Historical aspects of the creation of the first higher educational institution of industrial education of Volyn province (to the 100th anniversary of Zhytomyr Polytechnic)
In spite of considerable progresses in recent years, a quantitative and predictive understanding of atmospheric aerosol sources, chemical composition, transformation processes and environmental ...effects is still rather limited, and therefore represents a major research challenge in atmospheric science. This review begins with a historical perspective on the scientific questions regarding atmospheric aerosols over the past centuries, followed by a description of the distribution, sources, transformation processes, and chemical and physical properties as they are currently understood. The major open questions and suggestions for future research priorities are outlined to narrow the gap between the present understanding of the contribution of both anthropogenic and biogenic aerosols to radiative forcing resulting from the spatial non-uniformity, intermittency of sources, unresolved composition and reactivity.
► Historical perspective of atmospheric aerosols over the past centuries ► Survey of recent literature regarding aerosol sources and chemical composition ► Open questions and suggestions for future research priorities
The discovery and implementation of fluoride in the prevention of dental caries is often praised as one of the most important achievements in health care. In the early 20th century, it took 30 y to ...identify fluoride as the cause of enamel mottling but also of reduced caries prevalence in a population drinking water containing fluoride. Similarly, from 1960 to 1990, it took major efforts to unravel the working mode of fluoride in such detail that a rational scheme of caries prevention could be formulated. This article describes the scientific struggle leading to a consensus on the topic. For a historic purpose, the field, the actors, and their main research achievements are described. Ultimately it was generally agreed that the effect of fluoride is primarily topical by fluorides in the oral fluids rather than systemic by incorporation of fluoride in the enamel mineral crystals. Fluoride concentrations, even <1 mg/L, enhance the deposition of calcium phosphates during remineralization of enamel (and dentin). Similarly, such low levels of fluoride are effective in reducing the dissolution of the calcified tissues. This understanding has led to the development of fluoride-containing caries-preventive products that had an undisputed beneficial effect on the levels of dental caries.
Cholesterol biosynthesis is among the most intensely regulated processes in biology. Synthetic rates vary over hundreds of fold depending on the availability of an external source of cholesterol. ...Studies of this feedback regulatory process have a rich history. The field began 75 years ago when Rudolf Schoenheimer measured cholesterol balance in mice in a bottle. He found that cholesterol feeding led to decreased cholesterol synthesis, thereby introducing the general phenomenon by which end products of biosynthetic pathways inhibit their own synthesis. Recently, cholesterol feedback has been explained at a molecular level with the discovery of membrane-bound transcription factors called sterol regulatory element-binding proteins (SREBPs), and an appreciation of the sterol-sensing role of their partner, an escort protein called Scap. The key element in Scap is a hexapeptide sequence designated MELADL (rhymes with bottle). Thus, over 75 years, Schoenheimer's bottle led to Scap's MELADL. In addition to their basic importance in membrane biology, these studies have implications for the regulation of plasma cholesterol levels and consequently for the development of atherosclerotic plaques, myocardial infarctions, and strokes. In this article we review the major milestones in the cholesterol feedback story.
Since the early 20th century, the detection of intestinal parasites has improved with the development of several techniques for parasitic structures recovery and identification, which differ in ...sensitivity, specificity, practicality, cost, and infrastructure demand. This study aims to review, in chronological order, the stool examination techniques and discuss their advantages, limitations, and perspectives, and to provide professionals and specialists in this field with data that lays a foundation for critical analysis on the use of such procedures. The concentration procedures that constitute the main techniques applied in routine research and in parasitological kits are a) spontaneous sedimentation; b) centrifugation-sedimentation with formalin-ethyl acetate; and c) flotation with zinc sulfate solution. While selecting a technique, one should consider the purpose of its application and the technical-operational, biological, and physicochemical factors inherent in the procedures used in stool processing, which may restrict its use. These intrinsic limitations may have undergone procedural changes driven by scientific and technological development and by development of alternative methods, which now contribute to the improvement of diagnostic accuracy.
The histories of research regarding all plant hormones are similar. Identification and structural elucidation have been followed by analyses of their biosynthesis, distributions, signaling cascades, ...roles in developmental or stress response programs, and crosstalk. Jasmonic acid (JA) and its derivatives comprise a group of plant hormones that were discovered recently, compared to auxin, abscisic acid, cytokinins, gibberellic acid, and ethylene. Nevertheless, there have been tremendous advances in JA research, following the general progression outlined above and parallel efforts focused on several other “new” plant hormones (brassinosteroids, salicylate, and strigolactones). This review focuses on historical aspects of the identification of jasmonates, and characterization of their biosynthesis, distribution, perception, signaling pathways, crosstalk with other hormones and roles in plant stress responses and development. The aim is to illustrate how our present knowledge on jasmonates was generated and how that influences current efforts to extend our knowledge.