Structure-properties relationships of defined CNF single-networks crosslinked by telechelic PEGs.

The high structural anisotropy and colloidal stability of cellulose nanofibrils' enable the creation of self-standing fibrillar hydrogel networks at very low solid contents. Adding methacrylate moieties on the surface of TEMPO oxidized CNFs allows the formation of more robust covalently crosslinked networks by free radical polymerization of acrylic monomers, exploiting the mechanical properties of these networks more efficiently. This technique yields strong and elastic networks but with an undefined network structure. In this work, we use acrylate-capped telechelic polymers derived from the step-growth polymerization of PEG diacrylate and dithiothreitol to crosslink methacrylated TEMPO-oxidized cellulose nanofibrils (MATO CNF). This combination resulted in flexible and strong hydrogels, as observed through rheological studies, compression and tensile loading. The structure and mechanical properties of these hydrogel networks were found to depend on the dimensions of the CNFs and polymer crosslinkers. The structure of the networks and the role of individual components were evaluated with SAXS (Small-Angle X-ray Scattering) and photo-rheology. A thorough understanding of hybrid CNF/polymer networks and how to best exploit the capacity of these networks enable further advancement of cellulose-based materials for applications in packaging, soft robotics, and biomedical engineering.

Photocross-Linkable and Shape-Memory Biomaterial Hydrogel Based on Methacrylated Cellulose Nanofibres.

In the context of three-dimensional (3D) cell culture and tissue engineering, 3D printing is a powerful tool for customizing in vitro 3D cell culture models that are critical for understanding the cell-matrix and cell-cell interactions. Cellulose nanofibril (CNF) hydrogels are emerging in constructing scaffolds able to imitate tissue in a microenvironment. A direct modification of the methacryloyl (MA) group onto CNF is an appealing approach to synthesize photocross-linkable building blocks in formulating CNF-based bioinks for light-assisted 3D printing; however, it faces the challenge of the low efficiency of heterogenous surface modification. Here, a multistep approach yields CNF methacrylate (CNF-MA) with a decent degree of substitution while maintaining a highly dispersible CNF hydrogel, and CNF-MA is further formulated and copolymerized with monomeric acrylamide (AA) to form a super transparent hydrogel with tuneable mechanical strength (compression modulus, approximately 5-15 kPa). The resulting photocurable hydrogel shows good printability in direct ink writing and good cytocompatibility with HeLa and human dermal fibroblast cell lines. Moreover, the hydrogel reswells in water and expands to all directions to restore its original dimension after being air-dried, with further enhanced mechanical properties, for example, Young's modulus of a 1.1% CNF-MA/1% PAA hydrogel after reswelling in water increases to 10.3 kPa from 5.5 kPa.

Shape-recovering nanocellulose networks: Preparation, characterization and modeling.

Development of strong cellulose nanofibril (CNF) networks for advanced applications, such as in the biomedical field, is of high importance owing to the biocompatible nature and plant-based origin of cellulose nanofibrils. Nevertheless, lack of mechanical strength and complex synthesis methods hinder the application of these materials in areas where both toughness and manufacturing simplicity are required. In this work, we introduce a facile method for the synthesis of a low solid content (< 2 wt%), covalently crosslinked CNF hydrogel where Poly (N-isopropylacrylamide) (NIPAM) chains are utilized as crosslinks between the nanofibrils. The resulting networks have the capability to fully recover the shape in which they were formed after various drying and rewetting cycles. Characterization of the hydrogel and its constitutive components was performed using X-ray scattering, rheological investigations and uniaxial testing in compression. Influence of covalent crosslinks was compared with networks crosslinked by the addition of CaCl2. Among other things the results show that the mechanical properties of the hydrogels can be tuned by controlling the ionic strength of the surrounding medium. Finally, a mathematical model was developed based on the experimental results, which describes and predicts to a decent degree the large-deformation, elastoplastic behavior, and fracture of these networks.

Elastoplastic behavior of anisotropic, physically crosslinked hydrogel networks comprising stiff, charged fibrils in an electrolyte.

Fibrillar hydrogels are remarkably stiff, low-density networks that can hold vast amounts of water. These hydrogels can easily be made anisotropic by orienting the fibrils using different methods. Unlike the detailed and established descriptions of polymer gels, there is no coherent theoretical framework describing the elastoplastic behavior of fibrillar gels, especially concerning anisotropy. In this work, the swelling pressures of anisotropic fibrillar hydrogels made from cellulose nanofibrils were measured in the direction perpendicular to the fibril alignment. This experimental data was used to develop a model comprising three mechanical elements representing the network and the osmotic pressure due to non-ionic and ionic surface groups on the fibrils. At low solidity, the stiffness of the hydrogels was dominated by the ionic swelling pressure governed by the osmotic ingress of water. Fibrils with different functionality show the influence of aspect ratio, chemical functionality, and the remaining amount of hemicelluloses. This general model describes physically crosslinked hydrogels comprising fibrils with high flexural rigidity - that is, with a persistence length larger than the mesh size. The experimental technique is a framework to study and understand the importance of fibrillar networks for the evolution of multicellular organisms, like plants, and the influence of different components in plant cell walls.

Strong, Shape-Memory Lignocellulosic Aerogel via Wood Cell Wall Nanoscale Reassembly.

Polymer shape-memory aerogels (PSMAs) are prospects in various fields of application ranging from aerospace to biomedicine, as advanced thermal insulators, actuators, or sensors. However, the fabrication of PSMAs with good mechanical performance is challenging and is currently dominated by fossil-based polymers. In this work, strong, shape-memory bio-aerogels with high specific surface areas (up to 220 m2/g) and low radial thermal conductivity (0.042 W/mK) were prepared through a one-step treatment of native wood using an ionic liquid mixture of [MTBD]+[MMP]-/DMSO. The aerogel showed similar chemical composition similar to native wood. Nanoscale spatial rearrangement of wood biopolymers in the cell wall and lumen was achieved, resulting in flexible hydrogels, offering design freedom for subsequent aerogels with intricate geometries. Shape-memory function under stimuli of water was reported. The chemical composition and distribution, morphology, and mechanical performance of the aerogel were carefully studied using confocal Raman spectroscopy, AFM, SAXS/WAXS, NMR, digital image correlation, etc. With its simplicity, sustainability, and the broad range of applicability, the methodology developed for nanoscale reassembly of wood is an advancement for the design of biobased shape-memory aerogels.

Lifetime Victimization in Children and Adolescents With ADHD.

The objective of this study is to describe the frequency and type of victimization in a Spanish child and adolescent clinical ADHD sample and to analyze the association between the types of victimization and the severity of the symptoms. The sample is composed of 106 outpatients in treatment for ADHD, according to Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV) criteria. Symptom severity was measured by the Conners-3 scales. ADHD and comorbid diagnostics were evaluated with the Mini-Kid interview. The victimization experiences were studied using the Juvenile Victimization Questionnaire (JVQ). Children with child maltreatment history showed a greater intensity of hyperactivity/impulsivity, aggression and behavioral disorders as well as depression and anxiety disorders. The presence of peer victimization was associated with inattention, learning disorders, executive functioning, and relationship problems. Episodes of victimization should be considered in the treatment of the ADHD. Child maltreatment history is more associated with hyperactivity-impulsivity symptoms, while peer victimization is more associated with attentional symptoms.

Thermoresponsive Pentablock Copolymer on Silica: Temperature Effects on Adsorption, Surface Forces, and Friction.

The adsorption of hydrophilic or amphiphilic multiblock copolymers provides a powerful means to produce well-defined "smart" surfaces, especially if one or several blocks are sensitive to external stimuli. We focus here on an A-B-A-B-A copolymer, where A is a cationic poly((3-acrylamido-propyl)-trimethylammonium chloride) (PAMPTMA) block containing 15 (end blocks) or 30 (middle block) repeat units and B is a neutral thermosensitive water-soluble poly(2-isopropyl-2-oxazoline) (PIPOZ) block with 50 repeat units. X-ray reflectivity and quartz crystal microbalance with dissipation monitoring were employed to study the adsorption of PAMPTMA15-PIPOZ50-PAMPTMA30-PIPOZ50-PAMPTMA15 on silica surfaces. The latter technique was employed at different temperatures up to 50 °C. Surface forces and friction between the two silica surfaces across aqueous pentablock copolymer solutions at different temperatures were determined with the atomic force microscopy colloidal probe force and friction measurements. The cationic pentablock copolymer was found to have a high affinity to the negatively charged silica surface, leading to a thin (2 nm) and rigid adsorbed layer. A steric force was encountered at a separation of around 3 nm from hard wall contact. A capillary condensation of a polymer-rich phase was observed at the cloud point of the solution. The friction forces were evaluated using Amontons' rule modified with an adhesion term.

Conforming nanoparticle sheets to surfaces with Gaussian curvature.

Nanoparticle monolayer sheets are ultrathin inorganic-organic hybrid materials that combine highly controllable optical and electrical properties with mechanical flexibility and remarkable strength. Like other thin sheets, their low bending rigidity allows them to easily roll into or conform to cylindrical geometries. Nanoparticle monolayers not only can bend, but also cope with strain through local particle rearrangement and plastic deformation. This means that, unlike thin sheets such as paper or graphene, nanoparticle sheets can much more easily conform to surfaces with complex topography characterized by non-zero Gaussian curvature, like spherical caps or saddles. Here, we investigate the limits of nanoparticle monolayers' ability to conform to substrates with Gaussian curvature by stamping nanoparticle sheets onto lattices of larger polystyrene spheres. Tuning the local Gaussian curvature by increasing the size of the substrate spheres, we find that the stamped sheet morphology evolves through three characteristic stages: from full substrate coverage, where the sheet extends over the interstices in the lattice, to coverage in the form of caps that conform tightly to the top portion of each sphere and fracture at larger polar angles, to caps that exhibit radial folds. Through analysis of the nanoparticle positions, obtained from scanning electron micrographs, we extract the local strain tensor and track the onset of strain-induced dislocations in the particle arrangement. By considering the interplay of energies for elastic and plastic deformations and adhesion, we construct arguments that capture the observed changes in sheet morphology as Gaussian curvature is tuned over two orders of magnitude.

Health profiles in people with intellectual developmental disorders.

OBJECTIVE: To better understand the health profiles of people with intellectual disability (ID), focusing on the variables that are associated with a poorer health status. MATERIALS AND METHODS: Data were collected from the Survey on Disability, Personal Autonomy and Dependency (EDAD 2008) of the Spanish National Statistics Institute (INE). The health data of 2840 subjects with IDD were analyzed in order to verify the impact of different variables on their health profiles. RESULTS: People with severe and profound levels of IDD presented a higher number of medical diagnoses. At residence centers there was a larger proportion of individuals with a higher prevalence of chronic diseases and more severe conditions; age also was an important factor. CONCLUSION: The health profiles of individuals with IDD differ depending on the severity level of their IDD and their degree of institutionalization. Further research is needed to provide better health care for people with IDD.

[New considerations on the health of the persons with intellectual developmental disorders]. / Nuevas consideraciones sobre la salud de las personas con trastornos del desarrollo intelectual.

Recent literature indicates that people with Disorders of Intellectual Development (DID) experience health disparities in the pathologies that they present, and a worst access to health care. However, current evidence-based knowledge is still sparse outside the Anglo-Saxon countries. The POMONA-I and POMONA-II European projects aimed to collect information on the health status of people with DID in Europe. The POMONA-ESP project in Spain is meant to collect health information in a wide and representative sample of persons with DID. Also, there are studies that claim for the need of specialized services for people with DID at the public health system. There are also studies about the current state of the education and training about DID for students within the health sector. In this paper we review the latest evidences about the health of the persons with DID and we present the main research activities and care initiatives about this issue.

Resumen: La literatura reciente indica que las personas con trastornos del desarrollo intelectual (TDI) presentan diferencias respecto de la población general en cuanto a la prevalencia de determinadas enfermedades y a la atención sanitaria que reciben. El conocimiento actual con base en la evidencia es aún muy escaso en países no anglosajones. Los proyectos europeos POMONA-I y POMONA-II tenían el objetivo de recoger información sobre el estado de salud de las personas con TDI en Europa. Actualmente, el proyecto POMONA-ESP en España pretende recoger dicha información en una muestra amplia y representativa de personas con TDI. También se están llevando a cabo otros estudios sobre la necesidad de contar con servicios especializados y sobre la formación que reciben los profesionales sanitarios sobre TDI. En este artículo se revisan las últimas evidencias sobre la salud de las personas con TDI y se exponen las principales actividades de investigación y asistencia sanitaria sobre este tema.

Health profiles in people with intellectual developmental disorders / Perfiles de salud en personas con trastornos del desarrollo intelectual

Abstract: Objective: To better understand the health profiles of people with intellectual disability (ID), focusing on the variables that are associated with a poorer health status. Materials and methods: Data were collected from the Survey on Disability, Personal Autonomy and Dependency (EDAD 2008) of the Spanish National Statistics Institute (INE). The health data of 2840 subjects with IDD were analyzed in order to verify the impact of different variables on their health profiles. Results: People with severe and profound levels of IDD presented a higher number of medical diagnoses. At residence centers there was a larger proportion of individuals with a higher prevalence of chronic diseases and more severe conditions; age also was an important factor. Conclusion: The health profiles of individuals with IDD differ depending on the severity level of their IDD and their degree of institutionalization. Further research is needed to provide better health care for people with IDD.

Resumen: Objetivo: Conocer los perfiles de salud de las personas con discapacidad intelectual (DI), incidiendo en las variables que se relacionan con un peor estado de salud. Material y métodos: Se han empleado datos procedentes de la Encuesta sobre Discapacidades, Autonomía personal y situaciones de Dependencia (EDAD 2008) del Instituto Nacional de Estadística (INE). Se han comparado los datos de salud de 2840 sujetos con discapacidad intelectual para analizar las diferencias en sus perfiles de salud. Resultados: En los centros residenciales hay una mayor proporción de personas con DI profunda y severa, de edad más avanzada y con mayor prevalencia de enfermedades crónicas. Las personas con niveles más graves de DI presentan un mayor número de diagnósticos de enfermedades. Conclusión: Los perfiles de salud de las personas con DI difieren en función de su grado de institucionalización y su nivel de DI. Es necesario seguir investigando para ofrecer una mejor atención sanitaria a las personas con DI.

Nuevas consideraciones sobre la salud de las personas con trastornos del desarrollo intelectual / New considerations on the health of the persons with intellectual developmental disorders

Resumen: La literatura reciente indica que las personas con trastornos del desarrollo intelectual (TDI) presentan diferencias respecto de la población general en cuanto a la prevalencia de determinadas enfermedades y a la atención sanitaria que reciben. El conocimiento actual con base en la evidencia es aún muy escaso en países no anglosajones. Los proyectos europeos POMONA-I y POMONA-II tenían el objetivo de recoger información sobre el estado de salud de las personas con TDI en Europa. Actualmente, el proyecto POMONA-ESP en España pretende recoger dicha información en una muestra amplia y representativa de personas con TDI. También se están llevando a cabo otros estudios sobre la necesidad de contar con servicios especializados y sobre la formación que reciben los profesionales sanitarios sobre TDI. En este artículo se revisan las últimas evidencias sobre la salud de las personas con TDI y se exponen las principales actividades de investigación y asistencia sanitaria sobre este tema.

Abstract: Recent literature indicates that people with Disorders of Intellectual Development (DID) experience health disparities in the pathologies that they present, and a worst access to health care. However, current evidence-based knowledge is still sparse outside the Anglo-Saxon countries. The POMONA-I and POMONA-II European projects aimed to collect information on the health status of people with DID in Europe. The POMONA-ESP project in Spain is meant to collect health information in a wide and representative sample of persons with DID. Also, there are studies that claim for the need of specialized services for people with DID at the public health system. There are also studies about the current state of the education and training about DID for students within the health sector. In this paper we review the latest evidences about the health of the persons with DID and we present the main research activities and care initiatives about this issue.

[Delusions and their relation with temperament and character in psychotic patients]. / Delirios y su relación con el temperamento y carácter en pacientes con trastorno psicótico.

Delusions and their relation with temperament and character in psychotic patients. Recent studies have investigated the relationship between personality traits and symptomatology in schizophrenia. The aim of this study is to investigate whether Cloninger's dimensional personality traits are related to psychotic delusional symptomatology. In the study, we include a sample of 105 patients with DSM-IV diagnosis of schizophrenia or another psychotic disorder. Delusions were evaluated by the SCAN interview. Our results suggest that some personality traits may contribute to heterogeneity in the presentation of psychotic positive delusional disorder congruent with affective symptoms. Thus, Harm Avoidance would be related to delusions that course with a depressive state and Novelty Seeking to those concurrent with an expansive affectivity.

Delirios y su relación con el temperamento y carácter en pacientes con trastorno psicótico / Delusions and their relation with temperament and character in psychotic patients

En numerosos estudios y desde diferentes modelos se ha especulado sobre la relación entre personalidad y psicosis. El objetivo de este trabajo es estudiar si las dimensiones o rasgos de personalidad, evaluados con el Modelo de Cloninger y presentes en pacientes psicóticos, están relacionados con niveles de sintomatología delirante. Participaron en el estudio una muestra de 105 pacientes diagnosticados dentro del grupo de esquizofrenias u otros trastornos psicóticos no orgánicos según criterios DSM-IV. La evaluación de los delirios se realiza con la entrevista SCAN. Tras estudiar posibles relaciones y vínculos, nuestros resultados nos podrían llevar a pensar que exista relación entre síntomas delirantes y personalidad de acuerdo con una congruencia afectiva semejante. Así, Evitación del daño presentaría relación con síntomas que cursan con un estado de ánimo depresivo, y Búsqueda de novedades con síntomas que implican un ánimo expansivo (AU)

Recent studies have investigated the relationship between personality traits and symptomatology in schizophrenia. The aim of this study is to investigate whether Cloninger’s dimensional personality traits are related to psychotic delusional symptomatology. In the study, we include a sample of 105 patients with DSM-IV diagnosis of schizophrenia or another psychotic disorder. Delusions were evaluated by the SCAN interview. Our results suggest that some personality traits may contribute to heterogeneity in the presentation of psychotic positive delusional disorder congruent with affective symptoms. Thus, Harm Avoidance would be related to delusions that course with a depressive state and Novelty Seeking to those concurrent with an expansive affectivity (AU)