UV-crosslinked gelatin nanogel was prepared without using chemical crosslinking agents and its thermoresponsive behaviors were investigated. The particle size of the nanogels decreased on heating, which is attributed to the helix-to-coil transition of gelatin. On the other hand, the increase in the particle size on cooling was not observed in the quiescent solutions, but was noticeably accelerated by the application of shear stress.
{"title":"Preparation and thermoresponsive behaviors of UV-crosslinked gelatin nanogels","authors":"Y. Maki, W. Saito, T. Dobashi","doi":"10.17106/JBR.32.15","DOIUrl":"https://doi.org/10.17106/JBR.32.15","url":null,"abstract":"UV-crosslinked gelatin nanogel was prepared without using chemical crosslinking agents and its thermoresponsive behaviors were investigated. The particle size of the nanogels decreased on heating, which is attributed to the helix-to-coil transition of gelatin. On the other hand, the increase in the particle size on cooling was not observed in the quiescent solutions, but was noticeably accelerated by the application of shear stress.","PeriodicalId":39272,"journal":{"name":"Journal of Biorheology","volume":"32 1","pages":"15-19"},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.17106/JBR.32.15","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68196972","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
When biopolymer solutions come in contact with a coagulation bath containing a gelling factor such as ions, chemical crosslinkers, and pH conditioners, diffusion of the gelling factor through the contact interface into the polymer solutions induces gelation, which proceeds gradually in a direction along the diffusion of the gelling factor. In this directional gelation process, characteristic structures are frequently formed in the biopolymer gels. This review presents general features of the structure formation by the diffusion of the gelling factors and some specific examples for typical biopolymers.
{"title":"Structure formation in biopolymer gels induced by diffusion of gelling factors","authors":"Y. Maki, K. Furusawa, Takao Yamamoto, T. Dobashi","doi":"10.17106/JBR.32.27","DOIUrl":"https://doi.org/10.17106/JBR.32.27","url":null,"abstract":"When biopolymer solutions come in contact with a coagulation bath containing a gelling factor such as ions, chemical crosslinkers, and pH conditioners, diffusion of the gelling factor through the contact interface into the polymer solutions induces gelation, which proceeds gradually in a direction along the diffusion of the gelling factor. In this directional gelation process, characteristic structures are frequently formed in the biopolymer gels. This review presents general features of the structure formation by the diffusion of the gelling factors and some specific examples for typical biopolymers.","PeriodicalId":39272,"journal":{"name":"Journal of Biorheology","volume":"32 1","pages":"27-38"},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.17106/JBR.32.27","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68197216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
It is important to quantitatively evaluate the flow behaviour of complex fluids such as paste-like foods. In this study, we investigated the flow properties of a pastelike food model using a weak-gel model. As a model of pastelike food, agar microgel suspensions were prepared using a water-in-oil (W/O) emulsion system. Because the microgels prepared by this method have a spherical shape, their flow properties can be evaluated quantitatively. The steady state viscosity and dynamic modulus of the suspensions were measured with the volume fraction of the microgel particles ranging from 0.68 to 0.80. Because the flow curves showed a pseudo-plastic flow, they were analysed using the Herschel-Bulkley equation to obtain characteristic flow parameters, namely, the viscosity coefficient (k), apparent yield stress (σy), and the Herschel-Bulkley index (n). The frequency dependence of the complex modulus was analysed using the weak-gel model to obtain two parameters, namely the coordination number (z), which relates to the relaxation behaviour, and gel strength (Af). A sudden increase in both σy and z was observed when the volume fraction was close to 0.77. Moreover, k and Af were also found to undergo a sudden increase at the same volume fraction. This value is expected to be the critical volume fraction at which the microgel particles reach a random close packing state. The results showed that we can make quantitative evaluation of the flow behaviour of a complex fluid under a small deformation by using the weak-gel model.
{"title":"Attempt of the quantitative evaluation of flow properties of agar microgel suspensions using a weak-gel model","authors":"I. Kaneda","doi":"10.17106/JBR.32.9","DOIUrl":"https://doi.org/10.17106/JBR.32.9","url":null,"abstract":"It is important to quantitatively evaluate the flow behaviour of complex fluids such as paste-like foods. In this study, we investigated the flow properties of a pastelike food model using a weak-gel model. As a model of pastelike food, agar microgel suspensions were prepared using a water-in-oil (W/O) emulsion system. Because the microgels prepared by this method have a spherical shape, their flow properties can be evaluated quantitatively. The steady state viscosity and dynamic modulus of the suspensions were measured with the volume fraction of the microgel particles ranging from 0.68 to 0.80. Because the flow curves showed a pseudo-plastic flow, they were analysed using the Herschel-Bulkley equation to obtain characteristic flow parameters, namely, the viscosity coefficient (k), apparent yield stress (σy), and the Herschel-Bulkley index (n). The frequency dependence of the complex modulus was analysed using the weak-gel model to obtain two parameters, namely the coordination number (z), which relates to the relaxation behaviour, and gel strength (Af). A sudden increase in both σy and z was observed when the volume fraction was close to 0.77. Moreover, k and Af were also found to undergo a sudden increase at the same volume fraction. This value is expected to be the critical volume fraction at which the microgel particles reach a random close packing state. The results showed that we can make quantitative evaluation of the flow behaviour of a complex fluid under a small deformation by using the weak-gel model.","PeriodicalId":39272,"journal":{"name":"Journal of Biorheology","volume":"91 1","pages":"9-14"},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68197540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Collagenous tubular tissues “Biotubes,” formed by in-body tissue engineering, is implanted already as clinical vascular grafts in hemodialysis surgery. In almost all previous study, Biotubes were stored in 70% alcohol before implantation, but the influence of alcohol concentration on the mechanical properties of Biotubes has not been investigated in depth. In this study, the mechanical properties of Biotubes stored at room temperature in two different concentrations of ethanol (10% or 70%) were compared through fatigue and tensile tests. Biotubes with an internal diameter of 6 mm and wall thickness of ca. 2 mm was prepared by subcutaneous embedding of molds into goat for two months, and stored in 10% or 70% alcohol solution for 20 d. In the fatigue test, performed by repeatable loading of tension corresponding to arterial pressure (700,000 cycles at 10 Hz), Biotubes stored in 10% solution elongated by approximately 80%, but in 70% solution, the elongation was <20%. Storing Biotubes in high concentration ethanol solution improved practical compliance and prevented stretching. The preservation of ECM with 70% ethanol is a cost effective, safe and easy method.
{"title":"Comparison of ethanol concentration as stock solution on mechanical properties of iBTA-induced collagenous tubular tissue “Biotube”","authors":"T. Terazawa, Yi-Ping Lai, Y. Nakayama","doi":"10.17106/JBR.32.65","DOIUrl":"https://doi.org/10.17106/JBR.32.65","url":null,"abstract":"Collagenous tubular tissues “Biotubes,” formed by in-body tissue engineering, is implanted already as clinical vascular grafts in hemodialysis surgery. In almost all previous study, Biotubes were stored in 70% alcohol before implantation, but the influence of alcohol concentration on the mechanical properties of Biotubes has not been investigated in depth. In this study, the mechanical properties of Biotubes stored at room temperature in two different concentrations of ethanol (10% or 70%) were compared through fatigue and tensile tests. Biotubes with an internal diameter of 6 mm and wall thickness of ca. 2 mm was prepared by subcutaneous embedding of molds into goat for two months, and stored in 10% or 70% alcohol solution for 20 d. In the fatigue test, performed by repeatable loading of tension corresponding to arterial pressure (700,000 cycles at 10 Hz), Biotubes stored in 10% solution elongated by approximately 80%, but in 70% solution, the elongation was <20%. Storing Biotubes in high concentration ethanol solution improved practical compliance and prevented stretching. The preservation of ECM with 70% ethanol is a cost effective, safe and easy method.","PeriodicalId":39272,"journal":{"name":"Journal of Biorheology","volume":"32 1","pages":"65-70"},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68197421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Aims: The safety and efficacy of biodegradable polymer-based drug-eluting stents remain unclear. The aim of this study was to evaluate the safety and efficacy of biodegradable polymer-based sirolimus-eluting stent (SES) in a porcine coronary model. Methods and Results: Sirolimus and biodegradable PLGA (50:50) polymer were used to coat-a diamond-like carbon-coated bare metal stent (MOMO-BMS). The sirolimus content was 100 μg/cm2 (SES100) or 140 μg/cm2 (SES140). Stents were implanted in porcine coronaries. The animals were euthanized at 1 and 3 months (n = 4 each). At 1 month, histological analysis revealed that both SES100 and SES140 had significantly higher fibrin scores than MOMO-BMS, and like MOMOBMS, they decreased to baseline level at 3 months. Furthermore, both SES100 and SES140 showed less neointima than MOMO-BMS at 1 month (0.72 ± 0.35, 0.75 ± 0.20, 1.05 ± 0.42, respectively; p = 0.34), and this was maintained at 3 months with no increase of inflammatory reaction. Conclusion: The results indicate that the novel biodegradable polymer-based SES is safe and effective.
{"title":"Evaluation of safety and efficacy of biodegradable polymer-based sirolimus-eluting stent in a porcine coronary artery model","authors":"G. Nakazawa, Tooru Nakamura‐Hirota","doi":"10.17106/JBR.32.71","DOIUrl":"https://doi.org/10.17106/JBR.32.71","url":null,"abstract":"Aims: The safety and efficacy of biodegradable polymer-based drug-eluting stents remain unclear. The aim of this study was to evaluate the safety and efficacy of biodegradable polymer-based sirolimus-eluting stent (SES) in a porcine coronary model. Methods and Results: Sirolimus and biodegradable PLGA (50:50) polymer were used to coat-a diamond-like carbon-coated bare metal stent (MOMO-BMS). The sirolimus content was 100 μg/cm2 (SES100) or 140 μg/cm2 (SES140). Stents were implanted in porcine coronaries. The animals were euthanized at 1 and 3 months (n = 4 each). At 1 month, histological analysis revealed that both SES100 and SES140 had significantly higher fibrin scores than MOMO-BMS, and like MOMOBMS, they decreased to baseline level at 3 months. Furthermore, both SES100 and SES140 showed less neointima than MOMO-BMS at 1 month (0.72 ± 0.35, 0.75 ± 0.20, 1.05 ± 0.42, respectively; p = 0.34), and this was maintained at 3 months with no increase of inflammatory reaction. Conclusion: The results indicate that the novel biodegradable polymer-based SES is safe and effective.","PeriodicalId":39272,"journal":{"name":"Journal of Biorheology","volume":"14 1","pages":"71-77"},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.17106/JBR.32.71","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68197482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Hiroura, T. Hirota, J. Mukai, Ryoko Masaki, Yosuke Naoki, Yuta Tominaga, H. Date, Takeshi Yokoyama
We first developed a model of the normal human left heart and simulated blood and clarified the relationship between catheter insertion load and temperature in the coronary artery. The close feeling to insert a catheter into human vessels could be reproduced for medical staff. We also developed an arteriovenous circulation simulator (AVCS), simulating the normal heart and blood vessels, reproduced hemodynamics and simulated angiography and catheterization procedures. Using an auxiliary artificial heart, simulated blood was circulated through AVCS and blood pressure was set to 120/72 mmHg of peripheral vascular resistance by a pressure gradient regulator. Because the increase in contrast agent volume in the circulation fluid of AVCS affects X-ray fluoroscopy, we also developed methods for neutralization and removal of ionic contrast agents. The developed AVCS enabled to simulate following procedures:
{"title":"Construction of arteriovenous circulation system to gain of the close feeling to insert a catheter into human vessel","authors":"M. Hiroura, T. Hirota, J. Mukai, Ryoko Masaki, Yosuke Naoki, Yuta Tominaga, H. Date, Takeshi Yokoyama","doi":"10.17106/JBR.32.56","DOIUrl":"https://doi.org/10.17106/JBR.32.56","url":null,"abstract":"We first developed a model of the normal human left heart and simulated blood and clarified the relationship between catheter insertion load and temperature in the coronary artery. The close feeling to insert a catheter into human vessels could be reproduced for medical staff. We also developed an arteriovenous circulation simulator (AVCS), simulating the normal heart and blood vessels, reproduced hemodynamics and simulated angiography and catheterization procedures. Using an auxiliary artificial heart, simulated blood was circulated through AVCS and blood pressure was set to 120/72 mmHg of peripheral vascular resistance by a pressure gradient regulator. Because the increase in contrast agent volume in the circulation fluid of AVCS affects X-ray fluoroscopy, we also developed methods for neutralization and removal of ionic contrast agents. The developed AVCS enabled to simulate following procedures:","PeriodicalId":39272,"journal":{"name":"Journal of Biorheology","volume":"32 1","pages":"56-64"},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68197336","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We have developed a microporous covered stent (MCS) for the treatment of intracranial aneurysms (IAs). MCS promotes intentional thrombosis in the IA by blood stagnation and facilitates IA embolization treatment by clotting of whole blood in the IA. Flow reduction is a key property of such stent-type IA embolization devices. In this study, we evaluated the flow reduction property of MCS, and compered that of a general balloon expandable stent (bare stent, BS) for supporting a stenotic vessel and a typical flow diverter stent (FD) for IA treatment. This was carried out using particle imaging velocimetry (PIV) and an in vitro flow simulator with a saccular IA and straight parent vessel model. The PIV results show that the area mean shear rates in the IA flow were reduced to 34.7% (5.56 s–1) for the BS model, 9.2% (1.48 s–1) for the FD model, and 2.7% (0.43 s–1) for the MCS model with respect to the unstented condition (16.04 s–1) at a Reynolds number of 600. Considering that the flow reduction property of the MCS model is three times higher than that of the FD model, it is clear that the MCS facilitates more reliable IA embolization than FD.
{"title":"Hydrodynamical evaluation of microporous covered stent for the treatment of intracranial aneurysms: Comparison of flow reduction property with flow diverter stent by using particle imaging velocimetry and in vitro flow simulator","authors":"T. Moriwaki, T. Tajikawa, Y. Nakayama","doi":"10.17106/JBR.32.20","DOIUrl":"https://doi.org/10.17106/JBR.32.20","url":null,"abstract":"We have developed a microporous covered stent (MCS) for the treatment of intracranial aneurysms (IAs). MCS promotes intentional thrombosis in the IA by blood stagnation and facilitates IA embolization treatment by clotting of whole blood in the IA. Flow reduction is a key property of such stent-type IA embolization devices. In this study, we evaluated the flow reduction property of MCS, and compered that of a general balloon expandable stent (bare stent, BS) for supporting a stenotic vessel and a typical flow diverter stent (FD) for IA treatment. This was carried out using particle imaging velocimetry (PIV) and an in vitro flow simulator with a saccular IA and straight parent vessel model. The PIV results show that the area mean shear rates in the IA flow were reduced to 34.7% (5.56 s–1) for the BS model, 9.2% (1.48 s–1) for the FD model, and 2.7% (0.43 s–1) for the MCS model with respect to the unstented condition (16.04 s–1) at a Reynolds number of 600. Considering that the flow reduction property of the MCS model is three times higher than that of the FD model, it is clear that the MCS facilitates more reliable IA embolization than FD.","PeriodicalId":39272,"journal":{"name":"Journal of Biorheology","volume":"32 1","pages":"20-25"},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.17106/JBR.32.20","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68197168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xiaobo B Han, N. Sakamoto, N. Tomita, H. Meng, Masaaki Sato, M. Ohta
BACKGROUND: High shear stress (SS) could affect vascular remodeling during initiation of cerebral aneurysms. However, the response of smooth muscle cells (SMCs) to high SS, which is related to blood vessel remodeling, are poorly understood. OBJECTIVE: We explored the effect of high SS on SMCs in an EC-SMC coculture model to investigate blood vessel remodeling during aneurysm formation. METHODS: SMCs were three-dimensionally cultured in a collagen gel, with ECs cultured on a membrane filter above the SMCs. Then, the co-culture model was exposed to different SS of 0.2, 2, 6, and 10 Pa for 72 h. RESULTS: A physiological SS of 2 Pa maintained the expression of contractile proteins in SMCs, whereas lower or higher SS decreased the expression, suggesting a phenotypic change to a synthetic state. Furthermore, we found that a high SS of 10 Pa increased production of both matrix metalloproteinase (MMP) -2 and -9 from SMCs, which could induce destructive blood vessel remolding. CONCLUSIONS: High SS could change the SMC phenotype to a synthetic state and induce higher MMP production by SMCs in the co-culture model. These results may help to further elucidate blood vessel remodeling mechanisms under high SS conditions.
{"title":"Influence of shear stress on phenotype and MMP production of smooth muscle cells in a co-culture model","authors":"Xiaobo B Han, N. Sakamoto, N. Tomita, H. Meng, Masaaki Sato, M. Ohta","doi":"10.17106/JBR.31.50","DOIUrl":"https://doi.org/10.17106/JBR.31.50","url":null,"abstract":"BACKGROUND: High shear stress (SS) could affect vascular remodeling during initiation of cerebral aneurysms. However, the response of smooth muscle cells (SMCs) to high SS, which is related to blood vessel remodeling, are poorly understood. OBJECTIVE: We explored the effect of high SS on SMCs in an EC-SMC coculture model to investigate blood vessel remodeling during aneurysm formation. METHODS: SMCs were three-dimensionally cultured in a collagen gel, with ECs cultured on a membrane filter above the SMCs. Then, the co-culture model was exposed to different SS of 0.2, 2, 6, and 10 Pa for 72 h. RESULTS: A physiological SS of 2 Pa maintained the expression of contractile proteins in SMCs, whereas lower or higher SS decreased the expression, suggesting a phenotypic change to a synthetic state. Furthermore, we found that a high SS of 10 Pa increased production of both matrix metalloproteinase (MMP) -2 and -9 from SMCs, which could induce destructive blood vessel remolding. CONCLUSIONS: High SS could change the SMC phenotype to a synthetic state and induce higher MMP production by SMCs in the co-culture model. These results may help to further elucidate blood vessel remodeling mechanisms under high SS conditions.","PeriodicalId":39272,"journal":{"name":"Journal of Biorheology","volume":"31 1","pages":"50-56"},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.17106/JBR.31.50","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68196769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Stephen L Flores, F. B. Descallar, S. Matsukawa, R. Bacabac
In this experiment, large amplitude oscillatory shear, differential strain and pre-stress measurements were performed on sample solutions of mixed kappa carrageenan and iota carrageenan solutions. As measurements enter the nonlinear regime, properties of soft materials and complex fluids yield a wide array of responses due to flow instabilities or network structure. LAOS experiments reveal that mixed carrageenan solutions exhibit intermediate properties of the kappa and iota components. At large enough strains, all gels exhibit strain softening in the elastic moduli due to irreversible deformations introduced in the gel networks. However, there is an expressed increase in the viscous moduli of both iota and the mixed gel until both transitions from a predominantly elastic to a viscous material. The softening of the elastic moduli and expressed increase in the viscous moduli is a hallmark behavior of soft glassy materials.
{"title":"Dynamic rheological properties of mixed carrageenan gels under large strains","authors":"Stephen L Flores, F. B. Descallar, S. Matsukawa, R. Bacabac","doi":"10.17106/JBR.31.35","DOIUrl":"https://doi.org/10.17106/JBR.31.35","url":null,"abstract":"In this experiment, large amplitude oscillatory shear, differential strain and pre-stress measurements were performed on sample solutions of mixed kappa carrageenan and iota carrageenan solutions. As measurements enter the nonlinear regime, properties of soft materials and complex fluids yield a wide array of responses due to flow instabilities or network structure. LAOS experiments reveal that mixed carrageenan solutions exhibit intermediate properties of the kappa and iota components. At large enough strains, all gels exhibit strain softening in the elastic moduli due to irreversible deformations introduced in the gel networks. However, there is an expressed increase in the viscous moduli of both iota and the mixed gel until both transitions from a predominantly elastic to a viscous material. The softening of the elastic moduli and expressed increase in the viscous moduli is a hallmark behavior of soft glassy materials.","PeriodicalId":39272,"journal":{"name":"Journal of Biorheology","volume":"39 1","pages":"35-39"},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.17106/JBR.31.35","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68196916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The molecular motions in two aqueous maltotriose solutions with different weight fractions (85% and 50%) were investigated by the dielectric relaxation and differential scanning calorimetry. The 85% solution shows two relaxation modes with the different frequency and temperature dependences in the dielectric relaxation curves. The lower frequency mode is due to the hydrated maltotriose. This mode strongly depends on temperature, indicating the structural relaxation of the solution. The higher frequency mode shows an Arrehnius type of temperature dependence ascribed to the hydrated water molecules. The 50% maltotriose solution has another relaxation mode of ice Ih crystal in addition to these relaxation modes. The temperature dependences of both solutions were compared to interpret the molecular motions on the basis of the phase behaviors.
{"title":"Dielectric relaxation of aqueous solutions of maltotriose","authors":"K. Yoshiba, K. Soga","doi":"10.17106/JBR.31.16","DOIUrl":"https://doi.org/10.17106/JBR.31.16","url":null,"abstract":"The molecular motions in two aqueous maltotriose solutions with different weight fractions (85% and 50%) were investigated by the dielectric relaxation and differential scanning calorimetry. The 85% solution shows two relaxation modes with the different frequency and temperature dependences in the dielectric relaxation curves. The lower frequency mode is due to the hydrated maltotriose. This mode strongly depends on temperature, indicating the structural relaxation of the solution. The higher frequency mode shows an Arrehnius type of temperature dependence ascribed to the hydrated water molecules. The 50% maltotriose solution has another relaxation mode of ice Ih crystal in addition to these relaxation modes. The temperature dependences of both solutions were compared to interpret the molecular motions on the basis of the phase behaviors.","PeriodicalId":39272,"journal":{"name":"Journal of Biorheology","volume":"31 1","pages":"16-20"},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.17106/JBR.31.16","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68196310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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