Recent developments in conducting polymers: applications for electrochemistry

Scientists have categorized conductive polymers as materials having strongly reversible redox behavior and uncommon combined features of plastics and metal. Because of their multifunctional characteristics, e.g., simplistic synthesis, acceptable environmental stability, beneficial optical, electronic, and mechanical features, researchers have largely considered them for diverse applications. Therefore, their capability of catalyzing several electrode reactions has been introduced as one of their significant features. A thin layer of the conducting polymer deposited on the substrate electrode surface can augment the electrode process kinetics of several solution species. Such electrocatalytic procedures with modified conducting polymer electrodes can create beneficial utilization in diverse fields of applied electrochemistry. This review article explores typical recent applications of conductive polymers (2016–2020) as active electrode materials for energy storage applications, electrochemical sensing, and conversion fields such as electrochemical supercapacitors, lithium-ion batteries, fuel cells, and solar cells.

Scientists have categorized conductive polymers as materials having strongly reversible redox behavior and uncommon combined features of plastics and metal.     

Antibacterial activity and biofilm inhibition by surface modified titanium alloy medical implants following application of silver,titanium dioxide and hydroxyapatite nanocoatings

One of the most common causes of implant failure is peri-implantitis, which is caused by bacterial biofilm formation on the surfaces of dental implants. Modification of the surface nanotopography has been suggested to affect bacterial adherence to implants. Silver nanoparticles are also known for their antibacterial properties. In this study, titanium alloy implants were surface modified following silver plating, anodisation and sintering techniques to create a combination of silver, titanium dioxide and hydroxyapatite (HA) nanocoatings. Their antibacterial performance was quantitatively assessed by measuring the growth of Streptococcus sanguinis, proportion of live/dead cells and lactate production by the microbes over 24?h. Application of a dual layered silver–HA nanocoating to the surface of implants successfully inhibited bacterial growth in the surrounding media (100% mortality), whereas the formation of bacterial biofilm on the implant surfaces was reduced by 97.5%. Uncoated controls and titanium dioxide nanocoatings showed no antibacterial effect. Both silver and HA nanocoatings were found to be very stable in biological fluids with material loss, as a result of dissolution, to be less than 0.07% for the silver nanocoatings after 24?h in a modified Krebs-Ringer bicarbonate buffer. No dissolution was detected for the HA nanocoatings. Thus, application of a dual layered silver–HA nanocoating to titanium alloy implants creates a surface with antibiofilm properties without compromising the HA biocompatibility required for successful osseointegration and accelerated bone healing.     

An open-label phase 1 clinical trial of the allogeneic side population adipose-derived mesenchymal stem cells in SMA type 1 patients

Neurological Sciences - Spinal muscular atrophy (SMA), an autosomal recessive neurodegenerative disorder of alpha motor neurons of spinal cord associated with progressive muscle weakness and...     

Cell loss in the inferior olive of the staggerer mutant mouse is an indirect effect of the gene

Staggerer (sg) is an autosomal recessive mutation in mouse that causes severe cerebellar atrophy. In this mutant, the Purkinje cell (PC) number is reduced by about 75% and the remaining Purkinje cells have a reduced dendritic arbor and an ectopic location. Previous analysis of staggerer chimeras has demonstrated that the Purkinje cell phenotypes are all direct consequences of the cell-autonomous action of the staggerer gene. The two major afferents to the Purkinje cell are also affected. Virtually all of the granule cells die by the end of the first postnatal month. This death, however has been shown to be an indirect consequence of mutant gene action. The second major afferent system is from the cells of the inferior olive that projects to the main trunks of the Purkinje cell dendrite via the climbing fiber system. Quantitative studies of cell number in the inferior olive have shown that the number of cells is reduced by about 62% in adult sg/sg mutants. We report here the results of our quantitative analysis of three staggerer chimeras. beta-glucuronidase activity was used as an independent cell marker. Our findings demonstrate that inferior olive cell death in staggerer mutant mice is an indirect effect of staggerer gene action. Thus as for the granule cells, the loss of olivary neurons most likely results from a target related cell death.     

Validation of a measurement instrument for parental child feeding in a low and middle-income country

Background

Parental child feeding practices (PCFP) are a key factor influencing children’s dietary intake, especially in the preschool years when eating behavior is being established. Instruments to measure PCFP have been developed and validated in high-income countries with a high prevalence of childhood obesity. The aim of this study was to test the appropriateness, content, and construct validity of selected measures of PCFP in a low and middle-income country (LMIC) in which there is both undernutrition and obesity in children.

Methods

An expert panel selected subscales and items from measures of PCFP that have been well-tested in high-income countries to measure both “coercive” and “structural” behaviors. Two sequential cross-sectional studies (Study 1, n =?154; Study 2, n =?238) were conducted in two provinces in Indonesia. Findings of the first study were used to refine subscales used in Study 2. An additional qualitative study tested content validity from the perspective of mothers (the intended respondents). Factorial validation and reliability were also tested. Convergent validity was tested with child nutritional status.

Results

In Study 1, a confirmatory factor analysis (CFA) model with 11 factors provided good fit (RMSEA?=?0.045; CFI?=?0.95 and TLI?=?0.95) after two subscales were removed. Reliability was good among seven of the subscales. Following a decision to take out an additional subscale, the instrument was tested for factorial validity (Study 2). A CFA model with 10 subscales provided good fit (RMSEA?=?0.03; CFI?=?0.92 and TLI?=?0.90). The reliability of subscales was lower than in Study 1. Convergent validity with nutrition status was found with two subscales.

Conclusions

The two studies provide evidence of acceptable psychometric properties for 10 subscales from tested instruments to measure PCFP in Indonesia. This provides the first evidence of the validity of these measures in a LMIC setting. Some shortcomings, such in the reliability of some subscales and further tests of predictive validity, require further investigation.

     

Nanofiber technology in the ex vivo expansion of cord blood-derived hematopoietic stem cells

Umbilical cord blood (CB) can be used as an alternative source of hematopoietic stem cells (HSCs) for transplantation in hematological and non-hematological disorders. Despite several recognized advantages the limited cell number in CB one unit still restricts its clinical use. The success of transplantation greatly depends on the levels of total nucleated cell and CD34+ cell counts. Thus, many ex vivo strategies have been developed within the last decade in order to solve this obstacle, with more or less success, mainly determined by the degree of difficulty related with maintaining HSCs self-renewal and stemness properties after long-term expansion. Different research groups have developed very promising and diverse CB-derived HSC expansion strategies using nanofiber scaffolds. Here we review the state-of-the-art of nanofiber technology-based CB-derived HSC expansion.     

Microstructural white matter alterations associated with migraine headaches: a systematic review of diffusion tensor imaging studies

Brain Imaging and Behavior - The pathophysiology of migraine as a headache disorder is still undetermined. Diffusion tensor imaging (DTI) has significantly improved our knowledge about brain...     

Cognitive impairment and associations with structural brain networks,endocrine status,and risk genotypes in newly orchiectomized testicular cancer patients

Brain Imaging and Behavior - A higher incidence of cognitive impairment (CI) has previously been reported among orchiectomized testicular cancer patients (TCPs), but little is known about the...