全文获取类型
收费全文 | 15357篇 |
免费 | 772篇 |
国内免费 | 50篇 |
专业分类
耳鼻咽喉 | 333篇 |
儿科学 | 339篇 |
妇产科学 | 319篇 |
基础医学 | 2683篇 |
口腔科学 | 348篇 |
临床医学 | 1396篇 |
内科学 | 2544篇 |
皮肤病学 | 399篇 |
神经病学 | 1610篇 |
特种医学 | 828篇 |
外科学 | 2077篇 |
综合类 | 109篇 |
一般理论 | 2篇 |
预防医学 | 778篇 |
眼科学 | 530篇 |
药学 | 1039篇 |
中国医学 | 19篇 |
肿瘤学 | 826篇 |
出版年
2022年 | 96篇 |
2021年 | 171篇 |
2020年 | 110篇 |
2019年 | 189篇 |
2018年 | 246篇 |
2017年 | 189篇 |
2016年 | 299篇 |
2015年 | 302篇 |
2014年 | 358篇 |
2013年 | 453篇 |
2012年 | 852篇 |
2011年 | 784篇 |
2010年 | 511篇 |
2009年 | 511篇 |
2008年 | 693篇 |
2007年 | 800篇 |
2006年 | 848篇 |
2005年 | 866篇 |
2004年 | 804篇 |
2003年 | 707篇 |
2002年 | 752篇 |
2001年 | 335篇 |
2000年 | 273篇 |
1999年 | 274篇 |
1998年 | 212篇 |
1997年 | 174篇 |
1996年 | 154篇 |
1995年 | 129篇 |
1994年 | 109篇 |
1993年 | 104篇 |
1992年 | 138篇 |
1991年 | 151篇 |
1990年 | 152篇 |
1989年 | 155篇 |
1988年 | 156篇 |
1987年 | 119篇 |
1986年 | 105篇 |
1985年 | 124篇 |
1984年 | 118篇 |
1983年 | 84篇 |
1982年 | 72篇 |
1981年 | 86篇 |
1979年 | 110篇 |
1978年 | 82篇 |
1977年 | 88篇 |
1976年 | 77篇 |
1975年 | 78篇 |
1974年 | 83篇 |
1973年 | 73篇 |
1972年 | 83篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Kemp B Winkler M Maas A Maul H Ruck P Reineke T Rath W 《Acta obstetricia et gynecologica Scandinavica》2002,81(10):938-942
BACKGROUND: In previous studies a significant increase in interleukin (IL)-6 and IL-8 concentrations in the lower uterine segment parallel to cervical dilatation at term could be found, however only a weak correlation to duration of labor was detected. This study compares amniotic fluid concentrations of interleukin (IL)-6 and IL-8 with those in the lower uterine segment, and the duration of labor. METHODS: Amniotic fluid and lower uterine segment specimens were obtained from 29 patients during cesarean section at term. The patients were divided into groups according to cervical dilatation (< 2 cm, 2-3.9 cm, 4-6 cm, > 6 cm) and to labor (0 h, > 0-12 h, > 12 h). Interleukin-6 and IL-8 concentrations were determined by enzyme immunoassay. RESULTS: Amniotic fluid IL-6 already increased at 2-3.9 cm (p = 0.02), while the steepest increase in IL-8 was observed at > 6 cm (p = 0.003). No correlation with lower uterine segment values was observed for either of the cytokines. However, the amniotic fluid IL-6 concentration correlated with labor (p = 0.0008). CONCLUSION: The increase in the concentration of IL-6 in the amniotic fluid earlier than its increase in the lower uterine segment supports the hypothesis that IL-6 plays a crucial role for the promotion of labor in the first place, and afterwards for the biochemical degradation processes in the lower uterine segment. The fact that the greatest increase in IL-8 concentration occurs only at > 6 cm indicates that this chemotactic cytokine has only minor significance in the initiation of parturition by its concentration in the amniotic fluid. 相似文献
992.
993.
Salzer-Muhar U Herle M Floquet P Freilinger M Greber-Platzer S Haller A Leixnering W Marx M Wurst E Schlemmer M 《Clinical pediatrics》2002,41(1):17-24
Cognitive achievement, behavioural problems, and various dimensions of personality were assessed in 48 male and female patients with congenital heart disease (CHD) aged from 12 to 16 years in comparison to a control group. The CHD group showed a lower speed of cognitive processing but seemed to have less state-anxiety and to possess a higher superego strength. Male adolescents with CHD presented with a reduced perceived capacity and self-esteem. This was not true for adolescent girls with CHD. The negative self-concept of boys with CHD may be partly explained by reduced physical ability interfering with peer relationships. 相似文献
994.
Wenig BL Werner JA Castro DJ Sridhar KS Garewal HS Kehrl W Pluzanska A Arndt O Costantino PD Mills GM Dunphy FR Orenberg EK Leavitt RD 《Archives of otolaryngology--head & neck surgery》2002,128(8):880-885
OBJECTIVE: To determine the safety and efficacy of targeted antitumor therapy with cisplatin/epinephrine injectable gel in patients with advanced squamous cell carcinoma of the head and neck. DESIGN: Two prospective, double-blind, placebo-controlled phase III trials of identical design. Crossover from blinded to open-label phase was permitted for patients with disease progression. SETTING: Tertiary referral centers in North America and Europe. PATIENTS: One hundred seventy-nine intensively pretreated patients with recurrent or refractory squamous cell carcinoma of the head and neck. INTERVENTION: Cisplatin/epinephrine injectable or placebo gel was administered by direct intratumoral injection; up to 6 weekly treatments. Dose was 0.25 mL of active or placebo gel per cubic centimeter of tumor up to 10 mL total. Patient benefit after local tumor control of the most symptomatic tumor was assessed by patients and physicians using the Treatment Goals Questionnaire. MAIN OUTCOME MEASURES: Local tumor response and patient benefit attributable to improvements in tumor-related symptoms. RESULTS: Combined results for the 178 patients with evaluable data in the 2 trials confirmed objective tumor responses in 35 (29%) of 119 patients, including 23 (19%) complete responses achieved with cisplatin/epinephrine gel, vs 1 (2%) of 59 for placebo (P<.001). Tumor response and patient benefit were significantly correlated (P=.006): 47% (17/36) of patients with target tumor responses achieved a rigorously defined benefit based on a prospectively selected treatment goal vs 15% (22/142) of nonresponders. CONCLUSION: Cisplatin/epinephrine injectable gel reduces tumor burden, ameliorates tumor symptoms, and provides a new therapeutic option for treating patients with squamous cell carcinoma of the head and neck. 相似文献
995.
Mentzel HJ Kentouche K Kosmehl H Gruhn B Vogt S Sauerbrey A Behrendt W Fuchs D Zintl F Kaiser WA 《Pediatric radiology》2002,32(3):195-198
Abdominal problems often complicate the clinical course after bone marrow transplantation. Graft-versus-host disease occurs as a complication of allogenic bone marrow transplantation. In this report, the findings of intestinal involvement are described and correlated with histopathological findings. Increased bowel-wall thickness and increased vascularity were shown by US. MRI demonstrated generalised increased bowel-wall thickness associated with bowel-wall enhancement after administration of i.v. gadolinium. 相似文献
996.
Lippert BM Höft S Teymoortash A Wiedow O Rövert J Werner JA 《Otolaryngologia polska. The Polish otolaryngology》2002,56(6):661-667
Mycosis fungoides is a rare cutaneous lymphoma. Dissemination to extra-cutaneous sites occurs at advanced stages of disease. Laryngeal manifestations of mycosis fungoides have been reported in only 13 cases in the available literature. We present a further calla of mycosis fungoides of the larynx at the terminal stage of disease with an additional manifestation in the left maxillary sinus and review the cases published to date. To our knowledge this is the first reported case of mycosis fungoides with laryngeal and paranasal sinus manifestation. Concluding from the present case and from literature therapy should be palliative to improve quality of life. 相似文献
997.
Wishing to assess the effects of the dimensions of the middle ear on the auditory sensitivity of gekkonoid lizards, we measured middle ear components in preserved geckos, which in life had yielded 'cochlear microphonics' audiograms. We examined two to seven specimens of 14 species. The measures of middle ear elements varied relative to head or body length similarly within species and among species. The areas of the external ear opening, tympanic membrane, and columellar footplate, and the ratio between the last two ('hydraulic lever'), were correlated with animal length. The hydraulic and mechanical (extracolumellar) lever ratios appeared to complement each other, the former being emphasized in large animals, the latter in small animals. The apparent auditory sensitivity correlated with the sizes of the animal, head and external ear opening, and negatively (insignificantly) correlated with the mechanical lever ratio. The correlation of sensitivity with the hydraulic lever was insignificant, perhaps due to a 'tympanic membrane lever' (catenary effect). The most sensitive frequency negatively correlated with the area of the external ear opening, the area of the tympanic membrane, and with the level of greatest sensitivity. It was positively correlated with the relative length of the cartilaginous portion of the ossicular chain. However, the number of hair cells in the basilar papilla, too, is known to correlate with animal size. Moreover, the least sensitive species were not only the smallest species, they were also the species known to lack a zone of unidirectional hair cells in the basilar papilla. Hence the apparent sensitivity hypothetically depends on both middle ear dimensions and summation of inner ear output. This hypothesis requires verification by other methods. 相似文献
998.
999.
OBJECTIVE: To study basal C-peptide (BCP) and postglucagon C-peptide (PGCP) levels in Ethiopians with diabetes. RESEARCH DESIGN AND METHODS: A total of 56 subjects with type 1 diabetes, 97 subjects with type 2 diabetes, and 50 control subjects were recruited from a hospital in Ethiopia. BCP was determined in all subjects and PGCP in 86 subjects. RESULTS: Mean (+/- SEM) BCP, PGCP, and the increment after glucagon in type 1 diabetic subjects (0.14 +/- 0.04, 0.22 +/- 0.11, and 0.08 +/- 0.05 nmol/l, respectively) were lower (P < 0.001) than those in type 2 diabetic subjects (0.66 +/- 0.04, 1.25 +/- 0.10, and 0.56 +/- 0.06 nmol/l, respectively) or control subjects (0.54 +/- 0.04, 1.52 +/- 0.26, and 1.11 +/- 0.24 nmol/l, respectively). The mean BCP level was higher in type 2 diabetic subjects than control subjects (P=0.015), whereas the mean increment was lower (P=0.005). Insulin-treated type 2 diabetic subjects, compared with non-insulin-treated type 2 diabetic subjects, had lower mean BCP (0.55 +/- 0.08 nmol/l [n=37] vs. 0.73 +/- 0.04 [n=60], P=0.001), lower PGCP (0.97 +/- 0.20 nmol/l [n=18] vs. 1.40 +/- 0.11 [n=35], P=0.010), and a lower C-peptide increment (0.34 +/- 0.06 [n=18] vs. 0.67 +/- 0.07 nmol/l [n=35], P=0.003). In both the type 1 and type 2 diabetic groups, those with BCP levels <0.2 nmol/l had lower BMI than those with higher BCP levels (P=0.023 and P < 0.001, respectively). CONCLUSIONS: Combined with clinical criteria, C-peptide levels are good discriminators between type 1 and type 2 diabetes in Ethiopians and may also be useful in identifying subjects with type 2 diabetes who require insulin therapy. There is a subgroup of type 2 diabetic subjects with features of type 1 diabetes. 相似文献
1000.