The machining process remains relevant for manufacturing high-quality and high-precision parts,which can be found in industries such as aerospace and aeronautical,with many produced by turning,drilling,and milling pro...The machining process remains relevant for manufacturing high-quality and high-precision parts,which can be found in industries such as aerospace and aeronautical,with many produced by turning,drilling,and milling processes.Monitoring and analyzing tool wear during these processes is crucial to assess the tool’s life and optimize the tool’s performance under study;as such,standards detail procedures to measure and assess tool wear for various tools.Measuring wear in machining tools can be time-consuming,as the process is usually manual,requiring human interaction and judgment.In the present work,an automated offline flank wear measurement algorithm was developed in Python.The algorithm measures the flank wear of coated end-mills and slot drills from Scanning Electron Microscopy(SEM)images,according to the ISO 8688 standard,following the same wear measurement procedure.SEM images acquired with different magnifications and tools with varying machining parameters were analyzed using the developed algorithm.The flank wear measurements were then compared to the manually obtained,achieving relative errors for the most common magnifications of around 2.5%.Higher magnifications were also tested,yielding a maximum relative error of 13.4%.The algorithm can measure batches of images quickly on an ordinary personal computer,analyzing and measuring a 10-image batch in around 30 s,a process that would require around 30 min when performed manually by a skilled operator.Therefore,it can be a reliable alternative to measuring flank wear on many tools from SEM images,with the possibility of being adjusted for other wear measurements on different kinds of tools and different image types,for example,on images obtained by optical microscopy.展开更多
Endotoxins(also known as lipopolysaccharides(LPS)) are undesirable by-products of recombinant proteins,purified from Escherichia coli.LPS can be considered stable under a wide range of temperature and pH,making their ...Endotoxins(also known as lipopolysaccharides(LPS)) are undesirable by-products of recombinant proteins,purified from Escherichia coli.LPS can be considered stable under a wide range of temperature and pH,making their removal one of the most difficult tasks in downstream processes during protein purification.The inherent toxicity of LPS makes their removal an important step for the application of these proteins in several biological assays and for a safe parenteral administration.Immobilized metal affinity chromatography(IMAC) enables the affinity interactions between the metal ions(immobilized on the support through the chelating compound) and the target molecules,thus enabling high-efficiency separation of the target molecules from other components present in a mixture.Affinity chromatography is applied with Ca2+-iminodiacetic acid(IDA) to remove most of the LPS contaminants from the end product(more than90%).In this study,the adsorption of LPS on an IDA-Ca2+ was investigated.The adsorption Freundlich isotherm of LPS-IDA-Ca2+ provides a theoretical basis for LPS removal.It was found that LPS is bound mainly by interactions between the phosphate group in LPS and Ca2+ ligands on the beads.The factors such as pH(4.0 or 5.5) and ionic strength(1.0 mol/L) are essential to obtain effective removal of LPS for contaminant levels between endotoxin' concentration values less than100 EU/mL and 100 000 EU/mL.This new protocol represents a substantial advantage in time,effort,and production costs.展开更多
Objective The present study evaluated the antinociceptive activity of Calendula officinalis L.(Ca)cream on inflammatory hypernociception.Methods Creams with different Ca concentrations were tested for their ability to...Objective The present study evaluated the antinociceptive activity of Calendula officinalis L.(Ca)cream on inflammatory hypernociception.Methods Creams with different Ca concentrations were tested for their ability to ameliorate pain-related behavior and edema in rats using formalin test,carrageenan(Cg)-induced acute inflammation model,bradykinin(BK)-induced acute inflammation model,and complete Freund’s adjuvant(CFA)-induced chronic inflammation model.Using the formalin test,we also examined the implication of peripheral opioid receptors in the antinociceptive mechanisms of Ca cream,by means of Q-naloxone,a peripherally acting nonselective opioid antagonist.Furthermore,the effects of Ca cream compared with diclofenac on BK-induced edema were examined when the kininase II in tissue was preserved or inhibited by captopril.The local production of redox biomarkers in formalin model,tumor necrosis factor-α(TNF-α)in Cg model and histopathological changes in CFA model were also evaluated.Results A single application of Ca cream at a dose of 10%or 30%(w/w)decreased the formalin-induced licking/biting behavior during both phases of this test in a Q-naloxone-sensitive manner.This effect was associated with the reduction of oxidative stress in the injured paw and the edema associated with the later phase of formalin-induced pain.A single application of Ca cream(10%or 30%)reduced paw edema and thermal hypernociception in Cg-induced acute inflammation,corresponding with a local decrease in TNF-α.Ca cream also inhibited BK-induced spontaneous nociceptive behavior and paw inflammation in both paradigms studied.Repeated applications of Ca cream also decreased CFA-induced chronic inflammation,mechanical hypernociception and histopathological changes in the paw.Conclusion These results reveal the topical antinociceptive and antiedematogenic effects of Ca cream.A modulatory action on peripheral opioid receptors associated with its antioxidant mechanism may be involved,at least in part,in its analgesic effects.These findings may have an impact on the clinical management of painful inflammatory diseases.展开更多
A multilayer film,composed by ZrN‒Ag(20 nm)and Mo‒S‒N(10 nm)layers,combining the intrinsic lubricant characteristics of each layer was deposited using DC magnetron sputtering system,to promote lubrication in a wide-ra...A multilayer film,composed by ZrN‒Ag(20 nm)and Mo‒S‒N(10 nm)layers,combining the intrinsic lubricant characteristics of each layer was deposited using DC magnetron sputtering system,to promote lubrication in a wide-range of temperatures.The results showed that the ZrN‒Ag/Mo‒S‒N multilayer film exhibited a sharp interface between the different layers.A face-centered cubic(fcc)dual-phases of ZrN and Ag co-existed in the ZrN‒Ag layers,whilst the Mo‒S‒N layers displayed a mixture of hexagonal close-packed MoS_(2)(hcp-MoS_(2))nano-particles and an amorphous phase.The multilayer film exhibited excellent room temperature(RT)triblogical behavior,as compared to the individual monolayer film,due to the combination of a relative high hardness with the low friction properties of both layers.The reorientation of MoS_(2)parallel to the sliding direction also contributed to the enhanced anti-frictional performance at RT.At 400℃,the reorientation of MoS_(2)as well as the formation of MoO_(3)phase were responsible for the lubrication,whilst the hard t-ZrO_(2)phase promoted abrasion and,consequently,led to increasing wear rate.At 600℃,the Ag_(2)MoO_(4)double-metal oxide was the responsible for the low friction and wear-resistance;furthermore,the observed transformation from t-ZrO_(2)to m-ZrO_(2),could also have contributed to the better tribological performance.展开更多
文摘The machining process remains relevant for manufacturing high-quality and high-precision parts,which can be found in industries such as aerospace and aeronautical,with many produced by turning,drilling,and milling processes.Monitoring and analyzing tool wear during these processes is crucial to assess the tool’s life and optimize the tool’s performance under study;as such,standards detail procedures to measure and assess tool wear for various tools.Measuring wear in machining tools can be time-consuming,as the process is usually manual,requiring human interaction and judgment.In the present work,an automated offline flank wear measurement algorithm was developed in Python.The algorithm measures the flank wear of coated end-mills and slot drills from Scanning Electron Microscopy(SEM)images,according to the ISO 8688 standard,following the same wear measurement procedure.SEM images acquired with different magnifications and tools with varying machining parameters were analyzed using the developed algorithm.The flank wear measurements were then compared to the manually obtained,achieving relative errors for the most common magnifications of around 2.5%.Higher magnifications were also tested,yielding a maximum relative error of 13.4%.The algorithm can measure batches of images quickly on an ordinary personal computer,analyzing and measuring a 10-image batch in around 30 s,a process that would require around 30 min when performed manually by a skilled operator.Therefore,it can be a reliable alternative to measuring flank wear on many tools from SEM images,with the possibility of being adjusted for other wear measurements on different kinds of tools and different image types,for example,on images obtained by optical microscopy.
基金supported by grants from the Brazilian Agency Coordination of Graduate Level Training(CAPES,project 0366/09-9)State of So Paulo Research Support Foundation(FAPESP-Brazil,project 2005/60159-7)
文摘Endotoxins(also known as lipopolysaccharides(LPS)) are undesirable by-products of recombinant proteins,purified from Escherichia coli.LPS can be considered stable under a wide range of temperature and pH,making their removal one of the most difficult tasks in downstream processes during protein purification.The inherent toxicity of LPS makes their removal an important step for the application of these proteins in several biological assays and for a safe parenteral administration.Immobilized metal affinity chromatography(IMAC) enables the affinity interactions between the metal ions(immobilized on the support through the chelating compound) and the target molecules,thus enabling high-efficiency separation of the target molecules from other components present in a mixture.Affinity chromatography is applied with Ca2+-iminodiacetic acid(IDA) to remove most of the LPS contaminants from the end product(more than90%).In this study,the adsorption of LPS on an IDA-Ca2+ was investigated.The adsorption Freundlich isotherm of LPS-IDA-Ca2+ provides a theoretical basis for LPS removal.It was found that LPS is bound mainly by interactions between the phosphate group in LPS and Ca2+ ligands on the beads.The factors such as pH(4.0 or 5.5) and ionic strength(1.0 mol/L) are essential to obtain effective removal of LPS for contaminant levels between endotoxin' concentration values less than100 EU/mL and 100 000 EU/mL.This new protocol represents a substantial advantage in time,effort,and production costs.
基金This research was financed by the projects of Ministerio de Salud Pública(MINSAP)Cuba(No.0808001)Agencia Presidencial de Cooperación Internacional de Colombia(APC),Bilateral Program Cuba-Colombia,and Fondo Nacional de Desarrollo Científico y Tecnológico(FONDECYT)Chile(No.1130601).
文摘Objective The present study evaluated the antinociceptive activity of Calendula officinalis L.(Ca)cream on inflammatory hypernociception.Methods Creams with different Ca concentrations were tested for their ability to ameliorate pain-related behavior and edema in rats using formalin test,carrageenan(Cg)-induced acute inflammation model,bradykinin(BK)-induced acute inflammation model,and complete Freund’s adjuvant(CFA)-induced chronic inflammation model.Using the formalin test,we also examined the implication of peripheral opioid receptors in the antinociceptive mechanisms of Ca cream,by means of Q-naloxone,a peripherally acting nonselective opioid antagonist.Furthermore,the effects of Ca cream compared with diclofenac on BK-induced edema were examined when the kininase II in tissue was preserved or inhibited by captopril.The local production of redox biomarkers in formalin model,tumor necrosis factor-α(TNF-α)in Cg model and histopathological changes in CFA model were also evaluated.Results A single application of Ca cream at a dose of 10%or 30%(w/w)decreased the formalin-induced licking/biting behavior during both phases of this test in a Q-naloxone-sensitive manner.This effect was associated with the reduction of oxidative stress in the injured paw and the edema associated with the later phase of formalin-induced pain.A single application of Ca cream(10%or 30%)reduced paw edema and thermal hypernociception in Cg-induced acute inflammation,corresponding with a local decrease in TNF-α.Ca cream also inhibited BK-induced spontaneous nociceptive behavior and paw inflammation in both paradigms studied.Repeated applications of Ca cream also decreased CFA-induced chronic inflammation,mechanical hypernociception and histopathological changes in the paw.Conclusion These results reveal the topical antinociceptive and antiedematogenic effects of Ca cream.A modulatory action on peripheral opioid receptors associated with its antioxidant mechanism may be involved,at least in part,in its analgesic effects.These findings may have an impact on the clinical management of painful inflammatory diseases.
基金supported by the National Natural Science Foundation of China(Nos.52171071,51801081,and 52071159)national funds through FCT of Portugal-Fundação para a Ciência e a Tecnologia,under a scientific contract of 2021.04115.CEECIND,and the project of UIDB/00285/2020,LA/0112/2020,MCTool21-ref.“POCI-01-0247-FEDER-045940”cofinanced via FEDER and FCT-Fundação para a Ciência e a Tecnologia(COMPETE),Outstanding University Young Teachers of“Qing Lan Project”of Jiangsu Province of China,Excellent Talents of“Shenlan Project”of Jiangsu University of Science of China.
文摘A multilayer film,composed by ZrN‒Ag(20 nm)and Mo‒S‒N(10 nm)layers,combining the intrinsic lubricant characteristics of each layer was deposited using DC magnetron sputtering system,to promote lubrication in a wide-range of temperatures.The results showed that the ZrN‒Ag/Mo‒S‒N multilayer film exhibited a sharp interface between the different layers.A face-centered cubic(fcc)dual-phases of ZrN and Ag co-existed in the ZrN‒Ag layers,whilst the Mo‒S‒N layers displayed a mixture of hexagonal close-packed MoS_(2)(hcp-MoS_(2))nano-particles and an amorphous phase.The multilayer film exhibited excellent room temperature(RT)triblogical behavior,as compared to the individual monolayer film,due to the combination of a relative high hardness with the low friction properties of both layers.The reorientation of MoS_(2)parallel to the sliding direction also contributed to the enhanced anti-frictional performance at RT.At 400℃,the reorientation of MoS_(2)as well as the formation of MoO_(3)phase were responsible for the lubrication,whilst the hard t-ZrO_(2)phase promoted abrasion and,consequently,led to increasing wear rate.At 600℃,the Ag_(2)MoO_(4)double-metal oxide was the responsible for the low friction and wear-resistance;furthermore,the observed transformation from t-ZrO_(2)to m-ZrO_(2),could also have contributed to the better tribological performance.
