The Journal of Biophysical and Biochemical Cytology最新文献

筛选
英文 中文
Some unusual features of fine structure observed in HeLa cells. 在HeLa细胞中观察到一些不寻常的精细结构特征。
The Journal of Biophysical and Biochemical Cytology Pub Date : 1961-06-01 DOI: 10.1083/jcb.10.2.153
M A EPSTEIN
{"title":"Some unusual features of fine structure observed in HeLa cells.","authors":"M A EPSTEIN","doi":"10.1083/jcb.10.2.153","DOIUrl":"https://doi.org/10.1083/jcb.10.2.153","url":null,"abstract":"<p><p>HeLa cells from conventional culture media have been studied in thin sections with the electron microscope; in many cases cells were examined in sets of sections cut in series. The fine structure of the cells is described including three unusual features not hitherto reported. It has been found that numerous cells contained rows of parallel smooth surfaced cisternae spaced about 150 mmicro apart and communicating with rough surfaced elements of the endoplasmic reticulum. These cisternae resembled \"annulate lamellae\" but did not contain regular arrays of pores. In many cells an area of juxtanuclear cytoplasm was occupied by a membranous structure composed of closely applied pairs of narrow cisternae either arranged in concentric rings or else extending in several directions in a haphazard manner. Sparse particles were present on the outer membranes of each pair of cisternae. Communications between the double cisternae and other membrane-bounded structures were not observed. A small number of cells contained areas of cytoplasm devoid of organelles and filled with amorphous fuzzy material. The observations recorded are discussed.</p>","PeriodicalId":22618,"journal":{"name":"The Journal of Biophysical and Biochemical Cytology","volume":"10 ","pages":"153-62"},"PeriodicalIF":0.0,"publicationDate":"1961-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1083/jcb.10.2.153","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"23290556","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 99
Observations on sperm penetration in the rat. 大鼠精子穿透的观察。
The Journal of Biophysical and Biochemical Cytology Pub Date : 1961-06-01 DOI: 10.1083/jcb.10.2.275
D G SZOLLOSI, H RIS
{"title":"Observations on sperm penetration in the rat.","authors":"D G SZOLLOSI,&nbsp;H RIS","doi":"10.1083/jcb.10.2.275","DOIUrl":"https://doi.org/10.1083/jcb.10.2.275","url":null,"abstract":"<p><p>The structural aspects of sperm penetration in the rat egg were investigated by electron microscopy. Eggs were recovered at intervals between 8 and 10:30 A.M. from females which had mated during the previous night. The oviducts were flushed with hyaluronidase and the eggs transferred into a 2 per cent osmium tetroxide solution, buffered at pH 7.8. After fixation, the eggs were mounted individually in agar, dehydrated in ethyl alcohol, and embedded in butyl-methyl methacrylate (3:1). The sperm penetrating the egg is covered by a plasma membrane which is present only on the side facing toward the zona pellucida; no membrane is visible on the side facing toward the vitellus. The sperm plasma membrane becomes continuous with the egg plasma membrane and forms a deep fold around the entering sperm. Cross-sections through the sperm midpiece in the perivitelline space show an intact plasma membrane. At the place of entrance, the plasma membrane of the sperm appears to fuse with the egg plasma membrane. After the sperm has penetrated the vitellus, it has no plasma membrane at all. The nuclear membrane is also absent. These observations suggest a new hypothesis for sperm penetration. After the sperm has come to lie on the plasma membrane of the egg, the egg and sperm plasma membranes rupture and then fuse with one another to form a continuous cell membrane over the egg and the outer surface of the sperm. As a result the sperm comes to lie inside the vitellus, leaving its own plasma membrane incorporated into the egg membrane at the surface of the egg.</p>","PeriodicalId":22618,"journal":{"name":"The Journal of Biophysical and Biochemical Cytology","volume":"10 ","pages":"275-83"},"PeriodicalIF":0.0,"publicationDate":"1961-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1083/jcb.10.2.275","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"23369356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 95
Mitochondrial alterations in the myocardium of dogs with aortic stenosis. 主动脉瓣狭窄犬心肌线粒体的改变。
The Journal of Biophysical and Biochemical Cytology Pub Date : 1961-06-01 DOI: 10.1083/jcb.10.2.285
A WOLLENBERGER, W SCHULZE
{"title":"Mitochondrial alterations in the myocardium of dogs with aortic stenosis.","authors":"A WOLLENBERGER,&nbsp;W SCHULZE","doi":"10.1083/jcb.10.2.285","DOIUrl":"https://doi.org/10.1083/jcb.10.2.285","url":null,"abstract":"","PeriodicalId":22618,"journal":{"name":"The Journal of Biophysical and Biochemical Cytology","volume":"10 ","pages":"285-8"},"PeriodicalIF":0.0,"publicationDate":"1961-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1083/jcb.10.2.285","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"23379346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 76
Changes in the spermatozoon during fertilization in Hydroides hexagonus (Annelida). I. Passage of the acrosomal region through the vitelline membrane. 六角形水螅虫受精过程中精子的变化。顶体区域通过卵黄膜的通道。
The Journal of Biophysical and Biochemical Cytology Pub Date : 1961-06-01 DOI: 10.1083/jcb.10.2.231
L H COLWIN, A L COLWIN
{"title":"Changes in the spermatozoon during fertilization in Hydroides hexagonus (Annelida). I. Passage of the acrosomal region through the vitelline membrane.","authors":"L H COLWIN,&nbsp;A L COLWIN","doi":"10.1083/jcb.10.2.231","DOIUrl":"https://doi.org/10.1083/jcb.10.2.231","url":null,"abstract":"<p><p>In the previous paper the structure of the acrosomal region of the spermatozoon was described. The present paper describes the changes which this region undergoes during passage through the vitelline membrane. The material used consisted of moderately polyspermic eggs of Hydroides hexagonus, osmium-fixed usually 9 seconds after insemination. There are essentially four major changes in the acrosome during passage of the sperm head through the vitelline membrane. First, the acrosome breaks open apically by a kind of dehiscence which results in the formation of a well defined orifice. Around the lips of the orifice the edges of the plasma and acrosomal membranes are then found to be fused to form a continuous membranous sheet. Second, the walls of the acrosomal vesicle are completely everted, and this appears to be the means by which the apex of the sperm head is moved through the vitelline membrane. The lip of the orifice comes to lie deeper and deeper within the vitelline membrane. At the same time the lip itself is made up of constantly changing material as first the material of the outer zone and then that of the intermediate zone everts. One is reminded of the lip of an amphibian blastopore, which during gastrulation maintains its morphological identity as a lip but is nevertheless made up of constantly changing cells, with constantly changing outline and even constantly changing position. Third, the large acrosomal granule rapidly disappears. This disappearance is closely correlated with a corresponding disappearance of a part of the principal material of the vitelline membrane from before it, and the suggestion is made that the acrosomal granule is the source of the lysin which dissolves this part of the vitelline membrane. Fourth, in the inner zone the fifteen or so short tubular invaginations of the acrosomal membrane, present in the normal unreacted spermatozoon, lengthen considerably to become a tuft of acrosomal tubules. These tubules are the first structures of the advancing sperm head to touch the plasma membrane of the egg. It is notable that the surface of the acrosomal tubules which once faced into the closed acrosomal cavity becomes the first part of the sperm plasma membrane to meet the plasma membrane of the egg. The acrosomal tubules of Hydroides, which arise simply by lengthening of already existing shorter tubules, are considered to represent the acrosome filaments of other species.</p>","PeriodicalId":22618,"journal":{"name":"The Journal of Biophysical and Biochemical Cytology","volume":"10 ","pages":"231-54"},"PeriodicalIF":0.0,"publicationDate":"1961-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1083/jcb.10.2.231","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"23290140","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 84
Changes in the spermatozoon during fertilization in Hydroides hexagonus (Annelida). II. Incorporation with the egg. 六角形水螅虫受精过程中精子的变化。2和鸡蛋混合。
The Journal of Biophysical and Biochemical Cytology Pub Date : 1961-06-01 DOI: 10.1083/jcb.10.2.255
A L COLWIN, L H COLWIN
{"title":"Changes in the spermatozoon during fertilization in Hydroides hexagonus (Annelida). II. Incorporation with the egg.","authors":"A L COLWIN,&nbsp;L H COLWIN","doi":"10.1083/jcb.10.2.255","DOIUrl":"https://doi.org/10.1083/jcb.10.2.255","url":null,"abstract":"<p><p>This, the last of a series of three papers, deals with the final events which lead to the incorporation of the spermatozoon with the egg. The material used consisted of moderately polyspermic eggs of Hydroides hexagonus, osmium-fixed at various times up to five minutes after insemination. The first direct contact of sperm head with egg proper is by means of the acrosomal tubules. These deeply indent the egg plasma membrane, and consequently at the apex of the sperm head the surfaces of the two gametes become interdigitated. But at first the sperm and egg plasma membranes maintain their identity and a cross-section through the region of interdigitation shows these two membranes as a number of sets of two closely concentric rings. The egg plasma membrane rises to form a cone which starts to project into the hole which the spermatozoon earlier had produced in the vitelline membrane by means of lysis. But the cone does not literally engulf the sperm head. Instead, where they come into contact, sperm plasma membrane and egg plasma membrane fuse to form one continuous membranous sheet. At this juncture the two gametes have in effect become mutually incorporated and have formed a single fertilized cell with one continuous bounding membrane. At this time, at least, the membrane is a mosaic of mostly egg plasma membrane and a patch of sperm plasma membrane. The evidence indicates that the fusion of the two membranes results from vesiculation of the sperm and egg plasma membranes in the region at which they come to adjoin. Once this fusion of membranes is accomplished, the egg cytoplasm intrudes between the now common membrane and the internal sperm structures, such as the nucleus, and even extends into the flagellum; finally these sperm structures come to lie in the main body of the egg. The vesiculation suggested above appears possibly to resemble pinocytosis, with the difference that the vesicles are formed from the plasma membranes of two cells. At no time, however, is the sperm as a whole engulfed and brought to the interior of the egg within a large vesicle.</p>","PeriodicalId":22618,"journal":{"name":"The Journal of Biophysical and Biochemical Cytology","volume":"10 ","pages":"255-74"},"PeriodicalIF":0.0,"publicationDate":"1961-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1083/jcb.10.2.255","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"23290341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 92
The influence of iron-dextran complex on the strain L fibroblast. 右旋糖酐铁复合物对L株成纤维细胞的影响。
The Journal of Biophysical and Biochemical Cytology Pub Date : 1961-06-01 DOI: 10.1083/jcb.10.2.289
B S DANES, M STRUTHERS
{"title":"The influence of iron-dextran complex on the strain L fibroblast.","authors":"B S DANES,&nbsp;M STRUTHERS","doi":"10.1083/jcb.10.2.289","DOIUrl":"https://doi.org/10.1083/jcb.10.2.289","url":null,"abstract":"","PeriodicalId":22618,"journal":{"name":"The Journal of Biophysical and Biochemical Cytology","volume":"10 ","pages":"289-92"},"PeriodicalIF":0.0,"publicationDate":"1961-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1083/jcb.10.2.289","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"23311820","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 6
Fine structure of the spermatozoon of Hydroides hexagonus (Annelida), with special reference to the acrosomal region. 六角形水螅虫精子的精细结构,特别注意顶体区域。
The Journal of Biophysical and Biochemical Cytology Pub Date : 1961-06-01 DOI: 10.1083/jcb.10.2.211
A L COLWIN, L H COLWIN
{"title":"Fine structure of the spermatozoon of Hydroides hexagonus (Annelida), with special reference to the acrosomal region.","authors":"A L COLWIN,&nbsp;L H COLWIN","doi":"10.1083/jcb.10.2.211","DOIUrl":"https://doi.org/10.1083/jcb.10.2.211","url":null,"abstract":"<p><p>This paper describes in some detail the structure of the acrosomal region of the spermatozoon of Hydroides as a basis for subsequent papers which will deal with the structural changes which this region undergoes during fertilization. The material was osmium-fixed and mild centrifugation was used to aggregate the spermatozoa from collection to final embedding. The studies concern also the acrosomal regions of frozen-thawed sperm prepared by a method which previously had yielded extracts with egg membrane lytic activity. The plasma membrane closely envelops four readily recognizable regions of the spermatozoon: acrosomal, nuclear, mitochondrial, and flagellar. The acrosome consists of an acrosomal vesicle which is bounded by a single continuous membrane, and its periphery is distinguishable into inner, intermediate, and outer zones. The inner and intermediate zones form a pocket into which the narrowed apex of the nucleus intrudes. Granular material adjoins the inner surface of the acrosomal membrane, and this material is characteristically different for each zone. Centrally, the acrosomal vesicle is spanned by an acrosomal granule: its base is at the inner zone and its apex at the outer zone. The apex of the acrosomal granule flares out and touches the acrosomal membrane over a limited area. In this limited area the adjoining granular material of the outer zone is lacking. The acrosomal membrane of the inner zone is invaginated into about fifteen short tubules. The acrosomal membrane of the outer zone is closely surrounded by the plasma membrane. At the apex of the acrosomal region a small apical vesicle is sandwiched between the plasma membrane and the acrosomal membrane. Numerous frozen-thawed specimens and occasional specimens not so treated show acrosomal regions at the apex of which there is a well defined opening or orifice. Around the rim or lip of this orifice plasma and acrosomal membranes may even be fused into a continuum. The evidence indicates that the apical vesicle and the parts of the plasma and acrosomal membranes which surround it constitute a lid, and the rim of this lid constitutes a natural \"fracture line\" or rim of dehiscence. Should fracture occur, the lid would be removed and the acrosomal vesicle would be open to the exterior.</p>","PeriodicalId":22618,"journal":{"name":"The Journal of Biophysical and Biochemical Cytology","volume":"10 ","pages":"211-30"},"PeriodicalIF":0.0,"publicationDate":"1961-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1083/jcb.10.2.211","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"23290342","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 91
Glycogen synthesis from uridine diphosphate glucose. The distribution of the enzyme in liver cell fractions. 尿苷二磷酸葡萄糖合成糖原。酶在肝细胞组分中的分布。
The Journal of Biophysical and Biochemical Cytology Pub Date : 1961-06-01 DOI: 10.1083/jcb.10.2.195
D J LUCK
{"title":"Glycogen synthesis from uridine diphosphate glucose. The distribution of the enzyme in liver cell fractions.","authors":"D J LUCK","doi":"10.1083/jcb.10.2.195","DOIUrl":"https://doi.org/10.1083/jcb.10.2.195","url":null,"abstract":"<p><p>The distribution in liver cell fractions of UDPG-glycogen transferase has been studied. In fasting animals which have been refed 6 hours before sacrifice, the distribution of the enzyme in the various cell fractions can be correlated with the glycogen content of each fraction. A purified glycogen fraction has been prepared by differential centrifugation in sucrose gradients. This glycogen fraction contains vesicular structures which resemble those seen in association with glycogen deposits in the intact liver cell. In addition, the glycogen pellet contains UDPG-glycogen transferase in high specific activity. Subfractionation of the glycogen pellet separates the majority of vesicular elements from the bulk of transferase activity and glycogen. The evidence presented suggests that the presence of UPDG-glycogen transferase in the glycogen pellet is to be attributed to its binding to glycogen rather than to its association with the structural elements found in the glycogen fraction.</p>","PeriodicalId":22618,"journal":{"name":"The Journal of Biophysical and Biochemical Cytology","volume":"10 ","pages":"195-209"},"PeriodicalIF":0.0,"publicationDate":"1961-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1083/jcb.10.2.195","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"23355019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 117
Electron microscopic radioautography of thin sections: the Golgi zone as a site of protein concentration in pancreatic acinar cells. 电镜放射自显影薄切片:高尔基带作为胰腺腺泡细胞蛋白质浓度的位置。
The Journal of Biophysical and Biochemical Cytology Pub Date : 1961-05-01 DOI: 10.1083/jcb.10.1.37
L G CARO
{"title":"Electron microscopic radioautography of thin sections: the Golgi zone as a site of protein concentration in pancreatic acinar cells.","authors":"L G CARO","doi":"10.1083/jcb.10.1.37","DOIUrl":"https://doi.org/10.1083/jcb.10.1.37","url":null,"abstract":"<p><p>Electron microscopic radioautographs of guinea pig pancreatic exocrine cells were obtained by covering thin sections ( approximately 600 A) of OsO(4)-fixed, methacrylate-embedded tissue with thin layers of Ilford K-5 nuclear research emulsion. After an exposure of 13 days at 4 degrees C., the preparations were photographically processed, stained with uranyl acetate, and examined in an electron microscope. The label used was leucine-H(3) injected intravenously 20 minutes before collection of the specimens. Conventional radioautographs of thicker sections (0.4 micron) were also examined in a phase contrast microscope. The advantages obtained from electron microscopic radioautography are: the higher radioautographic resolution (of the order of 0.3 micron) due to the thinness of the emulsion and the specimen, and a high optical resolution permitting a clear identification of the labeled structure. In the guinea pig pancreas this technique demonstrated that, at the time studied, newly synthesized proteins were concentrated in the structures of the Golgi complex and especially in large vacuoles partially filled with a dense material. The vacuoles are probably a precursor to the secretion granules (zymogen granules) in which the label becomes segregated at a later time. These observations demonstrate directly the role of the Golgi complex in the secretion process. They also illustrate the possibilities of this method for radioautography at the intracellular level.</p>","PeriodicalId":22618,"journal":{"name":"The Journal of Biophysical and Biochemical Cytology","volume":"10 ","pages":"37-45"},"PeriodicalIF":0.0,"publicationDate":"1961-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1083/jcb.10.1.37","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"23287132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 176
Combined autoradiography and electron microscopy of thin sections of intestinal epithelial cells of the mouse labeled with H3-thymidine. 用h3胸腺嘧啶标记的小鼠肠上皮细胞薄片放射自显影和电镜相结合。
The Journal of Biophysical and Biochemical Cytology Pub Date : 1961-05-01 DOI: 10.1083/jcb.10.1.140
J C HAMPTON, H QUASTLER
{"title":"Combined autoradiography and electron microscopy of thin sections of intestinal epithelial cells of the mouse labeled with H3-thymidine.","authors":"J C HAMPTON,&nbsp;H QUASTLER","doi":"10.1083/jcb.10.1.140","DOIUrl":"https://doi.org/10.1083/jcb.10.1.140","url":null,"abstract":"","PeriodicalId":22618,"journal":{"name":"The Journal of Biophysical and Biochemical Cytology","volume":"10 ","pages":"140-4"},"PeriodicalIF":0.0,"publicationDate":"1961-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1083/jcb.10.1.140","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"23305155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 27
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
相关产品
×
本文献相关产品
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信