Matrix cracking in polymeric composites laminates: Modelling and experiments

Composites ability to retain functionality in the presence of damage is a crucial safety and economic issue. Generally the first damage mode in composite laminates is matrix cracking, which affects the mechanical properties of the structure long before its load-bearing capacity is exhausted. In this paper, a detailed analysis of the effect of matrix cracking on the behaviour of cross-ply [0/90]s and unbalanced symmetric [0/45]s glass/epoxy laminates loaded statically in tension is performed. Theoretical predictions of stiffness reduction due to damage are based on the Equivalent Constraint Model (ECM), which takes into account concurrent matrix cracking in all plies of the laminate, although matrix cracking under consideration is developing only within the off-axis ply of the laminates. The longitudinal Young’s modulus predictions are compared to experimentally derived data obtained using laser Raman spectroscopy (LRS). The good agreement between predicted and measured values of the reduced longitudinal Young’s modulus validates the ECM model and proves that its basic assumptions are accurate. Thus, the predictions for all the mechanical properties by the ECM model are within a realistic range, while experimental evidence is required for further validation

AMP-activated protein kinase inhibits NF-κB signaling and inflammation: impact on healthspan and lifespan

Adenosine monophosphate-activated protein kinase (AMPK) is a crucial regulator of energy metabolic homeostasis and thus a major survival factor in a variety of metabolic stresses and also in the aging process. Metabolic syndrome is associated with a low-grade, chronic inflammation, primarily in adipose tissue. A low-level of inflammation is also present in the aging process. There are emerging results indicating that AMPK signaling can inhibit the inflammatory responses induced by the nuclear factor-κB (NF-κB) system. The NF-κB subunits are not direct phosphorylation targets of AMPK, but the inhibition of NF-κB signaling is mediated by several downstream targets of AMPK, e.g., SIRT1, PGC-1α, p53, and Forkhead box O (FoxO) factors. AMPK signaling seems to enhance energy metabolism while it can repress inflammatory responses linked to chronic stress, e.g., in nutritional overload and during the aging process. AMPK can inhibit endoplasmic reticulum and oxidative stresses which are involved in metabolic disorders and the aging process. Interestingly, many target proteins of AMPK are so-called longevity factors, e.g., SIRT1, p53, and FoxOs, which not only can increase the stress resistance and extend the lifespan of many organisms but also inhibit the inflammatory responses. The activation capacity of AMPK declines in metabolic stress and with aging which could augment the metabolic diseases and accelerate the aging process. We will review the AMPK pathways involved in the inhibition of NF-κB signaling and suppression of inflammation. We also emphasize that the capacity of AMPK to repress inflammatory responses can have a significant impact on both healthspan and lifespan

Paediatric international travellers from Greece: Characteristics and pre-travel recommendations

The aim of this study was to describe the children who seek pre-travel advice in Greece. During 2008-2010, 4065 persons sought pre-travel services in the 57 Prefectures, including 128 (3.15%) children <15 years. Main travel destinations were sub-Saharan Africa (54 children; 42.2%), South America (18; 14.1%), the Middle East (16; 12.5%), the Indian subcontinent (12; 9.4%), and South East Asia (7; 5.5%). Seventy-six children (59.4%) stayed for <1 month, 34 (26.6%) for 1-6 months, and 10 (7.8%) for >6 months. Recreation was the main purpose of travel (81 children; 63.3%), followed by work (24; 18.8%), and to visit friends and relatives (VFRs) (14; 10.9%). Paediatric travellers VFRs stayed more frequently in local residences compared to non-VFR paediatric travellers (85.7% and 20.2%). Children stayed more frequently in local residences and travelled more frequently for recreational purposes or to VFRs (27.3%, 63.3%, and 10.9%, respectively), compared to older travellers (11.9%, 58.8%, and 4%, respectively). Malaria chemoprophylaxis was prescribed for 64.8% of children travelling to sub-Saharan Africa. This study demonstrated clearly that only a very small number of international paediatric travellers seek pre-travel services in Greece. Communication strategies to access paediatric travellers should be developed in order to improve travel medicine services for children in Greece. © 2012 Elsevier Ltd. All rights reserved

Vaccination coverage and susceptibility against vaccine-preventable diseases of healthcare students in Athens, Greece

Background: Vaccination of healthcare students is important to protect them from acquiring and transmitting vaccine-preventable diseases (VPDs) to high-risk patients and other healthcare workers (HCWs). The aim of the current study was to estimate the vaccination coverage, the susceptibility against VPDs, the knowledge and attitudes toward vaccinations of healthcare students studying at the Athens Technological Educational Institute. Methods: The study was conducted during the academic year 2012-2013 using a standardized questionnaire. Results: The mean knowledge score (correct answers) of healthcare students about the vaccines that are recommended by the Greek Ministry of Health for HCWs was 41%. Completed vaccination rates range from 19.6% for varicella to 80.2% for tetanus-diphtheria. A history of measles, mumps, rubella, varicella, hepatitis A, hepatitis B, or pertussis was reported by 8.2%, 4%, 5.4%, 70.4%, 1.5%, 0%, and 3% of students, respectively. Susceptibility rates were 20.5% against measles, 26.4% against mumps, 13.9% against rubella, 15.7% against varicella, 47.8% against hepatitis A, 17.3% against hepatitis B, and 19.8% against tetanus-diphtheria. Mandatory vaccination of HCWs was supported by 145 (96.7%) students. Conclusions: There are significant immunity gaps against all VPDs among healthcare students in Athens. A system to easily identify non-immune students should be established in association with efficient reminder systems. Education of healthcare students about VPDs and vaccines will improve their attitudes toward vaccinations and their vaccination coverage. Mandatory vaccinations should be considered for HCWs in order to promote safety within healthcare facilities. © 2014 Elsevier Ltd

Study of Greek children and youths with cystic fibrosis identifies immunisation gaps and delays

Aim: Data about immunisation rates in cystic fibrosis (CF) patients are scarce. We estimated the rates and timeliness of immunisations in CF patients aged 0.55–22 years. Methods: We studied 122 subjects at a hospital in Greece in 2014. A standard questionnaire was used to collect data and parents' opinions about immunisations. Results: The complete immunisation rates were 92.6% for diphtheria–tetanus–acellular pertussis-inactivated poliomyelitis-Haemophilus influenzae (DTaP-IPV-Hib), 96.7% for hepatitis A, 97.4% for hepatitis B, 97.4% for measles–mumps–rubella, 85.1% for the varicella zoster virus, 85.1% for the meningococcus C conjugate, 84.3% for the pneumococcus conjugate and 58.9% for the bacillus Calmette-Guérin vaccine. Immunisation rates in youths were 64.4% for DTaP-IPV, 26.8% for the tetravalent meningococcus conjugate vaccine and 54.1% for the human papilloma virus vaccine. In addition, 30.1% received the 23-valent pneumococcal polysaccharide vaccine and 45.6% received annual influenza vaccines. Complete, up-to-date immunisation rates fell from 61.4% at 12 months of age to 14.5% at six and 12 years. All vaccines experienced delays. Most parents believed vaccines were necessary to protect their child's health. Conclusion: Our study of children with CF found immunisation gaps with no catch-up immunisations and these need to be administered at follow-up visits. ©2016 Foundation Acta Pædiatrica. Published by John Wiley & Sons Lt

Prescription of antibiotics and awareness of antibiotic costs by paediatricians in two hospitals in Greece

Our aim was to study the antibiotic prescription practices and the knowledge about antibiotic costs, brand and generic drugs of paediatricians working in two hospitals in Greece. The 2007 national guidelines were used as the gold standard for antibiotic prescription. A total of 126 paediatricians participated in the study (50.4% response rate). The mean compliance rate with the guidelines was 50.1% (range per infection: 10.6-84.7%). The mean scores of knowledge about antibiotic costs and about brand name and generic drugs were 35.6 and 60.3%, respectively. Linear regression analysis found a significant association between the mean compliance rate with the national guidelines and the paediatricians' age (mean compliance rates were 49.1, 53.0, and 43.0% in the ≤ 30, 31-40, and > 40 years age-groups, respectively; P = 0.003).In conclusion, five years after the first national guidelines were issued in Greece only half of the paediatricians working in hospitals comply fully with them. © 2014 Edizioni Scientifiche per l'Informazione su Farmaci e Terapia

Attitudes toward mandatory occupational vaccinations and vaccination coverage against vaccine-preventable diseases of health care workers in primary health care centers

Background: The aim of this study was to assess the attitudes regarding mandatory occupational vaccinations and the vaccination coverage against vaccine-preventable diseases among health care workers (HCWs) working in primary health care centers in Greece. Methods: A standardized questionnaire was distributed to HCWs working in all primary health care centers in Greece (n = 185). Results: A total of 2,055 of 5,639 HCWs (36.4% response rate) from 152 primary health care centers participated. The self-reported completed vaccination rates were 23.3% against measles, 23.3% against mumps, 29.8% against rubella, 3% against varicella, 5.8% against hepatitis A, 55.7% against hepatitis B, and 47.3% against tetanus-diphtheria; corresponding susceptibility rates were 17%, 25%, 18.6%, 16.7%, 87.5%, 35%, and 52.6%. Mandatory vaccinations were supported by 65.1% of 1,807 respondents, with wide differences by disease. Multiple logistic regression analysis revealed higher rates of acceptance of mandatory vaccination in physicians compared with other HCW categories. Conclusions: Despite the fact that two-thirds of HCWs working in primary health care centers in Greece support mandatory vaccination for HCWs, completed vaccination rates against vaccine-preventable diseases are suboptimal. © 2013 by Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved

Infections caused by carbapenem-resistant gram-negative pathogens in hospitalized children

Background: Carbapenem-resistant Gram-negative pathogens (CRPs) are emerging as major causes of nosocomial infections that increase morbidity, mortality and healthcare costs. Little is known about CRP infections in children. Methods: All newly detected infections caused by carbapenem-resistant Klebsiella spp, Pseudomonas spp or Acinetabocater spp in hospitalized patients are prospectively reported to the Hellenic Center for Disease Control and Prevention. All children <15 years old with a CRP infection reported from November 1, 2010, through March 30, 2012, were included in this study. Results: Between November 2010 and March 2012, 71 CRP infections in 65 children (median age: 1 year) were reported. Underlying conditions existed in 50 (76.9%) children. Cases included pneumonia (25 [35.2%], including 20 ventilator-associated pneumonias), bacteremia (32.4%), urinary tract infection (19.7%) and surgical site infection (12.7%). Isolates were Pseudomonas spp (41.1%), Acinetobacter spp (39.7%) and Klebsiella spp (19.2%). The first positive culture occurred a median of 20 days (range: 0-313 days) after admission. Twenty-four (33.8%) infections occurred in patients with a history of hospitalization the previous 6 months; 42 (59.2%) and 36 (50.7%) infections occurred among patients who had received broad-spectrum antibiotics including carbapenems the previous 6 months, respectively. The crude mortality at 28 days after the first positive CRP culture was 21.1%. Conclusions: Infections caused by CRPs among children are associated with significant morbidity and mortality. Copyright © 2013 by Lippincott Williams & Wilkins

Attitudes regarding occupational vaccines and vaccination coverage against vaccine-preventable diseases among healthcare workers working in pediatric departments in Greece

We studied the attitudes with regard to occupational vaccines and vaccination coverage among healthcare workers in pediatric departments. Completed vaccination rates were 33%, 33%, 41.7%, 3%, 5.8%, 69.2% and 36.3% against measles, mumps, rubella, varicella, hepatitis A, hepatitis B and tetanus-diphtheria, respectively. Susceptibility rates were 14.2%, 15.7%, 14.6%, 7.6%, 87.4%, 22.6% and 61.8% for measles, mumps, rubella, varicella, hepatitis A, hepatitis B and tetanus-diphtheria, respectively. Mandatory vaccinations were supported by 70.6% of healthcare workers, with considerable differences by target disease. © 2012 Lippincott Williams & Wilkins

Preparedness of adolescents departing from Athens International Airport to Africa or Asia: A five-year airport-based prospective study

Background: The number of adolescents who travel has increased. We estimated the preparedness of adolescents (12–18 years) departing from Athens to Africa and Asia. Methods: An airport-based survey was conducted from 2011 to 2015. Results: Sixty-eight adolescents participated; 27/68 (40%) had the Greek nationality. Their main destinations were the Indian subcontinent (37%) and South-East Asia (32%). Most adolescents planned to stay for <1 month (69%) or for 1–3 months (22%). Their main purpose for travel was to visit friends and relatives (VFRs) (60%). Compared to non-VFR adolescents, VFRs more frequently travelled to sub-Saharan Africa and Southeast Asia, stayed in local residences and for longer periods. Twenty-one (31%) adolescents sought pre-travel counseling (in 57% of cases 8–14 days before departure). Having the Greek nationality was the only significant factor associated with an increased probability for seeking pre-travel counseling. Vaccination against rabies, typhoid fever, Japanese encephalitis and meningococcus was highly inadequate for adolescents travelling to endemic areas. Significant gaps in malaria chemoprophylaxis were found in those travelling to the Indian subcontinent. Conclusions: Less than one third of adolescents travelling to Africa and Asia seek counseling. There is a need to access adolescent travellers in Greece and improve pre-travel vaccinations and malaria chemoprophylaxis. © 2017 Elsevier Lt