东方次睾吸虫电镜研究(吸虫纲:后睾科)V.雌性生殖器官

东方次睾吸虫雌性生殖器官（卵巢、输卵管、卵黄－输卵管、卵模、梅氏腺和子宫）透射电镜 观察。卵巢内有不同成熟期的生殖细胞,成熟初级卵母细胞有几个靠近核的核仁样小聚体和许多沿 质膜的皮质颗粒。首次发现并描述卵巢和输卵管接合处（卵巢壶腹）的超微结构。输卵管上皮为纤 毛状。梅氏腺仅一种类型膜状小体细胞,经有微管支持的细小管道穿过卵模将膜状小体排入卵模腔 内。在卵黄－输卵管和卵模中有精子,卵模和子宫中有受精卵、虫卵（扫描电镜）：大小 ２６. ０５× １１．４６－１３．５５μｍ,卵盖直径６．２６－６. ８９μｐ,卵壳表面布满膜状隆起。文中对卵巢和梅氏腺的超微 结构特点进行了讨论。     

Enantioselective Preparation,Conformational Analysis and Absolute Configuration of Highly Substituted Aziridines

The first example of organocatalytic aziridination reaction of α‐substituted‐α,β‐unsaturated ketones is presented. The reaction was found to be highly enantio‐ and diastereoselective, yielding N‐tosylated aziridines. Low‐temperature nuclear magnetic resonance (NMR) spectra allowed for the determination of the N‐inversion barrier, that was found to be quite lower with respect to unsubstituted aziridines. A thorough conformational analysis supported by low‐temperature NMR data allowed for the determination of the absolute configuration of the main stereoisomer by means of time‐dependent Density Functional Theory simulation of the electronic circular dichroism spectra. Chirality 27:875–887, 2015. © 2015 Wiley Periodicals, Inc.     

Quartz crystal microbalance investigation of the interaction of bacterial toxins with ganglioside containing solid supported membranes

The binding of cholera toxin, tetanus toxin and pertussis toxin to ganglioside containing solid supported membranes has been investigated by quartz crystal microbalance measurements. The bilayers were prepared by fusion of phospholipid-vesicles on a hydrophobic monolayer of octanethiol chemisorbed on one gold electrode placed on the 5 MHz AT-cut quartz crystal. The ability of the gangliosides G_M1, G_M3, G_D1a, G_D1b, G_T1b and asialo-G_M1 to act as suitable receptors for the different toxins was tested by measuring the changes of quartz resonance frequencies. To obtain the binding constants of each ligand-receptor-couple Langmuir-isotherms were successfully fitted to the experimental adsorption isotherms. Cholera toxin shows a high affinity for G_M1 (K_a = 1.8 ⋅ 10⁸M^–1), a lower one for asialo-G_M1 (K_a = 1.0 ⋅ 10⁷ M^–1) and no affinity for G_M3. The C-fragment of tetanus toxin binds to ganglioside G_D1a, G_D1b and G_T1b containing membranes with similar affinity (K_a∼10⁶ M^–1), while no binding was observed with G_M3. Pertussis toxin binds to membranes containing the ganglioside G_D1a with a binding constant of K_a = 1.6 ⋅ 10⁶ M^–1, but only if large amounts (40 mol%) of G_D1a are present. The maximum frequency shift caused by the protein adsorption depends strongly on the molecular structure of the receptor. This is clearly demonstrated by an observed maximum frequency decrease of 99 Hz for the adsorption of the C-fragment of tetanus toxin to G_D1b. In contrast to this large frequency decrease, which was unexpectedly high with respect to Sauerbrey's equation, implying pure mass loading, a maximum shift of only 28 Hz was detected after adsorption of the C-fragment of tetanus toxin to G_D1a. Received: 14 January 1997 / Accepted: 15 April 1997     

Implant-supported palatal lift prosthesis in a patient with velopharyngeal incompetence: a case report

doi: 10.1111/j.1741‐2358.2011.00561.x Implant‐supported palatal lift prosthesis in a patient with velopharyngeal incompetence: a case report Objective: To describe the use of dental implants in the treatment of velopharyngeal incompetence. Background: Velopharyngeal incompetence is characterized by the inability to contract the tissues of the soft palate. The most common causes are neuromuscular problems resulting from concussion and degenerative conditions of the central nervous system. Materials and methods: The treatment using palatal lift prosthesis is well established in the literature; however, reports on the use of osseointegrated implants are scarce. Rehabilitation using only this type of fibromucosal support is difficult in edentulous patients, since the prosthesis has a palatal lift extension. Results: The implants provided retention and stability to the prosthesis, improving swallowing and speech and contributing to improve the patient’s quality of life. Conclusion: This article reports the rehabilitation of a patient with a totally edentulous maxilla with velopharyngeal incompetence using an implant‐retained palatal lift prosthesis.     

中国瘦寄蝇属一新种和一新纪录种(双翅目,寄蝇科)

瘦寄蝇属Leptothelaira Mesnil et Shima隶于长足寄蝇亚科Dexinae瘦寄蝇族Leptothelairini;其体细长,后足基节上部具1宽而闭合的骨化桥,翅R4 5脉基部背面具1根小鬃;已知分布于俄罗斯远东南部、日本、越南、尼泊尔和我国台湾.本文记述了采自我国广西龙胜华坪的瘦寄蝇属1新纪录种:东方瘦寄蝇L.orientalis Mesnil et Shima,1979和产自陕西太白山和山西沁源与方山的1新种:长茎瘦寄蝇L.longipennis sp.nov,新种与分布东洋区的南方瘦寄蝇L.meridionalis Mesnil et Shima近似,但单眼鬃弱于内顶鬃,腹部第4背板后1/4～1/5和第5背板完全黑,第5腹板基部圆,中央裂深且基部宽,侧尾叶端部较窄而尖等.新种模式标本保存在沈阳师范大学昆虫研究所.     

Charge displacements during ATP-hydrolysis and synthesis of the Na+-transporting FoF1-ATPase of Ilyobacter tartaricus

Transient electrical currents generated by the Na(+)-transporting F(o)F(1)-ATPase of Ilyobacter tartaricus were observed in the hydrolytic and synthetic mode of the enzyme. Two techniques were applied: a photochemical ATP concentration jump on a planar lipid membrane and a rapid solution exchange on a solid supported membrane. We have identified an electrogenic reaction in the reaction cycle of the F(o)F(1)-ATPase that is related to the translocation of the cation through the membrane bound F(o) subcomplex of the ATPase. In addition, we have determined rate constants for the process: For ATP hydrolysis this reaction has a rate constant of 15-30 s(-1) if H(+) is transported and 30-60 s(-1) if Na(+) is transported. For ATP synthesis the rate constant is 50-70 s(-1).     

Spatial-temporal reorganization of activated integrins

Integrin receptors play important roles in cell adhesion and tumor metastasis. The coupling of mechanical sensing and biochemical ligation is known to collectively regulate the activation of integrin receptors. Recently, oligomerization of activated integrins has been considered as the primordial signature of cytoskeletal remodeling and the initiation of various downstream signals, such as focal and fibrillar adhesions. However, spatio-temporal reorganization of activated integrins and associated proteins remains poorly understood. Here, we summarized the recent discovery of sequential biophysical events of integrin activation during early adhesion formation. Using the cyclic Arg-Gly-Asp (RGD) peptide as a mobile ligand on supported lipid membranes, a series of previously unreported events were observed following integrin αvβ3 clustering and cell spreading, including a long-range lateral translocation of the integrin clusters. With initial clustering, localized actin polymerization occurred in a Src family kinase dependent manner. Clustering of liganded integrins recruits various adaptor proteins and serves as a reaction core for mechanobiological activities. In addition, there are future possibilities to investigate the role of other synergetic interactions with the activated integrin receptors.     

放线菌结瘤植物根与根瘤中有机氮化物的组分及其上运形式

杨梅、沙棘和赤杨三种放线菌结瘤植物根瘤、根部有机氮化物的组分中,都含有占总有机氮化物50％以上的尿囊酸,说明在它们的根瘤中合成了大量的酰脲;同时,三种植物结瘤植株的茎木质部提取物中也含有大量的尿囊酸,表明根瘤将其合成的酰脲向植物地上部位运送。三种植物的根瘤还将其合成的特定的氨基酸及酰胺向地上部位转运,其中杨梅根瘤将固定的氮素以Asn和Gln的形式输出,而根部则以Arg的形式向上转运;沙棘根瘤以Ash,Gln及Ser,赤杨根瘤以Cit的形式合成并转运固定的氮素;后两种植物的无根瘤植株,以NH_4~+为氮源时,在转运的氨基酸组分中Arg的比例明显提高。     

Antimicrobial peptides temporins B and L induce formation of tubular lipid protrusions from supported phospholipid bilayers

The binding of the antimicrobial peptides temporins B and L to supported lipid bilayer (SLB) model membranes composed of phosphatidylcholine and phosphatidylglycerol (4:1, mol/mol) caused the formation of fibrillar protrusions, visible by fluorescent microscopy of both a fluorescent lipid analog and a labeled peptide. Multicolor imaging at low peptide-to-lipid ratios (P/L < approximately 1:5) revealed an initial in-plane segregation of membrane-bound peptide and partial exclusion of lipid from the peptide-enriched areas. Subsequently, at higher P/L numerous flexible lipid fibrils were seen growing from the areas enriched in lipid. The fibrils have diameters <250 nm and lengths of up to approximately 1 mm. Fibril formation reduces the in-plane heterogeneity and results in a relatively even redistribution of bound peptide over the planar bilayer and the fibrils. Physical properties of the lipid fibrils suggest that they have a tubular structure. Our data demonstrate that the peptide-lipid interactions alone can provide a driving force for the spontaneous membrane shape transformations leading to tubule outgrowth and elongation. Further experiments revealed the importance of positive curvature strain in the tubulation process as well as the sufficient positive charge on the peptide (>/=+2). The observed membrane transformations could provide a simplified in vitro model for morphogenesis of intracellular tubular structures and intercellular connections.