全文获取类型
收费全文 | 28282篇 |
免费 | 1318篇 |
国内免费 | 225篇 |
专业分类
耳鼻咽喉 | 289篇 |
儿科学 | 601篇 |
妇产科学 | 309篇 |
基础医学 | 3592篇 |
口腔科学 | 521篇 |
临床医学 | 1735篇 |
内科学 | 8275篇 |
皮肤病学 | 561篇 |
神经病学 | 1922篇 |
特种医学 | 1176篇 |
外科学 | 4579篇 |
综合类 | 93篇 |
预防医学 | 765篇 |
眼科学 | 508篇 |
药学 | 1635篇 |
中国医学 | 45篇 |
肿瘤学 | 3219篇 |
出版年
2023年 | 192篇 |
2022年 | 416篇 |
2021年 | 716篇 |
2020年 | 375篇 |
2019年 | 464篇 |
2018年 | 670篇 |
2017年 | 528篇 |
2016年 | 605篇 |
2015年 | 646篇 |
2014年 | 781篇 |
2013年 | 1005篇 |
2012年 | 1555篇 |
2011年 | 1808篇 |
2010年 | 1068篇 |
2009年 | 923篇 |
2008年 | 1615篇 |
2007年 | 1689篇 |
2006年 | 1676篇 |
2005年 | 1700篇 |
2004年 | 1722篇 |
2003年 | 1537篇 |
2002年 | 1565篇 |
2001年 | 464篇 |
2000年 | 418篇 |
1999年 | 438篇 |
1998年 | 345篇 |
1997年 | 284篇 |
1996年 | 236篇 |
1995年 | 228篇 |
1994年 | 216篇 |
1993年 | 208篇 |
1992年 | 357篇 |
1991年 | 326篇 |
1990年 | 258篇 |
1989年 | 320篇 |
1988年 | 265篇 |
1987年 | 265篇 |
1986年 | 266篇 |
1985年 | 235篇 |
1984年 | 170篇 |
1983年 | 143篇 |
1982年 | 83篇 |
1981年 | 88篇 |
1980年 | 77篇 |
1979年 | 100篇 |
1978年 | 80篇 |
1977年 | 73篇 |
1975年 | 58篇 |
1972年 | 54篇 |
1969年 | 60篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
41.
The activity of phrenic motor neurons is influenced by the cardiovascular control system of the supraspinal structures. In order to obtain the basic data for analyzing the anatomical relations between the cardiovascular and the pulmonary control system, supraspinal structures projecting to the phrenic motor nucleus of the cat spinal cord were studied using a horseradish peroxidase method. A double-barrel coaxial electrode was employed. To determine the site of the phrenic motor neurons, the inner barrel electrode, filled with 3 M NaCl solution, was used for recording the activity of these neurons. The outer barrel electrode, filled with a 20% HRP solution, was used for injecting HRP iontophoretically into the phrenic motor nucleus. Out of 13 experiments, 5 showed that the HRP-injection sites were centered in and almost confined to the phrenic motor nucleus. Some 1798 HRP-labeled cells were thus identified in the selected 5 experiments. They were distributed in the medulla oblongata (93.5%), pons (6.0%) and midbrain (0.5%). The majority were concentrated in the nucleus para-ambiguus (48.9%), nucleus tractus solitarii (21.5%) and in or around the nucleus retrofacialis (9.8%). A few labeled cells were scattered throughout the nucleus raphe (1.1%) and the parabrachial and Koelliker-Fuse nuclei (0.3%), suggesting that these nuclei may be, if any, only minor sources of input to the phrenic motor nucleus. 相似文献
42.
H Shiozaki T Ide J Nakao T Imamura M Nakamura K Shimada Y Miura T Suda 《Japanese journal of cancer research》1992,83(5):499-504
LD78 is a cDNA newly isolated from human stimulated tonsillar lymphocytes. The expression of LD78 is related to inflammatory responses and its structure has a homology with macrophage inflammatory protein 1-alpha, which is known to have an inhibitory effect on murine CFU-S. Using a colony assay technique, we examined the effects of LD78 on human hemopoietic progenitors. The addition of doses of 100 ng/ml or more of LD78 suppressed the colony formation of KMT-2, a factor-dependent myelomonocytic cell line established from cord blood cells; this suppressive activity was neutralized by the addition of antibody against LD78. The same doses of LD78 suppressed the formation of neutrophil, macrophage, and megakaryocytic colonies which were supported by human interleukin-3 and erythropoietin; however, LD78 did not affect colony formation by either non-phagocytic mononuclear cells or sorted CD34+ cells. The conditioned medium of KMT-2 cells or peripheral blood mononuclear cells cultured with LD78 suppressed colony formation by CD34+ cells. From these findings, it is suggested that LD78 affects phagocytic cells and induces factors that are inhibitory for hemopoiesis. We consider LD78 to be a new cytokine that plays an inhibitory role in hemopoiesis. 相似文献
43.
Minoru Yagi Takeshi Mishina Tsukasa Fujishima Kazutoshi Date Hiroshi Saito Nobuo Suzuki 《Surgery today》1997,27(1):84-87
The acute onset of peritoneal signs and shock in a 7year-old boy who had been hit in the epigastrium by a log-seesaw mandated surgical treatment. Enhanced computed tomography (CT) demonstrated complete laceration of the pancreas as well as duodenal injury, and a duodenoduodenostomy with distal pancreaticogastrostomy was subsequently performed. Temporary external drainage of the stomach and distal pancreas led to an uneventful recovery in the early postoperative period. Although the patient's postoperative development was appropriate for his age, the orifice of the distal pancreas spontaneously closed 2.5 years following surgery. We present this report to stress the fact that every effort should be made to preserve the pancreas following abdominal injury in children. 相似文献
44.
Genetic alteration in carcinoid tumors of the lung. 总被引:1,自引:0,他引:1
Kenji Sugio Toshihiro Osaki Tsunehiro Oyama Mitsuhiro Takenoyama Takeshi Hanagiri Masaru Morita Koji Yamazaki Akira Nagashima Hisashi Nakahashi Yoshihiko Maehara Kosei Yasumoto 《Annals of thoracic and cardiovascular surgery》2003,9(3):149-154
Surgically resected specimens of 13 carcinoid tumors of the lung including nine typical carcinoids and four atypical carcinoids, and eight salivary gland type carcinomas (six mucoepidermoid carcinomas and two adenoid cystic carcinomas) were analyzed regarding p53 expression, loss of heterozygosity (LOH) in chromosome 3p, 9p, and K-ras mutation. The overexpression of p53 was identified in four atypical carcinoid tumors, one mucoepidermoid carcinoma, and one adenoid cystic carcinoma, however, none of typical carcinoids showed p53 immunoreactivity. LOH in 3p14 was demonstrated in three of seven informative cases in all tumors. LOH in 9p was demonstrated in two of five informative cases in all tumors. Two of three cases with LOH at 3p14 had a poor prognosis, one of which also had LOH at 9p. No mutation of the K-ras gene was observed in any of these tumors. These data thus indicate that p53 overexpression might distinguish atypical carcinoid tumors from typical tumors and might therefore be useful as an adjunct modality in the differential diagnosis of pulmonary carcinoid tumors. The presence of LOH at 3p14 or 9p may thus help to identify lung cancer patients with a poor prognosis. 相似文献
45.
Leiomyosarcoma originating in Meckel's diverticulum: Report of a case and a review of 59 cases in the English literature 总被引:1,自引:0,他引:1
Nobuyuki Shimizu Shu Kuramoto Toshiki Mimura Kaoru Kobayashi Masanori Kobayashi Shigeru Sakai Michio Kaminishi Takeshi Oohara 《Surgery today》1997,27(6):546-549
A 49-year-old woman was referred to our hospital with complaints of epigastric colicky pain and high fever. Abdominal computed
tomography and ultrasonography showed a solid tumor in the lower abdomen. Laparotomy revealed a neoplastic mass arising in
Meckel's diverticulum; therefore, a segment of the ileum, including the tumor-possessing diverticulum, was resected with a
lymph node dissection. A histologic examination confirmed the lesion to be leiomyosarcoma. In the English literature, 59 cases
of leiomyosarcoma in Meckel's diverticulum were reported from 1941 to 1994. The majority of patients were in their 4th decade
of life, with both sexes equally affected. The most frequent symptoms associated with this disease were abdominal pain with
nausea, vomiting, and melena. The majority were larger than egg-size. Although Meckel's diverticulum is difficult to diagnose
preoperatively, mesenteric arteriography may at times prove useful. The standard management of this particular tumor is wide
segmental resection, including the tumor and diverticulum with lymph node dissection. 相似文献
46.
K Ishii M Oda S Kazemoto T Azuma H Kaneko H Yokomori H Saitoh S Miura M Tsuchiya 《Nihon Shokakibyo Gakkai zasshi》1992,89(2):552-557
47.
Eiichiro SUGIYAMA Takayoshi IKEDA Hiroshi MAEDA Takeshi MATSUO Masaru MATSUMOTO 《Congenital anomalies》1987,27(2):85-93
Abstract True incidence of this malformation is probably greater than that reported since the definitive diagnosis has been made at autopsy in most cases. Various hypotheses on the pathogenesis of tracheal agenesis have been proposed but they are still controversial.
In this report, we present a case of tracheal agenesis with a broncho-esophageal fistula and discuss the formal genesis. 相似文献
In this report, we present a case of tracheal agenesis with a broncho-esophageal fistula and discuss the formal genesis. 相似文献
48.
This experiment was designed to examine the effects of indomethacin, a potent prostaglandin synthesis inhibitor, on spontaneous mammary tumors in mice. The growth of established mammary tumors and the appearance of new tumors in multiparous SHN mice were significantly suppressed by the subcutaneous implantation of pellets of indomethacin diluted to 1/12 with cholesterol. Furthermore, the same treatment inhibited normal and preneoplastic mammary gland growth in virgin SHN mice. The pattern of estrous cycles, ovarian structure, and plasma prolactin levels were not affected significantly by the treatment. All results have demonstrated that indomethacin inhibits mammary tumorigenesis of mice primarily by route(s) other than the endocrine system under the present experimental conditions. Indomethacin would be the first agent that appears to inhibit the growth of spontaneous mammary tumors of palpable size in mice. 相似文献
49.
Toshihiro Kawamura Hiroshi Motoyama Atsushi Yanaihara Takeshi Yorimitsu Akane Arichi Yasuhiro Karasawa Kahori Suga Kaoru Miya Seika Ishikawa Shiho Mizushima Makiko Kawamura 《Reproductive Medicine and Biology》2007,6(1):53-57
Aim: To compare the clinical outcomes of cryopreserved-thawed embryo transfer among patients with a normal menstrual cycle who had natural or hormone-replacement cycles.
Methods: From January 2004 to June 2006, cryopreserved embryos following conventional in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) were thawed and transferred in a total of 720 natural cycles and 136 hormone-replacement cycles.
Results: Cryopreserved-thawed embryo transfer in patients who had a natural or hormone-replacement cycle resulted in clinical pregnancy in 43.1% and 40.4%, respectively; a rate of miscarriage of 14.5% and 23.6%, respectively; and a rate of ongoing pregnancy and delivery of 36.5% and 30.9%, respectively. None of these differences were statistically significant.
Conclusions: Patients with a normal menstrual cycle who have natural or hormone-replacement cycles can be expected to have comparable clinical outcomes with cryopreserved-thawed embryo transfer. (Reprod Med Biol 2007; 6 : 53–57) 相似文献
Methods: From January 2004 to June 2006, cryopreserved embryos following conventional in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) were thawed and transferred in a total of 720 natural cycles and 136 hormone-replacement cycles.
Results: Cryopreserved-thawed embryo transfer in patients who had a natural or hormone-replacement cycle resulted in clinical pregnancy in 43.1% and 40.4%, respectively; a rate of miscarriage of 14.5% and 23.6%, respectively; and a rate of ongoing pregnancy and delivery of 36.5% and 30.9%, respectively. None of these differences were statistically significant.
Conclusions: Patients with a normal menstrual cycle who have natural or hormone-replacement cycles can be expected to have comparable clinical outcomes with cryopreserved-thawed embryo transfer. (Reprod Med Biol 2007; 6 : 53–57) 相似文献
50.
Active oxygen species generated by monocytes and polymorphonuclear cells in Crohn's disease 总被引:4,自引:0,他引:4
Tetsuji Kitahora MD Koichi Suzuki MD Hitoshi Asakura MD Takeshi Yoshida MD Makoto Suematsu MD Mamoru Watanabe MD Sadakazu Aiso MD Dr. Masaharu Tsuchiya MD 《Digestive diseases and sciences》1988,33(8):951-955
Chemiluminescence (CL) analysis of monocytes and polymorphonuclear cells (PMNs) was performed on 13 patients with Crohn's disease (CD) and 10 healthy volunteers. The percentages of monocyte populations in mononuclear cells obtained from the patients with CD were greater than those from the healthy volunteers, but the numbers of PMNs were not different between the two groups. The peak level of phorbol myristate acetate (PMA)-induced CL activity generated by diluted whole blood from the patients with CD was more significantly elevated than that from the healthy volunteers, whereas the peak levels of opsonized zymosan-induced CL activity did not differ between the two groups. In monocytes, the peak levels of both PMA- and opsonized zymosan-induced CL activity were significantly higher in the patients with CD than in the healthy volunteers. CL in PMNs, however, showed no significant difference between CD and controls. It is suggested that monocytes of CD have a large capacity to generate active oxygen species. The present study suggests that excessive active oxygen species released by monocytes and perhaps macrophages may play an important role in formation of the intestinal lesions in CD.This work was supported by the Grant of Tokuteishitsukan from the Japanese Ministry of Welfare and Health. 相似文献