全文获取类型
收费全文 | 1985篇 |
免费 | 75篇 |
国内免费 | 76篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 62篇 |
妇产科学 | 14篇 |
基础医学 | 273篇 |
口腔科学 | 16篇 |
临床医学 | 293篇 |
内科学 | 423篇 |
皮肤病学 | 35篇 |
神经病学 | 32篇 |
特种医学 | 260篇 |
外科学 | 320篇 |
综合类 | 32篇 |
预防医学 | 104篇 |
眼科学 | 25篇 |
药学 | 82篇 |
中国医学 | 3篇 |
肿瘤学 | 160篇 |
出版年
2023年 | 9篇 |
2021年 | 16篇 |
2020年 | 13篇 |
2019年 | 16篇 |
2018年 | 21篇 |
2017年 | 11篇 |
2016年 | 19篇 |
2015年 | 34篇 |
2014年 | 33篇 |
2013年 | 51篇 |
2012年 | 74篇 |
2011年 | 82篇 |
2010年 | 69篇 |
2009年 | 78篇 |
2008年 | 88篇 |
2007年 | 116篇 |
2006年 | 77篇 |
2005年 | 82篇 |
2004年 | 56篇 |
2003年 | 59篇 |
2002年 | 77篇 |
2001年 | 93篇 |
2000年 | 57篇 |
1999年 | 54篇 |
1998年 | 91篇 |
1997年 | 78篇 |
1996年 | 64篇 |
1995年 | 55篇 |
1994年 | 48篇 |
1993年 | 50篇 |
1992年 | 43篇 |
1991年 | 30篇 |
1990年 | 38篇 |
1989年 | 44篇 |
1988年 | 53篇 |
1987年 | 39篇 |
1986年 | 34篇 |
1985年 | 28篇 |
1984年 | 27篇 |
1983年 | 17篇 |
1982年 | 20篇 |
1981年 | 12篇 |
1980年 | 15篇 |
1979年 | 5篇 |
1978年 | 6篇 |
1977年 | 17篇 |
1976年 | 13篇 |
1975年 | 14篇 |
1958年 | 2篇 |
1900年 | 2篇 |
排序方式: 共有2136条查询结果,搜索用时 15 毫秒
91.
92.
93.
94.
Numerous structures are included in the irradiated volume of patients presenting with head and neck cancer: skin, mucosa, bone, teeth, cartilage, muscles, salivary glands, etc. Curative intent treatment of such tumours requires aggressive approach which can lead to severe sequellae. These sequellae are in most cases dose-dependent and volume-dependent. However, an appropriate technique might decrease the severity of such sequellae. Details of these late changes are presented, including their pathophysiology, clinical syndromes, potential treatment, and prevention. 相似文献
95.
The STR system in the human phenylalanine hydroxylase gene: true fragment length obtained with fluorescent labelled PCR primers 总被引:5,自引:0,他引:5
J Zschocke CA Graham JJ McKnight NC Nevin 《Acta paediatrica (Oslo, Norway : 1992)》1994,83(S407):41-42
We present a simple, fast, non-radioactive method for the analysis of the polymorphic short tandem repeat (STR) system in the human phenylalanine hydroxylase gene. Previously, sizing of the STR marker involved radiolabelling of PCR amplified fragments and resolution on denaturing polyacrylamide gels using M13 sequencing ladder as a standard. However, this method consistently gave sizes 2 bp longer than the known sequence. The fluorescent method presented here employs internal lane standards and enables accurate sizing of the fragments. To avoid confusion, we suggest that the true fragment lengths are used as reference values in the future. The analysis of STR alleles is valuable for population genetic studies and for targeted mutation screening in phenylketonuria (PKU). It can replace RFLP-based haplotype analysis for carrier detection, and we report its use for prenatal diagnosis in a Northern Irish family with PKU. The analysis of 250 Northern Irish chromosomes, including 128 PKU alleles, showed no significant difference between normal and PKU alleles, with fragment lengths of 238 and 242 bp most common in both groups. 相似文献
96.
Recurrent squamous cell carcinoma of the vulva: clinicopathologic determinants identifying low risk patients 总被引:3,自引:0,他引:3
BACKGROUND: The identification of prognostic factors in the recurrence of vulvar squamous cell carcinoma is crucial for less invasive treatments. METHODS: The authors studied 101 patients treated for primary invasive squamous cell carcinoma of the vulva. Selected pathologic variables were observed in a standardized manner during treatment, and their association with disease free survival was investigated using the Cox model. Independent prognostic factors were selected by a stepwise procedure. The absolute survival of patient groups determined on the basis of such factors was computed by the product limit method. RESULTS: The median follow-up was 3.1 years (range, 56 days to 15.5 years). Recurrences developed in 33 patients. The independent recurrence predictors were as follows: International Federation of Gynecology and Obstetrics (FIGO) Stage IVA (vs. IB, II, or III) (risk ratio [RR]adjusted for other independent factors, 7.39), tumor multifocality (RR, 4.10), lymphovascular space involvement (LVSI) (RR, 2.96), the presence of associated vulvar intraepithelial neoplasia (VIN) Grade 2 or 3 (RR, 3.34), and the involvement of resection margins (RR, 4.88). By ignoring the FIGO stage and lymph node status, the independent predictors were then as follows: greatest tumor dimension < 2.5 cm, 2.5-4 cm (RR, 2.86), or > 4 cm (RR, 5.98); tumor multifocality (RR, 3.36); LVSI (RR, 4.19); the presence of VIN 2 or 3 (RR, 3.06); and the involvement of surgical margins (RR, 2.78). No recurrences were observed in 119 at-risk years among patients with unifocal tumors < 2.5 cm in greatest dimension, free surgical margins, no LVSI, and no associated VIN 2 or 3. CONCLUSIONS: The presence of associated VIN 2 or 3 was revealed to be a previously unidentified independent prognostic factor for recurrence. Subjects at low risk of recurrence could be identified even without consideration of lymph node status. 相似文献
97.
98.
Objective : To describe the obstetric and perinatal factors, in particular the method of delivery, associated with development of a subgaleal haematoma (SGH) and to determine the outcome of survivors with this type of birth trauma. Methodology : Perinatal and obstetric data were retrospectively reviewed for 37 infants admitted to the neonatal unit of the sole tertiary paediatric referral hospital in Western Australia with an SGH, over a 24 year period from 1970 to 1993. These data were compared to data for all Western Australian births. The long-term outcome was obtained through medical and private paediatric records for 26 of these infants. Results : All except one of the neonates had instrumental deliveries; 89% had a vacuum extractor applied to the head at some stage of delivery compared to 10% of the general population of births in Western Australia. There was also a significantly increased risk of failure of attempted vacuum extraction. Of the cases where a vacuum extraction was attempted, 45% also had forceps applied to the head. Coagulopathy was associated with the severity of the SGH. There was also a high frequency of occurrence (40%) of associated head trauma such as intracranial haemorrhage, skull fracture and cerebral oedema, as well as neonatal encephalopathy (73%). The occurrence of these associated features did not correlate significantly with the severity of SGH. Minor complications of SGH included jaundice and facial bruising. There was an excess mortality associated with SGH; however, the long-term outcome for neonatal survivors with this disorder was good. None of the cases studied subsequently developed cerebral palsy or intellectual disability, and minor neurological sequelae only were documented in four infants. Conclusions : SGH is an uncommon type of birth trauma, and is associated with delivery or attempted delivery by vacuum extraction. The most commonly associated clinical problems were hypovolaemia and coagulopathy. The long-term outcome for neonates with this condition is good. 相似文献
99.
A radiographic study of the ligamentous anatomy of the ankle 总被引:1,自引:0,他引:1
100.