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51.
T. Takaki 《Medical & biological engineering & computing》1988,26(4):397-403
The paper considers the limiting factors in EEG enhancement in the presence of electrosurgery interference and presents a
design for a useful fibre-optic EEG monitoring instrument which is free from such problems as electrical shock (micro and
macroshock), patient burns and susceptibility to electrosurgery interference associated with conventional EEG monitors. 相似文献
52.
Isolation and RNA-binding analysis of NAD+-isocitrate dehydrogenases from Kluyveromyces lactis and Schizosaccharomyces pombe 总被引:1,自引:0,他引:1
Krebs cycle NAD+-isocitrate dehydrogenase (Idh) binds to the 5-UTRs of all mitochondrial mRNAs in Saccharomyces cerevisiae. We hypothesize that this leader-binding activity plays a role in translational regulation, thereby linking mitochondrial
biogenesis to the need for respiratory function. Analysis of effects of leader binding on mitochondrial translation is complicated
by the involvement of the enzyme in mitochondrial metabolism. We have therefore searched for an Idh altered in RNA binding,
but retaining full enzyme activity. Idh from Kluyveromyces lactis and Schizosaccharomyces pombe was partially purified and examined for the ability to bind Cox2 mRNA. Sch. pombe Idh, like the S. cerevisiae enzyme, has high affinity for both its own, K. lactis and S. cerevisiaeCOX2 leaders. In contrast, Idh purified from K. lactis shows only low affinity for all mRNAs tested. To determine what distinguishes K. lactis Idh from S. cerevisiae Idh, genes encoding the two subunits of Idh in K. lactis were cloned and sequenced. Sequence comparison revealed high levels of similarity throughout the proteins, in particular
in regions involved in enzyme activity, co-factor and regulator binding. Non-conserved residues between the subunits from
the two yeasts are candidates for involvement in the interaction with RNA.
Received: 19 January 2000 / 24 March 2000 相似文献
53.
J. Rappaport M. W. Richardson P. E. Klotman S. K. Arya G. Baier-Bitterlich 《Journal of molecular medicine (Berlin, Germany)》1995,73(12):583-589
HIV-1 and HIV-2 are co-endemic in certain geographic areas. HIV-2 is more weakly pathogenic than HIV-1, and progression to AIDS occurs less frequently and over a longer period of time. Recent epidemiologic studies suggest that individuals infected with HIV-2 have a lower risk of HIV-1 infection. Both immune mechanisms and various modes of viral interference have been proposed to account for these results. Our findings, described in this paper, suggest that HIV-2 inhibits HIV-1 replication. To study the molecular interactions between HIV-1 and HIV-2, proviral clones were transfected alone or in combination into the human T cell line CEM. LTR-CAT indicator constructs were included for the purpose of monitoring viral promoter activity. Viral replication in transfected cells was monitored by p24 antigen capture assay of cell culture supernatants and Western blot analysis of cell extracts. HIV-2 inhibited HIV-1 replication as determined by intracellular and extracellular p24 antigen levels. Similar results were obtained with simultaneous virus infection using HIV-1 and HIV-2, rather than transfections of proviral DNA. Using cotransfection of HIV-1 and HIV-2 LTR indicator gene constructs, the mechanism of inhibition was found to be suppression of the HIV-1 LTR by HIV-2. The inhibitory effect of HIV-2 is not due to Tat-2, but appears to discriminate between the HIV-1 and HIV-2 LTRs based on differences in the Tat activation response element, TAR. These results suggest both a molecular mechanism for HIV-2 interference with HIV-1 replication and a potential molecular approach to therapy. 相似文献
54.
Dobrev D 《Medical & biological engineering & computing》2002,40(5):546-549
A circuit is proposed for a non-differential two-electrode biopotential amplifier, with a current source and a transimpedance
amplifier as a potential equaliser for its inputs, fully emulating a differential amplifier. The principle of operation is
that the current in the input of the transimpedance amplifier is sensed and made to flow with the same value in the other
input. The circuit has a simple structure and uses a small number of components. The current source maintains balanced common-mode
interference currents, thus ensuring high signal input impedance. In addition, these currents can be tolerated up to more
than 10μA per input, at a supply voltage of ±5V. A two-electrode differential amplifier with 2×10 MΩ input resistances to
the reference point allows less than 0.5μA per input. The circuit can be useful in cases of biosignal acquisition by portable
instruments, using low supply voltages, from subjects in areas of high electromagnetic fields. Examples include biosignal
recordings in electric power stations and electrically powered locomotives, where traditionally designed input amplifier stages
can be saturated. 相似文献
55.
Alanna M. Kongkriangkai Christopher King Lisa J. Martin Emily Wakefield Carlos E. Prada Geraldine Kelly‐Mancuso Elizabeth K. Schorry 《American journal of medical genetics. Part A》2019,179(4):602-607
Tumor growths, migraine headaches, and other health‐related complications reported in patients with neurofibromatosis type 1 (NF1) are often associated with pain. Thus, this study sought to describe and quantify the pain experience in children and young adults with NF1. Surveys were administered to 49 participants (28 children and 21 adults), ages 8 through 40 years. The survey included the Numeric Rating Scale 11 (NRS11) to assess pain intensity and the Patient Reported Outcomes Measurement Information System (PROMIS) to assess pain interference. A supplemental survey was created to measure pain frequency, chronicity, quality, and location. Results suggest pain is not only present in 55% of the cohort, but that it can begin at early ages. Pain was chronic in 35% of participants, with 41% reporting the use of medication to manage pain symptoms. Common sources of pain included migraine headaches and NF‐related tumors. Pain was described as having neuropathic features (i.e., burning, tingling, numbness, or itching), and was localized to the head, back, and extremities. Further, subsets of participants reported moderate‐to‐severe pain intensity, high frequency of pain, and interference of pain in daily activities. Continued investigation of the pain experience in a multisystem disorder, such as NF1, remains essential to providing guidance in the setting of complex pain management. 相似文献
56.
57.
Eiji Tanaka Kendo Kiyosawa Yoshiyuki Nakatsuji Yoshimichi Inoue Tatsuo Miyamura Joe Chiba Seiichi Furuta 《Journal of medical virology》1993,39(4):318-324
The prevalence of hepatitis C antibodies (anti- HCV) among multitransfused patients was studied and compared with predicted values obtained from a post-transfusion hepatitis study and from data on the prevalence of anti-HCV among blood donors. The prevalence of hepatitis B core antibodies (anti-HBc) was also studied to determine the routes of transmission of hepatitis C virus. The patients consisted of 65 dialysis patients (57 on haemodialysis and 8 on continuous ambulatory peritoneal dialysis) and 71 leukemia patients in long-term remission [49 with acute myeloid leukemia (AML) and 22 with acute lymphatic leukemia (ALL)]. The presence of anti-HCV was investigated using a second generation enzyme-linked immunosorbent assay. Reactive samples were confirmed by a second generation recombinant immunoblot assay. Anti-HBc was studied in the 65 dialysis patients and in 40 of the leukemia patients. Three (4.6%) of the 65 dialysis patients and 12 (24.5%) of the 49 AML patients were anti-HCV positive whereas all of the ALL patients were seronegative. The total number of blood units transfused to 134 patients (data on two dialysis patients were not available) was 18,148, out of which 17,575 units had been transfused prior to the initiation of anti- HCV screening of blood donors. On the basis of the anti-HCV prevalence among blood donors and the incidence of post-transfusion hepatitis, the predicted number of seropositive patients was 11 and 18, respectively. Five of the 65 dialysis patients were anti-HBc positive, compared with only one of the 40 leukemia patients. It is concluded that the anti-HCV prevalence among dialysis and leukemia patients is concordant with the risk of receiving contaminated blood products, whereas hepatitis B infection may have other routes of transmission in dialysis patients. © 1993 Wiley-Liss, Inc. 相似文献
58.
Summary Specific exclusion relations are know among the three Ustilago maydis viruses that are associated with the cytoplasmically transmitted killer phemomenon. Of the three viruses P1, P4 and P6, only P1, and P4 cancoexist in one host cell. Mutual exclusion occurs between P1 and P6 and P4 unilaterally excludes P6. The exclusion relations were originally defined among the wild-type viruses. Those relations can be modified by two specific segments that are a part of the P4 dsRNA genome and were also found in some sensitive strains that contained part of the viral genome. Also, deletion of the dsRNA segment that is assumed to encode the toxin information permits the formation of hybrid genomes that otherwise cannot be formed. The data is interpreted in terms of a dsRNA restriction modification system in which the killer toxin or a toxin-linked function acts as the restriction factor and segments H3 and H4 or H4 alone contain the necessary information for the modification of certain sites on the M and L segments of the P1 and P4 viruses but not on the P6 segments. 相似文献
59.
T. M. Sokolova N. G. Fatkhutdinova N. N. Nosik 《Bulletin of experimental biology and medicine》1991,112(1):1010-1013
D. I. Ivanovskii Institute of Virology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR D. K. L'vov) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 112, No. 7, pp. 80–83, July, 1991. 相似文献
60.
C. W. Pittius F. Ellendorff V. Höllt N. Parvizi 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》1987,69(1):208-212
Summary Using solution hybridization analysis and Northern blotting with complementary RNA probes labelled to high specific activity, levels of proenkephalin A and B mRNA were analyzed throughout prenatal development in the hippocampus and striatum of fetal pigs. A differential time course for the appearance of these opioid precursor mRNAs was observed: in hippocampus, both mRNAs increased linearly throughout development with proenkephalin B mRNA increasing faster than proenkephalin A mRNA. In striatum, both mRNAs behaved similarly, increasing to a maximum level around mid-gestation and declining thereafter. The differences might be attributed to differential localization of the two precursor systems in the tissues and might be of functional relevance.Abberviations PENK A, PENK B
Proenkephalin A, B
- mRNA
Messenger Ribonucleic Acid
- cRNA
Complementary RNA 相似文献