scholarly journals Surfactants: physicochemical interactions with biological macromolecules

2021 ◽  
Vol 43 (3) ◽  
pp. 523-535 ◽  
Author(s):  
M. Aguirre-Ramírez ◽  
H. Silva-Jiménez ◽  
I. M. Banat ◽  
M. A. Díaz De Rienzo
Keyword(s):  
Pharmaceutical Industry ◽  
Electrostatic Interactions ◽  
The Other ◽  
Biological Macromolecules ◽  
Basic Principles ◽  
Environmental Processes ◽  
Physicochemical Interactions ◽  
Different Types ◽  
Living Organisms ◽  
Cellular Components

AbstractMacromolecules are essential cellular components in biological systems responsible for performing a large number of functions that are necessary for growth and perseverance of living organisms. Proteins, lipids and carbohydrates are three major classes of biological macromolecules. To predict the structure, function, and behaviour of any cluster of macromolecules, it is necessary to understand the interaction between them and other components through basic principles of chemistry and physics. An important number of macromolecules are present in mixtures with surfactants, where a combination of hydrophobic and electrostatic interactions is responsible for the specific properties of any solution. It has been demonstrated that surfactants can help the formation of helices in some proteins thereby promoting protein structure formation. On the other hand, there is extensive research towards the use of surfactants to solubilize drugs and pharmaceuticals; therefore, it is evident that the interaction between surfactants with macromolecules is important for many applications which includes environmental processes and the pharmaceutical industry. In this review, we describe the properties of different types of surfactants that are relevant for their physicochemical interactions with biological macromolecules, from macromolecules–surfactant complexes to hydrophobic and electrostatic interactions.

BIOMEDICAL RESEARCH PAYS OFF

PEDIATRICS ◽  
1977 ◽  
Vol 59 (6) ◽  
pp. 832-832
Author(s):  
J. H. Comroe ◽  
R. D. Dripps
Keyword(s):  
Research And Development ◽  
Biomedical Research ◽  
Basic Research ◽  
The Other ◽  
Human Diseases ◽  
Different Types ◽  
Living Organisms

Our analysis showed . . . 41% of all work judged to be essential for later clinical advance was not clinically oriented at the time it was done. The scientists responsible for these key articles sought knowledge for the sake of knowledge. . . . Our data show that clinical advance requires different types of research and development and not one to the exclusion of the other. . . . Our data compel us to conclude (1) that a generous portion of the nation's biomedical research dollar should be used to identify and then provide long term support for creative scientists whose main goal is to learn how living organisms function, without regard to the immediate relation of their research to specific human diseases; and (2) that basic research, as we have defined it, pays off in terms of key discoveries almost twice as handsomely as other types of research and development combined.

scholarly journals THE INTERACTION OF FLOODS WITH TRANSPORT INFRASTRUCTURE

2018 ◽  
Vol 16 ◽  
pp. 32
Author(s):  
Ivan Vaníček ◽  
Jiří Vaníček
Keyword(s):  
Natural Hazards ◽  
Negative Impact ◽  
The Other ◽  
Transport Infrastructure ◽  
Sustainable Construction ◽  
Basic Principles ◽  
Proper Functioning ◽  
Different Types ◽  
Natural Aggregates

Current demands on transport infrastructure are very often associated with the terms of “sustainability, availability and affordability”. The first term directly refers to the basic principles of sustainable construction in transport infrastructure, primarily motorway and railways, and how they are related to a very significant consumption of land, energy and natural aggregates. This paper is focused on the other two terms, availability and affordability. These principles are intended to guarantee proper functioning of communication even in nonstandard situations such as natural hazards, most typically floods. To avoid a total collapse of transport infrastructure, the term robustness is often applied, recognizing that this term is not a substitute for another outcome – namely a more expensive structure. The paper shows the possibilities for elimination of the negative impact of floods on transport infrastructure as they relate to different types of interaction and different types of floods.

scholarly journals Structural Study of Heterogeneous Biological Samples by Cryoelectron Microscopy and Image Processing

2017 ◽  
Vol 2017 ◽  
pp. 1-23 ◽  
Author(s):  
H. E. White ◽  
A. Ignatiou ◽  
D. K. Clare ◽  
E. V. Orlova
Keyword(s):  
Three Dimensional ◽  
Particle Analysis ◽  
Biological Macromolecules ◽  
Structural Studies ◽  
Structural Variations ◽  
Conformational States ◽  
Basic Principles ◽  
Computing Power ◽  
Living Organisms ◽  
Multiple Conformations

In living organisms, biological macromolecules are intrinsically flexible and naturally exist in multiple conformations. Modern electron microscopy, especially at liquid nitrogen temperatures (cryo-EM), is able to visualise biocomplexes in nearly native conditions and in multiple conformational states. The advances made during the last decade in electronic technology and software development have led to the revelation of structural variations in complexes and also improved the resolution of EM structures. Nowadays, structural studies based on single particle analysis (SPA) suggests several approaches for the separation of different conformational states and therefore disclosure of the mechanisms for functioning of complexes. The task of resolving different states requires the examination of large datasets, sophisticated programs, and significant computing power. Some methods are based on analysis of two-dimensional images, while others are based on three-dimensional studies. In this review, we describe the basic principles implemented in the various techniques that are currently used in the analysis of structural conformations and provide some examples of successful applications of these methods in structural studies of biologically significant complexes.

Actual issues of hygienic regulation and creation of safe working conditions at pharmaceutical manufacturing enterprises

2020 ◽  
Vol 60 (10) ◽  
pp. 640-644
Author(s):  
Vadim M. Vasilkevich ◽  
Ruslan V. Bogdanov ◽  
Elena V. Drozdova
Keyword(s):  
Pharmaceutical Industry ◽  
Working Conditions ◽  
Experimental Studies ◽  
Pharmaceutical Products ◽  
Laboratory Animals ◽  
Production Environment ◽  
Basic Principles ◽  
Toxicological Studies ◽  
Health Disorders ◽  
Safe Working

Introduction. The working conditions of pharmaceutical industry workers are characterized by the combined effect of unfavorable factors of the production environment, among which the leading one is chemical. The aim of study is to substantiate the basic principles and criteria for hygienic regulation of pharmaceutical products in their production to ensure safe working conditions for employees based on the results of their own research and existing requirements of technical regulations. Materials and methods. Analysis of working conditions and the prevalence of health disorders in pharmaceutical workers (according to literature data), toxicological studies of pharmaceutical substances on laboratory animals, scientific justification of hygiene standards in the air of the working area. Results. Among employees of the pharmaceutical industry, the predominant forms of production-related health disorders are diseases of the respiratory system, as well as skin dermatitis of allergic origin, liver and biliary tract diseases. Based on the results of experimental studies of domestic pharmaceutical products for the treatment of cardiovascular, oncological and mental diseases that have priority socio-economic significance, the basic principles and features of the practice of justifying the hygienic standards of medicines in the air of the working area are developed and systematized. Conclusions. During hygienic rationing of medicines, it is necessary to use a differentiated approach that allows, based on the analysis of information about the chemical structure, physical and chemical characteristics, production conditions, pharmacotherapeutic activity, and the results of studying the toxic effect in an experiment on laboratory animals, to determine the maximum permissible content in the air of the working area of medicines or to justify the prohibition of isolation with reasoned recommendations for their safe production.

Epigenetic Mechanisms of Maternal Dietary Protein and Amino Acids Affecting Growth and Development of Offspring

2019 ◽  
Vol 20 (7) ◽  
pp. 727-735 ◽  
Author(s):  
Yi Wu ◽  
Zhibin Cheng ◽  
Yueyu Bai ◽  
Xi Ma
Keyword(s):  
Amino Acids ◽  
Dna Methylation ◽  
Dietary Protein ◽  
Growth And Development ◽  
Later Life ◽  
Biological Macromolecules ◽  
Epigenetic Mechanisms ◽  
Maternal Circulation ◽  
Energy Processing ◽  
Living Organisms

Nutrients can regulate metabolic activities of living organisms through epigenetic mechanisms, including DNA methylation, histone modification, and RNA regulation. Since the nutrients required for early embryos and postpartum lactation are derived in whole or in part from maternal and lactating nutrition, the maternal nutritional level affects the growth and development of fetus and creates a profound relationship between disease development and early environmental exposure in the offspring’s later life. Protein is one of the most important biological macromolecules, involved in almost every process of life, such as information transmission, energy processing and material metabolism. Maternal protein intake levels may affect the integrity of the fetal genome and alter DNA methylation and gene expression. Most amino acids are supplied to the fetus from the maternal circulation through active transport of placenta. Some amino acids, such as methionine, as dietary methyl donor, play an important role in DNA methylation and body’s one-carbon metabolism. The purpose of this review is to describe effects of maternal dietary protein and amino acid intake on fetal and neonatal growth and development through epigenetic mechanisms, with examples in humans and animals.

Comparative Surface Imaging Study of Multifocal Diffractive Intraocular Lenses

2021 ◽  
Author(s):  
Hyeck Soo Son ◽  
Jung Min Lee ◽  
Ramin Khoramnia ◽  
Chul Young Choi
Keyword(s):  
Imaging Study ◽  
The Other ◽  
Intraocular Lenses ◽  
Optical Surface ◽  
Diffractive Optic ◽  
Atomic Force ◽  
Acceptable Range ◽  
Different Types ◽  
Concentric Pattern

Abstract Purpose To analyse and compare the surface topography and roughness of three different types of diffractive multifocal IOLs. Methods Using scanning electron microscope (SEM, Inspect F, 5.0 KV, maximum magnification up to 20,000) and atomic force microscope (AFM, Park Systems, XE-100, non-contact, area profile comparison, 10 × 10 µm, 40 × 40 µm), the surface quality of the following diffractive IOLs was studied: the AcrySof IQ PanOptix (Alcon, USA), the AT LARA 829MP (Carl Zeiss Meditec, Germany), and Tecnis Symfony (Johnson&Johnson Vision, USA). The measurements were made over three representative areas (central non-diffractive optic, central diffractive optic, and diffractive step) of each IOL. Roughness profile in terms of mean arithmetic roughness (Ra) and root-mean-squared roughness (Rq) values were obtained and compared statistically. Results In SEM examination, all IOLs showed a smooth optical surface without any irregularities at low magnification. At higher magnification, Tecnis Symfony showed unique highly regular, concentric, and lineate structures in the diffractive optic area which could not be seen in the other studied diffractive IOLs. The differences in the measured Ra and Rq values of the Tecnis Symfony were statistically significant compared to the other models (p < 0.05). Conclusion Various different topographical traits were observed in three diffractive multifocal IOLs. The Ra values of all studied IOLs were within an acceptable range. Tecnis Symfony showed statistically significant higher surface Ra values at both central diffractive optic and diffractive step areas. Furthermore, compared to its counterparts, Tecnis Symfony demonstrated highly ordered, concentric pattern in its diffractive surfaces.

RADIATION EXPOSURE TO THE BACK WITH DIFFERENT TYPES OF APRONS

2021 ◽  
Author(s):  
Seung Wan Hong ◽  
Tae Won Kim ◽  
Jae Hun Kim
Keyword(s):  
Radiation Exposure ◽  
Effective Dose ◽  
Exposure Time ◽  
The Other ◽  
Lead Apron ◽  
Type Group ◽  
Air Kerma ◽  
Different Types ◽  
The Relationship

Abstract Physicians and nurses stand with their back towards the C-arm fluoroscope when using the computer, taking things out of closets and preparing drugs for injection or instruments for intervention. This study was conducted to investigate the relationship between the type of lead apron and radiation exposure to the backs of physicians and nurses while using C-arm fluoroscopy. We compared radiation exposure to the back in the three groups: no lead apron (group C), front coverage type (group F) and wrap-around type (group W). The other wrap-around type apron was put on the bed instead of on a patient. We ran C-arm fluoroscopy 40 times for each measurement. We collected the air kerma (AK), exposure time (ET) and effective dose (ED) of the bedside table, upper part and lower part of apron. We measured these variables 30 times for each location. In group F, ED of the upper part was the highest (p &lt; 0.001). ED of the lower part in group C and F was higher than that in group W (p = 0.012). The radiation exposure with a front coverage type apron is higher than that of the wrap-around type and even no apron at the neck or thyroid. For reducing radiation exposure to the back of physician or nurse, the wrap-around type apron is recommended. This type of apron can reduce radiation to the back when the physician turns away from the patient or C-arm fluoroscopy.

scholarly journals MITOTIC CROSSING OVER AND NONDISJUNCTION IN TRANSLOCATION HETEROZYGOTES OF ASPERGILLUS

Genetics ◽  
1976 ◽  
Vol 82 (4) ◽  
pp. 605-627
Author(s):  
Etta Käfer
Keyword(s):  
Selective Advantage ◽  
The Other ◽  
Translocation Chromosome ◽  
Crossing Over ◽  
Selective Marker ◽  
Reciprocal Translocations ◽  
Poor Growth ◽  
Different Types ◽  
Diploid Genotype ◽  
One Step

ABSTRACT To analyze mitotic recombination in translocation heterozygotes of A. nidulans two sets of well-marked diploids were constructed, homo- or heterozygous for the reciprocal translocations T1(IL;VIIR) or T2(IL;VIIIR) and heterozygous for selective markers on IL. It was found that from all translocation heterozygotes some of the expected mitotic crossover types could be selected. Such crossovers are monosomic for one translocated segment and trisomic for the other and recovery depends on the relative viabilities of these unbalanced types. The obtained segregants show characteristically reduced growth rates and conidiation dependent on sizes and types of mono- and trisomic segments, and all spontaneously produce normal diploid sectors. Such secondary diploid types either arose in one step of compensating crossing over in the other involved arm, or—more conspicuously—in two steps of nondisjunction via a trisomic intermediate.—In both of the analyzed translocations the segments translocated to IL were extremely long, while those translocated from IL were relatively short. The break in I for T1(I;VII) was located distal to the main selective marker in IL, while that of T2(I;VIII) had been mapped proximal but closely linked to it. Therefore, as expected, the selected primary crossover from the two diploids with T2(I;VIII) in coupling or in repulsion to the selective marker, showed the same chromosomal imbalance and poor growth. These could however be distinguished visually because they spontaneously produced different trisomic intermediates in the next step, in accordance with the different arrangement of the aneuploid segments. On the other hand, from diploids heterozygous for T1(I;VII) mitotic crossovers could only be selected when the selective markers were in coupling with the translocation; these crossovers were relatively well-growing and produced frequent secondary segregants of the expected trisomic, 2n+VII, type. For both translocations it was impossible to recover the reciprocal crossover types (which would be trisomic for the distal segments of I and monosomic for most of groups VII or VIII) presumably because these were too inviable to form conidia.—In addition to the selected segregants of expected types a variety of unexpected ones were isolated. The conditions of selection used favour visual detection of aneuploid types, even if these produce only a few conidial heads and are not at a selective advantage. For T2(I;VIII) these "non-selected" unbalanced segregants were mainly "reciprocal" crossovers of the same phenotype and imbalance as the selected ones. For T1(I;VII) two quite different types were obtained, both possibly originating with loss of the small VII-Itranslocation chromosome. One was isolated when the selective marker in repulsion to T1(I;VII) was used and, without being homo- or hemizygous for the selective marker, it produced stable sectors homozygous for this marker. The other was obtained from both coupling and repulsion diploids and showed a near-diploid genotype; it produced practically only haploid stable sectors of the type expected from monosomics, 2n-1 for the short translocation chromosome.

scholarly journals Development of Speech Recognition Systems in Emergency Call Centers

Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 634
Author(s):  
Alakbar Valizada ◽  
Natavan Akhundova ◽  
Samir Rustamov
Keyword(s):  
Speech Recognition ◽  
Markov Model ◽  
Hidden Markov ◽  
Call Centers ◽  
The Other ◽  
Language Models ◽  
Emergency Call ◽  
Acoustic Model ◽  
Different Types ◽  
Recognition Systems

In this paper, various methodologies of acoustic and language models, as well as labeling methods for automatic speech recognition for spoken dialogues in emergency call centers were investigated and comparatively analyzed. Because of the fact that dialogue speech in call centers has specific context and noisy, emotional environments, available speech recognition systems show poor performance. Therefore, in order to accurately recognize dialogue speeches, the main modules of speech recognition systems—language models and acoustic training methodologies—as well as symmetric data labeling approaches have been investigated and analyzed. To find an effective acoustic model for dialogue data, different types of Gaussian Mixture Model/Hidden Markov Model (GMM/HMM) and Deep Neural Network/Hidden Markov Model (DNN/HMM) methodologies were trained and compared. Additionally, effective language models for dialogue systems were defined based on extrinsic and intrinsic methods. Lastly, our suggested data labeling approaches with spelling correction are compared with common labeling methods resulting in outperforming the other methods with a notable percentage. Based on the results of the experiments, we determined that DNN/HMM for an acoustic model, trigram with Kneser–Ney discounting for a language model and using spelling correction before training data for a labeling method are effective configurations for dialogue speech recognition in emergency call centers. It should be noted that this research was conducted with two different types of datasets collected from emergency calls: the Dialogue dataset (27 h), which encapsulates call agents’ speech, and the Summary dataset (53 h), which contains voiced summaries of those dialogues describing emergency cases. Even though the speech taken from the emergency call center is in the Azerbaijani language, which belongs to the Turkic group of languages, our approaches are not tightly connected to specific language features. Hence, it is anticipated that suggested approaches can be applied to the other languages of the same group.

scholarly journals ID Learning Unit: Understanding and Interpreting Testing for Clostridium difficile

2014 ◽  
Vol 1 (1) ◽  
Author(s):  
Daniel A. Solomon ◽  
Danny A. Milner
Keyword(s):  
Clinical Practice ◽  
Clostridium Difficile ◽  
Basic Principles ◽  
Multiple Tests ◽  
Molecular Tests ◽  
Different Types

Abstract Understanding and interpreting the molecular tests for Clostridium difficile is challenging because there are several different types of assays and most laboratories combine multiple tests in order to assess for presence of disease. This learning unit demonstrates the basic principles of each test along with its strengths and weaknesses, and illustrates how the tests are used in clinical practice.

Sign in / Sign up

Export Citation Format

Share Document