Metals are widely used in engineering as well as medical applications. However, their surfaces are easily colonized by bacteria that form biofilms. Among the numerous concerns with biofilm formation, ...biocorrosion is of particular importance in industry, because structural integrity may be compromised, leading to technical failures. In the food industry and medical field, biofilms also pose health risks. To inhibit bacterial colonization, the surfaces of metals can be coated with a polymeric layer which is antiadhesive and/or bactericidal. This article describes polymers that have these desired properties and the methodologies for immobilizing them on metal surfaces of relevance to the marine and medical fields. The focus is on polymer coatings that have a high degree of stability in aqueous medium and do not leach out. The efficacies of the different polymer coatings against bacteria commonly encountered in marine (Desulfovibrio desulfuricans) and medical applications (Staphylococcus aureus, Staphylococcus epidermidis and Escherichia coli) are demonstrated.
Summary
Background
While studies report a lower incidence of skin cancer in white patients with vitiligo compared with controls, the skin cancer incidence in Asian patients with vitiligo is unknown.
...Objectives
To quantify the incidence of melanoma and nonmelanoma skin cancer (NMSC) in Korean patients with vitiligo and compare it with matched nonvitiligo controls.
Methods
A retrospective matched cohort study was performed with 131 245 incident vitiligo cases and 2 624 900 age‐ and sex‐matched (1 : 20) controls at index date, who were selected from the Korean National Health Insurance database between January 2005 and December 2017. Stratified Cox proportional hazards regression (stratified by sex, birth year and index year) was used to calculate the hazard ratio (HR) of skin cancer in patients with vitiligo.
Results
Patients with vitiligo were followed up for a mean duration of 6·34 years compared with a follow‐up period of 6·27 years for matched controls. Ultraviolet (UV) treatment‐adjusted HR for melanoma in patients with vitiligo was 3·32 95% confidence interval (CI) 2·29–4·81 and 1·29 (95% CI 1·06–1·56) for NMSC. The HRs for melanoma and NMSC in the vitiligo population without a history of UV treatment were 3·37 (95% CI 2·32–4·90) and 1·35 (95% CI 1·11–1·64), respectively.
Conclusions
In contrast to white patients with vitiligo, the risk of skin cancer was increased in the Korean vitiligo population. However, it is noteworthy that the skin cancer incidence in Korean patients with vitiligo was lower than that of their white counterparts. Owing to possible ethnic differences in the susceptibility to skin cancer, skin cancer surveillance in the vitiligo population may be adjusted for race.
What's already known about this topic?
Prior studies have reported a lower incidence of melanoma and nonmelanoma skin cancer (NMSC) in white patients with vitiligo compared with nonvitiligo controls.
The skin cancer incidence in Asian patients with vitiligo is unknown.
What does this study add?
In contrast to white patients, the risk of both melanoma and NMSC was increased in Korean patients with vitiligo compared with controls.
Owing to possible ethnic differences in susceptibility to skin cancer, skin cancer surveillance in the vitiligo population should be adjusted for race.
Linked Comment: Gran. Br J Dermatol 2020; 182:825–826.
Mechanisms implicated in disease progression in multiple sclerosis include continued oligodendrocyte (OL)/myelin injury and failure of myelin repair. Underlying causes include metabolic stress with ...resultant energy deficiency. Biotin is a cofactor for carboxylases involved in ATP production that impact myelin production by promoting fatty acid synthesis. Here, we investigate the effects of high dose Biotin (MD1003) on the functional properties of post-natal rat derived oligodendrocyte progenitor cells (OPCs). A2B5 positive OPCs were assessed using an in vitro injury assay, culturing cells in either DFM (DMEM/F12+N1) or "stress media" (no glucose (NG)-DMEM), with Biotin added over a range from 2.5 to 250 μg/ml, and cell viability determined after 24 hrs. Biotin reduced the increase in OPC cell death in the NG condition. In nanofiber myelination assays, biotin increased the percentage of ensheathing cells, the number of ensheathed segments per cell, and length of ensheathed segments. In dispersed cell culture, Biotin also significantly increased ATP production, assessed using a Seahorse bio-analyzer. For most assays, the positive effects of Biotin were observed at the higher end of the dose-response analysis. We conclude that Biotin, in vitro, protects OL lineage cells from metabolic injury, enhances myelin-like ensheathment, and is associated with increased ATP production.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The development of reliable synthetic routes to polymeric nanostructures of well-defined composition, morphology and function is of scientific importance and technological interest. The generation of ...functional hollow polymeric nanostructures, hollow nanospheres and nanotubes in particular, can be achieved through direct and template-directed synthesis, core–shell precursors, and self-assembly of copolymers and polymer conjugates, as well as from dendrimers. The ability to prepare precursor macromolecules of well-defined structure and architecture has been substantially enhanced by recent advances in controlled radical polymerizations. The application and potential application of the hollow polymeric nanospheres and nanotubes as nanoreactors, and in diagnostics, encapsulation, controlled release, and other stimuli-responsive systems are also described.
Abstract In order to elucidate the roles of aquaporins (AQPs) in astroglial responses, we investigated AQP expressions in the experimental epileptic hippocampus. In control animals, AQP1 protein ...expression was restricted to the ventricular-facing surface of the choroid plexus. AQP4 was expressed in astrocyte foot processes near blood vessels and in ependymal and pial surfaces in contact with cerebrospinal fluid. AQP9 protein has been detected in cells lining the cerebral ventricles, and in astrocytes. Six to eight weeks after status epilepticus (SE), AQP1 expression was mainly, but not all, detected in vacuolized astrocytes, which were localized in the stratum radiatum of the CA1 region. AQP4 was negligible in vacuolized CA1 astrocytes, although AQP4 immunoreactivity in non-vacuolized astrocytes was increased as compared to control level. AQP9 expression was shown to be mainly induced in non-vacuolized CA1 astrocytes. Therefore, our findings suggest that AQP subunits may play differential roles in various astroglial responses (including astroglial swelling and astroglial loss) in the chronic epileptic hippocampus.
Objectives
This study aimed to examine the association between statin exposure and dementia risk in individuals with hypercholesterolaemia using data from the NHIS‐HEALS database between 2002 and ...2015.
Methods
Subjects were classified into statin exposure and statin nonexposure groups according to medication possession ratio. Dementia was defined as those with primary diagnostic dementia codes such as F00‐F03, G30, G31.1, G31.9 or G31.82. Cox proportional hazards regression models were adopted after stepwise adjustment for confounders to investigate the prospective association between statin exposure and dementia risk.
Results
During the follow‐up period (median follow‐up 11.7 years), 711 cases of dementia occurred, accounting for 11.5% of the total study population (statin exposure group, 8.2%; statin nonexposure group, 12.9%). Compared to the statin nonexposure group, fully adjusted hazard ratios (HRs) (95% confidence intervals CIs) for overall dementia in the statin exposure group were 0.63 (0.43–0.91) and 0.62 (0.50–0.78) in men and women, respectively. Compared to the statin nonexposure group, the HRs (95% CIs) for Alzheimer’s disease and related dementia, vascular dementia and other types of dementia in the statin exposure group were 0.54 (0.32–0.91), 2.45 (0.69–8.68) and 0.59 (0.32–1.07), respectively, in men and 0.53 (0.38–0.73), 1.29 (0.42–3.96) and 0.70 (0.51–0.96), respectively, in women.
Conclusions
Hypercholesterolaemic individuals exposed to statin had a lower risk of overall dementia and Alzheimer’s disease and related dementia in both sexes, and a lower risk of other types of dementia in women, than subjects who were not exposed to statins.
In this work, a highly efficient, flexible electro thermal heater based on highly conductive carbon nanotube functionalized cotton fabrics has been studied. Cotton fabrics were functionalized with ...single walled carbon nanotubes through a simple dip coating method. To explore their potential as heaters, electrothermal performances of the devices were studied in terms of applied voltage, heating rate and input power density. The highly flexible heater is constructed based on uniformly interconnected CNT networks, which yields an effective and rapid heating of the heater at low input power. The investigation results suggest promising applications of these devices in wearable electronics and beyond and they could also be woven into textile materials.
Hydraulic injection by the Pohang enhanced geothermal systems (EGSs) has been suspected to trigger the 2017 moment magnitude (MW) 5.5 Pohang earthquake in South Korea. The last stimulation experiment ...in the EGS was conducted only 2 months before the disaster, which has led to this suspicion. In this study, we conducted a seismic analysis on the earthquakes that have occurred around the EGS site in the past 10 years. The study included the construction of a velocity model, earthquake detection, the determination of hypocenters, magnitudes, focal mechanisms, and stress inversion, and a clustering analysis. No seismic activity was detected near the study area until November 2015 when there was a loss of a large quantity of heavy drilling mud. For three stimulations of a geothermal well, earthquakes sequentially migrated to the southwest along a fault plane, leading to the location of the mainshock. The delineated fault plane crossed the injection well at approximately 3,800 m, which corresponds to the borehole interval of not only the mud loss but also the breakage of the well's casing due to the mainshock rupture. These findings can be treated as empirical evidence for the hypothesis that the 2017 MW 5.5 Pohang earthquake was initiated on a critically stressed fault zone by the anthropogenic activity of fluid injection, consequentially releasing accumulated strain energy via tectonic loading.
Key Points
On 15 November 2017, an MW 5.5 earthquake, one of the most devastating seismic events since the previous century, struck South Korea
The 2017 MW 5.5 Pohang earthquake occurred in a fault zone reactivated by fluid injection into a geothermal well
Heavy mud was lost from the fault zone during drilling, causing nearby microseismicity
The representative SEM images of (a) etched Cu and (b) Cu-
g-P(HFBA)2 surfaces, and the insets are contact angle profiles of water droplet on the corresponding etched Cu and Cu-
g-P(HFBA)2 surfaces.
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► Fabrication of superhydrophobic films on copper via surface graft polymerisation. ► The superhydrophobicity arising from surface compositions and microstructures. ► The substantially-enhanced corrosion resistance of the grafted fluoropolymer films. ► The gradual change of superhydrophobicity with immersion time.
With the objective of developing materials with repellent surfaces by combining both low surface energy and rough structure, superhydrophobic fluoropolymer films were prepared via surface graft polymerisation from copper substrates. A vinyl-terminated trimethoxysilane was firstly immobilised on the etched-copper surface to introduce active carbon–carbon double bonds. Subsequent graft polymerisation of 2,2,3,4,4,4-hexafluorobutyl acrylate (HFBA), in the presence of a polymerisation initiator 4,4′-azobis-(4-cyanpentanoic acid), yielded the fluoropolymer films on the copper substrates. The resultant P(HFBA)-grafted surfaces not only exhibited desired superhydrophobic property with water contact angle above 150°, but substantially improved the corrosion resistance of copper substrates.
ATR (ATM and Rad3-related) is an essential regulator of the nucleotide excision repair (NER) mechanism. For NER activation, ATR phosphorylates XPA, the rate-limiting factor in the NER pathway. ...However, the role of XPA phosphorylation at serine 196 by ATR has been elusive. Here we show that ATR-mediated XPA phosphorylation enhances XPA stability by inhibiting HERC2-mediated ubiquitination and subsequent degradation. We analyzed stabilization of XPA with substitutions of Ser 196 either to aspartate (S196D), a phosphomimetic mutation, or to alanine (S196A), a phosphodeficient mutation. Upon ultraviolet damage, ATR facilitated HERC2 dissociation from the XPA complex to induce XPA stabilization. However, this regulation was abrogated in S196A-complemented XPA-deficient cells due to persistent association of HERC2 with this XPA complex, resulting in enhanced ubiquitination of S196A. Conversely, the S196D substitution showed delayed degradation kinetics compared with the wild-type and less binding with HERC2, resulting in reduced ubiquitination of S196D. We also found that XPA phosphorylation enhanced the chromatin retention of XPA, the interaction with its binding partners following DNA damage. Taken together, our study presents a novel control mechanism in the NER pathway by regulating the steady-state level of XPA through posttranslational modifications by which ATR-mediated phosphorylation induces XPA stabilization by antagonizing HERC2-catalyzed XPA ubiquitination.
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