全文获取类型
收费全文 | 3550篇 |
免费 | 161篇 |
国内免费 | 37篇 |
专业分类
耳鼻咽喉 | 16篇 |
儿科学 | 40篇 |
妇产科学 | 35篇 |
基础医学 | 506篇 |
口腔科学 | 114篇 |
临床医学 | 184篇 |
内科学 | 1072篇 |
皮肤病学 | 33篇 |
神经病学 | 269篇 |
特种医学 | 92篇 |
外科学 | 496篇 |
综合类 | 12篇 |
预防医学 | 121篇 |
眼科学 | 116篇 |
药学 | 235篇 |
中国医学 | 3篇 |
肿瘤学 | 404篇 |
出版年
2023年 | 21篇 |
2022年 | 47篇 |
2021年 | 67篇 |
2020年 | 36篇 |
2019年 | 46篇 |
2018年 | 81篇 |
2017年 | 61篇 |
2016年 | 82篇 |
2015年 | 87篇 |
2014年 | 88篇 |
2013年 | 136篇 |
2012年 | 232篇 |
2011年 | 267篇 |
2010年 | 143篇 |
2009年 | 122篇 |
2008年 | 224篇 |
2007年 | 262篇 |
2006年 | 242篇 |
2005年 | 234篇 |
2004年 | 251篇 |
2003年 | 254篇 |
2002年 | 255篇 |
2001年 | 30篇 |
2000年 | 27篇 |
1999年 | 31篇 |
1998年 | 78篇 |
1997年 | 51篇 |
1996年 | 39篇 |
1995年 | 23篇 |
1994年 | 37篇 |
1993年 | 33篇 |
1992年 | 27篇 |
1991年 | 23篇 |
1990年 | 9篇 |
1989年 | 15篇 |
1988年 | 17篇 |
1987年 | 13篇 |
1986年 | 11篇 |
1985年 | 7篇 |
1984年 | 6篇 |
1983年 | 3篇 |
1982年 | 8篇 |
1981年 | 3篇 |
1980年 | 7篇 |
1978年 | 3篇 |
1977年 | 3篇 |
1976年 | 2篇 |
1974年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有3748条查询结果,搜索用时 15 毫秒
21.
Synchronous pulmonary atypical adenomatous hyperplasia and metastatic osteosarcoma in a young female
Ken Kodama Masahiko Higashiyama Koji Takami Naozumi Higaki Kazuyuki Oda Nobuhito Araki 《The Japanese Journal of Thoracic and Cardiovascular Surgery》2004,52(7):357-359
A 17-year-old female underwent metastasectomy of three synchronous lesions in the bilateral lungs under the diagnosis of metastatic
osteosarcoma, however, one of them was found to be atypical adenomatous hyperplasia (AAH). Since AAH is very rare among young
people, a careful evaluation of high-resolution computed tomographic image is important in determining the operative indications
and procedures in patients with multiple metastatic tumors. 相似文献
22.
23.
Eight adult cats of either sex were studied. The minimal alveolar concentration (MAC) for sevoflurane in the cats was found to be 2.58 ± 0.30% (mean ± SD). The ratios of MAC values between sevoflurane and halothane, enflurane and isoflurane in cats were very similar to those ratios found in humans and dogs. This observation suggests that the results of this study are correct and allows us to estimate unknown MAC values for sevoflurane in other species using known MAC values for other anesthetic agents.(Doi M, Yunoki H, Ikeda K: The minimum alveolar concentration of sevoflurane in cats. J Anesth 2: 113–114, 1988) 相似文献
24.
Takahashi S Ogasawara H Hiwatashi K Hata K Hori K Koizumi Y Sugiyama T 《Biomedical research (Tokyo, Japan)》2005,26(3):117-121
Our recent studies have demonstrated that the middle domain of N-acetyl-D-glucosamine (GlcNAc) 2-epimerase participates in the specificity for and binding of nucleotides. To identify the residue conferring nucleotide binding, amino acid substitutions were introduced in the human and rat GlcNAc 2-epimerases. The mutational analyses indicate that residue 171 of GlcNAc 2-epimerase is critical for the nucleotide binding of GlcNAc 2-epimerase. 相似文献
25.
Kai K Yoshida M Sugawara T Kato M Uchida K Yamaguchi R Tateyama S Furuhuma K 《Toxicologic pathology》2005,33(7):750-759
To investigate initial changes in the olfactory epithelium, vincristine sulphate (VCR) was administered intravenously once to male BALB/c mice on day 1 in comparison with unilateral bulbectomy (UBT). The light and electron microscopy of the olfactory epithelium, nerve and/or bulb with BrdU-morphometry was performed sequentially. Further, whole-body radioluminography was conducted at 1 and 24 hours postdose. Apoptosis and an increased number of mitotic cells with a tendency toward decreasing BrdU-positive olfactory epithelial cell counts were observed in olfactory epithelial cells at 6 hours postdose of VCR and became more pronounced at 24 hours postdose. These changes disappeared on days 4 or 15, but minimal axonal degeneration was seen in the olfactory nerve from day 4 onward. Semiquantitative measurement of VCR levels in the ethmoturbinals elicited high drug retention even 24 hours after administration. In contrast, UBT showed no effect on mitosis and BrdU-positive cell counts at 6 hours postdose, but severe lesions in the olfactory epithelium and nerve were seen on days 2, 4, and/or 15. The above results suggest that the initial event of VCR-induced apoptosis in the mouse olfactory epithelium would be mitotic arrest with high drug retention, unlike that evoked by UBT. 相似文献
26.
Repair of infarcted myocardium mediated by transplanted bone marrow-derived CD34+ stem cells in a nonhuman primate model 总被引:6,自引:0,他引:6
Yoshioka T Ageyama N Shibata H Yasu T Misawa Y Takeuchi K Matsui K Yamamoto K Terao K Shimada K Ikeda U Ozawa K Hanazono Y 《Stem cells (Dayton, Ohio)》2005,23(3):355-364
Rodent and human clinical studies have shown that transplantation of bone marrow stem cells to the ischemic myocardium results in improved cardiac function. In this study, cynomolgus monkey acute myocardial infarction was generated by ligating the left anterior descending artery, and autologous CD34(+) cells were transplanted to the peri-ischemic zone. To track the in vivo fate of transplanted cells, CD34(+) cells were genetically marked with green fluorescent protein (GFP) using a lentivirus vector before transplantation (marking efficiency, 41% on average). The group receiving cells (n = 4) demonstrated improved regional blood flow and cardiac function compared with the saline-treated group (n =4) at 2 weeks after transplant. However, very few transplanted cell-derived, GFP-positive cells were found incorporated into the vascular structure, and GFP-positive cardiomyocytes were not detected in the repaired tissue. On the other hand, cultured CD34(+) cells were found to secrete vascular endothelial growth factor (VEGF), and the in vivo regional VEGF levels showed a significant increase after the transplantation. These results suggest that the improvement is not the result of generation of transplanted cell-derived endothelial cells or cardiomyocytes; and raise the possibility that angiogenic cytokines secreted from transplanted cells potentiate angiogenic activity of endogenous cells. 相似文献
27.
28.
Fu J Hato M Ohmae H Matsuoka H Kawabata M Tanabe K Miyamoto Y Leafasia JL Chinzei Y Ohta N 《Parasitology research》2000,86(5):345-351
We analyzed the relationships between levels of antibody specific for merozoite surface glycoprotein-1 (MSP1) of Plasmodium falciparum and clinical manifestations in humans. We prepared recombinant MSP1 proteins representing block 3 (M3), block 6 (M6), blocks
1–6 (M1/6), and block 17. When we divided the slide-positive individuals in Guadalcanal into symptomatic and asymptomatic
groups, the former group showed lower IgG levels against M6 and block 17, but not against M3, than did the asymptomatic group
(P < 0.01). The possibility of nonspecific suppression was unlikely, given that the levels of antibody against poliomyelitis
virus observed in the two groups were almost the same. Among the IgG subclasses tested, production of cytophilic IgG3 seemed to be dominant. When we analyzed epitopes recognized by antibodies against block 17, a peptide (SSSNFLGIS) was preferentially
recognized by sera from asymptomatic individuals. These results suggest that clinical symptoms occurring during falciparum
malaria seem to be associated with the development of levels of antibody against particular epitopes on MSP1, which is under
the control of an immunoregulatory mechanism.
Received: 1 October 1999 / Accepted: 21 October 1999 相似文献
29.
Saito S Matsui T Kobayashi N Wakisaka H Mominoki K Matsuda S Taniguchi K 《Anatomy and embryology》2003,206(5):349-356
Expression patterns of glycoconjugates were examined by lectin histochemistry in the nasal cavity of the Japanese red-bellied newt, Cynops pyrrhogaster. Its nasal cavity consisted of two components, a flattened chamber, which was the main nasal chamber (MNC), and a lateral diverticulum called the lateral nasal sinus (LNS), which communicated medially with the MNC. The MNC was lined with the olfactory epithelium (OE), while the diverticulum constituting the LNS was lined with the vomeronasal epithelium (VNE). Nasal glands were observed beneath the OE but not beneath the VNE. In addition, a secretory epithelium was revealed on the dorsal boundary between the MNC and the LNS, which we refer to as the boundary secretory epithelium (BSE) in this study. The BSE seemed to play an important role in the construction of the mucous composition of the VNE. Among 21 lectins used in this study, DBA, SBA and Jacalin showed different staining patterns between the OE and the VNE. DBA staining showed remarkable differences between the OE and the VNE; there was intense staining in the free border and the supporting cells of the VNE, whereas there was no staining or weak staining in the cells of the OE. SBA and Jacalin showed different stainings in the receptor neurons for the OE and the VNE. Furthermore, UEA-I and Con A showed different stainings for the nasal glands. UEA-I showed intense staining in the BSE and in the nasal glands located in the ventral wall of the MNC (VNG), whereas Con A showed intense staining in the BSE and in the nasal glands located in the dorsal and medial wall of the MNC (DMNG). The DMNG were observed to send their excretory ducts into the OE, whereas no excretory ducts were observed from the VNG to the OE or the VNE. These results suggested that the secretion by the supporting cells as well as the BSE and the DMNG establishes that there are heterogeneous mucous environments in the OE and the VNE, although both epithelia are situated in the same nasal cavity. 相似文献
30.
Eisuke Kume Hisako Fujimura Naoaki Matsuki Masahito Ito Chinami Aruga Wataru Toriumi Kazuyuki Kitamura Kunio Doi 《Experimental and toxicologic pathology》2004,55(6):467-480
We have reported the streptozotocin (SZ)-induced hepatic lesions in the subacute phase (4 to 12 weeks after the treatment), which are characterized by appearance of oncocytic hepatocytes, cytomegalic hepatocytes and bile duct hyperplasia. In this study, we focused on the acute phase (6 to 48 hours after the treatment) of the SZ-induced hepatic lesions of mice to clarify the onset of the hepatic alterations, especially before the induction of hyperglycemia. Livers were taken from 8-week-old Crj:CD-1 (ICR) male mice at 6,12, 24, 36 and 48 hours after the 200 mg/kg b.w. of SZ-injection. SZ-induced hyperglycemia was noted at 36 and 48 hours after the treatment, but the hepatic changes including lipid peroxidation, mitochondrial swelling, peroxisome proliferation and inhibition of hepatocyte proliferation occurred before the elevation of the serum glucose levels. The present findings indicate the direct effects of SZ on hepatocytes rather than the secondary effects of diabetes, and certain correlations between the hepatocytic changes in the acute phase and those in the subacute one. In addition, ulcer and submucosal edema of the gallbladder were observed at 36 or 48 hours after the SZ-treatment, which can be a novel finding in SZ-treated animal. 相似文献