全文获取类型
收费全文 | 8408篇 |
免费 | 340篇 |
国内免费 | 63篇 |
专业分类
耳鼻咽喉 | 45篇 |
儿科学 | 167篇 |
妇产科学 | 75篇 |
基础医学 | 1004篇 |
口腔科学 | 128篇 |
临床医学 | 530篇 |
内科学 | 2340篇 |
皮肤病学 | 113篇 |
神经病学 | 594篇 |
特种医学 | 346篇 |
外科学 | 1322篇 |
综合类 | 58篇 |
一般理论 | 2篇 |
预防医学 | 236篇 |
眼科学 | 184篇 |
药学 | 473篇 |
中国医学 | 11篇 |
肿瘤学 | 1183篇 |
出版年
2023年 | 48篇 |
2022年 | 86篇 |
2021年 | 177篇 |
2020年 | 95篇 |
2019年 | 134篇 |
2018年 | 165篇 |
2017年 | 129篇 |
2016年 | 178篇 |
2015年 | 168篇 |
2014年 | 258篇 |
2013年 | 342篇 |
2012年 | 543篇 |
2011年 | 585篇 |
2010年 | 307篇 |
2009年 | 268篇 |
2008年 | 515篇 |
2007年 | 537篇 |
2006年 | 501篇 |
2005年 | 508篇 |
2004年 | 461篇 |
2003年 | 453篇 |
2002年 | 481篇 |
2001年 | 126篇 |
2000年 | 112篇 |
1999年 | 137篇 |
1998年 | 115篇 |
1997年 | 102篇 |
1996年 | 107篇 |
1995年 | 79篇 |
1994年 | 65篇 |
1993年 | 70篇 |
1992年 | 106篇 |
1991年 | 77篇 |
1990年 | 86篇 |
1989年 | 82篇 |
1988年 | 73篇 |
1987年 | 77篇 |
1986年 | 50篇 |
1985年 | 36篇 |
1984年 | 28篇 |
1983年 | 40篇 |
1982年 | 25篇 |
1981年 | 25篇 |
1980年 | 21篇 |
1979年 | 36篇 |
1978年 | 22篇 |
1977年 | 15篇 |
1970年 | 16篇 |
1969年 | 17篇 |
1968年 | 18篇 |
排序方式: 共有8811条查询结果,搜索用时 546 毫秒
51.
Nobuyuki Tanaka Kazumasa Sugihara Tetsuyo Odajima Masafumi Mimura Yutaka Kimijima Shizuko Ichinose 《Medical Electron Microscopy》2002,35(3):127-138
Oral squamous cell carcinoma is the most common oral malignancy, and we performed electron microscopic and immunohistochemical investigation of the tumor. In patients with cervical metastasis, microvilli were developed and a small number of desmosomes were found, regardless of the width of the intercellular spaces. In patients without the metastasis, few microvilli were found in relatively wide intercellular spaces, or numerous microvilli were found in narrow intercellular spaces, and a large number of desmosomes were shown. However, these findings were different from those of tumors that had received radiotherapy, in which numerous microvilli and a small number of desmosomes were found in the nonmetastatic cases. Transferrin receptor, which is a marker of cell proliferation, was localized on the cell membrane, especially in microvilli. Ultrastructural similarity between the primary tumor and the metastatic tumor was recognized, however, the features of microvilli, desmosomes, and the intercellular spaces differed between them in most cases. It is suggested that microvilli might be related to the metastasis of oral squamous cell carcinoma cells. Immunohistochemically, the protein expression of p53 and pRb2/p130 was related to the clinical course of the patients with oral squamous cell carcinoma; the mechanism of the synthesis of these proteins should be investigated in order to understand the biological behavior of the tumor. 相似文献
52.
Nobuyuki Tanaka Masafumi Mimura Yutaka Kimijima Kodo Sasaki Shizuko Ichinose Teruo Amagasa 《Medical Electron Microscopy》2002,35(4):204-216
Sarcoma of the oral region is extremely rare and ultrastructural studies of the tumor are limited in number. We collected oral sarcomas, such as fibrosarcoma, malignant fibrous histiocytoma, liposarcoma, leiomyosarcoma, rhabdomyosarcoma, angiosarcoma, alveolar soft-part sarcoma, solitary plasmacytoma, and osteosarcoma, and performed ultrastructural studies of these tumors. The value of these studies for an understanding of the biological behavior of the tumors was then investigated. In these studies, electron microscopic examinations of oral sarcoma were of assistance in our attempt to establish correct diagnosis and histogenesis. Data from the studies of oral sarcoma by light microscopy, electron microscopy, and immunohistochemistry should be accumulated. 相似文献
53.
The ultrasound examination of the deep vein thrombosis 总被引:2,自引:0,他引:2
Taniguchi N Ono T Itoh K 《Rinsho byori. The Japanese journal of clinical pathology》2003,51(8):761-769
Ultrasonography is very useful for detection of deep vein thrombosis. The purpose of this paper is to show a method for detecting them efficiently by high resolution transducer and color Doppler system. We examined patients in the supine and prone positions. To detect the venous flow easily and differentiate thrombi from simple venous dilatation, some maneuvers are useful; one is pushing the vein area using the transducer on examination, the second is breathing overload, and the last is so-called milking. We can find throombi in the external iliac or femoral veins of patients who have symptoms of lower leg swelling, however, we need to better detect venous thrombi in the lower leg in patients with a history of pulmonary embolism. Because deep venous thrombi are increasing, the role of ultrasound will expand in the future. 相似文献
54.
Yoshio Hiasa Noriyuki Ito Masato Ohshima Tomoyoshi Ohmori Asao Seki Toshikazu Tatsumi Hiromu Yokoi Chikayoshi Iwata Yoshio Murata Nobuyuki Ito † 《Pathology international》1978,28(4):637-644
Light and electron microscopic studies have been made on an anaplastic giant-cell tumor that developed in a woman 8 years after an operation on the thyroid for papillary carcinoma. Many giant cells were observed in the anaplastic tumor tissue, but no follicles. Numerous tightly-packed mitochondria and abundant ribosomes were present, but there were no desmosomes. The basement membrane was not distinct. 相似文献
55.
56.
Takahiro Tsujimura Masashi Takeda Nobuyuki Terada Hiroshi Uramoto 《Pathology international》1991,41(8):642-646
Two cases of peritoneal papillary carcinoma are reported. The patient in the first case was a 71-year-old woman with symptoms of obstructive ileus. Laparotomy revealed a tumor in the omentum involving the transverse colon, and several small tumors in the peritoneum and pelvic wall. However, no primary site of the tumor was seen in the ovary, pancreas, or gastrointestinal tract. The patient in the second case was a 44-year-old woman with carcinomatous peritonitis. Postmortem examination revealed multiple tumors in the peritoneum, omentum, and pelvic wall. Tumors were also found in the cortex with mild invasion of the underlying parenchyma of the bilateral ovaries, although these lesions were thought to be metastatic. The histologic features of the tumor in both cases were those of tubulopapillary adenocarcinoma containing scattered psammoma bodies. The cells were positive with the PAS D technique, but negative with alcian blue staining. In both cases, the serum levels of CA-125 were considerably elevated, and the tumor cells showed positivity for CA-125, S 100 protein, cytokeratin and EMA by im-munohistochemistry. The present cases were most likely peritoneal serous papillary adenocarcinoma derived from extraovarian peritoneal mesothelium with miillerian potential, being different from the usual type of diffuse malignant mesothelioma. Acta Pathol Jpn 41: 642-646, 1991. 相似文献
57.
Kazuo Takayama Kanichi Yagawa Akiko Takahashi Hironori Nishio Morio Sudo Nobuyuki Sasaki Toru Yoshida Masanobu Satoh Hisaaki Abiko Akio Nunokawa Mitsuo Okazaki 《Pathology international》1969,19(4):547-562
A typical case of the D uchenne type of progressive muscular dystrophy with autopsy findings was presented. Changes in the myocardial and smooth muscle of many organs were found, and the skeletal muscles also revealed florid changes.
Histopathological examination of the skeletal muscle was made in detail through light and electron microscopic observation. 相似文献
Histopathological examination of the skeletal muscle was made in detail through light and electron microscopic observation. 相似文献
58.
Catalase, a Specific Antigen in the Feces of Human Subjects Infected with Helicobacter pylori 下载免费PDF全文
Nobuyuki Suzuki Masahiko Wakasugi Seigo Nakaya Naomi Kokubo Masami Sato Hirofumi Kajiyama Ryoki Takahashi Haruhisa Hirata Yohji Ezure Yoshihiro Fukuda Takashi Shimoyama 《Clinical and Vaccine Immunology : CVI》2002,9(4):784-788
Recently, we reported the production of three new monoclonal antibodies with high specificity for a Helicobacter pylori antigen suitable for diagnosis of H. pylori infection. The aim of the present study was to identify the antigen recognized by these monoclonal antibodies concerning both H. pylori and the feces of human subjects infected with H. pylori. The cellular antigen was purified from an H. pylori cell extract by immunoaffinity column chromatography with the monoclonal antibody as a ligand. The amino-terminal amino acid sequences (eight residues) of the purified antigen and H. pylori catalase were the same. The molecular weights of native and subunit, specific catalase activity, and UV and visible spectra of the purified antigen were in good agreement with those of H. pylori catalase. The human fecal antigens were purified from two fecal samples of two H. pylori-positive subjects by ammonium sulfate precipitation, CM-Sephadex C50 chromatography, and the same immunoaffinity chromatography used for the H. pylori cellular antigen. The fecal antigens had catalase activity. The amino-terminal amino acid sequences (five residues) of the human fecal antigen and H. pylori catalase were the same. The monoclonal antibodies reacted with the native cellular antigen, but did not react with the denatured antigen, human catalase, and bovine catalase. The results show that the target antigen of the monoclonal antibodies is native H. pylori catalase and that the monoclonal antibodies are able to specifically detect the antigen, which exists in an intact form, retaining the catalase activity in human feces. 相似文献
59.
Owada-Makabe K Tsubota Y Yukawa K Kakimoto N Liang XM Ichinose M Maeda M 《Neuroscience letters》2005,378(1):18-21
Attempts at protein transduction into specific restricted brain areas have remained unsuccessful. We attempted targeted, direct in vivo protein transduction by microinjecting beta-galactosidase (beta-gal) with hemagglutinating virus of Japan envelope (HVJ-E) vector into the rat nucleus tractus solitarius (NTS). The medulla oblongata including the NTS was removed 6h post-injection and cryostat sections were histochemically stained to detect beta-gal enzymatic activity. beta-gal-positive cells were present in these sections as was beta-gal activity determined by colorimetric analysis. beta-gal-positive cells were not present in the rats microinjected only beta-gal protein without HVJ-E vector. Our findings suggest that direct in vivo protein transduction into specific restricted brain areas is possible. The type of targeted delivery system we present may have wide applications in the administration of therapeutic proteins to the central nervous system. 相似文献
60.
Hamada K Sasaki T Koni PA Natsui M Kishimoto H Sasaki J Yajima N Horie Y Hasegawa G Naito M Miyazaki J Suda T Itoh H Nakao K Mak TW Nakano T Suzuki A 《Genes & development》2005,19(17):2054-2065
PTEN is an important tumor suppressor gene. Hereditary mutation of PTEN causes tumor-susceptibility diseases such as Cowden disease. We used the Cre-loxP system to generate an endothelial cell-specific mutation of Pten (Tie2CrePten) in mice. Tie2CrePten(flox/+) mice displayed enhanced tumorigenesis due to an increase in angiogenesis driven by vascular growth factors. This effect was partially dependent on the PI3K subunits p85alpha and p110gamma. In vitro, Tie2CrePten(flox/+) endothelial cells showed enhanced proliferation/migration. Tie2CrePten(flox/flox) mice died before embryonic day 11.5 (E11.5) due to bleeding and cardiac failure caused by impaired recruitment of pericytes and vascular smooth muscle cells to blood vessels, and of cardiomyocytes to the endocardium. These phenotypes depend strongly on p110gamma rather than on p85alpha and were associated with decreased expression of Ang-1, VCAM-1, connexin 40, and ephrinB2 but increased expression of Ang-2, VEGF-A, VEGFR1, and VEGFR2. Pten is thus indispensable for normal cardiovascular morphogenesis and post-natal angiogenesis, including tumor angiogenesis. 相似文献