Recovery Of Activity Research Articles

The effect of transcranial magnetic stimulation on cognitive function in post-stroke patients: a systematic review and meta-analysis

Background and ObjectiveTranscranial magnetic stimulation (TMS) is considered as a promising treatment option for post-stroke cognitive impairment (PSCI).Some meta-analyses have indicated that TMS can be effective in treating cognitive decline in stroke patients, but the quality of the studies included and the methodologies employed were less than satisfactory. Thus, this meta-analysis aimed to evaluate the efficacy and safety of TMS for treating post-stroke cognitive impairment.MethodsWe searched online databases like PubMed, Embase, Cochrane Library, and Web of Science to retrieve randomized controlled trials (RCTs) of TMS for the treatment of patients with PSCI. Two independent reviewers identified relevant literature, extracted purpose-specific data, and the Cochrane Risk of Bias Assessment Scale was utilized to assess the potential for bias in the literature included in this study. Stata 17.0 software was used for data analysis.ResultsA total of 10 studies involving 414 patients were included. The results of the meta-analysis showed that TMS was significantly superior to the control group for improving the overall cognitive function of stroke patients (SMD = 1.17, 95% CI [0.59, 1.75], I2 = 86.1%, P < 0.001). Subgroup analyses revealed that high-frequency rTMS (HF-rTMS), low-frequency rTMS (LF-rTMS), and intermittent theta burst stimulation (iTBS) all have a beneficial effect on the overall cognitive function of stroke patients. However, another subgroup analysis failed to demonstrate any significant advantage of TMS over the control group in terms of enhancing scores on the Loewenstein Occupational Therapy Cognitive Assessment (LOTCA) and Rivermead Behavioral Memory Test (RBMT) scales. Nonetheless, TMS demonstrated the potential to enhance the recovery of activities of daily living in stroke patients, as indicated by the Modified Barthel Index (MBI) (SMD = 0.76; 95% CI [0.22, 1.30], I2 = 52.6%, P = 0.121).ConclusionThis meta-analysis presents evidence supporting the safety and efficacy of TMS as a non-invasive neural modulation tool for improving global cognitive abilities and activities of daily living in stroke patients. However, given the limited number of included studies, further validation of these findings is warranted through large-scale, multi-center, double-blind, high-quality randomized controlled trials.PROSPERO registration numberCRD42022381034.

A critically prolonged avalanche burial with recorded cardiac electrical activity and complete recovery - a case report

The probability of survival in avalanche accidents is time-dependent. Critically buried victims who undergo a long burial duration (over 60 min) face a possible mortality rate of over 80%. Understanding the physiological response during critical avalanche burial is crucial for improving rescue strategies and outcomes. We present the case of a 55-year-old male skier buried under an avalanche for 4 h and 51 min in the Italian Alps. Continuous heart rate monitoring revealed distinct phases of cardiac activity during burial. Despite severe hypothermia, the victim survived without extracorporeal rewarming. This case highlights the importance of continuous monitoring and appropriate on-site management in avalanche accidents. Factors such as the presence of an air pocket may positively influence survival. This case underscores the importance of comprehensive resuscitative measures and guidelines for managing avalanche victims with prolonged burial durations.

Venous thrombosis and embolism in surgical hospital patients in the conditions of the COVID-19 pandemic

Background. Venous thrombosis and embolism are one of the main and most threatening complications in emergency abdominal surgery in the conditions of global pandemic caused by the SARS-CoV-2, which is constantly worsening the morbidity and mortality rates. Despite the accumulation of sufficient knowledge on the problem of venous thromboembolism in general, understanding the unique prothrombotic pathophysiology of the virus and its potentiation of the coagulation system in patients with COVID-19 remains at a suboptimal level. The purpose of the study is to assess the extent of venous thrombosis in patients undergoing emergency surgery for abdominal pathology with concomitant coronavirus disease and to determine the main measures to improve the effectiveness of prevention and treatment. Materials and methods. The results of the treatment of 3,476 patients in the Surgical center 1 of the CNPE of the Lviv Territorial Medical Union “Multidisciplinary Clinical Hospital of Intensive Treatment Methods and Emergency Medical Care” from April 2021 to March 2022 were analyzed, 89.3 % of them were hospitalized urgently. One hundred and fifty-nine (4.6 %) patients died, mainly from purulent-septic complications, multi-organ (primarily severe respiratory) failure and venous thrombosis and embolism. Results. Non-specific prevention of venous thrombosis and embolism was carried out in all patients. It consisted in elastic compression of the legs before transporting the patient to the operating room and early ambulation after surgery. Adequate analgesia and assistance from medical staff were considered an important component of motor activity recovery. Specific prevention of venous thrombosis was carried out by subcutaneous injection of low-molecular-weight heparins once or twice a day. With the beginning of the pandemic and a sharp rise of thromboembolic complications, a longer prophylaxis with increased dose and frequency of anticoagulant administration began to be used in clinical practice. Conclusions. Unresolved issues that stood in the way of optimizing the prevention of venous thrombosis and embolism in the clinic are the new challenges associated with the COVID-19 pandemic, insufficient alertness of doctors to the problem of thromboembolic complications, difficulties in objective assessment of the risk of deep vein thrombosis in the presence of many factors, absence of scales for evaluating the risk of venous thrombosis adapted to today’s conditions.

Varied immune responses of HBV-specific B cells in patients undergoing pegylated interferon-alpha treatment for chronic hepatitis B

The changes in HBV-specific B cells in patients with chronic hepatitis B (CHB) undergoing pegylated interferon-α (PEG-IFNα) treatment and achieving functional cure remain unclear. We aimed to evaluate the alterations in HBV-specific B cells during treatment and therefore explored the mechanism of functional recovery of HBsAg-specific B cells. We included 39 nucleos(t)ide analogue-treated patients with CHB who received sequential combination therapy with PEG-IFNα and eight treatment-naïve patients. HBV-specific B cells were characterized exvivo using fluorescently labeled hepatitis B surface and core antigens (HBsAg and HBcAg). The frequency, phenotype, and subsets of HBV-specific B cells and follicular helper T cells (Tfh cells) were detected using flow cytometry. The functionality of HBV-specific B cells was quantified through ELISpot assays. During treatment, the fraction of activated memory B cells (MBCs) among HBsAg-specific B cells and the expression of IgG, CXCR3, and CD38 increased. The antibody-secretion capacity of HBsAg-specific B cells was only restored in patients achieving a functional cure after treatment and it positively correlated with serum hepatitis B surface antibody levels. The phenotype and function of HBsAg-specific B cells differed between patients with and without functional cure. Patients with functional cure exhibited IgG+ classical MBCs and plasmablasts among HBsAg-specific B cells. HBcAg-specific B cells displayed both attenuated antibody secretion with reduced IgG expression and an IgM+ atypical type of MBC after treatment, irrespective of functional cure. The number of CD40L+ Tfh cells increased after PEG-IFNα treatment and positively correlated with HBsAg-specific B-cell activation. After PEG-IFNα treatment, HBsAg- and HBcAg-specific B cells exhibit various changes in antibody secretion. Their functional differences are reflected in the alterations in phenotypes and subtypes. The presence of CD40L+ Tfh cells is associated with the active recovery of HBsAg-specific B cells. HBV-related complications and hepatocellular carcinoma remain the leading causes of mortality from chronic liver disease worldwide, and a cure is rarely achieved with antiviral therapies. Elucidating the immunological mechanisms underlying the functional cure of patients with chronic hepatitis B offers a promising therapeutic strategy for viral clearance, e.g. via therapeutic vaccination. We analyzed the alterations in HBV-specific B cells in patients treated with pegylated interferon-α and identified novel pathways for immunotherapeutic boosting of B cell immunity.

The Effects of Service Recovery Actions on Customers' Post‐Recovery Responses to Online Travel Agencies (OTAs): The Moderating Role of Price

ABSTRACTThe main purpose of this study is to investigate the impacts of service recovery actions on customers' post‐recovery responses to initial service failure and a double deviation and to investigate the moderating effect of price on the relationship between recovery actions and these responses. The findings show that active recovery actions led to more favorable post‐recovery responses than passive actions in both initial and double deviation situations. No moderating effect of price was found between recovery actions and customers' post‐recovery responses. From an academic perspective, this study helps researchers understand how customers positively perceive recovery actions that reflect procedural and interactional justice in service failure situations. The findings also suggest that practitioners of OTAs should engage in active recovery actions that include prompt communication on the progress of the incident (i.e., procedural justice) and a sincere apology (interactional justice) to alleviate customers' negative responses due to service failures.

The Effects of High-Intensity Interval Training (HIIT) on Ovarian Function and Fertility Potential in Women

Background: High-Intensity Interval Training (HIIT) has recently been recognized as one of the regimens encompassing various benefits for maintaining health across diverse populations. It is based on intense exercise with brief periods of rest or low-intensity activity, offering a time-efficient approach that appeals to individuals seeking maximal benefits with minimal time commitment. Methodology: Women aged 18-40 years with regular menstrual cycles and sedentary or moderately active lifestyles attending outpatient physiotherapy clinics in Lahore were divided into HIIT groups which engaged in supervised sessions for 4 days/week for 12 weeks, performed alternating periods of high-intensity exercise on a stationary bike for 1 minute with periods of active recovery for 30 seconds at 80-90% THR. Participants in the control group performed supervised aerobic exercise sessions 5 days/week for 12 weeks and performed moderate-intensity continuous exercises on a stationary cycle at 70-75% THR for 30 minutes. The hormonal markers and the regularity of menstruation were assessed at baseline and post-intervention. Results: Within-group analysis showed a notable increment in the level of estradiol and progesterone in both groups (p&lt;0.05). Between-group analysis also exposed the HIIT group as being superior to the aerobic. (p&lt;0.001). Conclusion: The findings of the study demonstrated the effectiveness of HIIT and aerobic exercise in impacting the hormonal markers and the regularity of menstruation among obese women. Although, the HIIT showed greater efficacy in improvising estradiol and progesterone levels and reducing menstrual cycle length. Keywords: Aerobic Exercise, Fertility, Interval Training, Obesity.

Untangling the relationship between power outage and population activity recovery in disasters

Despite recognition of the relationship between infrastructure resilience and community recovery, very limited empirical evidence exists regarding the extent to which the disruptions in and restoration of infrastructure services contribute to the speed of community recovery. To address this gap, this study investigates the relationship between community and infrastructure systems in the context of hurricane impacts, focusing on the recovery dynamics of population activity and power infrastructure restoration. Empirical observational data were utilized to analyze the extent of impact, recovery duration, and recovery types of both systems in the aftermath of Hurricane Ida. The study reveals three key findings. First, power outage duration positively correlates with outage extent until a certain impact threshold is reached. Beyond this threshold, restoration time remains relatively stable regardless of outage magnitude. This finding underscores the need to strengthen power infrastructure, particularly in extreme weather conditions, to minimize outage restoration time. Second, power was fully restored in 70% of affected areas before population activity levels normalized. This finding suggests the role infrastructure functionality plays in post-disaster community recovery. Quicker power restoration did not equate to rapid population activity recovery due to other possible factors such as transportation, housing damage, and business interruptions. Finally, if power outages last beyond two weeks, community activity resumes before complete power restoration, indicating adaptability in prolonged outage scenarios. This implies the capacity of communities to adapt to ongoing power outages and continue daily life activities. These findings offer valuable empirical insights into the interaction between human activities and infrastructure systems, such as power outages, during extreme weather events. They also enhance our empirical understanding of how infrastructure resilience influences community recovery. By identifying the critical thresholds for power outage functionality and duration that affect population activity recovery, this study furthers our understanding of how infrastructure performance intertwines with community functioning in extreme weather conditions. Hence, the findings can inform infrastructure operators, emergency managers, and public officials about the significance of resilient infrastructure in life activity recovery of communities when facing extreme weather hazards.

Age and sex effects on histological features and invitro culturing of Antillean manatee (Trichechus manatus manatus, Linnaeus 1758) dermis.

The biobanks from dermal biopsies represent an interesting strategy for biodiversity conservation. Nevertheless, the morphological and cellular patterns of the dermis can be influenced by the age and sex of the individual. Therefore, evaluating these factors is interesting for forming biobanks of Antillean manatees. These animals, representatives of marine fauna, have had their population reduced, and biobanks are essential for their conservation. Then, we evaluated the effects of age (3.5 years vs. 3.6-16 years vs. 23.6 years) and sex (males vs. females) on morphological and cellular parameters using histological and invitro culture techniques. Regardless of age, no differences were observed for dermal thickness, collagen fibres, tissue proliferative activity and viable cell recovery. Nonetheless, fibroblast reduction was observed in groups aged 23.6 years compared to other animals (p < 0.05). Additionally, cells from animals aged 3.6-16 years showed more significant mitochondrial damage than the other groups (p < 0.05). Regardless of sex, no differences were observed for dermal thickness, collagen fibres, tissue proliferative activity and viable cell recovery; however, females had fewer fibroblasts than males (p < 0.05). Cells from females showed lower mitochondrial damage when compared to cells from males. In summary, although age and sex do not influence dermal thickness and cell recovery, variations in the number of fibroblasts and mitochondrial characteristics were observed among the groups. These differences may be significant for understanding the dermis aspects to be correlated to biobank systems.

Maltodextrin-modified hyperoxic graphene oxide as potential matrix for one-step purification and immobilization of MBP-tagged proteins

One-step purification and immobilization directly from crude extracts is a development trend to obtain high purity and performance target proteins due to the simple operation and high efficiency. Maltose binding protein (MBP)-tagged proteins usually need to be purified in biological experiments. It is very necessary to develop a low-cost, environmentally friendly and one-step purification and immobilization matrix. In this study, maltodextrin-modified hyperoxic graphene oxide (MHGO) was prepared using hyperoxic graphene oxide (HGO) and maltodextrin, which was characterized by scanning electron microscopy (SEM), (powder X-ray diffraction) PXRD and Fourier transform infrared spectroscopy (FTIR). MHGO was then used as a one-step purification and immobilization matrix to treat the crude extract and obtain MlrA@MHGO with 84.2 % purity of MlrA. The loading capacity of MHGO for MlrA was 379 ± 26 mg g−1 MHGO. Furthermore, the activity recovery of MlrA using the one-step strategy with MHGO as the matrix was found to be 26.5 times that of the two-step strategy. The Kcat value of MlrA@MHGO was 1.84 times that of free MlrA. Compared with free MlrA, MlrA@MHGO demonstrated enhanced stability, including half-life, thermal stability and pH stability, which were significantly improved than free MlrA. Based on these findings, we proposed a new paradigm for the purification and immobilization of MlrA using MHGO can be an effective matrix for the one-step purification and immobilization of MBP-tagged proteases.

Perceptions and use of recovery strategies in water polo players and coaches: a worldwide survey

The objective of this study was to assess the perceived usefulness, actual use and limitations for the application of recovery strategies among water polo (WP) players and their coaches around the world. A total of 231 WP players and 76 coaches representing all continents, both genders and all levels of competition, completed a freely accessible online survey. This was divided into three sections: sociodemographic data (8 questions), importance of perceived usefulness of recovery strategies (3 questions), and actual use of recovery methods (6 questions). The majority of players and coaches considered recovery strategies as very important (52.4% and 59.2%, respectively) and posttraining session (28.1% and 26.5%) were the most frequently used times. The most selected reasons to justify their use were to reduce the injury risk (30.4% and 26.9%) and the most limitation to the use of recovery strategies were that they are too time-consuming (34.9% and 29%). In the case of the players, stretching were the strategies perceived as most useful and used (12.7% and 18.1%); and in the case of the coaches, it was active recovery (11.2% and 15%). The present study suggests a degree of discrepancy between the scientific literature and the research participants’ perceptions and usages of recovery methods. This information may be of interest for coaches and technical staff of WP teams to look for appropriate recovery strategies for the improvement of their players’ performance.

Propane dehydrogenation performance of titanosilicate-1 supported CoOx catalysts by adjusting the acidity and reducibility

The development of low-cost and toxicity-free cobalt oxide-based catalysts for propane dehydrogenation to propylene (PDH) has gained momentum. In this paper, titanosilicate-1 (TS-1) supported CoOx catalysts doped with different alkali and alkaline earth metal ions (M = Na, K, Mg, Ca and Ba) were prepared by adjusting the acidity, reducibility and oxidation state to increase the activity and stability during the PDH reaction. It was found that the decrease in the number of Lewis acid sites and lack of Co2+Ox species with the addition of K ions led to an almost complete loss of the activity of the Co-K catalyst. However, Co-Ca catalyst exhibited moderate acidity, more Lewis acid sites, a larger amount of the in-situ formed highly-dispersed metallic Co0 nanoparticles (∼5 nm) and Co2+Ox species strongly interacting with the support, all of which were responsible for its highest space-time yield (STY) of propylene formation (0.88 kg h−1 kgcat.−1). Though Co3O4 particles were more active for the side reactions, they could be readily reduced to metallic Co0 nanoparticles during the PDH process, and increased the selectivity to propylene with time on stream. Specifically, it was demonstrated that the highly-dispersed metallic Co0 nanoparticles were also active for the PDH activity, but was lower than Co2+Ox species that were strongly interacted with TS-1 support. The deposited coke on the catalysts was related to the catalyst deactivation. The Co0 species could not completely return to the oxidation states after burning off the deposited coke, which seemed to be related to the incomplete recovery of catalytic activity after regeneration.

Comparative analysis of five-year outcomes of anterior cruciate ligament tears repaired with different techniques

Introduction Primary repair of the anterior cruciate ligament (ACL) torn from the femur and the synovial membrane being intact can be an indication for two competing methods including dynamic intraligamentary stabilization (DIS) as the saving method and resection of the stump and primary autoplasty as a more traumatic option.The purpose was to evaluate the five-year results of DIS in comparison with early ACL reconstruction of the knee joint.Material and methods A review and statistical analysis of outcomes of 72 patients with ACL injuries (47 males and 25 females) were performed. The patients aged between 18 and 45 years (30.9 ± 8.5), with the length of time from injury ranging from 3 to 21 days (10.6 ± 5.0) and the Tegner activity score of 5 (1–9; 5.8 ± 0.9) prior to injury. DIS was performed for the first group of patients (n = 39) who arthroscopically were diagnosed with ACL torn off the femur with the synovial membrane preserved. Early ACL repair was performed for the controls (second group, n = 33).Results VAS scored 1.4 ± 0.8 in group I and 1.9 ± 0.8 in group II at 6 months, p = 0.004. Patient satisfaction scored 8.0 ± 0.8 in group I and 7.4 ± 0.8 in group II at 12 months, p = 0.003. Tegner activity level scored 6.5 ± 0.9 in group I and 6.3 ± 0.8 in group II at 12 months, p = 0.014. The Lysholm knee score measured 91.1 ± 2.2 in group I and 88.6 ± 3.5 in group II at 12 months, p = 0.001. Five-year dynamic observation showed relapses of anterior-medial instability of the knee joint in 10 patients (13.9 %), with 4 patients in group I (10.3 %) and 6 patients in group II (18.2 %).Discussion Outcomes of proximal ACL tears with intact synovium can be as good as with ACL repair. Removal of the torn cruciate ligament with the synovium being intact and grafting may be an unnecessary and aggressive approach.Conclusion Dynamic intraligamentous stabilization as compared to early ACL repair shows a faster recovery of physical activity at a short term and less relapses of knee joint instability at a long term.

Chronic effects of commercial pesticide preparations on biomarkers and reproductive success in earthworm Eisenia andrei

Chemical pollution resulting from pesticide usage has been a continuous issue since the 1960s, despite comprehensive European Union legislation designed to safeguard human health and the environment from the adverse effects of pesticides. While regulatory risk assessments primarily focus on the active ingredients, recent research indicates ecotoxicological impacts of commercial preparations on non-target organisms, particularly within the soil ecosystem where key species such as earthworms play a vital role in maintaining soil quality and fertility. Therefore, the aim of this study was the assessment of the long-term effects of the following respective commercial preparations: the insecticides Sumialfa (esfenvalerate) and Calypso (thiacloprid), as well as the herbicides Frontier (dimethenamid-p) and Filon (prosulfocarb) on the earthworm Eisenia andrei in standardized soil during long-term exposures of 7, 14, and 28 days. To study the possible effects on different levels of biological organization, enzymatic biomarkers: acetylcholinesterase (AChE), carboxylesterase (CES) glutathione S-transferase (GST), glutathione reductase (GR), glutathione peroxidase (GPx); non-enzymatic biomarkers: multixenobiotic resistance activity (MXR), levels of glutathione (GSH), and reactive oxygen species (ROS) as well as reproductive success were investigated. While Calypso appeared to be the least toxic substance, all pesticides showed significant effect on multiobiomarker response in E. fetida. That being said, the response of MXR activity was significantly altered by all tested pesticides indicating MXR being the most sensitive endpoint of the present research. Recovery of MXR was observed after 28 days, however, only in case of exposure to Filon, while the recovery of CAT activity was recorded after 28 days as well, subsequent to Sumialfa exposure. Reproductive success was negatively impacted regarding the Frontier and Sumialfa exposure at the highest concentration (100 mg/kg) reflected in reduced number of cocoons, while only the exposure to Frontier (100 mg/kg) reduced the number of juveniles. Based on the results, it is important to include commercial pesticide formulations in pesticide risk assessments. The toxicity classifications of the studied pesticides suggest the potential detrimental consequences to the key soil species in terrestrial ecosystems at various concentrations. Future studies should include other soil species as well as investigation of higher levels of biological organization, i.e., behavioral endpoints, to determine the potential risks to terrestrial ecosystems.

Purification and characterization of recombinant human superoxide dismutase integrated with resilin-like polypeptide

Human superoxide dismutase (hSOD1) plays an important role in the aerobic metabolism and free radical eliminating process in the body. However, the production of existing SOD faces problems such as complex purification methods, high costs, and poor product stability. This experiment achieved low-cost, rapid, and simple purification of hSOD1 through ammonium sulfate precipitation method and heat resistance of recombinant protein. We constructed a recombinant protein hSOD1-LR containing a resilin-like polypeptide tag and expressed it. The interest protein was purified by ammonium sulfate precipitation method, and the results showed that the purification effect of 1.5 M (NH4)2SO4 was the best, with an enzyme activity recovery rate of 80 % after purification. Then, based on its thermal stability, further purification of the interest protein at 60 °C revealed a purification fold of up to 24 folds, and the purification effect was similar to that of hSOD1-6xHis purified by nickel column affinity chromatography. The stability of hSOD1-LR showed that the recombinant protein hSOD1-LR has better stability than hSOD-6xHis. hSOD1-LR can maintain 76.57 % activity even after 150 min of reaction at 70 °C. At same time, hSOD1-LR had activity close to 80 % at pH < 5, indicating good acid resistance. In addition, after 28 days of storage at 4 °C and 40 °C, hSOD1-LR retained 92 % and 87 % activity, respectively. Therefore, the method of purifying hSOD1-LR through salt precipitation may have positive implications for the study of SOD purification.

Improvement of combined cross-linked enzyme aggregates of cyclodextrin glucanotransferase and maltogenic amylase by functionalization of cross-linker for maltooligosaccharides synthesis

Combined cross-linked enzyme aggregates of cyclodextrin glucanotransferase (CGTase) and maltogenic amylase (Mag1) from Bacillus lehensis G1 (Combi-CLEAs-CM) were successfully developed to synthesis maltooligosaccharides (MOS). Yet, the poor cross-linking performance between chitosan (cross-linker) and enzymes resulting low activity recovery and catalytic efficiency. In this study, we proposed the functionalization of cross-linkers with the integration of computational analysis to study the influences of different functional group on cross-linkers in combi-CLEAs development. From in-silico analysis, O-carboxymethyl chitosan (OCMCS) with the highest binding affinity toward both enzymes was chosen and showed alignment with the experimental result, in which OCMCS was synthesized as cross-linker to develop improved activity recovery of Combi-CLEAs-CM-ocmcs (74 %). The thermal stability and deactivation energy (205.86 kJ/mol) of Combi-CLEAs-CM-ocmcs were found to be higher than Combi-CLEAs-CM (192.59 kJ/mol). The introduction of longer side chain of carboxymethyl group led to a more flexible structure of Combi-CLEAs-CM-ocmcs. This alteration significantly reduced the Km value of Combi-CLEAs-CM-ocmcs by about 3.64-fold and resulted in a greater Kcat/Km (3.63-fold higher) as compared to Combi-CLEAs-CM. Moreover, Combi-CLEAs-CM-ocmcs improved the reusability with retained >50 % of activity while Combi-CLEAs-CM only 36.18 % after five cycles. Finally, maximum MOS production (777.46 mg/g) was obtained by Combi-CLEAs-CM-ocmcs after optimization using response surface methodology.

Construction of Immobilized Laccase System Based on ZnO and Degradation of Mesotrione.

Mesotrione (MES) is a new environmental pollutant. Some reports have indicated that microbial enzymes could be utilized for MES degradation. Laccase is a green biocatalyst whose potential use in environmental pollutant detoxification has been considered limited due to its poor stability and reusability. However, these issues may be addressed using enzyme immobilization. In the present study, we sought to optimize conditions for laccase immobilization, to analyze and characterize the characteristics of the immobilized laccase, and to compare its enzymatic properties to those of free laccase. In addition, we studied the ability of laccase to degrade MES, and analyzed the metabolic pathway of MES degradation by immobilized laccase. The results demonstrated that granular zinc oxide material (G-ZnO) was successfully used as the carrier for immobilization. G-ZnO@Lac demonstrated the highest recovery of enzyme activity and exhibited significantly improved stability compared with free laccase. Storage stability was also significantly improved, with the relative enzyme activity of G-ZnO@Lac remaining at about 54% after 28 days of storage (compared with only 12% for free laccase). The optimal conditions for the degradation of MES by G-ZnO@Lac were found to be 10 mg, 6 h, 30 °C, and pH 4; under these conditions, a degradation rate of 73.25% was attained. The findings of this study provide a theoretical reference for the laccase treatment of 4-hy-droxyphenylpyruvate dioxygenase (HPPD)-inhibiting herbicide contamination.

Opting for polyamines with specific structural traits as a strategy to boost performance of enzymatic membrane reactors

Enzymatic membrane reactor (EMR) is a type of continuous-flow bioreactor offering easy separation and reuse of biocatalyst while giving opportunities to improve its performance. However, simultaneous enhancement of activity and stability of enzyme while retaining high membrane permeability poses a challenge for a single reactor. Herein, we propose a new method to optimize EMR system − by employing cationic polyelectrolytes with selected molecular weight, backbone, and amino group type for modification of membrane surface; after we have evaluated the effect of polyamine chemistry and membrane properties on each aspect of EMR performance. Polydopamine (PDA)-assisted co-deposition of polyamines (polyethyleneimine (PEI), PEI-graft-poly(ethylene glycol) (PEI-g-PEG), poly(allylamine hydrochloride) (PAH), and poly(diallyldimethylammonium chloride) (PDADMAC)) was used as the modification method; the membranes were characterized by water permeability, water contact angle (WCA), zeta potential (ZP), FTIR spectra, and SEM/EDX; and EMRs were assessed by biocatalytic activity at various pH, flux, immobilization yield and efficiency (activity recovery), enzyme leakage, pH/storage and thermal stability, and reusability. In this work, EMRs with immobilized alcohol dehydrogenase (ADH) showed activities up to 8.9 mU/cm2, retained up to 86 % of initial activity in three conversion cycles without any reduction in flux, and allowed to increase non-optimal pH activity (pH 10) by up to 81 % and improve storage stability by up to 53 % compared to the free enzyme. We discovered statistically significant (p < 0.01) relationships between: (1) polyamine backbone type (linear vs branched) and membrane permeability; (2) membrane isoelectric point and immobilization yield; and (3) membrane WCA and immobilization efficiency. To our knowledge, this is the first systematic study of the effect of polyelectrolyte chemistry on performance of immobilized enzyme − which showed the method’s strong potential for customizing properties and maximizing the productivity of EMRs.

Insights into Na+/Ca2+ poisoning mechanisms of Zr-modified and unmodified La-Mn perovskite oxide catalysts for NH3-SCR reaction

The presence of alkali metal/alkaline earth metal in fuel gas is one of the important reasons for the deactivation of catalyst for selective catalytic reduction of NOx with NH3 (NH3-SCR). In this work, the Na+/Ca2+ poisoning mechanisms of Zr-modified and unmodified La-Mn perovskite oxides for NH3-SCR reaction were studied. It is found that the deposition of Na+ into LaMnO3 (LM) catalyst has a much larger effect than that of Ca2+, while such a result is opposite for the Na+/Ca2+-deposited La0.8Zr0.2MnO3 (ZLM) catalysts. The deposition of Na+/Ca2+ compounds can block the pores and affect the adsorption and activation of NH3 on the catalysts. After Zr modification, the catalyst with a higher Mn4+ content shows a better redox property and increased acid sites. These acidic sites can trap Na+, thereby delaying the catalyst poisoning and causing a better activity of ZLM catalyst than LM catalyst. The deposition of Ca2+ in the form of CaCO3 on the catalyst surface leads to a serious pore blockage, showing a poor resistance to Ca2+. After regeneration, the pores of the catalyst are dredged, and the active sites originally occupied by Na+/Ca2+ are released, resulting in an recovery of catalyst activity. The recovery of adsorbed oxygen and Mn4+ content is the key factor for returning the SCR activity.

Deactivation of layered MnO2 catalyst during room temperature formaldehyde degradation and its thermal regeneration mechanism

Layered δ-MnO2 prepared by a one-step redox method was shown to be deactivated during oxidation of formaldehyde at room temperature. Recovery of the formaldehyde degradation activity was investigated after thermal regeneration at different temperatures. XRD, SEM, TEM, H2-TPR, XPS, TGA and DRIFTS characterization were used to analyze the physical properties of fresh, deactivated and thermally regenerated catalysts. The results showed that deactivation of catalyst was caused by less oxygen vacancies due to increased Mn4+ content during formaldehyde degradation and formation of formate blocking active sites. Thermal regeneration helped to decompose formate at the catalyst surface, restoring some of the active sites. Interplanar spacing of MnO2 became wider and the number of Mn3+ on exposed crystal faces increased. More oxygen vacancies were formed. The activity of deactivated catalyst was restored. Formaldehyde degradation rate of catalyst regenerated at 200 °C remained above 80 % after 6 h, demonstrating the possibility of waste layered catalyst recycling.

Assessing Functional Recovery of Eupneic Diaphragm Activity Following Unilateral Cervical Spinal Cord Injury in Rats

Assessing Functional Recovery of Eupneic Diaphragm Activity Following Unilateral Cervical Spinal Cord Injury in Rats