Nanoscale Research Letters最新文献

In this paper, we present a new novel simple iTFET with overlapping gate on source-contact (SGO), Drain Schottky Contact, and intrinsic SiGe pocket (Pocket-SGO iTFET). The aim is to achieve steep subthreshold swing (S.S) and high I_ON current. By optimizing the gate and source-contact overlap, the tunneling efficiency is significantly enhanced, while the ambipolar effect is suppressed. Additionally, using a Schottky contact at the drain/source, instead of ion implantation drain/source, reduces leakage current and thermal budget. Moreover, the tunneling region is replaced by an intrinsic SiGe pocket posing a narrower bandgap, which increases the probability of band-to-band tunneling and enhances the I_ON current. Our simulations are based on the feasibility of the actual process, thorough Sentaurus TCAD simulations demonstrate that the Pocket-SGO iTFET exhibits an average and minimum subthreshold swing of S.S_avg = 16.2 mV/Dec and S.S_min = 4.62 mV/Dec, respectively. At V_D = 0.2 V, the I_ON current is 1.81 (times) 10^–6 A/μm, and the I_ON/I_OFF ratio is 1.34 (times) 10⁹. The Pocket-SGO iTFET design shows great potential for ultra-low-power devices that are required for the Internet of Things (IoT) and AI applications.

The development of nanoparticles capable of inducing reactive oxygen species (ROS) formation has become an important strategy for cancer therapy. Simultaneously, the preparation of multifunctional nanoparticles that respond to the tumor microenvironment is crucial for the diagnosis and treatment of tumors. In this study, we designed a Molybdenum disulfide (MoS₂) core coated with Manganese dioxide (MnO₂), which possessed a good photothermal effect and could produce Fenton-like Mn²⁺ in response to highly expressed glutathione (GSH) in the tumor microenvironment, thereby generating a chemodynamic therapy (CDT). The nanoparticles were further modified with Methoxypoly(Ethylene Glycol) 2000 (mPEG-NH₂) to improve their biocompatibility, resulting in the formation of MoS₂@MnO₂-PEG. These nanoparticles were shown to possess significant Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) imaging capabilities, making them useful in tumor diagnosis. In vitro and in vivo experiments demonstrated the antitumor ability of MoS₂@MnO₂-PEG, with a significant killing effect on tumor cells under combined treatment. These nanoparticles hold great potential for CDT/photothermal therapy (PTT) combined antitumor therapy and could be further explored in biomedical research.

Today performance and operational efficiency of computer systems on digital image processing are exacerbated owing to the increased complexity of image processing. It is also difficult for image processors based on complementary metal–oxide–semiconductor (CMOS) transistors to continuously increase the integration density, causing by their underlying physical restriction and economic costs. However, such obstacles can be eliminated by non-volatile resistive memory technologies (known as memristors), arising from their compacted area, speed, power consumption high efficiency, and in-memory computing capability. This review begins with presenting the image processing methods based on pure algorithm and conventional CMOS-based digital image processing strategies. Subsequently, current issues faced by digital image processing and the strategies adopted for overcoming these issues, are discussed. The state-of-the-art memristor technologies and their challenges in digital image processing applications are also introduced, such as memristor-based image compression, memristor-based edge and line detections, and voice and image recognition using memristors. This review finally envisages the prospects for successful implementation of memristor devices in digital image processing.

Background

It is known that some sectors of hospitals have high bacteria and virus loads that can remain as aerosols in the air and represent a significant health threat for patients and mainly professionals that work in the place daily. Therefore, the need for a respirator able to improve the filtration barrier of N95 masks and even inactivating airborne virus and bacteria becomes apparent. Such a fact motivated the creation of a new N95 respirator which employs chitosan nanoparticles on its intermediate layer (SN95 + CNP).

Results

The average chitosan nanoparticle size obtained was 165.20 ± 35.00 nm, with a polydispersity index of 0.36 ± 0.03 and a zeta potential of 47.50 ± 1.70 mV. Mechanical tests demonstrate that the SN95 + CNP respirator is more resistant and meets the safety requisites of aerosol penetration, resistance to breath and flammability, presenting higher potential to filtrate microbial and viral particles when compared to conventional SN95 respirators. Furthermore, biological in vitro tests on bacteria, fungi and mammalian cell lines (HaCat, Vero E6 and CCL-81) corroborate the hypothesis that our SN95 + CNP respirator presents strong antimicrobial activity and is safe for human use. There was a reduction of 96.83% of the alphacoronavirus virus and 99% of H1N1 virus and MHV-3 betacoronavirus after 120 min of contact compared to the conventional respirator (SN95), demonstrating that SN95 + CNP have a relevant potential as personal protection equipment.

Conclusions

Due to chitosan nanotechnology, our novel N95 respirator presents improved mechanical, antimicrobial and antiviral characteristics.

Amphiphilic polymers (HA-ANI) were prepared by grafting hyaluronic acid (HA) and 6-(2-nitroimidazole)hexylamine (ANI) and then self-assemble in water to form nanoparticles (NPs) that could be loaded with paclitaxel (PTX) and gemcitabine (GEM) by dialysis. Infrared spectroscopy and ¹H-NMR indicated the successful synthesis of HA-ANI. Three different ratios of NPs were prepared by adjusting the ratios of hydrophilic and hydrophobic materials, and the particle size decreased as the ratio of hydrophilic materials increased. When HA:ANI = 2.0:1, the nanoparticles had the smallest size distribution, good stability and near spherical shape and had high drug loading and encapsulation rates. In vitro release experiments revealed that NADPH could accelerate the drug release from NPs. Cellular uptake rate reached 86.50% at 6 h. The toxic effect of dual drug-loaded nanoparticles (P/G NPs) on MDA-MB-231 cells at 48 h was stronger than that of the free drug. The AO/EB double-staining assay revealed that a large number of late apoptotic cells appeared in the P/G NPs group, and the degree of cell damage was significantly stronger than that of the free drug group. In the cell migration assay, the 24 h-cell migration rate of the P/G NPs group was 5.99%, which was much lower than that of the free group (13.87% and 17.00%). In conclusion, MDA-MB-231 cells could effectively take up P/G NPs, while the introduction of the nano-codelivery system could significantly enhance the toxicity of the drug to MDA-MB-231 cells as well as the migration inhibition effect.

The effect of mechanical alloying on the development of Ni–Al–Ti–Mn–Co–Fe–Cr high entropy alloys (HEAs) utilizing the spark plasma sintering (SPS) method is the main goal of this study. A bulk sample was fabricated using SPS after the alloys were mixed for 12 h. Thermodynamic simulation, X-ray diffraction, scanning electron microscopy, nanoindentation, and microhardness were used to investigate the microstructure and mechanical properties of the as-mixed powders. The master alloy was made of NiAl and was subsequently alloyed with Ti, Mn, Co, Fe, and Cr at different compositions to develop HEAs at a sintering temperature of 850 °C, a heating rate of 100 °C/min, a pressure of 50 MPa, and a dwelling time of 5 min. A uniform dispersion of the alloying material can be seen in the microstructure of the sintered HEAs with different weight elements. The grain size analysis shows that the Ni₂₅Al₂₅Ti₈Mn₈Co₁₅Fe₁₄Cr₅ alloy exhibited a refined structure with a grain size of 2.36 ± 0.27 µm compared to a coarser grain size of 8.26 ± 0.43 μm attained by the NiAl master alloy. Similarly, the HEAs with the highest alloying content had a greater microstrain value of 0.0449 ± 0.0036, whereas the unalloyed NiAl had 0.00187 ± 0.0005. Maximum microhardness of 139 ± 0.8 HV, nanohardness of 18.8 ± 0.36 GPa, elastic modulus of 207.5 ± 1.65 GPa, elastic recovery (W_e/W_t) of 0.556 ± 0.035, elastic strain to failure (H/E_r) of 0.09.06 ± 0.0027, yield pressure (H³/(E_{{text{r}}}^{2})) of 0.154 ± 0.0055 GPa, and the least plasticity index (W_p/W_t) of 0.444 ± 0.039 were attained by Ni₂₅Al₂₅Ti₈Mn₈Co₁₅Fe₁₄Cr₅. A steady movement to the left may be seen in the load–displacement curve. Increased resistance to indentation by the developed HEAs was made possible by the increase in alloying metals, which ultimately led to higher nanohardness and elastic modulus.

HCV, hepatitis C virus, is a virus that causes damage to the liver. Both chronic infection or lack of treatment increase morbidity except if it is an acute infection, as the body clears the virus without any intervention. Also, the virus has many genotypes, and until now, there has yet to be a single treatment capable of affecting and treating all these genotypes at once. This review will discuss the main and most used old treatments, IFN-a, PEG IFN-a, Ribavirin, Celgosvir, and sofosbuvir alone and with the combination of other drugs and their drawbacks. They should be given in combination to improve the effect on the virus compared with being administrated independently, as in the case of sofosbuvir. For these reasons, the need for new treatments and diagnostic tools arises, and the rule of nanotechnology comes here. The role of carbon nanotubes, dendrimers, and fullerenes will be discussed. CNTs, carbon nanotubes, are one-dimensional structures composed of a cylindrical sheet of graphite and are mainly used for diagnostic purposes against HCV. Dendrimers, three-dimensional highly branched structures, are macromolecules that provide better drug delivery and treatment options due to their unique structure that can be modified, producing versatile types; each has unique properties. Fullerenes which are cage like structures derived and closely related to CNTs, and composed of carbon atoms that can be substituted by other atoms which in return open unlimited usage for these carbon based materials. Fullerenes rule is unique since it has two mechanisms that prevent the virus from binding and acting on the virus-replicating enzyme. However, their charge needs to be determined; otherwise, it will lead to cytotoxicity. Lastly, no review has been done on the role of nanotechnology against HCV yet.

Society 5.0 establishes innovations and innovativeness as the basic platforms for accelerating the development of solution-based strategies for the sustainability problems every society is facing. It features an interactive cycle operating at a society-wide level through which data are collected, analyzed and transformed into applicable technology for the real world. Transforming the current society into a super smart society requires in-depth knowledge of the Internet of Things, robotics and artificial intelligence. Being a member of the 4th industrial revolution is significant; however, it is equally important to alleviate the socioeconomic challenges associated with it and to maintain sustainability. From cellulose to carbon, fibers have utmost importance in technological applications, industrial developments and sustainability. Fibers are identified as useful energy resources, water treatment mediums, supercapacitors in electronic devices and wearable e-textiles. Therefore, knowing the chemistry behind fiber manipulation for advanced applications for Society 5.0 is beneficial. In this paper, we highlight the contributions of fibers to shaping Society 5.0 and their modifications and role in providing a sustainable environment. We highlight the chemical aspects behind tailoring fibers to provide state-of-the-art information on fiber-based products. We also provide background information on fiber technology and the sustainable development goals for a fiber-oriented Society 5.0. Scientists, researchers and specialists in this field should understand the impact of tailoring and influencing society as a whole.

Nanocarrier systems are widely used for drug delivery applications, but limitations such as the use of synthetic surfactants, leakage of toxic drugs, and a poor encapsulation capacity remain as challenges. We present a new hybrid nanocarrier system that utilizes natural materials to overcome these limitations and improve the safety and efficacy of drug delivery. The system comprises a biopolymeric shell and a lipid core, encapsulating the lipophilic anticancer drug paclitaxel. Bovine serum albumin and dextran, in various molecular weights, are covalently conjugated via Maillard reaction to form the shell which serves as a stabilizer to maintain nanoparticle integrity. The properties of the system, such as Maillard conjugate concentration, protein/polysaccharide molar ratio, and polysaccharide molecular weight, are optimized to enhance nanoparticle size and stability. The system shows high stability at different pH conditions, high drug loading capacity, and effective in vitro drug release through the trigger of enzymes and passive diffusion. Serine proteases are used to digest the protein portion of the nanoparticle shell to enhance the drug release. This nanocarrier system represents a significant advancement in the field of nanomedicine, offering a safe and effective alternative for the delivery of lipophilic drugs.

Graphical abstract

MOFs have considerable adsorption capacity due to their huge specific surface area. They have the characteristics of photocatalysts for their organic ligands can absorb photons and produce electrons. In this paper, the photodegradation properties of TiO₂ composites loaded with UiO-66 were investigated for the first time for MO. A series of TiO₂@UiO-66 composites with different contents of TiO₂ were prepared by a solvothermal method. The photocatalytic degradation of methyl orange (MO) was performed using a high-pressure mercury lamp as the UV light source. The effects of TiO₂ loading, catalyst dosage, pH value, and MO concentration were investigated. The results showed that the degradation of MO by TiO₂@UiO-66 could reach 97.59% with the addition of only a small amount of TiO₂ (5 wt%). TiO₂@UiO-66 exhibited significantly enhanced photoelectron transfer capability and inhibited efficient electron–hole recombination compared to pure TiO₂ in MO degradation. The composite catalyst indicated good stability and reusability when they were recycled three times, and the photocatalytic reaction efficiencies were 92.54%, 88.76%, and 86.90%. The results provide a new option to design stable, high-efficiency MOF-based photocatalysts.