Optimum Reaction Temperature Research Articles

Temperature-assisted crystallization and morphology for CH3NH3PbI3 perovskite solar cells using laser-induced heat treatment

In this study, perovskite solar cells (PSCs) were fabricated using a two-step solution deposition method. A laser beam was applied at the interface between lead iodide (PbI2) and methylammonium iodide to change the reaction temperature and stimulate the growth of perovskite crystals. A notable enhancement was observed in the power conversion efficiency of PSCs. The laser scanning speed was investigated to control the reaction temperature and further control the crystallization and morphology of the perovskite film. Based on the optimized laser scanning speed, the best and average PCEs obtained were 14.33 % and 13.92 ± 0.52 %, respectively, which were higher than those achieved using the conventional technique (12.18 % and 11.37 ± 0.74 %, respectively) and the conventional heating methods (14.09 % and 13.28 ± 0.56 %, respectively). The optimal reaction temperature at the interface was predicted to be 80 °C under optimized conditions using the COMSOL software. This study will help in scaling this technique for large–area PSCs, optimizing the laser parameters for different perovskite compositions, and investigating the long-term stability of enhanced PSCs, boosting their commercial viability.

Determination of extracellular proteinase in L. helveticus Lh191404 based on whole genome sequencing and proteomics analysis

Lactobacillus helveticus exhibits a remarkable proteolytic system. However, the etiology of these protein hydrolysis characteristics, whether caused by extracellular proteinases (EP) or cell envelope proteinases (CEP), has been puzzling researchers. In this study, third-generation Nanopore whole genome sequencing and proteomics analysis were used to unravel the root cause of the aforementioned confusion. The genome of L. helveticus Lh191404 was 2,117,643 bp in length, with 67 secreted proteins were found. Combined with proteomic analysis, it was found that the protein composition of extraction from CEP and EP were indeed the same substance. Bioinformatics analysis indicated that the CEP belonged to the PrtH1 Variant (PrtH1_V) genotype by phylogenetic analysis. The three-dimensional structures of various domains within the PrtH1_V-191404 had been characterized, providing a comprehensive understanding of its structural features. Results of proteinase activity showed that the optimal reaction temperature was 40 °C, with a pH of 6.50. These findings suggested that the origin of EP in L. helveticus Lh191404 may be due to CEP being released into the substrate after detaching from the cell wall. This research is of guiding significance for further understanding the operational mechanism of the protein hydrolysis system in lactic acid bacteria.

Decorated gelatin polymer onto copper aluminum layered double hydroxides for superior removal of Congo red: Optimization and adsorption evaluation of kinetics, isotherms, and thermodynamics

Azo-dyes are highly soluble in water and well documented by their toxic and nonbiodegradable characters and the removal of such dye pollutants from wastewater is aimed to control environmental pollution. Therefore, the current study is designed and executed to efficiently remove Congo Red dye pollutant (CRDP) as an example of azo-dye coloring materials by using a newly synthesized nanobiosorbent. The aimed Cu/Al-LDHs@Gltn nanobiosorbent was prepared by the direct combination and binding of gelatin as a sustainable biopolymeric material with copper aluminum layered double hydroxides (Cu/Al-LDHs) by using a green microwave synthesis approach. Several characterization techniques were applied to confirm the morphology and structure of Cu/Al-LDHs@Gltn. The particle size range was identified by using the SEM analysis from 16.54 nm to 30.68 nm and the EDX investigation confirmed the elemental existence of C (25.1%), O (41.9%), and N (13.5%), Al (3.2%), Cu (11.9%) and Cl (4.4%) elements. The FT-IR analysis referred to the incorporation of several surface functionalizations as –OH, COOH, metal-O and others, while the BET-surface area configuration was detected (41.35 m2 g−1). Zero-charge point of Cu/Al-LDHs@Gltn was also measured to provide (pHzpc = 6.0). The significant controlling parameters were testified to optimize the pollutant adsorption onto the aimed Cu/Al-LDHs@Gltn via batch removal experiments by using 5-15 mg/L CRDP concentrations. The optimum pH (2.0), reaction duration (35 min), dosage (15 mg) and reaction temperature (25°C) conditions were concluded. Several related models to adsorption isotherm and kinetic studies were explored. The thermodynamic parameters additionally estimated the spontaneity and the exothermal adsorptive reaction of CRDP onto Cu/Al-LDHs@Gltn. This was confirmed to afford high stability and sustainability providing successive efficiency up to 94.6%, 84.1% and 78.8% (1st cycle) and yielded 83.3%, 70.1% and 64.5% (3rd cycle) upon testifying 5, 10 and 15 mg/L CRDP concentrations, correspondingly. Cu/Al-LDHs@Gltn was finally characterized by excellent CRDP removal efficiency up to 92.1-95.1% (5 mg/L CRDP), 91.9-92.3% (10 mg/L CRDP) and 90.4-91.7% (15 mg/L CRDP) from drinking, sea and wastewaters, correspondingly.

Diols production from pyrolysis oil water‐soluble fraction

AbstractBACKGROUNDThe production of value‐added chemicals from pyrolysis oil or its fractions is of great significance for the valorization of biomass. Diols, including ethylene glycol (EG) and 1,2‐propylene glycol (1,2‐PG), are important bulk chemicals with widespread industrial applications. Here we investigated the production of diols from pyrolysis oil water‐soluble fraction (WS) using a hybrid catalyst (Ni + H2WO4).RESULTSFirstly, levoglucosan, glycolaldehyde and acetol, three main components in WS, were respectively selected as the single model compound, and their respective conversions into diols were investigated at different temperatures for different reaction times. The result showed the optimum reaction temperature and time were 180 °C and 2 h respectively, under which a EG yield of 53.8% and 1,2‐PG yield of 5.2% were obtained from levoglucosan conversion, a EG yield of 98.6% was obtained from glycolaldehyde conversion, and a 1,2‐PG yield of 98.5% was obtained from acetol conversion. The reaction pathway of levoglucosan conversion was analyzed. Secondly, the model mixture of levoglucosan, glycolaldehyde and acetol was used to simulate the real WS, and their conversion was investigated at different ratios of H2WO4 to Ni. The result showed the optimum catalyst composition was 0.15 g H2WO4 and 0.3 g Ni, under which a EG yield of 76.4% and 1,2‐PG yield of 38.4% were obtained. Thirdly, the real original WS was converted under the optimum reaction conditions and the result only gave a EG yield of 19.1% and 1,2‐PG yield of 25.8% (based on the carbon moles of main substrates), which were much less than the two yields of model mixture. That was related to the presences of other types of chemicals in original WS. After the original WS being adsorbed by activated carbon, the yields of EG and 1,2‐PG could be increased to 39.2% and 37.9%, respectively.CONCLUSIONThe presences of certain other types of chemicals (such as acids, furans, phenolics and cyclopentanones) in original WS inhibited the production of diols. The activated carbon adsorption could efficiently remove most of furans, phenolics and cyclopentanones in original WS and increased significantly the diols yields. © 2024 Society of Chemical Industry (SCI).

A Loop-Mediated Isothermal Amplification Assay for the Rapid Detection of Didymella segeticola Causing Tea Leaf Spot.

Tea leaf spot caused by Didymella segeticola is an important disease that threatens the healthy growth of tea plants (Camellia sinensis) and results in reductions in the productivity and quality of tea leaves. Early diagnosis of the disease is particularly important for managing the infection. Loop-mediated isothermal amplification (LAMP) assay is an efficient diagnostic technique with the advantages of simplicity, specificity, and sensitivity. In this study, we developed a rapid, visual, and high-sensitivity LAMP assay for D. segeticola detection based on sequence-characterized amplified regions. Two pairs of amplification primers (external primers F3 and B3 and internal primers FIP and BIP) were designed based on a specific sequence in D. segeticola (NCBI accession number: OR987684). Compared to common pathogens of other genera in tea plants and other species in the Didymella genus (Didymella coffeae-arabicae, Didymella pomorum, and Didymella sinensis), the LAMP method is specific for detecting the species D. segeticola. The assay was able to detect D. segeticola at a minimal concentration of 1 fg/μL genomic DNA at an optimal reaction temperature of 65 °C for 60 min. When healthy leaves were inoculated with D. segeticola in the laboratory, the LAMP method successfully detected D. segeticola in diseased tea leaves at 72 h post inoculation. The LAMP assays were negative when the DNA samples were extracted from healthy leaves. Leaf tissues with necrotic lesions from 18 germplasms of tea plants tested positive for the pathogen by the LAMP assay. In summary, this study established a specific, sensitive, and simple LAMP method to detect D. segeticola, which provides reliable technical support for estimating disease prevalence and facilitates sustainable management of tea leaf spot.

Modified sodium alginate-based three-dimensional network hydrogel dust suppressant: Preparation, characterization, and performance

Chemical dust suppression is typically associated with high economic costs, unclear efficacy, and poor degradability. In this study, sodium alginate (SA) was extracted from kelp and cross-linked with polyvinyl alcohol (PVA) and polyacrylamide (PAM). Sulfonated castor oil (CAS) was subsequently added to generate a three-dimensional network hydrogel dust suppressant (PVA-SA-PAM/CAS). Using single-factor experiments, the optimal reaction temperature (60 °C) and dosages of PVA, PAM, and the cross-linking agent (2.5, 4.5, and 0.1 g, respectively) were determined. The viscosity and compressive strength of the prepared hydrogel were 86 mPa·s and 218 kPa, respectively, which meet the requirements for mine dust suppression. Various analyses revealed the hydrogel's reaction process and microstructure changes. Additionally, thermogravimetric experiments proved that the hydrogel had good thermal stability. The specific surface area and pore size of the hydrogel were 0.0278 m2/g and 11.8 nm, respectively, improving its adsorption capacity. Additionally, PVA-SA-PAM/CAS exhibited a good water retention rate. The dust suppression efficiency of PVA-SA-PAM/CAS was >98 % under strong winds (12 m/s). Moreover, the degradation rate of PVA-SA-PAM/CAS was 37 % after eight cycles (56 d) under environmental conditions. Therefore, PVA-SA-PAM/CAS exhibits good wetting, dust suppression, and degradation properties, which can effectively alleviate mine dust pollution.

Optimizing removal of elemental mercury from flue gas using halide‐impregnated red mud

AbstractMercury (Hg0) emission from coal‐fired industrial plants poses severe threats to ecosystem sustainability and human health, urging the development of novel and cost‐effective adsorbents to treat industrial flue gas. Herein, the modification of industrial residual red mud (RM) through the impregnation of hydrogen halides (HH) and its adsorption characteristics for removing elemental mercury from combustion flue gas was reported. Experimental investigation of HH‐modified RM reveals that the hydrogen iodide (HI)‐modified RM with a concentration of 1.5 M had a maximum Hg0 removal efficiency of 98%, whereas hydrogen bromide (HBr) 1.5 M modified RM had a maximum Hg0 removal efficiency of 90%. The effect of various parameters, such as reaction temperature and halide concentrations, were also found to be influential for the adsorption efficiency of the modified RM. Moreover, it is important to highlight the chemisorption characteristics of HI‐modified RM, which significantly enhances the efficiency of the removal process. The Hg0 removal efficiency increases with the increase in HI concentration (1.5 M @ 93%) with an optimal reaction temperature of 140°C. Furthermore, the maximum Hg0 removal attained with a change in NO concentration was 98% at 200 ppm. However, increasing the SO2 concentration reduces the efficiency of RM for removing Hg0 in simulated coal combustion flue gas. The pseudo‐second‐order model (R2 = 0.98) accurately describes the adsorption of in kinetic investigations, indicating a chemisorption mechanism. This analysis of the chemisorption mechanism highlights the efficiency of halide‐modified industrial solid waste, which has the potential to be used in the design of economical and innovative adsorbents for reducing environmental pollution. The present study employed specific reaction parameters such as reaction temperature, halide loading contents, and different flue gas compositions, which had not been extensively explored.

The treatment strategies of autoimmune hemolytic anemia

Autoimmune hemolytic anemia (AIHA) is characterized by the accelerated destruction of erythrocytes due to the presence of antibodies and/or complement that bind to antigens on erythrocytes. It can be subdivided into warm, cold or mixed AIHA based on the type of autoantibody and the optimal temperature of antigen-antibody reaction. Glucocorticoid with or without rituximab is the first-line treatment of warm AIHA (wAIHA), and splenectomy was once the preferred second-line treatment for relapsed or refractory wAIHA. However, due to the various complications of splenectomy, rituximab has gradually become the preferred treatment for patients who have failed glucocorticoid therapy. Other available treatments including immunosuppressants and plasma exchange can be chosen. Rituximab with or without bendamustine is generally taken as the first-line regimen for cold autoimmune hemolytic anemia (cAIHA), while glucocorticoid and splenectomy are ineffective. Sutimlimab, a kind of complement inhibitor, has been approved for the treatment of cold agglutinin disease (CAD). In recent years, many new drugs have emerged as treatment options for AIHA. Emerging therapies, including B-cell-directed therapies, plasma cell-directed therapies, complement inhibitors, and phagocytosis inhibition, provide a new perspective for AIHA therapy, showing great potential for clinical applications.

Dual Gene Detection of H5N1 Avian Influenza Virus Based on Dual RT-RPA.

The H5N1 avian influenza virus seriously affects the health of poultry and humans. Once infected, the mortality rate is very high. Therefore, accurate and timely detection of the H5N1 avian influenza virus is beneficial for controlling its spread. This article establishes a dual gene detection method based on dual RPA for simultaneously detecting the HA and M2 genes of H5N1 avian influenza virus, for the detection of H5N1 avian influenza virus. Design specific primers for the conserved regions of the HA and M2 genes. The sensitivity of the dual RT-RPA detection method for HA and M2 genes is 1 × 10-7 ng/μL. The optimal primer ratio is 1:1, the optimal reaction temperature is 40 °C, and the optimal reaction time is 20 min. Dual RT-RPA was used to detect 72 samples, and compared with RT-qPCR detection, the Kappa value was 1 (p value < 0.05), and the clinical sample detection sensitivity and specificity were both 100%. The dual RT-RPA method is used for the first time to simultaneously detect two genes of the H5N1 avian influenza virus. As an accurate and convenient diagnostic tool, it can be used to diagnose the H5N1 avian influenza virus.

The types of metal M and crystal surface in the PtM (M = Co, Ni, Zn) IMCs catalysts to regulate catalytic performance of ethane direct dehydrogenation

PtM IMCs have improved catalytic performance of ethane dehydrogenation (EDH), however, identifying the functions of the types of metal M and crystal surface for the PtM IMCs catalysts in regulating EDH catalytic performance are still a challenge in experiment. This work fully investigated catalytic performance of EDH over three crystal surfaces (110), (111) and (200) of PtM IMCs (M = Co, Ni, Zn) by using density functional theory (DFT) calculations and kinetic Monte Carlo (kMC) simulations. The results show that the catalytic performance of EDH over PtM IMCs strongly depend on the types of metal M and crystal surfaces, the PtZn(111) catalyst is screened out as the most promising in EDH reaction with the optimal reaction temperature of 773.15 K. The geometrically isolated Pt site in the [PtM3] assembly of PtZn(111) could catalyze the CH cleavage, and C2H4* exhibits weak π-adsorption model at the individual Pt sites, promoting C2H4* desorption. Compared to (110) and (200) surfaces, the (111) surface with moderate Bader charge transfer showed the highest C2H4(g) production activity, and Zn atoms transferred more electrons to Pt atoms, which greatly weakened the charge transfer between C2H4* and the catalyst surface, favoring C2H4* desorption to inhibit C2H4* deep dehydrogenation. Moreover, the catalytic performance of PtZn(111) catalyst is superior to the industrially used PtSn catalyst. This work provides valuable structure clue for the design of high-performance catalyst in alkane direct dehydrogenation.

Organoborane Se and Te Precursors for Controlled Modulation of Reactivity in Nanomaterial Synthesis.

To exploit the distinctive optoelectrical properties of nanomaterials, precise control over the size, morphology, and interface structure is essential. Achieving a controlled synthesis demands precursors with tailored reactivity and optimal reaction temperatures. Here, we introduce organoborane-based selenium and tellurium precursors borabicyclononane-selenol (BBN-SeH) and tellurol (BBN-TeH). The reactivity of these precursors can be modified by commercially available additives, covering a wide range of intermediate reactivity and filling significant reactivity gaps in existing options. By allowing systematic adjustment of growth conditions, they achieve the controlled growth of quantum dots of various sizes and materials. Operating via a surface-assisted conversion mechanism, these precursors rely on surface coordination for activation and undergo quantitative deposition on coordinating surfaces. These properties allow precise control over the radial distribution and density of different chalcogenide atoms within the nanoparticles. Diborabicyclononanyl selane ((BBN)2Se), an intermediate from the BBN-SeH synthesis, can also serve as a selenium precursor. While BBN-SeH suppresses nucleation, (BBN)2Se exhibits efficient nucleation under specific conditions. By leveraging these distinct activation behaviors, we achieved a controlled synthesis of thermally stable nanoplates with different thicknesses. This study not only bridges critical reactivity gaps but also provides a systematic methodology for precise nanomaterial synthesis.

Identification of a Novel Chitinase from Bacillus paralicheniformis: Gene Mining, Sequence Analysis, and Enzymatic Characterization.

In this study, a novel strain for degrading chitin was identified as Bacillus paralicheniformis HL37, and the key chitinase CH1 was firstly mined through recombinant expression in Bacillus amyloliquefaciens HZ12. Subsequently, the sequence composition and catalytic mechanism of CH1 protein were analyzed. The molecular docking indicated that the triplet of Asp526, Asp528, and Glu530 was a catalytic active center. The enzymatic properties analysis revealed that the optimal reaction temperature and pH was 65 °C and 6.0, respectively. Especially, the chitinase activity showed no significant change below 55 °C and it could maintain over 60% activity after exposure to 85 °C for 30 min. Moreover, the optimal host strain and signal peptide were obtained to enhance the expression of chitinase CH1 significantly. As far as we know, it was the first time finding the highly efficient chitin-degrading enzymes in B. paralicheniformis, and detailed explanations were provided on the catalytic mechanism and enzymatic properties on CH1.

Molecular engineering of PETase for efficient PET biodegradation

The widespread utilization of polyethylene terephthalate (PET) has caused a variety of environmental and health problems. Compared with traditional thermomechanical or chemical PET cycling, the biodegradation of PET may offer a more feasible solution. Though the PETase from Ideonalla sakaiensis (IsPETase) displays interesting PET degrading performance under mild conditions; the relatively low thermal stability of IsPETase limits its practical application. In this study, enzyme-catalysed PET degradation was investigated with the promising IsPETase mutant HotPETase (HP). On this basis, a carbohydrate-binding module from Bacillus anthracis (BaCBM) was fused to the C-terminus of HP to construct the PETase mutant (HLCB) for increased PET degradation. Furthermore, to effectively improve PET accessibility and PET-degrading activity, the truncated outer membrane hybrid protein (FadL) was used to expose PETase and BaCBM on the surface of E. coli (BL21with) to develop regenerable whole-cell biocatalysts (D-HLCB). Results showed that, among the tested small-molecular weight ester compounds (p-nitrophenyl phosphate (pNPP), p-Nitrophenyl acetate (pNPA), 4-Nitrophenyl butyrate (pNPB)), PETase displayed the highest hydrolysing activity against pNPP. HP displayed the highest catalytic activity (1.94 μM(p-NP)/min) at 50 °C and increased longevity at 40 °C. The fused BaCBM could clearly improve the catalytic performance of PETase by increasing the optimal reaction temperature and improving the thermostability. When HLCB was used for PET degradation, the yield of monomeric products (255.7 μM) was ∼25.5 % greater than that obtained after 50 h of HP-catalysed PET degradation. Moreover, the highest yield of monomeric products from the D-HLCB-mediated system reached 1.03 mM. The whole-cell catalyst D-HLCB displayed good reusability and stability and could maintain more than 54.6 % of its initial activity for nine cycles. Finally, molecular docking simulations were utilized to investigate the binding mechanism and the reaction mechanism of HLCB, which may provide theoretical evidence to further increase the PET-degrading activities of PETases through rational design. The proposed strategy and developed variants show potential for achieving complete biodegradation of PET under mild conditions.

Establishment and evaluation of a new fluorescent probe method based on loop-mediated isothermal amplification for the detection of Mycobacterium tuberculosis complex.

We aimed to develop a novel diagnostic method called multiplex fluorescence of loop primer upon self-dequenching loop-mediated isothermal amplification (mFLOS-LAMP) for the rapid detection of Mycobacterium tuberculosis complex (MTBC). A set of specific primers was designed to target the detection of IS1081 and IS6110 genes, which are insertion sequences within the MTBC. The 110 sputum specimens collected were assessed using the established mFLOS-LAMP method, multiplex polymerase chain reaction, Xpert MTB/RIF, and smear microscopy. The optimal reaction temperature and duration for mFLOS-LAMP were determined to be 65°C and 30 min, respectively, by optimizing the entire system. The detection sensitivity of mFLOS-LAMP was 6.0 × 101 CFU/mL, by Bacillus Calmette-Guerin, and the mFLOS-LAMP sensitivity of M. tuberculosis H37Rv genomic DNA was 500 fg, and the specificity was 100%. The sensitivity of mFLOS-LAMP was 94.2% and the specificity was 96.6%, when Xpert MTB/RIF was used as the reference method. There was no statistically significant difference in their detection rate (χ2 = 0, P = 1.000), and the consistency was good (kappa = 0.909, P < 0.001). The receiver operating characteristic analysis yielded the maximum area under the curve of 0.954. The mFLOS-LAMP method demonstrated high sensitivity and specificity, allowing for swift and accurate detection of MTBC.

Non-oxidative ethane dehydrogenation reaction over molybdenum and chromium incorporated MgO encapsulated carbon-core catalysts in microwave reactor

Chromium and molybdenum incorporated MgO and MgO–C catalysts were synthesized for hydrogen production from a non-oxidative ethane dehydration reaction. Hydrogen production studies were carried out using a microwave-heated reactor system. The study investigated the effects of reaction temperature, type of active metal, and catalyst preparation method (physical mixture or core–shell structure) on hydrogen selectivity and ethane conversion during dehydrogenation reactions. The results showed that the optimal reaction temperature for the non-oxidative ethane dehydration reaction was 450 °C. Above this temperature, the selectivity of undesired byproducts increased. Catalysts containing molybdenum exhibited higher ethane conversion. Moreover, a comparison of MgO–C-supported catalysts with MgO-supported catalysts revealed that the core–shell catalysts exhibited superior ethane conversion. Notably, the 5Mo@MgO–C catalyst demonstrated exceptional catalytic activity, achieving a high ethane conversion rate of 72% along with excellent stability.

Stepwise Understanding on Hydrolysis Formation of the IrOx Nanoparticles as Highly Active Electrocatalyst for Oxygen Evolution Reaction

In this study, we have investigated the synthesis of supported iridium oxide (IrOx) nanoparticles (NPs) through hydrolysis in a surfactant-free aqueous bath as a possible route for the large-scale production of highly active electrocatalyst for oxygen evolution reaction (OER) in acidic water electrolyzers. The process involves (i) formation of Ir-hydroxides complex from an Ir precursor in basic media followed by (ii) protonation in acidic media to form colloidal hydrated IrOx NPs and (iii) conversion and deposition of IrOx NPs on the surface of carbon or TiN support by probe sonication. The IrOx NPs produced through hydrolysis route form highly stable colloidal solution. Since it is essential to precipitate the catalyst NPs from the colloidal solution for their use in water electrolyzer electrode development, here, we investigate the optimal reaction conditions, e.g., pH, temperature, time, and presence of support, for efficient synthesis of the catalyst NPs. The reaction intermediates formed at different reaction steps are explored to get insights into the chemistry of the process. Under the optimal synthesis conditions, 100% precipitation of IrOx NPs was achieved. Further, the precipitated TiN supported IrOx NPs exhibited high OER activity, superior to that of the commercial benchmark IrO2 electrocatalyst. The study provides a scalable synthesis route for highly active, low Ir-content OER electrocatalysts for acidic water electrolyzers. Graphical

Thermodynamic simulation of hydrogen production from the nano-CaO reactive sorption enhanced biomass steam reforming

Based on the principles of thermodynamic reaction equilibrium, a simulation method enhanced by the nano-CaO reactive sorption CO2 for hydrogen production from biomass steam reforming has been established. MATLAB R2022b software has been utilized to calculate the composition concentration of the product gas. Detailed simulations have been conducted to understand the changes in gas component concentration and yield under various reaction conditions, includes temperatures, steam to biomass (S/B) molar ratios, and CaO to carbon (CaO/C) molar ratios. The result demonstrated that temperature plays a significant role in both the concentration and yield of hydrogen. At an optimal reaction temperature of 650 °C, the concentration of H2 in the product reaches 77% (S/B = 2 and CaO/C = 0.5). S/B molar ratio over 2 is necessary to increase the H2 concentration. The study also reveals CaO/C molar ratio 0.5 enable successful removal of CO2 generated by reaction. The application of nano-CaO notably enhanced the efficiency of hydrogen production from biomass steam reforming, leading to a 25% increase in H2 concentration and a boost in H2 yield to 50 mL/gBiomass, and reaction temperature decrease 200 °C compared to the case without CaO.

Establishment of a reverse transcription-recombinase polymerase amplification-lateral flow dipstick method for the dual detection of Israeli acute paralysis virus and chronic bee paralysis virus.

As an important social insect, honey bees play crucial roles in agricultural production, sustainable development of agricultural production, and the balance of the natural environment. However, in recent years, Israeli acute paralysis virus (IAPV) and chronic bee paralysis virus (CBPV), the main pathogens of bee paralysis, have continuously harmed bee colonies and caused certain losses to the beekeeping industry. Some beekeeping farms are located in wild or remote mountainous areas, and samples from these farms cannot be sent to the laboratory for testing in a timely manner, thereby limiting the accurate and rapid diagnosis of the disease. In this study, we used a reverse transcription-recombinase polymerase amplification-lateral flow dipstick (RT-RPA-LFD) method for the dual detection of IAPV and CBPV. RPA primers and LFD detection probes were designed separately for their conserved genes. Primers and probes were screened, and the forward and reverse primer ratios, reaction times, and temperatures were optimized. According to the results of the optimization tests, the optimal reaction temperature for RT-RPA is 37°C, and when combined with LFD, detection with the naked eye requires <20 min. The developed RPA-LFD method specifically targets IAPV and CBPV and has no cross-reactivity with other common bee viruses. In addition, the minimum detection limit of the RT-RPA-LFD method is 101 copies/μL. Based this study, this method is suitable for the detection of clinical samples and can be used for field detection of IAPV and CBPV.

Activities of cell‐wall‐degrading enzymes produced by Pestalotiopsis guepinii

AbstractPestalotiopsis guepinii is a pathogenic fungus that causes grey blight on Camellia pitardii. In this study, we investigated the enzyme activity and kinetics of these cell‐wall‐degrading enzymes (CWDEs) produced by Pestalotiopsis guepinii in both C. pitardii leaves and culture medium. Our enzyme activity experiments revealed that the activities of xylanase, pectin methyl‐galacturonase (PMG), β‐1,4‐endoglucanase (Cx), and β‐glucosidase were high in both C. pitardii leaves and culture medium. These enzymes played a significant role in the pathogenic process. However, the activity of laccase was found to be very low and had a minor impact on the pathogenic process. Furthermore, our enzyme dynamics experiments demonstrated that the optimal reaction temperature for PMG and Cx was 50°C, while for β‐glucosidase and xylanase, it was 60°C. The optimal reaction pH for Cx, β‐glucosidase, and xylanase was 5.0, whereas for PMG, it ranged from 5.0 to 6.0. This indicates that these four enzymes prefer acidic conditions. Moreover, we observed that the activities of Cx, PMG, and xylanase decreased with increasing reaction time. On the other hand, the activity of β‐glucosidase initially increased sharply and then decreased slowly. The maximum reaction rates of the four cell‐wall‐degrading enzymes were ranked as follows: xylanase &gt; PMG &gt; β‐glucosidase &gt; Cx. Additionally, the affinities of these enzymes with substrates were ranked as follows: PMG &lt; Cx &lt; xylanase &lt; β‐glucosidase.

Characterization and Hydrolysis Mechanism Analysis of a Cold-Adapted Trypsin-Like Protease from Antarctic Krill.

Cold-adapted proteases are capable of efficient protein hydrolysis at reduced temperatures, which offer significant potential applications in the area of low temperature food processing. In this paper, we attempted to characterize cold-adapted proteases from Antarctic krill. Antarctic krill possesses an extremely active autolytic enzyme system in their bodies, and the production of peptides and free amino acids accompanies the rapid breakdown of muscle proteins following the death. The crucial role of trypsin in this process is recognized. A cold-adapted trypsin named OUC-Pp-20 from Antarctic krill genome was cloned and expressed in Pichia pastoris. Recombinant trypsin is a monomeric protein of 26.8 ± 1.0 kDa with optimum reaction temperature at 25 °C. In addition, the catalytic specificity of OUC-Pp-20 was assessed by identifying its hydrolysis sites through LC-MS/MS. OUC-Pp-20 appeared to prefer Gln and Asn at the P1 position, which is an amino acid with an amide group in its side chain. Hydrolysis reactions on milk and shrimp meat revealed that it can effectively degrade allergenic components in milk and arginine kinase in shrimp meat. These findings update the current knowledge of cold-adapted trypsin and demonstrate the potential application of OUC-Pp-20 in low temperature food processing.