Issue 2


Impact of digital transformation for Mass healthcare

Ashutosh Tiwari

Advanced Materials Letters, 2019, Volume 10, Issue 2, Pages 79-79
DOI: 10.5185/amlett.2019.1002

Mass Healthcare is the prominent field and it must be noted that over the last couple of decades, the entire healthcare industry has digitized health care landscape. Digitalization conveyed moment access to data, made the sharing of data simpler among social insurance experts and enhanced the efficiencies of patient results. Automation has substantially changed the medicinal services industry and made it more savvy for associations to run everyday tasks. Automation is the utilization of data innovation that lessens the requirement for human work in the making of results. The present mechanization advances are equipped for significantly more than human managers. For example, a decrease of managerial outstanding tasks at hand, enhancement of the consistency of patient consideration, end of waste, improvement of data trade, investigation of information, and checking of patients would all be able to be streamlined with information mechanization. There might be a piece of legitimacy to this stress; some social insurance clients essentially want to manage a human when they make arrangements or demand data. 

Preparation, stabilization, and self-assembly of gold nanoparticles by Chitosan derivatives

Jia-Jia Shen; Jia He; Ya Ding

Advanced Materials Letters, 2019, Volume 10, Issue 2, Pages 80-84
DOI: 10.5185/amlett.2019.2016

Gold nanoparticles (GNPs) are of unique and interesting materials being firstly reported 100 years ago. They are one of the most widely studied nanomaterials potential for disease cure. To improve the colloidal stability, biocompatibility, and hemocompatibility of GNPs, chitosan (CS), a naturally produced polysaccharide with excellent biocompatibility and biodegradation, has been modified to generate water-soluble derivatives and used as the stabilizing agent of GNPs. In the presence of these derivatives, GNPs are stabilized, functionalized, and assembled via electronic static and covalent bond interactions. Based on these works, GNPs with different dimensional, morphology, and crystal lattice are obtained, which can be further apply to a variety of applications in sensing, imaging, therapy, and catalysis. 

Development of Na+ superionic conducting Na5YSi4O12-type glass-ceramics

Toshinori Okura

Advanced Materials Letters, 2019, Volume 10, Issue 2, Pages 85-90
DOI: 10.5185/amlett.2019.1684

This review article describes a series of studies on the glass-ceramic Na + superionic conductors with Na5YSi4O12 (N5)-type structure synthesized using the composition formula of Na3+3x-yR1-xP < em>ySi3-yO9 for a variety of rare earth elements, R, under the appropriate composition parameters. Recent researches on structural control of the Na + superionic conducting glass-ceramics are also introduced. The optimum conditions for crystallization were discussed with reference to the conduction properties and the preparation of crack-free N5-type glass-ceramics. The effects of Si substitution with the various elements with tetrahedral oxygen coordination structure and Y substitution with the various R elements were also discussed on ionic conductivity of N5-type glass-ceramics, respectively. 

Chances and challenges in the application of fiber metal laminates

Daniel Stefaniak; Robert Prussak

Advanced Materials Letters, 2019, Volume 10, Issue 2, Pages 91-97
DOI: 10.5185/amlett.2019.2155

Fiber-metal laminates (FML) as a combination of metals and fiber reinforced plastic materials are investigated in a variety of current research projects. The intention of combining these two different materials is the compensation of their inherent weaknesses. Certain key parameters for the selection of the constituents of an FML are discussed based on different applications and the related challenges. Therefore, different applications using FML in current research projects at German Aerospace Center are discussed and requirements are deduced. The applications cover UD-CFRP steel laminates, local metal hybridization as well as the use for impact and crash prone structures. The specific challenges in the use of these hybrid laminates like manufacturing and residual stresses are then discussed in more detail as they should also be taken into account when selecting the constituents of an FML for a certain application. 

Low temperature processed efficient and stable perovskite solar cell

Ashraf Uddin; Md Arafat Mahmud; Naveen Kumar Elumalai; Mushfika Baishakhi Upama; Dian Wang; Faiazul Haque; Cheng Xu

Advanced Materials Letters, 2019, Volume 10, Issue 2, Pages 98-106
DOI: 10.5185/amlett.2019.2050

MA0.6FA0.4PbI3 material based efficient and stable perovskite solar cells (PSCs) are fabricated by electron transport layer (ETL) interfacial modification. The highest power conversion efficiency (PCE) of device was ~ 17%. Cesium acetate and cesium carbonate were used with low temperature processed sol-gel ZnO ETL for interface modifications. Low leakage current and enhanced dark injection current are observed from dark current-voltage measurement. From the electrochemical impedance spectroscopy (EIS) measurement higher recombination resistance and lower interfacial contact resistance are observed in the PSC devices. Mott-Schottky analysis also shows the higher flat-band potential and enhanced device performance with cesium acetate ETL. Cesium acetate related ZnO ETL has large grain size which leads to reduce the device series resistance and contact resistance in PSC compared to cesium carbonate ETL related device. Perovskite film on cesium acetate ETL has better surface morphology, topography and hydrophobicity characterization compared to perovskite film grown on cesium carbonate ETL film. The material work function and electron injection barrier are also investigated by X-Ray photoelectron spectroscopy (XPS) measurement and ultraviolet photoelectron spectroscopy (UPS). From electrochemical impedance spectroscopy measurements the charge transport behaviour and trap-assisted carrier recombination are estimated. Fabricated PSCs device stability has been measured for a month-long degradation study. The PSC device stability is observed four times higher with cesium acetate PSCs compared to cesium carbonate ETL related PSCs. The overall device PCE is around 82% higher with cesium acetate compared to cesium carbonate devices. 

Tuning Polydimethylsiloxane (PDMS) properties for biomedical applications

Etienne Mfoumou; Martin Tango; Pak Kin Wong

Advanced Materials Letters, 2019, Volume 10, Issue 2, Pages 107-111
DOI: 10.5185/amlett.2019.2130

Polydimethylsiloxane (PDMS) is used extensively to study cell-substrate interactions because its mechanical properties are easily tuned in physiologically relevant ranges. These changes in mechanical properties are also known to modulate surface chemistry and cell response. In this study, PDMS pre-polymer was combined with increasing amounts of cross-linker (3.3, 5.0, 10.0, 12.5, 20.0 and 33.3 wt.%). The solutions were mixed in sterile conditions and degassed, then poured into 60 mm cell culture dishes to a depth of 1 mm. This was followed by curing at a constant temperature of 75  o C for 2 hours. The PDMS substrates were then exposed to an air plasma for 10 minutes. All substrates were exposed to UV light for further sterilization and understanding of the structure/morphology of the substrates was obtained with microscopic techniques. A SH-SY5Y neuroblastoma cell line was used in cell culture experiment. Cells were plated at a concentration of 300 x 10 6 cells/dish on plasma treated PDMS substrates and incubated at 37  o C in a humidified 5 % CO2 environment. For the assessment of morphological changes, images of cells growing on each substrate were captured using an inverted phase contrast microscope. Cell adhesion as well as immunofluorescence analyses were conducted, and the mechanical as well as surface properties of PDMS were correlated to neuroblastoma cell behaviour. The results reveal that the physicality of the extracellular matrix/environment (ECM) substrate governs cell behavior regardless of hormones, cytokines, or other soluble regulatory factors. The approach used in this study may open up new avenues in translational medicine and pharmacodynamics research. 

Molecular origin of hardening effect 

Weifu Sun; Pengwan Chen

Advanced Materials Letters, 2019, Volume 10, Issue 2, Pages 112-115
DOI: 10.5185/amlett.2019.2187

Hardening effect is often observed in either experiments or simulations. And several continuum models or semi-empirical theories have been proposed to explain the origin, such as constraint-counting theory, the bond-order-length-strength (BOLS) correlation mechanism, equations of state-Murnaghan relationship, etc. However, the validity of these models or theories at the nanoscale have not been tested. In this work, high-speed head-on impact between silicon nanoparticles were studied using molecular dynamics (MD) simulations and their contact mechanics behaviours including contact force versus nominal displacement relationship were explored and the pronounced hardening effect was clearly observed. That’s, apparent Young’s modulus yielded is much higher than that of their bulk materials. The structure of silicon nanoparticles after compression was analysed in terms of bond length, bond angle, coordination number. The three existing relevant models were separately examined. The results show that any single of the three known theories cannot explain the higher elastic modulus obtained in present MD simulation. Probably, the three aspects contribute together to the hardening effect. This area awaits much more mature theory to explain the hardening effect under the influence of the dynamic effect.

Polypyrrole/MWCNT nanobiocomposite based electrochemical urease biosensor

Bhavna H. Meshram; Subhash B. Kondawar

Advanced Materials Letters, 2019, Volume 10, Issue 2, Pages 116-123
DOI: 10.5185/amlett.2019.1568

Fabrication of nanocomposite film of electrically conducting polypyrrole (PPy) and functionalized multi-walled carbon nanotubes (MWCNTs) on a stainless steel electrode by electro-deposition method and immobilization of urease onto the nanocomposite film to obtain a nanobiocomposite electrode as a sensitive electrochemical urease biosensor is reported. Cross-linking by glutaraldehyde (0.1%) method for the immobilization of urease (2 mg/mL) in a phosphate buffer solution of 0.1 molarity at a pH of 7.0 was used. The Characterization of the nanocomposite and nanobiocomposite film thus obtained was done by Scanning Electron Microscopy (SEM), Fourier Transform Infrared spectroscopy (FTIR), Cyclic Voltammetry (CV), and Electrochemical Impedance Spectroscopy (EIS). The increased size of the Cyclic voltammogram and shifting of anionic peaks towards the lower voltage indicates the incorporation of MWCNTs into the growing film during the electro-deposition of PPy on electrode. Reduction of the oxidation potential due to MWCNTs leads to lowering of potential for the electro-catalytic reduction of urea. The incorporation of functionalized MWCNT also made possible increased amount of enzyme concentration, an extended lifetime, long time stability and improved response times of the enzyme electrode. This modified nanobiocomposite electrode showed a good linear response to the urea concentration change in the range of 10 mM to 50 mM. The results obtained from Michaelis–Menten constant K´m, maximum current (Imax), detection limit, sensitivity, response time and shelf-life of electrochemical biosensor indicating good sensing for urea detection. 

Water vapor adsorption in silica gel for thermal energy storage application

Ye Hua; Amanda Godin; F. Handan Tezel

Advanced Materials Letters, 2019, Volume 10, Issue 2, Pages 124-127
DOI: 10.5185/amlett.2019.2181

Thermal energy storage (TES) by water vapor adsorption process has attracted increasing interest for its thermal applications such as space heating and cooling. However, the experimental energy density of the adsorbents may vary as the operating system and conditions change, which could be much lower than the theoretical energy density. In this manuscript, an experimental system has been designed and built to examine the effects of the regeneration temperature and relative humidity (RH) on a commercial silica gel material’s performance as adsorption TES material. The experimental energy density under different operating conditions were calculated. Up to 25 adsorption-desorption cycles were performed to examine the stability of the material and the repeatability of the results. 

Development of anti-bio deteriorate sustainable geopolymer by SiO2 NPs decorated ZnO NRs 

Manas Sarkar; Moumita Maiti; Muhammad Akbar Malik; Shilang Xu

Advanced Materials Letters, 2019, Volume 10, Issue 2, Pages 128-131
DOI: 10.5185/amlett.2019.2166

In concrete industry, geopolymer acts as an alternative building material of ordinary cement and possess similar/greater mechanical strength and durability, fashioned by industrial by-product; fly ash with alkaline activator. Accompanied by the chemical corrosion, biogenic corrosion is a foremost obstruction in sewer systems, bridge piers, pipelines and offshore platforms. The present works has been given an effort to introduce an anti-bio deteriorate sustainable geopolymer (GMZnO–Si) through the decoration of spherical nano silica (Si) on zinc oxide Nano-rods (ZnO NRs) surface. XRD, Zeta potential, FESEM, EDS and XPS were hired for the characterization of ZnO-SiO2 nanohybrid system and applicability of GMZnO–Si mortar was investigated against microbial species (E. coli, S. aureus, A. niger). MIC/MBC/MFC values, agar plating, Inner permeability assay and ROS generation results exhibited excellent mechanistic approaches, by showing its ability to resist the biogenic degradation. The mechanical and durability activities of the GMZnO–Si are found considerably higher in respect to conventional control samples. The experimental outcomes propose a promising way to inclusion of ZnO-SiO2 modified geopolymer for biodeterioration-resistant structure with significant mechanical properties in near future. 

Increasing the efficiency of graphene-based Schottky-barrier devices

Shuo-En Wu; Ya-Ping Hsieh

Advanced Materials Letters, 2019, Volume 10, Issue 2, Pages 132-135
DOI: 10.5185/amlett.2019.2183

Graphene’s high carrier mobility and ambipolar nature has the potential to improve electronic devices. The absence of a band-gap necessitates heterostructure devices. Schottky-barrier devices consisting of an interface between graphene and a semiconductor represent the simplest heterostructure. Despite its simplicity, graphene-based Schottky barrier devices are not well understood and exhibit low injection efficiencies. We here investigate the impact of graphene/metal interaction on the properties of the Schottky-barrier. Besides the commonly employed Au/graphene we use Pt/graphene contacts. We find that the injection efficiency for Pt is 5x higher than for Au and systematically study the origin of this behavior. We identify a large difference in Richardson’s constant due to changes in the density of surface states. The demonstrated ability to increase the injection current was applied to improve the efficiency of graphene-based Schottky solar cells by 13x. 

Modification of mesoporous titanium dioxide with cobalt oxide electrocatalyst for enhanced oxygen evolution reaction

Mabrook S. Amer; Mohamed A. Ghanem; Prabhakarn Arunachalam; Abdullah M. Al-Mayouf; Talal A. Aljohani

Advanced Materials Letters, 2019, Volume 10, Issue 2, Pages 136-144
DOI: 10.5185/amlett.2019.2139

Water electrolysis is an attractive approach for hydrogen production process and has enormous potential for sustainable clean energy development. This work demonstrates a controllable and reliable method for in-situ decorating of mesoporous titanium dioxide (m-TiO2) support with low loading (0.1- 2.1 wt. %) of cobalt oxide for an efficient electrocatalytic oxygen evolution (OE) in alkaline solution. The ordered (m-TiO2) support modified with cobalt oxide and having uniform mesopores (3-5 nm pore diameter) and a crystalline framework is successfully prepared via soft-template strategy using Pluronic ® F127 triblock copolymer as a mesopores template. Compared to the pure TiO2 mesoporous, the entire Co oxide doped (Co(x)/m-TiO2) catalysts exhibit greatly enhanced OE activity in spite of the low loading of Co oxide electrocatalyst. The Co(2.1)/m-TiO2 catalyst with 2.1 wt. % of Co oxide was the OER most active robust electrocatalyst with a mass activity of 31.5 mA cm 2 mg −1 , the specific activity of 12.6 mA cm −2 at h = 350 mV and 200 mV decrease in overpotential (h) compared to bare m-TiO2. The enhanced OE activity of (Co(x)/m-TiO2) catalysts was attributed to the existence of a uniform distribution of Co oxide electrocatalyst supported on a highly porous structure of the TiO2 substrate.

TiO2 nanoparticles induced oxidative stress mediated DNA damage in the liver of adult male Wistar rats

Dasal Vasantharaja; Venugopal Ramalingam; Shanmugam Thangapandiyan; Nagarajan Sridhar; Gaddam Dayanand Reddy

Advanced Materials Letters, 2019, Volume 10, Issue 2, Pages 145-150
DOI: 10.5185/amlett.2019.1532

Nanoparticles (NPs) are extensively being used in modern life due to their distinctive properties like small size having large surface area. Titanium dioxide (TiO2) NPs are mostly used in cosmetic products, food additives, pharmaceuticals and electronics. They are capable of inducing oxidative stress in both animals and human. The intention of this study was to find out the hepatotoxic effect of TiO2 NPs on the male Wistar rats. The animals were divided in to three groups. First group received normal saline; Second group received TiO2 NPs (50 mg/kg/bw) for 14 days continuously, while third group received TiO2 NPs (100 mg/kg/bw) for the same duration. The increased levels of specific markers AST, ALT, ALP, LDH and GGT along with the TBARS, LOOH, CD and PC in the liver clearly shows the hepatotoxic action of TiO2. The hepatotoxic nature of TiO2 NPs was more evidenced by the diminished activity of antioxidant enzymes levels and also showed augmented DNA damage and fragmentation in hepatocytes. In conclusion, the data indicated that TiO2 NPs induced oxidative stress which produces hepatotoxicity in the rat liver.