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At least 811 records · Page 45Linked to original sources
PubMed2004

[Principal component analysis of Y-chromosome haplotype distribution in 18 ethnic groups in Yunnan Province].

Based on the historical records, 18 of the 26 ethnic groups in Yunnan Province are the descendant populations of three ancient tribes, Bai-Yue, Bai-Pu and Di-Qiang, linguistically belonging to the Daic, Austro-Asiatic and Tibeto-Burman, respectively. In order to trace the origins of these native ethnic groups, a total of 13 East Asian specific Y-chromosome biallelic markers were used to study the genetic structure of 20 local populations covering all the 18 ethnic groups in Yunnan Province. Haplotypes were analysis by PCR-RFLP method. Our results showed that H11 and H12 were the predominant haplotypes in the descendant populations of Bai-Yue tribe. H5, H6 and H8 were the dominant haplotypes in Di-Qiang descendants, and the frequencies of H6, H8 and H11 were very high in the descendant populations of Bai-Pu. To investigate relationships among 20 populations, a three dimensional PC analysis were performed based on the distribution of the 13 haplotypes. All populations were divided into two clusters in the PC plot. The first cluster was mainly composed by the descendant populations of Bai-Yue, and the second one was mainly composed by the descendants of Di-Qiang tribe. This result indicated that Bai-Yue and Di-Qiang's paternal lineage had different origins, which was in agreement with the historical documents and linguistic classification.

Asian People↗
PubMed2004

Fourier transform ion cyclotron resonance mass spectrometry of principal components in oilsands naphthenic acids.

Naphthenic acids present formidable challenges for the petroleum industry and are a growing concern in the aquatic environment. For example, these acids are responsible for corrosion of refinery equipment, leading to the incurrence of additional costs to the consumer, and are toxic to aquatic wildlife, making disposal and remediation of contaminated waters and sediments a significant problem. The detection and characterization of naphthenic acids is therefore of considerable importance. Fourier transform ion cyclotron resonance mass spectrometry is presented as a technique with inherently ultra-high mass accuracy and resolution, affording unequivocal assignments. The suitability of the technique for environmental applications is demonstrated to characterize two different commercial mixtures of naphthenic acids and one oilsands tailings pond sample.

Carboxylic Acids↗
PubMed1989

[Changes in the mass of the principal components of the body and classification of the severity of lipid-protein insufficiency in patients with burns].

On the basis of studying the dynamics of losses in the reserve fat and active body mass during a catabolic phase of the burn disease, in 124 sufferers with the burns of 5 to 80% of the body surface, a classification of the severity degree of lipido-protein deficiency, which distinguishes a compensated, subcompensated and decompensated grade and subdivides the latter into the reversible and irreversible forms, is suggested. The classification permits to assess more objectively the severity of the state and prognosis in burned patients, and as well to define purposefully the methods for correction of the revealed disorders.

Adult↗
PubMedDate not supplied

[Evaluation of the probability of failure-free performance of the principal components of flexible endoscopes].

Reliability of flexible endoscopes is one of the most important characteristics. The reliability of these devices should be evaluated at the development and design stages and after they have been assembled. The proposed experimental and theoretical methods make it possible to evaluate the failure-free performance time expressed in the turn cycles of the distal end curve control knob.

Endoscopes↗