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941.
Polge C 《Studies in History and Philosophy of Science Part C: Studies in History and Philosophy of Biological and Biomedical Sciences》2007,38(2):511-520
This paper traces the history of the Animal Research Station, Cambridge from its establishment in 1932 to its closure in 1986. The author worked there for forty years and was Director from 1979. Originally set up as a field station for Cambridge University's School of Agriculture, the Station was expanded after World War II as the Agricultural Research Council's Unit of Animal Reproduction. Beginning with semen and artificial insemination, research at the Station soon embraced superovulation and embryo transfer in farm animals. Many other technologies were also developed here, including IVF in pigs, cloning by nuclear transplantation of early embryonic cells, and the first genetically modified farm animals in Britain. This account recalls the Directors of the Station and their research teams together with details of their pioneering contribution to reproductive biology. 相似文献
942.
Marko-Varga G Ogiwara A Nishimura T Kawamura T Fujii K Kawakami T Kyono Y Tu HK Anyoji H Kanazawa M Akimoto S Hirano T Tsuboi M Nishio K Hada S Jiang H Fukuoka M Nakata K Nishiwaki Y Kunito H Peers IS Harbron CG South MC Higenbottam T Nyberg F Kudoh S Kato H 《Journal of proteome research》2007,6(8):2925-2935
Personalized medicine allows the selection of treatments best suited to an individual patient and disease phenotype. To implement personalized medicine, effective tests predictive of response to treatment or susceptibility to adverse events are needed, and to develop a personalized medicine test, both high quality samples and reliable data are required. We review key features of state-of-the-art proteomic profiling and introduce further analytic developments to build a proteomic toolkit for use in personalized medicine approaches. The combination of novel analytical approaches in proteomic data generation, alignment and comparison permit translation of identified biomarkers into practical assays. We further propose an expanded statistical analysis to understand the sources of variability between individuals in terms of both protein expression and clinical variables and utilize this understanding in a predictive test. 相似文献
943.
Stylar micromorphological diversity of 42 Asteraceae species from Argentina was analysed considering species phylogenetic
membership and some floral reproductive functions (pollen presentation and pollen reception). In particular, the morphology
and organisation of pollen presenter (sweeping hairs) and pollen receptive structures (stigmatic papillae) were described.
Results showed that style morphology of the studied species is far more diverse than the categories previously established
for Asteraceae, and that it is problematic to relate the sweeping-hair arrangement of species to the only three modes of pollen
presentation described for the family, indicating that the hypothesised relationship could be more complex than was formerly
thought. For all species with di- or trimorphic florets, the styles of female florets were more slender and without or with
more reduced sweeping hairs than the styles of hermaphrodite florets, and divergences of sweeping hair arrangements and morphology
were higher among phylogenetically related species. These results suggest that functional aspects of floral morphology seem
to be more important than phylogenetic constraints as selective forces determining stylar pollen presentation structures.
In contrast, stigmatic-area organisation as well as the morphology of stigmatic papillae remain identical between female and
hermaphrodite florets and among phylogenetically related species. Thus, stigmatic papilla morphology seems to be a phylogenetically
constrained character in the studied species.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
944.
Variability and application of the chlorophyll fluorescence emission ratio red/far-red of leaves 总被引:1,自引:0,他引:1
Buschmann C 《Photosynthesis research》2007,92(2):261-271
945.
Two monoclonal antibodies (ADM-1-11 and 79-31 mAbs) were raised against daunomycin (DM) conjugated to bovine serum albumin
via the cross-linker N-(gamma-maleimidobutyryloxy)succinimide. The monoclonal antibodies (mAbs) specifically detected DM as well as its analogs
doxorubicin and epirubicin, but did not react with other anticancer antibiotics, including pepleomycin, mitomycin C, and actinomycin
D. The mAbs reacted strongly with glutaraldehyde-conjugated DM in an enzyme linked immunosorbent assay (ELISA) used as a model
system for immunocytochemistry as well as in appropriately pretreated sections of tissues from animals injected with DM. No
staining occurred in tissues from uninjected animals. In order to perform DM ICC a number of tissue treatment conditions critical
to the detection of low molecular weight substances were employed. Uptake of DM was studied in rats after a single i.v. or
i.p. administration of the drug. In the heart, accumulation of DM occurred in nuclei and in the cytoplasm. In the kidney,
DM immunoreactivity accumulated in all segments of the nephron except for the proximal tubules. Since the proximal tubules
are known to be where a variety of transport systems including P-glycoprotein (Pgp) and organic anion-transporting polypeptides
(OATPs) in drug interactions occur, the absence of DM accumulation in these segments may reflect a transport phenomenon depending
upon such transporters. The availability of methods to study sites of accumulation of DM offers possibilities for understanding
toxic side effects of this drug on the heart and kidney. Moreover, the immunocytochemical methodology developed may prove
useful for the localization of other low molecular weight drugs that can be fixed in situ by glutaraldehyde. 相似文献
946.
Increasing maize seed weight by enhancing the cytoplasmic ADP-glucose pyrophosphorylase activity in transgenic maize plants 总被引:2,自引:1,他引:2
Zhangying Wang Xiaoping Chen Jianhua Wang Tingsong Liu Yan Liu Li Zhao Guoying Wang 《Plant Cell, Tissue and Organ Culture》2007,88(1):83-92
ADP-glucose pyrophosphorylase (AGPase) plays a key role in regulating starch biosynthesis in cereal seeds and is likely the
most important determinant of seed strength. The Escherichia coli mutant glgC gene (glgC16), which encodes a highly active and allosterically insensitive AGPase, was introduced into maize (Zea mays L.) under the control of an endosperm-specific promoter. Developing seeds from transgenic maize plants showed up to 2–4-fold
higher levels of AGPase activity in the presence of 5 mM inorganic phosphate (Pi). Transgenic plants with higher cytoplasmic
AGPase activity under Pi-inhibitory conditions showed increases (13–25%) in seed weight over the untransformed control. In
addition, in all transgenic maize plants, the seeds were fully filled, and the seed number of transgenic plants had no significant
difference compared with that of untransformed control. These results indicate that increasing cytoplasmic AGPase activity
has a marked effect on sink activity and, in turn, seed weight in transgenic maize plants. 相似文献
947.
Is microbial community composition in boreal forest soils determined by pH,C-to-N ratio,the trees,or all three? 总被引:11,自引:0,他引:11
In Fennoscandian boreal forests, soil pH and N supply generally increase downhill as a result of water transport of base cations
and N, respectively. Simultaneously, forest productivity increases, the understory changes from ericaceous dwarf shrubs to
tall herbs; in the soil, fungi decrease whereas bacteria increase. The composition of the soil microbial community is mainly
thought to be controlled by the pH and C-to-N ratio of the substrate. However, the latter also determines the N supply to
plants, the plant community composition, and should also affect plant allocation of C below ground to roots and a major functional
group of microbes, mycorrhizal fungi. We used phospholipid fatty acids (PLFAs) to analyze the potential importance of mycorrhizal
fungi by comparing the microbial community composition in a tree-girdling experiment, where tree belowground C allocation
was terminated, and in a long-term (34 years) N loading experiment, with the shifts across a natural pH and N supply gradient.
Both tree girdling and N loading caused a decline of ca. 45% of the fungal biomarker PLFA 18:2ω6,9, suggesting a common mechanism,
i.e., that N loading caused a decrease in the C supply to ectomycorrhizal fungi just as tree girdling did. The total abundance
of bacterial PLFAs did not respond to tree girdling or to N loading, in which cases the pH (of the mor layer) did not change
appreciably, but bacterial PLFAs increased considerably when pH increased across the natural gradient. Fungal biomass was
high only in acid soil (pH < 4.1) with a high C-to-N ratio (>38). According to a principal component analysis, the soil C-to-N
ratio was as good as predictor of microbial community structure as pH. Our study thus indicated the soil C-to-N ratio, and
the response of trees to this ratio, as important factors that together with soil pH influence soil microbial community composition. 相似文献
948.
Lundström P Teilum K Carstensen T Bezsonova I Wiesner S Hansen DF Religa TL Akke M Kay LE 《Journal of biomolecular NMR》2007,38(3):199-212
A simple labeling approach is presented based on protein expression in [1-13C]- or [2-13C]-glucose containing media that produces molecules enriched at methyl carbon positions or backbone Cα sites, respectively. All of the methyl groups, with the exception of Thr and Ile(δ1) are produced with isolated 13C spins (i.e., no 13C–13C one bond couplings), facilitating studies of dynamics through the use of spin-spin relaxation experiments without artifacts
introduced by evolution due to large homonuclear scalar couplings. Carbon-α sites are labeled without concomitant labeling
at Cβ positions for 17 of the common 20 amino acids and there are no cases for which 13Cα−13CO spin pairs are observed. A large number of probes are thus available for the study of protein dynamics with the results
obtained complimenting those from more traditional backbone 15N studies. The utility of the labeling is established by recording 13C R
1ρ and CPMG-based experiments on a number of different protein systems. 相似文献
949.
This paper reports the characterization of an alkaline phosphatase (AP) from an aerobic hyperthermophilic Archaeon Aeropyrum pernix K1. The native AP was purified into homogeneity. The enzyme is predicted as a homodimeric structure with a native molecular
mass of about 75 kDa and monomer of about 40 kDa. Apparent optimum pH and temperature were estimated at 10.0 and above 95°C,
respectively. Magnesium ion increased both the stability and the activity of the enzyme. A. pernix AP has been demonstrated as a very thermostable AP, retaining about 76% of its activity after being incubated at 90°C for
5.5 h and 67% of its activity after being incubated at 100°C for 2.5 h, respectively, under the presence of Mg(II). Enzyme
activity was increased in addition of exogenous Mg(II), Ca(II), Zn(II), and Co(II). 相似文献
950.
Lian Pin Koh 《Biodiversity and Conservation》2007,16(13):3935-3938
Here, I report on how forest area in Southeast Asia has changed for different types of forest and across different countries
between the periods of 1990–2000 and 2000–2005. The loss of old growth forests has accelerated in Indonesia, Cambodia and
Vietnam but have ceased in Thailand, Malaysia, Laos and the Philippines. Secondary forests continue to be lost in Malaysia,
Cambodia, Laos, Myanmar, Indonesia, Thailand and the Philippines. Plantation forests have increased in area by 25.0% from
1990 to 2005 but still comprise only 6.2% of the total forest area in Southeast Asia. Overall, the loss of native forests
(old growth and secondary forests) has slowed down in Thailand, the Philippines and Brunei but has worsened in Laos, Myanmar,
Indonesia, Malaysia and Cambodia. 相似文献