Two-Dimensional Cr5Te8@Graphite Heterostructure for Efficient Electromagnetic Microwave Absorption.

Two-dimensional (2D) transition metal chalcogenides (TMCs) hold great promise as novel microwave absorption materials owing to their interlayer interactions and unique magnetoelectric properties. However, overcoming the impedance mismatch at the low loading is still a challenge for TMCs due to the restricted loss pathways caused by their high-density characteristic. Here, an interface engineering based on the heterostructure of 2D Cr5Te8 and graphite is in situ constructed via a one-step chemical vapor deposit to modulate impedance matching and introduce multiple attenuation mechanisms. Intriguingly, the Cr5Te8@EG (ECT) heterostructure exhibits a minimum reflection loss of up to - 57.6 dB at 15.4 GHz with a thin thickness of only 1.4 mm under a low filling rate of 10%. The density functional theory calculations confirm that the splendid performance of ECT heterostructure primarily derives from charge redistribution at the abundant intimate interfaces, thereby reinforcing interfacial polarization loss. Furthermore, the ECT coating displays a remarkable radar cross section reduction of 31.9 dB m2, demonstrating a great radar microwave scattering ability. This work sheds light on the interfacial coupled stimulus response mechanism of TMC-based heterogeneous structures and provides a feasible strategy to manipulate high-quality TMCs for excellent microwave absorbers.

Determination of detonation characteristics by laser-induced plasma spectra and micro-explosion dynamics.

Determination of macroscale detonation parameters of energetic materials (EMs) in a safe and rapid way is highly desirable. However, traditional experimental methods suffer from tedious operation, safety hazards and high cost. Herein, we present a micro-scale approach for high-precision diagnosis of explosion parameters based on radiation spectra and dynamic analysis during the interaction between laser and EMs. The intrinsic natures of micro-explosion dynamics covering nanosecond to millisecond and chemical reactions in laser-induced plasma are revealed, which reveal a tight correlation between micro-detonation and macroscopic detonation based on laser-induced plasma spectra and dynamics combined with statistic ways. As hundreds to thousands of laser pulses ablate on seven typical tetrazole-based high-nitrogen compounds and ten single-compound explosives, macroscale detonation performance can be well estimated with a high-speed and high-accuracy way. Thereby, the detonation pressure and enthalpies of formation can be quantitatively determined by the laser ablation processes for the first time to our knowledge. These results enable us to diagnose the performance of EMs in macroscale domain from microscale domain with small-dose, low-cost and multiple parameters.

Transmucosal Delivery of Self-Assembling Photosensitizer-Nitazoxanide Nanocomplexes with Fluorinated Chitosan for Instillation-Based Photodynamic Therapy of Orthotopic Bladder Tumors.

Theoretically, on account of improved local bioavailability of photosensitizers and attenuated systemic phototoxicity, intravesical instillation-based photodynamic therapy (PDT) for bladder cancer (BCa) would demonstrate significant advantages in comparison with the intravenous route. Actually, the low transmucosal efficiency, hypoxia regulation deficiency, as well as the biosafety risks of intravesical drug agents all have greatly limited the clinical development of instillation-based PDT for BCa. Herein, based on our recent findings on bladder intravesical vectors and photodynamic treatment, we explore and find that the conventional antiparasitic agent nitazoxanide (NTZ) by mixing with chlorine e6 (Ce6) conjugated human serum albumin (HSA), HSA-Ce6, is capable of forming self-assembled HSA-Ce6/NTZ nanoparticles (NPs). Then, the HSA-Ce6/NTZ complexes further fabricate with fluorinated chitosan (FCS), the synthesized transmucosal carrier, to form a biocompatible nanoscale system HSA-Ce6/NTZ/FCS NPs, which exhibit remarkably improved transmucosal delivery and uptake capacities compared with HSA-Ce6/NTZ alone or non-fluorinated HSA-Ce6/NTZ/CS NPs. Meanwhile, due to the metabolic regulation of tumor cells by NTZ, the tumor hypoxia could be efficaciously ameliorated to further favor PDT. This work represents a new photosensitizer nanomedicine formulation for the perfection of PDT performance through the modulation of tumor hypoxia by clinically approved agents. Thus, intravesical instillation of HSA-Ce6/NTZ/FCS NPs with favorable biocompatibility, followed by cystoscope-mediated PDT, could achieve a dramatically improved therapeutic effect to ablate orthotopic bladder tumors.

Strategies to Get Drugs across Bladder Penetrating Barriers for Improving Bladder Cancer Therapy.

Bladder cancer is a significant public health concern and social burden due to its high recurrence risk. Intravesical drug instillation is the primary therapy for bladder cancer to prevent recurrence. However, the intravesical drug therapeutic effect is limited by bladder penetrating barriers. The inadequate intravesical treatment might cause the low drug concentration in lesions, resulting in a high recurrence/progression rate of bladder cancer. Many strategies to get drugs across bladder penetrating barriers have been developed to improve intravesical treatment, including physical and chemical methods. This review summarizes the classical and updated literature and presents insights into great therapeutic potential strategies to overcome bladder penetrating barriers for improving the intravesical treatment of bladder cancer.

Synthesis and Microwave Absorption Properties of Sulfur-Free Expanded Graphite/Fe3O4 Composites.

In this study, sulfur-free expanded graphite (EG) was obtained by using flake graphite as the raw material, and EG/Fe3O4 composites with excellent microwave absorption properties were prepared by a facile one-pot co-precipitation method. The structure and properties of as-prepared EG/Fe3O4 were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR), X-ray diffraction (XRD), Raman, X-ray photoelectron spectrometry (XPS), thermogravimetric (TG), and vibrating sample magnetometry (VSM) characterizations. The Fe3O4 intercalated between the layers of expanded graphite forms a sandwich-like structure which is superparamagnetic and porous. When applied as a microwave absorber, the reflection loss (RL) of EG/Fe3O4 reaches -40.39 dB with a thickness of 3.0 mm (10 wt% loading), and the effective absorption bandwidth (EAB < -10 dB) with RL exceeding -10 dB is 4.76-17.66 GHz with the absorber thickness of 1.5-4.0 mm. Considering its non-toxicity, easy operation, low cost, suitability for large-scale industrial production, and excellent microwave absorbing performance, EG/Fe3O4 is expected to be a promising candidate for industrialized electromagnetic absorbing materials.

Efficient Gold Recovery from E-Waste via a Chelate-Containing Porous Aromatic Framework.

Extracting gold from wastes of electronic equipment (e-waste) is a sustainable strategy for the recovery of the precious metal, reducing environmental pollution, and addressing the growing demands for gold resources. In this work, we synthesized a thiourea-modified porous aromatic framework (PAF-1-thiourea) with exceptional gold-extraction ability. The optimum adsorption capacity for PAF-1-thiourea to gold reaches up to 2629.87 mg g-1. The adsorption process can be well fitted according to the pseudo-second-order kinetic model and Langmuir model, featuring strong affinity caused by strong soft-soft interactions between Au(III) and the S and N donor atoms of the modified PAF and the electrostatic interactions between protonated amino groups and AuCl4-. PAF-1-thiourea was especially capable of extracting gold rapidly and efficiently (capturing 98.73% of gold within 5 min) from a central processing unit (CPU) in extremely acidic conditions. It is found that PAF-1-thiourea captures gold ions and simultaneously converts it to a Au(0) solid, obtaining gold with purity up to 23.5 karat. PAF-1-thiourea with its high acid resistance and anti-interference against cheap metals in the recovery process presents a practical means to extract gold from e-waste.

Decompression Process of Glycerol Shock Treatment Can Overcome Endo-Lysosomal Barriers for Intracellular Delivery.

The glycerol shock treatment has been used to improve the calcium phosphate transfection efficacy for several decades because of its high effectiveness and low toxicity. However, the mechanism of glycerol shock treatment is still obscure. In this study, the endo-lysosomal leakage assay demonstrated that the decompression process of glycerol shock treatment could enhance endo-lysosomal membrane permeabilization, which resulted in facilitating endo-lysosomal escape for effective intracellular delivery. The enhanced decompression treatment derived from glycerol shock treatment could increase the change of osmotic pressure further, which showed higher efficacy for intracellular delivery. Herein, we speculated that the endo-lysosomal swelling originated from the decompression process of glycerol shock treatment could cause endo-lysosomal damage.

Surface Modification for Improving the Photocatalytic Polymerization of 3,4-Ethylenedioxythiophene over Inorganic Lead Halide Perovskite Quantum Dots.

Inorganic lead halide perovskite quantum dots (iLHP-QDs) have recently been used in the photocatalytic reaction. However, the factors that influence the photocatalytic performance of the iLHP-QDs have not been fully investigated. Herein, we synthesized a series of iLHP-QDs with varied halide ratios (CsPbX3, X = I, I0.67Br0.33, I0.5Br0.5, I0.33Br0.67, Br) and studied their influence on the photocatalytic performance by monitoring the polymerization of 2,2',5',2″-ter-3,4-ethylenedioxythiophene (TerEDOT). The CsPbI3 QDs showed the best performance owing to their narrow band gap and low exciton binding energy. Moreover, the photocatalytic performance of the iLHP-QDs could be simply improved by being treated with methyl acetate, which can be attributed to the replacement of the oleic acid by the short acetate acid and the introduction of the traps on the surface of QDs in the post-treatment. These results could help design a more efficient photocatalytic system and further promote the application of iLHP-QDs.

In Situ Synthesis of Fluorescent Mesoporous Silica-Carbon Dot Nanohybrids Featuring Folate Receptor-Overexpressing Cancer Cell Targeting and Drug Delivery.

Multifunctional nanocarrier-based theranostics is supposed to overcome some key problems in cancer treatment. In this work, a novel method for the preparation of a fluorescent mesoporous silica-carbon dot nanohybrid was developed. Carbon dots (CDs), from folic acid as the raw material, were prepared in situ and anchored on the surface of amino-modified mesoporous silica nanoparticles (MSNs-NH2) via a microwave-assisted solvothermal reaction. The as-prepared nanohybrid (designated MSNs-CDs) not only exhibited strong and stable yellow emission but also preserved the unique features of MSNs (e.g., mesoporous structure, large specific surface area, and good biocompatibility), demonstrating a potential capability for fluorescence imaging-guided drug delivery. More interestingly, the MSNs-CDs nanohybrid was able to selectively target folate receptor-overexpressing cancer cells (e.g., HeLa), indicating that folic acid still retained its function even after undergoing the solvothermal reaction. Benefited by these excellent properties, the fluorescent MSNs-CDs nanohybrid can be employed as a fluorescence-guided nanocarrier for the targeted delivery of anticancer drugs (e.g., doxorubicin), thereby enhancing chemotherapeutic efficacy and reducing side effects. Our studies may provide a facile strategy for the fabrication of multifunctional MSN-based theranostic platforms, which is beneficial in the diagnosis and therapy of cancers in future.

A novel cocrystal composed of CL-20 and an energetic ionic salt.

A novel nitroamine/energetic ionic salt cocrystal explosive containing CL-20 and 1-AMTN in a 1 : 1 molar ratio is presented. The structure of this cocrystal is determined by single-crystal X-ray diffraction (SC-XRD). The predicted detonation performance is slightly higher than that of RDX, a state-of-the-art explosive. In small-scale impact drop tests, the cocrystal exhibits a surprisingly low sensitivity relative to CL-20. These features make this cocrystal a very promising explosive to replace RDX.

Theoretical study of the heats of formation, detonation properties, and bond dissociation energies of substituted bis-1,2,4-triazole compounds.

The heats of formation (HOFs), detonation properties, and bond dissociation energies (BDEs) of a series of energetic bis-1,2,4-trizaole compounds with different substituents were studied using density functional theory at the 6-311 + G(2df, 2p) level. The HOF results indicated that the presence of the substituents -NH2, -NO2, -NHNO2, and -N3 markedly increases the HOFs of bis-1,2,4-trizaole compounds. The calculated detonation velocities and detonation pressures indicated that the presence of the substituents -NH2, -NO2, -NHNO2, -CH(NO2)2, and -OH strongly enhances the detonation properties of bis-1,2,4-trizaole compounds. The BDEs results indicated that the presence of the substituents -H, -NH2, and -OH substituent groups greatly improves the thermal stabilities of bis-1,2,4-trizaole compounds. Based on its detonation properties and BDEs, one of the bis-1,2,4-trizaole compounds (B6) is a potential alternative explosive to 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX).

Flavagline analog FL3 induces cell cycle arrest in urothelial carcinoma cell of the bladder by inhibiting the Akt/PHB interaction to activate the GADD45α pathway.

BACKGROUND: Prohibitin 1 (PHB) is a potential target for the treatment of urothelial carcinoma of the bladder (UCB). FL3 is a newly synthesized agent that inhibits cancer cell proliferation by targeting the PHB protein; however, the effect of FL3 in UCB cells remains unexplored. METHODS: FL3 was identified to be a potent inhibitor of UCB cell viability using CCK-8 (cell counting kit-8) assay. Then a series of in vitro and in vivo experiments were conducted to further demonstrate the inhibitory effect of FL3 on UCB cell proliferation and to determine the underlying mechanisms. RESULTS: FL3 inhibited UCB cell proliferation and growth both in vitro and in vivo. By targeting the PHB protein, FL3 inhibited the interaction of Akt and PHB as well as Akt-mediated PHB phosphorylation, which consequently decreases the localization of PHB in the mitochondria. In addition, FL3 treatment resulted in cell cycle arrest in the G2/M phase, and this inhibitory effect of FL3 could be mimicked by knockdown of PHB. Through the microarray analysis of mRNA expression after FL3 treatment and knockdown of PHB, we found that the mRNA expression of the growth arrest and DNA damage-inducible alpha (GADD45α) gene were significantly upregulated. When knocked down the expression of GADD45α, the inhibitory effect of FL3 on cell cycle was rescued, suggesting that FL3-induced cell cycle inhibition is GADD45α dependent. CONCLUSION: Our data provide that FL3 inhibits the interaction of Akt and PHB, which in turn activates the GADD45α-dependent cell cycle inhibition in the G2/M phase.

Preparation, characterization and thermal risk evaluation of dihydroxylammonium 5, 5'-bistetrazole-1, 1'-diolate based polymer bonded explosive.

Dihydroxylammonium 5,5'- bistetrazole-1,1'-diolate (TKX-50) was used to prepare TKX-50-based polymer bonded explosive (PBX) for the first time in this study. The thermal stabilities and the kinetic parameters of TKX-50 and TKX-50-based PBX were compared via Differential Scanning Calorimetry (DSC), Thermal Gravity-Differential Thermal Gravity (TG-DTG) and Accelerating Rate Calorimeter (ARC). Furthermore, in order to know about their thermal safeties comprehensively, an advanced thermal analysis program based on Friedman method was employed to calculate the thermal safety parameters for TKX-50 and its PBX. With its help, two important safety parameters (time to maximum rate under adiabatic conditions (TMRad) and self-accelerating decomposition temperature (SADT)) for the two energetic materials were calculated and discussed. Finally, based on the safety parameters, effects of storage conditions and ambient temperatures on the thermal explosions of TKX-50 and TKX-50-based PBX were further studied by using finite element analysis (FEA).

A single molecular fluorescent probe for selective and sensitive detection of nitroaromatic explosives: A new strategy for the mask-free discrimination of TNT and TNP within same sample.

A simple naphthalene based fluorescent probe was first time reported as dual sensing of 2,4,6-trinitrotolune (TNT) and 2,4,6-trinitrophenol (TNP) by distinguishable changes in both solution color change and fluorescence within same sample without any mask agent. Upon addition of TNT and TNP, the strong emission quenching at 412nm and a new emission band at 530nm was observed, respectively. In addition, the sensing mechanism was evaluated by DFT calculations by Gaussian 09 software.

A fluorescent carbon-dots-based mitochondria-targetable nanoprobe for peroxynitrite sensing in living cells.

Mitochondria, the power generators in cell, are a primary organelle of oxygen consumption and a main source of reactive oxygen/nitrogen species (ROS/RNS). Peroxynitrite (ONOO-), known as a kind of RNS, has been considered to be a significant factor in many cell-related biological processes, and there is great desire to develop fluorescent probes that can sensitively and selectively detect peroxynitrite in living cells. Herein, we developed a fluorescent carbon-dots (C-dots) based mitochondria-targetable nanoprobe with high sensitivity and selectivity for peroxynitrite sensing in living cells. The C-dots with its surface rich in amino groups was synthesized using o-phenylenediamine as carbon precursor, and it could be covalently conjugated with a mitochondria-targeting moiety, i.e. triphenylphosphonium (TPP). In the presence of peroxynitrite, the fluorescence of the constructed nanoprobe (C-dots-TPP) was efficiently quenched via a mechanism of photoinduced electron transfer (PET). The nanoprobe exhibited relatively high sensitivity (limit of detection: 13.5nM) and selectivity towards peroxynitrite in aqueous buffer. The performance of the nanoprobe for fluorescence imaging of peroxynitrite in mitochondria was investigated. The results demonstrated that the nanoprobe showed fine mitochondria-targeting ability and imaging contrast towards peroxynitrite in living cells. We anticipate that the proposed nanoprobe will provide a facile tool to explore the role played by peroxynitrite in cytobiology.

A new multifunctional Schiff-based chemosensor for mask-free fluorimetric and colorimetric sensing of F⁻ and CN⁻.

A Schiff-based chemosensor DSS was designed for selective and simultaneous detection and/or determination of F(-) and CN(-) by distinguishable changes in both solution color and spectroscopic responses within same sample due to the strong emission enhancement at distinct emission bands without any mask. In addition, the sensing mechanism was evaluated by NMR titration and DFT calculations.

Nitrogen-rich 4,4'-azo bis(1,2,4-triazolone) salts--the synthesis and promising properties of a new family of high-density insensitive materials.

4,4'-Azo-bis(1,2,4-triazolone) (ZTO) based salts from alkaline (Li(+), K(+), Na(+), and Cs(+)), alkaline earth metal salts (Mg(2+), Ca(2+), Sr(2+), and Ba(2+)) and hydrazinium salt were synthesized in a simple, straightforward manner and were characterized by IR and NMR spectroscopy, elemental analysis. The single-crystal X-ray diffraction of seven salts (Na(+), K(+), Cs(+), Mg(2+), Ca(2+), Sr(2+), Ba(2+), and N2H5(+)) are also reported. The X-ray structures show that in the title compounds, the metal atoms are bonded to the nitrogen and oxygen atoms in the bistetrazole ring to form a sandwich structure. In addition, the thermal stabilities of all the title compounds were determined using thermogravimetric-differential thermal analysis (TG-DTA). All these new materials exhibit excellent thermal stability, high density, acceptable detonation properties, and excellent insensitivity to impact (h50 > 60 cm). In particular, the barium, caesium and strontium salts are of great interest as potential high-density insensitive materials.

A simple ratiometric and colorimetric chemosensor for the selective detection of fluoride in DMSO buffered solution.

A derivative of squaramide (cyclobuta[b]quinoxaline-1, 2(3H, 8H)-dione) has been synthesized for the ratiometric and colorimetric sensing of F(-) in aqueous solution in competitive fashion. With F(-), probe 1 showed a highly selective naked-eye detectable color change along with a characteristic UV-Vis absorbance over other tested ions, which probably originates from the deprotonation occurred between 1 and F(-), as proved by the (1)H NMR titration experiments and DFT calculations.