全文获取类型
收费全文 | 16311篇 |
免费 | 949篇 |
国内免费 | 173篇 |
专业分类
耳鼻咽喉 | 175篇 |
儿科学 | 447篇 |
妇产科学 | 352篇 |
基础医学 | 1733篇 |
口腔科学 | 522篇 |
临床医学 | 1279篇 |
内科学 | 4353篇 |
皮肤病学 | 304篇 |
神经病学 | 1657篇 |
特种医学 | 773篇 |
外科学 | 2745篇 |
综合类 | 45篇 |
一般理论 | 4篇 |
预防医学 | 548篇 |
眼科学 | 214篇 |
药学 | 875篇 |
中国医学 | 18篇 |
肿瘤学 | 1389篇 |
出版年
2024年 | 13篇 |
2023年 | 201篇 |
2022年 | 404篇 |
2021年 | 746篇 |
2020年 | 430篇 |
2019年 | 542篇 |
2018年 | 641篇 |
2017年 | 507篇 |
2016年 | 524篇 |
2015年 | 610篇 |
2014年 | 714篇 |
2013年 | 882篇 |
2012年 | 1327篇 |
2011年 | 1301篇 |
2010年 | 723篇 |
2009年 | 681篇 |
2008年 | 1056篇 |
2007年 | 960篇 |
2006年 | 869篇 |
2005年 | 828篇 |
2004年 | 740篇 |
2003年 | 616篇 |
2002年 | 577篇 |
2001年 | 169篇 |
2000年 | 159篇 |
1999年 | 140篇 |
1998年 | 105篇 |
1997年 | 79篇 |
1996年 | 82篇 |
1995年 | 74篇 |
1994年 | 49篇 |
1993年 | 52篇 |
1992年 | 71篇 |
1991年 | 56篇 |
1990年 | 61篇 |
1989年 | 44篇 |
1988年 | 44篇 |
1987年 | 49篇 |
1986年 | 31篇 |
1985年 | 39篇 |
1984年 | 29篇 |
1983年 | 12篇 |
1979年 | 28篇 |
1978年 | 11篇 |
1977年 | 15篇 |
1976年 | 17篇 |
1975年 | 18篇 |
1974年 | 11篇 |
1971年 | 11篇 |
1968年 | 9篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
Gian Luca Armas Chih-Ying Su Chao-Cheng Huang Fu-Min Fang Ching-Mei Chen Chih-Yen Chien 《European archives of oto-rhino-laryngology》2008,265(11):1379-1384
This study is to determine the impact of virus in surgical outcomes among patients of head and neck cancer with N3 lymph node
metastasis. A retrospective analysis was conducted for 32 patients with operable N3 neck metastasis undergoing surgical treatment
between January 1987 and October 2006. The nuclei of the tumor cells were investigated for the presence of human papillomavirus
(HPV) and Epstein–Barr virus (EBV) DNAs and were taken into account as the variable for survival analysis. The primary sites
were oropharynx in 11 patients, tongue in 3, buccal mucosa in 1, hypopharynx in 8 and unknown primary in 9. The five-year
cumulative overall survival rate was 40.7% and 5-year cumulative regional control rate was 55.8%. The 5-year cumulative overall
survival rate of patients with unknown primary site (72.9%) and HPV or EBV positive in the tumor (77.8%) were significantly
higher than those patients with known primary site (31.3%) and HPV or EBV negative in the tumor (27.4%), respectively (P = 0.0335 and P = 0.0348, log rank test). In conclusion, surgery with adjuvant therapy offers reasonable outcomes for operable N3 node in
head and neck cancer in our cohort. In addition, patients with HPV or EBV positive in the tumor have a better survival. 相似文献
993.
BACKGROUND: Around 40% of the elderly population suffer from arterial hypertension. An effective antihypertensive treatment is therefore required. Calcium antagonists are used to treat hypertension because, owing to their mechanism of action, they can provoke systemic, as well as coronary vasodilatation. In this study the authors aimed to evaluate the activity and tolerability of diltiazem compared to ramipril in a group of elderly patients suffering from essential arterial hypertension. METHODS: A controlled single-blind study was performed in which patients were randomly assigned to one of two groups, A and B, consisting of 25 patients each, treated respectively with 300 mg sustained-release diltiazem or 5 mg ramipril in a single daily dose. The study lasted 6 months and evaluated systolic and diastolic pressure and heart rate. RESULTS: The evolution was positive in all patients in Group A and most patients in Group B, with the normalisation of both systolic and diastolic values. Heart rate showed a more persistent fall in Group A, but this was expected owing to the mechanism of action of diltiazem. No patient in Group A had to suspend treatment, whereas one patient in Group B had to interrupt therapy following the onset of a persistent cough. CONCLUSIONS: Both treatments resulted in similar changes in systolic and diastolic arterial blood pressure. In the light of these results, it can be affirmed that, at an oral dose of 300 mg/day, sustained-release diltiazem was found to be effective and well tolerated in the treatment of mild to moderate essential arterial hypertension in the aged. 相似文献
994.
T Arrigo D Cucinotta S Conti Nibali E Di Cesare A Di Benedetto G Magazzù F De Luca 《Acta paediatrica (Oslo, Norway : 1992)》1993,82(3):249-253
Thirty-two patients with cystic fibrosis and repeatedly normal fasting blood glucose underwent oral glucose tests and islet-cell antibody assessments on two occasions approximately two years apart. Fourteen patients underwent two iv glucose tolerance tests also. Although in the group as a whole mean glucose areas in response to the oral test remained substantially unmodified over the two-year period, the prevalence of glucose tolerance abnormalities increased from 37.5 to 50%. Insulin output in response to both oral and iv tolerance tests decreased over time. Worsening of insulin secretion and/or of glucose tolerance was never accompanied by deteriorating clinical status. Islet-cell antibodies were detected in no patients, even in those who developed a diabetic glucose tolerance. These results support, on a longitudinal basis, the view of a progressive impairment of B-cell function in cystic fibrosis, which may precede the onset of metabolic abnormalities and is not triggered by autoimmunity. 相似文献
995.
Final height in girls with central precocious puberty: comparison of two different luteinizing hormone-releasing hormone agonist treatments 总被引:2,自引:0,他引:2
F Antoniazzi M Cisternino G Nizzoli M Bozzola A Corrias F De Luca C De Sanctis F Rigon G Zamboni S Bernasconi G Chiumello F Severi L Tatò 《Acta paediatrica (Oslo, Norway : 1992)》1994,83(10):1052-1056
In order to evaluate the effects of two long-acting luteinizing hormone-releasing hormone agonists on growth, bone maturation and final height in girls with central precocious puberty, we analyzed growth data from 40 girls (15 treated with buserelin intranasal spray (group A), 15 treated with triptorelin depot im every 28 days (group B) and 10 untreated (group C)). Patients in group A started treatment when chronological age (CA) was 7.7 ± 0.9 years, bone age (BA) was 10.2 ± 1.1 years and height was 131.9 ± 5.0 cm. Patients in group B started therapy when CA was 7.6 ± 0.5 years, BA 9.8 ± 1.0 years and height 133.2 ± 7.6 m. The diagnosis of untreated patients (group C) was made when CA was 7.2 ± 0.9 years, BA 9.6 ± 2.2 years and height 130.2 ± 8.6cm. Both luteinizing hormone-releasing hormone agonists appeared to control precocious puberty. Final height in group B (160.6 ± 5.7 cm) was significantly higher than that of group A (153.2 ± 5.0 cm: p < 0.05) and group C (149.6 ± 6.3; p < 0 .01), whereas the difference between groups A and C was not statistically significant. In group B a positive difference was observed between final height (160.6 ± 5.7 cm) and target height (157.6 ± 5.9 cm) (ns); on the contrary, in groups A and C, final height was lower than target height (155.5 ± 5.3 and 156.4 ± 1.3cm, respectively), but only in group C the difference was statistically significant ( p < 0.01). The best results regarding final height obtained by slow-release depot im therapy may be associated with more stable agonist blood levels during treatment. 相似文献
996.
Italian multicentre study on very low-birth-weight babies. Neonatal mortality and two-year outcome 总被引:1,自引:0,他引:1
U de Vonderweid A Spagnolo C Corchia V Chiandotto S Chiappe F Chiappe P Colarizi TDe Luca M Didato MC Fertz F Macagno G Mansi R Paludetto A Priolisi A Spinelli P Zaramella C Zorzi 《Acta paediatrica (Oslo, Norway : 1992)》1994,83(4):391-396
The Italian multicentre study on very low-birth-weight babies is the first collaborative project in Italy on the health status of newborns weighing 500–1499 g at birth: 634 such babies were admitted in 1987–88 to eight Italian NICUs; 424 infants survived and were followed until two years of age, corrected for prematurity. Logistic regression analysis of pre-admission risk factors of in-hospital mortality identified eight statistically significant variables: birth weight, gestational age, sex, antepartum steroids, I-min Apgar score and, on admission to the NICU, body temperature, pH and absence of spontaneous respiration. Using the equation derived from the logistic model, a theoretical mortality rate was calculated for each centre, predicted on the basis of the local incidence of preadmission risk factors. In no case was the predicted mortality significantly different from the observed one. At two years of age, 8 children were blind and 48 had motor disability. Of these, 46 had cerebral palsy: based on a functional evaluation score 14 had severe (degree 4), 20 intermediate (degree 3) and 12 mild cerebral palsy (degree 2). Among 25 variables entered in a logistic regression as risk factors for cerebral palsy, only periventricular leucomalacia and acidosis were significantly associated with the outcome. 相似文献
997.
Gianaroli L Magli MC Munné S Fortini D Ferraretti AP 《Journal of assisted reproduction and genetics》1999,16(4):170-175
Purpose:
Following preimplantation genetic diagnosis of aneuploidy, embryo transfer was executed on day 4, with the aim of providing more time for expanding from six to nine the number of diagnosed chromosomes per single cell (Group 2; 45 cycles). The results obtained were compared to those derived from conventional day 3 transfer (Group 1; 71 cycles).
Methods:
For multicolor fluorescence in situ hybridization analysis, two panels of probes were used: the first, specific for chromosomes XY, 13, 16, 18, and 21, was tested in all patients (Groups 1 and 2); the second was implemented only in Group 2 patients for the detection of chromosomes 14, 15, and 22.
Results:
A total of 406 embryos underwent fluorescence in situ hybridization analysis in Group 1, and 236 in Group 2. Comparable percentages of both chromosomal abnormalities (61% and 62%) and pregnancy and implantation rates (36% and 24.5% in Group 1, 41% and 23.6% in Group 2) resulted, regardless of the higher mean age in Group 2.
Conclusions:
The diagnosis of the nine chromosomes which are most frequently associated with aneuploidy in humans could have an immediate impact on the rate of spontaneous abortions. Additional advantages are represented by the more accurate morphological evaluation of euploid embryos; the advanced compaction, which means that embryos are less exposed to damage during the transfer procedure; and the possibility of performing a reanalysis in cases where a fluorescence in situ hybridization diagnosis is not obtained. 相似文献
998.
Annexin V is a Ca2+-dependent phospholipid binding protein. Although it has been shown to inhibit protein kinase C (PKC) in cell-free systems, its role in the intact cell is unclear. A stable MCF-7 human breast cancer cell overexpression system was established to investigate the function of annexin V. In these cells, 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced phosphorylation and kinase activity of ERK1/2 were suppressed. Morphological changes induced by TPA were reduced by annexin V overexpression as well as by the pan-PKC inhibitor, bisindolylmaleimide I, and by the mitogen-activated protein kinase/extracellular signal-regulated kinase kinase (MEK) inhibitor, PD98059. TPA-induced MEK1/2 and Raf-1 phosphorylation were reduced in these cells. The TPA-enhanced active Ras, and its association with Raf-1, were reduced. TPA treatment of MCF-7 cells caused an increased association of Shc with Grb2. However, this increased association was prevented in the annexin V-overexpressors. p21WAF/CIP1 is responsible for inhibition of cell cycle progression in MCF-7 cells. TPA induced the expression of p21WAF/CIP1 to a greater extent in MCF-7 parent and control plasmid cells than in annexin V overexpressors. PD98059 inhibited this increase, suggesting that TPA upregulation of p21WAF/CIP1 occurs via the MEK pathway, and that annexin V overexpression blunts it. This work shows that annexin V overexpression suppresses the TPA-induced Ras/ERK signaling by inhibiting at/or upstream of Shc, possibly through the inhibition of PKCs. Oncogene (2000). 相似文献
999.
Pasquale Florio Luigi Nappi Luca Mannini Giovanni Pontrelli Raffaele Fimiani Paolo Casadio Ivano Mazzon Gioacchino Gonzales Vittorio Villani Mario Franchini Giampietro Gubbini Liliana Mereu Fabrizia Santangelo Attilio Di Spiezio Sardo 《Journal of minimally invasive gynecology》2019,26(4):733-739
Study Objective
To estimate the incidence of infection after diagnostic and operative hysteroscopic procedures performed in an in-office setting with different distension media (saline solution or CO2).Design
Prospective, multicenter, observational study (Canadian Task Force classification II-2).Setting
Tertiary women's health centers.Patients
A total of 42,934 women who underwent hysteroscopy between 2015 and 2017.Interventions
Of the 42,934 patients evaluated, 34,248 underwent a diagnostic intervention and 8686 underwent an operative intervention; 17,973 procedures used CO2 and 24,961 used saline solution as a distension medium. Patients were contacted after the procedure to record postprocedure symptoms suggestive of infection, including 2 or more of the following signs occurring within the 3 weeks after hysteroscopy: fever; lower abdominal pain; uterine, adnexal, or cervical motion tenderness; purulent leukorrhea; vaginal discharge or itchiness; and dysuria. Vaginal culture, clinical evaluation, transvaginal ultrasound, and histological evaluation were completed to evaluate symptoms.Measurements and Main Results
Operative hysteroscopies comprised polypectomies (n?=?7125; 82.0%), metroplasty (n?=?731; 15.0%), myomectomy (n?=?378; 7.8%), and tubal sterilization (n?=?194; 4.0%). Twenty-five of the 42,934 patients (0.06%) exhibited symptoms of infection, including 24 patients (96%) with fever, 11 (45.8%) with fever as a single symptom, 7 (29.2%) with fever with pelvic pain, and 10 (41.7%) with fever with dysuria. In 5 patients with fever and pelvic pain, clinical examination and transvaginal ultrasound revealed monolateral or bilateral tubo-ovarian abscess. In these patients, histological examination from surgical specimens revealed the presence of endometriotic lesions.Conclusion
The present study suggests that routine antibiotic prophylaxis is not necessary before hysteroscopy because the prevalence of infections following in-office hysteroscopy is low (0.06%). 相似文献1000.
Maurizio Barbara Edoardo Covelli Chiara Filippi Valerio Margani Alessandra De Luca Simonetta Monini 《Acta oto-laryngologica》2019,139(4):379-382
Background: The bone conductive implants (BCI) are nowadays a reliable alternative for rehabilitation of specific forms of hearing loss, i.e. conductive, mixed or single sided deafness (SSD).Aims/Objective: To analyse the various factors in play when considering an auditory rehabilitation with a bone-conductive device (BCI).Materials and Methods: The clinical charts of subjects who underwent BCI application at the same Implanting Center from 2005 to 2018 were retrieved analysing also the reason for eventual explantation and the alternative option (transition) for hearing rehabilitation.Results: Nine BAHA Compact, 4 BAHA Intenso, 21 BAHA Divino, 3 BAHA BP100, 4 Ponto, 2 Sophono, 5 Bonebridge, 5 BAHA5 Attract; 11 BAHA5 Connect were used in 12 unilateral COM; 16 bilateral COM; 3 unilateral cholesteatoma; 6 bilateral cholesteatoma; 2 unilateral otosclerosis; 5 bilateral otosclerosis; 9 congenital malformations; 6 major otoneurosurgical procedures; 5 sudden deafness. Explantation was necessary for five subjects.Conclusions: Middle ear pathology and sequels from surgery represent the most common reason for BCI implantation, both in unilateral and in bilateral cases. Transition from one implantable device to another one can be predictable, mostly when explantation is necessary.Significance: The role of BCI for rehabilitation in middle ear pathology may be extremely important. 相似文献