全文获取类型
收费全文 | 394篇 |
免费 | 21篇 |
国内免费 | 2篇 |
专业分类
儿科学 | 18篇 |
妇产科学 | 5篇 |
基础医学 | 86篇 |
口腔科学 | 7篇 |
临床医学 | 28篇 |
内科学 | 72篇 |
皮肤病学 | 4篇 |
神经病学 | 32篇 |
特种医学 | 12篇 |
外科学 | 39篇 |
综合类 | 2篇 |
现状与发展 | 1篇 |
预防医学 | 25篇 |
眼科学 | 10篇 |
药学 | 21篇 |
肿瘤学 | 55篇 |
出版年
2024年 | 1篇 |
2023年 | 5篇 |
2022年 | 12篇 |
2021年 | 25篇 |
2020年 | 13篇 |
2019年 | 9篇 |
2018年 | 13篇 |
2017年 | 12篇 |
2016年 | 15篇 |
2015年 | 11篇 |
2014年 | 21篇 |
2013年 | 22篇 |
2012年 | 20篇 |
2011年 | 27篇 |
2010年 | 14篇 |
2009年 | 11篇 |
2008年 | 22篇 |
2007年 | 16篇 |
2006年 | 20篇 |
2005年 | 26篇 |
2004年 | 17篇 |
2003年 | 25篇 |
2002年 | 12篇 |
2001年 | 1篇 |
2000年 | 5篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1995年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 3篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1984年 | 2篇 |
1983年 | 4篇 |
1982年 | 5篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1968年 | 1篇 |
1966年 | 1篇 |
1965年 | 1篇 |
1932年 | 1篇 |
排序方式: 共有417条查询结果,搜索用时 0 毫秒
1.
Nishida Koyo Mihara Kiyoshi Takino Toichi Nakane Sachi Takakura Yoshinobu Hashida Mitsuru Sezaki Hitoshi 《Pharmaceutical research》1991,8(4):437-444
The effect of electric charge on the hepatic disposition of macromolecules was studied in the rat. Charged derivatives of dextran (T-70) and bovine serum albumin (BSA), mitomycin C–dextran conjugates (MMC-D), and lactosaminated BSA (Lac-BSA) were employed as model macromolecules. After intravenous injection, cationic macromolecules were rapidly eliminated from plasma because of their extensive hepatic uptake, while anionic and neutral macromolecules were slowly eliminated. Cationic macromolecules were recovered from parenchymal and nonparenchymal hepatic cells at a cellular uptake (per unit cell number) ratio of 1.4–3.2, while that of Lac-BSA was 14. During liver perfusion using a single-pass constant infusion mode, cationic macromolecules were continuously extracted by the liver, with extraction ratios at steady-state (E
ss) ranging between 0.03 and 0.54, whereas anionic and neutral macromolecules were almost completely recovered in the outflow at steady state. The E
ss for cationized BSA (Cat-BSA) and cationic MMC-Dcat were concentration dependent and decreased at low temperatures and in the presence of colchicine and cytochalasin B. The possible participation of the internalization process in the uptake of cationic macromolecules by hepatocytes was suggested. 相似文献
2.
The conformational energies of poly(α-methylene-γ-butyrolactone) are calculated and compared with those of poly(methyl methacrylate). In spite of the structural resemblance of these two polymers, the patterns of the energy contour maps are clearly distinguishable from each other; the energy barriers between rotational isomeric states are appreciably higher in the former than in the latter polymer. The calculation indicates large non-bonded interactions between the protons in one lactone ring and those in the adjacent lactone rings. The broad NMR spectrum of poly(α-methylene-γ-butyrolactone) apparently reflects its rigid conformational structure. 1H and 13C NMR chemical shifts are calculated by theoretical shielding calculations based on conformational analysis. Much lower magnetic field resonances of the O? CH2 and α-CH2 carbons in poly(α-methylene-γ-butyrolactone) as compared with those of the O? CH3 and α-CH3 carbons in poly(methyl methacrylate) are well reproduced by the calculation. The shift to lower magnetic field is mainly attributed to paramagnetic shielding derived from the interaction between O? CH2 carbon and α-CH2 carbon. Tacticity- and conformation-dependent 1H and 13C NMR chemical shifts of poly(α-methylene-γ-butyrolactone) are well interpreted on the basis of the conformational analysis. 相似文献
3.
Sasaki F Doshita A Matsumoto Y Kuwahara S Tsukamoto Y Ogawa K 《Cells, tissues, organs》2003,173(2):65-74
Pituitary glands of chicken, from stages 20 (70 approximately 72 h of incubation) to 46 (20 days) of Hamburger and Hamilton (1951), were studied by immunocytochemical and histological stainings and India ink injection into blood vessels. Using the distribution pattern of 6 types of immunoreactive adenohypophyseal cells and the location of pituitary stalk as guideposts, we found how specific areas in the epithelium of Rathke's pouch differentiate into specific regions of the adenohypophysis at 20 days. In the sagittal plane, the walls of Rathke's pouch were tentatively divided into the upper part (A(1) + A(2)) and lower part (A(3)) of the anterior wall, and the posterior wall (P(1) + P(2) + P(3)). The cephalic lobe was mainly assembled by the proliferation of parenchymal cells in the areas A(2) + A(3) + P(2) of Rathke's pouch epithelia at 3 days of incubation. The caudal lobe was derived from A(1) + P(1) + P(3). The pars tuberalis was derived from A(1) + A(2). Thus, the avian adenohypophysis is established at 13 days, though the blood supply to the pars distalis is established at 20 days. Therefore, the cephalic lobe and caudal lobe of the pars distalis and the pars tuberalis of the chicken adenohypophysis are derived from specific areas of the cell cords of Rathke's pouch at 3 days of incubation. 相似文献
4.
Hideomi Koinuma Kota Sato Tsuneaki Tanabe Hidefumi Hirai 《Macromolecular chemistry and physics.》1982,183(6):1533-1544
In view of the structural resemblance of α-methylene-γ-butyrolactone to methyl methacrylate, conformation and NMR chemical shifts of poly(α-methylene-γ-butyrolactone-alt-styrene). are calculated and compared with those of poly(methyl methacrylate-alt-styrene). The conformational energy surfaces for the dyad sequence models of the both copolymers are analogous to each other, as is expected from the similarity in the constituting monomeric units. Agreement of calculation with observation is satisfactory with respect to the cotacticity-dependent splittings in the 13C NMR spectra and is improved by the fixation of a substituent in poly(α-methylene-γ-butyrolactone-alt-styrene). Calculation of 1H chemical shifts gives an alignment of NMR signals which is in accordance with the observation. 相似文献
5.
Yumi Saito Satoshi Koinuma Kenji Watanabe Kiyokazu Agata 《Developmental dynamics》2003,226(2):334-340
We investigated how planarians organize their left-right axis by using ectopic grafting. Planarians have three body axes: anteroposterior (A-P), dorsoventral (D-V), and left-right (L-R). When a small piece is implanted into an ectopic region along the A-P and D-V axes, intercalary structures are always formed to compensate for positional gaps. There are two hypotheses regarding L-R axis formation in this organism: first, that the left and right sides of the animal may be recognized as different parts, and L-R intercalation can induce midline structures (asymmetry hypothesis); second, that both sides may have symmetrical positional values, and mediolateral (M-L) intercalation creates positional values along the L-R axis (symmetry hypothesis). We performed ectopic grafting experiments in the head region of the planarian, Dugesia japonica, to examine these hypotheses. A left lateral fragment containing a left auricle was implanted into the medial region of the host. Ectopic structures were always formed only on the left side of the graft, where lateral tissues abutted onto the medial tissues. However, no morphologic change was induced on the right side of the graft, where left-sided tissues faced onto right-sided tissues. Molecular marker analyses indicated that ectopic structures formed on the left side of the graft were induced by M-L intercalation, supporting the "symmetry hypothesis." When the midline tissues were implanted into a lateral region, they induced a complete ectopic head, demonstrating that M-L intercalation may be sufficient to establish the L-R axis in planarians. 相似文献
6.
Shimpei Ariki Sotaro Ozaka Nozomi Sachi Thanyakorn Chalalai Yasuhiro Soga Chiaki Fukuda Yomei Kagoshima Supanuch Ekronarongchai Kazuhiro Mizukami Naganori Kamiyama Kazunari Murakami Takashi Kobayashi 《Genes to cells : devoted to molecular & cellular mechanisms》2023,28(4):267-276
Although excessive immune responses by Th17 cells, a helper T cell subset, are implicated in the pathogenesis of inflammatory bowel disease (IBD), the mechanism by which its localization in an inflamed colon is regulated remains unclear. Chemokines and their receptors are involved in the pathogenesis of IBD, however, the relative significance of each receptor on Th17 cells remains unknown. We generated C–C motif chemokine receptor 2 (CCR2) knockout (KO) and CCR6 KO mice in the syngeneic background using the CRISPR/Cas9 system and found that the phenotypes of experimental colitis worsened in both mutant mice. Surprisingly, the phenotype of colitis in CCR2/CCR6-double knockout (CCR2/6 DKO) mice was opposite to that of the single-deficient mice, with significantly milder experimental colitis (p < .05). The same was true for the symptoms in CCR6 KO mice, but not in wild type mice treated with a CCR2 inhibitor, propagermanium. Colonic CCR2+CCR6+ Th17 cells produced a potentially pathogenic cytokine GM-CSF whose levels in the gut were significantly reduced in CCR2/6 DKO mice (p < .05). These results suggest that GM-CSF-producing CCR2+CCR6+ Th17 cells are pathogenic and are attracted to the inflamed colon by either CCR2 or CCR6 gradient, which subsequently exacerbates experimental colitis in mice. 相似文献
7.
Takuji Suzuki Tatsuro Fukuhara Masashi Tanaka Akira Nakamura Kenichi Akiyama Tomohiro Sakakibara Daizo Koinuma Toshiaki Kikuchi Ryushi Tazawa Makoto Maemondo Koichi Hagiwara Yasuo Saijo Toshihiro Nukiwa 《Clinical cancer research》2005,11(1):58-66
Cancer immunotherapy by fusion of antigen-presenting cells and tumor cells has been shown to induce potent antitumor immunity. In this study, we characterized syngeneic and allogeneic, murine macrophage/dendritic cell (DC)-cancer fusion cells for the antitumor effects. The results showed the superiority of allogeneic cells as fusion partners in both types of antigen-presenting cells in an in vivo immunotherapy model. A potent induction of tumor-specific CTLs was observed in these immunized conditions. In addition, the immunization with DC-cancer fusion cells was better than that with macrophage-cancer fusion cells. Both syngeneic and allogeneic DC-cancer fusion cells induced higher levels of IFN-gamma production than macrophage-cancer fusion cells. Interestingly, allogeneic DC-cancer fusion cells were superior in that they efficiently induced Th1-type cytokines but not the Th2-type cytokines interleukin (IL)-10 and IL-4, whereas syngeneic DC-cancer fusion cells were powerful inducers of both Th1 and Th2 cytokines. These results suggest that allogeneic DCs are suitable as fusion cells in cancer immunotherapy. To further enhance the antitumor immunity in the clinical setting, we prepared DCs fused with IL-12 gene-transferred cancer cells and thus generated IL-12-secreting DC-cancer fusion cells. Immunization with these gene-modified DC-cancer fusion cells was able to elicit a markedly enhanced antitumor effect in the in vivo therapeutic model. This novel IL-12-producing fusion cell vaccine might be one promising intervention for future cancer immunotherapy. 相似文献
8.
Taro Horino Takeshi Kashio Satoshi Inotani Sachi Yamaguchi Masayuki Ishihara Osamu Ichii Yoshio Terada 《Internal medicine (Tokyo, Japan)》2022,61(14):2187
Lumbar hernias are extremely rare. The posterolateral abdominal wall has two susceptible areas - the superior (Grynfeltt-Lesshaft''s triangle) and the inferior (Petit''s triangle) lumbar triangles - that cause superior and inferior lumbar hernias, respectively. We herein report a 67-year-old woman with nephrotic-range proteinuria caused by primary superior lumbar hernia. Superior lumbar hernias should be considered as a differential disease causing massive orthostatic proteinuria in adults. The present case highlights the importance of considering lumbar hernia in patients with flank swelling and the potential complications that may result from a missed diagnosis. 相似文献
9.
10.
Kane Jeremy C. Sharma Anjali Murray Laura K. Chander Geetanjali Kanguya Tukiya Skavenski Stephanie Chitambi Chipo Lasater Molly E. Paul Ravi Cropsey Karen Inoue Sachi Bosomprah Samuel Danielson Carla Kmett Chipungu Jenala Simenda Francis Vinikoor Michael J. 《AIDS and behavior》2022,26(2):523-536
AIDS and Behavior - This randomized controlled trial tested the efficacy of a multi-session, evidence-based, lay counselor-delivered transdiagnostic therapy, the Common Elements Treatment Approach... 相似文献