全文获取类型
收费全文 | 1190篇 |
免费 | 63篇 |
国内免费 | 56篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 69篇 |
妇产科学 | 12篇 |
基础医学 | 148篇 |
口腔科学 | 21篇 |
临床医学 | 149篇 |
内科学 | 265篇 |
皮肤病学 | 51篇 |
神经病学 | 64篇 |
特种医学 | 299篇 |
外科学 | 46篇 |
综合类 | 23篇 |
预防医学 | 39篇 |
眼科学 | 5篇 |
药学 | 58篇 |
中国医学 | 3篇 |
肿瘤学 | 55篇 |
出版年
2023年 | 4篇 |
2021年 | 9篇 |
2020年 | 9篇 |
2019年 | 12篇 |
2018年 | 18篇 |
2017年 | 5篇 |
2016年 | 8篇 |
2015年 | 14篇 |
2014年 | 16篇 |
2013年 | 41篇 |
2012年 | 31篇 |
2011年 | 19篇 |
2010年 | 39篇 |
2009年 | 62篇 |
2008年 | 23篇 |
2007年 | 55篇 |
2006年 | 23篇 |
2005年 | 24篇 |
2004年 | 12篇 |
2003年 | 12篇 |
2002年 | 14篇 |
2001年 | 13篇 |
2000年 | 19篇 |
1999年 | 19篇 |
1998年 | 71篇 |
1997年 | 81篇 |
1996年 | 103篇 |
1995年 | 63篇 |
1994年 | 60篇 |
1993年 | 53篇 |
1992年 | 18篇 |
1991年 | 18篇 |
1990年 | 21篇 |
1989年 | 37篇 |
1988年 | 38篇 |
1987年 | 35篇 |
1986年 | 48篇 |
1985年 | 40篇 |
1984年 | 11篇 |
1983年 | 14篇 |
1982年 | 13篇 |
1981年 | 10篇 |
1980年 | 11篇 |
1979年 | 8篇 |
1978年 | 13篇 |
1977年 | 10篇 |
1976年 | 13篇 |
1975年 | 13篇 |
1974年 | 2篇 |
1973年 | 2篇 |
排序方式: 共有1309条查询结果,搜索用时 274 毫秒
81.
Cytogenetic and molecular genetic analysis of tumorigenic human bronchial epithelial cells induced by radon alpha particles 总被引:4,自引:1,他引:4
To establish a cell culture model for lung carcinogenesis, independent
populations of the human papillomavirus 18-immortalized human bronchial
epithelial cell line BEP2D were treated with high linear energy transfer
radon-simulated alpha-particles, expanded and xenotransplanted into Nu/Nu
mice. Six independent cell lines were established from tumors that
developed from three separate radiation treatments as follows: treatment
(Tx) 1 (30 cGy--two doses), H2BT, Tx 2 (30 cGy-- single dose), R30T1L,
R30T2 and R30T3L, Tx 3 (30 cGy--single dose), H1ATN and H1ATBA1.
Cytogenetic analysis revealed common changes in all tumor lines: loss of
the Y chromosome (ch), one of three copies of ch8, one of three copies of
ch14, and one of two copies of ch4p16-pter and ch11p15-pter. Analysis of
polymerase chain reaction-amplified short tandem repeats of informative
loci confirmed the loss of chY in all lines and loss of heterozygosity
(LOH) at eight loci spanning the length of ch8 in all lines from Tx's 1 and
2. Our data support previous studies indicating the presence of tumor
suppressor genes on ch8. LOH also was confirmed on ch14 at locus D14S306 in
all cell lines from Tx 2 and in one of two lines from Tx 3. This region,
14q12-q13, may contain changes in one of the five known somatostatin
receptor genes (SSTR1). No LOH was detected at any of the informative loci
tested for on ch4 or ch11.
相似文献
82.
HM Goodyear JC Moore-Gillon EH Price VF Larcher MO Savage CB Wood 《Archives of disease in childhood》1993,69(2):229-231
Childhood tuberculosis is perceived by many as a disease of the past. Experience in a children's hospital serving a deprived population suggested that tuberculosis and other mycobacterial infections were not declining in clinical practice. Fifty three tuberculous and 11 atypical mycobacterial infections were identified between 1978 and 1992. There was no decline in tuberculosis and nine of the 11 atypical infections occurred in the last five years. Altogether 40% of cases of tuberculosis were in non-Asian children; 32% had arrived in the UK or visited family overseas in the previous year; and 38% had a history of tuberculosis contact, usually a close adult relative. Nationally, the previous decline in tuberculosis in all ages has reversed. In the local health districts in London's east end, childhood tuberculosis has also stopped declining and seems to be increasing. It is regrettable that BCG vaccination has been abolished by some districts in the UK, against current recommendations. Childhood tuberculosis is still common in the practice described here, including among children who do not fall into conventionally recognised high risk groups. Inner city dwellers and junior doctors are both highly mobile populations, adding to the risk that paediatricians, particularly those in training, may encounter tuberculosis with little or no previous experience of the condition. 相似文献
83.
84.
85.
Hale JD; Valk PE; Watts JC; Kaufman L; Crooks LE; Higgins CB; Deconinck F 《Radiology》1985,157(3):727-733
Multisection, dual-echo magnetic resonance (MR) transaxial images of blood vessels contain both anatomic and qualitative information about flow. Even so, the images are produced as a series of two-dimensional tomographic sections from which full visualization of connected structures is difficult. A computer algorithm was developed that automatically detects flowing blood based on pixel intensity and calculated T2 and provides reconstructed views of vessels while analyzing and displaying flow characteristics. Images of abdominal vessels, aortic aneurysms, and the heart were encoded by flow and color to demonstrate depth. In addition, these data were reconstructed to derive a more accurate assessment of patency. With this technique, transaxial images can be used to analyze flow patterns, determine patent areas, and visualize all levels of vessels in a single image. 相似文献
86.
Drapier S Raoul S Drapier D Leray E Lallement F Rivier I Sauleau P Lajat Y Edan G Vérin M 《Journal of neurology》2005,252(5):583-588
Background
The well
known global improvement of
quality of life (QoL) after bilateral
high frequency chronic deep brain
stimulation of the subthalamic nucleus
(STN DBS) in Parkinsons disease
(PD) is in contrast to behavioral
disturbances as observed after
surgery. Indeed the impact of DBS
on physical versus mental aspects
of QoL in PD remains unknown.
Objective
To assess the influence of
bilateral STN DBS on physical versus
mental aspects of QoL in
Parkinsons disease.
Methods
The
results of 27 patients for the Unified
Parkinsons disease Rating
Scale (UPDRS), Parkinsons Disease
Questionnaire 39 (PDQ39) and
Short Form 36 health survey questionnaire
(SF36) were compared
before surgery and after 12 months
of bilateral STN DBS.
Results
Comparing
off–dopa conditions before
versus 12 months after surgery,
both UPDRS part II and part III
significantly improved: 32.6% and
52%, respectively. UPDRS part I
scores did not change significantly
at 12 months. As for PDQ39, the
global score significantly improved
after surgery (21.1 %) as did four
subscores: mobility (25.6 %), activity
of daily living (34.5 %), stigma
(40.1 %) and bodily discomfort
(30 %). Three PDQ39 subscores,
however, showed no significant
changes: emotional well–being
(10.7 %), social support (3.2%) and
cognition (8.5 %) and one item
even worsened: communication
(–7.7 %). In SF36, only physical
items significantly improved.
Conclusion
Using clinicians based rating
scale, bilateral STN DBS
showed significant improvement in
PD patients at 12 month follow up.
However, using patients self–assessment
scales, the clinical benefit
of STN DBS was more subtle: physical
items of QoL significantly improved,
whereas mental items such
as emotional well–being, social
support, cognition and communication
showed no improvement.
Our results are suggestive of a dissociation
of motor and non–motor
symptoms control after bilateral
STN DBS in PD patients. 相似文献
87.
OBJECTIVE: To determine whether children's food consumption is increased by the size of the group of children in which they are eating. DESIGN: Crossover study. SETTING: University based preschool. PARTICIPANTS: 54 children, aged 2.5-6.5 years. INTERVENTIONS: Each child ate a standardised snack in a group of three children, and in a group of nine children. MAIN OUTCOME MEASURES: Amount each individual child consumed, in grams. RESULTS: Amount eaten and snack duration were correlated (r = 0.71). The association between group size and amount eaten differed in the short (<11.4 min) versus the long (> or =11.4 min) snacks (p = 0.02 for the interaction between group size and snack duration). During short snacks, there was no effect of group size on amount eaten (16.7 (SD 11) g eaten in small groups vs 15.1 (6.6) g eaten in large groups, p = 0.42). During long snacks, large group size increased the amount eaten (34.5 (16) vs 26.5 (13.8), p = 0.02). The group size effect was partially explained by a shorter latency to begin eating, a faster eating rate and reduced social interaction in larger groups. CONCLUSIONS: Children consumed 30% more food when eating in a group of nine children than when eating in a group of three children during longer snacks. Social facilitation of food consumption operates in preschool-aged children. The group size effect merits consideration in creating eating behaviour interventions. 相似文献
88.
Volumetric rendering of MR images 总被引:1,自引:0,他引:1
The authors developed new techniques for three-dimensional display of magnetic resonance (MR) images that preserve soft-tissue definition, are fully automatic, and work with routinely used section thicknesses. MR images are segmented, selectively enhanced, and displayed by means of a volumetric rendering algorithm. These techniques were used to illustrate normal anatomy of the brain, knee, and liver. Three-dimensional rendering of balanced spin-echo images shows the ventricles and extracerebral veins and of T1-weighted images, the sulci and gyri. The large hepatic and portal vessels can be seen with these enhancement techniques. Three-dimensional views of the knee reveal articular surfaces of the tibia and clearly depict menisci and posterior and anterior cruciate ligaments. These techniques make it possible to image multiple soft tissues simultaneously while preserving the detail contained in the original images. Three-dimensional presentation of complex, overlapping anatomic regions is helpful in surgical planning and should lead to improved diagnosis. 相似文献
89.
Hasegawa BH; Naimuddin S; Dobbins JT d; Mistretta CA; Peppler WW; Hangiandreou NJ; Cusma JT; McDermott JC; Kudva BV; Melbye KM 《Radiology》1986,159(2):537-543
The feasibility of producing patient-specific beam attenuators for chest radiography has been investigated using an anthropomorphic phantom and a human volunteer. A low-dose test exposure is digitized, processed, and used to print a small cerium filter, which is placed in the x-ray beam near the collimator. The final radiograph is recorded on film. The technique results in relatively uniform film exposure, so that structures in all regions of the chest are simultaneously displayed with optimal film contrast. The equalized exposure improves image quality in the normally underpenetrated regions and reduces the role of cross-scatter from the lungs. The image is analogous to optical or computer-processed unsharp masking techniques, but the processing is accomplished in the x-ray beam and results in an improved exposure distribution, giving advantages that cannot be achieved with image processing techniques alone. 相似文献
90.
JC Szepietowski† J Salomon† P Pacan‡ E Hrehorów† A Zalewska§ 《Journal of the European Academy of Dermatology and Venereology》2008,22(7):795-799
The aim of this study was to determine the frequency of body dysmorphic disorder (BDD) identified by Polish dermatologists and to evaluate the treatment modalities applied by them.
Methods A specially designed questionnaire was distributed to 172 dermatologists. A total of 118 doctors responded (68.6%). The dermatologists were asked regarding demographic data, frequency of BDD in their everyday practice and methods of treatment they used in managing BDD patients.
Results During the whole working period, over the half of dermatologists (64%) had observed at least one BDD patient in their practice. One fifth (20%) of the respondents observed 1 or 2 BDD cases during the past 5 years, 14% observed 3 to 5 such patients, 7% observed 5 to 10 BDD cases, and 5% of the doctors reported seeing more than 10 BDD patients within this period. Almost 18% of dermatologists were currently treating a BDD patient. Our data show that 40.7% of the respondents always ask and 28.8% often ask for a psychiatric opinion. More experienced dermatologists statistically more frequently ( P < 0.05) obtained a psychiatric opinion about their patients. Only a small group of dermatologists (15.3%) use their own pharmacological treatment. If they do so, they first use anxiety-relieving drugs and placebo.
Conclusion BDD is a quite common disorder; however, not all dermatologists are sufficiently prepared to treat it. There is an urgent need for training of dermatologists on the effective approach to psychodermatoses. 相似文献
Methods A specially designed questionnaire was distributed to 172 dermatologists. A total of 118 doctors responded (68.6%). The dermatologists were asked regarding demographic data, frequency of BDD in their everyday practice and methods of treatment they used in managing BDD patients.
Results During the whole working period, over the half of dermatologists (64%) had observed at least one BDD patient in their practice. One fifth (20%) of the respondents observed 1 or 2 BDD cases during the past 5 years, 14% observed 3 to 5 such patients, 7% observed 5 to 10 BDD cases, and 5% of the doctors reported seeing more than 10 BDD patients within this period. Almost 18% of dermatologists were currently treating a BDD patient. Our data show that 40.7% of the respondents always ask and 28.8% often ask for a psychiatric opinion. More experienced dermatologists statistically more frequently ( P < 0.05) obtained a psychiatric opinion about their patients. Only a small group of dermatologists (15.3%) use their own pharmacological treatment. If they do so, they first use anxiety-relieving drugs and placebo.
Conclusion BDD is a quite common disorder; however, not all dermatologists are sufficiently prepared to treat it. There is an urgent need for training of dermatologists on the effective approach to psychodermatoses. 相似文献