Nanomaterials for refining tumor microenvironment and enhancing therapy in head and neck squamous cell carcinoma: a review

Head and neck squamous cell carcinoma (HNSCC) is a prevalent and lethal solid tumor with a high mortality rate. Conventional cancertreatments, including surgery, radiotherapy, and chemotherapy, primarily target cancer cell eradication. However, uncontrolled proliferation and metabolic activities of these cells result in abnormalities in nutrient levels, hypoxia, and immunosuppression within the tumor microenvironment (TME). These factors constrain the efficacy of traditional treatments by promoting drug resistance, recurrence, and metastasis. Nanomaterials (NMs), such as nanozymes, can exhibit enzymatic activity similar to that of natural enzymes and offer a promising avenuefor the direct modification of the TME through catalytic oxidation-reduction processes. Moreover, they can serve as sensitizers or drug deliverycarriers, enhancing the efficacy of traditional treatment methods. Recently, NMs have garnered significant attention from oncologists. Thisreview begins with an overview of the composition and unique characteristics of the TME. Subsequently, we comprehensively exploredthe application of NMs in the treatment of HNSCC. Finally, we discuss the potential prospects and challenges associated with usingNMs in biomedical research.

Optical properties and applications of SnS_(2) SAs with different thickness

Q-switched lasers have occupied important roles in industrial applications such as laser marking,engraving,welding,and cutting due to their advantages in high pulse energy.Here,SnS_(2)-based Q-switched lasers are implemented.Consid-ering that SnS_(2) inherits the thickness sensitive optical characteristics of TMD,three kinds of SnS2 with different thick-ness are characterized in terms of nonlinearity and used to realize the Q-switched pulses under consistent implementa-tion conditions for comparison tests.According to the results,the influence of thickness variation on the nonlinear per-formance of saturable absorber,such as modulation depth and absorption intensity,and the influence on the correspond-ing laser are analyzed.In addition,compared with other traditional saturable absorbers,the advantage of SnS_(2) in realiz-ing ultrashort pulses is also noticed.Our work explores the thickness-dependent nonlinear optical properties of SnS_(2),and the rules found is of great reference value for the establishment of target lasers.

Current diagnostic and therapeutic strategies for COVID-19

The outbreak and spread of novel coronavirus disease 2019(COVID-19) with pandemic features, which is caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2), have greatly threatened global public health. Given the perniciousness of COVID-19 pandemic, acquiring a deeper understanding of this viral illness is critical for the development of new vaccines and therapeutic options. In this review, we introduce the systematic evolution of coronaviruses and the structural characteristics of SARS-CoV-2. We also summarize the current diagnostic tools and therapeutic strategies for COVID-19.

Optical properties and applications for MoS_2-Sb_2Te_3-MoS_2 heterostructure materials

Two-dimensional(2D) materials with potential applications in photonic and optoelectronic devices have attracted increasing attention due to their unique structures and captivating properties. However, generation of stable high-energy ultrashort pulses requires further boosting of these materials' optical properties, such as higher damage threshold and larger modulation depth. Here we investigate a new type of heterostructure material with uniformity by employing the magnetron sputtering technique. Heterostructure materials are synthesized with van der Waals heterostructures consisting of MoS_2 and Sb_2Te_3. The bandgap, carrier mobility, and carrier concentration of the MoS_2-Sb_2Te_3-MoS_2 heterostructure materials are calculated theoretically. By using these materials as saturable absorbers(SAs), applications in fiber lasers with Q-switching and mode-locking states are demonstrated experimentally. The modulation depth and damage threshold of SAs are measured to be 64.17%and 14.13 J∕cm^2, respectively. Both theoretical and experimental results indicate that MoS_2-Sb_2Te_3-MoS_2 heterostructure materials have large modulation depth, and can resist high power during the generation of ultrashort pulses. The MoS_2-Sb_2Te_3-MoS_2 heterostructure materials have the advantages of low cost, high reliability, and suitability for mass production, and provide a promising solution for the development of 2D-material-based devices with desirable electronic and optoelectronic properties.

Earthworm regulation of nitrogen pools and dynamics and marker genes of nitrogen cycling: A meta-analysis

Earthworms, as the ecosystem engineers, both directly and indirectly affect the nitrogen(N) cycle. We aimed to provide a quantitative assessment of the contribution of earthworms to the terrestrial ecosystem N cycle using meta-analysis of 130 publications selected. The natural logarithm of the response ratio(lnRR) was used to indicate the effect size of earthworms on N dynamic variables. The results showed that earthworms significantly affected soil N-cycling microorganisms, including the amoA gene abundance of soil ammonia-oxidizing bacteria(AOB), and significantly promoted soil N cycle processes,including denitrification, mineralization, and plant assimilation. The effects of earthworms on the N cycle were experimental design dependent and affected by factors such as the functional group of earthworm and residue input. The presence of the anecic earthworms decreased the rates of mineralization and nitrification, and increased nitrification and denitrification responses were more pronounced in the presence of the endogeic earthworms than that of the other two functional groups of earthworms. In addition, residue input enhanced the effects of earthworms on the N cycle. The effects of earthworms on nitrous oxide(N_(2) O) emission increased when residues were added. These findings indicate that residue input and introducing suitable functional groups of earthworms into the field can lead to N sustainability without increasing N2 O emission. This meta-analysis also provides systematic evidence for the positive effects of earthworms on the plant N pool, N availability(soil ammonium(NH_(4)^(+)) content), and soil microbial biomass N content, showing the potential to alter ecosystem functions and services in relation to N cycling.

Multi-distributed probabilistically shaped PAM-4 system for intra-data-center networks

Probabilistically shaped(PS) pulse amplitude modulation(PAM) is a promising technique for intra-data-center networks due to its superior performance, for which a low-complexity and cost-effective distributed matching method is critical. In this work, we propose an energy-level-assigned method to yield PS-PAM-4 signals with various bit rates based on variable probabilistic distributions. We experimentally demonstrate the proposed method in a 25 Gbaud PS-PAM-4 transmission over a bandwidth of approximately 10 GHz. Compared to a uniform PAM-4 system, the proposed multi-distributed PS-PAM-4 system approaches the hard decision threshold at a wide range of received optical power for different applications.

Nonlinear optical properties of WSe_2 and MoSe_2 films and their applications in passively Q-switched erbium doped fiber lasers

Transition metal dichalcogenides(TMDs) are successfully applied in fiber lasers for their photoelectric properties.However, in previous work, how to improve the modulation depth of TMD-based saturable absorbers(SAs) has been a challenging issue. In this paper, WSe_2 and MoSe_2 SAs are fabricated with the chemical vapor deposition method. Compared with previous experiments, the modulation depths of WSe_2 and MoSe_2 SAs with sandwiched structures are effectively increased to 31.25% and 25.69%, respectively. The all-fiber passively Q-switched erbium doped fiber lasers based on WSe_2 and MoSe_2 SAs are demonstrated. The signal-to-noise ratios of those lasers are measured to be 72 and 57 dB, respectively. Results indicate that the proposed WSe_2 and MoSe_2 SAs are efficient photonic devices to realize stable fiber lasers.

Sulfur defect-rich WS nanosheet electrocatalysts for N reduction

Seeking catalysts with high electrocatalytic activity for ambient-condition N2 reduction reaction (NRR) remains an ongoing challenge due to the chemical inertness of N2.Herein,defect-rich WS2 nanosheets (WS2-x) were designed as an efficient electrocatalyst for NRR,which were prepared via vulcanizing the oxygen-vacancy-rich tungsten oxide in a vacuum tube.The sulfur defects were conducive to the adsorption and activation of N2.In neutral electrolyte of 0.1 mol L^(-1)Na2SO_(4) at-0.60 V vs.reversible hydrogen electrode,such WS2-xoffered a high Faradaic efficiency of 12.1%with a NH3generation rate of 16.38μg h-1mg-1cat..

An implantable antibacterial drug-carrier:Mesoporous silica coatings with size-tunable vertical mesochannels

Implant-associated bacterial infection remains one of the most common and serious complications.Therefore,a surface boasting long-term antibacterial ability for implants is highly desirable.Herein,mesoporous silica coatings(MSCs)with vertical and size-tunable mesochannels are fabricated on a variety of metal substrates via a nano-interfacial oriented assembly approach.Such facile and versatile approach relies on the vertically oriented fusion of composite micelles on the nanoscale flatness surface of substrates.Such orientation assembly process endows the MSCs with vertical mesochannels,tunable mesopore size(ca.5.5-13.5 nm),and switchable substrates even with complex and diversified surfaces.Importantly,the MSCs on titanium substrates(Ti@MSCs)exhibit excellent performances for drug adsorption and sustained release.The saturation adsorption capacity can reach 0.544 μg·cm^(-2) towards minocycline hydrochloride(MC-HCl)antibiotic molecules,which is 6.5 times as the bare titanium(Ti)substrate.In addition,the drug release time can be controlled from 84 to 216 h by simply adjusting the mesopore size.As a proof of concept,the Ti@MSCs can realize a higher antibacterial rate(95.9%),compared with the bare Ti(70.3%).The results highlight the high potential of MSCs as implant coating for long-term preventing and eliminating peri-implantitis.

Highly stable hybrid single-micelle:A universal nanocarrier for hydrophobic bioimaging agents

As the first-line technology,micelles play a pivotal role in in vivo delivery of theranostic agents because of their high biocompatibility and universality.However,in complex physiological environments(extreme dilution,pH,and oxidation or reduction,etc.),they generally suffer from structural instability and insufficient protection for encapsulated cargos.It is urgent to reinforce the structural stability of the micelles at the single-micelle level.By using the FDA-approved Pluronic F127 surfactants and indocyanine green(ICG)bioimaging agents as model,herein,we propose the silane-crosslinking assisted strategy to reinforce the structural stability of the single-micelle.Different from the traditional silane hydrolysis under the harsh experimental conditions(acidic,alkaline,and high temperature hydrothermal,etc.),the ICG loaded F127@SiO_(2) hybrid single-micelles(ICG@H-micelles)with controllable sizes(15-35 nm)are synthesized at neutral pH and room temperature,which is crucial for the maintenance of the physicochemical properties of the encapsulated cargos.With the ultra-thin SiO_(2)(<5 nm)at hydrophilic layer of the single-micelle,the structural and fluorescence stability of ICG@H-micelles are much higher than the conventional micelle(ICG@micelles)in the simulated physiological environments of dilution,oxidation or reduction,and low pH.Because of the high structural and fluorescence stability,the ICG@H-micelles also exhibit longer duration time in the tumor and gastrointestinal tract bioimaging.

Mode-locked all-fiber laser with high stability based on cobalt oxyfluoride

Recent years have witnessed the exploration of fiber laser technology focused on numerous pivotal optoelectronic applications from laser processing and remote sensing to optical communication. Here, using cobalt oxyfluoride(Co OF) as the nonlinear material, a 156 fs mode-locked fiber laser with strong stability is obtained. The rapid thermal annealing technique is used to fabricate the Co OF, which is subsequently transferred to the tapered region of the microfiber to form the effective pulse modulation device. Co OF interacts with the pulsed laser through the evanescent field to realize the intracavity pulse shaping, and then the stable mode-locked pulse is obtained. The mode-locked operation is maintained with the pulse duration of 156 fs and repetition rate of 49 MHz. In addition, the signal-to-noise ratio is about 90 d B. Those experimental results confirm the attractive nonlinear optical properties of Co OF and lay a foundation for the ultrafast application of lowdimensional transition metal oxides.

Spatially asymmetric cascade nanocatalysts for enhanced chemodynamic therapy

Chemodynamic therapy(CDT)based on cascade catalytic nanomedicine has emerged as a promising cancer treatment strategy.However,most of the reported cascade catalytic systems are designed based on symmetric-or co-assembly of multiple catalytic active sites,in which their functions are difficult to perform independently and may interfere with each other.Especially in cascade catalytic system that involves fragile natural-enzymes,the strong oxidation of free-radicals toward natural-enzymes should be carefully considered,and the spatial distribution of the multiple catalytic active sites should be carefully organized to avoid the degradation of the enzyme catalytic activity.Herein,a spatially-asymmetric cascade nanocatalyst is developed for enhanced CDT,which is composed by a Fe_(3)O_(4)head and a closely connected mesoporous silica nanorod immobilized with glucose oxidase(mSiO_(2)-GOx).The mSiO_(2)-GOx subunit could effectively deplete glucose in tumor cells,and meanwhile produce a considerable amount of H_(2)O_(2)for subsequent Fenton reaction under the catalysis of Fe_(3)O_(4)subunit in the tumor microenvironment.Taking the advantage of the spatial isolation of mSiO_(2)-GOx and Fe_(3)O_(4)subunits,the catalysis of GOx and freeradicals generation occur at different domains of the asymmetric nanocomposite,minimizing the strong oxidation of free-radicals toward the activity of GOx at the other side.In addition,direct exposure of Fe_(3)O_(4)subunit without any shelter could further enhance the strong oxidation of free-radicals toward objectives.So,compared with traditional core@shell structure,the long-term stability and efficiency of the asymmetric cascade catalytic for CDT is greatly increased by 138%,thus realizing improved cancer cell killing and tumor restrain efficiency.

Q-switched fiber laser operating at 1.5 μm based on WTe_2

Compared with the extensively studied MoS2 and WS2, WTe_2 owns a smaller bandgap, which is applicable to a near-infrared system in photodetectors, communications, and ultrafast optics. In this work, the WTe_2 saturable absorber(SA) with the tapered fiber structure is prepared by the magnetron-sputtering technology, which enables the prepared SA to be low in cost and have strong nonlinearity. The modulation depth of the prepared WTe_2 SA is measured as 31.06%. The Q-switched fiber laser operating at 1.5 μm is successfully investigated by incorporating the proposed SA into the prepared ring cavity. To the best of our knowledge, this is the first attempt of WTe_2 in the Q-switched fiber laser at 1.5 μm.

High-power MoTe_2-based passively Q-switched erbium-doped fiber laser

Materials in the transition metal dichalcogenide family, including WS2, MoS2, WSe2, and MoSe2, etc., have captured a substantial amount of attention due to their remarkable nonlinearities and optoelectronic properties.Compared with WS2 and MoS2, the monolayered MoTe2 owns a smaller direct bandgap of 1.1 eV. It is beneficial for the applications in broadband absorption. In this letter, using the magnetron sputtering technique, MoTe2 is deposited on the surface of the tapered fiber to be assembled into the saturable absorber. We first implement the MoTe2-based Q-switched fiber laser operating at the wavelength of 1559 nm. The minimum pulse duration and signal-to-noise ratio are 677 ns and 63 dB, respectively. Moreover, the output power of 25 mW is impressive compared with previous work. We believe that MoTe2 is a promising 2D material for ultrafast photonic devices in the high-power Q-switched fiber lasers.