On the nonextensive character of some magnetic systems

During the past few years, nonextensive statistics has been successfully applied to explain many different kinds of systems. Through these studies some interpretations of the entropic parameter q, which has major role in this statistics, in terms of physical quantities have been obtained. The aim of the present work is to yield an overview of the applications of nonextensive statistics to complex problems such as inhomogeneous magnetic systems.Comment: to appear in the Proceedings of the conference CTNEXT07, Complexity, Metastability and Nonextensivity, Catania, Italy, 1-5 July 2007, Eds. S. Abe, H.J. Herrmann, P. Quarati, A. Rapisarda and C. Tsallis (American Institute of Physics, 2007) in pres

EMG Signs of Motor Units’ Enlargement in Stroke Survivors

The degeneration of lower motoneurons has often been reported in stroke survivors, with possible collateral reinnervation from the surviving motoneurons to the denervated muscle fibers. Under this assumption, a stroke would be expected to increase the size of motor units in paretic muscles. We indirectly address this issue with electrical stimulation and surface electromyography, asking whether stroke leads to greater variations in the amplitude of M waves elicited in paretic muscles than in contralateral, non-paretic muscles. Current pulses at progressively greater intensities were applied to the musculocutaneous nerve, stimulating motoneurons supplying the biceps brachii of eight stroke patients. The size of increases in the amplitude of M waves elicited consecutively, hereafter defined as increments, was considered to evaluate changes in the innervation ratio of biceps brachii motor units following stroke. Our findings showed that patients presented significantly (p = 0.016) greater increments in muscles of paretic than in non-paretic limbs. This result corroborates the notion that collateral reinnervation takes place after stroke, enlarging motor units’ size and the magnitude of the muscle responses. Therefore, the non-invasive analysis proposed here may be useful for health professionals to assess disease progression by tracking for neuromuscular changes likely associated with clinical outcomes in stroke survivors, such as in the muscles’ strength

Characterization of Sequential Collagen-Poly(Ethylene Glycol) Diacrylate Interpenetrating Networks and Initial Assessment of Their Potential for Vascular Tissue Engineering

Collagen hydrogels have been widely investigated as scaffolds for vascular tissue engineering due in part to the capacity of collagen to promote robust cell adhesion and elongation. However, collagen hydrogels display relatively low stiffness and strength, are thrombogenic, and are highly susceptible to cell-mediated contraction. In the current work, we develop and characterize a sequentially-formed interpenetrating network (IPN) that retains the benefits of collagen, but which displays enhanced mechanical stiffness and strength, improved thromboresistance, high physical stability and resistance to contraction. In this strategy, we first form a collagen hydrogel, infuse this hydrogel with poly(ethylene glycol) diacrylate (PEGDA), and subsequently crosslink the PEGDA by exposure to longwave UV light. These collagen-PEGDA IPNs allow for cell encapsulation during the fabrication process with greater than 90% cell viability via inclusion of cells within the collagen hydrogel precursor solution. Furthermore, the degree of cell spreading within the IPNs can be tuned from rounded to fully elongated by varying the time delay between the formation of the cell-laden collagen hydrogel and the formation of the PEGDA network. We also demonstrate that these collagen-PEGDA IPNs are able to support the initial stages of smooth muscle cell lineage progression by elongated human mesenchymal stems cells

Polarized supramolecular aggregates based on luminescent perhalogenated gold derivatives

Reaction of [Au(C6F5)(tht)] (tht = tetrahydrothiophene) with 1,3,5-triaza-7-phosphaadamantane (PTA) and 3,7-diacetyl-1,3,7-triaza-5-phosphabicyclo[3.3.1]-nonane (DAPTA) leads to the formation of [Au(C6F5)(phosph)] (phosph = PTA, 1; phosph = DAPTA, 2). The compounds are slightly soluble in water and aggregate at higher concentrations giving rise to the formation of needle- and rod-like structures (1) and well-organized spherical aggregates (2). Compounds 1 and 2 were reacted with AgPF6 giving rise to the formation in all cases of luminescent water soluble 1:1 Au·Ag heterometallic complexes, as evidenced by X-ray crystal structure determination. The use of different silver salts that differ on the counterion induces changes on the resulting luminescence and aggregation morphology

The Estimates of Retinal Ganglion Cell Counts Performed Better than Isolated Structure and Functional Tests for Glaucoma Diagnosis

Purpose. To evaluate the diagnostic accuracy of retinal ganglion cell (RGC) counts as estimated by combining data from standard automated perimetry (SAP) and spectral domain optical coherence tomography (SD-OCT). Methods. Healthy individuals and glaucoma patients were included in this cross-sectional study. All eyes underwent 24-2 SITA SAP and structural imaging tests. RGC count estimates were obtained using a previously described algorithm, which combines estimates of RGC numbers from SAP sensitivity thresholds and SD-OCT retinal nerve fiber layer (RNFL) average thickness. Results. A total of 119 eyes were evaluated, including 75 eyes of 48 healthy individuals and 44 eyes of 29 glaucoma patients. RGC count estimates performed better than data derived from SD-OCT RNFL average thickness or SAP mean deviation alone (area under ROC curves: 0.98, 0.92, and 0.79; P<0.001) for discriminating healthy from glaucomatous eyes, even in a subgroup of eyes with mild disease (0.97, 0.88, and 0.75; P<0.001). There was a strong and significant correlation between estimates of RGC numbers derived from SAP and SD-OCT (R2=0.74; P<0.001). Conclusion. RGC count estimates obtained by combined structural and functional data showed excellent diagnostic accuracy for discriminating the healthy from the glaucomatous eyes and performed better than isolated structural and functional parameters

Antimicrobial performance of lignin embedded in bacterial nanocellulose membranes

The development of bio-based antimicrobial polymeric composites has never been so urgent. Novel antimi- crobial fibrous-based biocomposites will certainly allow the development of important solutions to fight the present and future Pandemics, while reducing the dependence of petrochemical based polymers and fibers. Lignin has a pivotal function in preventing the invasion of phytopathogens, thus, this work explores the anti- microbial potential of lignin when embedded in a biosynthesized fibrous nanomatrix with superior mechanical properties: bacterial nanocellulose (BNC). Lignin was subjected to alkali treatment to promote the inclusion of lignin within BNC which comprises pores ranging from 20 to 300 nm. Both alkali treatment efficiency, bac- tericidal and antiviral activities were investigatedThe authors would like to acknowledge the project PLASMAMED - PTDC/CTM-TEX/28295/2017 fnanced by FCT, FEDER and POCI in the frame of the Portugal 2020 program, the project UID/CTM/00264/2019 of 2C2T under the COMPETE and FCT/MCTES (PIDDAC) co-fnanced by FEDER through the PT2020 program. Liliana Melro acknowledges her Doctoral grant awarded by FCT (2020.04919.BD)

REQUIRED COEFFICIENT OF FRICTION ANALYSES IN RUNNING

The purpose of this study was to analyze the possible alterations in the required coefficient of friction (RCOF) in running under the following conditions: a) barefoot against shod; b) self-selected velocity and cadence versus imposed cadence and c) along three running phases (initial contact, mid-stance and propulsion). Two Kistler force plates were used to measure the horizontal and vertical components of ground reaction forces in order to calculate the RCOF. Statistical differences were found for cadence and phase factors. Barefoot-Shod conditions did not present statistical differences. An interaction between velocity and phase of cycle was found. At propulsion phase, an increased RCOF were revealed, especially with the interaction of an imposed cadence. In conclusion, the present study supports the relevance of RCOF as a variable affecting and being affected during running to be taken into consideration at many experimental conditions

Mental Illness Sexual Stigma: Implications for Health and Recovery

The majority of people in psychiatric care worldwide are sexually active, and studies have revealed sharply elevated rates of HIV infection in that group compared with the general population. Recovery-oriented treatment does not routinely address sexuality. We examined the relationship between gender, severe mental illness diagnosis, and stigma experiences related to sexuality among people in psychiatric outpatient care. Method: Sexually active adults attending 8 public outpatient psychiatric clinics in Rio de Janeiro (N = 641) were interviewed for psychiatric diagnosis and stigma experiences. Stigma mechanisms well-established in the literature but not previously examined in relation to sexuality were measured with the Mental Illness Sex Stigma Questionnaire, a 27-item interview about stigma in sexual situations and activities. Results: Experiences of stigma were reported by a majority of participants for 48% of questionnaire items. Most people reported supportive attitudes toward their sexuality from providers and family members. Those with severe mental illness diagnoses showed greater stigma on individual discrimination and structural stigma mechanisms than did those with nonsevere mental illness diagnoses, whereas there was no difference on the social psychological processes (internalized stigma) mechanism. Regardless of diagnosis or gender, a majority of participants devalued themselves as sexual partners. Conclusions and Implications for Practice: Adults in psychiatric outpatient care frequently reported stigma experiences related to aspects of their sexual lives. From the perspectives of both HIV prevention and recovery from mental illness, examinations of the consequences of stigma in the sexual lives of people in psychiatric care and improving their measurement would have wide applicability

Bio-synthesised fibrous-based meshes for abdominal hernia with enhanced mechanical and antimicrobial properties

Abdominal hernia (AH) encompasses the most prevalent types of hernia: inguinal, umbilical and incisional. Notwithstanding current hernia complications represent a low death toll (nearly 0.001 % in developed countries), non-reducible hernias are the most severe cases, which require urgent surgical intervention due to their life-threatening nature. In a single year, at the United States of America, more than 800 thousand surgeries are performed to repair inguinal hernias. Abdominal hernia ubiquitous symptoms include pain, which may represent a mild discomfort or even an impairing morbidity. Nevertheless, some patients suffer from morbidity in the post-operative period. Recurrence was reduced when the application of a propylene mesh replaced primary suture repair more than 60 years ago. Surprisingly, currently the most prevalent hernia mesh materials are based on petrochemical plastics such as polypropylene, polyester, polystyrene and expanded polytetrafluoroethylene. Unfortunately, despite the plethora of commercial hernia meshes, an improvement of the hernia meshes is still warranted, since petrochemical materials exhibit a deterioration over time which generate complications and recurrence. This project envisages the complete replacement of the conventional plastic-based material of hernia meshes by a fully bio- based material with superior mechanical properties: bacterial nanocellulose (BNC). BNC is synthesized by bacteria and is composed of a 3D matrix of 100 % nanofibrils of cellulose, each with a diameter ranging between 20 to 100 nm. When BNC producing bacterium are cultured in static culture, the BNC is formed as membrane (nanoporous mesh comprising pores of 100 to 300 nm in diameter) at the surface of the culture medium and adopts the shape of the available surface. Therefore, it is easy to control the membrane surface shape, as well as its thickness, which can be controlled by the incubation time (longer incubation time will result in a larger thickness). The selection of the most adequate bacterium for the production of the hernia mesh will be performed Nevertheless, for a hernia mesh to be viable it requires pores with a specific diameter to allow the permeability of leukocytes, fibroblasts, and permit the arrangement of collagen and blood vessels. Per se, the BNC mesh does not possess such large specific pores with the required diameter (> 75 μm), thus it is proposed the design and development of a template to achieve a AH mesh that meets the necessary requirements. Furthermore, due to the high complexity of hernia mesh infection, which is extremely difficult to adequately treat without removing the mesh, this project envisages the functionalization of BNC AH mesh with antimicrobial properties. Two approaches will be considered for the BNC AH mesh functionalization, namely: in situ synthesis and adsorption through filtration. NPs optimal concentration and functionalization process will be examined and tailored to obtain a BNC AH mesh with effective antimicrobial activity and negligible cytotoxicity. According the AH implantation site, three different hernia meshes classes are usually applied: low, medium and high weight, thus the optimal antimicrobial BNC meshes of each class will be patented to represent a viable commercial alternative, by displaying superior mechanical properties, biocompatibility and low infection propensity, to considerably improve AH patience overall wellbeing.FEDER funds under the COMPETE program and by National Funds through Fundação para a Ciência e Tecnologia (FCT) under the project POCI-01- 0145-FEDER-007136 and UID/CTM/00264/2013. PLASMAMED project PTDC/CTMTEX/28295/2017 funded by FCT, FEDER e POCI through the program Portugal 202