Factors affecting the ammonia content in the air surrounding a broiler farm     

K. von Bobrutzki  H.-J. Müller  D. Scherer   《Biosystems Engineering》2011,108(4):322-333

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Diethylstilboestrol—historical background and current regulatory status     

SW PAGE 《Australian veterinary journal》1991,68(7):224-225

Diethylstilboestrol is a non-steroidal orally active oestrogen that in the past has been widely used in a variety of conditions in both medical and veterinary fields. In recognition of potential systemic availability to man of DES in the tissues of treated food-producing animals, together with an understanding of the potential teratogenic and carcinogenic toxicity of DES in man, the veterinary use of DES has been restricted to oral use in small animals only. Use of DES is prohibited in all food-producing animals.  相似文献   

Ein Beitrag zum Eisen/Phosphat-Antagonismus     

H. W. Scherer  W. Hfner 《植物养料与土壤学杂志》1980,143(6):645-651

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Murine MHC polymorphism and T cell specificities   总被引：10，自引：0，他引：10  

S Roy  M T Scherer  T J Briner  J A Smith  M L Gefter 《Science (New York, N.Y.)》1989,244(4904):572-575

The major histocompatibility complex (MHC) genes are polymorphic in mouse and man. The products of these genes are receptors for peptides, which while bound, are displayed to T lymphocytes. When bound peptides from antigens are recognized by T lymphocytes, an immune response is initiated against the antigens. This study assessed the relation of the polymorphic MHC molecules to their peptide specificity. The results indicate that although an individual of the species has a limited ability to recognize antigens, the species as a whole has broad reactivity. This rationalizes the extreme polymorphism observed.  相似文献   

Science education. Educating future scientists     

Sung NS  Gordon JI  Rose GD  Getzoff ED  Kron SJ  Mumford D  Onuchic JN  Scherer NF  Sumners DL  Kopell NJ 《Science (New York, N.Y.)》2003,301(5639):1485

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Twin matter waves for interferometry beyond the classical limit     

Lücke B  Scherer M  Kruse J  Pezzé L  Deuretzbacher F  Hyllus P  Topic O  Peise J  Ertmer W  Arlt J  Santos L  Smerzi A  Klempt C 《Science (New York, N.Y.)》2011,334(6057):773-776

Interferometers with atomic ensembles are an integral part of modern precision metrology. However, these interferometers are fundamentally restricted by the shot noise limit, which can only be overcome by creating quantum entanglement among the atoms. We used spin dynamics in Bose-Einstein condensates to create large ensembles of up to 10(4) pair-correlated atoms with an interferometric sensitivity -1.61(-1.1)(+0.98) decibels beyond the shot noise limit. Our proof-of-principle results point the way toward a new generation of atom interferometers.  相似文献   

有机肥活化土壤中磷的微生物学机理     

章永松  罗安程  孙羲 《浙江大学学报(农业与生命科学版)》1994,(3)

在好气条件下，猪粪和纤维素对两种水稻土中的磷均能起活化作用，嫌气条件下，尽管猪粪和纤维素均能克服因嫌气而使土壤微生物数量的减少，但促进土壤固磷成为主要矛盾，因而显著降低土壤有效磷。通过微生物对难溶性Ｃａ＿３（ＰＯ４）＿２的溶磷量及培养基总酸度的测定，发现这些微生物具有转化难溶性磷为可溶性磷的能力，属溶磷微生物并有致酸作用。经相关分析，土壤中活化的磷量、微生物数量、培养基中的溶磷量和总酸度之间均存在看显著或极显著的相关关系，其中以总酸度与其它变量间的关系最好。因此，在好气条件下有机肥活化土壤中磷的机理可描述为：有机肥促进土壤微生物增长→微生物对其生长的局部位置的土壤起酸化作用→酸溶解难溶性磷为可溶性磷。  相似文献   

High deleterious genomic mutation rate in stationary phase of Escherichia coli     

Loewe L  Textor V  Scherer S 《Science (New York, N.Y.)》2003,302(5650):1558-1560

In natural habitats, bacteria spend most of their time in some form of growth arrest. Little is known about deleterious mutations in such stages, and consequently there is limited understanding of what evolutionary events occur. In a deleterious mutation accumulation experiment in prolonged stationary phase of Escherichia coli, about 0.03 slightly deleterious mutations were observed per genome per day. This is over an order of magnitude higher than extrapolations from fast-growing cells, but in line with inferences from observations in adaptive stationary phase mutation experiments. These findings may affect understanding of bacterial evolution and the emergence of bacterial pathogenicity.  相似文献   

Relative impact of nucleotide and copy number variation on gene expression phenotypes     

Stranger BE  Forrest MS  Dunning M  Ingle CE  Beazley C  Thorne N  Redon R  Bird CP  de Grassi A  Lee C  Tyler-Smith C  Carter N  Scherer SW  Tavaré S  Deloukas P  Hurles ME  Dermitzakis ET 《Science (New York, N.Y.)》2007,315(5813):848-853

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Mechanisms of fixation and release of ammonium in paddy soils after flooding III. Effect of the oxidation state of octahedral Fe on ammonium fixation     

Heinrich W. Scherer  Yongsong Zhang 《植物养料与土壤学杂志》2002,165(2):185-189

An experiment with two typical paddy soils from China and two clay minerals was conducted to study the effect of reduction of octahedral Fe^III on fixation of NH₄⁺ ions. Reduction of octahedral Fe^III was achieved by treating soils and clay minerals with dithionite‐citrate‐bicarbonate (DCB) followed by dialyzing the samples under oxygen free conditions. Reduction of Fe^III increased the negative charge of interlayers and resulted in a significantly higher ammonium fixation. Close positive correlations were found between the Fe²⁺ concentration or the ratio of Fe²⁺/Fe³⁺ and non‐exchangeable NH₄⁺‐N. Therefore, it is concluded that the reduction of octahedral Fe induced by flooding is one of the important prerequisites for the pronounced ammonium fixation in flooded soils. However, the relation between ΔFe²⁺ and Δfix‐N was not stoichiometric.  相似文献