Global warming and human activities have reduced the concentrations of dissolved oxygen in the bottom water of lakes,resulting in increased anoxia in surface sediments.This increased anoxia likely alters carbon cyclin...Global warming and human activities have reduced the concentrations of dissolved oxygen in the bottom water of lakes,resulting in increased anoxia in surface sediments.This increased anoxia likely alters carbon cycling processes(e.g.,organic carbon mineralization)by altering microbial community composition and functions in lakes.However,it remains unclear how organic carbon mineralization responds to increased anoxia in surface sediments of lakes(particularly saline lakes).In this study,CO_(2)production in surface sediments of six lakes with different salinity(0.47-250 g/L)on the Tibetan Plateau was investigated using microcosm incubations under aerobic and anaerobic conditions,respectively,followed by geochemical and microbial analyses.The results showed that for the freshwater lake,CO_(2)production rates in anaerobic sediment microcosms were significantly(P<0.05)lower than their aerobic counterparts.In contrast,an opposite trend was observed for CO_(2)production in saline lakes.Furthermore,the CO_(2)production rates decreased significantly(P<0.05)under aerobic conditions,while it exhibited a hump-like relationship with increasing salinity under anaerobic conditions.Taken together,our results suggest that increased anoxia would enhance organic carbon mineralization in surface sediments of saline lakes and help understand carbon feedback on global changes in saline lakes.展开更多
Microorganisms are crucial for the breakdown of proteins and lipids in dry-fermented sausages and are intimately associated with the flavor profile of sausages.In this study,we used a mixed starter culture to ferment ...Microorganisms are crucial for the breakdown of proteins and lipids in dry-fermented sausages and are intimately associated with the flavor profile of sausages.In this study,we used a mixed starter culture to ferment sausages and investigated the flavor turnover.During the fermentation of salami,the data from free amino acids(FAAs),free fatty acids(FFAs)and volatile flavor substances were used to assess the quality of salami.At the end of fermentation,the total FAAs increased from 1171.32 to 4582.48 mg/kg in the control group and 5053.25 mg/kg in the experimental group.Additionally,following inoculation with the mixed starter culture,the levels of glutamic acid,lysine,methionine,valine and leucine were significantly higher(P<0.05)than those in the control group.Oleic acid(C_(18:1))and chondritic acid(C_(16:0))were the two most abundant FFAs in both salami samples with 45.86%and 26.07%on the 23^(th)day in mixed culture inoculated salami.The mixed starter inoculated group had significantly lower saturated fatty acids and higher percentage levels of monounsaturated fatty acids than the control group(P<0.05).In the volatile flavor substance analysis,a total of 61 volatile compounds were found.Ester compounds were progressively enriched with drying time,significantly increasing the flavor substances,like ethyl diphosgene,1-octen-3-ol,and 2,3-butanediol at P<0.05.The correlation analysis between the core flora and volatile flavor compounds during fermentation and maturation of salami indicates Lactobacillus sakei and Lactobacillus rhamnosus were significantly higher and positively correlated with the major volatile organic compounds,which are the key core microorganisms affecting the flavor quality of fermented sausages.展开更多
Injuries caused by trauma and neurodegenerative diseases can damage the peripheral nervous system and cause functional deficits.Unlike in the central nervous system,damaged axons in peripheral nerves can be induced to...Injuries caused by trauma and neurodegenerative diseases can damage the peripheral nervous system and cause functional deficits.Unlike in the central nervous system,damaged axons in peripheral nerves can be induced to regenerate in response to intrinsic cues after reprogramming or in a growth-promoting microenvironment created by Schwann cells.However,axon regeneration and repair do not automatically result in the restoration of function,which is the ultimate therapeutic goal but also a major clinical challenge.Transforming growth factor(TGF)is a multifunctional cytokine that regulates various biological processes including tissue repair,embryo development,and cell growth and differentiation.There is accumulating evidence that TGF-βfamily proteins participate in peripheral nerve repair through various factors and signaling pathways by regulating the growth and transformation of Schwann cells;recruiting specific immune cells;controlling the permeability of the blood-nerve barrier,thereby stimulating axon growth;and inhibiting remyelination of regenerated axons.TGF-βhas been applied to the treatment of peripheral nerve injury in animal models.In this context,we review the functions of TGF-βin peripheral nerve regeneration and potential clinical applications.展开更多
To study the volatile organic compounds(VOCs)emission characteristics of industrial enterprises in China,6 typical chemical industries in Yuncheng City were selected as research objects,including the modern coal chemi...To study the volatile organic compounds(VOCs)emission characteristics of industrial enterprises in China,6 typical chemical industries in Yuncheng City were selected as research objects,including the modern coal chemical industry(MCC),pharmaceutical industry(PM),pesticide industry(PE),coking industry(CO)and organic chemical industry(OC).The chemical composition of 91 VOCs was quantitatively analyzed.The results showed that the emission concentration of VOCs in the chemical industry ranged from 1.16 to 155.59 mg/m^(3).Alkanes were the main emission components of MCC(62.0%),PE(55.1%),and OC(58.5%).Alkenes(46.5%)were important components of PM,followed by alkanes(23.8%)and oxygenated volatile organic compounds(OVOCs)(21.2%).Halocarbons(8.6%-71.1%),OVOCs(9.7%-37.6%)and alkanes(11.2%-27.0%)were characteristic components of CO.The largest contributor to OFP was alkenes(0.6%-81.7%),followed by alkanes(9.3%-45.9%),and the lowest onewas alkyne(0%-0.5%).Aromatics(66.9%-85.4%)were the largest contributing components to SOA generation,followed by alkanes(2.6%-28.5%),and the lowest one was alkenes(0%-4.1%).Ethylene and BTEX were the key active species in various chemical industries.The human health risk assessment showed workers long-term exposed to the air in the chemical industrial zone had a high cancer and non-cancer risk during work,and BTEX and dichloromethane were the largest contributors.展开更多
Whole wheat flour is a food raw material rich in macronutrients,but its application in baking industry is limited due to the existence of a large amount of insoluble dietary fiber in bran.In order to make full use of ...Whole wheat flour is a food raw material rich in macronutrients,but its application in baking industry is limited due to the existence of a large amount of insoluble dietary fiber in bran.In order to make full use of this resource,we first screened twelve cellulase-producing strains,and then extracted soluble dietary fiber(SDF)from whole wheat flour after fermentation with 3 strains of Aspergillus sp.and 2 strains of Bacillus sp.,respectively.The effects of different strains on nutritional characteristics,SDF yield,structure improvement,and antioxidant activity of whole wheat flour were compared.The results showed that fermentation of whole wheat significantly increased the yield of SDF,the content of nutritive active substances,and improved the physicochemical structure and antioxidant activity of SDF in vitro.Scanning electron microscopy(SEM),X-ray diffraction and liquidity characteristics show that the fermentation to make whole wheat SDF has more porous microstructure and crystallinity of lower molecular weight.Fourier transform infrared spectrum showed that there were differences in functional group types between soluble dietary fiber in control group(C-SDF)and soluble dietary fiber in the fermentation group(F-SDF).These changes together improved the hydration performance and antioxidant activity of whole wheat SDF,including water holding capacity,oil holding capacity,cholesterol adsorption,1,1-diphenyl-2-picrylhydrazyl(DPPH),2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS)and hydroxyl radical scavenging,and lipase activity inhibition.Bacillus sp.SH and Aspergillus oryzae Y21 are ideal strains for fermentation of improved whole wheat,which has the potential of antioxidant properties while improving nutritional properties and food quality.展开更多
Gastric cancer(GC)remains one of the most common cancers and leading causes of cancer deaths globally1with 60.0%of cases and 56.6%of deaths occurring in East Asia.South Korea and Japan have conducted nationwide GC scr...Gastric cancer(GC)remains one of the most common cancers and leading causes of cancer deaths globally1with 60.0%of cases and 56.6%of deaths occurring in East Asia.South Korea and Japan have conducted nationwide GC screening programs for decades but with essential differences in strategies,organization,and coverage2.展开更多
Compared to refined wheat flour,whole wheat flour contains higher nutrients,but its high content of dietary fiber can have a significant impact on the quality of the final product.Therefore,how to enable consumers to ...Compared to refined wheat flour,whole wheat flour contains higher nutrients,but its high content of dietary fiber can have a significant impact on the quality of the final product.Therefore,how to enable consumers to obtain health benefits from whole wheat flour and improve the processing performance of whole wheat products has become a concern.The purpose of this study is to apply 2 strains Bacillus sp.SH and Aspergillus oryzae Y21 with cellulase production capacity and study their adaptability in whole wheat dough.The results indicate that the addition of cellulase-producing strains enhanced the acid production ability of whole wheat dough,rapidly reduced its pH value and insoluble dietary fiber content,and significantly increased the water-soluble arabinoxylan and water-soluble dietary fiber content.During the fermentation process,the viscoelasticity of the dough decreased,free sulfhydryl content increased,wet gluten content decreased,and the degree of reduction was consistent with the degree of acidification.Moreover,the proteolytic activity of the dough was increased,and the hydrolysis of gliadin was the most extensive.SH showed a higher advantage and has been used in whole wheat bread making.Increasing the proportion of strain SH in whole wheat bread can improve the structural characteristics and texture of the bread.When SH(5×10~7 CFU/g)is added to whole wheat bread,its hardness,elasticity,chewiness,and resilience can be similar to those of bread made from control group wheat flour,far exceeding that of whole wheat bread without adding SH.The addition of cellulase producing strains has obvious advantages in the development of whole-wheat dough,and also promote the development of whole wheat fermented foods as staple foods.展开更多
Nutcracker phenomenon (NCP) is caused by a compression of left renal vein between aorta and superior mesenteric artery. The traditional clinical manifestations of nutcracker syndrome is usually accompanied with abdomi...Nutcracker phenomenon (NCP) is caused by a compression of left renal vein between aorta and superior mesenteric artery. The traditional clinical manifestations of nutcracker syndrome is usually accompanied with abdominal pain, hematuria, orthostatic proteinuria, and varicocele formation, however, hypertension is rarely reported as main clinical feature. We describe a male adolescent with manifestation of hypertension who was identified as NCP. Renal ultrasound and computed tomography angiography have provided evidences of left renal vein dilatation, probably due to the compression through the decreased angle between aorta and superior mesenteric artery. There were no other signs for secondary hypertension for the blood levels of renin and aldosterone being between normal limits and urinalysis being negative of hematuria and proteinuria. This patient was conservatively observed without any anti-hypertensive drugs and was asked for appropriately putting on weight. Three months later, the hypertension symptom was alleviated. In conclusion, although there were no established direct pathogenetic links between hypertension and NCP, no other definite etiology was shown to be the cause of this main manifestation. Thus we speculate that the NCP might be the main cause of hypertension in this patient.展开更多
Our previous studies have shown that long noncoding RNA(lncRNA)H19 is upregulated in injured rat sciatic nerve during the process of Wallerian degeneration,and that it promotes the migration of Schwann cells and slows...Our previous studies have shown that long noncoding RNA(lncRNA)H19 is upregulated in injured rat sciatic nerve during the process of Wallerian degeneration,and that it promotes the migration of Schwann cells and slows down the growth of dorsal root ganglion axons.However,the mechanism by which lncRNA H19 regulates neural repair and regeneration after peripheral nerve injury remains unclear.In this study,we established a Sprague-Dawley rat model of sciatic nerve transection injury.We performed in situ hybridization and found that at 4–7 days after sciatic nerve injury,lncRNA H19 was highly expressed.At 14 days before injury,adeno-associated virus was intrathecally injected into the L4–L5 foramina to disrupt or overexpress lncRNA H19.After overexpression of lncRNA H19,the growth of newly formed axons from the sciatic nerve was inhibited,whereas myelination was enhanced.Then,we performed gait analysis and thermal pain analysis to evaluate rat behavior.We found that lncRNA H19 overexpression delayed the recovery of rat behavior function,whereas interfering with lncRNA H19 expression improved functional recovery.Finally,we examined the expression of lncRNA H19 downstream target SEMA6D,and found that after lncRNA H19 overexpression,the SEMA6D protein level was increased.These findings suggest that lncRNA H19 regulates peripheral nerve degeneration and regeneration through activating SEMA6D in injured nerves.This provides a new clue to understand the role of lncRNA H19 in peripheral nerve degeneration and regeneration.展开更多
Wildfire events are increasing globally which may be partly associated with climate change,resulting in significant adverse impacts on local,regional air quality and global climate.In September 2020,a small wildfire(b...Wildfire events are increasing globally which may be partly associated with climate change,resulting in significant adverse impacts on local,regional air quality and global climate.In September 2020,a small wildfire(burned area:36.3 ha)event occurred in Souesmes(Loiret-Cher,Sologne,France),and its plume spread out over 200 km on the following day as observed by the MODIS satellite.Based on measurements at a suburban site(~50 km northwest of the fire location)in Orléans and backward trajectory analysis,young wildfire plumes were characterized.Significant increases in gaseous pollutants(CO,CH_(4),N_(2)O,VOCs,etc.)and particles(including black carbon)were found within the wildfire plumes,leading to a reduced air quality.Emission factors,defined as EF(X)=ΔX/ΔCO(where,X represents the target species),of various trace gases and black carbon within the young wildfire plumes were determined accordingly and compared with previous studies.Changes in the ambient ions(such as ammonium,sulfate,nitrate,chloride,and nitrite in the particle-and gasphase)and aerosol properties(e.g.,aerosol water content,aerosol p H)were also quantified and discussed.Moreover,we estimated the total carbon and climate-related species(e.g.,CO_(2),CH_(4),N_(2)O,and BC)emissions and compared them with fire emission inventories.Current biomass burning emission inventories have uncertainties in estimating small fire burned areas and emissions.For instance,we found that the Global Fire Assimilation System(GFAS)may underestimate emissions(e.g.,CO)of this small wildfire while other inventories(GFED and FINN)showed significant overestimation.Considering that it is the first time to record wildfire plumes in this region,related atmospheric implications are presented and discussed.展开更多
Wallerian degeneration is a complex biological process that occurs after nerve injury,and involves nerve degeneration and regeneration.Schwann cells play a crucial role in the cellular and molecular events of Walleria...Wallerian degeneration is a complex biological process that occurs after nerve injury,and involves nerve degeneration and regeneration.Schwann cells play a crucial role in the cellular and molecular events of Wallerian degeneration of the peripheral nervous system.However,Wallerian degeneration regulating nerve injury and repair remains largely unknown,especially the early response.We have previously reported some key regulators of Wallerian degeneration after sciatic nerve injury.Baculoviral inhibitor of apoptosis protein repeat-containing protein 3(BIRC3)is an important factor that regulates apoptosis-inhibiting protein.In this study,we established rat models of right sciatic nerve injury.In vitro Schwann cell models were also established and subjected to gene transfection to inhibit and overexpress BIRC3.The data indicated that BIRC3 expression was significantly up-regulated after sciatic nerve injury.Both BIRC3 upregulation and downregulation affected the migration,proliferation and apoptosis of Schwan cells and affected the expression of related factors through activating c-fos and ERK signal pathway.Inhibition of BIRC3 delayed early Wallerian degeneration through inhibiting the apoptosis of Schwann cells after sciatic nerve injury.These findings suggest that BIRC3 plays an important role in peripheral nerve injury repair and regeneration.The study was approved by the Institutional Animal Care and Use Committee of Nantong University,China(approval No.2019-nsfc004)on March 1,2019.展开更多
In recent years,electrically conductive hydrogel-based nerve guidance conduits(NGCs)have yielded promising results for treating peripheral nerve injuries(PNIs).However,developed ones are generally pre-manufactured and...In recent years,electrically conductive hydrogel-based nerve guidance conduits(NGCs)have yielded promising results for treating peripheral nerve injuries(PNIs).However,developed ones are generally pre-manufactured and exhibit a limited ability to achieve good contact with nerve tissue with irregu-lar surfaces.Herein,we developed a plasticine-like electrically conductive hydrogel consisting of gelatin,conducting polypyrrole,and tannic acid(named GPT)and assessed its ability to promote peripheral nerve regeneration.The shape-persistent GPT hydrogel exhibited good self-healing properties and could easily be molded to form a conduit that could match any injured nerve tissue.Their electrical properties could be tuned by changing the PPy concentration.In vitro,the improved conductivity of the hydrogel pro-moted dorsal root ganglion(DRG)axonal extension.More importantly,we found that the GPT hydrogel enhanced axonal regeneration and remyelination in vivo,preventing denervation atrophy and enhancing functional recovery in a mice model of sciatic nerve injury.These results suggest that our plasticine-like NGC has huge prospects for clinical application in the repair of PNI.展开更多
This experiment was conducted to investigate the effects of increased atmospheric temperature and CO2 concentration during crop growth on the chemical composition and in vitro rumen fermentation characteristics of whe...This experiment was conducted to investigate the effects of increased atmospheric temperature and CO2 concentration during crop growth on the chemical composition and in vitro rumen fermentation characteristics of wheat straw. The field experiment was carried out from November 2012 to June 2013 at Changshu （31°32′93″N, 120°41′88″E） agro-ecological experimental station. A total of three treatments were set. The concentration of CO2 was increased to 500 pmol/mol in the first treatment （CO2 group）. The temperature was increased by 2℃ in the second treatment （TEM group） and the concentration of CO2 and temperature were both increased in the third treatment （CO2 ＋ TEM group）. The mean temperature and concentration of CO2 in control group were 10.5 ℃ and 413μmol/mol. At harvesting, the wheat straws were collected and analyzed for chemical composition and in vitro digestibility. Results showed that dry matter was significantly increased in all three treatments. Ether extracts and neutral detergent fiber were significantly increased in TEM and CO2 ＋ TEM groups. Crude protein was significantly decreased in CO2＋TEM group. In vitro digestibility analysis of wheat straw revealed that gas production was significantly decreased in CO2 and CO2 ＋ TEM groups. Methane production was significantly decreased in TEM and CO2 ＋ TEM groups. Ammonia nitrogen and microbial crude protein were significantly decreased in all three treatments. Total volatile fatty acids were significantly decreased in CO2 and CO2 ＋ TEM groups. In conclusion, the chemical composition of the wheat straw was affected by temperature and CO2 and the in vitro digestibility of wheat straw was reduced, especially in the combined treatment of temperature and CO2.展开更多
Since the three-dimensional Network on Chip(3D NoC)uses through-silicon via technology to connect the chips,each silicon layer is conducted through heterogeneous thermal,and 3D NoC system suffers from thermal problems...Since the three-dimensional Network on Chip(3D NoC)uses through-silicon via technology to connect the chips,each silicon layer is conducted through heterogeneous thermal,and 3D NoC system suffers from thermal problems.To alleviate the seriousness of the thermal problem,the distribution of data packets usually relies on traffic information or historical temperature information.However,thermal problems in 3D NoC cannot be solved only based on traffic or temperature information.Therefore,we propose a Score-Based Traffic-and Thermal-Aware Adaptive Routing(STTAR)that applies traffic load and temperature information to routing.First,the STTAR dynamically adjusts the input and output buffer lengths of each router with traffic load information to limit routing resources in overheated areas and control the rate of temperature rise.Second,STTAR adopts a scoring strategy based on temperature and the number of free slots in the buffer to avoid data packets being transmitted to high-temperature areas and congested areas and to improve the rationality of selecting routing output nodes.In our experiments,the proposed scoring Score-Based Traffic-and Thermal-Aware Adaptive Routing(STTAR)scheme can increase the throughput by about 14.98%to 47.90%and reduce the delay by about 10.80%to 35.36%compared with the previous works.展开更多
In this paper,finite difference schemes for solving time-space fractional diffusion equations in one dimension and two dimensions are proposed.The temporal derivative is in the Caputo-Hadamard sense for both cases.The...In this paper,finite difference schemes for solving time-space fractional diffusion equations in one dimension and two dimensions are proposed.The temporal derivative is in the Caputo-Hadamard sense for both cases.The spatial derivative for the one-dimensional equation is of Riesz definition and the two-dimensional spatial derivative is given by the fractional Laplacian.The schemes are proved to be unconditionally stable and convergent.The numerical results are in line with the theoretical analysis.展开更多
BACKGROUND Our study investigated the role of FAM53B in regulating macrophage M2 polarization and its potential mechanisms in promoting pancreatic ductal adenocarcinoma(PDAC)metastasis.AIM To further investigate the r...BACKGROUND Our study investigated the role of FAM53B in regulating macrophage M2 polarization and its potential mechanisms in promoting pancreatic ductal adenocarcinoma(PDAC)metastasis.AIM To further investigate the role of FAM53B in regulating macrophage M2 polarization and its potential mechanism in promoting PDAC metastasis.Our goal is to determine how FAM53B affects macrophage M2 polarization and to define its underlying mechanism in PDAC metastasis.METHODS Cell culture and various experiments,including protein analysis,immunohisto-chemistry,and animal model experiments,were conducted.We compared FAM53B expression between PDAC tissues and healthy tissues and assessed the correlation of FAM53B expression with clinical features.Our study analyzed the role of FAM53B in macrophage M2 polarization in vitro by examining the expression of relevant markers.Finally,we used a murine model to study the role of FAM53B in PDAC metastasis and analyzed the potential underlying mechanisms.RESULTS Our research showed that there was a significant increase in FAM53B levels in PDAC tissues,which was linked to adverse tumor features.Experimental findings indicated that FAM53B can enhance macrophage M2 polarization,leading to increased anti-inflammatory factor release.The results from the mouse model further supported the role of FAM53B in PDAC metastasis,as blocking FAM53B prevented tumor cell invasion and metastasis.CONCLUSION FAM53B promotes PDAC metastasis by regulating macrophage M2 polarization.This discovery could lead to the development of new strategies for treating PDAC.For example,interfering with the FAM53B signaling pathway may prevent cancer spread.Our research findings also provide important information for expanding our understanding of PDAC pathogenesis.展开更多
Biopolymer based hydrogels are characteristic of their biocompatibility and capability of mimicking extracellular matrix structure to support cellular behavior.However,these hydrogels suffer from low mechanical proper...Biopolymer based hydrogels are characteristic of their biocompatibility and capability of mimicking extracellular matrix structure to support cellular behavior.However,these hydrogels suffer from low mechanical properties,uncontrolled degradation,and insufficient osteogenic activity,which limits their applications in bone regeneration.In this study,we developed hybrid gelatin(Gel)/oxidized chondroitin sulfate(OCS)hydrogels that incorporated mesoporous bioactive glass nanoparticles(MBGNs)as bioactive fillers for bone regeneration.Gel-OCS hydrogels could be self-crosslinked in situ under physiological conditions in the presence of borax.The incorporation of MBGNs enhanced the crosslinking and accelerated the gelation.The gelation time decreased with increasing the concentration of MBGNs added.Incorporation of MBGNs in the hydrogels significantly improved the mechanical properties in terms of enhanced storage modulus and compressive strength.The injectability of the hydrogels was not significantly affected by the MBGN incorporation.Also,the proliferation and osteogenic differentiation of rat bone marrow mesenchymal stem cells in vitro and rat cranial defect restoration in vivo were significantly promoted by the hydrogels in the presence of MBGNs.The hybrid Gel-OCS/MBGN hydrogels show promising potential as injectable biomaterials or scaffolds for bone regeneration/repair applications given their tunable degradation and gelation behavior as well as favorable mechanical behavior and osteogenic activities.展开更多
In this article,numerical algorithms are derived for ultra-slow(or superslow)diffusion equations in one and two space dimensions,where the ultra-slow diffusion is characterized by the Caputo-Hadamard fractional deriva...In this article,numerical algorithms are derived for ultra-slow(or superslow)diffusion equations in one and two space dimensions,where the ultra-slow diffusion is characterized by the Caputo-Hadamard fractional derivative of orderα∈(0,1).To describe the non-locality in spatial interaction,the Riesz fractional derivative and the fractional Laplacian are used in one and two space dimensions,respectively.The Caputo-Hadamard derivative is discretized by two typical approximate formulae,i.e.,L2-1_(σ)and L1-2 ones.The spatial fractional derivatives are discretized by the second order finite difference methods.When the L2-1_(σ)discretization is used,the derived numerical schemes are unconditionally stable,with both theoretical and numerical convergence order O(τ2+h2)for allα∈(0,1),in whichτand h are temporal and spatial stepsizes,respectively.When the L1-2 discretization is used,the derived numerical schemes are proved to be stable with the error estimate O(τ^(2)+h^(2))forα∈(0,0.3738),and numerically exhibit the stability for allα∈(0,1)with the numerical error being O(τ^(3−α)+h^(2)).The illustrative examples displayed are in line with the theoretical analysis.展开更多
In the feed injection zone of a multiphase fluidized bed reactor, nonuniform distribution exists due to the introduction of feed nozzle jets and circulating catalyst, which ultimately have an impact on the performance...In the feed injection zone of a multiphase fluidized bed reactor, nonuniform distribution exists due to the introduction of feed nozzle jets and circulating catalyst, which ultimately have an impact on the performance of the reactor. The transient sectional nonuniformity index (TSNI) is proposed as a new index to quantify the nonuniformity of solid distribution in both radial and circumferential dimensions at the same time, based on the transient solids holdup data in the feed zone. The temporal and spatial distributions of TSNI can more accurately reflect the changes in the real-time gas-solid distribution uniformity of the cross-sections and the efficiency of gas-solid contact in the feed injection zone. The feed injection zone can be divided into three regions according to the characteristics of TSNI: the bubble-influenced zone, the jet-influenced zone, and the acceleration zone. According to the numerical simulation results, it was analyzed that TSNI is highly correlated with operating conditions, such as nozzle gas velocity and catalyst circulation rate.展开更多
基金supported by grants from the National Natural Science Foundation of China(Nos.42272356,92251304)the Kunlun Talented People of Qinghai Province,High-End Innovation and Entrepreneurship talents(Grant to Jiang Hongchen)+4 种基金the Qinghai Provincial Key Laboratory of Geology and Environment of Salt Lakes(the Science and Technology Plan Project of Qinghai Province Incentive Fund,No.2024-KFKTA08)the 111 Program(the State Administration of Foreign Experts Affairs&the Ministry of Education of China,No.B18049)the Second Tibetan Plateau Scientific Expedition and Research Program(Polymenakou et al.)(No.2019QZKK0805)the Science and Technology Plan Project of Qinghai Province(No.2022-ZJ-Y08)Fundamental Research Funds for the Central Universities,China University of Geosciences(Wuhan)。
文摘Global warming and human activities have reduced the concentrations of dissolved oxygen in the bottom water of lakes,resulting in increased anoxia in surface sediments.This increased anoxia likely alters carbon cycling processes(e.g.,organic carbon mineralization)by altering microbial community composition and functions in lakes.However,it remains unclear how organic carbon mineralization responds to increased anoxia in surface sediments of lakes(particularly saline lakes).In this study,CO_(2)production in surface sediments of six lakes with different salinity(0.47-250 g/L)on the Tibetan Plateau was investigated using microcosm incubations under aerobic and anaerobic conditions,respectively,followed by geochemical and microbial analyses.The results showed that for the freshwater lake,CO_(2)production rates in anaerobic sediment microcosms were significantly(P<0.05)lower than their aerobic counterparts.In contrast,an opposite trend was observed for CO_(2)production in saline lakes.Furthermore,the CO_(2)production rates decreased significantly(P<0.05)under aerobic conditions,while it exhibited a hump-like relationship with increasing salinity under anaerobic conditions.Taken together,our results suggest that increased anoxia would enhance organic carbon mineralization in surface sediments of saline lakes and help understand carbon feedback on global changes in saline lakes.
基金supported by the National Key Research and Development Program of China(2023YFD2100104)Henan Provincial Major Science and Technology Special Fund(231100110400).
文摘Microorganisms are crucial for the breakdown of proteins and lipids in dry-fermented sausages and are intimately associated with the flavor profile of sausages.In this study,we used a mixed starter culture to ferment sausages and investigated the flavor turnover.During the fermentation of salami,the data from free amino acids(FAAs),free fatty acids(FFAs)and volatile flavor substances were used to assess the quality of salami.At the end of fermentation,the total FAAs increased from 1171.32 to 4582.48 mg/kg in the control group and 5053.25 mg/kg in the experimental group.Additionally,following inoculation with the mixed starter culture,the levels of glutamic acid,lysine,methionine,valine and leucine were significantly higher(P<0.05)than those in the control group.Oleic acid(C_(18:1))and chondritic acid(C_(16:0))were the two most abundant FFAs in both salami samples with 45.86%and 26.07%on the 23^(th)day in mixed culture inoculated salami.The mixed starter inoculated group had significantly lower saturated fatty acids and higher percentage levels of monounsaturated fatty acids than the control group(P<0.05).In the volatile flavor substance analysis,a total of 61 volatile compounds were found.Ester compounds were progressively enriched with drying time,significantly increasing the flavor substances,like ethyl diphosgene,1-octen-3-ol,and 2,3-butanediol at P<0.05.The correlation analysis between the core flora and volatile flavor compounds during fermentation and maturation of salami indicates Lactobacillus sakei and Lactobacillus rhamnosus were significantly higher and positively correlated with the major volatile organic compounds,which are the key core microorganisms affecting the flavor quality of fermented sausages.
基金supported by the National Natural Science Foundation of China,Nos.31971277 and 31950410551(both to DY)。
文摘Injuries caused by trauma and neurodegenerative diseases can damage the peripheral nervous system and cause functional deficits.Unlike in the central nervous system,damaged axons in peripheral nerves can be induced to regenerate in response to intrinsic cues after reprogramming or in a growth-promoting microenvironment created by Schwann cells.However,axon regeneration and repair do not automatically result in the restoration of function,which is the ultimate therapeutic goal but also a major clinical challenge.Transforming growth factor(TGF)is a multifunctional cytokine that regulates various biological processes including tissue repair,embryo development,and cell growth and differentiation.There is accumulating evidence that TGF-βfamily proteins participate in peripheral nerve repair through various factors and signaling pathways by regulating the growth and transformation of Schwann cells;recruiting specific immune cells;controlling the permeability of the blood-nerve barrier,thereby stimulating axon growth;and inhibiting remyelination of regenerated axons.TGF-βhas been applied to the treatment of peripheral nerve injury in animal models.In this context,we review the functions of TGF-βin peripheral nerve regeneration and potential clinical applications.
基金supported by the National Natural Science Foundation of China(No.41905108)the National Research Program for Key Issues in Air Pollution Control(No.DQ GG0532).
文摘To study the volatile organic compounds(VOCs)emission characteristics of industrial enterprises in China,6 typical chemical industries in Yuncheng City were selected as research objects,including the modern coal chemical industry(MCC),pharmaceutical industry(PM),pesticide industry(PE),coking industry(CO)and organic chemical industry(OC).The chemical composition of 91 VOCs was quantitatively analyzed.The results showed that the emission concentration of VOCs in the chemical industry ranged from 1.16 to 155.59 mg/m^(3).Alkanes were the main emission components of MCC(62.0%),PE(55.1%),and OC(58.5%).Alkenes(46.5%)were important components of PM,followed by alkanes(23.8%)and oxygenated volatile organic compounds(OVOCs)(21.2%).Halocarbons(8.6%-71.1%),OVOCs(9.7%-37.6%)and alkanes(11.2%-27.0%)were characteristic components of CO.The largest contributor to OFP was alkenes(0.6%-81.7%),followed by alkanes(9.3%-45.9%),and the lowest onewas alkyne(0%-0.5%).Aromatics(66.9%-85.4%)were the largest contributing components to SOA generation,followed by alkanes(2.6%-28.5%),and the lowest one was alkenes(0%-4.1%).Ethylene and BTEX were the key active species in various chemical industries.The human health risk assessment showed workers long-term exposed to the air in the chemical industrial zone had a high cancer and non-cancer risk during work,and BTEX and dichloromethane were the largest contributors.
基金supported by National Natural Science Foundation of China(32330081).
文摘Whole wheat flour is a food raw material rich in macronutrients,but its application in baking industry is limited due to the existence of a large amount of insoluble dietary fiber in bran.In order to make full use of this resource,we first screened twelve cellulase-producing strains,and then extracted soluble dietary fiber(SDF)from whole wheat flour after fermentation with 3 strains of Aspergillus sp.and 2 strains of Bacillus sp.,respectively.The effects of different strains on nutritional characteristics,SDF yield,structure improvement,and antioxidant activity of whole wheat flour were compared.The results showed that fermentation of whole wheat significantly increased the yield of SDF,the content of nutritive active substances,and improved the physicochemical structure and antioxidant activity of SDF in vitro.Scanning electron microscopy(SEM),X-ray diffraction and liquidity characteristics show that the fermentation to make whole wheat SDF has more porous microstructure and crystallinity of lower molecular weight.Fourier transform infrared spectrum showed that there were differences in functional group types between soluble dietary fiber in control group(C-SDF)and soluble dietary fiber in the fermentation group(F-SDF).These changes together improved the hydration performance and antioxidant activity of whole wheat SDF,including water holding capacity,oil holding capacity,cholesterol adsorption,1,1-diphenyl-2-picrylhydrazyl(DPPH),2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS)and hydroxyl radical scavenging,and lipase activity inhibition.Bacillus sp.SH and Aspergillus oryzae Y21 are ideal strains for fermentation of improved whole wheat,which has the potential of antioxidant properties while improving nutritional properties and food quality.
基金supported by grants from the Shanghai Key Disciplines of Public Health(2023-2025)for New Threeyear Action Plan(Grant Nos.GWVI-11.1-22 and GWVI-11.1-23)the Fudan School of Public Health-Jiading CDC key disciplines for the high-quality development of public health(Grant No.GWGZLXK-2023-02)the Fudan Undergraduate Research Opportunities Program(Grant No.FDUROP-24647)。
文摘Gastric cancer(GC)remains one of the most common cancers and leading causes of cancer deaths globally1with 60.0%of cases and 56.6%of deaths occurring in East Asia.South Korea and Japan have conducted nationwide GC screening programs for decades but with essential differences in strategies,organization,and coverage2.
基金supported by National Natural Science Foundation of China(32330081)。
文摘Compared to refined wheat flour,whole wheat flour contains higher nutrients,but its high content of dietary fiber can have a significant impact on the quality of the final product.Therefore,how to enable consumers to obtain health benefits from whole wheat flour and improve the processing performance of whole wheat products has become a concern.The purpose of this study is to apply 2 strains Bacillus sp.SH and Aspergillus oryzae Y21 with cellulase production capacity and study their adaptability in whole wheat dough.The results indicate that the addition of cellulase-producing strains enhanced the acid production ability of whole wheat dough,rapidly reduced its pH value and insoluble dietary fiber content,and significantly increased the water-soluble arabinoxylan and water-soluble dietary fiber content.During the fermentation process,the viscoelasticity of the dough decreased,free sulfhydryl content increased,wet gluten content decreased,and the degree of reduction was consistent with the degree of acidification.Moreover,the proteolytic activity of the dough was increased,and the hydrolysis of gliadin was the most extensive.SH showed a higher advantage and has been used in whole wheat bread making.Increasing the proportion of strain SH in whole wheat bread can improve the structural characteristics and texture of the bread.When SH(5×10~7 CFU/g)is added to whole wheat bread,its hardness,elasticity,chewiness,and resilience can be similar to those of bread made from control group wheat flour,far exceeding that of whole wheat bread without adding SH.The addition of cellulase producing strains has obvious advantages in the development of whole-wheat dough,and also promote the development of whole wheat fermented foods as staple foods.
文摘Nutcracker phenomenon (NCP) is caused by a compression of left renal vein between aorta and superior mesenteric artery. The traditional clinical manifestations of nutcracker syndrome is usually accompanied with abdominal pain, hematuria, orthostatic proteinuria, and varicocele formation, however, hypertension is rarely reported as main clinical feature. We describe a male adolescent with manifestation of hypertension who was identified as NCP. Renal ultrasound and computed tomography angiography have provided evidences of left renal vein dilatation, probably due to the compression through the decreased angle between aorta and superior mesenteric artery. There were no other signs for secondary hypertension for the blood levels of renin and aldosterone being between normal limits and urinalysis being negative of hematuria and proteinuria. This patient was conservatively observed without any anti-hypertensive drugs and was asked for appropriately putting on weight. Three months later, the hypertension symptom was alleviated. In conclusion, although there were no established direct pathogenetic links between hypertension and NCP, no other definite etiology was shown to be the cause of this main manifestation. Thus we speculate that the NCP might be the main cause of hypertension in this patient.
基金supported by the National Natural Science Foundation of China,Nos.31971277(to DBY),31950410551(to DBY)Scientific Research Foundation for Returned Scholars,Ministry of Education of China(to DBY)+2 种基金a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)(to DBY)the Postgraduate Research&Practice Innovation Program of Jiangsu Province of China,No.KYCX 19-2050(to JS)Jiangsu College Students’Innovation and Entrepreneurship Training Program,No.202213993005Y(to YY)。
文摘Our previous studies have shown that long noncoding RNA(lncRNA)H19 is upregulated in injured rat sciatic nerve during the process of Wallerian degeneration,and that it promotes the migration of Schwann cells and slows down the growth of dorsal root ganglion axons.However,the mechanism by which lncRNA H19 regulates neural repair and regeneration after peripheral nerve injury remains unclear.In this study,we established a Sprague-Dawley rat model of sciatic nerve transection injury.We performed in situ hybridization and found that at 4–7 days after sciatic nerve injury,lncRNA H19 was highly expressed.At 14 days before injury,adeno-associated virus was intrathecally injected into the L4–L5 foramina to disrupt or overexpress lncRNA H19.After overexpression of lncRNA H19,the growth of newly formed axons from the sciatic nerve was inhibited,whereas myelination was enhanced.Then,we performed gait analysis and thermal pain analysis to evaluate rat behavior.We found that lncRNA H19 overexpression delayed the recovery of rat behavior function,whereas interfering with lncRNA H19 expression improved functional recovery.Finally,we examined the expression of lncRNA H19 downstream target SEMA6D,and found that after lncRNA H19 overexpression,the SEMA6D protein level was increased.These findings suggest that lncRNA H19 regulates peripheral nerve degeneration and regeneration through activating SEMA6D in injured nerves.This provides a new clue to understand the role of lncRNA H19 in peripheral nerve degeneration and regeneration.
基金supported by the VOLTAIRE project (ANR-10-LABX-100-01)funded by the ANR and the PIVOTS project provided by the Region Centre−Val de Loire (ARD 2020 program and CPER 2015−2020).
文摘Wildfire events are increasing globally which may be partly associated with climate change,resulting in significant adverse impacts on local,regional air quality and global climate.In September 2020,a small wildfire(burned area:36.3 ha)event occurred in Souesmes(Loiret-Cher,Sologne,France),and its plume spread out over 200 km on the following day as observed by the MODIS satellite.Based on measurements at a suburban site(~50 km northwest of the fire location)in Orléans and backward trajectory analysis,young wildfire plumes were characterized.Significant increases in gaseous pollutants(CO,CH_(4),N_(2)O,VOCs,etc.)and particles(including black carbon)were found within the wildfire plumes,leading to a reduced air quality.Emission factors,defined as EF(X)=ΔX/ΔCO(where,X represents the target species),of various trace gases and black carbon within the young wildfire plumes were determined accordingly and compared with previous studies.Changes in the ambient ions(such as ammonium,sulfate,nitrate,chloride,and nitrite in the particle-and gasphase)and aerosol properties(e.g.,aerosol water content,aerosol p H)were also quantified and discussed.Moreover,we estimated the total carbon and climate-related species(e.g.,CO_(2),CH_(4),N_(2)O,and BC)emissions and compared them with fire emission inventories.Current biomass burning emission inventories have uncertainties in estimating small fire burned areas and emissions.For instance,we found that the Global Fire Assimilation System(GFAS)may underestimate emissions(e.g.,CO)of this small wildfire while other inventories(GFED and FINN)showed significant overestimation.Considering that it is the first time to record wildfire plumes in this region,related atmospheric implications are presented and discussed.
基金supported by the National Natural Science Foundation of China,Nos.31971277,31950410551Scientific Research Foundation for Returned Scholars+2 种基金Ministry of Education of ChinaPriority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the Postgraduate Research&Practice Innovation Program of Jiangsu Province of China,No.KYCX 19-2050(all to DBY)。
文摘Wallerian degeneration is a complex biological process that occurs after nerve injury,and involves nerve degeneration and regeneration.Schwann cells play a crucial role in the cellular and molecular events of Wallerian degeneration of the peripheral nervous system.However,Wallerian degeneration regulating nerve injury and repair remains largely unknown,especially the early response.We have previously reported some key regulators of Wallerian degeneration after sciatic nerve injury.Baculoviral inhibitor of apoptosis protein repeat-containing protein 3(BIRC3)is an important factor that regulates apoptosis-inhibiting protein.In this study,we established rat models of right sciatic nerve injury.In vitro Schwann cell models were also established and subjected to gene transfection to inhibit and overexpress BIRC3.The data indicated that BIRC3 expression was significantly up-regulated after sciatic nerve injury.Both BIRC3 upregulation and downregulation affected the migration,proliferation and apoptosis of Schwan cells and affected the expression of related factors through activating c-fos and ERK signal pathway.Inhibition of BIRC3 delayed early Wallerian degeneration through inhibiting the apoptosis of Schwann cells after sciatic nerve injury.These findings suggest that BIRC3 plays an important role in peripheral nerve injury repair and regeneration.The study was approved by the Institutional Animal Care and Use Committee of Nantong University,China(approval No.2019-nsfc004)on March 1,2019.
基金financially supported by the National Natural Science Foundation of China(Nos.51932002 and 51903087)the Science and Technology Innovation Team Project of Foshan(No.2018IT100101)the Joint Fund of Ministry of Education for Equipment Preresearch(No.6141A02022632).
文摘In recent years,electrically conductive hydrogel-based nerve guidance conduits(NGCs)have yielded promising results for treating peripheral nerve injuries(PNIs).However,developed ones are generally pre-manufactured and exhibit a limited ability to achieve good contact with nerve tissue with irregu-lar surfaces.Herein,we developed a plasticine-like electrically conductive hydrogel consisting of gelatin,conducting polypyrrole,and tannic acid(named GPT)and assessed its ability to promote peripheral nerve regeneration.The shape-persistent GPT hydrogel exhibited good self-healing properties and could easily be molded to form a conduit that could match any injured nerve tissue.Their electrical properties could be tuned by changing the PPy concentration.In vitro,the improved conductivity of the hydrogel pro-moted dorsal root ganglion(DRG)axonal extension.More importantly,we found that the GPT hydrogel enhanced axonal regeneration and remyelination in vivo,preventing denervation atrophy and enhancing functional recovery in a mice model of sciatic nerve injury.These results suggest that our plasticine-like NGC has huge prospects for clinical application in the repair of PNI.
基金supported by the Special Fund for Agro-scientific Research in the Public Interest in China(No.200903003)
文摘This experiment was conducted to investigate the effects of increased atmospheric temperature and CO2 concentration during crop growth on the chemical composition and in vitro rumen fermentation characteristics of wheat straw. The field experiment was carried out from November 2012 to June 2013 at Changshu （31°32′93″N, 120°41′88″E） agro-ecological experimental station. A total of three treatments were set. The concentration of CO2 was increased to 500 pmol/mol in the first treatment （CO2 group）. The temperature was increased by 2℃ in the second treatment （TEM group） and the concentration of CO2 and temperature were both increased in the third treatment （CO2 ＋ TEM group）. The mean temperature and concentration of CO2 in control group were 10.5 ℃ and 413μmol/mol. At harvesting, the wheat straws were collected and analyzed for chemical composition and in vitro digestibility. Results showed that dry matter was significantly increased in all three treatments. Ether extracts and neutral detergent fiber were significantly increased in TEM and CO2 ＋ TEM groups. Crude protein was significantly decreased in CO2＋TEM group. In vitro digestibility analysis of wheat straw revealed that gas production was significantly decreased in CO2 and CO2 ＋ TEM groups. Methane production was significantly decreased in TEM and CO2 ＋ TEM groups. Ammonia nitrogen and microbial crude protein were significantly decreased in all three treatments. Total volatile fatty acids were significantly decreased in CO2 and CO2 ＋ TEM groups. In conclusion, the chemical composition of the wheat straw was affected by temperature and CO2 and the in vitro digestibility of wheat straw was reduced, especially in the combined treatment of temperature and CO2.
基金The work of BJUT researchers Fang et al.was partly supported by the Beijing Natural Science Foundation(4192007)the National Natural Science Foundation of China(61202076)Beijing University of Technology Project No.2021C02.
文摘Since the three-dimensional Network on Chip(3D NoC)uses through-silicon via technology to connect the chips,each silicon layer is conducted through heterogeneous thermal,and 3D NoC system suffers from thermal problems.To alleviate the seriousness of the thermal problem,the distribution of data packets usually relies on traffic information or historical temperature information.However,thermal problems in 3D NoC cannot be solved only based on traffic or temperature information.Therefore,we propose a Score-Based Traffic-and Thermal-Aware Adaptive Routing(STTAR)that applies traffic load and temperature information to routing.First,the STTAR dynamically adjusts the input and output buffer lengths of each router with traffic load information to limit routing resources in overheated areas and control the rate of temperature rise.Second,STTAR adopts a scoring strategy based on temperature and the number of free slots in the buffer to avoid data packets being transmitted to high-temperature areas and congested areas and to improve the rationality of selecting routing output nodes.In our experiments,the proposed scoring Score-Based Traffic-and Thermal-Aware Adaptive Routing(STTAR)scheme can increase the throughput by about 14.98%to 47.90%and reduce the delay by about 10.80%to 35.36%compared with the previous works.
基金the National Natural Science Foundation of China under Grant Nos.12271339 and 12201391.
文摘In this paper,finite difference schemes for solving time-space fractional diffusion equations in one dimension and two dimensions are proposed.The temporal derivative is in the Caputo-Hadamard sense for both cases.The spatial derivative for the one-dimensional equation is of Riesz definition and the two-dimensional spatial derivative is given by the fractional Laplacian.The schemes are proved to be unconditionally stable and convergent.The numerical results are in line with the theoretical analysis.
文摘BACKGROUND Our study investigated the role of FAM53B in regulating macrophage M2 polarization and its potential mechanisms in promoting pancreatic ductal adenocarcinoma(PDAC)metastasis.AIM To further investigate the role of FAM53B in regulating macrophage M2 polarization and its potential mechanism in promoting PDAC metastasis.Our goal is to determine how FAM53B affects macrophage M2 polarization and to define its underlying mechanism in PDAC metastasis.METHODS Cell culture and various experiments,including protein analysis,immunohisto-chemistry,and animal model experiments,were conducted.We compared FAM53B expression between PDAC tissues and healthy tissues and assessed the correlation of FAM53B expression with clinical features.Our study analyzed the role of FAM53B in macrophage M2 polarization in vitro by examining the expression of relevant markers.Finally,we used a murine model to study the role of FAM53B in PDAC metastasis and analyzed the potential underlying mechanisms.RESULTS Our research showed that there was a significant increase in FAM53B levels in PDAC tissues,which was linked to adverse tumor features.Experimental findings indicated that FAM53B can enhance macrophage M2 polarization,leading to increased anti-inflammatory factor release.The results from the mouse model further supported the role of FAM53B in PDAC metastasis,as blocking FAM53B prevented tumor cell invasion and metastasis.CONCLUSION FAM53B promotes PDAC metastasis by regulating macrophage M2 polarization.This discovery could lead to the development of new strategies for treating PDAC.For example,interfering with the FAM53B signaling pathway may prevent cancer spread.Our research findings also provide important information for expanding our understanding of PDAC pathogenesis.
基金the fellowship from the China Scholarship Council(No.201708440027)This work was supported by the National Key R&D Program of China(Grant Nos.2018YFC1105304, 2018YFC1105301)+2 种基金the National Natural Science Foundation of China(Grant Nos.51932002,31771080,51702104,51903087 , 51772106)the Natural Science Foundation of Guangdong Province(Grant No.2016A030308014)China Postdoctoral Science Foundation(Grant No.2017M622641).
文摘Biopolymer based hydrogels are characteristic of their biocompatibility and capability of mimicking extracellular matrix structure to support cellular behavior.However,these hydrogels suffer from low mechanical properties,uncontrolled degradation,and insufficient osteogenic activity,which limits their applications in bone regeneration.In this study,we developed hybrid gelatin(Gel)/oxidized chondroitin sulfate(OCS)hydrogels that incorporated mesoporous bioactive glass nanoparticles(MBGNs)as bioactive fillers for bone regeneration.Gel-OCS hydrogels could be self-crosslinked in situ under physiological conditions in the presence of borax.The incorporation of MBGNs enhanced the crosslinking and accelerated the gelation.The gelation time decreased with increasing the concentration of MBGNs added.Incorporation of MBGNs in the hydrogels significantly improved the mechanical properties in terms of enhanced storage modulus and compressive strength.The injectability of the hydrogels was not significantly affected by the MBGN incorporation.Also,the proliferation and osteogenic differentiation of rat bone marrow mesenchymal stem cells in vitro and rat cranial defect restoration in vivo were significantly promoted by the hydrogels in the presence of MBGNs.The hybrid Gel-OCS/MBGN hydrogels show promising potential as injectable biomaterials or scaffolds for bone regeneration/repair applications given their tunable degradation and gelation behavior as well as favorable mechanical behavior and osteogenic activities.
基金supported in part by the National Natural Science Foundation of China under Grant No.12201391 and Chunhui Project from Education Ministry of China under Grant No.HZKY20220092supported in part by the National Natural Science Foundation of China under Grant No.12271339.
文摘In this article,numerical algorithms are derived for ultra-slow(or superslow)diffusion equations in one and two space dimensions,where the ultra-slow diffusion is characterized by the Caputo-Hadamard fractional derivative of orderα∈(0,1).To describe the non-locality in spatial interaction,the Riesz fractional derivative and the fractional Laplacian are used in one and two space dimensions,respectively.The Caputo-Hadamard derivative is discretized by two typical approximate formulae,i.e.,L2-1_(σ)and L1-2 ones.The spatial fractional derivatives are discretized by the second order finite difference methods.When the L2-1_(σ)discretization is used,the derived numerical schemes are unconditionally stable,with both theoretical and numerical convergence order O(τ2+h2)for allα∈(0,1),in whichτand h are temporal and spatial stepsizes,respectively.When the L1-2 discretization is used,the derived numerical schemes are proved to be stable with the error estimate O(τ^(2)+h^(2))forα∈(0,0.3738),and numerically exhibit the stability for allα∈(0,1)with the numerical error being O(τ^(3−α)+h^(2)).The illustrative examples displayed are in line with the theoretical analysis.
基金support from the Technology Development Program of China National Petroleum Corporation(grant No.2023ZZ36).
文摘In the feed injection zone of a multiphase fluidized bed reactor, nonuniform distribution exists due to the introduction of feed nozzle jets and circulating catalyst, which ultimately have an impact on the performance of the reactor. The transient sectional nonuniformity index (TSNI) is proposed as a new index to quantify the nonuniformity of solid distribution in both radial and circumferential dimensions at the same time, based on the transient solids holdup data in the feed zone. The temporal and spatial distributions of TSNI can more accurately reflect the changes in the real-time gas-solid distribution uniformity of the cross-sections and the efficiency of gas-solid contact in the feed injection zone. The feed injection zone can be divided into three regions according to the characteristics of TSNI: the bubble-influenced zone, the jet-influenced zone, and the acceleration zone. According to the numerical simulation results, it was analyzed that TSNI is highly correlated with operating conditions, such as nozzle gas velocity and catalyst circulation rate.
