Dielectric barrier discharge(DBD)plasma excited by a high-frequency alternating-current(AC)power supply is widely employed for the degradation of volatile organic compounds(VOCs).However,the thermal effect generated d...Dielectric barrier discharge(DBD)plasma excited by a high-frequency alternating-current(AC)power supply is widely employed for the degradation of volatile organic compounds(VOCs).However,the thermal effect generated during the discharge process leads to energy waste and low energy utilization efficiency.In this work,an innovative DBD thermally-conducted catalysis(DBD-TCC)system,integrating high-frequency AC-DBD plasma and its generated thermal effects to activate the Co/SBA-15 catalyst,was employed for toluene removal.Specifically,Co/SBA-15 catalysts are closely positioned to the ground electrode of the plasma zone and can be heated and activated by the thermal effect when the voltage exceeds 10 k V.At12.4 k V,the temperature in the catalyst zone reached 261℃ in the DBD-TCC system,resulting in an increase in toluene degradation efficiency of 17%,CO_(2)selectivity of 21.2%,and energy efficiency of 27%,respectively,compared to the DBD system alone.In contrast,the DBD thermally-unconducted catalysis(DBD-TUC)system fails to enhance toluene degradation due to insufficient heat absorption and catalytic activation,highlighting the crucial role of AC-DBD generated heat in the activation of the catalyst.Furthermore,the degradation pathway and mechanism of toluene in the DBD-TCC system were hypothesized.This work is expected to provide an energy-efficient approach for high-frequency AC-DBD plasma removal of VOCs.展开更多
As the Reynolds number increases, the skin friction has been identified as the dominant drag in many practical applications. In the present paper, the effects of the Reynolds number on the mean skin friction decomposi...As the Reynolds number increases, the skin friction has been identified as the dominant drag in many practical applications. In the present paper, the effects of the Reynolds number on the mean skin friction decomposition in turbulent channel flows up to Reτ= 5 200 are investigated based on two different methods, i.e., the FukagataIwamoto-Kasagi(FIK) identity(FUKAGATA, K., IWAMOTO, K., and KASAGI, N.Contribution of Reynolds stress distribution to the skin friction in wall-bounded flows.Physics of Fluids, 14(11), L73–L76(2002)) and the Renard-Deck(RD) identity(DECK,S., RENARD, N., LARAUFIE, R., and WEISS, P.′E. Large-scale contribution to mean wall shear stress in high-Reynolds-number flat-plate boundary layers up to Reθ= 13 650.Journal of Fluid Mechanics, 743, 202–248(2014)). The direct numerical simulation(DNS) data provided by Lee and Moser(LEE, M. and MOSER, R. D. Direct numerical simulation of turbulent channel flow up to Reτ≈ 5 200. Journal of Fluid Mechanics,774, 395–415(2015)) are used. For these two skin friction decomposition methods, their decomposed constituents are discussed and compared for different Reynolds numbers.The integrands of the decomposed constituents are locally analyzed across the boundary layer to assess the actions associated with the inhomogeneity and multi-scale nature of turbulent motion. The scaling of the decomposed constituents and their integrands are presented. In addition, the boundary layer is divided into three sub-regions to evaluate the contributive proportion of each sub-region with an increase in the Reynolds number.展开更多
[ Objective] This study aimed to investigate the biological effects of laser-induced mutation on fibrous roots of yellow skin onion. [ Method] Wet seeds of two yellow skin onion cultivars were irradiated by CO2 laser ...[ Objective] This study aimed to investigate the biological effects of laser-induced mutation on fibrous roots of yellow skin onion. [ Method] Wet seeds of two yellow skin onion cultivars were irradiated by CO2 laser and He-Ne laser at three dosage levels separately. A randomized complete block design with three replications was adopted. The biological effects of laser-induced mutation on fibrous roots of Ll-generation yellow skin onion were investigated with biostatistics and physiological and biochemical methods. [Result] Significant variations in the biological effects caused by various laser treatments were observed in the length, quantity, fresh weight and activity of onion fibrous roots. Specifically, the variation in fibrous root length induced by different types of laser reached 5% significance level; significant variation was observed in fibrous roots of different onion cultivars induced by laser, while the variation among each treatment did not reach 5% sig- nifieance level ; the variation in fibrous root quantity induced by different dosage levels of laser reached 5% significance level ; laser radiation showed stimulating effect on root activity of onion. [ Conclusion] This study provided reference for laser-induced breeding of yellow skin onion.展开更多
This paper proposes the‘skin effect’of the machining-induced damage at high strain rates.The paper first reviews the published research work on machining-induced damage and then identifies the governing factors that...This paper proposes the‘skin effect’of the machining-induced damage at high strain rates.The paper first reviews the published research work on machining-induced damage and then identifies the governing factors that dominate damage formation mechanisms.Among many influential factors,such as stress-strain field,temperature field,material responses to loading and loading rate,and crack initiation and propagation,strain rate is recognized as a dominant factor that can directly lead to the‘skin effect’of material damage in a loading process.The paper elucidates that material deformation at high strain rates(>103 s−1)leads to the embrittlement,which in turn contributes to the‘skin effect’of subsurface damage.The paper discusses the‘skin effect’based on the principles of dislocation kinetics and crack initiation and propagation.It provides guidance to predicting the material deformation and damage at a high strain-rate for applications ranging from the armor protection,quarrying,petroleum drilling,and high-speed machining of engineering materials(e.g.ceramics and SiC reinforced aluminum alloys).展开更多
In the present investigations, the antitumorigenic effect of black tea polyphenols (BTP) in twcrstage mouse skin model of carcinogenesis was studied. The animals were initiated with a single 'subcarcinogenic' ...In the present investigations, the antitumorigenic effect of black tea polyphenols (BTP) in twcrstage mouse skin model of carcinogenesis was studied. The animals were initiated with a single 'subcarcinogenic' topical dose (52 μg/200 μl acetone ) of 7, 12-dimethylbenzanthracene (DMBA). To evaluate the anti-tumour initiating activity, BTP was topically applied twice a week for three weeks prior to DMBA application, followed by topical treatment with 12-o-tetradecanoyl phorbol-13-acetate (TPA) (5 μg/200 μl acetone, 2x/wk. ) as promoter. For evaluation of antitumor promoting activity, BTP was applied prior to each treatment of TPA. BTP application showed marked inhibitory effect as antitumour initiator as well as antitumour promoter in mouse skin medel of two-stage carcinogenesis. Since initiation involves genetic pathway and tumour promotion involves epigenetic pathway, it seems that BTP exerts its antitumorigenic effect by altering both genetic and epigenetic pathways展开更多
Background: Magnetic resonance image-guided radiation therapy (MR-IGRT) promises more precise and effective radiation treatments compared to conventional IGRT by using real-time on-board MR imaging. Under the influenc...Background: Magnetic resonance image-guided radiation therapy (MR-IGRT) promises more precise and effective radiation treatments compared to conventional IGRT by using real-time on-board MR imaging. Under the influence of a magnetic field, however, secondary electrons exiting a surface can be forced in a circular path and re-enter the medium, resulting in dose increase at a beam-exit surface, called the electron return effect (ERE). The purpose of the study is to compare the exit skin dose computed by Monte Carlo dose calculation with measurements using an adult anthropomorphic phantom and to measure the effect of skin dose reduction by adding 1 cm-thick bolus. Method: The plan was compared with measurements using an adult anthropomorphic phantom combined with radiochromic films and thermoluminescent dosimeters. We also measured the skin dose reduction by adding 1 cm-thick bolus on the frontal surface of the phantom. Results: We found that 1 cm-thick bolus reduced the skin dose by up to 20% both in measurements and calculations. The plan was found to overestimate the measured skin dose by about 10% and there was no significant difference in the bolus effect between the breast skin and the skin (without breast attachment) doses. Conclusion: In conclusion, we confirmed the ERE effect on the anthropomorphic phantom under the magnetic field and the exit skin dose reduction by adding a bolus. Skin dose measurements using anthropomorphic phantom may be helpful to evaluate more realistic skin dose and the bolus effect in the magnetic field.展开更多
Epilepsy is a neurodegenerative disease that interrupts the normal electrical activity of the brain and promotes abnormal wiring in this organ.Epileptic seizures are often associated with significant changes in the fu...Epilepsy is a neurodegenerative disease that interrupts the normal electrical activity of the brain and promotes abnormal wiring in this organ.Epileptic seizures are often associated with significant changes in the functioning of the autonomic nervous system(ANS).展开更多
Micro fabrication of freeform surface parts made of hard and brittle materials is always a tough job in micro machining field. This paper tries to fabricate freeform surface feature by using smooth surface of tool ele...Micro fabrication of freeform surface parts made of hard and brittle materials is always a tough job in micro machining field. This paper tries to fabricate freeform surface feature by using smooth surface of tool electrode after tool wear in micro EDM. According to the skin effect theory, the tool end shape in the stage of uniform wear can be changed by adjusting the frequency of discharge pulse. The electrical energy distributing rule of tool electrode section in RC circuit has been investigated under the influence of skin effect, and the law of spark location change has been summarized. The experimental studies demonstrate that different shapes of tool ends can be achieved by varying the pulse frequencies of discharge power supply. Additionally, a micro part of freeform surface feature with high precision and good surface quality has been successfully obtained by micro EDM through adopting the smooth surface after tool wear.展开更多
We studied the effects of butyric acid (BA) on mouse skin tumorigenesis using chronicanimal bioassays. Topical application of BA immediately after each treatment with 12-0-te-t radecanoyl phorbol-13-acetate (TPA) prom...We studied the effects of butyric acid (BA) on mouse skin tumorigenesis using chronicanimal bioassays. Topical application of BA immediately after each treatment with 12-0-te-t radecanoyl phorbol-13-acetate (TPA) promoter' inhi bi ted skint umors. The effect was depe n -dent on the dose of BA applied. BA showed no marked inhibitory effect on either skin tumorinitiation or complete tumorigenesis induced by dimet hyl benzant hracene (DMBA ). Si nce t u -mor promotion reportedly involves epigenetic events whereas tumor initiation or complete tu-morigenesis takes place through genetic pathways, it is Possible that BA exerts its antitumori-genic effects mainly by altering the epigenetic events responsible for tumor promotion. The re-sults of the study could further be used to study the mechanism of action and modification ofantitumorigenic effects of BA in combination with other substances展开更多
The action of micromolar concentrations of Deltamethrin on sodium net transport through the in vivo skin of the South American toad Bufo arenarum was studied. The effect of pure ethanolic insecticide solutions and com...The action of micromolar concentrations of Deltamethrin on sodium net transport through the in vivo skin of the South American toad Bufo arenarum was studied. The effect of pure ethanolic insecticide solutions and commercial formulations when applied on the mucosal surface was assayed. Deltamethrin provoked a concentration-independent inhibition; the highest inhibition was found at the lowest concentrations. At highest concentrations of the insecticide the J Na was not altered展开更多
A high peak power IPL system (Lumecca) was tested to determine the correlation between a high peak power and the successful treatment of pigmented and vascular lesions. Short pulse duration in the millisecond range an...A high peak power IPL system (Lumecca) was tested to determine the correlation between a high peak power and the successful treatment of pigmented and vascular lesions. Short pulse duration in the millisecond range and high peak power of 3.3 kW/cm<sup>2</sup> enabled selective and effective destruction, not only of pigment, but also of vessels in a comparable manner to a pulsed dye laser. Only one treatment session at a low fluence (8 - 16 J/cm<sup>2</sup>) was sufficient to achieve the desired results.展开更多
The skin effect in the reversely switched dynistor (RSD) devices is investigated in this paper. Based on the plasma bipolar drift model of the RSD, the current density distributions on the chip are simulated with co...The skin effect in the reversely switched dynistor (RSD) devices is investigated in this paper. Based on the plasma bipolar drift model of the RSD, the current density distributions on the chip are simulated with considering the skin effect. The results indicate that the current density on the border can be several hundred to a thousand A/cm2 higher than that in the center of the chip. The skin effect becomes more prominent as the voltage increases and the inductance decreases in the main circuit. The phenomenon that most of a certain group of chips break over on the border has proved the existence of the skin effect.展开更多
The non-Hermitian skin effect breaks the conventional bulk–boundary correspondence and leads to non-Bloch topological invariants.Inspired by the fact that the topological protected zero modes are immune to perturbati...The non-Hermitian skin effect breaks the conventional bulk–boundary correspondence and leads to non-Bloch topological invariants.Inspired by the fact that the topological protected zero modes are immune to perturbations,we construct a partner of a non-Hermitian system by getting rid of the non-Hermitian skin effect.Through adjusting the imbalance hopping,we find that the existence of zero-energy boundary states still dictate the bulk topological invariants based on the band-theory framework.Two non-Hermitian Su–Schrieffer–Heeger(SSH)models are used to illuminate the ideas.Specially,we obtain the winding numbers in analytical form without the introduction of the generalized Brillouin zone.The work gives an alternative method to calculate the topological invariants of non-Hermitian systems.展开更多
Hydrogel-based tissue-engineered skin has attracted increased attention due to its potential to restore the structural integrity and functionality of skin.However,the mechanical properties of hydrogel scaffolds and na...Hydrogel-based tissue-engineered skin has attracted increased attention due to its potential to restore the structural integrity and functionality of skin.However,the mechanical properties of hydrogel scaffolds and natural skin are substantially different.Here,we developed a polyvinyl alcohol(PVA)/acrylamide based interpenetrating network(IPN)hydrogel that was surface modified with polydopamine(PDA)and termed Dopa-gel.The Dopa-gel exhibited mechanical properties similar to native skin tissue and a superior ability to modulate paracrine functions.Furthermore,a tough scaffold with tensile resistance was fabricated using this hydrogel by three-dimensional printing.The results showed that the interpenetration of PVA,alginate,and polyacrylamide networks notably enhanced the mechanical properties of the hydrogel.Surface modification with PDA endowed the hydrogels with increased secretion of immunomodulatory and proangiogenic factors.In an in vivo model,Dopa-gel treatment accelerated wound closure,increased vascularization,and promoted a shift in macrophages from a proinflammatory M1 phenotype to a prohealing and anti-inflammatory M2 phenotype within the wound area.Mechanistically,the focal adhesion kinase(FAK)/extracellular signal-related kinase(ERK)signaling pathway may mediate the promotion of skin defect healing by increasing paracrine secretion via the Dopa-gel.Additionally,proangiogenic factors can be induced through Rho-associated kinase-2(ROCK-2)/vascular endothelial growth factor(VEGF)-mediated paracrine secretion under tensile stress conditions.Taken together,these findings suggest that the multifunctional Dopa-gel,which has good mechanical properties similar to those of native skin tissue and enhanced immunomodulatory and angiogenic properties,is a promising scaffold for skin tissue regeneration.展开更多
We investigate novel features of three-dimensional non-Hermitian Weyl semimetals,paying special attention to the unconventional bulk-boundary correspondence.We use the non-Bloch Chern numbers as the tool to obtain the...We investigate novel features of three-dimensional non-Hermitian Weyl semimetals,paying special attention to the unconventional bulk-boundary correspondence.We use the non-Bloch Chern numbers as the tool to obtain the topological phase diagram,which is also confirmed by the energy spectra from our numerical results.It is shown that,in sharp contrast to Hermitian systems,the conventional(Bloch)bulk-boundary correspondence breaks down in non-Hermitian topological semimetals,which is caused by the non-Hermitian skin effect.We establish the non-Bloch bulk-boundary correspondence for non-Hermitian Weyl semimetals:the topological edge modes are determined by the non-Bloch Chern number of the bulk bands.Moreover,these topological edge modes can manifest as the unidirectional edge motion,and their signatures are consistent with the non-Bloch bulk-boundary correspondence.Our work establishes the non-Bloch bulk-boundary correspondence for non-Hermitian topological semimetals.展开更多
One of the most important functions of skins is to protect our bodies from microbes or pollutant sources. Skins containing physical substances serve as a physical barrier which protects our bodies from pathogens. A he...One of the most important functions of skins is to protect our bodies from microbes or pollutant sources. Skins containing physical substances serve as a physical barrier which protects our bodies from pathogens. A healthy skin contains a variety of antibacterial substances such as defensin, cathelicidin and psoriasin. However deep and wide burns cause the skin to lose its original functions, so our skins are exposed to various danger factors. For the burn patients, human alloskin graft serves as a very important temporary biological wound dressing. It protects the wound before autograft procedure, forms revascularization and granulation tissues and protects the wound from an invasion of microbes. This study was conducted with the aim to analyze the antimicrobial effect of cryopreserved allograft (CPA) and glycerol-preserved allograft (GPA) which was a type of allograft widely used for burn patients, and measure the difference in comparison with the fresh skin before processing it. The most common contaminants found in burn patients such as S. aureus, P. aeruginosa, C. albicans and E. coli, were used for experiment. The antimicrobial effect against S. aureus and E. coli was observed in fresh skin and some CPA. In some clinical cases, infection is frequently observed in the wounds treated with allograft, indicating the allograft completely block every kind of microbes. To prevent the infection, it is required to use antibiotics and manage wounds thoroughly.展开更多
The mathematic model of heat transfer through ventilated double glazing was verified with the measured data,which were from a test chamber equipped with glass face temperature,solar radiation,ambient temperature,and w...The mathematic model of heat transfer through ventilated double glazing was verified with the measured data,which were from a test chamber equipped with glass face temperature,solar radiation,ambient temperature,and wind speed measurement facility.After the model validation,the double-skin facade assessment was carried out through simulation with ESP-r software integrating thermal simulation and air low net work module.The air flow situation in the air gap was analyzed on the basis of the hourly air velocity simulation data within typical winter week,summer week,spring week and autumn week.The differences of chimney effect in different seasons were discussed,and the thermal loads resulted from the ventilated and unventilated double skin facade were presented.展开更多
The skin is a formidable physical and biological barrier which communicates continuously with the outside of the body. And the stratum corneum, the outermost layer of human epidermis, plays a central role in the inter...The skin is a formidable physical and biological barrier which communicates continuously with the outside of the body. And the stratum corneum, the outermost layer of human epidermis, plays a central role in the interaction between the cutaneous tissue and the external environment. The horny layer, and more generally the whole skin layers, avoid the penetration of harmful exogenous agents, produce molecules named anti-microbial peptides which impact the composition of the cutaneous microbiota, regulate the internal corporal temperature, avoid the water loss from the inside of the body and constitute an incredible efficient anti-oxidant network. Nevertheless, nowadays, the skin is more and more solicited by the different elements of the cutaneous exposome, including atmospheric pollution and solar radiations, which can cause a dramatic acceleration of the skin ageing process. As a consequence, due to the multifunctional protective role of the skin, during the recent decade the cosmetic industry invested massively in the development of new raw materials and end-products (dermo-cosmetics) able to preserve an optimal state of the skin regarding the external environment. Based on their physical-chemical properties thermal spring waters, which are extremely rich in inorganics ions, are interesting and powerful candidates to be part, as integral component, of new efficient dermo-cosmetic formulations dedicated to protect the skin from the external stimuli. The aim of the present work was to investigate and characterize the activity of Jonzac thermal spring water on the skin. Using different models, we proved for the first time that Jonzac thermal spring water reinforces the barrier function of the skin by modulating the expression of key markers including filaggrin and human beta defensin 2 on ex vivo human skin. The ex vivo and in vivo hydration activity, by Raman spectroscopy and corneometry respectively, has been also demonstrated. We have also shown that Jonzac thermal spring water ameliorates significantly the cutaneous microrelief in vivo. To conclude, we characterize the soothing effect of Jonzac thermal spring water by the analysis of histamine release in Substance P treated skin explants and by measuring the redness of the skin following UV exposure of the skin in vivo. We observed that both parameters decreased following a preventive treatment of the skin with Jonzac thermal spring water. Taken together our results indicate that Jonzac thermal spring water is a promising and powerful dermo-cosmetic which can be used to preserve an optimal state of the cutaneous tissue.展开更多
Acute toxicity of 0.3 ppm mercuric chloride on the mucocytes of the branchial diverticulum and skin of Heteropneustes fossilis results in cyclic increases followed by decreases in the density, area occupancy and volum...Acute toxicity of 0.3 ppm mercuric chloride on the mucocytes of the branchial diverticulum and skin of Heteropneustes fossilis results in cyclic increases followed by decreases in the density, area occupancy and volume at different intervals of exposure. The alterations in the two tissues do not follow the same path perhaps due to different modes of action of the mercury salt: The skin comes under direct contact effects, while the branchial diverticulum may be affected by hormonal imbalance caused by a stress effect.展开更多
In most studies of microstrip circuits, the majority of researchers assume that the microstrip structures studied have flat metallic conductors of finite widths but without thickness. But in reality these types of str...In most studies of microstrip circuits, the majority of researchers assume that the microstrip structures studied have flat metallic conductors of finite widths but without thickness. But in reality these types of structures integrate metallic copper conductors of different thicknesses. If we neglect this thickness we introduce error in the electrical parameters of the microstrip structure, which affects the effective permittivity, the characteristic impedance, the adaptation of the circuit, the resonance frequency, etc. Given the importance of this parameter (thickness of the metal of micro rubon structures), rigorous electromagnetic modeling of the thick micro rubon line based on the skin effect phenomenon (In fact at high frequency the skin effect phenomenon occurs and the current only flows on the periphery of the conductor) has been proposed to improve the studied electric model and ensure the increase in the precision of the analysis method used: Wave concept iterative process. The good agreement between the simulated and published data justifies the improvement of the model.展开更多
基金supported by National Natural Science Foundation of China(No.52177130)the Key Projects for Industrial Prospects and Core Technology Research in Suzhou City(No.SYC2022029)。
文摘Dielectric barrier discharge(DBD)plasma excited by a high-frequency alternating-current(AC)power supply is widely employed for the degradation of volatile organic compounds(VOCs).However,the thermal effect generated during the discharge process leads to energy waste and low energy utilization efficiency.In this work,an innovative DBD thermally-conducted catalysis(DBD-TCC)system,integrating high-frequency AC-DBD plasma and its generated thermal effects to activate the Co/SBA-15 catalyst,was employed for toluene removal.Specifically,Co/SBA-15 catalysts are closely positioned to the ground electrode of the plasma zone and can be heated and activated by the thermal effect when the voltage exceeds 10 k V.At12.4 k V,the temperature in the catalyst zone reached 261℃ in the DBD-TCC system,resulting in an increase in toluene degradation efficiency of 17%,CO_(2)selectivity of 21.2%,and energy efficiency of 27%,respectively,compared to the DBD system alone.In contrast,the DBD thermally-unconducted catalysis(DBD-TUC)system fails to enhance toluene degradation due to insufficient heat absorption and catalytic activation,highlighting the crucial role of AC-DBD generated heat in the activation of the catalyst.Furthermore,the degradation pathway and mechanism of toluene in the DBD-TCC system were hypothesized.This work is expected to provide an energy-efficient approach for high-frequency AC-DBD plasma removal of VOCs.
基金Project supported by the National Basic Research Program of China(973 Program)(No.2014CB744802)the National Natural Science Foundation of China(No.11772194)
文摘As the Reynolds number increases, the skin friction has been identified as the dominant drag in many practical applications. In the present paper, the effects of the Reynolds number on the mean skin friction decomposition in turbulent channel flows up to Reτ= 5 200 are investigated based on two different methods, i.e., the FukagataIwamoto-Kasagi(FIK) identity(FUKAGATA, K., IWAMOTO, K., and KASAGI, N.Contribution of Reynolds stress distribution to the skin friction in wall-bounded flows.Physics of Fluids, 14(11), L73–L76(2002)) and the Renard-Deck(RD) identity(DECK,S., RENARD, N., LARAUFIE, R., and WEISS, P.′E. Large-scale contribution to mean wall shear stress in high-Reynolds-number flat-plate boundary layers up to Reθ= 13 650.Journal of Fluid Mechanics, 743, 202–248(2014)). The direct numerical simulation(DNS) data provided by Lee and Moser(LEE, M. and MOSER, R. D. Direct numerical simulation of turbulent channel flow up to Reτ≈ 5 200. Journal of Fluid Mechanics,774, 395–415(2015)) are used. For these two skin friction decomposition methods, their decomposed constituents are discussed and compared for different Reynolds numbers.The integrands of the decomposed constituents are locally analyzed across the boundary layer to assess the actions associated with the inhomogeneity and multi-scale nature of turbulent motion. The scaling of the decomposed constituents and their integrands are presented. In addition, the boundary layer is divided into three sub-regions to evaluate the contributive proportion of each sub-region with an increase in the Reynolds number.
基金Supported by Natural Science Foundation of Sichuan Education Department(2008ZA033)
文摘[ Objective] This study aimed to investigate the biological effects of laser-induced mutation on fibrous roots of yellow skin onion. [ Method] Wet seeds of two yellow skin onion cultivars were irradiated by CO2 laser and He-Ne laser at three dosage levels separately. A randomized complete block design with three replications was adopted. The biological effects of laser-induced mutation on fibrous roots of Ll-generation yellow skin onion were investigated with biostatistics and physiological and biochemical methods. [Result] Significant variations in the biological effects caused by various laser treatments were observed in the length, quantity, fresh weight and activity of onion fibrous roots. Specifically, the variation in fibrous root length induced by different types of laser reached 5% significance level; significant variation was observed in fibrous roots of different onion cultivars induced by laser, while the variation among each treatment did not reach 5% sig- nifieance level ; the variation in fibrous root quantity induced by different dosage levels of laser reached 5% significance level ; laser radiation showed stimulating effect on root activity of onion. [ Conclusion] This study provided reference for laser-induced breeding of yellow skin onion.
基金The authors would like to acknowledge the supports by the National Natural Science Foundation of China(Grant No.51575084)and the Peacock Program of Shenzhen(Grant No.KQJSCX20180322152221965).
文摘This paper proposes the‘skin effect’of the machining-induced damage at high strain rates.The paper first reviews the published research work on machining-induced damage and then identifies the governing factors that dominate damage formation mechanisms.Among many influential factors,such as stress-strain field,temperature field,material responses to loading and loading rate,and crack initiation and propagation,strain rate is recognized as a dominant factor that can directly lead to the‘skin effect’of material damage in a loading process.The paper elucidates that material deformation at high strain rates(>103 s−1)leads to the embrittlement,which in turn contributes to the‘skin effect’of subsurface damage.The paper discusses the‘skin effect’based on the principles of dislocation kinetics and crack initiation and propagation.It provides guidance to predicting the material deformation and damage at a high strain-rate for applications ranging from the armor protection,quarrying,petroleum drilling,and high-speed machining of engineering materials(e.g.ceramics and SiC reinforced aluminum alloys).
文摘In the present investigations, the antitumorigenic effect of black tea polyphenols (BTP) in twcrstage mouse skin model of carcinogenesis was studied. The animals were initiated with a single 'subcarcinogenic' topical dose (52 μg/200 μl acetone ) of 7, 12-dimethylbenzanthracene (DMBA). To evaluate the anti-tumour initiating activity, BTP was topically applied twice a week for three weeks prior to DMBA application, followed by topical treatment with 12-o-tetradecanoyl phorbol-13-acetate (TPA) (5 μg/200 μl acetone, 2x/wk. ) as promoter. For evaluation of antitumor promoting activity, BTP was applied prior to each treatment of TPA. BTP application showed marked inhibitory effect as antitumour initiator as well as antitumour promoter in mouse skin medel of two-stage carcinogenesis. Since initiation involves genetic pathway and tumour promotion involves epigenetic pathway, it seems that BTP exerts its antitumorigenic effect by altering both genetic and epigenetic pathways
文摘Background: Magnetic resonance image-guided radiation therapy (MR-IGRT) promises more precise and effective radiation treatments compared to conventional IGRT by using real-time on-board MR imaging. Under the influence of a magnetic field, however, secondary electrons exiting a surface can be forced in a circular path and re-enter the medium, resulting in dose increase at a beam-exit surface, called the electron return effect (ERE). The purpose of the study is to compare the exit skin dose computed by Monte Carlo dose calculation with measurements using an adult anthropomorphic phantom and to measure the effect of skin dose reduction by adding 1 cm-thick bolus. Method: The plan was compared with measurements using an adult anthropomorphic phantom combined with radiochromic films and thermoluminescent dosimeters. We also measured the skin dose reduction by adding 1 cm-thick bolus on the frontal surface of the phantom. Results: We found that 1 cm-thick bolus reduced the skin dose by up to 20% both in measurements and calculations. The plan was found to overestimate the measured skin dose by about 10% and there was no significant difference in the bolus effect between the breast skin and the skin (without breast attachment) doses. Conclusion: In conclusion, we confirmed the ERE effect on the anthropomorphic phantom under the magnetic field and the exit skin dose reduction by adding a bolus. Skin dose measurements using anthropomorphic phantom may be helpful to evaluate more realistic skin dose and the bolus effect in the magnetic field.
基金supported by the Research Fund of the Erciyes University(TSD-09-1039)
文摘Epilepsy is a neurodegenerative disease that interrupts the normal electrical activity of the brain and promotes abnormal wiring in this organ.Epileptic seizures are often associated with significant changes in the functioning of the autonomic nervous system(ANS).
基金Supported by the National Natural Science Foundation of China (50635040) and the National Science Foundation of USA(CMMI-0728294 and CMMI- 0928873)
文摘Micro fabrication of freeform surface parts made of hard and brittle materials is always a tough job in micro machining field. This paper tries to fabricate freeform surface feature by using smooth surface of tool electrode after tool wear in micro EDM. According to the skin effect theory, the tool end shape in the stage of uniform wear can be changed by adjusting the frequency of discharge pulse. The electrical energy distributing rule of tool electrode section in RC circuit has been investigated under the influence of skin effect, and the law of spark location change has been summarized. The experimental studies demonstrate that different shapes of tool ends can be achieved by varying the pulse frequencies of discharge power supply. Additionally, a micro part of freeform surface feature with high precision and good surface quality has been successfully obtained by micro EDM through adopting the smooth surface after tool wear.
文摘We studied the effects of butyric acid (BA) on mouse skin tumorigenesis using chronicanimal bioassays. Topical application of BA immediately after each treatment with 12-0-te-t radecanoyl phorbol-13-acetate (TPA) promoter' inhi bi ted skint umors. The effect was depe n -dent on the dose of BA applied. BA showed no marked inhibitory effect on either skin tumorinitiation or complete tumorigenesis induced by dimet hyl benzant hracene (DMBA ). Si nce t u -mor promotion reportedly involves epigenetic events whereas tumor initiation or complete tu-morigenesis takes place through genetic pathways, it is Possible that BA exerts its antitumori-genic effects mainly by altering the epigenetic events responsible for tumor promotion. The re-sults of the study could further be used to study the mechanism of action and modification ofantitumorigenic effects of BA in combination with other substances
文摘The action of micromolar concentrations of Deltamethrin on sodium net transport through the in vivo skin of the South American toad Bufo arenarum was studied. The effect of pure ethanolic insecticide solutions and commercial formulations when applied on the mucosal surface was assayed. Deltamethrin provoked a concentration-independent inhibition; the highest inhibition was found at the lowest concentrations. At highest concentrations of the insecticide the J Na was not altered
文摘A high peak power IPL system (Lumecca) was tested to determine the correlation between a high peak power and the successful treatment of pigmented and vascular lesions. Short pulse duration in the millisecond range and high peak power of 3.3 kW/cm<sup>2</sup> enabled selective and effective destruction, not only of pigment, but also of vessels in a comparable manner to a pulsed dye laser. Only one treatment session at a low fluence (8 - 16 J/cm<sup>2</sup>) was sufficient to achieve the desired results.
基金supported by the National Natural Science Foundation of China under Grant No.50577028the Specialized Research Fund for the Doctoral Program of Higher Education of China under Grant No.20050487044the China Postdoctoral Science Foundation under Grant No.20080440931
文摘The skin effect in the reversely switched dynistor (RSD) devices is investigated in this paper. Based on the plasma bipolar drift model of the RSD, the current density distributions on the chip are simulated with considering the skin effect. The results indicate that the current density on the border can be several hundred to a thousand A/cm2 higher than that in the center of the chip. The skin effect becomes more prominent as the voltage increases and the inductance decreases in the main circuit. The phenomenon that most of a certain group of chips break over on the border has proved the existence of the skin effect.
基金Project supported by Hebei Provincial Natural Science Foundation of China(Grant Nos.A2012203174 and A2015203387)the National Natural Science Foundation of China(Grant Nos.10974169 and 11304270)
文摘The non-Hermitian skin effect breaks the conventional bulk–boundary correspondence and leads to non-Bloch topological invariants.Inspired by the fact that the topological protected zero modes are immune to perturbations,we construct a partner of a non-Hermitian system by getting rid of the non-Hermitian skin effect.Through adjusting the imbalance hopping,we find that the existence of zero-energy boundary states still dictate the bulk topological invariants based on the band-theory framework.Two non-Hermitian Su–Schrieffer–Heeger(SSH)models are used to illuminate the ideas.Specially,we obtain the winding numbers in analytical form without the introduction of the generalized Brillouin zone.The work gives an alternative method to calculate the topological invariants of non-Hermitian systems.
基金supported by the National Natural Science Foundation of China(32271413 and 32271408)the National Basic Research Program of China(2021YFA1201404)+2 种基金the Natural Science Foundation of Jiangsu Province(BK20232023)the Science Program of Jiangsu Province Administration for Market Regulation(KJ2024010)the Jiangsu Provincial Key Medical Center Foundation,and the Jiangsu Provincial Medical Outstanding Talent Foundation.
文摘Hydrogel-based tissue-engineered skin has attracted increased attention due to its potential to restore the structural integrity and functionality of skin.However,the mechanical properties of hydrogel scaffolds and natural skin are substantially different.Here,we developed a polyvinyl alcohol(PVA)/acrylamide based interpenetrating network(IPN)hydrogel that was surface modified with polydopamine(PDA)and termed Dopa-gel.The Dopa-gel exhibited mechanical properties similar to native skin tissue and a superior ability to modulate paracrine functions.Furthermore,a tough scaffold with tensile resistance was fabricated using this hydrogel by three-dimensional printing.The results showed that the interpenetration of PVA,alginate,and polyacrylamide networks notably enhanced the mechanical properties of the hydrogel.Surface modification with PDA endowed the hydrogels with increased secretion of immunomodulatory and proangiogenic factors.In an in vivo model,Dopa-gel treatment accelerated wound closure,increased vascularization,and promoted a shift in macrophages from a proinflammatory M1 phenotype to a prohealing and anti-inflammatory M2 phenotype within the wound area.Mechanistically,the focal adhesion kinase(FAK)/extracellular signal-related kinase(ERK)signaling pathway may mediate the promotion of skin defect healing by increasing paracrine secretion via the Dopa-gel.Additionally,proangiogenic factors can be induced through Rho-associated kinase-2(ROCK-2)/vascular endothelial growth factor(VEGF)-mediated paracrine secretion under tensile stress conditions.Taken together,these findings suggest that the multifunctional Dopa-gel,which has good mechanical properties similar to those of native skin tissue and enhanced immunomodulatory and angiogenic properties,is a promising scaffold for skin tissue regeneration.
基金the National Natural Science Foundation of China(Grants No.11504143).
文摘We investigate novel features of three-dimensional non-Hermitian Weyl semimetals,paying special attention to the unconventional bulk-boundary correspondence.We use the non-Bloch Chern numbers as the tool to obtain the topological phase diagram,which is also confirmed by the energy spectra from our numerical results.It is shown that,in sharp contrast to Hermitian systems,the conventional(Bloch)bulk-boundary correspondence breaks down in non-Hermitian topological semimetals,which is caused by the non-Hermitian skin effect.We establish the non-Bloch bulk-boundary correspondence for non-Hermitian Weyl semimetals:the topological edge modes are determined by the non-Bloch Chern number of the bulk bands.Moreover,these topological edge modes can manifest as the unidirectional edge motion,and their signatures are consistent with the non-Bloch bulk-boundary correspondence.Our work establishes the non-Bloch bulk-boundary correspondence for non-Hermitian topological semimetals.
文摘One of the most important functions of skins is to protect our bodies from microbes or pollutant sources. Skins containing physical substances serve as a physical barrier which protects our bodies from pathogens. A healthy skin contains a variety of antibacterial substances such as defensin, cathelicidin and psoriasin. However deep and wide burns cause the skin to lose its original functions, so our skins are exposed to various danger factors. For the burn patients, human alloskin graft serves as a very important temporary biological wound dressing. It protects the wound before autograft procedure, forms revascularization and granulation tissues and protects the wound from an invasion of microbes. This study was conducted with the aim to analyze the antimicrobial effect of cryopreserved allograft (CPA) and glycerol-preserved allograft (GPA) which was a type of allograft widely used for burn patients, and measure the difference in comparison with the fresh skin before processing it. The most common contaminants found in burn patients such as S. aureus, P. aeruginosa, C. albicans and E. coli, were used for experiment. The antimicrobial effect against S. aureus and E. coli was observed in fresh skin and some CPA. In some clinical cases, infection is frequently observed in the wounds treated with allograft, indicating the allograft completely block every kind of microbes. To prevent the infection, it is required to use antibiotics and manage wounds thoroughly.
基金Supported by Shanghai Science and Technology Supporting Program(08DZ1203500)City University of Hong Kong(7002004)+1 种基金Shanghai Local University Fund(071605124)Undergraduates Education Fund for University of Shanghai
文摘The mathematic model of heat transfer through ventilated double glazing was verified with the measured data,which were from a test chamber equipped with glass face temperature,solar radiation,ambient temperature,and wind speed measurement facility.After the model validation,the double-skin facade assessment was carried out through simulation with ESP-r software integrating thermal simulation and air low net work module.The air flow situation in the air gap was analyzed on the basis of the hourly air velocity simulation data within typical winter week,summer week,spring week and autumn week.The differences of chimney effect in different seasons were discussed,and the thermal loads resulted from the ventilated and unventilated double skin facade were presented.
文摘The skin is a formidable physical and biological barrier which communicates continuously with the outside of the body. And the stratum corneum, the outermost layer of human epidermis, plays a central role in the interaction between the cutaneous tissue and the external environment. The horny layer, and more generally the whole skin layers, avoid the penetration of harmful exogenous agents, produce molecules named anti-microbial peptides which impact the composition of the cutaneous microbiota, regulate the internal corporal temperature, avoid the water loss from the inside of the body and constitute an incredible efficient anti-oxidant network. Nevertheless, nowadays, the skin is more and more solicited by the different elements of the cutaneous exposome, including atmospheric pollution and solar radiations, which can cause a dramatic acceleration of the skin ageing process. As a consequence, due to the multifunctional protective role of the skin, during the recent decade the cosmetic industry invested massively in the development of new raw materials and end-products (dermo-cosmetics) able to preserve an optimal state of the skin regarding the external environment. Based on their physical-chemical properties thermal spring waters, which are extremely rich in inorganics ions, are interesting and powerful candidates to be part, as integral component, of new efficient dermo-cosmetic formulations dedicated to protect the skin from the external stimuli. The aim of the present work was to investigate and characterize the activity of Jonzac thermal spring water on the skin. Using different models, we proved for the first time that Jonzac thermal spring water reinforces the barrier function of the skin by modulating the expression of key markers including filaggrin and human beta defensin 2 on ex vivo human skin. The ex vivo and in vivo hydration activity, by Raman spectroscopy and corneometry respectively, has been also demonstrated. We have also shown that Jonzac thermal spring water ameliorates significantly the cutaneous microrelief in vivo. To conclude, we characterize the soothing effect of Jonzac thermal spring water by the analysis of histamine release in Substance P treated skin explants and by measuring the redness of the skin following UV exposure of the skin in vivo. We observed that both parameters decreased following a preventive treatment of the skin with Jonzac thermal spring water. Taken together our results indicate that Jonzac thermal spring water is a promising and powerful dermo-cosmetic which can be used to preserve an optimal state of the cutaneous tissue.
文摘Acute toxicity of 0.3 ppm mercuric chloride on the mucocytes of the branchial diverticulum and skin of Heteropneustes fossilis results in cyclic increases followed by decreases in the density, area occupancy and volume at different intervals of exposure. The alterations in the two tissues do not follow the same path perhaps due to different modes of action of the mercury salt: The skin comes under direct contact effects, while the branchial diverticulum may be affected by hormonal imbalance caused by a stress effect.
文摘In most studies of microstrip circuits, the majority of researchers assume that the microstrip structures studied have flat metallic conductors of finite widths but without thickness. But in reality these types of structures integrate metallic copper conductors of different thicknesses. If we neglect this thickness we introduce error in the electrical parameters of the microstrip structure, which affects the effective permittivity, the characteristic impedance, the adaptation of the circuit, the resonance frequency, etc. Given the importance of this parameter (thickness of the metal of micro rubon structures), rigorous electromagnetic modeling of the thick micro rubon line based on the skin effect phenomenon (In fact at high frequency the skin effect phenomenon occurs and the current only flows on the periphery of the conductor) has been proposed to improve the studied electric model and ensure the increase in the precision of the analysis method used: Wave concept iterative process. The good agreement between the simulated and published data justifies the improvement of the model.