中山杉及其父母本幼苗对干旱胁迫和复水的响应

本文研究了落羽杉和墨杉及其杂交后代中山杉302(落羽杉♀×墨杉♂)、中山杉407(墨杉♀×落羽杉♂)、回交代中山杉118(中山杉302♀×墨杉♂)在自然干旱胁迫和复水过程中,光合特征、抗氧化酶系统和形态特性等的响应.结果表明:随干旱时间的延长,所有植株的净光合速率逐渐降低、脯氨酸开始积累且抗氧化酶系统逐渐清除丙二醛的毒性.胁迫至第8天,落羽杉净光合速率的下降幅度最大,而中山杉118的水分利用效率最高、丙二醛含量最少;墨杉的超氧化物歧化酶活性和脯氨酸含量增长最大.复水2 d后,所有植物的参数均有不同程度的恢复,其中,中山杉118恢复速率最快,其净光合速率和脯氨酸含量分别恢复了74.4%和60.2%.复水9 d后,所有植株的测定指标基本恢复至或接近正常水平,其中,中山杉118的生物量未受影响且根冠比显著增加.植物的耐旱能力依次为墨杉>中山杉118>中山杉407>中山杉302>落羽杉.回交品种中山杉118的杂种优势明显,较大程度地遗传了墨杉的耐旱性,该结论可为耐旱中山杉品种的杂交选育和推广应用提供科学依据.     

不同坡度下植物散流-过滤带对地表股流氮磷的消除效果

在植物过滤带前设置0.8~1.2 m宽的散流带,能提高过滤带对地表股流中氮、磷营养物质的去除,发生明显增效作用。之前研究均基于平缓的坡度(4%~6%),对较倾斜坡度,设置散流带是否具有增效作用尚不清楚。研究通过在黄荆(Vitex negundo)过滤带前设置五节芒(Miscanthus floridulus)散流带,观测五节芒-黄荆和纯黄荆过滤带在5%、10%、15%坡度下对氮、磷的消除,探讨散流带在不同坡度下对过滤带的增效作用。结果表明:五节芒-黄荆和黄荆过滤带对总氮、铵氮、硝氮、总磷的去除均随坡度的增加而减小,在15%坡度下的去除效率最低;3种坡度下,五节芒-黄荆对总氮、铵氮、硝氮、总磷的消除均极显著(P0.01)或显著性(P0.05)高于黄荆过滤带,表明在较大坡度下(10%、15%),五节芒散流带对黄荆缓冲带的增效作用仍然存在。研究结果能深化植物散流-过滤带水质保护功能的认识,为农业非点源污染管理提供启示。     

放射污染区古菌分离及多样性分析

【目的】研究放射污染区古菌多样性。【方法】放射污染区采集土样,采用甘油-精氨酸培养基(GJ)、甘油-天冬氨酸培养基(C1)、海藻糖-肌酸培养基(B7)、甘露醇-丙氨酸培养基(Z5)、干酪素-甘露醇培养基(CMKA)、壳聚糖-天冬酰胺培养基(F6)、甘露醇-酸水解酪蛋白培养基(GW1)、CM培养基、HP培养基和KC培养基10种分离培养基,采用梯度稀释法对古菌进行分离,将分离获得的菌株经形态特征,16S rRNA基因片段扩增及限制性内切酶酶切,选取酶切图谱中存在差异性的条带进行测序,最终通过序列比对,聚类分析,获得不同种类的古菌资源。【结果】从该土样中共获得了256株古菌,最终筛选出71株不同类型的古菌,这71株古菌均属于广古菌门,盐杆菌纲,盐杆菌目,盐杆菌科,分布于盐陆生菌属(Haloterrigena)、纳白菌属(Natrialba)、盐球菌属(Halococcus)、盐红菌属(Halorubrum)、盐长寿菌属(Halovivax)、纳线菌属(Natrinema)、盐碱球菌属(Natronococcus)、盐二型菌属(Halobiforma)、盐惰菌属(Halopiger)、盐池栖菌属(Halostagnicola)、富盐菌属(Haloferax)11个属,26个种,其中31株菌的16S rRNA基因序列与已有效发表菌株的序列相似性小于98%,Haloterrigena为该土样的优势菌属。对于分离效果较好的F6培养基采用了梯度营养成分的稀释,最终获得了19株古菌,这些菌株相互之间存在一定的差异性。【结论】本次分离获得了大量的古菌,表明放射污染区存在着较为丰富的古菌资源,其中蕴藏着多种新的物种类型,具有较大的研究价值。     

The direct effect of estrogen on cell viability and apoptosis in human gastric cancer cells

Epidemiology researches indicated that gastric cancer is a male-predominant disease; both expression level of estrogen and expression pattern of estrogen receptors (ERs) influence its carcinogenesis. But the direct effect of estrogen on gastric cancer cells is still unclear. This study aimed to explore the direct effect of β-estradiol (E2) on gastric cancer cells. SGC7901 and BGC823 were treated with a serial of concentrations of E2. The survival rates of both the cell lines were significantly reduced, and the reduction of viability was due to apoptosis triggered by E2 treatment. Caspase 3 was activated in response to the increasing E2 concentration in both SGC7901 and BGC823. Cleaved Caspase 3 fragments were detected, and the expression levels of Bcl-2 and Bcl-xL were reduced. Apoptosis was further confirmed by flow cytometry. The expression level of PEG10, an androgen receptor target gene, was reduced during E2 treatment. Both ERα and ERβ were expressed in these cell lines, and the result of bioinformatics analysis of gastric cancer from GEO datasets indicated that the expression levels of both ERα and ERβ were significantly higher in noncancerous gastric tissues than in gastric cancer tissues. Our research indicated that estrogen can reduce cell viability and promote apoptosis in gastric cancer cells directly; ERs expression level is associated with gastric cancer. Our research will help to understand the mechanism of gender disparity in gastric cancer.     

Generation and Characterization of a Nanobody Against SARS-CoV

Virologica Sinica - The sudden emergence of severe acute respiratory syndrome coronavirus (SARS-CoV) has caused global panic in 2003, and the risk of SARS-CoV outbreak still exists. However, no...     

Correction to: Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

Virologica Sinica - The corrected legend is given below.     

Intrinsic Effects of Gold Nanoparticles on Oxygen–Glucose Deprivation/Reperfusion Injury in Rat Cortical Neurons

This study aimed to investigate the potential effects of gold nanoparticles (Au-NPs) on rat cortical neurons exposed to oxygen–glucose deprivation/reperfusion (OGD/R) and to elucidate the corresponding mechanisms. Primary rat cortical neurons were exposed to OGD/R, which is commonly used in vitro to mimic ischemic injury, and then treated with 5- or 20-nm Au-NPs. We then evaluated cell viability, apoptosis, oxidative stress, and mitochondrial respiration in these neurons. We found that 20-nm Au-NPs increased cell viability, alleviated neuronal apoptosis and oxidative stress, and improved mitochondrial respiration after OGD/R injury, while opposite effects were observed for 5-nm Au-NPs. In terms of the underlying mechanisms, we found that Au-NPs could regulate Akt signaling. Taken together, these results show that 20-nm Au-NPs can protect primary cortical neurons against OGD/R injury, possibly by decreasing apoptosis and oxidative stress, while activating Akt signaling and mitochondrial pathways. Our results suggest that Au-NPs may be potential therapeutic agents for ischemic stroke.

     

慢性乙型肝炎患者肠道菌群与肝脏生化指标的相关性

乙型肝炎病毒感染引起的慢性乙型肝炎(Chronic hepatitis B,CHB)是一种全球性流行疾病,严重时可引起肝功能衰竭,甚至发展成肝硬化和肝癌.也已发现CHB的发生和发展与肠道菌群的组成和结构的变化密切相关.为进一步探究肠道菌群结构与肝脏生化指标之间的联系,文中随机纳入14名CHB患者和11名健康对照者(Co...     

Complete mitochondrial genome of the Teinopalpus aureus guangxiensis (Lepidoptera: Papilionidae) and related phylogenetic analyses

In this study, we sequenced the complete mitochondrial genome of Teinopalpus aureus guangxiensis (Lepidoptera: Papilionidae), which is considered as an endemic species in China. It is listed as a vulnerable species by International Union for Conservation of Nature and Natural Resources Red List and also a first class endangered species in China. The complete mtDNA from T. aureus guangxiensis was 15,235 base pairs in length and contained 13 protein-coding genes (PCGs), 2 rRNA genes, 22 tRNA genes, and a control region. The T. aureus guangxiensis genes were in the same order and orientation as the completely sequenced mitogenomes of other lepidopteran species. All PCGs of T. aureus guangxiensis mitogenome start with a typical ATN codon and terminate in the common stop codon TAA, except that ND1 gene uses TTA, ND3 gene uses ATT, and ND4 and ND4L gene use TAA. The phylogenetic relationships were reconstructed with the concatenated sequences of the 13 PCGs of the mitochondrial genome, and phylogenetic results confirmed that Nymphalidae, Lycaenidae, Papilionidae, Pieridae are monophyletic clades.     

The NH2-terminal and COOH-terminal fragments of dentin matrix protein 1 (DMP1) localize differently in the compartments of dentin and growth plate of bone

Multiple studies have shown that dentin matrix protein 1 (DMP1) is essential for bone and dentin mineralization. After post-translational proteolytic cleavage, DMP1 exists within the extracellular matrix of bone and dentin as an NH2-terminal fragment, a COOH-terminal fragment, and the proteoglycan form of the NH2-terminal fragment (DMP1-PG). To begin to assess the biological function of each fragment, we evaluated the distribution of both fragments in the rat tooth and bone using antibodies specific to the NH2-terminal and COOH-terminal regions of DMP1 and confocal microscopy. In rat first molar organs, the NH2-terminal fragment localized to predentin, whereas the COOH-terminal fragment was mainly restricted to mineralized dentin. In the growth plate of bone, the NH2-terminal fragment appeared in the proliferation and hypertrophic zones, whereas the COOH-terminal fragment occupied the ossification zone. Forster resonance energy transfer analysis showed colocalization of both fragments of DMP1 in odontoblasts and predentin, as well as hypertrophic chondrocytes within the growth plates of bone. The biochemical analysis of bovine teeth showed that predentin is rich in DMP1-PG, whereas mineralized dentin primarily contains the COOH-terminal fragment. We conclude that the differential patterns of expression of NH2-terminal and COOH-terminal fragments of DMP1 reflect their potentially distinct roles in the biomineralization of dentin and bone matrices.