全文获取类型
收费全文 | 1043619篇 |
免费 | 72159篇 |
国内免费 | 2894篇 |
专业分类
耳鼻咽喉 | 14120篇 |
儿科学 | 32260篇 |
妇产科学 | 28476篇 |
基础医学 | 145597篇 |
口腔科学 | 27798篇 |
临床医学 | 88965篇 |
内科学 | 213208篇 |
皮肤病学 | 21995篇 |
神经病学 | 84850篇 |
特种医学 | 42692篇 |
外国民族医学 | 349篇 |
外科学 | 164823篇 |
综合类 | 20823篇 |
一般理论 | 345篇 |
预防医学 | 75463篇 |
眼科学 | 23141篇 |
药学 | 73037篇 |
中国医学 | 2014篇 |
肿瘤学 | 58716篇 |
出版年
2021年 | 8943篇 |
2019年 | 9277篇 |
2018年 | 12355篇 |
2017年 | 9709篇 |
2016年 | 10558篇 |
2015年 | 12020篇 |
2014年 | 17063篇 |
2013年 | 25502篇 |
2012年 | 35044篇 |
2011年 | 37335篇 |
2010年 | 22370篇 |
2009年 | 21265篇 |
2008年 | 35013篇 |
2007年 | 37040篇 |
2006年 | 37116篇 |
2005年 | 36632篇 |
2004年 | 34774篇 |
2003年 | 33279篇 |
2002年 | 32523篇 |
2001年 | 43243篇 |
2000年 | 44171篇 |
1999年 | 38143篇 |
1998年 | 11700篇 |
1997年 | 10547篇 |
1996年 | 10255篇 |
1995年 | 9557篇 |
1994年 | 9085篇 |
1993年 | 8490篇 |
1992年 | 29290篇 |
1991年 | 28015篇 |
1990年 | 27288篇 |
1989年 | 26186篇 |
1988年 | 24329篇 |
1987年 | 23928篇 |
1986年 | 23004篇 |
1985年 | 21901篇 |
1984年 | 16620篇 |
1983年 | 14178篇 |
1982年 | 8936篇 |
1979年 | 15162篇 |
1978年 | 10769篇 |
1977年 | 9088篇 |
1976年 | 8603篇 |
1975年 | 9346篇 |
1974年 | 11158篇 |
1973年 | 10585篇 |
1972年 | 10019篇 |
1971年 | 9197篇 |
1970年 | 8854篇 |
1969年 | 8250篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
Five patients with orbital pseudotumor refractive to initial therapy are discussed. Three had a destructive granulomatous process associated with a sclerosing component. Two exhibited a predominantly lymphocytic infiltration. Chemotherapy with Prednisone (100 mg/day) and either Cytoxan (100 mg/day) or Chlorambucil (10 mg/day) in 5-day pulses is described. All patients responded clinically to this treatment without unfavorable side effects. 相似文献
993.
P. Praamstra A. R. Cools D. F. Stegeman M. W. I. M. Horstink 《Journal of the neurological sciences》1996,140(1-2):67-74
Movement-related potentials were recorded preceding self-paced voluntary movements in patients with Parkinson's disease and in healthy subjects of the same age group. We compared the Readiness Potential preceding joystick movements in a fixed direction and preceding joystick movements in freely selected directions. In normal subjects the Readiness Potential amplitude was higher preceding freely selected movements than preceding movements in a fixed direction. The Readiness Potential in Parkinson patients failed to be modified by the different modes of movement selection. The modulation of the Readiness Potential by different ways of preparing for movement might be due to the supplementary motor area (SMA) being more strongly engaged by tasks requiring internal control of movements than by tasks that are externally structured. The results suggest that this task-dependent variation of SMA activity is reduced in Parkinson's disease. A failing capacity to adapt SMA activity to different task demands has previously been suggested by evidence from positron emission tomography studies using similar tasks. 相似文献
994.
995.
F. Röpke K. Klingebiel H. J. Hein R. Taute 《Archives of gynecology and obstetrics》1993,254(1-4):1159-1160
Schlu?folgerungen Aus der Me?wert-Verteilung der Grauwerte im Sonogramm lassen sich Kennwerte berechnen, die eine computergestützte sonographische
Reifebeurteilung der Plazenta erm?glichen. Allerdings sind die Verteilungsparameter (Median, Varianz, Schiefe, Exze?) abh?ngig
von den Ger?teparametern. Zuverl?ssiger ist die Berechnung von Kennwerten, die sich auf die strukturellen Eigenschaften des
Sonogramms beziehen. Bei den hier dargestellten Untersuchungen k?nnen Kennwerte für den Kontrast bzw. für die Ansammlung gleichartiger
Grauwerte um einen bestimmten Punkt die sonographische Beurteilung der Plazenta optimieren. Damit erweitern sich die M?glichkeiten
für die Zustandsdiagnostik der intrauterinen Lebensbedingungen. 相似文献
996.
Laorden M. L. Miralles F. S. Cárceles M. D. Hernández J. Puig M. M. 《Journal canadien d'anesthésie》1990,37(4):482-485
Canadian Journal of Anesthesia/Journal canadien d'anesthésie - The aim of the present study was to examine whether changes in temperature alter the effects of halothane and isoflurane on... 相似文献
997.
998.
The course of the subscapular artery was studied in 20 rabbits. Its course was constant, giving two branches to the latissimus dorsi muscle after which the vessel sent a branch (S1) that perforated the panniculus carnosus to supply a large territory of skin. In a separate experiment, the contribution of the S1 branch to the viability of the rabbit latissimus dorsi musculocutaneous flap was evaluated. From this experiment it can be concluded that, first, it is possible in a rabbit to elevate a large skin flap based solely on a muscle perforator (S1), which survives completely. Second, in the rabbit latissimus dorsi musculocutaneous flap, S1 is the major blood supply to the skin component. Damage to it severely diminishes skin flap survival, even if the vascular supply to the underlying muscle is completely intact. 相似文献
999.
N. Glajchen S. Thomas P. Jowell S. Epstein M.D. F. Ismail M. Fallon 《Calcified tissue international》1990,46(1):28-32
Summary The paucity of information on the effect of long-term high-dose salmon calcitonin administration on normal bone mineral metabolism
and histology prompted an investigation of the influence of high-dose synthetic calcitonin in the rat. Serum ionized calcium,
osteocalcin or BGP (bone gla protein), and immunoreactive PTH were measured serially during calcitonin administration and
bone histomorphometry analyzed at 6 weeks (after sacrifice). Daily injections of salmon calcitonin, 0.4 IU/100 g (group B)
and 2 IU/100 g (group C), resulted in significant hypocalcemia at 4 hours for both experimental groups (P<0.004). Serium iPTH was significantly higher over the study period for both groups administered calcitonin. Serum BGP levels
were significantly lower than controls during the study in group C (P<0.002) and to a lesser extent in group B (P<0.05). In group C, bone histomorphometry revealed increased resorption (onteoclast count), decreased trabecular bone volume,
and decreased double-labeled tetracycline surface (bone formation). In group B an increase in osteoclast count but no alteration
in bone formation was observed. To assess the role of PTH in the above findings, high-dose calcitonin was administered to
parathyroidectomized rats. All of the above changes in bone histomorphometry were not observed in this group of animals. In
conclusion, high doses of calcitonin promote hypocalcemia, secondary hyperparathyroidism, and osteoclastosis in the normal
rat in a dose-dependent manner with very high-dose calcitonin impairing bone formation. 相似文献
1000.
We describe a prospective, long-term evaluation of the Schultz metacarpophalangeal joint implant. The prosthesis is a semiconstrained, cemented implant with a ball-in-socket articulation. Thirty-six implants were followed for an average of 10.9 years. There was a progressive decrease in range of motion and strength and a recurrence of ulnar deviation. The neck of the proximal phalangeal component fractured in 39% of the joints. Periarticular heterotopic bone formed in all joints, but was extensive in only 22%. Although some lucency of the bone-cement interface was seen in 80% of the joints, no prosthetic loosening occurred in this series. Our results indicate that long-term, intramedullary cement fixation of relatively long-stemmed components can be satisfactory. However, the articulated portion of this implant does not consistently withstand the stresses transmitted across the joint and does not provide long-term joint stability. 相似文献