全文获取类型
收费全文 | 18876篇 |
免费 | 823篇 |
国内免费 | 85篇 |
专业分类
耳鼻咽喉 | 145篇 |
儿科学 | 262篇 |
妇产科学 | 226篇 |
基础医学 | 2407篇 |
口腔科学 | 436篇 |
临床医学 | 1154篇 |
内科学 | 4215篇 |
皮肤病学 | 1135篇 |
神经病学 | 1916篇 |
特种医学 | 738篇 |
外科学 | 3032篇 |
综合类 | 118篇 |
预防医学 | 525篇 |
眼科学 | 193篇 |
药学 | 1701篇 |
中国医学 | 45篇 |
肿瘤学 | 1536篇 |
出版年
2022年 | 160篇 |
2021年 | 284篇 |
2020年 | 162篇 |
2019年 | 215篇 |
2018年 | 297篇 |
2017年 | 240篇 |
2016年 | 303篇 |
2015年 | 310篇 |
2014年 | 389篇 |
2013年 | 470篇 |
2012年 | 766篇 |
2011年 | 791篇 |
2010年 | 472篇 |
2009年 | 417篇 |
2008年 | 799篇 |
2007年 | 852篇 |
2006年 | 836篇 |
2005年 | 848篇 |
2004年 | 923篇 |
2003年 | 918篇 |
2002年 | 846篇 |
2001年 | 629篇 |
2000年 | 698篇 |
1999年 | 650篇 |
1998年 | 320篇 |
1997年 | 230篇 |
1996年 | 202篇 |
1995年 | 191篇 |
1994年 | 171篇 |
1993年 | 168篇 |
1992年 | 479篇 |
1991年 | 427篇 |
1990年 | 434篇 |
1989年 | 455篇 |
1988年 | 419篇 |
1987年 | 387篇 |
1986年 | 341篇 |
1985年 | 312篇 |
1984年 | 199篇 |
1983年 | 175篇 |
1982年 | 95篇 |
1981年 | 83篇 |
1979年 | 180篇 |
1978年 | 97篇 |
1977年 | 107篇 |
1976年 | 81篇 |
1974年 | 80篇 |
1973年 | 83篇 |
1972年 | 86篇 |
1969年 | 76篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Y Konishi T Hashimoto T Okuno Y Takamine T Tani T Kajiwatra 《Nihon Geka Gakkai zasshi》1992,93(10):1330-1336
US findings of 81 patients with breast cancer were analyzed respectively to evaluate the usefulness of US in the preoperative diagnosis of internal mammary mode metastases. The internal mammary area (I.M.A.) in which internal mammary nodes lie was shown as a hypoechoic stripe in a sagittal scan along the sternum and as a triangular or spindle-shaped hypoechoic area in a transverse scan in the intercostal space. The US features of each I.M.A. in the first three intercostal spaces were divided into three patterns: Pattern-A wad defined as widening of the ipsilateral side of the I.M.A. compared with the contralateral side; Pattern-C was defined as normal at both sides of the I.M.A. Pathological examination confirmed the node metastases in 85.7% of intercostal scans showing Pattern-A and in 35% of intercostal scans showing Pattern-B. Only one of 189 intercostal scans showing Pattern-C had nodal metastases. The overall accuracy was 88.1% in 243 intercostal scans and 90.1% in 81 patients. We conclude that US is useful in the detection of internal mammary node metastases in patients with breast cancer. 相似文献
32.
33.
T Hashimoto H Kambara T Fudo K Uozu S Tokunaga S Tamaki C Kawai 《Journal of cardiology》1988,18(2):291-297
To evaluate the clinical significance of scintigraphic overlap of thallium-201 (201T1) and technetium-99m pyrophosphate (99mTc), we observed 28 patients with acute myocardial infarction (AMI) in whom coronary reperfusion was attempted. All patients underwent dual energy emission computed tomography (D-ECT) on the third post AMI day which facilitated comparing 99mTc and 201T1 images from identical slices simultaneously. The scintigraphic results of the 28 patients were as follows: (table, see text) In conclusion, (1) significant 201T1 and 99mTc overlap on D-ECT suggest very early and successful reperfusion, and (2) none of the patients with unsuccessful reperfusion exhibits overlap. 相似文献
34.
K. Püschel Y. Hashimoto T. Löning E. Lignitz 《International journal of legal medicine》1988,99(4):281-289
Zusammenfassung Es erfolgte eine retrospektive mikromorphologische Analyse der Glandula parotis und/oder der Glandula submandibularis von 180 plötzlichen Kindstodesfällen in Berlin und 75 Fällen in Hamburg. Erfaßt wurden Fälle der letzten 10 Jahre mit einem Alter zwischen 2 Wochen und einem Lebensjahr. — Typische CMV-Einschlußkörper wurden im Berliner Material in 18 Fällen (10%; Mädchen mehr als Jungen) und im Hamburger Material in 6 Fällen (7%; Jungen mehr als Mädchen) diagnostiziert. Während die meisten SIDS-Fälle sich im zweiten und dritten Lebensmonat ereigneten, war bei den CMV-Infektionen kein Altersgipfel festzustellen. Virusmaterial war mit immunhistochemischen Unterschungen sowie in-situ-Hybridisierung auch in histologisch unauffälligen Zellen nachzuweisen. — Unter Berücksichtigung der bekannten klinischen und epidemiologischen Daten zur Cytomegalie stellt die Diagnose einer lokalisierten Infektion der Kopf-speicheldrüsen keine befriedigende Erklärung für den plötzlichen Tod der Säuglinge dar; diese Befunde sind jedoch besonders beachtenswert als Hinweis auf eine Schwäche des Immunsystems. 相似文献
35.
Five cynomolgus monkeys treated with unilateral carotid ligation, renal hypertension, and beta-aminopropionitrile feeding were studied repeatedly by cerebral angiography to clarify the growth process of saccular cerebral aneurysms. Repeated angiography demonstrated saccular cerebral aneurysms in three of five monkeys; two aneurysms were found 15 months and a third 12 months after the operation. At autopsy, one saccular aneurysm was found to be bilocular in shape, and the others were unilocular. Fusiform aneurysms were also observed in four monkeys. Microscopic studies revealed the walls of the saccular aneurysms were very thin and consisted of fibrous tissue. In one aneurysm, the aneurysmal sac was almost obstructed by a well-organized thrombus. No evidence of intramural hemorrhage was found in any of the saccular cerebral aneurysms. The conversion of early aneurysmal changes into saccular aneurysms was found to occur abruptly, and no consistent growth rate was noted. The multiloculation of saccular aneurysms was closely related to the size of an aneurysm. The present study indicates that a saccular cerebral aneurysm may grow abruptly from one of several different kinds of early aneurysmal changes. 相似文献
36.
Osamu Mori Minoru Miyasato Tadashi Karashima Takashi Hashimoto 《The Journal of dermatology》1998,25(8):497-502
Previous studies using primary monolayer cultures of epithelial cells from the involved epidermis of patients with mammary and extramammary Paget's disease investigated whether Paget cells proliferate as other malignant cells do. Although epithelial monolayers from the involved skin were maintained for approximately 45 days, no permanent cell lines were established. The proportion of carcinoembryonic antigen (CEA)-positive cells did not increase in the long-term cultures. Herein, we report studies of whether there is a real reduction of Paget cell numbers or if this is merely a decrease in the expression of CEA by the cells. Furthermore, we investigated whether Paget cells survive longer when cultured free from any potential inhibitory keratinocytes or other epidermal cells. Skin samples were obtained from one patient with mammary Paget's disease and three with extramammary Paget's disease; epidermal cells were cultured in vitro. An enrichment of Paget cells was carried out from the cultured epidermal cells by combining an anti-epithelial membrane antigen monoclonal antibody, binding to immunobeads, and density gradient centrifugation in Nycodenz. The separated cells were re-cultured in Keratinocyte-SFM serum-free media. The proportion of CEA-positive cells did not increase in the cultures, and the purified cells did not show any increase in survival times compared to the non-purified cultured cells. These results suggest that the decrease of CEA-positive cells noted during culture results from a decline in expression of CEA in the Paget cells. Paget cells in the involved epidermis do not proliferate significantly and thus differ from many other malignant cells. 相似文献
37.
Mycosis fungoides (M.F.) is a rare cutaneous malignancy of childhood and adolescence. The disease commonly presents with the classic sequence of erythematous patches and plaques. Hypopigmentation as the presenting symptom is distinctly rare. This is the 9th case report of M.F. presenting with hypopigmentation in a patient under 20 years of age. The disease was only partially controlled with PUVA therapy, necessitating nitrogen mustard treatment. 相似文献
38.
A 42-year-old woman with progressive myelopathy and mononeuritis multiplex is reported. The neurological examination on admission revealed hyperreflexia of the four extremities with pathological reflexes and moderate muscle weakness of the lower extremities with spasticity. Sensory disturbance was distributed on the areas of the bilateral lateral cutaneous femoral, the superficial peroneal and sural nerves. The antibody to HTLV-I in the serum and cerebrospinal fluid was more than 8192X and 512X, respectively. No sensory potential was recorded in the sensory conduction study of bilateral lateral femoral cutaneous nerves. Corticosteroid therapy caused a marked improvement of the sensory and urinary disturbances and had a slight effect on the spastic gait. Our nerve conduction study found small sensory potentials with normal conduction velocities in the bilateral lateral femoral cutaneous nerves. These results suggested the presence of an axonal degeneration in the peripheral nerves in this case. There have been no reports in the literature regarding a case of HAM with mononeuritis multiplex. 相似文献
39.
M Yoshida T Takahashi H Hashimoto T Noro Y Hino T Hirashima H Terashima H Tsubuku N Wakakuri M Yamashiro 《Nihon Ronen Igakkai zasshi. Japanese journal of geriatrics》1992,29(11):836-840
A 10-year experience with 2,441 patients over 65 years of age undergoing operations for non-upper gastrointestinal tracts was reviewed to evaluate both the incidence of postoperative upper gastrointestinal bleeding and the clinical risk factors associated with the complication. A total of 18 (0.7%, 7 males and 11 females) patients had overt postoperative upper gastrointestinal bleeding of non-variceal origin documented by endoscopic findings or blood transfusions. Of these, the complication developed in 10 (1.5%) of 646 patients after an operation for biliary or pancreatic disease, 1 (1.5%) of 64 for aneurysmal or obstructive arterial disease, 5 (1.1%) of 43 for colorectal cancer and 2 (0.3%) of 916 for hernia. The incidences of bleeding after an operation for obstructive jaundice (3.8%), for biliary or pancreatic malignancy (4.5%), and of unavoidable diversion colostomy for colorectal anastomosis (3.1%) were significantly higher than for non-jaundice (0.6%), for non-malignancy (1.1%) and of postoperative upper gastrointestinal bleeding in the present study. The origins of bleeding were gastric ulcer in 11, acute gastric mucosal lesion in 4, duodenal ulcer in 1 and other in 2. All cases of bleeding were treated and met success in hemostasis using H2-blockers. Of these, however, 5 patients died of multiple organ failure despite discontinued hemorrhage, prophylactic use of H2-blockers showed a decrease in occurrence of postoperative upper gastrointestinal bleeding in the present study. 相似文献
40.
OBJECTIVE: We aimed to determine whether or not the potential distribution of the sympathetic skin response (SSR) on the palm and dorsum of the hand can be described by an equivalent current dipole (ECD) as an SSR source model. METHODS: The SSR of 22 normal subjects were simultaneously obtained from two electrodes placed on the palm and the dorsum of hand, with an indifferent electrode on the thumbnail. We then measured the SSR potential distribution in 10 of the 20 subjects who had responded to stimulation with a clear dorsal SSR. To do this, 18 electrodes were attached to the palm and dorsum of the hand. SSR-evoking stimulation (sound, voice and rapid inspiration) were randomly delivered to the subject at time intervals of more than 1min to minimize the habituation effect. We estimated the ECD from the measured potential distribution. RESULTS AND CONCLUSIONS: The SSR-evoked by stimulation was negative in potential at the palmar sites of all 22 subjects, and was positive in potential at the dorsal sites of the hand in 20 of the 22 subjects. The SSR potential distribution, which was measured in 10 subjects, reached its maximum negative and positive potential near the base of the middle finger on the palm, and near the corresponding site on the dorsum of the hand, respectively. The SSR potential measured on the dorsum of the hand, however, was about 1/3 in amplitude of those on the palmar sites. These results suggest that the SSR source is located on the palm (probably the sweat glands) as confirmed by the estimated ECD (a negative pole on the palm and a positive pole on the dorsum of the hand). We speculate that the SSR may result from the potential difference caused by the Na(+) concentration gradient in the sweat, which results from intracanal reabsorption of Na(+). SIGNIFICANCE: The ECD resulting from the Na(+) concentration gradient within the canal of sweat glands is thought to be the source of the SSR from the negative pole on the palm to the positive pole on the dorsum. 相似文献