全文获取类型
收费全文 | 1888篇 |
免费 | 127篇 |
国内免费 | 8篇 |
学科分类
医药卫生 | 2023篇 |
出版年
2022年 | 7篇 |
2021年 | 17篇 |
2020年 | 9篇 |
2019年 | 17篇 |
2018年 | 26篇 |
2017年 | 15篇 |
2016年 | 18篇 |
2015年 | 26篇 |
2014年 | 29篇 |
2013年 | 55篇 |
2012年 | 66篇 |
2011年 | 77篇 |
2010年 | 44篇 |
2009年 | 36篇 |
2008年 | 64篇 |
2007年 | 97篇 |
2006年 | 74篇 |
2005年 | 86篇 |
2004年 | 78篇 |
2003年 | 81篇 |
2002年 | 64篇 |
2001年 | 69篇 |
2000年 | 88篇 |
1999年 | 78篇 |
1998年 | 54篇 |
1997年 | 74篇 |
1996年 | 51篇 |
1995年 | 40篇 |
1994年 | 46篇 |
1993年 | 37篇 |
1992年 | 66篇 |
1991年 | 44篇 |
1990年 | 32篇 |
1989年 | 46篇 |
1988年 | 40篇 |
1987年 | 35篇 |
1986年 | 39篇 |
1985年 | 40篇 |
1984年 | 28篇 |
1983年 | 15篇 |
1982年 | 18篇 |
1981年 | 11篇 |
1980年 | 12篇 |
1979年 | 10篇 |
1978年 | 12篇 |
1977年 | 12篇 |
1976年 | 7篇 |
1975年 | 10篇 |
1970年 | 6篇 |
1968年 | 4篇 |
排序方式: 共有2023条查询结果,搜索用时 31 毫秒
1.
Intracranial circulation: pulse-sequence considerations in three- dimensional (volume) MR angiography 总被引:2,自引:0,他引:2
The technique and feasibility of magnetic resonance (MR) angiography of intracranial vessels were studied in 35 healthy volunteers. Variations in image orientation, repetition time (TR), and flip angle were evaluated to determine their effects on flow-related enhancement. Gradient modifications--including echo time (TE), motion compensation, bandwidth, and field of view--were also studied in an effort to reduce motion-induced phase shifts. Results indicated that a FISP (fast imaging with steady precession) sequence with a TR of 50 msec, TE of 15 msec, velocity compensation in the read and section-select directions, acceleration compensation in the read direction, anisotropic volume, and a 1.25-mm partition thickness produced three-dimensional angiographic MR images that were accurate and reproducible in the depiction of the major intracranial vessels. Difficulties with field of view, persistent signal void secondary to higher-order motion, and spatial resolution remain major problems requiring additional study. 相似文献
2.
Paediatric dacryocystorhinostomy 总被引:1,自引:0,他引:1
KN Hakin FRCS FRCOphth TJ Sullivan FRACO FRACS A Sharma FCOphth † RAN Welham FRCS FCOphth † 《Clinical & experimental ophthalmology》1994,22(4):231-235
Of 258 cases of dacryocystorhinostomy performed on children in the period September 1981 to September 1991, 130 were for simple, unresolved congenital nasolacrimal duct obstruction. Other indications for surgery included punctal agenesis, lacrimal fistula, post-traumatic and post-inflammatory canalicular obstruction. Of 177 children without canalicular pathology, 171 (96%) were relieved of symptoms with one operation, without canalicular intubation. Of 81 cases with canalicular disease, 55 of 70 (79%) who underwent DCR plus canalicular intubation, and 10 of 11 who underwent DCR plus Lester-Jones tube, were substantially improved with one operation. No child required peroperative or postoperative blood transfusion. Dacryocystorhinostomy in childhood, in experienced surgical hands, is a safe procedure, achieving relief of symptoms in most cases, particularly in the absence of canalicular disease. 相似文献
3.
4.
5.
Keratoconus and ocular massage 总被引:1,自引:0,他引:1
6.
Susan D. Ross M.D. Angela DiGeorge B.S. Janet E. Connelly B.S. Gregory W. Whiting B.S Neil McDonnell Pharm.D. 《Pharmacotherapy》1998,18(6):1290-1297
We performed a literature search for all clinical studies reporting outcomes in patients with the acquired immunodeficiency syndrome (AIDS) receiving granulocyte-macrophage colony-stimulating factor (GM-CSF) for any indication. Safety outcomes included human immunodeficiency virus replication, immune status, and frequency of opportunistic infections and neoplasms. Data were synthesized qualitatively. We identified 22 studies (274 patients): 12 addressed AIDS neutropenia, 8 AIDS cancer therapy, and 2 opportunistic infections. Viral burden was assessed by serum p24Ag in 15 studies. Nine reported no change in levels, three net decreases, and three net increases. All studies showing net increases involved patients receiving GM-CSF without a concurrent antiretroviral. The CD4 counts were unchanged in 5 studies, increased in 3, and not reported in 14. The incidence of neoplasms or new opportunistic infections was low. The literature suggests no increased risk of viral replication or clinical deterioration in patients with AIDS who take GM-CSF concurrently with zidovudine. 相似文献
7.
A newborn infant presenting with a divided congenital melanocytic naevus of the eyelid is described. Because of the severe disfigurement, risk of later malignant change in the lesion, and the possibility of deprivation amblyopia, early surgical treatment is recommended for all medium and large congenital melanocytic naevi of the eyelid. Surgery in the first few months of life gives the best cosmetic results. 相似文献
8.
Factors influencing women to undergo screening mammography 总被引:2,自引:0,他引:2
9.
10.
P L Glick C L Leach G E Besner E A Egan F C Morin A Malanowska-Kantoch L K Robinson A Brody A S Lele M McDonnell 《Journal of pediatric surgery》1992,27(7):866-869
Exogenous surfactant therapy (EST) in surfactant-deficient premature infants has been shown to improve lung compliance, decrease morbidity, and improve survival. Reports have demonstrated that newborns with congenital diaphragmatic hernia (CDH) have lung compliance, pressure-volume curves, and hyaline membrane formation resembling those changes seen in surfactant deficient premature newborns. We hypothesize that EST may also benefit infants with CDH. All high risk cases of prenatally diagnosed CDH at Children's Hospital of Buffalo from November 1988 to February 1991 were prospectively evaluated for EST. In those families who chose to participate, the surfactant preparation, Infasurf (100 mg/kg), was instilled into the newborn's lungs prior to the first breath. The remainder of the perinatal, neonatal, and surgical care was performed in a routine manner. Three high-risk prenatally diagnosed newborns with left CDH were treated with EST. All showed signs of decreased pulmonary compliance, but could still be adequately oxygenated and ventilated. Surgical correction was performed after stabilization and all required patch closures. Two of the three infants suffered no life-threatening episodes of pulmonary hypertension and all survived. These infants had many known indicators for poor outcome in CDH with an expected survival of less than 20%. We believe that EST in these neonates with CDH contributed to their survival with minimum morbidity. These results suggest that surfactant replacement for the high-risk neonate with CDH warrants further consideration and a randomized clinical trial is being planned. 相似文献