scholarly journals Mechanism studies on the cellular internalization of nanoparticles using computer simulations: A review

2021 ◽  
Author(s):  
Yun Hao Feng ◽  
Bo Zhi Chen ◽  
Wen Min Fei ◽  
Yong Cui ◽  
CAN YANG ZHANG ◽  
...  
Keyword(s):  
Computer Simulations ◽  
Drug Loading ◽  
Interaction Mechanism ◽  
Current Status ◽  
Negative Effects ◽  
Cell Internalization ◽  
Time Space ◽  
Mesoscopic Structure ◽  
Structure Of Nanoparticles ◽  
Nanoparticle Structure

Nanomaterial drug delivery systems have become one of the most important targeted therapy technologies. Although great efforts have been made to study the self-assembled mesoscopic structure of nanoparticles and understand drug loading and release mechanisms, the interaction between nanoparticles and cell membranes has not yet been clearly studied. Moreover, the research of experimental methods in this field has been greatly restricted due to its special time-space scale, so it is necessary to apply computer simulations to visualize the cell internalization of the nanoparticle. This review covers modelling methods and the current status and viewpoints of research on the influencing factors of the nanoparticle-biomembrane interaction mechanism. In particular, we discussed in detail the positive and negative effects of various nanoparticle properties. This article may assist researchers in rationally optimize the nanoparticle structure to improve therapeutic efficiency.

scholarly journals Radio imaging-spectroscopy observations of the Sun in decimetric and centimetric wavelengths

2012 ◽  
Vol 8 (S294) ◽  
pp. 489-494 ◽  
Author(s):  
Yihua Yan ◽  
Wei Wang ◽  
Fei Liu ◽  
Lihong Geng ◽  
Zhijun Chen ◽  
...  
Keyword(s):  
Radio Emission ◽  
Solar Flares ◽  
Inner Mongolia ◽  
Imaging Spectroscopy ◽  
Current Status ◽  
The Sun ◽  
Radio Imaging ◽  
Time Space ◽  
Decimetric Wave ◽  
Wave Range

AbstractTo address fundamental processes in the solar eruptive phenomena it is important to have imaging-spectroscopy over centimetric-decimetric wave range. The Chinese Spectral Radioheliograph (CSRH) in 0.4-15 GHz range with high time, space and frequency resolutions is being constructed to achieve this goal. The perspectives to open new observational windows on solar flares and CMEs will be achieved by mapping the radio emission from unstable electron populations during the basic processes of energy release. CSRH is located in a radio quiet region in Inner Mongolia of China. The array of CSRH-I in 0.4-2.0 GHz with 40 4.5m antennas has been established and starts test observations. The 60 2m antennas for array of CSRH-II in 2-15 GHz have been mounted and assembled. The progress and current status of CSRH are introduced.

Community-based island tourism: the case of Boa Vista in Cape Verde

2014 ◽  
Vol 8 (2) ◽  
pp. 219-233 ◽  
Author(s):  
Sandra M. Sánchez-Cañizares ◽  
Ana María Castillo-Canalejo
Keyword(s):  
Local Community ◽  
Service Providers ◽  
Cape Verde ◽  
Current Status ◽  
Supply Side ◽  
Demand Side ◽  
Negative Effects ◽  
Community Based ◽  
Content Type ◽  
Positive Effects

Purpose – This paper tries to explore the possibilities of developing sustainable, community-based tourism (CBT) in Boa Vista in Cape Verde, Africa. Island territories are generally considered preferential tourist destinations. However, the negative effects of tourism in these destinations should not be overlooked, among them environmental concerns and impacts on the culture of the island’s inhabitants. The development of CBT takes on special relevance, as it based on planning schemes in conjunction with the local community who share the positive effects derived from tourism. Design/methodology/approach – The methodology used consisted in designing two surveys: one focusing on the supply side and another on the demand side of tourism to define and analyse the current status of this sector in Boa Vista. The survey on tourism supply was distributed among a panel of experts formed by tourism service providers located in Boa Vista. The statistical results of the responses and the discussion carried out by the panel of experts permitted the development of a SWOT matrix. The survey on demand was administered to foreign tourists in different parts of the island. A total of 202 valid surveys were obtained. Findings – The main results of the fieldwork are twofold. On the supply side of tourism, the community is making an enormous effort to actively participate in the development of sustainable tourism, efforts which are often constrained by the geographical barriers of Boa Vista (sandy soil, poor accessibility to other islands) and the institutional and political situation of the island. As regards the demand side of tourism, the vast majority of tourists stay at the island’s all-inclusive resorts, whereas few tourists require the services provided by the community, mainly because they are unaware that such services exist. Originality/value – Certain island destinations are more appropriate for tourists wishing to flee mass tourism enclaves due to their natural environment, relative isolation and the traditional culture of their inhabitants. For this reason, it is important to develop a CBT model for these destinations in which initiatives are planned in conjunction with members of the local community who participate in decision-making processes and benefit equally from the positive effects of tourism. Although several case studies have been reported in the research on CBT initiatives, few studies have been carried out on CBT in island territories. This is the main contribution in this paper.

scholarly journals Interaction mechanism of doxorubicin and SWCNT: protonation and diameter effects on drug loading and releasing

RSC Advances ◽  
2016 ◽  
Vol 6 (1) ◽  
pp. 314-322 ◽  
Author(s):  
Yixuan Wang ◽  
Zhenfeng Xu
Keyword(s):  
Drug Delivery ◽  
Drug Delivery System ◽  
Delivery System ◽  
Drug Loading ◽  
Interaction Mechanism ◽  
System P

The encapsulation of DOX plays an important role in the design of a CNT-based drug delivery system.

scholarly journals Are Agricultural Commodity Prices on a Conventional Wisdom with Inflation?

SAGE Open ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 215824402110383
Author(s):  
Ting-Ting Sun ◽  
Chi-Wei Su ◽  
Ran Tao ◽  
Meng Qin
Keyword(s):  
Mutual Influence ◽  
Supply And Demand ◽  
Interaction Mechanism ◽  
Commodity Prices ◽  
Chinese Government ◽  
Agricultural Commodity ◽  
Negative Effects ◽  
Positive Effects ◽  
Price Levels ◽  
Causality Tests

The study investigates the mutual influence between agricultural commodity prices (ACP) and inflation (INF) in China by employing the bootstrap full- and sub-sample rolling-window Granger causality tests. We find that ACP has positive effects on INF, indicating that agricultural commodities play a significant role in stabilizing general price levels, but the higher ACP may create inflationary pressures. However, the negative effects suggest that under the shock of external uncertainty, the rise of ACP is not always regarded as the prime driver of INF. The results are not consistent with Hypothesis 1, which highlights that INF is positively affected by ACP. In turn, we also find positive and negative impacts of INF on ACP, showing that the level of INF can affect the supply and demand of agricultural commodity markets, it can be considered as a factor affecting ACP. The findings support Hypothesis 2 derived from the interaction mechanism. These analyses can assist the Chinese government to understand that ACP is not an effective indicator for forecasting INF. It also can prompt them to pay attention to the transmission effect of price levels on ACP, to maintain the stability of the agricultural commodity market.

scholarly journals Actividad Física y sedentarismo: Repercusiones sobre la salud y calidad de vida de las personas mayores (Physical activity and sedentary lifestyle: Impact on health and quality of life of older people)

Retos ◽  
2015 ◽  
pp. 126-129
Author(s):  
Francisco Salinas Martínez ◽  
Armando Cocca ◽  
Kamal Mohamed ◽  
Jesús Viciana Ramírez
Keyword(s):  
Quality Of Life ◽  
Physical Activity ◽  
Older People ◽  
Sedentary Lifestyle ◽  
The Elderly ◽  
Current Status ◽  
Negative Effects ◽  
Calidad De Vida ◽  
Elderly Health

Realizamos un análisis del estado actual de las personas mayores en relación con la actividad física y el sedentarismo, éste último aspecto convertido en la actualidad como una de las principales fuentes de amenaza para la salud pública de los países europeos y americanos. Damos a conocer los efectos negativos de la inactividad física sobre los parámetros cardiovasculares, diabetes, depresión y cáncer, entre otros. Mostramos los beneficios de la actividad física (herramienta clave para solucionar los problemas propios del sedentarismo) para la salud de este colectivo de la población; al tiempo que estudiamos las razones por las que las personas mayores acuden a los programas de actividad física. Finalmente, aportamos una serie de conclusiones.Palabras clave: Actividad Física. Calidad de Vida. Personas mayores. Salud. Sedentarismo.Abstract: We analyzed the current status of the elderly in relation to physical activity and sedentary, the latter now become a major source of threat to public health in the European and American countries. We report the negative effects of physical inactivity on cardiovascular parameters, diabetes, depression and cancer, among others. We show the benefits of physical activity (a key tool to solve the problems of the sedentary lifestyle) for the health of this group of the population while we study the reasons why older people attend physical activity programs. Finally, we provide a number of conclusions. Keywords: Physical Activity. Quality of Life. Elderly. Health. Sedentary.

scholarly journals A Bibliometric Analysis of Research on Acid Rain

2019 ◽  
Vol 11 (11) ◽  
pp. 3077 ◽  
Author(s):  
Ziqiang Liu ◽  
Jiayue Yang ◽  
Jiaen Zhang ◽  
Huimin Xiang ◽  
Hui Wei
Keyword(s):  
United States ◽  
Surface Water ◽  
Acid Rain ◽  
Bibliometric Analysis ◽  
Regional Scale ◽  
The United States ◽  
Research Area ◽  
Phosphorus Fractionation ◽  
Current Status ◽  
Negative Effects

With the continuation of industrialization and urbanization, acid rain (AR) has aroused extensive concern because of its potential negative effects on ecosystems. However, analysis of the current status and development trends in AR research area has seldom been systematically studied. Therefore, we motivated to conduct a bibliometric analysis of AR publications (1900–2018) using HistCite and CiteSpace software programs. Compared to traditional reviews by experts, this study offers an alternative method to quantitatively analyze and visualize the development of AR field at a large time scale. The results indicated that the overall concern of AR research studies had increased from 1900 to 2018. The most productive country was the United States, while the institution with the most publications was Chinese Academy of Sciences. “Environmental Sciences” was the most popular subject category, Water, Air, and Soil Pollution was the dominant journal, and C.T. Driscoll was the most prominent author in AR field. There were three hotspots in the field of AR, including analyzing AR status and its control policies in Europe, the United States, and China in the past few decades, investigating the ecological consequences of AR on plant histological, physiological, and biochemical traits, as well as surface water and soil properties, and the model application for quantitatively assessing AR and its effects on terrestrial and aquatic ecosystems at regional scale. Further, “behavior”, “phosphorus”, “fractionation”, “soil acidification”, “corrosion”, “performance”, “recovery”, “rainwater”, “trace element”, and “surface water” have been emerging active topics in recent years. This study can help new researchers to find out the most relevant subject categories, countries, institutions, journals, authors, and articles, and identify research trends and frontiers in the field of AR.

Computer study of the solubilization of polymer chains in polyelectrolyte complex cores of polymeric nanoparticles in aqueous media

2018 ◽  
Vol 20 (47) ◽  
pp. 29876-29888 ◽  
Author(s):  
Karel Šindelka ◽  
Zuzana Limpouchová ◽  
Karel Procházka
Keyword(s):  
Computer Simulations ◽  
Polyelectrolyte Complex ◽  
Polymeric Nanoparticles ◽  
Aqueous Media ◽  
Polymer Chains ◽  
Coarse Grained ◽  
Computer Study ◽  
Interpolyelectrolyte Complex ◽  
Structure Of Nanoparticles ◽  
Polar Polymer

The formation and structure of nanoparticles containing non-polar polymer chains solubilized in interpolyelectrolyte complex (IPC) cores and the partitioning of non-polar chains between bulk solvent and IPC cores were studied by coarse-grained computer simulations.

Prenatal stress and its role in children's pathology: historical aspects and the current status of the question (review of literature)

2020 ◽  
Vol 24 (3) ◽  
pp. 28-41
Author(s):  
A. A. Vyalkova ◽  
B. A. Frolov ◽  
E. V. Savelyeva ◽  
S. A. Chesnokova
Keyword(s):  
Oxidative Stress ◽  
Kidney Diseases ◽  
Scientific Evidence ◽  
Current Status ◽  
Stress Reactions ◽  
Metabolic Disturbances ◽  
Negative Effects ◽  
Adaptation Mechanism ◽  
Increased Risk

The article presents an analysis of fundamental data on the problem of stress and its role in the development of stressful diseases. Scientific evidence on the role of stress in childhood pathology indicates the extreme pathogenetic significance of stress. It is proved that stress has three interconnected faces: stress as a link in the adaptation mechanism, stress as a link in the pathogenesis of diseases and adaptation to stressful situations as a natural prevention of stressful diseases. The scientific substantiation of the main evolutionarily determined role of stress as an adaptation link indicates the possibility of acquiring some degree of resistance to stressful situations. Prevention of reducing the excess of stress reactions and reducing the possibility of its transformation into a link in the pathogenesis of diseases limits the complex of mechanisms designated as a stress-limiting system. Important information is the development and coordination of the stress response, which is provided by a complex set of mechanisms of neuroendocrine regulation, united by the concept of “stress-implementing system”. The most common forms of stress are fetal hypoxia, metabolic disturbances, and toxic effects leading to uncontrolled oxidative stress at the cellular and tissue levels with the development of pregnancy complications, intrauterine growth retardation syndrome (IUGR), persistent changes and pathological conditions. As the fetus grows, the flow of oxygen and nutrients from the mother through the placenta increases, which is accompanied by an increased risk of the formation of pathologies of the brain, heart, liver and kidneys with the development of a multi-organ pathology in the subsequent life. It has been proven that oxidative stress combined with stress of malnutrition in the prenatal period increases the risk of endocrinopathies, kidney diseases, and a number of other chronic diseases in the adult state. In practical terms, the negative effects of stress are of particular interest. Early detection of psychosocial and sympathomimetic factors causing stress is the basis for the prevention of childhood pathology.

scholarly journals Silk Particles as Carriers of Therapeutic Molecules for Cancer Treatment

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4946
Author(s):  
Anna Florczak ◽  
Inga Grzechowiak ◽  
Tomasz Deptuch ◽  
Kamil Kucharczyk ◽  
Alicja Kaminska ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Cancer Treatment ◽  
Cancer Cells ◽  
Silk Fibroin ◽  
Drug Delivery Systems ◽  
Inorganic Compounds ◽  
Release Kinetics ◽  
Drug Loading ◽  
Delivery Systems ◽  
Current Status

Although progress is observed in cancer treatment, this disease continues to be the second leading cause of death worldwide. The current understanding of cancer indicates that treating cancer should not be limited to killing cancer cells alone, but that the target is the complex tumor microenvironment (TME). The application of nanoparticle-based drug delivery systems (DDS) can not only target cancer cells and TME, but also simultaneously resolve the severe side effects of various cancer treatment approaches, leading to more effective, precise, and less invasive therapy. Nanoparticles based on proteins derived from silkworms’ cocoons (like silk fibroin and sericins) and silk proteins from spiders (spidroins) are intensively explored not only in the oncology field. This natural-derived material offer biocompatibility, biodegradability, and simplicity of preparation methods. The protein-based material can be tailored for size, stability, drug loading/release kinetics, and functionalized with targeting ligands. This review summarizes the current status of drug delivery systems’ development based on proteins derived from silk fibroin, sericins, and spidroins, which application is focused on systemic cancer treatment. The nanoparticles that deliver chemotherapeutics, nucleic acid-based therapeutics, natural-derived agents, therapeutic proteins or peptides, inorganic compounds, as well as photosensitive molecules, are introduced.

scholarly journals Lyoprotective Effects of Mannitol and Lactose Compared to Sucrose and Trehalose: Sildenafil Citrate Liposomes as a Case Study

Pharmaceutics ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1164
Author(s):  
María José de Jesús Valle ◽  
Andreía Alves ◽  
Paula Coutinho ◽  
Maximiano Prata Ribeiro ◽  
Cristina Maderuelo ◽  
...  
Keyword(s):  
Large Scale ◽  
Drug Loading ◽  
Thermal Characteristics ◽  
Pulmonary Delivery ◽  
Entrapment Efficiency ◽  
Sildenafil Citrate ◽  
Scale Production ◽  
Stabilizing Agents ◽  
Cell Internalization ◽  
Large Scale Production

The lyoprotective effects of mannitol and lactose have been evaluated in the production of sildenafil citrate liposomes. Liposomes were prepared by mixing the components under ultrasonic agitation, followed by a transmembrane pH gradient for remote drug loading. Mannitol and lactose, as compared to sucrose and trehalose, were used as the stabilizing agents, and different freeze-drying cycles were assayed. The remaining moisture and the thermal characteristics of the lyophilized samples were analyzed. Size, entrapment efficiency, biocompatibility, and cell internalization of original and rehydrated liposomes were compared. The type of additive did not affect the biocompatibility or cell internalization, but did influence other liposome attributes, including the thermal characteristics and the remaining moisture of the lyophilized samples. A cut-off of 5% (w/w) remaining moisture was an indicator of primary drying completion—information useful for scaling up and transfer from laboratory to large-scale production. Lactose increased the glass transition temperature to over 70 °C, producing lyoprotective effects similar to those obtained with sucrose. Based on these results, formulations containing liposomes lyophilized with lactose meet the FDA’s requirements and can be used as a biocompatible and biodegradable vehicle for the pulmonary delivery of therapeutic doses of sildenafil citrate.

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