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排序方式: 共有292条查询结果,搜索用时 15 毫秒
31.
Analysis of p53 mutations in a large series of lymphoid hematologic malignancies of childhood 总被引:7,自引:4,他引:7
Wada M; Bartram CR; Nakamura H; Hachiya M; Chen DL; Borenstein J; Miller CW; Ludwig L; Hansen-Hagge TE; Ludwig WD 《Blood》1993,82(10):3163-3169
p53 mutations are found in a wide variety of cancers, including hematologic malignancies. These alterations apparently contribute to development of the malignant phenotype. We analyzed a large series of lymphoid (330 cases) and a smaller series of myeloid (29 cases) malignancies of childhood for p53 mutations by single-strand conformational polymorphism (SSCP) following polymerase chain reaction. Samples with abnormal SSCP were reamplified and analyzed by direct sequencing method. p53 mutations were detected within the known mutational hotspots (exons 5 to 8) in 8 of 330 lymphoid malignancies, and in none of 29 myeloid malignancies, showing that the frequency of p53 mutations in childhood lymphoid malignancies was very low (8 of 330 cases [2%]). Four of these patients had very aggressive, fatal acute lymphocytic leukemia (ALL). None of 13 infants and none of 48 patients with T-lineage leukemia had detectable p53 mutations in their ALL cells. Exceptionally, p53 mutations were comparatively frequent in a small sample of B-cell non-Hodgkin's lymphomas (2 of 8 cases). Mutations were detected in samples from two patients with ALL at relapse; these were not detected in samples at initial diagnosis from the same patients, suggesting that p53 mutations may be associated with progression to a more malignant phenotype. Seven of eight alterations of p53 were missense mutations, and seven of eight samples may be heterozygous for the mutant p53, indicating that p53 protein may act in a dominant negative fashion. 相似文献
32.
Kishore Guda Martina L. Veigl Vinay Varadan Arman Nosrati Lakshmeswari Ravi James Lutterbaugh Lydia Beard James K. V. Willson W. David Sedwick Zhenghe John Wang Neil Molyneaux Alexander Miron Mark D. Adams Robert C. Elston Sanford D. Markowitz Joseph E. Willis 《Proceedings of the National Academy of Sciences of the United States of America》2015,112(4):1149-1154
We used whole-exome and targeted sequencing to characterize somatic mutations in 103 colorectal cancers (CRC) from African Americans, identifying 20 new genes as significantly mutated in CRC. Resequencing 129 Caucasian derived CRCs confirmed a 15-gene set as a preferential target for mutations in African American CRCs. Two predominant genes, ephrin type A receptor 6 (EPHA6) and folliculin (FLCN), with mutations exclusive to African American CRCs, are by genetic and biological criteria highly likely African American CRC driver genes. These previously unsuspected differences in the mutational landscapes of CRCs arising among individuals of different ethnicities have potential to impact on broader disparities in cancer behaviors.Colorectal cancer (CRC) is a leading cause of cancer mortality world-wide. CRC incidence and mortality rates are both increased in African Americans (AA) compared with Caucasians Americans (1–3). Although several factors likely play a role, the contribution of potential differences in tumor genetics to this disparity have yet to be fully explored (1, 3). In particular, AA CRCs were notably underrepresented in the four major published CRC sequencing studies (4–7), accounting for only two annotated AA cases of the 333 total CRCs studied (4–7). Accordingly, we initiated this study to compare the mutational landscapes of CRCs from AA individuals versus Caucasians. 相似文献
33.
Biochemical markers of bone turnover in seronegative spondylarthropathy: relationship to disease activity 总被引:1,自引:0,他引:1
MacDonald AG; Birkinshaw G; Durham B; Bucknall RC; Fraser WD 《Rheumatology (Oxford, England)》1997,36(1):50-53
To investigate bone turnover in patients with seronegative
spondylarthropathy, a bone formation marker, type 1 procollagen carboxy-
terminal propeptide (P1CP), and resorption markers, the pyridinium
cross-links of collagen [urinary free (f) PYR and DPYR], were measured. The
median f-PYR, f-DPYR and P1CP (+/-interquartile range) were 15.8 (6.00)
nmol/mmol creatinine, 3.8 (2.2) nmol/mmol creatinine and 101.5 (38)
micrograms/1, respectively. There was a positive correlation between
resorption markers and acute-phase reactants such as C-reactive protein (r
= 0.42 for PYR, r = 0.42 for DPYR, P < 0.05), and a negative correlation
observed between P1CP and the erythrocyte sedimentation rate (r = -0.64, P
< 0.05). In the subgroup of patients with an elevated CRP concentration,
the concentration of PYR and DPYR was significantly increased (f-PYR 25.7
vs 15.8 and f-DPYR 6.6 vs 3.8, P < 0.01 for f-PYR, P < 0.05 for
f-DPYR). This study suggests than an elevation in acute-phase response in
patients with seronegative spondylarthropathy is associated with increased
concentration of bone resorption markers with a tendency for reduction in
bone formation markers. This may represent uncoupling of bone formation and
resorption, leading to bone loss in such patients.
相似文献
34.
Digital and conventional chest images: observer performance with Film Digital Radiography System 总被引:5,自引:0,他引:5
The Film Digital Radiography System (FilmDRS) is a device with a laser optical film digitizer, 2,000 X 2,000 X 12-bit memory, and a 1,000-line video display. To evaluate the adequacy of this device for general radiography of the chest, four readers independently analyzed both radiographs and the corresponding video display of the digitized chest images of 150 patients, consisting of 100 images of abnormalities and 50 normal images. The overall results indicate equal sensitivity for the two systems. The FilmDRS, with interactive windowing, proved superior in the detection of hilar and mediastinal disease. X-ray film was superior in allowing detection of hyperlucent states. There was equivalent sensitivity for other disease categories. Superior specificity was achieved with conventional radiographs. 相似文献
35.
Orbital dermoids: features on CT 总被引:3,自引:0,他引:3
The computed tomographic (CT) features of orbital dermoids were retrospectively reviewed in 17 patients; 15 of the lesions were proved histologically. On the basis of clinical and CT features, the tumors were classified as superficial or deep. All but one were extraconal in location. Seven lesions appeared cystic; only six showed typical fat density. The presence of a margin or rim, often partially calcified, was identified in ten lesions. Irregular scalloping of adjacent bone was a highly suggestive feature, occurring with 11 dermoids. Other bone changes, such as linear defects, thinning, or sclerosis, also occurred. Superficial dermoids showed less apparent bone changes. An extraconal orbital lesion associated with adjacent bone thinning or notching should raise the possibility of a dermoid, especially if a rim with calcification is seen. The appearance is pathognomonic if fat density is also present. 相似文献
36.
37.
Primary biliary carcinoma: CT evaluation 总被引:19,自引:0,他引:19
38.
39.
L A Sedwick 《Survey of ophthalmology》1992,36(5):366-372
A 62-year-old lady with hypertension and diabetes developed bilateral, sequential ischemic optic neuropathy, progressive in the right eye. Because of a reported association between amiodarone and optic neuropathy with disc edema, the patient discontinued taking this medication; however, her visual loss continued. The differential diagnoses of bilateral ischemic optic neuropathy--including infiltrative optic neuropathy and temporal arteritis--were exhaustively investigated in this patient. 相似文献
40.
Turner DA; Alcorn FS; Shorey WD; Stelling CB; Mategrano VC; Merten CW; Silver B; Economou SG; Straus AK; Witt TR 《Radiology》1988,168(1):49-58
Detectability of breast cancer with magnetic resonance (MR) imaging versus xeromammography was quantitatively compared. MR images were obtained of breasts of 120 women who underwent xeromammography. T1 values were determined for masses larger than 2 cm. Cancer was histologically confirmed in 39 breasts and was considered excluded from 81 due to results of biopsy, cyst aspiration, or sonography or absence of change in xeromammographic findings over time. Images were blindly interpreted by three observers, and results were expressed as receiver operating characteristic curves. Detectability of breast cancer was substantially better with xeromammography than with MR imaging for all observers (P less than .03, 10(-6), and .001). On MR images, spiculation of a mass, distorted architecture, skin thickening, and nipple or skin retraction were specific but relatively insensitive indicators of cancer. Masses with smooth, distinct margins and signal intensity greater than that of fat on T2-weighted images were always benign. Other findings and T1 values were not diagnostically useful. The authors conclude that xeromammography is superior to MR imaging in detection of breast cancer. 相似文献