Synthesis of a novel CO2-based alcohol amine compound and its usage in obtaining a water- and solvent-resistant coating

A five-membered cyclo-carbonate, prepared by cycloaddition reaction from CO₂ and 1,4-butanediol diglycidyl ether, was reacted with excessive diamine and formed a urethane group-containing new product. Structural characterization was performed for the new alcohol amine, which can be applied to the manufacture of polyurethane coatings as a chain extender. The new chain extender-based polyurethane coatings exhibited excellent water, salt, and solvent resistance and promising mechanical strength. Importantly, the unique performance of the prepared polyurethane coatings should be ascribed to the introduction of a hydroxyl group in the polyurethane molecule. The strengthened hydrogen bonding enlarged the cohesion of the polyurethane coatings and prohibited the solvents from permeating.

The novelty of the work: a water- and solvent-resistant coating was produced from a novel CO₂-based alcohol amine chain extender.     

Highly stretchable,mechanically stable,and weavable reduced graphene oxide yarn with high NO2 sensitivity for wearable gas sensors

Stretchable gas sensors are important components of wearable electronic devices used for human safety and healthcare applications. However, the current low stretchability and poor stability of the materials limit their use. Here, we report a highly stretchable, stable, and sensitive NO₂ gas sensor composed of reduced graphene oxide (RGO) sheets and highly elastic commercial yarns. To achieve high stretchability and good stability, the RGO sensors were fabricated using a pre-strain strategy (strain-release assembly). The fabricated stretchable RGO gas sensors showed high NO₂ sensitivity (55% at 5.0 ppm) under 200% strain and outstanding mechanical stability (even up to 5000 cycles at 400% applied strain), making them ideal for wearable electronic applications. In addition, our elastic graphene gas sensors can also be woven into fabrics and clothes for the creation of smart textiles. Finally, we successfully fabricated wearable gas-sensing wrist-bands from superelastic graphene yarns and stretchable knits to demonstrate a wearable electronic device.

Highly stretchable, mechanically stable and weavable RGO elastic electronic yarns were developed using dip-coating with pre-straining. We demonstrate wearable gas sensors that can be worn on the wrist.     

An environmentally sustainable plasticizer toughened polylactide

Cardanol (CD), derived from renewable natural cashew nutshell liquid, has been used as a new plasticizer for polylactide (PLA), to create blends which retain the environmentally friendly features of PLA. The differential scanning calorimetry (DSC), dynamic mechanical thermal analysis (DMTA) and scanning electron microscopy (SEM) results all reveal that PLA and CD show good miscibility at low CD content. CD significantly decreased the glass transition temperature and enhanced the crystallization ability of PLA, demonstrating good plasticizing efficiency with PLA. At 10 wt% CD, ultimate elongation and impact toughness increased to 472% and 9.4 kJ m⁻², respectively, which represented improvements of 31-fold and 2.6-fold over the corresponding measurements for neat PLA. The plasticization effect of CD was also demonstrated by the decreased melt complex viscosity and shear storage modulus at lower CD content for the blends when compared with neat PLA. Thus, the investigated CD presents an interesting candidate for a PLA plasticizer, meeting “double green” criteria. No cytotoxicity was found for the blends and hence they may be suitable for biomedical applications.

Cardanol, derived from renewable resources, exhibits good plasticizing efficiency for PLA, meeting “double green” criteria.     

Speech perception in children with cochlear implants for continua varying in formant transition duration

Purpose: To examine the developmental course of labial and alveolar manner of articulation contrasts, and to determine how that course may be different for typically developing (TD) children with cochlear implants (CI).

Method: Eight young adults, eight TD 5–8 year-old children, and seven 5–8 year-old children with CIs participated. Labial /ba/–/wa/ and alveolar /da/–/ja/ continua stimuli were presented, with each continuum consisting of nine synthetic stimuli varying in F2 and F3 transition duration. Participants were asked to label the stimuli as either a stop or glide, and responses were analysed for phonetic boundaries and slopes.

Result: For the /ba/–/wa/ contrast, children with CIs required longer transition durations compared to TD children or adults to cross from one phoneme category to another. The children with CIs demonstrated less confidence in labelling the stimuli (i.e. less steep slopes) than the TD children or the adults. For the /da/–/ja/ contrast, the children with CIs showed less steep slope values than adults.

Conclusion: These results suggest that there are differences in the way TD children and children with CIs develop and maintain phonetic categories, perhaps differences in phonetic representation or in linking acoustic and phonetic representations.     

Hybrid scaffolds of Mg alloy mesh reinforced polymer/extracellular matrix composite for critical‐sized calvarial defect reconstruction

The challenge of developing scaffolds to reconstruct critical‐sized calvarial defects without the addition of high levels of exogenous growth factor remains relevant. Both osteogenic regenerative efficacy and suitable mechanical properties for the temporary scaffold system are of importance. In this study, a Mg alloy mesh reinforced polymer/demineralized bone matrix (DBM) hybrid scaffold was designed where the hybrid scaffold was fabricated by a concurrent electrospinning/electrospraying of poly(lactic‐co‐glycolic acid) (PLGA) polymer and DBM suspended in hyaluronic acid (HA). The Mg alloy mesh significantly increased the flexural strength and modulus of PLGA/DBM hybrid scaffold. In vitro results demonstrated that the Mg alloy mesh reinforced PLGA/DBM hybrid scaffold (Mg‐PLGA@HA&DBM) exhibited a stronger ability to promote the proliferation of bone marrow stem cells (BMSCs) and induce BMSC osteogenic differentiation compared with control scaffolding materials lacking critical components. In vivo osteogenesis studies were performed in a rat critical‐sized calvarial defect model and incorporated a variety of histological stains and immunohistochemical staining of osteocalcin. At 12 weeks, the rat model data showed that the degree of bone repair for the Mg‐PLGA@HA&DBM scaffold was significantly greater than for those scaffolds lacking one or more of the principal components. Although complete defect filling was not achieved, the improved mechanical properties, promotion of BMSC proliferation and induction of BMSC osteogenic differentiation, and improved promotion of bone repair in the rat critical‐sized calvarial defect model make Mg alloy mesh reinforced PLGA/DBM hybrid scaffold an attractive option for the repair of critical‐sized bone defects where the addition of exogenous isolated growth factors is not employed.     

Evolution and Progression of Spondylodiskitis: A Case Presentation

Pyogenic infection of the spinal column is a relatively rare condition. Spondylodiskitis is characterized by infection of the intervertebral disk and the adjacent vertebrae. Diagnosis is often delayed because the symptoms are often nonspecific and also because of the high incidence of nonspecific low back pain in the general population. We report the case of a 42-year-old woman who developed low back pain secondary to spondylodiskitis. Her diagnosis was delayed because of a lack of supporting findings on initial magnetic resonance imaging. The case highlights the clinical scenario in which maintaining a high index of suspicion may lead to follow-up imaging and an accurate diagnosis.

Evaluation of factors related to glycaemic control among South Korean patients with type 2 diabetes

Aims

To examine specific self‐care behaviours, depression, and diabetes‐related stress among South Korean patients with type 2 diabetes and to evaluate whether these factors are related to glycaemic control.

Methods

This cross‐sectional study included 171 patients with type 2 diabetes who visited an endocrinology clinic. A structured questionnaire and electronic medical records were used to collect data regarding self‐care behaviours, depression, diabetes‐related distress, and glycaemic control between May 2015 and July 2015.

Results

Compared with the group with good glycaemic control, the group with poor glycaemic control had significantly lower values for medication adherence and significantly greater values for regimen‐related distress. Depression was not significantly associated with glycaemic control. In logistic regression analysis, only medication adherence was independently associated with glycaemic control.

Conclusions

Medication adherence should be continuously emphasized and monitored in clinical practice to effectively manage glycaemic control among patients with type 2 diabetes. Furthermore, consideration of diabetes‐related distress may help improve glycaemic control among patients with type 2 diabetes.     

Opsoclonus-myoclonus syndrome following long-term use of cyclosporine

Background: Cyclosporine A (CsA) is a widely used immunosuppressive agent that may provoke unexpected neurologic complications. The mechanism is unclear and variable intervals have been reported between CsA administration and onset of the related side effects. Here, we describe a case of delayed-onset CsA neurotoxicity presenting as opsoclonus-myoclonus syndrome (OMS).

Case details: A 37-year-old woman with a two-week period of opsoclonus and upper extremity myoclonus was admitted to our hospital. The patient had been taking CsA for 17 years after receiving a kidney transplant. Further evaluation did not reveal any other abnormalities. Seven days after switching from CsA to tacrolimus, in the absence of additional immune-modulating therapy, her neurologic symptoms improved considerably.

Conclusion: This is the case of delayed, long-term complications of CsA presenting as OMS. Symptoms resolved by substituting CsA with another immunomodulating drug. The etiology of the neurologic complications may involve paradoxically-enhanced delayed-type hypersensitivity.