Flexible Electrochemical Sensor Based on NiCu(OOH) for Monitoring Urea in Human Sweat

Wearable and flexible electrochemical sweat analysis for monitoring health-related urea concentrations with high sensitivity and selectivity is highly required for individual medical care and disease diagnosis. Herein, we report a sensitive and selective sweat sensor based on a flexible NiCu(OOH)/polystyrene (PS) electrode to detect a urea biomarker. The non-enzymatic sensor was fabricated using electrospinning PS containing carbon nanotube as a conductive component and co-sputtering Ni-Cu alloys as a catalyst. The flexible PS provided a porous structure, leading to sufficient active sites, easy access to reactants, and adequate water wettability for effective charge transfer. The sputtered Ni-Cu alloys deposited on the PS were transformed to a Ni-Cu oxyhydroxide form by cyclic voltammetry treatment, managing the detection of the urea molecule in a neutral pH environment. This urea sensor displayed an excellent linear response with a sensitivity of 10.72 μAmM–1cm–2 toward a physiologically appropriate linear range of 2.00–30.00 mM, and negligible interferences from co-existing common species. Furthermore, bending tests demonstrated excellent mechanical tolerance where electrochemical performance was not affected under 200 cycles and 150° bending. The flexible electrochemical urea sensor platform can provide noninvasive monitoring of urea levels in sweat fluids, ensuring clinical diagnosis for biomedical applications.

Intrinsically Conductive Polymers for Striated Cardiac Muscle Repair

One of the most important features of striated cardiac muscle is the excitability that turns on the excitation-contraction coupling cycle, resulting in the heart blood pumping function. The function of the heart pump may be impaired by events such as myocardial infarction, the consequence of coronary artery thrombosis due to blood clots or plaques. This results in the death of billions of cardiomyocytes, the formation of scar tissue, and consequently impaired contractility. A whole heart transplant remains the gold standard so far and the current pharmacological approaches tend to stop further myocardium deterioration, but this is not a long-term solution. Electrically conductive, scaffold-based cardiac tissue engineering provides a promising solution to repair the injured myocardium. The non-conductive component of the scaffold provides a biocompatible microenvironment to the cultured cells while the conductive component improves intercellular coupling as well as electrical signal propagation through the scar tissue when implanted at the infarcted site. The in vivo electrical coupling of the cells leads to a better regeneration of the infarcted myocardium, reducing arrhythmias, QRS/QT intervals, and scar size and promoting cardiac cell maturation. This review presents the emerging applications of intrinsically conductive polymers in cardiac tissue engineering to repair post-ischemic myocardial insult.

SPECIFIC FEATURES OF THE STRUCTURAL ORGANIZATION OF THE PARANEURAL CONNECTIVE TISSUE OF THE RAT SITIATIC NERVE IN DIFFERENT PERIODS OF POSTNATAL DEVELOPMENT

The lack of a sufficient amount of data on the structural features of the paraneural structures of the sciatic nerve at different periods of ontogenesis contributed to the conduct of this study, as a result of which it was revealed that with an increase in the number of days from the moment of birth, a complication of the structure of the «paraneuria» was observed in an inextricable connection with the complication of the structure of the endo, peri-, epineuria and the conductive component of the sciatic nerve. «Morphological improvement» was manifested both in the appearance of new structures in the «paraneuria» and in a change in the ratio of the cellular and fibrous components of the connective tissue, which is its morphological substrate.

The use of laser therapy in children with allergic rhinitis complicated by exudative otitis media

Background. The prevalence of allergic rhinitis, which is an intermittent or permanent inflammation of the nasal mucosa caused by exposure to allergens, reaches 35%, according to different authors. Currently, this pathology is often complicated by exudative otitis media, especially in young children. Aim: to develop and justify the feasibility of using laser phoresis of sodium deoxyribonucleate for the treatment of exudative otitis media in children with allergic rhinitis. Methods. A clinical examination, a clinical blood test, rhinoscopy and otoscopy, as well as rhinocytogram, tympanometry (impedance audiometer Heinemann Titan) were performed. In diagnostics of allergic rhinitis, methods of a multifaceted otorhinolaryngological and allergological examination of the patient were used, as well as immunological tests (determination of the level of IgE and allergen-specific antibodies in the blood serum), and skin allergological tests. The examination was conducted before and after the course of treatment, as well as after 6 and 12 months. Results. With drug laser phoresis of sodium deoxyribonucleate administered endonasally and endourally, a stable result was obtained in restoring the drainage functions of the pharyngotympanic tube and reducing the symptoms of allergic rhinitis in preschool children and primary school children. Hearing is objectively improved in patients, and the conductive component is stopped, there is no fluid in the middle ear, sleep improves, the sense of smell is restored, physical performance increases, and childrens fatigue decreases in doing sports. A comparative analysis of the effectiveness of treatment in two groups showed the best results in the group of children receiving laser therapy using sodium desoxyribonucleate from medicinal non-woven textiles for up to 1 year. Repeated treatment with exacerbation of exudative otitis media was necessary to 40% of children in the control group, 12% of children after a course of laser therapy, and only one patient after a course of laser phoresis of sodium deoxyribonucleate. Conclusion. The use of laser radiation reduces the manifestations of the inflammatory process, and the allergic component.

USING 3D MODELS FROM CONDUCTIVE PLASTIC FOR GALVANOPLASTICS

The possibility of using 3D models from a number of conductive plastics for electroforming is investigated. The ohmic resistances of a number of plastics have been experimentally determined, it is shown that the resistance is determined by the number and type of conductive component in the composite material and depends on the temperature. A comparative analysis of the galvanically deposited copper surface of a number of conductive plastics and ABS plastic with a conductive layer applied with a spray has been carried out. The possibility of forming high-quality galvanoplastic copper layers on the surface of 3D models of conductive VOLTA plastic is shown.

Influence of conductive PEDOT:PSS in a hard tissue scaffold: In vitro and in vivo study

The presence of a conductive component in bone scaffolds can be helpful in facilitating the intracellular electrical signaling among cells as well as improving bone healing when electromagnetic stimulation is applied. In this study, poly(3,4-ethylenedioxythiophene): poly(4-styrene sulfonate) as a biocompatible conductive polymer was incorporated into a hard tissue scaffold made of gelatin (Gel) and bioactive glass. The in vitro results revealed that incorporation of an optimized amount of poly(3,4-ethylenedioxythiophene): poly(4-styrene sulfonate) into the scaffold composition enhanced cell viability more than four times after 14 days incubation, compared to the scaffold without poly(3,4-ethylenedioxythiophene): poly(4-styrene sulfonate). The in vivo studies demonstrated the amount of new bone formation of Gel/bioactive glass/poly(3,4-ethylenedioxythiophene): poly(4-styrene sulfonate) scaffolds was significantly higher than the Gel/bioactive glass scaffolds.

Morphology and electrical properties of polypropylene/polyamide 6/glass fiber composites with low carbon black loading

The objective of this study is to investigate the electrically conductive properties and percolation thresholds of carbon black (CB)-filled polypropylene (PP)/glass fiber (GF), PP/polyamide 6 (PA6), and PP/PA6/GF composites. Compared to CB-filled PP/GF and PP/PA6 composites, PP/PA6/GF/CB composites exhibited a reduction of the percolation threshold. Under the same CB loading, the surface resistivity of PP/PA6/GF/CB composites was much lower, indicating a better conductivity. According to the morphology images characterized by transmission electron microscopy, CB was preferentially located in the PA6 phase due to the good interaction between CB and PA6 and the lower viscosity of PA6. The addition of GF formed a PA6-coated GF structure. This structure with a relatively long diameter can effectively assist the construction of conductive paths. Meanwhile, GF also played a volume-occupying role and improved the effective concentration of the conductive component in the system. The influences of GF and PA6 mass fraction on the surface resistivity of PP/PA6/GF/CB composites were also explored, respectively. It was found that appropriate amounts of GF and PA6 could effectively increase the electrical conductivity, providing guidance for fabricating an antistatic or conductive material with high comprehensive performance.

Otosclerosis Revisited

Introduction: Otosclerosis usually manifests as a progressive conductive or mixed hearing loss occurring clinically to varying degrees in 0.5% - 1% of the general population. Stapedectomy /stapedotomy is the current treatment of choice for conductive component of Otosclerosis. Materials and Methods: Sixty patients attending the department of ENT of a Medical College Hospital in Bangalore between October 2012 and October 2017 were included in the study. Results: The incidence of otosclerosis is highest in the 3rd and 4th decade. Bilateral symptoms were present in 25% and 75% had unilateral symptoms, right side being more common in our study. Tinnitus and vertigo with deafness are seen in 60% and 25 % of the patients respectively. Ninety percent of the patients presented with moderate to moderately severe hearing loss. Twenty four (40%) out of 60 audiograms studied showed Carhart's notch. Postoperativeclosure of a-b gap to within 10dB could be achieved in 65% cases. The p value calculated comparing pre and post op results is <0.0001 and significant. Vertigo was found to be most common post-operative complication (35%) followed by sensorineural hearing loss (6.6%). Other complications observed during the study include - tympanic membrane tears, foot plate extrusion, lax long process of incus, perilymph leak. Conclusion: From the assessment of the postoperative hearing gain and postoperative complications, it can be concluded that small fenestra stapedotomy gives satisfactory post-operative outcome and may be appropriatein the Indian scenario.