Determination of Metal Content in Soil and Wheat Plant by Inductively Coupled Plasma Mass Spectrometry

This study aims to investigate the level of soil pollution and the grade of accumulation of metals and heavy metals by wheat plants from the soil in different parts of the crop: root, stem, leaf, spike and grain. Sampling campaigns took place in February, April and July when wheat plants were at different growth stages. A number of eight soil samples and eight wheat plant samples were collected. The sampled wheat plant was taken at the same time and from the same place as the soil. Concentrations of Al (aluminium), Cr (chromium), Mn (manganese), Fe (iron), Ni (nickel), Co (cobalt), Cu (copper), Zn (zinc), Sr (strontium), Cd (cadmium) and Pb (lead) were determined by inductively coupled plasma mass spectrometry. Bioconcentration and translocation factors were calculated for the samples analysed.

Evaluation on the corrosion resistance, antibacterial property and osteogenic activity of biodegradable Mg-Ca and Mg-Ca-Zn-Ag alloys

The rapid degradation of magnesium(Mg)-based implants in physiological environment limits its clinical applications, and alloying treatment is an effective way to regulate the degradation rate of Mg-based materials. In the present study, three Mg alloys, including Mg-0.8Ca(denoted as ZQ), Mg-0.8Ca-5Zn-1.5Ag(denoted as ZQ71) and Mg-0.8Ca-5Zn-2.5Ag(denoted as ZQ63), were fabricated by alloying with calcium(Ca), zinc(Zn) and silver(Ag). The results obtained from electrochemical corrosion tests and in vitro degradation evaluation demonstrated that the three Mg alloys exhibited distinct corrosion resistance, and ZQ71 exhibited the lowest degradation rate in vitro among them. After addition of Zn and Ag, the antibacterial potential of Mg alloys was also enhanced. The in vitro cell experiments showed that all the three Mg alloys had good biocompatibility. After implantation in a rat femoral defect, ZQ71 showed significantly higher osteogenic activity and bone substitution rate than ZQ63 and ZQ, due to its higher corrosion resistance as well as the stimulatory effects of the released metallic ions. In addition, the average daily degradation rate of each Mg alloy in vivo was significantly higher than that in vitro, as could be due to the implantation site located in the highly vascularized trabecular region. Importantly, the correlations between the in vitro and in vivo degradation parameters of the Mg alloys were systematically analyzed to find out the potential predictors of the in vivo degradation performance of the materials. The current work not only evaluated the clinical potential of the three biodegradable Mg alloys as bone grafts but also provided a feasible approach for predicting the in vivo degradation behavior of biodegradable materials.

Non-axisymmetric Homann stagnation-point flow of Walter’s B nanofluid over a cylindrical disk

The study of non-axisymmetric Homann stagnation-point flow of Walter’s B nanofluid along with magnetohydrodynamic(MHD) and non-linear Rosseland thermal radiation over a cylindrical disk in the existence of the time-independent free stream is considered. Moreover, the notable impacts of thermophoresis and Brownian motion are analyzed by Buongiorno’s model. The momentum, energy, and concentration equations are converted into the dimensionless coupled ordinary differential equations via similarity transformations, which are later numerically solved by altering the values of the pertinent parameters. The numerical and asymptotic solutions for the large shear-to-strain rate ratio γ =a/bfor the parameters of the displacement thicknesses and the wall-shear stress are computed by perturbative expansion and analyzed. Furthermore, the technique bvp4c in MATLAB is deployed as an efficient method to analyze the calculations for the non-dimensional velocities, temperature, displacement thickness, and concentration profiles. It is observed that the two-dimensional displacement thickness parameters α andβ are reduced due to the viscoelasticity and magnetic field effects. Moreover, when the shear-to-strain rate ratio approaches infinity, α is closer to its asymptotic value, while βand the three-dimensional displacement thickness parameter δ1 show the opposite trend.The outcomes of the viscoelasticity and the magnetic field on the skin friction are also determined. It is concluded that ■ reaches its asymptotic behavior when the shearto-strain rate ratio approaches infinity. Meanwhile, ■ shows different results.

Results in Sizing and Simulation of PV Applications Based on Different Solar Cell Technologies

Modeling and simulation of photovoltaic (PV) systems represents an essential task for the integration of PV panels in current power applications. At the present time, there are sizing tools of photovoltaic systems available on the market, taking into account the proposed energy consumption, site localization and system cost. An advanced specialized program (PVSyst) was considered. The sizing and simulations of two PV important applications were developed using PV modules based on three different technologies: monocrystalline and polycrystalline silicon, as well as CIS. Our results showed how different types of solar cell technologies influenced the final power output and performances for a PV LED lighting, as well as for a PV water pumping system, in terms of overall yield, efficiency and system availability.

Toxicological characterization and central nervous system effects of Calotropis procera Ait. aqueous extracts in mice

Objective: To evaluate the toxicological and psychotropic properties of Calotropis(C.) procera. Methods: C. procera leaves and root-bark aqueous extracts were evaluated for their toxic and behavioral effects using adult mice. Toxicity studies were carried out using Organisation for Economic Cooperation and Development guidelines 423 and 407 for acute and subacute evaluation. Behavioral studies were performed using traction test, fireplace test, hole-board test and forced-swimming test to evaluate the sedative, anxiety and depressive-like activities of the extracts. Results: Very low acute toxicity was observed in mice that received both leaves and rootbark extracts. The subacute test showed some morphological, biochemical and hematological changes in the treated groups. Behavioral assessment demonstrated anxiety effects on mice for C. procera leaf extract(400 mg/kg of body weight). Conclusions: The acute use of C. procera(leaves and root-barks) aqueous extracts could be considered as low toxic. However, their repeated uses could have harmful effect on some organs. Likewise, a single dose up to 400 mg/kg body weight of these extracts produce no sedative or depressive-like effect, but they possess possible dose dependent anxiety effect. Yet, more studies are necessary to relate these results to the chemical profile of the plant extracts.

Numerical Analysis of an Industrial Polycrystalline Silicon Photovoltaic Module Based on the Single-Diode Model Using Lambert W Function

It is adopted the single-diode solar cell model and extended for a PV module. The current vs. voltage (I-V) characteristic based on the Lambert W-function was used. The estimation parameters for the simulation approach of the photovoltaic (PV) module make use of Levenberg-Marquardt method. It was considered an industrial polycrystalline silicon photovoltaic (PV) module and the simulated results were compared with the experimental ones extracted from a specific datasheet. The I-V characteristic for the analysed PV module and its maximum output power are investigated for different operating conditions of incident solar radiation flux and temperature, as well as parameters related to the solar cells material and technology (series resistance, shunt resistance and gamma factor). The analysis gives indications and limitations for design and optimization of the performance for industrial PV modules. This study can be implemented in any type of PV module.

Optical Analysis of a ZnO/Cu_(2)O Subcell in a Silicon-Based Tandem Heterojunction Solar Cell

Research on silicon-based tandem heterojunction solar cells (STHSC) incorporating metal oxides is one of the main directions for development of high-efficiency solar cells. In this work, the optical characteristics of a STHSC consisting of a ZnO/Cu2O subcell on top of a silicon-based subcell were studied by optical modelling. Cu2O is a direct-gap p-type semiconductor which is attractive for application in solar cells due to its high absorptance of ultra-violet and visible light, nontoxicity, and low-cost producibility. Highly Al-doped ZnO and undoped Cu2O thin films were prepared on quartz substrates by magnetron sputter deposition. Thermal annealing of the Cu2O layer at 900°C enhances the electrical properties and reduces optical absorption, presumably as a result of increased grain size. Hall effect measurements show that the majority carrier (hole) mobility increases from 10 to 50 cm2/V×s and the resistivity decreases from 560 to 200 Ω×cm after annealing. A Cu2O absorber layer of 2 μm thickness will generate about 10 mA/cm2 of photocurrent under AM1.5G illumination. The optical analysis of the STHSC involved calculating the spectral curves for absorptance, transmittance, and reflectance for different thicknesses of the thin film layers constituting the ZnO/Cu2O subcell. The complex refractive indices of the thin films were derived from spectroscopic ellipsometry measurements and implemented in the simulation model. The lowest reflectance and highest transmittance for the ZnO/Cu2O subcell are obtained for a thickness of approximately 80 nm for both the top and bottom AZO layers. The SiNx anti-reflection coating for the c-Si bottom subcell must be optimized to accommodate the shift of the photon spectrum towards longer wavelengths. By increasing the thickness of the SiNx layer from 80 nm to 120 nm, the total reflectance for the STHSC device is reduced from 12.7% to 9.7%.

Versatile techniques based on the Thermionic Vacuum Arc(TVA)and laser-induced TVA methods for Mg/Mg:X thin films deposition-A review

Magnesium and magnesium thin alloy films were deposited using a thermionic vacuum arc(TVA),which has multiple applications in the field of metallic electrodes for diodes and batteries or active corrosion protection.An improved laser-induced TVA(LTVA)method favors the crystallization processes of the deposited magnesium-based films because the interaction between laser and plasma discharge changes the thermal energy during photonic processes due to the local temperature variation.Plasma diagnosis based on current discharge measurements suggests an inelastic collision between the laser beam and the atoms from the plasma discharge.The morphology and surface properties of the obtained thin films differ between these two methods.While the amorphous character is dominant for TVA thin films,enabling a smooth surface,the LTVA method produces rough surfaces with prominent crystallinity,less hydrophobic character and lower surface energy.The smooth surfaces obtained by the TVA methods produce metallic electrodes with good electrical contact,ensuring better diodes and battery charge transport.Both methods allow uniform magnesium alloys to be obtained,but the laser used in the LTVA on the discharge plasma controls the added metal or element ratio.

Three-dimensional mixed convection stagnation-point fow past a vertical surface with second-order slip velocity

This study is concerned with the three-dimensional(3D)stagnation-point for the mixed convection flow past a vertical surface considering the first-order and secondorder velocity slips.To the authors’knowledge,this is the first study presenting this very interesting analysis.Nonlinear partial differential equations for the flow problem are transformed into nonlinear ordinary differential equations(ODEs)by using appropriate similarity transformation.These ODEs with the corresponding boundary conditions are numerically solved by utilizing the bvp4c solver in MATLAB programming language.The effects of the governing parameters on the non-dimensional velocity profiles,temperature profiles,skin friction coefficients,and the local Nusselt number are presented in detail through a series of graphs and tables.Interestingly,it is reported that the reduced skin friction coefficient decreases for the assisting flow situation and increases for the opposing flow situation.The numerical computations of the present work are compared with those from other research available in specific situations,and an excellent consensus is observed.Another exciting feature for this work is the existence of dual solutions.An important remark is that the dual solutions exist for both assisting and opposing flows.A linear stability analysis is performed showing that one solution is stable and the other solution is not stable.We notice that the mixed convection and velocity slip parameters have strong effects on the flow characteristics.These effects are depicted in graphs and discussed in this paper.The obtained results show that the first-order and second-order slip parameters have a considerable effect on the flow,as well as on the heat transfer characteristics.

Therapeutic advances of targeting receptor tyrosine kinases in cancer

Receptor tyrosine kinases(RTKs),a category of transmembrane receptors,have gained significant clinical attention in oncology due to their central role in cancer pathogenesis.Genetic alterations,including mutations,amplifications,and overexpression of certain RTKs,are critical in creating environments conducive to tumor development.Following their discovery,extensive research has revealed how RTK dysregulation contributes to oncogenesis,with many cancer subtypes showing dependency on aberrant RTK signaling for their proliferation,survival and progression.These findings paved the way for targeted therapies that aim to inhibit crucial biological pathways in cancer.As a result,RTKs have emerged as primary targets in anticancer therapeutic development.Over the past two decades,this has led to the synthesis and clinical validation of numerous small molecule tyrosine kinase inhibitors(TKIs),now effectively utilized in treating various cancer types.In this manuscript we aim to provide a comprehensive understanding of the RTKs in the context of cancer.We explored the various alterations and overexpression of specific receptors across different malignancies,with special attention dedicated to the examination of current RTK inhibitors,highlighting their role as potential targeted therapies.By integrating the latest research findings and clinical evidence,we seek to elucidate the pivotal role of RTKs in cancer biology and the therapeutic efficacy of RTK inhibition with promising treatment outcomes.

Construction of a magnesium hydroxide/graphene oxide/hydroxyapatite composite coating on Mg-Ca-Zn-Ag alloy to inhibit bacterial infection and promote bone regeneration

The improved corrosion resistance, osteogenic activity, and antibacterial ability are the key factors for promoting the large-scale clinical application of magnesium (Mg)-based implants. In the present study, a novel nanocomposite coating composed of inner magnesium hydroxide, middle graphene oxide, and outer hydroxyapatite (Mg(OH)_(2)/GO/HA) is constructed on the surface of Mg-0.8Ca-5Zn-1.5Ag by a combined strategy of hydrothermal treatment, electrophoretic deposition, and electrochemical deposition. The results of material characterization and electrochemical corrosion test showed that all the three coatings have high bonding strength, hydrophilicity and corrosion resistance. In vitro studies show that Mg(OH)2 indeed improves the antibacterial activity of the substrate. The next GO and GO/HA coating procedures both promote the osteogenic differentiation of MC3T3-E1 cells and show no harm to the antibacterial activity of Mg(OH)2 coating, but the latter exhibits the best promoting effect. In vivo studies demonstrate that the Mg alloy with the composite coating not only ameliorates osteolysis induced by bacterial invasion but also promotes bone regeneration under both normal and infected conditions. The current study provides a promising surface modification strategy for developing multifunctional Mg-based implants with good corrosion resistance, antibacterial ability and osteogenic activity to enlarge their biomedical applications.

In vitro characterization of novel nanostructured collagen-hydroxyapatite composite scaffolds doped with magnesium with improved biodegradation rate for hard tissue regeneration

New materials are required for bone healing in regenerative medicine able to temporarily substitute damaged bone and to be subsequently resorbed and replaced by endogenous tissues.Taking inspiration from basic composition of the mammalian bones,composed of collagen,apatite and a number of substitution ions,among them magnesium(Mg2+),in this work,novel composite scaffolds composed of collagen(10%)-hydroxyapatite(HAp)(90%)and collagen(10%)-HAp(80%)-Mg(10%)were developed.The lyophilization was used for composites preparation.An insight into the nanostructural nature of the developed scaffolds was performed by Scanning Electron Microscopy coupled with Energy Dispersive X-Ray and Transmission Electron Microscopy coupled with Energy Dispersive X-Ray.The HAp nanocrystallite clusters and Mg nanoparticles were homogeneously distributed within the scaffolds and adherent to the collagen fibrils.The samples were tested for degradation in Simulated Body Fluid(SBF)solution by soaking for up to 28 days.The release of Mg from collagen(10%)-HAp(80%)-Mg(10%)composite during the period of up to 21 days was attested,this composite being characterized by a decreased degradation rate with respect to the composite without Mg.The developed composite materials are promising for applications as bone substitute materials favouring bone healing and regeneration.

Peristaltic Flow of Couple Stress Fluid in a Non-Uniform Rectangular Duct Having Compliant Walls

The present study investigates the peristaltic flow of couple stress fluid in a non-uniform rectangular duct with compliant walls.Mathematical modeling is based upon the laws of mass and linear momentum.Analytic solutions are carried out by the eigen function expansion method under long-wavelength and low-Reynolds number approximations.The features of the flow characteristics are analyzed by plotting the graphs of various values of physical parameters of interest.Trapping bolus scheme is also presented through streamlines.

A semiclassical perspective on nuclear chirality

The application of the semiclassical description to a particle-core system with imbued chiral symmetry is presented.The classical features of the chiral geometry in atomic nuclei and the associated dynamics are investigated for various core deformations and single-particle alignments.Distinct dynamical characteristics are identified in specific angular momentum ranges,triaxiality and alignment conditions.Quantum observables will be extracted from the classical picture for a quantitative description of experimental data provided as numerical examples of the model’s performance.

Magnesium-based alloys with adapted interfaces for bone implants and tissue engineering

Magnesium and its alloys are one of the most used materials for bone implants and tissue engineering.They are characterized by numerous advantages such as biodegradability,high biocompatibility and mechanical properties with values close to the human bone.Unfortunately,the implant surface must be adequately tuned,or Mg-based alloys must be alloyed with other chemical elements due to their increased corrosion effect in physiological media.This article reviews the clinical challenges related to bone repair and regeneration,classifying bone defects and presenting some of the most used and modern therapies for bone injuries,such as Ilizarov or Masquelet techniques or stem cell treatments.The implant interface challenges are related to new bone formation and fracture healing,implant degradation and hydrogen release.A detailed analysis of mechanical properties during implant degradation is extensively described based on different literature studies that included in vitro and in vivo tests correlated with material properties’characterization.Mg-based trauma implants such as plates and screws,intramedullary nails,Herbert screws,spine cages,rings for joint treatment and regenerative scaffolds are presented,taking into consideration their manufacturing technology,the implant geometrical dimensions and shape,the type of in vivo or in vitro studies and fracture localization.Modern technologies that modify or adapt the Mg-based implant interfaces are described by presenting the main surface microstructural modifications,physical deposition and chemical conversion coatings.The last part of the article provides some recommendations from a translational perspective,identifies the challenges associated with Mg-based implants and presents some future opportunities.This review outlines the available literature on trauma and regenerative bone implants and describes the main techniques used to control the alloy corrosion rate and the cellular environment of the implant.

General Solutions for Hydromagnetic Free Convection Flow over an Infinite Plate with Newtonian Heating, Mass Diffusion and Chemical Reaction

The problem of hydromagnetic free convection flow over a moving infinite vertical plate with Newtonian heating, mass diffusion and chemical reaction in the presence of a heat source is completely solved. Radiative and porous effects are not taken into consideration but they can be immediately included by a simple rescaling of Prandtl number and magnetic parameter. Exact general solutions for the dimensionless velocity and concentration fields and the corresponding Sherwood number and skin friction coefficient are determined under integral form in terms of error function or complementary error function of Gauss. They satisfy all imposed initial and boundary conditions and can generate exact solutions for any problem with technical relevance of this type. As an interesting completion, uncommon in the literature, the differential equations which describe the thermal, concentration and momentum boundary layer, as well as the exact expressions for the thicknesses of thermal, concentration or velocity boundary layers were determined.Numerical results have shown that the thermal boundary layer thickness decreases for increasing values of Prandtl number and the concentration boundary layer thickness is decreasing with Schmidt number. Finally, for illustration,three special cases are considered and the influence of physical parameters on some fundamental motions is graphically underlined and discussed. The required time to reach the flow according with post-transient solution(the steady-state),for cosine/sine oscillating concentrations on the boundary is graphically determined. It is found that, the presence of destructive chemical reaction improves this time for increasing values of chemical reaction parameter.

Enhance Stability and in vitro Cell Response to a Bioinspired Coating on Zr Alloy with Increasing Chitosan Content

The aim of the present paper is to characterize bioinspired chitosan （CS） ＋ hydroxyapatite （HA） coatings with various components ratio on a zirconium alloy with titanium. The coatings were characterized by FT-IR, SEM, hydrophilic/hydrophobic balance, adherence, roughness, electrochemical stability and in vitro cell response. Electrochemical tests, including potentio- dynamic polarization curves and electrochemical impedance spectroscopy, were performed in normal saline physiological solution. Cell viability of MC3T3-E1 osteoblasts, lactate dehydrogenase, nitric oxide, and Reactive Oxygen Species （ROS） levels, as well as actin cytoskeleton morphology, were evaluated as biological in vitro tests. The results on in vitro cell response indicated good cell membrane integrity and viability for all samples, but an increased cell number, a decreased ROS level and a better cytoskeleton organization were noticed for the sample with a higher CS content. The coating with highest CS concen- tration indicated the best performance based on the experimental data. The highest hydrophilic character, highest resistance to corrosion and best biocompatibility as well recommend this coating for bioapplications in tissue engineering.

Unique Continuation Property with Partial Information for Two-Dimensional Anisotropic Elasticity Systems

In this paper,we establish a novel unique continuation property for two-dimensional anisotropic elasticity systems with partial information.More precisely,given a homogeneous elasticity system in a connected open bounded domain,we investigate the unique continuation by assuming only the vanishing of one component of the solution in a subdomain.Using the corresponding Riemann function,we prove that the solution vanishes in the whole domain provided that the other component vanishes at one point up to its second derivatives.Further,we construct several examples showing the possibility of further reducing the additional information of the other component.This result possesses remarkable significance in both theoretical and practical aspects because the required data are almost halved for the unique determination of the whole solution.

Mn^(5+)-activated Ca_(6)Ba(PO_(4))_(4)O near-infrared phosphor and its application in luminescence thermometry

The near-infrared luminescence of Ca_(6)Ba(PO_(4))_(4)O∶Mn^(5+)is demonstrated and explained.When excited into the broad and strong absorption band that spans the 500-1000 nm spectral range,this phosphor provides an ultranarrow(FWHM=5 nm)emission centered at 1140 nm that originates from a spin-forbidden ^(1)E → ^(3)A_(2) transition with a 37.5%internal quantum efficiency and an excited-state lifetime of about 350 μs.We derived the crystal field and Racah parameters and calculated the appropriate Tanabe-Sugano diagram for this phosphor.We found that 1E emission quenches due to the thermally-assisted cross-over with the ^(3)T_(2) state and that the relatively high Debye temperature of 783 K of Ca_(6)Ba(PO_(4))_(4)O facilitates efficient emission.Since Ca_(6)Ba(PO_(4))_(4)O also provides efficient yellow emission of the Eu^(2+)dopant,we calculated and explained its electronic band structure,the partial and total density of states,effective Mulliken charges of all ions,elastic constants,Debye temperature,and vibrational spectra.Finally,we demonstrated the application of phosphor in a luminescence intensity ratio thermometry and obtained a relative sensitivity of 1.92%K^(-1) and a temperature resolution of 0.2 K in the range of physiological temperatures.

Swelling-Based Chemical Sensing With Unmodified Optical Fibers

We use distributed fiber optic strain sensing to examine swelling of the fiber’s polymer coating.The distributed sensing technique that uses unmodified low-cost telecom fibers opens a new dimension of applications that include leak detection,monitoring of water quality,and waste systems.On a short-range length scale,the technology enables“lab-on-a-fiber”applications for food processing,medicine,and biosensing for instance.The chemical sensing is realized with unmodified low-cost telecom optical fibers,namely,by using swelling in the coating material of the fiber to detect specific chemicals.Although generic and able to work in various areas such as environmental monitoring,food analysis,agriculture or security,the proposed chemical sensors can be targeted for water quality monitoring,or medical diagnostics where they present the most groundbreaking nature.Moreover,the technique is without restrictions applicable to longer range installations.