scholarly journals Towards Promising Platform by Using Annular Photonic Crystals to Simulate and Design Useful Mask

Photonics ◽  
2021 ◽  
Vol 8 (9) ◽  
pp. 349
Author(s):  
Ayman A Ameen ◽  
Hussein A Elsayed ◽  
Sagr Alamri ◽  
Z.S. Matar ◽  
M. Al-Dossari ◽  
...  
Keyword(s):  
Inner Core ◽  
Viral Infections ◽  
Main Role ◽  
Irradiation Effect ◽  
Core Radius ◽  
Air Filtration ◽  
Ultraviolet Germicidal Irradiation ◽  
Wide Range ◽  
Novel Design

Human masks are considered the mainstay in air filtration and purification technologies and against the spreading of bacterial and viral infections. This paper introduces a novel design of a human mask to increase the ultraviolet germicidal irradiation effect on pathogens. The proposed design consists of a tube with an annular photonic crystal (APC) attached to the mask’s orifice, and a UV source is located in the tube’s center. The main role of this study is the enhancement of UV doses based on the reflectivity of the proposed APC. Therefore, increasing pathogens’ inactivation level in the incoming air to the mask’s orifice could be investigated. The numerical investigations demonstrated that the proposed APC could provide a complete photonic bandgap with a high reflectivity in the wavelength regime from 207 to 230 nm. In addition, we have considered the roles of the thickness of layers, inner core radius, and the azimuthal number. Meanwhile, the results showed the ability to use a wide range of core radius values without almost any variations in the optical properties of the proposed design. Such results could grant the advantage of using this design by the manufacturing of human masks with different sizes besides the inclusions in other ultraviolet germicidal irradiation applications.

scholarly journals A functional spleen contributes to afucosylated IgG in humans

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Iwona Wojcik ◽  
David E. Schmidt ◽  
Lisa A. de Neef ◽  
Minke A. E. Rab ◽  
Bob Meek ◽  
...  
Keyword(s):  
Immune Responses ◽  
Viral Infections ◽  
Immune Cell ◽  
Lymphoid Organ ◽  
Immune Effector ◽  
Adaptive Immune ◽  
Wide Range ◽  
Humoral Responses ◽  
First Time

AbstractAs a lymphoid organ, the spleen hosts a wide range of immune cell populations, which not only remove blood-borne antigens, but also generate and regulate antigen-specific immune responses. In particular, the splenic microenvironment has been demonstrated to play a prominent role in adaptive immune responses to enveloped viral infections and alloantigens. During both types of immunizations, antigen-specific immunoglobulins G (IgGs) have been characterized by the reduced amount of fucose present on N-linked glycans of the fragment crystallizable (Fc) region. These glycans are essential for mediating the induction of immune effector functions. Therefore, we hypothesized that a spleen may modulate humoral responses and serve as a preferential site for afucosylated IgG responses, which potentially play a role in immune thrombocytopenia (ITP) pathogenesis. To determine the role of the spleen in IgG-Fc glycosylation, we performed IgG subclass-specific liquid chromatography–mass spectrometry (LC–MS) analysis of Fc glycosylation in a large cohort of individuals splenectomized due to trauma, due to ITP, or spherocytosis. IgG-Fc fucosylation was consistently increased after splenectomy, while no effects for IgG-Fc galactosylation and sialylation were observed. An increase in IgG1- and IgG2/3-Fc fucosylation level upon splenectomy has been reported here for the first time, suggesting that immune responses occurring in the spleen may be particularly prone to generate afucosylated IgG responses. Surprisingly, the level of total IgG-Fc fucosylation was decreased in ITP patients compared to healthy controls. Overall, our results suggest a yet unrecognized role of the spleen in either the induction or maintenance of afucosylated IgG responses by B cells.

scholarly journals Recent Updates on Research Models and Tools to Study Virus–Host Interactions at the Placenta

Viruses ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 5 ◽  
Author(s):  
Jae Kyung Lee ◽  
Soo-Jin Oh ◽  
Hosun Park ◽  
Ok Sarah Shin
Keyword(s):  
Viral Infections ◽  
Protective Role ◽  
Biological Mechanisms ◽  
Cellular Targets ◽  
Host Interactions ◽  
Wide Range ◽  
Hofbauer Cells ◽  
Maternal Fetal Transmission ◽  
Immunological Barrier

The placenta is a unique mixed organ, composed of both maternal and fetal tissues, that is formed only during pregnancy and serves as the key physiological and immunological barrier preventing maternal–fetal transmission of pathogens. Several viruses can circumvent this physical barrier and enter the fetal compartment, resulting in miscarriage, preterm birth, and birth defects, including microcephaly. The mechanisms underlying viral strategies to evade the protective role of placenta are poorly understood. Here, we reviewed the role of trophoblasts and Hofbauer cells in the placenta and have highlighted characteristics of vertical and perinatal infections caused by a wide range of viruses. Moreover, we explored current progress and future opportunities in cellular targets, pathogenesis, and underlying biological mechanisms of congenital viral infections, as well as novel research models and tools to study the placenta.

scholarly journals The Multifarious Role of 14-3-3 Family of Proteins in Viral Replication

Viruses ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 436 ◽  
Author(s):  
Kavitha Ganesan Nathan ◽  
Sunil K. Lal
Keyword(s):  
Protein Interactions ◽  
Viral Infections ◽  
Pharmaceutical Research ◽  
Host Protein ◽  
Dna Viruses ◽  
Wide Range ◽  
Host Virus Interactions ◽  
Virus Interactions ◽  
Rna And Dna

The 14-3-3 proteins are a family of ubiquitous and exclusively eukaryotic proteins with an astoundingly significant number of binding partners. Their binding alters the activity, stability, localization, and phosphorylation state of a target protein. The association of 14-3-3 proteins with the regulation of a wide range of general and specific signaling pathways suggests their crucial role in health and disease. Recent studies have linked 14-3-3 to several RNA and DNA viruses that may contribute to the pathogenesis and progression of infections. Therefore, comprehensive knowledge of host–virus interactions is vital for understanding the viral life cycle and developing effective therapeutic strategies. Moreover, pharmaceutical research is already moving towards targeting host proteins in the control of virus pathogenesis. As such, targeting the right host protein to interrupt host–virus interactions could be an effective therapeutic strategy. In this review, we generated a 14-3-3 protein interactions roadmap in viruses, using the freely available Virusmentha network, an online virus–virus or virus–host interaction tool. Furthermore, we summarize the role of the 14-3-3 family in RNA and DNA viruses. The participation of 14-3-3 in viral infections underlines its significance as a key regulator for the expression of host and viral proteins.

scholarly journals Regulation of Chemokines and Cytokines by Histone Deacetylases and an Update on Histone Decetylase Inhibitors in Human Diseases

2019 ◽  
Vol 20 (5) ◽  
pp. 1110 ◽  
Author(s):  
Himavanth Gatla ◽  
Nethaji Muniraj ◽  
Prashanth Thevkar ◽  
Siddhartha Yavvari ◽  
Sahithi Sukhavasi ◽  
...  
Keyword(s):  
Histone Deacetylases ◽  
Viral Infections ◽  
Kidney Diseases ◽  
Hdac Inhibitors ◽  
Cardiovascular Complications ◽  
Human Diseases ◽  
Wide Range ◽  
Hematological Cancers ◽  
Anti Tumor Activity

Histone acetyltransferases (HATs) and histone deacetylases (HDACs) counteract with each other to regulate gene expression by altering chromatin structure. Aberrant HDAC activity was reported in many human diseases including wide range of cancers, viral infections, cardiovascular complications, auto-immune diseases and kidney diseases. HDAC inhibitors are small molecules designed to block the malignant activity of HDACs. Chemokines and cytokines control inflammation, immunological and other key biological processes and are shown to be involved in various malignancies. Various HDACs and HDAC inhibitors were reported to regulate chemokines and cytokines. Even though HDAC inhibitors have remarkable anti-tumor activity in hematological cancers, they are not effective in treating many diseases and many patients relapse after treatment. However, the role of HDACs and cytokines in regulating these diseases still remain unclear. Therefore, understanding exact mechanisms and effector functions of HDACs are urgently needed to selectively inhibit them and to establish better a platform to combat various malignancies. In this review, we address regulation of chemokines and cytokines by HDACs and HDAC inhibitors and update on HDAC inhibitors in human diseases.

KATERYNOSLAV AND SIMFEROPOL CHARITABLE SOCIETIES: COMPARATIVE ANALYSIS OF ACTIVITY О. Balukhtina

2020 ◽  
pp. 6-9
Author(s):  
О. Balukhtina
Keyword(s):  
Comparative Analysis ◽  
Social Protection ◽  
Social Needs ◽  
Entrepreneurial Activity ◽  
Vulnerable Groups ◽  
Soviet Period ◽  
Main Role ◽  
Public Care ◽  
Wide Range

The article aims at studying the largest charitable societies in Katerynoslav and Simferopol as an example of public care in the Ukrainian lands in the pre-Soviet period. The main directions of their activity are highlighted, common features and peculiarities are determined. Charitable institutions were established, which functioned at the expense of societies. It is proved that charitable activity was one of the factors increasing the level of social protection of the most vulnerable segments of the population in provincial cities. Interest in the topic of charity is inexhaustible, as it is associated with the study of cultural and spiritual traditions, which this phenomenon is associated with in society. Among a wide range of problematic issues, today the activities of charitable societies at the level of the regions of Ukraine are insufficiently studied. The aim of the article is to study and compare the activities of Katerynoslav and Simferopol charitable societies to improve financial situation of vulnerable groups in Katerynoslav and Tavriya provinces. The method of comparative analysis is applied. The main amount of funds came from the collection of direct donations through the organization of charity events (concerts, performances), through salary books and subscription letters. Katerynoslav Charitable Society had a much larger turnover of funds, revenues and expenditures. It is obvious that it collected more donations and was more active in entrepreneurial activity. The successful activity of Katerynoslav and Simferopol charitable societies reflected a wide range of social needs of Southern Ukrainians and was directed, first of all to financial support of vulnerable segments of the population. Over the time, help became more targeted. Attempts were made to solve the problems of social care for the infirm, professional begging and unemployment by creating shelters and working houses. Attention was paid to the main role of women in managing societies and cooperation with local authorities was monitored.

scholarly journals ThHog1 controls the hyperosmotic stress response in Trichoderma harzianum

Microbiology ◽  
2006 ◽  
Vol 152 (6) ◽  
pp. 1687-1700 ◽  
Author(s):  
Jesús Delgado-Jarana ◽  
Sonia Sousa ◽  
Fran González ◽  
Manuel Rey ◽  
Antonio Llobell
Keyword(s):  
Oxidative Stress ◽  
Stress Response ◽  
Trichoderma Harzianum ◽  
Hyperosmotic Stress ◽  
Stress Conditions ◽  
Cross Resistance ◽  
Main Role ◽  
Wide Range ◽  
Mutant Strains

Trichoderma harzianum is a widespread mycoparasitic fungus, able to successfully colonize a wide range of substrates under different environmental conditions. Transcript profiling revealed a subset of genes induced in T. harzianum under hyperosmotic shock. The hog1 gene, a homologue of the MAPK HOG1 gene that controls the hyperosmotic stress response in Saccharomyces cerevisiae, was characterized. T. harzianum hog1 complemented the hog1Δ mutation in S. cerevisiae, but showed different features to yeast alleles: improved osmoresistance by expression of the hog1 allele and a lack of lethality when the hog1 F315S allele was overexpressed. ThHog1 protein was phosphorylated in T. harzianum under different stress conditions such as hyperosmotic or oxidative stress, among others. By using a ThHog1-GFP fusion, the protein was shown to be localized in nuclei under these stress conditions. Two mutant strains of T. harzianum were constructed: one carrying the hog1 F315S allele, and a knockdown hog1-silenced strain. The silenced strain was highly sensitive to osmotic stress, and showed intermediate levels of resistance against oxidative stress, indicating that the main role of ThHog1 protein is in the hyperosmotic stress response. Stress cross-resistance experiments showed evidences of a secondary role of ThHog1 in oxidative stress. The strain carrying the hog1 F315S allele was highly resistant to the calcineurin inhibitor cyclosporin A, which suggests the existence of links between the two pathways. The two mutant strains showed a strongly reduced antagonistic activity against the plant pathogens Phoma betae and Colletotrichum acutatum, which points to a role of ThHog1 protein in fungus–fungus interactions.

scholarly journals The Intestinal Microbiota: Impacts of Antibiotics Therapy, Colonization Resistance, and Diseases

2021 ◽  
Vol 22 (12) ◽  
pp. 6597
Author(s):  
Taif Shah ◽  
Zulqarnain Baloch ◽  
Zahir Shah ◽  
Xiuming Cui ◽  
Xueshan Xia
Keyword(s):  
Intestinal Microbiota ◽  
Short Chain Fatty Acids ◽  
Intestinal Microbiome ◽  
Main Role ◽  
Colonization Resistance ◽  
Wide Range ◽  
Pathogenic Microbes ◽  
Pathogen Colonization ◽  
Antimicrobial Metabolites

Trillions of microbes exist in the human body, particularly the gastrointestinal tract, coevolved with the host in a mutually beneficial relationship. The main role of the intestinal microbiome is the fermentation of non-digestible substrates and increased growth of beneficial microbes that produce key antimicrobial metabolites such as short-chain fatty acids, etc., to inhibit the growth of pathogenic microbes besides other functions. Intestinal microbiota can prevent pathogen colonization through the mechanism of colonization resistance. A wide range of resistomes are present in both beneficial and pathogenic microbes. Giving antibiotic exposure to the intestinal microbiome (both beneficial and hostile) can trigger a resistome response, affecting colonization resistance. The following review provides a mechanistic overview of the intestinal microbiome and the impacts of antibiotic therapy on pathogen colonization and diseases. Further, we also discuss the epidemiology of immunocompromised patients who are at high risk for nosocomial infections, colonization and decolonization of multi-drug resistant organisms in the intestine, and the direct and indirect mechanisms that govern colonization resistance to the pathogens.

scholarly journals The Basal Ganglia and Motor Control

2003 ◽  
Vol 10 (1-2) ◽  
pp. 107-120 ◽  
Author(s):  
Henk J. Groenewegen
Keyword(s):  
Motor Control ◽  
Basal Ganglia ◽  
Functional Organization ◽  
Functional Anatomy ◽  
Main Role ◽  
Brain Functions ◽  
Wide Range ◽  
Selection Mechanisms ◽  
Selection Of

This paper briefly reviews the functional anatomy of the basal ganglia and their relationships with the thalamocortical system. The basal ganglia, including the striatum, pallidum, subthalamic nucleus, and substantia nigra, are involved in a number of parallel, functionally segregated cortical-subcortical circuits. These circuits support a wide range of sensorimotor, cognitive and emotional-motivational brain functions. A main role of the basal ganglia is the learning and selection of the most appropriate motor or behavioral programs. The internal functional organization of the basal ganglia is very well suited for such selection mechanisms, both in development and in adulthood. The question of whether clumsiness may be, at least in part, attributed to dysfunction of the basal ganglia is discussed in the context of the differential, complementary, or interactive roles of the basal ganglia and the cerebellum in the development of motor control.

Role of spectrin in membrane fusion and in shape change of human erythrocyte ghost

1978 ◽  
Vol 36 (2) ◽  
pp. 328-329
Author(s):  
Hideo Hayashi ◽  
Yoshikazu Hirai ◽  
John T. Penniston
Keyword(s):  
Conformational Changes ◽  
Human Erythrocyte ◽  
Shape Change ◽  
Membrane Surface ◽  
Slight Modification ◽  
Active Role ◽  
Main Role ◽  
Bank Blood ◽  
Human Erythrocyte Ghost

Spectrin is a membrane associated protein most of which properties have been tentatively elucidated. A main role of the protein has been assumed to give a supporting structure to inside of the membrane. As reported previously, however, the isolated spectrin molecule underwent self assemble to form such as fibrous, meshwork, dispersed or aggregated arrangements depending upon the buffer suspended and was suggested to play an active role in the membrane conformational changes. In this study, the role of spectrin and actin was examined in terms of the molecular arrangements on the erythrocyte membrane surface with correlation to the functional states of the ghosts.Human erythrocyte ghosts were prepared from either freshly drawn or stocked bank blood by the method of Dodge et al with a slight modification as described before. Anti-spectrin antibody was raised against rabbit by injection of purified spectrin and partially purified.

Mesophyll conductance: the leaf corridors for photosynthesis

2020 ◽  
Vol 48 (2) ◽  
pp. 429-439 ◽  
Author(s):  
Jorge Gago ◽  
Danilo M. Daloso ◽  
Marc Carriquí ◽  
Miquel Nadal ◽  
Melanie Morales ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Current Knowledge ◽  
Main Role ◽  
Mesophyll Conductance ◽  
Future Studies ◽  
Cell Structures ◽  
Leaf Tissues ◽  
Change Framework ◽  
Chloroplast Stroma

Besides stomata, the photosynthetic CO2 pathway also involves the transport of CO2 from the sub-stomatal air spaces inside to the carboxylation sites in the chloroplast stroma, where Rubisco is located. This pathway is far to be a simple and direct way, formed by series of consecutive barriers that the CO2 should cross to be finally assimilated in photosynthesis, known as the mesophyll conductance (gm). Therefore, the gm reflects the pathway through different air, water and biophysical barriers within the leaf tissues and cell structures. Currently, it is known that gm can impose the same level of limitation (or even higher depending of the conditions) to photosynthesis than the wider known stomata or biochemistry. In this mini-review, we are focused on each of the gm determinants to summarize the current knowledge on the mechanisms driving gm from anatomical to metabolic and biochemical perspectives. Special attention deserve the latest studies demonstrating the importance of the molecular mechanisms driving anatomical traits as cell wall and the chloroplast surface exposed to the mesophyll airspaces (Sc/S) that significantly constrain gm. However, even considering these recent discoveries, still is poorly understood the mechanisms about signaling pathways linking the environment a/biotic stressors with gm responses. Thus, considering the main role of gm as a major driver of the CO2 availability at the carboxylation sites, future studies into these aspects will help us to understand photosynthesis responses in a global change framework.

Sign in / Sign up

Export Citation Format

Share Document