In this study, the Zn nanoparticles were synthesized using the peel extract of Citrus aurantium. The nanoparticles were characterized by different chemical techniques including UV-Vis. and FT-IR spectroscopy, and SEM technique. The results revealed a spherical shape with an average size of 41.17 nm was identified for the green-synthesized nanoparticles. In the antioxidant test, the IC50 of nanoparticles and butylated hydroxytoluene (BHT) against DPPH free radicals were 115 and 96 μg/mL, respectively. In the cellular and molecular part of the recent study, the treated cells with nanoparticles were assessed by the MTT assay for 48 h about the cytotoxicity and anti-human bone cancer properties on normal (HUVEC) and cancer cell lines, that is, A-673 and HS-729. The IC50 of nanoparticles were 278 and 256 μg/mL against A-673 and HS-729 cell lines, respectively. The viability of malignant cell lines reduced dose-dependently in the presence of Zn nanoparticles. It seems that the anti-cancer effect of recent nanoparticles is due to their anti-oxidant effects. After evaluating the effectiveness of this formulation in clinical trial researches, it can be a good alternative to chemotherapy drugs.
{"title":"Facile preparation of zinc nanoparticles mediated by plant aqueous extract and assessment of the antioxidant, cytotoxicity and anti-human bone carcinoma properties","authors":"Tao Li, Maohua Li","doi":"10.1049/mna2.12156","DOIUrl":"https://doi.org/10.1049/mna2.12156","url":null,"abstract":"<p>In this study, the Zn nanoparticles were synthesized using the peel extract of <i>Citrus aurantium</i>. The nanoparticles were characterized by different chemical techniques including UV-Vis. and FT-IR spectroscopy, and SEM technique. The results revealed a spherical shape with an average size of 41.17 nm was identified for the green-synthesized nanoparticles. In the antioxidant test, the IC<sub>50</sub> of nanoparticles and butylated hydroxytoluene (BHT) against DPPH free radicals were 115 and 96 μg/mL, respectively. In the cellular and molecular part of the recent study, the treated cells with nanoparticles were assessed by the MTT assay for 48 h about the cytotoxicity and anti-human bone cancer properties on normal (HUVEC) and cancer cell lines, that is, A-673 and HS-729. The IC<sub>50</sub> of nanoparticles were 278 and 256 μg/mL against A-673 and HS-729 cell lines, respectively. The viability of malignant cell lines reduced dose-dependently in the presence of Zn nanoparticles. It seems that the anti-cancer effect of recent nanoparticles is due to their anti-oxidant effects. After evaluating the effectiveness of this formulation in clinical trial researches, it can be a good alternative to chemotherapy drugs.</p>","PeriodicalId":18398,"journal":{"name":"Micro & Nano Letters","volume":"18 3","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/mna2.12156","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50134579","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Italian Thermotechnical Committee is drafting a new standard for the life assessment of creep-operated pressure equipment, including modern steam boilers. For the evaluation of the spent life ratio several methods are available, even if each of them is not exhaustive. It should be noted that the methods described must be considered in combination with NDTs and other kinds of tests, e.g., hardness tests. X-ray diffraction (XRD) is one of the methods that could be used to assess material evolution under creep conditions. The method allows for the study of phase transitions involving structural variations. It is possible to operate on both massive samples and powders. In this paper, work done with XRD, in the frame of a wider project regarding the study of the high-temperature behavior of welded martensitic steels, is presented. The results of the XRD analysis were compared with the results of the extraction replicas. This work concerns the controls of eight failed crept specimens submitted to XRD examinations. Eight XRD diagrams were produced and subsequently compared with 12 replicas for each specimen; that is, 96 extraction replicas were produced for this work. Then, around 5000 precipitates were analyzed for each specimen; therefore, for this work, around 40,000 precipitates were characterized with their chemical compositions. The average size of the precipitates was around 97 nm.
{"title":"The New Italian Standard on the Life Assessment of Martensitic Steels—First Results of the Experimental Validation Activity of XRD by Testing P91 and P92 Samples from Interrupted Uniaxial Creep Tests","authors":"A. Tonti, Pietro De Blasi","doi":"10.3390/micro3010020","DOIUrl":"https://doi.org/10.3390/micro3010020","url":null,"abstract":"The Italian Thermotechnical Committee is drafting a new standard for the life assessment of creep-operated pressure equipment, including modern steam boilers. For the evaluation of the spent life ratio several methods are available, even if each of them is not exhaustive. It should be noted that the methods described must be considered in combination with NDTs and other kinds of tests, e.g., hardness tests. X-ray diffraction (XRD) is one of the methods that could be used to assess material evolution under creep conditions. The method allows for the study of phase transitions involving structural variations. It is possible to operate on both massive samples and powders. In this paper, work done with XRD, in the frame of a wider project regarding the study of the high-temperature behavior of welded martensitic steels, is presented. The results of the XRD analysis were compared with the results of the extraction replicas. This work concerns the controls of eight failed crept specimens submitted to XRD examinations. Eight XRD diagrams were produced and subsequently compared with 12 replicas for each specimen; that is, 96 extraction replicas were produced for this work. Then, around 5000 precipitates were analyzed for each specimen; therefore, for this work, around 40,000 precipitates were characterized with their chemical compositions. The average size of the precipitates was around 97 nm.","PeriodicalId":18398,"journal":{"name":"Micro & Nano Letters","volume":"5 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85159554","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nooshin Yousefpour, O. Björnberg, I. Yao Mattisson, O. Axelsson
A novel ICP-OES method has been developed for the determination of Si concentration, originating from polyorganophosphosilanes, in biological specimens that also contain metal ions. The method is free of hazardous hydrofluoric acid (HF) and involves digestion with HNO3/H2O2 prior to the analysis by ICP-OES. High and reproducible spike recovery was obtained from the controls.
{"title":"Hydrofluoric Acid-Free Digestion of Organosilicon Nanoparticles for Bioanalysis by ICP-OES","authors":"Nooshin Yousefpour, O. Björnberg, I. Yao Mattisson, O. Axelsson","doi":"10.3390/micro3010019","DOIUrl":"https://doi.org/10.3390/micro3010019","url":null,"abstract":"A novel ICP-OES method has been developed for the determination of Si concentration, originating from polyorganophosphosilanes, in biological specimens that also contain metal ions. The method is free of hazardous hydrofluoric acid (HF) and involves digestion with HNO3/H2O2 prior to the analysis by ICP-OES. High and reproducible spike recovery was obtained from the controls.","PeriodicalId":18398,"journal":{"name":"Micro & Nano Letters","volume":"52 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73434982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Gaylarde, M. P. de Almeida, Charles V. Neves, José Antônio Baptista Neto, E. M. da Fonseca
Although plastic is ubiquitous in marine systems, our current knowledge of its transport is limited. Recent studies suggest size-selective removal of small plastic particles (<5 mm) from the ocean surface as a result of the formation of a biofilm (the “plastisphere”) on the microplastic particle (MP) surface. This localized microenvironment can isolate the microcosm from the adjacent aqueous medium, and thus protect component alien species from the surrounding physico-chemical conditions. Apart from resulting in specific conditions for the transfer of alien species through the environment, the plastisphere can impact MP hydrodynamics and cause MPs to move through the water column, initially sinking. The importance of this phenomenon has not been previously considered for these particles. The size-dependent vertical movement of MPs through the water column determines their distribution, which will vary with time of exposure and colonization. Some plastisphere organisms have plastic-degrading activities, which could be harnessed in marine depollution strategies. This article seeks to increase our understanding of the role of biofilms in the biological dynamics and diffusion of plastic microparticles.
{"title":"The Importance of Biofilms on Microplastic Particles in Their Sinking Behavior and the Transfer of Invasive Organisms between Ecosystems","authors":"C. Gaylarde, M. P. de Almeida, Charles V. Neves, José Antônio Baptista Neto, E. M. da Fonseca","doi":"10.3390/micro3010022","DOIUrl":"https://doi.org/10.3390/micro3010022","url":null,"abstract":"Although plastic is ubiquitous in marine systems, our current knowledge of its transport is limited. Recent studies suggest size-selective removal of small plastic particles (<5 mm) from the ocean surface as a result of the formation of a biofilm (the “plastisphere”) on the microplastic particle (MP) surface. This localized microenvironment can isolate the microcosm from the adjacent aqueous medium, and thus protect component alien species from the surrounding physico-chemical conditions. Apart from resulting in specific conditions for the transfer of alien species through the environment, the plastisphere can impact MP hydrodynamics and cause MPs to move through the water column, initially sinking. The importance of this phenomenon has not been previously considered for these particles. The size-dependent vertical movement of MPs through the water column determines their distribution, which will vary with time of exposure and colonization. Some plastisphere organisms have plastic-degrading activities, which could be harnessed in marine depollution strategies. This article seeks to increase our understanding of the role of biofilms in the biological dynamics and diffusion of plastic microparticles.","PeriodicalId":18398,"journal":{"name":"Micro & Nano Letters","volume":"77 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90447985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L. Alamo-Nole, Adriana Ponton-Almodovar, Ivan Ortiz-Laboy
In the last few years, quantum dots (QDs) have attracted research interest in different fields of science and technology. Despite their applications, it is essential to understand how nanomaterials (with different crystal sizes) are metabolized inside organisms. Thus, the focus of this study was on an evaluation of how crystal sizes of CdSTe QDs affect the viability and response of the cytochrome P450 system in CHO-K1 and HEP-G2 cells. CdSTe QDs were synthesized using a microwave-assisted system at different reaction temperatures (60, 120, 150, and 180 °C) to obtain different crystal sizes. The optical and structural characterization confirmed four crystal sizes from 3 to 8 nm. Fluorescence microscopy confirmed that CdSTe QDs are incorporated into both cell lines. Viability studies suggested that CHO-K1 cells are more sensitive than HEP-G2 cells to CdSTe QDs and Cd+2 ions. The responsible mechanisms for the toxicity of QDs and Cd+2 are apoptosis followed by necrosis. The activity of CYP 1A1, 1A2, and 3A4 isoenzymes suggests that the smallest CdSTe crystals are recognized in a manner similar to that of Cd+2. Furthermore, the largest CdSTe crystals can have different metabolic routes than Cd+2.
{"title":"Effect of CdSTe QDs’ Crystal Size on Viability and Cytochrome P450 Activity of CHO-K1 and HEP-G2 Cells","authors":"L. Alamo-Nole, Adriana Ponton-Almodovar, Ivan Ortiz-Laboy","doi":"10.3390/micro3010021","DOIUrl":"https://doi.org/10.3390/micro3010021","url":null,"abstract":"In the last few years, quantum dots (QDs) have attracted research interest in different fields of science and technology. Despite their applications, it is essential to understand how nanomaterials (with different crystal sizes) are metabolized inside organisms. Thus, the focus of this study was on an evaluation of how crystal sizes of CdSTe QDs affect the viability and response of the cytochrome P450 system in CHO-K1 and HEP-G2 cells. CdSTe QDs were synthesized using a microwave-assisted system at different reaction temperatures (60, 120, 150, and 180 °C) to obtain different crystal sizes. The optical and structural characterization confirmed four crystal sizes from 3 to 8 nm. Fluorescence microscopy confirmed that CdSTe QDs are incorporated into both cell lines. Viability studies suggested that CHO-K1 cells are more sensitive than HEP-G2 cells to CdSTe QDs and Cd+2 ions. The responsible mechanisms for the toxicity of QDs and Cd+2 are apoptosis followed by necrosis. The activity of CYP 1A1, 1A2, and 3A4 isoenzymes suggests that the smallest CdSTe crystals are recognized in a manner similar to that of Cd+2. Furthermore, the largest CdSTe crystals can have different metabolic routes than Cd+2.","PeriodicalId":18398,"journal":{"name":"Micro & Nano Letters","volume":"16 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90847699","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In an attempt to widen the family of Phosphorus Metal Halides (MxPyXz) and enable new applications, post-synthetic modifications to the MxPyXz, Cu2P3I2 have been reported. While such a technique suggests access to an entirely new family of MxPyXz-based materials, we report, in this work, that the ion-exchange process seemingly influences important properties such as the crystallographic pattern and vibrational modes.
{"title":"Structural Consequences of Post-Synthetic Modification of Cu2P3I2","authors":"Gregory R. Schwenk, John T. Walters, H. Ji","doi":"10.3390/micro3010018","DOIUrl":"https://doi.org/10.3390/micro3010018","url":null,"abstract":"In an attempt to widen the family of Phosphorus Metal Halides (MxPyXz) and enable new applications, post-synthetic modifications to the MxPyXz, Cu2P3I2 have been reported. While such a technique suggests access to an entirely new family of MxPyXz-based materials, we report, in this work, that the ion-exchange process seemingly influences important properties such as the crystallographic pattern and vibrational modes.","PeriodicalId":18398,"journal":{"name":"Micro & Nano Letters","volume":"131 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82666670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mushtaq Obaid Oleiwi, Baqer O. Al-Nashy, Sadeq Kh. Ajeel, Amin H. Al-Khursan
<p>This work studies the modal gain from <math> <semantics> <mrow> <mi>I</mi> <msub> <mi>n</mi> <mi>x</mi> </msub> <mi>G</mi> <msub> <mi>a</mi> <mrow> <mn>1</mn> <mo>−</mo> <mi>x</mi> </mrow> </msub> <mi>A</mi> <msub> <mi>s</mi> <mi>y</mi> </msub> <mi>S</mi> <msub> <mi>b</mi> <mrow> <mn>1</mn> <mo>−</mo> <mi>y</mi> </mrow> </msub> <mo>/</mo> <mi>G</mi> <mi>a</mi> <mi>A</mi> <mi>s</mi> <mi>S</mi> <mi>b</mi> </mrow> <annotation>$I{n_x}G{a_{1 - x}}A{s_y}S{b_{1 - y}}/GaAsSb$</annotation> </semantics></math> quaternary quantum dots (QD) structures at different mole fractions of the structure. The quaternary structures are more flexible in attaining lattice-matching systems. First, the In- and As-mole fractions are varied. Four In-mole fractions are studied <math> <semantics> <mrow> <mo>(</mo> <mi>x</mi> <mspace></mspace> <mo>=</mo> <mspace></mspace> <mn>0.01</mn> <mo>,</mo> <mspace></mspace> <mn>0.03</mn> <mo>,</mo> <mspace></mspace> <mn>0.05</mn> <mo>,</mo> <mspace></mspace> </mrow> <annotation>$(x; = ;0.01,;0.03,;0.05,;$</annotation> </semantics></math> and 0.07), and their emitted wavelengths cover the range <math> <semantics> <mrow> <mn>571.4</mn> <mo>−</mo> <mn>5000</mn> <mspace></mspace> <mi>nm</mi> </mrow> <annotation>$571.4 - 5000 {rm nm}$</annotation> </semantics></math>. Both In- and the As-mole fraction increment results in a red-shifted wavelength. Doping is also investigated where the structures are exhibited five times increment of modal gain, and the wavelength is blue-shifted under doping. A multi-peak behaviour
这项工作研究了I n x G a 1−x的模态增益A s y s b 1−y/Ga a s s b$I{n_x}G｛a_｛1-x｝｝a{s_y}S{b_{1-y}}/GaAsSb$四元量子点（QD）结构。四元结构在实现晶格匹配系统方面更加灵活。首先，In和As的摩尔分数是不同的。研究了四种摩尔分数（x=0.01，0.03，0.05，$（x；=；0.01，；0.03，；0.05，；$和0.07），并且它们的发射波长覆盖范围571.4−5000 nm$571.4-5000 nm｝$。In和As摩尔分数的增加都会导致波长红移。还研究了掺杂，其中结构表现出五倍的模态增益增量，并且在掺杂下波长发生蓝移。这些结构表现出多峰行为，这在选择所需波长的应用中是必不可少的。这些结果表明，这些结构可以在紫外线、可见光和红外（IR）波长范围内工作。
{"title":"InGaAsSb/GaAsSb quantum dot structures","authors":"Mushtaq Obaid Oleiwi, Baqer O. Al-Nashy, Sadeq Kh. Ajeel, Amin H. Al-Khursan","doi":"10.1049/mna2.12159","DOIUrl":"https://doi.org/10.1049/mna2.12159","url":null,"abstract":"<p>This work studies the modal gain from <math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>I</mi>\u0000 <msub>\u0000 <mi>n</mi>\u0000 <mi>x</mi>\u0000 </msub>\u0000 <mi>G</mi>\u0000 <msub>\u0000 <mi>a</mi>\u0000 <mrow>\u0000 <mn>1</mn>\u0000 <mo>−</mo>\u0000 <mi>x</mi>\u0000 </mrow>\u0000 </msub>\u0000 <mi>A</mi>\u0000 <msub>\u0000 <mi>s</mi>\u0000 <mi>y</mi>\u0000 </msub>\u0000 <mi>S</mi>\u0000 <msub>\u0000 <mi>b</mi>\u0000 <mrow>\u0000 <mn>1</mn>\u0000 <mo>−</mo>\u0000 <mi>y</mi>\u0000 </mrow>\u0000 </msub>\u0000 <mo>/</mo>\u0000 <mi>G</mi>\u0000 <mi>a</mi>\u0000 <mi>A</mi>\u0000 <mi>s</mi>\u0000 <mi>S</mi>\u0000 <mi>b</mi>\u0000 </mrow>\u0000 <annotation>$I{n_x}G{a_{1 - x}}A{s_y}S{b_{1 - y}}/GaAsSb$</annotation>\u0000 </semantics></math> quaternary quantum dots (QD) structures at different mole fractions of the structure. The quaternary structures are more flexible in attaining lattice-matching systems. First, the In- and As-mole fractions are varied. Four In-mole fractions are studied <math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>(</mo>\u0000 <mi>x</mi>\u0000 <mspace></mspace>\u0000 <mo>=</mo>\u0000 <mspace></mspace>\u0000 <mn>0.01</mn>\u0000 <mo>,</mo>\u0000 <mspace></mspace>\u0000 <mn>0.03</mn>\u0000 <mo>,</mo>\u0000 <mspace></mspace>\u0000 <mn>0.05</mn>\u0000 <mo>,</mo>\u0000 <mspace></mspace>\u0000 </mrow>\u0000 <annotation>$(x; = ;0.01,;0.03,;0.05,;$</annotation>\u0000 </semantics></math> and 0.07), and their emitted wavelengths cover the range <math>\u0000 <semantics>\u0000 <mrow>\u0000 <mn>571.4</mn>\u0000 <mo>−</mo>\u0000 <mn>5000</mn>\u0000 <mspace></mspace>\u0000 <mi>nm</mi>\u0000 </mrow>\u0000 <annotation>$571.4 - 5000 {rm nm}$</annotation>\u0000 </semantics></math>. Both In- and the As-mole fraction increment results in a red-shifted wavelength. Doping is also investigated where the structures are exhibited five times increment of modal gain, and the wavelength is blue-shifted under doping. A multi-peak behaviour","PeriodicalId":18398,"journal":{"name":"Micro & Nano Letters","volume":"18 2","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/mna2.12159","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50140836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The mechanical and chemical behaviors of cast cobalt-base superalloys are governed by the carbides and by a reactive element, which is often chromium. The content of this later element, which is efficient in resisting hot oxidation and also hot corrosion, may have consequences on the melting temperature, microstructure, and mechanical properties at high temperatures and at room temperature. Seemingly, the effect of chromium content on the microstructure and properties of cast equi-axed Co-Cr-Ta-C superalloys containing TaC as single reinforcing carbide and in high-enough quantities to achieve a high level of creep resistance has not been the subject of previous investigations. The present work is devoted to the exploration of this influence of Cr content on the as-cast microstructure of a model alloy in this category, as well as on its microstructure transformations at high temperatures. The work aims to help rate the Cr content to achieve the best characteristics in machinability and high-temperature properties. This is of great importance for fabricability (production cost) and sustainability in service (long enough lifetime performance). A series of six alloys derived from a rather well-known alloy and presenting various Cr contents were thus elaborated by casting. Their microstructures were investigated in their as-cast state as well as in an aged state resulting from a 4-day stage at 1400 K. Vickers indentation was also carried out to study how hardness may evolve with Cr content. It was seen that the higher the Cr content, the lower the solidus temperature, the coarser the TaC population, the harder the alloy, and the higher the risk of brittleness. In order to reach the best compromise, the preferred Cr weight content range, as identified by this work, is 20–30%; indeed, for such Cr contents: (1) the matrix is austenitic, then dense, and then hard and not brittle, and thus is mechanically resistant and tough; (2) the TaC carbides are script-shaped and resistant against morphology changes at high temperatures, and thus efficiently preserve interdendritic cohesion for a long time, and, consequently, (3) the alloys are machinable, have expected good toughness, and can be resistant against creep deformation as well as oxidation and corrosion at high temperatures thanks to the Cr content, allowing for chromium-forming behavior.
{"title":"Influence of the Chromium Content on the Characteristics of the Matrix, the Tantalum Carbides Population, and the Hardness of Cast Co(Cr)-0.4C-6Ta Alloys","authors":"P. Berthod, Merzouk Bouaraba, Junfu Cai","doi":"10.3390/micro3010017","DOIUrl":"https://doi.org/10.3390/micro3010017","url":null,"abstract":"The mechanical and chemical behaviors of cast cobalt-base superalloys are governed by the carbides and by a reactive element, which is often chromium. The content of this later element, which is efficient in resisting hot oxidation and also hot corrosion, may have consequences on the melting temperature, microstructure, and mechanical properties at high temperatures and at room temperature. Seemingly, the effect of chromium content on the microstructure and properties of cast equi-axed Co-Cr-Ta-C superalloys containing TaC as single reinforcing carbide and in high-enough quantities to achieve a high level of creep resistance has not been the subject of previous investigations. The present work is devoted to the exploration of this influence of Cr content on the as-cast microstructure of a model alloy in this category, as well as on its microstructure transformations at high temperatures. The work aims to help rate the Cr content to achieve the best characteristics in machinability and high-temperature properties. This is of great importance for fabricability (production cost) and sustainability in service (long enough lifetime performance). A series of six alloys derived from a rather well-known alloy and presenting various Cr contents were thus elaborated by casting. Their microstructures were investigated in their as-cast state as well as in an aged state resulting from a 4-day stage at 1400 K. Vickers indentation was also carried out to study how hardness may evolve with Cr content. It was seen that the higher the Cr content, the lower the solidus temperature, the coarser the TaC population, the harder the alloy, and the higher the risk of brittleness. In order to reach the best compromise, the preferred Cr weight content range, as identified by this work, is 20–30%; indeed, for such Cr contents: (1) the matrix is austenitic, then dense, and then hard and not brittle, and thus is mechanically resistant and tough; (2) the TaC carbides are script-shaped and resistant against morphology changes at high temperatures, and thus efficiently preserve interdendritic cohesion for a long time, and, consequently, (3) the alloys are machinable, have expected good toughness, and can be resistant against creep deformation as well as oxidation and corrosion at high temperatures thanks to the Cr content, allowing for chromium-forming behavior.","PeriodicalId":18398,"journal":{"name":"Micro & Nano Letters","volume":"59 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77249497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Ture, Shruthy D. Pattathil, Bertrand Zing Zing, V. Abbaraju
Conducting polymers (CPs) have contributed significantly to the field of sensing. The sensing of nitroaromatic compounds by fluorescence has recently gained more attention due to its sensitivity and selectivity. In this study, polyaniline (PANI) was functionalized by forming a polyaniline-Ag (PANI-Ag) composite and used as a fluorophore for sensing. The nitro groups present in nitroaromatic compounds (NACs) such as 2,4,6-trinitrophenol (picric acid-TNP) and Dinitrobenzene (DNB) act as electron-accepting molecules and quench the fluorescence of polymer chains by showing an amplified quenching effect in which trace amounts of electron-accepting NACs quench emissions of several fluorophore units. The PANI-Ag composite synthesized by interfacial polymerization was analyzed using UV-vis spectroscopy and Fourier-transform infrared (FTIR) spectroscopy for determination of molecular structure; X-ray powder diffraction (XRD) and scanning electron microscopy (SEM/EDAX) for its morphology, which is cubic crystalline silver; and thermogravimetric analysis (TGA) for the thermal stability. The fluorescence quenching mechanism was deduced from the Stern–Volmer plot. The quenching constant value (Ksv) obtained from the Stern–Volmer (S–V) plot was found to be Ksv = 0.1037 × 106 M−1 (TNP) and Ksv = 0.161 × 104 M−1 (DNB). The plot shows a single mechanism with formation of an exciplex complex for TNP with a photoinduced electron transfer (PET) mechanism. The limit of detection (LOD) is found to be TNP = 5.58 × 10−7 M, whereas DNB = 23.30 × 10−6 M shows that the PANI-Ag composite is a potential fluorophore for sensing of nitroaromatic compounds in trace levels.
{"title":"Fluorescence Sensing of Some Important Nitroaromatic Compounds by Using Polyaniline Ag Composite","authors":"S. Ture, Shruthy D. Pattathil, Bertrand Zing Zing, V. Abbaraju","doi":"10.3390/micro3010016","DOIUrl":"https://doi.org/10.3390/micro3010016","url":null,"abstract":"Conducting polymers (CPs) have contributed significantly to the field of sensing. The sensing of nitroaromatic compounds by fluorescence has recently gained more attention due to its sensitivity and selectivity. In this study, polyaniline (PANI) was functionalized by forming a polyaniline-Ag (PANI-Ag) composite and used as a fluorophore for sensing. The nitro groups present in nitroaromatic compounds (NACs) such as 2,4,6-trinitrophenol (picric acid-TNP) and Dinitrobenzene (DNB) act as electron-accepting molecules and quench the fluorescence of polymer chains by showing an amplified quenching effect in which trace amounts of electron-accepting NACs quench emissions of several fluorophore units. The PANI-Ag composite synthesized by interfacial polymerization was analyzed using UV-vis spectroscopy and Fourier-transform infrared (FTIR) spectroscopy for determination of molecular structure; X-ray powder diffraction (XRD) and scanning electron microscopy (SEM/EDAX) for its morphology, which is cubic crystalline silver; and thermogravimetric analysis (TGA) for the thermal stability. The fluorescence quenching mechanism was deduced from the Stern–Volmer plot. The quenching constant value (Ksv) obtained from the Stern–Volmer (S–V) plot was found to be Ksv = 0.1037 × 106 M−1 (TNP) and Ksv = 0.161 × 104 M−1 (DNB). The plot shows a single mechanism with formation of an exciplex complex for TNP with a photoinduced electron transfer (PET) mechanism. The limit of detection (LOD) is found to be TNP = 5.58 × 10−7 M, whereas DNB = 23.30 × 10−6 M shows that the PANI-Ag composite is a potential fluorophore for sensing of nitroaromatic compounds in trace levels.","PeriodicalId":18398,"journal":{"name":"Micro & Nano Letters","volume":"50 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86106767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Miaoqing Shu, Behnam Mahdavi, Aiste Balčiūnaitienė, Samaneh Goorani, Amir Ali Mahdavi
In the present study, tin nanoparticles were green-synthesized using the aqueous extract of Foeniculum vulgare leaf aqueous extract. The synthesized SnNPs (tin nanoparticles) were characterized by analytical techniques including EDX (energy dispersive X-ray), FE-SEM (field emission scanning electron microscopy), XRD (X-ray diffraction), UV–vis and FT-IR (Fourier transform-infrared). The cytotoxicity activity of SnNPs was evaluated using MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay. The nanoparticles were formed in a spherical shape in the range size of 26.45–38.53 nm. In the antioxidant test, the IC50 of F. vulgare, SnNPs@FV (Sn nanoparticles@ F. vulgare) and BHT (butylated hydroxytoluene) against DPPH (2,2-diphenyl-1-picrylhydrazyl) free radicals were 384, 119 and 71 µg/mL, respectively. In the cellular and molecular part of the recent study, the treated cells with SnNPs@FV were assessed by MTT assay for 48h about the cytotoxicity property on normal HUVEC (human umbilical vein endothelial cells) cell line. In vivo experiment, SnNPs@FV ointment significantly decreased (p ≤ 0.01) the wound area, total cells, neutrophil and lymphocyte and notably increased (p ≤ 0.01) the wound contracture, vessel, hydroxyl proline, hexosamine, hexuronic acid and fibrocyte compared to other groups in rats. Further clinical trials are necessary for confirmation of these remedial properties of SnNPs@FV in humans.
{"title":"Novel green synthesis of tin nanoparticles by medicinal plant: Chemical characterization and determination of cytotoxicity, cutaneous wound healing and antioxidant properties","authors":"Miaoqing Shu, Behnam Mahdavi, Aiste Balčiūnaitienė, Samaneh Goorani, Amir Ali Mahdavi","doi":"10.1049/mna2.12157","DOIUrl":"https://doi.org/10.1049/mna2.12157","url":null,"abstract":"<p>In the present study, tin nanoparticles were green-synthesized using the aqueous extract of <i>Foeniculum vulgare</i> leaf aqueous extract. The synthesized SnNPs (tin nanoparticles) were characterized by analytical techniques including EDX (energy dispersive X-ray), FE-SEM (field emission scanning electron microscopy), XRD (X-ray diffraction), UV–vis and FT-IR (Fourier transform-infrared). The cytotoxicity activity of SnNPs was evaluated using MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay. The nanoparticles were formed in a spherical shape in the range size of 26.45–38.53 nm. In the antioxidant test, the IC50 of <i>F. vulgare</i>, SnNPs@FV (Sn nanoparticles@ <i>F. vulgare</i>) and BHT (butylated hydroxytoluene) against DPPH (2,2-diphenyl-1-picrylhydrazyl) free radicals were 384, 119 and 71 µg/mL, respectively. In the cellular and molecular part of the recent study, the treated cells with SnNPs@FV were assessed by MTT assay for 48h about the cytotoxicity property on normal HUVEC (human umbilical vein endothelial cells) cell line. In vivo experiment, SnNPs@FV ointment significantly decreased (<i>p</i> ≤ 0.01) the wound area, total cells, neutrophil and lymphocyte and notably increased (<i>p</i> ≤ 0.01) the wound contracture, vessel, hydroxyl proline, hexosamine, hexuronic acid and fibrocyte compared to other groups in rats. Further clinical trials are necessary for confirmation of these remedial properties of SnNPs@FV in humans.</p>","PeriodicalId":18398,"journal":{"name":"Micro & Nano Letters","volume":"18 2","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/mna2.12157","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50135971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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