全文获取类型
收费全文 | 8101篇 |
免费 | 316篇 |
国内免费 | 88篇 |
专业分类
耳鼻咽喉 | 33篇 |
儿科学 | 112篇 |
妇产科学 | 102篇 |
基础医学 | 1162篇 |
口腔科学 | 93篇 |
临床医学 | 379篇 |
内科学 | 2232篇 |
皮肤病学 | 147篇 |
神经病学 | 806篇 |
特种医学 | 290篇 |
外科学 | 1506篇 |
综合类 | 20篇 |
预防医学 | 223篇 |
眼科学 | 58篇 |
药学 | 491篇 |
中国医学 | 41篇 |
肿瘤学 | 810篇 |
出版年
2023年 | 42篇 |
2022年 | 67篇 |
2021年 | 108篇 |
2020年 | 68篇 |
2019年 | 82篇 |
2018年 | 129篇 |
2017年 | 102篇 |
2016年 | 117篇 |
2015年 | 140篇 |
2014年 | 188篇 |
2013年 | 242篇 |
2012年 | 364篇 |
2011年 | 467篇 |
2010年 | 271篇 |
2009年 | 265篇 |
2008年 | 473篇 |
2007年 | 478篇 |
2006年 | 494篇 |
2005年 | 538篇 |
2004年 | 540篇 |
2003年 | 595篇 |
2002年 | 610篇 |
2001年 | 108篇 |
2000年 | 104篇 |
1999年 | 127篇 |
1998年 | 172篇 |
1997年 | 158篇 |
1996年 | 122篇 |
1995年 | 113篇 |
1994年 | 127篇 |
1993年 | 110篇 |
1992年 | 79篇 |
1991年 | 71篇 |
1990年 | 67篇 |
1989年 | 67篇 |
1988年 | 72篇 |
1987年 | 47篇 |
1986年 | 41篇 |
1985年 | 31篇 |
1984年 | 48篇 |
1983年 | 45篇 |
1982年 | 50篇 |
1981年 | 47篇 |
1980年 | 43篇 |
1979年 | 28篇 |
1978年 | 35篇 |
1976年 | 20篇 |
1975年 | 19篇 |
1967年 | 14篇 |
1966年 | 20篇 |
排序方式: 共有8505条查询结果,搜索用时 15 毫秒
81.
Hitoshi Kameyama Yoshio Shirai MD Kazutoshi Date Akifumi Kuwabara Ryo Kurosaki Katsuyoshi Hatakeyama 《Journal of gastrointestinal cancer》2005,35(2):153-155
Although exfoliative dermatitis (erythroderma) secondary to malignancy is commonly associated with lymphomas or leukemias, coincident gastrointestinal (GI) malignancy and erythroderma is rare. The authors recently encountered a patient with gallbladder carcinoma presenting as erythroderma. A 77-yr-old Japanese man presented with a 3-mo history of erythematous eruptions with pruritus over almost the entire body. After confirming the diagnosis of erythroderma, asymptomatic gallbladder carcinoma was found. Further investigations detected no malignancies in other organs. An extended cholecystectomy was performed. Histologic examination of resected specimens revealed poorly differentiated adenocarcinoma with negative resection margins. The eruptions with pruritus resolved within 1 wk after the operation. This is the first report, to our knowledge, of coincident biliary malignancy and erythroderma. The experience of the current patient suggests that erythroderma secondary to GI malignancy may resolve spontaneously after curative resection of the tumor. 相似文献
82.
Kiyokazu Takebayashi Yoshimoto Sekine Nori Takei Yoshio Minabe Haruo Isoda Hiroyasu Takeda Katsuhiko Nishimura Kazuhiko Nakamura Katsuaki Suzuki Yasuhide Iwata Harumi Sakahara Norio Mori 《Neuropsychopharmacology》2004,29(5):1019-1026
Long-term toluene abuse causes a variety of psychiatric symptoms. However, little is known about abnormalities at the neurochemical level in the living human brain after long-term exposure to toluene. To detect neurochemical changes in the basal ganglia of subjects with a history of long-term toluene use, proton magnetic resonance spectroscopy (1H MRS) was performed in 12 abstinent toluene users and 13 healthy comparisons with no history of drug abuse. N-acetylaspartate (NAA), creatine plus phosphocreatine (Cr + PCr), choline-containing compounds (Cho), and myo-inositol (MI) levels were measured in the left and right basal ganglia. The Cho/Cr + PCr ratio, a marker of membrane metabolism, was significantly increased in the basal ganglia of toluene users in comparison to that of the control subjects. Furthermore, the increase in the Cho/Cr + PCr ratio was significantly correlated with the severity of residual psychiatric symptoms. These findings suggest that long-term toluene use causes membrane disturbance in the basal ganglia, which is associated with residual psychiatric symptoms that persist even after long-term abstinence from toluene use. 相似文献
83.
Daigo Murata Yoshio Endo Tohru Obata Kazuki Sakamoto Yasuhiro Syouji Masakazu Kadohira Akira Matsuda Takuma Sasaki 《Drug metabolism and disposition》2004,32(10):1178-1182
The antitumor 3'-ethynyl nucleosides, 1-(3-C-ethynyl-beta-D-ribopentofuranosyl)cytosine (ECyd) and 1-(3-C-ethynyl-beta-D-ribopentofuranosyl)uridine (EUrd), are potent inhibitors of RNA polymerases and show excellent antitumor activity against various human solid tumors in xenograft models. ECyd is being investigated in phase I clinical trials as a novel anticancer drug possessing a unique antitumor action. ECyd and EUrd require the activity of uridine/cytidine kinase (UCK) to produce the corresponding active metabolite. The UCK family consists of two members, UCK1 and UCK2, and both UCKs are expressed in many tumor cells. It was unclear, however, whether UCK1 or UCK2 is responsible for the phosphorylation of the 3'-ethynyl nucleosides. We therefore established cell lines that are highly resistant to the 3'-ethynyl nucleosides from human fibrosarcoma HT-1080 and gastric carcinoma NUGC-3. All the resistant cell lines showed a high cross-resistance to ECyd and EUrd. As a result of cDNA sequence analysis, we found that UCK2 mRNA expressed in EUrd-resistant HT-1080 cells has a 98-base pair deletion of exon 5, whereas EUrd-resistant NUGC-3 cells were harboring the point mutation at nucleotide position 484 (C to T) within exon 4 of UCK2 mRNA. This mutation was confirmed by genome sequence analysis of the UCK2 gene. Moreover, the expression of UCK2 protein was decreased in these resistant cells. In contrast, no mutation in the mRNA or differences in protein expression levels of UCK1 were shown in the EUrd-resistant HT-1080 and NUGC-3 cells. These results suggest that UCK2 is responsible for the phosphorylation and activation of the antitumor 3'-ethynyl nucleosides. 相似文献
84.
快速加热型石膏包埋料对铸造精度影响的研究 总被引:2,自引:0,他引:2
目的研究快速加热型石膏包埋料包埋后放置时间对其膨胀及铸件铸造精度的影响。方法选用传统型石膏包埋料CRISTOBALITE P(CBP)、快速加热型石膏包埋料CRISTOBALITE PF(CBPF)和CRISTQUICK20(CQ)。根据包埋料类型及包埋后放置时间不同分组为CBP、CBPF-30、CBPF-60、CQ-20、CQ-40、CQ-60。分别测定各组包埋料的硬化膨胀率和热膨胀率。以六棱柱形状蜡型为铸件原型,应用各组包埋料包埋铸造,测量各组所得铸件的尺寸变化率。结果CBPF-30组、CQ-20组的硬化膨胀率和热膨胀率均小于CBP组。随着包埋后放置时间的延长,CBPF和CQ各组的硬化膨胀率明显增大,热膨胀率逐渐减小。CBPF-30组和CQ-20组包埋料所得铸件的收缩率均大于CBP组。CBPF两组所得铸件的尺寸变化率无差别,CQ3组所得铸件的尺寸变化率无差别。结论在一定限度内适当延长快速加热型石膏包埋料包埋后放置时间对铸件的铸造精度无明显影响。 相似文献
85.
T Okuyama M Takata J Takayasu T Hasegawa H Tokuda A Nishino H Nishino A Iwashima 《Planta medica》1991,57(3):242-246
Potent anti-tumor promoter activity has been found in the nonpolar extracts of the root of "Ashita-Ba", Angelica keiskei Koidz. (Umbelliferae), which is eaten as a vegetable in Japan. From this active fraction, two angular furanocoumarins, archangelicin (1) and 8(S),9(R)-9-angeloyloxy-8,9-dihydrooroselol (2), three linear furanocoumarins, psoralen (3), bergapten (4) and xanthotoxin (5), and three chalcones, 4-hydroxyderricin (6), xanthoangelol (7) and a novel chalcone named ashitaba-chalcone (8), were isolated. Among these compounds, two angular type furanocoumarins, 1 and 2, and three chalcones, 6-8, suppressed 12-O-tetradecanoylphorbol-13-acetate (TPA)-stimulated 32Pi-incorporation into phospholipids of cultured cells, whereas coumarins 3-5 were less effective. In addition, chalcones 6 and 7 were proved to have anti-tumor-promoting activity in mouse skin carcinogenesis induced by 7,12-dimethylbenz[a]anthracene (DMBA) plus TPA. Since chalcones 6 and 7 showed calmodulin-interacting property, both chalcones may reveal anti-tumor-promoting activity via the modulation of calmodulin involved systems. These chalcones may be useful to develop the effective method for cancer prevention. 相似文献
86.
Takeyama K Ogura M Morishima Y Kasai M Kiyama Y Ohnishi K Mitsuya H Kawano F Masaki Y Sasaki T Chou T Yokozawa T Tobinai K;Lenograstim/Lymphoma Study Group 《Japanese journal of clinical oncology》2003,33(2):78-85
BACKGROUND: Peripheral blood stem cell (PBSC) reinfusion has been widely used for hematopoietic reconstitution after high-dose chemotherapy. However, the optimal dose of granulocyte colony-stimulating factor (G-CSF) for PBSC mobilization in combination with chemotherapy for autograft remains unknown. METHODS: To find the optimal dose of glycosylated G-CSF (lenograstim) for PBSC mobilization in combination with chemotherapy for aggressive non-Hodgkin's lymphoma (NHL), we conducted a dose-finding study on 43 newly diagnosed patients who had unfavorable prognostic factors. They received four to six courses of cyclophosphamide, doxorubicin, vincristine and prednisolone combined with lenograstim every 2 weeks (biweekly CHOP therapy). PBSC apheresis was started after the third course of biweekly CHOP therapy. Lenograstim was given daily from day 3 until the day of the last apheresis. The optimum dose of lenograstim was assessed based on mobilization efficacy and safety profiles at a daily single dose of 2, 5 and 10 microg/kg for eight patients in each level. RESULTS: The collected number of CD34+ cells in the first apheresis products was higher in the 5 microg/kg group than in the 2 microg/kg group (median, 4.22 x 10(6) vs 2.49 x 10(6) CD34+ cells/kg, P = 0.051). The highest dose of 10 microg/kg (median, 2.99 x 10(6) CD34+ cells/kg) failed to show a dose dependence in PBSC mobilization. The efficacy and safety of the 5 microg/kg dose were further confirmed in an additional 19 patients. CONCLUSIONS: The present study suggests that the recommended dose of lenograstim for PBSC mobilization with CHOP therapy in untreated NHL is 5 microg/kg. 相似文献
87.
88.
89.
Miyake Y Sasaki S Ohya Y Miyamoto S Matsunaga I Yoshida T Hirota Y Oda H;Osaka Maternal Child Health Study Group 《Annals of epidemiology》2006,16(8):614-621
PURPOSE: It may be worthwhile to assess the possible protective effect of the traditional Japanese diet on allergic disorders. This cross-sectional study investigated the relationship between dietary intake of seaweed, vegetables, fruit, antioxidants, fiber, and minerals and the prevalence of allergic rhinitis. METHODS: Study subjects were 1002 Japanese pregnant women. Allergic rhinitis (including cedar pollinosis) was defined as present if subjects had received drug treatment at some point during the previous 12 months. Information on dietary factors was collected by using a self-administered diet history questionnaire. RESULTS: Seaweed intake was associated independently with a decreased prevalence of allergic rhinitis. Significant inverse dose-response relationships were found between calcium and phosphorus intake and allergic rhinitis prevalence. There also was a tendency for an inverse association between magnesium consumption and allergic rhinitis. Additional adjustment for calcium or magnesium intake apparently did not influence the inverse association with seaweed consumption. Consumption of vegetables, fruit, vitamins C and E, fiber, and zinc showed no association with allergic rhinitis, whereas a significant positive relationship was observed between beta-carotene intake and allergic rhinitis. CONCLUSIONS: High dietary intake of seaweed, calcium, magnesium, and phosphorus may be associated with a decreased prevalence of allergic rhinitis. 相似文献
90.
N. Motoi Tsuyoshi Ishida Imaharu Nakano Nobu Akiyama Kinuko Mitani Hisamaru Hirai Yoshio Yazaki Rikuo Machinami 《Acta neuropathologica》1997,93(3):301-305
A 64-year-old man in a severely immunocompromised state due to acute myelogenous leukemia died, respirator-unaided, about
10 h after the abrupt onset of coma. An earlier blood culture had yielded Bacillus cereus. The autopsy, performed 2 h after death, demonstrated diffuse subarachnoid hemorrhage without berry aneurysms, and the formalin-fixed
brain was tinged with gray-brownish discoloration. The sections of the brain presented a whitish tint of the surface layer
of all portion of the cerebral cortices, even those in the sulci. Histological examination of the brain revealed leptomeningeal
B. cereus dissemination, and widespread necrosis of the leptomeninges and arachnoid vessels without inflammatory cell reaction. The
grossly recognizable whitish surface layer of the cerebral cortex showed overt hyperchromatism, and contained neurons more
degenerative than those located in the deeper cortical layer. The total absence of inflammatory reaction may be explained
by a combination of the immunocompromised state of the patient and the character of B. cereus infection, which in itself induces little inflammatory reaction. The prominent lesions were confined to the cerebral surface
layer and leptomeningeal tissue including the arachnoid vessels, which were all bathed in the cerebrospinal fluid, suggesting
that some necrotizing toxins had been secreted into the fluid by the B. cereus. The necrosis of arachnoid vessels is thought to have in turn caused diffuse subarachnoid hemorrhage and marked disturbance
of the cerebral blood flow, resulting in the terminal coma.
Received: 4 April 1996 / Revised, accepted: 8 September 1996 相似文献