Optimizing the intrinsic activity of non-noble metal by precisely tailoring electronic structure offers an appealing way to construct cost-effective catalysts for selective biomass valorization.Herein,we reported a P-...Optimizing the intrinsic activity of non-noble metal by precisely tailoring electronic structure offers an appealing way to construct cost-effective catalysts for selective biomass valorization.Herein,we reported a P-doping bifunctional catalyst(Ni-P/mSiO_(2))that achieved 96.6%yield for the hydrogenation rearrangement of furfural to cyclopentanone at mild conditions(1 MPaH_(2),150°C).The turnover frequency of Ni-P/mSiO_(2)was 411.9 h^(-1),which was 3.2-fold than that of Ni/mSiO_(2)(127.2 h^(-1)).Detailed characterizations and differential charge density calculations revealed that the electron-deficient Niδ+species were generated by the electron transfer from Ni to P,which promoted the ring rearrangement reaction.Density functional theory calculations illustrated that the presence of P atoms endowed furfural tilted adsorb on the Ni surface by the C=O group and facilitated the desorption of cyclopentanone.This work unraveled the connection between the localized electronic structures and the catalytic properties,so as to provide a promising reference for designing advanced catalysts for biomass valorization.展开更多
The liquid phase Beckmann rearrangement of cyclohexanone oxime (CHO) using fuming sulfuric acid as a catalyst is a traditional method for preparing ε-caprolactam (CPL). This process has drawbacks, such as environment...The liquid phase Beckmann rearrangement of cyclohexanone oxime (CHO) using fuming sulfuric acid as a catalyst is a traditional method for preparing ε-caprolactam (CPL). This process has drawbacks, such as environmental pollution, corrosion of equipment, and low added value of by-product ammonium sulfate. This article designed and prepared a green silica gel-supported trifluoromethanesulfonic acid catalyst for the liquid-phase Beckmann rearrangement of CHO to prepare (CPL). The influencing factors of catalyst preparation and the optimal reaction conditions for Beckmann rearrangement were investigated. It was found that the optimal conditions for catalyst preparation were as follows: raw material silica gel:trifluoromethanesulfonic acid = 1:0.2 (mass ratio), room temperature, stirring time of 2.5 hours, and solvent of acetonitrile, silica gel mesh size is 100 - 200. The optimal reaction conditions for Beckmann rearrangement are CHO: catalyst = 1:2 (mass ratio), temperature of 130˚C, solvent of benzonitrile, volume of 30 mL/g CHO, and reaction time of 4 hours. Under the above conditions, the conversion of CHO is 90%, and the selectivity of CPL is 90%.展开更多
Background:Polymethoxylatedflavones(PMFs)are compounds present in citrus peels and other Rutaceae plants,which exhibit diverse biological activities,including robust antitumor and antioxidant effects.However,the mechan...Background:Polymethoxylatedflavones(PMFs)are compounds present in citrus peels and other Rutaceae plants,which exhibit diverse biological activities,including robust antitumor and antioxidant effects.However,the mechanism of PMFs in reversing drug resistance to colon cancer remains unknown.In the present study,we aimed to investigate the potential connection between the aerobic glycolysis-ROS-autophagy signaling axis and the reversal of PTX resistance in colon cancer by PMFs.Methods:MTT Cell viability assay and colony formation assay were used to investigate the effect of PMFs combined with PTX in reversing HCT8/T cell resistance ex vivo;the mRNA and protein levels of the target were detected by SDS-PAGE(sodium dodecyl sulfate-polyacrylamide gel electrophoresis),quantitative real-timefluorescence polymerase chain reaction(qRT-PCR)and Western blot protein immunoblotting(WB);An HCT8/T cell xenograft model was established to investigate the MDR reversal activity of PMFs in vivo;The extracellular acidification rate(ECAR)and the oxygen consumption rate(OCR)were detected to assess the cellular oxygen consumption rate and glycolytic process.Results:HCT8/T cells demonstrated significant resistance to PTX,up-regulating the expression levels of ABCB1 mRNA,P-gp,LC3-I,and LC3-II protein,and increasing intracellular reactive oxygen species(ROS)content.PMFs mainly contain two active ingredients,nobiletin,and tangeretin,which were able to reverse drug resistance in HCT8/T cells in a concentration-dependent manner.PMFs exhibited high tolerance in the HCT8/T nude mouse model while increasing the sensitivity of PTX-resistant cells and suppressing tumor growth significantly.PMFs combined with PTX reduced extracellular acidification rate(ECAR)and oxygen consumption rate(OCR)in HCT8/T cells.Additionally,PMFs reduced intracellular ROS content,down-regulated the expression levels of autophagy-related proteins LC3-I,LC3-II,Beclin1,and ATG7,and significantly reduced the number of autophagosomes in HCT8/T cells.Conclusions:The present study demonstrated that PMFs could potentially reverse PTX resistance in colon cancer by regulating the aerobic glycolysis-ROS-autophagy signaling axis,which indicated that PMFs would be potential potentiators for future chemotherapeutic agents in colon cancer.展开更多
A growing body of studies and systematic reviews show evidence of the beneficial effects of physical exercise on core symptoms of ADHD. Furthermore, studies indicate that physical exercise as an adjuvant can enhance t...A growing body of studies and systematic reviews show evidence of the beneficial effects of physical exercise on core symptoms of ADHD. Furthermore, studies indicate that physical exercise as an adjuvant can enhance the effects of medication in the treatment of ADHD. Aerobic and coordinative exercises improve executive functioning through their effect on neurocognitive domains that are implicated in ADHD. It is postulated that through their specific modus operandi, aerobic exercise, by raising cortical arousal levels, improves impaired alerting functions whereas coordinative exercises improve the regulation of inhibitory control through the involvement of a higher variety of frontal-dependent cognitive processes. The increasing use of routine neurocognitive testing with continuous performance tests (CPT), such as the QbTest, at clinical assessments for ADHD allows for an innovative approach to identify the assessment impairments in alerting function and inhibition control that are related to ADHD and accordingly choose aerobic or coordinative physical exercise in a more targeted fashion.展开更多
BACKGROUND Pulmonary hypertension is a serious complication in the treatment of maintenance hemodialysis patients,which seriously affects the quality of life of patients and threatens their life safety.Prevention,trea...BACKGROUND Pulmonary hypertension is a serious complication in the treatment of maintenance hemodialysis patients,which seriously affects the quality of life of patients and threatens their life safety.Prevention,treatment and improvement of pulmonary hypertension are of great significance to improve the quality of life of patients.AIM To investigate the intervention and control of pedal-powered bicycle in maintaining quality of life and pulmonary hypertension in hemodialysis patients.METHODS 73 patients with maintenance hemadialysis combined with pulmonary arterial hypertension at a hemodialysis center in a certain hospital from May 2021 to May 2022 are selected.Patients are divided into two groups,37 cases in the control group(group C)and 36 cases in the intervention group(group I).Patients are divided into two groups,group C is treated with oral administration of betaglandin sodium combined with routine nursing care.Based on group C,group I conducts power cycling exercises.RESULTS After treatment,group I patients had higher muscle strength,36-Item Short Form Health Survey scores,and Kidney Disease Targets Areas scores;The 6-minute walk distance test index level was higher and the Borg score was lower;The group I had lower systolic blood pressure,greater vital capacity,higher positive emotion,lower systolic pulmonary artery pressure index level,higher arterial partial oxygen pressure level,lower pulmonary vascular resistance index level,and higher blood oxygen saturation level[158.91±11.89 vs 152.56±12.81,1795.01±603.18 vs 1907.20±574.15,24.00(22.00,29.00)vs 24.00(22.00,28.00),P<0.001].CONCLUSION Aerobic exercise combined with Western medicine treatment can effectively improve patients'pulmonary hypertension,alleviate their negative emotions,and enable them to achieve a higher level of quality of life.展开更多
Alzheimer's disease (AD) is an irreversible neurodegenerative disease with a variety of pathogenic factors and complex pathogenesis, so that the disease has a high prevalence and mortality in the world. Although t...Alzheimer's disease (AD) is an irreversible neurodegenerative disease with a variety of pathogenic factors and complex pathogenesis, so that the disease has a high prevalence and mortality in the world. Although the current diagnosis and treatment equipment and drug research and development keep pace with the times, the current medical technology still can not completely cure the disease, so it is of great significance to explore the pathogenesis and treatment target of AD. The disorder of energy metabolism is one of the characteristic changes in the pathological process of AD. Aerobic glycolysis (AEG) is a special metabolic pathway in the brain, which can rapidly consume glucose to produce energy and substrate for neurons, improve synaptic plasticity, neuroinflammation and oxidative damage, and contribute to the recovery of memory and cognitive function. In recent years, many literatures have reported the mechanism of AEG in AD and the intervention of Tradit Chin Med on this mechanism. The purpose of this paper is to summarize the role of AEG in AD and the related research on the regulation and control of AEG in the treatment of AD by Tradit Chin Med, in order to provide reference and ideas for the prevention and treatment of AD with Tradit Chin Med in the future.展开更多
BACKGROUND Flight cadets need to have good physical fitness to cope with the challenges of flying missions.The continuous development of science and technology has led to the constant upgrading of fighter jets and the...BACKGROUND Flight cadets need to have good physical fitness to cope with the challenges of flying missions.The continuous development of science and technology has led to the constant upgrading of fighter jets and the improvement of their performance,which has resulted in new and higher requirements for the physical fitness of flight personnel.The traditional physical training mode,method,and assessment have been used for many years and do not meet current fitness needs.AIM To investigate the impact of a 12-wk comprehensive anti-G fitness training program on the aerobic capacity of aviation cadets and to evaluate its effectiveness.METHODS Fifty-five cadets were randomly assigned to control and experimental groups using a randomized,single-blind design.The control group maintained their existing training regimen,while the experimental group participated in a 12-wk comprehensive training intervention.The training program comprised strength training twice per week,high-intensity interval training three times per week,and supplemental nutritional and psychological support.Maximal oxygen uptake(VO2max),lower limb strength,and hemoglobin levels were measured at baseline,at 6 wk and 12 wk post-intervention.RESULTS Repeated measures analysis of variance revealed significant differences of both VO2max and relative VO2 in both groups across time points(P<0.05).However,no significant time-group interaction was observed(P>0.05).Paired t-tests comparing baseline and 12-wk results showed that VO2max and relative VO2 were significantly higher in the experimental group than the control group(P<0.05).This suggests that the training program effectively enhanced the aerobic capacity of the experimental group.Key indicators of aerobic capacity,bilateral lower limb strength and hemoglobin levels,were also significantly different over time and between groups(P<0.05).No significant differences were noted in heart-rate metrics(P>0.05).CONCLUSION A 12-wk comprehensive anti-G fitness training program significantly improved the aerobic capacity of aviation cadets,thereby enhancing their overall capacity and laying a physiological foundation for enduring high-G flights.展开更多
This study evaluated the bioaugmentation potential of a quinoline-degrading strain Pseudomonas citronellolis LV1 inoculation into activated sludge for treating quinoline wastewater, and results indicated the inoculati...This study evaluated the bioaugmentation potential of a quinoline-degrading strain Pseudomonas citronellolis LV1 inoculation into activated sludge for treating quinoline wastewater, and results indicated the inoculation of LV1 in aerobic continuous MBBR could substantially improve the quinoline removal performance with an improved removal efficiency of 34% averagely when quinoline was used as the sole carbon and nitrogen source. Additionally, efficient removal of quinoline in enhanced MBBR occurred at the influent p H of 7.0–8.0, hydraulic retention time(HRT) of 24–28 h and influent quinoline concentration of 100–700 mg·L^(-1). High-throughput sequencing analysis indicated that bioaugmentation could increase microbial diversity and shape the microbial community structure. Although the inoculant LV1 did not remain its dominance in stage Ⅲ, bioaugmentation indeed induced the formation of effective microbial community, and the indigenous microbes including Flavobacterium, Pseudoxanthomonas,Pseudomonas, Vermamoeba, Dyadobacter and Sphingomonas might play the key role in quinoline removal.According to the PICRUSt, the enhanced genes encoding aromatic ring-cleavage enzyme, especially for Nheterocyclic ring-cleavage enzymes, could lead to the improved removal performance of quinoline in bioaugmentation stage. Moreover, the enhanced MBBR treated well actual coking wastewater, as indicated by high removal performance of quinoline, phenol and COD.展开更多
Hydrogenative rearrangement of biomas s-derived furfurals(furfural and 5-hydroxymethyl furfural) to C_(5) cyclic compounds(such as cyclopentanones and cyclopentanols) offers an expedient reaction route for acquiring O...Hydrogenative rearrangement of biomas s-derived furfurals(furfural and 5-hydroxymethyl furfural) to C_(5) cyclic compounds(such as cyclopentanones and cyclopentanols) offers an expedient reaction route for acquiring O-containing value-added chemicals thereby replacing the traditional petroleum-based approaches.The scope for developing efficient bifunctional catalysts and establishing mild reaction conditions for upgrading furfurals to cyclic compounds has stimulated immense deliberation in recent years.Extensive efforts have been made toward developing catalysts for multiple tandem conversions,including those with various metals and supports.In this scientific review,we aim to summarize the research progress on the synergistic effect of the metal-acid sites,including simple metal-supported acidic supports,adjacent metal acid sites-supported catalysts,and in situ H_(2)-modified bifunctional catalysts.Distinctively,the catalytic performance,catalytic mechanism,and future challenges for the hydrogenative rearrangement are elaborated in detail.The methods highlighted in this review promote the development of C_(5) cyclic compound synthesis and provide insights to regulate bifunctional catalysis for other applications.展开更多
Objective:To investigate the impact of resistance training and aerobic exercise before doula-assisted delivery on the psychological well-being and labor duration of parturients.Methods:105 cases of parturients who gav...Objective:To investigate the impact of resistance training and aerobic exercise before doula-assisted delivery on the psychological well-being and labor duration of parturients.Methods:105 cases of parturients who gave birth in our hospital from February 2021 to April 2023 were included in this study.The patients were divided into a control group of 52 cases and an observation group of 53 cases.The patients in the control group received no particular intervention before delivery and only received doula assistance.The patients in the observation group received resistance training,aerobic exercise,and doula assistance prior to giving birth.After delivery,the mothers were observed for 2 hours in the delivery room and then returned to the maternal and infant ward.The observation indicators of the two groups were compared.Results:In comparison to the control group,the observation group exhibited shorter durations in the first,second,and third stages of labor,as well as the total delivery time.Additionally,the amount of postpartum blood loss at 2 hours was smaller in the observation group.The rate of cesarean section was lower,and the rate of vaginal natural delivery was higher in the observation group.Following the intervention,both groups of postpartum women showed decreased SAS and SDS scores compared to before the intervention.Moreover,the observation group had lower scores than the control group.These differences were all statistically significant(P<0.05).Conclusion:Resistance training and aerobic exercise before doula-assisted delivery can effectively improve the psychological state of parturients,shorten labor duration,increase the rate of natural vaginal delivery,and reduce pain and postpartum hemorrhage.展开更多
Different types of neuroendocrine cancer,including medullary thyroid cancer(MTC)and thyroid C-cell hyperplasia,are part of multiple endocrine neoplasia type 2(MEN2).A proto-oncogene mutation of the rearranged during t...Different types of neuroendocrine cancer,including medullary thyroid cancer(MTC)and thyroid C-cell hyperplasia,are part of multiple endocrine neoplasia type 2(MEN2).A proto-oncogene mutation of the rearranged during transfection(RET)gene changes the way that receptor tyrosine kinases work.Multiple endocrine neoplasia,a pathological condition,involves these kinases.When the RET protooncogene changes,it can cause endocrine adenomas and hyperplasia to happen at the same time or one after the other.Pheochromocytoma,medullary thyroid carcinoma,and hyperparathyroidism,alone or in combination,are present in MEN2A patients.Some patients may also have skin lichen amyloidosis or Hirschsprung's disease.Patients with MEN2A often present with MTC.MTC is aggressive and has the worst prognosis,as most patients exhibit lymph node metastasis.MTC is one of the important causes of death in patients with MEN2A.RET mutation analysis aids in identifying MEN2A symptoms and monitoring levels of calcium,thyroid hormones,calcitonin,normetanephrine,fractionated metanephrines,and parathyroid hormone.The earlier diagnosis of MTC significantly improves survival and prompts better management of MEN2A.In this editorial,we will discuss the significance of molecular diagnostic approaches in detecting RET oncogene mutations in MEN2A.展开更多
[ Objective ] The paper was to screen intestinal aerobic bacteria from 2nd instar larvae of Dendrolimu kikuchii and determine its toxicity. [ Method ] The intestinal samples of 2nd instar larvae of D. kikuchii were di...[ Objective ] The paper was to screen intestinal aerobic bacteria from 2nd instar larvae of Dendrolimu kikuchii and determine its toxicity. [ Method ] The intestinal samples of 2nd instar larvae of D. kikuchii were diluted in gredient and coated on plates to isolate strains, and a total of 5 strains of aerobic bacteria were isolated. With bacterial genomic DNA as template, the universal primers of bacterial 16S rDNA (27f and 1 492r) were used to amplify the template, 4 restriction enzymes Hae Ⅲ and Hind Ⅲ, Hinf Ⅰ and Taq Ⅰ were used to carry out ARDRA polymorphism analysis on PCR products. [ Result] Clustering map analysis showed that 5 strains of aerobic bacteria clustered into two different taxonomic operating units (OTU) in 95% similarity level, this indicated that the genetic diversity level of intestinal aerobic bacteria in 2nd instar larvae of D. kikuchii was relatively low. The indoor toxicity test showed that the death peaks of insects killed by intestinal bacteria were during 4 - 10 d, the insecticidal effect of strain 4 was the best with corrected mortality rate of 53.57% at 12 d. [ Conclusion] The paper provided reference for control of D. kikuchii.展开更多
Alkaline and ultrasonic sludge disintegration can be used as the pretreatment of waste activated sludge (WAS) to promote the subsequent anaerobic or aerobic digestion. In this study, different combinations of these ...Alkaline and ultrasonic sludge disintegration can be used as the pretreatment of waste activated sludge (WAS) to promote the subsequent anaerobic or aerobic digestion. In this study, different combinations of these two methods were investigated. The evaluation was based on the quantity of soluble chemical oxygen demand (SCOD) in the pretreated sludge as well as the degradation of organic matter in the subsequent aerobic digestion. For WAS samples with combined pretreatment, the released COD levels were higher than those with ultrasonic or alkaline pretreatment alone. When combined with the ultrasonic treatment, NaOH treatment was more efficient than Ca(OH)2 for WAS solubilization. The COD levels released in various sequential options of combined NaOH and ultrasonic treatments were in the the following descending order: simultaneous treatment 〉 NaOH treatment followed by ultrasonic treatment 〉 ultrasonic treatment followed by NaOH treatment. For simultaneous treatment, low NaOH dosage (100 g/kg dry solid), short duration (30 min) of NaOH treatment, and low ultrasonic specific energy (7500 kJ/kg dry solid) were suitable for sludge disintegration. Using combined NaOH and ultrasonic pretreatment with optimal parameters, the degradation efficiency of organic matter was increased from 38.0% to 50.7%, which is much higher than that with ultrasonic (42.5%) or with NaOH pretreatment (43.5%) in the subsequent aerobic digestion at the same retention time.展开更多
Bacterium Providencia rettgeri YL was found to exhibit an unusual ability to heterotrophically nitrify and aerobically denitrify various concentrations of ammonium (NH4^+-N). In order to further understand its remo...Bacterium Providencia rettgeri YL was found to exhibit an unusual ability to heterotrophically nitrify and aerobically denitrify various concentrations of ammonium (NH4^+-N). In order to further understand its removal ability, several experiments were conducted to identify the growth and ammonium removal response at different carbon to nitrogen (C/N) mass ratios, shaking speeds, temperatures, ammonium concentrations and to qualitatively verify the production of nitrogen gas using gas chromatography techniques. Results showed that under optimum conditions (C/N 10, 30℃, 120 r/min), YL can significantly remove low and high concentrations of ammonium within 12 to 48 h of growth, respectively. The nitrification products hydroxylamine (NHzOH), nitrite (NO2^-) and nitrate (NO3^-) as well as the denitrification product, nitrogen gas (N2), were detected under completely aerobic conditions.展开更多
Nitrogen loss without organic removal in biofilter was observed and its possible reason was explained. A lower hydraulic loading could improve aerobic denitrification rate. Aerobic denitrification was seriously affect...Nitrogen loss without organic removal in biofilter was observed and its possible reason was explained. A lower hydraulic loading could improve aerobic denitrification rate. Aerobic denitrification was seriously affected by low temperature(below 10℃). However, nitrification rate remained high when the temperature dropped from 15℃ to 5℃. It seemed the autotrophic biofilm in BAF could alleviate the adverse effect of low temperature.展开更多
Aerobic granular sludge was cultivated adopting internal-circulate sequencing batch airlift reactor. The contradistinctive experiment about short-term membrane fouling between aerobic granular sludge system and activa...Aerobic granular sludge was cultivated adopting internal-circulate sequencing batch airlift reactor. The contradistinctive experiment about short-term membrane fouling between aerobic granular sludge system and activated sludge system were investigated. The membrane foulants was also characterized by Fourier transform infrared (FTIR) spectroscopy technique. The results showed that the aerobic granular sludge had excellent denitrification ability; the removal efficiency of TN could reach 90%. The aerobic granular sludge could alleviate membrane fouling effectively. The steady membrane flux of aerobic granular sludge was twice as much as that of activated sludge system. In addition, it was found that the aerobic granular sludge could result in severe membrane pore-blocking, however, the activated sludge could cause severe cake fouling. The major components of the foulants were identified as comprising of proteins and polysaccharide materials.展开更多
Aerobic granular sludge was cultivated in sequencing batch airlift reactors (SBAR) at 25, 30, and 35℃, respectively. The effect of temperature on the granules characteristics was analyzed and the microbial communit...Aerobic granular sludge was cultivated in sequencing batch airlift reactors (SBAR) at 25, 30, and 35℃, respectively. The effect of temperature on the granules characteristics was analyzed and the microbial community structures of the granules were probed using scanning electron microscope (SEM) and polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). The results showed that 30℃ is optimum for matured granule cultivation, where the granules had a more compact structure, better settling ability and higher bioactivity, the oxygen utilization rate (OUR) reached 1.14 mg O2/(g MLVSS.min) with COD removal rate of 97% and TP removal rate of 75%. The removal efficiency of NH3-N increased from 68.5% to 87.5% along with the temperature increment from 25 to 35℃. The DGGE profiles revealed that the microbial community structure at 25℃ showed the least similarity with those at other temperatures. The sequencing results indicated that the majority of dominant microbes belonged to Actinobacteria and Proteobacterium. Thermomonas sp., Ottowia sp. and Curtobacteriurn ammoniigenes might play important roles at different temperatures, respectively.展开更多
Moisture regime plays a crucial role in the mineralization of soil organic carbon (SOC). In this paper, the dynamics of SOC mineralization in typical paddy soils of Changshu, Jiangsu Province, China, was investigate...Moisture regime plays a crucial role in the mineralization of soil organic carbon (SOC). In this paper, the dynamics of SOC mineralization in typical paddy soils of Changshu, Jiangsu Province, China, was investigated by incubation test in laboratory. The differences in SOC mineralization under aerobic and submerged conditions of paddy soils were also studied. Results showed that the daily mineralization of SOC under different moisture regimes was significantly different in the whole incubation period, at the beginning of the incubation, it decreased quickly under aerobic condition, but increased rapidly under submerged condition, and both remained constant after 10 d of incubation. The differences in SOC mineralization were found to be mainly at the beginning period of the incubation and decreased along with the incubation time. Thus, the difference was not significantly different at the later incubation period. The respiration intensity, daily and cumulative mineralization of SOC under aerobic condition was 2.26-19.11, 0.96-2.41, and 0.96-2.41 times than those .under submerged condition, respectively. Statistic analyses showed that the higher the contents of microbial biomass carbon and nitrogen, the more significant difference in respiration intensity between aerobic and submerged conditions, but the higher the contents of microbial biomass nitrogen and dissolved organic carbon, the more significant difference in daily mineralization of SOC between the two conditions. The decrease in soil microbial activity under submerged condition was the main reason leading to the decrease in respiration intensity, but the decrease in SOC mineralization was also correlated with the changes in dissolved organic carbon over the whole incubation period.展开更多
A bench-scale anaerobic/anoxic/aerobic process-biological aerated filter (A^2/O-BAF) combined system was carded out to treat wastewater with lower C/N and C/P ratios. The A^2/O process was operated in a short aerobi...A bench-scale anaerobic/anoxic/aerobic process-biological aerated filter (A^2/O-BAF) combined system was carded out to treat wastewater with lower C/N and C/P ratios. The A^2/O process was operated in a short aerobic sludge retention time (SRT) for organic pollutants and phosphorus removal, and denitrification. The subsequent BAF process was mainly used for nitrification. The BAF effluent was partially returned to anoxic zone of the A^2/O process to provide electron acceptors for denitrification and anoxic P uptake. This unique system formed an environment for reproducing the denitdfying phosphate-accumulating organisms (DPAOs). The ratio of DPAOs to phosphorus accumulating organisms (PAOs) could be maintained at 28% by optimizing the organic loads in the anaerobic zone and the nitrate loads into the anoxic zone in the A^2/O process. The aerobic phosphorus over-uptake and discharge of excess activated sludge was the main mechanism of phosphorus removal in the combined system. The aerobic SRT of the A^2/O process should meet the demands for the development of aerobic PAOs and the restraint on the nitrifiers growth, and the contact time in the aerobic zone of the A^2/O process should be longer than 30 min, which ensured efficient phosphorus removal in the combined system. The adequate BAF effluent return rates should be controlled with 1--4 mg/L nitrate nitrogen in the anoxic zone effluent of A^2/O process to achieve the optimal nitrogen and phosphorus removal efficiencies.展开更多
基金supported by the National Key R&D Program of China(2023YFD1701504)the 2115 Talent Development Program of China Agricultural University Fund(1011-00109018)the Beijing Innovation Team of the Modern Agricultural Research System(BAIC08-2023-FQ02)。
文摘Optimizing the intrinsic activity of non-noble metal by precisely tailoring electronic structure offers an appealing way to construct cost-effective catalysts for selective biomass valorization.Herein,we reported a P-doping bifunctional catalyst(Ni-P/mSiO_(2))that achieved 96.6%yield for the hydrogenation rearrangement of furfural to cyclopentanone at mild conditions(1 MPaH_(2),150°C).The turnover frequency of Ni-P/mSiO_(2)was 411.9 h^(-1),which was 3.2-fold than that of Ni/mSiO_(2)(127.2 h^(-1)).Detailed characterizations and differential charge density calculations revealed that the electron-deficient Niδ+species were generated by the electron transfer from Ni to P,which promoted the ring rearrangement reaction.Density functional theory calculations illustrated that the presence of P atoms endowed furfural tilted adsorb on the Ni surface by the C=O group and facilitated the desorption of cyclopentanone.This work unraveled the connection between the localized electronic structures and the catalytic properties,so as to provide a promising reference for designing advanced catalysts for biomass valorization.
文摘The liquid phase Beckmann rearrangement of cyclohexanone oxime (CHO) using fuming sulfuric acid as a catalyst is a traditional method for preparing ε-caprolactam (CPL). This process has drawbacks, such as environmental pollution, corrosion of equipment, and low added value of by-product ammonium sulfate. This article designed and prepared a green silica gel-supported trifluoromethanesulfonic acid catalyst for the liquid-phase Beckmann rearrangement of CHO to prepare (CPL). The influencing factors of catalyst preparation and the optimal reaction conditions for Beckmann rearrangement were investigated. It was found that the optimal conditions for catalyst preparation were as follows: raw material silica gel:trifluoromethanesulfonic acid = 1:0.2 (mass ratio), room temperature, stirring time of 2.5 hours, and solvent of acetonitrile, silica gel mesh size is 100 - 200. The optimal reaction conditions for Beckmann rearrangement are CHO: catalyst = 1:2 (mass ratio), temperature of 130˚C, solvent of benzonitrile, volume of 30 mL/g CHO, and reaction time of 4 hours. Under the above conditions, the conversion of CHO is 90%, and the selectivity of CPL is 90%.
基金supported by National Natural Science Foundation of China(82104446)Guangdong Basic and Applied Basic Research Foundation(2023A1515011961)+3 种基金Guangdong Province Characteristic Innovation Project of Universities(2022KTSCX100)Guangzhou University(College)-(High Level University/Deng feng Hospital)Basic and Applied Basic Research Project(2023A03J0397)Guangdong Medical Science and Technology Research Foundation(A2023460)Plan on Enhancing Scientific Research in GMU(2024SRP117).
文摘Background:Polymethoxylatedflavones(PMFs)are compounds present in citrus peels and other Rutaceae plants,which exhibit diverse biological activities,including robust antitumor and antioxidant effects.However,the mechanism of PMFs in reversing drug resistance to colon cancer remains unknown.In the present study,we aimed to investigate the potential connection between the aerobic glycolysis-ROS-autophagy signaling axis and the reversal of PTX resistance in colon cancer by PMFs.Methods:MTT Cell viability assay and colony formation assay were used to investigate the effect of PMFs combined with PTX in reversing HCT8/T cell resistance ex vivo;the mRNA and protein levels of the target were detected by SDS-PAGE(sodium dodecyl sulfate-polyacrylamide gel electrophoresis),quantitative real-timefluorescence polymerase chain reaction(qRT-PCR)and Western blot protein immunoblotting(WB);An HCT8/T cell xenograft model was established to investigate the MDR reversal activity of PMFs in vivo;The extracellular acidification rate(ECAR)and the oxygen consumption rate(OCR)were detected to assess the cellular oxygen consumption rate and glycolytic process.Results:HCT8/T cells demonstrated significant resistance to PTX,up-regulating the expression levels of ABCB1 mRNA,P-gp,LC3-I,and LC3-II protein,and increasing intracellular reactive oxygen species(ROS)content.PMFs mainly contain two active ingredients,nobiletin,and tangeretin,which were able to reverse drug resistance in HCT8/T cells in a concentration-dependent manner.PMFs exhibited high tolerance in the HCT8/T nude mouse model while increasing the sensitivity of PTX-resistant cells and suppressing tumor growth significantly.PMFs combined with PTX reduced extracellular acidification rate(ECAR)and oxygen consumption rate(OCR)in HCT8/T cells.Additionally,PMFs reduced intracellular ROS content,down-regulated the expression levels of autophagy-related proteins LC3-I,LC3-II,Beclin1,and ATG7,and significantly reduced the number of autophagosomes in HCT8/T cells.Conclusions:The present study demonstrated that PMFs could potentially reverse PTX resistance in colon cancer by regulating the aerobic glycolysis-ROS-autophagy signaling axis,which indicated that PMFs would be potential potentiators for future chemotherapeutic agents in colon cancer.
文摘A growing body of studies and systematic reviews show evidence of the beneficial effects of physical exercise on core symptoms of ADHD. Furthermore, studies indicate that physical exercise as an adjuvant can enhance the effects of medication in the treatment of ADHD. Aerobic and coordinative exercises improve executive functioning through their effect on neurocognitive domains that are implicated in ADHD. It is postulated that through their specific modus operandi, aerobic exercise, by raising cortical arousal levels, improves impaired alerting functions whereas coordinative exercises improve the regulation of inhibitory control through the involvement of a higher variety of frontal-dependent cognitive processes. The increasing use of routine neurocognitive testing with continuous performance tests (CPT), such as the QbTest, at clinical assessments for ADHD allows for an innovative approach to identify the assessment impairments in alerting function and inhibition control that are related to ADHD and accordingly choose aerobic or coordinative physical exercise in a more targeted fashion.
基金Zhejiang Province Medicine and Health Science and Technology Programme,No.2019RC092 and No.2020KY394the Public Welfare Project of Zhejiang Provincial Department of Science and Technology,No.LGF19H170003.
文摘BACKGROUND Pulmonary hypertension is a serious complication in the treatment of maintenance hemodialysis patients,which seriously affects the quality of life of patients and threatens their life safety.Prevention,treatment and improvement of pulmonary hypertension are of great significance to improve the quality of life of patients.AIM To investigate the intervention and control of pedal-powered bicycle in maintaining quality of life and pulmonary hypertension in hemodialysis patients.METHODS 73 patients with maintenance hemadialysis combined with pulmonary arterial hypertension at a hemodialysis center in a certain hospital from May 2021 to May 2022 are selected.Patients are divided into two groups,37 cases in the control group(group C)and 36 cases in the intervention group(group I).Patients are divided into two groups,group C is treated with oral administration of betaglandin sodium combined with routine nursing care.Based on group C,group I conducts power cycling exercises.RESULTS After treatment,group I patients had higher muscle strength,36-Item Short Form Health Survey scores,and Kidney Disease Targets Areas scores;The 6-minute walk distance test index level was higher and the Borg score was lower;The group I had lower systolic blood pressure,greater vital capacity,higher positive emotion,lower systolic pulmonary artery pressure index level,higher arterial partial oxygen pressure level,lower pulmonary vascular resistance index level,and higher blood oxygen saturation level[158.91±11.89 vs 152.56±12.81,1795.01±603.18 vs 1907.20±574.15,24.00(22.00,29.00)vs 24.00(22.00,28.00),P<0.001].CONCLUSION Aerobic exercise combined with Western medicine treatment can effectively improve patients'pulmonary hypertension,alleviate their negative emotions,and enable them to achieve a higher level of quality of life.
基金National Natural Science Foundation of China Regional Fund(No.82060844)Guangxi Natural Science Foundation General Project(No.2022GXNSFAA035461)+4 种基金Guangxi Clinical Medical Research Center for Tradit Chin Med Encephalopathy(No.Guike AD20238028)Academic Team Construction Project of the First Affiliated Hospital of Guangxi Univ Tradit Chin Med[Hospital Letter(2018)No.146]The 2020 Guangxi Higher Education High level Innovation Team and Outstanding Scholar Program[Guijiao Talent(2020)No.6]Guangxi Univ Tradit Chin Med"Qihuang Project"High level Talent Team Cultivation Project(No.2018003)Guangxi Key Discipline Construction Project of Tradit Chin Med(No.GZXK-Z-20-13)Alzheimer’s disease(AD)is an irreversible neurodegenerative disease.At present,the number of AD cases has exceeded 30 million and continues to rise in the world,especially in developing countries including China.Due to the superposition of factors such as an aging population,social pressure and improper lifestyle,it is speculated that the number of AD cases will double in the next 30 years[1].Although a large amount of money has been invested in the drug development and diagnosis and treatment of AD,the current medical methods can only delay the disease of AD but can not cure it completely.It is undeniable that AD is a recognized health problem and health problem in the current society.Therefore,it is particularly important to further study the molecular mechanism of AD in order to identify the pathogenic factors and therapeutic targets,and to explore effective treatment.Modern medicine believes that its pathological mechanism is complex and interact with each other,includingβ-amyloid(Aβ)toxic damage,abnormal modification of Tau protein,oxidative stress,neuroinflammation,mitochondrial dysfunction and so on[2].In fact,in the process of inevitable aging,the metabolic network is affected by related signal pathways,proteins and genes,which leads to the gradual down-regulation of aerobic glycolysis(AEG),which can directly or indirectly participate in the pathogenesis of the above-mentioned AD and affect its pathological changes.Therefore,taking AEG as the research target can provide a new idea for the prevention and treatment of AD.The name of AD disease is not seen in Tradit Chin Med,and it is Alzheimer's disease(AD)is an irreversible neurodegenerative disease with a variety of pathogenic factors and complex pathogenesis,so that the disease has a high prevalence and mortality in the world.Although the current diagnosis and treatment equipment and drug research and development keep pace with the times,the current medical technology still can not completely cure the disease,so it is of great significance to explore the pathogenesis and treatment target of AD.The disorder of energy metabolism is one of the characteristic changes in the pathological process of AD.Aerobic glycolysis(AEG)is a special metabolic pathway in the brain,which can rapidly consume glucose to produce energy and substrate for neurons,improve synaptic plasticity,neuroinflammation and oxidative damage,and contribute to the recovery of memory and cognitive function.In recent years,many literatures have reported the mechanism of AEG in AD and the intervention of Tradit Chin Med on this mechanism.The purpose of this paper is to summarize the role of AEG in AD and the related research on the regulation and control of AEG in the treatment of AD by Tradit Chin Med,in order to provide reference and ideas for the prevention and treatment of AD with Tradit Chin Med in the future。
文摘Alzheimer's disease (AD) is an irreversible neurodegenerative disease with a variety of pathogenic factors and complex pathogenesis, so that the disease has a high prevalence and mortality in the world. Although the current diagnosis and treatment equipment and drug research and development keep pace with the times, the current medical technology still can not completely cure the disease, so it is of great significance to explore the pathogenesis and treatment target of AD. The disorder of energy metabolism is one of the characteristic changes in the pathological process of AD. Aerobic glycolysis (AEG) is a special metabolic pathway in the brain, which can rapidly consume glucose to produce energy and substrate for neurons, improve synaptic plasticity, neuroinflammation and oxidative damage, and contribute to the recovery of memory and cognitive function. In recent years, many literatures have reported the mechanism of AEG in AD and the intervention of Tradit Chin Med on this mechanism. The purpose of this paper is to summarize the role of AEG in AD and the related research on the regulation and control of AEG in the treatment of AD by Tradit Chin Med, in order to provide reference and ideas for the prevention and treatment of AD with Tradit Chin Med in the future.
基金the Ethics Committee of Beijing Sport University(No.2019113H).
文摘BACKGROUND Flight cadets need to have good physical fitness to cope with the challenges of flying missions.The continuous development of science and technology has led to the constant upgrading of fighter jets and the improvement of their performance,which has resulted in new and higher requirements for the physical fitness of flight personnel.The traditional physical training mode,method,and assessment have been used for many years and do not meet current fitness needs.AIM To investigate the impact of a 12-wk comprehensive anti-G fitness training program on the aerobic capacity of aviation cadets and to evaluate its effectiveness.METHODS Fifty-five cadets were randomly assigned to control and experimental groups using a randomized,single-blind design.The control group maintained their existing training regimen,while the experimental group participated in a 12-wk comprehensive training intervention.The training program comprised strength training twice per week,high-intensity interval training three times per week,and supplemental nutritional and psychological support.Maximal oxygen uptake(VO2max),lower limb strength,and hemoglobin levels were measured at baseline,at 6 wk and 12 wk post-intervention.RESULTS Repeated measures analysis of variance revealed significant differences of both VO2max and relative VO2 in both groups across time points(P<0.05).However,no significant time-group interaction was observed(P>0.05).Paired t-tests comparing baseline and 12-wk results showed that VO2max and relative VO2 were significantly higher in the experimental group than the control group(P<0.05).This suggests that the training program effectively enhanced the aerobic capacity of the experimental group.Key indicators of aerobic capacity,bilateral lower limb strength and hemoglobin levels,were also significantly different over time and between groups(P<0.05).No significant differences were noted in heart-rate metrics(P>0.05).CONCLUSION A 12-wk comprehensive anti-G fitness training program significantly improved the aerobic capacity of aviation cadets,thereby enhancing their overall capacity and laying a physiological foundation for enduring high-G flights.
基金financially supported by the Basic Research Project for Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering (2021SX-AT004)the Shanxi Province Science Foundation for Youths (20210302124348, 202103021223099)the National Natural Science Foundation of China (51778397)。
文摘This study evaluated the bioaugmentation potential of a quinoline-degrading strain Pseudomonas citronellolis LV1 inoculation into activated sludge for treating quinoline wastewater, and results indicated the inoculation of LV1 in aerobic continuous MBBR could substantially improve the quinoline removal performance with an improved removal efficiency of 34% averagely when quinoline was used as the sole carbon and nitrogen source. Additionally, efficient removal of quinoline in enhanced MBBR occurred at the influent p H of 7.0–8.0, hydraulic retention time(HRT) of 24–28 h and influent quinoline concentration of 100–700 mg·L^(-1). High-throughput sequencing analysis indicated that bioaugmentation could increase microbial diversity and shape the microbial community structure. Although the inoculant LV1 did not remain its dominance in stage Ⅲ, bioaugmentation indeed induced the formation of effective microbial community, and the indigenous microbes including Flavobacterium, Pseudoxanthomonas,Pseudomonas, Vermamoeba, Dyadobacter and Sphingomonas might play the key role in quinoline removal.According to the PICRUSt, the enhanced genes encoding aromatic ring-cleavage enzyme, especially for Nheterocyclic ring-cleavage enzymes, could lead to the improved removal performance of quinoline in bioaugmentation stage. Moreover, the enhanced MBBR treated well actual coking wastewater, as indicated by high removal performance of quinoline, phenol and COD.
基金support from the National Natural Science Foundation of China (Nos. 22178158, 52162014 and 22065024)Science and Technology Project of Education Department of Jiangxi Province (No. GJJ2200402)+3 种基金Jiangxi Provincial Natural Science Foundation (No. 20224BAB213023)the Outstanding Youth Science Fund Project of Jiangxi Province (No. 20224ACB213008)the Jiangxi Provincial Double Thousand Talents Plan-Youth Program (No. S2021GDQN0947)Natural Science Foundation of Chongqing (No. 2023NSCQ-MSX0052)
文摘Hydrogenative rearrangement of biomas s-derived furfurals(furfural and 5-hydroxymethyl furfural) to C_(5) cyclic compounds(such as cyclopentanones and cyclopentanols) offers an expedient reaction route for acquiring O-containing value-added chemicals thereby replacing the traditional petroleum-based approaches.The scope for developing efficient bifunctional catalysts and establishing mild reaction conditions for upgrading furfurals to cyclic compounds has stimulated immense deliberation in recent years.Extensive efforts have been made toward developing catalysts for multiple tandem conversions,including those with various metals and supports.In this scientific review,we aim to summarize the research progress on the synergistic effect of the metal-acid sites,including simple metal-supported acidic supports,adjacent metal acid sites-supported catalysts,and in situ H_(2)-modified bifunctional catalysts.Distinctively,the catalytic performance,catalytic mechanism,and future challenges for the hydrogenative rearrangement are elaborated in detail.The methods highlighted in this review promote the development of C_(5) cyclic compound synthesis and provide insights to regulate bifunctional catalysis for other applications.
文摘Objective:To investigate the impact of resistance training and aerobic exercise before doula-assisted delivery on the psychological well-being and labor duration of parturients.Methods:105 cases of parturients who gave birth in our hospital from February 2021 to April 2023 were included in this study.The patients were divided into a control group of 52 cases and an observation group of 53 cases.The patients in the control group received no particular intervention before delivery and only received doula assistance.The patients in the observation group received resistance training,aerobic exercise,and doula assistance prior to giving birth.After delivery,the mothers were observed for 2 hours in the delivery room and then returned to the maternal and infant ward.The observation indicators of the two groups were compared.Results:In comparison to the control group,the observation group exhibited shorter durations in the first,second,and third stages of labor,as well as the total delivery time.Additionally,the amount of postpartum blood loss at 2 hours was smaller in the observation group.The rate of cesarean section was lower,and the rate of vaginal natural delivery was higher in the observation group.Following the intervention,both groups of postpartum women showed decreased SAS and SDS scores compared to before the intervention.Moreover,the observation group had lower scores than the control group.These differences were all statistically significant(P<0.05).Conclusion:Resistance training and aerobic exercise before doula-assisted delivery can effectively improve the psychological state of parturients,shorten labor duration,increase the rate of natural vaginal delivery,and reduce pain and postpartum hemorrhage.
文摘Different types of neuroendocrine cancer,including medullary thyroid cancer(MTC)and thyroid C-cell hyperplasia,are part of multiple endocrine neoplasia type 2(MEN2).A proto-oncogene mutation of the rearranged during transfection(RET)gene changes the way that receptor tyrosine kinases work.Multiple endocrine neoplasia,a pathological condition,involves these kinases.When the RET protooncogene changes,it can cause endocrine adenomas and hyperplasia to happen at the same time or one after the other.Pheochromocytoma,medullary thyroid carcinoma,and hyperparathyroidism,alone or in combination,are present in MEN2A patients.Some patients may also have skin lichen amyloidosis or Hirschsprung's disease.Patients with MEN2A often present with MTC.MTC is aggressive and has the worst prognosis,as most patients exhibit lymph node metastasis.MTC is one of the important causes of death in patients with MEN2A.RET mutation analysis aids in identifying MEN2A symptoms and monitoring levels of calcium,thyroid hormones,calcitonin,normetanephrine,fractionated metanephrines,and parathyroid hormone.The earlier diagnosis of MTC significantly improves survival and prompts better management of MEN2A.In this editorial,we will discuss the significance of molecular diagnostic approaches in detecting RET oncogene mutations in MEN2A.
基金Supported by Opening Fund for Key Laboratory of Forest Disaster Warning and Control in Yunnan Province(ZK09A102)National Natural Science Founda-tion of China(31100007)~~
文摘[ Objective ] The paper was to screen intestinal aerobic bacteria from 2nd instar larvae of Dendrolimu kikuchii and determine its toxicity. [ Method ] The intestinal samples of 2nd instar larvae of D. kikuchii were diluted in gredient and coated on plates to isolate strains, and a total of 5 strains of aerobic bacteria were isolated. With bacterial genomic DNA as template, the universal primers of bacterial 16S rDNA (27f and 1 492r) were used to amplify the template, 4 restriction enzymes Hae Ⅲ and Hind Ⅲ, Hinf Ⅰ and Taq Ⅰ were used to carry out ARDRA polymorphism analysis on PCR products. [ Result] Clustering map analysis showed that 5 strains of aerobic bacteria clustered into two different taxonomic operating units (OTU) in 95% similarity level, this indicated that the genetic diversity level of intestinal aerobic bacteria in 2nd instar larvae of D. kikuchii was relatively low. The indoor toxicity test showed that the death peaks of insects killed by intestinal bacteria were during 4 - 10 d, the insecticidal effect of strain 4 was the best with corrected mortality rate of 53.57% at 12 d. [ Conclusion] The paper provided reference for control of D. kikuchii.
基金supported by the China NationalEleventh Five-Year Scientific and Technical Support Plan(No. 2006BAC02A18)
文摘Alkaline and ultrasonic sludge disintegration can be used as the pretreatment of waste activated sludge (WAS) to promote the subsequent anaerobic or aerobic digestion. In this study, different combinations of these two methods were investigated. The evaluation was based on the quantity of soluble chemical oxygen demand (SCOD) in the pretreated sludge as well as the degradation of organic matter in the subsequent aerobic digestion. For WAS samples with combined pretreatment, the released COD levels were higher than those with ultrasonic or alkaline pretreatment alone. When combined with the ultrasonic treatment, NaOH treatment was more efficient than Ca(OH)2 for WAS solubilization. The COD levels released in various sequential options of combined NaOH and ultrasonic treatments were in the the following descending order: simultaneous treatment 〉 NaOH treatment followed by ultrasonic treatment 〉 ultrasonic treatment followed by NaOH treatment. For simultaneous treatment, low NaOH dosage (100 g/kg dry solid), short duration (30 min) of NaOH treatment, and low ultrasonic specific energy (7500 kJ/kg dry solid) were suitable for sludge disintegration. Using combined NaOH and ultrasonic pretreatment with optimal parameters, the degradation efficiency of organic matter was increased from 38.0% to 50.7%, which is much higher than that with ultrasonic (42.5%) or with NaOH pretreatment (43.5%) in the subsequent aerobic digestion at the same retention time.
基金supported by the National Natural Science Foundation of China (No 20676078)
文摘Bacterium Providencia rettgeri YL was found to exhibit an unusual ability to heterotrophically nitrify and aerobically denitrify various concentrations of ammonium (NH4^+-N). In order to further understand its removal ability, several experiments were conducted to identify the growth and ammonium removal response at different carbon to nitrogen (C/N) mass ratios, shaking speeds, temperatures, ammonium concentrations and to qualitatively verify the production of nitrogen gas using gas chromatography techniques. Results showed that under optimum conditions (C/N 10, 30℃, 120 r/min), YL can significantly remove low and high concentrations of ammonium within 12 to 48 h of growth, respectively. The nitrification products hydroxylamine (NHzOH), nitrite (NO2^-) and nitrate (NO3^-) as well as the denitrification product, nitrogen gas (N2), were detected under completely aerobic conditions.
文摘Nitrogen loss without organic removal in biofilter was observed and its possible reason was explained. A lower hydraulic loading could improve aerobic denitrification rate. Aerobic denitrification was seriously affected by low temperature(below 10℃). However, nitrification rate remained high when the temperature dropped from 15℃ to 5℃. It seemed the autotrophic biofilm in BAF could alleviate the adverse effect of low temperature.
基金Project supported by the University Doctorial Research Foundation.Ministry of Education of China(No.20030141022).
文摘Aerobic granular sludge was cultivated adopting internal-circulate sequencing batch airlift reactor. The contradistinctive experiment about short-term membrane fouling between aerobic granular sludge system and activated sludge system were investigated. The membrane foulants was also characterized by Fourier transform infrared (FTIR) spectroscopy technique. The results showed that the aerobic granular sludge had excellent denitrification ability; the removal efficiency of TN could reach 90%. The aerobic granular sludge could alleviate membrane fouling effectively. The steady membrane flux of aerobic granular sludge was twice as much as that of activated sludge system. In addition, it was found that the aerobic granular sludge could result in severe membrane pore-blocking, however, the activated sludge could cause severe cake fouling. The major components of the foulants were identified as comprising of proteins and polysaccharide materials.
基金supported by the Hi-Tech Re-search and Development Program (863) of China (No.2002AA601310)the Natural Science Foundation ofHeilongjiang Province (No. E200824)
文摘Aerobic granular sludge was cultivated in sequencing batch airlift reactors (SBAR) at 25, 30, and 35℃, respectively. The effect of temperature on the granules characteristics was analyzed and the microbial community structures of the granules were probed using scanning electron microscope (SEM) and polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). The results showed that 30℃ is optimum for matured granule cultivation, where the granules had a more compact structure, better settling ability and higher bioactivity, the oxygen utilization rate (OUR) reached 1.14 mg O2/(g MLVSS.min) with COD removal rate of 97% and TP removal rate of 75%. The removal efficiency of NH3-N increased from 68.5% to 87.5% along with the temperature increment from 25 to 35℃. The DGGE profiles revealed that the microbial community structure at 25℃ showed the least similarity with those at other temperatures. The sequencing results indicated that the majority of dominant microbes belonged to Actinobacteria and Proteobacterium. Thermomonas sp., Ottowia sp. and Curtobacteriurn ammoniigenes might play important roles at different temperatures, respectively.
基金supported by the National Natural Science Foundation of China (40471066)the Natural Science Foundation of Jiangsu Province,China (BK2007266)
文摘Moisture regime plays a crucial role in the mineralization of soil organic carbon (SOC). In this paper, the dynamics of SOC mineralization in typical paddy soils of Changshu, Jiangsu Province, China, was investigated by incubation test in laboratory. The differences in SOC mineralization under aerobic and submerged conditions of paddy soils were also studied. Results showed that the daily mineralization of SOC under different moisture regimes was significantly different in the whole incubation period, at the beginning of the incubation, it decreased quickly under aerobic condition, but increased rapidly under submerged condition, and both remained constant after 10 d of incubation. The differences in SOC mineralization were found to be mainly at the beginning period of the incubation and decreased along with the incubation time. Thus, the difference was not significantly different at the later incubation period. The respiration intensity, daily and cumulative mineralization of SOC under aerobic condition was 2.26-19.11, 0.96-2.41, and 0.96-2.41 times than those .under submerged condition, respectively. Statistic analyses showed that the higher the contents of microbial biomass carbon and nitrogen, the more significant difference in respiration intensity between aerobic and submerged conditions, but the higher the contents of microbial biomass nitrogen and dissolved organic carbon, the more significant difference in daily mineralization of SOC between the two conditions. The decrease in soil microbial activity under submerged condition was the main reason leading to the decrease in respiration intensity, but the decrease in SOC mineralization was also correlated with the changes in dissolved organic carbon over the whole incubation period.
文摘A bench-scale anaerobic/anoxic/aerobic process-biological aerated filter (A^2/O-BAF) combined system was carded out to treat wastewater with lower C/N and C/P ratios. The A^2/O process was operated in a short aerobic sludge retention time (SRT) for organic pollutants and phosphorus removal, and denitrification. The subsequent BAF process was mainly used for nitrification. The BAF effluent was partially returned to anoxic zone of the A^2/O process to provide electron acceptors for denitrification and anoxic P uptake. This unique system formed an environment for reproducing the denitdfying phosphate-accumulating organisms (DPAOs). The ratio of DPAOs to phosphorus accumulating organisms (PAOs) could be maintained at 28% by optimizing the organic loads in the anaerobic zone and the nitrate loads into the anoxic zone in the A^2/O process. The aerobic phosphorus over-uptake and discharge of excess activated sludge was the main mechanism of phosphorus removal in the combined system. The aerobic SRT of the A^2/O process should meet the demands for the development of aerobic PAOs and the restraint on the nitrifiers growth, and the contact time in the aerobic zone of the A^2/O process should be longer than 30 min, which ensured efficient phosphorus removal in the combined system. The adequate BAF effluent return rates should be controlled with 1--4 mg/L nitrate nitrogen in the anoxic zone effluent of A^2/O process to achieve the optimal nitrogen and phosphorus removal efficiencies.