Detection of moving sources of ionizing radiations

We consider the principles of remote detection of stationary and moving sources of ionizing radiations. The chief factors influencing the results of the detection are analyzed.Translated from Izmeritel'naya Tekhnika, No. 8, pp. 63–64, August, 1994.     

Analysis of the immunologic heterogeneity of HIV-1: I. "Arginine-glutamine trigger" in the fourth position of the central tetrapeptide of the V3 loop of gp120

This article reviews the existing knowledge base concerning the biology of spinal fusion, with the understanding that the focus is weighted toward posterolateral lumbar spinal fusion because of a relative paucity of biologic information on healing of other types of fusions. The discussion focuses first on the basic science of spinal fusion healing from the standpoint of animal modeling. Next, the discussion centers on the multitude of local factors that can affect fusion healing. Finally, the numerous systemic factors known to affect fusion healing are discussed.     

Kappa chain monoallelic demethylation and the establishment of allelic exclusion

Allelic exclusion in kappa light-chain synthesis is thought to result from a feedback mechanism by which the expression of a functional kappa light chain on the surface of the B cell leads to an intracellular signal that down-regulates the V(D)J recombinase, thus precluding rearrangement of the other allele. Whereas such a feedback mechanism clearly plays a role in the maintenance of allelic exclusion, here we provide evidence suggesting that the initial establishment of allelic exclusion involves differential availability of the two kappa alleles for rearrangement. Analysis of kappa+ B-cell populations and of individual kappa+ B cells that have rearranged only one allele demonstrates that in these cells, critical sites on the rearranged allele are unmethylated, whereas the nonrearranged allele remains methylated. This pattern is apparently generated by demethylation that is initiated at the small pre-B cell stage, on a single allele, in a process that occurs prior to rearrangement and requires the presence in cis of both the intronic and 3' kappa enhancers. Taken together with data demonstrating that undermethylation is required for rearrangement, these results indicate that demethylation may actually underly the process of allelic exclusion by directing the initial choice of a single kappa allele for rearrangement.     

Foot asymmetry in healthy adults: elliptic fourier analysis of standardized footprints

Issues regarding the deaths of patients in the ED arise on a regular basis for emergency physicians. These issues include physician discomfort with death notification, the approach to families after ED deaths, autopsies, donation of organs and tissues, and procedures on the newly dead. If physicians were more comfortable with death notification, not only would families be better served but benefits to society could be realized through the increased use of autopsy and organ/tissue donation. The controversial topic of physician education through practice of medical procedures on the newly dead weighs the benefits to society against the rights of the individual. Improved physician education, including the need for a death notification plan and enlistment of the support of nursing personnel, social workers, and clergy, may improve the experience of events surrounding ED deaths for physicians, families, and society. We review the literature and give recommendations on approaches to deal with these issues.     

HYDROGENATION OF 1,5-CYCLOOCTADIENE IN A TRICKLE BED REACTOR ACCOMPANIED BY PHASE TRANSITION

This paper examined the evaporation and condensation of the reaction mixture within the trickle bed reactor during 1,5-cyclooctadiene hydrogenation. The aim of study has been to formulate a mathematical model of heat and mass transfer influenced the exothermic reaction of a volatile reaction mixture apt to evaporation by the reaction heat in the system which is often accompanied by a hot spot temperature formation in the reactor followed by the enhancement of undesirable side reactions and/or catalyst deactivation. The numerical solution of the proposed model agreed quite well with the experimental temperature profiles in the trickle bed reactor.