Self-standing 3D-printed PEGDA–PANIs electroconductive hydrogel composites for pH monitoring

Additive manufacturing (AM), or 3D printing processes, is introducing new possibilities in electronic, biomedical, sensor-designing, and wearable technologies. In this context, the present work focuses on the development of flexible 3D-printed polyethylene glycol diacrylate (PEGDA)- sulfonated polyaniline (PANIs) electrically conductive hydrogels (ECHs) for pH-monitoring applications. PEGDA platforms are 3D printed by a stereolithography (SLA) approach. Here, we report the successful realization of PEGDA–PANIs electroconductive hydrogel (ECH) composites produced by an in situ chemical oxidative co-polymerization of aniline (ANI) and aniline 2-sulfonic acid (ANIs) monomers at a 1:1 equimolar ratio in acidic medium. The morphological and functional properties of PEGDA–PANIs are compared to those of PEGDA–PANI composites by coupling SEM, swelling degree, I–V, and electro–chemo–mechanical analyses. The differences are discussed as a function of morphological, structural, and charge transfer/transport properties of the respective PANIs and PANI filler. Our investigation showed that the electrochemical activity of PANIs allows for the exploitation of the PEGDA–PANIs composite as an electrode material for pH monitoring in a linear range compatible with that of most biofluids. This feature, combined with the superior electromechanical behavior, swelling capacity, and water retention properties, makes PEGDA–PANIs hydrogel a promising active material for developing advanced biomedical, soft tissue, and biocompatible electronic applications

Anticipated and experienced discrimination amongst people with schizophrenia, bipolar disorder and major depressive disorder: a cross-sectional study.

BACKGROUND: The unfair treatment of individuals with severe mental illness has been linked to poorer physical and mental health outcomes. Additionally, anticipation of discrimination may lead some individuals to avoid participation in particular life areas, leading to greater isolation and social marginalisation. This study aimed to establish the levels and clinical and socio-demographic associations of anticipated and experienced discrimination amongst those diagnosed with a schizophrenia and comparator severe mental illnesses (bipolar and major depressive disorders). METHODS: This study was a cross-sectional analysis of anticipated and experienced discrimination from 202 individuals in South London (47% with schizophrenia, 32% with depression and 20% with bipolar disorder). RESULTS: 93% of the sample anticipated discrimination and 87% of participants had experienced discrimination in at least one area of life in the previous year. There was a significant association between the anticipation and the experience of discrimination. Higher levels of experienced discrimination were reported by those of a mixed ethnicity, and those with higher levels of education. Women anticipated more discrimination than men. Neither diagnosis nor levels of functioning were associated with the extent of discrimination. Clinical symptoms of anxiety, depression and suspiciousness were associated with more experienced and anticipated discrimination respectively. CONCLUSIONS: The unfair treatment of individuals with severe mental illnesses remains unacceptably common. Population level interventions are needed to reduce levels of discrimination and to safeguard individuals. Interventions are also required to assist those with severe mental illness to reduce internalised stigma and social avoidance

Age-related changes in the human optic nerve

BACKGROUND: Recent morphologic research has demonstrated the presence of nerve fibres of different diameters in the human optic nerve. The purpose of this study was to investigate age-related changes in fibres of the human optic nerve. METHODS: We studied the left optic nerve of 50 male cadaveric donors, 16 aged 18 to 22 years (mean 20 [standard deviation 1.2] years) and 34 aged 68 to 76 years (mean 72 [standard deviation 1.6] years). The samples were carefully harvested during autopsy from the intracranial portion of the optic nerve. Each nerve was cut into four 4-mm segments. After morphologic, histochemical and immunohistochemical staining, the optic nerve fibres were counted and measured. Each segment was evaluated under light microscopy for microanatomic details, glial cells and glial fibrillary acidic protein (GFAP) staining. The protein content was determined under biochemical analysis. We performed morphometric analysis by examining the optic nerve images quantitatively. RESULTS: Compared with the younger group, in the older group there was an increase in mean diameter of the optic nerve (p < 0.001), due to an increase in the optic nerve:meningeal membrane ratio. There was also an increase in mean optic nerve area (p < 0.001) and in mean number of astrocytes and the related GFAP-immunoreactive area (p < 0.001). The mean number of nerve fibres of large diameter (greater than 4 pm) was decreased (p < 0.001). There was no difference in mean protein content of the fibres between the two groups. INTERPRETATION: The human optic nerve is sensitive to the aging process and may be considered as a model for studies on neuronal aging

DISTRIBUTION OF PEPTIDERGIC NERVE FIBERS IN THE GUINEA PIG TRABECULAR MESHWORK

A quantitative analysis of peptidergic nerve fibres located in the trabecular meshwork of the guinea pig has been performed. Our results confirm that this structure contains VIP-, NPY- and substance P-like immunoreactivity as major neurotransmitters. These findings were obtained using immunohistochemical techniques. For this purpose serial sections of the eye were stained by immunohistochemistry for each of three neurotransmitters and stained sections were analysed by quantitative image analysis. Our findings demonstrate that SP-positive, NPY-positive and VIP-positive nerve fibres occupy 11.2, 4.9 and 2.4%, respectively, of the observed area (expressed as conventional units, C.U.) in the trabecular meshwork of the guinea pig eye. It is relevant to emphasize that the area containing these three types of peptidergic nerve fibres appears to be large (18.5 +/- 6.6 C.U.) in proportion to the total observed area. The innervation of the drainage angle of the guinea pig eye has been well described by many authors. This is the first study to report quantitative measurements of three types of peptidergic nerve fibres identified and measured in this area. The presence of these three neurotransmitters in the trabecular meshwork of guinea pig eye suggests their possible participation in aqueous humor regulation

Age-related changes in the human retina

Background: In a previous study, scanning electron microscopy (SEM) showed agerelated changes in the rat retina. We carried out a study to evaluate age-related changes in the human retina. Methods: Samples of fresh retinal tissue obtained from younger (age 22 years or less) and older (age 66 years or more) donors were studied by means of traditional histologic methods and by SEM. Eight retinas were obtained from four donors whose corneas had been used for transplantation, and four retinas were obtained from four subjects whose eyes had been enucleated owing to injury.All morphologic results were subjected to quantitative analysis of images. The concentration of cytoplasmic (free) and structural (tissue-associated) protein in retinal tissue homogenates was determined by means of biochemical methods. Results: There was a decrease in all features studied with the exception of structural protein concentration. The mean retinal thickness (and standard error of the mean) was 426 (34.2) mum in the younger subjects and 261 (18.9) mum in the older subjects. The mean numbers of ganglion cells (and standard error of the mean) were 413.5/mm(2) (32.3/mm(2)) and 256.2/mm(2) (26.8/mm(2)) respectively, of capillaries 3.6/mm(2) (1.4/mm(2)) and 1.8/mm(2) (1.2/mm(2)) respectively, of synaptic bodies 122.4 (4.9) conventional units (CU)/area observed and 38.5 (1.6) CU/area observed respectively, of cellular processes 82.3 (3.1) CU/area observed and 13.1 (1.5) CU/ area observed respectively, and of intercellular connections 36.4 (2.5) CU/area observed and 14.3 (1.4) CU/area observed respectively. The mean concentration of total protein per milligram of fresh tissue (and standard error of the mean) was 92.1 (1.8) mug in the younger subjects and 78.7 (1.3) mug in the older subjects; the corresponding values for cytoplasmic protein were 27.6 (1.3) mug and 11.8 (0.8) mug, and for structural protein, 64.4 (1.6) mug and 86.9 (1.4) mug. All differences between the younger and older subjects were significant (p < 0.001) with the exception of mean concentration of cytoplasmic and of structural protein. Interpretation: The human retina undergoes specific changes with aging. SEM provides new morphometric information regarding age-related changes in photoreceptor cells, bipolar cells and ganglion cells that increases our understanding of this topic. Our results may be adopted as a model or as normal values when studying other changes that may occur in the human retina in pathological conditions

Occurrence of cholinergic nerve fibres in the human uveoscleral tissue

We have studied the cholinergic nerve fibers (CNF) of human uveoscleral tissue in normal and pathological conditions (intraocular pressure: (IOP) of various degrees ) and have performed a quantitative image analysis of CNF with the aim of studying an hypothetical association between IOP and the uveoscleral level of cholinergic neurotransmitter in nerve fiber of the enucleated human eyes. Eleven patients, previously enrolled in our medical protocols are affected by an increase of IOP of various degrees, were subjected to surgical enucleation of one eyeball for traumatic or neoplastic reasons and were the donors of samples of the uveoscleral tissue for CNF demonstration. The samples were also submitted to quantitative image analysis. An enzymatic activity, Acetylcholinesterase (AChe), is present in nerve fibers that innervate the human uveoscleral tissue. The AChe-positive nerve fibers represent about 7.2% of the observed area in normal conditions, while in patients with elevated IOP AChe activity is about 20.3% of the total observed area. The increase of AChe activity in our experiments, all performed under the same conditions, and therefore, with comparable results, may be related with the increase of IOP

A Sustainable Hydroxypropyl Cellulose-Nanodiamond Composite for Flexible Electronic Applications

Designing fully green materials for flexible electronics is an urgent need due to the growing awareness of an environmental crisis. With the aim of developing a sustainable, printable, and biocompatible material to be exploited in flexible electronics, the rheological, structural and charge transport properties of water-based hydroxypropyl cellulose (HPC)-detonation nanodiamond (DND) viscous dispersions are investigated. A rheological investigation disclosed that the presence of the DND affects the orientation and entanglement of cellulose chains in the aqueous medium. In line with rheological analyses, the NMR diffusion experiments pointed out that the presence of DND modifies the hydrodynamic behavior of the cellulose molecules. Despite the increased rigidity of the system, the presence of DND slightly enhances the ionic conductivity of the dispersion, suggesting a modification in the charge transport properties of the material. The electrochemical analyses, performed through Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS), revealed that the HPC-DND system is remarkably stable in the explored voltage range (&minus;0.1 to +0.4 V) and characterized by a lowered bulk resistance with respect to HPC. Such features, coupled with the printability and filmability of the material, represent good requirements for the exploitation of such systems in flexible electronic applications

A new strong-acid free route to produce xanthan gum-PANI composite scaffold supporting bioelectricity

Conductive hybrid xanthan gum (XG)-polyaniline (PANI) biocomposites forming 3D structures able to mimic electrical biological functions are synthesized by a strong-acid free medium. In situ aniline oxidative chemical polymerizations are performed in XG water dispersions to produce stable XG-PANI pseudoplastic fluids. XG-PANI composites with 3D architectures are obtained by subsequent freeze-drying processes. The morphological investigation highlights the formation of porous structures; UV-vis and Raman spectroscopy characterizations assess the chemical structure of the produced composites. I-V measurements evidence electrical conductivity of the samples, while electrochemical analyses point out their capability to respond to electric stimuli with electron and ion exchanges in physiological-like environment. Trial tests on prostate cancer cells evaluate biocompatibility of the XG-PANI composite. Obtained results demonstrate that a strong acid-free route produces an electrically conductive and electrochemically active XG-PANI polymer composite. The investigation of charge transport and transfer, as well as of biocompatibility properties of composite materials produced in aqueous environments, brings new perspective for exploitation of such materials in biomedical applications. In particular, the developed strategy can be used to realize biomaterials working as scaffolds that require electrical stimulations for inducing cell growth and communication or for biosignals monitoring and analysis

«Mia parte conia femminile». Amelia Rosselli nell'opera di Dario Bellezza

Verso la fine degli anni Sessanta Amelia Rosselli e Dario Bellezza intrattengono uno stretto legame e per alcuni mesi condividono la casa. Dai racconti ricavabili da amici poeti comuni si evince che il rapporto fra i due si interrompe bruscamente. Sono anni molto importanti che segnano la pubblicazione di Serie ospedaliera (1969) e la produzione di parte di Documento (1976) per la Rosselli, e la pubblicazione di Invettive e licenze (1971) per Bellezza, opera in cui è presente un’importante testimonianza su Rosselli. Ci si propone di ricostruire – all’interno delle impor- tanti amicizie e influenze poetiche – il legame fra Rosselli e Bellezza, che investe tanto il piano biografico quanto quello poetico, al fine di individuare le reciproche influenze nel periodo com- preso fra la fine degli anni ‘60 e la metà dei ’70.Around the late Sixties, Amelia Rosselli and Dario Bellezza had frequent contacts and for a few months they lived together. The stories told by some common poet friends suggest that the rela- tionship between them suddenly broke. These are very important years that see Rosselli publish her Serie ospedaliera (1969) and write part of Documento (1976), with Bellezza publishing Invettive e licenze (1971), a work that contains strong associations with Rosselli. The intent of this paper is to re-enact – in their important friendships and poetic influences – the relationship between Rosselli and Bellezza, which affects as much the biographical sphere as the poetic one, in the attempt to find mutual influences, in the years between the late Sixties and the mid-Seventies