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PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0260108
Author(s):  
Gregory Baramidze ◽  
Victoria Baramidze ◽  
Ying Xu

In this paper we introduce a system of partial differential equations that is capable of modeling a variety of dynamic processes in soft tissue cellular populations and their microenvironments. The model is designed to be general enough to simulate such processes as tissue regeneration, tumor growth, immune response, and many more. It also has built-in flexibility to include multiple chemical fields and/or sub-populations of cells, interstitial fluid and/or extracellular matrix. The model is derived from the conservation laws for mass and linear momentum and therefore can be classified as a continuum multi-phase model. A careful choice of state variables provides stability in solving the system of discretized equations defining advective flux terms. A concept of deviation from normal allows us to use simplified constitutive relations for stresses. We also present an algorithm for computing numerical approximations to the solutions of the system and discuss properties of these approximations. We demonstrate several examples of applications of the model. Numerical simulations show a significant potential of the model for simulating a variety of processes in soft tissues.


Symmetry ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2112
Author(s):  
Ahmed Elshahhat ◽  
Berihan R. Elemary

Censoring mechanisms are widely used in various life tests, such as medicine, engineering, biology, etc., as they save (overall) test time and cost. In this context, we consider the problem of estimating the unknown xgamma parameter and some survival characteristics, such as reliability and failure rate functions in the presence of adaptive type-II progressive hybrid censored data. For this purpose, the maximum likelihood and Bayesian inferential approaches are used. Using the observed Fisher information under s-normal approximation, different asymptotic confidence intervals for any function of the unknown parameter were constructed. Using the gamma flexible prior, Bayes estimators against the squared-error loss were developed. Two procedures of Bayesian approximations—Lindley’s approximation and Metropolis–Hastings algorithm—were used to carry out the Bayes estimates and to construct the associated credible intervals. An extensive simulation study was implemented to compare the performance of the different methods. To validate the proposed methodologies of inference—two practical studies using datasets that form engineering and chemical fields are discussed.


2021 ◽  
Vol 2109 (1) ◽  
pp. 012025
Author(s):  
Qiuli Zhao ◽  
Qinghao Yang

Abstract 1,8-naphthalimide (NI) dyes are one class of important organic luminophores with good photo-stability, high fluorescent quantum yields and broad emission color-tunability, which are widely used in biological and chemical fields. However, they exhibit bad ACQ property, which heavily limits their application in real word. Contrary to ACQ, tetraphenylethene (TPE) is an AIE luminogen. To eliminate the ACQ effect of NI, TPE was used as core and NI chromophores was used as peripheries to obtain a new dye TPEDNI. TPEDNI dye demonstrates typical aggregation-enhanced emission (AEE) characteristic with high fluorescence Φ>F, solid up to 100% in the film state, which is 24 times of that for its THF solution. Besides, TPEDNI exhibits marked solvatochromism, and the emission peak red-shifts from 505 nm in hexane to 610 nm in acetonitrile. TPENI also displays evident intramolecular charge transfer property in THF/water mixtures


Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2389
Author(s):  
Tiantian Wei ◽  
Jingjing Wu ◽  
Xiran Shen ◽  
Zhifeng Qiu ◽  
Li Guo

Sequentially defined membrane-like nanomaterials have potential applications in biomedical and chemical fields due to their unique physical and chemical properties. However, these natural and synthetic nanomaterials have not been widely developed due to their complicated molecular sequence and structure, difficulties in synthesis etc. Here, we report a stable membrane-like nanomaterial composed of a monolayer or bilayer that was self-assembled from sequence-defined amphiphilic peptoid triblock (poly(N-aminoethyl glycine)-b-poly(N-octyl glycine)-b-poly(N-carboxyethyl glycine)) and diblock (poly(N-carboxyethyl glycine)-b-poly(N-octyl glycine) and poly(N-aminoethyl glycine)-b-poly(N-octyl glycine)) copolymers separately. A series of peptoid block copolymers were synthesized, and it was observed that long alkyl side chains and abundant hydrophobic blocks were necessary to form the membranes. The prepared membrane-like nanomaterials were fairly stable. They did not change obviously in shape and size with time, and they can survive after sonication. This study is expected to enrich the nanomaterial family, as well as polypeptoid science, and expand their applications in biomedicine and other fields.


2021 ◽  
Vol 5 (1) ◽  
pp. 85-92
Author(s):  
Alfinur Alfinur ◽  
Candra Wahyu Hidayat

This study aims to explain the effect of firm size, sales growth, and profitability on firm value in manufacturing companies in the basic and chemical fields. The sampling technique using the purposive sampling technique was obtained by 40 companies in the basic and chemical fields listed on the Indonesia Stock Exchange (IDX). This type of research is quantitative research, using secondary data in the form of company financial statements obtained from www.idx.co.id, and multiple linear regression data analysis techniques. The results of this study indicate that firm size and profitability affect firm value, while sales growth does not affect firm value.


Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Felix Sima ◽  
Koji Sugioka

Abstract In the last decades, research and development of microfluidics have made extraordinary progress, since they have revolutionized the biological and chemical fields as a backbone of lab-on-a-chip systems. Further advancement pushes to miniaturize the architectures to nanoscale in terms of both the sizes and the fluid dynamics for some specific applications including investigation of biological sub-cellular aspects and chemical analysis with much improved detection limits. In particular, nano-scale channels offer new opportunities for tests at single cell or even molecular levels. Thus, nanofluidics, which is a microfluidic system involving channels with nanometer dimensions typically smaller than several hundred nm, has been proposed as an ideal platform for investigating fundamental molecular events at the cell-extracellular milieu interface, biological sensing, and more recently for studying cancer cell migration in a space much narrower than the cell size. In addition, nanofluidics can be used for sample manipulation in analytical chemistry, such as sample injections, separation, purifications or for quantitative and qualitative determinations. Among the nanofabrication technologies, ultrafast laser manufacturing is a promising tool for fabrication of nanofluidics due to its flexibility, versatility, high fabrication resolution and three dimensional (3D) fabrication capability. In this paper, we review the technological advancements of nanofluidic systems, with emphasis on fabrication methods, in particular ultrafast laser manufacturing. We present the challenges for issues concerning channel sizes and fluid dynamics, and introduce the applications in physics, biology, chemistry and engineering with future prospects.


2021 ◽  
Author(s):  
carla gasbarri ◽  
maurizio ronci ◽  
antonio aceto ◽  
tullio florio ◽  
Federica Barbieri ◽  
...  

<p>In this work high resolution techniques as transmission electron microscopy (TEM), scanning electron microscopy (SEM), Zeta Potential measurements, and matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF) have been employed to deeply investigate about silver nanoparticles (AgNPs) electrochemically synthesized and successfully applied in biological and chemical fields. Strong brightness, as well as the tendency to generate odd number nanoclusters, and the absence of free silver ion in solution have been observed. The chemical and physical properties of the AgNPs seem to be related to their peculiar oxidative state as suggested by X-ray photoelectron spectroscopy (XPS) and X-ray powder diffraction analysis (XRPD). Finally, cytotoxicity of the investigated AgNPs has been tested by MTT assay.</p>


2021 ◽  
Author(s):  
carla gasbarri ◽  
maurizio ronci ◽  
antonio aceto ◽  
tullio florio ◽  
Federica Barbieri ◽  
...  

<p>In this work high resolution techniques as transmission electron microscopy (TEM), scanning electron microscopy (SEM), Zeta Potential measurements, and matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF) have been employed to deeply investigate about silver nanoparticles (AgNPs) electrochemically synthesized and successfully applied in biological and chemical fields. Strong brightness, as well as the tendency to generate odd number nanoclusters, and the absence of free silver ion in solution have been observed. The chemical and physical properties of the AgNPs seem to be related to their peculiar oxidative state as suggested by X-ray photoelectron spectroscopy (XPS) and X-ray powder diffraction analysis (XRPD). Finally, cytotoxicity of the investigated AgNPs has been tested by MTT assay.</p>


Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1937
Author(s):  
Jiri Militky ◽  
Ondrej Novak ◽  
Dana Kremenakova ◽  
Jakub Wiener ◽  
Mohanapriya Venkataraman ◽  
...  

COVID-19, classified as SARS-CoV-2, is causing an ongoing global pandemic. The pandemic has resulted in the loss of lives and has caused economic hardships. Most of the devices used to protect against the transmission of the novel COVID-19 disease are related to textile structures. Hence, the challenge for textile professionals is to design and develop suitable textile structures with multiple functionalities for capturing viruses, passivating them, and, at the same time, having no adverse effects on humans during the complete period of use. In addition to manufacturing efficient, biocompatible, and cost-effective protective face masks, it is also necessary to inform the public about the benefits and risks of protective face mask materials. The purpose of this article is to address the concerns of efficiency and efficacy of face masks by primarily reviewing the literature of research conducted at the Technical University of Liberec. The main focus is on the presentation of problems related to the specification of aims of face mask applications, mechanisms of capture, durability, and modes of sterilization. The recommendations, instead of conclusions, are addressed to the whole textile society because they should be leading players in the design, creation, and proper treatment of face masks due to their familiarity with the complex behavior of textile structures and targeted changes of structural hierarchy starting from polymeric chains (nano-level) and ending in planar textile structures (millimeter level) due to action by mechanical, physical and chemical fields. This becomes extremely critical to saving hundreds of thousands of lives from COVID-19.


2020 ◽  
pp. 174751982094287
Author(s):  
Shangfeng Ren ◽  
Nianhua Luo ◽  
Kunming Liu ◽  
Jin-Biao Liu

Organosulfur compounds with unsymmetrical S–S bonds are usually called unsymmetrical disulfides and are widely used in the biological, medicinal, and chemical fields. Their versatility has guided the development of various new methods for the synthesis of disulfides. In recent years, the synthesis of disulfides by cross-dehydrogenation of thiols has attracted much attention due to its high atomic economy. Herein, this review summarizes progress toward the synthesis of unsymmetrical disulfides under chemical oxidation, electrooxidation, or photocatalysis by cross-dehydrogenation of thiols.


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