全文获取类型
收费全文 | 22646篇 |
免费 | 1089篇 |
国内免费 | 107篇 |
专业分类
耳鼻咽喉 | 115篇 |
儿科学 | 341篇 |
妇产科学 | 271篇 |
基础医学 | 2809篇 |
口腔科学 | 655篇 |
临床医学 | 1498篇 |
内科学 | 5686篇 |
皮肤病学 | 340篇 |
神经病学 | 1855篇 |
特种医学 | 1166篇 |
外科学 | 4360篇 |
综合类 | 86篇 |
一般理论 | 1篇 |
预防医学 | 573篇 |
眼科学 | 394篇 |
药学 | 1655篇 |
中国医学 | 51篇 |
肿瘤学 | 1986篇 |
出版年
2023年 | 105篇 |
2022年 | 255篇 |
2021年 | 502篇 |
2020年 | 218篇 |
2019年 | 324篇 |
2018年 | 452篇 |
2017年 | 342篇 |
2016年 | 392篇 |
2015年 | 391篇 |
2014年 | 506篇 |
2013年 | 692篇 |
2012年 | 1046篇 |
2011年 | 1162篇 |
2010年 | 596篇 |
2009年 | 537篇 |
2008年 | 967篇 |
2007年 | 1125篇 |
2006年 | 1140篇 |
2005年 | 1098篇 |
2004年 | 1026篇 |
2003年 | 1001篇 |
2002年 | 999篇 |
2001年 | 802篇 |
2000年 | 818篇 |
1999年 | 747篇 |
1998年 | 269篇 |
1997年 | 235篇 |
1996年 | 197篇 |
1995年 | 152篇 |
1994年 | 152篇 |
1993年 | 156篇 |
1992年 | 529篇 |
1991年 | 475篇 |
1990年 | 445篇 |
1989年 | 442篇 |
1988年 | 428篇 |
1987年 | 365篇 |
1986年 | 363篇 |
1985年 | 362篇 |
1984年 | 208篇 |
1983年 | 174篇 |
1982年 | 91篇 |
1981年 | 86篇 |
1979年 | 170篇 |
1978年 | 126篇 |
1977年 | 93篇 |
1974年 | 124篇 |
1973年 | 113篇 |
1970年 | 83篇 |
1969年 | 102篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
121.
Tsukasa Tsunoda Toshifumi Eto Takahito Tsurifune Shigeki Tokunaga Tatsuhiro Ishii Koichi Motojima Teiji Matsumoto Tohru Segawa Kazuhide Ura Hiroshi Fukui 《Pathology international》1991,41(10):763-770
A solid and cystic tumor (SCT) was located at the head of the pancreas in a 43-year-old Japanese male, and pancreatoduodenectomy was performed on the suspicion of papillary carcinoma or cystadenocarcinoma of the pancreas. The lesion, which measured 4.5 X 4.5 X 4.0 cm, was clearly demarcated by connective tissue. The cut surface showed solid grayish-white areas with central cystic degenerative changes. The solid areas consisted of small round cells proliferating in a small solid or a pseudopapillary pattern. The tumor cells partially invaded the surrounding normal pancreatic parenchyma. Immunohistochemical studies revealed positive staining for alpha-1-antitrypsin and neuron-specific enolase, but no staining for known pancreatic hormones. Moreover, ultrastructural studies showed the absence of zymogen granules and the presence of anullate lamellae and neurosecretory granules. On the basis of these findings, a diagnosis of SCT of the pancreas was established. In order to clarify the histogenesis and biological behavior of the tumor, it is necessary to accumulate and analyze similar cases, an endeavor which in turn will contribute to the successful management of this disease. Acta Pathol Jpn 41: 763-770, 1991. 相似文献
122.
Fukui K Kominami R Kaneuji A Matsumoto T Shinohara H 《Okajimas folia anatomica Japonica》2004,81(4):57-62
We report a new method of perfusion fixation for the proximal one-third of the femur of the Japanese white rabbit. Fluids to flush the blood and fix the marrow were injected into the abdominal aorta and drained from the stump of the femur. The oozing of the fluids from the stumps guaranteed complete flushing and fixation. The new method facilitated fixation and decreased the volume of necessary fluids. Scanning electron microscopy (SEM) images of bone marrow fixed using the new method and using the conventional method did not differ. Large fat globules were not observed in the SEM specimens produced using either the new or the conventional method. 相似文献
123.
Histogenesis of the duodenum, especially changes in the epithelium in relation to temporal occlusion and re-canalization of
the lumen, was investigated by light microscopy together with morphometric analysis, as well as by scanning and transmission
electron microscopy of 133 externally normal human embryos ranging from Carnegie stage 12 to 23. A series of morphogenetic
events passed the duodenum in a cranio-caudal (proximo-distal) wave like fashion during the period examined. They included:
(1) a decrease in the caliber and area of the lumen, (2) ’occlusion’ of the lumen, (3) vacuole formation, (4) ’re-canalization’
and villi formation. The only exemption to this rule was that, in the upper part of the duodenum, the lumen was not obliterated
in the embryos examined. Morphometric analyses revealed that both the area of the epithelium and the number of epithelial
cells decreased during the ’occlusion’ phase. This result suggests that, unlike the classical view, epithelial cell proliferation
does not play an important role in occluding the lumen, but the predominant morphogenetic event during this phase is convergence
of the epithelial cells to elongate the duodenum. Apoptosis, contrary to some classical views, decreased during the ’re-canalization’
phase, and it appeared to be involved in the formation of the small lumens in the epithelial ’plug’ and in villi formation,
but not in enlarging the secondary lumens. The secondary small lumens in the occluded lumen were frequently formed near the
border between the central ’plug’ and peripheral basal cells on the basement membrane. This and other findings of concentric
differentiation in both the epithelial and mesenchymal layers suggested a possible control mechanism by the epithelium-mesenchymal
interaction on human duodenal morphogenesis and histogenesis. The present electron microscopic observations also provided
details on the mechanisms involved in the enlargement of the secondary lumen and differentiation of villi. The implications
of these findings to duodenal anomalies are also discussed.
Accepted: 12 November 2001 相似文献
124.
Hydroxyapatite (HAp) was synthesized in the presence of a variety of amino acids in order to investigate the effect of amino acid on the crystallinity and the solubility characteristics of HAp in the HAp-synthesizing condition. In the results of X-ray diffraction analysis, HAp synthesized in the presence of glycine (HAp-Gly), serine (HAp-Ser), aspartic acid (HAp-Asp) and glutamic acid (HAp-Glu) showed poor crystallinity compared with HAp synthesized in the absence of amino acid (HAp-con). The results of Fourier transform infrared spectroscopy suggested the adsorption of these amino acids on HAp. Scanning electron microphotographs showed that the size and morphology of HAp adsorbed amino acids changed significantly. Furthermore, the solubility of these HAps increased significantly compared to HAp-con, each differing in four amino acids. However, other amino acids did not affect the crystallinity and morphology of HAp and had no significant change in their solubility. Collectively, this study suggests that the crystallinity and the solubility of synthesized HAp are different owing to the variation of amino acids in the HAp synthesizing condition. It is expected that digestion-regulated HAp materials could be synthesized by using amino acid in their synthesizing condition. 相似文献
125.
Satoko Arai Yuka Shinohara Yasuyuki Kato Satoshi Hirano Atsuto Yoshizawa Masaaki Hojyo Nobuyuki Kobayashi Haruhito Sugiyama Koichiro Kudo 《Arerugī》2007,56(10):1293-1297
A 51-year-old man was admitted to our hospital with fever, dry cough and dyspnea. He had taken minocycline for 11 days because of urinary tract infection. Chest X-ray on admission showed diffuse reticular shadows in bilateral lung fields with bilateral pleural effusion. Cessation of minocycline led to spontaneous improvement of symptoms and radiographic findings. The lymphocyte stimulation test for minocycline with peripheral blood and pleural effusion were negative. After provocation test with minocycline, he developed fever and dry cough and bilateral ground glass opacity appeared on his chest X-ray. He was diagnosed as minocycline-induced pneumonitis and recovered rapidly following corticosteroid therapy. 相似文献
126.
Shoji T Nakanishi I Kunitou K Tsubakihara Y Hirooka Y Kishi Y Hatanaka M Matsumoto M Toyoshima K Seya T 《Clinical immunology (Orlando, Fla.)》2000,95(2):163-169
Soluble membrane cofactor protein (MCP, CD46) has not been detected by conventional ELISA in human urine. Here, we established a highly sensitive assay method for determination of urinary MCP (uMCP) using monoclonal antibody-coated paramagnetic beads. This method enabled us to detect less than 0.05 ng/ml of purified membrane and recombinant soluble MCP, a sensitivity 10-fold higher than that of conventional ELISA. In normal subjects, the levels of uMCP were <0. 05 ng/ml. The levels of uMCP were elevated in patients with IgA nephropathy and more prominently in patients with rapidly progressive glomerulonephritis. The levels of uMCP were correlated significantly with those of serum MCP (sMCP) and N-acetyl-beta-glucosaminidase and nonsignificantly with those of beta(2)-microglobulin, total urine protein, or serum creatinine. The properties of uMCP were inconsistent with those of the reported sMCP, since uMCP showed three bands on SDS-PAGE/immunoblotting with molecular mass profiles different from those of sMCP. uMCP exhibited factor I cofactor activity for cleavage of C3b comparable to that of sMCP. The origin of uMCP, however, remains to be determined. These results, taken together with the parameter correlation profiles, suggested that uMCP is secreted or produced secondary to tubular or glomerular damage. The physiological role and clinical significance of uMCP are now within the scope of our investigation by establishment of this assay. 相似文献
127.
Koichiro Yuji Shigesaburo Miyakoshi Daisuke Kato Yuji Miura Tomohiro Myojo Naoko Murashige Yukiko Kishi Kazuhiro Kobayashi Eiji Kusumi Hiroto Narimatsu Tamae Hamaki Tomoko Matsumura Masahiro Kami Takahiro Fukuda Shigeru Masuo Kazuhiro Masuoka Atsushi Wake Junichi Ueyama Akiko Yoneyama Ko Miyamoto Haruhisa Nagoshi Michio Matsuzaki Shinichi Morinaga Yoshitomo Muto Yoichi Takeue Shuichi Taniguchi 《Biology of blood and marrow transplantation》2005,11(4):314-318
We report the results of reduced-intensity unrelated cord blood transplantation (RI-UCBT) in patients with advanced malignant lymphoma. Twenty patients (median age, 46.5 years; range, 27-66 years) underwent RI-UCBT with a preparative regimen consisting of fludarabine 125 mg/m2 , melphalan 80 mg/m 2 , and 4 Gy of total body irradiation. The median infused total cell dose was 2.75 x 10(7)/kg (range, 2.3-3.4 x 10(7)/kg). Graft-versus-host disease (GVHD) prophylaxis was composed of cyclosporine or tacrolimus alone. Fifteen patients achieved primary neutrophil engraftment after a median of 20 days. Eight patients developed grade II to IV acute GVHD, and 2 developed chronic GVHD. Of the 16 patients with evaluable disease, 10 achieved a complete response. Primary disease recurred in 1 patient, and transplant-related mortality within 100 days occurred in 8 of 20 patients. The estimated 1-year probability of progression-free survival was 50%. These data suggest that RI-UCBT is a feasible option for patients with refractory lymphoma who lack an HLA-matched donor. 相似文献
128.
Enhanced expression of type I interferon and toll-like receptor-3 in primary biliary cirrhosis 总被引:6,自引:0,他引:6
Takii Y Nakamura M Ito M Yokoyama T Komori A Shimizu-Yoshida Y Nakao R Kusumoto K Nagaoka S Yano K Abiru S Ueki T Matsumoto T Daikoku M Taniguchi K Fujioka H Migita K Yatsuhashi H Nakashima M Harada M Ishibashi H 《Laboratory investigation; a journal of technical methods and pathology》2005,85(7):908-920
129.
Metal ions induce bone-resorbing cytokine production through the redox pathway in synoviocytes and bone marrow macrophages 总被引:6,自引:0,他引:6
Niki Y Matsumoto H Suda Y Otani T Fujikawa K Toyama Y Hisamori N Nozue A 《Biomaterials》2003,24(8):1447-1457
To evaluate the biological reactions to metal ions potentially released from prosthetic implants, we examined the ability of metal ions to produce bone-resorbing cytokines and the underlying mechanism using synoviocytes and bone marrow (BM) macrophages. The cells were incubated with NiCl(2), CoCl(2), CrCl(3) or Fe(2)(SO(4))(3) at optimal concentrations, which are detectable in joint fluid following total joint arthroplasty. The production of interleukin-1beta, interleukin-6 and tumor necrosis factor-alpha were enhanced by all metal ions tested as determined by enzyme-linked immunosorbent assay. From the results of electrophoresis mobility shift assay, all metal ions enhanced the DNA-binding activity of nuclear factor kappaB (NF-kappaB), and p50-p65 heterodimers and p50 homodimers were the major subunits. These effects of the metal ions were considerably blocked by pyrrolidine dithiocarbamate (PDTC) known as a radical scavenger. An electron spin resonance study clearly demonstrated the ability of metal ions to generate activated oxygen species (AOS), especially hydroxyl radicals (*OH), which accounts for PDTC-blockade of metal ion-induced NF-kappaB activation and subsequent cytokine production. Taken together, our data raised the possibility that small amounts of metal ions released from prosthetic implants activate synoviocytes and BM macrophages through the AOS-mediated process (i.e. the redox pathway), and contribute to the initiation of osteolysis at the bone-implant interface. 相似文献