全文获取类型
收费全文 | 13471篇 |
免费 | 658篇 |
国内免费 | 79篇 |
专业分类
耳鼻咽喉 | 178篇 |
儿科学 | 153篇 |
妇产科学 | 115篇 |
基础医学 | 1633篇 |
口腔科学 | 271篇 |
临床医学 | 845篇 |
内科学 | 3314篇 |
皮肤病学 | 225篇 |
神经病学 | 1090篇 |
特种医学 | 505篇 |
外科学 | 2696篇 |
综合类 | 75篇 |
一般理论 | 3篇 |
预防医学 | 462篇 |
眼科学 | 211篇 |
药学 | 1033篇 |
中国医学 | 41篇 |
肿瘤学 | 1358篇 |
出版年
2023年 | 70篇 |
2022年 | 174篇 |
2021年 | 291篇 |
2020年 | 146篇 |
2019年 | 211篇 |
2018年 | 252篇 |
2017年 | 222篇 |
2016年 | 276篇 |
2015年 | 276篇 |
2014年 | 313篇 |
2013年 | 447篇 |
2012年 | 605篇 |
2011年 | 681篇 |
2010年 | 363篇 |
2009年 | 349篇 |
2008年 | 522篇 |
2007年 | 641篇 |
2006年 | 566篇 |
2005年 | 577篇 |
2004年 | 560篇 |
2003年 | 516篇 |
2002年 | 564篇 |
2001年 | 443篇 |
2000年 | 456篇 |
1999年 | 427篇 |
1998年 | 165篇 |
1997年 | 139篇 |
1996年 | 120篇 |
1995年 | 90篇 |
1994年 | 89篇 |
1993年 | 87篇 |
1992年 | 358篇 |
1991年 | 319篇 |
1990年 | 317篇 |
1989年 | 294篇 |
1988年 | 286篇 |
1987年 | 282篇 |
1986年 | 278篇 |
1985年 | 214篇 |
1984年 | 145篇 |
1983年 | 144篇 |
1982年 | 51篇 |
1981年 | 57篇 |
1979年 | 117篇 |
1978年 | 60篇 |
1977年 | 55篇 |
1974年 | 52篇 |
1973年 | 60篇 |
1972年 | 65篇 |
1970年 | 49篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
Pharmaceutical studies on crude drugs. I. Effect of the Zingiberaceae crude drug extracts on sulfaguanidine absorption from rat small intestine 总被引:2,自引:0,他引:2
992.
Noboru Sakai Hiroaki Nokura Kazuki Deguchi Estela Decarlini Atsuro Futamura Hiromu Yamada 《Child's nervous system》1990,6(8):447-450
Thirty-four cases of infantile subdural effusion (ISE) were reviewed in relation to surgical treatment and its prognosis during an average of 4 years of extended follow-up. The surgical indications were determined mainly by the size of the ISE on computed tomography (CT) scan and by metrizamide CT cisternography (MCTC). Consequently, 18 cases were categorized as type A according to MCTC, including 11 cases (61.1%) of ISE CT grade 1. All type A cases were closely observed. This nontreatment regimen yielded excellent results in 15 cases (83.3%). For 10 cases categorized as type B according to MCTC, including 5 cases (50%) of ISE CT grade 3, surgical treatment was indicated and excellent results were obtained in 8 cases (80%). For 6 cases categorized as type C according to MCTC and as ISE CT grade 3, surgery yielded excellent results in 4 cases (66.7%). Antiepleptic drugs have been given to three (27.3%) of the 11 patients who had convulsive attacks. In conclusion, the surgical indications for ISE were based mainly on MCTC in addition to the clinical course, and it is emphasized that, in the early stages, surgery on ISE cases categorized as MCTC types B and C is necessary. 相似文献
993.
K Sakai T Fujino S Hoshi N Shinkai M Hashimoto T Yasuda H Kato H Yamada N Wake K Ichinoe 《Nippon Sanka Fujinka Gakkai zasshi》1987,39(5):807-814
Choriocarcinoma cells grown in the presence of MTX have developed resistance in two ways. The HCCM derived sublines (relatively high MTX resistant) produced enhanced levels of DHFR and had relatively unimpaired transport of MTX, though altered transport was the primary determinant of response in the CC1 derived sublines (low MTX resistant). Since the selection procedure used was identical, it was assumed that altered MTX transport was insufficient to account entirely for various degrees of resistance. Increased DHFR activity was necessary for the development of high MTX resistance. The overproduction of DHFR was the consequence of amplification of the DHFR gene sequence. The incidence of DMs in metaphases paralleled the degree of resistance. Since DMs were also present in the cells not showing DHFR gene amplification, mechanisms other than DHFR gene multiplication were responsible for the de novo synthesis of DMs. 相似文献
994.
H Takeda K Watanabe D Suzuki R Miyano K Tanaka H Machimura M Yagame W Inoue H Kaneshige H Sakai 《The Tokai journal of experimental and clinical medicine》1991,16(1):73-76
A 72-year-old patient was referred to our hospital because of a hypoglycemic crisis possibly due to an insulin secreting-tumor. Although its localization was assumed to be at the head of the pancreas as assessed by transhepatic venography with sampling, no mass lesion was detected by selective angiography, ultrasound, computerized axial tomography, magnetic resonance imaging and 67Ga-citrate scan. The patient was treated with diazoxide, because of poor localization and his age, insulin secretion was improved after both 30 and 60 min in the 75 g oral glucose tolerance test. The total amount of urinary C-peptide excretion decreased from 70.8 to 29.2 mcg/day. Thereafter, no hypoglycemic symptoms were observed during his admission. No side effects except mild liver damage were observed. 相似文献
995.
The blood level of endotoxin after operations in patients with digestive diseases, mainly liver cirrhosis and obstructive jaundice, and the complications most likely related to the presence of endotoxemia were investigated. Twenty-seven patients without either liver cirrhosis or obstructive jaundice showed a minimal elevation of the endotoxin level in blood, as shown by 6.1 +/- 3.9 pg/ml at the first postoperative day and there was only one anastomotic leakage. On the other hand, 18 patients with liver cirrhosis showed a notable and persistent endotoxemia after surgery. The cirrhotic patients who especially underwent splenectomy and hepatectomy showed marked elevations of endotoxin level at the first postoperative day, with values of 151.0 +/- 46.1 pg/ml and 101.3 +/- 36.2 pg/ml, respectively, and one of these patients died of hepatic failure. Thirteen patients with obstructive jaundice developed endotoxemia evidenced by the value of 21.6 +/- 4.8 pg/ml at the first day after surgery. Among these patients, two had gastrointestinal bleeding and one developed DIC. The markedly high and persistent levels of endotoxin in patients with liver cirrhosis or obstructive jaundice may be possibly related with the development of MOF. 相似文献
996.
Hisaka Igarashi Fumihiko Sakai Shinichi Kan Jun Okada Yoshiaki Tazaki 《Cephalalgia : an international journal of headache》1991,11(2):69-74
Magnetic resonance imaging (MRI) was studied in 91 patients with migraine and in 98 controls. Risk factors known to cause MRI lesions were carefully examined. In 36 patients with migraine (39.6%), small foci of high intensity on T2-weighted and proton-density-weighted images were seen in the white matter. Of patients with migraine who were less than 40 years old and without any risk factor, 29.4% showed lesions on MRI; this was significantly higher than the 11.2% for the group of age-matched controls (n = 98). The lesions were distributed predominantly in the centrum semiovale and frontal white matter in young patients, but extended to the deeper white matter at the level of basal ganglia in the older age group. The side of the MRI lesions did not always correspond to the side of usual aura or headache. Migraine-related variables such as type of migraine, frequency, duration or intensity of headache or consumption of ergotamine showed no significant correlation with the incidence of MRI abnormalities. Our data indicated that migraine may be associated with early pathologic changes in the brain. 相似文献
997.
After a consecutive oral administration of 200 mg/kg/day of 14C-rokitamycin (TMS-19-Q) daily for 28 days to male rats, the accumulation of radioactivity in tissues and its disappearance after the cessation of the administration was studied. Blood concentrations at peak times and 24 hours after each administration were determined daily. Both values increased gradually until the 14th day and thereafter remained roughly constant. The extent of elimination of radioactivity from the blood was practically not affected by the consecutive administration. Affinities of radioactivity to the liver, kidney, spleen, adrenal, pituitary gland, preputial gland, thyroid, intraorbital lacrimal gland and bone marrow were comparatively higher than those to other tissues. Tissue concentrations in the above mentioned tissues at the 1st day after the completion of consecutive administrations for 14 and 28 days were 2.6-6.1 and 3.2-6.8 times higher, respectively, than those at the 1st day after a single administration. The elimination of radioactivity from the tissue after the consecutive administration for 28 days was slightly slower than that after a single administration. In the consecutive daily administration for 28 days, the metabolic fate of radioactivity reached a steady state after 14 days of consecutive daily administration. Hence, the accumulation of the radioactivity did not particularly occurred. During the consecutive administration, recoveries of radioactivity in the urine and feces were almost at a constant rates, with 8.0 and 93.8% of the total radioactivity given excreted in the urine and feces, respectively, within 10 days after the last administration. 相似文献
998.
999.
1000.
Y Sakai A Nomura K Masumori J Kawamura S Nagayama 《Asian journal of endoscopic surgery》2009,2(1):8-12
The terms “Denonvilliers' fascia” and “lateral ligament of the rectum” will be very familiar to colorectal surgeons. However, how these structures are conceptualized remains controversial. Here, we review past and recent interpretations of these two terms. Denonvilliers' fascia is likely derived from the fusion of the two walls of an embryonic cul‐de‐sac to form a clear boundary between the neurovascular bundle and the mesorectum. When performing anterior dissection for mobilization of the rectum, it remains unclear whether the optimal dissection plane is in front of or behind Denonvilliers' fascia. Anatomical studies have shown that the lateral ligament may not be a clearly definable structure and that the middle rectal artery is not clinically significant. In the future, careful laparoscopic observations will give us a better understanding of these currently controversial anatomical features. 相似文献