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1.
为了探索家蝇幼虫抗菌物质的提取方法,本文采用醋酸提取蝇蛆的抗菌物质,通过加热去除其中不稳定的蛋白成分,再通过切向流超滤和直接冻干法获得复合抗菌物质,测定其中可溶蛋白的含量、抗菌组分的抗菌活性及组成的差异。结果表明,和冻干法相比,利用切向流超滤法可以显著提高抗菌复合物质中可溶蛋白的含量。利用切向流超滤浓缩制备的抗菌物质和直接冻干制备的抗菌物质经过凝胶过滤层析及抗菌活性分析表明,非蛋白组分(A20-A21和B6-B12)比蛋白组分(A1-A2、A10-A13、B1-B2)抗菌谱广。电泳分析蛋白组分表明,其抗菌蛋白组分处在6 k Da-35 k Da的某些蛋白组分中。  相似文献   

2.
抗菌塑料是含锌离子的可溶性玻璃粉,具有杀菌、抑菌性能的新型功能材料。国外抗菌塑料的研究应用起始于20世纪80年代初。欧美国家早期在日用品中应用,近年在玩具产品上应用较多。日本在应用抗菌塑料方面发展更快。首先在家电产品中应用抗菌塑料,抗菌电话等产品一面市,就深受消费者的欢迎。抗菌材料一般具有抗菌、杀菌、防霉、消毒、除臭、防潮等功能。抗菌材料应用范围十分广泛,主要应用于家电设备、医院设施和医疗卫生器具、商店和其他公共场所的设备用具及其他生活日常用品等。随着抗菌材料研究开发的不断进展,其应用范围也必然日益广泛,功能也必然更加齐全。20世纪90年代中后期,抗菌塑料在我国飞速发展。其抗菌塑料产品不断增加,现在已经有抗菌塑料碗、塑料盘、塑料电话、以及食品加工业和餐饮业的机械设备等抗菌塑料产品在我国问世。本文根据抗菌塑料的作用原理和特性,对抗菌塑料效果进行监测探讨,为抗菌塑料的推广和应用提供依据。  相似文献   

3.
??????? 目的 分析和调查抗菌药物临床应用的情况,研究规范化应用抗菌药物在临床使用的效果。方法 根据计算机管理系统提供的抗菌药物用药信息,对某三甲综合医院抗菌药物临床应用专项整治前、后医院门诊患者抗菌药物处方比例及住院患者抗菌药物使用率、使用强度、I类手术预防用药率等指标进行调查及分析。结果 门诊患者抗菌药物处方比例降低至6.2﹪;住院患者抗菌药物使用率降低至49.7﹪;抗菌药物使用强度降低至42.48;I类手术预防用药率降低至32.1﹪。结论 抗菌药物临床规范化应用,促进医院抗菌药物临床合理使用的效果显著。  相似文献   

4.
鉴于禽类细菌性疾病对养禽业健康发展的不利影响,人们急需开发改善细菌耐药性的新型敏感性抗菌药物,使其达到治疗细菌性疾病的目的。环肽较线性肽因具有更多的生物活性和医药价值而成为抗菌药物的候选者。主要从天然抗菌环肽的发现、抗菌环肽的合成、环肽类抗菌药物的应用现状三个方面进行综述,期望有利于读者进一步了解抗菌环肽的研究概况,为开发新型抗菌环肽药物提供帮助。  相似文献   

5.
利用医院计算机网络管理抗菌药物使用,提高抗菌药物使用的合理性。经统计学检验,说明计算机网络在抗菌药物管理中的应用是有效的。它能准确、高效、有效地协助管理部门做好抗菌药物合理使用的管理工作,协助临床医生规范、合理地使用抗菌药物。  相似文献   

6.
依据生物活性跟踪法的程序(体外抗菌为药理筛选指标),通过萃取、沉淀、硅胶吸附柱色谱、Sephadex LH-20凝胶柱色谱的现代分离手段,对传统外用抗菌中药枫杨树皮的抗菌物质进行了系统筛选,发现乙醇提取物的亲脂性萃取部位(氯仿部位、乙酸乙酯部位、石油醚部位)有抗菌作用,其他部位无活性;首次从氯仿部位和乙酸乙酯部位筛选出4个抗菌活性单体,TLC确定纯度后,经EI-MS、1D NMR(1H、13C、DEPT)和2D NMR(HSQC、1H-1H COSY、HMBC)分别鉴定为5-羟基-1,4-萘醌(1)、5-羟基-2-甲氧基-1,4-萘醌(2)、2,6-二甲氧基-1,4-对苯醌(3)、没食子酸(4)。3个类别抗菌化学母核(苯醌、萘醌、苯甲酰)的多个抗菌成分共同构成枫杨的抗菌物质基础。多成分活性中心抗菌物质基础的阐明,可为研发不易产生耐药性的枫杨抗菌部位药和药材质量标准研究奠定理论基础。  相似文献   

7.
抗菌豆豉发酵菌株的筛选及其脂肽组分鉴定和特性研究   总被引:1,自引:0,他引:1  
目的:从豆豉中分离广谱抗菌活性菌株,并鉴定其发酵产物中的抗菌成分.方法:采用生理生化实验结合16SrRNA序列测定法鉴定目标分离株,通过LC-MS和ESI/CID技术对其抗菌组分进行鉴定.结果:从8个豆豉样品中分离出7株具有抗菌活性菌株,其中抗菌活性较强的分离株NT-6为枯草芽孢杆菌(Bacillus subtilis),其发酵液抗菌提取物的主要成分是抗菌脂肽类物质iturin、fengycin、surfactin同系物的混合物.该提取物对供试革兰氏阳性、阴性细菌、霉菌等指示菌具有广谱的抗菌活性,在pH 2~ 12、121℃条件下加热30min活性不丧失,说明具有广泛的pH适应范围和良好的耐热性.结论:该菌株产生多组分抗菌脂肽,其抑菌谱宽,适应性好,显示了在食品、农业、医药等领域具有良好的应用前景.  相似文献   

8.
目的 研究蛇毒粗毒的抗菌作用,并比较不同蛇毒对不同细菌的抑制效果.方法 采用抑菌环法测定蛇岛蝮、江浙蝮和短尾蝮蛇毒粗毒对金黄色葡萄球菌、枯草芽孢杆菌、大肠埃希菌、铜绿假单胞菌以及白色念珠菌的抗菌作用,比较不同蛇毒粗毒的抗菌效果;加入过氧化氢酶(catalase),考察蛇毒抗菌作用的变化.结果 (1)3种蛇毒粗毒对5种细菌均呈现不同程度的抑制作用.(2)3种蛇毒粗毒对5种细菌的抑制作用大小依次为:金黄色葡萄球菌>白色念珠菌>大肠埃希菌或铜绿假单胞菌>枯草芽孢杆菌.(3)加入catalase后,蛇毒的抗菌作用明显减弱.结论 (1)3种蛇毒粗毒均具有一定的抗菌作用,并具有明显抑菌选择性.(2)3种蛇毒的抗菌效果不同,蛇岛蝮蛇抗菌作用最强.(3) catalase能显著降低蛇毒的抗菌活性,表明L-氨基酸氧化酶是蛇毒起抗菌作用的主要成分.  相似文献   

9.
?????? 目的 分析抗菌药物临床应用专项整治对医院住院患者抗菌药物临床用药的持续效果。方法 采用回顾性调查方法,以开展抗菌药物临床应用专项整治前后的2010—2012为研究时间,对医院住院患者抗菌药物使用率、使用强度、用药金额及清洁手术预防用药率、清洁手术术后24小时停药率进行调查及分析。结果 2010—2012年,抗菌药物使用率分别为70.0%、64.4%和49.3%,抗菌药物使用强度分别为73.3、58.2和37.9,抗菌药物用药金额占药费总额比例分别为21.9%、16.2%和11.1%;清洁手术预防用抗菌药物比率分别为95.5%、91.0%和50.3%,清洁手术术后24小时停药率分别为11.0%、27.2%和42.0%。结论 抗菌药物临床应用专项整治对抗菌药物的合理使用起到了积极的促进作用。  相似文献   

10.
抗生素在临床抗菌中发挥越来越重要作用,然而,其滥用也带来了毒副反应、出现耐药病原、免疫力降低等问题,临床亟需新的抗菌方案。近年来,纳米金属及其氧化物由于广谱抗菌活性而受到广泛关注,纳米银、纳米铜、纳米锌及其氧化物等逐渐应用于生物医用领域。本文介绍了纳米金属材料分类和导电、超塑延展、催化、抗菌等基本性能;概述了物理法、化学法和生物法等常见制备技术;总结了细胞膜、氧化应激、破坏DNA和降低细胞呼吸等4种主要抗菌机理;并综述了纳米金属及其氧化物的尺寸、形状、浓度和表面化学特性对抗菌有效性的影响以及细胞毒性、遗传毒性、生殖毒性等生物安全性的研究现状。尽管目前纳米金属及其氧化物已在医用抗菌、癌症治疗等临床领域得到应用,但诸如绿色制备工艺开发、抗菌机理完善、生物安全性改进以及应用领域拓展仍有待深入探索。  相似文献   

11.
The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.  相似文献   

12.
The epipleurites were originally described by Hopkins in 1909 on the imago and larva of a beetle. Then this term was widely used in insect morphology, mainly for larvae, to designate certain sclerites of the pleural region. They have recently been interpreted as tergopleural (i.e. pleural but not strictly appendicular) by Deuve in 2001, but a study of embryonic development by Kobayashi et al. in 2013 has shown that they are instead eupleural (i.e. appendicular) and correspond to a dorsal part of the subcoxa. Their presence in the abdominal segments of insects illustrates the fundamental importance of the subcoxa in segmental structure, with a function of anchoring and supporting the appendage when the latter is present. However, the epipleurites are normally separated and functionally dissociated from the coxosternum, which integrates the ventral component of the subcoxa. In females, the epipleurite of segment IX of the abdomen corresponds to the gonangulum, as already pointed out by Deuve in 1994 and 2001, and it is involved in gonopod articulation. At segments VIII and IX of both males and females of holometabolans, the formation process of the genital ducts leads to an internalisation of the whole subcoxosternum (i.e. the coxosternum with the exception of the coxal and telopodal territories), and it is the two flanking epipleurites that ventrally close the abdomen in relation to the rearward displacement of the gonopore. This model may be generalised, in its broad lines, to a large part of the hemimetabolans. The body plan of the insect abdomen underlines the morphological and functional importance of the subcoxa in its fundamental structure, but the study of the Hexapoda in general also indicates the presence of a more proximal segment, the precoxa, which would belong to the groundplan but is more cryptic because it is often closely associated with the subcoxa and/or the paranotal lobe. Its location, which is sometimes on the ventral flank of the paranotal lobe, is in line with the hypothesis of a dual origin of the pterygote wing.  相似文献   

13.
The gross morphology and the flexibility along the neck of the ostrich (Struthio camelus) were examined using fresh tissue as well as neck skeletons. The results of the morphologic studies were compared with results from observations of living ostriches. The investigation was focused on differences in the morphology and the function between different sections of the neck. Additionally, the function of major dorsal neck ligaments was examined, including measurements of force-strain-relations. Comparative studies of giraffes (Giraffa camelopardalis) and camels (Camelus bactrianus) were conducted to find relations between the flexibility along the neck and the general feeding strategy. The examinations revealed that the neck of the ostrich can be divided into four sections with different functions. The first is the atlas-axis-complex which is responsible for torsion. The adjacent cranial section of the neck is flexible in dorsoventral and lateral directions but this part of the neck is usually kept straight at rest and during feeding. Dorsoventral flexibility is highest in the middle section of the neck, whereas the base of the neck is primarily used for lateral excursions of the neck. For giraffes and camels, the posture and utilization of the neck are also reflected in the flexibility of the neck. For all three species, it is possible to reconstruct the pattern of flexibility of the neck by using the neck skeletons alone. Therefore, it appears reasonable to reconstruct the neck utilization and the feeding strategies of dinosaurs with long necks by deriving the flexibility of the neck from preserved vertebrae. For Diplodocus carnegii the neck posture and the feeding strategy were reconstructed. Two neck regions, one around the 9th neck vertebra and the second at the base of the neck, indicate that Diplodocus, like the ostrich, adopted different neck postures. The neck was probably kept very low during feeding. During interruptions of the feeding, e.g., in an alert, the head could have been lifted in an economic way by raising the cranial section of the neck. During standing and locomotion the head was probably located well above the shoulders.  相似文献   

14.
Gaspar  M. B.  Dias  M. D.  Campos  A.  Monteiro  C.C.  Santos  M. N.  Chicharo  A.  Chicharo  L. 《Hydrobiologia》2001,465(1-3):153-167
To evaluate a possible introduction of a new dredge in the fishery of Callista chione (Linnaeus, 1758), IPIMAR has conducted a study with the objective of comparing the efficiency of two dredges (traditional dredge and the new dredge design) and evaluating their impact on the benthic community. The experiments were carried out during March 1999 on the Southwest coast of Portugal, from a site off Troia. Three different tow durations of 5, 10 and 20 min were investigated. A total of 24 hauls were accomplished, 4 for each tow duration and dredge. The experiments were conducted by attaching a cover bag with a 20 mm mesh to the gear. After each haul, the catches in the bag and in the cover were sorted separately. All individuals retained were attributed scores on a scale of 1–4 in which 1 equates to good and 4 equates to dead. The results obtained showed that catches from the traditional dredge (TD) are composed of a great fraction of juveniles of C. chione, while in the new dredge (NDD) catches are composed, almost entirely, by individuals with a superior size to the minimum legal length (50 mm). This result indicates that the mesh of the bag of the TD used in the exploitation of this resource is not adequate. For the 3 different tow durations, the mean fishing yield obtained for the NDD was always superior to the TD, due to its greater efficiency in capture. The proportion of by-catch is significantly higher when the TD is used. For all 3 tow duration, the TD caused mortalities on the target species and on the macrobenthic community in the same order of magnitude as the NDD. Since the fishery of C. chione is managed by daily quotas per boat, when using the NDD the impact on the macrobenthic community is reduced by about 50% due to its greater efficiency of capture. Another advantage in the usage of the NDD relatively to the TD, is to allow the smallest individuals (independently of the species) to escape rapidly through the metallic bars on the grid, increasing their probability of survival.  相似文献   

15.
The birth of the oil shale industry, in the Autun basin (Saône-et-Loire, department in Burgundy), at the beginning of the 1830s, corresponded to a time during which the scientific progress in geology and paleontology was quite fast-paced. The development of the schist industry happened at a time when landmark works were published such as those by Louis Agassiz or Adolphe Brongniart. These scientists relied upon the on-going findings in the Autunois area. An outstanding dynamics was on its way. It brought about the updating of many samples sparking off important paleontological studies. A remarkable coordination set up between the industrial workers of the schist industry, the local scholars on the one hand and the National Museum of Natural History in Paris on the other hand. There resulted from it a frequent if not constant interest in the discovery of the fossils that the layers of schists – exploited with the aim of obtaining oil used as a quaffing product – can contain. This dynamics kept going on till the beginning of the 19th century. It was carried out by outstanding personalities such as Bernard Renault or Auguste Roche who were at the origin of the first collections gathered by the Society of Natural History in Autun, founded in 1886. But then, the findings were made rare. The mechanization of the chopping down and crushing of the schist did not any more offer the suitable conditions to discover new specimens. Anyway, the accumulated collections are already considerable and make of the Autunois one of the major places of great French paleontological progress in the years 1870 and 1880.  相似文献   

16.
A new species of the Osmundaceae, Plenasium xiei sp. nov., is herein described from the Cretaceous of Northeast China. The specimens examined here represent the earliest unequivocal record of the extant genus Plenasium in Eurasia based on fossil rhizomes. The rhizome consists of a central stem with a mantle of petiole bases and adventitious roots. The stem contains an ectophloic‐dictyoxylic siphonostele and a two‐layered cortex. The C‐shaped leaf trace bears two protoxylem bundles at the point of separation from the stele. The pith is heterogeneous. The parenchymatous inner cortex is thinner than the sclerenchymatous outer cortex. Lobed sclerenchyma bands occur at the adaxial sides of the stem xylem strands, in the concavity of the leaf trace, and along the adaxial side of the vascular bundles of the petiole base. In distal petiole portions, the sclerenchyma band splits into several groups in the transverse view. Sclerenchyma rings are heterogeneous with an abaxial sclerenchymatous arc of thick‐walled fibers. Numerous sclerenchyma strands of thick‐walled fibers appear in the petiolar inner cortex and the stipular wing. These fossils provide unambiguous evidence for the existence of subgenus Plenasium of modern Plenasium by at least the Late Cretaceous, demonstrating the longevity of this extant subgenus. Altogether the leaf and rhizome fossil records of Plenasium indicate that this genus was widely distributed across North America and Eurasia from the Early Cretaceous to the Early Cenozoic, followed by a range restriction to Eurasia in the Late Cenozoic. Extant Plenasium species are only known from East and Southeast Asia.  相似文献   

17.
Ontogeny and variation of head stripes were investigated in Stenella attenuata, S. longirostris , and Delphinus delphis . The eye stripe and the blowhole stripe together comprise the bridle . The Anlage of the bridle is a line extending across the back of the head in small fetuses. As the blowhole moves posteriorly and the rostrum lengthens, an inflection point develops in the line above the eye. This point moves forward, creating a progressively greater triangular area between the incipient eye and blowhole stripes. Well before birth, the inflection point is close to the apex of the melon, and the eye and blowhole stripes are narrow and well defined. This process proceeds to varying degrees in the other delphinoids. For example, in Peponocephala electra and in Cephalorhynchus spp., the inflection point migrates only part of the way to the apex of the melon, and the resulting "blowhole stripe" remains a broad caplike feature, resembling the state of development in small fetuses of Stenella and Delphinus . A simple eye spot without a stripe may be primitive, as it occurs in non-delphinoid cetaceans. Presence of the bridle only in the delphinids and phocoenids may unite them in a clade exclusive of the monodontids.  相似文献   

18.
In this paper, we try to document butchery practices from the past. We attempt to characterize through experimental data the marks produced when dismembering using overextension of the elbow of Sheep and several bird species. For birds, the experimentation was realized with uncooked carcasses. In many cases, overextension produced break down of the olecranon fossa of the humerus, with medial wrench of the distal part. Moreover, the proximal joints of the radius and ulna are broken. Bony and uncooked forelimb Sheep bones have been dismembered by overextension. Observations were noticed only on the radio-ulnar. The ulnas had a negative wear scar up to the anconeus process. Sometimes, these marks are associated with lateral crushing of the bone. In the second part of the article, we compare our experimental data with archaeological material. Although we found many cases of dismembering by overextension on bird bones, no data were found on small ungulates material.  相似文献   

19.
20.
The reaction beneath the mouth parts of an adult, female Rhipicephalus sanguineus attached to a dog develops progressively over 4–5 days. The cement substance is confined to the external surface of the epidermis and does not form any organized structure in the dermis. The hypostome is imbedded in the cement substance and does not penetrate the epidermis. The cheliceral shafts are at the epidermal-dermal junction and do not extend into the dermis to any degree. Thus, it is the adhesive quality of the cement for the dog's skin that holds this tick firmly attached to its host.Edema of the epidermis appears 24 hr after attachment of the tick; the dermal infiltrate becomes prominent from 24 hr after attachment onward and initially consists of polymorphonuclear leukocytes. This cell type predominates until the tick has detached. Rupture of lymphatics occurs and infiltrated cells can be found entering these open channels. Degranulation of mast cells is associated with polymorphonuclear leukocytic infiltration. A cavity develops in the dermis progressively over the period of tick attachment and feeding. This cavity appears during the first 24 hr and its full development depends upon leukocyte infiltration and the feeding activity of the tick. During the healing phase, macrophages, lymphocytes and fibroblasts gradually replace the polymorphonuclear leukocytes. The dermis is still hypercellular in the area of former attachment 2 wk after a female tick has detached fully engorged. The dog does not appear to develop resistance to the tick's engorgment even after 2 yr of intermittent exposure, nor does the host's reaction hinder the tick's engorgment. A dog never before exposed to arthropods of any kind reacted, histologically, to tick exposure with a very similar infiltration of polymorphonuclear leukocytes as seen in dogs repeatedly exposed. It is suggested that the inflammatory response by the host to the feeding tick may play an important role in the development and spread of infectious agents transmitted by this pool feeding arthropod.  相似文献   

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