全文获取类型
收费全文 | 6995篇 |
免费 | 317篇 |
国内免费 | 38篇 |
专业分类
耳鼻咽喉 | 63篇 |
儿科学 | 112篇 |
妇产科学 | 189篇 |
基础医学 | 860篇 |
口腔科学 | 226篇 |
临床医学 | 516篇 |
内科学 | 1579篇 |
皮肤病学 | 97篇 |
神经病学 | 763篇 |
特种医学 | 478篇 |
外国民族医学 | 1篇 |
外科学 | 987篇 |
综合类 | 60篇 |
预防医学 | 334篇 |
眼科学 | 73篇 |
药学 | 432篇 |
中国医学 | 4篇 |
肿瘤学 | 576篇 |
出版年
2023年 | 49篇 |
2022年 | 89篇 |
2021年 | 182篇 |
2020年 | 95篇 |
2019年 | 119篇 |
2018年 | 170篇 |
2017年 | 102篇 |
2016年 | 128篇 |
2015年 | 139篇 |
2014年 | 194篇 |
2013年 | 244篇 |
2012年 | 352篇 |
2011年 | 368篇 |
2010年 | 222篇 |
2009年 | 196篇 |
2008年 | 303篇 |
2007年 | 326篇 |
2006年 | 338篇 |
2005年 | 335篇 |
2004年 | 310篇 |
2003年 | 330篇 |
2002年 | 309篇 |
2001年 | 178篇 |
2000年 | 203篇 |
1999年 | 173篇 |
1998年 | 70篇 |
1997年 | 64篇 |
1996年 | 51篇 |
1995年 | 55篇 |
1994年 | 38篇 |
1993年 | 41篇 |
1992年 | 168篇 |
1991年 | 139篇 |
1990年 | 132篇 |
1989年 | 150篇 |
1988年 | 126篇 |
1987年 | 99篇 |
1986年 | 104篇 |
1985年 | 89篇 |
1984年 | 63篇 |
1983年 | 65篇 |
1980年 | 29篇 |
1979年 | 37篇 |
1977年 | 30篇 |
1974年 | 31篇 |
1973年 | 28篇 |
1972年 | 26篇 |
1971年 | 27篇 |
1967年 | 21篇 |
1966年 | 26篇 |
排序方式: 共有7350条查询结果,搜索用时 15 毫秒
31.
Kobayashi S Iwasaki K Asano T Ochiai T 《International journal of molecular medicine》2002,10(6):749-753
In hepatitis C virus (HCV)-associated hepatocellular carcinoma (HCC), serum alanine aminotransferase (ALT) is frequently sustained on a high level after hepatectomy, with the formation of recurrent HCC tumors during follow-up periods. We investigated whether or not postoperative serum ALT level affects the interval before recurrence in hepatitis C virus-associated HCC. The subjects studied were 50 hepatectomized HCC patients who were HCV-Ab(+), and underwent a curable surgery in our Hospital from June 1990 to December 1999. We assessed the significance of the postoperative serum ALT level affecting tumor-free survival rates, as compared with other clinicopathological parameters, using univariate and multivariate Cox proportional hazard analysis. Thereafter, tumor-free and overall survival rates after hepatectomy were compared between high and low ALT groups, using Kaplan-Meier plotting and a log-rank test. The factor of ALT levels (a high or low ALT group) was most strongly associated with a tumor-free survival rate. Both tumor-free and overall survival rates were significantly poorer in the high ALT group than in the low ALT group among HCV-associated HCC cases (p<0.05). The results in this study suggest that postoperative hepatitis, which is indicated by sustained high ALT levels, may shorten the interval before recurrence in HCV-associated HCC. We should take care to control postoperative hepatitis to improve the prognoses of HCV-associated HCC cases. 相似文献
32.
Okamoto T Hashimoto M Samejima H Mori A Wakabayashi M Takeda A Nakamura H Naruse H Bouike Y Araki N 《Immunopharmacology and immunotoxicology》2004,26(4):645-652
Immediate hemolytic transfusion reactions (IHTR) occurred in the course of delayed hemolytic transfusion reactions (DHTR). An 84-year-old man had received a blood transfusion 20 years ago. Progressive anemia developed, because of continuous bleeding from a bladder tumor. He was transfused with concentrated red blood cells (CRC) which were Rh-E antigen negative, because he had anti-E antibodies (day 0). He received CRC on day 3, and underwent resection of bladder tumor on day 6. Although crossmatch-compatible CRCs were prepared for the operation, those were not required and were kept in a refrigerator in the ward. On day 9, when a CRC kept in the ward was transfused, he suddenly had a IHTR. In order to analyze a mechanism of IHTR, the anti-Jk(b) and anti-Di(b) antibodies, anti-HLA antibodies and the concentrations of inflammatory cytokines were measured in serum samples. The anti-Jk(b) and anti-Di(b) antibodies increased prior to IHTR experienced on day 9. The concentrations of IL-6 and IL-1beta increased from day 2, while the concentration of IL-8 increased from day 7. The anti-HLA class I antibody could be detected 2 days before IHTR. Thus, the anti-Jk(b) and anti-Di(b) antibodies induced the production of inflammatory cytokines and symptoms of DHTR and IHTR. The anti-HLA class I antibody could be produced in spite of using the filer for removing leukocytes, and may take part in the induction of IHTR. Further, blood products should be transfused soon after completing a crossmatch test in patients with anti-RBC alloantibodies. 相似文献
33.
Kawashita M Shineha R Kim HM Kokubo T Inoue Y Araki N Nagata Y Hiraoka M Sawada Y 《Biomaterials》2003,24(17):2955-2963
Radiotherapy is one of the most effective treatments for cancers. However, external irradiation provides only small doses to deep-seated cancers, and often causes damage to healthy tissues. It has been reported that 20-30 microm diameter 17Y(2)O(3)-19Al(2)O(3)-64SiO(2) (mol%) glass microspheres are useful for the in situ irradiation of cancers. Yttrium-89 (89Y) in this glass can be neutron bombarded to form the beta-emitter 90Y (half-life=64.1h). When injected in the vicinity of the cancer, such activated glass microspheres can provide a large localized dose of beta-radiation. The Y(2)O(3) content of the glass in the microspheres is limited to only 17 mol%. Chemically durable microspheres with a higher Y(2)O(3) content need to be developed. Phosphorus-31 (31P) with 100% natural abundance can also be activated by neutron bombardment to form the beta-emitter 32P (half-life=14.3d). Chemically durable microspheres containing a high phosphorus content are expected to be more effective for cancer treatment. We prepared pure Y(2)O(3) and YPO(4) microspheres using a high-frequency induction thermal plasma melting technique, and investigated the resulting structure and chemical durability. We successfully prepared smooth, highly spherical polycrystalline Y(2)O(3) and YPO(4) microspheres with diameters in the range 20-30 microm. Both the Y(2)O(3) and YPO(4) microspheres showed high chemical durability in saline solutions buffered at pH=6 and 7. These microspheres are expected to be more effective than the conventional glass microspheres for the in situ radiotherapy of cancer. 相似文献
34.
Cytologic examination of 3H-thymidine-labeled mesothelial cells in the pleural fluid revealed that single and small-sized cells with slight basophilic cytoplasm scarcely stainable by PAS and colloidal iron are in the DNA-synthetic phase and that these are exfoliating cells from the pleural surface. While abnormal labeling in a few arranged and binuclear cells suggesting accelerated or disturbed mesothelial mobilization was frequently found in congestive cardiac failure, liver cirrhosis, and uremia, it never occurred in single and large-sized activated cells possessing rich PAS-positive granules, cells in large clusters or sheet-like arrangements, or multinuclear giant cells. Transmission electron microscopical observation of these labeled cells proved that a smooth cellular surface and scant intracytoplasmic organelles, by which undifferentiated cells are generally characterized, are essential for DNA-synthesizing mesothelial cells. Probably as a result of some pleural irritation, surface lining cells immediately enter the cell cycle and at once revert to an undifferentiated form capable of DNA synthesis, after which they may be released as a single form, and differentiate and transform into mature, activated cells with a bleb-like surface structure or microvilli, and finally may proliferate in the fluid. ACTA PATHOL. JPN. 36: 1279–1296, 1986. 相似文献
35.
61 patients suffering from chronic pancreatitis were studied in order to clarify the psychosomatic aspects of this disease. They were classified into 5 types, out of which 3 types were examined in detail according to their personality traits and life habits. It was found that the mind-body relationship took the primary form in the psychosomatic and neurotic types, while in the organic type it took the secondary form such as distorted life habits. This finding indicated that the distortion in the personality structure and that of life habits were closely interrelated. The authors also discussed the clinical features of chronic pancreatitis from the standpoint of alexithymia. The patients with the organic type were most alexithymic, which were followed by the psychosomatic type. It was learned that alexithymic problems were reflected in the patients' life habits. 相似文献
36.
BACKGROUND: Japanese cedar pollinosis is an important allergic rhinoconjunctivitis in Japan in spring. We investigated the relationship between the amount of pollen in the air and the prevalence of the disease and sensitization to Japanese cedar pollen in this ecological study. METHODS: The IgE antibody to Japanese cedar pollen (JCP-IgE) was determined in human serum and rhinoconjunctival symptoms were surveyed in 407-510 children in May or June every year from 1995 to 2001. Japanese cedar pollinosis was defined as being JCP-IgE >or=1.5 IU/ml and having any rhinoconjunctival symptom lasting 3 weeks or longer in March or April. RESULTS: Prevalence rates of Japanese cedar pollinosis were 13.8-22.9%. Prevalence rates of being JCP-IgE >or=1.5 IU/ml were 39.0-50.1%, and those of being JCP-IgE >or=15.01 IU/ml were 11.4-23.2%. All prevalence rates were significantly related to the amount of pollen in the air. The proportion of subjects with rhinoconjunctival symptoms was relatively constant in each stratum of low JCP-IgE levels (<0.35, 1.50-2.99, 3.0-14.9 IU/ml). CONCLUSION: High exposure to Japanese cedar pollen was associated with higher levels of JCP-IgE antibody and a high prevalence of Japanese cedar pollinosis. The relationship between the level of JCP-IgE and the proportion of subjects with symptoms was relatively constant. 相似文献
37.
An SH2-domain-containing kinase negatively regulates the phosphatidylinositol-3 kinase pathway 总被引:1,自引:0,他引:1 下载免费PDF全文
Moniakis J Funamoto S Fukuzawa M Meisenhelder J Araki T Abe T Meili R Hunter T Williams J Firtel RA 《Genes & development》2001,15(6):687-698
SHK1 is a novel dual-specificity kinase that contains an SH2 domain in its C-terminal region. We demonstrate that SHK1 is required for proper chemotaxis and phagocytosis. Mutant shk1 null cells lack polarity, move very slowly, and exhibit an elevated and temporally extended chemoattractant-mediated activation of the kinase Akt/PKB. GFP fusions of the PH domain of Akt/PKB or the PH-domain-containing protein CRAC, which become transiently associated with the plasma membrane after a global stimulation with a chemoattractant, remain associated with the plasma membrane for an extended period of time in shk1 null cells. These results suggest that SHK1 is a negative regulator of the PI3K (phosphatidylinositol-3 kinase) pathway. Furthermore, when a chemoattractant gradient is applied to a wild-type cell, these PH-domain-containing proteins and the F-actin-binding protein coronin localize to its leading edge, but in an shk1 null cell they become randomly associated with the plasma membrane and cortex, irrespective of the direction of the chemoattractant gradient, suggesting that SHK1 is required for the proper spatiotemporal control of F-actin levels in chemotaxing cells. Consistent with such functions, SHK1 is localized at the plasma membrane/cortex, and we show that its SH2 domain is required for this localization and the proper function of SHK1. 相似文献
38.
Frequency-coded impulses are known to be converted into postsynaptic potentials (PSPs) at the synapse of a target neuron. This can be termed frequency-voltage (F-V) conversion. Studies on this problem in pyramidal tract neurons (PTNs) showed that not only the amplitude but also the duration of depolarizing PSPs was determined as a function of the input impulse frequency. Two opposite patterns of F-V conversion were observed following activation of two input systems to PTNs. Inhibitory postsynaptic potentials were found to play an important role in the regulation of the duration of PSPs by curtailing excitatory post-synaptic potentials. 相似文献
39.
Takasago T Goto Y Hata K Saeki A Nishioka T Taylor TW Iribe G Mohri S Shimizu J Araki J Suga H 《The Japanese journal of physiology》2000,50(2):257-265
Caffeine causes a considerable O(2) waste for positive inotropism in myocardium by complex pharmacological mechanisms. However, no quantitative study has yet characterized the mechanoenergetics of caffeine, particularly its O(2) cost of contractility in the E(max)-PVA-VO(2) framework. Here, E(max) is an index of ventricular contractility, PVA is a measure of total mechanical energy generated by ventricular contraction, and VO(2) is O(2) consumption of ventricular contraction. The E(max)-PVA-VO(2) framework proved to be powerful in cardiac mechanoenergetics. We therefore studied the effects of intracoronary caffeine at concentrations lower than 1 mmol/l on left ventricular (LV) E(max) and VO(2) for excitation-contraction (E-C) coupling in the excised cross-circulated canine heart. We enhanced LV E(max) by intracoronary infusion of caffeine after beta-blockade with propranolol and compared this effect with that of calcium. We obtained the relation between LV VO(2) and PVA with E(max) as a parameter. We then calculated the VO(2) for the E-C coupling by subtracting VO(2) under KCl arrest from the PVA-independent (or zero-PVA) VO(2) and the O(2) cost of E(max) as the slope of the E-C coupling VO(2)-E(max) relation. We found that this cost was 40% greater on average for caffeine than for calcium. This result, for the first time, characterized integratively cardiac mechanoenergetics of the O(2) wasting effect of the complex inotropic mechanisms of intracoronary caffeine at concentrations lower than 1 mmol/l in a beating whole heart. 相似文献
40.