全文获取类型
收费全文 | 8859篇 |
免费 | 658篇 |
国内免费 | 35篇 |
专业分类
耳鼻咽喉 | 78篇 |
儿科学 | 265篇 |
妇产科学 | 80篇 |
基础医学 | 1194篇 |
口腔科学 | 202篇 |
临床医学 | 1003篇 |
内科学 | 2064篇 |
皮肤病学 | 79篇 |
神经病学 | 652篇 |
特种医学 | 316篇 |
外科学 | 1337篇 |
综合类 | 116篇 |
一般理论 | 7篇 |
预防医学 | 712篇 |
眼科学 | 171篇 |
药学 | 747篇 |
中国医学 | 3篇 |
肿瘤学 | 526篇 |
出版年
2023年 | 54篇 |
2022年 | 85篇 |
2021年 | 253篇 |
2020年 | 126篇 |
2019年 | 224篇 |
2018年 | 279篇 |
2017年 | 179篇 |
2016年 | 203篇 |
2015年 | 200篇 |
2014年 | 339篇 |
2013年 | 421篇 |
2012年 | 634篇 |
2011年 | 708篇 |
2010年 | 389篇 |
2009年 | 356篇 |
2008年 | 588篇 |
2007年 | 561篇 |
2006年 | 552篇 |
2005年 | 586篇 |
2004年 | 520篇 |
2003年 | 490篇 |
2002年 | 441篇 |
2001年 | 109篇 |
2000年 | 95篇 |
1999年 | 91篇 |
1998年 | 102篇 |
1997年 | 77篇 |
1996年 | 59篇 |
1995年 | 53篇 |
1994年 | 43篇 |
1993年 | 39篇 |
1992年 | 48篇 |
1991年 | 44篇 |
1990年 | 47篇 |
1989年 | 40篇 |
1988年 | 28篇 |
1987年 | 36篇 |
1986年 | 32篇 |
1985年 | 39篇 |
1984年 | 43篇 |
1983年 | 37篇 |
1982年 | 33篇 |
1981年 | 34篇 |
1980年 | 29篇 |
1979年 | 16篇 |
1978年 | 20篇 |
1977年 | 21篇 |
1976年 | 18篇 |
1975年 | 17篇 |
1972年 | 14篇 |
排序方式: 共有9552条查询结果,搜索用时 15 毫秒
71.
Luis I. Ruffolo Marsha Pulhamus Theresa Foito Elizabeth Levatino Heather Martin Julie Michels Jan Schriefer Kori Wolcott Derek Wakeman 《Journal of pediatric surgery》2021,56(1):30-36
PurposePediatric gastrostomy tubes (G-tubes) are associated with considerable utilization of healthcare resources. G-tube dislodgement can result in tract disruption and abdominal sepsis. We aimed to reduce early G-tube dislodgement by 25%.MethodsAn interdisciplinary team convened to identify key drivers of G-tube dislodgement and implement initiatives to reduce this complication. A G-tube care bundle was implemented in 2018. Rates of early G-tube dislodgement (within 90 days of insertion) were tracked. 15 months of cases after bundle implementation were compared to 20 months of cases before implementation. Length of stay (LOS, balancing measure) and bundle compliance (process measure) were tracked.ResultsG-tube dislodgements decreased 47% after bundle implementation. Overall, dislodgements after G-tube insertion decreased from 43% to 19% dislodgements per tube inserted, p = 0.004. Reductions were observed for dislodgements occurring in both the inpatient (14% vs. 1.5%) and outpatient (29% vs. 18%) settings. Median LOS was reduced from 15.3 to 7.1 days following implementation, p = 0.004. Process measures demonstrated 75% or greater compliance one year after implementation.ConclusionAn interdisciplinary team using quality improvement science methodology can significantly reduce G-tube dislodgement and improve value after pediatric gastrostomy tube insertion.Type of studyLongitudinal cohort study.Level of evidenceIII. 相似文献
72.
Gordon Nicole T. Alberty-Oller Jaime J. Fei Kezhen Greco Giampaolo Gallagher Emily J. LeRoith Derek Feldman Sheldon M. Killilea Bridgid Boolbol Susan K. Choi Lydia Friedman Neil Pilewskie Melissa Port Elisa Tiersten Amy Bickell Nina A. 《Annals of surgical oncology》2021,28(11):5941-5947
Annals of Surgical Oncology - Black women with breast cancer have a worse overall survival compared with White women; however, no difference in Oncotype DX? (ODX) recurrence scores has been... 相似文献
73.
74.
75.
Eleanor J. Reimer Carolyne J. Montgomery Joan C. Bevan Pamela M. Merrick Derek Blackstock Vladan Popovic 《Journal canadien d'anesthésie》1993,40(10):927-933
Propofol anaesthesia may reduce postoperative emesis. The purpose of this study was to compare the incidence of emesis after propofol anaesthesia with and without nitrous oxide, compared with thiopentone and halothane anaesthesia, in hospital and up to 24 hr postoperatively, in outpatient paediatric patients after strabismus surgery. Seventy-five ASA class I or II, unpremedicated patients, aged 2–12 yr were randomly assigned to one of three groups: Thiopentone, 6.0 mg · kg? 1 iv induction followed by halothane and N2O/O2 for maintenance (T/H); propofol for induction, followed by propofol and oxygen for maintenance (P/O2); and propofol for iv induction, followed by propofol infusion and N2O/O2 for maintenance (P/N2O). All received vecuronium, controlled ventilation, and acetaminophen pr. Morphine was given as needed for postoperative analgesia. There were no differences in age, weight, number of eye muscles operated upon, duration of anaesthesia or surgery. The P/N2O group (255 ± 80 μg· kg? 1· min? 1) received less propofol than the P/O2 group (344 ± 60 μg · kg? 1· min? 1) (P ≤ 0.0001) and had shorter extubation (P < 0.001) and recovery (P < 0.01) times. Emesis in the hospital, in both the P/N2O (4.0%) and P/O2 group (4.0%) was less than in the T/H group (32%) (P < 0.01). Antiemetics were required in four patients in the T/H group (16.0%). Overall emesis after surgery was not different among the groups: T/H (48%), P/O2 (28%) and P/N2O (42%). The use of propofol anaesthesia with and without N2O decreased only early emesis. This supports the concept of a short-acting, specific antiemetic effect of propofol. 相似文献
76.
Hugh J Herdon Jeffrey C Jerman Tania O Stean Derek N Middlemiss Wai N Chan Antonio K Vong John M Evans Mervyn Thompson Neil Upton 《British journal of pharmacology》1997,121(8):1687-1691
- SB-204269 (trans-(+)-6-acetyl-4S-(4-fluorobenzoylamino)-3,4-dihydro-2,2-dimethyl-2H-benzol[b]pyran-3R-ol, hemihydrate) shows potent anticonvulsant activity in a range of animal seizure models, with a lack of neurological or cardiovascular side-effects. The profile of the compound suggests that it may have a novel mechanism of action. This study describes the characteristics of a binding site for [3H]-SB-204269 in rat forebrain membranes.
- Specific [3H]-SB-204269 binding was saturable and analysis indicated binding to a homogenoeous population of non-interacting binding sites with a dissociation constant (KD) of 32±1 nM and a maximum binding capacity (Bmax) of 253±18 fmol mg−1 protein. Kinetic studies indicated monophasic association and dissociation. Binding was similar in HEPES or Tris-HCl buffers and was unaffected by Na+, K+, Ca2+ or Mg2+ ions. Specific binding was widely distributed in brain, but was minimal in a range of peripheral tissues.
- Specific [3H]-SB-204269 binding was highly stereoselective, with a 1000 fold difference between the affinities of SB-204269 and its enantiomer SB-204268 for the binding site. The affinities of analogues of SB-204269 for binding can be related to their activities in the mouse maximal electroshock seizure threshold (MEST) test of anticonvulsant action.
- None of the standard anticonvulsant drugs, phenobarbitone, phenytoin, sodium valproate, carbamazepine, diazepam and ethosuximide, or the newer anticonvulsants, lamotrigine, vigabatrin, gabapentin and levetiracetam, showed any affinity for the [3H]-SB-204269 binding site. A wide range of drugs active at amino acid receptors, Na+ or K+ channels or various other receptors did not demonstrate any affinity for the binding site.
- These studies indicate that SB-204269 possesses a specific CNS binding site which may mediate its anticonvulsant activity. This binding site does not appear to be directly related to the sites of action of other known anticonvulsant agents, but may have an important role in regulating neuronal excitability.
77.
Derek J. Pearce 《Journal canadien d'anesthésie》1994,41(4):314-316
A case is presented of a healthy 69-yr-old woman who underwent elective laparoscopic cholecystectomy under general anaesthesia. As surgery proceeded she developed hypercapnia (arterial blood PaCO2 = 100 mmHg) and a related respiratory acidosis (arterial blood pH 7.07). The cause was attributed to subcutaneous insufflation and absorption of CO2, directly related to the surgical pneumoperitoneum. 相似文献
78.
Derek McCormick Ian Wallace A. Thompson M. Hutchinson S. A. Hawkins et al. 《Journal of neurology》1995,242(Z2):S109-S112
Poster Session 3
Multiple sclerosis 相似文献79.
Derek J. Smithies Philip H. Butler W. Antony Day E. Peter Walker 《Lasers in medical science》1995,10(2):93-104
This paper reports the electron microscopy results obtained from two patients who were treated with 5 W of yellow (578 nm) light from a copper vapour laser with an illumination time of 3.6 ms and a 0.3 mm spot diameter. The endpoint of treatment was transient blanching. Following treatment, erythema was observed. There was minimal damage to the epidermis and non-vascular tissue such as the nerve fibres. There was severe damage to the endothelial cells of the ectatic vessels. Twenty-four hours after treatment, platelet activation and collagen were present, indicating that these vessels were no longer viable. Theoretical calculations are used to determine the flow of heat within and away from a 50m diameter vessel. From this, heating of the entire vessel is shown to occur with illumination times of 4 ms, with minimal heating of the non-vascular tissue. Shorter illuminations do not heat the entire vessel, while the use of longer illumination times will cause excessive damage to the surrounding non-vascular tissue. Illumination times close to 4 ms must be regarded as optimal. 相似文献
80.
Sinus histiocytosis (Rosai-Dorfman disease) of the suprasellar region: MR imaging findings--a case report 总被引:2,自引:0,他引:2
Sinus histiocytosis with massive lymphadenopathy (SHML) is an uncommon disorder that typically manifests as systemic symptoms and lymphadenopathy. Extranodal, intracranial disease is uncommon. The authors report on a 15-year-old adolescent girl who had a suprasellar mass at magnetic resonance imaging. Biopsy results demonstrated lymphophagocytosis consistent with a diagnosis of SHML. The clinical, radiologic, and histologic aspects of the disease are discussed. 相似文献