siRNA nanotherapeutics: a promising strategy for anti‐HBV therapy

Chronic hepatitis B (CHB) is the most common cause of hepatocellular carcinoma (HCC) and liver cirrhosis worldwide. In spite of the numerous advances in the treatment of CHB, drugs and vaccines have failed because of many factors like complexity, resistance, toxicity, and heavy cost. New RNA interference (RNAi)‐based technologies have developed innovative strategies to target Achilles'' heel of the several hazardous diseases involving cancer, some genetic disease, autoimmune illnesses, and viral disorders particularly hepatitis B virus (HBV) infections. Naked siRNA delivery has serious challenges including failure to cross the cell membrane, susceptibility to the enzymatic digestion, and excretion by renal filtration, which ideally can be addressed by nanoparticle‐mediated delivery systems. cccDNA formation is a significant problem in obtaining HBV infections complete cure because of strength, durability, and lack of proper immune response. Nano‐siRNA drugs have a great potential to address this problem by silencing specific genes which are involved in cccDNA formation. In this article, the authors describe siRNA nanocarrier‐mediated delivery systems as a promising new strategy for HBV infections therapy. Simultaneously, the authors completely represent the clinical trials which use these strategies for treatment of the HBV infections.Inspec keywords: tumours, drugs, genetics, cellular biophysics, RNA, nanomedicine, diseases, molecular biophysics, microorganisms, cancer, liver, nanoparticles, patient treatmentOther keywords: siRNA nanotherapeutics, anti‐HBV therapy, chronic hepatitis B, CHB, HCC, hazardous diseases, cancer, genetic disease, autoimmune illnesses, viral disorders, hepatitis B virus infections, naked siRNA delivery, cell membrane, enzymatic digestion, renal filtration, nanoparticle‐mediated delivery systems, cccDNA formation, HBV infections complete cure, nanosiRNA drugs, siRNA nanocarrier‐mediated delivery systems, HBV infections therapy, liver cirrhosis, RNA interference, immune response, hepatocellular carcinoma     

Mitigation of wind‐induced motion of Milad Tower by tuned mass damper

With a height of 435 m, Milad Tower, situated in north‐west of Tehran, Iran, would be the fourth highest telecommunication tower of the world. This tower has the largest head structure among its counterparts. Preliminary studies demonstrate that the upper part of the tower has excessive wind‐induced acceleration‐related vibrations beyond human comfort limit during wind events. In this paper, the effectiveness of tuned mass damper (TMD) on the suppression of wind‐induced motion of Milad Tower is examined through mathematical analyses. The tower is modelled as a vertical linear cantilever beam, with 57 degrees of freedom. The fluctuating wind speed is assumed to be a stochastic process which is identified by an appropriate power spectral density function. Random vibration analyses were carried out to determine response statistics. The possible application of TMDs in suppressing wind‐induced motions of the tower was investigated, and a TMD was designed to be installed at the sky dome. The results clearly show that the designed TMD has a considerable influence on the suppression of the structural response of the tower below human comfort limits. The authors believe that Milad Tower can be considered as a benchmark control problem for television and telecommunication towers by the structural control community. Copyright © 2008 John Wiley & Sons, Ltd.     

Intelligent anticancer drug delivery performances of two poly(N-isopropylacrylamide)-based magnetite nanohydrogels

This article evaluates the anticancer drug delivery performances of two nanohydrogels composed of poly(N-isopropylacrylamide-co-itaconic anhydride) [P(NIPAAm-co-IA)], poly(ethylene glycol) (PEG), and Fe₃O₄ nanoparticles. For this purpose, the magnetite nanohydrogels (MNHGs) were loaded with doxorubicin hydrochloride (DOX) as a universal anticancer drug. The morphologies and magnetic properties of the DOX-loaded MNHGs were investigated using transmission electron microscopy (TEM) and vibrating–sample magnetometer (VSM), respectively. The sizes and zeta potentials (ξ) of the MNHGs and their corresponding DOX-loaded nanosystems were also investigated. The DOX-loaded MNHGs showed the highest drug release values at condition of 41?°C and pH 5.3. The drug-loaded MNHGs at physiological condition (pH 7.4 and 37?°C) exhibited negligible drug release values. In vitro cytotoxic effects of the DOX-loaded MNHGs were extensively evaluated through the assessing survival rate of HeLa cells using the MTT assay, and there in vitro cellular uptake into the mentioned cell line were examined using fluorescent microscopy and fluorescence-activated cell sorting (FACS) flow cytometry analyses. As the results, the DOX-loaded MNHG1 exhibited higher anticancer drug delivery performance in the terms of cytotoxic effect and in vitro cellular uptake. Thus, the developed MNHG1 can be considered as a promising de novo drug delivery system, in part due to its pH and thermal responsive drug release behavior as well as proper magnetite character toward targeted drug delivery.     

Histopathological graded liver lesions: what role does the IVIM analysis method have?

Magnetic Resonance Materials in Physics, Biology and Medicine - This study aims to investigate three different image processing methods on quantitative parameters of IVIM sequence, as well as...     

Hourly River Flow Forecasting: Application of Emotional Neural Network Versus Multiple Machine Learning Paradigms

Water Resources Management - Monitoring hourly river flows is indispensable for flood forecasting and disaster risk management. The objective of the present study is to develop a suite of hourly...     

Annual Rainfall Forecasting Using Hybrid Artificial Intelligence Model: Integration of Multilayer Perceptron with Whale Optimization Algorithm

Water Resources Management - Rainfall, as one of the key components of hydrological cycle, plays an undeniable role for accurate modelling of other hydrological components. Therefore, a precise...     

Environmental vulnerability assessment of Choghakhor International Wetland during 1985 to 2018

As of natural constraints, and the specific climate of Iran, as well as the increasing importance of international water resources in the socio‐economic development of societies, studies on surface water resources, especially wetlands, merit special attention. Accordingly, the TM, ETM+ and OLI satellite images of 1985, 2000 and 2018 were used in the present study to detect changes in the Choghakhor international wetland. Classifying the images with a supervised method, and using maximum likelihood algorithms, the distinct land use/land cover classes of waterbody, aquatic plants, pasture and forest, agricultural lands, bare land and human built lands were ranked. Selected landscape metrics information on the spatial pattern of the Choghakhor wetland was quantitatively determined, using Fragstats software, and the spatial composition and vulnerability of the wetland were evaluated. The vulnerability assessment of wetland contamination was investigated using the WRASTIC index based on the catchment area scale. Time processing of the data obtained from the maps indicated a 26.63% decrease in the pasture and forest area, and a 12.1% increase in the area of human built lands and agriculture lands during the period from 1985 to 2018. Further, in spite of the waterbody area expanding during 1985 to 2000, it subsequently shrunk in size from 2000 to 2018, with the area of aquatic plants lands increasing during the same period. Analysis of landscape metrics generally indicated the natural wetland cover has been changing during this period along with increasing anthropogenic impacts. Degradation, rotation and replacement of natural land cover such as pastures and forests with human built areas can be considered undesirable development effects on the Choghakhor wetland. The results of the WRASTIC index calculation indicated a major impact of Choghakhor wetland components from water pollution. The results of the present study place an emphasis on more sustainable land use and prevention of land destruction in the Choghakhor wetland basin.     

An Analytical Elasto-Creep Model of Solder Joints in Leadless Chip Resistors: Part 1—Development and Verification

A novel two-dimensional model is presented for multiaxial thermal stresses, elastic strains, creep strains, and creep energy density at the interfaces of solder joints in leadless chip resistor (LCR) assemblies. The model is applicable to both plane stress and plane strain conditions, and incorporates both global and local expansivity mismatches. Interfacial thermal stresses are approximated using elementary strength of materials theory under arbitrary time-dependent thermal loading. Partial differential equations are linearized through a simple finite difference discretization procedure. The model is mathematically straightforward, and can be extended to include plastic behavior and problems involving external loads and a variety of geometries. The paper presents comparisons with finite element results and considers the mechanics of solder creep accumulation and stress relaxation as predicted by the model.     

Influence of Nitrogen on Hydrogenated Amorphous Carbon Thin Films Deposited by Plasma Focus Device

To carry out our research, a plasma focus device is used to deposit thin films of nitrogen doped hydrogenated amorphous carbon (a-C:H:N) onto the stainless steel-AISI-304 substrates at room temperature. Thin films are deposited with the same numbers of focus shots, at the same distance from the anode tip and with different partial pressures of nitrogen in the mixtures of acetylene/nitrogen as working gas. The nitrogen contents of deposited films are studied using nuclear reaction analysis (NRA) techniques. The results prove that nitrogen contents of the samples do not increase significantly by increasing partial pressure of nitrogen of the working gas for both sets of the samples. Moreover, NRA results exhibit the limitation of nitrogen incorporated into the samples, when this experimental setup is used. G-peak position and peak intensity ratio of the D-band to G-band (I_D/I_G) are used to investigate the diamond characters. Also, they show that sp² clustering is highly dependent on the nitrogen atomic contents and angular position of the samples. Scanning electron microscopy (SEM) shows the granular surface morphology of the films. Furthermore, it shows that angular position of the samples with respect to the anode axis plays an important role in the grain size of the surface of the samples. The thickness of the films decreases significantly by increasing angular position of the samples, while it decreases slightly by increasing partial pressure of nitrogen of the working gas. The Vickers surface hardness of the thin films exhibits significant dependency on the sp² clustering.