Search

Carbon monoxide (CO) is a harmful gas with significant impacts on human health and the environment. Its timely detection, especially in the event of thermal runaway in automotive lithium batteries, is crucial to prevent casualties. This paper reviews the progress in the development of efficient, sensitive, and reliable CO sensors, focusing on electrochemical, optical, and resistive sensing materials. Low-dimensional materials have a large specific surface area, providing an abundant number of active sites, which has drawn extensive attention from researchers. According to the different sensor signals, we categorized these sensors into electrical and optical signal sensors. We hope that by systematically introducing the sensing mechanism and sensing performance of these two kinds of sensors, appropriate CO sensors can be developed in different application scenarios so as to realize early warning and monitoring to the maximum extent, reduce industrial losses, and ensure the life and health of personnel.

ABSTRACTTransition to renewable energy sources, rapid rise in the use of Li-ion batteries for energy storage has warranted a search for efficient lithium extraction methods from low grade lithium ores such as clays and sediments since supply from conventional sources is insufficient to meet the increasing demand. In this effort, classical base – acid – carbonate method was found to be ineffective for the extraction of lithium from minerals with very low lithium content such as hectorite clay with of 0.137 ± 0.004 % (w/w) lithium. The key finding in this work is a new microwave heating assisted base – acid – carbonate method for the extraction of lithium from low lithium content clay minerals, where lithium could be extracted from hectorite clay mineral in 98% efficiency as lithium carbonate. Leaching of lithium from hectorite clay was evaluated by studying Scanning electron microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX) analyses, ATR-IR and X-ray crystallography of hectorite and leach residues.

Oxidation of glycerol to lactic and glycolic acids is one of the most sought-after upgrades for this waste product in the biodiesel industry. These renewable glycerol-based hydroxy—carboxylic acid products are valuable monomers for the synthesis of new generation biodegradable polymers. In this work, a practically no-cost catalyst was prepared by using electrode coatings in 18,650 type Li-ion cells found in a spent DELL laptop battery. The combined cathode and anode coatings collected from Li-ion cells were pyrolyzed at 600 °C in air for 30 min. to prepare the catalyst with formula LiNi0.03Mn0.02Co0.11O0.85/C. Oxidation of glycerol using 25 mg/mmol catalyst in 0.50 M aqueous NaOH, under 3.4 atm. O2, 230 °C, 4 h. gave the highest yields of lactic and glycolic acids, 54 and 41%, respectively. Next, this hydroxy acid mixture was directly polymerized using p-toluene sulfonic acid—SnCl2catalyst in refluxing xylene to give poly(lactic-co-glycolic acid) with Mw= 8017, Mw/Mn= 1.435, Tg= 41 °C, Tm= 182 °C and in 74% yield.

Sulfur-based cathode materials have become a research hot spot as one of the most promising candidates for next-generation, high-energy lithium batteries. However, the insulating nature of elemental sulfur or organosulfides has become the biggest challenge that leads to dramatic degradation and hinders their practical application. The disadvantage is more obvious for all-solid-state battery systems, which require both high electronic and ionic migration at the same sites to realize a complete electrochemical reaction. In addition to adding conductive components into the cathode composites, another effective way to realize high-reversibility sulfur-based cathodes is by optimizing the inherent nature of sulfur-based materials to make them “conductive”. Inorganic polysulfide materials including polysulfide molecules, selenium-sulfur solid solutions, and (lithium) metal polysulfides are promising, as they have different structures that can make them intrinsically conductive or becoming conductive during lithiation. They all contain at least one −S–S– bridged bond, which is the intrinsic structural characteristic and the source of the chemical properties of these polysulfide compounds. For example, by balancing the conductivity and reversible capacity, researchers in the US National Aeronautics and Space Administration (NASA) have shown that 500 Wh/kg solid-state Li–Se/S batteries can power cars and even electric aircraft.

The development of chronic, nonhealing wounds is a persistent medical problem that drives patient morbidity and increases healthcare costs. Angiogenesis is a critical accompanying activity in the proliferation stage during the wound healing process. Notoginsenoside R1 (NGR1) isolated from Radix notoginsenghas been reported to alleviate diabetic ulcers by promoting angiogenesis and decreasing inflammatory responses and apoptosis. In the present study, we investigated the effect of NGR1 on angiogenesis and its therapeutic functions in cutaneous wound healing. For in vitro evaluation, cell counting kit-8 assays, migration assays, Matrigel-based angiogenic assays, and western blotting were conducted. The experimental results showed that NGR1 (10–50 μM) had no cytotoxicity to human skin fibroblasts (HSFs) and human microvascular endothelial cells (HMEC), and NGR1 treatment facilitated the migration of HSFs and enhanced angiogenesis in HMECs. Mechanistically, NGR1 treatment inhibited the activation of Notch signaling in HMECs. For in vivo analysis, hematoxylin-eosin staining, immunostaining, and Masson’s trichrome staining were performed, and we found that NGR1 treatment promoted angiogenesis, reduced wound widths, and facilitated wound healing. Furthermore, HMECs were treated with N-[N-(3,5-difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester (DAPT; a Notch inhibitor), and DAPT treatment was found to exert pro-angiogenic effects. Simultaneously, DAPT was administrated into experimental cutaneous wound healing model, and we found that DAPT administration prevented the development of cutaneous wounds. Collectively, NGR1 promotes angiogenesis and wound repair via activation of the Notch pathway and exhibits therapeutic effects on cutaneous wound healing.

PMMA bone cement has been clinically used for decades in vertebroplasty due to its high mechanical strength and satisfactory injectability. However, the interface between bone and PMMA is fragile and more prone to refracture in situbecause PMMA lacks a proper biological response from the host bone with minimal bone integration and dense fibrous tissue formation. Here, we modified PMMA by incoporating borosilicate glass (BSG) with a dual glass network of [BO3] and [SiO4], which spontaneously modulates immunity and osteogenesis. In particular, the BSG modified PMMA bone cement (abbreviated as BSG/PMMA cement) provided an alkaline microenvironment that spontaneously balanced the activities between osteoclasts and osteoblasts. Furthermore, the trace elements released from the BSGs enhanced the osteogenesis to strengthen the interface between the host bone and the implant. This study shows the first clinical case after implantation of BSG/PMMA for three months using the dual-energy CT, which found apatite nucleation around PMMA instead of fibrous tissues, indicating the biological interface was formed. Therefore, BSG/PMMA is promising as a biomaterial in vertebroplasty, overcoming the drawback of PMMA by improving the biological response from the host bone.

Over the past three decades, lithium-based batteries have greatly influenced our daily lives. However, their limited energy density poses challenges in meeting growing demand. To increase energy density, lithium metal anode is considered critical. This review systematically examines the history of lithium metal anode development, highlights notable advances in fundamental understandings, materials design, and characterization techniques. Forthcoming opportunities are discussed to promote the practical applications of lithium metal anodes. The development of lithium metal anodes is crucial for achieving high energy density of batteries. The history of lithium metal anode development is systematically examined, and the notable advances in fundamental understandings, materials design, and characterization techniques are highlighted, indicating forthcoming opportunities to promote the practical applications of lithium metal anodes.

Carbon number upgrading of bio-furans by coupling with other renewable feedstocks is an attractive approach for producing renewable fuel and polymer feedstocks. In this work, used Li-ion battery waste based low cost catalyst was shown as an alternative to expensive noble metal catalysts for coupling furfural with alcohols to give 2-alkyl-3-(2-furyl) acroleins. The catalyst was prepared by pyrolyzing the black electrode coating from 18650 Li-ion cells in a used laptop battery at 600 °C in air. Highest furfural conversions of 72.6, 83.6, 100.0 and 95.4 % were observed for 1-propanol, 1-butanol, 1-pentanol and 1-hexanol respectively, using 0.6 mmol LiOH/mmol of furfural and using 25 mg/mmol of furfural catalyst loading, 0.345 MPa O2, 110 °C for 4.0 h. However, recycling of LiNiaMnbCocOd/graphite catalyst showed significant loss in catalytic activity in four cycles of reuse. A reaction scheme involving oxidation of alcohols to aldehydes followed by base catalyzed aldol condensation was proposed to explain the coupling to give 2-alkyl-3-(2-furyl) acroleins.

β-Glucuronidase (GUS) plays a key role in tumor initiation, metastasis, and progression, and thus, has been proposed as a promising cancer biomarker. In this study, we designed an enzyme-activatable near-infrared (NIR) fluorescent probe (DCM-βGlcA) for the rapid and accurate detection of GUS activity in vitro, in vivoand ex vivo. The DCM-βGlcA was prepared by linking a glucuronic acid residue to dicyanomethylene-4H-pyran (DCM). This probe exhibited significant light-up NIR fluorescent signals at 680 nm after reacting with GUS and the Stokes shift could reach 150 nm. The DCM-βGlcA showed a high sensitivity toward GUS and an excellent linear relationship at concentrations ranging between 0 and 4 U L−1(R2= 0.9974) with the limit of detection as low as 0.19 U L−1. We used the DCM-βGlcA to identify GUS serum levels in both cancer patients and healthy individuals with a similar accuracy as that of an enzyme-linked immunosorbent assay (ELISA) while being easier and faster to perform. Moreover, the DCM-βGlcA was used for tracking endogenous GUS in living cells, thereby discriminating GUS-overexpressed liver cancer from normal cells. Additionally, the DCM-βGlcA was able to detect and image endogenous GUS in liver cancer tissue and tumor-bearing mouse models. These findings demonstrate the potential of the DCM-βGlcA as a promising tool for detecting and monitoring GUS activity in preclinical applications.

Calcium phosphate cements (CPC) are widely anticipated to be an optimum bone repair substitute due to its satisfied biocompatibility and degradability, suitable to be used in minimally invasive treatment of bone defects. However the clinical application of CPC is still not satisfied by its poor cohesiveness and mechanical properties, in particular its osteoinductivity. Hyaluronic acid reinforced calcium phosphate cements (HA/CPC) showed extroadinary potential not only enhancing the compressive strength of the cements but also significantly increasing its osteoinductivity. In our study, the compressive strength of HA/CPC increased significantly when the cement was added 1% hyaluronic acid (denoted as 1-HA/CPC). In the meantime, hyaluronic acid obviously promoted ALP activity, osteogenic related protein and mRNA expression of hBMSCs (human bone marrow mesenchymal stem cells) in vitro, cement group of HA/CPC with 4% hyaluronic acid adding (denoted as 4-HA/CPC) showed optimal enhancement in hBMSCs differentiation. After being implanted in rat tibial defects, 4-HA/CPC group exhibited better bone repair ability and bone growth promoting factors, comparing to pure CPC and 1-HA/CPC groups. The underlying biological mechanism of this stimulation for HA/CPC may be on account of higher osteogenic promoting factors secretion and osteogenic genes expression with hyaluronic acid incorporation. These results indicate that hyaluronic acid is a highly anticipated additive to improve physicochemical properties and osteoinductivity performance of CPCs for minimally invasive healing of bone defects.

The hypoxia-inducible factor 1-alpha (HIF-1a) pathway plays a key role in regulating angiogenesis during wound healing. However, the diabetic condition hampers the stabilization of HIF-1a and thus inhibits the subsequent angiogenesis, and meanwhile, the function and phenotype transition of macrophage are impaired in the diabetic condition, which leads to prolonged and chronic inflammation. Both angiogenesis inhibition and inflammatory dysfunction make diabetic wound healing a major clinical challenge. Here, borosilicate (BS), a new group of bioceramics with a coupled network of interconnected [BO3] and [SiO4] which can incorporate therapeutic ions such as Cu2+, is synthesized and combined with silk fibroin (SF), a biocompatible natural amino acid polymer whose composition and structure are similar to a natural extracellular matrix (ECM), to obtain a compound system which can transform into a SF-MA-BS hydrogel under UV radiation via methacryloyloxy (MA) groups modified on both BS and SF. When in use, the compound system can thoroughly spread to the whole wound surface and be in situ photo-cross-linked to form an integral SF-MA-BS hydrogel that firmly adheres to the wound, protects the wound from external contamination, and further spontaneously promotes wound regeneration by releasing therapeutic ions. The wound repair of Streptozotocin-induced diabetic rats shows that diabetic wound healing is obviously accelerated by SF-MA-BS, interestingly the HIF-1a pathway is restored via interaction between HIF-1a and Cu2+, and angiogenesis is therefore enhanced. Meanwhile, inflammation is well regulated by SF-MA-BS, and long-term detrimental inflammation is avoided. These findings indicate that the SF-MA-BS hydrogel regenerates diabetic wounds, and further clinical trials are anticipated.

Diabetic wounds are a prevalent and devastating complication of diabetes, which may impede their healing and regeneration. In diabetic wounds, excess reactive oxygen species (ROS) activate the nuclear factor kappa‐B pathway, leading to transcriptional silencing of nuclear factor erythroid 2‐related factor 2 (Nrf2), resulting in a vicious cycle of oxidative stress and inflammation. Conventional nanozymes have limitations in preventing the continuous production of ROS, including the most oxidizing reactive hydroxyl radical (·OH), although they can remove pre‐existing ROS. Herein, a novel antioxidant nanoplatform addresses this challenge by incorporating JSH‐23 into the mesoporous of cupric‐doped cerium oxide nanozymes. Additionally, for rapid wound adaptability and durable tissue adhesion, a nanozyme hydrogel spray consisting of oxidized sodium alginate and methacrylate gelatin is constructed, named OG@CCJs. This platform resurrects Nrf2 transcriptional activity of macrophages in vitro, curbing the production of ROS at its source, particularly ·OH, while enabling the nanozymes to scavenge previously generated ROS. OG@CCJs significantly alleviate oxidative stress in diabetic wounds in vivo, promoting wound healing. Overall, the proposed nanozyme‐hydrogel spray with enhanced ·OH‐scavenging activity uses a “two‐track” antioxidant strategy to rebuild the antioxidant defense barrier of macrophages. This pioneering approach highlights the tremendous potential of OG@CCJs for facilitating diabetic wound healing. OG@CCJs allow for easy spraying apply and complete coverage of irregular wounds. OG@CCJs possess ROS‐scavenging activity and regulate macrophage polarization. OG@CCJs exhibit enhanced ·OH‐scavenging activity due to reactivation of Nrf2 transcription activity. OG@CCJs alleviate the oxidative stress on diabetic wounds and promote diabetic wounds healing.

A Pd-catalyzed double annulation reaction of 1-(2,6-dibromophenyl)-1H-pyrroles with arynes to synthesize π-extended dibenzo[d,k]ullazines is presented.

A class of 2-aminopyridine 1-oxides are discovered to be effective ligands for the Cu-catalyzed amination of less reactive (hetero)aryl chlorides. A wide range of functionalized (hetero)aryl chlorides reacted with various aliphatic amines to afford the desired products in good to excellent yields under the catalyst of CuI/2-aminopyridine 1-oxides. Furthermore, the catalyst system worked well for the coupling of cyclic secondary amines and N-methyl benzylamine with (hetero)aryl chlorides.

There is a need for synthetic grafts to reconstruct large bone defects using minimal invasive surgery. Our previous study showed that incorporation of Sr into bioactive borate glass cement enhanced the osteogenic capacity in vivo. However, the amount of Sr in the cement to provide an optimal combination of physicochemical properties and capacity to stimulate bone regeneration and the underlying molecular mechanism of this stimulation is yet to be determined. In this study, bone cements composed of bioactive borosilicate glass particles substituted with varying amounts of Sr (0 mol% to 12 mol% SrO) were created and evaluated in vitroand in vivo. The setting time of the cement increased with Sr substitution of the glass. Upon immersion in PBS, the cement degraded and converted more slowly to HA (hydroxyapatite) with increasing Sr substitution. The released Sr2+modulated the proliferation, differentiation, and mineralization of hBMSCs (human bone marrow mesenchymal stem cells) in vitro. Osteogenic characteristics were optimally enhanced with cement (designated BG6Sr) composed of particles substituted with 6mol% SrO. When implanted in rabbit femoral condyle defects, BG6Sr cement supported better peri-implant bone formation and bone-implant contact, comparing to cements substituted with 0mol% or 9mol% SrO. The underlying mechanism is involved in the activation of Wnt/β-catenin signaling pathway in osteogenic differentiation of hBMSCs. These results indicate that BG6Sr cement has a promising combination of physicochemical properties and biological performance for minimally invasive healing of bone defects.

The thermal runaway (TR) of lithium-ion batteries (LIBs) is hindering the large-scale promotion of new energy vehicles. The process of TR is often accompanied by high-temperature air flow and the eruption of particles. The particle emission was supposed to pose a risk of igniting combustibles in the surrounding environment. Relevant studies have been conducted, but reviews of these studies are lacked. Therefore, we summarize the properties of particles released upon the TR of LIBs, including morphology, mass, size, thermal stability, chemical composition, spread and deposition, temperature, and eruption distance. It was found that most of the particles appear as black, irregular-shaped powders, and their main components are carbon, carbonates, metals, metal oxides and various organic matter. Particle contains >30 elements, of which up to 40 % are metals, and >70 % of metals are polluting to the atmosphere, soil or water. Owing to different particle sizes, particles may eventually be deposited or suspended in the air, harming the environment and human body. Therefore, it is necessary to strengthen the research, supervision and treatment of LIB particle emissions. Specifically, conduct an in-depth study of the temperature and eruption range of sparks, and focus on the analysis of non-metallic elements, and conduct a comprehensive composition analysis and determination, and study the influencing factors of particle size distribution and guide the design of protective masks. Our work may pave the way for providing theoretical guidance for improving the safety of LIBs and establishing effective particle emission management methods.

Metal–organic frameworks (MOFs) have a high specific surface area, adjustable pores and can be used to obtain functional porous materials with diverse and well-ordered structures through coordination and self-assembly, which has intrigued wide interest in a broad range of disciplines. In the arena of biomedical engineering, the functionalized modification of MOFs has produced drug carriers with excellent dispersion and functionalities such as target delivery and response release, with promising applications in bio-detection, disease therapy, tissue healing, and other areas. This review summarizes the present state of research on the functionalization of MOFs by physical binding or chemical cross-linking of small molecules, polymers, biomacromolecules, and hydrogels and evaluates the role and approach of MOFs functionalization in boosting the reactivity of materials. On this basis, research on the application of functionalized MOFs composites in biomedical engineering fields such as drug delivery, tissue repair, disease treatment, bio-detection and imaging is surveyed, and the development trend and application prospects of functionalized MOFs as an important new class of biomedical materials in the biomedical field are anticipated, which may provide some inspiration and reference for further development of MOF for bio-medical applications.

Chronic hypoxia and ischemia make diabetic wounds non‐healing. Cellular functions of diabetic chronic wounds are inhibited under a pathological environment. Therefore, this work develops a composite hydrogel system to promote diabetic wound healing. The composite hydrogel system consists of ε‐poly‐lysine (EPL), calcium peroxide (CP), and borosilicate glass (BG). The hydrogel supplies continuous dissolved oxygen molecules to the wound that can penetrate the skin tissue to restore normal cellular function and promote vascular regeneration. Biofunctional ions released from BGs can recruit more macrophages through neovascularization and modulate macrophage phenotypic transformation. Combining oxygen‐mediated vascular regeneration and ion‐mediated inflammatory regulation significantly accelerated diabetic wound healing. These findings indicate that this composite hydrogel system holds promise as a novel tissue engineering material. A composite hydrogel (EPL@CP@BG) is developed for treatment of diabetic wounds. This oxygen and biofunctional ions delivery hydrogel effectively regulates the cell function for angiogenesis, inflammatory, and regeneration. Combining oxygen‐mediated vascular regeneration and ion‐mediated inflammatory regulation significantly accelerated diabetic wound healing.

It is generally accepted that biodegradable materials greatly influence the nearby microenvironment where cells reside; however, the range of interfacial properties has seldom been discussed due to technical bottlenecks. This study aims to depict biomaterial microenvironment boundaries by correlating interfacial H+distribution with surrounding cell behaviors. Using a disuse-related osteoporotic mouse model, we confirmed that the abnormal activated osteoclasts could be suppressed under relatively alkaline conditions. The differentiation and apatite-resorption capability of osteoclasts were “switched off” when cultured in titrated material extracts with pH values higher than 7.8. To generate a localized alkaline microenvironment, a series of borosilicates were fabricated and their interfacial H+distributions were monitored spatiotemporally by employing noninvasive microtest technology. By correlating interfacial H+distribution with osteoclast “switch on/off” behavior, the microenvironment boundary of the tested material was found to be 400 ± 50 μm, which is broader than the generally accepted value, 300 μm. Furthermore, osteoporotic mice implanted with materials with higher interfacial pH values and boarder effective ranges had lower osteoclast activities and a thicker new bone. To conclude, effective proton microenvironment boundaries of degradable biomaterials were depicted and a weak alkaline microenvironment was shown to promote regeneration of osteoporotic bones possibly by suppressing abnormal activated osteoclasts.

Described herein is a palladium-catalyzed dearomative annulation of alkyl bromoarenes with internal alkynes. Challenges in this spiroannulation include the chemoselectivity among [2 + 2 + 1], [2 + 2 + 2], and [3 + 2] annulations and the E/Z-selectivity associated with the generated exocyclic double bond. In the presence of Pd(OAc)2and a phosphine ligand, a variety of highly functionalized spirocyclopentadienes with an exocyclic carbon–carbon double bond are provided in good to excellent yields with high chemo-, regio-, and E/Z-selectivity via a Heck-type pathway.

[Cp*RhCl2]2is the most prevailing catalyst employed for rhodium-catalyzed chelation-assisted C−H/C−H cross-coupling reactions due to the special ligand effect of Cp*. In this article, a novel concept of using a simple inorganic rhodium salt, RhCl3·3H2O, as the catalyst by taking advantage of in situ π-coordination to Rh with a (hetero)aromatic reaction component to stabilize Rh intermediates is proposed and evaluated. Our studies not only prove the feasibility of this concept but also disclose a novel 2-fold C−H/C−H cross-coupling reaction of N-(hetero)arylimidazolium salts with various (hetero)arenes to access water-soluble, fluorescent, cationic, and planar polycyclic heteroaromatic molecules, in which RhCl3·3H2O outperforms [Cp*RhCl2]2. Mechanistic experiments and DFT calculations reveal that this successive quadruple C−H activation reaction consists of two different C−H activation modes, i.e., concerted metalation−deprotonation (CMD) and oxidative addition. Notably, this is the first report of a C−H bond activation via oxidative addition to RhIin a bi(hetero)aryl formation with hydrogen evolution. Finally, the different ligand electrochemical parameters of neutral (hetero)arenes and anionic Cp* are used to explain the different catalytic behaviors of RhCl3·3H2O and [Cp*RhCl2]2.

There is an urgent demand for wound healing biomaterials because of the increasing frequency of traffic accidents, industrial contingencies, and natural disasters. Borate bioactive glass has potential applications in bone tissue engineering and wound healing; however, its uncontrolled release runs a high risk of rapid degradation and transient biotoxicity. In this study, a novel organic–inorganic dressing of copper-doped borate bioactive glass/poly(lactic-co-glycolic acid) loaded with vitamin E (0–3.0 wt % vitamin E) was fabricated to evaluate its efficiency for angiogenesis in cells and full-thickness skin wounds healing in rodents. In vitro results showed the dressing was an ideal interface for the organic–inorganic mixture and a controlled release system for Cu2+and vitamin E. Cell culture suggested the ionic dissolution product of the copper-doped and vitamin E-loaded dressing showed the best migration, tubule formation, and vascular endothelial growth factor (VEGF) secretion in human umbilical vein endothelial cells (HUVECs) and higher expression levels of angiogenesis-related genes in fibroblasts in vitro. Furthermore, this dressing also suggested a significant improvement in the epithelialization of wound closure and an obvious enhancement in vessel sprouting and collagen remodeling in vivo. These results indicate that the copper-doped borate bioactive glass/poly(lactic-co-glycolic acid) dressing loaded with vitamin E is effective in stimulating angiogenesis and healing full-thickness skin defects and is a promising wound dressing in the reconstruction of full-thickness skin injury.

Yb3+and Er3+ions co-doped NaYF4nanocrystals were synthesized with different amounts of NaOH via oleic acid (OA)-assisted hydrothermal process. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and photoluminescence spectra were used to characterize the products. The result indicated that the introduction of NaOH into the initial reaction solution effectively promoted the cubic (α-) to hexagonal (β-) phase transition of NaYF4:Yb3+,Er3+nanocrystals, while excessive amount of NaOH favored the formation of α-NaYF4:Yb3+,Er3+nanocrystals. Besides, with the increase of NaOH amount, the morphologies of β-NaYF4:Yb3+,Er3+nanocrystals varied from irregular nanobranch to uniform nanorod. Further investigation revealed that the addition of NaOH could facilitate the deprotonation of OA, leading to the formation of oleate (OA−), and meanwhile increased the concentration of OH−ions, inducing consequently the phase transition and morphology evolution of NaYF4:Yb3+,Er3+nanocrystals. Moreover, the upconversion luminescence properties of NaYF4:Yb3+,Er3+nanocrystals were systematically investigated. It was found that the upconversion emissions not only depended on the phase and morphology but also were influenced by the surface groups.

Four Fe-containing ionic liquids (ILs) were synthesized by coupling of conventional imidazole ionic liquids [Cxmim]Cl (x= 4, 8, 12, 16) with FeCl3and were characterized by FT-IR, Raman, ESI–MS and TG. All of the Fe-containing ILs were applied to the conversion of fructose into 5-hydroxymethylfurfural (HMF) in 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) subsequently and the result showed that [C16mim]FeCl4exhibited excellent catalytic performance. Then the different reaction parameters with [C16mim]FeCl4as catalyst were studied in detail. A 92.8% yield of HMF was obtained with 0.03 g [C16mim]FeCl4and 0.1 g fructose in 1.0050 g [Bmim]Cl at 80 °C for 40 min in fructose/[Bmim]Cl solution.

Supplemental Digital Content is available in the text

Antiretroviral therapy inhibits HIV-1 replication but is not curative due to establishment of a persistent reservoir after virus integration into the host genome. Reservoir reduction is therefore an important HIV-1 cure strategy. Some HIV-1 nonnucleoside reverse transcriptase inhibitors induce HIV-1 selective cytotoxicity in vitro but require concentrations far exceeding approved dosages. Focusing on this secondary activity, we found bifunctional compounds with HIV-1–infected cell kill potency at clinically achievable concentrations. These targeted activator of cell kill (TACK) molecules bind the reverse transcriptase–p66 domain of monomeric Gag-Pol and act as allosteric modulators to accelerate dimerization, resulting in HIV-1+cell death through premature intracellular viral protease activation. TACK molecules retain potent antiviral activity and selectively eliminate infected CD4+T cells isolated from people living with HIV-1, supporting an immune-independent clearance strategy.

Integration of strong upconversion emission with deep tissue penetration and stable photothermal generation is of great significance for imaging-guided photothermal therapy under infrared excitation. Herein, the NaYF4:Yb3+,Ho3+,Ce3+@NaGdF4:Yb3+,Nd3+@NaGdF4core-shell-shell upconversion nanoparticles (UCNPs) with increasing Ce3+doping concentration were firstly synthesized, in which the size manipulation, enhanced red to green emission intensity ratio (IR/IG), 980 and 808 nm dual-modal excitations, as well as improved total upconversion emission intensity can be achieved. After the coating of polydopamine (PDA) through dopamine spontaneous polymerization on the UCNPs surface under alkaline condition, the obtained UCNP@PDA nanocomposites show efficient photothermal effect under 808 nm excitation, while the thickness variation of PDA can be indicated by the upconversion spectra under 980 nm excitation. Interestingly, the photothermal effect of the UCNP@PDA nanocomposites with high IR/IGratio is more stable with PDA thickness variation, which benefits from the structure design that allows PDA to simultaneously absorb the visible emission from inside UCNPs and the external 808 nm infrared light. Further in vitrocytotoxicity assay and photothermal therapy demonstrate that the UCNP@PDA nanocomposite has good biocompatibility and ability to kill tumor cells by photothermal effect under 808 nm excitation. This research may provide a nanoplatform for integrating deep bioimaging with highly stable photothermal therapy without the sacrifice of radiative transitions of rare earth ions.

Abstract

The Tb3+single-doped and Tb3+-Yb3+co-doped glass ceramics with the precipitation of CaF2, CaF2-SrF2solid state solution and SrF2nanocrystals were designed and prepared by taking different amounts of CaF2and SrF2as the starting fluorides to investigate the influence of the crystalline phase on the total quantum efficiency. The formation of the fluoride nanocrystals and the incorporation of the doped rare earth ions into the fluoride nanocrystals were proved by the XRD measurement. The energy transfer from Tb3+to Yb3+was studied by the steady and time resolved spectra. The total internal quantum efficiencies were calculated based on the measured Tb3+lifetime, which was about 10.5% improved in the SrF2nanocrystals precipitated glass ceramics compared with that in the CaF2nanocrystals precipitated glass ceramics mainly due to the lower phonon energy environment. Meanwhile, the total external quantum efficiencies were evaluated with the integrating sphere measurement system, which were 18.6%, 19.3% and 24.4%, respectively, for the CaF2, CaF2-SrF2and SrF2nanocrystals precipitated glass ceramics. Additionally, obvious difference between the calculated total internal quantum efficiency and the measured total external quantum efficiency was also discussed.

ABSTRACTDoravirine (DOR, formerly known as MK-1439) is a human immunodeficiency type 1 virus (HIV-1) nonnucleoside reverse transcriptase inhibitor (NNRTI) that is currently in phase 2b clinical trials. In vitroresistance selection of subtype B virus (MT4-green fluorescent protein [GFP] cells), as well as subtype A and C viruses (MT4-GFP/CCR5 cells) was conducted with DOR, rilpivirine (RPV), and efavirine (EFV) under low-multiplicity-of-infection conditions in a 96-well format. Resistance selection was performed with escalating concentrations of the NNRTIs ranging from the 95% effective concentration (1× EC95) to 1,000× EC95in the presence of 10% fetal bovine serum. In the resistance selection of subtype B virus with DOR, a V106A mutant virus led to two mutation pathways, followed by the emergence separately of either F227L or L234I. In the resistance selection of subtype A and C viruses, similar mutation development pathways were detected, in which a V106A or V106M mutant was also the starting virus in the pathways. Mutations that are commonly associated with RPV and EFV in clinical settings were also identified in subtype B viruses such as the E138K and K103N mutants, respectively, in this in vitroresistance selection study. The susceptibility of subtype B mutant viruses selected by DOR, RPV, and EFV to NNRTIs was evaluated. Results suggest that mutant viruses selected by DOR are susceptible to RPV and EFV and mutants selected by RPV and EFV are susceptible to DOR. When the replication capacity of the V106A mutant was compared with that of the wild-type (WT) virus, the mutant virus was 4-fold less fit than the WT virus.

N-Acetyl-l-cysteine-capped CdSe–polyelectrolytes @ hydroxyapatite (NAC–CdSe–PEs@HA) composite microspheres were fabricated through a stepwise layer-by-layer method and used for fluorescence detection of Cu2+ ions. The hollow HA microsphere was confirmed to be an ideal host to load CdSe quantum dots (QDs) due to their large surface area, well-defined porous structure, and large inner hollow size. Furthermore, the introduction of polyelectrolyte layers contributed to the increase of the loading amount and the electrostatic interaction between microsphere and QDs. Experiments results showed that among various metal ions investigated, Cu2+ exhibited the highest quenching effect on the fluorescence of CdSe QDs loaded in the composite microspheres. Additionally, the composite exhibited improved sensibility in detecting Cu2+ due to the presence of HA microspheres. Importantly, it is easy to separate and recycle the composite microspheres from the detection solution due to their relatively large size and high stability, thereby avoiding secondary contamination. [ABSTRACT FROM AUTHOR]

DARPins (designed ankyrin repeat proteins), new kinds of binding proteins, have the potential to overcome the defects of monoclonal antibodies, and hence may become the alternatives to antibodies and generate a novel therapeutic approach. DARPins can be selected to bind any given target proteins with high affinity and specificity. In the process of binding to target proteins, the reason why DARPins have high affinity to target proteins as well as the correlation among sequences, structures, dynamical behaviors and binding to target proteins are still unknown. This paper studied DARPins using the AMBER package with ff03 force field for molecular dynamics simulations, providing a theoretical basis for the research on a new type of protein drug. This shows that the DARPins have more dynamical behaviors regularity after binding to target proteins compared with non-binding DARPins, but the binding to target proteins does not always stabilize the structures of DARPins, and the changes in the regions of β-turn and loop are the most obvious. The changes in hydrogen bonds and hydrophobic interactions have close relationship with the changes in the stability and cross correlation of DARPins.

Hybrid mesoporous silica nanoparticles (MSNs), which were synthesized using the co-condensation method and engineered with unique redox-responsive gatekeepers, were developed for studying the glutathione-mediated controlled release. These hybrid nanoparticles constitute a mesoporous silica core that can accommodate the guests (i.e., drug, dye) and the PEG shell that can be connected with the core via disulfide-linker. Interestingly, the PEG shell can be selectively detached from the inner core at tumor-relevant glutathione (GSH) levels and facilitate the release of the encapsulated guests at a controlled manner. The structure of the resulting hybrid nanoparticles (MSNs-SS-mPEG) was comprehensively characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (XRD), and nitrogen adsorption/desorption isotherms analysis. The disulfide-linked PEG chains anchored on MSNs could serve as efficient gatekeepers to control the on–off of the pores. Compared with no GSH, fluorescein dye as the model drug loaded into MSNs showed rapid release in 10 mM GSH, indicating the accelerated release after the opening of the pores regulated by GSH. Confocal microscopy images showed a clear evidence of the dye-loaded MSNs-SS-mPEG nanoparticles endocytosis into MCF-7 cells and releasing guest molecules from the pore inside cells. Moreover, in vitro cell viability test using MTT assay indicated that MSNs-SS-mPEG nanoparticles had no obvious cytotoxicity. These results indicate that MSNs-SS-mPEG nanoparticles can be used in the biomedical field.

The ZnO-LiYbO2 hybrid phosphors with various Yb2O3 and Li2CO3 starting concentrations were prepared by using the solid-state reaction method in a weak reducing atmosphere. Under the excitation of ZnO absorption with near-UV photons, the intense near infrared emission originated from Yb3+: 2F5/2 - 2F7/2 transition can be observed due to the efficient energy transfer from ZnO to Yb3+ ions. This efficient energy transfer is benefit from the introduction of Yb3+ ions into ZnO lattice at the interfacial diffusion layers between ZnO and LiYbO2 crystals. The luminescence decay of Yb3+ were recorded under the excitation of ZnO intrinsic absorption at 350 nm and excitonic absorption at 395 nm, in which the rise component can be clearly observed and the simulated rise lifetime that describing the population speed are 0.006 and 0.035 ms, respectively. The obvious different population speed of Yb3+: 2F5/2 excited level indicates two energy transfer mechanisms from ZnO to Yb3+: the cooperative energy transfer process under the excitation of intrinsic absorption and the phonon-assistant energy transfer process under the excitation of excitonic absorption, respectively.

Monoclonal antibodies capable of recognizing antigens with high affinity and specificity represent a wellestablished class of biological agents. Since the development of hybridoma technology in 1975, advances in recombinant DNA technologies and computational and biophysical methods have allowed us to develop a better understanding of the relationships between antibody sequence, structure, and function. These advances enable us to manipulate antibody sequences with the goal of improving upon, or creating new biological or biophysical properties. In this review we will focus on recent successes in using structure-guided computational methods to design antibodies and antibody-like molecules with optimized affinity and specificity to antigen and for enhancing protein stability.

Accumulating evidence indicates that survivin plays a pivotal role in not only cell survival but also cell cycle progression. Op18/stathmin is an oncoprotein that regulates microtubule stabilization. Both survivin and Op18 have been proposed as therapeutic targets for cancer. However, few small molecule inhibitors of survivin and Op18 have been reported. In this study, we have identified a novel small molecule compound (GDP366) which potently and selectively inhibited the expression of both survivin and Op18. It decreased both the mRNA and protein levels of survivin and Op18. This inhibitory effect was not dependent on the status of p53 and p21 although GDP366 potently increased p53 and p21 levels. GDP366 significantly inhibited the growth of tumor cells in vitro and in vivo (nude mouse model) without rapid induction of apoptosis. GDP366 induced polyploidy in multiple types of cancer cell lines. GDP366 increased chromosomal instability, and induced cellular senescence by inhibiting telomerase activity. We conclude that GDP366 is a novel dual inhibitor of survivin and Op18. Our results warrant further translational evaluation of this compound.

The copperI bromide15,6,7,8tetrahydroquinolin8yl2methylpropan1one CuBrL3 combination catalyzed the crosscoupling reactions between aryl or heteroaryl halides and aqueous ammonia with high yields to produce primary aromatic or heteroaromatic amines at room temperature or under mild conditions.

The preparation of hollow hydroxyapatite (HA) microspheres as potential drug-delivery vehicles was investigated. A lithium-calcium-borate (10Li2O-15CaO-75B2O3) (mol%) glass, made by fusing the components at 1100°C for 1 h, was ground to a powder and passed through a flame at ∼1400°C to spheroidize the particles. The resulting glass microspheres (106–125 μm in diameter) were reacted in 0.25 M K2HPO4solution for 5 days at 37°C and pH 10–12, resulting in the formation of porous, hollow microspheres of a calcium phosphate (Ca-P) material with external diameters similar to those of the original glass particles. Heat treatment at 600°C for 4 h partially converted the Ca-P material to HA, as confirmed by X-ray diffraction, and also increased the strength of the hollow microspheres.

A novel type of glass-based nanoscale hydorxypatite (HAP) bioactive bone cement (designed as GBNHAPC) was synthesized by adding nanoscale hydroxyapatite (HAP) crystalline (20–40 nm), into the self-setting glass-based bone cement (GBC). The inhibition rate of nanoscale HAP and micron HAP on osteosarcoma U2-OS cells was examined. The effects of nanoscale HAP on the crystal phase, microstructure and compressive strength of GBNHAPC were studied respectively. It was concluded that nanoscale HAP could inhibit the cell proliferation, while micron HAP could not, and that nanoscale HAP could be dispersed in the cement evenly and the morphology did not change significantly after a longer immersion time. XRD and FTIR results show nanoscale HAP did not affect the setting reaction of the cement. Furthermore, GBNHAPC had a higher compressive strength (92 MPa) than GBC. It was believed that GBNHAPC might be a desirable biomaterial that could not only fill bone defects but also inhibit cancer cell growth.

The high theoretical capacity makes metal phosphides appropriate anode candidates for Li-ion batteries, but their applications are restricted due to the limited structural instability caused by the huge volume change, as in other high-capacity materials. Here, we design an integrated electrode consisting of Sn4P3nanoparticles sandwiched between transition-metal carbide (MXene) nanosheets. Tetramethylammonium hydroxide (TMAOH) plays an essential role in the formation of such sandwich structures by producing negatively charged MXene sheets with expanded layer spacings. The strong C–O–P oxygen bridge bond enables tight anchoring of Sn4P3nanoparticles on the surface of MXene layers. The obtained Sn4P3-based nanocomposites exhibit high reversible capacity with an initial Coulombic efficiency of 82% and outstanding rate performance (1519 mAh cm–3at a current density of 5 A g–1). The conductive and flexible MXene layers on both sides of Sn4P3nanoparticles provide the desired electric conductivity and elastomeric space to accommodate the large volume change of Sn4P3during lithiation. Therefore, the Sn4P3@MXene hybrid exhibits an enhanced cyclic performance of 820 mAh g–1after 300 cycles at a current density of 1 A g–1.

Critical bone defects caused by extensive excision of malignant bone tumor and the probability of tumor recurrence due to residual tumor cells make malignant bone tumor treatment a major clinical challenge. The present therapeutic strategy concentrates on implanting bone substitutes for defect filling but suffers from failures in both enhancing bone regeneration and inhibiting the growth of tumor cells. Herein, Cu and Mn-doped borosilicate nanoparticles (BSNs) were developed for syncretic bone repairing and anti-tumor treatment, which can enhance bone regeneration through the osteogenic effects of Cu2+and Mn3+ions and meanwhile induce tumor cells apoptosis through the hydroxyl radicals produced by the Fenton-like reactions of Cu2+and Mn3+ions. In vitrostudy showed that both osteogenic differentiation of BMSCs and angiogenesis of endothelial cells were promoted by BSNs, and consistently the critical bone defects of rats were efficiently repaired by BSNs through in vivoevaluation. Meanwhile, BSNs could generate hydroxyl radicals through Fenton-like reactions in the simulated tumor microenvironment, promote the generation of intracellular reactive oxygen species, and eventually induce tumor cell apoptosis. Besides, subcutaneous tumors of mice were effectively inhibited by BSNs without causing toxic side effects to normal tissues and organs. Altogether, Cu and Mn-doped BSNs developed in this work performed dual functions of enhancing osteogenesis and angiogenesis for bone regeneration, and inhibiting tumor growth for chemodynamic therapy, thus holding a great potential for syncretic bone repairing and anti-tumor therapy.

Inhibitor cystine knot peptides, derived from venom, have evolved to block ion channel function but are often toxic when dosed at pharmacologically relevant levels in vivo. The article describes the design of analogues of ProTx-II that safely display systemic in vivoblocking of Nav1.7, resulting in a latency of response to thermal stimuli in rodents. The new designs achieve a better in vivoprofile by improving ion channel selectivity and limiting the ability of the peptides to cause mast cell degranulation. The design rationale, structural modeling, in vitroprofiles, and rat tail flick outcomes are disclosed and discussed.

Kombucha SCOBY pellicle formed as a waste product in the kombucha tea fermentation industry can be used as a potential source for bacterial cellulose. We have compared four simple, scalable purification methods for the purification of this jelly like cellulosic matrix containing bacteria, yeast cells, proteins and polyphenols as impurities. The method using two successive 1.0 M NaOH washings at 90 °C, followed by the treatment with 1.5% (w/w) aq. NaOCl for 2 h, was the most effective method and gave the purified cellulose sample with the highest leucometer whiteness value of 81.4 ± 4.8. The purified cellulose samples were analyzed using FT-IR, TGA, SEM, EDX, X-ray and water absorption at room temperature.

The micro-mesoporous composite phase structure of the analcime and the glass phase was successfully synthesized at 200∘C by using hydrothermal method, in which the soda–lime–silica glass was used as the silica source and the sodium hydroxide and aluminum oxide were used as additive. The TEM and SEM results showed that the obtained rod-shaped analcime was growing on the surface of glass particles. Thermogravimetric analysis indicated that they are stable and the adsorption isotherm shape indicated the coexistence of micropores and mesopores.

Kulman: Biogen Idec: Employment. Bou-Assaf:Biogen Idec: Employment. Berkowitz:Biogen Idec: Employment. Light:biogenidec: Employment. Mezo:Biogen Idec: Employment. Wang:Biogen Idec: Employment. Whitlow:Colabrativ Inc.: Employment; Biogen Idec: Consultancy. Culyba:Biogen Idec: Employment. Peters:Biogen Idec: Employment.

Abstract 1135

The scope is investigated providing a straightforward preparation of quinolinone, pyridinones, and heteroannnulated analogues in moderate to good yields.

The ZnO-LiYbO2hybrid phosphors with various Yb2O3and Li2CO3starting concentrations were prepared by using the solid-state reaction method in a weak reducing atmosphere. Under the excitation of ZnO absorption with near-UV photons, the intense near infrared emission originated from Yb3+: 2F5/2→ 2F7/2transition can be observed due to the efficient energy transfer from ZnO to Yb3+ions. This efficient energy transfer is benefit from the introduction of Yb3+ions into ZnO lattice at the interfacial diffusion layers between ZnO and LiYbO2crystals. The luminescence decay of Yb3+were recorded under the excitation of ZnO intrinsic absorption at 350 nm and excitonic absorption at 395 nm, in which the rise component can be clearly observed and the simulated rise lifetime that describing the population speed are 0.006 and 0.035 ms, respectively. The obvious different population speed of Yb3+: 2F5/2excited level indicates two energy transfer mechanisms from ZnO to Yb3+: the cooperative energy transfer process under the excitation of intrinsic absorption and the phonon-assistant energy transfer process under the excitation of excitonic absorption, respectively.

The optimized conditions allow an efficient N‐arylation of a variety of heterocycles with (het)aryl bromides and iodides.