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1.
Volatile smelling compounds of freezed egg white, freshness of which was kept by freezed storage, were collected by steam-distillation. After DNP-hydrazones of volatile carbonyl compounds were separated into four classes by column chromatography, DNP-hydrazones contained in each class were separated by thin layer chromatography. Rf and melting point of recrystalized compounds were compared with those of authentic compounds. Volatile basic compounds were collected as hydrochlorides and detected by paper and thin layer chromatography.

Acetone, acetaldehyde, formaldehyde, 2-pentanone, 2-butanone diacetyl except two unknown compounds as volatile carbonyl compounds, and ammonia, methylamine, dime-thylamine and putrescine as volatile basic compounds were tentatively identified.

Correlations between these compounds and smell of freezed egg white were discussed.  相似文献   

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An inexpensive and easily automated flow injection method for determination of urea in cow’s milk was evaluated. Urea is hydrolysed by urease and in a gas diffusion cell the ammonia formed passes a membrane into an indicator solution. The resulting colour change of the indicator is measured at 590 nm. The repeatability of the analysis, expressed as the coefficient of variation (C.V.), was between 0.5 and 1.2%. Measured (y) and expected (x) milk urea concentrations after addition of known amounts of urea were related according to the equation y = 1.00× – 0.12 with a C.V. for the regression of 1.8%. Recommended amounts (0.02 %) of the preservative bronopol (2-bromo-2-nitropropane-1,3-diol) added to the milk did not affect the results (P > 0.05).  相似文献   

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The name of Natal’ya Nikolaevna Traugott is closely associated with the history of human higher nervous activity studies in Russia. Destiny gifted to N.N. Traugott the opportunity to communicate with many outstanding scientists; she regularly attended the “Pavlov Wednesdays”, took part in V.M. Bechterev’s clinical discussions, visited L.S. Vygotskii’s lectures on the problems of children higher psychic functions development. For many years N.N. Traugott had a professional relationship with A.R. Luriya and his colleagues, at the suggestion of L.A. Orbeli she had headed the laboratory of pathology of higher nervous function from the beginning of 1956. The paramount importance for the development of new directions in evolutionary physiology had N.N. Traugott’s works on the principles of cortical dysfunction in different psychopathological conditions and her recommendations aimed at a strategy for individual corrections of speech in children.  相似文献   

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A cosmid library and physical maps of mitochondrial DNA (mtDNA) from a liverwort, Marchantia polymorpha, were constructed using the cosmid clones. Electrophoresis profile and the physical maps indicated that the liverwort mtDNA was approximately 183 kb long, the smallest among plant mtDNAs, and that it consisted of a single circular molecule. Southern hybridization analysis showed that genes typical to the mitochondrial genome existed in a single copy, and also that there was no incorporation of chloroplast DNA fragments into the mitochondrial genome.  相似文献   

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Kaev  A. M. 《Journal of Ichthyology》2019,59(6):885-894
Journal of Ichthyology - Data characterizing the number of individual generations of pink salmon Oncorhynchus gorbuscha (the volume of harvest, entry of spawners into the rivers, and subsequent...  相似文献   

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The paper describes one of the central areas of research of Professor Natal’ya N. Traugott, a famous Russian neurophysiologist. In particular, Prof. Traugott identified the general neurophysiological mechanisms responsible for speech disorders in children with alalia and in adults with aphasia caused by focal brain lesions. Physiological experiments showed that both sensory alalia in children and sensory aphasia in adults are associated with the deficiency of auditory analyzer; such deficiency leads to disorders in the formation of conditional reactions to sounds and sound complexes. Moreover, a general development pattern was identified in the ontogeny of interaction of signal systems and in the degradation of such interaction caused by the lesions of particular analyzers. This finding of Prof. Traugott is very important in both theory of cerebral speech mechanisms and speech therapy practices aimed at speech system development and rehabilitation following cerebral dysfunctions.  相似文献   

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Flies make up more than 10% of the planetary biota and our well-being depends on how we manage our coexistence with flies. Storing and accessing relevant knowledge about flies is intimately connected with using correct names, and Systema Dipterorum provides a single authoritative classification for flies developed by consensus among contributors. The 160,000 species of flies currently known are distributed among 160 recent families and some 12,000 genera, which with their synonyms encompass a total of more than a quarter of a million names. These names and their associated classification are shared with relevant global solutions. Sherborn appears to have done remarkably well indexing Diptera names with an overall error rate estimated to be close to 1%.  相似文献   

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Background

Alzheimer disease (AD) is a progressive neurodegenerative disease that destroys memory and cognitive skills. AD is characterized by the presence of two types of neuropathological hallmarks: extracellular plaques consisting of amyloid β-peptides and intracellular neurofibrillary tangles of hyperphosphorylated tau proteins. The disease affects 5 million people in the United States and 44 million world-wide. Currently there is no drug that can cure, stop or even slow the progression of the disease. If no cure is found, by 2050 the number of alzheimer’s patients in the U.S. will reach 15 million and the cost of caring for them will exceed $ 1 trillion annually.

Results

The present paper develops a mathematical model of AD that includes neurons, astrocytes, microglias and peripheral macrophages, as well as amyloid β aggregation and hyperphosphorylated tau proteins. The model is represented by a system of partial differential equations. The model is used to simulate the effect of drugs that either failed in clinical trials, or are currently in clinical trials.

Conclusions

Based on these simulations it is suggested that combined therapy with TNF- α inhibitor and anti amyloid β could yield significant efficacy in slowing the progression of AD.
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The objective of this study was to use pyrosequencing of the 16S rRNA genes to describe the microbial diversity of bovine milk samples derived from clinically unaffected quarters across a range of somatic cell counts (SCC) values or from clinical mastitis, culture negative quarters. The obtained microbiota profiles were used to distinguish healthy, subclinically and clinically affected quarters. Two dairy farms were used for the collection of milk samples. A total of 177 samples were used. Fifty samples derived from healthy, culture negative quarters with a SCC of less than 20,000 cells/ml (group 1); 34 samples derived from healthy, culture negative quarters, with a SCC ranging from 21,000 to 50,000 cells/ml (group 2); 26 samples derived from healthy, culture negative quarters with a SCC greater than 50,000 cells/ml (group 3); 34 samples derived from healthy, culture positive quarters, with a SCC greater than 400,000 (group 4, subclinical); and 33 samples derived from clinical mastitis, culture negative quarters (group 5, clinical). Bacterial DNA was isolated from these samples and the 16S rRNA genes were individually amplified and pyrosequenced. All samples analyzed revealed great microbial diversity. Four bacterial genera were present in every sample obtained from healthy quarters (Faecalibacterium spp., unclassified Lachnospiraceae, Propionibacterium spp. and Aeribacillus spp.). Discriminant analysis models showed that samples derived from healthy quarters were easily discriminated based on their microbiota profiles from samples derived from clinical mastitis, culture negative quarters; that was also the case for samples obtained from different farms. Staphylococcus spp. and Streptococcus spp. were among the most prevalent genera in all groups while a general multivariable linear model revealed that Sphingobacterium and Streptococcus prevalences were associated with increased 10 log SCC. Conversely, Nocardiodes and Paenibacillus were negatively correlated, and a higher percentage of the genera was associated with a lower 10 log SCC.  相似文献   

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