全文获取类型
收费全文 | 7436篇 |
免费 | 321篇 |
国内免费 | 69篇 |
专业分类
耳鼻咽喉 | 118篇 |
儿科学 | 154篇 |
妇产科学 | 98篇 |
基础医学 | 808篇 |
口腔科学 | 93篇 |
临床医学 | 547篇 |
内科学 | 2049篇 |
皮肤病学 | 73篇 |
神经病学 | 925篇 |
特种医学 | 161篇 |
外科学 | 1499篇 |
综合类 | 21篇 |
预防医学 | 254篇 |
眼科学 | 85篇 |
药学 | 413篇 |
中国医学 | 9篇 |
肿瘤学 | 519篇 |
出版年
2023年 | 59篇 |
2022年 | 113篇 |
2021年 | 216篇 |
2020年 | 135篇 |
2019年 | 193篇 |
2018年 | 213篇 |
2017年 | 152篇 |
2016年 | 169篇 |
2015年 | 198篇 |
2014年 | 277篇 |
2013年 | 303篇 |
2012年 | 517篇 |
2011年 | 530篇 |
2010年 | 327篇 |
2009年 | 283篇 |
2008年 | 447篇 |
2007年 | 482篇 |
2006年 | 453篇 |
2005年 | 441篇 |
2004年 | 402篇 |
2003年 | 378篇 |
2002年 | 330篇 |
2001年 | 94篇 |
2000年 | 100篇 |
1999年 | 87篇 |
1998年 | 67篇 |
1997年 | 43篇 |
1996年 | 57篇 |
1995年 | 35篇 |
1994年 | 46篇 |
1993年 | 37篇 |
1992年 | 69篇 |
1991年 | 42篇 |
1990年 | 53篇 |
1989年 | 44篇 |
1988年 | 39篇 |
1987年 | 33篇 |
1986年 | 35篇 |
1985年 | 33篇 |
1984年 | 31篇 |
1983年 | 33篇 |
1982年 | 20篇 |
1981年 | 16篇 |
1980年 | 13篇 |
1979年 | 24篇 |
1978年 | 20篇 |
1977年 | 21篇 |
1976年 | 16篇 |
1975年 | 15篇 |
1974年 | 16篇 |
排序方式: 共有7826条查询结果,搜索用时 15 毫秒
81.
Scuderi GJ Vaccaro AR Brusovanik GV Kwon BK Berta SC 《Journal of spinal disorders & techniques》2004,17(2):86-93
Nerve root anomalies are frequently underrecognized on advanced imaging studies and may account for some percentage of failed spinal surgical procedures. The conjoined nerve root represents the most common nerve root anomaly. It is a well-known cause of false-positive readings for bulging and herniated disks in patients with purely axial neuroimaging studies. A retrospective evaluation of consecutive microsurgical lumbar diskectomies in 80 patients during a 5-year period was undertaken. A total of four patients (5%) were found intraoperatively to have evidence of a conjoined nerve root by the classification of Neidre. None was diagnosed preoperatively. Coronal magnetic resonance imaging offers the best means of visualizing a conjoined nerve root. The chance for a successful operation can be significantly enhanced if the surgeon is prepared to encounter this pathology. 相似文献
82.
Extraaxial cavernous hemangiomas are rare intracranial lesions that can be located in different cranial compartments. Extension across different tissue planes such as the subcutaneous tissue, skull, orbital cavity, intracranial dura mater, and extracranial trigeminal divisions within the same patient has not been previously reported. This 32-year-old woman suffered left exophthalmos, left sixth nerve palsy, and trigeminal neuropathy. Magnetic resonance imaging studies revealed an extensive multicompartmental lesion, with enhancement following Gd administration. A left orbitopterional approach allowed removal of several cavernomatous lesions located in the orbit, frontotemporal dura, and lateral wall of the cavernous sinus. A histologically based diagnosis of extraaxial cavernous hemangioma was made. In the postoperative period the patient experienced a regression of her symptoms. The authors report on a case of cavernous hemangioma with a unique extension to different intracranial/extracranial compartments. Although radical removal of the lesion was not feasible, partial excision allowed for satisfactory clinical control of the patient's symptoms. 相似文献
83.
Purpose
We used quantitative CT in conjunction with finite element analysis to provide a new tool for assessment of bone quality after total hip arthroplasty in vivo. The hypothesis of this prospective five-year study is that the combination of the two modalities allows 3D patient-specific imaging of cortical and cancellous bone changes and stress shielding.Method
We tested quantitative CT in conjunction with finite elements on a cohort of 29 patients (31 hips) who have been scanned postoperatively and at one year, two years and five years follow-up. The method uses cubic Hermite finite element interpolation for efficient mesh generation directly from qCT datasets. The element Gauss points that are used for the geometric interpolation functions are also used for interpolation of osteodensitometry data.Results
The study showed changes of bone density suggestive of proximal femur diaphysis load transfer with osteointegration and moderate metaphyseal stress shielding. Our model revealed that cortical bone initially became porous in the greater trochanter, but this phenomenon progressed to the cortex of the lesser trochanter and the posterior aspect of the metaphysis. The diaphyseal area did not experience major change in bone density for either cortical or cancellous bone.Conclusion
The combination of quantitative CT with finite element analysis allows visualization of changes to bone density and architecture. It also provides correlation of bone density/architectural changes with stress patterns enabling the study of the effects of stress shielding on bone remodelling in vivo. This technology can be useful in predicting bone remodeling and the quality of implant fixation using prostheses with different design and/or biomaterials. 相似文献84.
Joshi S Ayyathurai R Eldefrawy A Aminsharifi J Ekwenna O Sageshima J Chen L Burke G Ciancio G 《International urology and nephrology》2012,44(4):1107-1111
Purpose
Deceased patients with acute kidney injury (AKI) from rhabdomyolysis can be considered as potential kidney donors.Methods
We performed a retrospective chart review from January 2005 to January 2011 of three donors with AKI from rhabdomyolysis and the four recipients of the donated kidneys. Three donors had AKI from rhabdomyolysis as evidenced by elevated serum creatinine levels, myoglobinuria, and plasma creatinine kinase levels greater than five times the upper limit of normal. All grafts were maintained on pulsatile machine perfusion (MP) prior to transplantation. In one of the patients, serial venous perfusate myoglobin levels were measured from the donor kidney while on MP.Results
Three of the four recipients had delayed graft function, but all had normalized creatinine function after 1?month. One recipient had a creatinine of 1.2 after 79?months, the longest documented follow-up of this kind. Although we measured venous perfusate myoglobin levels from one of the grafts, we found the levels to decrease with increasing time spent on MP.Conclusion
Potential donors with AKI secondary to rhabdomyolysis should not be restricted from the donor pool. MP may play a role in minimizing the effects of AKI in these types of donors. 相似文献85.
Jerrilynn D Burrowes Brett Larive David B Cockram Johanna Dwyer John W Kusek Sandra McLeroy Diane Poole Michael V Rocco 《Journal of renal nutrition》2003,13(3):191-198
OBJECTIVE: To evaluate differences between dietary energy intake (DEI), dietary protein intake (DPI), appetite, dietary patterns, and eating habits during dialysis treatment days (DD) and non-dialysis treatment days (NDD) in 1,901 adults receiving maintenance hemodialysis who were enrolled in the baseline phase of the National Institutes of Health-sponsored Hemodialysis (HEMO) study. DESIGN: A cross-sectional analysis of participants at baseline (before randomization). SETTING: Fifteen clinical centers across the United States. MEASUREMENTS: DEI, DPI, and self-reported assessment of appetite, dietary patterns, and eating habits. RESULTS: For the entire study cohort, total mean (+/- SD) DEI (1,566 +/- 636 kcal/day) and weight-adjusted DEI (23.2 +/- 9.5 kcal/kg/day) were significantly higher (P <.0001) on NDD than on DD (1,488 +/- 620 kcal/day and 22.2 +/- 9.6 kcal/kg/day), respectively. Similarly, DPI was significantly higher (P <.0001) on NDD (65.0 +/- 29.0 g/day and 0.96 +/- 0.43 g/kg/day) than on DD (60.2 +/- 26.5 g/day and 0.90 +/- 0.41 g/kg/day). On DD and NDD, the mean weight-adjusted DEI for the entire cohort was less than the HEMO study standard of care (SOC) of > or =28 kcal/kg/day, whereas on NDD, several subgroups reported dietary protein intakes that were closer to the study's SOC. These included men, patients under 50 years of age, nonblack participants, those without diabetes, those with a normal or mild Index of Co-Existing Disease score, and those on dialysis for more than 5 years. Protein and energy intakes declined with worsening self-reported appetites in both DD and NDD after adjusting for other subgroup effects. CONCLUSION: Dietary energy and protein intakes of HEMO study participants were lower on DD than on NDD, and also lower than the SOC on both days, particularly with regard to energy intake. People receiving maintenance hemodialysis should be counseled to consume adequate amounts of energy and protein daily, especially on DD. Practitioners should monitor closely those patients who report poor appetite and should intervene appropriately. 相似文献
86.
Grilli P D'Ercole C Vendettuoli D Fornari S Vendettuoli M Di Rocco G Blotta A Manni C Falvo L De Antoni E 《Chirurgia italiana》2003,55(5):663-667
Well-differentiated thyroid neoplasms may be included among the most frequently occurring thyroid carcinomas. Papillary ca. is without doubt the best behaved type. The aim of the present work is to perform a retrospective case history study to assess patients with con papillary ca. who have been treated surgically over the last 17 years and have been subjected to periodic checks. A sample of patients was therefore extrapolated who had all undergone total thyroidectomy for papillary ca. of the thyroid. The incidence of local recurrence of the disease was verified, together with the results at distance. Furthermore, the assessments performed were evaluated and compared. From the sample of patients observed we inferred that papillary carcinoma of the thyroid can have a good prognosis over time provided periodic random checks are carried out. 相似文献
87.
Bellantone R Lombardi CP Bossola M Boscherini M De Crea C Alesina P Traini E Princi P Raffaelli M 《World journal of surgery》2002,26(12):1468-1471
Total thyroidectomy is not frequently performed in cases of benign disease because of the associated risk of postoperative hypoparathyroidism and recurrent laryngeal nerve (RLN) damage. We chose a series of patients who had undergone total thyroidectomy (TT) for benign thyroid tumors to evaluate the safety of this approach and its role in the treatment of nonmalignant lesions of the thyroid. We considered only patients with a minimum follow-up of 24 months. Records of 526 patients who underwent TT were carefully reviewed, assessing for perioperative complications and late sequelae. The mean age was 44 +/- 15.7 years; 109 patients (20.7%) were male and 417 (79.3%) were female. Altogether, 65 patients (12.3%) were operated on for toxic goiter, 429 (81.6%) for bilateral nodular goiter, and 32 (6.1%) for thyroiditis. Postoperative hemorrhage requiring reoperation occurred in 8 cases (1.5%). The incidences of permanent RLN palsy (considered as a percentage of the nerves at risk) and permanent hypocalcemia were 0.4% and 3.4%, respectively. A trend toward a decrease in the complication rate was observed during the last 5 years. There were no disease recurrences during a mean follow-up of 44 months. The results of our series show that TT can be performed safely in patients, with a low incidence of lifetime disabilities. TT has the advantage of reducing/avoiding the risk of disease recurrence and reoperation and should therefore be considered a valuable option for treating benign thyroid diseases. 相似文献
88.
Olimpio Galasso Massimo Mariconda Gaetano Romano Nicola Capuano Luigi Romano Bruno Iannò Carlo Milano 《Journal of orthopaedics and traumatology》2008,9(3):129-134
Background Roentgenographic and functional outcomes of expandable self locking intramedullary nailing and platelet rich plasma (PRP)
gel in the treatment of long bone non-unions are reported.
Materials and methods Twenty-two patients suffering from atrophic diaphyseal long bone non-unions were enrolled in the study. Patients were treated
with removal of pre-existing hardware, decortication of non-union fragments, and fixation of pseudoarthrosis with expandable
intramedullary nailing (Fixion™, Disc’O Tech, Tel Aviv, Israel). At surgery, PRP was placed in the pseudoarthrosis rim.
Results The thirteen-month follow-up showed 91% (20/22 patients) of patients attaining bony union. The average time to union was 21.5 weeks.
No infection, neurovascular complication, rotational malalignment, or limb shortening >4 mm were observed. The healing rate
of non-unions was comparable to that observed in previous studies but with a lower complication frequency.
Conclusions The combined use of self locking intramedullary nailing and PRP in the management of atrophic diaphyseal long bone non-unions
seems to produce comparable results with less complications than previously reported. Further data are warranted to investigate
the single contribution of PRP gel and Fixion nail. 相似文献
89.
90.
Garcia-Covarrubias L Salerno TA Robinson PG Ciancio G 《Journal of cardiac surgery》2008,23(6):778-780
A 66-year-old male presented with rhabdomyosarcoma of the right kidney with inferior vena cava tumor thrombus and with tumor emboli to right pulmonary artery and two large fragments of tumor thrombus free floating in the right atrium. The patient underwent right radical nephrectomy and thrombectomy of the right atrium and pulmonary artery. He was discharged on postoperative day 13. To our knowledge this is the first case of large tumor embolism to the right atrium and pulmonary artery from renal rhabdomyosarcoma reported in the literature. 相似文献