全文获取类型
收费全文 | 7799篇 |
免费 | 422篇 |
国内免费 | 37篇 |
专业分类
耳鼻咽喉 | 82篇 |
儿科学 | 172篇 |
妇产科学 | 199篇 |
基础医学 | 1219篇 |
口腔科学 | 159篇 |
临床医学 | 795篇 |
内科学 | 1587篇 |
皮肤病学 | 90篇 |
神经病学 | 556篇 |
特种医学 | 754篇 |
外国民族医学 | 2篇 |
外科学 | 881篇 |
综合类 | 36篇 |
一般理论 | 1篇 |
预防医学 | 436篇 |
眼科学 | 79篇 |
药学 | 522篇 |
中国医学 | 8篇 |
肿瘤学 | 680篇 |
出版年
2022年 | 54篇 |
2021年 | 129篇 |
2020年 | 63篇 |
2019年 | 105篇 |
2018年 | 119篇 |
2017年 | 91篇 |
2016年 | 115篇 |
2015年 | 131篇 |
2014年 | 196篇 |
2013年 | 229篇 |
2012年 | 390篇 |
2011年 | 329篇 |
2010年 | 186篇 |
2009年 | 198篇 |
2008年 | 328篇 |
2007年 | 353篇 |
2006年 | 370篇 |
2005年 | 345篇 |
2004年 | 336篇 |
2003年 | 320篇 |
2002年 | 324篇 |
2001年 | 354篇 |
2000年 | 335篇 |
1999年 | 245篇 |
1998年 | 98篇 |
1997年 | 97篇 |
1996年 | 63篇 |
1995年 | 53篇 |
1993年 | 46篇 |
1992年 | 130篇 |
1991年 | 149篇 |
1990年 | 127篇 |
1989年 | 151篇 |
1988年 | 121篇 |
1987年 | 117篇 |
1986年 | 98篇 |
1985年 | 106篇 |
1984年 | 75篇 |
1983年 | 63篇 |
1982年 | 45篇 |
1979年 | 91篇 |
1978年 | 50篇 |
1977年 | 47篇 |
1976年 | 50篇 |
1975年 | 46篇 |
1974年 | 67篇 |
1973年 | 62篇 |
1972年 | 56篇 |
1970年 | 54篇 |
1969年 | 42篇 |
排序方式: 共有8258条查询结果,搜索用时 15 毫秒
61.
The devastating consequences of the Fascist dictatorship in Germany for the ethical thinking of the physicians are particularly clearly recognizable by the mass killings of severely damaged children and patients with chronic psychic diseases which were performed at that time. Recent investigations of the developments which began in 1938 show that by way of intensive efforts for a juridicial legalization of the "active euthanasia" an enlargement of this killing practice has been striven after. References to a motive of compassion and the free decision of the affected persons should cover the real intention for reducing welfare services. A bill presented in 1940 for a law "on euthanasia for incurable ill persons" found the unanimous consent of the renowned physicians consulted for this purpose. Though this law finally did not become legal beginning with 1941 the medical practice showed further forms of the repressive and antihumane association with ill persons who were regarded as incurable, which must be valuated as practical consequences of an unadmissible relativation of the life-preserving task of medicine. 相似文献
62.
Ghazal Arabidarrehdor Ali Tivay Ramin Bighamian Chris Meador George C. Kramer Jin-Oh Hahn Jose Salinas 《Burns : journal of the International Society for Burn Injuries》2021,47(2):371-386
This paper presents a mathematical model of blood volume kinetics and renal function in response to burn injury and resuscitation, which is applicable to the development and non-clinical testing of burn resuscitation protocols and algorithms. Prior mathematical models of burn injury and resuscitation are not ideally suited to such applications due to their limited credibility in predicting blood volume and urinary output observed in wide-ranging burn patients as well as in incorporating contemporary knowledge of burn pathophysiology. Our mathematical model consists of an established multi-compartmental model of blood volume kinetics, a hybrid mechanistic-phenomenological model of renal function, and novel lumped-parameter models of burn-induced perturbations in volume kinetics and renal function equipped with contemporary knowledge on burn-related physiology and pathophysiology. Using the dataset collected from 16 sheep, we showed that our mathematical model can be characterized with physiologically plausible parameter values to accurately predict blood volume kinetic and renal function responses to burn injury and resuscitation on an individual basis against a wide range of pathophysiological variability. Pending validation in humans, our mathematical model may serve as an effective basis for in-depth understanding of complex burn-induced volume kinetic and renal function responses as well as development and non-clinical testing of burn resuscitation protocols and algorithms. 相似文献
63.
Die Anaesthesiologie - 相似文献
64.
Joseph G. Cheaib Lauren E. Claus Hiten D. Patel Max R. Kates Andres Matoso Noah M. Hahn Trinity J. Bivalacqua Jean H. Hoffman-Censits Phillip M. Pierorazio 《Urologic oncology》2021,39(1):74.e9-74.e16
PurposeMetastatic recurrence occurs in over 25% of upper tract urothelial carcinoma patients treated with radical nephroureterectomy. While metastatic recurrence suggests poor prognosis, the impact of the specific site of recurrence on prognosis is not well documented.Materials and methodsWe retrospectively analyzed 188 patients who underwent radical nephroureterectomy for high-grade, node-negative upper tract urothelial carcinoma at our institution from 2003 to 2018 without receiving neoadjuvant or adjuvant chemotherapy. Competing-risks survival analysis was performed to evaluate the cumulative incidence and predictors of metastatic recurrence. The Kaplan-Meier method and log-rank test were used to estimate and compare recurrence site-specific survival probabilities following metastatic recurrence. Cox regression analyses were performed to assess site-specific prognoses.ResultsOf the 188 patients, 47 (25%) developed metastatic recurrence over a median follow-up of 30 months (interquartile range: 10.5–58.5 months). The 1- and 2-year cumulative incidences of metastatic recurrence were 13.6% and 23.6%, respectively. On multivariable analysis, lymphovascular invasion was significantly predictive of metastatic recurrence (subhazard ratio: 2.6, P = 0.01). Of the 47 patients who developed recurrence, 38 (80.9%) died over a median follow-up of 10 months (interquartile range: 5–20 months). Metastatic recurrence was most common in the lungs (n= 13, 28%) and at multiple sites (n= 14, 30%). Median time to recurrence was shorter for recurrences at multiple sites (6.5 months) and those in the liver (13 months) and bone (18 months) compared to other sites. Patients who recurred in the liver (hazard ratio: 6.3, P = 0.007), bone (hazard ratio: 4.9, P = 0.02), and multiple sites (hazard ratio: 4.6, P = 0.01) had significantly worse prognosis compared to those who recurred in lymph nodes. Statistical significance persisted after adjusting for treatment with salvage therapy.ConclusionsA significant proportion of high-grade upper tract urothelial carcinoma patients recur systemically after radical nephroureterectomy. Lymphovascular invasion is a predictor of metastatic recurrence and may inform decisions regarding perioperative chemotherapy. Hepatic and osseous recurrences have relatively quicker onset and less favorable prognosis compared to other sites. These findings may benefit future efforts to develop recurrence site-specific treatment plans and highlight the necessity of subsequent endeavors to explore the genetic associations of recurrence in upper tract urothelial carcinoma. 相似文献
65.
66.
The pharmacokinetics of tranylcypromine enantiomers in healthy subjects after oral administration of racemic drug and the single enantiomers 下载免费PDF全文
Weber-Grandke H Hahn G Mutschler E Möhrke W Langguth P Spahn-Langguth H 《British journal of clinical pharmacology》1993,36(4):363-365
The pharmacokinetics of the two enantiomers of tranylcypromine were evaluated in six healthy subjects after oral dosage of the racemate (20 mg of the sulphate) and the single enantiomers (10 mg of the sulphate) using an enantiospecific assay. Significant differences in AUC, Cmax, lambda(z), and CLR of the two enantiomers were observed both on administration of the racemate and of the individual enantiomers. The plasma concentrations and urinary excretion rates of (-)-tranylcypromine exceeded those of (+)-tranylcypromine. AUCs of the (-)-enantiomer [arithmetical means 197 ng ml(-1) h after the racemate, 130 ng ml(-1) h after the enantiomer] were greater than those of the (+)-enantiomer [26 ng ml(-1) h after the racemate, 28 ng ml(-1) h after the enantiomer] (P = 0.0001). No in vivo racemisation was detected. The power of the study was insufficient to establish any enantiomer-enantiomer interaction except for a possible interaction at the level of renal clearance (P = 0.013 for both enantiomers). 相似文献
67.
F. Stelzner S. Beyenburg N. Hahn 《Langenbeck's archives of surgery / Deutsche Gesellschaft fur Chirurgie》1993,378(1):49-59
Zusammenfassung Die Bauchhöhle hat ein Faszienskelett, das durch ihren permanenten veränderhchen Ruhetonus verspannt gehalten wird. Zur Bauchhöhle gehören mit der seitlichen Bauchmuskulatur auch das Zwerchfell und der Beckenboden. Willkürliche und reflektorische Tonusänderungen bedingen ihre Verformung und ihren Verschluß oder ihre Eröffnung. Am Versuchstier haben wir diesen Ruhetonus schon in der Schwanzmuskulatur nachgewiesen, von der der Beckenboden des Menschen stammesgeschichtlich abstammt. Der Beckenboden bildet mit den Sphinkteren das anorektale Kontinenzorgan. Es ist, phylogenetisch erklärbar, bei der Frau viel schwächer entwickelt als beim Mann. Diese unterschiedliche Mächtigkeit ist his zu den Kernen des Rückenmarks, die diese Muskulatur steuern, zu verfolgen. Diese Asthenie des weiblichen Kontinenzorgans wird durch das Gebären und die Obstipation noch zusätzlich belastet. Das gleiche gilt für die Bauchdecke der Frau, die, wie hier nachgewiesen wird, nach einer Gravidität die gleichen, bleibenden Denervationserscheinungen ihrer Muskulatur erkennen läß t. Es sind die gleichen Schäden, die der Beckenboden mit den Sphinkteren erleidet. In schwereren Fällen ist neben der Inkontinenz also auch ein Schlotterbauch die Folge dieser Belastungen. Der ruhetonisierte Beckenboden kann das spastische Beckenbodensyndrom, die kontinente Obstipation, zur Folge haben. Sic kann psychotherapeutisch geheilt werden. Davon muß die inkontinente Obstipation unterschieden werden, die manchmal mit einem Mastdarmvorfall einhergeht. Bei ihr liegt das Hindernis im Darm. Sic kann in schweren Fällen durch eine Sigmaresektion gebessert werden. Die Denervationsinkontinenz ist am besten durch das operative Engerstellen des ganzen Levatortrichters zu bessern. Voraussetzung ist: Der gelähmte Beckenboden muß noch eine Restruheaktivität aufweisen.
Acquired disturbances of muscles of the peritoneal cavity
The peritoneal cavity has a fascial skeleton that is kept under tension by permanent variable resting tone maintained by the abdominal muscles. The lateral abdominal muscles, the diaphragm and the pelvic floor are all components of this fasciomuscular support system. Voluntary and reflective changes in muscle tension allow the entry and exit of matter into and out of the spherical abdominal cavity by opening and closing of specialized wall segments called sphincters. We have previously demonstrated the existence of a resting tone in the tail muscles of mammals from which the human pelvic floor muscles are derived. The pelvic floor and its integrated sphincters form the anorectal organ of continence. This organ is much weaker in females than in males. The spinal centers that govern continence, contain in the female significantly fewer ganglion cells than the corresponding centers in the male. Childbirth and a commonly found tendency to develop constipation are additional stressors for the congenitally weaker female organ of continence. We explain in this paper why the abdominal wall and the pelvic floor may suffer stretch-induced denervation injuries during pregnancy and delivery. Such damage may persist in later life and can give rise to incontinence and flabby abdomen. Based on our work in this field, we found a new differentiation between continent and incontinent constipation. Continent constipation is caused by spasticity of the pelvic floor characterized by abnormally high sphincter activity. This spastic pelvic floor syndrome can be treated successfully by psychotherapeutic techniques. Incontinent constipation, in contrast, is always associated with subnormal activity of the sphincters and may be a cause of rectal prolapse. It can be treated successfully by anterior rectosigmoid resection. Incontinent constipation will also require operative approximation of the levators in many cases. Improvement cannot be expected to result from this procedure, however, unless the pelvic floor shows some residual resting activity.
Korrespondenz an: em. Prof. Dr. Dr. h. c. mult. F. Stelzner 相似文献
68.
A total of 225 human gallbladder stones were divided into sets of two, three, or four identical calculi (with maximum diameters of 6-26 mm) and submitted to piezoelectric shock wave lithotripsy in vitro in order to investigate the influence of the following parameters on stone disintegration: shock wave intensity, pulse frequency, and various physicochemical parameters such as the volume and viscosity of the fluid surrounding the stone, the hardness of the calculus, and its chemical composition. The fragmentation efficacy increased with enhanced shock wave energy (P less than 0.01). If the volume of the fluid (30 mL) surrounding the calculus was small, the disintegration end-point (defined by maximum fragment diameters less than or equal to 4 mm) was achieved after a lower number of pulses (median: 250 pulses) than in the case of a large fluid volume (80 mL) (500 pulses; P less than 0.01). On the other hand, however, factors such as the shock wave pulse rate (0.9 Hz vs 1.6 Hz), variations in viscosity of a water-jelly mixture surrounding the stone, the chemical composition of the stones as determined by X-ray diffractometry, and stone hardness were found to have no significant influence on the fragmentation efficacy. 相似文献
69.
These experiments examined the role of substance P-selective neurokinin 1 receptors in the restraint-induced activation of the rat locus coeruleus. Immunohistochemistry revealed high levels of neurokinin 1 receptor expression in the plasma membrane of tyrosine hydroxylase-positive locus coeruleus neurons. The selective neurokinin 1 receptor antagonists, RP 67580 (5 nmol) and L-760,735 (3.4 nmol), were administered intracerebroventricularly prior to restraint stress, and c-fos protein was measured as an index of locus coeruleus activation. Both antagonists attenuated the restraint-induced increase in locus coeruleus c-fos expression, whereas their inactive enantiomers were ineffective. These results suggest that neurokinin 1 receptors may mediate activation of locus coeruleus neurons during stress. Neurokinin 1 receptor antagonists may prove to be novel therapeutic compounds in the treatment of anxiety and depression. 相似文献
70.
Purpose. In a patient with internal derangement of the shoulder, the diagnostic method of choice is controversial. Conventional arthrography
can diagnose most rotator cuff tears accurately; however, in many institutions MR arthrography is usually necessary to diagnose
labral tears. We utilized decision tree methodology to compare the cost- effectiveness of conventional arthrography and conventional
MRI with a hypothetical algorithm in which a patient underwent arthrography, performed with admixed gadolinium, which if negative,
was followed by MRI.
Design. The use of double-contrast arthrography alone, conventional MRI alone, and gadolinium-enhanced MRI used as an adjunct to
conventional arthrography were modeled for the diagnosis of full-thickness rotator cuff tears (RCT), partial RCTs, labral
tears, and the absence of cuff/labral tears using decision analysis methodology. English language medical publications were
searched to determine the base probabilities for the accuracy of the diagnostic tests. The outcome utilities ranged from –1
to +1 to reflect the value of correct diagnostic evaluation. Charges for diagnostic tests and appropriate surgical treatments
were based on 1997 Medicare reimbursement rates for professional fees and hospital charges in an outpatient setting. Sensitivity
analyses were performed to evaluate the effects of uncertainty regarding the prevalence of each disease state and the accuracy
of several diagnostic tests.
Results. In the base-case analysis, the average effectiveness of double-contrast arthrography alone, MRI alone and arthrography selectively
followed by MRI were 0.6610, 0.6715, and 0.7204, respectively. The average costs for each of these strategies were $1090,
$2033, and $2339, respectively.
Conclusion. Arthrography performed with admixed diluted gadolinium, which if negative is immediately followed by MRI, was somewhat more
expensive than conventional MRI. However, because of much greater effectiveness, cost-effectiveness was significantly higher
for our proposed algorithm. Conventional arthrography without gadolinium, although less expensive, had severely limited effectiveness.
Received: 4 June 1999 Revision requested: 6 August 1999 Revision received: 30 August 1999 Accepted: 1 September 1999 相似文献