全文获取类型
收费全文 | 6937篇 |
免费 | 382篇 |
国内免费 | 50篇 |
专业分类
耳鼻咽喉 | 114篇 |
儿科学 | 164篇 |
妇产科学 | 136篇 |
基础医学 | 857篇 |
口腔科学 | 214篇 |
临床医学 | 444篇 |
内科学 | 1719篇 |
皮肤病学 | 163篇 |
神经病学 | 536篇 |
特种医学 | 334篇 |
外科学 | 899篇 |
综合类 | 20篇 |
一般理论 | 1篇 |
预防医学 | 365篇 |
眼科学 | 151篇 |
药学 | 489篇 |
中国医学 | 15篇 |
肿瘤学 | 748篇 |
出版年
2023年 | 57篇 |
2022年 | 96篇 |
2021年 | 173篇 |
2020年 | 84篇 |
2019年 | 139篇 |
2018年 | 156篇 |
2017年 | 123篇 |
2016年 | 135篇 |
2015年 | 151篇 |
2014年 | 216篇 |
2013年 | 251篇 |
2012年 | 416篇 |
2011年 | 447篇 |
2010年 | 253篇 |
2009年 | 198篇 |
2008年 | 377篇 |
2007年 | 396篇 |
2006年 | 367篇 |
2005年 | 372篇 |
2004年 | 396篇 |
2003年 | 341篇 |
2002年 | 339篇 |
2001年 | 171篇 |
2000年 | 204篇 |
1999年 | 163篇 |
1998年 | 78篇 |
1997年 | 60篇 |
1996年 | 50篇 |
1995年 | 64篇 |
1994年 | 40篇 |
1993年 | 41篇 |
1992年 | 97篇 |
1991年 | 93篇 |
1990年 | 67篇 |
1989年 | 85篇 |
1988年 | 66篇 |
1987年 | 66篇 |
1986年 | 74篇 |
1985年 | 60篇 |
1984年 | 46篇 |
1983年 | 40篇 |
1982年 | 19篇 |
1979年 | 32篇 |
1978年 | 23篇 |
1977年 | 24篇 |
1976年 | 18篇 |
1975年 | 25篇 |
1974年 | 24篇 |
1973年 | 23篇 |
1972年 | 23篇 |
排序方式: 共有7369条查询结果,搜索用时 15 毫秒
1.
Shingo Hashimoto Masaki Katsurada Rie Muramatsu Kumiko Asai Kenichiro Tanaka Kensuke Hayashi Yoshiaki Kibe Koichiro Nakajima Yukiko Hattori Hiromitsu Iwata Jun-etsu Mizoe Hiroyuki Ogino Yuta Shibamoto 《Practical radiation oncology》2019,9(2):e149-e155
Purpose
Suppression of respiratory movement of the liver would be desirable for high-precision radiation therapy for liver tumors. We aimed to investigate the effect of our original device-free compressed shell fixation method and breathing instruction on suppression of respiratory movement. The characteristics of liver motion based on the movement of a fiducial marker were also analyzed.Methods and Materials
First, respiratory amplitudes of the liver with the device-free compressed shell were analyzed from the data of 146 patients. The effect of this shell fixing method on liver movement was evaluated. Second, as another cohort study with 166 patients, interfractional internal motion of the liver for patients fixed in the shell was calculated using the fiducial marker coordinate data of images for position setting before daily irradiation. Third, in another 12 patients, intrafractional internal motion was calculated from the fiducial marker coordinate data using x-ray images before and after irradiation.Results
The median respiratory movement without the shell, after fixing with the shell, and after instructing on the breathing method with the shell was 14.2 (interquartile range, 10.7-19.8), 11.5 (8.6-17.5), and 10.4 mm (7.3-15.8), respectively. Systematic and random errors of interfractional internal motion were all ≤2 mm in the left-right and anteroposterior directions and 3.7 and 3.0 mm, respectively, in the craniocaudal direction. Systematic and random errors of intrafractional internal motion were all ≤1.3 mm in the left-right and anteroposterior directions and 0.8 and 2.4 mm, respectively, in the craniocaudal direction.Conclusions
The device-free compressed shell fixation method was effective in suppressing the respiratory movement of the liver. Irradiation position matching using the fiducial marker can correct the interfractional internal motion on each day, which would contribute to the reduction of the margin to be given around the target. 相似文献2.
Takako Miyamae Masaaki Mori Yasuji Inamo Youichi Kohno Shuji Takei Motoharu Maeda Takuji Murata Shuji Nakata Hiroshi Kawai Yukiko Hirano Yukiji Date Katsuhiko Kitamura Shumpei Yokota 《Ryūmachi》2003,43(3):538-543
OBJECTIVES: To reveal the frequency and the clinical characteristics of dystrophic calcification that occurs in children with juvenile dermatomyositis, multi-center analysis was constructed. METHOD: Fifty children with JDM were enrolled, and 14 of them (28.0%) were complicated with calcinosis. Clinical symptoms and laboratory tests at onset, initial therapy and disease course were compared in children with and without calcinosis. RESULTS: The mean age of the onset of calcinosis was 4.78 +/- 3.33 years, and it was younger than those of children without calcinosis (8.66 +/- 3.85 years) (P = 0.0017). No differences of clinical manifestation except Gower's sign were observed. The frequency of positive anti-nuclear antibody was 7.1% in children with calcinosis and 52.9% without calcinosis (P = 0.0112). The initial therapy of methylprednisolon pulses gave no effects on prognosis of calcium deposition. The calcinosis appeared in 1.56 +/- 1.91 year after the onset of the disease. The various types of calcium deposition including large tumorous clumps, subcutaneous plaques or nodules, sheet-type calcification were deserved. They appeared over knee joints (64.3%), elbow joint (64.3%), and hip processes (50.0%). Calcinosis affecting the subcutaneous tissues frequently resulted in painful superficial ulceration of the overlying skin (42.9%), local infection (50.0%), and limitation of joint movement (14.3%). Although aluminum phosphate was effective in 2 children among 7, no other effective treatment was recommended. In 5 cases, surgical removal of tumorous clumps was operated. Thus, juvenile dermatomyositis is frequently complicated with calcinosis. This type of calcinosis was found to be unlikely to resolve completely, and resulted in severe disability in children. 相似文献
3.
Yukiko Kaizu Sakae Ohkawa Hiromichi Kumagai 《Nephrology, dialysis, transplantation》2002,17(3):442-448
BACKGROUND: Measurement of muscle mass is useful for evaluating protein nutritional status. Various methods for estimating muscle mass in haemodialysis patients have recently been developed. METHODS: The validity of the estimate of creatinine production calculated with the creatinine kinetic model (CKM) was examined in 46 haemodialysis patients by comparing it with the actual creatinine production, this being determined from the sum of creatinine appearing in the dialysate and the estimated metabolic degradation. The correlation of various other muscle mass indices with creatinine production was also investigated in these patients. RESULTS: The estimate of creatinine production using CKM was significantly correlated with creatinine production calculated from the spent dialysate plus an estimate for the extra-renal creatinine degradation (r=0.90, P<0.001). A Bland-Altman analysis revealed that the mean prediction error for the estimate of creatinine production by CKM was +0.10 g/day and the limits of agreement were +0.34 to -0.14 g/day. The cross-sectional area of the thigh muscle measured by computed tomography (CT) was also significantly correlated with creatinine production (r=-0.86, P<0.01). In contrast, the correlations of 3-methylhistidine production measured in the spent dialysate, the mid-upper arm muscle circumference and the skeletal muscle mass estimated by an anthropometric prediction model with creatinine production were lower (r<0.82). CONCLUSION: Creatinine production calculated using CKM and CT measurement of thigh muscle area are valid methods for estimating muscle mass during routine clinical examinations of haemodialysis patients. 相似文献
4.
Hideki Ioi Shunsuke Nakata Akihiko Nakasima Amy L Counts 《American journal of orthodontics and dentofacial orthopedics》2005,128(2):206-211
INTRODUCTION: Soft tissue analysis is a basic tool in planning orthodontic treatment. However, the components of a well-balanced Japanese facial profile have not yet been established. The purpose of this study was to assess the most-favored or most well-balanced profile from a series of facial silhouettes with varying anteroposterior lip positions by a group of Japanese orthodontists and a group of young adult Japanese dental students. METHODS: Average female and male profiles were constructed from the profiles of 30 Japanese men and women with normal occlusions. The lips in each average profile were protruded or retruded in 1-mm increments, and the 13 images were arranged with the average profile in the center. Forty two orthodontists and 42 dental students were asked to select the 3 most-favored, well-balanced profiles for each sex and rank them in order of preference. RESULTS: Both the orthodontists and the students preferred a profile with slightly retruded lips. The dental students favored a more retruded lip position for women. The least-favored profile was the most protrusive. CONCLUSIONS: These findings suggest that Japanese orthodontists and young adults prefer a retruded profile, even though Japanese profiles have historically been characterized by more convex facial features. 相似文献
5.
Ocular allergic reactions and inflammatory cascades in the eye involve various arachidonic acid metabolites. One such metabolite, leukotriene B4 (LTB4) was detected in bovine lenses after incubation in Tyrode's solution and analyzed by reverse phase and normal phase high-performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS). LTB4, a product of the lipoxygenase pathway has a chemotactic potency, and may play an important role in the inflammatory cascade. Our results demonstrate the capacity of the bovine lens to synthesize LTB4. It is possible that LTB4 synthesized in lenses under some conditions plays an important role in ocular inflammatory and allergic reactions. 相似文献
6.
Yukiko Hasuike Takeshi Nakanishi Rintarou Moriguchi Yoshinaga Otaki Masayoshi Nanami Yasue Hama Miki Naka Koji Miyagawa Masaaki Izumi Yoshihiro Takamitsu 《Nephrology, dialysis, transplantation》2004,19(6):1474-1479
BACKGROUND: Cyanide is a toxic agent, and its detoxification product, thiocyanate, may be a major pathogenetic substance in uraemia. Recent studies examining the myeloperoxidase(MPO)/thiocyanate system have suggested a link between thiocyanate and atherosclerosis. However, inaccuracies in conventional assays for cyanide and thiocyanate have limited the understanding of their metabolism in haemodialysis (HD) patients. METHODS: We used high-performance liquid chromatography to measure cyanide in erythrocytes and thiocyanate in plasma in 43 HD patients and in a group of 46 healthy controls that included 15 current smokers. To clarify the metabolic conversion of cyanide to thiocyanate in uraemic patients, we also measured cysteine and sulfate. We then used stepwise regression analysis to analyse factors that determine erythrocyte cyanide and plasma thiocyanate. RESULTS: Mean cyanide and thiocyanate were significantly greater in HD patients than in non-smoking controls. However, cyanide was far below lethal concentrations in dialysis patients. Thiocyanate was six to seven times greater in HD patients than in non-smoking controls, and decreases in thiocyanate following dialysis were only 19.3+/-3.5%. Multiple regression analysis showed a positive correlation between cyanide and thiocyanate in controls, but a negative correlation in HD patients. In patients, an inverse relationship between thiocyanate and BUN was also observed. CONCLUSIONS: The elevation of thiocyanate in patients undergoing dialysis probably is secondary to both limited efficiency of HD and deranged metabolism of cyanide and thiocyanate. Because thiocyanate is a preferred substrate for MPO, it may play a role in uraemic complications including cardiovascular events. 相似文献
7.
Yu-Yan Fan Ryoko Baba Yukiko Nagai Akira Miyatake Naohisa Hosomi Shoji Kimura Guang-Ping Sun Masakazu Kohno Mamoru Fujita Youichi Abe Akira Nishiyama 《Hypertension research》2006,29(3):169-178
Recent studies have suggested that aldosterone plays a role in the pathogenesis of renal injury. In this study, we investigated whether local angiotensin II (Ang II) activity contributes to the progression of renal injury in aldosterone/salt-induced hypertensive rats. Uninephrectomized rats were treated with 1% NaCl in a drinking solution and one of the following combinations for 6 weeks: vehicle (2% ethanol, s.c.; n=9), aldosterone (0.75 mug/h, s.c.; n=8), aldosterone+Ang II type 1 receptor blocker olmesartan (10 mg/kg/day, p.o.; n=8), or aldosterone+olmesartan (100 mg/kg/day, p.o.; n=9). Aldosterone/salt-treated hypertensive rats exhibited severe proteinuria and renal injury characterized by glomerular sclerosis and tubulointerstitial fibrosis. Aldosterone/salt-induced renal injury was associated with augmented expression of angiotensin converting enzyme and Ang II levels in the renal cortex and medullary tissues. Renal cortical and medullary mRNA expression of transforming growth factor-beta (TGF-beta) and connective tissue growth factor (CTGF) as well as the collagen contents were increased in aldosterone/salt-treated hypertensive rats. Treatment with olmesartan (10 or 100 mg/kg/day) had no effect on blood pressure but attenuated proteinuria in a dose-dependent manner. Olmesartan at 10 mg/kg/day tended to decrease renal cortical and medullary Ang II levels, TGF-beta and CTGF expression, and collagen contents; however, these changes were not significant. On the other hand, an ultrahigh dose of olmesartan (100 mg/kg/day) significantly decreased these values and ameliorated renal injury. These data suggest that augmented local Ang II activity contributes, at least partially, to the progression of aldosterone/salt-dependent renal injury. 相似文献
8.
Yasuhiko Tamada Kikuka Yokochi Yoshimi Oshitani Yukiko Nitta Toshihiko Ikeya Kazuo Hara Katsushi Owaribe 《The Journal of dermatology》1995,22(3):201-204
We report a 73-year-old woman with typical clinical, histological and immunofluorescence features of pemphigoid nodularis. Direct immunofluorescence studies of prurigo nodularis-like lesions and peribullous skin showed the linear deposition of IgG and C3 at the basement membrane zone. Circulating IgG against the basement membrane was also detected by indirect immunofluorescence. The serum from the patient was shown to contain the autoantibody against 230 kDa hemidesmosomal antigen associated with bullous pemphigoid antigen. 相似文献
9.
Minoru Sasano Mihoko Tanaka Katsuhiko Nakata Shiro Mita 《Immunopharmacology and immunotoxicology》1991,13(1):121-133
(4R)-Hexahydro-7, 7-dimethyl-6-oxo-1, 2, 5-dithiazocine-4-carboxylic acid (SA3443) is a newly synthesized cyclic disulfide compound which offers potential hepatoprotective properties.
The effect of SA3443 on the induction of natural killer (NK) and cytotoxic T lymphocyte (CTL) activities was investigated. NK activity in BALB/c mice splenic cells was investigated using YAC-1 cells as target cells. SA3443, at a dose range of 30-300 mg/kg/day, augmented NK activity significantly when administered orally once daily for 4 days before the assay. Alloantigen-specific CTL activity in splenic cells from BALB/c mice was detected 9 days after sensitization with C57BL/6 mice splenic cells. SA3443, at a dose of 100 mg/kg/day, augmented CTL activity significantly when administered orally, once daily for 4 days beginning after the sensitization and for 2 days before the assay, while a high dose of SA3443, at 300mg/kg, suppressed CTL activity.
From these results, it is thought that SA3443 may assist in the elimination of hepatitis viruses from the liver in patients with chronic active hepatitis, by the activation of NK and/or CTL activities. 相似文献
The effect of SA3443 on the induction of natural killer (NK) and cytotoxic T lymphocyte (CTL) activities was investigated. NK activity in BALB/c mice splenic cells was investigated using YAC-1 cells as target cells. SA3443, at a dose range of 30-300 mg/kg/day, augmented NK activity significantly when administered orally once daily for 4 days before the assay. Alloantigen-specific CTL activity in splenic cells from BALB/c mice was detected 9 days after sensitization with C57BL/6 mice splenic cells. SA3443, at a dose of 100 mg/kg/day, augmented CTL activity significantly when administered orally, once daily for 4 days beginning after the sensitization and for 2 days before the assay, while a high dose of SA3443, at 300mg/kg, suppressed CTL activity.
From these results, it is thought that SA3443 may assist in the elimination of hepatitis viruses from the liver in patients with chronic active hepatitis, by the activation of NK and/or CTL activities. 相似文献
10.
E Kumura N Arita T Hayakawa Y Ushio H Nakata A Murasawa H Mogami J Ikezoe Y Minami 《Neurosurgery》1986,18(6):802-804
We found combination chemotherapy with cisplatinum, vinblastine, and bleomycin (PVB therapy) effective in the treatment of a patient with a pineal germ cell tumor with peritoneal dissemination. The metastatic complication may have been attributable to the ventriculoperitoneal shunt tube. After the first course of PVB therapy, the disseminated tumors were decreased in size; no residual tumors were detected after the third course by laparoscopic examination, computed tomographic scanning, or echogram. Our results suggest that combined PVB therapy is effective in the treatment of extraneural metastasis from intracranial germ cell tumors. 相似文献