/c-Myc pathway may provide a novel therapeutic strategy for ESCC. 展开更多
关键词 Esophageal squamous cell carcinoma NS1-BP Prognostic biomarker RADIOTHERAPY C-MYC
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Snow and ice thicknesses derived from Fast Ice Prediction System Version 2.0(FIPS V2.0)in Prydz Bay,East Antarctica:comparison with in-situ observations 被引量:3
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作者 Jiechen Zhao jingjing cheng +5 位作者 Zhongxiang Tian Xiaopeng Han Hui Shen Guanghua Hao Honglin Guo Qi Shu 《Big Earth Data》 EI 2022年第4期492-503,共12页
In this paper,snow and ice thickness products derived from an updated Fast Ice Prediction System Version 2.0(FIPS V2.0)in Prydz Bay,East Antarctica,are introduced and compared with in-situ obser-vations.FIPS V2.0 is c... In this paper,snow and ice thickness products derived from an updated Fast Ice Prediction System Version 2.0(FIPS V2.0)in Prydz Bay,East Antarctica,are introduced and compared with in-situ obser-vations.FIPS V2.0 is comprised of a newly-developed snowdrift parameterization compared to the original FIPS V1.0.The simulation domain covers the entire fast ice region in Prydz Bay and is config-ured to 720 grid cells,with a spatial resolution of 0.125°.The ERAInterim reanalysis from the European Centre for Medium-Range Weather Forecasting(ECMWF)were used as the atmospheric forcing.The in-situ observations were obtained near Zhongshan Station by the wintering team,and the measurement frequency of the snow and ice thicknesses was around one week.Both the FIPS V2.0 pro-ducts and in-situ observations introduced in this paper cover the time periods from 2012 to 2016.The primary assessments based on the in-situ observations show that FIPS V2.0 has mean biases of 0.01±0.07 m and 0.23±0.09 m for snow and ice thickness simula-tions,respectively.The results indicate that the updated FIPS V2.0 produces a reasonable snow thickness due to the newly-developed snowdrift parameterization,but it overestimates the ice thickness due to the cold bias in the air temperature forcing.These 2-D snow and ice thickness distributions provide important references for sea ice thermodynamic studies,remote sensing validations,and ice-breaker navigation assessments in this region.The dataset is avail-able at http://www.doi.org/10.11922/sciencedb.j00076.00066. 展开更多
关键词 Snow thickness ice thickness FIPS V2.0 Prydz Bay East Antarctica
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Superhydrophobic photothermal coatings based on candle soot for prevention of biofilm formation 被引量:2
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作者 Yuancheng Lin Haixin Zhang +7 位作者 Yi Zou Kunyan Lu Luohuizi Li Yan Wu jingjing cheng Yanxia Zhang Hong Chen Qian Yu 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2023年第1期18-26,共9页
Bacterial biofilms formed on the material surfaces have posed a series of serious problems for human health and industries.The treatment of mature biofilms is particularly difficult because they are inher-ently highly... Bacterial biofilms formed on the material surfaces have posed a series of serious problems for human health and industries.The treatment of mature biofilms is particularly difficult because they are inher-ently highly resistant against antibiotics and other adverse factors.The prevention is strategically advan-tageous over the treatment,and thus the development of innovative surfaces with capability to inhibit biofilm formation is highly demanded.In this work,we developed a superhydrophobic photothermal coating for prevention of biofilm formation,which was based on candle soot with hierarchical structure and excellent light-to-heat conversion ability.This coating was fabricated by deposition of a candle soot layer on the substrate,followed by sequential chemical vapor deposition of tetraethoxysilane and immo-bilization of fluorinated silane to make the coating robust and superhydrophobic.The resulted coating could repel a majority of bacteria from the surface at the early stage,and then eradicate a small number of bacteria remained on the surface under a short-term irradiation of near-infrared laser.The combi-nation of anti-adhesive property and photothermal bactericidal property endowed the coating with good antibiofilm property to prevent biofilm formation for at least 2 weeks.This coating is facile for deposition on various substrates with good storage stability,showing great potential for diverse practical applications to solve the biofilm-associated problems of materials and devices. 展开更多
关键词 ANTIBIOFILM Candle soot Superhydrophobic surface Anti-adhesive Photothermal surface
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Toll-Like Receptor 4 Deficiency Causes Reduced Exploratory Behavior in Mice Under Approach-Avoidance Conflict 被引量:5
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作者 Chunlu Li Yixiu Yan +7 位作者 jingjing cheng Gang Xiao Jueqing Gu Luqi Zhang Siyu Yuan Junlu Wang Yi Shen Yu-Dong Zhou 《Neuroscience Bulletin》 SCIE CAS CSCD 2016年第2期127-136,共10页
Abnormal approach-avoidance behavior has been linked to deficits in the mesolimbic dopamine(DA)system of the brain. Recently, increasing evidence has indicated that toll-like receptor 4(TLR4), an important pattern... Abnormal approach-avoidance behavior has been linked to deficits in the mesolimbic dopamine(DA)system of the brain. Recently, increasing evidence has indicated that toll-like receptor 4(TLR4), an important pattern-recognition receptor in the innate immune system,can be directly activated by substances of abuse, resulting in an increase of the extracellular DA level in the nucleus accumbens. We thus hypothesized that TLR4-dependent signaling might regulate approach-avoidance behavior. To test this hypothesis, we compared the novelty-seeking and social interaction behaviors of TLR4-deficient(TLR4^(-/-))and wild-type(WT) mice in an approach-avoidance conflict situation in which the positive motivation to explore a novel object or interact with an unfamiliar mouse was counteracted by the negative motivation to hide in exposed,large spaces. We found that TLR4^(-/-)mice exhibitedreduced novelty-seeking and social interaction in the large open spaces. In less stressful test apparatuses similar in size to the mouse cage, however, TLR4^(-/-)mice performed normally in both novelty-seeking and social interaction tests. The reduced exploratory behaviors under approachavoidance conflict were not due to a high anxiety level or an enhanced fear response in the TLR4^(-/-)mice, as these mice showed normal anxiety and fear responses in the open field and passive avoidance tests, respectively. Importantly,the novelty-seeking behavior in the large open field induced a higher level of c-Fos activation in the nucleus accumbens shell(NAc Sh) in TLR4^(-/-)mice than in WT mice. Partially inactivating the NAc Sh via infusion of GABA receptor agonists restored the novelty-seeking behavior of TLR4^(-/-)mice. These data suggested that TLR4 is crucial for positive motivational behavior under approach-avoidance conflict. TLR4-dependent activation of neurons in the NAc Sh may contribute to this phenomenon. 展开更多
关键词 Toll-like receptor 4 Novelty-seeking Social interaction Approach-avoidance conflict Nucleus accumbens shell
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A numerical study of convective-scale downdrafts in the outer core of tropical cyclones in vertically varying environmental flows 被引量:2
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作者 jingjing cheng Qingqing Li 《Tropical Cyclone Research and Review》 2020年第3期143-161,共19页
The characteristics of convective-scale downdrafts in the outer core of tropical cyclones in the lower-and upper-layer vertical wind shear(VWS)are investigated based on two high-resolution idealized numerical experime... The characteristics of convective-scale downdrafts in the outer core of tropical cyclones in the lower-and upper-layer vertical wind shear(VWS)are investigated based on two high-resolution idealized numerical experiments.Four types of outer-core downdrafts,originating from the lower troposphere,the midtroposphere,the upper level,and the tropopause,respectively,are found.The downdrafts originating from the lower and mid troposphere can penetrate down near the surface,and those originating from the tropopause in upper-layer VWS tend to penetrate more downward than in lower-layer VWS.Downdrafts tend to be located in the more upwind portion of the downshear-right quadrant in lower-layer VWS than in upper-layer VWS.The frequency of downdrafts outside and upwind of the parent updraft increases with the increasing downdraft top height.Vertical momentum budgets indicate that downward-oriented buoyancy due to the evaporational cooling of rainwater and precipitation drag mainly contribute to the occurrence of low-level downdrafts,and the midlevel and upper-level downdrafts originate due to precipitation drag and are strengthened by the downward-oriented,buoyancy-induced perturbation pressure gradient.The processes governing the downdrafts from the tropopause are different between the two experiments.More icy-type particles are produced and transported outward at upper levels in the lower-layer shear experiment,resulting in larger downward-oriented buoyancy due to the sublimational cooling of icy-type particles and contributing to the development/maintenance of the downdraft from the tropopause in that experiment.However,the downwardoriented perturbation pressure gradient leads to the development/maintenance of the downdraft from the tropopause in the upper-layer shear experiment. 展开更多
关键词 Vertical wind shear Tropical cyclone Outer core Convective-scale downdraft
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Hyperbolic metamaterial using chiral molecules 被引量:1
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作者 JieXing Zhao jingjing cheng +3 位作者 YingQi Chu YanXiang Wang FuGuo Deng Qing Ai 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2020年第6期13-21,共9页
We theoretically investigate the intra-band transitions in Mobius molecules.Due to the weak magnetic response,the relative permittivity is significantly modified by the presence of the medium while the relative permea... We theoretically investigate the intra-band transitions in Mobius molecules.Due to the weak magnetic response,the relative permittivity is significantly modified by the presence of the medium while the relative permeability is not.We show that there is hyperbolic dispersion relation induced by the intra-band transitions because one of the eigen-values of permittivity possesses a different sign from the other two,while all three eigen-values of permeability are positive.We further demonstrate that the bandwidth of negative refraction is 0.165 eV for the H-polarized incident light,which is broader than the ones for inter-band transitions by 3 orders of magnitude.Moreover,the frequency domain has been shifted from ultra-violet to visible domain.Although there is negative refraction for the E-polarized incident light,the bandwidth is much narrower and depends on the incident angle. 展开更多
关键词 negative refraction hyperbolic dispersion Mobius molecules visible light broad bandwidth
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