108 research outputs found
Single molecule electronic devices with carbon-based materials: Status and opportunity
The field of single molecule electronics has progressed remarkably in the past decades by allowing for more versatile molecular functions and improving device fabrication techniques. In particular, electrodes made from carbon-based materials such as graphene and carbon nanotubes (CNTs) may enable parallel fabrication of multiple single molecule devices. In this perspective, we review the recent progress in the field of single molecule electronics, with a focus on devices that utilizes carbon-based electrodes. The paper is structured in three main sections: (i) controlling the molecule/graphene electrode interface using covalent and non-covalent approaches, (ii) using CNTs as electrodes for fabricating single molecule devices, and (iii) a discussion of possible future directions employing new or emerging 2D materials. This journal i
The Role of Therapeutic Landscape in Improving Mental Health of People with PTSD
Post-traumatic stress disorder (PTSD) as a complex disorder, with serious consequences, affects the quality of life of the individual, the family, as well as the community. Therefore, the subject of this chapter is to study how to reduce stress and improve the quality of life of these people and consequently the community. This chapter is based on documentary studies including the foundations of the theory, the study of the results of experiments in the world, and case studies in this field, which shows that the interaction of individuals with PTSD and therapeutic landscapes can act as a therapeutic mechanism. In the following, features from therapeutic landscapes that help to optimize mental health levels are reviewed in people with PTSD, briefly
A constructability assessment model based on BIM in urban renewal projects in limited lands
One of the most significant concerns in urban development today is the organization of areas of cities that have become run-down over time. In order to complete previous constructability studies in other fields of construction, the current study evaluates constructability based on BIM, specifically in the context of the Tehran limited land renewal project. The motivation for this study is the current difficulties facing renewal designs for limited lands, and the lack of a quantitative constructability model for urban renewal projects in Iran. This paper aims (1) to discuss the design elements that should be considered in the design phase of urban renewal projects; (2) to identify the factors that may affect constructability; and (3) to propose a framework for assessing urban renewal designs by considering constructability factors using building information modeling (BIM). To meet these needs, this paper investigates constructability factors and their relative importance, considering the design elements that should be acknowledged in limited land renewal, using a multicriteria techniques. Some 28 constructability factors are identified through a literature review, and based on 52 responses received from a questionnaire survey, the factors are ranked using pairwise comparisons of the analytic hierarchy process (AHP). The final constructability factors that are identified through the technique for order preference using the similarity to ideal solution (TOPSIS) method are standard dimensions, safety, simplification of structure, resource intelligence and alignment, and skilled labor availability. The contribution of this research to the body of knowledge is, firstly, the development of constructability factors for measuring the constructability of urban renewal designs, and secondly, the introduction of BIM as a most beneficial tool for assessing the constructability of the proposed designs. In using the constructability assessment framework and identifying the trade-offs between the constructability of renewal projects in the limited areas of urban spaces, design alternatives become more feasible
Encapsulation of orange peel oil in biopolymeric nanocomposites to control its release under different conditions
Orange peel oil (OPO) is one of the most common flavorings used in the food industry, but it is volatile under environmental conditions (the presence of light, oxygen, humidity, and high temperatures). Encapsulation by biopolymer nanocomposites is a suitable and novel strategy to improve the bioavailability and stability of OPO and its controlled release. In this study, we investigated the release profile of OPO from freeze-dried optimized nanocomposite powders as a function of pH (3, 7, 11) and temperature (30, 60, and 90 °C), and within a simulated salivary system. Finally, its release kinetics modelling was performed using experimental models. The encapsulation efficiency of OPO within the powders, along with the morphology and size of the particles, were also evaluated by an atomic force microscopy (AFM) analysis. The results showed that the encapsulation efficiency was in the range of 70–88%, and the nanoscale size of the particles was confirmed by AFM. The release profile showed that the lowest and the highest release rates were observed at the temperatures of 30 and 90 °C and in the pH values of 3 and 11, respectively, for all three samples. The Higuchi model provided the best model fitting of the experimental data for the OPO release of all the samples. In general, the OPO encapsulates prepared in this study showed promising characteristics for food flavoring applications. These results suggest that the encapsulation of OPO may be useful for controlling its flavor release under different conditions and during cooking
Effect of Post-space Preparation with Rotary Devices and Heated Instruments on Microbial Leakage of Gutta-percha and Resilon-Epiphany Obturated Canals
Introduction: After endodontic procedures, root canal reinfection is a main concern for dentists. However, application of a proper apical seal can prevent such contamination. Therefore, it seems necessary to study the factors affecting the development of a suitable apical seal. Materials and Methods: In this study, 64 extracted human single-canal premolars were used. An equal length of roots was obtained by cutting the crown. The teeth were randomly divided into four experimental groups of 15 premolars, as well as 2 positive and negative controls. The root canal was manually prepared using K-file and step back method through canal filling by lateral compaction technique. In GP and GH groups, gutta-percha and AH 26 sealer were used to fill the canals, while Resilon and Epiphany sealer were used in RP and RH groups, respectively. Then, to prepare the post space, Peeso Reamer drill was used in GP and RP groups while heat carrier was applied in GH and RH groups to prepare the post space, respectively. The coronal part of each root was contacted with enterococcus faecalis leachate in BHI medium and the root end was placed in the same culture medium. The samples were daily checked for turbidity in the lower culture medium for 90 days. The average duration of bacterial leakage between the groups wascompared using independent Student t-test. Results: All the positive control samples showed bacterial infiltration within 24 to 48 hours, while the negative control teeth remained uninfected during the test. Comparison of bacterial leakage rates between GP and GH groups showed no significant difference, which was similar to comparison results between RP and RH groups (P=0.549 and P=0.097, respectively). Comparison of bacterial leakage between GP and RP groups, as well as between GH and RH groups, showed a significant difference (P=0.018 and
Evaluation of the effect of IL-36γ expression on chronic periodontitis by enhancing the MAPK and TLR4 signaling pathways: A basic research
Background. Periodontitis is an infectious and inflammatory disease of the supporting tissues of the tooth caused by specific microorganisms or a group of microorganisms and, if not treated, leads to progressive degradation of the supporting tissues and subsequent loss of the teeth affected. The aim of this study was to evaluate the effects of IL-36γ on periodontitis by enhancing the TLR4 and MAPK signaling pathways. Methods. In this pilot study, 50 patients with generalized moderate-to-severe chronic periodontitis and 50 individuals with healthy periodontium, who were candidates for crown lengthening (CL), were selected based on inclusion criteria. The tissue samples were taken during pocket depth surgery (for the test group) and CL surgery (for the control group). The macrophage cells of the inflammatory tissues were extracted and stimulated by TLR4 proteins in a time-dependent manner; then IL-36γ levels in macrophages were investigated. Data were analyzed using descriptive statistics (means ± standard deviations and frequency percentages). Repeat measurement test was used to compare IL36γ expression in MAPK and TLR4 pathways at different time intervals. ANCOVA was used to compare IL36γ expression at different time intervals between the two pathways. Statistical analysis was performed using SPSS 17 at a significance level of P<0.05. Results. The results of the current study showed a significant relation between TLR4 and IL-36γ (P<0.001); in tissues with generalized moderate-to-severe chronic periodontitis, there was a significant relation between the condition and IL-36γ (P<0.0001). This study also showed that TLR4 and MAPK levels increased in the presence of IL-36γ. Conclusion. According to the present study, it was concluded that IL-36γ concentrations increased in periodontitis, which could trigger MAPK and TLR4 pathways
Rutin via Increase in the CA3 Diameter of the Hippocampus Exerted Antidepressant-Like Effect in Mouse Model of Maternal Separation Stress: Possible Involvement of NMDA Receptors
Background and Aim. Rutin is a flavonol with neuroprotective activity. The aim of the present study is to investigate the role of the glutamatergic system in the antidepressant-like effect of rutin in a mouse model of maternal separation (MS) stress focusing on histological changes in the CA3 area of the hippocampus. Methods. Mouse neonates were exposed to MS paradigm 3 hours daily from postnatal days (PND) 2 to 14. The control and MS mice were divided separately into 16 groups (n=8) (8 groups for each set) including mice that received normal saline, mice that received rutin at doses of 10, 50, and 100 mg/kg, mice that received NMDA at a dose of 150 mg/kg, mice that received ketamine (NMDA antagonist) at a dose of 0.25 mg/kg, mice that received NMDA antagonist plus a subeffective dose of rutin, and mice that received NMDA plus an effective dose of rutin. Forced swimming test (FST) was performed. Afterwards, the hippocampus was evaluated in cases of histopathological changes as well as expression of NR2A and NR2B genes. Results. Rutin significantly reduced immobility time in the FST. The expression of NR2A and NR2B subunits of NMDA receptor in MS mice was significantly higher than that in the control group. Rutin significantly decreased the expression of NR2B and NR2A subunits in the hippocampus. The CA3 diameter and percentage of dark neurons in the hippocampus of MS mice significantly decreased and increased, respectively, which partially reversed following rutin administration. Conclusion. Rutin, partially, through a neuroprotective effect on the hippocampus exerted antidepressant-like effect. We concluded that NMDA receptors, at least in part, mediated the beneficial effect of rutin
The effects of curcumin on hepatic T2*MRI and liver enzymes in patients with β‐thalassemia major: a double‐blind randomized controlled clinical trial
Background: Curcumin present in turmeric has been considered due to its cancer-preventive features, antioxidant and anti-inflammatory properties. This double-blind, randomized, controlled clinical trial with a reasonable sample size and longer intervention period was conducted to investigate how oral curcumin affected cardiac and hepatic T2*MRI and liver enzymes in patients with β‐thalassemia major.Method: This clinical trial study was conducted on 171 patients over 5 years old. The subjects were randomly divided into a curcumin-treatment group and a placebo group to receive either curcumin capsules twice daily or placebo for 6 months. Patients were examined once a month for 6 months to receive capsules and measure the levels of alanine aminotransferase (ALT), aspartate transferase (AST), alkaline phosphatase (ALP), direct and total bilirubin, ferritin and cardiac and hepatic T2*MRI.Result: There was a significant decrease in levels of AST, ALT, ALP, and bilirubin (direct and total) in the curcumin group compared with the placebo group by the end of the study (p < 0.05). The levels of serum ferritin remained unchanged in both groups at the end of the follow‐up period (p > 0.05). No significant differences were observed between the curcumin and placebo groups at baseline values or at the end of the study of cardiac and hepatic T2*MRI and serum magnesium.Conclusion: Administration of curcumin has some beneficial effects on liver function by reducing liver enzymes in patients with beta-thalassemia major
Recyclable optical bioplastics platform for solid state red light harvesting via triplet-triplet annihilation photon upconversion
Sustainable photonics applications of solid-state triplet-triplet annihilation photon upconversion (TTA-UC) are limited by a small UC spectral window, low UC efficiency in air, and non-recyclability of polymeric materials used. In a step to overcome these issues, we have developed new recyclable TTA-UC bioplastics by encapsulating TTA-UC chromophores liquid inside the semicrystalline gelatin films showing broad-spectrum upconversion (red/far-red to blue) with high UC efficiency in air. For this, we synthesized a new anionic annihilator, sodium-TIPS-anthracene-2-sulfonate (TIPS-AnS), that combined with red/far-red sensitizers (PdTPBP/Os(m-peptpy)2(TFSI)2), a liquid surfactant Triton X-100 reduced (TXr) and protein gelatin (G) formed red/far-red to blue TTA-UC bioplastic films just by air drying of their aqueous solutions. The G-TXr-TIPS-AnS-PdTPBP film showed record red to blue (633 to 478 nm) TTA-UC quantum yield of 8.5% in air. The high UC quantum yield has been obtained due to the fluidity of dispersed TXr containing chromophores and oxygen blockage by gelatin fibers that allowed efficient diffusion of triplet excited chromophores. Further, the G-TXr-TIPS-AnS-Os(m-peptpy)2(TFSI)2 bioplastic film displayed far-red to blue (700-730 nm to 478 nm) TTA-UC, demonstrating broad-spectrum photon harvesting. Finally, we demonstrated the recycling of G-TXr-TIPS-AnS-PdTPBP bioplastics by developing a downstream approach that gives new directions for designing future recyclable photonics bioplastic materials.Pankaj Bharmoria acknowledges Marie Skłodowska-Curie Actions – European Commission post-doctoral grant (NIRLAMS, Grant agreement ID: 844972) for research funding. Hakan Bildirir and Kasper Moth-Poulsen acknowledges funding from the Swedish Energy Agency, the Swedish Research Agency FORMAS, the Swedish Strategic Foundation, and the K & A Wallenberg foundation. Bo Albinsson acknowledges Swedish Energy Agency and the Swedish Research Council (VR). Nobuhiro Yanai acknowledges JSPS KAKENHI (grant numbers JP20H02713, JP20K21211, JP20H05676, JP18J21140).With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917-S).Peer reviewe
Far-red triplet sensitized Z-to-E photoswitching of azobenzene in bioplastics
We report the first example of direct far-red triplet sensitized molecular photoswitching in a condensed phase wherein a liquid azobenzene derivative (Azo1) co-assembled within a liquid surfactant-protein film undergoes triplet sensitized Z-to-E photoswitching upon far-red/red light excitation in air. The role of triplet sensitization in photoswitching has been confirmed by quenching of sensitizer phosphorescence by Z-Azo1 and temperature-dependent photoswitching experiments. Herein, we demonstrate new biosustainable fabrication designs to address key challenges in solid-state photoswitching, effectively mitigating chromophore aggregation and requirement of high energy excitations by dispersing the photoswitch in the trapped liquid inside the solid framework and by shifting the action spectrum from blue-green light (450-560 nm) to the far-red/red light (740/640 nm) region.Pankaj Bharmoria acknowledges the Marie Skłodowska-Curie Actions—European Commission post-doctoral grant (NIRLAMS, Grant agreement ID: 844972) for research funding. Bo Albinsson acknowledges the Swedish Energy Agency and the Swedish Research Council (VR). Nobuo Kimizuka acknowledges JSPS KAKENHI Grant Number JP20H05676. Kasper Moth-Poulsen acknowledges funding from the European Research Council (ERC), the Göran Gustafson Foundation, the Swedish Energy Agency, and the Swedish Research Council (VR). The authors would like to thank Monika Shamsabadi and Lidiya M. Muhammad for proofreading this manuscript.With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917-S).Peer reviewe
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