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Biomedical subjects

B S Liu

Publications and source records attributed to B S Liu.

9 recordsLinked to original sources

[Molecular tagging of a major powdery mildew resistance gene MlG in wheat derived from wild Emmer by using microsatellite marker].

Powdery mildew caused by Erysiphe graminis f. sp. tritici is one of the most important wheat diseases in many regions of the world. Breeding for resistant cultivars has been proved to be an effective and environmentally safe method to control diseases in wheat production. It is necessary to search for more resistance genes for the diversification of resistance genes in wheat breeding. An Isreali wild emmer wheat (Triticum dicoccoides) accession "G-305-M" was found resistant to the prevailing E. graminis f. sp. tritici isolate Race No. 15 in Beijing region. The powdery mildew resistance has been transferred from G-305-M into common wheat by crossing and backcrossing (G-305-M/781//Jing 411* 3). Genetic analysis showed that the resistance was controlled by a single dominant gene at the seedling stage. A segregating BC2F3 family of the cross "G-305-M/781//Jing 411* 3" with 167 plants was chosen for SSR analysis. Totally 96 wheat microsatellite primer pairs were screened, only one primer pair WMS570 could generate polymorphic DNA fragments between the resistant and susceptible plants. After evaluating this polymorphic marker in the segregating population, the microsatellite locus Xgwm570 mapped on chromosome 6AL was found to be linked to the resistance gene, with the estimated genetic distance of 14.9 +/- 3.0 cM. Based on the origin and chromosomal location of the gene, it is suggested that the resistance gene derived from G-305-M should be a novel Pm gene and is temporarily designated MlG.

Chromosome Mapping↗

[A clinical analysis of pupillary membrane formation after intraocular lens implantation].

In 540 cases having undertaken extracapsular cataract extraction and intraocular lens implantation, a pupillary membrane developed in 76 cases, the rate of occurrence being 14%. Generally, the membrane appears on the fifth post-operative day and corticosteroids are effective in its treatment. After treatment no significant sequela is left and the corrected postoperative visual acuity is not affected. The pathogenesis, treatment and prognosis of the pupillary membrane are briefly discussed in the report.

Adolescent↗

Successful healing of a burn injury covering 100% of TBSA and 96% IIIrd degree with inhalation injury.

The authors describe successful healing of a burn injury covering 100% of TBSA with 96% full-thickness skin loss and inhalation injury. The patient was admitted to the burn department of our hospital on September the 4th 1987. He smoothly overcame the shock stage with help of fluid replacement and application of alkaline drugs in large quantities. Early escharectomy and repeated micrografting were performed. The treatment is discussed.

Adult↗

Crystal structure of an engrailed homeodomain-DNA complex at 2.8 A resolution: a framework for understanding homeodomain-DNA interactions.

The crystal structure of a complex containing the engrailed homeodomain and a duplex DNA site has been determined at 2.8 A resolution and refined to a crystallographic R factor of 24.4%. In this complex, two separate regions of the 61 amino acid polypeptide contact a TAAT subsite. An N-terminal arm fits into the minor groove, and the side chains of Arg-3 and Arg-5 make contacts near the 5' end of this "core consensus" binding site. An alpha helix fits into the major groove, and the side chains of IIe-47 and Asn-51 contact base pairs near the 3' end of the TAAT site. This "recognition helix" is part of a structurally conserved helix-turn-helix unit, but these helices are longer than the corresponding helices in the lambda repressor, and the relationship between the helix-turn-helix unit and the DNA is significantly different.

Amino Acid Sequence↗

Combining thermostable mutations increases the stability of lambda repressor.

We have combined three mutations previously shown to stabilize lambda repressor against thermal denaturation. Two of these mutations are in helix 3, where Gly-46 and Gly-48 have been replaced by alanines [Hecht, M. H., et al. (1986) Proteins: Struct., Funct., Genet. 1, 43-46]. The other mutation, which replaces Tyr-88 with cysteine, allows the protein to form an intersubunit disulfide bond [Sauer, R. T., et al. (1986) Biochemistry 25, 5992-5998]. Calorimetric measurements show that the two alanine substitutions stabilize repressor by about 8 degrees C, that the disulfide bond stabilizes repressor by about 8 degrees C, and that the triple mutant is 16 degrees C more stable than wild-type repressor.

Amino Acid Sequence↗

Developing oscillatory flow in a circular pipe: a new solution.

The problem of oscillatory flow in a circular pipe was analyzed by Atabek and associates more than two decades ago. Their formulas for velocity and pressure distributions in developing pipe flows under oscillatory conditions have been often cited. However, the application of these formulas for flow field computations requires a rather complex procedure involving plotting of a set of curves and predetermination of the phase angles. This paper presents a method using the imaginary argument of the Bessel function to solve the Navier-Stokes equations. A different set of solution formulas are obtained. A comparison of the formulas obtained in this paper with those of Atabek shows that the former is considerably simpler and more convenient to use in flow computations. Numerical results computed using this paper's formulas are consistent with Atabek's and with the experimental measurements.

Biomechanical Phenomena↗