全文获取类型
收费全文 | 9792篇 |
免费 | 432篇 |
国内免费 | 132篇 |
专业分类
耳鼻咽喉 | 76篇 |
儿科学 | 155篇 |
妇产科学 | 63篇 |
基础医学 | 1066篇 |
口腔科学 | 269篇 |
临床医学 | 605篇 |
内科学 | 2674篇 |
皮肤病学 | 145篇 |
神经病学 | 664篇 |
特种医学 | 407篇 |
外科学 | 2092篇 |
综合类 | 37篇 |
预防医学 | 203篇 |
眼科学 | 115篇 |
药学 | 546篇 |
中国医学 | 15篇 |
肿瘤学 | 1224篇 |
出版年
2024年 | 4篇 |
2023年 | 75篇 |
2022年 | 115篇 |
2021年 | 277篇 |
2020年 | 161篇 |
2019年 | 177篇 |
2018年 | 230篇 |
2017年 | 184篇 |
2016年 | 239篇 |
2015年 | 247篇 |
2014年 | 358篇 |
2013年 | 433篇 |
2012年 | 656篇 |
2011年 | 704篇 |
2010年 | 387篇 |
2009年 | 338篇 |
2008年 | 611篇 |
2007年 | 639篇 |
2006年 | 640篇 |
2005年 | 699篇 |
2004年 | 678篇 |
2003年 | 628篇 |
2002年 | 612篇 |
2001年 | 106篇 |
2000年 | 75篇 |
1999年 | 119篇 |
1998年 | 166篇 |
1997年 | 120篇 |
1996年 | 116篇 |
1995年 | 79篇 |
1994年 | 73篇 |
1993年 | 74篇 |
1992年 | 44篇 |
1991年 | 43篇 |
1990年 | 35篇 |
1989年 | 38篇 |
1988年 | 28篇 |
1987年 | 18篇 |
1986年 | 19篇 |
1985年 | 15篇 |
1984年 | 16篇 |
1983年 | 15篇 |
1982年 | 7篇 |
1981年 | 11篇 |
1980年 | 8篇 |
1979年 | 8篇 |
1978年 | 8篇 |
1977年 | 4篇 |
1975年 | 6篇 |
1973年 | 3篇 |
排序方式: 共有10000条查询结果,搜索用时 406 毫秒
941.
Kitajima K Nakamoto Y Senda M Onishi Y Okizuka H Sugimura K 《Annals of nuclear medicine》2007,21(7):405-410
Objective The aim of this study was to assess the physiological uptake of 18F-fluoro-2-deoxyglucose (FDG) by an apparently normal testis with combined positron emission tomography–computed tomography
(PET/CT) and its correlation with age, blood glucose level, and testicular volume.
Methods The testicular uptake of 18F-FDG, expressed as the standardized uptake value (SUV), was measured on PET/CT images in 203 men. The correlation between
SUV and age, blood glucose level, and testicular volume was assessed.
Results The SUV in the total of 406 testes was 2.44 ± 0.45 (range 1.23–3.85). The SUV was 2.81 ± 0.43 (2.28–3.85) for 30–39 years
(n = 12), 2.63 ± 0.45 (1.77–3.75) for 40–49 years (n = 64), 2.46 ± 0.35 (1.44–3.15) for 50–59 years (n = 82), 2.51 ± 0.41 (1.50–3.46) for 60–69 years (n = 86), 2.43 ± 0.47 (1.42–3.29) for 70–79 years (n = 86), and 2.18 ± 0.45 (1.23–3.03) for 80–89 years (n = 76). When we calculated the mean SUV of bilateral testes in each patient, there were significant statistical differences
between those in the age group of 30–39 years and 80–89 years, 40–49 years and 80–89 years, and 50–60 years and 80–89 years,
when using an unpaired test with Bonferroni correction. The laterality index (|L − R|/(L + R) × 2) in 203 men was 0.066 ±
0.067 (0–0.522). There was a mild correlation between the mean SUV and age (r = −0.284, P < 0.001) as well as between the mean SUV and mean volume (r = +0.368, P < 0.001). There was no correlation between the mean SUV and glucose blood level (r = −0.065, P = 0.358).
Conclusions Some uptake of FDG is observed in the normal testis and declines slightly with age. Physiological FDG uptake in the testis
should not be confused with pathological accumulation. 相似文献
942.
Tokulmine J Nitta K Higa T Gushiken K Okayama H Sugahara K 《Masui. The Japanese journal of anesthesiology》2007,56(4):453-458
BACKGROUND: We checked for the occurrence of any leakage in an anesthesia circuit to estimate the present situation of airtightness of an anesthesia circuit in 55 anesthesia machines at various medical institutions in Okinawa. METHODS: Leakage was detected and measured by a leak checker. RESULTS: A certain degree of leakage was found in 28 of the anesthesia machines (51%). The average and maximal amounts of leakage in the anesthesia machines were 0.26, and 1.29 l x min(-1), respectively. Thirty-eight of anesthesia machines met the standards of a low flow leak test (69%). The average and maximal amounts of leakage in the inside circuit were 0.02, and 0.20 l x min(-1), respectively. The leak points of the inside circuit were present in a unidirectional valve for an oxygen sensor (14%) and for unknown reason (7%). The average and maximal amounts of leakage in the outside circuit were 0.24, and 1.29 l x min(-1), respectively. Leak points in the inside circuit were found in the corrugated breathing tube (82%) and canister (32%). CONCLUSIONS: Most instances of leakage of the above described anesthesia circuits were identified in the corrugated breathing tube and canister. As a result of our findings, we strongly recommend that these parts be checked very carefully during pre-anesthetic leak tests. 相似文献
943.
Akita S Murase T Yonenobu K Shimada K Masada K Yoshikawa H 《The Journal of bone and joint surgery. American volume》2007,89(9):1993-1999
BACKGROUND: Surgical treatment of forearm deformities in patients with multiple cartilaginous exostoses remains controversial. The purpose of the present study was to determine the reasonable indications for operative treatment and to evaluate long-term results of forearm surgery in these patients. METHODS: We retrospectively reviewed twenty-three patients (thirty-one forearms) after a mean duration of follow-up of nearly thirteen years. The mean age at the time of the initial procedure was eleven years. The patients underwent a variety of surgical procedures, including excision of exostoses; corrective procedures (lengthening of the radius or ulna and/or corrective osteotomy of the radius and/or ulna) and open reduction or excision of a dislocated radial head. Clinical evaluation involved the assessment of pain, activities of daily living, the cosmetic outcome, and the ranges of motion of the wrist, forearm, and elbow. The radiographic parameters that were assessed were ulnar variance, the radial articular angle, and carpal slip. RESULTS: Four patients had mild pain, and five patients had mild restriction of daily activities at the time of follow-up. Eight patients stated that the appearance of the forearm was unsatisfactory. Radiographic parameters (ulnar variance, radial articular angle, carpal slip) were initially improved; however, at the time of the final follow-up visit, the deformities had again progressed and showed no significant improvement. The only procedure that was associated with complications was ulnar lengthening. Complications included nonunion (three forearms), fracture of callus at the site of lengthening (two forearms), and temporary radial nerve paresis following an ulnar distraction osteotomy (one forearm). Excision of exostoses significantly improved the range of pronation (p = 0.036). CONCLUSIONS: In our patients with multiple cartilaginous exostoses, corrective osteotomy and/or lengthening of forearm bones was not beneficial. The most beneficial procedure was excision of exostoses. Reasonable indications for forearm surgery in these patients are (1) to improve forearm rotation and (2) to improve the appearance. 相似文献
944.
The authors report a case in which a 62-year-old woman with a history of subarachnoid hemorrhage due to a ruptured aneurysm was found to have a de novo paraclinoid aneurysm in the right internal carotid artery during a routine medical examination. Surgical clip placement was performed via a contralateral pterional approach under visual evoked potential (VEP) monitoring. The superior hypophyseal artery (SHA) was found to originate from the aneurysm body. The artery was temporarily occluded prior to application of the clip to the aneurysm neck. The VEP signal was lost 3 minutes after the SHA was occluded, and the potentials gradually recovered 10 minutes after the artery was released. The disappearance of VEP signal was reproducible with SHA occlusion. The clip was applied to the aneurysm body to preserve the origin of the SHA. The patient did not have any deterioration of vision after surgery. Intraoperative VEP monitoring can be used to help determine whether the SHA can be sacrificed safely. 相似文献
945.
946.
Toshinori Kawanami Kazumasa Fukuda Kazuhiro Yatera Takashi Kido Chiharu Yoshii Hatsumi Taniguchi Masamitsu Kido 《Journal of clinical microbiology》2009,47(2):496-498
We present the first case of severe pneumonia possibly caused by Leptotrichia species with oral bacteria. This was found in a healthy but elderly subject whose bronchoalveolar lavage fluid was analyzed by 16S rRNA gene sequencing analysis. The combination of this method and microscopic observation provided useful information for diagnosis and treatment. 相似文献
947.
Misu M Furukawa H Kwon HJ Shikinaka K Kakugo A Satoh T Osada Y Gong JP 《Journal of biomedical materials research. Part A》2009,89(2):424-431
We developed a novel in situ method for the control of F-actin assembly by using a synthetic photoresponsive polycation. The photoresponsive polycation mainly comprises a water-soluble cationic monomer and also contains a small amount of the monomer of a triphenylmethane leucohydroxide derivative (20 mol %), which is a well-known photochromic molecule that can be cationized in aqueous solution by ultra violet (UV) irradiation, thereby causing an increase in the total charge on the photoresponsive polycation. Thus, by exposure to UV radiation in aqueous solution, F-actin and the photoresponsive polycation start assembling into F-actin/photoresponsive polycation complexes of various morphologies such as bundles, coils, and networks, depending upon the concentrations of both the F-actin and salt. Further, localized UV irradiation can be applied in order to control the local formation of F-actin/photoresponsive polycation complexes. Thus, this technique provides a novel method for the spatiotemporal control of F-actin assembly and can be applied to investigate the unknown characteristics of F-actin. 相似文献
948.
Temperature-responsive glass coverslips with an ultrathin poly(N-isopropylacrylamide) layer 总被引:1,自引:0,他引:1
A temperature-responsive cross-linked polymer gel was covalently grafted onto glass coverslips by electron beam irradiation. The grafted thickness and amount of polymer as well as the surface wettability increased with the initial monomer concentration. When the monomer concentration was 5 wt.%, the grafted polymer density was 0.84microgcm(-2), and cells adhered and spread on the surface at 37 degrees C, but detached at 20 degrees C. In contrast, when the monomer concentration was 35 wt.%, the polymer density was 1.28microgcm(-2), and the surfaces were cell repellent even at 37 degrees C. These results show a remarkable contrast to those obtained from temperature-responsive polymer-grafted tissue culture polystyrene dishes, since various types of cells showed temperature-dependent cell adhesion/detachment when the grafted density was around 2microgcm(-2) on these surfaces. We discuss the possible molecular mechanisms underlying this discrepancy. 相似文献
949.
Tomoko Watanabe Takuto Fujii Takeshi Oya Naoki Horikawa Yoshiaki Tabuchi Yuji Takahashi Magotoshi Morii Noriaki Takeguchi Kazuhiro Tsukada Hideki Sakai 《The journal of physiological sciences : JPS》2009,59(2):113-122
Litttle is known about the function of aquaporin (AQP) water channels in human gastric cancer. In the upper or middle part
of human stomach, we found that expression level of AQP5 protein in intestinal type of adenocarcinoma was significantly higher
than that in accompanying normal mucosa. AQP5 was localized in the apical membrane of the cancer cells. On the other hand,
both AQP3 and AQP4 were not up-regulated in the adenocarcinoma. To elucidate the role of AQP5 in cancer cells, AQP5 was exogenously
expressed in a cell line of poorly differentiated human gastric adenocarcinoma (MKN45). The AQP5 expression significantly
increased the proportion of differentiated cells with a spindle shape, the activity of alkaline phosphatase, a marker for
the intestinal epithelial cell type of cancer cells, and the expression level of laminin, an epithelial cell marker. Treatment
of the MKN45 cells stably expressing AQP5 with HgCl2, an inhibitor of aquaporins, significantly decreased the proportion of differentiated cells and the activity of alkaline
phosphatase. Our results suggest that up-regulation of AQP5 may be involved in differentiation of human gastric cancer cells.
T. Watanabe and T. Fujii have equally contributed to this work. 相似文献
950.
Takayuki Ishii Tomoyuki Fujita Takashi Matsushita Koichi Yanaba Minoru Hasegawa Hiroko Nakashima Fumihide Ogawa Kazuhiro Shimizu Kazuhiko Takehara Thomas F. Tedder Shinichi Sato Manabu Fujimoto 《The American journal of pathology》2009,174(6):2225-2233
Prominent eosinophil infiltration is a characteristic of some forms of vasculitis, such as Churg-Strauss syndrome, also known as allergic granulomatous vasculitis. In the current study, we established a mouse model of cutaneous eosinophilic vasculitis by the cutaneous reverse passive Arthus reaction using IgE injection instead of IgG. Wild-type C57BL/6 mice were injected with IgE anti-trinitrophenyl antibodies, followed immediately by intravenous administration of trinitrophenyl bovine serum albumin. IgE-mediated immune complex challenge induced substantial hemorrhage with marked infiltration of eosinophils in which neutrophils, mast cells, and macrophages were also mixed. This finding contrasted remarkably with the neutrophil-dominant infiltration pattern in IgG-mediated immune complex challenge. In the lesion, the expression level of monocyte chemotactic protein-3 was increased, and anti-monocyte chemotactic protein-3 treatment resulted in a significant but incomplete blockade of eosinophil recruitment. Furthermore, mice lacking E-selectin, P-selectin, L-selectin, or intercellular adhesion molecule-1, as well as wild-type mice that received anti-vascular cell adhesion molecule-1-blocking antibodies were assessed for the IgE-mediated Arthus reaction. After 24 hours, the loss of P-selectin resulted in a significant reduction in eosinophil accumulation compared with both wild-type mice and other mouse mutants. Collectively, the Fc class of immunoglobulins, which forms these immune complexes, critically determines the disease manifestation of vasculitis. The IgE-mediated cutaneous reverse passive Arthus reaction may serve as an experimental model for cutaneous eosinophilic infiltration in vasculitis as well as in other diseases.Eosinophilia is associated with a variety of infectious, allergic, and inflammatory diseases, including helminth infection, asthma, allergic rhinitis, atopic skin diseases, and inflammatory bowel disease, as well as idiopathic hypereosinophilic syndrome.1,2 Eosinophils also play a major role in some forms of vasculitis.3,4 The most prominent example is Churg-Strauss syndrome (CSS; also known as allergic granulomatous vasculitis), which occurs in patients with a history of asthma and is characterized by a necrotizing vasculitis of small arteries and veins, with extravascular granulomas and a marked eosinophilia in the lesion and in the peripheral blood.3,5,6,7 Activated eosinophils induce tissue destruction and inflammation, while the mechanism that generates eosinophilic vasculitis remains unclear. Several lines of evidence have suggested a role of IgE in CSS. Serum IgE levels are elevated and often correlate with disease activity in CSS. IgE deposition in affected blood vessels is also observed occasionally.8 Therefore, the pathogenesis of CSS may involve IgE through immune complex (IC) deposition containing IgE.IC-mediated tissue injury has been implicated in the pathogenesis of vasculitis syndrome. The classical experimental model for such IC-mediated tissue injury is the Arthus reaction, which induces edema and hemorrhage in the skin.9,10 Currently, most the frequently used is the reverse passive Arthus reaction, in which IgG antibody (Ab) is injected at the site where the investigator wishes the inflammatory response to develop, followed immediately by an intravenous application of the antigen.9,10,11,12,13 IgG-induced IC-mediated vascular tissue damage requires the accumulation of neutrophils and mast cells.11,12,14,15,16,17,18 This process is tightly regulated by chemotactic factors and adhesive interactions between leukocytes and the vascular endothelium, including selectins, integrins, and Ig superfamily members, including intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1).19,20,21 Nonetheless, it remains unknown which molecules are responsible for the development of eosinophilic vasculitis.In this study, an experimental mouse model of cutaneous eosinophilic vasculitis was established using the IgE-mediated cutaneous reverse passive Arthus reaction. This model developed a marked accumulation of eosinophils surrounding the blood vessels, resulting in substantial hemorrhage. Thus, this model demonstrates that the Fc class of Ig that forms IC can critically determine the disease manifestation. 相似文献