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71.
A method to measure the "in vitro" RNA release from rat brain cell nuclei was described. Nuclear RNA was prelabelled "in vivo" for 30 or 120 min. In the first case the released RNA was heterogeneous and its electrophoretic mobility was similar to that of cytoplasmic messenger RNAs; nuclei prelabelled for 120 min mostly released the two major species of ribosomal RNAs. The release of mRNAs from the nuclei increased during cerebral development while that of the ribosomal RNAs did not. The increased capacity of the nuclei to release "radidly labelled" RNA with age neither determined an increase of the polysomal population, nor seemed to be dependent on cytoplasmic macromolecules. 相似文献
72.
The vasa vasorum and angioplasty 总被引:2,自引:0,他引:2
Cragg AH; Einzig S; Rysavy JA; Castaneda-Zuniga WR; Borgwardt B; Amplatz K 《Radiology》1983,148(1):75-80
Interruption of flow in the vasa vasorum may lead to medial necrosis and aneurysm formation. The purpose of this study was to determine whether angioplasty produces significant alterations in the morphology or blood flow of the vasa vasorum of the dilated artery. The morphology of the canine vasa vasorum was studied before and after angioplasty; in a separate experiment vessel wall blood flow (VWBF) in canine carotid arteries was measured after angioplasty to determine whether physiologic regulation of the blood flow was disrupted by arterial dilation. No morphologic changes could be demonstrated in the vasa vasorum of the dilated artery; however, VWBF was increased by 1194 +/- 215% (mean +/- standard error, p less than 0.01) between 90 and 120 minutes after angioplasty. VWBF in the adjacent nondilated arterial segment was also increased (720 +/- 177% between 10-30 minutes, p less than 0.01) but returned toward normal after 60 minutes. Adenosine caused a "paradoxical" decrease in VWBF (p less than 0.05) of the dilated arterial segment while causing increased VWBF (p less than 0.05) in the thoracic aorta. Angioplasty appears to produce persistent hyperemia in the dilated arterial wall. A paradoxical response to adenosine suggests that vasa vasorum in the dilated arterial segment are maximally vasodilated. This may be due to mechanical disruption of vasomotor tone or to release of vasoactive substances. 相似文献
73.
O M Ramirez 《Annals of plastic surgery》1992,28(3):218-32; discussion 233-4
The subperiosteal frontal rhytidectomy described by Tessier was the departure point for a new approach for facial rejuvenation. Psillakis described the subperiosteal face-lift "as an improved concept for correction of the aging face." However, this technique has a high incidence of frontal nerve injury and because of the limitations in the subperiosteal dissection, the facial soft tissues cannot be lifted reliably to the desired position. Other authors have repeated the Psillakis experience with the same frustrations and complication rate. In this report, I describe the evolution of the subperiosteal face-lift and the significant modifications that I have introduced, making this procedure safer and improving results in the degree of facial rejuvenation. My approach of subperiosteal rhytidectomy has been used in 34 patients with a minimal complication rate. This technique also addresses the rejuvenation of the central portion of the face and the restoration of tension of the facial mimetic musculature not obtained by current brow/face-lift procedures. 相似文献
74.
Irma Ramirez Margaret P. Sullivan Yeu-ming Wang R. G. Martin J. J. Butler 《Cancer chemotherapy and pharmacology》1979,3(2):103-109
Summary A new treatment for Burkitt's lymphoma (BL) has been devised with coordinated intrathecal (IT) methotrexate (MTX) + high-dose intravenous (IV) MTX with citrovorum factor (CF) rescue and high-dose Cytoxan (CYT). Six patients have been entered on the study. Five patients continue in complete remission at 13+–31+ months (median, 29+ months). One died of septicemia during myelosuppression. Only minor toxicity was seen in four patients. Two patients had severe metabolic disturbances following initial CYT therapy; one of these patients also had reversible, moderately severe hepatorenal MTX toxicity. No neurotoxicity was observed. Results of therapy are impressive in this limited patient group, four of whom were poor-prognosis (Stage C or D) and two of whom were good-prognosis patients (Stage B or AR). The potential for severe toxicity is great; adherence to the criteria for drug administration and close surveillance of the patient in the post-treatment period are mandatory.Plasma and cerebrospinal fluid (CSF) MTX pharmacokinetics were studied in three patients. CSF MTS levels exceeded 10-6 M with coordinated IT-IV MTX (150 mg/kg body wt.) With MTX infusions at the 200 mg/kg level, therapeutic concentrations were maintained in the CSF for approximately 60 h. Plasma MTX concentrations exceeded 10-6 M at all infusion dose levels, the duration of the therapeutic concentration increasing with the dose level. Priming IT MTX followed in 24 h by IV MTX, 200 mg/kg assured therapeutic concentrations in plasma and CSF of sufficient duration to cover two generation times of the BL cell. 相似文献
75.
Ramirez Basco M Bostic JQ Davies D Rush AJ Witte B Hendrickse W Barnett V 《The American journal of psychiatry》2000,157(10):1599-1605
OBJECTIVE: This study determined the extent to which adding structured procedures improved diagnostic accuracy for outpatients with severe mental illness in a community mental health setting. METHOD: The Structured Clinical Interview for DSM-III-R (SCID) was used to interview 200 psychiatric outpatients. A research nurse reviewed medical records and amended the SCID diagnoses accordingly. A research psychiatrist or psychologist reviewed the diagnostic data and interviewed each patient to verify or further modify the previous findings. Diagnostic outcomes at each step of the procedure were compared to determine whether adding additional data improved diagnostic accuracy. The additional time required for each element of the diagnostic procedure was also assessed. RESULTS: Kappa comparisons of the different diagnostic levels showed that adding additional data significantly improved accuracy. Diagnoses rendered by combining the SCID and review of the medical record were the most accurate, followed by the SCID alone, and then diagnoses made by psychiatrists during routine care. In addition, the SCID alone identified five times as many current and past secondary diagnoses as were documented routinely in patients' charts. CONCLUSIONS: Combining structured interviewing with a review of the medical record appears to produce more accurate primary diagnoses and to identify more secondary diagnoses than routine clinical methods. The patients' knowledge of their diagnoses was limited, suggesting a need for patient education in this setting. Whether use of structured interviewing in routine practice improves patient outcomes deserves further study. 相似文献
76.
Chanita Hughes Susan K Peterson Amelie Ramirez Kipling J Gallion Paige Green McDonald Celette Sugg Skinner Deborah Bowen 《Cancer epidemiology, biomarkers & prevention》2004,13(7):1146-1155
Although recruitment of ethnic and racial minorities in medical research has been evaluated in several studies, much less is known about the methods used to recruit these populations to participate in cancer genetics research. This report reviews the resources that have been used to identify and recruit ethnic and racial minorities to participate in hereditary breast cancer research. Overall, hospital-based resources were used most often to identify potential subjects, and active recruitment methods were used most frequently to enroll eligible subjects. This review suggests that there appears to be a finite number of resources and strategies to identify and recruit potential subjects to participate in cancer genetics research; however, options for improving awareness about cancer genetics research among ethnic and racial minorities have not been extensively evaluated. To study ethnic and racial minority participation in cancer genetics research, stronger evaluation components will need to be integrated into research methods. Both observational and experimental studies are needed to determine resources that are most effective for identifying potential subjects who are ethnic and racial minorities and to evaluate the effects of different recruitment strategies on enrollment decisions among these populations. 相似文献
77.
Objective: To identify factors that influence a woman's decision to breast-feed.
Methodology: Five hundred and fifty-six women were recruited from the maternity wards of two Perth hospitals. Data were collected from a self-administered questionnaire completed by participants prior to discharge. Logistic regression analysis was used to determine factors influencing the initiation of breast-feeding.
Results: At discharge from hospital 83.8% of women were breast-feeding, including 6% who were giving complementary formula feeds. After controlling for potentially confounding demographic and biomedical factors, the father's reported preference for breast-feeding was found to be the most important factor influencing a woman's decision to breast-feed (OR 10.18).
Conclusion: Fathers participate in and influence the choice of infant feeding method and should be included in breast-feeding discussions. 相似文献
Methodology: Five hundred and fifty-six women were recruited from the maternity wards of two Perth hospitals. Data were collected from a self-administered questionnaire completed by participants prior to discharge. Logistic regression analysis was used to determine factors influencing the initiation of breast-feeding.
Results: At discharge from hospital 83.8% of women were breast-feeding, including 6% who were giving complementary formula feeds. After controlling for potentially confounding demographic and biomedical factors, the father's reported preference for breast-feeding was found to be the most important factor influencing a woman's decision to breast-feed (OR 10.18).
Conclusion: Fathers participate in and influence the choice of infant feeding method and should be included in breast-feeding discussions. 相似文献
78.
79.
80.
Abril N; Luque-Romero FL; Prieto-Alamo MJ; Rafferty JA; Margison GP; Pueyo C 《Carcinogenesis》1997,18(10):1883-1888
Here we confirm and extend our previous studies demonstrating that the
mutagenic potency of 1,2-dibromoethane (DBE) and dibromomethane (DBM) is
markedly enhanced (not prevented) in bacteria expressing the O6-
alkylguanine-DNA alkyltransferase (ATase) encoded by the Escherichia coli
ogt gene. We demonstrate that, in close parallel with mutagenesis, the Ogt
ATase sensitizes the bacteria to the lethal effects of these carcinogens,
suggesting that one or more of the potentially mutagenic lesions induced by
DBE and DBM in the presence of Ogt has additional lethal capacity. We
further demonstrate that the sensitization to both lethality and
mutagenesis by DBE and DBM is a property shared by other DNA
alkyltransferases. This objective was accomplished by quantifying the
induction of mutations and lethal events in ogt- ada- E. coli expressing an
exogenous bacterial or mammalian ATase from a multicopy plasmid. Mammalian
recombinant ATases enhanced the lethal and mutagenic actions of DBE and
suppressed the lack of sensitivity of the vector- transformed bacteria to
DBM. In most cases the order of effectiveness of the ATases ranked: murine
> human > Ogt > rat. Further comparisons included the full-length
Ada ATase from E. coli and a truncated Ada version (T-ada) that retains the
O6-methylguanine binding domain of the protein. The full-length Ada ATase
was effective in enhancing the lethality but not the mutagenicity induced
by DBE and DBM. The T-ada ATase provided less sensitization than Ada to
lethality by DBE, but of the three bacterial ATases T-ada yielded the
highest sensitization to mutagenesis by this compound. T-ada and Ada ATases
were in general less effective than the mammalian versions, with the
exception of the rat recombinant ATase. The effectiveness of the different
mammalian and bacterial ATases in promoting the deleterious actions of
dibromoalkanes was compared with the effectiveness of these proteins in
suppressing the lethal and mutagenic effects induced by
N-nitroso-N-methylurea. The ability to sensitize E. coli to the lethal and
mutagenic effects of DBE and DBM seems restricted to DNA alkyltransferase,
since overexpression of thioredoxin (Trx) or glutaredoxin (Grx1) in ogt-
ada- cells showed no effect, in spite of the reported potential of
bioactive dihaloethane- derived species to alkylate Trx.
相似文献