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排序方式: 共有622条查询结果,搜索用时 15 毫秒
601.
Nuclear genes of human complex I of the mitochondrial electron transport chain: state of the art 总被引:4,自引:3,他引:4
Smeitink JA; Loeffen JL; Triepels RH; Smeets RJ; Trijbels JM; van den Heuvel LP 《Human molecular genetics》1998,7(10):1573-1579
The mitochondrial electron transport chain (mtETC) consists of four
multi-subunit enzyme complexes. Complex I or NADH:ubiquinone
oxidoreductase, the largest mtETC multisubunit complex, consists of
approximately 41 subunits. Seven of these subunits are encoded by the
mitochondrial genome, the remainder by the nuclear genome. Among the
mitochondriocytopathies, complex I deficiencies are encountered frequently.
Although some complex I deficiencies have been associated with
mitochondrial DNA mutations, the genetic defect has not been elucidated in
the majority of complex I-deficient patients. It is expected that many of
these patients have mutations in the nuclear- encoded subunits of this
complex, so vital for cellular energy production. After a brief summary of
the current knowledge of complex I from cow, bacteria and fungi, this
review presents the state of the art of the knowledge of the human
nuclear-encoded complex I genes which, in the last 18 months, has made
enormous progress. At present, the complete gene structure of four subunits
and the cDNA structure of 18 of the 34 complex I nuclear-encoded subunits
are known. Mapping of these subunits shows a random distribution over the
chromosomes. The chromosomal localization is known for 14 complex I genes.
Recently, the first mutation, a 5 bp duplication in the 18 kDa (AQDQ)
subunit, has been reported. We expect that within 1 year all human
nuclear-encoded complex I subunits will be cloned. Mutational analysis of
these subunits is warranted in complex I-deficient patients and will not
only be important for genetic counselling but will also extend the
knowledge regarding the functional properties of the individual human
complex I subunits.
相似文献
602.
According to a recent hypothesis the therapeutic effects of antidepressants might be related to acute or cumulative suppression of NREM sleep intensity. This intensity has been proposed to be expressed in the EEG power density in NREM sleep. In the present study the relationship was examined between the changes of EEG power density in NREM sleep and the changes in clinical state in 16 depressed patients during treatment with citalopram, a highly specific serotonin uptake inhibitor. A one-week wash-out period was followed by 1 week of placebo administration, a medication period of 5 weeks, and a one-week placebo period. In order to minimize systematic influences of sleep duration and NREM-REM sleep alterations, EEG power was measured over the longest common amount of NREM sleep stages 2, 3 and 4 (91.5 min). During the last treatment week and the week after withdrawal, a significant decrease of EEG power as compared to baseline was found in the 8-9 Hz frequency range. No clear-cut change, however, was observed in the EEG power of the delta frequency range (1-4 Hz), which is considered to be the principle manifestation of NREMS intensity. Furthermore, no relationship between changes in EEG power density and changes in clinical state could be demonstrated. 相似文献
603.
The intake of nutrients over a five day period was studied in 23 children whose atopic eczema was being treated by the avoidance of multiple foods. The results were compared with those from 23 healthy control children not on a diet. Significantly low intakes of calcium were discovered in 13 patients but not in controls. Avoidance of multiple foods is potentially hazardous and requires continued paediatric and dietetic supervision. 相似文献
604.
Lower esophageal sphincter pressures and serum gastrin levels after cholinergic stimulation 总被引:2,自引:0,他引:2
Higgs RH; Humphries TJ; Castell DO; McGuigan JE 《The American journal of physiology》1976,231(4):1250-1253
605.
Gray RH; Simpson JL; Bitto AC; Queenan JT; Li C; Kambic RT; Perez A; Mena P; Barbato M; Stevenson W; Jennings V 《Human reproduction (Oxford, England)》1998,13(5):1397-1400
This was a multicentred, prospective study of pregnancies among women using
natural family planning. The women maintained natural family planning
charts of the conception cycle, recording acts of intercourse and signs of
ovulation (cervical mucus changes, including peak day and basal body
temperature). Charts were used to assess the most probable day of
insemination relative to the day of ovulation and length of the follicular
phase of the cycle. The sex ratio (males per 100 females) for 947 singleton
births was 101.5, not significantly different from the expected value of
105. The sex ratio did not vary consistently or significantly with the
estimated timing of insemination relative to the day of ovulation, with the
estimated length of the follicular phase or with the planned or unplanned
status of the pregnancy. Although these findings may be affected by
imprecision of the data, the study suggests that manipulation of the timing
of insemination during the cycle cannot be used to affect the sex of
offspring.
相似文献
606.
607.
W A Van Staveren P Deurenberg J Burema L C De Groot J G Hautvast 《International journal of obesity (2005)》1986,10(2):133-145
The effect of season on the energy balance was examined in 114 young adult Dutch women consuming self-selected diets. Energy intakes and patterns of physical activity were assessed monthly 14 times with the 24-h recall method. After this period of 14 months, in the second year the same estimates were made with intervals of 2-3 months to check if the seasonal variations observed were not accidental. The study did not demonstrate seasonal variations in the mean energy intake of the group under study. However, the intake of fat appeared to be higher in the winter and spring than in the summer and autumn, whereas for the intake of mono- and di-saccharides the reverse seemed to be true. The intake of dietary fibre was higher in the autumn than in the summer, with intermediate values for winter and spring. Small seasonal fluctuations were observed in body weight and time spent on various physical activities. On the one hand, these fluctuations are too small to indicate physiological significance, on the other hand they are wide enough to be taken into account in the design of many longitudinal studies on the relation between diet and disease. 相似文献
608.
Kerst JM; Sanders JB; Slaper-Cortenbach IC; Doorakkers MC; Hooibrink B; van Oers RH; von dem Borne AE; van der Schoot CE 《Blood》1993,81(2):344-351
To study the receptors involved in the interaction between extracellular matrix proteins and hematopoietic progenitor cells, we analyzed the expression of beta 1 integrins on CD34+ bone marrow cells by means of immunoflowcytometry. Alpha 4 beta 1 and alpha 5 beta 1 were expressed, whereas alpha 1 beta 1, alpha 2 beta 1, alpha 3 beta 1, alpha 6 beta 1, and alpha v beta 1 were virtually absent. Furthermore, we assessed the alpha 4 and alpha 5 expression on committed myeloid progenitor cells. These colony-forming cells were detected in the alpha 4 dull fraction and the alpha 5 dull fraction. During myeloid differentiation, both in vivo and in vitro, a differential expression of alpha 4 beta 1 and alpha 5 beta 1 was observed. alpha 5 beta 1 was found to be lost at the myelocytic-metamyelocytic stage, before the loss of alpha 4 beta 1, at the band stage. Functional studies showed no binding of erythroid progenitor-depleted, CD34+ bone marrow cells to fibronectin. However, protein kinase C activation strongly induced fibronectin binding (68% of the cells). Inhibition experiments with specific antibodies and peptides showed the binding to be mediated by both alpha 4 beta 1 and alpha 5 beta 1. Also, colony-forming cells of granulocytes and macrophages were demonstrated to adhere to fibronectin in an activation-dependent way. During granulocyte colony-stimulating factor-induced in vitro maturation, the activation-dependent fibronectin binding capacity is gradually lost. We conclude that: (1) CD34+ bone marrow cells express alpha 4 beta 1 and alpha 5 beta 1; (2) the expression of alpha 4 beta 1 and alpha 5 beta 1 is differentially expressed during myeloid differentiation; and (3) binding of CD34+ bone marrow cells to fibronectin is activation dependent. 相似文献
609.
High prolactin and low dehydroepiandrosterone sulphate serum levels in patients with severe systemic sclerosis 总被引:2,自引:2,他引:2
Straub RH; Zeuner M; Lock G; Scholmerich J; Lang B 《Rheumatology (Oxford, England)》1997,36(4):426-432
The aim was to determine serum levels of prolactin (PRL) and
dehydroepiandrosterone sulphate (DHEAS), and to demonstrate a link between
PRL or DHEAS and soluble immune mediators in patients with systemic
sclerosis (SSc) with different degrees of disease-induced organ
involvement. Thirty-one patients with SSc were studied to evaluate 18
possible disease manifestations. In the serum, PRL, DHEAS and soluble
immune mediators were determined by ELISA. Compared to SSc with <9
disease manifestations, patients with > or =9 disease manifestations had
higher PRL (P = 0.044), higher soluble interleukin 2 receptor (sIL-2R, P =
0.004) and vascular cell adhesion molecule (sVCAM, P = 0.044), and lower
DHEAS (P = 0.029). PRL (R(Rank) = 0.490, P = 0.003) and DHEAS (R(Rank) =
-0.399, P = 0.013) were significantly correlated with the number of disease
manifestations. The inverse correlation between PRL and DHEAS showed a
trend (P = 0.059). PRL correlated with sIL-2R (R(Rank) = 0.553, P = 0.001)
and sVCAM (R(Rank) = 0.520, P = 0.002). The number of disease
manifestations and sIL-2R correlated significantly (R(Rank) = 0.463, P =
0.006). Psychometric variables to examine the presence of depression were
not measured, but from the general aspect, the patients were not suffering
from major depression which may have influenced our results. In conclusion,
this study demonstrates the close association between DHEAS and,
particularly, PRL and SSc severity and T-lymphocyte mechanisms.
相似文献
610.
Goldman JM; Szydlo R; Horowitz MM; Gale RP; Ash RC; Atkinson K; Dicke KA; Gluckman E; Herzig RH; Marmont A 《Blood》1993,82(7):2235-2238
We analyzed the outcome of 450 HLA-identical sibling bone marrow transplants for chronic myelogenous leukemia (CML) in chronic phase performed between 1985 and 1990 and reported to the International Bone Marrow Transplant Registry (IBMTR). All patients received either hydroxyurea (n = 292) or busulfan (n = 158) to treat their CML before transplant. The median interval between diagnosis and transplant was 10 months (range, 1 to 191). Patients treated with hydroxyurea had a higher probability (95% confidence interval) of leukemia-free survival (LFS) at 3 years than those treated with busulfan (61% [51% to 70%] v 45% [36% to 55%], P < .0003). Probability of LFS was also higher in patients transplanted within 1 year of diagnosis (61% [53 to 68%] v 47% [38% to 57%], P < .001). After adjustment for patient and transplant covariables in a multivariate analysis, prior chemotherapy and duration of disease pretransplant were independently associated with LFS. These data support the use of hydroxyurea rather than busulfan and transplant within 1 year of diagnosis for patients with CML and an HLA-identical sibling. 相似文献