Electrical conductivity measured in atomic carbon chains

The first electrical conductivity measurements of monoatomic carbon chains are reported in this study. The chains were obtained by unraveling carbon atoms from graphene ribbons while an electrical current flowed through the ribbon and, successively, through the chain. The formation of the chains was accompanied by a characteristic drop in the electrical conductivity. The conductivity of carbon chains was much lower than previously predicted for ideal chains. First-principles calculations using both density functional and many-body perturbation theory show that strain in the chains determines the conductivity in a decisive way. Indeed, carbon chains are always under varying non-zero strain that transforms its atomic structure from cumulene to polyyne configuration, thus inducing a tunable band gap. The modified electronic structure and the characteristics of the contact to the graphitic periphery explain the low conductivity of the locally constrained carbon chain.Comment: 21 pages, 9 figure

Hematopoietic Stem Cell Mobilization and Homing after Transplantation: The Role of MMP-2, MMP-9, and MT1-MMP

Hematopoietic stem/progenitor cells (HSPCs) are used in clinical transplantation to restore hematopoietic function. Here we review the role of the soluble matrix metalloproteinases MMP-2 and MMP-9, and membrane type (MT)1-MMP in modulating processes critical to successful transplantation of HSPC, such as mobilization and homing. Growth factors and cytokines which are employed as mobilizing agents upregulate MMP-2 and MMP-9. Recently we demonstrated that MT1-MMP enhances HSPC migration across reconstituted basement membrane, activates proMMP-2, and contributes to a highly proteolytic bone marrow microenvironment that facilitates egress of HSPC. On the other hand, we reported that molecules secreted during HSPC mobilization and collection, such as hyaluronic acid and thrombin, increase MT1-MMP expression in cord blood HSPC and enhance (prime) their homing-related responses. We suggest that modulation of MMP-2, MMP-9, and MT1-MMP expression has potential for development of new therapies for more efficient mobilization, homing, and engraftment of HSPC, which could lead to improved transplantation outcomes

Body dysmorphic disorder in patients with acne: treatment challenges

Body dysmorphic disorder (BDD) is defined as a constant preoccupation with one or more non-existent or slight defects or flaws in the physical appearance, often resulting in repetitive behaviours like mirror checking and camouflaging. The prevalence is around 2% in the general population with up to 10% in dermatology patients. The prevalence of BDD in patients with acne ranges between 9% and 15%. BDD is associated with considerable psychosocial deterioration, poor quality of life, and development of comorbid mental health disorders, including obsessive compulsive disorder, depression, social anxiety and alcohol or illicit drug use. Such patients suffer tremendously and are at high risk of suicide. The rate of suicidal ideation reaches 79.5%. Of this number, nearly 27.6% make failed suicidal attempts each year and 0.3% of these attempts are successful..

Water Defluoridation: Nanofiltration vs Membrane Distillation

Nowadays, fluoride contamination of drinking water is a major problem for various countries, because high concentrations of fluoride pose a risk of dental and skeletal fluorosis. Over past years, membrane nanofiltration (NF) has been proposed as convenient defluoridation technology. However, NF cannot be applied to water systems with high fluoride concentration, and the disposal of the membrane concentrate remains an issue. In this work, we compared a commercial polyester NF membrane and a polypropylene hollow-fiber membrane distillation (MD) module for their ability to remove fluoride ions from water in the presence of hardness ions and organic fouling agents. The NF membrane can offer more than 10 times higher water productivity than MD, under realistic gradients of temperature and pressure, respectively. Despite that, after reaching a concentration factor of about 3, fouling and scaling caused the flux to drop to about 80% with respect to its initial value. Moreover, F- retention decreased from 90% to below 80%, thus providing a permeate of scarce quality. MD was operated in the direct-contact mode on a polypropylene hollow-fiber membrane, which was charged with a hot feed flow (average T = 58 °C) on one side and a cooled (20 °C) permeate flow of distilled water on the other side. The concentration of fluoride ions in the permeate was always below the detection limit of our electrode (0.2 ppm), regardless of the fluoride concentration in the feed. Moreover, the MD module showed higher resistance to fouling and scaling than NF, and CaF2 crystals were recovered from the MD concentrate after cooling. These results suggest that the synergic combination of the two techniques might be beneficial for the purification of fluoride-contaminated water systems: MD can be used to further concentrate the NF retentate, thus producing high-purity water and recovering CaF2 crystals.Fil: Moran Ayala, Lucia Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Paquet, Marie. University of Aalborg; DinamarcaFil: Janowska, Katarzyna. University of Aalborg; DinamarcaFil: Jamard, Paul. University of Aalborg; DinamarcaFil: Quist Jensen, Cejna A.. University of Aalborg; DinamarcaFil: Bosio, Gabriela Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Martire, Daniel Osvaldo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Fabbri, Debora. Università di Torino; ItaliaFil: Boffa, Vittorio. University of Aalborg; Dinamarc

Surrounding skin management in venous leg ulcers: A systematic review

Objectives: Chronic venous insufficiency may lead to the development of venous leg ulcers, the most common form of chronic wounds in the lower extremity. Key to venous leg ulcer care is the maintenance of healthy skin surrounding the ulcer, as failure to maintain skin integrity may influence the healing outcome. We thus reviewed the scientific literature looking for assessment and management instruments regarding this common but often neglected issue. Method: The search included all studies published between 2000 and May 2019. Keywords used were: “peri-wound skin care”, “surrounding skin venous ulcers”, “surrounding skin management leg ulcers”, and “peri-lesional skin management”. Results: Management of moisture-balance with the selection of appropriate dressings is the most important target in surrounding-wound skin care. Moreover, contact dermatitis related to products and the dressings themselves is a neglected problem in patients with chronic leg ulcers which clinicians increasingly have to manage. The literature search revealed that there is an increasing interest in the use of noninvasive assessment tools in the field of wound care, and focusing on the surrounding-wound skin plays a role in assessing the potential of wound healing. Transepidermal water loss measurement (TEWL) and ultrasonography are two of the measurement techniques available. Conclusion: The integrity of the surrounding skin is necessary for wound healing, and appropriate management is needed to address this aspect which is part of an overall approach to treating wounds

Atypical ulcers: Diagnosis and management

Atypical ulcers show atypical clinical features, histology, localization, and resistance to standard therapies. The persistence of a chronic ulcer despite treatment with standard therapies requires a more specific diagnostic investigation. Diagnosis involves obtaining the history and performing clinical examination and additional tests. A skin biopsy is frequently used to confirm unclear diagnosis. In difficult cases, microbiological and immunohistochem-ical examinations, laboratory blood tests, or instrumental tests should be evaluated. The treatment of atypical wounds is characterized by local systemic therapy and pain control. Our results highlight the need for early diagnosis, and standardized and targeted management by a multidisciplinary wound healing center

Physico-chemical characterization and in vitro biological evaluation of a bionic hydrogel based on hyaluronic acid and l-lysine for medical applications

Hyaluronic acid (HA) is an endogenous polysaccharide, whose hydrogels have been used in medical applications for decades. Here, we present a technology platform for stabilizing HA with a biocrosslinker, the amino acid L-Lysine, to manufacture bionic hydrogels for regenerative medicine. We synthetized bionic hydrogels with tailored composition with respect to HA concentration and degree of stabilization depending on the envisaged medical use. The structure of the hydrogels was assessed by microscopy and rheology, and the resorption behavior through enzymatic degradation with hyaluronidase. The biological compatibility was evaluated in vitro with human dermal fibroblast cell lines. HA bionic hydrogels stabilized with lysine show a 3D network structure, with a rheological profile that mimics biological matrixes, as a harmless biodegradable substrate for cell proliferation and regeneration and a promising candidate for wound healing and other medical applications

Kidins220/ARMS binds to the B cell antigen receptor and regulates B cell development and activation

B cell antigen receptor (BCR) signaling is critical for B cell development and activation. Using mass spectrometry, we identified a protein kinase D\u2013interacting substrate of 220 kD (Kidins220)/ankyrin repeat\u2013rich membrane-spanning protein (ARMS) as a novel interaction partner of resting and stimulated BCR. Upon BCR stimulation, the interaction increases in a Src kinase\u2013independent manner. By knocking down Kidins220 in a B cell line and generating a conditional B cell\u2013specific Kidins220 knockout (B-KO) mouse strain, we show that Kidins220 couples the BCR to PLC\u3b32, Ca2+, and extracellular signal-regulated kinase (Erk) signaling. Consequently, BCR-mediated B cell activation was reduced in vitro and in vivo upon Kidins220 deletion. Furthermore, B cell development was impaired at stages where pre-BCR or BCR signaling is required. Most strikingly, \u3bb light chain\u2013positive B cells were reduced sixfold in the B-KO mice, genetically placing Kidins220 in the PLC\u3b32 pathway. Thus, our data indicate that Kidins220 positively regulates pre-BCR and BCR functionin

A 3D insight on the catalytic nanostructuration of few-layer graphene

The catalytic cutting of few-layer graphene is nowadays a hot topic in materials research due to its potential applications in the catalysis field and the graphene nanoribbons fabrication. We show here a 3D analysis of the nanostructuration of few-layer graphene by iron-based nanoparticles under hydrogen flow. The nanoparticles located at the edges or attached to the steps on the FLG sheets create trenches and tunnels with orientations, lengths and morphologies defined by the crystallography and the topography of the carbon substrate. The cross-sectional analysis of the 3D volumes highlights the role of the active nanoparticle identity on the trench size and shape, with emphasis on the topographical stability of the basal planes within the resulting trenches and channels, no matter the obstacle encountered. The actual study gives a deep insight on the impact of nanoparticles morphology and support topography on the 3D character of nanostructures built up by catalytic cutting