In this article,we explored the role of adipose tissue,especially mesenteric adipose tissue and creeping fat,and its association with the gut microbiota in the pathophysiology and progression of Crohn’s disease(CD).C...In this article,we explored the role of adipose tissue,especially mesenteric adipose tissue and creeping fat,and its association with the gut microbiota in the pathophysiology and progression of Crohn’s disease(CD).CD is a form of inflammatory bowel disease characterized by chronic inflammation of the gastrointestinal tract,influenced by genetic predisposition,gut microbiota dysbiosis,and environmental factors.Gut microbiota plays a crucial role in modulating immune response and intestinal inflammation and is associated with the onset and progression of CD.Further,visceral adipose tissue,particularly creeping fat,a mesenteric adipose tissue characterized by hypertrophy and fibrosis,has been implicated in CD pathogenesis,inflammation,and fibrosis.The bacteria from the gut microbiota may translocate into mesenteric adipose tissue,contributing to the formation of creeping fat and influencing CD progression.Although creeping fat may be a protective barrier against bacterial invasion,its expansion can damage adjacent tissues,leading to complications.Modulating gut microbiota through interventions such as fecal microbiota transplantation,probiotics,and prebiotics has shown potential in managing CD.However,more research is needed to clarify the mechanisms linking gut dysbiosis,creeping fat,and CD progression and develop targeted therapies for microbiota modulation and fat-related complications in patients with CD.展开更多
Inflammatory bowel disease,particularly Crohn's disease(CD),has been linked to modifications in mesenteric adipose tissue(MAT)and the phenomenon known as"creeping fat"(CrF).The presence of CrF is believe...Inflammatory bowel disease,particularly Crohn's disease(CD),has been linked to modifications in mesenteric adipose tissue(MAT)and the phenomenon known as"creeping fat"(CrF).The presence of CrF is believed to serve as a predictor for early clinical recurrence following surgical intervention in patients with CD.Notably,the incorporation of the mesentery during ileocolic resection for CD has been correlated with a decrease in surgical recurrence,indicating the significant role of MAT in the pathogenesis of CD.While numerous studies have indicated that dysbiosis of the gut microbiota is a critical factor in the development of CD,the functional implications of translocated microbiota within the MAT of CD patients remain ambiguous.This manuscript commentary discusses a recent basic research conducted by Wu et al.In their study,intestinal bacteria from individuals were transplanted into CD model mice,revealing that fecal microbiota trans-plantation(FMT)from healthy donors alleviated CD symptoms,whereas FMT from CD patients exacerbated these symptoms.Importantly,FMT was found to affect intestinal permeability,barrier function,and the levels of proinflammatory factors and adipokines.Collectively,these findings suggest that targeting MAT and CrF may hold therapeutic potential for patients with CD.However,the study did not evaluate the composition of the intestinal microbiota of the donors or the subsequent alterations in the gut microbiota.Overall,the gut microbiota plays a crucial role in the histopathology of CD,and thus,targeting MAT and CrF may represent a promising avenue for treatment in this patient population.展开更多
In this manuscript,we comment on the article by Hasnaoui et al.Specifically,we delve into the characteristic manifestation of Crohn’s disease(CD)known as creeping fat(CF).Our primary focus is to investigate the poten...In this manuscript,we comment on the article by Hasnaoui et al.Specifically,we delve into the characteristic manifestation of Crohn’s disease(CD)known as creeping fat(CF).Our primary focus is to investigate the potential of imaging features of CF in predicting the response of small bowel CD to biologic therapies and fecal microbiota transplantation.We believe that further research should be dedicated to developing methods for quantifying CF in order to provide more accurate predictive tools for the treatment of small bowel CD.展开更多
In contrast to glaciological studies in Mexico,periglacial studies are very recent and limited to the analysis of the general permafrost cover in the high mountains of the country.Although some of the studies on the r...In contrast to glaciological studies in Mexico,periglacial studies are very recent and limited to the analysis of the general permafrost cover in the high mountains of the country.Although some of the studies on the reconstruction of Pleistocene glaciers in Mexico mention the existence of rock glaciers,to date no work has been done to study their physical properties or determining their state of conservation.Since rock glaciers are the most important visible indicators of mountain permafrost(along with features such as gelifluction lobes and patterned ground)and given that the“Nevado”rock glacier is the main example of its kind in Mexico,this study analyzes its internal temperature and assesses its state of conservation.The investigation was carried out by drilling and thermal monitoring of rock profiles as well as air.The results indicate that at present,the“Nevado”seems to lack permafrost inside.Although there is evidence of surface freezing during the winter months in the upper part of the rock glacier,in the lower portion it is almost unnoticed;and in both parts the internal temperature shows a tendency towards positive values as depth increases,a situation that predominates throughout the year.In addition,according to the records of the climatological station located in the lower part of the rock glacier,although the annual rainfall regime could be favorable for the formation and feeding of interstitial or segregated ice,the air temperature conditions throughout the year prevent permanent freezing.The sum of the above determines that at present the“Nevado”could be considered as an inactive and relict-type rock glacier;the presence of vegetation on the surface of the debris that make it up corroborates its inactivity.展开更多
In the long-term exploitation of natural gas hydrate,the stress change intensifies the creep effect and leads to the destruction of pore structures,which makes it difficult to predict the permeability of hydrate reser...In the long-term exploitation of natural gas hydrate,the stress change intensifies the creep effect and leads to the destruction of pore structures,which makes it difficult to predict the permeability of hydrate reservoir.Although permeability is crucial to optimize gas recovery for gas hydrate reservoirs,until now,accurately modeling the permeability of hydrate-bearing clayey-silty sediments during the creep process remains a significant challenge.In this study,by combining the nonlinear fractional-order constitutive model and the Kozeny-Carman(KC)equation,a novel creep model for predicting the permeability of hydrate-bearing clayey-silty sediments has been proposed.In addition,experimental tests have been conducted to validate the derived model.The proposed model is further validated against other available test data.When the yield function F<0,the permeability decreases gradually due to the shrinkage of pore space.However,when the yield function F≥0,the penetrating damage bands will be generated.Results show that,once the model parameters are determined appropriately by fitting the test data,the model can also be used to predict permeability under any other stress conditions.This study has a certain guiding significance for elucidating the permeability evolution mechanisms of hydrate-bearing clayey-silty sediments during the extraction of marine gas hydrates.展开更多
The three largest earthquakes in northern California since 1849 were preceded by increased decadal activity for moderate-size shocks along surrounding nearby faults. Increased seismicity, double-difference precise loc...The three largest earthquakes in northern California since 1849 were preceded by increased decadal activity for moderate-size shocks along surrounding nearby faults. Increased seismicity, double-difference precise locations of earthquakes since 1968, geodetic data and fault offsets for the 1906 great shock are used to re-examine the timing and locations of possible future large earthquakes. The physical mechanisms of regional faults like the Calaveras, Hayward and Sargent, which exhibit creep, differ from those of the northern San Andreas, which is currently locked and is not creeping. Much decadal forerunning activity occurred on creeping faults. Moderate-size earthquakes along those faults became more frequent as stresses in the region increased in the latter part of the cycle of stress restoration for major and great earthquakes along the San Andreas. They may be useful for decadal forecasts. Yearly to decadal forecasts, however, are based on only a few major to great events. Activity along closer faults like that in the two years prior to the 1989 Loma Prieta shock needs to be examined for possible yearly forerunning changes to large plate boundary earthquakes. Geodetic observations are needed to focus on identifying creeping faults close to the San Andreas. The distribution of moderate-size earthquakes increased significantly since 1990 along the Hayward fault but not adjacent to the San Andreas fault to the south of San Francisco compared to what took place in the decades prior to the three major historic earthquakes in the region. It is now clear from a re-examination of the 1989 mainshock that the increased level of moderate-size shocks in the one to two preceding decades occurred on nearby East Bay faults. Double-difference locations of small earthquakes provide structural information about faults in the region, especially their depths. The northern San Andreas fault is divided into several strongly coupled segments based on differences in seismicity.展开更多
This paper investigates the adjacent interactions of three novel solitons for the quintic complex Ginzburg-Landau equation, which are plain pulsating, erupting and creeping solitons. It is found that different perform...This paper investigates the adjacent interactions of three novel solitons for the quintic complex Ginzburg-Landau equation, which are plain pulsating, erupting and creeping solitons. It is found that different performances are presented for different solitons due to isolated regions of the parameter space where they exist. For example, plain pulsating and erupting solitons exhibit mutual annihilation during collisions with the decrease of total energy, but for creeping soliton, the two adjacent pulses present soliton fusion without any loss of energy. Otherwise, the method for restraining the interactions is also found and it can suppress interactions between these two adjacent pulses effectively.展开更多
It is well known that plane creeping Couette flow of UCM and Oldroy-B fluids are linearly stable. However, for Burges fluid, which includes UCM and Oldroyd-B fluids as special cases, unstable modes are detected in the...It is well known that plane creeping Couette flow of UCM and Oldroy-B fluids are linearly stable. However, for Burges fluid, which includes UCM and Oldroyd-B fluids as special cases, unstable modes are detected in the present work. The wave speed, critical parameters and perturbation mode are studied for neutral waves. Energy analysis shows that the sustaining of perturbation energy in Poiseuille flow and Couette flow is completely different. At low Reynolds number limit, analytical solutions are obtained for simpli- fied perturbation equations. The essential difference between Burgers fluid and Oldroyd-B fluid is revealed to be the fact that neutral mode exists only in the former.展开更多
The two dimensional equations of motions for the slowly flowing and heat transfer in second grade fluid are written in Cartesian coordinates neglecting the inertial terms. When the inertia terms are simply omitted fro...The two dimensional equations of motions for the slowly flowing and heat transfer in second grade fluid are written in Cartesian coordinates neglecting the inertial terms. When the inertia terms are simply omitted from the equations of motions the resulting solutions are valid approximately for Re1. This fact can also be deduced from the dimensionless form of the momentum and energy equations. By employing Lie group analysis, the symmetries of the equations are calculated. The Lie algebra consists of four finite parameter and one infinite parameter Lie group transformations, one being the scaling symmetry and the others being translations. Two different types of solutions are found using the symmetries. Using translations in x and y coordinates, an exponential type of exact solution is presented. For the scaling symmetry, the outcoming ordinary differential equations are more involved and only a series type of approximate solution is presented. Finally, some boundary value problems are discussed.展开更多
A mechanical model was established for modeⅡinterfacial crack static growing along an elastic_elastic power law creeping bimaterial interface. For two kinds of boundary conditions on crack faces, traction free and fr...A mechanical model was established for modeⅡinterfacial crack static growing along an elastic_elastic power law creeping bimaterial interface. For two kinds of boundary conditions on crack faces, traction free and frictional contact, asymptotic solutions of the stress and strain near tip_crack were given. Results derived indicate that the stress and strain have the same singularity, there is not the oscillatory singularity in the field; the creep power_hardening index n and the ratio of Young's module notably influence the crack_tip field in region of elastic power law creeping material and n only influences distribution of stresses and strains in region of elastic material. When n is bigger, the creeping deformation is dominant and stress fields become steady,which does not change with n. Poisson's ratio does not affect the distributing of the crack_tip field.展开更多
Sustainable forage production is one of the most important factors in livestock production system. Smallholder livestock production system is a part of agricultural practice in Indonesia. Limited land owned by farmers...Sustainable forage production is one of the most important factors in livestock production system. Smallholder livestock production system is a part of agricultural practice in Indonesia. Limited land owned by farmers was dominantly cultivated for food crops, and very small part of it used for cultivating forage plants. This leads to restriction of smallholder livestock development, because no more land available for forage production. Integrated forage production system by planting forage plants and food crops or trees in the same area becomes a considerable cropping system that widely practiced by the farmers in Indonesia. Some grasses and legumes have morphological advantages overcoming growth condition under shading. These growth characteristics are benefit in designing compatible system components for enhanced productivity in tree-pasture systems. Four potential shade-tolerant creeping forages that were combined with 2 levels of nitrogen application were tested using factorial completely randomized design 3 replicates. The first factor was species of creeping forages （stoloniferous）： BH = Brachiaria humidicola, PN = Paspalum notatum, AC - Axonopus compressus and, AP = Arachis pintoi. The second factor was nitrogen （urea） fertilizer： A = without N fertilizer and B = with N fertilizer （300 kg Urea/ha）. The observations included the growth rates of plant length, plant length, number of leaves, herbages yield （shoot）, root dry weight, senescence, total N-shoot, N-soil and N-uptake. The results showed that growth characteristics and productivity of creeping forage plants was significantly differed by the species. Most species showed an increase in growth trend, except P. notatum. A. compressus significantly showed as the best performance species compared to other, in terms of growth rates, plant length, number of leaves, herbage yield （shoot） and root dry weight, N-uptake and N-shoot. This was lbllowed by B. humidicola, P. notatum, and A. pintoi. Based on previous study, A. compressus found as one of the native species in most tree system. It indicated its superior growth compared to other species tested. However, it is needed further research to observe the compatibility of each species in tree-pasture systems.展开更多
This paper presents an experimental study on the creeping discharge propagating over the pressboard surface in two vegetable oils(PFAE(palm fatty acid ester)oil and CRS(crude rapeseed)oil)and commercial mineral oil un...This paper presents an experimental study on the creeping discharge propagating over the pressboard surface in two vegetable oils(PFAE(palm fatty acid ester)oil and CRS(crude rapeseed)oil)and commercial mineral oil under the quasi-square impulse voltage with any pulse width.The pressboard impregnated with the sample oil is immersed completely into the same oil.The tungsten needle electrode is installed in the pressboard surface with and without the counter electrode to generate a creeping discharge.The other side of pressboard has the thin copper rod as a back side electrode.A comparison of the shape and stopping length of positive and negative streamers,discharge current,emitted light signal,and temporal variation and velocity of streamer propagation is reported for all different oil-pressboard interfaces.It has been shown that the behavior of creeping streamers has unique characteristics and polarity effects,and the traveling mode and propagation velocity of streamers are greatly different depending on the type of oil.展开更多
The behaviors of creeping streamer progressed in the narrow gap with the range of 0.1 mm to 0.2 mm between the pressboard mounted a BSE （back side electrode） and the acrylic resin plate were carried out in PFAE （pa...The behaviors of creeping streamer progressed in the narrow gap with the range of 0.1 mm to 0.2 mm between the pressboard mounted a BSE （back side electrode） and the acrylic resin plate were carried out in PFAE （palm fatty acid ester） oil under variable impulse voltage up to -4-140 kVpeak with ＋1.2/50 μs and ±1.2/1,000μs waveforms. The growth of positive and negative streamers depends on the gap space between two solid dielectrics. And the distinctive polarities of impulse voltage affect in the streamer length and flashover voltage between needle and counter electrodes as well. By decreasing the gap space, the flashover voltage largely increased while the mean velocity of positive streamer significantly decreased under the both polarities of impulse voltage. These results have been compared to commercial mineral oil （transformer oil： JIS-C2320）. It is shown that the behaviors of creeping discharge in both oils elegantly reveal the distinctive phenomena.展开更多
The conserved microRNA396(miR396)is involved in plant growth,development,and abiotic stress response in multiple plant species through regulating its targets,Growth Regulating Factor(GRF)transcription factor genes.How...The conserved microRNA396(miR396)is involved in plant growth,development,and abiotic stress response in multiple plant species through regulating its targets,Growth Regulating Factor(GRF)transcription factor genes.However,the role of miR396 has not yet been characterized in perennial monocot species.In addition,the molecular mechanism of miR396-mediated abiotic stress response remains unclear.To elucidate the role of miR396 in perennial monocot species,we generated transgenic creeping bentgrass(Agrostis stolonifera)overexpressing Osa-miR396c,a rice miRNA396 gene.Transgenic plants exhibited altered development,including less shoot and root biomass,shorter internodes,smaller leaf area,fewer leaf veins,and epidermis cells per unit area than those of WT controls.In addition,transgenics showed enhanced salt tolerance associated with improved water retention,increased chlorophyll content,cell membrane integrity,and Na^(+)exclusion during high salinity exposure.Four potential targets of miR396 were identified in creeping bentgrass and up-regulated in response to salt stress.RNA-seq analysis indicates that miR396-mediated salt stress tolerance requires the coordination of stress-related functional proteins(antioxidant enzymes and Na+/H+antiporter)and regulatory proteins(transcription factors and protein kinases).This study establishes a miR396-associated molecular pathway to connect the upstream regulatory and downstream functional elements,and provides insight into the miRNA-mediated regulatory networks.展开更多
High temperature is one of the major abiotic stresses limiting growth and development of cool-season grass species,but chitosan could effectively enhance heat tolerance and improve plant growth.The objective of this s...High temperature is one of the major abiotic stresses limiting growth and development of cool-season grass species,but chitosan could effectively enhance heat tolerance and improve plant growth.The objective of this study was to determine the optimal concentration of chitosan that could alleviate heat stress in creeping bentgrass(Agrostis stolonifera)and investigate the effects of exogenous chitosan on photosynthesis and cell membrane stability under heat stress.Under heat stress(38/28°C,day/night),different chitosan concentrations of 0,50,100 and 500 mg·L−1 were applied on the leaves of creeping bentgrass(cv.'Penn-A4').Foliar application of chitosan exhibited the positive effects on plant growth and the optimal concentration was 100 mg·L−1 which significantly improved turf quality,root length,root-shoot ratio as well as shoot and root biomass.Chitosan-treated plants subjected to high temperature stress had a lower decline in photosynthetic rate and photochemical efficiency as well as less increase in electrolyte leakage and malondialdehyde content.The results demonstrate that chitosan-improved heat tolerance as reflected by the superior growth performance of both shoot and root,photosynthesis and cell membrane stability in creeping bentgrass under heat stress.展开更多
Materials in engineering applications are rarely uniaxially-loaded.In reality,failures under multiaxial loading has been widely observed in engineering structures.The life prediction of a component under multiaxial st...Materials in engineering applications are rarely uniaxially-loaded.In reality,failures under multiaxial loading has been widely observed in engineering structures.The life prediction of a component under multiaxial stresses has long been a challenging issue,particularly for high temperature applications.To distinguish the mode of failure ranging from a maximum principal stress intergranular damage to von Mises effective stress rupture mode a multiaxial stress rupture criterion(MSRC)was originally proposed by Sdobyrev and then Hayhurst and Leckie(SHL MSRC).A multiaxial-factor,α,was developed as a result which was intended to be a material constant and differentiates the bias of the MSRC between maxi-mum principal stress and effective stress.The success of the SHL MSRC relies on accurately calibrating the value ofαto quantify the multiaxial response of the material/geometry combination.To find a more suitable approach for determining MSRC,the applicability of different methods are evaluated.Given that the resulting analysis of the various approaches can be affected by the creep failure mechanism,princi-ples in the determination of MSRC with and without using continuum damage mechanics approaches are recommended.The viability of uniaxial material parameters in correlating withαthrough the analysis of available data in literature is also presented.It is found that the increase of the uniaxial creep dam-age tolerance parameterλis accompanied bythe decreaseof theα-value,whichimplies thatthe creep ductility plays an important role in affecting the multiaxial rupture behavior of materials.展开更多
This paper describes the creeping principle. Based on this principle, a pocket-sized electrode creep-feeding mechanism applied to electrical discharge machining(EDM) is designed. Features of the mechanism: the structu...This paper describes the creeping principle. Based on this principle, a pocket-sized electrode creep-feeding mechanism applied to electrical discharge machining(EDM) is designed. Features of the mechanism: the structure of two-layer parallel plate is employed as its moving pairs, and an integral structure is adoped in the design of the mechanism. This mechanism can drive an electrode by piezoelectric element in steps of order of nanometer (the minimum feeding step of 78nm).展开更多
The atmospheric carbon dioxide level has increased and is predicted to continue increasing,which may affect various aspects of plant growth.The objective of this study was to investigate the effects of doubling the ca...The atmospheric carbon dioxide level has increased and is predicted to continue increasing,which may affect various aspects of plant growth.The objective of this study was to investigate the effects of doubling the carbon dioxide level on the growth and physiological activities of a widely utilized cool-season turfgrass species,creeping bentgrass(Agrostis stolonifera L.‘Penncross’).‘Penncross’plants were established in fritted clay medium and maintained under well-irrigated and well-fertilized conditions in growth chambers.The plants were exposed to either ambient carbon dioxide concentrations(400±10 mmol L^(-1))or elevated carbon dioxide concentrations(800±10 mmol L^(-1))for 12 weeks.Plants grown under elevated carbon dioxide displayed a significantly faster growth rate of their lateral stems(stolons)and increased shoot and root dry weight but a reduced specific leaf area compared to those plants at ambient carbon dioxide levels.Fast stolon growth is a highly desirable trait for turfgrass establishment and recovery from physical damage.The root length and surface area were also increased due to the elevated CO_(2),which may facilitate water uptake and serve critical drought-avoidance roles when irrigation water is limited.Elevated carbon dioxide caused an increase in the leaf net photosynthetic rate but a reduction in the stomatal conductance and transpiration rate,contributing to improved water use efficiency in creeping bentgrass.Efficient water use is especially important for turfgrass plant survival when irrigation water is limited.Our results suggested that cool-season turfgrass species may greatly benefit from increasingly elevated carbon dioxide concentrations via growth promotion and increasing water use efficiency.展开更多
In this paper, a incremental form of constitutive laws for creeping studies are proposed. The equations are based on the concept of creep hardening surface. Damage effects were introduced to the new constitutive relat...In this paper, a incremental form of constitutive laws for creeping studies are proposed. The equations are based on the concept of creep hardening surface. Damage effects were introduced to the new constitutive relations to study solids creeping effects with pre-existing damages. The present formula is easy to be adopted into other numerical procedures such as finite element methods.展开更多
In a soft clay layer overlain by a thick man made ground layer, as in the case of the Unkapam shores of the Golden Horn, excess pore pressures have remained for long periods and the soft clay layer has hardly undergon...In a soft clay layer overlain by a thick man made ground layer, as in the case of the Unkapam shores of the Golden Horn, excess pore pressures have remained for long periods and the soft clay layer has hardly undergone few volumetric deformations. Along the shores of the Golden Horn such creep of the soil towards the sea has been detected at more than 40 mm in the last 26 months. The measurements of those movements are examined in this paper. Our research points out that the local failure of a soil element or of a particular layer differs from the general failure of the soil mass. Furthermore, the large masses of unfailed soil which overlie the soft layer along the shores of the Golden Horn delay the general failure of the slopes. We conclude that the shear strains producing excessive pore pressures is the cause of the creep observed. Because a proper solution still need to be found for a sustainable stability of the area, it is necessary to continue with the measurements of the Golden Horn＇s creeping shores.展开更多
基金Supported by the Postdoctoral Scholarship Grant,No.5552/2024 PROPG/PROPE N°06/2024.
文摘In this article,we explored the role of adipose tissue,especially mesenteric adipose tissue and creeping fat,and its association with the gut microbiota in the pathophysiology and progression of Crohn’s disease(CD).CD is a form of inflammatory bowel disease characterized by chronic inflammation of the gastrointestinal tract,influenced by genetic predisposition,gut microbiota dysbiosis,and environmental factors.Gut microbiota plays a crucial role in modulating immune response and intestinal inflammation and is associated with the onset and progression of CD.Further,visceral adipose tissue,particularly creeping fat,a mesenteric adipose tissue characterized by hypertrophy and fibrosis,has been implicated in CD pathogenesis,inflammation,and fibrosis.The bacteria from the gut microbiota may translocate into mesenteric adipose tissue,contributing to the formation of creeping fat and influencing CD progression.Although creeping fat may be a protective barrier against bacterial invasion,its expansion can damage adjacent tissues,leading to complications.Modulating gut microbiota through interventions such as fecal microbiota transplantation,probiotics,and prebiotics has shown potential in managing CD.However,more research is needed to clarify the mechanisms linking gut dysbiosis,creeping fat,and CD progression and develop targeted therapies for microbiota modulation and fat-related complications in patients with CD.
文摘Inflammatory bowel disease,particularly Crohn's disease(CD),has been linked to modifications in mesenteric adipose tissue(MAT)and the phenomenon known as"creeping fat"(CrF).The presence of CrF is believed to serve as a predictor for early clinical recurrence following surgical intervention in patients with CD.Notably,the incorporation of the mesentery during ileocolic resection for CD has been correlated with a decrease in surgical recurrence,indicating the significant role of MAT in the pathogenesis of CD.While numerous studies have indicated that dysbiosis of the gut microbiota is a critical factor in the development of CD,the functional implications of translocated microbiota within the MAT of CD patients remain ambiguous.This manuscript commentary discusses a recent basic research conducted by Wu et al.In their study,intestinal bacteria from individuals were transplanted into CD model mice,revealing that fecal microbiota trans-plantation(FMT)from healthy donors alleviated CD symptoms,whereas FMT from CD patients exacerbated these symptoms.Importantly,FMT was found to affect intestinal permeability,barrier function,and the levels of proinflammatory factors and adipokines.Collectively,these findings suggest that targeting MAT and CrF may hold therapeutic potential for patients with CD.However,the study did not evaluate the composition of the intestinal microbiota of the donors or the subsequent alterations in the gut microbiota.Overall,the gut microbiota plays a crucial role in the histopathology of CD,and thus,targeting MAT and CrF may represent a promising avenue for treatment in this patient population.
文摘In this manuscript,we comment on the article by Hasnaoui et al.Specifically,we delve into the characteristic manifestation of Crohn’s disease(CD)known as creeping fat(CF).Our primary focus is to investigate the potential of imaging features of CF in predicting the response of small bowel CD to biologic therapies and fecal microbiota transplantation.We believe that further research should be dedicated to developing methods for quantifying CF in order to provide more accurate predictive tools for the treatment of small bowel CD.
文摘In contrast to glaciological studies in Mexico,periglacial studies are very recent and limited to the analysis of the general permafrost cover in the high mountains of the country.Although some of the studies on the reconstruction of Pleistocene glaciers in Mexico mention the existence of rock glaciers,to date no work has been done to study their physical properties or determining their state of conservation.Since rock glaciers are the most important visible indicators of mountain permafrost(along with features such as gelifluction lobes and patterned ground)and given that the“Nevado”rock glacier is the main example of its kind in Mexico,this study analyzes its internal temperature and assesses its state of conservation.The investigation was carried out by drilling and thermal monitoring of rock profiles as well as air.The results indicate that at present,the“Nevado”seems to lack permafrost inside.Although there is evidence of surface freezing during the winter months in the upper part of the rock glacier,in the lower portion it is almost unnoticed;and in both parts the internal temperature shows a tendency towards positive values as depth increases,a situation that predominates throughout the year.In addition,according to the records of the climatological station located in the lower part of the rock glacier,although the annual rainfall regime could be favorable for the formation and feeding of interstitial or segregated ice,the air temperature conditions throughout the year prevent permanent freezing.The sum of the above determines that at present the“Nevado”could be considered as an inactive and relict-type rock glacier;the presence of vegetation on the surface of the debris that make it up corroborates its inactivity.
基金support from the Open Research Fund of the National Center for International Research on Deep Earth Drilling and Resource Development,Ministry of Science and Technology (Grant No.DEDRD-2023-04)the National Natural Science Foundation of China (Grant No.42306237)the Fundamental Research Funds for the Central Universities,China University of Geosciences,Wuhan (Grant No.107-G1323523046).
文摘In the long-term exploitation of natural gas hydrate,the stress change intensifies the creep effect and leads to the destruction of pore structures,which makes it difficult to predict the permeability of hydrate reservoir.Although permeability is crucial to optimize gas recovery for gas hydrate reservoirs,until now,accurately modeling the permeability of hydrate-bearing clayey-silty sediments during the creep process remains a significant challenge.In this study,by combining the nonlinear fractional-order constitutive model and the Kozeny-Carman(KC)equation,a novel creep model for predicting the permeability of hydrate-bearing clayey-silty sediments has been proposed.In addition,experimental tests have been conducted to validate the derived model.The proposed model is further validated against other available test data.When the yield function F<0,the permeability decreases gradually due to the shrinkage of pore space.However,when the yield function F≥0,the penetrating damage bands will be generated.Results show that,once the model parameters are determined appropriately by fitting the test data,the model can also be used to predict permeability under any other stress conditions.This study has a certain guiding significance for elucidating the permeability evolution mechanisms of hydrate-bearing clayey-silty sediments during the extraction of marine gas hydrates.
文摘The three largest earthquakes in northern California since 1849 were preceded by increased decadal activity for moderate-size shocks along surrounding nearby faults. Increased seismicity, double-difference precise locations of earthquakes since 1968, geodetic data and fault offsets for the 1906 great shock are used to re-examine the timing and locations of possible future large earthquakes. The physical mechanisms of regional faults like the Calaveras, Hayward and Sargent, which exhibit creep, differ from those of the northern San Andreas, which is currently locked and is not creeping. Much decadal forerunning activity occurred on creeping faults. Moderate-size earthquakes along those faults became more frequent as stresses in the region increased in the latter part of the cycle of stress restoration for major and great earthquakes along the San Andreas. They may be useful for decadal forecasts. Yearly to decadal forecasts, however, are based on only a few major to great events. Activity along closer faults like that in the two years prior to the 1989 Loma Prieta shock needs to be examined for possible yearly forerunning changes to large plate boundary earthquakes. Geodetic observations are needed to focus on identifying creeping faults close to the San Andreas. The distribution of moderate-size earthquakes increased significantly since 1990 along the Hayward fault but not adjacent to the San Andreas fault to the south of San Francisco compared to what took place in the decades prior to the three major historic earthquakes in the region. It is now clear from a re-examination of the 1989 mainshock that the increased level of moderate-size shocks in the one to two preceding decades occurred on nearby East Bay faults. Double-difference locations of small earthquakes provide structural information about faults in the region, especially their depths. The northern San Andreas fault is divided into several strongly coupled segments based on differences in seismicity.
基金Project supported by the National Natural Science Foundation of China （Grant No 60477026）.
文摘This paper investigates the adjacent interactions of three novel solitons for the quintic complex Ginzburg-Landau equation, which are plain pulsating, erupting and creeping solitons. It is found that different performances are presented for different solitons due to isolated regions of the parameter space where they exist. For example, plain pulsating and erupting solitons exhibit mutual annihilation during collisions with the decrease of total energy, but for creeping soliton, the two adjacent pulses present soliton fusion without any loss of energy. Otherwise, the method for restraining the interactions is also found and it can suppress interactions between these two adjacent pulses effectively.
基金supported by the National Natural Science Foundation of China (11172152)
文摘It is well known that plane creeping Couette flow of UCM and Oldroy-B fluids are linearly stable. However, for Burges fluid, which includes UCM and Oldroyd-B fluids as special cases, unstable modes are detected in the present work. The wave speed, critical parameters and perturbation mode are studied for neutral waves. Energy analysis shows that the sustaining of perturbation energy in Poiseuille flow and Couette flow is completely different. At low Reynolds number limit, analytical solutions are obtained for simpli- fied perturbation equations. The essential difference between Burgers fluid and Oldroyd-B fluid is revealed to be the fact that neutral mode exists only in the former.
文摘The two dimensional equations of motions for the slowly flowing and heat transfer in second grade fluid are written in Cartesian coordinates neglecting the inertial terms. When the inertia terms are simply omitted from the equations of motions the resulting solutions are valid approximately for Re1. This fact can also be deduced from the dimensionless form of the momentum and energy equations. By employing Lie group analysis, the symmetries of the equations are calculated. The Lie algebra consists of four finite parameter and one infinite parameter Lie group transformations, one being the scaling symmetry and the others being translations. Two different types of solutions are found using the symmetries. Using translations in x and y coordinates, an exponential type of exact solution is presented. For the scaling symmetry, the outcoming ordinary differential equations are more involved and only a series type of approximate solution is presented. Finally, some boundary value problems are discussed.
基金theNaturalScienceFoundationofHeilongjiangProvince China (A0 0 9)
文摘A mechanical model was established for modeⅡinterfacial crack static growing along an elastic_elastic power law creeping bimaterial interface. For two kinds of boundary conditions on crack faces, traction free and frictional contact, asymptotic solutions of the stress and strain near tip_crack were given. Results derived indicate that the stress and strain have the same singularity, there is not the oscillatory singularity in the field; the creep power_hardening index n and the ratio of Young's module notably influence the crack_tip field in region of elastic power law creeping material and n only influences distribution of stresses and strains in region of elastic material. When n is bigger, the creeping deformation is dominant and stress fields become steady,which does not change with n. Poisson's ratio does not affect the distributing of the crack_tip field.
文摘Sustainable forage production is one of the most important factors in livestock production system. Smallholder livestock production system is a part of agricultural practice in Indonesia. Limited land owned by farmers was dominantly cultivated for food crops, and very small part of it used for cultivating forage plants. This leads to restriction of smallholder livestock development, because no more land available for forage production. Integrated forage production system by planting forage plants and food crops or trees in the same area becomes a considerable cropping system that widely practiced by the farmers in Indonesia. Some grasses and legumes have morphological advantages overcoming growth condition under shading. These growth characteristics are benefit in designing compatible system components for enhanced productivity in tree-pasture systems. Four potential shade-tolerant creeping forages that were combined with 2 levels of nitrogen application were tested using factorial completely randomized design 3 replicates. The first factor was species of creeping forages （stoloniferous）： BH = Brachiaria humidicola, PN = Paspalum notatum, AC - Axonopus compressus and, AP = Arachis pintoi. The second factor was nitrogen （urea） fertilizer： A = without N fertilizer and B = with N fertilizer （300 kg Urea/ha）. The observations included the growth rates of plant length, plant length, number of leaves, herbages yield （shoot）, root dry weight, senescence, total N-shoot, N-soil and N-uptake. The results showed that growth characteristics and productivity of creeping forage plants was significantly differed by the species. Most species showed an increase in growth trend, except P. notatum. A. compressus significantly showed as the best performance species compared to other, in terms of growth rates, plant length, number of leaves, herbage yield （shoot） and root dry weight, N-uptake and N-shoot. This was lbllowed by B. humidicola, P. notatum, and A. pintoi. Based on previous study, A. compressus found as one of the native species in most tree system. It indicated its superior growth compared to other species tested. However, it is needed further research to observe the compatibility of each species in tree-pasture systems.
文摘This paper presents an experimental study on the creeping discharge propagating over the pressboard surface in two vegetable oils(PFAE(palm fatty acid ester)oil and CRS(crude rapeseed)oil)and commercial mineral oil under the quasi-square impulse voltage with any pulse width.The pressboard impregnated with the sample oil is immersed completely into the same oil.The tungsten needle electrode is installed in the pressboard surface with and without the counter electrode to generate a creeping discharge.The other side of pressboard has the thin copper rod as a back side electrode.A comparison of the shape and stopping length of positive and negative streamers,discharge current,emitted light signal,and temporal variation and velocity of streamer propagation is reported for all different oil-pressboard interfaces.It has been shown that the behavior of creeping streamers has unique characteristics and polarity effects,and the traveling mode and propagation velocity of streamers are greatly different depending on the type of oil.
文摘The behaviors of creeping streamer progressed in the narrow gap with the range of 0.1 mm to 0.2 mm between the pressboard mounted a BSE （back side electrode） and the acrylic resin plate were carried out in PFAE （palm fatty acid ester） oil under variable impulse voltage up to -4-140 kVpeak with ＋1.2/50 μs and ±1.2/1,000μs waveforms. The growth of positive and negative streamers depends on the gap space between two solid dielectrics. And the distinctive polarities of impulse voltage affect in the streamer length and flashover voltage between needle and counter electrodes as well. By decreasing the gap space, the flashover voltage largely increased while the mean velocity of positive streamer significantly decreased under the both polarities of impulse voltage. These results have been compared to commercial mineral oil （transformer oil： JIS-C2320）. It is shown that the behaviors of creeping discharge in both oils elegantly reveal the distinctive phenomena.
基金supported by Biotechnology Risk Assessment Grant Program competitive grant no.2010-33522-21656from the USDA National Institute of Food and Agriculture,as well as the USDA grant CSREES SC-1700450.
文摘The conserved microRNA396(miR396)is involved in plant growth,development,and abiotic stress response in multiple plant species through regulating its targets,Growth Regulating Factor(GRF)transcription factor genes.However,the role of miR396 has not yet been characterized in perennial monocot species.In addition,the molecular mechanism of miR396-mediated abiotic stress response remains unclear.To elucidate the role of miR396 in perennial monocot species,we generated transgenic creeping bentgrass(Agrostis stolonifera)overexpressing Osa-miR396c,a rice miRNA396 gene.Transgenic plants exhibited altered development,including less shoot and root biomass,shorter internodes,smaller leaf area,fewer leaf veins,and epidermis cells per unit area than those of WT controls.In addition,transgenics showed enhanced salt tolerance associated with improved water retention,increased chlorophyll content,cell membrane integrity,and Na^(+)exclusion during high salinity exposure.Four potential targets of miR396 were identified in creeping bentgrass and up-regulated in response to salt stress.RNA-seq analysis indicates that miR396-mediated salt stress tolerance requires the coordination of stress-related functional proteins(antioxidant enzymes and Na+/H+antiporter)and regulatory proteins(transcription factors and protein kinases).This study establishes a miR396-associated molecular pathway to connect the upstream regulatory and downstream functional elements,and provides insight into the miRNA-mediated regulatory networks.
基金supported by the Chongqing Key Laboratory of Germplasm Innovation and Utilization of Native Plants(XTZW2021-KF04)Innovation and Promotion of Forestry Science and Technology of Jiangsu Province(LYKJ[2021]29).
文摘High temperature is one of the major abiotic stresses limiting growth and development of cool-season grass species,but chitosan could effectively enhance heat tolerance and improve plant growth.The objective of this study was to determine the optimal concentration of chitosan that could alleviate heat stress in creeping bentgrass(Agrostis stolonifera)and investigate the effects of exogenous chitosan on photosynthesis and cell membrane stability under heat stress.Under heat stress(38/28°C,day/night),different chitosan concentrations of 0,50,100 and 500 mg·L−1 were applied on the leaves of creeping bentgrass(cv.'Penn-A4').Foliar application of chitosan exhibited the positive effects on plant growth and the optimal concentration was 100 mg·L−1 which significantly improved turf quality,root length,root-shoot ratio as well as shoot and root biomass.Chitosan-treated plants subjected to high temperature stress had a lower decline in photosynthetic rate and photochemical efficiency as well as less increase in electrolyte leakage and malondialdehyde content.The results demonstrate that chitosan-improved heat tolerance as reflected by the superior growth performance of both shoot and root,photosynthesis and cell membrane stability in creeping bentgrass under heat stress.
基金This work was financially supported by Projects of the National Natural Science Foundation of China(Nos.521130511,11502082,52075174)the Higher Education Discipline Innovation Project("111 Project")(No.B13020).Helpful discussions with Jian-Feng Wen and Guo-Zhen Wang at the East China University of Science and Technology and Qiang Xu at the University of Huddersfield are gratefully acknowledged.
文摘Materials in engineering applications are rarely uniaxially-loaded.In reality,failures under multiaxial loading has been widely observed in engineering structures.The life prediction of a component under multiaxial stresses has long been a challenging issue,particularly for high temperature applications.To distinguish the mode of failure ranging from a maximum principal stress intergranular damage to von Mises effective stress rupture mode a multiaxial stress rupture criterion(MSRC)was originally proposed by Sdobyrev and then Hayhurst and Leckie(SHL MSRC).A multiaxial-factor,α,was developed as a result which was intended to be a material constant and differentiates the bias of the MSRC between maxi-mum principal stress and effective stress.The success of the SHL MSRC relies on accurately calibrating the value ofαto quantify the multiaxial response of the material/geometry combination.To find a more suitable approach for determining MSRC,the applicability of different methods are evaluated.Given that the resulting analysis of the various approaches can be affected by the creep failure mechanism,princi-ples in the determination of MSRC with and without using continuum damage mechanics approaches are recommended.The viability of uniaxial material parameters in correlating withαthrough the analysis of available data in literature is also presented.It is found that the increase of the uniaxial creep dam-age tolerance parameterλis accompanied bythe decreaseof theα-value,whichimplies thatthe creep ductility plays an important role in affecting the multiaxial rupture behavior of materials.
文摘This paper describes the creeping principle. Based on this principle, a pocket-sized electrode creep-feeding mechanism applied to electrical discharge machining(EDM) is designed. Features of the mechanism: the structure of two-layer parallel plate is employed as its moving pairs, and an integral structure is adoped in the design of the mechanism. This mechanism can drive an electrode by piezoelectric element in steps of order of nanometer (the minimum feeding step of 78nm).
基金This research was supported by the Rutgers Center for Turfgrass Science and the New Jersey Agricultural Experiment Station at Rutgers University.
文摘The atmospheric carbon dioxide level has increased and is predicted to continue increasing,which may affect various aspects of plant growth.The objective of this study was to investigate the effects of doubling the carbon dioxide level on the growth and physiological activities of a widely utilized cool-season turfgrass species,creeping bentgrass(Agrostis stolonifera L.‘Penncross’).‘Penncross’plants were established in fritted clay medium and maintained under well-irrigated and well-fertilized conditions in growth chambers.The plants were exposed to either ambient carbon dioxide concentrations(400±10 mmol L^(-1))or elevated carbon dioxide concentrations(800±10 mmol L^(-1))for 12 weeks.Plants grown under elevated carbon dioxide displayed a significantly faster growth rate of their lateral stems(stolons)and increased shoot and root dry weight but a reduced specific leaf area compared to those plants at ambient carbon dioxide levels.Fast stolon growth is a highly desirable trait for turfgrass establishment and recovery from physical damage.The root length and surface area were also increased due to the elevated CO_(2),which may facilitate water uptake and serve critical drought-avoidance roles when irrigation water is limited.Elevated carbon dioxide caused an increase in the leaf net photosynthetic rate but a reduction in the stomatal conductance and transpiration rate,contributing to improved water use efficiency in creeping bentgrass.Efficient water use is especially important for turfgrass plant survival when irrigation water is limited.Our results suggested that cool-season turfgrass species may greatly benefit from increasingly elevated carbon dioxide concentrations via growth promotion and increasing water use efficiency.
文摘In this paper, a incremental form of constitutive laws for creeping studies are proposed. The equations are based on the concept of creep hardening surface. Damage effects were introduced to the new constitutive relations to study solids creeping effects with pre-existing damages. The present formula is easy to be adopted into other numerical procedures such as finite element methods.
文摘In a soft clay layer overlain by a thick man made ground layer, as in the case of the Unkapam shores of the Golden Horn, excess pore pressures have remained for long periods and the soft clay layer has hardly undergone few volumetric deformations. Along the shores of the Golden Horn such creep of the soil towards the sea has been detected at more than 40 mm in the last 26 months. The measurements of those movements are examined in this paper. Our research points out that the local failure of a soil element or of a particular layer differs from the general failure of the soil mass. Furthermore, the large masses of unfailed soil which overlie the soft layer along the shores of the Golden Horn delay the general failure of the slopes. We conclude that the shear strains producing excessive pore pressures is the cause of the creep observed. Because a proper solution still need to be found for a sustainable stability of the area, it is necessary to continue with the measurements of the Golden Horn＇s creeping shores.
