While extensive research has focused on understanding the degradation mechanisms of Poly(vinyl acetate) (PVAC) paint under different environmental conditions, limited attention has been paid to the long-term stability of PVAC-based white glues, especially when used in artworks. This study investigates the accelerated degradation, under simulated photoaging, and isothermal treatment of a commercial PVAC-based white glue considered representative of this class of materials used in contemporary artworks to predict its durability and assess its behavior in art objects. Through accelerated aging experiments and comparison with natural aging observed in artworks, the study reveals the formation of chromophores and the release of plasticizers as key processes; in particular, the progressive darkening was considered an early indicator of degradation processes, before structural changes could be detected by FTIR or NMR spectroscopies. The plasticizer loss induces an increase in glass transition temperature, from 7 °C to temperatures higher than room temperature, affecting the adhesive's cohesive strength and contributing to the detachment of materials in artworks. The findings underscore the importance of preventive conservation measures to mitigate degradation issues in PVAC-based artworks.
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http://dx.doi.org/10.3390/polym16121712 | DOI Listing |
Gastrointest Endosc
October 2024
Department of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota, USA.
Background And Aims: Gastric variceal bleeding occurs less commonly than bleeding from esophageal varices (EVs), although it is associated with higher morbidity and mortality. Bleeding from gastroesophageal varices type 1 (GOV1) is treated like EVs. In contrast, other forms of gastric variceal bleeding, including gastroesophageal varices type 2 (GOV2) and isolated gastric varices types 1 (IGV1) and 2 (IGV2), are treated with varying endoscopic approaches.
View Article and Find Full Text PDFClin Orthop Relat Res
December 2024
Dr. Li Dak Sum-Yip Yio Chin Center for Stem Cells and Regenerative Medicine and Department of Orthopedic Surgery of The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, PR China.
Background: Massive rotator cuff defects represent an important source of shoulder pain and functional debilitation, substantially diminishing patients' quality of life. The primary treatment of massive rotator cuff defects includes complete or partial repair and patch augmentation. However, because of the tendon's limited regenerative ability, the tendon retear risk after rotator cuff defect repair is still high.
View Article and Find Full Text PDFRadiology
September 2024
From the Department of Radiology, University of Michigan Medicine, Ann Arbor, Mich (M.M.L., N.D.P., C.C.); Institut für Röntgendiagnostik und Nuklearmedizin, Städtisches Klinikum Braunschweig, Braunschweig, Germany (P.W., M.P.); Klinik für Radiologie und Nuklearmedizin, Universitätsklinikum Magdeburg, Magdeburg, Germany (M.P., M.T.); Department of Radiology, Vall d'Hebrón University Hospital, Barcelona, Spain (X.S.C.); Department of Radiology, Medical College of Wisconsin, Milwaukee, Wis (S.B.W.); Department of Radiology, Tampa General Hospital, Tampa, Fla (C.D.); Department of Interventional Radiology, University of Chicago Pritzker School of Medicine, Chicago, Ill (O.A.); Departments of Biomedical Engineering, Radiology, and Neurosurgery, University of Michigan, Ann Arbor, Mich (Z.X.); Department of Radiology, University of Kansas Medical Center, Kansas City, Kan (Z.C.); Department of Interventional Radiology, Baptist Hospital of Miami, Miami, Fla (G.N.); Department of Biomedical Science, Humanitas University & Humanitas Clinical and Research Hospital IRCCS, Rozzano, Italy (G.T., L.S.); Department of Radiology, Freeman Hospital, Newcastle, United Kingdom (P.L.); Department of Diagnostic and Interventional Radiology, Leeds Teaching Hospital and Trust, West Yorkshire, United Kingdom (T.M.W.); and Department of Radiology, University of Wisconsin School of Medicine and Public Health, 600 Highland Ave, Madison, WI 53792 (T.J.Z.).
Background Histotripsy is a nonthermal, nonionizing, noninvasive, focused US technique that relies on cavitation for mechanical tissue breakdown at the focal point. Preclinical data have shown its safety and technical success in the ablation of liver tumors. Purpose To evaluate the safety and technical success of histotripsy in destroying primary or metastatic liver tumors.
View Article and Find Full Text PDFMaterials (Basel)
August 2024
Department of Strength of Materials and Structures in Engineering, Polytechnic University of Catalonia, 08222 Terrassa, Spain.
This study investigated the utilization of innovative green composites made from hemp shiv, a waste by-product of hemp cultivation, with the aim of promoting sustainability within the construction industry. The manufacturing method involved the application of pressure in a mold to create the samples. These materials were produced using an environmentally friendly binder consisting of colophony, arabic gum, and corn starch.
View Article and Find Full Text PDFJ Med Entomol
November 2024
Department of Zoology, Comenius University in Bratislava, Ilkovičova 6, Bratislava, Slovakia.
The landing patterns of blood-sucking females (Diptera: Tabanidae) are largely influenced by their visual perceptions. When attacking humans, the shape of different body parts and overall brightness of the body could be the factors determining the place of blood-sucking. The visual attractiveness of the human body for tabanids was investigated through a black and a white mannequin in the Danube floodplain, Slovakia.
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