Failure criteria of fibre reinforced composites in homogeneous temperature field

The present paper examines the failure criteria of layered composites with orthotropic properties in the homogeneous temperature field. The composite has modeled by two mechanically equivalent families of fibres. The paper formulates constitutive equations in terms of intrinsic preferred directions, which are defined by the orientation of fibers at any point of the composite. A uniformly heated, thermoelastic solid undergoes distortion as well as volume change because it experiences differential expansions in different directions. This effect is more complicated if, in addition of being anisotropic, the material is inhomogeneous, as in the case with laminated materials. In order to illustrate the influence of temperature on the failure of this group of materials constitutive equations are derived and adoptedforuse in failure criteria, without the influence of temperatures, and with the influence of increased temperature

Chemical Composition, Antioxidant, and Antimicrobial Activities of Lichen Umbilicaria cylindrica (L.) Delise (Umbilicariaceae)

The phytochemical analysis of methanol and chloroform extracts of Umbilicaria cylindrica was determined by HPLC-UV method. The predominant phenolic compound in both extracts was depsidone, salazinic acid (1). Besides salazinic acid, the tested extracts of U. cylindrica contain norstictic acid (2), methyl-β-orcinol carboxylate (3), ethyl haematommate (4), atranorin (5), and usnic acid (6), in different amounts and relations. The lichen extracts showed comparable and strong antioxidant activity, exhibited higher DPPH and hydroxyl radical scavengings, chelating activity, and inhibitory activity towards lipid peroxidation. The lichen extracts demonstrated important antimicrobial activity against eight strains with MIC values from 15.62 to 62.50 μg/mL. This is the first report of the detail chemical composition and antioxidant activity of the lichen Umbilicaria cylindrica, and the results suggest that this lichen can be used as a new source of the natural antioxidants and the substances with antimicrobial features

Uv light impact on phthalates migration from children's toys into artificial saliva

Phthalates has been widely used in children?s toys as plastic plasticizers and softeners. Therefore, attention should be paid to plastic toys, especially those that children can put in their mouths. In this paper quantification of five phthalates: DMP, DnBP, BBP, DEHP and DnOP in plastic toys, as well as irradiation of toys with UV light was performed. After sample preparation and development of the liquid?liquid phthalate extraction method from artificial saliva phthalate quantitative determination using the GC?MS technique was performed. The mean recovery value for DEHP is 77.03?2.76 %. The determination of phthalate in the recipient models (artificial saliva and n-hexane) was performed after 6, 15 and 30 days of the migration test using the GC?MS technique. Based on the known mass % DEHP in the analyzed toys, the percentage of phthalate migration from each analyzed toy to the recipient model after 6, 15 and 30 days of the migration test was calculated. The results show that there is no significant migration of DEHP into artificial saliva, due to high polarity of the recipient (artificial saliva is polar), unlike n-hexane where the migration of DEHP is significant because it is a non-polar solvent

Leptin Reverts Pro-Apoptotic and Antiproliferative Effects of α-Linolenic Acids in BCR-ABL Positive Leukemic Cells: Involvement of PI3K Pathway

It is suspected that bone marrow (BM) microenvironmental factors may influence the evolution of chronic myeloid leukaemia (CML). In this study, we postulated that adipocytes and lipids could be involved in the progression of CML. To test this hypothesis, adipocytes were co-cultured with two BCR-ABL positive cell lines (PCMDS and K562). T cell (Jurkat) and stroma cell (HS-5) lines were used as controls. In the second set of experiments, leukemic cell lines were treated with stearic, oleic, linoleic or α-linolenic acids in presence or absence of leptin. Survival, proliferation, leptin production, OB-R isoforms (OB-Ra and OB-Rb), phosphoinositide 3-kinase (PI3k) and BCL-2 expression have been tested after 24h, 48h and 72h of treatment. Our results showed that adipocytes induced a decrease of CML proliferation and an increase in lipid accumulation in leukemic cells. In addition, CML cell lines induced adipocytes cell death. Chromatography analysis showed that BM microenvironment cells were full of saturated (SFA) and monounsaturated (MUFA) fatty acids, fatty acids that protect tumor cells against external agents. Stearic acid increased Bcl-2 expression in PCMDS, whereas oleic and linoleic acids had no effects. In contrast, α-linolenic acid decreased the proliferation and the survival of CML cell lines as well as BCL-2 and OB-R expression. The effect of α-linolenic acids seemed to be due to PI3K pathway and Bcl-2 inhibition. Leptin production was detected in the co-culture medium. In the presence of leptin, the effect of α-linolenic acid on proliferation, survival, OB-R and BCl-2 expression was reduced

Presence of Immune Complexes of IgG/IgM Bound to B2-glycoprotein I Is Associated With Non-criteria Clinical Manifestations in Patients With Antiphospholipid Syndrome

Background: Antiphospholipid syndrome (APS) is an acquired autoimmune disorder defined by the presence of both clinical (thromboembolic events or pregnancy morbidity) and laboratory (antiphospholipid antibodies, aPL) manifestations. Despite their importance, several clinical manifestations strongly associated with APS such as livedo reticularis (LR), thrombocytopenia, sicca-ophthalmic(sicca), heart, or neurological manifestations are not included in the APS clinical classification criteria. Circulating immune complexes (CIC) formed by Beta-2-glycoprotein I (B2GPI) and aPL (B2-CIC) have been described and their presence has been related with thrombotic events.Methods: Cross-sectional and observational cohort study in APS patients with thrombotic symptomatology.Setting and Participants: Fifty-seven patients from the University Hospital Center Bezanijska Kosa (Belgrade, Serbia) who met the APS classification criteria (35 with primary APS and 22 with APS associated to systemic lupus erythematosus). This study aimed to determine the prevalence of B2-CIC in APS patients and to evaluate their association with clinical manifestations of APS not included in the classification criteria.Results: B2-CIC prevalence in APS patients was 19.3%. The presence of thrombocytopenia (OR:5.7), livedo reticularis (OR:5.6), sicca (OR:12.6), and leukopenia (OR:5.6) was significantly higher in patients with B2-CIC than in the rest of APS patients. C3 and C4 complement factor levels were significantly lower in B2-CIC positive patients, which suggests a greater consumption of complement. Patients with quadruple aPL positivity (triple aPL-positivity plus the presence of B2-CIC) showed a higher prevalence of thrombocytopenia, leucopenia and LR than those with single/double aPL-positivity. No significant differences were found in the frequencies observed in patients with triple-only vs. single/double aPL-positivity. There were no significant differences between patients with primary APS and lupus-associated APS regarding the prevalence of B2-CIC and outcomes.Conclusions: Presence of B2-CIC is strongly associated with several non-criteria clinical manifestations related to APS and to higher complement consumption. More studies are required to better understand the clinical significance of B2-CIC

Probabilistic classification of anti-SARS-CoV-2 antibody responses improves seroprevalence estimates.

OBJECTIVES: Population-level measures of seropositivity are critical for understanding the epidemiology of an emerging pathogen, yet most antibody tests apply a strict cutoff for seropositivity that is not learnt in a data-driven manner, leading to uncertainty when classifying low-titer responses. To improve upon this, we evaluated cutoff-independent methods for their ability to assign likelihood of SARS-CoV-2 seropositivity to individual samples. METHODS: Using robust ELISAs based on SARS-CoV-2 spike (S) and the receptor-binding domain (RBD), we profiled antibody responses in a group of SARS-CoV-2 PCR+ individuals (n = 138). Using these data, we trained probabilistic learners to assign likelihood of seropositivity to test samples of unknown serostatus (n = 5100), identifying a support vector machines-linear discriminant analysis learner (SVM-LDA) suited for this purpose. RESULTS: In the training data from confirmed ancestral SARS-CoV-2 infections, 99% of participants had detectable anti-S and -RBD IgG in the circulation, with titers differing > 1000-fold between persons. In data of otherwise healthy individuals, 7.2% (n = 367) of samples were of uncertain serostatus, with values in the range of 3-6SD from the mean of pre-pandemic negative controls (n = 595). In contrast, SVM-LDA classified 6.4% (n = 328) of test samples as having a high likelihood (> 99% chance) of past infection, 4.5% (n = 230) to have a 50-99% likelihood, and 4.0% (n = 203) to have a 10-49% likelihood. As different probabilistic approaches were more consistent with each other than conventional SD-based methods, such tools allow for more statistically-sound seropositivity estimates in large cohorts. CONCLUSION: Probabilistic antibody testing frameworks can improve seropositivity estimates in populations with large titer variability

Robust T Cell Immunity in Convalescent Individuals with Asymptomatic or Mild COVID-19

SARS-CoV-2-specific memory T cells will likely prove critical for long-term immune protection against COVID-19. Here, we systematically mapped the functional and phenotypic landscape of SARS-CoV-2-specific T cell responses in unexposed individuals, exposed family members, and individuals with acute or convalescent COVID-19. Acute-phase SARS-CoV-2-specific T cells displayed a highly activated cytotoxic phenotype that correlated with various clinical markers of disease severity, whereas convalescent-phase SARS-CoV-2-specific T cells were polyfunctional and displayed a stem-like memory phenotype. Importantly, SARS-CoV-2-specific T cells were detectable in antibody-seronegative exposed family members and convalescent individuals with a history of asymptomatic and mild COVID-19. Our collective dataset shows that SARS-CoV-2 elicits broadly directed and functionally replete memory T cell responses, suggesting that natural exposure or infection may prevent recurrent episodes of severe COVID-19.Fil: Sekine, Takuya. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Perez Potti, André. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Rivera Ballesteros, Olga. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Strålin, Kristoffer. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Gorin, Jean Baptiste. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Olsson, Annika. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Llewellyn Lacey, Sian. University Hospital of Wales; Reino UnidoFil: Kamal, Habiba. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Bogdanovic, Gordana. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Muschiol, Sandra. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Wullimann, David J.. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Kammann, Tobias. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Emgård, Johanna. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Parrot, Tiphaine. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Folkesson, Elin. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Rooyackers, Olav. Karolinska Huddinge Hospital. Karolinska Institutet; Suecia. Karolinska University Hospital; SueciaFil: Eriksson, Lars I.. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Henter, Jan Inge. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Sönnerborg, Anders. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Allander, Tobias. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Albert, Jan. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Nielsen, Morten. Technical University of Denmark; Dinamarca. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas; ArgentinaFil: Klingstrom, Jonas. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Gredmark Russ, Sara. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Björkström, Niklas K.. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Sandberg, Johan K.. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Price, David A.. Cardiff University School of Medicine; Reino UnidoFil: Ljunggren, Hans Gustaf. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Aleman, Soo. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Buggert, Marcus. Karolinska Huddinge Hospital. Karolinska Institutet; Sueci

Robust T cell immunity in convalescent individuals with asymptomatic or mild COVID-19

SARS-CoV-2-specific memory T cells will likely prove critical for long-term immune protection against COVID-19. Here, we systematically mapped the functional and phenotypic landscape of SARS-CoV-2-specific T cell responses in unexposed individuals, exposed family members, and individuals with acute or convalescent COVID-19. Acute-phase SARS-CoV-2-specific T cells displayed a highly activated cytotoxic phenotype that correlated with various clinical markers of disease severity, whereas convalescent-phase SARS-CoV-2-specific T cells were polyfunctional and displayed a stem-like memory phenotype. Importantly, SARS-CoV-2-specific T cells were detectable in antibody-seronegative exposed family members and convalescent individuals with a history of asymptomatic and mild COVID-19. Our collective dataset shows that SARS-CoV-2 elicits broadly directed and functionally replete memory T cell responses, suggesting that natural exposure or infection may prevent recurrent episodes of severe COVID-19

Studies on human polyomavirus infection in association with central nervous system disorders and bone marrow transplantation

Human polyomaviruses BK virus (BKV) and JC virus (JCV) do not generally cause diseases in healthy immunocompetent individuals. However both BKV and JCV can establish persistent infections that can be reactivated and associated with serious clinical diseases in some innmunocompromised patients. The present studies have focused on infections with BKV and JCV in patients with central nervous system disorders (CNS) and bone marrow transplant (BMT) patients. In order to screen and follow BKV and JCV infections, a nested PCR specific for both BKV and JCV DNA was developed. This PCR had a sensitivity of 10 genome copies for each virus. Furthermore, previously established serological tests such as a BKV specific alzyme linked immunosorbent assay (EUSA) and a hemagglutination-inhibition assay (HAI) were used to follow BKV infection. Progressive multifocal leukoencephalopathy (PML) is a fatal neurological disease caused by JCV. In recent years most PML cases occur in AIDS patients, and there is a need for an accurate and rapid diagnosis of PML, since other CNS diseases with similar symptoms may be accessible for treatment. Detection of JCV DNA by the nested PCR in the cerebrospinal fluid (CSF) was evaluated as a diagnostic tool for PML. CSF samples from HIV-infected patients and from HIV negative patients in general with innmunological disorders, with PML or other neurological symptoms were included in this study. JCV DNA was detected exclusively in CSF specimens of patients with PML. To exclude that JCV is reactivated in the CNS by other viruses or multiple sclerosis (MS), CSF samples from patients with herpes simplex encephalitis, enteroviral meningitis and MS were examined for the presence of JCV DNA. JCV DNA was not detected in the CSF samples of any of these patients, which further supports that the detection of JCV DNA in the CSF is an efficient marker for PML. To follow if human polyomaviruses contributed to the pathology of Alzheimer's disease or to the development of astrocytomas, the presence of JCV and BKV DNA in the brain or tumor tissue of such patients was examined. There was no evidence that JCV or BKV contributed to either of these conditions. In BMT patients with a late onset of hemorrhagic cystitis (HC) BKV is excreted in the urine. However, not all BMT patients with BK viruria develop HC. To analyze if the presence of BKV DNA in the peripheral circulation was associated with HC in BMT patients, blood samples from both BMT patients with and without HC were examined by PCR. BKV and JCV DNA was found in peripheral blood leukocytes, plasma and serum of patients with and without HC and was subsequentdy not diagnostic for HC. To test if BMT patients encountering a primary BKV infection were at risk for HC development, serum samples from children before and after BMT and their corresponding donors were analyzed for the presence of antibodies against BKV. Primary BKV infection was not dhe major cause of HC, since most children were seropositive before transplantation. However, significandy more patients with HC than without HC exhibited BKV specific serological changes, such as presence of BKV IgM antibodies or HAI titer increase, but these changes occurred mainly late after the onset of HC