Rolling of a cylinder with slip-dependent friction: The Carter solution revisited

The problem of a wheel under tractive rolling of Carter is revisited here by assuming a slip-dependent friction force. By assuming a change from static to dynamic friction coefficient occurs over a small distance, we develop effectively a fracture mechanics solution for the shear tractions, which describes some aspects of “falling friction” creepage forces which are commonly observed experimentally. Possible agreement with experiments is discussed, suggesting that friction may include also rate-dependent effects. A simple strip theory is used to estimate 3D effects, which reduce the strength of the singularity at the edges being the peak pressure lower there

Impact of Freeze-Drying on Cord Blood (CB), Serum (S), and Platelet-Rich Plasma (CB-PRP) Preparations on Growth Factor Content and In Vitro Cell Wound Healing

Blood-based preparations are used in clinical practice for the treatment of several eye disorders. The aim of this study is to analyze the effect of freeze-drying blood-based preparations on the levels of growth factors and wound healing behaviors in an in vitro model. Platelet-rich plasma (PRP) and serum (S) preparations from the same Cord Blood (CB) sample, prepared in both fresh frozen (FF) and freeze-dried (FD) forms (and then reconstituted), were analyzed for EGF and BDNF content (ELISA Quantikine kit). The human MIO-M1 glial cell line (Moorfield/Institute of Ophthalmology, London, UK) was incubated with FF and FD products and evaluated for cell migration with scratch-induced wounding (IncuCyte S3 Essen BioScience), proliferation with cyclin A2 and D1 gene expression, and activation with vimentin and GFAP gene expression. The FF and FD forms showed similar concentrations of EGF and BDNF in both the S and PRP preparations. The wound healing assay showed no significant difference between the FF and FD forms for both S and PRP. Additionally, cell migration, proliferation, and activation did not appear to change in the FD forms compared to the FF ones. Our study showed that reconstituted FD products maintained the growth factor concentrations and biological properties of FF products and could be used as a functional treatment option

Human glial müller and umbilical vein endothelial cell coculture as an in vitro model to investigate retinal oxidative damage. A morphological and molecular assessment

The aim of this study was to optimize a coculture in vitro model established between the human Muller glial cells and human umbilical vein endothelial cells, mimicking the inner blood-retinal barrier, and to explore its resistance to damage induced by oxidative stress. A spontaneously immortalized human Muller cell line MIO-M1 and human umbilical vein endothelial cells (HUVEC) were plated together at a density ratio 1:1 and maintained up to the 8th passage (p8). The MIO-M1/HUVECs p1 through p8 were treated with increasing concentrations (range 200-800 mu M) of H2O2 to evaluate oxidative stress induced damage and comparing data with single cell cultures. The following features were assayed p1 through p8: doubling time maintenance, cell viability using MTS assay, ultrastructure of cell-cell contacts, immunofluorescence for Vimentin and GFAP, molecular biology (q-PCR) for GFAP and CD31 mRNA. MIO-M1/HUVECs cocultures maintained distinct cell cytotype up to p8 as shown by flow cytometry analysis, without evidence of cross activation, displaying cell-cell tight junctions mimicking those found in human retina, only acquiring a slight resistance to oxidative stress induction over the passages. This MIO-M1/HUVECs coculture represents a simple, reproducible and affordable model for in vitro studies on oxidative stress-induced retinal damages

Human cadaver multipotent stromal/stem cells isolated from arteries stored in liquid nitrogen for 5 years

Introduction: Regenerative medicine challenges researchers to find noncontroversial, safe and abundant stem cell sources. In this context, harvesting from asystolic donors could represent an innovative and unlimited reservoir of different stem cells. In this study, cadaveric vascular tissues were established as an alternative source of human cadaver mesenchymal stromal/stem cells (hC-MSCs). We reported the successful cell isolation from postmortem arterial segments stored in a tissue-banking facility for at least 5 years. Methods: After thawing, hC-MSCs were isolated with a high efficiency (12 × 106) and characterized with flow cytometry, immunofluorescence, molecular and ultrastructural approaches. Results: In early passages, hC-MSCs were clonogenic, highly proliferative and expressed mesenchymal (CD44, CD73, CD90, CD105, HLA-G), stemness (Stro-1, Oct-4, Notch-1), pericyte (CD146, PDGFR-β, NG2) and neuronal (Nestin) markers; hematopoietic and vascular markers were negative. These cells had colony and spheroid-forming abilities, multipotency for their potential to differentiate in multiple mesengenic lineages and immunosuppressive activity to counteract proliferation of phytohemagglutinin-stimulated blood mononuclear cells. Conclusions: The efficient procurement of stem cells from cadaveric sources, as postmortem vascular tissues, demonstrates that such cells can survive to prolonged ischemic insult, anoxia, freezing and dehydration injuries, thus paving the way for a scientific revolution where cadaver stromal/stem cells could effectively treat patients demanding cell therapies

Quantum characterization of superconducting photon counters

We address the quantum characterization of photon counters based on transition-edge sensors (TESs) and present the first experimental tomography of the positive operator-valued measure (POVM) of a TES. We provide the reliable tomographic reconstruction of the POVM elements up to 11 detected photons and M=100 incoming photons, demonstrating that it is a linear detector.Comment: 3 figures, NJP (to appear

Evaluation of qualitative and quantitative taste alterations in COVID-19

Taste dysfunctions occur in a large proportion of COVID-19 patients. This observational study compared interleukin-6 (IL-6) levels in mild and moderate COVID-19 patients with the type (quantitative or qualitative) of taste disorders. The 208 COVID-19 patients (118 men and 90 women) showing only taste dysfunctions as prodromic symptoms were classified as mild and moderate patients. The evaluation of the taste disorder was carried out using a survey. The IL-6 levels were measured with a chemiluminescence assay. Statistical analysis was performed using the Wilcoxon rank, Welch's, and Mann-Whitney tests (p <0.05). The results showed that there were no statistically significant differences in the perception of sour and salty, nor in the presence of dysgeusia and phantogeusia in moderate versus mild patients (p>0.05). However, there were statistically significant differences in the perception of umami, bitter, sweet, and the presence of parageusia in moderate versus mild patients (p<0.05). There was an impairment of multiple tastes up to ageusia in patients with high IL-6 levels. The results showed that dysfunctions in the perception of sweet, bitter, umami, and the presence of parageusia can be considered as signs of more severe forms of COVID-19

Evaluation of qualitative and quantitative taste alterations in COVID-19

Taste dysfunctions occur in a large proportion of COVID-19 patients. This observational study compared interleukin-6 (IL-6) levels in mild and moderate COVID-19 patients with the type (quantitative or qualitative) of taste disorders. The 208 COVID-19 patients (118 men and 90 women) showing only taste dysfunctions as prodromic symptoms were classified as mild and moderate patients. The evaluation of the taste disorder was carried out using a survey. The IL-6 levels were measured with a chemiluminescence assay. Statistical analysis was performed using the Wilcoxon rank, Welch’s, and Mann-Whitney tests (p 0.05). However, there were statistically significant differences in the perception of umami, bitter, sweet, and the presence of parageusia in moderate versus mild patients (p<0.05). There was an impairment of multiple tastes up to ageusia in patients with high IL-6 levels. The results showed that dysfunctions in the perception of sweet, bitter, umami, and the presence of parageusia can be considered as signs of more severe forms of COVID-19

FATAL DOG ATTACKS: AN EIGHT-YEAR STUDY FROM 2009 TO 2016 IN ITALY

Domesticated animals, particularly dogs, have provided companionship, labor, recreation, and entertainment for humans. However, as the result of the most diverse causes, this interaction has not been free of conflicts. The alarming statistics reported around the world have shown that dog attacks today represent a health hazard where prevention strategies have not always been successful 1,2. Most of the dogs involved in these events are known to the victim or belong to him. The researchers identified a striking co-occurrence of multiple, controllable factors: no able- bodied person being present to intervene; the victim having no familiar relationship with the dog(s); the dog(s) owner failing to neuter/spay the dog(s); a victim’s compromised ability, whether based on age or physical condition, to manage their interactions with the dog(s); the owner keeping dog(s) as resident dog(s), rather than as family pet(s); the owner’s prior mismanagement of the dog(s); and the owner’s abuse or neglect of dog(s). Four or more of these factors were present in 80.5% of cases; breed was not one of those factors. This DBRF study was based primarily on media reports to identified the Italian number of fatal dog attacks, victims' sex and age and the breed of the dogs. From our study we found 19 DBRFs in Italy from 2009 to 2016 (2,37 cases for year); these data are sharply increased in relationship with previous study that describes 32 DWARFs between 1984 to 2009 3 with a frequency of 1,28 cases for year. We do not find a significantly difference on victim’s sex (8 women against 11 male). As previously described, we confirm that dogs are known to the victim or belong to him (14 cases); in 4 of the other cases where the victim did not know the dog, the aggression was carried out by mongrel dogs. As previously described, the victims are often over 65 years old (47,4%) or under 5 years old (42,1%). Finally we do not find a race dog that was more likely to injure a human rather another race. We know poorly on aggression causes, for example, if the death is caused by the human aggressor to the dog or if it is an unexplained event. Certainly, when DBRF occurs leads emotional implications in public opinion: it should promote the use of targeted studies, which still lack both internationally and, to a greater extent, national

Early and late implant failure of submerged versus non-submerged implant healing: a systematic review, meta-analysis and trial sequential analysis

The aim of this systematic review is to analyze current evidence regarding differences in early and late implant failure as well as in marginal bone level (MBL) changes between submerged and non-submerged healed dental implants