全文获取类型
收费全文 | 8272篇 |
免费 | 892篇 |
国内免费 | 34篇 |
学科分类
医药卫生 | 9198篇 |
出版年
2023年 | 79篇 |
2021年 | 113篇 |
2020年 | 103篇 |
2019年 | 136篇 |
2018年 | 155篇 |
2017年 | 105篇 |
2016年 | 148篇 |
2015年 | 168篇 |
2014年 | 245篇 |
2013年 | 352篇 |
2012年 | 335篇 |
2011年 | 334篇 |
2010年 | 236篇 |
2009年 | 227篇 |
2008年 | 287篇 |
2007年 | 316篇 |
2006年 | 360篇 |
2005年 | 309篇 |
2004年 | 267篇 |
2003年 | 278篇 |
2002年 | 247篇 |
2001年 | 229篇 |
2000年 | 251篇 |
1999年 | 228篇 |
1998年 | 145篇 |
1997年 | 162篇 |
1996年 | 146篇 |
1995年 | 122篇 |
1994年 | 109篇 |
1993年 | 104篇 |
1992年 | 183篇 |
1991年 | 174篇 |
1990年 | 179篇 |
1989年 | 200篇 |
1988年 | 174篇 |
1987年 | 158篇 |
1986年 | 165篇 |
1985年 | 169篇 |
1984年 | 123篇 |
1983年 | 80篇 |
1982年 | 81篇 |
1981年 | 87篇 |
1979年 | 88篇 |
1978年 | 79篇 |
1977年 | 73篇 |
1976年 | 72篇 |
1974年 | 62篇 |
1973年 | 76篇 |
1971年 | 57篇 |
1970年 | 56篇 |
排序方式: 共有9198条查询结果,搜索用时 9 毫秒
1.
Lisa A. Lang DDS MS David C. Holmes DDS MS Craig Passon DDS MS Robert M. Trombly DDS JD Jeffrey D. Astroth DDS MSPH Arnold F. Tavel DMD 《Journal of prosthodontics》2003,12(3):206-210
Using complete denture treatment as an introduction to clinical patient care for dental students, the purposes of the Complete Denture Prosthodontics Transition Clinic at the University of Colorado School of Dentistry are to reduce the time lapse between the preclinical complete denture prosthodontics course and the first denture patient experience, and to encourage development of student self-confidence and skills. In the 2002 spring semester, faculty at the University of Colorado School of Dentistry initiated the Complete Denture Prosthodontics Transition Clinic for DS-II (second-year) dental students, as an introduction to clinical patient care. Each patient was assigned to a team of two dental students. Three Division of Prosthodontics faculty members staffed each clinic session, providing a student-to-faculty ratio of approximately 6.6:1 and a patient-to-faculty ratio of approximately 3.3:1. All DS-II students in the Class of 2004 delivered their first complete dentures no later than 8 months (average, 184 days) after the last day of the preclinical complete denture prosthodontics course. The time from the diagnostic appointment through the denture placement appointment averaged 39 days for patients treated in this program, compared with an average of 98 days or more for previous classes. The program was successful in achieving the goal of reducing the time lapse between the preclinical complete denture prosthodontics course and the first denture patient experience. 相似文献
2.
N A Athanasou C A Wells J Quinn D P Ferguson A Heryet J O McGee 《British journal of cancer》1989,59(4):491-498
The origin and nature of osteoclast-like multinucleated giant cells (OMGCs), in extraskeletal neoplasms, is uncertain. The ultrastructure, antigenic phenotype and function of OMGCsm in a breast carcinoma were studied in order to clarify the relationship between OMGCs, osteoclasts and other cells of the mononuclear phagocyte system (MPS). OMGCs resorbed cortical bone in a manner similar to osteoclasts. However, unlike osteoclasts, OMGCs did not possess a ruffled border or clear zone, and expressed HLA-DR and Fc receptors and CD14, CD16, CD18 and CD11 (p150,95) antigens. In addition, OMGCs failed to respond morphologically to calcitonin and were directly stimulated by parathyroid hormone (PTH) to increase bone resorption. These findings suggest that OMGCs are a specific type of macrophage polykaryon distinct from both osteoclasts and other types of inflammatory polykaryon. Occasional smaller (20-25 microns) macrophage-like cells were also associated with resorption pits. Bone resorption by OMGCs isolated from the breast indicates that a cell of the MPS can be transplanted to a new tissue location and perform a highly specialised function appropriate to an MPS cell of that tissue (i.e. the osteoclast). PTH stimulation of bone resorption by OMGCs suggests that PTH or a PTH-like protein, may be involved in the bone resorption and consequent hypercalcaemia associated with metastatic breast cancer. 相似文献
3.
4.
5.
6.
Peter B. Richman MD Shari Dominguez MD David Kasper MD Frederick Chen MD Jeremy Friese MD Joseph Wood MD JD Joseph Collins MD Jeffrey A. Kline MD 《Academic emergency medicine》2006,13(3):295-301
Objectives: To determine interobserver agreement between radiologists for computed tomography (CT) angiography and venography. CT venography of the lower extremities combined with standard CT angiography of the chest may result in an increased overall diagnosis rate of venous thromboembolism (pulmonary embolism or deep venous thrombosis).
Methods: The study had a retrospective cohort design. The population consisted of emergency department patients who were evaluated for suspected pulmonary embolism. A random sample of 50 patients diagnosed and treated for venous thromboembolism and 50 age- and gender-matched patients whose CT angiograms and venograms were read as negative were enrolled. The original reading (R1) was compared with readings of two study radiologists: R2, a general radiologist, and R3, a radiologist with fellowship training in cross-sectional imaging. All readers were blinded to each other.
Results: Both R2 and R3 found both CT angiogram and venogram components technically adequate in 95% (95% CI = 89% to 98%) and 86% (95% CI = 78% to 92%) of studies, respectively. The agreement was very good for CT angiography (lowest agreement = 92%; lowest κ = 0.83) and was good for CT venography (85%, κ = 0.65). In nine cases, R1 read the CT angiogram as negative but the venogram as positive for DVT, whereas both R2 and R3 read both components as negative in four of these nine, suggesting a false-positive isolated DVT rate of 44% (95% CI = 19% to 73%). In no case did R1 read both scan components as negative when R2 and R3 agreed on presence of pulmonary embolism or DVT.
Conclusions: Diagnosis of pulmonary embolism on CT angiography is more reliable than diagnosis of isolated DVT on CT venography. 相似文献
Methods: The study had a retrospective cohort design. The population consisted of emergency department patients who were evaluated for suspected pulmonary embolism. A random sample of 50 patients diagnosed and treated for venous thromboembolism and 50 age- and gender-matched patients whose CT angiograms and venograms were read as negative were enrolled. The original reading (R1) was compared with readings of two study radiologists: R2, a general radiologist, and R3, a radiologist with fellowship training in cross-sectional imaging. All readers were blinded to each other.
Results: Both R2 and R3 found both CT angiogram and venogram components technically adequate in 95% (95% CI = 89% to 98%) and 86% (95% CI = 78% to 92%) of studies, respectively. The agreement was very good for CT angiography (lowest agreement = 92%; lowest κ = 0.83) and was good for CT venography (85%, κ = 0.65). In nine cases, R1 read the CT angiogram as negative but the venogram as positive for DVT, whereas both R2 and R3 read both components as negative in four of these nine, suggesting a false-positive isolated DVT rate of 44% (95% CI = 19% to 73%). In no case did R1 read both scan components as negative when R2 and R3 agreed on presence of pulmonary embolism or DVT.
Conclusions: Diagnosis of pulmonary embolism on CT angiography is more reliable than diagnosis of isolated DVT on CT venography. 相似文献
7.
Tolerance of ocular iontophoresis in healthy volunteers. 总被引:4,自引:0,他引:4
Thomas M Parkinson Elizabeth Ferguson Salvatore Febbraro Arash Bakhtyari Martin King Mohan Mundasad 《Journal of ocular pharmacology and therapeutics》2003,19(2):145-151
To evaluate ocular tolerance, healthy volunteers were iontophoresed transclerally using novel OcuPhor trade mark hydrogel drug delivery applicators filled with balanced salt solution. In this three-period crossover study in 24 male and female subjects, 16 subjects received 0 mA and two of the following DC currents: 0.1, 0.5., 1.0, 2.0, 3.0, or 4.0 mA for 20 min; 6 subjects received 3 mA for 20 min and 1.5 mA for 40 min (both equivalent to 60 mAmin total charge). Safety and tolerance were determined by subjective VAS and objective ophthalmic assessments. Subjects were evaluated before and up to 22 hr after dosing. The applicators were well-tolerated and no clinically significant changes in symptomology or in ophthalmic assessments were seen following exposure to 0-3.0 mA for 20 min or 1.5 mA for 40 min. At 4.0 mA 2 of 4 subjects reported a burning sensation under the applicator during dosing which resolved by 22 hr post-dose; superficial changes in fluorescein staining were observed at 1 hr, but not at 22 hr. The OcuPhor trade mark system has promise for noninvasive drug delivery to the eye. 相似文献
8.
9.
S. A. R. Nouraei C. B. Singh M. S. Ferguson K. Young D. Roy J. M. Philpott 《European journal of plastic surgery》2007,30(4):153-157
The objective of this study is to assess the results of repairing septal perforations with a vascularized pedicled alar cartilage
island flap. Using the external rhinoplasty approach, a vascularized flap of alar cartilage, harvested as a cephalic trim
and pedicled on the ascending columellar branches of the superior labial artery was raised. Bilateral mucoperichondrial septal
flaps were elevated and the alar flap was transposed and secured within the defect and bilaterally overlaid with temporalis
fascia. Silastic sheets were placed and remained in situ until the grafts were revascularized from the peripheries of the
defect as well as centrally from the alar flap. The revascularized temporalis fascia acted as a scaffold for nasal remucosalization.
The alar flap also increased the long-term structural robustness of the repair. Between 1999 and 2003, 14 patients with septal
perforations ranging from 10 to 31 mm underwent septal reconstruction using this technique. There were nine males and five
females. The flap was successfully raised in all cases and long-term closure was maintained in 12 patients (86%). The alar
cartilage flap is an effective technique for repairing septal perforations in selected patients. It provides vascularized
tissue which nourishes the grafts during remucosalization, and a cartilaginous framework, which affords long-term structural
support to the repair. It also obviates the need to transpose nasal mucosa and create a secondary defect. The rhinoplasty
approach furthermore permits additional nasal deformities to be corrected at the same time.
Presented at the British Association of Plastic Surgeons Summer Scientific Meeting, Sheffield, UK (12 July 2006). 相似文献
10.
Ten test materials derived from petroleum or hydrotreated shale oils were applied 3 times/week for up to 105 weeks to the shaved skin of 25 male and 25 female C3H/HeN mice per group. Mineral oil and benzo(a) pyrene (0.15%) were control materials. Clinical observations were recorded during the study. At death, histopathologic examination was conducted on skin, internal organs and any gross lesions. Exposures to some materials were ended midway in the study due to severe irritation. Chronic toxicity of all materials was limited to inflammatory and degenerative skin changes. Significant increases over control incidence of skin tumors (squamous cell carcinoma and fibrosarcoma) occurred with both petroleum and shale-derived naphtha (21%, 50%), Jet A (26%, 28%), JP-4 (26%, 50%), and crude oils (84%, 54%). Severely hydrotreated shale oil and petroleum and shale-derived diesel distillates were not considered tumorigenic. Results indicate that toxicity of comparable petroleum and shale-derived fractions was qualitatively similar and confirm earlier findings that hydrotreating reduces or eliminates carcinogenicity of raw shale oil. 相似文献