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101.
The effect of folate analogues and vitamin B12 on provision of thymine nucleotides for DNA synthesis in megaloblastic anemia 总被引:2,自引:0,他引:2
The role of vitamin B12 in the folate dependent biosynthesis of thymidine nucleotides is controversial. In an attempt to clarify this, three methods have been used to assess the relative efficacy of vitamin B12 (hydroxocobalamin) and various folate analogues in titrated concentrations at correcting 'de novo' thymidylate synthesis by megaloblastic human marrow cells: (1) The deoxyuridine (dU) suppression test which analyses the reduction in (3H)-thymidine labeling of DNA by unlabeled dU. Marrow cells were also labeled with (6-3H)-dU with assessment of (2) its incorporation into DNA and (3) the accumulation of (6-3H)-deoxyuridine monophosphate (3H-dUMP). The three methods gave similar results. In both, N6-formyl tetrahydrofolate (formyl-FH4) was the most effective agent at correcting thymidylate synthesis in megaloblastic anemia due to vitamin B12 or folate deficiency. Vitamin B12 corrected the lesion in vitamin B12 deficiency but not in folate deficiency. Tetrahydrofolate (FH4) and folic acid were effective in deficiency of vitamin B12 or folate, although in both deficiencies they were less effective than formyl-FH4. Methyl-FH4 was effective in folate deficiency but not in vitamin B12 deficiency. These results confirm the failure of methyl-FH4 utilisation in vitamin B12 deficiency. They suggest that if vitamin B12 is needed in the formylation of FH4, this is a minor role in provision of the correct coenzyme for thymidylate synthesis compared with its major role of provision of FH4 from methyl- FH4. 相似文献
102.
Kriger AG Zviagin AA Korolev SV Zhukov AO Kochatkov AV Bozh'eva EI Ikramov RZ Berelavichus SV Kozlov IA Kolygin AV Akhtanin EA 《Khirurgiia》2011,(7):4-13
Treatment results of 5 patients with unformed intestinal fistulae are represented. High unformed intestinal fistulae are acknowledged to be completely unsuitable for conservative treatment and should be operated on. Complex treatment should include complete parenteral feeding, adequate fecal diversion with the use of aspirational drainage. Surgical treatment must be y the increase of fistula discharge or absence of fistula formation. Low intestinal fistulae should better be surgically dissected after their organization, otherwise urgent surgery is to be performed by complications development, such as purulent leakage into the abdominal cavity or severe wound infection. 相似文献
103.
CZ Zhu JP Mikusa Y Fan PR Hollingsworth M Pai P Chandran AV Daza BB Yao MJ Dart MD Meyer MW Decker GC Hsieh P Honore 《British journal of pharmacology》2009,157(4):645-655
Background and purpose:
Activation of cannabinoid (CB) receptors decreases nociceptive transmission in inflammatory or neuropathic pain states. However, the effects of CB receptor agonists in post-operative pain remain to be investigated. Here, we characterized the anti-allodynic effects of WIN 55,212-2 (WIN) in a rat model of post-operative pain.Experimental approach:
WIN 55,212-2 was characterized in radioligand binding and in vitro functional assays at rat and human CB1 and CB2 receptors. Analgesic activity and site(s) of action of WIN were assessed in the skin incision-induced post-operative pain model in rats; receptor specificity was investigated using selective CB1 and CB2 receptor antagonists.Key results:
WIN 55,212-2 exhibited non-selective affinity and agonist efficacy at human and rat CB1 versus CB2 receptors. Systemic administration of WIN decreased injury-induced mechanical allodynia and these effects were reversed by pretreatment with a CB1 receptor antagonist, but not with a CB2 receptor antagonist, given by systemic, intrathecal and supraspinal routes. In addition, peripheral administration of both CB1 and CB2 antagonists blocked systemic WIN-induced analgesic activity.Conclusions and implications:
Both CB1 and CB2 receptors were involved in the peripheral anti-allodynic effect of systemic WIN in a pre-clinical model of post-operative pain. In contrast, the centrally mediated anti-allodynic activity of systemic WIN is mostly due to the activation of CB1 but not CB2 receptors at both the spinal cord and brain levels. However, the increased potency of WIN following i.c.v. administration suggests that its main site of action is at CB1 receptors in the brain.British Journal of Pharmacology (2009) 157, 645–655; doi:10.1111/j.1476-5381.2009.00184.x; published online 3 April 2009 相似文献104.
105.
MS Chaya AV Kurpad HR Nagendra R Nagarathna 《BMC complementary and alternative medicine》2006,6(1):28-6
Background
Different procedures practiced in yoga have stimulatory or inhibitory effects on the basal metabolic rate when studied acutely. In daily life however, these procedures are usually practiced in combination. The purpose of the present study was to investigate the net change in the basal metabolic rate (BMR) of individuals actively engaging in a combination of yoga practices (asana or yogic postures, meditation and pranayama or breathing exercises) for a minimum period of six months, at a residential yoga education and research center at Bangalore. 相似文献106.
107.
108.
109.
DG Schroeder B. Torún AV Bartlett H. Miracle-McMahill 《Acta paediatrica (Oslo, Norway : 1992)》1997,86(11):1155-1161
A community-based, randomized trial was conducted to evaluate a locally available diet for the management of acute diarrhea ( n = 99 episodes) in 90 Guatemalan children, 4–42 months of age. The Test Diet (TD), a combination of a semi-solid pap (maize flour, black beans, oil) and a liquid gruel, Incaparina (maize flour, cotton seed flour, sugar), in addition to breast-milk and other home foods (group TD, n = 45 episodes) was offered for 14 d and compared to usual home feeding (group HF, n = 54 episodes). Diarrhea episodes after admission were significantly shorter for group TD (median 2. 0 d) than group HF (median 4. 4 d, p = 0. 003) after adjusting for potential confounders. Weight gains did not differ significantly between groups. We conclude that community-based dietary management of acute childhood diarrhea using energy-dense, locally available foods is feasible and may shorten diarrhea duration. This may encourage mothers to follow recommendations for continued feeding during diarrhea in developing country environments. 相似文献
110.
Age-related differences in distractibility and response to methylphenidate in monkeys 总被引:2,自引:0,他引:2
Prendergast MA; Jackson WJ; Terry AV Jr; Kille NJ; Arneric SP; Decker MW; Buccafusco JJ 《Cerebral cortex (New York, N.Y. : 1991)》1998,8(2):164-172
Increased susceptibility to distraction is a symptom of normal aging and
several clinical syndromes, including Alzheimer's disease and attention
deficit disorders. In the present study, aged and young adult macaques were
well-trained to perform an automated delayed matching-to- sample (DMTS)
task which assesses both attention and short-term memory. On 19% of all
trials, a task-relevant distracting stimulus was presented during either
the initial 1 or 3 s of delay intervals (early onset) or the final 1 or 3 s
of delay intervals (late onset). In aged monkeys, both early and late onset
distractors lasting 1 or 3 s impaired delayed recall on trials with the
shortest delay intervals, but did not affect accuracy on trials with long
delay intervals. In contrast, young adult monkeys were impaired only by the
presence of an early onset distractor lasting 3 s. Impairment was selective
for only those trials with the shortest delay intervals. Late onset
distractors were relatively ineffective in producing distractibility in
young adult animals. Methylphenidate (MPH; 0.005-1.0 mg/kg) failed to
reduce distractibility in aged monkeys, producing locomotor abnormalities
and hypophagia at doses ranging from 0.25 to 1.0 mg/kg. In young adult
monkeys, however, distractibility was significantly attenuated by
administration of the 0.125 mg/kg dose. Habituation to the distracting
stimulus (under saline conditions) was assessed throughout the study and
was not evident at any time point of testing. These data indicate that
attention and recall after brief delays are impaired following exposure to
a task-relevant distracting stimulus in both aged and young adult monkeys,
but that aged monkeys are more susceptible to distraction and do not
receive significant benefit from MPH administration.
相似文献