全文获取类型
收费全文 | 3320716篇 |
免费 | 234376篇 |
国内免费 | 5820篇 |
专业分类
耳鼻咽喉 | 47680篇 |
儿科学 | 105337篇 |
妇产科学 | 91760篇 |
基础医学 | 482501篇 |
口腔科学 | 94835篇 |
临床医学 | 295846篇 |
内科学 | 637617篇 |
皮肤病学 | 74436篇 |
神经病学 | 263495篇 |
特种医学 | 126664篇 |
外国民族医学 | 894篇 |
外科学 | 503688篇 |
综合类 | 71253篇 |
现状与发展 | 16篇 |
一般理论 | 1215篇 |
预防医学 | 250745篇 |
眼科学 | 78867篇 |
药学 | 248562篇 |
15篇 | |
中国医学 | 6848篇 |
肿瘤学 | 178638篇 |
出版年
2018年 | 35340篇 |
2017年 | 27088篇 |
2016年 | 30416篇 |
2015年 | 33811篇 |
2014年 | 47582篇 |
2013年 | 72428篇 |
2012年 | 98104篇 |
2011年 | 104578篇 |
2010年 | 62099篇 |
2009年 | 58660篇 |
2008年 | 98951篇 |
2007年 | 106347篇 |
2006年 | 106960篇 |
2005年 | 103978篇 |
2004年 | 99820篇 |
2003年 | 96647篇 |
2002年 | 93972篇 |
2001年 | 149755篇 |
2000年 | 153893篇 |
1999年 | 129615篇 |
1998年 | 37372篇 |
1997年 | 33008篇 |
1996年 | 32600篇 |
1995年 | 30907篇 |
1994年 | 28605篇 |
1993年 | 26953篇 |
1992年 | 100624篇 |
1991年 | 98194篇 |
1990年 | 96046篇 |
1989年 | 93024篇 |
1988年 | 86021篇 |
1987年 | 84597篇 |
1986年 | 79968篇 |
1985年 | 76738篇 |
1984年 | 57209篇 |
1983年 | 48771篇 |
1982年 | 29226篇 |
1981年 | 26371篇 |
1979年 | 53565篇 |
1978年 | 38406篇 |
1977年 | 32592篇 |
1976年 | 30564篇 |
1975年 | 33704篇 |
1974年 | 40215篇 |
1973年 | 38629篇 |
1972年 | 36531篇 |
1971年 | 34478篇 |
1970年 | 32203篇 |
1969年 | 30782篇 |
1968年 | 28470篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
D P Taggart D C McMillan T Preston R Richardson A Shenkin H J Burns D J Wheatley 《Nutrition (Burbank, Los Angeles County, Calif.)》1991,7(4):271-274
Total energy expenditure (TEE) was measured by doubly labeled water in 13 preoperative patients undergoing elective coronary artery surgery and compared to resting energy expenditure (REE) measured by indirect calorimetry (IC) calculated from the Harris-Benedict (HB) formula or from formulas based on midarm circumference and arm muscle circumference. Mean REE measured by IC and calculated from the HB, midarm circumference, arm muscle circumference formulas were 62, 75, 62, and 69%, respectively, of TEE measured by doubly labeled water. REE measured by IC correlated significantly with that predicted by the HB (p = 0.006) but not the anthropometric formulas. The relationship between REE derived from anthropometric predictive formulas and REE measured by IC is altered in ischemic heart disease. 相似文献
992.
C Leclercq G Maiani A Polito A Ferro-Luzzi 《Nutrition (Burbank, Los Angeles County, Calif.)》1991,7(5):350-354
The p-aminobenzoic acid (PABA) test has been successfully used as an indicator of completeness of 24-h urine collection in field studies of the general population. Our study was designed to investigate its validity for elderly people. Urinary excretion of fractionated oral doses of PABA was measured in 21 young control subjects (19-39 yr old) and 356 elderly (60-89 yr old) men and women. PABA excretion over 24 h was lower in elderly than in control subjects. Subjects aged greater than or equal to 70 yr had a lower recovery of the PABA dose than subjects aged 60-69 yr over the first 24 h, followed by a higher recovery over the next 24-48 h. The cumulative 48-h recovery was similar in all age classes of elderly subjects. However, 48% of the elderly subjects had a cumulative PABA recovery below the conventional cutoff for completeness (85%). These subjects also had consistently lower creatinine output and urinary volume. The lower 24-h urinary PABA recovery over 70 yr of age is interpreted to reflect the delayed renal clearance of the marker substance and indicates that the PABA test is unsuitable for this age group. The low 48-h cumulative recoveries found in all age classes of the elderly are thought to be caused by small unreported losses, which are recurrent in free-living populations. 相似文献
993.
U Caliceti A Rinaldi Ceroni G Lisignoli P Chieco O Cavicchi 《Archives of oto-rhino-laryngology》1989,246(5):365-367
A microfluorometric method was used to determine the nuclear DNA content in the nasopharyngeal carcinomas (NPC) of 25 patients treated before 1983. Eleven patients are still alive with no evidence of disease (NED), while the rest died of their disease (DOD). All of the patients received a cycle of radiotherapy, while some also received chemotherapy or neck dissections. The neoplastic cells studied were taken from the original biopsy blocks, deparaffinized, isolated by enzymatic treatment and mechanical fragmentation, and then Feulgen-stained. The cytofluorometric measurement was carried out by a microphotometer equipped for fluorescence excitation and connected to a computer. This method allowed us to construct a histogram of the DNA content in the neoplastic cells. Different neoplastic classes were identified and represent the heteroclonality of the tumor, which can be expressed by the heteroclonality index (HCT). From the collected data it appears that the NED patients all had a low HTC (less than 1) and only 7 of the DOD patients had low HTCs (less than 1). Six of the DOD patients with a low HTC were in advanced stages of their tumor at the time of diagnosis, while the remaining patient did not complete his treatment. Our results show that the DNA analysis of the NPC cell population may offer a useful tool in predicting the biological behavior of this tumor and also improving its treatment. 相似文献
994.
Nonsyndromal autosomal recessive profound childhood deafness will affect about one in 4000 children in western Europe. A nonsyndromal autosomal recessive type of profound childhood deafness was thought to be the cause of deafness in at least eight and probably 12 children from a large family with various consanguineous matings and other family interrelations. Audiograms of all affected deaf children showed a profound childhood deafness with only a very slight variation. Audiometric examinations, such as pure-tone audiometry, high-frequency audiometry, stapedial reflexes, and Bekesy audiometry, of ten obligate or presumed carriers did not show any significant findings that would allow identification of carriers of this autosomal recessive gene. Families like this one seem to be very rare. Large clinically well-studied families like this one are indispensable for gene linkage studies of nonsyndromal autosomal recessive types of profound childhood deafness. Such studies should make it possible to trace the origin of these types of childhood deafness at an early age. In consequence, carrier detection should also become available. 相似文献
995.
After ingesting or inhaling laundry detergent powder, eight children required hospital admission. The predominant symptoms were stridor, drooling, and respiratory distress. All but one patient underwent endoscopy of the airways and the esophagus, five children were admitted to the intensive care unit, and four children required endotracheal intubation. Laundry detergent ingestions are generally considered to have minor consequences, and there exists a paucity of literature on the subject. Evidence of significant morbidity incurred because of ingestion or inhalation of sodium carbonate-containing laundry detergent powder is presented, together with a review of the existing literature. 相似文献
996.
997.
998.
Twenty two patients (age range: 1 month to 11 years) were treated for congenital diaphragmatic defects (excluding hiatus hernia) in the six year period 1983-8. Presenting features were failure to thrive (n = 7), abdominal pain and vomiting (n = 4), chronic respiratory symptoms (n = 3), and inability to wean from ventilatory support (n = 3). The defect was an incidental finding in five patients. Operative repair was performed with no mortality or serious postoperative morbidity. Dramatic improvement occurred in 15 of the 17 symptomatic patients. Awareness of the differential diagnosis should avoid delay in diagnosis or inappropriate treatment. Surgical correction is strongly recommended in all cases. 相似文献
999.
A I Eidelman 《The Journal of pediatrics》1989,114(2):340-341
1000.
From October to December 1984, examination has been carried out on Salmonella-typhi cultures from blood, bone marrow, faeces and urine of 43 patients suffering from suspected typhoid fever treated in the Department of Child Health, Medical School/Hasan Sadikin General Hospital, Bandung. It was apparent that among these 43 patients, 51.2% were males and 48.8% females. The greater number of them were more than 5 years old (64.4%). The results of Salmonella-typhi cultures were obtained from 65% of the patients, consisting of 65% positive cultures from bone-marrow and 40% positive cultures from blood that showed a statistically significant difference (p less than 0.05). Likewise, the time for matter-sampling for the examinations was based on the culture results, both on blood-culture and that of bone-marrow, statistically a significant was found (p less than 0.05), whereas the results of cultures based on previous vaccination history and the administration of chloramphenicol prior to treatment did not differ significantly. It was obviously clear that the results of bone-marrow culture were more successful compared to those from blood culture, so that it should necessarily be emphasized, as to these examinations on culture from each patient with suspected typhoid fever, especially those patients hospitalized during the third week of their illness. 相似文献