Dramatically Enhanced Mechanical Properties of Nano-TiN-Dispersed n-Type Bismuth Telluride by Multi-Effect Modulation.

Bismuth telluride (Bi2Te3)-based alloys have been extensively employed in energy harvesting and refrigeration applications for decades. However, commercially produced Bi2Te3-based alloys using the zone-melting (ZM) technique often encounter challenges such as insufficient mechanical properties and susceptibility to cracking, particularly in n-type Bi2Te3-based alloys, which severely limit the application scenarios for bismuth telluride devices. In this work, we seek to enhance the mechanical properties of n-type Bi2Te2.7Se0.3 alloys while preserving their thermoelectrical performance by a mixed mechanism of grain refinement and the TiN composite phase-introduced pinning effect. These nanoscale processes, coupled with the addition of TiN, result in a reduction in grain size. The pinning effects of nano-TiN contribute to increased resistance to crack propagation. Finally, the TiN-dispersed Bi2Te2.7Se0.3 samples demonstrate increased hardness, bending strength and compressive strength, reaching 0.98 GPa, 36.3 MPa and 74 MPa. When compared to the ZM ingots, those represent increments of 181%, 60% and 67%, respectively. Moreover, the thermoelectric performance of the TiN-dispersed Bi2Te2.7Se0.3 samples is identical to the ZM ingots. The samples exhibit a peak dimensionless figure of merit (ZT) value of 0.957 at 375 K, with an average ZT value of 0.89 within the 325-450 K temperature range. This work has significantly enhanced mechanical properties, increasing the adaptability and reliability of bismuth telluride devices for various applications, and the multi-effect modulation of mechanical properties demonstrated in this study can be applied to other thermoelectric material systems.

Production, physico-chemical properties and antioxidant activity of melanin from Annulohypoxylon stygium (Lév.) Y.M. Ju, J.D. Rogers and H.M. Hsieh.

To obtain higher melanin production in liquid culture, culture conditions of Annulohypoxylon stygium (Lév.) Y.M. Ju, J.D. Rogers and H.M. Hsieh were optimised. The results showed that using single factor experiment and orthogonal test, the optimised production of melanin reached 2.20 g/L, which was 2.06 times higher than that of the control group. In addition, it was speculated that A. stygium melanin (AsM) was 3,4-dihydroxyphenylalanine (DOPA) melanin and showed an amorphous irregular structure. Moreover, it had good solubility in alkaline solution. AsM showed good antioxidant activity at a concentration of 500 mg/L, with DPPH, ABTS and OH radicals scavenging activities of 90.83%, 75.36% and 70.90%, respectively. AsM prevented alcohol-induced oxidative damage and oxidative stress in HepG2 cells by inhibiting the decrease of antioxidant key enzyme activity under alcohol stimulation. It was proved to have a great potential for application as a natural antioxidant and a substitute for synthetic pigments.

Fusing Positive and Negative CT Contrast Nanoagent for the Sensitive Detection of Hepatoma.

Positive computed tomography (CT) contrast nanoagent has significant applications in diagnosing tumors. However, the sensitive differentiation between hepatoma and normal liver tissue remains challenging. This challenge arises primarily because both normal liver and hepatoma tissues capture the nanoagent, resulting in similar positive CT contrasts. Here, a strategy for fusing positive and negative CT contrast nanoagent is proposed to detect hepatoma. A nanoagent Hf-MOF@AB@PVP initially generates a positive CT contrast signal of 120.3 HU in the liver. Subsequently, it can specifically respond to the acidic microenvironment of hepatoma to generate H2 , further achieving a negative contrast of -96.0 HU. More importantly, the relative position between the negative and positive signals area is helpful to determine the location of hepatoma and normal liver tissues. The distinct contrast difference of 216.3 HU and relative orientation between normal liver and tumor tissues are meaningful to sensitively distinguish hepatoma from normal liver tissue utilizing CT imaging.

An Adaptable Nanoprobe Integrated with Quantitative T1 -Mapping MRI for Accurate Differential Diagnosis of Multidrug-Resistant Lung Cancer.

Multidrug resistance (MDR) is one of the major factors causing failure of non-small-cell lung cancer (NSCLC) chemotherapy. Real-time and accurate differentiation between drug-resistant and sensitive NSCLC is of primary importance for guiding the subsequent treatments and improving the therapeutic outcome. However, there is no effective method to provide such an accurate differentiation. This study creates an innovative strategy of integrating H2 O2 -responsive nanoprobes with the quantitative T1 -mapping magnetic resonance imaging (MRI) technique to achieve an accurate differential diagnosis between drug-resistant and sensitive NSCLC in light of differences in H2 O2 content in the tumor microenvironment (TME). The result demonstrates that the synthesized MIL-53(Fe)@MnO2 nanocomposites possess an excellent capability of shortening the cancer longitudinal relaxation time (T1 ) when meeting H2 O2 in TME. T1 -mapping MRI could sensitively detect this T1 variation (about 2.6-fold that of T1-weighted imaging (T1 WI)) to accurately differentiate the H2 O2 content between drug-resistant and sensitive NSCLC. In addition, the quantitative data provided by the T1 -mapping MRI dedicates correct comparison across imaging tests and is more reliable than T1 WI, thus giving it a chance for precise assessment of the anti-cancer effect. This innovative strategy of merging TME adaptable nanoprobes with the quantitative MRI technique provides a new approach for the precise diagnosis of multidrug-resistant NSCLC.

A novel CEST-contrast nanoagent for differentiating the malignant degree in breast cancer.

Different subtypes of breast cancer (BCC) have variable degrees of malignancy, which is closely related to their extracellular pH (pHe). Therefore, it is increasingly significant to monitor the extracellular pH sensitively to further determine the malignancy of different subtypes of BCC. Here, a l-arginine and Eu3+ assembled nanoparticle Eu3+@l-Arg was prepared to detect the pHe of two breast cancer models (TUBO is non-invasive and 4T1 is malignant) using a clinical chemical exchange saturation shift imaging technique. The experiments in vivo showed that Eu3+@l-Arg nanomaterials could respond sensitively to changes of pHe. In 4T1 models, the CEST signal enhanced about 5.42 times after Eu3+@l-Arg nanomaterials were used to detect the pHe. In contrast, few enhancements of the CEST signal were seen in the TUBO models. This significant difference had led to new ideas for identifying subtypes of BCC with different degrees of malignancy.

Reactive metal boride nanoparticles trap lipopolysaccharide and peptidoglycan for bacteria-infected wound healing.

Bacteria and excessive inflammation are two main factors causing non-healing wounds. However, current studies have mainly focused on the inhibition of bacteria survival for wound healing while ignoring the excessive inflammation induced by dead bacteria-released lipopolysaccharide (LPS) or peptidoglycan (PGN). Herein, a boron-trapping strategy has been proposed to prevent both infection and excessive inflammation by synthesizing a class of reactive metal boride nanoparticles (MB NPs). Our results show that the MB NPs are gradually hydrolyzed to generate boron dihydroxy groups and metal cations while generating a local alkaline microenvironment. This microenvironment greatly enhances boron dihydroxy groups to trap LPS or PGN through an esterification reaction, which not only enhances metal cation-induced bacterial death but also inhibits dead bacteria-induced excessive inflammation both in vitro and in vivo, finally accelerating wound healing. Taken together, this boron-trapping strategy provides an approach to the treatment of bacterial infection and the accompanying inflammation.

Melanin of fungi: from classification to application.

Melanin is a secondary metabolite composed of complex heterogeneous polymers. Fungal melanin is considered to be a sustainable and biodegradable natural pigment and has a variety of functional properties and biological activities. On one hand, due to its own specific properties it can play the role of antioxidant, anti-radiation, adsorption, and photoprotection. On the other hand, it has good biological activities such as hepatoprotective effect, hypolipidemic effect and anti-cancer. Therefore, it is widely used in various fields of daily life, including dyeing, food, biomedical and commercial industry. It is conducive to environmental protection and human health. However, the insolubility of fungal melanin in water, acids and organic solvents has been an obstacle to its commercial applications. Thus, the chemical modification methods of fungal melanin are summarized to increase its solubility and expand the application fields. Although fungal melanin has been used in many industries, as the structure and function of fungal melanin and modified melanin are further studied, more functional properties and bioactivities are expected to be discovered for a wide range of applications in the future.

Green Triplet Self-Trapped Exciton Emission in Layered Rb3Cd2Cl7:Sb3+ Perovskite: Comparison with RbCdCl3:Sb3.

Metal halide materials have recently sparked intense research because of their excellent photophysical properties and chemical stability. For example, RbCdCl3:Sb3+ exhibits broad emission at about 600 nm with a high photoluminescence quantum yield (PLQY) over 91% and double emission bands with bright white color. Herein, we obtained a novel Rb and Cd layered perovskite Rb3Cd2Cl7 doped with Sb3+, which gives luminescence at 525 nm with a large Stokes shift of 200 nm, originating from a self-trapped exciton (STE). Its PLQY is 57.47%, but its low-temperature PLQY becomes much higher at the same wavelength. When Rb3Cd2Cl7:Sb3+ and RbCdCl3:Sb3+ were compared, the two classes of quantum confinement effects by Rb and Cd ions in the lattice were identified to describe their electronic states and different optical properties. These results suggest that properties of Sb-doped cadmium halides could be modified by the structure type and local atomic confinement to find applications as promising luminescent materials for optoelectronic devices.

An Ion-Enhanced Oncolytic Virus-Like Nanoparticle for Tumor Immunotherapy.

T lymphocytes (T cells) are essential for tumor immunotherapy. However, the insufficient number of activated T cells greatly limits the efficacy of tumor immunotherapy. Herein, we proposed an oncolytic virus-mimicking strategy to enhance T cell recruitment and activation for tumor treatment. We constructed an oncolytic virus-like nanoplatform (PolyIC@ZIF-8) that was degraded in the acidic tumor environment to release PolyIC and Zn2+ . The released PolyIC exhibited an oncolytic virus-like function that induced tumor cell apoptosis and promoted T cell recruitment and activation through a tumor antigen-dependent manner. More importantly, the released Zn2+ not only enhanced T cell recruitment by inducing CXCL9/10/11 expression but also promoted T cell activation to increase interferon-γ (INF-γ) expression by inducing the phosphorylation of ZAP-70 via a tumor antigen-independent manner. This Zn2+ -enhanced oncolytic virus-mimicking strategy provides a new approach for tumor immunotherapy.

H2O-NH4+-Induced Emission Modulation in Sb3+-Doped (NH4)2InCl5·H2O.

Lead-based metal halide perovskites have received widespread attention for their promising application prospects in the field of lighting and display due to their excellent optical properties. However, the toxicity of lead may hinder their further commercial application. Herein, a zero-dimensional (0D) metal halide (NH4)2InCl5·H2O with an orthorhombic structure and the Pnma space group was produced. With doping with Sb3+, these products exhibit one highly efficient and wide yellow emission band (∼450-850 nm) in their photoluminescence (PL) spectra, which covers almost the entire visible spectral range at room temperature; however, they give two emission bands with long decay lifetimes (microseconds) at low temperature. Temperature-dependent steady-state PL, transient PL spectroscopy, temperature-dependent Raman spectra characterization, and theoretical band structure calculations confirm that the dual-band emission at low temperature originates from the dual vibronic levels of the self-trapped exciton (STE) in the hole-vibration state, whose vibration energy is related to the H2O-NH4+ connection in the valence band. This result proves that the vibronic state in STE formation involves both electrons and holes in the excited states, the opposite of this happens in the electron-vibration band in most perovskite halides. These results provide new insight into the luminescent mechanism of Sb3+ in halide perovskites, especially used for emission color modulation by the temperature-dependent electron- or hole-vibration processes.

Efficient Yellow Self-Trapped Exciton Emission in Sb3+-Doped RbCdCl3 Metal Halides.

Metal halide perovskites have flexible crystal and electronic structures and adjustable emission characteristics, which have very broad applications in the optoelectronic field. Among them, all-inorganic perovskites have attracted more attention than others in recent years because of their characteristics of large diffusion length, high luminescence efficiency, and good stability. In this work, Sb3+-doped RbCdCl3 crystalline powder was synthesized by a simple hydrothermal method, and its luminescence properties were studied, which showed a broad emission band with a large Stokes shift and efficient yellow light emission at about 596 nm at room temperature with a photoluminescence quantum yield of 91.7%. The emission came from the transition of the self-trapped exciton 1 (STE1) out of 3Pn (n = 0, 1, and 2) to S0 due to strong electron-phonon coupling, which scaled with increasing temperature. Moreover, its emission color became white at low temperatures due to the occurrence of transition of other self-trapped exciton 0 (STE0) state emission out of the 1S states of Sb ions to S0 in the lattice. These emission color changes may be used for temperature sensing, and this Sb3+-doped RbCdCl3 material expands the knowledge of the efficient luminescent inorganic material family for further applications of all-inorganic perovskites.

Self-Enhanced Acoustic Impedance Difference Strategy for Detecting the Acidic Tumor Microenvironment.

B-mode ultrasound imaging is a significant anatomic technique in clinic, which can display the anatomic variation in tissues. However, it is difficult to evaluate the functional state of organs and display the physiological information in organisms such as the tumor acidic microenvironment (TME). Herein, inspired by the phenomenon of sonographic acoustic shadow during detecting calculus in clinic, a strategy of self-enhanced acoustic impedance difference is proposed to monitor the acidic TME. BiF3@PDA@PEG (BPP) nanoparticles can self-aggregate in a specific response to the acidic TME to form huge "stones" BiF3@PDA, resulting in an increase of local tumor density, and further causing a significant acoustic impedance difference. In in vitro experiments, the enhanced ultrasound signals change from 15.2 to 196.4 dB, which can discriminate different pH values from 7.0 to 5.0, and the sensitivity can reach to 0.2 value. In in vivo experiments, the enhanced ultrasound signal is 107.7 dB after BPP self-aggregated, displaying the weak acidic TME that has a close relationship with the size and species of the tumor. More importantly, the accuracy is away from the interference of pressure because huge "stones" BiF3@PDA change little. However, SonoVue microbubbles will diffuse and rupture under pressure, which results in false positive signals. To sum up, this strategy will be helpful to the further development of ultrasound molecular imaging.

Superior Radiation Resistance of ZrO2-Modified W Composites.

The microstructure and mechanical properties of pure W, sintered and swaged W-1.5ZrO2 composites after 1.5 × 1015 Au+/cm2 radiation at room temperature were characterized to investigate the impact of the ZrO2 phase on the irradiation resistance mechanism of tungsten materials. It can be concluded that the ZrO2 phase near the surface consists of two irradiation damage layers, including an amorphous layer and polycrystallization regions after radiation. With the addition of the ZrO2 phase, the total density and average size of dislocation loops, obviously, decrease, attributed to the reason that many more glissile 1/2<111> loops migrate to annihilate preferentially at precipitate interfaces with a higher sink strength of 7.8 × 1014 m−2. The swaged W-1.5ZrO2 alloys have a high enough density of precipitate interfaces and grain boundaries to absorb large numbers of irradiated dislocations. This leads to the smallest irradiation hardening change in hardness of 4.52 Gpa, which is far superior to pure W materials. This work has a collection of experiments and conclusions that are of crucial importance to the materials and nuclear communities.

Harnessing X-Ray Energy-Dependent Attenuation of Bismuth-Based Nanoprobes for Accurate Diagnosis of Liver Fibrosis.

Timely detection of liver fibrosis by X-ray computed tomography (CT) can prevent its progression to fatal liver diseases. However, it remains quite challenging because conventional CT can only identify the difference in density instead of X-ray attenuation characteristics. Spectral CT can generate monochromatic imaging to specify X-ray attenuation characteristics of the scanned matter. Herein, an X-ray energy-dependent attenuation strategy originated from bismuth (Bi)-based nanoprobes (BiF3 @PDA@HA) is proposed for the accurate diagnosis of liver fibrosis. Bi element in BiF3 @PDA@HA can exhibit characteristic attenuation depending on different levels of X-ray energy via spectral CT, and that is challenging for conventional CT. In this study, selectively accumulating BiF3 @PDA@HA nanoprobes in the hepatic fibrosis areas can significantly elevate CT value for 40 Hounsfield units on 70 keV monochromatic images, successfully differentiating from healthy livers and achieving the diagnosis of liver fibrosis. Furthermore, the enhancement produced by the BiF3 @PDA@HA nanoprobes in vivo increases as the monochromatic energy decreases from 70 to 40 keV, optimizing the conspicuity of the diseased areas. As a proof of concept, the strategically designed nanoprobes with energy-dependent attenuation characteristics not only expand the scope of CT application, but also hold excellent potential for precise imaging-based disease diagnosis.

Functional CT Contrast Nanoagents for the Tumor Microenvironment.

Understanding the detailed tumor microenvironment (TME) is essential to achieve effective treatment of tumor, because TME has an extremely profound influence on the occurrence, development, invasion, and metastasis of tumor. It is of great significance to realize accurate diagnosis of the TME by using functional computed tomography (CT) contrast nanoagents (FCTNAs). Here, an overview of FCTNAs that respond to the overexpressed receptors, acidic microenvironment, overexpressed glutathione and enzymes, and hypoxia in tumor is provided, and also prospects the advance of novel spectral CT technique to detect the TME precisely. Utilizing FCTNAs is expected to achieve accurate monitoring of the TME and further provide guidance for the effective personalized tumor treatment in clinic.

Near-Infrared Light-Triggered Chlorine Radical (. Cl) Stress for Cancer Therapy.

Free radicals with reactive chemical properties can fight tumors without causing drug resistance. Reactive oxygen species (ROS) has been widely used for cancer treatment, but regrettably, the common O2 and H2 O2 deficiency in tumors sets a severe barrier for sufficient ROS production, leading to unsatisfactory anticancer outcomes. Here, we construct a chlorine radical (. Cl) nano-generator with SiO2 -coated upconversion nanoparticles (UCNPs) on the inside and Ag0 /AgCl hetero-dots on the outside. Upon near-infrared (NIR) light irradiation, the short-wavelength emission UCNP catalyzes . Cl generation from Ag0 /AgCl with no dependence on O2 /H2 O2 . . Cl with strong oxidizing capacity and nucleophilicity can attack biomolecules in cancer cells more effectively than ROS. This . Cl stress treatment will no doubt broaden the family of oxidative stress-induced antitumor strategies by using non-oxygen free radicals, which is significant in the development of new anticancer agents.

Accurate and Real-Time Temperature Monitoring during MR Imaging Guided PTT.

Photothermal therapy (PTT) is an efficient approach for cancer treatment. However, accurately monitoring the spatial distribution of photothermal transducing agents (PTAs) and mapping the real-time temperature change in tumor and peritumoral normal tissue remain a huge challenge. Here, we propose an innovative strategy to integrate T1-MRI for precisely tracking PTAs with magnetic resonance temperature imaging (MRTI) for real-time monitoring temperature change in vivo during PTT. NaBiF4: Gd@PDA@PEG nanomaterials were synthesized with favorable T1-weighted performance to target tumor and localize PTAs. The extremely weak susceptibility (1.04 × 10-6 emu g-1 Oe1-) of NaBiF4: Gd@PDA@PEG interferes with the local phase marginally, which maintains the capability of MRTI to dynamically record real-time temperature change in tumor and peritumoral normal tissue. The time resolution is 19 s per frame, and the detection precision of temperature change is approximately 0.1 K. The approach achieving PTT guided by multimode MRI holds significant potential for the clinical application.

A systems biology approach for defining the potential molecular framework of idiopathic hypereosinophilic syndrome with cutaneous involvement.

Hypereosinophilic syndrome (HES) is a rare multisystem disease that predominantly includes skin with severe and persistent itching. A lack of understanding about the pathological condition and mechanism of dermatosis caused by HES hinders its treatment. In the present study, we applied a quantitative proteomics approach to characterize the cellular responses of skin tissue to idiopathic HES (IHES) at the proteome level. We identified hundreds of skin tissue proteins that were differentially expressed between IHES patients and healthy individuals. IHES patients display severely damaged microenvironment, including extracellular matrix (ECM) organization and disassembly, immune disorders, decreased metabolic capacity, and susceptibility to microbial infection. Moreover, there was abnormal proliferation of basal epidermal stem cells, which was closely related to high expression of the epigenetic regulator, histone deacetylase 2, providing mechanistic insight into the abnormal epidermal thickening of IHES skin tissues. Overall, our study provides a comprehensive framework for a system-level understanding of IHES-induced dermatosis (IHESiD) tissues at the protein and cell pathway levels. Our findings may facilitate a new approach to diagnosis and treatment to alleviate skin clinical symptoms, monitor the activity of IHES, and determine therapeutic effects.

Efficacy and Influence Factors of 308-nm Excimer Lamp with Minoxidil in the Treatment of Alopecia Areata.

BACKGROUND AND OBJECTIVES: Alopecia areata (AA) is an autoimmune disease characterized by T cell-mediated attack on the hair follicle. Although there are a wide range of therapies, the majority of them are not satisfactory due to side effects or limited efficacy. In this study, we sought to evaluate the efficacy, influence factors, and safety of 308-nm excimer lamp with minoxidil in the treatment of AA. STUDY DESIGN/MATERIALS AND METHODS: This was a prospective, single-blinded, self-control study, using 308-nm excimer lamp with minoxidil for the treatment of AA. One selected alopecia lesion was divided into the control and treated side. Topical minoxidil (2% solution) was used on both sides, but 308-nm excimer lamp was only added to the treated side. The primary endpoint was the discrepancy of hair growth on each side. RESULTS: A total of 38 patients (24 males and 14 females) with AA were enrolled in this study, and 34 of them (21 males and 13 females) completed the whole treatment. Thirty-two (94.2%) patients achieved clinical response, and 21 (44.1%) patients achieved with >50% hair regrowth on the treated side after a 12-week treatment. The hair number and diameter on the treated side had significantly increased compared with the control side with statistical differences. Hyperpigmentation and erythema occurred on the treated side of all the patients but they were considered tolerable. Patients of younger age or with smaller area of lesion had better effect. CONCLUSIONS: The 308-nm excimer lamp with minoxidil therapy can be considered as an effective and safe treatment for single or multiple AA. Lasers Surg. Med. © 2020 Wiley Periodicals, Inc.