Limited Rate Research Articles

Polydopamine‐modified black phosphorus/microcapsule composite material used to enhance the solar thermal conversion and self‐healing performance of SBS modified asphalt

AbstractThis study developed UV‐responsive microcapsules to enhance the self‐healing properties of asphalt, addressing the limitations of low survival rates and single‐release mechanisms in current encapsulated rejuvenators. The microcapsules, featuring a urea‐formaldehyde shell embedded with polydopamine‐coated black phosphorus nanosheets (BP/DA) and microalgae bio‐oil as the core, can convert solar energy into thermal energy, promoting proactive self‐healing in asphalt materials. BP/DA expands the microcapsules' light absorption range, enhancing their photothermal conversion efficiency. When incorporated into styrene‐butadiene‐styrene (SBS)‐modified asphalt at a 1.5% dosage, the microcapsules (BP/DA/MC) improved the mechanical properties: ductility increased by 13.7%, softening point rose by 2%, and penetration decreased by 3.3%. The storage modulus (G′) at 46 and 64°C increased by 35.9% and 24.3%, respectively, compared to SBS asphalt. Additionally, the ductility self‐healing rate of BP/DA/MC/SBS asphalt improved by 209.7%, with a healing index (HI) of 78.16%. The microcapsules also demonstrated excellent photothermal conversion, increasing the asphalt's temperature by 22.6% under identical lighting conditions. This research offers a new method for developing intelligent self‐healing asphalt with multi‐mechanism activation, providing theoretical support for future third‐generation microcapsule‐based asphalt with remote‐controlled release and activation response.

Bioaugmentation with targeted recombinant functional consortia to improve lignocellulosic biowaste co-anaerobic digestion performance

Hydrolysis rate limitation and acid-methanogenesis phase imbalance are critical challenges in the anaerobic digestion (AD) of lignocellulosic substrates, hindering substrate utilization and methane conversion. Bioaugmentation is widely employed to promote biochemical and metabolic reactions at all stages of AD to enhance methanogenic efficiency. However, synergistic reinforcement for simultaneous enhancement of the hydrolysis and methanogenesis phases requires further elucidation. This study investigated the effect of lignocellulolytic mutualistic methanogenic culture (LMMC) obtained by targeted domestication on the AD system. The results showed that the bioaugmented reactor enhanced the methane production by 21.03%-239.12% and the peak daily methanogenesis by 6.54%-127.85%. Introducing LMMC was directly related to improving methanogenic performance and significantly affected the AD key indicator, which facilitated the timely consumption of volatile fatty acid (VFA) for utilization. Microbial analysis results showed that the enriched hydrolytic acidifying bacteria, anaerobic fungi, and acetoclastic methanogens formed a microbial synergistic reinforcement alliance, which jointly stimulated methane production, alleviated the potential risk of instability, and promoted the stable operation of the AD system. Collectively, the role of synergistic reinforcement in the microbial consortium was highlighted to improve the stability and efficiency of AD process of lignocellulosic biomass.

Universal fragmentation in annihilation reactions with constrained kinetics

In reaction-diffusion models of annihilation reactions in low dimensions, single-particle dynamics provides a bottleneck for reactions, leading to an anomalously slow approach to the empty state. Here, we construct a reaction model with a reciprocal bottleneck of reactions on particle dynamics in which single-particle motion conserves the center of mass. We show that such a constrained reaction-diffusion dynamics does not approach an empty state but freezes at late times in a state with fragmented particle clusters. The late-time dynamics and final density are universal, and we provide exact results for the final density in the large-reaction rate limit. Thus, our setup constitutes a minimal model for the fragmentation of a one-dimensional lattice into independent particle clusters. We suggest that the universal reaction dynamics could be observable in experiments with cold atoms or in the Auger recombination of exciton gases. Published by the American Physical Society 2024

Study on the reaction mechanism of multi-source metallurgical dust for zinc extraction and iron enrichment

Multi-source metallurgical dust can realize the purpose of zinc extraction and iron enrichment by high-temperature reduction. In this paper, based on the zinc extraction and iron enrichment from multi-source metallurgical dust in rotary kiln process, thermodynamic calculations and reduction kinetic experiments were carried out to clarify the thermodynamic conditions and kinetic limiting factors of the reduction of Fe-Zn-C-O system of metallurgical dust, and to obtain the suitable parameters of reduction temperature and reaction time, etc. The results showed that Fe mainly existed in the form of Fe2O3 and Fe3O4 in metallurgical dust. Zn mainly existed in the form of ZnO and ZnFe2O4, with a small amount existed in ZnS. The starting temperatures of the reduction of ZnO, ZnFe2O4, ZnS with C were 951.09 °C, 581.55 °C and 1862.44 °C, respectively. Combined with the temperature of the smelting condition of rotary kiln, it was known that the presence of ZnS was the key factor leading to the limitation of zinc removal rate. ZnO and ZnFe2O4 showed higher reduction difficulty compared to iron oxides, so the metallization rate of rotary kiln slag could be improved by controlling the smelting atmosphere. The weight loss rate, metallization rate and dezincification rate of multi-source metallurgical dust showed an increasing trend with the change of temperature and time, and the more desirable effect of weight loss rate, metallization rate and dezincification rate were 46.7%, 87.1%, and 92.5% under laboratory conditions at reduction temperature 1100 °C and reaction time 50 min.

Eravacycline improves the efficacy of anti-PD1 immunotherapy via AP1/CCL5 mediated M1 macrophage polarization in melanoma

Screening approved library is a promising and safe strategy to overcome the limitation of low response rate and drug resistance in immunotherapy. Accumulating evidence showed that the application of antibiotics has been considered to reduce the effectiveness of anti-PD1 immunotherapy in tumor treatment, however, in this study, an antibiotic drug (Eravacycline, ERV) was identified to improve the efficacy of anti-PD1 immunotherapy in melanoma through screening approved library. Administration of ERV significantly attenuated melanoma cells growth as well as directly or indirectly benefited M1 macrophage polarization. Meanwhile, ERV treatment significantly induced cellular autophagy via damage of mitochondria, leading to up-regulation of ROS production, subsequently, raised CCL5 secretion through elevation AP1 binding to CCL5 promoter via p38 or JNK1/2 activation. Knockdown of Ccl5 expression attenuated ERV triggered M1 macrophage polarization in melanoma cells. Clinical analysis revealed a positive association between high expression of CCL5 and improved prognosis as well as a favorable anti-PD1 therapy in melanoma patients. As expected, application of ERV improved the efficacy of anti-PD1. Overall, our results approved that ERV enhances the efficacy of anti-PD1 immunotherapy in melanoma by promoting the polarization of M1 macrophages, which provided novel therapeutic strategy for improving the effectiveness of melanoma anti-PD1 immunotherapy.

Study on the Selection of Recycling Strategies for the Echelon Utilization of Electric Vehicle Batteries under the Carbon Trading Policy

Global climate change has prompted all sectors of society to take urgent action to reduce carbon emissions. Electric vehicles are the key to low-carbon transportation transformation, but their popularity has led to difficulties in disposing of used batteries. Improper handling will pollute the environment and violate the original goal of promoting low-carbon practices. Therefore, it is crucial to establish a sustainable battery-recycling and disposal system. This study uniquely incorporates the concept of battery echelon utilization into its analytical framework using a Stackelberg game model, exploring the equilibrium strategies for stakeholders in a closed-loop supply chain under carbon emission constraints. We analyzed the impact of multiple factors in the recycling process, as well as the influence of digital technology, on enterprise pricing, recycling efficiency, and the choice of recycling channels. The study found that the market pricing of batteries and electric vehicles is not influenced by recycling participants, but is instead related to the application of digital technology. Numerical simulations further reveal that the battery’s echelon utilization rate and carbon emission limit policies jointly motivate enterprises to be more proactive in recycling. In the joint recycling model, battery suppliers can achieve more substantial profit growth compared to electric vehicle manufacturers, providing new insights and directions for innovation and the development of collaborative models within the supply chain.

Analytical and Diagnostic Performance of a Dual-Target Blood Detection Test for Hepatocellular Carcinoma.

Surveillance approaches with high sensitivity and specificity for hepatocellular carcinoma (HCC) are still urgently needed. Previous studies have shown that methylation of GNB4 and Riplet can effectively diagnose HCC. This study plan to analyze the performance of a blood test for detecting HCC using GNB4 and Riplet methylation. This study mainly investigated the analytical performance of the dual-target HCC blood test (DT-HBT), including cut-off value, limit of detection (LOD), precision, analytical specificity, and coincidence rate. In addition, the detection performance for HCC was validated in 1030 clinical plasma samples (214 HCC and 816 non-HCC). Plasma samples from 25 HCC patients after hepatectomy were collected to assess the feasibility of the kit for postoperative recurrence monitoring. All analytical performance of the DT-HBT met prespecified requirements. The LOD for GNB4, Riplet, and β-actin was 1% methylation/100 copies/μL with cut-offs of 43, 43, and 35, respectively. The DT-HBT showed excellent precision, within 5% CV. It had a specificity of 91.5% for detecting other cancers, and 100% for breast, lung, and bladder cancer. No cross-reactions were observed with 9 potential interfering substances. The DT-HBT achieved a 100% coincidence rate in detecting reference and clinical samples. The clinical performance study found that the kit showed a sensitivity of 81.7% for stage I HCC, and an overall sensitivity and specificity of 87.4% and 92.3%, respectively. The detection sensitivity for postoperative recurrent patients was 95.8%, with a specificity of 100%. The analytical performance of the DT-HBT met prespecified criteria. It provided HCC patients with a reliable and high-performing new blood test for the HCC diagnosis and surveillance. ClinicalTrials.gov identifier: NCT05685524.

Influence of sweep duration on debonding detection of honeycomb structures based on acoustic band gap

Abstract Honeycomb structure is widely used in many fields, and its bond quality needs to be tested during manufacture process and in service. However, the efficiency, sensitivity, and feasibility can hardly be achieved simultaneously for traditional non-destructive testing methods. In the previous work, we have proposed a new debonding detection method using the acoustic band gap of honeycomb structures. Nevertheless, the influence of the detection parameters on the testing result has not been thoroughly investigated. In this paper, the effect of duration variation of the sweep signal used for exciting on the results is studied. Experimental results demonstrate that the transmission frequency response (TFR) of both the intact and the debonding area almost keep unchanged as the sweep duration varies from 1 s to 0.001 s. Theoretical analysis shows that the upper limit of the sweep rate is about 500 MHz/s, i.e., the minimum sweep duration is about 1.2 × 10−5 s to detect a bandgap with a bandwidth of about 6 kHz. Therefore, a shorter sweep duration can be used to further improve the detection efficiency.

Temporal fine structure sensitivity measured with pulse-spreading harmonic complexes.

Two experiments investigated sensitivity to temporal fine structure (TFS) in a group of normal hearing participants. The stimuli were bandpass filtered pulse-spreading harmonic complexes (PSHCs) with a regular envelope repetition rate and a phase adjusted so that the TFS peaks were progressively shifted across envelope periods. For up-PSHCs, the TFS peaks were advanced, yielding a rising pitch percept, while for down-PSHCs, the peaks were delayed, yielding a falling pitch percept. Experiment 1 showed that in a fixed frequency region, there was a range of rates for which the direction of the pitch change could be identified. Cochlear model simulations suggested that participants may use either place-of-excitation and/or temporal cues to perform this task. Experiment 2 showed that there was an envelope rate below which down-PSHCs and up-PSHCs could not be discriminated. This lower envelope rate limit of TFS sensitivity significantly increased with increases in frequency region and was similar to the lower rate limit of melodic pitch. The results in high frequency regions suggest that TFS cues are available up to 10 kHz when the rank of the lowest component present in the passband is 18, and all harmonics are presumably unresolved.

Optimizing gas lift for enhanced recovery in the Asmari formation: a case study of Abu Ghirab field in Southeastern Iraq

The gas lift technique applies gas bubble injection into the vertical wells to raise production. Gas and liquid rates, shifts in flow regimes, and system equilibrium influence this process. This study explores the efficient implementation of gas lift techniques to maximize production from the Asmari Formation in the Abu Ghirab Field, southeastern Iraq, using a continuous gas lift for maximum production rate by PIPESIM TM software. The results of the gas lift design for the four wells (AGCS-33, 26, 28, and 36) show that the Vogel method provided the best results for the gas lift design, and faults and facies distribution impact the gas lift injection and oil production rates. These will become evident with wells AGCS-33 and 36 as their proximity to faults will increase oil production rates with a gas injection rate limit of 7 MMSCF/d. Conversely, for wells 26 and 28, the limit will marginally rise, starting at 5 MMSCF/d. In addition, the effect of gas lift is clearly in the middle western of the crest, which shows an increasing percentage of oil production of 136.6% at minimum rate and 198.5% at maximum for the well AGCS-26, 89.7% and 105.7% for the well AGCS-36. Wellhead pressure has a significant impact on gas-lift performance, and improving gas-lift efficiency can be accomplished using an electric control valve. The feasibility of implementing gas lift in the Asmari Formation depends on the water cut, well location, and water saturation distribution within the Formation.

Lessons learned from a one-year study of Legionella spp. cultivation from activated sludge samples

Risk assessment and management of Legionella spp. contamination in activated sludge in wastewater treatment plants is carried out using the culture method. Underestimation of Legionella spp. is frequently reported in the literature, but a comprehensive long-term study of the performance of the method under comparable conditions is still lacking. The aim of this study is to evaluate the recovery rate and limit of detection of the culture method for Legionella spp. from activated sludge samples collected during the different seasons of the year. Activated sludge samples spiked with Legionella pneumophila subsp. pneumophila strain Philadelphia-1 (mean concentration 5.2 ± 0.35 logCFU/mL) were analysed monthly for one year using the culture method. Three different sample pre-treatments were compared, namely filtration, acid treatment and thermal treatment, and the recovery rate and limit of detection were assessed for each. The recovery rate of the culture method for Legionella spp. depended on the type of sample pre-treatment and the season of activated sludge sampling, while the limit of detection depended only on the sample pre-treatment. The best performance of the culture method, defined as the combination of the highest recovery rate and lowest limit of detection, was obtained for the filtered acid pre-treated samples (recovery rate: 89 ± 4 %; limit of detection: 1.3 logCFU/mL in 83 % of the samples). The lowest limit of detection was observed for the filtered thermally pre-treated samples (1.0 logCFU/mL in 93 % of the samples). Simultaneously, both thermally pre-treated samples showed up to a third lower recovery rates than the other pre-treatments in winter, while untreated and acid pre-treated samples showed consistently high recovery rates (>80%, logCFU/mL). The recovery rates of the unfiltered and filtered thermally pre-treated samples showed significant weak to strong positive correlations with the organic and phosphorus load in the influent as well as with the water and atmospheric temperatures, indicating that the recovery rate depends on the seasonal variation of the wastewater composition. This study presents new insights into the detection and quantification of Legionella spp. in activated sludge samples and considers seasonal dependencies in analytical results.

Selective trimethylamine sensors based on Co3O4 modified WO3 spheres

Co3O4 modified WO3 microspheres with excellent trimethylamine (TMA) gas sensitive performance were prepared by a simple hydrothermal method using ZIF-67 as a template. The morphology, elemental composition, structure of the compounds, and gas-sensitive properties of the sensors based on them were researched by SEM, XRD, XPS as well as the gas-sensing analysis system. The prepared Co3O4 modified WO3 spheres exhibit significantly enhanced TMA gas sensitive properties, such as high response (198) to 100 ppm TMA, excellent selectivity, rapid response/recovery rate (11.7/2.1 s), good repeatability, long-term stability, and low detection limit (0.17 ppm) at 285 ℃. The sensing properties of the WO3/Co3O4 sensor may be due to the large surface area, significant resistance modulation effect of the p-n heterostructure, and catalytic effect of Co3O4. This work suggests that Co3O4 modified WO3 spheres may play an important role in the field of high-performance TMA sensors.

THE EFFECT OF RISK BASED CAPITAL ON THE PROFITABILITY OF INSURANCE COMPANIES REGISTERED WITH THE FINANCIAL SERVICES AUTHORITY

This research aims to determine the development of Risk Based Capital, profitability, and the effect of Solvency Rate Limit (RBC) on profitability in Syariah Unit Insurance registered with the Financial Services Authority. This research is a quantitative research, and the source of data obtained is secondary data. The population is 25 Syariah Unit General Insurance companies registered with Financial Services Authority (OJK). This research sample uses a purposive sampling technique by 9 Syariah Unit General Insurance companies registered with OJK using annual financial statements in accordance with the variables used during the period (2018-2023). The data analysis uses multiple linear regression analysis with a constant of 41.513 which means, if the Risk Based Capital variable is fixed, then the Return On Asset will increase by 41.513 and the regression coefficient value for the Investment variable in the regression equation shows a positive value of 0.023 X, this means that if the Risk Based Capital variable is fixed, then the Return On Asset variable will increase by 0.023. The Coefficient of Determination (R) for Risk Based Capital on Return On Asset is 0.609, then for the Risk Based Capital variable on Return On is 0.515. And the Analysis of the Hypothesis Test is known that Risk Based Capital (X) shows at an alpha coefficient of 5% (t-stat = 3.119 > 1.674) and prob. 0.006 < 0.05. So the hypothesis is accepted, namely Risk Based Capital has a significant effect on Return On Equity in the Alpha 5% Syariah unit insurance company.

Performance of mesoporous ceria supported Ru catalysts for oxidative degradation of aqueous solution of plastic monomer bisphenol A in a fixed bed flow reactor: Structure-activity insights, optimization of reaction conditions, kinetics, catalyst stability, and characterization

One of the important defects is the oxygen vacancy on metal oxide surfaces, and the defects function as the active sites in different catalytic reactions. Herein, Ru/CeO2-rod and Ru/CeO2-cube catalysts were prepared via the ESI method, and CeO2-rod and CeO2-cube supports were synthesized by hydrothermal processes. The activity of these catalysts was tested in a high-pressure fixed-bed reactor, and the oxidative degradation of industrial organic raffinate containing the plastic chemical bisphenol A (BPA) was compared with their oxygen vacancy concentration estimated after calcination. The Ru/CeO2-rod catalyst showed higher catalytic activity with 90 % BPA conversion at 453 K, 30 bar, 0.5 % Ru metal content, 15 O2 to BPA molar ratio, and 2 g−1.h−1 BPA feed weight hourly space velocity (WHSV). In contrast, 80 % BPA degradation was achieved using the Ru/CeO2-cube catalyst under similar reaction conditions. The higher oxygen vacancy concentration and the higher interfacial surface area between metal and the support of the CeO2-rod supported Ru catalyst triggered the higher BPA degradation at low oxidation conditions. Besides, the atomic ratio, Ce3+/Ce4+, is lower in the Ru/CeO2-rod catalyst than that of the Ru/CeO2-cube catalyst, indicating the higher Ce4+ available in the catalyst, leading to the higher degradation of BPA. Moreover, the Ru/CeO2-rod catalyst possesses {111} planes that boost the generation of energetic Ru to improve the pursuit of the catalyst. The Weisz-Prater modulus and Thiele modulus values indicated that the surface reaction is the rate limitation step and there is no diffusion limitation. TEM, HRTEM, XPS, Raman, H2-TPR, XRD, CO chemisorption and BET surface area analyzers were used to characterize the catalysts.

Z boson emission by an electron and the decays of Z boson into fermions in a de Sitter universe

In this paper we develop a method to obtain the rates for the decay of a Z boson into fermions in de Sitter geometry. Our general results obtained in de Sitter space-time allow us to obtain the Minkowski limits for the transition rates when the expansion parameter vanishes. Another important result reported in the present study is related to the emission of Z bosons by electrons and positrons. All the processes were studied by implementing perturbative methods that allow us to define the transition amplitudes in the first order of perturbation theory. The variation of probabilities and rates in terms of expansion parameter and particles masses is also given, pointing out that the processes that generate particle production are possible only in the early universe. For computing the transition rates and probabilities we use the dimensional regularization method and the minimal substraction method.

Constructing hybrid nitrogen/oxygen-rich surface and hierarchically porous in lignite-based activated carbons as supercapacitor electrode by in-situ soda ash activate strategy

Coal-based activated carbon materials have the limitations of low specific surface area and limited ion mobilization rate, restricting their practical applications. In this study, porous coal-based activated carbon electrodes were prepared via chemical activation using lignite as a precursor for electrochemical energy storage. Using response surface methodology (RSM), the optimal conditions for preparing porous lignite-based activated carbon were identified: an activation temperature of 856 °C, an activation time of 2.6 hours, and a Na2CO3-coal mass ratio of 4.1:1. The pure alkali carbonization process enriched the activated carbon's three-dimensional pore structure, creating numerous ion-transport channels. The best sample (CAC-3) achieved a surface area of 1847.3 m2 g−1. Process optimization enhanced its electrochemical performance, resulting in a specific capacitance of 219.7 F g−1 at 1 A g−1. It maintained good cycling performance after 5000 cycles in a 6 M KOH aqueous solution at a current density of 10 A g−1. In a two-electrode system, the specific capacitance was 175.3 F g−1 at a current density of 1 A g−1. This study offers new insights for advanced energy storage technologies.

Mechanism Study on the Immobilization of Cu2+/Pb2+ in Aqueous Phase by Mineral Co-Milling-Modified Biochar.

A large number of studies have shown that the modification of biochar can greatly improve its adsorption capacity. This study adopts a one-step ball milling technology without solvent medium, using sawdust biochar (600 °C) and attapulgite/diatomaceous earth to prepare MABC10%/MDBC10% (mass ratio: 10% attapulgite/diatomite +90% biochar coabrasive). Characterization experiments show that attapulgite/diatomite was successfully loaded on biochar and has more C/O functional groups and wider adsorption pore sizes. Adsorption kinetics and isotherm experiments show that the adsorption process of MABC10% and MDBC10% on Cu2+/Pb2+ was mainly multilayer chemical adsorption. The adsorption capacities of MABC10% and MDBC10% for Cu2+ were 40.85 and 65.20 mg·L-1, respectively. The adsorption amounts of Pb2+ were 82.63 and 71.32 mg·L-1, respectively. The particle diffusion model shows that the adsorption process was controlled by both the surface adsorption rate limitation and boundary layer diffusion. The higher acidity in the solution will cause part of the negative charges on the surface of attapulgite/diatomite to be neutralized, thereby hindering its adsorption of Cu2+/Pb2+. The presence of coexisting ions did not significantly affect the adsorption performance. Mechanistic studies have shown that pore diffusion, active sites provided by C/O functional groups, electrostatic interactions, and cation exchange are the main mechanisms of MABC10% adsorption of Cu2+/Pb2+. In summary, MABC10% has a significant adsorption synergistic effect compared to MBC. It was an economical and effective adsorbent, and the higher the pH value of the wastewater, the more significant the adsorption effect.

Fundamental Studies of Discharge Mechanism and Capacity Limits of Lead Acid Battery Electrodes

Long-duration energy storage provides key benefits such as consistent power supply during periods of high demand for grid reliability and flexibility. For environmental benefits, it allows for more renewable energy integration and helps reduce reliance on fossil fuels to lower greenhouse gas emission. Lead batteries have the economic potential to continue serving as an important energy storage technology for a decarbonized sustainable energy future given they are earth-abundant, inexpensive, and 99% recyclable. Advancing the design of lead batteries with higher material utilization, fast recharge rates, and long-cycle life requires a fundamental understanding of the electrochemical and chemical processes taking place at the atomic and molecular scales. In this work, we will discuss how the use of well-defined electrode interfaces allows us to gain insights into the fundamental limits of discharge capacity and recharge rates. We were able to unveil the relationships between discharge rates and PbSO4 particle size/layer thickness that ultimately governs the maximum discharge capacity accessible as a function of discharge rate on both the negative and positive lead electrodes. This data helped us develop a mathematical model that captures the key processes concerning lead ion and (bi)sulfate ion gradients coupled to nucleation and growth that explain, from first principles, the origin of the well-known empirical Peukert law. In this context, exploring how variables such as acid concentration, temperature, and the presence of lignosulfonate additives in the electrolyte further influence discharge capacity allows us to understand how thermodynamic, kinetic, and even mass transport play a huge role in governing the accessible capacity from the electrodes. This study paves the way for a deeper understanding of the variables that are most important in improving the discharge capacity of lead-acid batteries, and thus batteries that can be utilized at their full potential.

Assessment of Photoactivated Chlorophyllin Production of Singlet Oxygen and Inactivation of Foodborne Pathogens

Singlet oxygen (1O2) is known to have antibacterial activity; however, production can involve complex processes with expensive chemical precursors and/or significant energy input. Recent studies have confirmed the generation of 1O2 through the activation of photosensitizer molecules (PSs) with visible light in the presence of oxygen. Given the increase in the incidence of foodborne diseases associated with cross-contamination in food-processing industries, which is becoming a major concern, food-safe additives, such as chlorophyllins, have been studied for their ability to act as PSs. The fluorescent probe Singlet Oxygen Sensor Green (SOSG®) was used to estimate 1O2 formation upon the irradiation of traditional PSs (rose bengal (RB), chlorin 6 (ce6)) and novel chlorophyllins, sodium magnesium (NaChl) and sodium copper (NaCuChl), with both simulated-solar and visible light. NaChl gave rise to a similar 1O2 production rate when compared to RB and ce6. Basic mixing was shown to introduce sufficient oxygen to the PS solutions, preventing the limitation of the 1O2 production rate. The NaChl-based inactivation of Gram-positive S. aureus and Gram-negative E. coli was demonstrated with a 5-log reduction with UV–Vis light. The NaChl-based inactivation of Gram-positive S. aureus was accomplished with a 2-log reduction after 105 min of visible-light irradiation and a 3-log reduction following 150 min of exposure from an initial viable bacterial concentration of 106 CFU mL−1. CHS-NaChl-based photosensitization under visible light enhanced Gram-negative E. coli inactivation and provided a strong bacteriostatic effect preventing E. coli proliferation. The difference in the ability of NaChl and CHS-NaChl complexes to inactivate Gram-positive and Gram-negative bacteria was confirmed to result from the cell wall structure, which impacted PS–bacteria attachment and therefore the production of localized singlet oxygen.

Effects of Drought Stress on Photosynthesis and Chlorophyll Fluorescence in Blue Honeysuckle.

Blue honeysuckle (Lonicera caerulea L.) is a deciduous shrub with perennial rootstock found in China. The objectives of this study were to explore the drought tolerance of blue honeysuckle, determine the effect of drought stress on two photosystems, and examine the mechanism of acquired drought tolerance. In this study, blue honeysuckle under four levels of simulated field capacity (100%, 85%, 75%, and 65% RH) was grown in split-root pots for drought stress treatment, for measuring the changes in chlorophyll content, photosynthetic characteristics, and leaf chlorophyll fluorescence parameters. The chlorophyll content of each increased under mild stress and decreased under moderate and severe stress. The net photosynthetic rate, transpiration rate, intercellular carbon dioxide concentration, and stomatal conductance of blue honeysuckle decreased with the increase in water stress. However, the water utilization rate and stomatal limit system increased under mild and moderate stress and decreased under severe stress. The maximum fluorescence (Fm), maximum photochemical efficiency, and quantum efficiency of photosystem II decreased with the decrease in soil water content, and the initial fluorescence increased significantly (p < 0.01). With the decrease in soil water content, the energy allocation ratio parameters decreased under severe drought stress. The main activity of the unit reaction center parameters first increased and then decreased. ABS/CSm, TRo/CSm, ETo/CSm, and REo/CSm gradually declined. After a comprehensive analysis, the highest scores were obtained under adequate irrigation (CK). Overall, we concluded that the water irrigation system of blue honeysuckle should be considered adequate.