Blood clotting is a process by which a haemostatic plug is assembled at the site of injury. The formation of such a plug, which is essentially a (bio)polymer-colloid composite, is believed to be driven by shear flow in its initial phase, and contrary to our intuition, its assembly is enhanced under stronger flowing conditions. Here, inspired by blood clotting, we show that polymer-colloid composite assembly in shear flow is a universal process that can be tailored to obtain different types of aggregates including loose and dense aggregates, as well as hydrodynamically induced 'log'-type aggregates. The process is highly controllable and reversible, depending mostly on the shear rate and the strength of the polymer-colloid binding potential. Our results have important implications for the assembly of polymercolloid composites, an important challenge of immense technological relevance. Furthermore, flow-driven reversible composite formation represents a new paradigm in non-equilibrium self-assembly.
The application of multiphoton microscopy in the field of biomedical research and advanced diagnostics promises unique insights into the pathophysiology of inflammatory skin diseases. In the present study, we combined multiphoton-based intravital tomography (MPT) and fluorescence lifetime imaging (MPT-FLIM) within the scope of a clinical trial of atopic dermatitis with the aim of providing personalised data on the aetiopathology of inflammation in a non-invasive manner at patients’ bedsides. These ‘optical biopsies’ generated via MPT were morphologically analysed and aligned with classical skin histology. Because of its subcellular resolution, MPT provided evidence of a redistribution of mitochondria in keratinocytes, indicating an altered cellular metabolism. Two independent morphometric algorithms reliably showed an even distribution in healthy skin and a perinuclear accumulation in inflamed skin. Moreover, using MPT-FLIM, detection of the onset and progression of inflammatory processes could be achieved. In conclusion, the change in the distribution of mitochondria upon inflammation and the verification of an altered cellular metabolism facilitate a better understanding of inflammatory skin diseases and may permit early diagnosis and therapy.
Purpose
This paper aims to investigate the relationship between corporate governance (CG) and corporate social responsibility (CSR) disclosure in a sample of 64 companies listed on the Tehran Stock Exchange.
Design/methodology/approach
This study opts for a descriptive-correlational method. To measure the extent of CSR disclosure and CG variables, companies’ annual reports and websites during 2014-2015 are content analyzed by applying a 64-item checklist. Boards’ size, age, tenure and independence, CEO duality, audit committee (AC) composition and ownership concentration are considered as CG variables. To ascertain the CG–CSR disclosure relationship, multivariate linear regression analysis is incorporated.
Findings
Based on the results, audit committee composition, board tenure and ownership concentration positively influence CSR disclosure level with ownership concentration as the most influential variable, that is, in companies with majority shareholders ownership, managers tend to disclose more CSR information.
Research limitations/implications
Only annual reports and company websites are analyzed. Researchers are encouraged to apply other methods such as interview and to consider other variables, such as board diversity, proportion of female members and the extent of shareholders activities, to measure CG.
Practical implications
This paper provides implications at the policy level to identify governance mechanisms to increase CSR awareness of heavy-pollution industries in developing countries.
Originality/value
Studies rarely examined CSR reporting in Iran, particularly among heavy-pollution companies. Besides, the paper highlights the role of majority shareholders and non-executive AC members in CSR disclosure.
Surface-enhanced infrared absorption spectroscopy (SEIRA) is applied to study protein conformational changes. In general, the appropriate functionalization of metal surfaces with biomolecules remains a challenge if the conformation and activity of the biomolecule shall be preserved. Here we present a SEIRA study to monitor pH-induced conformational changes of poly-l-lysine (PLL) covalently bound to a thin gold layer via self-assembled monolayers (SAMs). We demonstrate that the composition of the SAM is crucial. A SAM of 11-mercaptoundecanonic acid (MUA) can link PLL to the gold layer, but pH-driven conformational transitions were hindered compared to poly-l-lysine in solution. To address this problem, we devised a variety of SAMs, i.e., mixed SAMs of MUA with either octanethiol (OT) or 11-mercapto-1-undecanol (MUoL) and furthermore SAMs of MT(PEG)4 and NHS-PEG10k-SH. These mixed SAMs modify the surface properties by changing the polarity and the morphology of the surface present to nearby PLL molecules. Our experiments reveal that mixed SAMs of MUA-MUoL and SAMs of NHS-PEG10k-SH-MT(PEG)4 are suitable to monitor pH-driven conformational changes of immobilized PLL. These SAMs might be applicable for chemoselective protein immobilization in general.
Silymarin contains a group of closely-related flavonolignan compounds including silibinin, and is extracted from
Silybum marianum
species, also called milk thistle. Silymarin has been shown to protect the liver in both experimental models and clinical studies. The chemopreventive activity of silymarin has shown some efficacy against cancer both in vitro and in vivo. Silymarin can modulate apoptosis in vitro and survival in vivo, by interfering with the expression of cell cycle regulators and apoptosis-associated proteins. In addition to its anti-metastatic activity, silymarin has also been reported to exhibit anti-inflammatory activity. The chemoprotective effects of silymarin and silibinin (its major constituent) suggest they could be applied to reduce the side effects and increase the anti-cancer effects of chemotherapy and radiotherapy in various cancer types, especially in gastrointestinal cancers. This review examines the recent studies and summarizes the mechanistic pathways and down-stream targets of silymarin in the therapy of gastrointestinal cancer.
The intrinsically disordered protein α-synuclein (αS), a known pathogenic factor for Parkinson's disease, can adopt defined secondary structures when interacting with membranes or during fibrillation. The αS-lipid interaction and the implications of this process for aggregation and damage to membranes are still poorly understood. Therefore, we established a label-free infrared (IR) spectroscopic approach to allow simultaneous monitoring of αS conformation and membrane integrity. IR showed its unique sensitivity for identifying distinct β-structured aggregates. A comparative study of wild-type αS and the naturally occurring splicing variant αS Δexon3 yielded new insights into the membrane's capability for altering aggregation pathways.
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