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61.
62.
Heterozygous TGFBR2 mutations in Marfan syndrome 总被引:24,自引:0,他引:24
Mizuguchi T Collod-Beroud G Akiyama T Abifadel M Harada N Morisaki T Allard D Varret M Claustres M Morisaki H Ihara M Kinoshita A Yoshiura K Junien C Kajii T Jondeau G Ohta T Kishino T Furukawa Y Nakamura Y Niikawa N Boileau C Matsumoto N 《Nature genetics》2004,36(8):855-860
Marfan syndrome is an extracellular matrix disorder with cardinal manifestations in the eye, skeleton and cardiovascular systems associated with defects in the gene encoding fibrillin (FBN1) at 15q21.1 (ref. 1). A second type of the disorder (Marfan syndrome type 2; OMIM 154705) is associated with a second locus, MFS2, at 3p25-p24.2 in a large French family (family MS1). Identification of a 3p24.1 chromosomal breakpoint disrupting the gene encoding TGF-beta receptor 2 (TGFBR2) in a Japanese individual with Marfan syndrome led us to consider TGFBR2 as the gene underlying association with Marfan syndrome at the MSF2 locus. The mutation 1524G-->A in TGFBR2 (causing the synonymous amino acid substitution Q508Q) resulted in abnormal splicing and segregated with MFS2 in family MS1. We identified three other missense mutations in four unrelated probands, which led to loss of function of TGF-beta signaling activity on extracellular matrix formation. These results show that heterozygous mutations in TGFBR2, a putative tumor-suppressor gene implicated in several malignancies, are also associated with inherited connective-tissue disorders. 相似文献
63.
Kobasa D Jones SM Shinya K Kash JC Copps J Ebihara H Hatta Y Kim JH Halfmann P Hatta M Feldmann F Alimonti JB Fernando L Li Y Katze MG Feldmann H Kawaoka Y 《Nature》2007,445(7125):319-323
The 1918 influenza pandemic was unusually severe, resulting in about 50 million deaths worldwide. The 1918 virus is also highly pathogenic in mice, and studies have identified a multigenic origin of this virulent phenotype in mice. However, these initial characterizations of the 1918 virus did not address the question of its pathogenic potential in primates. Here we demonstrate that the 1918 virus caused a highly pathogenic respiratory infection in a cynomolgus macaque model that culminated in acute respiratory distress and a fatal outcome. Furthermore, infected animals mounted an immune response, characterized by dysregulation of the antiviral response, that was insufficient for protection, indicating that atypical host innate immune responses may contribute to lethality. The ability of influenza viruses to modulate host immune responses, such as that demonstrated for the avian H5N1 influenza viruses, may be a feature shared by the virulent influenza viruses. 相似文献
64.
Germline KRAS and BRAF mutations in cardio-facio-cutaneous syndrome 总被引:15,自引:0,他引:15
Niihori T Aoki Y Narumi Y Neri G Cavé H Verloes A Okamoto N Hennekam RC Gillessen-Kaesbach G Wieczorek D Kavamura MI Kurosawa K Ohashi H Wilson L Heron D Bonneau D Corona G Kaname T Naritomi K Baumann C Matsumoto N Kato K Kure S Matsubara Y 《Nature genetics》2006,38(3):294-296
Cardio-facio-cutaneous (CFC) syndrome is characterized by a distinctive facial appearance, heart defects and mental retardation. It phenotypically overlaps with Noonan and Costello syndrome, which are caused by mutations in PTPN11 and HRAS, respectively. In 43 individuals with CFC, we identified two heterozygous KRAS mutations in three individuals and eight BRAF mutations in 16 individuals, suggesting that dysregulation of the RAS-RAF-ERK pathway is a common molecular basis for the three related disorders. 相似文献
65.
内蒙古岱海古盐度定量复原初探 总被引:18,自引:1,他引:17
通过分析湖泊表层沉积物中活体介形类(Limnocythere cf。inopinata)壳体的Sr,Ca比值以及湖水的Sr^2+,Ca^2+比值,获取岱海介形类壳体的Sr分配系数Kd(Sr)。利用湖水Sr^2+/Ca^2+值与盐度的相关关系,建立岱海湖水盐度与水介质离子比函数方程。结合岱海沉积钻孔中同种介形类壳体的 Sr,Ca比值,定量恢复湖水的古盐度。 相似文献
66.
67.
Enzymes catalyse specific reactions and are essential for maintaining life. Although some are referred to as being bifunctional, they consist of either two distinct catalytic domains or a single domain that displays promiscuous substrate specificity. Thus, one enzyme active site is generally responsible for one biochemical reaction. In contrast to this conventional concept, archaeal fructose-1,6-bisphosphate (FBP) aldolase/phosphatase (FBPA/P) consists of a single catalytic domain, but catalyses two chemically distinct reactions of gluconeogenesis: (1) the reversible aldol condensation of dihydroxyacetone phosphate (DHAP) and glyceraldehyde-3-phosphate (GA3P) to FBP; (2) the dephosphorylation of FBP to fructose-6-phosphate (F6P). Thus, FBPA/P is fundamentally different from ordinary enzymes whose active sites are responsible for a specific reaction. However, the molecular mechanism by which FBPA/P achieves its unusual bifunctionality remains unknown. Here we report the crystal structure of FBPA/P at 1.5-? resolution in the aldolase form, where a critical lysine residue forms a Schiff base with DHAP. A structural comparison of the aldolase form with a previously determined phosphatase form revealed a dramatic conformational change in the active site, demonstrating that FBPA/P metamorphoses its active-site architecture to exhibit dual activities. Thus, our findings expand the conventional concept that one enzyme catalyses one biochemical reaction. 相似文献
68.
K. Matsumoto M. Shimojo M. Nogawa M. Okudomi 《复旦学报(自然科学版)》2005,44(5):768-769
Enzymatic kinetic resolution of racemic alcohols or esters is known as a useful method for the preparation of optically active secondary alcohols. However, the work-up including the separation of the mixture of the remaining substrate and the resulting compound spend a lot of time and waste much amount of solvents. On the other hand, organic synthesis based on polymer supports has made rapid progress. Although the methodology is potentially useful for the easy separation of compounds obtained by the enzymatic reaction, there have been relatively few reports on enzymatic resolutions of using a polymer so far. We have noticed that using a watersoluble polymer could be suitable for enzymatic transformation. Here, we report the first example of an enzyme-mediated enantioseleetive hydrolysis of poly(ethylene glycol)(PEG)-supported substrates with a carbonate moiety to afford optically active compounds, and the method enables us to achieve the easy separation of the products. See Scheme 1. 相似文献
69.
Shinya Oshita Akikazu Matsumoto 《复旦学报(自然科学版)》2005,44(5):913-914
We reported that layered polymer crystals are obtained by the topochemical polymerization of 1,3-diene monomers and provided as host material for organic intercalation. For intercalation using various long-alkyl amines as the guest species, its reaction behavior, mechanism, characteristics, and potential to application have been clarified. We also succeeded in the synthesis of several host layered polymer crystals with different tacticities and layer structures. We describe here intercalation using various stereoregular poly(muconic acid)s (PMA) and n-alkylamines as the host and guest compounds, respectively. The reaction behavior and the layered structure of the obtained ammonium polymers are discussed from the viewpoint of stereochemical structure of the host polymers. 相似文献
70.
1Introduction
Enzymatic kinetic resolution of racemic alcohols or esters is known as a useful method for the preparation of optically active secondary alcohols. However, the work-up including the separation of the mixture of the remaining substrate and the resulting compound spend a lot of time and waste much amount of solvents. On the other hand, organic synthesis based on polymer supports has made rapid progress. Although the methodology is potentially useful for the easy separation of compounds obtained by the enzymatic reaction, there have been relatively few reports on enzymatic resolutions of using a polymer so far. We have noticed that using a watersoluble polymer could be suitable for enzymatic transformation. Here, we report the first example of an enzyme-mediated enantioselective hydrolysis of poly(ethylene glycol)(PEG)-supported substrates with a carbonate moiety to afford optically active compounds, and the method enables us to achieve the easy separation of the products[1]. See Scheme 1. 相似文献