全文获取类型
收费全文 | 6029篇 |
免费 | 347篇 |
国内免费 | 33篇 |
专业分类
耳鼻咽喉 | 42篇 |
儿科学 | 108篇 |
妇产科学 | 108篇 |
基础医学 | 744篇 |
口腔科学 | 293篇 |
临床医学 | 396篇 |
内科学 | 1737篇 |
皮肤病学 | 128篇 |
神经病学 | 490篇 |
特种医学 | 193篇 |
外科学 | 855篇 |
综合类 | 27篇 |
预防医学 | 199篇 |
眼科学 | 78篇 |
药学 | 435篇 |
中国医学 | 6篇 |
肿瘤学 | 570篇 |
出版年
2023年 | 37篇 |
2022年 | 76篇 |
2021年 | 108篇 |
2020年 | 61篇 |
2019年 | 89篇 |
2018年 | 119篇 |
2017年 | 102篇 |
2016年 | 124篇 |
2015年 | 133篇 |
2014年 | 190篇 |
2013年 | 201篇 |
2012年 | 331篇 |
2011年 | 396篇 |
2010年 | 200篇 |
2009年 | 174篇 |
2008年 | 308篇 |
2007年 | 295篇 |
2006年 | 278篇 |
2005年 | 285篇 |
2004年 | 264篇 |
2003年 | 308篇 |
2002年 | 299篇 |
2001年 | 169篇 |
2000年 | 172篇 |
1999年 | 184篇 |
1998年 | 83篇 |
1997年 | 65篇 |
1996年 | 61篇 |
1995年 | 56篇 |
1994年 | 40篇 |
1993年 | 28篇 |
1992年 | 112篇 |
1991年 | 93篇 |
1990年 | 105篇 |
1989年 | 89篇 |
1988年 | 80篇 |
1987年 | 85篇 |
1986年 | 79篇 |
1985年 | 77篇 |
1984年 | 63篇 |
1983年 | 53篇 |
1982年 | 25篇 |
1980年 | 22篇 |
1979年 | 29篇 |
1978年 | 31篇 |
1977年 | 23篇 |
1976年 | 19篇 |
1971年 | 24篇 |
1970年 | 18篇 |
1969年 | 24篇 |
排序方式: 共有6409条查询结果,搜索用时 14 毫秒
41.
OBJECTIVE: This study examined the effects of varying magnitudes of controlled spinal cord impact to the mouse spinal cord on neurological and histopathological variables to obtain a mouse model of spinal cord injury (SCI). METHODS: A laminectomy of the T10 vertebra was performed on anesthetized C57BL/6 mice. A pneumatic pressure-driven impact was performed on the spinal cord through the dura mater. Experimental groups were subdivided according to the energy of impact (0.25-mm-deep deformations): Group 1 (n = 5), impact velocity at 1 m/s; Group 2 (n = 5), impact velocity at 2 m/s; and Group 3 (n = 5), impact velocity at 3 m/s. Functional deficits over time were evaluated up to 28 days after SCI by testing hindlimb reflex and coordinated motor function. The extent of the lesions was analyzed histopathologically and quantified by a morphometric measurement. RESULTS: Mice of all groups exhibited profound functional deficits immediately after injury and subsequent gradual symptomatic recovery. The degrees of recovery were precisely correlated with the magnitudes of impact. The extent of resultant cord lesions was highly reproducible among animals, with little variance: means +/- standard deviation, 0.86 +/- 0.06/100 mm3 in Group 1; 2.4 +/- 0.28/100 mm3 in Group 2; and 11.0 +/- 1.0/100 mm3 in Group 3. CONCLUSION: Our results indicate that this model provides constant functional and histopathological lesions according to impact energy. This new mouse model of SCI opens a new avenue for studies investigating roles and/or effects of specific genes in the recovery process of SCI. 相似文献
42.
Yoshitaka Tanaka Mitsuhiro Aoki Tomoki Izumi Mineko Fujimiya Toshihiko Yamashita Tomohito Imai 《Journal of orthopaedic science》2010,15(1):118-124
Background
Thoracic outlet syndrome is thought to be caused by compression of the brachial plexus or subclavian artery in the interscalene, costoclavicular, or subcoracoid space. Some provocative tests are widely used for diagnosing thoracic outlet syndrome. However, whether provocative positions actually compress the neurovascular bundle in these spaces remains unclear. The purpose of this study was to investigate the possibility of neurovascular bundle compression in the costoclavicular space by measuring the pressure applied to the brachial plexus and subclavian artery in provocative positions. 相似文献43.
Verica Aleksic Akira Aoki Kengo Iwasaki Aristeo Atsushi Takasaki Chen-Ying Wang Yoshimitsu Abiko Isao Ishikawa Yuichi Izumi 《Lasers in medical science》2010,25(4):559-569
Although the use of high-level Er:YAG laser irradiation has been increasing in periodontal and peri-implant therapy, the effects
of low-level Er:YAG laser on surrounding tissues and cells remain unclear. In the present study, the effects of low-level
Er:YAG laser irradiation on osteoblast proliferation were investigated. Cells of the osteoblastic cell line MC3T3-E1 were
treated with low-level Er:YAG laser irradiation with various combinations of laser settings (fluence 0.7–17.2 J/cm2) and in the absence or presence of culture medium during irradiation. On day 1 and/or day 3, cell proliferation and death
were determined by cell counting and by measurement of lactate dehydrogenase (LDH) levels. Further, the role of mitogen-activated
protein kinase (MAPK) pathways in laser-enhanced cell proliferation was investigated by inhibiting the MAPK pathways and then
measuring MAPK phosphorylation by Western blotting. Higher proliferation rates were found with various combinations of irradiation
parameters on days 1 and 3. Significantly higher proliferation was also observed in laser-irradiated MC3T3-E1 cells at a fluence
of approximately 1.0–15.1 J/cm2, whereas no increase in LDH activity was observed. Further, low-level Er:YAG irradiation induced the phosphorylation of extracellular
signal-regulated protein kinase (MAPK/ERK) 5 to 30 min after irradiation. Although MAPK/ERK 1/2 inhibitor U0126 significantly
inhibited laser-enhanced cell proliferation, activation of stress-activated protein kinases/Jun N-terminal kinase (SAPK/JNK)
and p38 MAPK was not clearly detected. These results suggest that low-level Er:YAG laser irradiation increases osteoblast
proliferation mainly by activation of MAPK/ERK, suggesting that the Er:YAG laser may be able to promote bone healing following
periodontal and peri-implant therapy. 相似文献
44.
Osteoprotegerin (OPG) inhibits interaction of the receptor-activator of nuclear factor-kappaB (RANK) ligand (RANKL) with its receptor RANK, which is expressed on osteoclasts. OPG appeared to accelerate vascular calcification in vitro by the inhibition of vascular osteoclast-like cells. On the contrary, early-onset arterial calcification was observed in OPG-deficient mice. We measured the coronary artery calcification score (CACS) and abdominal aortic calcification score (AAoCS) by multi-detector computed tomography in 30 pre-dialysis CKD patients (eGFR 20 mL/min on average). Biomarkers were measured, including serum OPG, soluble RANKL (sRANKL) and tartrate-resistant acid phosphatase (TRACP) -5b (the biomarker of osteoclasts independent of renal function). The median values of CACS and AAoCS were 54.4 and 1,088 Agatston units (AU), respectively. Serum OPG was increased and serum sRANKL was decreased. In a multivariate logistic regression analysis using CACS > or = 100 AU as the outcome variable, CACS was found to be positively correlated with serum corrected Ca x iP product and serum OPG, though it was not correlated with serum TRACP-5b. ROC curve analysis showed that the serum OPG cutoff value predicting CACS > or = 100 AU was 5.2 pmol/L (624 pg/mL). In a stepwise regression analysis, log (AAoCS + 1) was positively correlated with serum OPG alone, but it was not correlated with age, eGFR, serum albumin and bone alkaline phosphatase (BAP). No correlation was found between serum OPG and serum TRACP-5b. In conclusion, vascular calcification in pre-dialysis CKD patients was correlated with an increase in OPG, but was independent of serum TRACP-5b. The decrease in serum sRANKL may have been caused by the increase in OPG production. 相似文献
45.
Zabetian CP Morino H Ujike H Yamamoto M Oda M Maruyama H Izumi Y Kaji R Griffith A Leis BC Roberts JW Yearout D Samii A Kawakami H 《Neurology》2006,67(4):697-699
LRRK2 G2019S is the most common known cause of Parkinson disease (PD) in patients of European origin, but little is known about its distribution in other populations. The authors identified two of 586 Japanese patients with PD heterozygous for the mutation who shared a haplotype distinct from that observed in Europeans. This suggests that G2019S originated from separate founders in Europe and Japan and is more widely dispersed than previously recognized. 相似文献
46.
Soyama A Eguchi S Takatsuki M Hidaka M Muraoka I Tomonaga T Kanematsu T 《Digestive surgery》2011,28(3):222-225
This report presents a case of a patient with a huge hepatocellular carcinoma in the right lobe of the liver with an extensive portal venous tumor thrombus extending into the main portal trunk and left portal branch. The patient underwent extended right hemihepatectomy with tumor thrombectomy with direct extraction from an opening of the ventral wall of the right portal vein and using a balloon catheter to push the tumor thrombus via the surgically reopened umbilical vein. This technique seems useful in cases of tumor thrombus that extend deep into the umbilical portion of the left portal vein. In addition, this technique may have minimized the intraoperative migration of the tumor thrombus into the future remnant liver by occluding portal flow with the balloon catheter during the thrombectomy. 相似文献
47.
A 45-year-old woman presented with a rare case of traumatic carotid cavernous fistula (CCF) complicated with intracerebral hemorrhage after injury in a car accident. She had multiple injuries including facial bone fracture and slight subarachnoid hemorrhage around the left sylvian fissure. Emergent plastic surgery for the facial deformity was performed. Next day, she suffered intracerebral hemorrhage in the left frontal lobe. Angiography revealed CCF, predominantly draining to the left superficial sylvian vein. The left internal carotid artery was occluded by endovascular treatment. The clinical triad of traumatic CCF is orbital bruit, exophthalmos, and chemosis. Hemorrhagic complication such as subarachnoid hemorrhage, epistaxis, and otorrhagia may occur according to the venous drainage pattern. Traumatic CCF may be accompanied by intracerebral hemorrhage. 相似文献
48.
Internal mammary artery embolization for hemoptysis 总被引:2,自引:0,他引:2
Hashimoto M Heianna J Okane K Izumi J Watarai J 《Acta radiologica (Stockholm, Sweden : 1987)》1999,40(2):187-190
PURPOSE: The purpose of this study was to determine the factors influencing development of blood supply from the internal mammary artery and to discuss the value of embolization of the abnormal branches from this vessel using small particles following occlusion of the normal distal branches using microcoils in treating hemoptysis. MATERIAL AND METHODS: Five patients with hemoptysis underwent internal mammary artery embolization with coaxial microcatheter systems. Bronchoscopy, chest radiographs, and CT were performed to determine the site and extent of the basic disease before embolotherapy in all patients. RESULTS: In all patients, pulmonary lesions had extended from the lung to the adjacent pleural surface at the anterior lung field. Four patients underwent embolization from the proximal portion of the internal mammary artery following distal coil embolization. One patient who underwent only proximal embolization had recurrent bleeding. CONCLUSION: The internal mammary artery contributes to the perfusion of lesions responsible for hemoptysis when the basic lesion involves the pulmonary parenchyma adjacent to the anterior pleural surface. Initial distal occlusion of the internal mammary artery may improve the efficacy of embolization of this artery for hemoptysis. 相似文献
49.
Maruyama H Aoki A Sasaki KM Takasaki AA Iwasaki K Ichinose S Oda S Ishikawa I Izumi Y 《Lasers in surgery and medicine》2008,40(3):211-222
BACKGROUND AND OBJECTIVES: This study compared the surface morphology as well as the biocompatibility of dental root cementum treated with Er:YAG laser irradiation alone and with the laser irradiation followed by chemical and/or mechanical conditioning. STUDY DESIGN/MATERIALS AND METHODS: Healthy cementum plates were randomly assigned to the following control and treatment groups: (1) untreated control (C), (2) Er:YAG laser irradiation (L), (3) laser plus tetracycline HCl (TC) placement (L+TP), (4) laser plus TC burnishing (L+TB), (5) laser plus EDTA gel placement (L+EP), (6) laser plus EDTA gel burnishing (L+EB), (7) laser plus saline solution burnishing (L+SB), and (8) laser plus minocycline-HCl paste placement (L+MP). Specimens were subjected to scanning electron microscopy (SEM), histological observation and attachment assay using periodontal ligament (PDL) fibroblasts. RESULTS: The laser irradiation produced a thin affected layer (5.7 microm thickness) with a superficial microstructure on the cementum surface. The characteristic microstructures of the lased surface were fragile and could be removed by chemical and/or mechanical conditioning treatments. The L+TB group exhibited marked exposure of collagen fibers after removal of the microstructures on the lased surface. The L+EP group presented a peculiar, smooth surface without exposure of collagen fibers and a uniform arrangement of spherical microparticles on the ultra-high magnification of SEM. In cell attachment assay, the L+TB group exhibited the greatest number of attached cells among all the groups, followed by the L+EP, L+SB and control group. The laser alone group exhibited the lowest number of cells. CONCLUSIONS: The characteristic microstructure of the root cementum surface after Er:YAG laser irradiation has a tendency to hinder the early attachment of PDL cells. However, chemical and/or mechanical root conditioning treatment may improve and increase the biocompatibility of the Er:YAG laser-treated root cementum by removing the microstructures of the surface and/or further exposing the collagen fibers. 相似文献
50.
Tajima K Kawagoe I Kanai M Mitsuhata H 《Masui. The Japanese journal of anesthesiology》2008,57(7):874-878
BACKGROUND: The incidence of herpes zoster increases with age. Immediate pain relief is required for prevention of postherpetic neuralgia (PHN) and also its related symptoms that worsen the general condition because acute herpetic pain often interferes with sleep, mood, and general activities in elderly patients. Nerve block is useful to relief acute pain and recommended for prevention of PHN. Tricyclic antidepressant drugs have antinoticeptive effect in acute pain in experimental models, in addition to its antidepressant effect. METHODS: Forty elderly patients with herpes zoster within 3 months after the onset underwent nerve blocks and received tricyclic antidepressant drugs. We assessed the effect of treatments and adverse effects. RESULTS: No significant adverse effects were found in elderly patients who had received nerve blocks and/or tricyclic antidepressant drugs. Alleviation of acute pain was obtained in more than 80% of patients, and in all patients depressive state and/or disturbance of the general condition were significantly improved. CONCLUSIONS: With careful technique and assessment of patients, both nerve block and tricyclic antidepressant drugs were beneficial and safe treatments in elderly patients with herpes zoster. 相似文献