Comparative study of 2mol% Li- and Mn-substituted lead-free potassium sodium niobate ceramics

The effect of Li and Mn substitution on the dielectric, ferroelectric and piezoelectric properties of lead free K0.5Na0.5NbO3 （KNN） was investigated. Samples were prepared using a conventional solid state reaction method. The sintefing temperature for all the samples was 1050℃. The optimum doping concentration for the enhancement of different properties without the introduction of any other co-dopants such as Ti, Sb, and La was investigated. X-ray diffraction analysis confirmed that all the samples crystallize in a single phase perovskite structure. The dielectric properties were investigated as a function of temperature and applied electric field frequency. Compared with Li-substituted KNN （KLNN）, Mn-substituted KNN （KMNN） exhibited a higher dielectric constant εmax （i.e., 4840） at its critical transition temperature Tc （i.e., 421℃） along with a lower value of tangent loss at 10 kHz and greater values of saturation polarisation Ps （i.e., 20.14 μC/cm^2） and remnant polarisation Pr （i.e., 15.48 μC/cm^2）. The piezoelectric constant （d33） of KMNN was 178 pC/N, which is comparable to that of lead-based hard ceramics. The results presented herein suggest that B-site or Mn substitution at the optimum concentration results in good enhancement of different properties required for materials used in memory devices and other applications.

Antimicrobial Activity of Acidified Sodium Chlorite and Cell Free Culture Supernatent of Lactic Acid Bacteria against <i>Salmonella</i>Typhimurium

Most methods used by food industries to decontaminate eggs involve washing of egg surface with various chemicals. In this study, the effectiveness of two organic decontaminants viz., acidified sodium chlorite (ASC) and cell free culture supernatant (CFCS) of two lactic acid bacteria (Lactobacillus plantarum and Pediococcus cerevisiae) was evaluated for the decontamination of spiked Salmonella Typhimurium on chicken egg shell surface. Acidified sodium chlorite at 100 μl/L concentration with the contact time of 20 min completely inhibited S. Typhimurium on egg shell surface while at 50 μl/L concentration 1 - 2 log10 units reduction was observed in counts of S. Typhimurium as compared to control group. Likewise, CFCS of P. cerevisiae completely inhibited the growth of S. Typhimurium on 30 min contact, whereas L. plantarum and combination of both were revealed significant reduction in the counts of S. Typhimurium counts.

Stem cell technologies in human health: Boon or bane?

The stem cells of an organism only possess extraordinary capacity to change into different cell types during the early life and growth of an organism. When these stem cells divide into different new cells, these either remain as stem cells or develop to become other cells with specialized function. For this reason, stem cells offer direct relevance to human health, as theoretically, using stem cell technology, different organs are expected to be regenerated. To this, the Human Embryonic Stem Cells (HESCs) are natural pluripotent cell, but ethical issues covering many countries have put research work on a bit back-foot. However, the Induced Pluripotent Stem Cells (iPSCs) technology has completely revitalized the world to use this technology universally and it therefore seems that more research on this technology will surely be of enormous help in public health. In addition, application of the stem cell technology in personalized-medicine has been started recently. In this concern, the stem cell banking facilities have provided new avenues for preserving the cord blood of the new-borne child and treat them in future by using her/his own preserved stem cells. However, like all new technologies, the output from stem cell research requires to be evaluated more closely. Furthermore, with proper guidelines on ethical issues and extended research following these strategies, the stem cell technology is expected to not only be of huge benefit to human health, but also the benefit can be extended to the survival of endangered animals as well.

Biomaterial types,properties,medical applications,and other factors:a recent review

Biomaterial research has been going on for several years,and many companies are heavily investing in new product development.However,it is a contentious field of science.Biomaterial science is a field that combines materials science and medicine.The replacement or restoration of damaged tissues or organs enhances the patient’s quality of life.The deciding aspect is whether or not the body will accept a biomaterial.A biomaterial used for an implant must possess certain qualities to survive a long time.When a biomaterial is used for an implant,it must have specific properties to be long-lasting.A variety of materials are used in biomedical applications.They are widely used today and can be used individually or in combination.This review will aid researchers in the selection and assessment of biomaterials.Before using a biomaterial,its mechanical and physical properties should be considered.Recent biomaterials have a structure that closely resembles that of tissue.Antiinfective biomaterials and surfaces are being developed using advanced antifouling,bactericidal,and antibiofilm technologies.This review tries to cover critical features of biomaterials needed for tissue engineering,such as bioactivity,self-assembly,structural hierarchy,applications,heart valves,skin repair,bio-design,essential ideas in biomaterials,bioactive biomaterials,bioresorbable biomaterials,biomaterials in medical practice,biomedical function for design,biomaterial properties such as biocompatibility,heat response,non-toxicity,mechanical properties,physical properties,wear,and corrosion,as well as biomaterial properties such surfaces that are antibacterial,nanostructured materials,and biofilm disrupting compounds,are all being investigated.It is technically possible to stop the spread of implant infection.

Transient performance estimation of charge plasma based negative capacitance junctionless tunnel FET

We investigate the transient behavior of an n-type double gate negative capacitance junctionless tun- nel field effect transistor （NC-JLTFET）. The structure is realized by using the work-function engineering of metal electrodes over a heavily doped n＋ silicon channel and a ferroelectric gate stack to get negative capacitance be- havior. The positive feedback in the electric dipoles of ferroelectric materials results in applied gate bias boosting. Various device transient parameters viz. transconductance, output resistance, output conductance, intrinsic gain, intrinsic gate delay, transconductance generation factor and unity gain frequency are analyzed using ac analysis of the device. To study the impact of the work-function variation of control and source gate on device performance, sensitivity analysis of the device has been carried out by varying these parameters. Simulation study reveals that it preserves inherent advantages of charge-plasma junctionless structure and exhibits improved transient behavior as well.

Impact of strained silicon on the device performance of a bipolar charge plasma transistor

In this manuscript we analyze a unique approach to improve the performance of the bipolar charge plasma transistor(BCPT) by introducing a strained Si/SiGe1-x layer as the active device region. For charge plasma realization different metal work-function electrodes are used to induce n+ and p+ regions on undoped strained silicon-on-insulator(sSOI or SiGe) to realize emitter, base, and collector regions of the BCPT. Here,by using a calibrated 2-D TCAD simulation the impact of a Si mole fraction x(in SiGe) on device performance metrics is investigated. The analysis demonstrates the band gap lowering with decreasing Si content or effective strain on the Si layer, and its subsequent advantages. This work reports a significant improvement in current gain, cutoff frequency, and lower collector breakdown voltage(BVCEO) for the proposed structure over the conventional device. The effect of varying temperature on the strained Si layer and its implications on the device performance is also investigated. The analysis demonstrates a fair device-level understanding and exhibits the immense potential of the SiGematerial as the device layer. In addition to this, using extensive 2-D mixed-mode TCAD simulation, a considerable improvement in switching transient times are also observed compared to its conventional counterpart.

Dopingless impact ionization MOS(DL-IMOS)—a remedy for complex process flow

We propose a unique approach for realizing dopingless impact ionization MOS （DL-IMOS） based on the charge plasma concept as a remedy for complex process flow. It uses work-function engineering of electrodes to form charge plasma as surrogate doping. This charge plasma induces a uniform p-region in the source side and an n-region in the drain side on intrinsic silicon film with a thickness less than the intrinsic Debye length. DL-IMOS offers a simple fabrication process flow as it avoids the need of ion implantation, photo masking and complicated thermal budget via annealing devices. The lower thermal budget is required for DL-IMOS fabrication enables its fabrication on single crystal silicon-on-glass substrate realized by wafer scale epitaxial transfer. It is highly immune to process variations, doping control issues and random dopant fluctuations, while retaining the inherent advantages of conventional IMOS. To epitomize the fabrication process flow for the proposed device a virtual fabrication flow is also proposed here. Extensive device simulation of the major device performance metrics such as subthreshold slope, threshold voltage, drain induced current enhancement, and breakdown voltage have been done for a wide range of electrodes work-function. To evaluate the potential applications of the proposed device at circuit level, its mixed mode simulations are also carried out.

Role of extracellular vesicles secretion in paclitaxel resistance of prostate cancer cells

Aim:The development of chemotherapy resistance is the major obstacle in the treatment of advanced prostate cancer(PCa).Extracellular vesicles(EVs)secretion plays a significant role among different mechanisms contributing to chemoresistance.Hence,inhibition of EVs release may increase the efficacy of chemotherapeutic drugs against PCa.Methods:Paclitaxel(PTX)resistant PCa cells(PC3-R and DU145-R)were treated with GW4869,a known exosome biogenesis inhibitor.EVs were isolated from the conditioned media by ExoQuick-based precipitation method and characterized for concentration and size distribution by nanoparticle tracking analysis.The effect of GW4869 treatment on the survival and growth of PCa cells was assessed by MTT,and colony formation assays in vitro,and ectopic PC3-R xenografts in male athymic nude mice in vivo.The effect of other EV biogenesis inhibitors,imipramine and dimethyl amiloride(DMA),treatment was also analyzed on the survival of PC3-R cells.Results:GW4869(10-20μM)treatment of PTX resistant PCa cells significantly reduced the release of small EVs(50-100 nm size range)while increasing the release of larger EVs(>150 nm in size),and inhibited their clonogenicity.Moreover,GW4869(5-20μM)treatment(24-72h)significantly inhibited the survival of PC3-R cells in a dose-dependent manner.We observed a similar growth inhibition with both imipramine(5-20μg/mL)and DMA(5-20μg/mL)treatment in PC3-R cells.Furthermore,GW4869 treatment(IP)in mice bearing PC3-R xenografts significantly reduced the tumor weight(65%reduction,P=0.017)compared to the vehicle-treated control mice without causing any noticeable toxicity.Conclusion:Inhibiting the release of EVs could sensitize the resistant PCa cells to chemotherapy.