全文获取类型
收费全文 | 9409篇 |
免费 | 696篇 |
国内免费 | 20篇 |
专业分类
耳鼻咽喉 | 119篇 |
儿科学 | 267篇 |
妇产科学 | 276篇 |
基础医学 | 1596篇 |
口腔科学 | 205篇 |
临床医学 | 1115篇 |
内科学 | 1814篇 |
皮肤病学 | 190篇 |
神经病学 | 989篇 |
特种医学 | 378篇 |
外科学 | 1131篇 |
综合类 | 67篇 |
一般理论 | 3篇 |
预防医学 | 808篇 |
眼科学 | 103篇 |
药学 | 550篇 |
中国医学 | 11篇 |
肿瘤学 | 503篇 |
出版年
2023年 | 57篇 |
2022年 | 88篇 |
2021年 | 160篇 |
2020年 | 122篇 |
2019年 | 202篇 |
2018年 | 206篇 |
2017年 | 169篇 |
2016年 | 215篇 |
2015年 | 196篇 |
2014年 | 253篇 |
2013年 | 397篇 |
2012年 | 524篇 |
2011年 | 517篇 |
2010年 | 294篇 |
2009年 | 267篇 |
2008年 | 443篇 |
2007年 | 485篇 |
2006年 | 495篇 |
2005年 | 439篇 |
2004年 | 412篇 |
2003年 | 383篇 |
2002年 | 378篇 |
2001年 | 281篇 |
2000年 | 293篇 |
1999年 | 277篇 |
1998年 | 124篇 |
1997年 | 91篇 |
1996年 | 85篇 |
1995年 | 66篇 |
1994年 | 77篇 |
1993年 | 62篇 |
1992年 | 187篇 |
1991年 | 156篇 |
1990年 | 141篇 |
1989年 | 161篇 |
1988年 | 126篇 |
1987年 | 127篇 |
1986年 | 110篇 |
1985年 | 106篇 |
1984年 | 103篇 |
1983年 | 73篇 |
1982年 | 51篇 |
1981年 | 41篇 |
1979年 | 70篇 |
1978年 | 39篇 |
1977年 | 50篇 |
1975年 | 35篇 |
1974年 | 44篇 |
1973年 | 38篇 |
1971年 | 38篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
92.
E. E. Petersen 《Der Gyn?kologe》1997,30(9):694-701
Zum Thema
Oftmals fatal verlaufende Infektionen in der Gravidit?t – vor allem postpartal – spielen immer noch trotz verbesserter Kenntnis
zur Bakteriologie und Therapie, zur Infektionsprophylaxe und Hygiene eine gro?e Rolle. Als Folge der ver?nderten Immunlage
in der Schwangerschaft kommt es h?ufig zu atypischen Verl?ufen, wodurch die Diagnostik erschwert wird. Auch zun?chst harmlos
erscheinende Virusinfektionen k?nnen exazerbieren. Die einzelnen Krankheitsbilder (Sepsis, Amnioninfektionssyndrom, septischer
Abort, Peritonitis und extragenitale Infektionen) sowie deren Diagnostik und Erreger werden besprochen. Besonders auf die
antibiotische Kombinationstherapie wird eingegangen.
Zusammenfassung
Schwangere mit Grundkrankheiten, Vorsch?den und Neigung zu rezidivierenden Genitalinfektionen sind in bezug auf lebensbedrohliche
Infektionen vermehrt gef?hrdet. In Einzelf?llen bei hochpathogenen Erregern wie den Streptokokken der Gruppe A kann es nach
Blasensprung oder operativen Eingriffen zu einer febrilen oder auch afebrilen t?dlichen Sepsis kommen. Die Beachtung der Vaginalflora,
die Erkennung von Risikofaktoren und die frühzeitige und wirksame Antibiotikagabe verhindern sogenannte schicksalhafte Verl?ufe. 相似文献
93.
94.
95.
Although effective in neuropathic pain, the efficacy of systemic lidocaine in non-neuropathic pain remains uncertain. We investigated the analgesic effect of systemic lidocaine on the heat/capsaicin sensitization model of experimental pain in 24 volunteers. Sensitization was produced by heating the skin to 45 degrees C for 5 min, followed by a 30-min application of 0.075% capsaicin cream, and maintained by periodically reheating the sensitized skin. Subjects received IV lidocaine (bolus 2 mg/kg, then infusion 3 mg. kg. h), or saline for 85 min. Areas of secondary hyperalgesia, heat pain detection thresholds, and painfulness of stimulation with 45 degrees C for 1 min (long thermal stimulation) were quantified. Systemic lidocaine reduced the area of secondary hyperalgesia to brush, but not to von Frey hair stimulation. Lidocaine did not alter heat pain detection thresholds or painfulness of long thermal stimulation in normal skin. We conclude that, at infusion rates in the low- to mid-antiarrhythmic range, lidocaine has no effect on acute nociceptive pain but does have a limited and selective effect on secondary hyperalgesia. Implications: The efficacy of systemic lidocaine in nonneuropathic pain remains uncertain. This study investigates the effect of systemic lidocaine on experimental-induced hyperalgesia in 25 volunteers. Hyperalgesia was induced by using an experimental pain model that uses heat and capsaicin in combination. Systemic lidocaine showed a selective effect on secondary hyperalgesia. 相似文献
96.
The pathogenesis of Achilles tendon rupture remains unclear, but vascular patterns may play an important role. We determined the intravascular volume of the Achilles tendon using a new method with injection of radioisotopes. A solution of Tc-99m and gelatin-ink was injected into the lower limbs of body donors. The intravascular volume of each 1 cm section of the Achilles tendon was measured using a gamma well counter. We found that the distal part of the Achilles tendon (0-2 cm above the calcaneus) had an intravascular volume of 59-98 microL/g tendon tissue. In the middle part of the tendon (3-6 cm above the calcaneal insertion), the intravascular volume was much less: 2743 microL/g tissue. The proximal part of the tendon (7-9 cm) had an intravascular volume between 51-100 microL/g tendon tissue. The reduced vascularization in the middle part of the human Achilles tendon may play a role in degeneration and spontaneous rupture of the tendon. 相似文献
97.
Lean body mass in small for gestational age and appropriate for gestational age infants 总被引:1,自引:0,他引:1
Dual photon absorptiometry using 153Gd in a whole-body scanner was used to measure lean body mass (LBM) in 51 newborn infants. LBM% decreased exponentially with increasing gestational age in both small for gestational age (SGA) and appropriate for gestational age (AGA) infants. In preterm SGA and AGA infants LBM was 104% and 103%, respectively, indicating that no fat was detectable. In term SGA infants LBM was 98%, which corresponded to 48 gm fat on average, and in term AGA infants LBM was 87%, which corresponded to 452 gm fat on average. The LBM%, ponderal index, and skinfold thickness were significantly different between AGA and SGA infants. Infants with clinical signs of intrauterine wastage had significantly higher LBM% than did infants without signs of weight loss. Our results on LBM% by dual photon absorptiometry agree with earlier dissection data; the clinically applicable methods of (1) height combined with weight (i.e., ponderal index), (2) skinfold thickness, and (3) scoring by clinical observations are useful for the estimation of lack of fat as an indicator of intrauterine growth retardation. 相似文献
98.
Monika Zdanyte Peter Martus Jeremy Nestele Alexander Bild Lars Mizera Andreas Glatthaar lvaro Petersen Uribe Frederic Emschermann JessicaKristin Henes Tobias Geisler Karin Müller Meinrad Gawaz Dominik Rath 《Clinical cardiology》2022,45(9):943
BackgroundCardiovascular risk factors and comorbidities are highly prevalent among COVID‐19 patients and are associated with worse outcomes.HypothesisWe therefore investigated if established cardiovascular risk assessment models could efficiently predict adverse outcomes in COVID‐19. Furthermore, we aimed to generate novel risk scores including various cardiovascular parameters for prediction of short‐ and midterm outcomes in COVID‐19.MethodsWe included 441 consecutive patients diagnosed with SARS‐CoV‐2 infection. Patients were followed‐up for 30 days after the hospital admission for all‐cause mortality (ACM), venous/arterial thromboembolism, and mechanical ventilation. We further followed up the patients for post‐COVID‐19 syndrome for 6 months and occurrence of myocarditis, heart failure, acute coronary syndrome (ACS), and rhythm events in a 12‐month follow‐up. Discrimination performance of DAPT, GRACE 2.0, PARIS‐CTE, PREDICT‐STABLE, CHA2‐DS2‐VASc, HAS‐BLED, PARIS‐MB, PRECISE‐DAPT scores for selected endpoints was evaluated by ROC‐analysis.ResultsOut of established risk assessment models, GRACE 2.0 score performed best in predicting combined endpoint and ACM. Risk assessment models including age, cardiovascular risk factors, echocardiographic parameters, and biomarkers, were generated and could successfully predict the combined endpoint, ACM, venous/arterial thromboembolism, need for mechanical ventilation, myocarditis, ACS, heart failure, and rhythm events. Prediction of post‐COVID‐19 syndrome was poor.ConclusionRisk assessment models including age, laboratory parameters, cardiovascular risk factors, and echocardiographic parameters showed good discrimination performance for adverse short‐ and midterm outcomes in COVID‐19 and outweighed discrimination performance of established cardiovascular risk assessment models. 相似文献
99.
Franco JG Baruffi RL Mauri AL Petersen CG Oliveira JB Vagnini L 《Reproductive biomedicine online》2008,17(1):42-45
The aim of this study was to determine the extent of DNA fragmentation and the presence of denatured single-stranded or normal double-stranded DNA in spermatozoa with large nuclear vacuoles (LNV) selected by high magnification. Fresh semen samples from 30 patients were prepared by discontinuous isolate concentration gradient. Spermatozoa with normal nucleus (NN) and LNV were selected at x8400 magnification and placed on different slides. DNA fragmentation was determined by TUNEL assay. Denatured and double-stranded DNA was identified by the acridine orange fluorescence method. DNA fragmentation in spermatozoa with LNV (29.1%) was significantly higher (P < 0.001) than in spermatozoa with NN (15.9%). Therefore, cleavage of genomic DNA in low molecular weight DNA fragments (mono- and oligonucleosomes), and single-strand breaks (nicks) in high molecular weight DNA occur more frequently in spermatozoa with LNV. Similarly, the percentage of denatured-stranded DNA in spermatozoa with LNV (67.9%) was significantly higher (P < 0.0001) than in spermatozoa with NN (33.1%). The high level of denatured DNA in spermatozoa with LNV suggests precocious decondensation and disaggregation of sperm chromatin fibres. The results show an association between LNV and DNA damage in spermatozoa, and support the routine morphological selection and injection of motile spermatozoa at high magnification for ICSI. 相似文献
100.
OBJECTIVE: To report our experience with the prenatal diagnosis of fetal genital anomalies and suggest a protocol for management. METHODS: A retrospective review of all the cases with fetal genital anomalies or phenotype and genotype discrepancy identified by prenatal ultrasound. RESULTS: Twenty cases with abnormal fetal genitalia and four with a phenotype and genotype discrepancy were diagnosed prenatally. Genital anomalies were rarely found in isolation, most were found in combination with renal or multiple structural anomalies. The etiology of abnormal genitalia was broad and included metabolic, chromosomal and genetic syndromes. CONCLUSION: Prenatal detection of genital anomalies should stimulate a detailed ultrasound examination and determination of genotypic sex. Measurement of 17-OHP and Delta(4)-androstenedione or metabolites of the cholesterol pathway in the amniotic fluid and/or maternal urine may be helpful in making a definitive diagnosis. Identification of genital anomalies in fetuses with renal or multiple abnormalities can aid prenatal diagnosis, thereby facilitating accurate counseling of parents who are then in a better position to make informed choices. 相似文献