全文获取类型
收费全文 | 13974篇 |
免费 | 592篇 |
国内免费 | 61篇 |
专业分类
耳鼻咽喉 | 99篇 |
儿科学 | 307篇 |
妇产科学 | 261篇 |
基础医学 | 1788篇 |
口腔科学 | 448篇 |
临床医学 | 865篇 |
内科学 | 3573篇 |
皮肤病学 | 230篇 |
神经病学 | 726篇 |
特种医学 | 483篇 |
外科学 | 2695篇 |
综合类 | 41篇 |
预防医学 | 304篇 |
眼科学 | 201篇 |
药学 | 945篇 |
中国医学 | 39篇 |
肿瘤学 | 1622篇 |
出版年
2023年 | 65篇 |
2022年 | 141篇 |
2021年 | 205篇 |
2020年 | 104篇 |
2019年 | 169篇 |
2018年 | 207篇 |
2017年 | 164篇 |
2016年 | 193篇 |
2015年 | 203篇 |
2014年 | 262篇 |
2013年 | 358篇 |
2012年 | 558篇 |
2011年 | 608篇 |
2010年 | 402篇 |
2009年 | 313篇 |
2008年 | 592篇 |
2007年 | 676篇 |
2006年 | 712篇 |
2005年 | 694篇 |
2004年 | 699篇 |
2003年 | 676篇 |
2002年 | 669篇 |
2001年 | 450篇 |
2000年 | 477篇 |
1999年 | 435篇 |
1998年 | 166篇 |
1997年 | 146篇 |
1996年 | 152篇 |
1995年 | 108篇 |
1994年 | 112篇 |
1993年 | 91篇 |
1992年 | 359篇 |
1991年 | 324篇 |
1990年 | 286篇 |
1989年 | 319篇 |
1988年 | 249篇 |
1987年 | 245篇 |
1986年 | 248篇 |
1985年 | 285篇 |
1984年 | 138篇 |
1983年 | 133篇 |
1982年 | 77篇 |
1979年 | 106篇 |
1978年 | 87篇 |
1977年 | 75篇 |
1973年 | 64篇 |
1971年 | 66篇 |
1969年 | 80篇 |
1968年 | 91篇 |
1966年 | 83篇 |
排序方式: 共有10000条查询结果,搜索用时 30 毫秒
21.
K Ohtsuka K Tsuji Y Nakagawa H Ueda O Ozawa T Uchida T Ichikawa 《Journal of nutritional science and vitaminology》1990,36(3):265-276
O-beta-D-Galactopyranosyl-(1----4)-O-beta-D-galactopyranosyl-(1----4)-D- glucopyranose (designated as 4'GL) is produced from lactose by Cryptococcus laurentii. The influence of chronic ingestion of 4'GL on body weight gain, organ weight, serum lipids, and liver lipids was investigated in rats. The body weight gains of the 5% and 10% 4'GL-diet groups were higher than that of the control group. Food intake and fecal dry weight were significantly increased (p less than 0.05) by 4'GL feeding. The 4'GL diet produced a significant increase (p less than 0.01) in the wet weight and contents of both the cecum and the colon. However, no significant increase was observed in the weight of the stomach, small intestine, liver, or other organs. The effects of 4'GL on serum and liver lipid levels were not observed in this experiment. The digestion of 4'GL was measured in vitro using the artificial gastric juice, alpha-amylase of human saliva, alpha-amylase of hog pancreas, and mucosa of rat intestine. 4'GL was not hydrolyzed by these enzymes. Long-term ingestion of 4'GL did not cause any induction of 4'GL hydrolyzing enzyme activity in the rat small intestine. 相似文献
22.
K Tanaka L A Turka J W Kupiec-Weglinski E L Milford H Ueda T Diamantstein C B Carpenter N L Tilney 《Transplantation》1990,50(1):125-131
Although the ability of Ts to prevent allograft rejection has been well established, their intrinsic characteristics and dependence upon lymphokines remain poorly defined. The cells from unmodified LEWxBN bulk 5-day rat MLR inhibit both proliferation in test MLR and generation of CTL, as well as prolonging the survival of donor-specific test cardiac allografts following adoptive transfer. We have examined the effects of a panel of mAb directed against functionally distinct epitopes on the p55 subunit of rat IL-2R on the generation and in vitro/in vivo activity of MLR-generated Ts. ART-18 (which blocks IL-2-dependent T cell growth) was the only mAb from the panel that profoundly suppressed alloreactive T cell proliferation in primary MLR (47.5%). However, the generation of Ts was never affected by any mAb (% suppression in test MLR = 40-60%). Neither ART-18 nor ART-65 (which does not affect T cell proliferation) interfered with the efficacy of Ts to inhibit CTL generation in fresh bulk MLR. Adoptive transfer of cells (3-10 x 10(6] from ART-18 or ART-65-modulated MLR into naive LEW rats prolonged (LEW x BN)F1 test cardiac allograft survival to 11-13 days (P less than 0.05 as compared with acutely rejecting hosts). All in vitro and in vivo effects exerted by MLR-generated cells were antigen-specific. In unmodified MLR, Ts were IL-2R+ (ca. 50% of total blasts), as shown by cell separation using magnetic beads. In contrast, in MLR with ART-18 added, Ts were primarily IL-2R- (ca. 10% of blasts). Thus, antirat p55 subunit IL-2R mAb do not inhibit MLR-generated Ts functionally operative in vitro and in vivo. IL-2R- Ts precursors requiring lymphokine(s) other than IL-2 may differentiate into IL-2-dependent Ts effectors. Such divergent IL-2 requirements for Ts growth in vitro may explain the Ts-sparing effects in allograft recipients treated with anti-IL-2R mAb. 相似文献
23.
M Tsuchiya W Ueda M Tomoda E Takimoto K Furuno Y Kuzume H Kanaya T Hasegawa J Aono M Maesako 《Masui. The Japanese journal of anesthesiology》1990,39(7):915-917
The dynamic and functional state of soda lime can be more precisely assessed by measuring changes in wall temperatures of the absorption chambers rather than observing color change of the soda lime granules. We demonstrated in this report that the liquid crystal thermometer is an inexpensive and reliable measuring device for this purpose. 相似文献
24.
25.
Senichiro Kikuchi Kazuhiko Iwata Yasunori Onishi Fumio Kubota Koichi Nisijima Hideaki Tamai Yuiko Koizumi Eiju Watanabe Satoshi Kato 《Psychiatry Research: Neuroimaging》2007,156(3):199-208
We conducted a noninvasive near-infrared spectroscopy (NIRS) study using the game of rock, paper, scissors (RPS) as a simple neurocognitive task for the prefrontal cortex (PFC) in 15 healthy volunteers. We employed an opposite “to lose” RPS task coupled with a normal “to win” RPS task, since the former requires inhibition of behavior, one of the most important functions of the prefrontal cortex. During the NIRS examination, subjects had to present one of the three RPS hands in response to hands displayed randomly on a computer screen every 1.5 s, and were required to show hands that lose to the computer, or that beat the computer. We measured the relative concentrations of oxyhemoglobin (oxy-Hb) using the prefrontal probes of the NIRS system during the tasks. The increases in oxy-Hb during the “to win” RPS task were small, but were quite large and laterally dominant during the “to lose” RPS task. The difference between the two tasks might have been due to the participants’ cognitive conflict with losing on the RPS. We conclude that losing is better than winning on the RPS as a sensitive indicator in the NIRS examination of PFC. 相似文献
26.
p53 mutations in non-small cell lung cancer in Japan: association between mutations and smoking. 总被引:20,自引:0,他引:20
H Suzuki T Takahashi T Kuroishi M Suyama Y Ariyoshi T Takahashi R Ueda 《Cancer research》1992,52(3):734-736
The p53 gene has been implicated as a tumor suppressor gene involved in the pathogenesis of lung cancer. Our previous study revealed that the p53 gene is frequently mutated with a distinct nucleotide substitution pattern in small cell lung cancer specimens in Japanese patients. In this study, we examined 30 primary, resected non-small cell lung cancer samples in Japanese patients using complementary DNA-polymerase chain reaction and sequencing. Mutations changing the p53 coding sequence were found in 14 of 30 tumor samples (47%), while G:C to T:A transversions which are uncommon in other cancers such as colon cancer were the most frequently observed mutations, in agreement with an earlier report on non-small cell lung cancer in American patients. Furthermore, the present study shows for the first time that in univariate and multivariate analyses, the presence of p53 mutations is closely associated with lifetime cigarette consumption. 相似文献
27.
In vivo 19F NMR at 4.7 T has shown that the biphasic elimination of the vapor anesthetic isoflurane from rat brain is ca 15% slower in old (23-24 months) animals compared with young (5-6 months) animals. The fast kinetic component has a t1/2 of ca 7-9 min and the slow event, 100-115 min. Gas chromatographic measurement of arterial blood elimination displays age attenuation to the same extent, although a monophasic kinetic process (6-7 min). The slow wash-out from brain is thought to involve elimination from intracranial fatty tissue as postulated by others in rabbit brain. Longitudinal relaxation time measurements show monoexponential recovery and essentially identical values for young (1.09 + 0.11 s) and old (1.04 +/- 0.09 s) animals. For dipalmitoylphosphatidylcholine vesicles the monoexponential recovery also suggests rapidly exchanging averaged homogeneous lipid environments for the anesthetic, but the longer T1s (2.75 +/- 0.25 s) imply less restricted mobility compared with brain. Single T2 values were obtained in vivo, indicating either a single compartment or rapid exchange between multiple environments. These measurements were inconsistent, undoubtedly as a result of B1 inhomogeneity. The age-attenuated elimination kinetics for isoflurane are consistent with poorer cardiopulmonary function, whereas the T1 data suggest similar environments for the anesthetic in young and old brain tissue. 相似文献
28.
Kentaro Yamashita Hiroyuki Tsukuda Yasuyo Mizukami Jun Ito Shigeo Ikuta Yoshihiro Kondo Hiroshi Kinoshita Yasunori Fujisawa Kohzoh Imai 《Journal of gastroenterology》1997,32(5):684-688
A case of hepatic infarction with portal thrombosis is reported. A 63-year-old woman with liver cirrhosis and esophageal varices
was admitted for treatment of the esophagel varices. Endoscopic variceal ligation (EVL) and endoscopic injection sclerotherapy
(EIS) were performed. Two months later, she experienced right hypochondralgia and right flank pain. Serum transaminase levels
were suddenly elevated, and computed tomography scans of the liver showed multiple small nodular lesions. Her condition worsened,
and she died of hepatic failure. Autopsy revealed splenic and portal vein thrombosis, multiple hepatic infarction, and evidence
of chronic pancreatitis. We believe that liver cirrhosis and chronic pancreatitis were the main risk factors for the portal
thrombosis, and the treatment for esophageal varices appeared to have triggered the thrombosis. The hepatic infarction was
caused by the portal thrombosis. 相似文献
29.
K Ueda H Sakagami F Kato T Mogami K Ohtaguro Y Masui 《Nihon Hinyōkika Gakkai zasshi. The japanese journal of urology》1990,81(9):1330-1336
Hyperthermia was induced for the treatment of invasive bladder carcinoma in order to study its usefulness. The subjects were 12 cases of invasive bladder cancer; including 5 cases of T2, 3 cases of T3, 2 cases of T4, and 2 cases of recurrence after total cystectomy. As previous treatment, 4 patients received radiotherapy and the other received TUR, systemic chemotherapy, and intravesical injection of anticancer drugs. For hyperthermia treatment, a Thermotron RF-8 was used for heating a deep seated tumor. Each case received hyperthermia 2 to 10 times. Combined therapy included injection of HPC-adriamycin into the urinary bladder in 5 cases, immunotherapy in 3 cases, M-VAC therapy in one case, radiotherapy in one case, radiotherapy and intra-arterial injection in one case, and Peplomycin and OK-432 local injection in one case. The treatment results showed a 75% effectiveness; with CR in 4 cases, PR in 5 cases, MR in 2 cases and PD in one case. Three patients died and 9 survived. Of four patients who had received radiotherapy as a previous treatment 3 cases obtained CR and one case MR. Therefore, it was considered that a favorable treatment effect with hyperthermia could be obtained after radiotherapy. 相似文献
30.
J Iemura T Yamada M Ueda F Ando H Suzuki 《Kyobu geka. The Japanese journal of thoracic surgery》1990,43(11):908-911
A 67-year-old man with positive serum reaction for syphilis had been followed by cardiologist for his moderate-sized saccular ascending aortic aneurysm and small-sized abdominal aortic aneurysm. Because of his transient ischemic attack probably secondary to the thrombo-embolism of the aneurysm and rapid growing of its size, surgical treatment was recommended. Resection of the saccular aneurysm with patch plasty of the ascending aorta was performed under the cardiopulmonary bypass associated with right side cerebral perfusion. At the time of operation, the mildly dilated ascending aorta and arch with multiple intimal ulceration were noted. Although his postoperative hemodynamic condition was stable, he suffered from multiple cerebral infarction, probably due to embolism migrated from the fragile aortic intima. His neurological condition was improved promptly, trivial hemi-paralysis was remained. The specimen of resected aneurysmal wall revealed syphilitic changes microscopically. We concluded that the extent of the aortic replacement with prosthetic graft should be deceived not only with its external appearance, but also with the changes of its inside. 相似文献