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The precise control of the assembly structure and size of gold nanoclusters (AuNCs) can potentially amplify their near-infrared II (NIR-II) fluorescence imaging and targeting properties. However, the conventional electrostatic assembly of AuNCs and charged molecules faces challenges in balancing the inherent electrostatic repulsions among charged units and regulating the diffusion of assembly units. These difficulties limit precise control over assembly size and structure, along with limited options for coassembled molecules, thereby restricting imaging properties and targeting capability. To circumvent this challenge, we developed a reverse emulsion-confined electrostatic assembly method. This technique efficiently constructs AuNC nanoassemblies with diverse coassembled molecules, allowing for the fine-tuning of assembly size and structure, including both core-satellite and homogeneous AuNC nanoassemblies. The development of two distinct nanoassemblies can be partially attributed to the varying diffusive rates of AuNCs or the AuNCs/polymer complex within the fused emulsion droplets. This variance arises from steric hindrances encountered during the emulsion fusion process. Interestingly, core-satellite nanoassemblies exhibit the strongest NIR-II fluorescence enhancement. Finally, the introduction of a hyaluronic acid coating on the surfaces of nanoassemblies with varying sizes enables the nanoprobes to achieve enhanced lymph node imaging through size modulation and macrophage targeting, which are used for surgical navigation to remove lymph node metastases. We envision that this self-assembly strategy can be extended to a wide range of electrostatic assembly systems for the development of multicomponent functional materials.

Conductive hydrogels have shown promising application prospects in the field of flexible sensors, but they often suffer from poor mechanical properties, low sensitivity, and lack of frost resistance. Herein, we report a tough, highly sensitive, and antifreeze strain sensor assembled from a conductive organohydrogel composed of a dual-cross-linked polyacrylamide and poly(vinyl alcohol) (PVA) network, as well as MXene nanosheets as nanofillers and poly(3,4-ethylenedioxythiophene)-doped poly(styrenesulfonate) (PEDOT/PSS) as the main conducting component (PPMP-OH organohydrogel). The tensile strength and toughness of PPMP-OH had been greatly enhanced by MXene nanosheets due to the mechanical reinforcement of MXene nanosheets, as well as various strong noncovalent interactions formed in the organohydrogels. The PPM 1 P-OH organohydrogels showed a tensile strength of 1.48 MPa at 772% and a toughness of 5.59 MJ/m 3 . Moreover, the conductivity and strain-sensing performance of PPMP-OH were significantly improved by PEDOT/PSS, which can form hydrogen bonds with PVA and electrostatic interactions with MXene. This was greatly beneficial for constructing a uniformly distributed and stable 3D conductive network and helped to obtain strain-dependent resistance of PPMP-OH. The strain sensors assembled from PPMP 1 -OH exhibited a high sensitivity of 5.16, a wide range of detectable strains up to 500%, and a short response time of 122 ms, which can effectively detect various physiological activities of the human body with high stability. In addition, the corresponding pressure sensor array also showed high sensitivity in identifying pressure magnitude and position.

The saturated flue gas is difficult to recover and use as low-grade waste heat in a coal-fired power plant. The absorption heat pump is important equipment for recovering low-grade waste heat. In this article, the saturated flue gas waste heat is recovered to reduce the turbine extraction steam of low-pressure heaters. The simulation system is built, and the operational characteristics are analyzed. The feasibility of saturated flue gas waste heat recovered is verified by the absorption heat pump to heat the boiler feedwater. The results show that generator pressure and throttle pressure have significant influence on the operational performance of the absorption heat pump. There is the risk of solution crystallization with the high-concentration dehumidification solution. The equivalent enthalpy drop of the extraction steam is lower in the higher number of heater stages, representing the weaker electricity generation capacity. The waste heat temperature of saturated flue gas can be raised by 30-40 °C, which is used as the low-grade heat source for the absorption heat pump. The feedwater of low-pressure heaters is heated by the absorption heat pump, and its temperature ranges from 59.2 to 83.8 °C. The simulation system can efficiently recover the waste heat of saturated flue gas up to 9.99 MW and achieve additional electricity generation up to 0.56 MW in the coal-fired power plant., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

Dopant-free defective carbon electrocatalysts have been considered as promising alternatives to traditional precious metal electrocatalysts recently. Compared with precious metal catalysts and transition-metal catalysts, since there are no metals doped, electrochemical devices assembled with dopant-free defective carbons are free from environmental pollution and subsequent recovery problems. In order to obtain abundant carbon defects with high-intrinsic catalytic activity, the synthesis of dopant-free defective carbons requires complex and harsh preparation conditions. Therefore, the construction of active defects with efficient utilization, especially through a simple process, is still a great challenge for the development of dopant-free defective carbon electrocatalysts. Herein, dissolution-recrystallization strategy was employed to design Zn-MOF-74 precursors for the synthesis of dopant-free defective carbons, realizing the synchronous manipulation of high ratio of carbon defects and highly exposed mass transfer channels. One-dimensional porous defective carbon nanorods (d-CNRs), which exhibited excellent oxygen reduction reaction (ORR), electrocatalytic activity, and molecular selectivity, were synthesized by directly carbonizing rodlike Zn-MOF-74 precursors. Attributed to the dissolution-recrystallization strategy, with the activation of in situ-formed ZnO, the synthesized d-CNRs exhibited unique pore-crack nested porous structures, which carried abundant defects as activity sites for ORR and showed a surprisingly high specific surface area of 2459 m 2 /g with a high ratio of mesopores. d-CNRs also showed promising applications in Zn-air batteries with a stable long-term discharge of no obvious voltage drop after 60 h. The dissolution-recrystallization strategy provided a simple controllable pathway for the efficient construction of dopant-free defective carbon electrocatalysts.

Psoriasis is an inflammatory skin disease. Microneedle (MN) patches can improve psoriasis treatment outcomes by increasing local drug content in the skin. As psoriasis frequently relapses, developing intelligent MN-based drug delivery systems with prolonged therapeutic drug levels and improved treatment efficiency is of great significance. Here, we designed detachable H 2 O 2 -responsive gel-based MN patches containing methotrexate (MTX) and epigallocatechin gallate (EGCG) by using EGCG as both cross-linkers for needle-composited materials and anti-inflammatory drugs. The gel-based MNs had dual-mode drug release kinetics, which quickly released MTX diffusively and sustainably released EGCG in an H 2 O 2 -responsive way. Compared with dissolving MNs, the gel-based MNs extended skin retention of EGCG, leading to prolonged reactive oxygen species (ROS) scavenging effects. The ROS-responsive MN patches that transdermally delivered antiproliferative and anti-inflammatory drugs improved treatment outcomes in both psoriasis-like and prophylactic psoriasis-like animal models.

Tumor recurrence and metastasis are the main causes of cancer mortality; traditional chemotherapeutic drugs have severe toxicity and side effects in cancer treatment. To overcome these issues, here, we present a pH-responsive, self-destructive intelligent nanoplatform for magnetic resonance/fluorescence dual-mode image-guided mitochondrial membrane potential damage (MMPD)/photodynamic (PDT)/photothermal (PTT)/immunotherapy for breast cancer treatment with external near infrared (NIR) light irradiation. To do so, we construct multifunctional monolayer-layered double hydroxide (LDH) nanosheets (MICaP), co-loading indocyanine green (ICG) with ultrahigh loading content realized via electrostatic interactions, and calcium phosphate (Ca 3 (PO 4 ) 2 ) coating via biomineralization. Such a combined therapy design is featured by the outstanding biocompatibility and provokes immunogenic cell death (ICD) of tumors toward cancer immunotherapy. The active transport of excess Ca 2+ released from pH-sensitive Ca 3 (PO 4 ) 2 can induce MMPD of tumor cells to minimize oxygen consumption in the tumor microenvironment (TME). The presence of ICG not only generates singlet oxygen ( 1 O 2 ) to induce apoptosis by photodynamic therapy (PDT) but also initiates tumor cell necrosis by photothermal therapy (PTT) under near-infrared (NIR) light radiation. Eventually, the immune response generated by MMPD/PDT/PTT greatly promotes a cytotoxic T lymphocyte (CTL) response that can limit tumor growth and metastasis. Both in vitro and in vivo studies indeed illustrate outstanding antitumor efficiency and outcomes. We anticipate that such precisely designed nanoformulations can contribute in a useful and advantageous way that is conducive to explore novel nanomedicines with notable values in antitumor therapy.

As an emerging antibacterial strategy, photothermal disinfection attracts increasing attention due to its advantages of high efficacy, wide pertinence, and non-drug resistance. However, the unavoidable shielding of observation by photothermal components and the possible damage to normal tissue caused by hyperthermia restrict its applications. Herein, we propose a composite hydrogel with the ability of on-demand generation of photothermal components and mild-temperature photothermal disinfection by elegantly tuning the binding and release of iodine and starch. The composite hydrogel is obtained by blending iodine-adsorbed pH-responsive ZIF-8 nanoparticles (NPs) with a starch-based hydrogel matrix. Through a convenient pH response, the composite hydrogel leverages the triple functions of iodine, which serves as a disinfectant and reacts with starch to generate a photothermal agent and color indicator, allowing photothermal-chemotherapy combined disinfection on demand. In vitro antibacterial experiments show that the composite hydrogel can respond to the acidification of the microenvironment caused by bacterial metabolism and produce corresponding color changes, realizing naked-eye observation. Meanwhile, under the combined treatment of heating/I 2 /Zn 2+ , the composite hydrogel can completely kill Escherichia coli and Staphylococcus aureus at a mild temperature of ∼41 °C. This study represents a breakthrough in on-demand generation of photothermal hydrogels for mild-temperature photothermal disinfection.

This study aimed to investigate the effect of the urea content on the characteristics and distribution of nitrogen-rich bio-oil and nitrogen-doped biochar. Cellulose, cellobiose, and glucose were used as feedstock. Urea was used as the exogenous nitrogen source in nitrogen-rich pyrolysis at 500 °C. The order of the nitrogen increase in the nitrogen-doped biochar was cellulose < cellobiose < glucose. Nitrogen-doped biochar consisted of abundant nitrogen and nitrogenous functional groups, and the stability of biochar was optimal. The nitrogen-doped biochar obtained from cellulose showed the optimal adsorption performance for diethyl phthalate with 50% urea addition. When the proportion of urea was 20%, the content of anhydro-sugars in bio-oil reached the maximum value (61.86%). Furans and other small-molecule oxygenates were intermediates to produce nitrogenous heterocyclic compounds (NHCs) from cellulose. When the proportion of urea was 40%, the bio-oil had the highest selectivity (91.63%) of NHCs. The NHCs in the obtained bio-oil mainly consisted of pyrroles, pyrimidines, pyridines, imidazoles, and pyrazines. Therefore, the excellent proportion of urea in the blend could promote the generation of high-value NHCs and nitrogen-doped biochar from the nitrogen-rich pyrolysis of cellulose (and its model compounds)., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)

Interface instability has evolved into the primary aspect that limits the durability improvement of perovskite solar cells (PSCs). Interface modification with suitable molecules is widely considered an effective path for improving the interface state. Herein, an ionic liquid modified layer, 1-ethyl-3-methylimidazolium aminoacetate (EMIMAE), is brought to modify NiO x /perovskite interface. The EMIMAE layer can interact with the adjacent layer to regulate the perovskite growth, passivate defects in the film, and promote charge transport in PSCs. Eventually, the optimized device's efficiency rises to 18.6%, which is a substantial improvement over the control device. Particularly, after 1000 h of continuous maximum power point tracking, the device can still retain 95% of its initial efficiency. This work proposes a simple idea to ameliorate the device interface and boost the commercialization of NiO x based devices.

The effects of various factors on NO x reduction by urea solution injection in the fuel-rich zone (UIFR) under a reducing atmosphere at high temperature were experimentally investigated in a 330 MW tangentially pulverized coal-fired boiler. The experimental results indicated that the NO x emission of the boiler could be effectively reduced by using the UIFR method, and the NO x reduction efficiency was mostly affected by the operating load of the boiler, the air distribution condition, and the boiler operating oxygen content (BOOC). The higher the load was, the larger the optimal normalized stoichiometric ratio (NSR) and the lower the NO x reduction efficiency became. As compared with the condition of conventional air distribution mode, the reducing atmosphere in the combustion zone could be enhanced under the condition of limiting air distribution (LAD) mode, which thus increased the NO x reduction efficiency of UIFR and reduced the optimal NSR value. A low BOOC could further increase the NO x reduction efficiency of UIFR. When the BOOC was, respectively, reduced to 1.71 and 1.85 vol % under 210 and 240 MW loads, the corresponding NO x reduction efficiencies of UIFR reached 45.3 and 41.3% in the LAD mode, respectively. However, the low BOOC increased the CO emission concentration, which could be avoided by the combined use of UIFR and high-velocity over-fire air. These experimental results can provide guidance for the ultra-low NO x emission of coal-fired boilers., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)

Nitrogen-doped nanocarbon materials (NCMs) have been developed as promising metal-free oxygen reduction reaction (ORR) electrocatalysts. However, insufficient attention on the balance of N-doping engineering and carbon chemistry significantly suppressed the revelation of the real active configurations as well as the ORR mechanism for NCMs. Herein, 1,4-phenylenediurea (BDU) with multifunctional blocks was designed for the synthesis of NCMs, realizing synchronous manipulation of N-doping engineering and carbon chemistry. The good balance between N-doping engineering (especially graphitic edge N configurations) and carbon chemistry (including the specific surface area, porosity distribution, and graphitization degree) at a pyrolysis temperature of 1000 °C resulted in the best ORR performance for obtaining N-doped carbon nanorod (NCR) materials. A general descriptor χ was then proposed for evaluating the balance states between N-doping engineering and carbon chemistry. The prediction of the ORR performance of NCMs from their physical properties as well as searching for the optimal active configuration from the relationships between ORR performance and different configurations can be realized from such a practical descriptor, which can also be extended to other nanocarbon-based metal-free electrocatalytic reactions for deeply understanding their electrocatalytic mechanisms.

The black-phase formamidinium lead triiodide (α-FAPbI 3 ) perovskite has turned out to be one of the most efficient light harvesting materials. However, the phase stability of FAPbI 3 is a long-standing issue. Herein, we introduce a layer of tetrabutylammonium fluoride (TBAF) on SnO 2 , which would form an in situ layer of TBAPbI 3 perovskitoid at the SnO 2 /FAPbI 3 interface by interacting with PbI 2 . The results show that this strategy could improve the conductivity of SnO 2 , passivate the defects in perovskite, improve the phase stability of α-FAPbI 3 , and retard the nonradiative recombination in the device. As a result, we obtain a champion device with a power conversion efficiency of 23.1% under AM 1.5 G illumination of 100 mW/cm 2 . The unencapsulated devices can maintain excellent stability under illumination, thermal stress, and humidity conditions, respectively.

Polymannuronate (PM) is an acidic polysaccharide prepared from alginate, contained in edible brown seaweeds. An unsaturated mannuronate oligosaccharide (MOS) is an enzymatically depolymerized oligosaccharide prepared from PM. The effects of MOS on attenuating tauopathy were studied in HEK293/Tau cells and primary triple transgenic (3×Tg) neurons. MOS inhibited heparin-induced aggregation of the Tau-K18 oligomer and suppressed the levels of phosphorylated Tau protein. MOS treatment reduced the activity of glycogen synthase kinase-3β (GSK-3β) by decreasing its phosphorylation levels on the sites of Y216 and increasing phosphorylation levels on the sites of S9. MOS treatment increased the ratio of LC3-II/LC3-I levels and reduced the expression of p62, indicating an increase in autophagy. Finally, MOS-induced decrease in Tau protein expression was attenuated by the addition of an autophagy inhibitor, confirming the involvement of autophagy. These data support MOS as a promising functional food or potential pharmaceutics for attenuating Tau protein-related disease.

Layered 2D perovskites have been extensively investigated by scientists with photovoltaics (PV) expertise due to their good environmental stability. However, a random phase distribution in the perovskite film could affect both the performance and stability of the devices. To overcome this problem, we propose multifunctional interface engineering of 2D GA 2 MA 4 Pb 5 I 16 perovskite by employing guanidinium bromide (GABr) on top of it to optimize the secondary crystallization process. It is found that GABr treatment can facilitate to form a shiny and smooth surface of the 2D GA 2 MA 4 Pb 5 I 16 film with excellent optoelectronic properties. Thus, we realize efficient and stable 2D perovskite solar cells (PSCs) with a champion power conversion efficiency (PCE) of 19.3% under AM 1.5G illumination. Additionally, the optimized device without encapsulation could retain 94% of the initial PCE for more than 3000 h after being stored under ambient conditions.

Sirtuin isoform 2 (SIRT2) is an enzyme that catalyzes the removal of acyl groups from lysine residues. SIRT2's catalytic domain has a hydrophobic tunnel where its substrate acyl groups bind. Here, we report that the fluorescent probe 1-aminoanthracene (AMA) binds within SIRT2's hydrophobic tunnel in a substrate-dependent manner. AMA's interaction with SIRT2 was characterized by its enhanced fluorescence upon protein binding (>10-fold). AMA interacted weakly with SIRT2 alone in solution ( K d = 37 μM). However, when SIRT2 was equilibrated with a decanoylated peptide substrate, AMA's affinity for SIRT2 was enhanced ∼10-fold ( K d = 4 μM). The peptide's decanoyl chain and AMA co-occupied SIRT2's hydrophobic tunnel when bound to the protein. In contrast, binding of AMA to SIRT2 was competitive with a myristoylated substrate whose longer acyl chain occluded the entire tunnel. AMA competitively inhibited SIRT2 demyristoylase activity with an IC 50 of 21 μM, which was significantly more potent than its inhibition of other deacylase activities. Finally, binding and structural analysis suggests that the AMA binding site in SIRT2's hydrophobic tunnel was structurally stabilized when SIRT2 interacted with a decanoylated or 4-oxononanoylated substrate, but AMA's binding site was less stable when SIRT2 was bound to an acetylated substrate. Our use of AMA to explore changes in SIRT2's hydrophobic tunnel that are induced by interactions with specific acylated substrates has implications for developing ligands that modulate SIRT2's substrate specificity.

A three-dimensional trial bed is established for a staged combustion boiler, and a modeling method based on similarity theory is proposed. The aerodynamic field of the 35 t/h layer combustion-composite combustion chamber-in the stoker boiler with staged combustion was evaluated. Further, a three-dimensional calculation model based on computational fluid dynamics (CFD) was used to simulate the aerodynamic field of the reformed boiler under normal operation, which facilitated convenience in the boiler design. Hot-wire anemometer and other instruments were used for the characteristic test of damper, a velocity field test in the furnace, wall wind test, temperature balance test at the outlet of the furnace, etc., and the law of motion for the flow field in the furnace was obtained. By analyzing the structure of staged combustion, the emission of nitrogen oxides and the combustion stability of a novel layer-fired boiler were studied. The calculated results are in excellent agreement with the experimental data. The results revealed that the combustion efficiency of the boiler and the reduction of nitrogen oxides were significantly improved by the staged combustion technology. There was no erosion on the water wall, and the flow velocity at the outlet of the furnace was uniform. This modeling method exhibits good adaptability to the combustion of stratified combustion boilers and is potentially useful for optimizing furnaces in a variety of applications., Competing Interests: The authors declare no competing financial interest., (Copyright © 2020 American Chemical Society.)

Alzheimer's disease (AD) is a common neurodegenerative disease which is partly characterized by the aggregation of hyperphosphorylated Tau proteins forming neurofibrillary tangles that promote AD pathogenesis. In this study, we investigated the effects of tanshinone IIA (Tan IIA) isolated from Salvia miltiorrhiza on Tau degradation in the treatment of AD. The results showed that Tan IIA reduced the Tau expression and attenuated Tau phosphorylation in N2a cells, Tau-overexpressing cells, and 3×Tg-AD mouse primary neuron cells. Moreover, Tan IIA increased polyubiquitinated Tau accumulation and induced proteasomal degradation of the Tau protein. Additionally, Tan IIA became bound to the Tau protein and inhibited the formation of heparin-induced Tau fibrils. In summary, Tan IIA can increase polyubiquitinated Tau accumulation and induce the proteasomal degradation of the Tau protein and the binding of Tan IIA to the Tau protein, inhibiting the formation of Tau fibrils. Tan IIA may be further explored as a potential candidate for AD treatment.

Fucoidan, a sulfated polysaccharide extracted from brown seaweeds, has been shown to possess various bioactivities. In particular, low molecular weight fucoidan (LMWF) has been shown to have better bioactivities. In this study, a LMWF (<10 kDa) was extracted from New Zealand Undaria pinnatifida and investigated for its immune modulation effects. LMWF at a concentration range from 1 to 50 μg/mL exerted an effective immune activation in RAW264.7 macrophages. LMWF treatment promoted significant NO release, iNOS expression, and TNF-α and IL-6 secretion in a concentration-dependent manner. It also significantly stimulated the activation of NF-κB and MAPK signaling pathways, and specific inhibitors of NF-κB and MAPK pathways diminished the stimulation, confirming the activation pathways. These results indicate that LMWF possesses potential health benefits through immune-stimulation, which may lead to future pharmaceutical development.

Alginate-derived polymannuronate (PM) is a type of polysaccharide found in edible brown seaweeds. Seleno-polymannuronate (Se-PM) was prepared from PM via synthesis using sulfation- and selenation-replacement reactions. The anti-inflammatory activity of Se-PM and its corresponding molecular mechanisms were investigated. In lipopolysaccharide (LPS)-activated murine macrophage RAW264.7 cells, Se-PM significantly attenuated the production of nitric oxide (NO), prostaglandin E 2 (PGE 2 ), and reactive oxygen species (ROS); the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2); and the secretion of proinflammatory cytokines. Moreover, Se-PM remarkably suppressed the LPS-induced activation of the nuclear-factor (NF)-κB and mitogen-activated-protein-kinase (MAPK) signaling pathways in RAW264.7 cells. Furthermore, Se-PM also decreased the production of proinflammatory mediators in LPS-triggered primary murine macrophages. Additionally, Se-PM inhibited the inflammatory response in the air-pouch inflammation model. These results might contribute to the overall understanding of the potential health benefits of Se-PM for food and drug applications.

Methylammonium (MA)- and formamidinium (FA)-based organic-inorganic lead halide perovskites provide outstanding performance as photovoltaic materials, due to their versatility of fabrication and their power conversion efficiencies reaching over 22%. The proposition of guanidinium (GUA)-doped perovskite materials generated considerable interest due to their potential to increase carrier lifetimes and open-circuit voltages as compared to pure MAPbI 3 . However, simple size considerations based on the Goldschmidt tolerance factor suggest that guanidinium is too big to completely replace methylammonium as an A cation in the APbI 3 perovskite lattice, and its effect was thus ascribed to passivation of surface trap states at grain boundaries. As guanidinium was not thought to incorporate into the MAPbI 3 lattice, interest waned since it appeared unlikely that it could be used to modify the intrinsic perovskite properties. Here, using solid-state NMR, we provide for the first time atomic-level evidence that GUA is directly incorporated into the MAPbI 3 and FAPbI 3 lattices, forming pure GUA x MA 1- x PbI 3 or GUA x FA 1- x PbI 3 phases, and that it reorients on the picosecond time scale within the perovskite lattice, which explains its superior charge carrier stabilization capacity. Our findings establish a fundamental link between charge carrier lifetimes observed in photovoltaic perovskites and the A cation structure in ABX 3 -type metal halide perovskites.

A two-step wet chemical synthesis method for methylammonium lead(II) triiodide (CH3NH3PbI3) perovskite is further developed for the preparation of highly reproducible solar cells, with the following structure: fluorine-doped tin oxide (FTO)/TiO2 (compact)/TiO2 (mesoporous)/CH3NH3PbI3/spiro-OMeTAD/Ag. The morphology of the perovskite layer could be controlled by careful variation of the processing conditions. Specifically, by modifying the drying process and inclusion of a dichloromethane treatment, more uniform films could be prepared, with longer emission lifetime in the perovskite material and longer electron lifetime in solar cell devices, as well as faster electron transport and enhanced charge collection at the selective contacts. Solar cell efficiencies up to 13.5% were obtained.

The electronic structure and chemical composition of efficient CH3NH3PbI3 perovskite solar cell materials deposited onto mesoporous TiO2 were studied using photoelectron spectroscopy with hard X-rays. With this technique, it is possible to directly measure the occupied energy levels of the perovskite as well as the TiO2 buried beneath and thereby determine the energy level matching of the interface. The measurements of the valence levels were in good agreement with simulated density of states, and the investigation gives information on the character of the valence levels. We also show that two different deposition techniques give results indicating similar electronic structures.

Efficient solid state dye-sensitized solar cells (sDSCs) were obtained using a small hole transport material, MeO-TPD (N,N,N',N'-tetrakis(4-methoxyphenyl)benzidine), after an initial light soaking treatment. It was discovered that the light soaking treatment for the MeO-TPD based solar cells is essential in order to achieve the high efficiency (4.9%), which outperforms spiro-OMeTAD based sDSCs using the same dye and device preparation parameters. A mechanism based on Li(+) ion migration is suggested to explain the light soaking effect. It was observed that the electron lifetime for the MeO-TPD based sDSC strongly increases after the light soaking treatment, which explains the higher efficiency. After the initial light soaking treatment the device efficiency remains considerably stable with only 0.2% decrease after around 1 month (unsealed cells stored in dark).

We report on perovskite (CH3NH3)PbI3-sensitized solid-state solar cells using spiro-OMeTAD, poly(3-hexylthiophene-2,5-diyl) (P3HT) and 4-(diethylamino)benzaldehyde diphenylhydrazone (DEH) as hole transport materials (HTMs) with a light to electricity power conversion efficiency of 8.5%, 4.5%, and 1.6%, respectively, under AM 1.5G illumination of 1000 W/m(2) intensity. Photoinduced absorption spectroscopy (PIA) shows that hole transfer occurs from the (CH3NH3)PbI3 to HTMs after excitation of (CH3NH3)PbI3. The electron lifetime (τe) in these devices are in the order Spiro-OMeTAD > P3HT > DEH, while the charge transport time (ttr) is rather similar. The difference in τe can therefore explain the lower efficiency of the devices based on P3HT and DEH. This report shows that the nature of the HTM is essential for charge recombination and elucidates that finding an optimal HTM for the perovskite solar cell includes controlling the perovskite/HTM interaction. Design routes for new HTMs are suggested.

The dielectric strength of the Debye relaxation in the binary mixtures of two isomeric monohydroxy alcohols, 2-ethyl-1-butanol (2E1B) and 4-methyl-2-pentanol (4M2P), is studied at low temperature near glass transition. Enhanced dielectric strength is exhibited in the mixtures, remarkably different from the mixing behaviors of the structural (α-) relaxation of generic liquids. A similar result is observed when analyzing the dielectric data of the binary mixtures of 2-ethyl-1-hexanol and 2-methyl-1-butanol reported in an early study. The unusual behavior of the dielectric strength in the mixtures reveals a new feature of the Debye relaxation in monohydroxy alcohols. Yet, the calorimetric measurements of the glass transition temperature in 2E1B-4M2P mixtures show a distinct negative deviation from the ideal mixing law. The explanation of the Debye relaxation is discussed with the results.

Molecular iodine has been studied, for the first time, as a sensitizer for the degradation of 2,4,6-trichlorophenol (TCP) in aqueous solution under visible light (λ ≥ 450 nm). TCP was degraded in the presence of commercial I(2), but the reaction rate decreased significantly after 2 h. When a solution of NaI and H(2)O(2) was used as an iodine source with phosphotungstic acid (PW) as a catalyst, TCP degradation was not only fast but also followed zero-order kinetics. Importantly, the I(2) concentration remained unchanged with time, indicative of I(2) recycling as a kind of photocatalyst. During TCP degradation, 2,6-dichloro-1,4-benzoquinone was produced as the main intermediate (76%), which slowly degraded in the irradiated solution. For every equivalent of TCP consumed at the 2 h time point, approximately 1.7 equivalents of chloride ions were produced. Further study of the effect of variables including the type of polyoxometalates (POM) and the initial concentration of each component revealed that the rate of TCP degradation under visible light was determined by the rate of I(2) production in the dark. The optimum pH and apparent activation energy for TCP disappearance were 4.5 and 42.8 kJ/mol, respectively. It is proposed that TCP degradation is initiated by iodine radicals produced from I(2) photolysis, followed by I(2) regeneration through a POM-catalyzed oxidation of I(3)(-) by H(2)O(2).

Photocatalytic degradation of organic substrates over WO(3) in an aerated aqueous suspension is very slow due to the difficulty of O(2) reduction by the conduction band electron on WO(3). In this work, we report on H(2)O(2) as an electron scavenger significantly accelerating the photodegradation of phenol and azo-dye X3B in water under UV or visible light. More importantly, an iron-containing WO(3) (FeW) synthesized through thermal decomposition of a ferrotungstenic acid displayed a much higher activity than pure WO(3) (HW) prepared in parallel. As the sintering temperature increased, both FeW and HW showed an exponential increase in activity. The maximum rate constant of phenol degradation obtained with FeW at 400 °C was about 2 times larger than that with HW at 600 °C. Sample characterization with electron paramagnetic resonance (EPR) spectroscopy and other techniques revealed that ferric species (0.3 wt % Fe(2)O(3)) were mainly present as clusters on the oxide surface at 120 °C and then they diffused toward the lattice sites of WO(3) at high temperature, which was detrimental to the photocatalytic reaction. 5,5-Dimethyl-1-pyrroline N-oxide spin-trapping EPR showed that the production of hydroxyl radicals was greatly enhanced upon the addition of H(2)O(2), the trend of which among different catalysts was the same as that of the rate of phenol degradation. The catalysts after excitation at 350 nm displayed a blue emission centered at 469 nm, the intensity of which varied with the catalyst activity nearly as expected. A possible mechanism for the improved photoactivity of WO(3) is proposed involving the electron transfer from WO(3) to Fe(2)O(3) and the reaction of the reduced oxide with H(2)O(2) to generate hydroxyl radicals.

A rapid and sensitive immunochromatographic assay (ICA) based on competitive format was developed and validated for simultaneous detection of sulfamethazine (SM(2)), sulfadiazine (SDZ), and sulfaquinoxaline (SQX) in chicken breast muscle and egg samples. For this purpose, three monoclonal antibodies raised against those three sulfonamides were conjugated to colloidal gold particles and applied to the conjugate pads of the test strip. The competitors of the sulfonamides (SM(2)/SDZ/SQX-bovine serum albumin conjugates) were immobilized onto a nitrocellulose membrane at three detection zones to form T(1), T(2), and T(3), respectively. With this method, the cutoff values for the three test lines were achieved at 80 μg/kg, which is lower than the maximum residue levels (MRLs) established for sulfonamides. The recoveries in negative samples spiked at concentrations of 10, 50, and 100 μg/kg ranged from 75% to 82% for egg samples and from 78% to 81% for chicken samples. The method was compared with the HPLC method by testing 180 eggs and chicken breast samples from local markets, and an agreement rate of 99.7% was obtained between the two methods.

A rapid immunochromatographic lateral-flow test strip was developed in the competitive reaction format for the detection of sulfonamides in eggs and chicken muscle. A monoclonal antibody against the common structure of sulfonamides was conjugated to colloidal gold particles as the detection reagent and an N-sulfanilyl-4-aminobenzoic acid (SUL)-bovine serum albumin (BSA) conjugate was immobilized to a nitrocellulose membrane as the capture reagent to prepare the test strip. With this method, it required only 15 min to accomplish the semiquantitative or quantitative detection of sulfonamides. The sensitivity to sulfonamides (sulfamonomethoxine, sulfamethoxydiazine, sulfadimethoxine, and sulfadiazine) was at least 10 ng/mL, as determined with an optical density scanner. By eye measurement, the sensitivity was 20 ng/mL for sulfamonomethoxine, sulfamethoxydiazine, and sulfadimethoxine and 40 ng/mL for sulfadiazine. On the basis of a sulfamonomethoxine standard curve, recoveries were from 89.5 to 95.6% for sulfamonomethoxine, from 89.5 to 95.1% for sulfamethoxydiazine, from 85.0 to 95.6% for sulfadimethoxine, and from 44.8 to 60.9% for sulfadiazine in egg and chicken muscle samples. A parallel analysis of 27 egg samples and 28 chicken muscle samples from the animal experiment showed that the differences between test strips and high-performance liquid chromatography (HPLC) were from 0.8 to 11.2% for egg samples and from 2.2 to 34% for chicken muscle samples for the quantitative detection, and the agreement rates between test strips and HPLC were 100%, based on the maximum allowed residue level of sulfadiazine (100 ng/g) established by the European Union and China. In conclusion, the method is rapid and accurate for the detection of sulfonamides in eggs and chicken muscles.