全文获取类型
收费全文 | 4444篇 |
免费 | 366篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 26篇 |
儿科学 | 175篇 |
妇产科学 | 211篇 |
基础医学 | 625篇 |
口腔科学 | 139篇 |
临床医学 | 518篇 |
内科学 | 744篇 |
皮肤病学 | 46篇 |
神经病学 | 341篇 |
特种医学 | 183篇 |
外科学 | 576篇 |
综合类 | 90篇 |
一般理论 | 1篇 |
预防医学 | 419篇 |
眼科学 | 112篇 |
药学 | 282篇 |
中国医学 | 9篇 |
肿瘤学 | 324篇 |
出版年
2021年 | 57篇 |
2020年 | 38篇 |
2019年 | 58篇 |
2018年 | 66篇 |
2017年 | 35篇 |
2016年 | 57篇 |
2015年 | 54篇 |
2014年 | 79篇 |
2013年 | 152篇 |
2012年 | 181篇 |
2011年 | 170篇 |
2010年 | 141篇 |
2009年 | 117篇 |
2008年 | 169篇 |
2007年 | 181篇 |
2006年 | 163篇 |
2005年 | 145篇 |
2004年 | 158篇 |
2003年 | 146篇 |
2002年 | 122篇 |
2001年 | 119篇 |
2000年 | 119篇 |
1999年 | 103篇 |
1998年 | 69篇 |
1997年 | 63篇 |
1996年 | 69篇 |
1995年 | 67篇 |
1994年 | 58篇 |
1993年 | 44篇 |
1992年 | 123篇 |
1991年 | 110篇 |
1990年 | 117篇 |
1989年 | 106篇 |
1988年 | 107篇 |
1987年 | 124篇 |
1986年 | 74篇 |
1985年 | 112篇 |
1984年 | 80篇 |
1983年 | 74篇 |
1982年 | 48篇 |
1981年 | 52篇 |
1980年 | 54篇 |
1979年 | 87篇 |
1978年 | 55篇 |
1977年 | 39篇 |
1976年 | 35篇 |
1972年 | 38篇 |
1970年 | 45篇 |
1968年 | 31篇 |
1967年 | 36篇 |
排序方式: 共有4821条查询结果,搜索用时 0 毫秒
1.
A Ascari-Raccagni†‡ MG Righini† 《Journal of the European Academy of Dermatology and Venereology》2006,20(5):514-516
BACKGROUND: Repairing dorsal nasal defects is a frequent challenge for dermatologic surgeons, mainly due to the high frequency of basal cell carcinomas on this site. Obvious scars, mismatched skin and distortion of the nasal contour are the surgical hazards that must be avoided in these cases. AIM: Our aim was to perform surgery involving a simple flap in order to repair medium to large defects on the dorsal side of the nose. METHODS: The dorsal horizontal advancement flap was studied in 12 patients, in order to evaluate the benefits and limits of this surgical procedure. RESULTS: The resulting scars on most of our patients were well-camouflaged among their natural skin lines, and there was neither distortion of the alar contour nor the nostril. CONCLUSIONS: This flap is easy to perform and, in selected cases, provides an outstanding alternative to second-intention healing, full-thickness skin grafts, transposition, rotation and pedicle flaps. 相似文献
2.
We examined several possible causes for the high incidence of poor sensory acuity in the limbs of 176 patients with moderate to severe peripheral vascular insufficiency. We investigated the relationships of diabetes, alcoholism, and smoking, as well as the severity of peripheral vascular disease, to the integrity of basic sensory modalities such as two-point discrimination and perception of light touch. The presence or absence of diabetes exerted the strongest effect on peripheral sensation. In patients who did not have diabetes, sensation in the limbs was most strongly affected by whether the patient was an alcoholic. Smoking did not have a significant effect on limb sensation. Among nondiabetic, nonalcoholic patients, there was a weak residual effect related to the severity of the peripheral vascular insufficiency. Even among these patients, however, systemic factors predominated in determining the loss of sensation. We also examined the extent to which loss of sensation might be related to the development of ulcers. Among patients who were not diabetic, there was a highly significant relationship between loss of sensation and the presence of limb ulceration. Surprisingly, however, there was no discernable relationship between the presence of ulcers in diabetic patients and the degree of loss of peripheral sensation. This result suggests that a large percentage of ulcers seen in diabetic patients are not of neurogenic origin. 相似文献
3.
4.
Cognitive evoked potentials and disorders of recent memory 总被引:1,自引:0,他引:1
P3 potentials evoked by spoken words were recorded from seven patients with disorders of recent memory and seven age-matched controls. Inclusion criteria included a clearly identifiable P3 to pure tone stimuli. Absence or marked decrement of P3 to word stimuli was seen in the patients even though they could perform the word task. The results are consistent with an encoding disorder and failure in elaboration of information processing. 相似文献
5.
Kevin O'Brien Jean Wright Frances Conboy YeWeng Sanjie Nicky Mandall Stephen Chadwick Ivan Connolly Paul Cook David Birnie Mark Hammond Nigel Harradine David Lewis Cathy McDade Laura Mitchell Alison Murray Julian O'Neill Mike Read Stephen Robinson Dai Roberts-Harry Jonathan Sandler Ian Shaw 《American journal of orthodontics and dentofacial orthopedics》2003,124(3):234-43; quiz 339
This study evaluated the effectiveness of early orthodontic treatment with the Twin-block appliance for the developing Class II Division 1 malocclusion. This multicenter trial was carried out in the United Kingdom. A total of 174 children, aged 8 to 10 years old, with Class II Division 1 malocclusion were randomly allocated to receive treatment with a Twin-block appliance or to an untreated, control group. Data were collected at the start of the study and 15 months later. Results showed that early treatment with Twin-block appliances resulted in reduction of overjet, correction of molar relationships, and reduction in severity of malocclusion. Most of this correction was due to dentoalveolar change, but some was due to favorable skeletal change. Early treatment with the Twin-block appliance is effective in reducing overjet and severity of malocclusion. The small change in the skeletal relationship might not be considered clinically significant. 相似文献
6.
7.
L J Hammond 《Journal of pediatric health care》1991,5(1):31-33
Venous access in acute and chronically ill patients can become problematic when attempting to maintain a reliable system. The need for safe and dependable intravascular systems has become quite evident. This article examines the Port-A-Cath (Pharmacia, Inc., St. Paul, MN) and the Per-Q-Cath (Gesco International, Inc., San Antonio, TX). These systems are preferred by several patient populations who require frequent or prolonged intravenous therapy. 相似文献
8.
TP Amadeu† AB Seabra‡ MG de Oliveira‡ AMA Costa† 《Journal of the European Academy of Dermatology and Venereology》2007,21(5):629-637
BACKGROUND: Nitric oxide (NO) plays a key role in wound repair and S-nitrosothiols like S-nitrosoglutathione (GSNO) are well known NO donors. METHODS: Animals were separated in two groups and submitted to excisional wounds on the dorsal surface at the first day. GSNO (100 microm)-containing hydrogels were topically applied on the wound bed in the GSNO group, daily, during the first 4 days. Control group was topically treated with hydrogel without GSNO for the same period. Wound contraction and re-epithelialization were measured. Animals were sacrificed 21 days after wounding. Samples of lesion and normal tissue were formalin-fixed, paraffin embedded for histological analysis. RESULTS: Wound contraction, measured 14 and 21 days after wounding, was greater in the GSNO group than in the control group (P<0.05 for both). The re-epithelialized wound area, measured 14 days after wounding, was higher in the GSNO group than in the control group (P<0.05). A higher amount of inflammatory cells was observed in superficial and deep areas of the granulation tissue of the control group compared to the GSNO group. Twenty-one days after wounding, thin red-yellow collagen fibers arranged perpendicularly to the surface were found in the granulation tissue of the control group, whereas in the GSNO-treated group collagen fibers were thicker and arranged parallel to the surface. Increased number of mast cells was observed in the GSNO group compared with that in the control group. Vascularization and myofibroblast distribution were similar in both groups. CONCLUSION: Topical application of GSNO-containing hydrogel during the early phases of rat cutaneous wound repair accelerates wound closure and re-epithelialization and affects granulation tissue organization. 相似文献
9.
M R Hamre L L Robison M E Nesbit H N Sather A T Meadows J A Ortega G J D'Angio G D Hammond 《Journal of clinical oncology》1987,5(11):1759-1765
The Childrens Cancer Study Group has assessed serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), and pubertal development in 97 long-term female survivors of childhood acute lymphoblastic leukemia (ALL). All patients received identical induction and maintenance therapy with either 18 or 24 Gy of radiation therapy (RT) to one of the following fields: cranial, craniospinal, or craniospinal plus 12 Gy abdominal RT including the ovaries. Thirty-six percent (35 patients) were found to have above normal levels of FSH and/or LH. The percentages of elevated values for RT fields were 93% for craniospinal plus abdominal RT, 49% for craniospinal RT, and 9% for cranial RT (P less than .001). A dose-response relationship was observed between 18 Gy and 24 Gy in females receiving only craniospinal RT (P = .01). Craniospinal plus abdominal RT and abnormal FSH/LH levels were significantly associated with lack of pubertal development and delayed onset of menses. Duration of maintenance chemotherapy was not associated with abnormal gonadotropin levels or the development of secondary sexual characteristics. Additional follow-up of this cohort is needed to establish the ultimate pubertal development and fertility of these patients. 相似文献
10.
J S Miser J Roloff J Blatt G H Reaman M D Krailo G D Hammond 《American journal of clinical oncology》1992,15(6):490-493
Forty-nine children with recurrent acute lymphoblastic leukemia (ALL) were entered into a randomized Phase II trial evaluating 2'-deoxycoformycin (dCF) alone or in combination with adenine arabinoside (ara-A). 2'-Deoxycoformycin is an inhibitor of adenosine deaminase (ADA), an enzyme found in relatively high amounts in malignant lymphoid cells. Ara-A inhibits DNA polymerase and DNA synthesis. Because its efficacy in vivo as an anticancer agent is limited by its rapid inactivation by ADA, ara-A was combined with dCF to produce cytoreductive levels of ara-A. Twenty-four patients were assigned to receive dCF alone and 25 to receive the combination. No patient responded to dCF alone, and one patient developed a complete remission after treatment with the combination. The toxicity of dCF alone was minimal, except for one patient who became obtunded on day 5 following the first cycle of therapy. In contrast, five patients developed severe toxicity with the combination, including renal failure (three patients), hepatic failure (three patients), and neurologic toxicity (two patients). These results indicate that, at the doses and schedule used in this study, the combination of dCF and ara-A has significant toxicity and minimal activity against recurrent ALL in children. 相似文献