全文获取类型
收费全文 | 7352篇 |
免费 | 374篇 |
国内免费 | 76篇 |
专业分类
耳鼻咽喉 | 28篇 |
儿科学 | 176篇 |
妇产科学 | 133篇 |
基础医学 | 1136篇 |
口腔科学 | 146篇 |
临床医学 | 455篇 |
内科学 | 1804篇 |
皮肤病学 | 254篇 |
神经病学 | 611篇 |
特种医学 | 254篇 |
外科学 | 1097篇 |
综合类 | 23篇 |
预防医学 | 182篇 |
眼科学 | 73篇 |
药学 | 520篇 |
中国医学 | 18篇 |
肿瘤学 | 892篇 |
出版年
2023年 | 29篇 |
2022年 | 96篇 |
2021年 | 148篇 |
2020年 | 77篇 |
2019年 | 107篇 |
2018年 | 152篇 |
2017年 | 161篇 |
2016年 | 171篇 |
2015年 | 171篇 |
2014年 | 247篇 |
2013年 | 285篇 |
2012年 | 473篇 |
2011年 | 524篇 |
2010年 | 309篇 |
2009年 | 250篇 |
2008年 | 430篇 |
2007年 | 510篇 |
2006年 | 500篇 |
2005年 | 502篇 |
2004年 | 484篇 |
2003年 | 503篇 |
2002年 | 481篇 |
2001年 | 88篇 |
2000年 | 70篇 |
1999年 | 94篇 |
1998年 | 124篇 |
1997年 | 82篇 |
1996年 | 70篇 |
1995年 | 75篇 |
1994年 | 65篇 |
1993年 | 54篇 |
1992年 | 53篇 |
1991年 | 49篇 |
1990年 | 50篇 |
1989年 | 56篇 |
1988年 | 32篇 |
1987年 | 29篇 |
1986年 | 17篇 |
1985年 | 21篇 |
1984年 | 21篇 |
1983年 | 12篇 |
1982年 | 19篇 |
1981年 | 9篇 |
1980年 | 12篇 |
1979年 | 15篇 |
1978年 | 11篇 |
1977年 | 9篇 |
1974年 | 9篇 |
1973年 | 10篇 |
1969年 | 7篇 |
排序方式: 共有7802条查询结果,搜索用时 15 毫秒
31.
Yasuyuki Sumikawa Yuriko Ueki Akira Miyoshi Lei Cheng Min Yin Hai-Bo Shi Masuko Daitoku Sumikawa Takeshi Kono Toshiyuki Aoki Ichiro Katayama 《Arerugī》2007,56(10):1270-1275
BACKGROUND: The comparative studies of the prevalence of atopic dermatitis and skin barrier functions in Japanese and Chinese were performed. METHODS: Clinical investigations were performed in 68 elementary school students in Lhasa, Tibet Autonomous Region and 67 students in Yixing, Jiangsu Province in China, and 99 students in Nishinomiya, Hyogo in Japan. Transepidermal water loss (TEWL) and capacitance were measured. Questionary survey about bathing frequency was also performed for students in Lhasa, Yixing and Osaka. RESULT: The prevalence rate of atopic dermatitis was 0% in Lhasa, 2.63% in Yixing, 4.26% in Nishinomiya. TEWL of students in Nishinomiya was higher than that in Yixing and Lhasa. Capacitance of students in Lhasa was lower than that in Nishinomiya and Yixing. The frequency of taking a bath in Lhasa was about 2.2 times per month and fewer than that in Nishinomiya and Yixing. CONCLUSION: There was tendency that the prevalence of atopic dermatitis increased according to increase of TEWL. It was thought that more investigations are necessary whether the development of habitat and environment influence the prevalence of atopic dermatitis and skin barrier function. 相似文献
32.
33.
Zou Jian-Ping; Yamamoto Norihiko; Fujii Tetsuya; Takenaka Hiroshi; Kobayashi Michiko; Herrmann Steven H.; Wolf Stanley F.; Fujiwara Hiromi; Hamaoka Toshiyuki 《International immunology》1995,7(7):1135-1145
Unfractionated spleen cells taken from tumor-bearing mice 2weeks after tumor implantation contained tumor-primed T cellswhich produced cytokines including IL-2 and IFN- when culturedin vitro. With progressive tumor growth this initial lymphokine-producingcapacity decreased. Here, we investigated the ability of IL-12to (I) restore suppressed IFN- production, (II) cause tumorregression and (II) induce anti-tumor protective immunity. Additionof rIL-12 to spleen cell cultures from 4- to 10-week-old tumor-bearingmice resulted in a striking enhancement in the production ofIFN- compared with cultures of these cells in the absence ofrIL-12 or of normal spleen cells in the presence of rIL-12.Five I.p. injections of rIL-12 into mice bearing s.c. tumorsinduced complete tumor regression. This was found when rIL-12was given at early (1–2 weeks), intermediate (4–5weeks) or even late (7 weeks) stages of tumor growth. Furthermore,IL-12-treated mice which rejected the primary tumor exhibitedcomplete resistance to a rechallenge with the same tumor butdid not reject a second syngenetic tumor. Immunohistochemicalanalyses following IL-12 treatment revealed that CD4+ and CD8+T cells infiltrate the tumor. More importantly, IFN- mRNA expressionwas observed in fresh tumor masses from tumor-bearing mice receivingIL-12 treatment The importance of IFN- was further demonstratedby the observation that the systemic administration of anti-IFN-mAb prior to IL-12 treatment completely abrogated the anti-tumoreffect of IL-12. Thus, these results indicate that administrationof modest levels of rIL-12 to tumor-bearing mice results intumor regression through mechanisms involving reversal of suppressedIFN- production by anti-tumor T cells and the establishmentof a tumor-specific protective immune response. 相似文献
34.
Toshiyuki Uryu Kenichi Hatanaka Kei Matsuzaki 《Macromolecular chemistry and physics.》1980,181(10):2137-2149
The cationic, ring-opening copolymerization of 1,6-anhydro-2,3,4-tri-O-benzyl-ß-D -glucopyranose with epichlorohydrin, 3,3-bis(chloromethyl)oxetane and 1,3-dioxolane was investigated with phosphorus pentafluoride as catalyst at low temperatures. Besides, copolymerization of 1,6-anhydro-2,3,4-tri-O-methyl-ß-D -glucopyranose with epichlorohydrin was studied. Structure and composition of the copolymers were determined by 1H and 13C NMR spectroscopy, indicating that copolymerization occurred in each combination of monomers. Number-average molecular weights of copolymers were in the range of 1 400 to 22 800. From the specific rotation and 13C NMR spectrum of copolymers, it was revealed that the ring-opening copolymerization of the benzylated 1,6-anhydro-glucopyranose with the cyclic monomers occurred in a stereoregular manner to give the C-1 carbon of glucose unit with α-configuration. Debenzylation of a copolymer prepared from 1,6-anhydro-2,3,4-tri-Obenzyl-ß-D -glucopyranose and 1,3-dioxolane gave a copolymer composed of free sugar units in the polymer main chain. Assignment of 13C NMR spectra of 2,3,4-tri-O-benzyl-ß-D -glucopyranan and of a copolymer of 1,6-anhydro-2,3,4-tri-O-benzyl-ß-ß-glucopyranose with 1,3-dioxolane was attempted. 相似文献
35.
Iwasaki M Yu WG Uekusa Y Nakajima C Yang YF Gao P Wijesuriya R Fujiwara H Hamaoka T 《International immunology》2000,12(5):701-709
While IL-12 administration induces tumor regression through stimulating T cells in tumor-bearing mice, this IL-12 effect is observed in some but not all tumor models. The present study aimed to compare IL-12 responsiveness of T cells from tumor-bearing mice in IL-12-responsive (CSA1M and OV-HM) and -unresponsive (Meth A) tumor models. Tumor regression in IL-12-responsive tumor models required the participation of T cells, but not of NK1.1(+) cells. Because a NK1.1(+) cell population was the major producer of IFN-gamma, comparable levels of IFN-gamma production were induced in IL-12-responsive and -unresponsive tumor-bearing mice. This indicates that the amount of IFN-gamma produced in tumor-bearing individuals does not correlate with the anti-tumor efficacy of IL-12. In contrast, IL-12 responsiveness of T cells differed between the responsive and unresponsive models: purified T cells from CSA1M/OV-HM-bearing or Meth A-bearing mice exhibited high or low IL-12 responsiveness respectively, when evaluated by the amounts of IFN-gamma produced in response to IL-12. T cells from CSA1M- or OV-HM-bearing but not from Meth A-bearing mice exhibited enhanced levels of mRNA for the IL-12 receptor (IL-12R). These results indicate that a fundamental difference exists in IL-12 responsiveness of T cells between IL-12-responsive and -unresponsive tumor models, and that such a difference is associated with the expression of IL-12R on T cells. 相似文献
36.
37.
Toshiyuki Uryu Katsuhiro Ito Ken-Ichi Kobayashi Kei Matsuzaki 《Macromolecular chemistry and physics.》1979,180(6):1509-1519
In order to elucidate the catalytic behavior of phosphorus pentafluoride in the polymerization of anhydro sugars, 13P and 19F NMR spectra were measured on a reaction mixture of 1,6-anhydro-2,3,4-tri-O-benzyl-β-D -glucopyranose (LGTBE) and PF5 with different mole ratios in a temperature range of ?40 to ?80°C. In the 31P NMR spectrum measured at low temperatures, there was a total of 16 peaks, which consisted of a broad quintet, a septet, and a sharp quartet, being assigned to the PF4O-group, to PF, and to POF3, respectively. These fluoro compounds were also determined by the 19F NMR spectrum of the reaction mixture. The concentration of PF ions was found to correspond to that of oxonium ions, which are assumed to be actual propagating species, by determining both the concentration of PF from 19F NMR spectrum and the degree of polymerization of 2,3,4-tri-O-benzyl-α-D -glucopyranan obtained. Formation of the PF5: LGTBE complex was observed from the 31P NMR spectrum of the polymerization system at ?80°C, which exhibits a broad sextet as well as absorptions due to POF3, PF4O–, and PF. To confirm the PF5:LGTBE complex, the NMR measurement of the PF5: tetrahydropyran complex was carried out. A polymerization mechanism of LGTBE by PF5 catalyst is discussed on the basis of the NMR measurement of the polymerization system. 相似文献
38.
Yoshitake Baba Shun Inagaki Sae Nakagawa Makoto Kobayashi Toshiyuki Kaneko Takanobu Takihara 《Nutrients》2021,13(5)
Matcha, a type of green tea, has a higher amino acid content than other types of tea. We previously examined the ability of matcha to improve cognitive function in older adults and determined that continuous matcha intake improves attention and executive function. This study aimed to compare the effects of matcha and caffeine and clarify the differences between these effects. The study was registered at the University Hospital Medical Information Network (UMIN000036578). The effect of single and continuous intake was compared, and the usefulness of continuous intake was evaluated under the stress condition. The Uchida–Kraepelin test (UKT) was used to induce mild acute stress, and the Cognitrax was used to evaluate cognitive function. A single dose of caffeine improved attentional function during or after stress loading. The reduced reaction time in the Cognitrax, observed following a single dose of matcha, was likely due to caffeine. The matcha group showed an increase in the amount of work after continuous intake, whereas the caffeine group only showed an increase in the amount of work for the UKT after a single dose. Ingesting matcha with caffeine improves both attention and work performance when suffering from psychological stress compared with caffeine alone. 相似文献
39.
Ryo KANEMATSU Junya HANAKITA Toshiyuki TAKAHASHI Manabu MINAMI Tomoo INOUE Fumiaki HONDA 《Neurologia medico-chirurgica》2021,61(1):40
Posterior stabilization is a common surgical procedure, which aims for rigid stabilization by facet fusion. Facet non-union has a potential risk of the screw loosening and malalignment. Although some authors have reported the influencing factors about screw loosening in the lumbar spine, there are few reports about the risk factor contributing to the facet non-union in the cervical spine. In all, 22 patients (78 facets and 122 screws) with degenerative cervical kyphosis or spondylolisthesis who underwent decompression and lateral mass screw (LMS) fixation were analyzed. Age, gender, smoking, bone mineral density (BMD), the degree of facet decortication with bone packing, and screw loosening were investigated as risk factors contributing to the facet non-union at each segmental fused level. Facet fusion rate was 85.9% (67/78 facets) and the incidence of loosening was 4.9% (6/122 screws, 4 patients). Insufficient facet decortication with bone packing is a significant risk factor of facet non-union (p <0.05, odds ratio: 26.5). All six loosened screws were associated with bony non-union of the facet and were located in the uppermost or lowermost vertebrae. Comparing loosened screws and stable screws, the average maximal insertional screw torque (MIT) was 9.8 cNm and 39.5 cNm, respectively (p <0.05). Additionally, the length of the stable screws was significantly longer versus the loosened screws (p <0.05). Lower MIT and shorter screw length located near the ends of the lateral mass may predict loosening, which can lead to facet non-union. Sufficient facet decortication with bone packing is one of the important factors contributing to the facet fusion. 相似文献
40.
Hideyuki Arima Yu Yamato Kimihito Sato Yoshihiro Uchida Toshiyuki Tsuruta Kanehisa Hashiguchi Hajime Hamamoto Eiichiro Watanabe Kaoru Yamanaka Tomohiko Hasegawa Go Yoshida Tatsuya Yasuda Tomohiro Banno Shin Oe Hiroki Ushirozako Tomohiro Yamada Koichiro Ide Yuh Watanabe Yukihiro Matsuyama 《Journal of orthopaedic science》2021,26(4):577-583
BackgroundSagittal spino-pelvic malalignment in patients with chronic low back pain (CLBP) have been reported in the past, which may also affect cervical spine lesions. The purpose of this study is to investigate the cervical alignment in patients with CLBP.MethodOf the patients who visited an orthopedic specialist due to low back pain lasting more than three months, 121 cases (average 71.5-years-old, 46 male and 75 female) with whole standing spinal screening radiographs were reviewed (CLBP group). Cervical parameters included cervical lordosis (CL), C2–C7 sagittal vertical axis (C2-7 SVA), and the T1 slope minus CL (T1S-CL). Cervical spine deformity was defined as C2-7 SVA >4 cm, CL <0°, or T1S-CL ≧20°. We compared the cervical alignment of these patients with 121 age and gender matched volunteers (control group).ResultsThe prevalence of cervical spine deformity was significantly higher in the CLBP group than in the control group (20.7% vs. 10.7%, P = 0.034). The mean CL was smaller in the CLBP group than in the control group (16.1° vs. 21.4°, P = 0.002). The mean C2-7 SVA was 17.6 mm vs. 18.7 mm in the CLBP group and in the control group, respectively (P = 0.817). The mean T1S-CL was larger in the CLBP group than in the control group (9.1° vs. 3.5°, P < 0.001). Multivariate analysis showed that people with CLBP were more likely to have cervical deformities than people without CLBP (odds ratio 2.16, 95% confidence interval 1.006 to 4.637).ConclusionsThis study results suggest that people with CLBP present with worse cervical sagittal alignment and higher prevalence of cervical spine deformities than age and gender matched volunteers with no CLBP. This means CLBP impacts cervical spine lesions negatively.Level of evidenceⅣ 相似文献