Search

A method for fabricating adhesively bonded joints with graded properties along the bond-line was proposed. By utilizing two types of acrylic adhesives, one hard and the other soft, the properties of the mixture were changed by controlling the mixing ratio. An applicator for the adhesives was developed and used for the experiments, in which property-graded adhesive layers were actually produced. The properties, i.e., stress-strain curves at various points of the property-graded adhesive layer, were experimentally measured, and the validity of the proposed method was confirmed. The Young's moduli at multiple points of the adhesive layer changed from 34.7 MPa to 634 MPa by changing the mixing ratio of the adhesives. [ABSTRACT FROM AUTHOR]

A novel method to manufacture functionally graded adhesive joints that is easier to implement than previous methods is proposed and investigated in this study. For this method, a mixture of two adhesives, one that is rigid and brittle and one that is flexible, was applied to adherends with various mixing ratios. Second generation acrylic adhesives (SGAs) were used in this study because they can be cured at a wide range of mixing ratios. To evaluate the mechanical properties of the resulting adhesive mixtures, bulk specimens with different mixing ratios were prepared and tested. Each of the adhesives had two components (e.g., agents A and B), with similar chemical compositions, but agent A includes an oxidizer, and agent B includes a reducer. Thus, mixing of both agents A does not produce any chemical reaction and similarly for agents B; this property enabled us to perform honeymoon adhesion. A mixture of agents A was applied to the surface of an adherend, and a mixture of agents B was applied to that of the other adherend at various mixing ratios. Then, one of the adherends was placed onto the other to make a joint. After the joint cured, the hardness of the adhesive layer was evaluated at certain points on the surface using nano-indentation to verify the applicability of the proposed method. Based on bulk tensile tests, it was concluded that the mechanical properties of SGAs could be controlled by changing the mixing ratio of the SGAs. In addition, the results of the hardness test of the adhesive layer, which corresponds to the Young’s modulus of the material, depended strongly on the mixing ratio of adhesive. [ABSTRACT FROM PUBLISHER]

Stress concentration in adhesively bonded joints, which is considered a major factor affecting their strength, can be avoided by tailoring the material properties of the adhesives using a functionally graded adhesive (FGA). The material properties of second-generation acrylic (SGA) adhesives can be simply changed by changing the mixing ratio of the agents. However, the superiority of FGA joints using SGA adhesives has not been experimentally clarified yet. Therefore, in this study, a shear strength test and a constant load low-cycle shear test were conducted on single lap joint (SLJ) specimens tailoring the adhesive layer stepwise. The FGA specimen was compared with the non-tailored specimens using stiff or flexible adhesives. The SLJ test results showed 16% improvement in the joint strength by stepwise tailoring of the adhesive layer. Additionally, the difference in the strain distributions among the different adhesive layers was investigated via a digital image correlation (DIC) method, and the shear strain at the edge of the FGA specimen was more than 40% decreased compared to the non-tailored specimen using the flexible adhesive. The low-cycle test results also showed the superiority of the FGA specimen to the other specimens. The FGA specimen held up more than 4 times the number of cycle of other specimens with an applied load of 18 kN or more. This was attributed to the suppressed plastic deformation at the edges of the adhesive layer owing to the introduction of FGAs. [ABSTRACT FROM AUTHOR]

Background: Nature therapies are gaining attention as non-pharmacological treatments for depressive and anxiety disorders, but research on their effectiveness in patients is limited. This study investigates the mood-improving effects of visual stimulation with natural environmental images in patients with depressive and anxiety disorders., Methods: We conducted a randomized crossover comparison trial involving 60 right-handed adult participants with depressive or anxiety disorders and receiving outpatient treatment. Visual stimuli of natural environments consisted of green-themed nature images, while the control stimuli featured urban scenes dominated by buildings. The stimulation lasted for 3 min, during which orbital prefrontal brain activity was measured using a 2-channel Near-infrared Spectroscopy (NIRS) system, and heart rate variability was assessed using fingertip accelerated plethysmography., Results: Mood enhancement effects were observed in both the depressive and anxiety disorder groups following visual stimulation with nature images. In the depression group, orbital prefrontal oxygenated hemoglobin concentration significantly increased after visual stimulation with nature images, while there were no significant changes in the anxiety group. However, in the anxiety group, a correlation was found between reduced orbital prefrontal oxygenated hemoglobin in response to nature images and increased mood-enhancement. Furthermore, the severity of depressive symptoms did not significantly affect the intervention effects, whereas heightened anxiety symptoms was associated with a smaller mood enhancement effect., Discussion: Our study demonstrates the benefits of nature image stimulation for patients with depressive and anxiety disorders. Differential orbital prefrontal brain activity impacts notwithstanding, both conditions exhibited mood enhancement, affirming the value of nature image stimulation., Competing Interests: Declaration of competing interest C.C. is the author of CleverLand: The Psychology of How Nature Nurtures. The other authors declare no conflict of interest., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

An open-label study was performed to investigate the clinical efficacy and tolerability of olanzapine orally disintegrating tablets (Zyprexa Zydis) in ameliorating excitement symptoms in the acute phase of schizophrenia. Fifty-three patients meeting DSM-IV criteria for first-episode schizophrenia and treated with olanzapine monotherapy were evaluated with regard to their clinical improvement, behavioural response to medication, and extrapyramidal side effects using the Positive and Negative Syndrome Scale Excited Component (PANSS-EC), Nursing Assessment of Medication Acceptance (NAMA), and Drug-Induced Extra-Pyramidal Symptoms Scale (DIEPSS), respectively. Scores of PANSS-EC were significantly reduced after 3 days of olanzapine administration. A reduction in NAMA scores was also observed 7 days after administration of olanzapine. The DIEPSS score was unaffected by olanzapine administration. These results suggest that olanzapine orally disintegrating tablets are effective and well-tolerated for treatment excitement in the acute phase of schizophrenic patients. In addition, it is possible that adherence to medications is improved by using olanzapine orally disintegrating tablets.