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81.

Background  

Variance of peak bone mass has a substantial genetic component, as has been shown with twin studies examining quantitative measures such as bone mineral density (BMD) and quantitative ultrasound (QUS). Evidence implicating single nucleotide polymorphisms (SNPs) of the transforming growth factor beta-1 (TGFB1) gene is steadily accumulating. However, a comprehensive look at multiple SNPs at this locus for their association with indices of peak bone mass has not been reported.  相似文献   
82.
Lasser  EC; Lang  JH; Lyon  SG; Hamblin  AE; Howard  MM 《Radiology》1981,140(1):11-15
An in vitro is described that attempts to detect patients with a potential for adverse systemic reactions to contrast material. This test involves measuring the rate of conversion of prekallikrein to kallikrein under certain standard conditions. In a preliminary retrospective study, the test could be used to identify such patients with a sensitivity of 88%, a specificity of 82%, and a predictive value of 79%.  相似文献   
83.
Patient dosage in computed tomography   总被引:1,自引:0,他引:1  
McCullough  EC; Payne  JT 《Radiology》1978,129(2):457
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84.
85.
Necrotic cells are generally considered to stimulate inflammation, whereas apoptotic cells should not. However, apoptotic cells have pro-inflammatory properties since they can activate complement. To what extent this activation compares to that by necrotic cells is not known. We compared complement activation by necrotic cells and apoptotic cells in plasma. Jurkat cells were made apoptotic or necrotic by incubation with etoposide or by heat shock, respectively. Cells incubated in recalcified plasma were tested for C3 and C4 fixation and fluid phase generation of complement activation products. Fixation of C3 and C4 to necrotic cells occurred mainly via the classical pathway, independent from the method of necrosis induction and the cell type. Depletion of IgM from plasma almost completely abrogated complement fixation by necrotic cells, which was restored by supplementation with purified IgM. Complement activation by late apoptotic cells was comparable to that by necrotic cells regarding the extent and dependence on IgM. Moreover, incubation of plasma with necrotic or late apoptotic cells led to the generation of comparable amounts of complement activation products. These results indicate that late apoptotic and necrotic cells employ similar complement activation mechanisms in the plasma environment.  相似文献   
86.
87.

Background/purpose

The aim of this study was to retrospectively review the findings at orchidopexy in acquired undescended testis (UDT).

Methods

The authors reviewed a 14-year (1986 through 1999) surgical experience in 360 boys in whom 461 orchidopexies were performed for acquired-UDT. The operative notes were reviewed to determine at operation testis position and volume, persistence of patent processus vaginalis (PV), and attachment of the gubernaculum. Also, testis position after orchidopexy was evaluated.

Results

Age at operation ranged from 2 to 19 years (mean, 8.9 years), 205 of the 461 orchidopexies (44.5%) had been performed between 9 and 12 years of age. In 327 of the 461 cases (70.9%), testis position was documented as intraoperative; in 281 of these cases (86.0%), the testis was located in the superficial inguinal pouch (SIP). A note was made regarding the presence or absence of a hernial sac in 207 of the cases: 113 (54.6%) were associated with an open PV, which usually was slightly open. In 122 of the 461 cases (26.5%), the gubernacular attachment was assessed; in 121 of these (99.2%), a normal attachment of the gubernaculum was noted. At the end of orchidopexy, in 438 of the 461 cases (95.0%), testis position was recorded. Three hundred eighty-two of these testes (87.2%) were at the bottom of the scrotum.

Conclusions

Acquired UDT usually is characterized by SIP position, closed or (small) open PV, and normal gubernaculum attachment. The results of surgery seem excellent.  相似文献   
88.
Progression of progenitor cells towards neuronal differentiation is tightly linked with cell cycle control and the switch from proliferative to neuron-generating divisions. We have previously shown that the neuronal protein BM88 drives neuroblastoma cells towards exit from the cell cycle and differentiation into a neuronal phenotype in vitro. Here, we explored the role of BM88 during neuronal birth, cell cycle exit and the initiation of differentiation in vivo. By double- and triple-labelling with the S-phase marker BrdU or the late G2 and M-phase marker cyclin B1, antibodies to BM88 and markers of the neuronal or glial cell lineages, we demonstrate that in the rodent forebrain, BM88 is expressed in multipotential progenitor cells before terminal mitosis and in their neuronal progeny during the neurogenic interval, as well as in the adult. Further, we defined at E16 a cohort of proliferative progenitors that exit S phase in synchrony, and by following their fate for 24 h we show that BM88 is associated with the dynamics of neuron-generating divisions. Expression of BM88 was also evident in cycling cortical radial glial cells, which constitute the main neurogenic population in the cerebral cortex. In agreement, BM88 expression was markedly reduced and restricted to a smaller percentage of cells in the cerebral cortex of the Small eye mutant mice, which lack functional Pax6 and exhibit severe neurogenesis defects. Our data show an interesting correlation between BM88 expression and the progression of progenitor cells towards neuronal differentiation during the neurogenic interval.  相似文献   
89.
Inconsistent reports of the prevalence of risk perception accuracy may be related to the use of different classification strategies. The purpose of this study was to compare two approaches for assessing the accuracy of women's breast cancer risk perceptions. A telephone survey was conducted with an age-stratified random sample of British Columbian women 20-79 years of age without a breast cancer diagnosis (n = 761). A comparison of two methods employed to determine perception accuracy revealed substantial differences between the methods with regard to the classification of women as under- and over-estimators. The study highlights the need for researchers to consider the method used to determine the accuracy of risk perceptions and the implications of using different strategies to assess risk perception accuracy when such information is used in research or to guide interventions.  相似文献   
90.
OBJECTIVE: To examine the dose effect of maternal milk on neonatal morbidity of very low-birth-weight (<1.5 kg) infants. DESIGN: Prospective observational study. SETTING: An urban tertiary care neonatal intensive care unit and follow-up clinic. POPULATION: One hundred nineteen singleton very low-birth-weight infants admitted from January 1, 1997, to February 14, 1999 (mean birth weight, 1056 g; mean gestational age, 28 weeks; 57% male; and 43% white). METHODS: A comparison of the effect on neonatal outcomes of daily graded doses (1-24, 25-49, and > or = 50 mL/kg of body weight) of maternal milk through week 4 of life vs a reference group receiving no maternal milk. MAIN OUTCOME MEASURES: Neonatal outcomes examined included rates of sepsis after age 5 days, retinopathy of prematurity, chronic lung disease, necrotizing enterocolitis, jaundice, duration of ventilator dependence, and length of hospital stay. RESULTS: Seventy-nine infants (66%) received maternal milk, of whom 32 received at least 50 mL/kg per day through week 4 of life. Poisson regression analysis adjusting for birth weight, sex, and ethnicity revealed that the mean number of episodes of sepsis for infants receiving at least 50 mL/kg per day was lower by a factor of 0.27 (95% confidence interval, 0.08-0.95) compared with infants receiving no maternal milk. There was no effect of maternal milk on other neonatal outcomes. CONCLUSIONS: A daily threshold amount of at least 50 mL/kg of maternal milk through week 4 of life is needed to decrease the rate of sepsis in very low-birth-weight infants, but maternal milk does not affect other neonatal morbidities.  相似文献   
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