全文获取类型
收费全文 | 8438篇 |
免费 | 383篇 |
国内免费 | 30篇 |
专业分类
耳鼻咽喉 | 52篇 |
儿科学 | 150篇 |
妇产科学 | 76篇 |
基础医学 | 1062篇 |
口腔科学 | 227篇 |
临床医学 | 553篇 |
内科学 | 2578篇 |
皮肤病学 | 202篇 |
神经病学 | 496篇 |
特种医学 | 304篇 |
外科学 | 1278篇 |
综合类 | 19篇 |
预防医学 | 312篇 |
眼科学 | 142篇 |
药学 | 630篇 |
中国医学 | 11篇 |
肿瘤学 | 759篇 |
出版年
2021年 | 139篇 |
2020年 | 92篇 |
2019年 | 96篇 |
2018年 | 143篇 |
2017年 | 110篇 |
2016年 | 127篇 |
2015年 | 138篇 |
2014年 | 155篇 |
2013年 | 203篇 |
2012年 | 306篇 |
2011年 | 354篇 |
2010年 | 194篇 |
2009年 | 169篇 |
2008年 | 351篇 |
2007年 | 369篇 |
2006年 | 338篇 |
2005年 | 364篇 |
2004年 | 375篇 |
2003年 | 327篇 |
2002年 | 356篇 |
2001年 | 284篇 |
2000年 | 288篇 |
1999年 | 245篇 |
1998年 | 91篇 |
1997年 | 79篇 |
1996年 | 85篇 |
1995年 | 74篇 |
1994年 | 75篇 |
1993年 | 74篇 |
1992年 | 267篇 |
1991年 | 228篇 |
1990年 | 189篇 |
1989年 | 245篇 |
1988年 | 213篇 |
1987年 | 218篇 |
1986年 | 217篇 |
1985年 | 189篇 |
1984年 | 120篇 |
1983年 | 95篇 |
1982年 | 47篇 |
1981年 | 42篇 |
1979年 | 83篇 |
1978年 | 53篇 |
1977年 | 48篇 |
1975年 | 44篇 |
1972年 | 46篇 |
1971年 | 46篇 |
1970年 | 42篇 |
1969年 | 47篇 |
1968年 | 45篇 |
排序方式: 共有8851条查询结果,搜索用时 234 毫秒
81.
Bradykinin Stimulates Type II Alveolar Cells to Release Neutrophil and Monocyte Chemotactic Activity and Inflammatory Cytokines 总被引:2,自引:0,他引:2 下载免费PDF全文
Sekiya Koyama Etsuro Sato Hiroshi Nomura Keishi Kubo Masakazu Miura Tetsuji Yamashita Sonoko Nagai Takateru Izumi 《The American journal of pathology》1998,153(6):1885-1893
In the present study, we evaluated the potential of bradykinin (BK) to induce the release of neutrophil and monocyte chemotactic activity (NCA and MCA) and cytokines from an alveolar type II epithelial cell line, A549 cells. BK stimulated A549 cells to release NCA and MCA in a dose- and time-dependent manner (P < 0.001). Checkerboard analysis revealed that both NCA and MCA involved chemotactic and chemokinetic activity. Molecular sieve column chromatography showed three molecular weight masses (near 19 kd, 8 kd, and 400 d) for NCA and several molecular weight peaks (near 66 kd, 25 kd, 19 kd, 16 kd, and 400 d) for MCA. The release of NCA and MCA was inhibited by cycloheximide and lipoxygenase inhibitors (P < 0.01). The NCA and MCA were inhibited by leukotriene B4 (LTB4) receptor antagonist (P < 0.01), and the concentration of LTB4 was high enough for NCA and MCA. Antibodies to interleukin (IL)-8 and granulocyte colony-stimulating factor (G-CSF) attenuated NCA (P < 0.01), and antibodies to monocyte chemotactic protein-1 (MCP-1), G-CSF, and transforming growth factor (TGF)-β attenuated MCA (P < 0.01). The levels of IL-8, G-CSF, MCP-1, and TGF-β increased time dependently (P < 0.01). BK also stimulated the release of ILeukin-6 from A549 cells (P < 0.001). The receptors responsible for the release of NCA, MCA, and individual chemokines involved both BKB1 and BKB2 receptors. These data suggest that BK may stimulate alveolar type II pneumocytes to release inflammatory cytokines, which then may modulate the lung inflammation. 相似文献
82.
Muneo Igarashi Nozomi Hosoda Yuki Bando Kaoru Shimanuki Wataru Sunaoshi Hiroyuki Shirai Hisao Miura 《Journal of clinical immunology》1992,12(5):335-340
An anticarbamazepine antibody was detected in the serum of a patient with severe carbamazepine-induced serum sickness. We found that the patient's T cells and IgG antibody recognized an epitope which appeared in subjects showing an allergic reaction, as well as that in subjects who showed no allergic reaction, after long-term carbamazepine therapy. These results show that an anti-carbamazepine immune response does not occur in the majority of subjects who undergo long-term carbamazepine therapy without developing allergic symptoms, although the immunodominant haptenic epitope of carbamazepine is present in their sera. 相似文献
83.
Comparative studies with various substrains of Mycobacterium bovis BCG on the production of an antigenic protein, MPB70. 总被引:14,自引:7,他引:14 下载免费PDF全文
A protein, isolated and purified from the unheated culture filtrate of Mycobacterium bovis BCG (substrain Tokyo 172) and designated MPB70, elicited a delayed skin reaction in guinea pigs sensitized with viable cells of BCG but not in those sensitized with heat-killed cells. The skin reaction reached the maximum 4 to 8 weeks after the inoculation of the BCG and then decreased gradually, resulting in conversion to negative after 20 weeks, whereas the skin reaction to purified protein derivative (PPD) continued to be positive. Guinea pigs immunized with viable cells of various substrains of BCG were skin tested with MPB70 and PPD. Guinea pigs immunized with the BCG substrain Tokyo 172 and the substrain Moreau (Brazil) showed strong delayed skin reactions to both MPB70 and PPD. On the other hand, guinea pigs immunized with the Pasteur substrain 1173P2, the Glaxo substrain 1077, the Copenhagen substrain 1331, the Tice substrain, or the Beijing substrain 64-42 showed negative skin reactions to MPB70, whereas they were strongly positive to PPD. In a two-dimensional acrylamide gel electrophoretic analysis of proteins from the culture filtrates of the BCG substrains, the culture filtrates of the Tokyo and Moreau substrains showed the spot of MPB70 on the gel slabs, whereas those of the other BCG substrains did not. 相似文献
84.
The role of the solitary and paramedian reticular nuclei in mediating cardiovascular reflex responses from carotid baro- and chemoreceptors 总被引:4,自引:4,他引:4
1. With dye-filled micro-electrodes single neurones in the medulla of anaesthetized paralysed cats were identified which: (a) fired rhythmically in synchrony with or were modulated by the cardiac cycle, and which ceased firing with occlusion of the ipsilateral common carotid artery (carotid sinus baroreceptor neurones); (b) were excited by stimulation of carotid body chemoreceptors by close intra-arterial injection of lobeline into the thyroid artery (carotid body chemoreceptor neurones).2. Twelve carotid baroreceptor neurones were identified, in thirty-three cats, nine of which were localized in the intermediate area of the nucleus of the solitary tract (NTS) within 1 mm ahead of or behind the obex; three units were located either in the parahypoglossal area or the dorsal portion of the paramedian reticular nucleus (PRN).3. Of the twenty-one carotid chemoreceptor neurones which were identified, thirteen were localized in the NTS, three in the parahypoglossal area and four in the dorsal PRN.4. Bilateral lesions of the paramedian reticular area of medulla destroying the PRN, abolished or reversed the depressor response to electrical stimulation of myelinated fibres of the carotid sinus nerve (CSN), attenuated the depressor response to carotid sinus stretch and augmented the pressor response to chemoreceptor stimulation by lobeline. Such lesions did not significantly alter the reflex heart rate responses.5. Small lesions of the NTS within an area 1 mm rostral to the obex abolished all reflex blood pressure and heart rate responses to electrical stimulation of the CSN or natural stimulation of carotid baro- or chemoreceptors.6. Baroreceptors and chemoreceptors of the CSN project both to the intermediate zone of the NTS and to more medial areas of the medulla, particularly the dorsal PRN and parahypoglossal area.7. The PRN serves to mediate the reflex depressor, but not cardio-vagal, response from myelinated baroreceptors and buffers the pressor responses from chemoreceptors; it may serve as an important area integrating cardiovascular activity descending from forebrain, brain stem and cerebellum with baroreceptor reflexes.8. Cardiovascular reflex responses arising from non-myelinated baroreceptors and all chemoreceptors are mediated by neurones in the intermediate area of the NTS. 相似文献
85.
Chuji Aso Toyoki Kunitake Masanobu Miura Katsuhisa K
yama 《Macromolecular chemistry and physics.》1968,117(1):153-162
Polymerizations of malealdehyde were carried out with alkalimetal alkoxides, AlEt3, pyridine, AlEt3? TiCl4 and BF3OEt2 as catalysts. All the polymers obtained with other catalysts than AlEt3 and AlEt3? TiCl4 were composed only of the cyclized unit (dialkoxydihydrofuran ring) (> 95%) and the 1.2-addition structure (< 5%). IR spectra of the polymers obtained with AlEt3 and AlEt3? TiCl4 catalysts were suggestive of the presence of five-membered lactone rings which may occur as a result of termination by hydride transfer. The steric structure (cis vs. trans) of the dialkoxydihydrofuran ring in polymer was inferred from the comparison of the IR spectra of the polymer with those of the isomeric dialkoxydihydrofurans in the 800 cm?1 region. Anionic catalysts gave higher contents of the cis configuration, while coordinated anionic catalysts gave comparable amounts of the cis and trans structures. 相似文献
86.
Detection of IgA-class circulating immune complexes (CIC) in sera from patients with IgA nephropathy using a solid-phase anti-C3 Facb enzyme immunoassay (EIA) 总被引:3,自引:0,他引:3 下载免费PDF全文
M Yagame Y Tomino M Miura T Tanigaki T Suga Y Nomoto H Sakai 《Clinical and experimental immunology》1987,67(2):270-276
The detection of circulating immune complexes (CIC) in sera from patients with IgA nephropathy is described. A solid-phase anti-C3 Facb enzyme immunoassay (EIA) was employed for detection of IgA-, IgG- and IgM-CIC in sera. The C1q-binding enzyme assay was also used for the detection of CIC in sera from these patients and healthy adults. Twenty-two patients with IgA nephropathy, 14 patients with other glomerular diseases and 19 healthy adults were examined by anti-C3 Facb EIA. The levels of IgA-CIC in sera from patients with IgA nephropathy were significantly higher than those in sera from patients with other glomerular diseases and healthy adults. CIC measured by the C1q-binding enzyme assay was detected in some patients with IgA nephropathy. The levels of serum IgA in patients with IgA nephropathy were significantly higher than those in patients with other glomerular diseases and healthy adults. However, there was no significant correlation between the levels of IgA-CIC in sera and those of serum IgA in patients with IgA nephropathy. There was also no significant correlation between the levels of IgA-CIC in sera and the degree of histopathological injuries in the patients. It is concluded that the solid-phase anti-C3 Facb EIA is useful for the detection of IgA-CIC in sera from patients with IgA nephropathy. 相似文献
87.
T-cell variant of classical Hodgkin's lymphoma with nodal and cutaneous manifestations demonstrated by single-cell polymerase chain reaction 总被引:4,自引:0,他引:4
Willenbrock K Ichinohasama R Kadin ME Miura I Terui T Meguro K Fukuhara O DeCoteau JF Hansmann ML 《Laboratory investigation; a journal of technical methods and pathology》2002,82(9):1103-1109
The atypical cells of CD30(+) cutaneous lymphoproliferative disorders (CD30CLD) are commonly of T-cell origin and frequently have a similar morphology as Hodgkin or Reed-Sternberg cells of Hodgkin's lymphoma (HL). HL is one of the tumors associated with CD30CLD. Although most studies support a B-cell derivation of the tumor cells in HL, recently a few cases of classical HL with T-cell genotype have been reported. We report a patient who presented with CD30CLD whose lymph nodes showed classical HL of mixed cellularity subtype at presentation. By single-cell PCR, the same clonal gene rearrangements of the T cell receptor-beta gene locus could be assigned to the CD30(+) and CD15(+) cells of both skin and lymph node. In a lymph node biopsy specimen taken in relapse after several courses of chemotherapy, the CD30(+) tumor cells were abundant. The T cell-derived tumor cells displayed aberrant expression of the Pax-5 gene in all specimens. A common clonal origin of both CD30CLD and HL of the lymph node in the patient presented here suggests that HL with T-cell genotype exists in association with CD30CLD as well as in sporadic cases and may share clonal origin with the skin tumor. 相似文献
88.
Host resistance to Listeria monocytogenes infection is enhanced but resistance to Staphylococcus aureus infection is reduced in acute graft-versus-host disease in mice 下载免费PDF全文
Miura T Mizuki D Sasaki S Hasegawa S Sashinami H Nakane A 《Infection and immunity》2000,68(7):4340-4343
Acute graft-versus-host disease (GVHD) is characterized by the production of high levels of T helper 1 (Th1)-type cytokines. Bone marrow transplantation from allogeneic C57BL/6 cells to CBF(1) mice produced acute GVHD. Host resistance to Th1-driven Listeria monocytogenes was enhanced, whereas host resistance to Th2-driven Staphylococcus aureus was reduced during acute GVHD. These results suggest that opposite host responses are observed between Th1-driven and Th2-driven bacterial infections in acute GVHD. 相似文献
89.
Noriko Kimura Mika Watanabe Tsuneo Ookuma Wakako Miura Takao Noshiro Yukio Miura Hiroshi Nagura 《Endocrine pathology》1994,5(3):178-182
Pheochromocytoma usually shows prominent nuclear atypia, but the presence of such atypical cells is known to be an unreliable
predictor of malignancy. DNA ploidy of pheochromocytomas has been analyzed by flow cytometry or photospectrometry on paraffinem-bedded
tissue, but the results were controversial. We performed DNA analysis on cytology specimens of 11 pheochromocytomas using
an image analysis system. All tumors had a mixed pattern of a large population of diploid cells and a small population of
polyploid cells. DNA content correlated with nuclear size, and larger cells had more DNA content. Such larger tumor cells
had polyploid nuclei, such as 4 C, 8 C, 16 C, and 32 C, in both malignant and benign pheochromocytomas. The larger polyploid
nuclei may result from difficulty of duplication at the mitotic phase of the cell cycle. 相似文献
90.
Hisao Kondo Midori Miura Yoshinori Itokawa 《Pflügers Archiv : European journal of physiology》1993,422(4):404-406
To clarify the mechanism of oxidative stress in skeletal muscle atrophied by immobilization, we investigated the change of antioxidant enzyme activities in a typical slow red muscle, the soleus. Atrophied soleus muscles were collected from male Wistar rats (16 weeks old), one ankle joint of which had been immobilized in the fully extended position for 7 days. Also, soleus muscles were collected from intact age-matched rats as control. The activities of Mn-containing superoxide dismutase (Mn-SOD), Cu,Zn-containing superoxide dismutase (Cu,Zn-SOD), Se-dependent glutathione peroxidase (Se-GSHPx), glutathione S-transferase (GST), catalase, and glutathione reductase (GSSGRx) were measured. The activities of Cu,Zn-SOD, GST, and GSSGRx were significantly higher in atrophied muscles, while the others were unchanged. Increased Cu,Zn-SOD and unchanged Mn-SOD levels might reflect increased generation of superoxide anions in the cytoplasm rather than in the mitochondria. Owing to the enhancement of Cu,Zn-SOD and the unaltered Se-GSHPx and catalase activities, hydrogen peroxide is thought to be increased in the cytoplasm. Because there is also an increase of iron in the microsomes of atrophied muscles, the production of hydroxyl radicals, the most aggressive of radicals, might consequently be elevated. 相似文献