全文获取类型
收费全文 | 11475篇 |
免费 | 680篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 141篇 |
儿科学 | 515篇 |
妇产科学 | 125篇 |
基础医学 | 1473篇 |
口腔科学 | 391篇 |
临床医学 | 846篇 |
内科学 | 2466篇 |
皮肤病学 | 172篇 |
神经病学 | 1138篇 |
特种医学 | 294篇 |
外科学 | 1612篇 |
综合类 | 266篇 |
一般理论 | 2篇 |
预防医学 | 634篇 |
眼科学 | 210篇 |
药学 | 871篇 |
中国医学 | 70篇 |
肿瘤学 | 951篇 |
出版年
2023年 | 72篇 |
2022年 | 161篇 |
2021年 | 373篇 |
2020年 | 182篇 |
2019年 | 274篇 |
2018年 | 311篇 |
2017年 | 217篇 |
2016年 | 236篇 |
2015年 | 267篇 |
2014年 | 403篇 |
2013年 | 548篇 |
2012年 | 849篇 |
2011年 | 811篇 |
2010年 | 446篇 |
2009年 | 401篇 |
2008年 | 613篇 |
2007年 | 609篇 |
2006年 | 578篇 |
2005年 | 540篇 |
2004年 | 483篇 |
2003年 | 469篇 |
2002年 | 394篇 |
2001年 | 297篇 |
2000年 | 294篇 |
1999年 | 260篇 |
1998年 | 114篇 |
1997年 | 97篇 |
1996年 | 68篇 |
1995年 | 70篇 |
1994年 | 58篇 |
1993年 | 65篇 |
1992年 | 165篇 |
1991年 | 154篇 |
1990年 | 129篇 |
1989年 | 127篇 |
1988年 | 107篇 |
1987年 | 113篇 |
1986年 | 89篇 |
1985年 | 90篇 |
1984年 | 77篇 |
1983年 | 70篇 |
1982年 | 33篇 |
1981年 | 35篇 |
1980年 | 24篇 |
1979年 | 50篇 |
1978年 | 37篇 |
1975年 | 27篇 |
1974年 | 30篇 |
1973年 | 29篇 |
1970年 | 26篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Thoracic outlet syndrome is uncommon in adolescence. Cervical rib fracture is an extremely rare cause of thoracic outlet syndrome in this age group. We report an unusual case of thoracic outlet syndrome in a 14-year-old girl caused by pseudarthrosis of the cervical rib. A magnetic resonance imaging scan showed significant compression of the brachial plexus by the pseudarthrosis mass. Excision of the cervical rib through a supraclavicular approach gave excellent results in this case. 相似文献
92.
Phadke CP Thompson FJ Kukulka CG Nair PM Bowden MG Madhavan S Trimble MH Behrman AL 《The journal of spinal cord medicine》2010,33(4):371-378
Objective:
To examine position-dependent (semireclined to standing) and walking speed–dependent soleus H-reflex modulation after motor incomplete spinal cord injury (SCI).Participants:
Twenty-six patients with motor incomplete SCI (mean: 45 ± 15 years) and 16 noninjured people (mean: 38 ± 14 years).Methods:
Soleus H-reflexes were evoked by tibial nerve stimulation. Patients were tested in semireclined and standing positions (experiment 1) and in midstance and midswing positions (experiment 2).Results:
H-reflexes were significantly greater after SCI in all positions compared with noninjured people (P < 0.05). Position-dependent modulation from semireclined to standing (normally observed in noninjured people) was absent after SCI. In SCI patients, H-reflex modulation was not significantly different at 1.2 m/s compared with 0.6 m/s treadmill walking speed; in noninjured people, H-reflex modulation was significantly greater at 1.2 m/s compared with 0.6 m/s treadmill walking speed. There was a significant positive correlation between modified Ashworth scores, a clinical measure of spasticity and soleus H-reflex amplitudes tested in all positions. A significant negative correlation was also found between H-reflexes in standing and midstance positions and the amount of assistance patients required to walk.Conclusions:
An improvement in position-dependent and walking speed–dependent reflex modulation after SCI may indicate functional recovery. Future studies will use H-reflex testing to track changes as a result of therapeutic interventions. 相似文献93.
94.
Owen M McKay Arun V Krishnan Mark Davis Matthew C Kiernan 《Clinical neurophysiology》2006,117(9):2064-2068
OBJECTIVE: To investigate the cause of the transient weakness that occurs in recessive myotonia congenita (RMC) following sustained muscle contraction. METHODS: Nerve excitability studies were performed on a 35-year-old male with RMC due to a novel 696+1G>A CLCN1 mutation. The median nerve was stimulated at the wrist and compound muscle action potentials (CMAPs) were recorded from abductor pollicis brevis (APB). Stimulus-response behaviour using two stimulus durations, threshold electrotonus to 100-ms polarizing currents, a current threshold relationship and the recovery of excitability following supramaximal stimulation were recorded at rest. Excitability parameters were also recorded before and after maximal voluntary contraction (MVC) of APB against resistance for 60s. Results were compared to data obtained from 12 normal controls. RESULTS: Baseline axonal excitability parameters were all normal, indicating that axonal function was normal at the point of stimulation. Following one minute of MVC, excitability parameters demonstrated a significant increase in threshold when compared to controls (RMC 54.9%; controls 15.5+/-3.1%). In the RMC patient, this increase in threshold was associated with a 39% reduction in the amplitude of the maximal CMAP, which remained unaffected in controls. CONCLUSIONS: The reduction in maximal CMAP is likely to represent muscle activation failure due to depolarization block, with the increase in threshold possibly reflecting a compensatory attempt by motor axons to overcome prolonged contraction-induced changes in the muscle membrane. SIGNIFICANCE: The prolonged recovery of excitability following sustained muscle contraction is likely to be a contributing factor to symptoms of weakness and fatigue experienced by RMC patients. 相似文献
95.
M. Z. Molnar C. P. Kovesdy S. Bunnapradist E. Streja R. Mehrotra M. Krishnan A. R. Nissenson K. Kalantar‐Zadeh 《American journal of transplantation》2011,11(5):1006-1015
The association between pretransplant serum albumin concentration and post‐transplant outcomes in kidney transplant recipients is unclear. We hypothesized that in transplant‐waitlisted hemodialysis patients, lower serum albumin concentrations are associated with worse post‐transplant outcomes. Linking the 5‐year patient data of a large dialysis organization (DaVita) to the Scientific Registry of Transplant Recipients, we identified 8961 hemodialysis patients who underwent first kidney transplantation. Mortality or graft failure and delayed graft function (DGF) risks were estimated by Cox regression (hazard ratio [HR]) and logistic regression (Odds ratio [OR]), respectively. Patients were 48 ± 13 years old and included 37% women and 27% diabetics. The higher pretransplant serum albumin was associated with lower mortality, graft failure and DGF risk even after multivariate adjustment for case‐mix, malnutrition–inflammation complex and transplant related variable. Every 0.2 g/dL higher pretransplant serum albumin concentration was associated with 13% lower all‐cause mortality (HR = 0.87 [95% confidence interval: 0.82–0.93]), 17% lower cardiovascular mortality (HR = 0.83[0.74–0.93]), 7% lower combined risk of death or graft failure (HR = 0.93[0.89–0.97]) and 4% lower DGF risk (OR = 0.96[0.93–0.99]). Hence, lower pretransplant serum albumin level is associated with worse post‐transplant outcomes. Clinical trials to examine interventions to improve nutritional status in transplant‐waitlisted hemodialysis patients and their impacts on post‐transplant outcomes are indicated. 相似文献
96.
Tejwani PL Srivastava A Nerkar H Dhar A Hari S Thulkar S Chumber S Kumar S 《The Indian journal of surgery》2011,73(3):199-205
We conducted a randomized trial to evaluate effectiveness of Centchroman in control of mastalgia and compared it with Danazol. Research Question- Is proportion of pain relief achieved by Centchroman similar to or inferior to that achieved by Danazol? In a randomized controlled trial of Centchroman vs. Danazol in mastalgia, 81 patients with mastalgia were studied. Thirty-nine patients were randomized to Danazol arm and 42 in Centchroman arm. The treatment was given for 12 weeks, followed by observation for 12 weeks. The pain was measured by visual analogue scale (VAS) of 0–10. At 12 weeks 89.7% women achieved reduction in pain score to ≤3 in Centchroman group (pvalue 0.001). In Danazol group 69.44% women achieved reduction in pain score to ≤ 3 (p = 0.001). Three months after stopping therapy, Centchroman was more effective in pain score reduction at 24 weeks as compared to Danazol (p = 0.019). Centchroman is an effective, safe and inexpensive alternative to Danazol for treatment of mastalgia.
Electronic supplementary material
The online version of this article (doi:10.1007/s12262-010-0216-z) contains supplementary material, which is available to authorized users. 相似文献97.
Ahmad M Krishnan A Kelman E Allen V Bargman JM 《International urology and nephrology》2008,40(3):815-819
Listeria monocytogenes (LM) is one of the rare microorganisms causing peritonitis in peritoneal dialysis (PD) patients. We report a sporadic case of peritonitis caused by LM in a young female PD patient with lupus receiving corticosteroid therapy, who presented with abdominal pain, cloudy PD effluent, nausea, and conjunctivitis. The effluent showed a high PD effluent white cell count and monocytosis, and gram staining showed gram-positive bacilli in single or short chains and PD effluent culture grew LM. She was treated successfully with beta lactum antibiotics. LM peritonitis should be suspected if a patient presents with gram-positive bacilli and monocytosis in dialysis effluent. 相似文献
98.
S M Studer J B Orens I Rosas J A Krishnan K A Cope S Yang J V Conte P B Becker T H Risby 《The Journal of heart and lung transplantation》2001,20(11):1158-1166
BACKGROUND: Obliterative bronchiolitis (OB) remains one of the leading causes of death in lung transplant recipients after 2 years, and acute rejection (AR) of lung allograft is a major risk factor for OB. Treatment of AR may reduce the incidence of OB, although diagnosis of AR often requires bronchoscopic lung biopsy. In this study, we evaluated the utility of exhaled-breath biomarkers for the non-invasive diagnosis of AR. METHODS: We obtained breath samples from 44 consecutive lung transplant recipients who attended ambulatory follow-up visits for the Johns Hopkins Lung Transplant Program. Bronchoscopy within 7 days of their breath samples showed histopathology in 21 of these patients, and we included them in our analysis. We measured hydrocarbon markers of pro-oxidant events (ethane and 1-pentane), isoprene, acetone, and sulfur-containing compounds (hydrogen sulfide and carbonyl sulfide) in exhaled breath and compared their levels to the lung histopathology, graded as stable (non-rejection) or AR. None of the study subjects were diagnosed with OB or infection at the time of the clinical bronchoscopy. RESULTS: We found no significant difference in exhaled levels of hydrocarbons, acetone, or hydrogen sulfide between the stable and AR groups. However, we did find significant increase in exhaled carbonyl sulfide (COS) levels in AR subjects compared with stable subjects. We also observed a trend in 7 of 8 patients who had serial sets of breath and histopathology data that supported a role for COS as a breath biomarker of AR. CONCLUSIONS: This study demonstrated elevations in exhaled COS levels in subjects with AR compared with stable subjects, suggesting a diagnostic role for this non-invasive biomarker. Further exploration of breath analysis in lung transplant recipients is warranted to complement fiberoptic bronchoscopy and obviate the need for this procedure in some patients. 相似文献
99.
Shoulder arthroplasty for the treatment of the sequelae of fractures of the proximal humerus 总被引:7,自引:0,他引:7
Boileau P Trojani C Walch G Krishnan SG Romeo A Sinnerton R 《Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.]》2001,10(4):299-308
The purpose of this multicenter study was to analyze the results of shoulder arthroplasty for the treatment of the sequelae of proximal humerus fractures and establish an updated classification system and treatment guidelines for these complex situations. Seventy-one sequelae of proximal humerus fractures were treated with shoulder replacement with the use of the same nonconstrained, modular, and adaptable prosthesis: the Aequalis prosthesis (Tornier Inc, St Ismier, France). The average time between initial fracture and shoulder arthroplasty was 5 years and 5 months. On the basis of anatomic classification schemes, sequelae were divided into 4 types: type 1, humeral head collapse or necrosis with minimal tuberosity malunion (40 cases); type 2, locked dislocations or fracture-dislocations (9 cases); type 3, nonunions of the surgical neck (6 cases); and type 4, severe malunions of the tuberosities (16 cases). The mean postoperative follow-up was 19 months (range, 12 to 48 months). Overall, the postoperative Constant score was excellent in 11 cases (16%), good in 19 cases (26%), fair in 18 cases (25%), and poor in 23 cases (33%). There were 18 complications (27%). Fifty-nine of 70 patients (81%) stated that they were satisfied with the result. The most significant factor affecting functional outcome was greater tuberosity osteotomy (P <.005). Regarding both surgical treatment and postoperative prognosis, we identify 2 categories of proximal humerus fracture sequelae: category 1, intracapsular/impacted fractures sequelae (associated with both cephalic collapse or necrosis [type 1] and chronic dislocation or fracture-dislocation [type 2]), in which an articulating joint can be reconstructed without a greater tuberosity osteotomy; and category 2, extracapsular/disimpacted fractures sequelae (associated with both surgical neck nonunions [type 3] and severe tuberosity malunions [type 4]) where the proximal humerus cannot be reconstructed without a greater tuberosity osteotomy. All of the excellent and good postoperative Constant scores were obtained in type 1 and 2, in which osteotomy of the greater tuberosity was not required. All patients in type 3 and 4, who underwent a greater tuberosity osteotomy, had either fair or poor results and did not regain active elevation above 90 degrees. We conclude that a greater tuberosity osteotomy is the most likely reason for poor and unpredictable results after shoulder replacement arthroplasty for the treatment of the complex sequelae of proximal humerus fractures. Shoulder arthroplasty for the treatment of the sequelae of fractures of the proximal humerus should be performed without an osteotomy of the greater tuberosity when possible. If prosthetic replacement is possible without an osteotomy, surgeons should accept the distorted anatomy of the proximal humerus and adapt the prosthesis and their technique to the modified anatomy. A modular and adaptable prosthesis with both adjustable offsets and inclination may allow surgeons to adapt to a large number of malunions and may help to avoid the troublesome greater tuberosity osteotomy in a higher proportion of cases. 相似文献
100.