全文获取类型
收费全文 | 66342篇 |
免费 | 4014篇 |
国内免费 | 638篇 |
专业分类
耳鼻咽喉 | 1224篇 |
儿科学 | 787篇 |
妇产科学 | 947篇 |
基础医学 | 10947篇 |
口腔科学 | 1720篇 |
临床医学 | 5630篇 |
内科学 | 12437篇 |
皮肤病学 | 2456篇 |
神经病学 | 5062篇 |
特种医学 | 4232篇 |
外国民族医学 | 1篇 |
外科学 | 8448篇 |
综合类 | 348篇 |
现状与发展 | 4篇 |
一般理论 | 23篇 |
预防医学 | 2949篇 |
眼科学 | 1357篇 |
药学 | 6261篇 |
中国医学 | 852篇 |
肿瘤学 | 5309篇 |
出版年
2023年 | 488篇 |
2022年 | 1562篇 |
2021年 | 2504篇 |
2020年 | 1187篇 |
2019年 | 1703篇 |
2018年 | 2024篇 |
2017年 | 1638篇 |
2016年 | 2378篇 |
2015年 | 3207篇 |
2014年 | 3601篇 |
2013年 | 4128篇 |
2012年 | 6175篇 |
2011年 | 5833篇 |
2010年 | 3409篇 |
2009年 | 2897篇 |
2008年 | 3969篇 |
2007年 | 3652篇 |
2006年 | 3213篇 |
2005年 | 2904篇 |
2004年 | 2359篇 |
2003年 | 2084篇 |
2002年 | 1772篇 |
2001年 | 1385篇 |
2000年 | 1251篇 |
1999年 | 937篇 |
1998年 | 391篇 |
1997年 | 285篇 |
1996年 | 221篇 |
1995年 | 173篇 |
1994年 | 180篇 |
1993年 | 164篇 |
1992年 | 285篇 |
1991年 | 314篇 |
1990年 | 305篇 |
1989年 | 263篇 |
1988年 | 230篇 |
1987年 | 215篇 |
1986年 | 187篇 |
1985年 | 141篇 |
1984年 | 94篇 |
1983年 | 85篇 |
1982年 | 59篇 |
1981年 | 73篇 |
1979年 | 90篇 |
1978年 | 68篇 |
1977年 | 58篇 |
1975年 | 79篇 |
1972年 | 56篇 |
1971年 | 66篇 |
1970年 | 62篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
In contrast to other types of congenital heart defects, the treatment of hypoplastic left heart syndrome (HLHS) has become comparably successful only within the last decade. Postnatal management of circulatory disturbances of HLHS was previously often performed, similarly to other types of neonatal shock, without considering the peculiarities of postnatal hemodynamics. It is of overwhelming importance to limit pulmonary hyperperfusion by reducing systemic afterload and avoiding artificial respiration. The invention of selective hypothermic cerebral perfusion using the modified Blalock-Taussig shunt has decreased the need for long circulatory arrest times involving the brain, and promises a better neurological outcome. Postoperatively, sophisticated hemodynamic monitoring is mandatory to provide sufficient systemic oxygen delivery. α-blockers are usually given for strong afterload reduction. Hospital mortality is as low as 10–15% in centers experienced with the Norwood operation. The next surgical steps to create a serial systemic and pulmonary circulation involve superior cavopulmonary anastomosis performed as early as possible (4–6 months) and finally total cavopulmonary connection at an age of 3–4 years. 相似文献
82.
3-Monochloro-1,2-propanediol (MCPD) is a well-known by-product of acid-hydrolyzed soy sauce during its manufacturing process. MCPD has been reported genotoxic in vitro, and reproductive toxicity and carcinogenicity in rats. To evaluate the immunomodulatory effect of MCPD on murine splenocyte and macrophage in vitro, we investigated splenocyte blastogenesis by concanavalin A (Con A), anti-CD3, and lipopolyssacharide (LPS), the production of cytokines from splenocyte, and the activity of mouse peritoneal macrophages. There was a significant decrease in lymphocyte blastogenesis to Con A or anti-CD3 at subtoxic dose of MCPD. A significant decrease in splenocyte blastogenesis to LPS was also observed. The production level of interferon (IFN)-gamma on splenocyte culture with Con A was significantly reduced at the higher concentration than 1.0mM of MCPD. The levels of interleukin (IL)-4 and IL-10 were also decreased at high concentrations of MCPD. There was a significant decrease in production of nitric oxide (NO) by peritoneal macrophages treated with MCPD. MCPD also inhibits tumor necrosis factor (TNF)-alpha production of stimulated macrophages. These results indicate that MCPD might be able to reduce the functionality of lymphocytes and peritoneal macrophages in vitro. 相似文献
83.
E Jung H-S Won S-K Kim J-Y Shim P R Lee A Kim J K Kim 《Ultrasound in obstetrics & gynecology》2006,27(5):562-565
Fetal thrombosis of the dural sinus is an extremely rare congenital cerebrovascular condition that is potentially fatal. We report a case of dural sinus thrombosis diagnosed by prenatal ultrasonography and fetal magnetic resonance imaging (MRI) in the second trimester. The thrombosis showed partial resolution during pregnancy and resolved spontaneously after birth without neurological complications. This is the first report of spontaneous postnatal resolution, and may provide helpful information on the natural history and prenatal counseling of fetal thrombosis of the dural sinus. 相似文献
84.
Soo Jeong Lim Jin Chul Paeng Sung Jin Kim Sang Yoon Kim Heuiran Lee Dae Hyuk Moon 《Journal of nuclear medicine》2007,48(3):398-404
Increased expression of the sodium iodide symporter (NIS) is required for effective radioiodine treatment and reporter gene imaging of breast cancer. We investigated the effect of retinoic acid on adenovirus-mediated expression of the human NIS gene in the MCF-7 breast cancer cell line. METHODS: The MCF-7 cell line was infected with recombinant adenovirus carrying the human NIS gene (Rad-NIS). Levels of NIS messenger RNA (mRNA) and protein expression and radioiodine ((125)I) uptake were measured to evaluate adenovirus-mediated NIS gene expression in wild-type and Rad-NIS-infected MCF-7 cells after treatment with all-trans-retinoic acid (ATRA; 10(-8)-10(-6) mol/L). RESULTS: The transduction efficiency of adenovirus in MCF-7 cells at a multiplicity of infection (MOI) of 50 was >60%. After incubation with 10(-6) mol/L ATRA, the mRNA level in Rad-NIS-infected MCF-7 cells increased to 118.5 times that of wild-type MCF-7 cells, whereas the mRNA level in wild-type MCF-7 cells showed only a 2.1-fold increase. Western blot, immunocytochemical staining, and flow cytometry analyses showed that NIS protein expression in MCF-7 cells infected with Rad-NIS increased after ATRA treatment. With ATRA treatment, the amount of (125)I uptake increased in a dose-dependent manner (P < 0.001). The (125)I uptake in wild-type MCF-7 cells increased 3.1-, 5.5-, and 7.6-fold with treatment with 10(-8), 10(-7), and 10(-6) mol/L ATRA, respectively. Rad-NIS-infected cells showed a 4.0-fold increase in (125)I uptake. Treatment of Rad-NIS-infected cells with 10(-8), 10(-7), and 10(-6) mol/L ATRA increased (125)I uptake by 4.9-, 8.2-, and 27.6-fold, respectively, compared with wild-type MCF-7 cells. The level of NIS expression in Rad-NIS-infected MCF-7 cells treated with 10(-6) mol/L ATRA (245.0 +/- 13.7 pmol/10(6) cells) was much greater than the sum of the expression levels seen in ATRA-treated wild-type cells and Rad-NIS-infected wild-type cells. CONCLUSION: Retinoic acid increases adenovirus-mediated NIS expression in MCF-7 cells. Our results indicate that improved efficiency of NIS gene therapy or reporter imaging in breast cancer may be possible with retinoic acid treatment. 相似文献
85.
Jun-Seok Lee Byung-Hwan Yang Jang-Han Lee Jun-Ho Choi Ihn-Geun Choi Sae-Byul Kim 《Clinical neurophysiology》2007,118(11):2489-2496
OBJECTIVE: Recent findings have demonstrated that the EEG possesses long-range temporal (auto-) correlations (LRTC) in the dynamics of broad band oscillations. The analysis of LRTC provides a quantitative index of statistical dependencies in oscillations on different time scales. We analyzed LRTC in resting EEG signals in depressed outpatients and healthy controls. METHODS: The participants in this study were 11 non-depressed, age-matched controls, and 11 unmedicated unipolar depressed patients. EEG data were obtained from each participant during 5-min resting baseline periods with eyes closed and then analyzed with detrended fluctuation analysis (DFA), a scaling analysis method that quantifies a simple parameter to represent the correlation properties of a time series. The scaling exponent, the result of DFA, provides a quantitative measure of LRTC from the EEG. RESULTS: The present study demonstrates that all the scaling exponents in depressed patients and healthy controls were greater than 0.5 and less than 1.0, regardless of condition. Furthermore, the scaling exponents of depressed patients have relatively higher values in whole brain regions compared to healthy controls, with significant differences at F3, C3, T3, T4 and O1 channels (p<0.05). Finally, a significant linear correlation was observed between the severity of depression and the scaling exponent over most of the channels, except O2. CONCLUSIONS: These results suggest that the brain affected by a major depressive disorder shows slower decay of the LRTC, and that the persistence of the LRTC of EEG in depressed patients was associated with the severity of depression over most of the cortical areas. SIGNIFICANCE: The DFA method may broaden our understanding of the psychophysiological basis of depression. 相似文献
86.
87.
A. Mori S. Urabe M. Asada Y. Tanaka H. Tazaki I. Yamamoto N. Kimura T. Ozawa S. T. Morris R. Hickson P. R. Kenyon H. Blair C. B. Choi T. Arai 《Transboundary and Emerging Diseases》2007,54(7):342-345
Concentrations of metabolites and immunoreactive insulin (IRI) and activities of enzymes related to energy metabolism were measured in plasma of Korean and Japanese beef cattle, which were raised by the indoor feeding system programmed to feed larger amount of roughage in their growing periods and larger amount of concentrate diet in their finishing periods (Japanese feeding system), and grazing New Zealand beef cattle. By the Japanese beef grading system, Korean and Japanese beef cattle showed high beef quality score, average grade 3.3 and 3.6, respectively. The plasma free fatty acid and lactate concentrations and lactate dehydrogenase (LDH), malate dehydrogenase (MDH) and aspartate aminotransferase (AST) activities in Korean beef cattle were significantly higher than those in Japanese beef cattle. The plasma lactate concentration in Korean beef cattle was 8.40 mmol/l, which was similar to the values observed in lactic acidosis. The higher activities of plasma LDH, MDH and AST may indicate slight liver damage by slightly acidotic conditions in Korean beef cattle. New Zealand beef cattle fed on pasture which they harvest by grazing showed significantly lower plasma glucose, cholesterol, lactate and IRI concentrations and enzyme activities than those in Korean and Japanese beef cattle fed on larger amount of concentrate diets. Plasma metabolite concentrations and energy metabolism‐related enzyme activities may be good indicators for evaluating metabolic conditions of beef cattle raised by different feeding systems. 相似文献
88.
89.
Marcelo Miranda MD Claudia Castiglioni MD Beat M. Frey MD Martin Hergersberg PhD Adrian Danek MD Hans H. Jung MD 《Movement disorders》2007,22(9):1358-1361
The X‐linked McLeod neuroacanthocytosis syndrome strongly resembles Huntington's disease and has been reported in various countries world‐wide. Herein, we report two Chilean brothers with predominant psychiatric features at disease onset including schizophrenia‐like psychosis and obsessive compulsive disorder. Molecular genetic analysis revealed a small deletion in the XK gene (938‐942delCTCTA), which has been already described in a North American patient of Anglo‐Saxon descent and a Japanese family, presenting with seizures, muscle atrophy or chorea yet absence of psychiatric features. These findings argue against a founder effect and indicate a profound phenotypic variability associated with the 938‐942delCTCTA deletion. Our report supports the inclusion of McLeod syndrome in the differential diagnosis of Huntington's disease as well as acute psychosis in male subjects. © 2007 Movement Disorder Society 相似文献
90.
Bum Soon Choi Mi Jung Shin Suk Joon Shin Young Soo Kim Yeong Jin Choi Yong-Soo Kim In Sung Moon Suk Young Kim Yong Bok Koh Byung Kee Bang Chul Woo Yang 《American journal of transplantation》2005,5(6):1354-1360
We report here our 10-year experience of a biopsy performed at day 14 after transplantation in 304 patients with stable graft function. The factors that may have influenced subclinical rejection were analyzed according to histology. The incidence of subclinical rejection was 13.2%. Addition of mycophenolate mofetile (MMF) as a primary immunosuppressant significantly decreased the incidence of subclinical rejection compared with patients without such treatment (odds ratio, 0.23; p < 0.05). On the other hand, HLA-DR antigen mismatch (odds ratio, 2.39) and unrelated donor (odds ratio, 2.10) were also significantly associated with decreased subclinical rejection (p < 0.05). The incidence of acute rejection in patients with normal findings was lower than in those with borderline changes or subclinical rejection (0.23 +/- 0.05 vs. 0.48 +/- 0.07 and 0.60 +/- 0.11, respectively; p < 0.05). The graft survival rates in patients with subclinical rejection were lower than in patients with normal or borderline changes at 1 (88.4% vs. 97.9% and 99.1%; p < 0.05), 5 (77.8% vs. 96.2% and 95.9%; p < 0.05) and 10 (62.3% vs. 96.2% and 93.7%; p < 0.05) years. Thus, a protocol biopsy performed on day 14 after transplantation is useful for predicting graft survival. Triple therapy including MMF, related donor and HLA-DR antigen match are important factors for reducing subclinical rejection in living-donor renal transplantation. 相似文献