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51.
Andrea Harničarová Horáková Gabriela Galiová Soňa Legartová Stanislav Kozubek Pavel Matula Eva Bártová 《Journal of structural biology》2010,169(1):124-133
The epigenetic modification of histones dictates the formation of euchromatin and heterochromatin domains. We studied the effects of a deficiency of histone methyltransferase, SUV39h, and trichostatin A-dependent hyperacetylation on the structural stability of centromeric clusters, called chromocentres. We did not observe the expected disintegration of chromocentres, but both SUV39h deficiency and hyperacetylation in SUV39h+/+ cells induced the re-positioning of chromocentres closer to the nuclear periphery. Conversely, TSA treatment of SUV39h?/? cells re-established normal nuclear radial positioning of chromocentres. This structural re-arrangement was likely caused by several epigenetic events at centromeric heterochromatin. In particular, reciprocal exchanges between H3K9me1, H3K9me2, H3K9me3, DNA methylation, and HP1 protein levels influenced chromocentre nuclear composition. For example, H3K9me1 likely substituted for the function of H3K9me3 in chromocentre nuclear arrangement and compaction. Our results illustrate the important and interchangeable roles of epigenetic marks for chromocentre integrity. Therefore, we propose a model for epigenetic regulation of nuclear stability of centromeric heterochromatin in the mouse genome. 相似文献
52.
Alzheimer’s disease (AD) is characterized by an excessive accumulation of toxic amyloid beta (Aβ) plaques and memory dysfunction. The onset of AD is influenced by age, genetic background, and impaired glucose metabolism in the brain. Several studies have demonstrated that diabetes involving insulin resistance and glucose tolerance could lead to AD, ultimately resulting in cognitive dysfunction. Even though the relationship between diabetes and AD was indicated by significant evidences, the critical mechanisms and metabolic alterations in diabetes induced AD are not clear until now. Recently, iron metabolism has been shown to play multiple roles in the central nervous system (CNS). Iron deficiency and overload are associated with neurodegenerative diseases. Iron binds to Aβ and subsequently regulates Aβ toxicity in the CNS. In addition, previous studies have shown that iron is involved in the aggravation of insulin resistance. Considering these effects of iron metabolism in CNS, we expect that iron metabolism may play crucial roles in diabetic AD brain. Thus, we review the recent evidence regarding the relationship between diabetes-induced AD and iron metabolism. 相似文献
53.
Muhammad Shahid Minhyung Kim Min Young Lee Austin Yeon Sungyong You Hyung L. Kim Jayoung Kim 《Proteomics》2019,19(11)
Metabolic alterations in prostate cancer (PC) are associated with progression and aggressiveness. However, the underlying mechanisms behind PC metabolic functions are unknown. The authors’ group recently reported on the important role of centromere protein F (CENPF), a protein associated with the centromere–kinetochore complex and chromosomal segregation during mitosis, in PC MRI visibility. This study focuses on discerning the role of CENPF in metabolic perturbation in human PC3 cells. A series of bioinformatics analyses shows that CENPF is one gene that is strongly associated with aggressive PC and that its expression is positively correlated with metastasis. By identifying and reconstructing the CENPF network, additional associations with lipid regulation are found. Further untargeted metabolomics analysis using gas chromatography‐time‐of‐flight‐mass spectrometry reveals that silencing of CENPF alters the global metabolic profiles of PC cells and inhibits cell proliferation, which suggests that CENPF may be a critical regulator of PC metabolism. These findings provide useful scientific insights that can be applied in future studies investigating potential targets for PC treatment. 相似文献
54.
55.
Bo Yeon Kim Kwang Sik Lee Mi Ri Sohn Soo Dong Woo Sung Sik Yoo Yeon Ho Je Byung Rae Jin 《Journal of Asia》2012,15(1):114-120
The expression of viral antigens in baculovirus-infected insect cells is often ineffective. As an alternative approach, therefore, we developed the recombinant polyhedra technology, which is an efficient strategy for the production of viral subunit vaccine. Here, we report a strategy for the large-scale production of a pseudorabies virus (PRV) gB or gC in the larvae of a baculovirus-infected silkworm, Bombyx mori. We constructed a recombinant B. mori nucleopolyhedrovirus (BmNPV) that expressed recombinant polyhedra together with the epitope regions of PRV gB or heparin-binding domains of PRV gC. Recombinant BmNPV-PRV-gB or BmNPV-PRV-gC-infected silkworm larvae expressed native polyhedrin and fusion protein that was detected using both anti-polyhedrin and anti-PRV gB or anti-PRV-gC antibodies. Electron and confocal microscopy demonstrated that the recombinant polyhedra contained both the fusion protein and native polyhedrin with a normal morphology and that the recombinant polyhedra contained PRV gB or gC. The yield of gB or gC antigen produced in BmNPV-PRV-gB or BmNPV-PRV-gC-infected silkworm larvae reached 0.69 or 0.46 mg per larva, respectively, at 6 days post-infection. These results demonstrate that the recombinant polyhedra strategy can be used for the large-scale production of PRV gB or gC antigen. 相似文献
56.
Yong-ho Lee Mi Hyang Kown Kwang Joon Kim Eun Young Lee Daham Kim Byung-Wan Lee Eun Seok Kang Bong Soo Cha Hyun Chul Lee 《PloS one》2014,9(9)
Background
Glycated albumin (GA) has been increasingly used as a reliable index for short-term glycemic monitoring, and is inversely associated with β-cell function. Because the pathophysiologic nature of type 2 diabetes (T2D) is characterized by progressive decline in insulin secretion, the aim was to determine whether GA levels were affected by diabetes duration in subjects with T2D.Methods
To minimize the effect of glucose variability on GA, subjects with stably maintained HbA1c levels of <0.5% fluctuation across 6 months of measurements were included. Patients with newly diagnosed T2D (n = 1059) and with duration>1 year (n = 781) were recruited and categorized as New-T2D and Old-T2D, respectively. Biochemical, glycemic, and C-peptide parameters were measured.Results
GA levels were significantly elevated in HbA1c-matched Old-T2D subjects compared to New-T2D subjects. Duration of diabetes was positively correlated with GA, whereas a negative relationship was found with C-peptide increment (ΔC-peptide). Among insulin secretory indices, dynamic parameters such as ΔC-peptide were inversely related to GA (r = −0.42, p<0.001). Multiple linear regression analyses showed that duration of diabetes was associated with GA (standardized β coefficient [STDβ] = 0.05, p<0.001), but not with HbA1c (STDβ = 0.04, p<0.095). This association disappeared after additional adjustment with ΔC-peptide (STDβ = 0.02, p = 0.372), suggesting that β-cell function might be a linking factor of close relationship between duration of diabetes and GA values.Conclusions
The present study showed that GA levels were significantly increased in subjects with longer duration T2D and with decreased insulin secretory function. Additional caution should be taken when interpreting GA values to assess glycemic control status in these individuals. 相似文献57.
Human L-type amino acid transporter 1 (LAT1): characterization of function and expression in tumor cell lines 总被引:15,自引:0,他引:15
Yanagida O Kanai Y Chairoungdua A Kim DK Segawa H Nii T Cha SH Matsuo H Fukushima J Fukasawa Y Tani Y Taketani Y Uchino H Kim JY Inatomi J Okayasu I Miyamoto K Takeda E Goya T Endou H 《Biochimica et biophysica acta》2001,1514(2):291-302
System L is a major nutrient transport system responsible for the transport of large neutral amino acids including several essential amino acids. We previously identified a transporter (L-type amino acid transporter 1: LAT1) subserving system L in C6 rat glioma cells and demonstrated that LAT1 requires 4F2 heavy chain (4F2hc) for its functional expression. Since its oncofetal expression was suggested in the rat liver, it has been proposed that LAT1 plays a critical role in cell growth and proliferation. In the present study, we have examined the function of human LAT1 (hLAT1) and its expression in human tissues and tumor cell lines. When expressed in Xenopus oocytes with human 4F2hc (h4F2hc), hLAT1 transports large neutral amino acids with high affinity (K(m)= approximately 15- approximately 50 microM) and L-glutamine and L-asparagine with low affinity (K(m)= approximately 1.5- approximately 2 mM). hLAT1 also transports D-amino acids such as D-leucine and D-phenylalanine. In addition, we show that hLAT1 accepts an amino acid-related anti-cancer agent melphalan. When loaded intracellularly, L-leucine and L-glutamine but not L-alanine are effluxed by extracellular substrates, confirming that hLAT1 mediates an amino acid exchange. hLAT1 mRNA is highly expressed in the human fetal liver, bone marrow, placenta, testis and brain. We have found that, while all the tumor cell lines examined express hLAT1 messages, the expression of h4F2hc is varied particularly in leukemia cell lines. In Western blot analysis, hLAT1 and h4F2hc have been confirmed to be linked to each other via a disulfide bond in T24 human bladder carcinoma cells. Finally, in in vitro translation, we show that hLAT1 is not a glycosylated protein even though an N-glycosylation site has been predicted in its extracellular loop, consistent with the property of the classical 4F2 light chain. The properties of the hLAT1/h4F2hc complex would support the roles of this transporter in providing cells with essential amino acids for cell growth and cellular responses, and in distributing amino acid-related compounds. 相似文献
58.
Masayuki Adachi Masatomo So Kazumasa Sakurai József Kardos Yuji Goto 《The Journal of biological chemistry》2015,290(29):18134-18145
Although amyloid fibrils and amorphous aggregates are two types of aggregates formed by denatured proteins, their relationship currently remains unclear. We used β2-microglobulin (β2m), a protein responsible for dialysis-related amyloidosis, to clarify the mechanism by which proteins form either amyloid fibrils or amorphous aggregates. When ultrasonication was used to accelerate the spontaneous fibrillation of β2m at pH 2.0, the effects observed depended on ultrasonic power; although stronger ultrasonic power effectively accelerated fibrillation, excessively strong ultrasonic power decreased the amount of fibrils formed, as monitored by thioflavin T fluorescence. An analysis of the products formed indicated that excessively strong ultrasonic power generated fibrillar aggregates that retained β-structures but without high efficiency as seeds. On the other hand, when the spontaneous fibrillation of β2m was induced at higher concentrations of NaCl at pH 2.0 with stirring, amorphous aggregates became more dominant than amyloid fibrils. These apparent complexities in fibrillation were explained comprehensively by a competitive mechanism in which supersaturation-limited reactions competed with supersaturation-unlimited reactions. We link the kinetics of protein aggregation and a conformational phase diagram, in which supersaturation played important roles. 相似文献
59.
So-Yeon Lee Jinho Yu Kang-Mo Ahn Kyung Won Kim Youn Ho Shin Kyung-shin Lee Seo Ah Hong Young-ho Jung Eun Lee Song-I Yang Ju-hee Seo Ji-Won Kwon Byoung-Ju Kim Hyo-Bin Kim Woo-Kyung Kim Dae Jin Song Gwang Cheon Jang Jung Yeon Shim Soo-Young Lee Ja-Young Kwon Suk-Joo Choi Kyung-Ju Lee Hee Jin Park Hye-Sung Won Ho-Sung Yoo Mi-Jin Kang Hyung-Young Kim Soo-Jong Hong 《PloS one》2014,9(5)
Background
Although cesarean delivery and prenatal exposure to antibiotics are likely to affect the gut microbiome in infancy, their effect on the development of atopic dermatitis (AD) in infancy is unclear. The influence of individual genotypes on these relationships is also unclear. To evaluate with a prospective birth cohort study whether cesarean section, prenatal exposure to antibiotics, and susceptible genotypes act additively to promote the development of AD in infancy.Methods
The Cohort for Childhood of Asthma and Allergic Diseases (COCOA) was selected from the general Korean population. A pediatric allergist assessed 412 infants for the presence of AD at 1 year of age. Their cord blood DNA was subjected to interleukin (IL)-13 (rs20541) and cluster-of-differentiation (CD)14 (rs2569190) genotype analysis.Results
The combination of cesarean delivery and prenatal exposure to antibiotics associated significantly and positively with AD (adjusted odds ratio, 5.70; 95% CI, 1.19–27.3). The association between cesarean delivery and AD was significantly modified by parental history of allergic diseases or risk-associated IL-13 (rs20541) and CD14 (rs2569190) genotypes. There was a trend of interaction between IL-13 (rs20541) and delivery mode with respect to the subsequent risk of AD. (P for interaction = 0.039) Infants who were exposed prenatally to antibiotics and were born by cesarean delivery had a lower total microbiota diversity in stool samples at 6 months of age than the control group. As the number of these risk factors increased, the AD risk rose (trend p<0.05).Conclusion
Cesarean delivery and prenatal antibiotic exposure may affect the gut microbiota, which may in turn influence the risk of AD in infants. These relationships may be shaped by the genetic predisposition. 相似文献60.
Bong Jin Kim Kyung Seob Song Hyun-Hee Kong Hee-Jae Cha Meesun Ock 《The Korean journal of parasitology》2014,52(1):85-87
We encountered a patient with heavy Hymenolepis nana infection. The patient was a 44-year-old Korean man who had suffered from chronic hepatitis (type B) for 15 years. A large number of H. nana adult worms were found during colonoscopy that was performed as a part of routine health screening. The parasites were scattered throughout the colon, as well as in the terminal ileum, although the patient was immunocompetent. Based on this study, colonoscopy may be helpful for diagnosis of asymptomatic H. nana infections. 相似文献