全文获取类型
收费全文 | 1707篇 |
免费 | 101篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 36篇 |
儿科学 | 118篇 |
妇产科学 | 168篇 |
基础医学 | 162篇 |
口腔科学 | 137篇 |
临床医学 | 138篇 |
内科学 | 241篇 |
皮肤病学 | 63篇 |
神经病学 | 130篇 |
特种医学 | 50篇 |
外科学 | 208篇 |
综合类 | 32篇 |
预防医学 | 59篇 |
眼科学 | 50篇 |
药学 | 84篇 |
中国医学 | 54篇 |
肿瘤学 | 86篇 |
出版年
2024年 | 2篇 |
2023年 | 33篇 |
2022年 | 45篇 |
2021年 | 72篇 |
2020年 | 39篇 |
2019年 | 63篇 |
2018年 | 70篇 |
2017年 | 63篇 |
2016年 | 89篇 |
2015年 | 75篇 |
2014年 | 95篇 |
2013年 | 105篇 |
2012年 | 129篇 |
2011年 | 159篇 |
2010年 | 81篇 |
2009年 | 93篇 |
2008年 | 130篇 |
2007年 | 102篇 |
2006年 | 102篇 |
2005年 | 96篇 |
2004年 | 67篇 |
2003年 | 62篇 |
2002年 | 31篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1979年 | 2篇 |
排序方式: 共有1816条查询结果,搜索用时 0 毫秒
91.
Achievement of pregnancy in globozoospermia with Y chromosome microdeletion after ICSI 总被引:5,自引:0,他引:5
Zeyneloglu HB Baltaci V Duran HE Erdemli E Batioglu S 《Human reproduction (Oxford, England)》2002,17(7):1833-1836
Pregnancy achieved with sperm from a patient with globozoospermia is rare, even after ICSI, since the activation of the oocyte may not occur in this disorder. Therefore, activation of the oocytes by piezoelectricity or calcium ionophores has been suggested, although spontaneous activation of the oocyte after ICSI has been reported in some cases. We report a successful pregnancy in a couple in which the male partner had globozoospermia with microdeletions in the Y chromosome with no further assisted activation after ICSI. During the diagnostic study of the husband, increased numerical chromosome abnormalities after fluorescent in-situ hybridization (FISH) and microdeletions in AZFa; sY86 and AZFb; sY 131 were detected. Out of the 13 oocytes injected, four fertilized and a twin pregnancy was obtained after replacement of four embryos. Healthy twin girls were delivered after a term pregnancy. Some patients with globozoospermia may also have Y chromosome microdeletions, which subsequently may be inherited by the male offspring in cases of achievement of pregnancy. 相似文献
92.
A case of a 12-year-old girl presenting with headache and splenomegaly and fulfilling the diagnostic criteria of polycythemia vera is reported. Her peripheral blood values were as follows: hemoglobin 18 g/dL, red blood cells 7,000,000/mm 3 , white blood cells 22,000/mm 3 , and platelets 1,248,000/mm 3 . Phlebotomy was performed initially but was ineffective. Afterward 100 mg/kg per day aspirin and 30/mg/kg per day hydroxyurea were given. The patient has been asypmtomatic for 1 year and her recent hemoglobin level is 15.5 g/dL, platelet count 922,000/mm 3 , and white blood cell 12,800/mm 3 . Polycythemia vera is an extremely uncommon disease in childhood and for this reason its treatment is not well established. 相似文献
93.
Orbital schwannoma: correlation of magnetic resonance imaging and pathologic findings 总被引:3,自引:0,他引:3
Kaan?GündüzEmail author Carol?L.?Shields Ilhan?Günalp Esra?Erden Jerry?A.?Shields 《Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie》2003,241(7):593-597
Purpose To report the correlation between magnetic resonance imaging (MRI) findings and histopathology of orbital schwannomas.Methods This study is a retrospective noncomparative interventional case series of three consecutive patients with orbital schwannoma. After preoperative MRI, all patients underwent orbitotomy and tumor removal. Histopathologic and immunopathologic studies of the excised tumors were performed. The main outcome measures were MRI features, histopathology, and their relationship to the cohesiveness of the tumor.Results The patients ages were 56 years (patient 1), 43 years (patient 2), and 18 (patient 3) years. MRI demonstrated that the tumors were well-circumscribed, intraconal in patient 1, superior extraconal in patient 2 and inferotemporal extraconal in patient 3. The tumor in patient 1 had a partly cavitary appearance, while the tumors in patients 2 and 3 had a solid appearance on MRI. The tumor had heterogeneous signal intensity in patients 1 and 2 and homogeneous signal intensity in patient 3 on T2-weighted images. All patients underwent orbitotomy and tumor removal. In patients 1 and 2, the tumor was gelatinous and fragmented during removal. The fragments were completely excised in patient 1 and an incomplete piecemeal tumor excision was made in patient 2. In patient 3, complete excision without fragmentation was performed. Pathologic examination revealed that the tumor was of Antoni B pattern in patient 1, mixed Antoni A and B patterns in patient 2, and marked Antoni A pattern in patient 3. At a mean follow-up of 23.7 months (range: 22–26 months) after surgery, all patients retained preoperative visual acuity. Patient 2 developed recurrence at 21 months follow-up and underwent Krönlein orbitotomy for excision of the recurrent tumor.Conclusions MRI is useful in depicting both the anatomic location and internal consistency of orbital tumors. Schwannomas with MRI evidence of cavitary change or heterogeneous signal intensity on T2-weighted images were found to have marked Antoni B pattern on histopathology, imparting a friable structure and fragmented excision.An erratum to this article can be found at 相似文献
94.
Four taxoids (taxusin, baccatin VI, baccatin III and 1beta-hydroxybaccatin I) and five lignans (lariciresinol, taxiresinol, 3'-demethylisolariciresinol-9'-hydroxyisopropylether, isolariciresinol and 3-demethylisolariciresinol) were isolated from the heartwood of Taxus baccata L. (Taxaceae) growing in Turkey through chromatographic techniques. In vivo anti-inflammatory and antinociceptive activity of these compounds were investigated. All the compounds were shown to possess significant antinociceptive activity against p-benzoquinone-induced abdominal contractions, while only lignan derivatives significantly inhibited carrageenan-induced hind paw edema in mice. 相似文献
95.
Topcu G Altiner EN Gozcu S Halfon B Aydogmus Z Pezzuto JM Zhou BN Kingston DG 《Planta medica》2003,69(5):464-467
A new ursane-type triterpenoid, 3 beta,11 alpha,21 alpha-trihydroxyurs-12-ene, named salvistamineol (1), has been isolated from the methanol extract of Salvia staminea. In addition to 1, the methanol extract yielded four known compounds and the acetone extract yielded twelve known compounds consisting of two sesquiterpenes, six diterpenoids, a triterpenoid, two steroids and one flavone. DNA damaging properties of the extracts and some isolated diterpenes were investigated against three yeasts and only taxodione gave a positive response and also showed the highest cytotoxic activity against a panel of cell lines among the investigated compounds in this study. 相似文献
96.
Childhood nasopharyngeal carcinoma: from biology to treatment 总被引:3,自引:0,他引:3
Nasopharyngeal carcinoma is a rare disease in children with distinct epidemiological, histopathological, and clinical characteristics. Incidence varies widely around the world but bimodal incidence graphs show that in some populations a disproporionate number of cases occur in late childhood. Children with nasopharyngeal carcinoma almost always have the undifferentiated variant of the disease, which is associated with advanced locoregional spread and distant metastases. Both genetic and environmental factors contribute to the development of nasopharyngeal carcinoma, as evidenced by its risk factors which include: specific HLA subtypes; deletions of chromosomes 3p, 9p, 11q, 13q, and 14q; mutations of p53 and RB2/p130; polymorphism of the CYP2E1; and infection with Epstein-Barr virus. Traditional treatment consists of high-dose radiotherapy and cure rates range between 30% and 60%. The high incidence of failure due to systemic disease in children means that chemotherapy is preferable for first-line treatment in advanced-stage disease. Currently, cisplatin-based induction or adjuvant chemotherapy combinations are used along with high-dose radiotherapy. Although combined modality treatment has increased 5-year survival to 70-90%, late morbidity is a major concern. 相似文献
97.
Is a filum terminale with a normal appearance really normal? 总被引:5,自引:0,他引:5
Mehmet Selçuki Seda Vatansever Sevinç Inan Esra Erdemli Celal Bağdatoğlu Ayse Polat 《Child's nervous system》2003,19(1):3-10
INTRODUCTION. Tethered spinal cord is defined as a condition in which the conus medullaris ends at a level below the L1-2 intervertebral space. The spinal cord is considered to be tethered when there is a thick filum terminale or low-lying conus medullaris. It has also been reported that a normal level of the conus medullaris and normal thickness of the filum terminale do not mean that there is no cord tethering. MATERIALS AND METHODS. In this investigation, we examined 21 fila terminalia; 5 of them were taken from cadavers, and these were used as a control group (group 1; n/n), 8 from patients with a normal appearance of the filum terminale but with clinical symptoms (incontinence) and pathologic results of a urodynamic study (group 2; n/ab), and 8 from patients with an abnormal appearance of the filum terminale and with clinical symptoms (group 3; ab/ab). Interestingly, we found that while fila terminalia in the control group were made up mainly of collagen fibers, more connective tissue with dense collagen fibers, some hyalinization and dilated capillaries were noticed in the fila from group 2. RESULTS. Our results suggest that these histological features may reflect a decreased elasticity within the filum terminale, resulting in a tethering effect on the lower conus in otherwise normal physiological conditions. CONCLUSION. These findings lead us to reconsider sectioning of the filum terminale in incontinent patients with normal results in radiological studies, whose condition is called "nonneurogenic neurogenic bladder." 相似文献
98.
Belde Kasap Nuray Duman Esra Ozer Mansur Tatli Abdullah Kumral Hasan Ozkan 《Pediatrics international》2008,50(1):81-84
BACKGROUND: Because there is a lack of well-established criteria, the aim of the present paper was to determine risk factors to predict the duration of tachypnea in transient tachypnea of the newborn (TTN). METHODS: Data from 95 newborns with TTN were evaluated retrospectively. Clinical and laboratory findings were compared between patients in whom tachypnea lasted <72 h (group 1) or >72 h (group 2). RESULTS: Male gender, prematurity and delivery by cesarean section were the major risk factors for TTN. Parenteral furosemide had no effect on the clinical course. Peak respiratory rate (RRpeak) at the first 36 h was significantly higher in group 2 (P > 0.000). The cut-off for RRpeak during the first 36 h (RRpeak36) was 90/min and RRpeak36 > 90/min caused a 7.04-fold risk of prolonged tachypnea. White blood cell count and hematocrit levels were lower whereas duration of hospitalization and antibiotic treatment were longer in group 2. CONCLUSIONS: Assessment of RRpeak36 may be useful in predicting clinical course of TTN. 相似文献
99.
100.
Turan Olgar Esra Onal Dogan Bor Nurullah Okumus Yildiz Atalay Canan Turkyilmaz Ebru Ergenekon Esin Koc 《Korean journal of radiology》2008,9(5):416-419
OBJECTIVE: The aim of this work was to determine the radiation dose received by infants from radiographic exposure and the contribution from scatter radiation due to radiographic exposure of other infants in the same room. MATERIALS AND METHODS: We retrospectively evaluated the entrance skin doses (ESDs) and effective doses of 23 infants with a gestational age as low as 28 weeks. ESDs were determined from tube output measurements (ESD(TO)) (n = 23) and from the use of thermoluminescent dosimetry (ESD(TLD)) (n = 16). Scattered radiation was evaluated using a 5 cm Perspex phantom. Effective doses were estimated from ESD(TO) by Monte Carlo computed software and radiation risks were estimated from the effective dose. ESD(TO) and ESD(TLD) were correlated using linear regression analysis. RESULTS: The mean ESD(TO) for the chest and abdomen were 67 microGy and 65 microGy per procedure, respectively. The mean ESD(TLD) per radiograph was 70 microGy. The measured scattered radiation range at a 2 m distance from the neonatal intensive care unit (NICU) was (11-17 microGy) per radiograph. Mean effective doses were 16 and 27 microSv per procedure for the chest and abdomen, respectively. ESD(TLD) was well correlated with ESD(TO) obtained from the total chest and abdomen radiographs for each infant (R(2) = 0.86). The radiation risks for childhood cancer estimated from the effective dose were 0.4 x 10(-6) to 2 x 10(-6) and 0.6 x 10(-6) to 2.9 x 10(-6) for chest and abdomen radiographs, respectively. CONCLUSION: The results of our study show that neonates received acceptable doses from common radiological examinations. Although the contribution of scatter radiation to the neonatal dose is low, considering the sensitivity of the neonates to radiation, further protective action was performed by increasing the distance of the infants from each other. 相似文献