76 research outputs found

    New Catalytic Systems for Fixation of Carbon Dioxide into Valuable Poly(Alkylene Carbonates)

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    Fixation of carbon dioxide into valuable products is a promising method to mitigate the issues of global warming and decrease the consumption of fossil-fuel carbon sources. Poly alkylene carbonates (PACs) are environmentally friendly and low-cost polymers that are synthesized from copolymerization of carbon dioxide and epoxides. PACs are contemplated as an alternative to commercially available non-degradable polymers in the market for a broad range of applications. However, a burden for the synthesis of this group of polymers is the chemical activation of thermodynamically stable CO2. It is, therefore, imperative to develop a catalyst with high efficiency to overcome this hurdle. In this chapter, we describe the development and recent advances in the catalytic systems that have been designed to activate CO2 for copolymerization with epoxides. In particular, we will focus on the industrial trends presented in the patents for conversion of CO2 into PACs

    Citrus peel flavonoids as potential cancer prevention agents

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    Citrus fruit and in particular flavonoid compounds from citrus peel have been identified as agents with utility in the treatment of cancer. This review provides a background and overview regarding the compounds found within citrus peel with putative anticancer potential as well as the associated in vitro and in vivo studies. Historical studies have identified a number of cellular processes that can be modulated by citrus peel flavonoids including cell proliferation, cell cycle regulation, apoptosis, metastasis, and angiogenesis. More recently, molecular studies have started to elucidate the underlying cell signaling pathways that are responsible for the flavonoids' mechanism of action. These growing data support further research into the chemopreventative potential of citrus peel extracts, and purified flavonoids in particular. This critical review highlights new research in the field and synthesizes the pathways modulated by flavonoids and other polyphenolic compounds into a generalized schema

    Dental Pulp Polyps Contain Stem Cells Comparable to the Normal Dental Pulps

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    Objectives: Few studies investigated the isolation of stem cells from pathologically injured dental tissues. The aim of this study was to assess the possibility of isolation of stem cells from pulp polyps (chronic hyperplastic pulpitis), a pathological tissue produced in an inflammatory proliferative response within a tooth. Study design: Pulp polyp tissues were enzymatically digested and the harvested single cells were cultured. Cultured cells underwent differentiation to adipocytes and osteoblasts as well as flowcytometric analysis for markers such as: CD90, CD73, CD105, CD45, and CD14. In addition we tried to compare other characteristics (including colonigenic efficacy, population doubling time and the cell surface antigen panels) of these cells to that of healthy dental pulp stem cells (DPSCs). Results: Cells isolated from pulp polyps displayed spindle shape morphology and differentiated into adipocytes and osteoblasts successfully. These cells expressed CD90, CD73, and CD105 while were negative for CD45, CD14. Number of colonies among 104 tissue cells was higher in the normal pulp tissue derived cells than the pulp polyps (P=0.016); but as polyp tissues are larger and contain more cells (P=0.004), the total number of the stem cell in a sample tissue was higher in polyps but not significantly (P=0.073). Conclusions: The cells isolated from pulp polyps fulfill minimal criteria needed for MSC definition; hence, it can be concluded that pulp polyps contain stem cells. Although pulp polyps are rare tissues in daily practice but when they are present, may serve as a possible new non-invasively acquired tissue resource of stem cells for affected patients. List of abbreviations: APC = allophycocyanin, BM = Bone Marrow, CFU-F = Colony Forming Unit Fibroblast, DPSC = Dental Pulp Stem Cell, FITC = fluorescein isothiocyanate, MNC = mononuclear cells, MSC = Multipotent Mesenchymal Stromal Cell, PE = Phycoerythrin, PerCP = Peridinin chlorophyll protein, PPSC = Pulp Polyp Stem Cell

    Biopolymeric Coatings for Local Release of Therapeutics from Biomedical Implants

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    Funding Information: S.T., B.M., and J.C. contributed equally to this work. The authors are grateful for funding received from the Australian Research Council Centre of Excellence program (Project Number CE 140100012). J.C. acknowledges the European Research Council Starting Grant (ERC‐StG‐2019‐848325). S.N. and F.D. acknowledge the financial support of Australian Research Council through DP200102164. Publisher Copyright: © 2023 The Authors. Advanced Science published by Wiley-VCH GmbH.The deployment of structures that enable localized release of bioactive molecules can result in more efficacious treatment of disease and better integration of implantable bionic devices. The strategic design of a biopolymeric coating can be used to engineer the optimal release profile depending on the task at hand. As illustrative examples, here advances in delivery of drugs from bone, brain, ocular, and cardiovascular implants are reviewed. These areas are focused to highlight that both hard and soft tissue implants can benefit from controlled localized delivery. The composition of biopolymers used to achieve appropriate delivery to the selected tissue types, and their corresponding outcomes are brought to the fore. To conclude, key factors in designing drug-loaded biopolymeric coatings for biomedical implants are highlighted.publishersversionepub_ahead_of_prin

    The Relationship Between Perception of Disease and Quality of Life in Patients with Acne Vulgaris from 2013 to 2014

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    Background: Acne vulgaris is a common skin disease that can affect people in any ages. The development of acne have adverse effects on life quality. Psychological disorders increased in these patients and their psycho social activities have been affected. Since few studies have been done regarding illness perception in people with acne in Iran, this study aimed to investigate the association of perception of acne disease and quality of life in central of IranMethods: we analyzed 200 patients Acne Vulgaris referred to Khatam-Al Anbia in 2013-14 by questionnaire of perception of disease (Brief IPQ) and quality of life (DLQL. the data was analyzed using t-test and Chi-square by SPSS-16Results: Mean age of patients was 24.3 years and 158 people (79%) were women and 42 people (21 %) were men. Mean quality life score in women was 8.79±5.3 and in men was 8.69±5.18. Most patients had moderate acne and duration of their disease was between 1 to 5 years. 136 people were 18 to 25 years old and 64 persons were higher than 25 years. The mean perception scores in men and women were 51.83 and 53.26 respectively In this study, there was a relation between sex (P=0.03), Acne severity and duration with quality of life score.Conclusion: Women and patients with severe acne and longer duration of symptoms had higher quality life score that had more disorder in life.. There was relation between perception and sex and duration of symptoms

    Concomitant Transurethral and Transvaginal-Periurethral Injection of Autologous Adipose Derived Stem Cells for Treatment of Female Stress Urinary Incontinence: A Phase One Clinical Trial

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    Stress urinary incontinence is a common medical problem among women. The urethral closure complex and/or the supportive mechanisms are responsible for incontinence in the majority of patients. Several surgical procedures with different degrees of invasiveness and outcomes have been reported to treat the problem. Although most of these procedures are reasonably effective, a general trend towards the study of natural and biocompatible tissues is emerging over popular synthetic materials. Here we report our experience of autologous adipose-derived stem cells transplantation into the periurethral region as a new method of stress urinary incontinence treatment. Ten women with symptoms of stress urinary incontinence were treated by injections of autologous adipose-derived stem cells into the periurethral region via transurethral and transvaginal approach under urethroscopic observation. This report presents the short-term outcome of the patients. The outcome measured by pad test results, ICIQ-SF scores, and Qmax. The mean age of the participants was 45.8±8.7 years. Urinary incontinence significantly decreased through the first two, 6 and 24 weeks after the injection therapy. The difference was significant in pad test results (P<0.001) and ICIQ-SF scores (P<0.001), especially comparing results between 2 and 6 weeks and among 6 and 24 weeks, but not for 2 and 6 weeks compared to each other. Surprisingly, Qmax showed improvement after the study period (means 32.6 vs. 35.7; P=0.002). This study showed that injection of the autologous adipose-derived stem cells to the periurethral region is a safe, yet short-term effective treatment option for stress urinary incontinence. Further studies with longer follow up are needed to confirm its long term efficacy

    Conventional and Dense Gas Techniques for the Production of Liposomes: A Review

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    The aim of this review paper is to compare the potential of various techniques developed for production of homogenous, stable liposomes. Traditional techniques, such as Bangham, detergent depletion, ether/ethanol injection, reverse-phase evaporation and emulsion methods, were compared with the recent advanced techniques developed for liposome formation. The major hurdles for scaling up the traditional methods are the consumption of large quantities of volatile organic solvent, the stability and homogeneity of the liposomal product, as well as the lengthy multiple steps involved. The new methods have been designed to alleviate the current issues for liposome formulation. Dense gas liposome techniques are still in their infancy, however they have remarkable advantages in reducing the use of organic solvents, providing fast, single-stage production and producing stable, uniform liposomes. Techniques such as the membrane contactor and heating methods are also promising as they eliminate the use of organic solvent, however high temperature is still required for processing

    Effect of Dense Gas CO2 on the Coacervation of Elastin

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    How does the CNS control arm reaching movements? Introducing a hierarchical nonlinear predictive control organization based on the idea of muscle synergies.

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    In this study, we introduce a hierarchical and modular computational model to explain how the CNS (Central Nervous System) controls arm reaching movement (ARM) in the frontal plane and under different conditions. The proposed hierarchical organization was established at three levels: 1) motor planning, 2) command production, and 3) motor execution. Since in this work we are not discussing motion learning, no learning procedure was considered in the model. Previous models mainly assume that the motor planning level produces the desired trajectories of the joints and feeds it to the next level to be tracked. In the proposed model, the motion control is described based on a regulatory control policy, that is, the output of the motor planning level is a step function defining the initial and final desired position of the hand. For the command production level, a nonlinear predictive model was developed to explain how the time-invariant muscle synergies (MSs) are recruited. We used the same computational model to explain the arm reaching motion for a combined ARM task. The combined ARM is defined as two successive ARM such that it starts from point A and reaches to point C via point B. To develop the model, kinematic and kinetic data from six subjects were recorded and analyzed during ARM task performance. The subjects used a robotic manipulator while moving their hand in the frontal plane. The EMG data of 15 muscles were also recorded. The MSs used in the model were extracted from the recorded EMG data. The proposed model explains two aspects of the motor control system by a novel computational approach: 1) the CNS reduces the dimension of the control space using the notion of MSs and thereby, avoids immense computational loads; 2) at the level of motor planning, the CNS generates the desired position of the hand at the starting, via and the final points, and this amounts to a regulatory and non-tracking structure
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