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The association of circulating endotoxin with the development of the adult respiratory distress syndrome 总被引:6,自引:0,他引:6
P E Parsons G S Worthen E E Moore R M Tate P M Henson 《The American review of respiratory disease》1989,140(2):294-301
Despite extensive investigation, the pathogenesis of the adult respiratory distress syndrome (ARDS) remains uncertain. As yet, there is no clear explanation of why some patients at risk for ARDS develop the syndrome, whereas others do not. Neutrophils and complement fragments have been implicated in the acute lung injury, but it is clear from published data that evidence of complement activation alone predicts neither the development nor the severity of ARDS. We investigated whether the combination of endotoxin, a leukocyte-priming agent, and complement fragments, leukocyte-stimulating agents, was associated with the development of ARDS. Ninety-eight patients were identified as being either at risk for the development of ARDS or having ARDS, and serial blood samples were obtained. There was no correlation between C5 fragments and the development of ARDS. C3 fragment levels were increased in 89% of the patients with ARDS, but they were also increased in 62% of patients at risk. Endotoxin was detected in 74% of the plasma samples obtained from patients at risk who subsequent developed ARDS and in 64% of the plasma samples obtained from the patients with ARDS. In contrast, only 22% of the plasma samples obtained from the patients at risk who did not develop ARDS had measurable endotoxin. We suggest that the combination of endotoxin and complement fragments may be one mechanism involved in the development of ARDS. 相似文献
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Breuer J.; Moniz C.; Baldwin D.; Parsons V. 《Nephrology, dialysis, transplantation》1987,2(5):347-350
The effect of oral magnesium carbonate aluminium hydroxide onserum ionised calcium, total calcium, aluminium and magnesium,was assessed in 31 patients with chronic renal failure, duringand after one haemodialysis. The behaviour of ionised calcium and total calcium was the samein both groups. Each showed a slight fall during dialysis, whichwas not significant. Serum total calcium was 0.20.3 mmol/l(0.81.2 mg/dl) greater throughout the period of dialysisin the group taking aluminium hydroxide. Serum magnesium andaluminium were both lower in the group treated with magnesiumcarbonate. In the group taking magnesium carbonate, serum magnesium concentrationsfell markedly during dialysis, but otherwise were maintainedwithin the reference range by the use of a magnesium-free dialysate.These results show the effectiveness of magnesium carbonateoral phosphate-binding agents and zero magnesium dialysate inreducing serum aluminium without affecting the behaviour ofserum calcium fractions during dialysis. 相似文献
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J Halbrecht C A Carlstedt J R Parsons D A Grande 《Clinical orthopaedics and related research》1990,(259):245-255
Growth hormone has chondrogenic affects on normal as well as on damaged articular cartilage. In this study, the influence of growth hormone is investigated on early degenerative changes in the articular cartilage in 72 New Zealand white rabbits. Cartilage lesions were created in femoral condyles using an immobilization model. Cartilage damage was assessed using biochemical, histologic, and biomechanical criteria. Growth hormone had no influence on prevention of immobilization abnormalities but had a significant affect on healing of established lesions. 相似文献
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C. L. Parsons 《World journal of urology》1994,12(1):38-42
Summary Investigations into the antibacterial defense mechanisms of the urinary tract revealed an important function for cell surface glycosaminoglycans (GAG), that of a generalized antiadherent activity. This activity was found to prevent bacterial, protein, and ionic adherence to the cell membrane. A model was developed to explain mechanically the activity of sulfated polysaccharides at the bladder surface. The model predicted injurious effects of quaternary amines and also that the mucus would be the so-called blood-urine barrier. It also led to the hypothesis that exogenous polysaccharides may be important in treating bladder disease such as infection and interstitial cystitis. For the first clinical test of these concepts, a polysaccharide was employed in several double-blind studies and was shown to ameliorate significantly the symptoms of interstitial cystitis. These discoveries suggest new methods to manipulate the microenvironment between the transitional cell surface and the urine, leading to novel therapies in regulating disease of the genitourinary tract. They also stress the importance of understanding the mechanisms by which GAGs exert their effect in the urinary tract and how they are produced, maintained, and even inactivated (e.g., by urinary substances such as protamine).Supported by the Medical Research Service of the Veterans Administration, Urological Research and Education Foundation, and by National Institutes of Health grant R01DK39239. 相似文献
7.
Darren S Parsons David A Reaveley Darrell V Pavitt Madhukar Misra Edwina A Brown 《Nephrology, dialysis, transplantation》2003,18(9):1848-1853
BACKGROUND: Studies have reported an increase in median Lipoprotein (Lp) (a) in patients with high molecular weight (HMW) apolipoprotein (apo) (a) isoforms and renal impairment. Some studies identify Lp (a) levels as a risk factor for vascular disease in renal failure whilst others have demonstrated an association with apo (a) isoform type and vascular disease. METHODS: A total of 239 patients at end-stage renal failure (ESRF) were studied prior to the initiation of dialysis. Blood was taken for Lp (a) levels and apo (a) isoforms. Clinical vascular disease (CVD) was assessed on the basis of clinical history and Rose questionnaire. The control group for Lp (a) levels consisted of 228 healthy volunteers. RESULTS: Despite a higher median Lp (a) level in those with HMW isoforms, 30% of patients had Lp (a) levels <10 mg/dl. Overall, 49% patients were identified as having CVD. Diabetes, smoking history and Lp (a) levels were significantly associated with CVD in logistic regression analysis, although when patients with low molecular weight (LMW) and HMW isoforms were analysed separately, Lp (a) levels were not significantly associated with CVD in those with LMW isoforms. The rates of CVD in those with HMW isoform and low Lp (a) levels were significantly lower than those with HMW isoforms and elevated Lp (a) levels, 34 vs 57% (P < 0.01). CONCLUSIONS: Although median Lp (a) levels in those patients at ESRF with HMW isoforms are higher than controls, in a third of such patients Lp (a) levels remain relatively low. These patients have lower rates of CVD than those with high levels of Lp (a). 相似文献
8.
Functional and structural characteristics of the glycosaminoglycans of the bladder luminal surface 总被引:7,自引:0,他引:7
The glycosaminoglycan layer of bladder has been proposed to play a crucial role in protecting the bladder from harmful substances in urine. Rats were partially cystectomized to determine whether bladder glycosaminoglycans are routinely eluted from the bladder surface in detectable quantities. Cystectomy produced no detectable qualitative or quantitative changes in excreted GAG thereby showing that most urinary glycosaminoglycan originates in the kidney and not from the bladder. Damaging the glycosaminoglycan layer by a dilute acid wash, however, leads to a consistent decrease in the output of urinary GAG which recovers to normal at the same rate as the layer regenerates. This suggests that the newly exposed sites tightly bind urinary GAG. We suggest that such binding may be a component of the normal physiological defense mechanism of the bladder. The bladder glycosaminoglycan layer was isolated, dilute acid being used to elute ionically-bound material and brief trypsinization to elute intercalated proteoglycans from the luminal surface. The GAG from the luminal surface, which was present at a density of one chain per 50 nm.2 of bladder surface, was quite different in composition from that isolated from the whole bladder. 相似文献
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Positive, negative, unknown: assumptions of HIV status among HIV-positive men who have sex with men.
Jeffrey T Parsons Joseph Severino Jose Nanin Joseph C Punzalan Kirk von Sternberg Whitney Missildine David Frost 《AIDS education and prevention》2006,18(2):139-149
Serosorting (i.e., engaging in unprotected sex with partners known to be of the same serostatus) can be a difficult process for men who have sex with men (MSM) who frequently make assumptions about their partners' serostatus. This process can be further complicated by a partner's dishonesty as well as other individual and contextual factors. The present study specifically examined how assumptions of serostatus made about unknown serostatus partners impact on the sexual behavior of 110 alcohol-abusing HIV-positive MSM. Although previous research has shown that HIV-positive MSM are more likely to serosort with other known HIV-positive men than with known HIV-negative men, our data suggest that unprotected sex behavior may not be specifically driven by whether or not they made assumptions of seroconcordance or serodiscordance. The types of assumptions these HIV-positive MSM made about their unknown status sexual partners and the basis for such assumptions were also examined. Owing to the ambiguities involved in assumptions of a partner's serostatus in sexual encounters, the 'unknown status' partner category is analytically distinct from 'known status' categories, and needs to be more fully explored because of its impact on perceived serosorting, rather than actual serosorting, among HIV-positive men. 相似文献