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A three-dimensional fully auxetic cellular structure with negative Poisson’s ratio is presented. Samples are fabricated from Ti6Al4V powder via selective electron beam melting. The influence of the strut thickness and the amplitude of the strut on the mechanical properties and the deformation behaviour of cellular structures is studied. [ABSTRACT FROM AUTHOR]

To investigate the influence of auxetic behavior on thermally induced stresses, finite element analysis simulations of the displacement and stress fields in locally heated three dimensional auxetic and cubic structures are compared. The simulations were carried out in Comsol for a cubic as well as a chiral array of 30 mm length in each spatial dimension (3 × 3 × 3 unit cells). The center cells of these arrays were heated for 20 s. For two boundary conditions (free and clamped), deformation mechanisms are analyzed. It is found, that the auxetic behavior can effectively reduce thermal stresses by internal node rotation and strut bending, especially for constrained (clamped) boundary conditions. A stress reduction of a factor of 3.3 in comparisons to a simple cubic cell array could be evaluated. [ABSTRACT FROM AUTHOR]

Purpose: Selective electron beam melting (SEBM) is a highly versatile powder bed fusion additive manufacturing method. SEBM is characterized by high energy densities which can be applied with nearly inertia free beam deflection at high speeds (<8.000 m/s). This paper aims to determine processing maps for Ti-6Al-4V on an Arcam Q10 machine with LaB6 cathode design. Design/methodology/approach: Scan line spacings of 100, 50 and 20 µm in a broad parameter range, focusing on high deflection and build speeds are investigated. Findings: There are broad processing windows for dense parts without surface flaws for all scan line spacings which are defined by the total energy input and the area melting velocity. Originality/value: The differences and limitations are discussed taking into account the beam properties at high beam energy and velocity as well as evaporation related loss of alloying components. [ABSTRACT FROM AUTHOR]

Background: Babesiosis in the US is caused primarily by B. microti, transmitted to humans by the I. scapularis tick. Babesiosis due to B. microti infection is endemic in New England, Long Island, New Jersey, and the upper Midwest. Because B. microti can infect humans chronically and without symptoms, but can also be a clinically serious infection, babesiosis is a potential threat to the blood supply. Methods: To estimate the prevalence of B. microti infection in CT blood donors, retained samples from donors were tested during the summer of 1999 (1745 donors each from endemic and nonendemic areas of CT) and the summer of 2000 (2583 endemic donors). Samples were screened by ELISA (Corixa Corp.) using recombinant protein antigens. Reactive results were confirmed by IFA using a cut-off titer of 1:64 or greater as positive. IFA positive donors were recruited to give a sample for nested PCR (summer 1999, 2000 donors) and inoculation into hamsters (summer 2000 donors). Lookback was performed for the previous year for donors positive by PCR or hamster inoculation, following the center's procedures when donors are found to have babesiosis. Results: 58 of 6073 (0.9%) donations were IFA positive. 19 of 34 (56%) IFA positive donors were PCR positive on a subsequent sample. 3 of 9 (33%) PCR positive donors were hamster inoculation positive. 4 of 13 evaluable red cell recipients and 1 of 6 evaluable platelet recipients were infected on Lookback (overall 26% Lookback positive). Lookback recipients were all PCR or blood smear positive and 4 of 5 were antibody positive. One recipient had been diagnosed clinically before Lookback notification. Infectious donors were identified in endemic and non-endemic areas. Conclusions: B. microti was identified in 19 of 6073 Connecticut blood donors by PCR. Approximately one in four PCR positive donors were documented to be infectious. We estimate 1 in 1800 CT blood donors are infectious for B. microti. Babesiosis is a common transfusion transmitted infection in CT, whose incidence based on case reports has been underestimated. [ABSTRACT FROM AUTHOR]

Diamond coating of suitable template materials and subsequent delamination allows for the manufacturing of free-standing diamond foil. The evolution of the microstructure can be influenced by secondary nucleation via control of process conditions in the hot-filament chemical vapour deposition process. Bending tests show extraordinarily high strength (more than 8 GPa), especially for diamond foils with nanocrystalline structure. A detailed fractographic analysis is conducted in order to correlate measured strength values with crack-initiating defects. The size of the failure causing flaw can vary from tens of micrometres to tens of nanometres, depending on the diamond foil microstructure as well as the loading conditions. [ABSTRACT FROM AUTHOR]

Printer toner particles (TPs) are a common, potentially hazardous substance, with an unclear toxicological impact on the respiratory mucosa. Most of the airways surface is covered by a ciliated respiratory mucosa, therefore appropriate tissue models of the respiratory epithelium with a high in vivo correlation are necessary for in vitro evaluation of airborne pollutants toxicology and the impact on the functional integrity. The aim of this study is the evaluation of TPs toxicology in a human primary cell-based air-liquid-interface (ALI) model of respiratory mucosa. The TPs were analyzed and characterized by scanning electron microscopy, pyrolysis and X-ray fluorescence spectrometry. ALI models of 10 patients were created using the epithelial cells and fibroblasts derived from nasal mucosa samples. TPs were applied to the ALI models via a modified Vitrocell® cloud and submerged in the dosing 0.89 – 892.96 µg/ cm2. Particle exposure and intracellular distribution were evaluated by electron microscopy. The MTT assay and the comet assay were used to investigate cytotoxicity and genotoxicity, respectively. The used TPs showed an average particle size of 3 – 8 µm. Mainly carbon, hydrogen, silicon, nitrogen, tin, benzene and benzene derivates were detected as chemical ingredients. By histomorphology and electron microscopy we observed the development of a highly functional, pseudostratified epithelium with a continuous layer of cilia. Using electron microscopy, TPs could be detected on the cilia surface and also intracellularly. Cytotoxicity was detected from 9 µg/ cm2 and higher, but no genotoxicity after ALI and submerged exposure. The ALI with primary nasal cells represents a highly functional model of the respiratory epithelium in terms of histomorphology and mucociliary differentiation. The toxicological results indicate a weak TP-concentration-dependent cytotoxicity. The datasets used and analysed during the current study are available from the corresponding author on reasonable request. • Mucosa model based on primary cells resembles the situation in vivo. • Visualization of cell-particle interaction at the ultrastructural level. • Printer toner particle SEM-analysis showed particle diameters of 3 – 8 µm. • Toner particles induce concentration-dependent cytotoxicity, but no genotoxicity. [ABSTRACT FROM AUTHOR]

Background: Babesia microti is a tick borne agent increasingly implicated in transfusion acquired infection especially in immunocompromised and elderly recipients. Observed transfusion cases coupled with seroprevalence rate in donors of 1-2% or higher, suggest there may be a growing need to test blood donors for B. microti. To facilitate specific evaluation of seroprevalence, peptide epitopes identified in two complementary B. microti specific antigens were combined and used in a prototype ELISA for identifying patients infected with B. microti. Methods: A prototype peptide ELISA was used to detect B. microti specific antibodies using 14 pre and 53 post infection sera from 35 individuals with known tick infections previously tested by IgG and IgM immunoblot, PCR, IFA or blood smear. Three additional groups of samples were also tested: a proficiency panel of 18 sera positive for B. microti by IFA, 38 sera from blood donors confirmed positive by IFA and 30 sera from random blood donors. Results: The combination peptide accurately detected 51/53 post infection sera that were IgG blot positive (2 equivocal), including 12/12 samples that were PCR positive. Also within this group, six sera were positive by ELISA, and smear negative, but positive by PCR, blot or IFA. Of the IgG blot positive samples equivocal (2) or not detected (2), 3 had IFA titers of <1:64 and one of 1:64. Three of these specimens were from clinically resolved cases >1 year after documented infection. Of the pre-infection sere 13/14 were negative. In an additional study 15/15 Babesia IFA positive sera and 3/3 Babesia/ Ehrlichia IFA positive sera were positive while sera from 30 random donors were negative. Of the blood donor IFA positive samples 35/38 were positive by peptide ELISA and the three negative sere were Western blot negative. Conclusion: The data indicate that B. microti specific peptide ELISA shows a very high correlation to IFA, PCR and immunoblot. Furthermore the ELISA can be readily adapted for testing of blood donors in the existing blood bank environment if testing is required in the future. [ABSTRACT FROM AUTHOR]

Aim There are conflicting data regarding the risk of osteoporosis in patients with Type 1 diabetes. We investigated an association between diabetes, bone mineral density and prevalent fractures. Methods A single-centre, cross-sectional study of men and pre-menopausal women with Type 1 diabetes (n = 128) and a matched control group (n = 77) was conducted. The primary outcome measure was bone mineral density and secondary measures were markers of bone metabolism and prevalent fractures. Results Hip and total body bone mineral densities were significantly lower in women with diabetes compared with control subjects. In men, no difference in bone mineral density was found. A multivariate regression analysis in women with diabetes revealed higher BMI as the strongest predictor of higher total hip, femoral neck and total body bone mineral density, whereas previous fractures were inversely associated with total hip bone mineral density and C-terminal telopeptide of type I collagen with total body bone mineral density. Poor long-term glycaemic control was not associated with low bone mineral density. Fracture frequency was higher in patients with diabetes compared with control subjects (1.64 vs. 0.62 per 100 patient-years; P < 0.05). In a multivariable model, long-term HbA1c control was associated with increased clinical fracture prevalence (OR 1.92; 95% CI 1.09-2.75) in those with diabetes. Conclusions Type 1 diabetes contributes to low bone mineral density in women. Previous fractures and low BMI were strong predictors of impaired bone mineral density and should therefore be considered in risk estimation. Fractures are more frequent in Type 1 diabetes. Long-term hyperglycaemiamay account for impaired bone strength, independently from bone mineral density. [ABSTRACT FROM AUTHOR]

The Gulf of California is an archetype of continental rupture through transtensional rifting, and exploitation of a thermally weakened arc to produce a rift. Volcanic rocks of central Baja California record the transition from calcalkaline arc magmatism, due to subduction of the Farallon plate (ca. 24-12 Ma), to rift magmatism, related to the opening of the Gulf of California (<12 Ma). In addition, a suite of postsubduction rocks (<12 Ma), referred to as "bajaites," are enriched in light rare-earth and other incompatible elements (e.g., Ba and Sr). These are further subdivided into high-magnesian andesite (with 50%-58% SiO2 and MgO >4%) and adakite (>56% SiO2 and MgO <3%). The bajaites correlate spatially with a fossil slab imaged under central Baja and are inferred to record postsubduction melting of the slab and subduction-modified mantle by asthenospheric upwelling associated with rifting or slab breakoff. We report on volcanic rocks of all three suites, which surround and underlie the Santa Rosalía sedimentary rift basin. This area represents the western margin of the Guaymas basin, the most magmatically robust segment of the Gulf of California rift, where seafloor spreading occurred in isolation for 3-4 m.y. (starting at 6 Ma) before transtensional pull-apart basins to the north and south ruptured the continental crust. Outcrops of the Santa Rosalía area thus offer the opportunity to understand the magmatic evolution of the Guaymas rift, which has been the focus of numerous oceanographic expeditions. We describe 21 distinct volcanic and hypabyssal map units in the Santa Rosalía area, using field characteristics, petrographic data, and major- and trace-element geochemical data, as well as zircon isotopic data and ten new 40Ar-39Ar ages. Lithofacies include lavas and lava domes, block-and-ash-flow tuffs, ignimbrites, and hypabyssal intrusions (plugs, dikes, and peperites). Calcalkaline volcanic rocks (13.81-10.11 Ma) pass conformably upsection, with no time gap, into volcanic rocks with rift transitional chemistry (9.69-8.84 Ma). The onset of rifting was marked by explosive eruption of silicic ignimbrite (tuff of El Morro), possibly from a caldera, similar to the onset of rifting or accelerated rifting in other parts of the Gulf of California. Epsilon Hf zircon data are consistent with a rift transitional setting for the tuff of El Morro. Arc and rift volcanic rocks were then juxtaposed by normal faults and tilted eastward toward a north-south fault that lay offshore, likely related to the north-south normal faults documented for the early history of the Guaymas basin, prior to the onset of northwest-southeast transtenional faulting. Magmatism in the Santa Rosalía area resumed with emplacement of high-magnesian andesite lavas and intrusions, at 6.06 Ma ± 0.27 Ma, coeval with the onset of seafloor spreading in the Guaymas basin at ca. 6 Ma. The 9.69-8.84 Ma rift transitional volcanic rocks underlying the Santa Rosalía sedimentary basin provide a maximum age on its basal fill. Evaporites in the Santa Rosalía sedimentary basin formed on the margin of the Guaymas basin, where thicker evaporites formed. Overlying coarse-grained clastic sedimentary fill of the Santa Rosalía basin and its stratiform Cu-Co-Zn-Mn sulfides may have accumulated rapidly, coeval with emplacement of 6.06 Ma high-magnesian andesite intrusions and the ca. 6 Ma onset of seafloor spreading in the Guaymas basin. [ABSTRACT FROM AUTHOR]

Novel monolithic structures with zeolitic [sodalite (SOD), Linde-Type A (LTA) and faujasite (FAU)-type] architectures having well-defined pores, cages and channels are successfully fabricated by selective electron beam melting (SEBM) using Ti–6Al–4V powder. The open porosities of the monoliths are 92.87% (SOD), 94.64% (LTA) and 95.67% (FAU), respectively. Although the porosity of the FAU monolith is relatively higher than the other two monoliths (SOD and LTA), but exhibits higher normalized pressure drop due to its inherent pore tortuosity (supercages interconnected by 12-ring channels in all three dimensions). This represents a significant step forward for the design and development of innovative structured supports and/or reactors with desired porosities and pressure drop characteristics. [ABSTRACT FROM AUTHOR]

Background: Staphylococcus aureus (S. aureus) infections range in severity due to expression of certain virulence factors encoded on mobile genetic elements (MGE). As such, characterization of these MGE, as well as single nucleotide polymorphisms, is of high clinical and microbiological importance. To understand the evolution of these dangerous pathogens, it is paramount to define reference strains that may predate MGE acquisition. One such candidate is S. aureus Tager 104, a previously uncharacterized strain isolated from a patient with impetigo in 1947. Results: We show here that S. aureus Tager 104 can survive in the bloodstream and infect naïve organs. We also demonstrate a procedure to construct and validate the assembly of S. aureus genomes, using Tager 104 as a proofof- concept. In so doing, we bridged confounding gap regions that limited our initial attempts to close this 2.82 Mb genome, through integration of data from Illumina Nextera paired-end, PacBio RS, and Lucigen NxSeq mate-pair libraries. Furthermore, we provide independent confirmation of our segmental arrangement of the Tager 104 genome by the sole use of Lucigen NxSeq libraries filled by paired-end MiSeq reads and alignment with SPAdes software. Genomic analysis of Tager 104 revealed limited MGE, and a Saβ island configuration that is reminiscent of other hospital acquired S. aureus genomes. Conclusions: Tager 104 represents an early-branching ancestor of certain hospital-acquired strains. Combined with its earlier isolation date and limited content of MGE, Tager 104 can serve as a viable reference for future comparative genome studies. [ABSTRACT FROM AUTHOR]

Thermus aquaticus Y51MC23 was isolated from a boiling spring in the Lower Geyser Basin of Yellowstone National Park. Remarkably, this T. aquaticus strain is able to grow anaerobically and produces multiple morphological forms. Y51MC23 is a Gram-negative, rod-shaped organism that grows well between 50°C and 80°C with maximum growth rate at 65°C to 70°C. Growth studies suggest that Y51MC23 primarily scavenges protein from the environment, supported by the high number of secreted and intracellular proteases and peptidases as well as transporter systems for amino acids and peptides. The genome was assembled de novo using a 350 bp fragment library (paired end sequencing) and an 8 kb long span mate pair library. A closed and finished genome was obtained consisting of a single chromosome of 2.15 Mb and four plasmids of 11, 14, 70, and 79 kb. Unlike other Thermus species, functions usually found on megaplasmids were identified on the chromosome. The Y51MC23 genome contains two full and two partial prophage as well as numerous CRISPR loci. The high identity and synteny between Y51MC23 prophage 2 and that of Thermus sp. 2.9 is interesting, given the 8,800 km separation of the two hot springs from which they were isolated. The anaerobic lifestyle of Y51MC23 is complex, with multiple morphologies present in cultures. The use of fluorescence microscopy reveals new details about these unusual morphological features, including the presence of multiple types of large and small spheres, often forming a confluent layer of spheres. Many of the spheres appear to be formed not from cell envelope or outer membrane components as previously believed, but from a remodeled peptidoglycan cell wall. These complex morphological forms may serve multiple functions in the survival of the organism, including food and nucleic acid storage as well as colony attachment and organization. [ABSTRACT FROM AUTHOR]

Background: The majority of infections treated by surgeons are nosocomial infections (NI). The frequency of these infections in relation to the organ operated on as well as the organisms involved are not well defined. Detailed knowledge of these issues is essential for optimal care of surgical patients. This study aimed to determine infection rates and the responsible pathogens after major elective surgery of the pancreas, liver, stomach, and esophagus. Methods: Between January 1, 2005 and August 31, 2007, the records of all patients of the Department of General, Abdominal and Vascular Surgery, University Hospital Magdeburg (Germany) with elective resection of the pancreas, liver, stomach, and esophagus were evaluated retrospectively. Study parameters were: Patient number, age, gender, body mass index (BMI), American Society of Anesthesiologists (ASA) classification, indication for resection, operation duration, length of stay (LOS) in the intensive care unit (ICU) and in hospital, mortality, organ-related rate and kind of NI, and microbiologic spectrum. Nosocomial infections were defined as: Surgical site infection (U.S. Centers for Disease Control and Prevention [CDC] 1 or 2) and intra-abdominal infection (CDC 3), urinary tract infection, clinical sepsis, blood stream and catheter-related infection, respiratory tract infection, and pneumonia. Results: A total of 358 patients were included: 150 (42%) with pancreas resection, 91 (25%) with liver resection, 105 (29%) with gastric resection, and 12 (3%) with esophagus resection. Median LOS in the ICU for all groups was 48.8 h (interquartile range [IQR] 24.9-91.8 h), median LOS in hospital was 16 d (IQR 13-23 d), and in-hospital mortality was 4.5%. Patients with NI had significantly greater in-hospital death and prolonged stay in hospital and ICU (p<0.001). In 120 (33.5%) patients, one or more NI occurred (range, 83% in esophagus patients to 21% in liver patients). Intra-abdominal (16.5%) and surgical site infections (12.3%) were most frequent; 80.8% of the NI were culture-positive. The most frequent clinically relevant isolates were Escherichia coli (12.4%), coagulase-negative staphylococci (CoNS) (12.2%), and Enterococcus faecium (9.7%). The highest resistance rates were found for Staphylococcus aureus (methicillin-resistant S. aureus [MRSA] 29.4%) and Pseudomonas aeruginosa (23.5%). Conclusions: For patients undergoing elective surgery of the pancreas, liver, stomach, and esophagus, considerable differences in demographic factors, frequency, and kind of NI exist. The consequences of NI force surgeons to analyze pre-operative risk factors carefully, assess indications for operation thoroughly, and optimize all controllable parameters. [ABSTRACT FROM AUTHOR]

The population of elderly individuals with rheumatoid arthritis (RA) is expanding, due mainly to increasing life expectancy. A variety of theories have been proposed to explain the ageing process, including accumulation of DNA damage and resultant changes in biological processes. Such changes can influence the development and/or course of disease. Furthermore, alterations in biological function determine the biological age--as opposed to chronological age--of an individual, which strongly influences their ability to cope with disease. Moreover, comorbidities are more frequent in elderly individuals. Together, these factors complicate treatment of disease and necessitate careful patient management. Indeed, although evidence from clinical trials suggests that DMARDs and biologic agents have good efficacy and are well tolerated in elderly patients with RA, such individuals are often undertreated and inadequately managed. Unfortunately, insufficient data are available for the development of evidence-based guidelines for this population, as elderly patients are often excluded from clinical trials owing to age restrictions or comorbidities. Thus, additional clinical studies in elderly patients are warranted, with treatment regimens tailored according to vitality or frailty parameters. This Review focuses on the pathophysiological aspects of ageing and their implications for the management of RA in elderly patients. [ABSTRACT FROM AUTHOR]

Examines the relationship between tick bites and the seroprevalence of Babesia microti and Anaplasma phagocytophila. Transmission of B. burgdorferi to humans by black-legged ticks of the genus Ixodes; Presentation of survey regarding tick bites; Detection of B. microti using a synthetic peptide prototype ELISA.

Describes the identification of babesia microti-specific immunodominant epitopes and development of a peptide EIA for detection of antibodies in serum in the U.S. Documentation of the cases of transfusion-related transmission of babesiosis; Determination of the relationship of peptide EIA reactivity to the performance of other established methods; Identification of recombinant proteins using serologoic expression cloning of babesia microti.