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Solar-driven CO2 with H2O conversion into valuable chemical fuels has attracted considerable attention. However, the low separation efficiency of photogenerated carriers and deficient surface-active sites on catalysts result in low CO2 reduction activity. Herein, the bulk Bi2O2(OH)-(NO3) material was exfoliated to atomically thin nanosheets for shortening the migration distance of photoinduced carriers and enlarging the specific surface area. Photoreduction CO2 test results showed that the CO yield of nanosheets could be enhanced up to nearly six times compared to that of the bulk catalyst. Moreover, a series of ultrathin Bi2O2(OH)1+x(NO3)1–x nanosheets were constructed based on the surface regulation of the OH– concentration on ultrathin nanosheets. The optimized catalyst had an elevated CO yield of 16.7 μmol/g after irradiation for 3 h, about 10 times higher than that of the bulk catalyst. Further theoretical calculations revealed that the superficial NO3– has stronger charge accumulation/depletion behavior with the adjacent Bi atom than surface OH–, conducive to the transfer of photogenerated charge from the bulk phase to the catalyst surface. This work may provide a powerful strategy for the design of a surface-controlled 2D ultrathin photocatalyst for efficient CO2 reduction. [ABSTRACT FROM AUTHOR]

A new class of macrocyclic lanthanide complexes, Ln/DTPA-PDA-C(sub n), is developed for cellular labeling and magnetic resonance imaging (MRI) applications. These agents, combining with 3-dimensional MRI microscopy, have broad applications in imaging cell movement and localization in different biological systems in vivo.

The electric responses detected with single-walled carbon-nanotube field-effect transistors (SWCNT-FET) and the morphological changes acquired by atomic force microscopy (AFM) were used to study the exocytosis of a single bovine adrenal chromaffin cell. The results demonstrated the successful application of SWCNT-FET and AFM to detect the tiny amount of chromogranin A (CgA) release and the small fusion pores in single chromaffin cells as well as fundamental properties of exocytosis in neuroendocrine cells.

Michel-addition polymerization of disulfide-based diacrylate and equimolar N-methyl ethylenediamine (MEDA) has formed ABB' type intermediates. The poly(amino ester)s have stimuli-sensitive disulfide bonds in the backbone that can be cleaved under dithiothreitol (DTT), affording these poly(amino ester)s with potential applications.

We develop an N-coordination strategy to design a robust CO2 reduction reaction (CO2RR) electrocatalyst with atomically dispersed Co-N5 site anchored on polymer-derived hollow N-doped porous carbon spheres. Our catalyst exhibits high selectivity for CO2RR with CO Faradaic efficiency (FECO) above 90% over a wide potential range from -0.57 to -0.88 V (the FECO exceeded 99% at -0.73 and -0.79 V). The CO current density and FECO remained nearly unchanged after electrolyzing 10 h, revealing remarkable stability. Experiments and density functional theory calculations demonstrate single-atom Co-N5 site is the dominating active center simultaneously for CO2 activation, the rapid formation of key intermediate COOH* as well as the desorption of CO. [ABSTRACT FROM AUTHOR]

The high-gravity carbonation process for CO2 mineralization and product utilization as a green cement was evaluated using field operation data from the steelmaking industry. The effect of key operating factors, including rotation speed, liquid-to-solid ratio, gas flow rate, and slurry flow rate, on CO2 removal efficiency was studied. The results indicated that a maximal CO2 removal of 97.3% was achieved using basic oxygen furnace slag at a gas-to-slurry ratio of 40, with a capture capacity of 165 kg of CO2 per day. In addition, the product with different carbonation conversions (i.e., 0%, 17%, and 48%) was used as supplementary cementitious materials in blended cement at various substitution ratios (i.e., 0%, 10%, and 20%). The performance of the blended cement mortar, including physicochemical properties, morphology, mineralogy, compressive strength, and autoclave soundness, was evaluated. The results indicated that the mortar with a high carbonation conversion of slag exhibited a higher mechanical strength in the early stage than pure portland cement mortar, suggesting its suitability for use as a high early strength cement. It also possessed superior soundness compared to the mortar using fresh slag. Furthermore, the optimal operating conditions of the high-gravity carbonation were determined by response surface models for maximizing CO2 removal efficiency and minimizing energy consumption. [ABSTRACT FROM AUTHOR]

A palladium-catalyzed isocyanide insertion-cyclization using low-cost and readily accessible 2-haloanilines, 2-iodophenylethanones, and isocyanides for efficient synthesis of 3-iminoindol-2-amine and cyclic enaminone derivatives has been developed. The method features low-cost and readily accessible starting materials, reliable scalability, and bond-forming efficiency as well as simple one-pot operation, which makes this strategy highly attractive. A reasonable mechanism for forming 3-iminoindol-2-amine involved double isocyanide insertion/cyclization process is proposed. [ABSTRACT FROM AUTHOR]

Accelerated carbonation of basic oxygen furnace slag (BOFS) coupled with cold-rolling wastewater (CRW) was performed in a rotating packed bed (RPB) as a promising process for both CO2 fixation and wastewater treatment. The maximum achievable capture capacity (MACC) via leaching and carbonation processes for BOFS in an RPB was systematically determined throughout this study. The leaching behavior of various metal ions from the BOFS into the CRW was investigated by a kinetic model. In addition, quantitative X-ray diffraction (QXRD) using the Rietveld method was carried out to determine the process chemistry of carbonation of BOFS with CRW in an RPB. According to the QXRD results, the major mineral phases reacting with C02 in BOFS were Ca(OH)2, Ca2(HSiO4)(OH), CaSiO3 and Ca2Fe1.04Al0.986O5. Meanwhile, the carbonation product was identified as calcite according to the observations of SEM, XEDS, and mappings. Furthermore, the MACC of the lab-scale RPB process was determined by balancing the carbonation conversion and energy consumption. In that case, the overall energy consumption, including grinding, pumping, stirring, and rotating processes, was estimated to be 707 kWh/t-CO2. It was thus concluded that CO2 capture by accelerated carbonation of BOFS could be effectively and efficiently performed by coutilizing with CRW in an RPB. [ABSTRACT FROM AUTHOR]

Both basic oxygen furnace (BOF) slag and cold-rolling wastewater (CRW) exhibiting highly alkaline characteristics require stabilization and neutralization prior to utilization and/or final disposal. Using CO2 from flue gases as the stabilizing and neutralizing agents could also diminish CO2 emissions. In this investigation, ex situ hot stove gas containing 30 vol% CO2 in the steelmaking process was captured by accelerated carbonation of BOF slag coupled with CRW in a rotating packed bed (RPB). The developed RPB process exhibits superior results, with significant CO2 removal efficiency (η) of 96-99% in flue gas achieved within a short reaction time of 1 min at 25 °C and 1 atm. Calcite (CaCO3) was identified as the main product according to XRD and SEM-XEDS observations. In addition, the elimination of lime and Ca(OH)2 in the BOF slag during carbonation is beneficial to its further use as construction material. Consequently, the developed RPB process could capture the CO2 from the flue gas, neutralize the CRW, and demonstrate the utilization potential for BOF slag. It was also concluded that carbonation of BOF slag coupled with CRW in an RPB is a viable method for CO2 capture due to its higher mass transfer rate and CO2 removal efficiency in a short reaction time. [ABSTRACT FROM AUTHOR]

A water-soluble, biodegradable and fluorescent hyperbranched poly(amidoamine) with mannose groups on their surface (M-HPAMAM) has been successfully prepared, and the synthetic strategy includes Michael addition polymerization of diacrylamide with 1-(2-aminoethyl)piperazine and, subsequently, surface modification with mannosamine. The photoluminescence of M-HPAMAM was enhanced significantly due to the surface mannose groups. Incubation of E. coliwith M-HPAMAMs yielded brightly fluorescent bacteria clusters, but the fluorescent intensity of the aqueous solution lowered. This indicates that the M-HPAMAMs have strong affinity with bacteria due to their polyvalent interactions. Based on the size and the amount of bacteria clusters formed, the bacteria with the concentrations higher than 102cfu/mL can be detected. [ABSTRACT FROM AUTHOR]

The atom transfer radical dispersion polymerization of 4-vinylpyridine (4VP) in an ethanol/H2O mixture displayed two stages of polymerization; the first stage is the formation of a diblock copolymer with the polymerization rate of 1.21 mol·L-1·h-1before 1 h of polymerization, and the second is the main polymerization in micelles formed from the aggregation of the resultant block copolymers with the polymerization rate of 0.009 mol·L-1·h-1. The 2-bromoisobutyryl-terminated poly(ethylene glycol) methyl ether used in the polymerization acts as both a stabilizer and an initiator. The stable micelles with functional core were synthesized by a one-pot strategy via atom transfer radical dispersion copolymerization (ATRDCP) of 4VP and N,N‘-methylenebisacrylamide (MBA) in an ethanol/H2O solution for the first time. In the initial stage of polymerization, 4VP and MBA were copolymerized to form a block copolymer, PEG-b-(4VP-co-MBA), with pendent unreacted vinyl groups, and after phase separation at a critical chain length of P4VP-co-PMBA, the cross-linking reaction and polymerization occurred at the same time, resulting in cross-linked micelles. The volume ratio of ethanol/H2O had a big influence on the ATRDCP. An increase in the relative amount of ethanol in the solvent mixture will increase the solubility of P4VP in the polymerization system, the phase separation will be postponed, and the critical chain length of 4VP blocks at the phase separation becomes longer. As a result, the particles size and the 4VP content in the resultant micelles increase. The Au/polymer composite nanoparticles were successfully prepared by complexation of P4VP with HAuCl4and following reduction with NaBH4. [ABSTRACT FROM AUTHOR]

A cyclization of propargylic alcohols with tert-butyl nitrite at room temperature in air was achieved using Pd(OAc) 2 as catalyst. The first reported 4-oxoisoxazoline N-oxides could be directly accessed from a range of multisubstituted propargylic alcohols in moderate to excellent yields under mild conditions. Density functional theory calculations indicated that the reaction proceeds through a palladium-catalyzed NO 2 addition that efficiently generates a ketoxime radical, which eventually produces 4-oxoisoxazoline N-oxide.

Image-guided photothermal therapy (PTT) is an attractive strategy to improve the diagnosis accuracy and treatment outcomes by monitoring the accumulation of photothermal agents in tumors in real-time and determining the best treatment window. Taking advantage of the superior imaging quality of NIR-II fluorescence imaging and remote-controllable phototherapy modality of PTT, we developed a facile macromolecular fluorophore (PF) by conjugating a small-molecule NIR-II fluorophore (Flav7) with an amphiphilic polypeptide. The PF can form uniform micelles in aqueous solution, which exhibit a slight negative charge. In vitro experimental results showed that the PF nanoparticles showed satisfactory photophysical properties, prominent photothermal conversion efficiency (42.3%), excellent photothermal stability, negligible cytotoxicity, and photothermal toxicity. Meanwhile, the PF can visualize and feature the tumors by NIR-II fluorescence imaging owing to prolonged blood circulation time and enhanced accumulation in tumors. Moreover, in vivo studies revealed that the PF nanoparticles achieved an excellent photothermal ablation effect on tumors with a low dose of NIR-II dye and light irradiation, and the process can be traced by NIR fluorescence imaging.

The aerobic dehydrogenative cyclization of alkenes with easily accessible diselenides facilitated by visible light is reported. Notably, the features of this transition-metal-free protocol are pronounced efficiency and practicality, good functional group tolerance, atom economy, and high sustainability, since ambient air and visible light are adequate for the clean construction of five- and six membered heterocycles in yields of up to 98%.

Precise detection of the tumor environment for cancer diagnosis has been strongly demanded for further therapies. Here, a redox-responsive fluorescence switch off/on system PCQ was designed and synthesized conjugated with near-infrared (NIR) cyanine dyes (Cy5.5) and relevant quencher (FQ) in mixed polymeric micelles (PCy and PFQ). The mixed PCQ micelles were prepared with two kinds of polymers with poly(oligo (ethylene glycol) methacrylate) (POEGMA) as the hydrophilic shell, in which fluorescence emission was quenched by fluorescence resonance energy transfer (FRET) effect. The FQ was conjugated with POEGMA by disulfide linkage, which could be broken with a redox environment such as high glutathione (GSH) concentration in tumor cells. After the PCQ micelles got into tumor cells, PFQ blocks in PCQ would be disassembled to recompose PCy micelles. During that process, drugs like doxorubicin (DOX) could be loaded inside and formed PCQ@DOX nanoparticles and then released for accurate NIR bioimaging and drug delivery instantly.

NIR photosensitizer is attractive for photodynamic therapy (PDT). Low-power light irradiation and imaging-guided PDT makes it possible to increase tissue penetration depth. The pyrrole-substituted iodinated BODIPY (BDPI) molecule was designed and synthesized, and it possesses an intense NIR absorption and emission band, and exhibits a high singlet oxygen quantum yield (Φ Δ = 0.80) which leads remarkable cytotoxicity upon low power illumination (IC50 = 0.60 μg/mL, 6.1 mW/cm 2 ). After being encapsulated with biocompatibility polypeptide PEG-PLys, polymeric micelles nanoparticles (PBDPI NPs) was obtained that are water-dispersed and passively tumor-targetable. Such enhanced accumulation in tumor area makes it easily traced in vivo due to its NIR fluorescence. In addition, such nanoparticles offer an unprecedented photodynamic therapeutic effect by using a low-power irradiation light, which makes it possible to kill cancer cells in deep tissue efficiently.

Photobleaching and biotoxicity are the main bottlenecks for organic fluorescent dyes applied in real-time dynamic monitoring of living cells. Here, an unnatural amino acid, 4-nitro-3-phenyl-l-alanine (NPA), was used as a scaffold to covalently link a near-infrared fluorophore Cy5.5 and an amphiphilic polypeptide, poly[oligo(ethylene glycol) methyl ether methacrylate]- block-poly[2-amino-N 4 -(2-diisopropylamino-ethyl)-l-aspartic acid] (P(OEGMA) 21 -P(Asp) 16 -iPr), was then conjugated for increasing the photostability and improving the biocompatibility simultaneously. The protective agent of NPA can service as an effective triplet state quenching by intramolecular electron transfer between Cy5.5 and NPA. The less sensitivity of the electron-transfer process for molecular oxygen makes it an ideal photostabilized strategy for fluorophores applied in live-cell imaging. Bonding to copolymer is a common way for hydrophobic dyes to expand their application in biomedical imaging and increase their functionality, depending on the delivery system. The results indicate that Cy5.5-NPA-linked polypeptide copolymer exhibited an enhanced photostability and an excellent biocompatibility, which means this scaffolding strategy has a potential application in fluorescence-guided surgery, lived-cell imaging, and super-resolution microscopy.