全文获取类型
收费全文 | 12476篇 |
免费 | 686篇 |
国内免费 | 85篇 |
专业分类
耳鼻咽喉 | 142篇 |
儿科学 | 231篇 |
妇产科学 | 118篇 |
基础医学 | 1537篇 |
口腔科学 | 251篇 |
临床医学 | 777篇 |
内科学 | 3371篇 |
皮肤病学 | 287篇 |
神经病学 | 789篇 |
特种医学 | 465篇 |
外科学 | 2206篇 |
综合类 | 56篇 |
预防医学 | 264篇 |
眼科学 | 209篇 |
药学 | 840篇 |
中国医学 | 22篇 |
肿瘤学 | 1682篇 |
出版年
2024年 | 15篇 |
2023年 | 153篇 |
2022年 | 286篇 |
2021年 | 466篇 |
2020年 | 263篇 |
2019年 | 346篇 |
2018年 | 404篇 |
2017年 | 321篇 |
2016年 | 354篇 |
2015年 | 337篇 |
2014年 | 441篇 |
2013年 | 480篇 |
2012年 | 831篇 |
2011年 | 812篇 |
2010年 | 464篇 |
2009年 | 412篇 |
2008年 | 677篇 |
2007年 | 759篇 |
2006年 | 702篇 |
2005年 | 696篇 |
2004年 | 687篇 |
2003年 | 620篇 |
2002年 | 609篇 |
2001年 | 219篇 |
2000年 | 197篇 |
1999年 | 224篇 |
1998年 | 120篇 |
1997年 | 112篇 |
1996年 | 98篇 |
1995年 | 77篇 |
1994年 | 70篇 |
1993年 | 63篇 |
1992年 | 103篇 |
1991年 | 81篇 |
1990年 | 94篇 |
1989年 | 90篇 |
1988年 | 95篇 |
1987年 | 68篇 |
1986年 | 55篇 |
1985年 | 58篇 |
1984年 | 35篇 |
1983年 | 48篇 |
1982年 | 23篇 |
1981年 | 20篇 |
1979年 | 26篇 |
1978年 | 11篇 |
1977年 | 15篇 |
1974年 | 15篇 |
1972年 | 12篇 |
1969年 | 13篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Yasushi Sano Hirohisa Machida Kuang‐I. Fu Hiroaki Ito Takahiro Fujii 《Digestive endoscopy》2004,16(Z1):S93-S96
The goal of endoscopic mucosal resection (EMR) is to allow the endoscopist to obtain tissue or resect lesions not previously amenable to standard biopsy or excisional techniques and to remove malignant lesions without open surgery. In this article, we describe the results of conventional EMR and EMR using an insulation‐tipped (IT) electrosurgical knife (submucosal dissection method) for large colorectal mucosal neoplasms and discuss the problems and future prospects of these procedures. At present, conventional EMR is much more feasible than EMR using IT‐knife from the perspectives of time, money, complication, and organ preservation. However, larger lesions tend to be resected in a piecemeal fashion; and it is difficult to confirm whether EMR has been complete. For accurate histopathological assessment of the resected specimen en bloc EMR is desirable although further experience is needed to establish its safety and efficacy. Further improvements of in EMR with special knife techniques are required to simply and safely remove large colorectal neoplasms. 相似文献
52.
Hiroyuki Oka Taiji Kondoh Atsushi Seichi Takahiro Hozumi Kozo Nakamura 《Journal of orthopaedic science》2006,11(1):13-19
Background Few previous studies have analyzed the incidence of bone metastases in a defined population of Japanese breast cancer patients
and their prognosis after chemotherapy.
Methods This is a retrospective cohort study. We investigated 695 patients who underwent surgery for breast cancer. The strategy of
adjuvant therapy was as follows. Patients with both estrogen receptors (ERs) and progesterone receptors (PgRs) had endocrine
therapy as initial adjuvant therapy (n = 239). Patients with neither ERs nor PgRs had chemotherapy. When metastasis to other organs, including bone, was identified,
patients received chemotherapy. The survival rates after surgery and after the onset of bone metastasis, as well as the incidence
of bone metastasis, were calculated. We also evaluated the prognostic and predictive factors.
Results Bone metastases developed in 148 of 695 patients. All 148 received chemotherapy, and 121 of them developed spinal metastases.
The 5-year survival rate after bone metastases was 26.1%. Prognostic factors for bone metastases were visceral metastases
and PgR status. Cord compression was observed in 17 of the 148 patients, with the thoracic spine being the most common. The
1-year survival rate for patients with bone metastases who received chemotherapy was 66.3%, whereas that of patients with
paralysis after spinal metastases was 17.6%. Within 6 months of the development of spinal cord compression, 70.6% of the patients
died.
Conclusions We reported the incidence and prognostic factors for a defined population of Japanese breast cancer patients with bone and
spinal metastases. Our results suggest that the expected survival time for patients with paralysis who received adequate endocrine
therapy or chemotherapy is generally poor. However, to detect a predictive factor of long survival after paralysis and establish
the indications for surgery, a comparative study among large groups of patients with paralysis and with different backgrounds
is necessary. 相似文献
53.
Takahiro Narishige Kensuke Egashira M.D. Yutaka Akatsuka Teisuke Takahashi Akira Takeshita 《Cardiovascular and interventional radiology》1993,16(6):343-347
The effects of an intracoronary administration of iomeprol, a new nonionic tri-iodinated water-soluble contrast medium, on
coronary circulation were compared to those of iopamidol and those of nitroglycerin in 6 chronically instrumented conscious
dogs. A pair of 10 MHz piezoelectric crystals and an electromagnetic flow probe were placed on the left circumflex coronary
artery (LCCA) to measure the epicardial coronary diameter (CD) and coronary blood flow (CBF). Polyethylene tubing for drug
administration was inserted into the LCCA proximal to the sonomicrometers. Iomeprol at the dose of 1 ml and 3 ml/min for 1
min significantly increased CD by 0.6±0.1% and 1.4±0.3%, respectively and CBF by 44.5±9% and 70±10%, respectively. Iopamidol
at the same rates also significantly increased CD by 0.8±0.1% and 1.5±0.3% and CBF by 50±11% and 82±14%, respectively. There
was no statistically significant difference between iomeprol-and iopamidol-induced increases in CD and CBF. However, the duration
of the increase in CD was significantly shorter (p<0.05) after iomeprol than after iopamidol. Nitroglycerin (10 μg/kg) significantly increased CD by 4.5±1% and CBF by 105±10%.
The increases in CD and CBF in response to iopamidol and iomeprol were significantly smaller (p<0.01) than to nitroglycerin. We conclude that vasodilating effects of iomeprol and iopamidol on the large epicardial coronary
artery and coronary blood flow are comparable in conscious dogs and significantly lower than after nitroglycerin in the doses
used by us.
This study was supported by a grant from the EI-ZA1 Pharmaceutical Co., Tokyo, Japan. 相似文献
54.
Magnetic resonance imaging (MRI) has greatly facilitated morphologic evaluation of spinal cord lesions. Eleven cases representative of inflammatory, demyelinating, neoplastic and vascular diseases, are presented which illustrate and summarize important abnormal features in spinal cord imaging, particularly MR findings. Recently, specialised techniques such as MR angiography, fat-inhibiting methods, dynamic MRI and functional imaging have been developed. These methods have facilitated not only lesion diagnosis but also qualitative assessment, and are being used to analyze pathophysiology. Comprehensive diagnoses based on such modalities may be important in determining indications for surgery or defining the extent of surgery or the intensity of other treatments. 相似文献
55.
Light-scattering study of depolymerization kinetics of sickle hemoglobin polymers inside single erythrocytes. 总被引:2,自引:1,他引:1
下载免费PDF全文
![点击此处可从《Proceedings of the National Academy of Sciences of the United States of America》网站下载免费的PDF全文](/ch/ext_images/free.gif)
J Peetermans I Nishio S T Ohnishi T Tanaka 《Proceedings of the National Academy of Sciences of the United States of America》1986,83(2):352-356
The time course of intracellular depolymerization of hemoglobin S aggregates is directly observed by using microscope laser light-scattering spectroscopy in single sickle erythrocytes upon slow reoxygenation. From the correlation functions of the light intensity scattered from a single cell, we determine the average diffusion coefficient as well as the fraction of hemoglobin aggregates that have intracellular mobility. The oxygen saturation of the hemoglobin of the same cell is measured by single-cell absorption spectrophotometry. Combining the results obtained with these techniques and information on the cellular morphology, we propose a model for the depolymerization process of hemoglobin inside single erythrocytes as they transform from the fully sickled to the normal biconcave shape upon reoxygenation. 相似文献
56.
Takahiro Nishida Hisanori Mayumi Yoshito Kawachi Shigehiko Tokunaga Yoshiyuki Maruyama Atsuhiro Nakashima Hisataka Yasui Kouichi Tokunaga 《Surgery today》1994,24(7):651-654
A case of active prosthetic valve infective endocarditis (PVE) due toCandida glabrata was successfully treated by the systemic administration of fluconazole. A 66-year-old Japanese man with infective endocarditis of unknown etiology underwent aortic and mitral valve replacement to treat severe aortic and mitral regurgitation associated with multiple organ failure. Postsurgical cultures of arterial blood were repeatedly positive forC. glabrata, and therefore fluconazole was administered either intravenously or orally at a dose of 400 mg/day for 46 days. During that time the signs of inflammation including fever such as an elevated white blood cell count and the presence of C-reactive protein (CRP) all improved while the blood cultures became negative. Fluconazole is thus considered to be effective in treating PVE caused byC. glabrata. When administering this treatment, it is also important to monitor the patient's renal and liver function. 相似文献
57.
58.
Tadaki Yasumura MD Toshikazu Akami Manabu Mitsuo Takahiro Oka Kazuo Naitoh Takara Yamamoto Hideo Honjyo Hiroji Okada 《Surgery today》1990,20(4):369-375
The ovarian and pituitary functions of 64 operable breast cancer patients undergoing adjuvant therapy with cytotoxic chemotherapy
and/or tamoxifen were investigated. The post menopausal patients, divided into 3 treatment groups, one with tamoxifen alone,
one with tamoxifen and chemotherapy and the other with chemotherapy alone had serum estradiol 17-β (E2) and progesterone levels
lower than the evaluable limits. Although there was no significant difference in the level of estrone sulfate (E1-S) between
these three groups, the level of lutainizing hormone (LH) and follicle stimulating hormone (FSH) in the patients treated with
tamoxifen alone and tamoxifen and chemotherapy were significantly lower than those treated with chemotherapy alone. The decrease
in gonadotropin levels induced by tamoxifen treatment was reversible as it appeared after the initiation of tamoxifen and
recovered after its cessation. In the premenopausal patients, a group treated with tamoxifen and chemotherapy had significantly
higher E1-S, E2 and progesterone levels and significantly lower gonadotropin levels than a group treated with chemotherapy
alone or one treated with a cyclophosphamide regimen. These increases in the levels of estrogen and progesterone were also
reversible, and induced by tamoxifen. Thus, adjuvant endocrinochemotherapy causes profound alteration in the hypothalamo-pituitary-ovarian
axis and therefore, monitoring a variety of hormonal levels is thought to be necessary for assessing the consequences of adjuvant
therapy in breast cancer patients, especially in premenopausal patients using tamoxifen. 相似文献
59.
Hidehito Matsuoka Wataru Nishio Toshihiko Sakamoto Hiroaki Harada Noriaki Tsubota 《European journal of cardio-thoracic surgery》2004,26(3):480-482
OBJECTIVE: To predict accurate morbidity after lung resection using treadmill exercise test. METHODS: A total of 130 patients (108 men and 22 women, with mean age 67.1+/-11.4 years (range, 34-78 years)) of 1129 patients underwent standard lobectomy were performed both treadmill exercise test and spirometry preoperatively. We measured maximum oxygen uptake/body weight (VO2max/BW) and change in arterial blood oxygen pressure from rest to symptom-limited maximum loading (delta aPaO2) and calculated exercise-induced hypoxemia (delta PaO2/delta VO2/BW), and retrospectively compared these parameters for patients with and without complications. RESULTS: There were five patients with severe postoperative complications, including three requiring use of a respirator, two with home oxygen therapy. %Vital capacity, VC (%, 80.2+/-13.2 vs. 92.5+/-20.9, P=0.026), delta PaO2 (Torr, -29.3+/-4.3 vs. -13.2+/-10.8, P=0.0004), VO2max/BW (ml/min/kg, 16.5+/-2.9 vs. 20.6+/-5.1, P=0.018) and delta PaO2/delta VO2/BW (Torr/ml/min/kg, -1.98+/-0.26 vs. -0.57+/-0.47) were significantly associated with worse outcome. All the five patients with complications had delta PaO2/delta VO2/BW<-1.7. CONCLUSIONS: Treadmill exercise testing is a good method for assessment of cardiopulmonary reserve. Limited resection must be performed if delta PaO2/delta VO2/BW is under -1.7. 相似文献
60.
Yoshito Matsui Tomoatsu Kimura Noriyuki Tsumaki Haruhiko Nakahara Nobuhito Araki Natsuo Yasui Takahiro Ochi 《Journal of orthopaedic science》1996,1(2):130-135
Recent DNA studies performed by several groups have detected mutations of the gene encoding fibroblast growth factor receptor
3 (FGFR3) in patients with achondroplasia-group disorders, including achondroplasia (ACH), hypochondroplasia (HCH), and thanatophoric
dysplasia (TD). For this study, we analyzed theFGFR3 gene in 31 Japanese patients with typical ACH, four with HCH, three with a condition intermediate between ACH and HCH (ACH/HCH-intermediate),
and one with TD. Of the 31 typical ACH patients, 29 showed a G1138 to A transition and the other two a G1138 to C transversion,
both resulting in a common Gly380Arg substitution in the transmembrane domain of FGFR3. The one TD and the four HCH patients
did not display any mutations in the transmembrane domain of FGFR3. Of the three ACH/HCH-intermediate cases, one patient showed
the Gly380Arg substitution and one did not, and further analysis of the second patient revealed the presence of Asn540Lys
substitution. The first patient was, therefore, genotypically diagnosed as ACH and the second as HCH. Peripheral blood leukocyte
DNA analysis in the remaining ACH/HCH-intermediate patient indicated an unequal ratio of mutant to normal PCR products, possibly
representing a somatic mosaic for the Gly380Arg mutation. Analysis of the common FGFR3 mutation thus appears to help in the
molecular diagnosis of patients with achondroplasia-group disorders. 相似文献