scholarly journals Hybrid RF-Si Xerogels: A Cost-Effective Proposal for Insulator Materials

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 265
Author(s):  
Samantha L. Flores-López ◽  
Sara F. Villanueva ◽  
Natalia Rey-Raap ◽  
Ana Arenillas
Keyword(s):  
Cost Effective ◽  
Material Design ◽  
Structural Features ◽  
Polymerization Process ◽  
Drying Methods ◽  
Molar Ratios ◽  
Starting Point ◽  
Good Starting Point ◽  
Hybrid Xerogels ◽  
Lengthy Process

Hybrid xerogels RF/Si were synthesized by controlling the chemical variables involved in the polymerization process (i.e., molar ratios, dilution ratio, catalysts, etc.) and evaluated as insulator materials. Higher insulating performances were recorded for these hybrids compared with their counterparts made from only one of their components (i.e., RF or Si xerogels with similar porous characteristics). The analysis of chemical and structural features correlated with heat transfer methods was useful in understanding the sum of contributions involved in the thermal conductivity of RF/Si xerogels. Variables such as roughness and tortuosity can be used to improve the performance of xerogels from a different perspective. In this way, thermal conductivities of 25 mW/mK were achieved without lengthy process steps or special drying methods. Knowledge of material design and the use of microwave heating during the synthesis allowed us to approach a simple and cost-effective process. These results suggest that the hybrid materials developed in this work are a good starting point for the future of the massive production of insulation materials.

Beyond Textbooks

2019 ◽  
pp. 182-200 ◽  
Author(s):  
Lesley S. J. Farmer
Keyword(s):  
Teaching And Learning ◽  
Online Courses ◽  
Cost Effective ◽  
Open Educational Resources ◽  
Educational Resources ◽  
Academic Needs ◽  
Online Instructors ◽  
Starting Point ◽  
Good Starting Point ◽  
Reference Tool

Textbooks can serve as a good starting point for learning concepts or serve as a reinforcing reference tool for students. However, to address the various academic needs of students, as well as to affirm the richness and depth of the knowledge, skills, and dispositions in online courses, online instructors should complement and supplement textbooks with other resources in various formats. Education has a growing need for digital resources, starting with digital textbooks, and expanding to other kinds of educational resources. Open educational resources, in particular, provide cost-effective and flexible tools for teaching and learning.

scholarly journals Investigation of the influence of relative humidity and temperature on the IOT solution with low cost air quality monitoring

2020 ◽  
Author(s):  
Ivan Vajs ◽  
◽  
Dejan Dragić ◽  
Ilija Radovanović ◽  
◽  
...  
Keyword(s):  
Air Quality ◽  
Relative Humidity ◽  
Low Cost ◽  
Cost Effective ◽  
Air Monitoring ◽  
Measuring Error ◽  
Monitoring Systems ◽  
Starting Point ◽  
Different Types ◽  
Good Starting Point

Due to the rising air pollution in densely populated areas, the need for reliable and cost-effective air monitoring systems is on the rise. Low-cost off-the-shelf air quality sensors available on the market provide a good starting point as they are readily available and inexpensive but fall short when it comes to accuracy and reliability. In this paper, the influence of relative humidity and temperature on the accuracy of these sensors is analyzed. Different types of statistical models are used in order to model the measuring error of the sensors caused by relative humidity and temperature. Obtained results show that the accuracy of the off-the-shelf system can be improved by adequate compensation and a more reliable, yet inexpensive air monitoring systems could be implemented.

Biological and In silico Studies on Synthetic Analogues of Tyrosine Betaine as Inhibitors of Neprilysin - A Drug Target for the Treatment of Heart Failure

2018 ◽  
Vol 24 (17) ◽  
pp. 1899-1904
Author(s):  
Daniel Fabio Kawano ◽  
Marcelo Rodrigues de Carvalho ◽  
Mauricio Ferreira Marcondes Machado ◽  
Adriana Karaoglanovic Carmona ◽  
Gilberto Ubida Leite Braga ◽  
...  
Keyword(s):  
Heart Failure ◽  
Secondary Metabolites ◽  
Structural Similarity ◽  
Structural Features ◽  
Major Constituent ◽  
Binding Modes ◽  
Starting Point ◽  
In Silico Studies ◽  
Nep Inhibition

Background: Fungal secondary metabolites are important sources for the discovery of new pharmaceuticals, as exemplified by penicillin, lovastatin and cyclosporine. Searching for secondary metabolites of the fungi Metarhizium spp., we previously identified tyrosine betaine as a major constituent. Methods: Because of the structural similarity with other inhibitors of neprilysin (NEP), an enzyme explored for the treatment of heart failure, we devised the synthesis of tyrosine betaine and three analogues to be subjected to in vitro NEP inhibition assays and to molecular modeling studies. Results: In spite of the similar binding modes with other NEP inhibitors, these compounds only displayed moderate inhibitory activities (IC50 ranging from 170.0 to 52.9 µM). However, they enclose structural features required to hinder passive blood brain barrier permeation (BBB). Conclusions: Tyrosine betaine remains as a starting point for the development of NEP inhibitors because of the low probability of BBB permeation and, consequently, of NEP inhibition at the Central Nervous System, which is associated to an increment in the Aβ levels and, accordingly, with a higher risk for the onset of Alzheimer's disease.

Polyamines and Related Nitrogen Compounds in the Chemotherapy of Neglected Diseases Caused by Kinetoplastids

2018 ◽  
Vol 18 (5) ◽  
pp. 321-368 ◽  
Author(s):  
Juan A. Bisceglia ◽  
Maria C. Mollo ◽  
Nadia Gruber ◽  
Liliana R. Orelli
Keyword(s):  
Drug Targets ◽  
Redox Homeostasis ◽  
Cost Effective ◽  
Structural Features ◽  
Mammalian Host ◽  
Neglected Diseases ◽  
Nitrogen Compounds ◽  
Chemical Structures

Neglected diseases due to the parasitic protozoa Leishmania and Trypanosoma (kinetoplastids) affect millions of people worldwide, and the lack of suitable treatments has promoted an ongoing drug discovery effort to identify novel nontoxic and cost-effective chemotherapies. Polyamines are ubiquitous small organic molecules that play key roles in kinetoplastid parasites metabolism, redox homeostasis and in the normal progression of cell cycles, which differ from those found in the mammalian host. These features make polyamines attractive in terms of antiparasitic drug development. The present work provides a comprehensive insight on the use of polyamine derivatives and related nitrogen compounds in the chemotherapy of kinetoplastid diseases. The amount of literature on this subject is considerable, and a classification considering drug targets and chemical structures were made. Polyamines, aminoalcohols and basic heterocycles designed to target the relevant parasitic enzyme trypanothione reductase are discussed in the first section, followed by compounds directed to less common targets, like parasite SOD and the aminopurine P2 transporter. Finally, the third section comprises nitrogen compounds structurally derived from antimalaric agents. References on the chemical synthesis of the selected compounds are reported together with their in vivo and/or in vitro IC50 values, and structureactivity relationships within each group are analyzed. Some favourable structural features were identified from the SAR analyses comprising protonable sites, hydrophobic groups and optimum distances between them. The importance of certain pharmacophoric groups or amino acid residues in the bioactivity of polyamine derived compounds is also discussed.

scholarly journals Discovery and Optimization of Selective Inhibitors of Meprin α (Part I)

2021 ◽  
Vol 14 (3) ◽  
pp. 203 ◽  
Author(s):  
Shurong Hou ◽  
Juan Diez ◽  
Chao Wang ◽  
Christoph Becker-Pauly ◽  
Gregg B. Fields ◽  
...  
Keyword(s):  
Inhibitory Activity ◽  
De Novo ◽  
Selective Inhibitors ◽  
Preclinical Development ◽  
Starting Point ◽  
Good Starting Point ◽  
Parallel Screening ◽  
Low Cytotoxicity

Meprin α and β are zinc-dependent proteinases implicated in multiple diseases including cancers, fibrosis, and Alzheimer’s. However, until recently, only a few inhibitors of either meprin were reported and no inhibitors are in preclinical development. Moreover, inhibitors of other metzincins developed in previous years are not effective in inhibiting meprins suggesting the need for de novo discovery effort. To address the paucity of tractable meprin inhibitors we developed ultrahigh-throughput assays and conducted parallel screening of >650,000 compounds against each meprin. As a result of this effort, we identified five selective meprin α hits belonging to three different chemotypes (triazole-hydroxyacetamides, sulfonamide-hydroxypropanamides, and phenoxy-hydroxyacetamides). These hits demonstrated a nanomolar to micromolar inhibitory activity against meprin α with low cytotoxicity and >30-fold selectivity against meprin β and other related metzincincs. These selective inhibitors of meprin α provide a good starting point for further optimization.

scholarly journals Advances on the Implementation of Circular Economy Techniques in Rural Areas in Colombia under a Sustainable Development Framework

2021 ◽  
Vol 13 (7) ◽  
pp. 3816
Author(s):  
Javier Rodrigo-Ilarri ◽  
Camilo-A. Vargas-Terranova ◽  
María-Elena Rodrigo-Clavero ◽  
Paula-A. Bustos-Castro
Keyword(s):  
Sustainable Development ◽  
Waste Management ◽  
Circular Economy ◽  
Rural Areas ◽  
Development Framework ◽  
Starting Point ◽  
Management Plans ◽  
Good Starting Point ◽  
Depressed Regions ◽  
First Time

For the first time in the scientific literature, this research shows an analysis of the implementation of circular economy techniques under sustainable development framework in six municipalities with a depressed economy in Colombia. The analysis is based on solid waste data production at a local scale, the valuation of the waste for subsequent recycling, and the identification and quantification of the variables associated with the treatment and final disposal of waste, in accordance with the Colombian regulatory framework. Waste generation data are obtained considering three different scenarios, in which a comparison between the simulated values and those established in the management plans are compared. Important differences have been identified between the waste management programs of each municipality, specifically regarding the components of waste collection, transportation and disposal, participation of environmental reclaimers, and potential use of materials. These differences are fundamentally associated with the different administrative processes considered for each individual municipality. This research is a good starting point for the development of waste management models based on circular economy techniques, through the subsequent implementation of an office tool in depressed regions such as those studied.

Industry-Sponsored Medical Education — In the Quest for Professional Integrity and Legal Certainty

2007 ◽  
Vol 14 (4) ◽  
pp. 313-319
Author(s):  
Benedikt Buchner
Keyword(s):  
Medical Education ◽  
Self Regulation ◽  
State Regulation ◽  
General Question ◽  
Legal Certainty ◽  
European Directive ◽  
Starting Point ◽  
Good Starting Point ◽  
Advertising Law ◽  
The Right

AbstractIndustry-sponsored medical education is a much disputed issue. So far, there has been no regulatory framework which provides clear and definite rules as to whether and under what circumstances the sponsorship of medical education is acceptable. State regulation does not exist, or confines itself to a very general principle. Professional regulation, even though applied frequently, is rather vague and indefinite, raising the general question as to whether self-regulation is the right approach at all. Certainly, self-regulation by industry cannot and should not replace other regulatory approaches. Ultimately, advertising law in general and the European Directive 2001/83/EC specifically, might be a good starting point in providing legal certainty and ensuring the independence of medical education. Swiss advertising law illustrates how the principles of the European Directive could be implemented clearly and unambiguously.

scholarly journals Multiple Myeloma Inhibitory Activity of Plant Natural Products

Cancers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2678
Author(s):  
Karin Jöhrer ◽  
Serhat Sezai Ҫiҫek
Keyword(s):  
Multiple Myeloma ◽  
Natural Products ◽  
Myeloma Cell ◽  
Myeloma Cell Line ◽  
Antiproliferative Effects ◽  
Plant Natural Products ◽  
Starting Point ◽  
Human Myeloma Cell Line ◽  
Group A ◽  
Good Starting Point

A literature search on plant natural products with antimyeloma activity until the end of 2020 resulted in 92 compounds with effects on at least one human myeloma cell line. Compounds were divided in different compound classes and both their structure–activity-relationships as well as eventual correlations with the pathways described for Multiple Myeloma were discussed. Each of the major compound classes in this review (alkaloids, phenolics, terpenes) revealed interesting candidates, such as dioncophyllines, a group of naphtylisoquinoline alkaloids, which showed pronounced and selective induction of apoptosis when substituted in position 7 of the isoquinoline moiety. Interestingly, out of the phenolic compound class, two of the most noteworthy constituents belong to the relatively small subclass of xanthones, rendering this group a good starting point for possible further drug development. The class of terpenoids also provides noteworthy constituents, such as the highly oxygenated diterpenoid oridonin, which exhibited antiproliferative effects equal to those of bortezomib on RPMI8226 cells. Moreover, triterpenoids containing a lactone ring and/or quinone-like substructures, e.g., bruceantin, whitaferin A, withanolide F, celastrol, and pristimerin, displayed remarkable activity, with the latter two compounds acting as inhibitors of both NF-κB and proteasome chymotrypsin-like activity.

COVID-19, Business, and Human Rights

2021 ◽  
Vol 23 (5) ◽  
pp. 433-449
Author(s):  
Surya Deva
Keyword(s):  
Human Rights ◽  
Full Range ◽  
International Human Rights Law ◽  
Human Rights Law ◽  
International Human Rights ◽  
Economic Problems ◽  
Business And Human Rights ◽  
Starting Point ◽  
Good Starting Point ◽  
International Human

Abstract COVID-19 has affected the full range of human rights, though some rights holders have experienced a disproportionate impact. This has triggered debate about the respective obligations and responsibilities of states and business enterprises under international human rights law. Against this backdrop, this article examines critically whether the “protect, respect and remedy” framework operationalised by the UN Guiding Principles on Business and Human Rights is “fit for the purpose” to deal with the COVID-19 crisis. I argue that while the UNGPs’ framework provides a good starting point, it is inadequate to bring transformative changes to overcome deep-rooted socio-economic problems exposed by this pandemic. Realising human rights fully would not only require harnessing the potential of states’ tripartite obligations, but also move beyond limiting the responsibility of businesses to respect human rights.

Search for active candidates in a range of flavonoids regarding SARS-CoV-2 by the method of molecular docking

2021 ◽  
pp. 22-35
Author(s):  
Stanislav V. Pechinskii ◽  
Eduard T. Oganesyan ◽  
Anna G. Kuregyan
Keyword(s):  
Molecular Docking ◽  
Antiviral Activity ◽  
Cost Effective ◽  
Structural Features ◽  
Biologically Active ◽  
Active Structures ◽  
Main Protease ◽  
Targeted Screening ◽  
The Relationship ◽  
Structure And Activity

Molecular docking is a convenient and cost-effective tool for targeted screening of biologically active structures. This method makes it possible to reveal the relationship between structure and activity, as well as to search for new active compounds. Due to the fact that the antiviral activity of flavonoids and their derivatives has been shown experimentally and clinically, the study of their antiviral activity against SARS-CoV-2 is a promising study. In an in silico experiment, the possibility of binding 20 flavonoid ligands and the main protease SARS-CoV-2 was studied. The structural features of flavone and flavanone derivatives have been determined, which determine their ability to block the main protease of the SARS-CoV-2 virus. Structures of eight new candidates that bind the main protease SARS-CoV-2, which have the prospect of synthesis and further pharmacological research, have been proposed.

Sign in / Sign up

Export Citation Format

Share Document