Cancer cell membrane camouflaging mesoporous nanoplatform interfering with cellular redox homeostasis to amplify photodynamic therapy on oral carcinoma.

The efficacy of photodynamic therapy (PDT) is still limited by the inefficient utilisation of generated ROS in tumours due to cellular redox homeostasis. To improve the therapeutic efficacy for oral carcinoma, biomimetic cell membrane-coated mesoporous nanoplatform was tailored to interfere with cellular redox homeostasis for amplified PDT. In this study, CAL-27 cancer cell membrane (CM) was encapsulated onto the mesoporous silica NPs (MSN), which were preloaded with Chlorin e6 (Ce6) and Curcumin (Cur). The biomimetic nanoparticles displayed a size of around 120 nm, which had excellent cytotoxicity under a laser and increased uptake ability to tumour cell. After internalised by cancer cells, the released Cur could effectively disturb ROS-defence system by suppressing TrxR activity, and decreasing TrxR-2 expression (p < 0.05), leading to enhanced cancer cell killing ability of PDT. The biomimetic system was found to selectively accumulate in the tumour due to its homologous targeting capability and inhibit tumour growth significantly. In a word, the biomimetic nanoplatform apparently enhanced the therapeutic effect of PDT on tumours by Cur disturbing the ROS-defence system, which exhibited a new way to enhance PDT.

Prospects for Anti-Tumor Mechanism and Potential Clinical Application Based on Glutathione Peroxidase 4 Mediated Ferroptosis.

Ferroptosis, characterized by excessive iron accumulation and lipid peroxidation, is a novel form of iron-dependent cell death, which is morphologically, genetically, and biochemically distinct from other known cell death types, such as apoptosis, necrosis, and autophagy. Emerging evidence shows that glutathione peroxidase 4 (GPX4), a critical core regulator of ferroptosis, plays an essential role in protecting cells from ferroptosis by removing the product of iron-dependent lipid peroxidation. The fast-growing studies on ferroptosis in cancer have boosted a perspective on its use in cancer therapeutics. In addition, significant progress has been made in researching and developing tumor therapeutic drugs targeting GPX4 based on ferroptosis, especially in acquired drug resistance. Selenium modulates GPX4-mediated ferroptosis, and its existing form, selenocysteine (Sec), is the active center of GPX4. This review explored the structure and function of GPX4, with the overarching goal of revealing its mechanism and potential application in tumor therapy through regulating ferroptosis. A deeper understanding of the mechanism and application of GPX4-mediated ferroptosis in cancer therapy will provide new strategies for the research and development of antitumor drugs.

Effect of 3D Printing Process Parameters on Damping Characteristic of Cantilever Beams Fabricated Using Material Extrusion.

The present paper aims to investigate the process parameters and damping behaviour of the acrylonitrile butadiene styrene (ABS) cantilever beam manufactured using material extrusion (MEX). The research outcome could guide the manufacture of MEX structures to suit specific operating scenarios such as energy absorption and artificially controlled vibration responses. Our research used an experimental approach to examine the interdependencies between process parameters (nozzle size, infill density and pattern) and the damping behaviour (first-order modal damping ratio and loss factor). The impact test was carried out to obtain the damping ratio from the accelerometer. A dynamic mechanical analysis was performed for the loss factor measurement. The paper used statistical analysis to reveal significant dependencies between the process parameters and the damping behaviour. The regression models were also utilised to evaluate the mentioned statistical findings. The multiple third-order polynomials were developed to represent the relation between process parameters and modal damping ratio using stiffness as the mediation variable. The obtained results showed that the infill density affected the damping behaviour significantly. Higher infill density yielded a lower damping ratio. Nozzle size also showed a notable effect on damping. A high damping ratio was observed at a significantly low value of nozzle size. The results were confirmed using the theoretical analysis based on the underlying causes due to porosity in the MEX structure.

Twelve-month specific IgG response to SARS-CoV-2 receptor-binding domain among COVID-19 convalescent plasma donors in Wuhan.

To investigate the duration of humoral immune response in convalescent coronavirus disease 2019 (COVID-19) patients, we conduct a 12-month longitudinal study through collecting a total of 1,782 plasma samples from 869 convalescent plasma donors in Wuhan, China and test specific antibody responses. The results show that positive rate of IgG antibody against receptor-binding domain of spike protein (RBD-IgG) to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the COVID-19 convalescent plasma donors exceeded 70% for 12 months post diagnosis. The level of RBD-IgG decreases with time, with the titer stabilizing at 64.3% of the initial level by the 9th month. Moreover, male plasma donors produce more RBD-IgG than female, and age of the patients positively correlates with the RBD-IgG titer. A strong positive correlation between RBD-IgG and neutralizing antibody titers is also identified. These results facilitate our understanding of SARS-CoV-2-induced immune memory to promote vaccine and therapy development.

Turning-on persistent luminescence out of chromium-doped zinc aluminate nanoparticles by instilling antisite defects under mild conditions.

Spinel oxide nanocrystals are appealing hosts for Cr3+ for forming persistent luminescent nanomaterials due to their suitable fundamental bandgaps. Benefiting from their antisite defect-tolerant nature, zinc gallate doped with Cr3+ ions has become the most studied near-infrared (NIR) persistent luminescent material. However, it remains challenging to achieve persistent luminescence from its inexpensive analogs, e.g., zinc aluminate (ZnAl2O4). Because the radius difference of the cations in the latter system is bigger, it is intrinsically unfavorable for ZnAl2O4 to form Zn-Al antisite defects under mild conditions. Herein, we report a wet-chemical synthetic route for preparing Cr3+-doped ZnAl2O4 nanoparticles with long NIR persistent luminescence. It was demonstrated that methanol (MeOH) as an important component of the mixed solvent played a critical role in tailoring the morphology of the resulting ZnAl2O4:Cr nanocrystals. It could particularly drive the formation of antisite defects in the resulting coral-like nanoparticles bearing zinc-rich cores and zinc gradient peripheries. To disclose the effects of MeOH on the formation of antisite defects as well as particle morphologies, small molecules released during the pyrolysis of metal acetylacetonate precursors were analyzed by using gas chromatography-mass spectrometry. In combination with density functional theory (DFT) calculations, it was found that MeOH can effectively catalyze the thermolysis of metal acetylacetonate precursors, in particular Zn(acac)2. Therefore, MeOH exhibits remarkable effects on the formation of antisite defects by balancing the decomposition rates of Zn(acac)2 and Al(acac)3 through its volume fraction in the reaction system. This work thus constitutes a hitherto less common strategy for achieving NIR persistent luminescence from Cr3+-doped ZnAl2O4 nanoparticles by engineering the cation defects under mild conditions.

Two-Dimensional and Subnanometer-Thin Quasi-Copper-Sulfide Semiconductor Formed upon Copper-Copper Bonding.

Ultrathin two-dimensional (2D) semiconductors exhibit outstanding properties, but it remains challenging to obtain monolayer-structured inorganic semiconductors naturally occurring as nonlayered crystals. Copper sulfides are a class of widely studied nonlayered metal chalcogenide semiconductors. Although 2D copper sulfides can provide extraordinary physical and chemical applications, investigations of 2D copper sulfides in the extreme quantum limit are constrained by the difficulty in preparing monolayered copper sulfides. Here, we report a subnanometer-thin quasi-copper-sulfide (q-CS) semiconductor formed upon self-assembly of copper(I)-dodecanethiol complexes. Extended X-ray absorption fine structure analysis revealed that the existence of Cu-Cu bonding endowed the layer-structured q-CS with semiconductor properties, such as appreciable interband photoluminescence. Theoretical studies on the band structure demonstrated that the optical properties of copper-dodecanethiol assemblies were dominated by the q-CS layer and the photoluminescence originated from exciton radiative recombination across an indirect band gap, borne out by experimental observation at higher temperatures, but with the onset of a direct emission process at cryogenic temperatures. The following studies revealed that the metal-metal bonding occurred not only in copper-alkanethiolate complex assemblies with variable alkyl chain length but also in silver-alkanethiolate and cadmium-alkanethiolate assemblies. Therefore, the current studies may herald a class of 2D semiconductors with extremely thin thickness out of nonlayered metal sulfides to bridge the gap between conventional inorganic semiconductors and organic semiconductors.

Doping Lanthanide Nanocrystals With Non-lanthanide Ions to Simultaneously Enhance Up- and Down-Conversion Luminescence.

The rare-earth nanocrystals containing Er3+ emitters offer very promising tools for imaging applications, as they can not only exhibit up-conversion luminescence but also down-conversion luminescence in the second near-infrared window (NIR II). Doping non-lanthanide cations into host matrix was demonstrated to be an effective measure for improving the luminescence efficiency of Er3+ ions, while still awaiting in-depth investigations on the effects of dopants especially those with high valence states on the optical properties of lanthanide nanocrystals. To address this issue, tetravalent Zr4+ doped hexagonal NaGdF4:Yb,Er nanocrystals were prepared, and the enhancement effects of the Zr4+ doping level on both up-conversion luminescence in the visible window and down-conversion luminescence in NIR II window were investigated, with steady-state and transient luminescence spectroscopies. The key role of the local crystal field distortions around Er3+ emitters was elucidated in combination with the results based on both of Zr4+ and its lower valence counterparts, e.g., Sc3+, Mg2+, Mn2+. Univalent ions such as Li+ was utilized to substitute Na+ ion rather than Gd3+, and the synergistic effects of Zr4+ and Li+ ions by co-doping them into NaGdF4:Yb,Er nanocrystals were investigated toward optimal enhancement. Upon optimization, the up-conversion emission of co-doped NaGdF4:Yb,Er nanocrystals was enhanced by more than one order of magnitude compared with undoped nanocrystals. The current studies thus demonstrate that the local crystal field surrounding emitters is an effective parameter for manipulating the luminescence of lanthanide emitters.

Longer and Stronger: Improving Persistent Luminescence in Size-Tuned Zinc Gallate Nanoparticles by Alcohol-Mediated Chromium Doping.

Benefiting from near-infrared persistent luminescence, chromium-doped zinc gallate nanoparticles have become appealing for background-free biomedical imaging applications, where autofluorescence from adjacent tissues no longer poses a problem. Nevertheless, the synthesis of persistent luminescent nanoparticles with controllable and biologically appropriate size, high luminescence intensity, and long persistent duration remains very challenging. Herein, we report a solvothermal synthetic route for preparing differently sized ZnGa2O4:Cr nanoparticles with a particle size tunable from 4 to 31 nm and afterglow duration longer than 20 h. The route involves lower reaction temperatures and involves no reworking of the particles postsynthesis, providing materials that have far fewer unwanted defects and much higher luminescence yields (up to 51%). It was found that methanol played a paramount role in obtaining the Cr3+-doped ZnGa2O4 nanoparticles. The effects of methanol were discussed in combination with NMR spectroscopy studies and theoretical calculations, and the underlying alcohol-mediated growth and doping mechanisms were elucidated, which will be beneficial for developing highly persistent luminescent nanoparticles.

Manganese-Mediated Growth of ZnS Shell on KMnF3:Yb,Er Cores toward Enhanced Up/Downconversion Luminescence.

Epitaxially growing a semiconductor shell on the surface of upconversion nanocrystals to form a core/shell structure is believed to be a promising strategy to improve the luminescent efficiency of lanthanide ions doped in particle cores and, meanwhile, enriches the optical properties of the resulting nanocrystals. However, liquid-phase synthesis of such core/shell-structured nanocrystals comprised of a lanthanide ion-doped core and semiconductor shell remains challenging because of the chemical incompatibilities between lanthanides and the most intermediate gap semiconductors. In this context, the successful growth of ZnS shell on a KMnF3 core codoped with Yb3+/Er3+ ions is reported to enhance the upconversion luminescence of Er3+ ions. The underlying core/shell formation mechanism is elucidated in detail combining the hard-soft acid-base theory with structural analysis of the resulting nanocrystals. Quite unexpectedly, Mn2+ diffusion across the core/shell interface occurs during ZnS shell growth, giving rise to Mn2+ emission from the ZnS shell. Thus, the resulting core/shell particles exhibited unique up/downconversion luminescence from doped lanthanide metal ions and transition-metal ions, respectively. By manipulating the ion diffusion and shell growth kinetics, the upconversion and downconversion luminescent performance of KMnF3:Yb,Er@ZnS nanocrystals are further optimized and the related mechanisms are discussed. Further, temperature-dependent upconversion and downconversion photoluminescence properties of KMnF3:Yb,Er@ZnS nanocrystals show potential for ratiometric luminescence temperature sensing.

Emitting/Sensitizing Ions Spatially Separated Lanthanide Nanocrystals for Visualizing Tumors Simultaneously through Up- and Down-Conversion Near-Infrared II Luminescence In Vivo.

Near-infrared lights have received increasing attention regarding imaging applications owing to their large tissue penetration depth, high spatial resolution, and outstanding signal-to-noise ratio, particularly those falling in the second near-infrared window (NIR II) of biological tissues. Rare earth nanoparticles containing Er3+ ions are promising candidates to show up-conversion luminescence in the first near-infrared window (NIR I) and down-conversion luminescence in NIR II as well. However, synthesizing particles with small size and high NIR II luminescence quantum yield (QY) remains challenging. Er3+ ions are herein innovatively combined with Yb3+ ions in a NaErF4 @NaYbF4 core/shell manner instead of being codoped into NaLnF4 matrices, to maximize the concentration of Er3+ in the emitting core. After further surface coating, NaErF4 @NaYbF4 @NaYF4 core/shell/shell particles are obtained. Spectroscopy studies are carried out to show the synergistic impacts of the intermediate NaYbF4 layer and the outer NaYF4 shell. Finally, NaErF4 @NaYbF4 @NaYF4 nanoparticles of 30 nm with NIR II luminescence QY up to 18.7% at room temperature are obtained. After covalently attaching folic acid on the particle surface, tumor-specific nanoprobes are obtained for simultaneously visualizing both subcutaneous and intraperitoneal tumor xenografts in vivo. The ultrahigh QY of down-conversion emission also allows for visualization of the biodistribution of folate receptors.

Microfiber-Reinforced Composite Hydrogels Loaded with Rat Adipose-Derived Stem Cells and BMP-2 for the Treatment of Medication-Related Osteonecrosis of the Jaw in a Rat Model.

Severe adverse reactions of bisphosphonates and anti-resorptive or anti-angiogenic medications, termed medication-related osteonecrosis of the jaw (MRONJ), have been reported. MRONJ are difficult to completely cure and could cause great pain to patients. Recent studies have shown that mesenchymal stem cell (MSC) therapies are effective for treating MRONJ, but the method of intravenous injection is unstable and increases the risk of producing tumors. In the present study, low-acyl gellan gum (LAGG) hydrogels were modified with hemicellulose polysaccharide microfibers (PMs) to improve the performance of supporting three-dimensional (3D) cell growth. LAGG-PM composite hydrogels were found to be nontoxic to rat adipose-derived stem cells (rADSCs) in vitro. The hydrogels also promoted the secretion of angiogenic factors, induced osteoclastogenesis by conditioned medium, and supported osteogenic marker expression after the addition of human bone morphogenetic protein-2 (BMP-2). Due to its injectability, the LAGG-PM composite hydrogel incorporated with rADSCs and BMP-2 could be applied into the MRONJ lesion site, which promoted mucosal recovery, bone tissue reconstruction, and osteoclastogenesis. This study confirms the potential applications of LAGG-PM composite hydrogels as 3D cell culture platforms and delivery vehicles for the treatment of MRONJ in a rat model.

"Smart" Nanoprobes for Visualization of Tumor Microenvironments.

Physiological parameters in tumor microenvironments, including hypoxia, low extracellular pH, enzymes, reducing conditions, and so on, are closely associated with the proliferation, angiogenesis, invasion, and metastasis of cancer, and impact the therapeutic administrations. Therefore, monitoring the tumor microenvironment is significant for diagnosing tumors, predicting the invasion potential, evaluating therapeutic efficacy, planning the treatment, and cancer prognostics. Noninvasive molecular imaging technologies combined with novel "smart" nanoparticle-based activatable probes provide a feasible approach to visualize tumor-associated microenvironment factors. This review summarizes recent achievements in the designs of "smart" molecular imaging nanoprobes responding to the tumor microenvironment-related features, and highlights the state of the art in tumor heterogeneity imaging.

Graphene Oxide-Based Sensor for Ultrasensitive Visual Detection of Fluoride.

Visual fluoride ion detection with a detection limit down to pmol L-1 is achieved through quenching/reactivating the fluorescence of N-doped graphene oxide.

Complete mitochondrial genome of the Mongolia pheasant, Phasianus colchicus kiangsuensis (Galliformes, Phasianidae, Phasianus).

The pheasant (Phasianus colchicus) is raised by commercial farms in most parts of China because of special fleshy flavour. In the study, complete mitochondrial genome of the Mongolia pheasant was sequenced by polymerase chain reaction (PCR) as well as the primer walking sequence method. The entire mitochondrial genome of Mongolia pheasant was 16,673 bp in length, gene composition and arrangement conformed to most bird, which contained the typical structure of 22 tRNAs, 2 rRNAs, 13 protein-coding genes and a non-coding region. The phylogenetic tree of 20 Phasianidaes showed that Mongolia pheasant had close relationship to ring-necked pheasant. Our complete mitochondrial genome sequence will be useful phylogenetics, and be available as basic data for the breeding and genetics.

Human thermal physiological and psychological responses under different heating environments.

Anecdotal evidence suggests that many residents of severely cold areas of China who use floor heating (FH) systems feel warmer but drier compared to those using radiant heating (RH) systems. However, this phenomenon has not been verified experimentally. In order to validate the empirical hypothesis, and research the differences of human physiological and psychological responses in these two asymmetrical heating environments, an experiment was designed to mimic FH and RH systems. The subjects participating in the experiment were volunteer college-students. During the experiment, the indoor air temperature, air speed, relative humidity, globe temperature, and inner surface temperatures were measured, and subjects' heart rate, blood pressure and skin temperatures were recorded. The subjects were required to fill in questionnaires about their thermal responses during testing. The results showed that the subjects' skin temperatures, heart rate and blood pressure were significantly affected by the type of heating environment. Ankle temperature had greatest impact on overall thermal comfort relative to other body parts, and a slightly cool FH condition was the most pleasurable environment for sedentary subjects. The overall thermal sensation, comfort and acceptability of FH were higher than that of RH. However, the subjects of FH felt drier than that of RH, although the relative humidity in FH environments was higher than that of the RH environment. In future environmental design, the thermal comfort of the ankles should be scrutinized, and a FH cool condition is recommended as the most comfortable thermal environment for office workers. Consequently, large amounts of heating energy could be saved in this area in the winter. The results of this study may lead to more efficient energy use for office or home heating systems.

The effects of the preferential dopamine D(3) receptor antagonist S33138 on ethanol binge drinking in C57BL/6J mice.

The mesolimbic dopamine (DA) pathway plays an integral role in the reinforcing properties of many drugs of abuse, including alcohol (ethanol/EtOH). It has been reported that selective and acute blockade of the DA D3 receptor by SB-277011A will attenuate EtOH preference, intake, and lick responses in EtOH preferring rats. However, alcohol consumption that leads to abuse is often marked by binge drinking-which is characterized as bringing ones blood EtOH levels to ≥80 mg/dL within 2 hours of the initial drink. It is unclear if brain mechanisms implicated in EtOH reward are equally implicated in EtOH binge consumption and abuse. Therefore, in this study, we examined the effect of the preferential D3 receptor antagonist S33138 on ethanol (6% v/v) and water consumption in male C57BL/6J mice using a restricted-access binge-drinking model. Ethanol drinking was not significantly altered by the intraperitoneal (i.p.) administration of 0.16 mg/kg of S33138. In contrast, the i.p. administration of 0.64 or 2.5 mg/kg i.p. of S33138 produced a significant decrease in ethanol consumption on days 1 and 7 and days 7-14 compared to vehicle treated animals. However, the mean water consumption was significantly decreased by (1) 0.16 and 0.64 mg/kg i.p. of S33138 on Day 1 and (2) 2.5 mg/kg i.p. of S33138 at Days 1, 7, and 7-14. Our studies indicate that a low dose of S33138 significantly decreases binge drinking, and that it does not significantly alter the consumption of water. In addition, S33138 alone is not appetitive.