全文获取类型
收费全文 | 8149篇 |
免费 | 340篇 |
国内免费 | 39篇 |
专业分类
耳鼻咽喉 | 80篇 |
儿科学 | 212篇 |
妇产科学 | 109篇 |
基础医学 | 1207篇 |
口腔科学 | 191篇 |
临床医学 | 435篇 |
内科学 | 2344篇 |
皮肤病学 | 148篇 |
神经病学 | 495篇 |
特种医学 | 282篇 |
外科学 | 1234篇 |
综合类 | 32篇 |
一般理论 | 1篇 |
预防医学 | 188篇 |
眼科学 | 96篇 |
药学 | 519篇 |
中国医学 | 23篇 |
肿瘤学 | 932篇 |
出版年
2023年 | 35篇 |
2022年 | 66篇 |
2021年 | 126篇 |
2020年 | 89篇 |
2019年 | 119篇 |
2018年 | 114篇 |
2017年 | 113篇 |
2016年 | 139篇 |
2015年 | 130篇 |
2014年 | 214篇 |
2013年 | 298篇 |
2012年 | 490篇 |
2011年 | 530篇 |
2010年 | 285篇 |
2009年 | 254篇 |
2008年 | 499篇 |
2007年 | 568篇 |
2006年 | 599篇 |
2005年 | 597篇 |
2004年 | 543篇 |
2003年 | 498篇 |
2002年 | 488篇 |
2001年 | 101篇 |
2000年 | 88篇 |
1999年 | 112篇 |
1998年 | 160篇 |
1997年 | 112篇 |
1996年 | 99篇 |
1995年 | 80篇 |
1994年 | 69篇 |
1993年 | 74篇 |
1992年 | 61篇 |
1991年 | 71篇 |
1990年 | 59篇 |
1989年 | 60篇 |
1988年 | 44篇 |
1987年 | 45篇 |
1986年 | 33篇 |
1985年 | 39篇 |
1984年 | 40篇 |
1983年 | 33篇 |
1982年 | 29篇 |
1981年 | 37篇 |
1980年 | 38篇 |
1979年 | 21篇 |
1978年 | 21篇 |
1977年 | 21篇 |
1975年 | 21篇 |
1973年 | 22篇 |
1968年 | 17篇 |
排序方式: 共有8528条查询结果,搜索用时 15 毫秒
1.
Shigeko Tanaka Minoru Yoshiyama Yukihiro Imanishi Koichi Nakahira Takashi Hanaki Yukari Naito Mizue Imai Masahiro Tanaka 《Magnetic resonance in medical sciences》2006,5(4):207-210
One diagnostic criterion for metabolic syndrome is obesity from the accumulation of visceral fat; others include abdominal circumference and area of visceral fat as measured by computed tomography (CT) at the umbilical level. We evaluated visceral fat using frequency-selective excitation magnetic resonance (MR) imaging SPAIR (spectral attenuation with inversion recovery) water suppression THRIVE (3D T1-high resolution isotropic volume examination). Fifty of 70 slices with 2-mm interval were used to render and measure volume of visceral fat ranging within 10 cm of the umbilicus; the area of visceral fat at the umbilical level was also measured. Imaging was completed using breath hold within 14 s. Image processing was easier than using CT. 相似文献
2.
Takayuki Sakurai Satoshi Watanabe Minoru Kimura Masahiro Sato 《Reproductive Medicine and Biology》2006,5(1):43-50
Background and Aims: The aim of this study was to determine which mouse strains exhibit tolerance to cooling when fertilized oocytes have been stored at 4°C.
Methods: In-vitro -fertilization-derived oocytes of eight mouse strains were incubated at 4°C in 20 mmol/L Hepes-potassium modified simplex optimized medium (KSOM) medium for 0, 24, 48, 60 or 72 h, and then returned to normal culture conditions at 37°C in KSOM medium. The rates of development of cultured oocytes into blastocysts and cell numbers of blastocysts were examined. In some cases, a Comet assay was carried out to evaluate DNA damage. In addition, the effects of β-mercaptoethanol on the development of the 4°C-treated oocytes were assessed.
Results: Of the eight strains tested, BDF1, B6C3F1 and FVB/N strains exhibited relatively higher degrees of tolerance to 4°C treatment and approximately 90%, 83% and 78% of oocytes treated at 4°C for 48 h developed to morphologically normal blastocysts, respectively. Comet assay revealed no clear DNA damage in oocytes treated at 4°C. Treatment with β-mercaptoethanol failed to improve the in vitro survival rate of low-temperature-treated oocytes.
Conclusion: Strain differences were observed in tolerance to cooling treatment when fertilized oocytes were temporarily treated with 4°C, although the reasons for this remain unclear. (Reprod Med Biol 2006; 5 : 43–50) 相似文献
Methods: In-vitro -fertilization-derived oocytes of eight mouse strains were incubated at 4°C in 20 mmol/L Hepes-potassium modified simplex optimized medium (KSOM) medium for 0, 24, 48, 60 or 72 h, and then returned to normal culture conditions at 37°C in KSOM medium. The rates of development of cultured oocytes into blastocysts and cell numbers of blastocysts were examined. In some cases, a Comet assay was carried out to evaluate DNA damage. In addition, the effects of β-mercaptoethanol on the development of the 4°C-treated oocytes were assessed.
Results: Of the eight strains tested, BDF1, B6C3F1 and FVB/N strains exhibited relatively higher degrees of tolerance to 4°C treatment and approximately 90%, 83% and 78% of oocytes treated at 4°C for 48 h developed to morphologically normal blastocysts, respectively. Comet assay revealed no clear DNA damage in oocytes treated at 4°C. Treatment with β-mercaptoethanol failed to improve the in vitro survival rate of low-temperature-treated oocytes.
Conclusion: Strain differences were observed in tolerance to cooling treatment when fertilized oocytes were temporarily treated with 4°C, although the reasons for this remain unclear. (Reprod Med Biol 2006; 5 : 43–50) 相似文献
3.
Sachiko Goto Akiyoshi Tsuji Teiko Murai Minoru Nishida Hiroko Tsukano Haruo Watanabe 《Journal of infection and chemotherapy》1998,4(1):16-19
Although there are effective antibacterial agents against plague, newer antibacterial agents have been developed which show
more potent activity against other bacterial organisms, but have not been tested againstYersinia pestis. A strain ofYersinia pestis was selected (no. 22; National Institute of Infectious Diseases, Tokyo, Japan) that caused a systemic infection in mice.Y. pestis no. 22 was intraperitoneally inoculated into DDY-strain mice, and 13 oral or 6 injectable antibacterial drugs given to the
infected mice at varying doses 1 and 24 hours after infection. Levofloxacin, sparfloxacin and ofloxacin were the most effective
oral agents against the infection, and prulifloxacin and pazufloxacin were also effective but to a lesser extent. Also, gentamicin
and arbekacin were the most potent injectable antibacterial agents againstY. pestis. These results suggest that there are several new drugs, both oral and injectable, which exert excellent in vivo antibacterial
activity against a mouse infection model and may be useful for the clinical treatment of plague. 相似文献
4.
Masao Amari Katsuji Taguchi Minoru Iwahara K Shibuya Shiro Naoe 《Medical Electron Microscopy》2002,35(4):225-233
To elucidate the effect of fibroblast growth factor on the phenotypical conversion of fibroblasts to mesothelial cells, both immunohistochemical and ultrastructural examinations were carried out on cultured spheroids that were composed of fibroblasts obtained from the parietal pleura of rats with and without addition of antifibroblast growth factor receptor antibody. In the present study, antifibroblast growth factor receptor antibody was employed to block the effect of the autocrine component of fibroblast growth factor in the culture medium. Phenotypical conversion from fibroblast to mesothelial cells was clearly blocked in the experimental group, to which culture medium had been added with antifibroblast growth factor receptor antibody, whereas the control group, cultured without addition of antifibroblast growth factor receptor antibody, showed phenotypical conversion of fibroblasts that was confirmed by the development of macula adherens, microvilli, and positive expression of cytokeratin. These results indicate the possibility that fibroblast growth factor plays a key role in the process of phenotypic conversion of fibroblasts to regenerated mesothelial cells. 相似文献
5.
Changes in central dopaminergic systems with the expression of Shh or GDNF in mice perinatally exposed to bisphenol-A. 总被引:1,自引:0,他引:1
Kazuya Miyagawa Minoru Narita Michiko Narita Keiichi Niikura Hisahiko Akama Yuri Tsurukawa Tsutomu Suzuki 《Nihon shinkei seishin yakurigaku zasshi》2007,27(2):69-75
In the previous study, we reported that exposure to bisphenol-A induced the potentiation of dopamine receptor functions in the mouse limbic area, resulting in supersensitivity to methamphetamine-induced pharmacological actions. The present study was undertaken to investigate whether prenatal exposure to bisphenol-A could produce morphological change in dopaminergic neuron and the pattern of expression of genes regulating the dopaminergic neuron development. Here we found that prenatal and neonatal exposures to bisphenol-A increased the tyrosine hydroxylase- and dopamine transporter-like immunoreactivities in the adult mouse limbic area. The present molecular biological study shows that chronic bisphenol-A treatment produced a significant decrease in the dopaminergic neuron development factors, sonic hedgehog and glial cell line-derived neurotrophic factor, which were also decreased by prenatal exposure to bisphenol-A. These results suggest that chronic exposure to bisphenol-A could disrupt the dopaminergic neurotransmission in the process of dopaminergic neuron development. 相似文献
6.
Kentaroh Miyoshi Minoru Naito Tsuyoshi Ueno Shinji Hato Hideo Ino 《General thoracic and cardiovascular surgery》2009,57(11):629-632
A benign esophageal leiomyoma with abnormally increased fluorine-18-fluorodeoxyglucose uptake on positron emission tomography
(PET) was resected thoracoscopically. The tumor, of which the maximum standardized uptake value of the lesion was 4.7, was
well defined and 38 mm in diameter. Neither mitotic activity nor degeneration was found histologically; and immunoreactivity
for CD34, CD117, MIB-1, and glucose transporter-1 was negative immunohistochemically. A diagnosis of gastrointestinal stromal
tumor was ruled out by an oncogenic kinase gene mutation study. This case cautions against PET-dependent evaluation for malignant
potential of esophageal submucosal tumors. 相似文献
7.
8.
Hirofumi Tomiyama Jiko Yamada Yutaka Koji Minoru Yambe Kohki Motobe Kazuki Shiina Yoshio Yamamoto Akira Yamashina 《Hypertension research》2007,30(5):417-426
This observational study of Japanese men without metabolic syndrome (MetS) (age: 41+/-8 years) was conducted to clarify whether or not heart rate elevation precedes the development of full-blown MetS. MetS was defined based on two modifications of the criteria of the Japanese Expert Committee on the Diagnosis and Classification of Metabolic Syndrome. Premetabolic syndrome subjects were defined as those having one component of MetS with increased body mass index (BMI). Among the subjects without MetS (n=1,859 when the BMI criterion was >or=25 and n=2,020 when the BMI criterion was >or=27.5), the incidence of progression to full-blown MetS by the time of the second examination at the end of the 3-year study period was higher in the subjects with premetabolic syndrome than in those without it. The receiver-operator characteristic curve analysis and binary logistic regression analysis revealed that the odds ratio (OR) of a heart rate >or=69 beats/min at the first examination for progression to full-blown MetS by the time of the second examination was significant in subjects with premetabolic syndrome (BMI>or=25: OR=3.64 [1.22-10.88]; BMI>or=27.5: OR=3.67 [1.28-10.55]; p<0.05). Thus, heart rate elevation appears to precede the development of full-blown MetS in subjects with premetabolic syndrome. Heart rate seems to be a simple and useful marker for predicting the progression to full-blown MetS of middle-aged Japanese men with premetabolic syndrome. 相似文献
9.
Ryotaro Wake Masaaki Takeuchi Junichi Yoshikawa Minoru Yoshiyama 《Circulation journal》2007,71(7):1060-1066
BACKGROUND: Gender differences in the predictors of outcome among patients with known or suspected coronary artery disease (CAD) undergoing contrast-enhanced dobutamine stress echocardiography (CE-DSE) have not been completely determined. METHODS AND RESULTS: Follow-up (30+/-17 months) data for 581 men and 309 women with known or suspected CAD who underwent CE-DSE (mean age: 66 years) were obtained. Hard cardiac events included cardiac death and nonfatal myocardial infarction. Total cardiac events included hard cardiac events, unstable angina, congestive heart failure, and late revascularization (>3 months). Cardiac events occurred in 123 male and 50 female patients. Positive results for CE-DSE were associated with worse prognosis in both men and women (2-year total event free rate: 73.5% vs 88.2% in men, p<0.0001, 80.3% vs 91.3% in women, p<0.01). Addition of CE-DSE results, including abnormal left ventricular end-systolic volume response and left ventricular ejection fraction at peak stress <50%, to the clinical and rest echocardiography model provided incremental information for predicting total cardiac events (increase in chi-square value for the model from 60 to 72, p<0.001) in men and (increase in chi-square value for the model from 17 to 32, p<0.001) in women. CONCLUSIONS: CE-DSE provides incremental information for predicting future cardiac events in both men and women. 相似文献
10.
Yoshinori Itoh Yutaka Kohgo Naoki Watanabe Yuji Kanisawa Sumio Sakamaki Minoru Takahashi Yasuo Hirayama Hiroyuki Ono Takeshi Himeno Yoshiro Niitsu 《Cancer science》1991,82(11):1203-1206
Human tumor–infiltrating lymphocytes (TILs) derived from pleural or ascitic fluid were incubated with recombinant interleukin 2 and transfected with human tumor necrosis factor (TNF) a gene by the lipofection procedure. The resulting TILs secreted significant amounts of TNF in the culture supernatant and exhibited cytotoxicity against established cell lines, such as K562 and Daudi, and autologous tumor cells. The TNF gene–transfected TILs exhibited an augmented killing of autologous tumor cells. 相似文献