David W. Johnson

Bio: David W. Johnson is an academic researcher from University of Queensland. The author has contributed to research in topics: Peritoneal dialysis & Kidney disease. The author has an hindex of 160, co-authored 2714 publications receiving 140778 citations. Previous affiliations of David W. Johnson include Minnesota Department of Transportation & Open University.

Multiplying the serum aminotransferase by the acetaminophen concentration to predict toxicity following overdose

Abstract: Context. The first available predictors of hepatic injury following acetaminophen (APAP) overdose are the serum APAP and aminotransferases [AT, i.e., aspartate (AST) aminotransferase or alanine (ALT) aminotransferase]. Objective. We describe the initial value, rate of change, and interrelationship between these biomarkers in patients who develop hepatotoxicity despite treatment following acute overdose. A new parameter, the APAP × AT multiplication product, is proposed for early risk stratification. Methods. We conducted a descriptive study of individuals selected from a multicenter retrospective cohort of patients hospitalized for APAP poisoning. We selected those acute APAP overdose patients who subsequently developed AT > 1,000 IU/L. Rising serum AT values were compared to simultaneously measured (or estimated) falling serum APAP. The APAP × AT was expressed relative to initiation of acetylcysteine therapy and grouped by time to meeting hepatotoxicity criteria. Results. In the 94 cases studied, serum ...

In-plane thermal and thermoelectric properties of misfit-layered [(PbSe)0.99]x(WSe2)x superlattice thin films

Abstract: The in-plane thermal conductivity is measured to be three times lower in misfit-layered [(PbSe)0.99]x(WSe2)x superlattice thin films than disordered-layered WSe2 because of interface scattering despite a higher cross-plane value in the former than the latter. While having little effect on the in-plane thermal conductivity, annealing the p-type [(PbSe)0.99]2(WSe2)2 films in Se increases the in-plane Seebeck coefficient and electrical conductivity because of decreased defect and hole concentrations. Increasing interface density of the annealed films by decreasing x from 4 to 2 has weak influence on the in-plane thermal conductivity but increases the Seebeck coefficient and decreases the room-temperature electrical conductivity.

Different Cooperative Learning Procedures and Cross-Handicap Relationships

Abstract: The effects of different levels of cooperation on cross-handicap interaction were Compared in two studies. In the first study 72 sixth-grade students were randomly assigned to three conditions (cooperative controversy, cooperative debate, and individualistic) stratifying for sex, ability level, and handicap. They participated in the study for 55 minutes a day for 11 instructional days. In the second study, 51 fourth-grade students were randomly assigned to two conditions (intergroup cooperation and intergroup competition) stratifying for sex, ability, and handicap. They participated in the study for 55 minutes a day for 10 instructional days. An Activity Report Scale was given to students to determine who they interacted with in structured class activities, unstructured class activities, school activities outside of class, and activities in the home. The results indicated that pure cooperation promoted more frequent cross-handicap interaction than did a mixture of cooperation and competition. The interact...

Single-dose antibiotic treatment of asymptomatic gonorrhea in hospitalized women.

Abstract: Single-dose treatment of asymptomatic gonorrhea was studied in 396 Filipino women hospitalized to prevent reinfections. Endocervical cultures were obtained for six days after treatment to detect failures. Failure rates of 13 to 44 per cent were seen with varying doses of a parenteral penicillin G preparation given without probenecid. No failures occurred in 80 patients given 6,000,000 units of parenteral penicillin G with probenecid, or in 108 patients given 3.5 g of ampicillin orally with or without probenecid. These two regimens with probenecid and another with tetracycline were then compared in a prospective program of treatment. After one year, resistance of isolates of Neisseria gonorrhoeae to penicillin and ampicillin was unchanged, but over one third of isolates became resistant to 2 μg per milliliter of tetracycline. The use of penicillin G or of ampicillin, in association with probenecid, is recommended for treatment of women who are infected but have neither acute perineal discomfort no...

Designed Synthesis, Structure, and Properties of a Family of Ferecrystalline Compounds [(PbSe)1.00]m(MoSe2)n

Abstract: The targeted synthesis of multiple compounds with specific controlled nanostructures and identical composition is a grand challenge in materials chemistry. We report the synthesis of the new metastable compounds [(PbSe)1.00]m(MoSe2)n using precursors each designed to self-assemble into a specific compound. To form a compound with specific values for m and n, the number of atoms within each deposited elemental layer was carefully controlled to provide the correct absolute number of atoms to form complete layers of each component structural unit. On low-temperature annealing, these structures self-assemble with a specific crystallographic orientation between the component structural units with atomically abrupt interfaces. There is rotational disorder between the component structural units and between MoSe2 basal plane units within the MoSe2 layers themselves. The lead selenide constituent has a distorted rock salt structure exactly m bilayers thick leading to peaks in the off-axis diffraction pattern as a ...

Initial sequencing and analysis of the human genome.

Abstract: The human genome holds an extraordinary trove of information about human development, physiology, medicine and evolution. Here we report the results of an international collaboration to produce and make freely available a draft sequence of the human genome. We also present an initial analysis of the data, describing some of the insights that can be gleaned from the sequence.

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

The social identity theory of intergroup behavior

Abstract: This chapter presents an outline of a theory of intergroup conflict and some preliminary data relating to the theory. Much of the work on the social psychology of intergroup relations has focused on patterns of individual prejudices and discrimination and on the motivational sequences of interpersonal interaction. The intensity of explicit intergroup conflicts of interests is closely related in human cultures to the degree of opprobrium attached to the notion of "renegade" or "traitor." The basic and highly reliable finding is that the trivial, ad hoc intergroup categorization leads to in-group favoritism and discrimination against the out-group. Many orthodox definitions of "social groups" are unduly restrictive when applied to the context of intergroup relations. The equation of social competition and intergroup conflict rests on the assumptions concerning an "ideal type" of social stratification in which the salient dimensions of intergroup differentiation are those involving scarce resources.