全文获取类型
收费全文 | 8497篇 |
免费 | 391篇 |
国内免费 | 48篇 |
专业分类
耳鼻咽喉 | 73篇 |
儿科学 | 154篇 |
妇产科学 | 56篇 |
基础医学 | 984篇 |
口腔科学 | 208篇 |
临床医学 | 547篇 |
内科学 | 2286篇 |
皮肤病学 | 205篇 |
神经病学 | 591篇 |
特种医学 | 376篇 |
外国民族医学 | 2篇 |
外科学 | 1468篇 |
综合类 | 57篇 |
预防医学 | 145篇 |
眼科学 | 227篇 |
药学 | 595篇 |
中国医学 | 29篇 |
肿瘤学 | 933篇 |
出版年
2023年 | 44篇 |
2022年 | 73篇 |
2021年 | 178篇 |
2020年 | 79篇 |
2019年 | 109篇 |
2018年 | 166篇 |
2017年 | 123篇 |
2016年 | 178篇 |
2015年 | 208篇 |
2014年 | 225篇 |
2013年 | 293篇 |
2012年 | 487篇 |
2011年 | 564篇 |
2010年 | 335篇 |
2009年 | 274篇 |
2008年 | 447篇 |
2007年 | 483篇 |
2006年 | 486篇 |
2005年 | 515篇 |
2004年 | 495篇 |
2003年 | 490篇 |
2002年 | 507篇 |
2001年 | 137篇 |
2000年 | 140篇 |
1999年 | 146篇 |
1998年 | 121篇 |
1997年 | 115篇 |
1996年 | 124篇 |
1995年 | 73篇 |
1994年 | 80篇 |
1993年 | 77篇 |
1992年 | 107篇 |
1991年 | 100篇 |
1990年 | 76篇 |
1989年 | 61篇 |
1988年 | 80篇 |
1987年 | 67篇 |
1986年 | 44篇 |
1985年 | 45篇 |
1984年 | 51篇 |
1982年 | 30篇 |
1981年 | 30篇 |
1980年 | 36篇 |
1979年 | 51篇 |
1978年 | 37篇 |
1977年 | 34篇 |
1975年 | 33篇 |
1974年 | 32篇 |
1968年 | 30篇 |
1967年 | 30篇 |
排序方式: 共有8936条查询结果,搜索用时 15 毫秒
1.
Shingo Hashimoto Masaki Katsurada Rie Muramatsu Kumiko Asai Kenichiro Tanaka Kensuke Hayashi Yoshiaki Kibe Koichiro Nakajima Yukiko Hattori Hiromitsu Iwata Jun-etsu Mizoe Hiroyuki Ogino Yuta Shibamoto 《Practical radiation oncology》2019,9(2):e149-e155
Purpose
Suppression of respiratory movement of the liver would be desirable for high-precision radiation therapy for liver tumors. We aimed to investigate the effect of our original device-free compressed shell fixation method and breathing instruction on suppression of respiratory movement. The characteristics of liver motion based on the movement of a fiducial marker were also analyzed.Methods and Materials
First, respiratory amplitudes of the liver with the device-free compressed shell were analyzed from the data of 146 patients. The effect of this shell fixing method on liver movement was evaluated. Second, as another cohort study with 166 patients, interfractional internal motion of the liver for patients fixed in the shell was calculated using the fiducial marker coordinate data of images for position setting before daily irradiation. Third, in another 12 patients, intrafractional internal motion was calculated from the fiducial marker coordinate data using x-ray images before and after irradiation.Results
The median respiratory movement without the shell, after fixing with the shell, and after instructing on the breathing method with the shell was 14.2 (interquartile range, 10.7-19.8), 11.5 (8.6-17.5), and 10.4 mm (7.3-15.8), respectively. Systematic and random errors of interfractional internal motion were all ≤2 mm in the left-right and anteroposterior directions and 3.7 and 3.0 mm, respectively, in the craniocaudal direction. Systematic and random errors of intrafractional internal motion were all ≤1.3 mm in the left-right and anteroposterior directions and 0.8 and 2.4 mm, respectively, in the craniocaudal direction.Conclusions
The device-free compressed shell fixation method was effective in suppressing the respiratory movement of the liver. Irradiation position matching using the fiducial marker can correct the interfractional internal motion on each day, which would contribute to the reduction of the margin to be given around the target. 相似文献2.
T. Yoshikawa H. Tohyama H. Enomoto H. Matsumoto Y. Toyama K. Yasuda 《Knee surgery, sports traumatology, arthroscopy》2006,14(9):804-810
The aim of this study was to clarify vascular endothelial growth factor (VEGF) expression and angiogenesis in the patellar tendon (PT) autograft in the early phase after anterior cruciate ligament (ACL) reconstruction using a rabbit model. The right knees of 30 Japanese white rabbits underwent ACL reconstruction using the medial third of the PT complex. We evaluated the grafted tendon at 1, 2, 3, 4, and 8 weeks after ACL reconstruction by immunohistology for proliferating cell nuclear antigen, VEGF, and CD31, which is a marker for vascular endothelial cells. At week 1 , few cells were observed at the midsubstance of the grafted tendon. A number of proliferating cells were observed at the surface area of the PT graft 2 weeks after graft transplantation, while no vessel formation was observed in the graft at the same time. VEGF was highly expressed 2-3 weeks postoperatively. Vessel formation in the PT graft increased with time from 3 to 8 weeks after ACL reconstruction. The rates of proliferating cells and VEGF-expressing cells decreased with time from 3 to 8 weeks. This study has suggested that VEGF is involved in the graft remodeling process particularly at the early phase after ACL reconstruction. 相似文献
3.
4.
5.
Alf Lamprecht Hiromitsu Yamamoto Hirofumi Takeuchi Yoshiaki Kawashima 《European journal of pharmaceutics and biopharmaceutics》2005,59(2):367-371
5-Fluorouracil (5-FU) in combination with leucovorin (LV) is nowadays the standard treatment in colon cancer and would be a candidate to be delivered orally to the colon. Eudragit P-4135F or Eudragit RS100 were used separately to prepare microspheres by an oil/oil emulsification process trapping 5-FU and LV simultaneously. Scanning electron microscopy permitted a structural analysis, process parameters were analyzed and drug loading and release profiles were recorded. Particle size varied between 123 (RS100) and 146 microm (P-4135F). Generally, higher encapsulation rates were found with RS100 (5-FU, 60.3+/-9.7%; LV, 81.4+/-8.6%) compared to P-4135F (5-FU, 48.3+/-2.0%; LV, 55.4+/-2.7%). Microparticles made from Eudragit RS100 released the incorporated drug combination within 8 h not exhibiting general differences between the kinetics of both drugs. P-4135F was found to maintain the undesired 5-FU release at pH 6.8 lower than 25% within 4 h while at pH 7.4, a nearly immediate release (within 15 min) was observed. Although the release was similar at pH 7.4, at pH 6.8 LV showed a distinct initial drug loss of about 60% and a complete release within 2 h. SEM analyses revealed a substantial presence of LV crystals on the particle surface provoking a distinct burst effect of LV. These observations were concluded to be related to the high lipophilicity of P-4135F provoking a separation between P-4135F and LV during the preparation process. 相似文献
6.
Masahiro Miyashita Junko Otsuki Yosuke Hanai Yoshiaki Nakagawa Hisashi Miyagawa 《Toxicon》2007,50(3):428-437
Scorpion venoms are composed of a number of neurotoxic peptides. A variety of toxins have been isolated from the venoms of scorpions of the family Buthidae, however, little interest has been paid to non-Buthidae scorpions. In this study, we examined the toxicity of the venom of Liocheles australasiae (Hemiscorpiidae) to mice and crickets, and characterized the peptide components by HPLC and mass spectrometry. Over 200 components were detected in the L. australasiae venom by LC/MS analysis, with components of molecular masses ranging from 500 to 5000 Da being particularly abundant. A number of peptides contained two to four disulfide bridges, which was estimated based on the mass difference after derivatization of Cys residues. A peptide having a monoisotopic molecular mass of 7781.6 Da and four disulfide bridges was isolated from the venom. The peptide has a primary structure similar in terms of the position of eight Cys residues to those observed in several peptides found from scorpions, ticks and insects, although biological roles of these peptides are unknown. 相似文献
7.
Testicular cancer with tumor thrombus extending to the inferior vena cava successfully removed using veno-venous bypass: A case report 总被引:1,自引:0,他引:1
Yoshiaki Kinebuchi Teruyuki Ogawa Haruaki Kato Yasuhiko Igawa Osamu Nishizawa Shin-Ichi Miyagawa 《International journal of urology》2007,14(5):458-460
A 33-year-old man with a left testicular tumor was referred to Shinshu University Hospital for advanced therapy. Radiographic imaging revealed multiple metastases in the retroperitoneal lymph nodes (RPLN) and bilateral lungs, as well as tumor thrombus that extended from the left renal vein to the inferior vena cava (IVC) adjacent to the right atrium. After orchidectomy, a diagnosis of embryonal carcinoma was made with a clinical stage of T1N2M1bS3, which has a poor prognosis, based on the International Germ Cell Cancer Collaborative Group consensus. After eight courses of chemotherapy, the patient's tumor markers normalized and the lung metastases disappeared, but the RPLN and tumor thrombus remained. Retroperitoneal lymph node dissection and thrombectomy were performed using a veno-venous bypass (VVB). The pathological examination of the thrombus revealed a mature teratoma. The patient has been disease-free since surgery. 相似文献
8.
Solitary fibrous tumors (SFT) have recently been established to be of mesenchymal origin. Although there are numerous reports
of SFTs arising from the pleura, reports of the tumor arising from extrapleural sites are comparatively rare [Fletcher CDM,
Unni K, Mertens F (eds) World Health Organization classification of tumors, pathology & genetics, tumors of soft tissue and bone. IARC Press, Lyon, pp 86–901, 2002]. We report a case of SFT arising in the inguinal region. 相似文献
9.
Shinichiro Yasumoto Jun Tsujita Shuhei Imayama Yoshiaki Hori 《The Journal of dermatology》1996,23(7):499-501
We report a case of Gianotti-Crosti syndrome associated with human herpesvirus-6 (HHV-6) infection. An eight-month-old girl developed monomorphous papules on her cheeks, buttocks, and extremities after the subsidence of exanthema subitum. Viral antibody analysis confirmed primary HHV-6 infection. HHV-6 may be added to the list of causative agents of Gianotti-Crosti syndrome. 相似文献
10.
Michiko Oka Y. Itoh Shigeru Tatsumi F.-H. Ma Yojiro Ukai Yoshiaki Yoshikuni Kiyoshi Kimura 《Naunyn-Schmiedeberg's archives of pharmacology》1997,356(2):189-196
The effect of (+)-5-oxo-D-prolinepiperidinamide monohydrate (NS-105), a novel cognition enhancer, on adenylate cyclase activity
was investigated in cultured neurons of the mouse cerebral cortex. NS-105 (10–7 and 10–6 M) inhibited forskolin-stimulated cyclic AMP formation, an action that was dependent on pertussis toxin-sensitive G proteins.
Conversely, in pertussis toxin-pretreated neurons, NS-105 (10–7 –10–5 M) significantly enhanced the forskolin-stimulated cyclic AMP formation, and this action was completely reversed by cholera
toxin. A metabotropic glutamate receptor agonist (1S, 3R)-1-aminocyclopentane-1, 3-dicarboxylic acid (1S, 3R-ACPD) produced
similar bi-directional actions on the cyclic AMP formation. Both of these inhibitory and facilitatory actions of NS-105 and
1S, 3R-ACPD were blocked by L(+)-2-amino-3-phosphopropinoic acid (L-AP3). NS-105 (10–6 M) and 1S, 3R-ACPD (10–4 M) significantly enhanced isoproterenol- and adenosine-stimulated cyclic AMP formation. The enhancement of such Gs-coupled
receptor agonists-stimulated cyclic AMP formation was also produced by quisqualate but not by L(+)-2-amino-4-phosphonobutanoate
(L-AP4). The phosphoinositides hydrolysis was enhanced by 1S, 3R-ACPD (10–4 M) but not by NS-105 (10–6 M), however, 1S, 3R-ACPD-induced increase in phosphoinositides turnover was attenuated by NS-105. These findings suggest
that NS-105 stimulates metabotropic glutamate receptor subclasses that are coupled both negatively and positively to adenylate
cyclase, but it acts as an antagonist at the receptor subclasses that are linked to phosphoinositides hydrolysis.
Received: 3 February 1997 / Accepted: 25 April 1997 相似文献