bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamic Modeling and Analysis of an Origami-Inspired Optical Shield for the Starshade Spacecraft
Authors: Bowen Landen , Trease Brian , Frecker Mary , Simpson Timothy 
Published: November 2016

The Starshade is a future exoplanet discovery mission consisting of a satellite and a 34 meter diameter starshade used to block the light of a star of interest, enhancing visualization of the orbiting planets. The starshade itself is composed of a number of 7 meter long petals surrounding a 20 meter diameter optical shield. A critical design requirement of the optical shield is stowage in a 3 meter diameter area during launch. Origami has been investigated as a means of collapsing the optical shield, specifically a family of action origami models known as “flashers.”
In this paper a dynamic model of an optical shield design candidate based on a flasher pattern is created in Adams 2014. As these patterns can have many parts and joints, a method for the automatic creation of dynamic models using information about the geometry of the crease pattern is utilized. As the fabricated optical shield panels will be somewhat flexible, each quadrilateral panel is modeled as two rigid triangles connected with a joint. The effect of joint stiffness on the forces and torques developed during deployment is investigated.
It is found that the optical shield design is rigid foldable if the panel flexibility is taken into account by additional joints, which are found to bend from 10° – 40°. Joint forces are predicted over the deployment, and maximum and average joint forces are tabulated. These and other insights gained from the dynamic model can help guide future Starshade design decisions, and similar analyses can be performed for other origami-inspired deployable structures.
Carbon Fiber Composite Beam Damage Model Identification
Authors: Pesch Alexander H. , Madden Ryan J. , Martin Richard E. , Sawicki Jerzy T. 
Published: November 2016

The technique of model-based identification is proposed to extract a model for damage in composite materials from experimental data. The proposed method is demonstrated on a unidirectional carbon fiber reinforced polymer (CFRP) beam. Impact damage is seeded in the CFRP beam using a spherical punch, causing localized damage. The specimen is evaluated through modal testing before and after the damage is seeded, with the healthy case modeled using the FEM. Finally, a virtual controller is found which eliminates error in response between the healthy model and damaged experimental system. The virtual controller, being in feedback with the healthy model at the FE node where the damage occurs, reflects the effect of the localized damage.
It is found that the seeded impact damage reduces stiffness and is a source of damping inside the composite beam. Interpretation of the local damage is made through the curve fitting of the identified dynamics. To confirm the efficacy of the fit, a closed-loop is made with the healthy model which is then compared to the data from the damaged system.
Graphene Nanoplatelets-Based Self-Sensing Cementitious Composites
Authors: Jiang Zhangfan , Ozbulut Osman E. , Harris Devin K. 
Published: November 2016

Over the past two decades, numerous research studies have been conducted to explore behavior of self-sensing cementitious composites with different functional fillers. Most of these studies investigated the use of fillers such as carbon nanofiber (CNF), carbon black, and carbon nanotubes (CNTs) in cement composites to develop a multifunctional material. Since its discovery in 2004, graphene has also raised significant attention as 2D nanoscale reinforcement for composite materials. The planar structure of graphene sheets provides more contact area with the host material. However, high cost and dispersion difficulties are among the drawbacks of graphene. More recently, graphene nanoplatelets (GNPs), which have very thin but wide aspect ratio, are drawing the graphene market due to their advantages such as ease of processing and excellent material properties at a very low cost. The application of two-dimensional graphene nanoplatelets in cementitious composites has yet to gain widespread attention.
This paper investigates the self-sensing capabilities of GNP-reinforced hydraulic Portland cement composites. In particular, the effects of GNP content on the electrical properties and piezoresistive characteristics of mortar specimens are explored. In addition, a simple fabrication method that does not require special treating procedures such as ultrasonication and chemical (covalent) treatments for the dispersion of GNPs is pursued. The GNPs used in this study have an average thickness of 8 nanometers and a diameter of 25 microns. Standard prismatic mortar specimens containing different GNP concentrations are prepared using three different mixing procedures. The resistivity of the specimens is measured using a four-point probe method. The piezoresistive response of GNP-reinforced cement composites is evaluated under cyclic compressive loads.
The Effect of Porosity Type on the Mechanical Performance of Porous NiTi Bone Implants
Authors: Amerinatanzi Amirhesam , Shayesteh Moghaddam Narges , Ibrahim Hamdy , Elahinia Mohammad 
Published: November 2016

NiTi has been shown to be of great interest for bone implant applications. Introducing porosity to NiTi bone implants is an effective technique to tune their equivalent modulus of elasticity in order to acquire similar value to that of cortical bone. Moreover, such porous implants allow for better tissue ingrowth due to the interconnecting open pore structure. The effect of porosity percentage on the NiTi equivalent modulus of elasticity is well understood. However, the effect of porosity type on NiTi bone implant’s performance, in terms of the geometrical structure and other mechanical properties, has not yet been investigated. To this end, we simulated three porous structures made of shape memory Ti-rich Ni50.09Ti alloy. The effect of porosity type on the NiTi implant’s geometrical structure and mechanical properties was studied using numerical tests. The purpose is to compare three NiTi implants with different kinds of porosities, at a similar level of porosity (i.e., 69 %). The assigned porosity types in this study are Schwartz-type, Gyroid-type, and Diamond-type.
Three triply periodic minimal surface (TPMS) models (9mm×9mm×9mm) with the assigned fixed level of porosity (69 %) were designed as CAD files using Solidworks. Each model was meshed, and the convergence study was conducted. The three models were then imported into a finite element package (ABAQUS). A UMAT code developed by IUT (Isfahan University of Technology) group was used to simulate the mechanical behavior of the shape memory NiTi alloy. All boundary conditions and loading conditions were applied to the models. Compressive mechanical tests were simulated in the finite element, and the resultant equivalent modulus of elasticity, elongations, stress, and strain was estimated.
The results show anisotropic behavior within the three different porous structures. With the same level of porosity (i.e., 69 %), equivalent modulus of elasticity was observed to be 48.9, 34.8, and 30.2 GPa for Schwartz-type, Gyroid-type, and Diamond-type, respectively. Moreover, the Schwartz-type scaffold was seen to offer the highest stress at plateau start and the lowest residual strain after unloading, in comparison with the other two types of structure.
Molecular Investigation of Resistance to Second-Line Injectable Drugs in Multidrug-Resistant Clinical Isolates of
Mycobacterium tuberculosi
s in France
Authors: Brossier Florence , Pham Anne , Bernard Christine , Aubry Alexandra , Jarlier Vincent , Veziris Nicolas , Sougakoff Wladimir ,   on behalf of the CNR-MyRMA
Published: November 2016

ABSTRACT

The second-line injectable drugs (SLID, i.e., amikacin, kanamycin, capreomycin) are key drugs for the treatment of multidrug-resistant tuberculosis. Mutations in
rrs
region 1400,
tlyA
, and
eis
promoter are associated with resistance to SLID, to capreomycin, and to kanamycin, respectively. In this study, the sequencing data of SLID resistance-associated genes were compared to the results of phenotypic drug susceptibility testing by the proportion method for the SLID in 206 multidrug-resistant clinical isolates of
Mycobacterium tuberculosis
collected in France. Among the 153 isolates susceptible to the 3 SLID, 145 showed no mutation, 1 harbored T1404C and G1473A mutations in
rrs
, and 7 had an
eis
promoter mutation. Among the 53 strains resistant to at least 1 of the SLID, mutations in
rrs
accounted for resistance to amikacin, capreomycin, and kanamycin for 81%, 75%, and 44% of the isolates, respectively, while mutations in
eis
promoter were detected in 44% of the isolates resistant to kanamycin. In contrast, no mutations in
tlyA
were observed in the isolates resistant to capreomycin. The discrepancies observed between the genotypic (on the primary culture) and phenotypic drug susceptibility testing were explained by (i) resistance to SLID with MICs close to the critical concentration used for routine DST and not detected by phenotypic testing (
n
= 8, 15% of SLID-resistant strains), (ii) low-frequency heteroresistance not detected by sequencing of drug resistance-associated genes on the primary culture (
n
= 8, 15% of SLID-resistant strains), and (iii) other resistance mechanisms not yet characterized (
n
= 7, 13% of SLID-resistant strains).
In Vitro
and
In Vivo
Activities of Sulfur-Containing Linear Bisphosphonates against Apicomplexan Parasites
Authors: Szajnman Sergio H. , Galaka Tamila , Li Zhu-Hong , Li Catherine , Howell Nathan M. , Chao María N. , Striepen Boris , Muralidharan Vasant , Moreno Silvia N. J. , Rodriguez Juan B. 
Published: November 2016

ABSTRACT

We tested a series of sulfur-containing linear bisphosphonates against
Toxoplasma gondii
, the etiologic agent of toxoplasmosis. The most potent compound (compound 22; 1-[(
n
-decylsulfonyl)ethyl]-1,1-bisphosphonic acid) is a sulfone-containing compound, which had a 50% effective concentration (EC
50
) of 0.11 ± 0.02 μM against intracellular tachyzoites. The compound showed low toxicity when tested in tissue culture with a selectivity index of >2,000. Compound 22 also showed high activity
in vivo
in a toxoplasmosis mouse model. The compound inhibited the
Toxoplasma
farnesyl diphosphate synthase (
Tg
FPPS), but the concentration needed to inhibit 50% of the enzymatic activity (IC
50
) was higher than the concentration that inhibited 50% of growth. We tested compound 22 against two other apicomplexan parasites,
Plasmodium falciparum
(EC
50
of 0.6 ± 0.01 μM), the agent of malaria, and
Cryptosporidium parvum
(EC
50
of ∼65 μM), the agent of cryptosporidiosis. Our results suggest that compound 22 is an excellent novel compound that could lead to the development of potent agents against apicomplexan parasites.
The Plasmodium falciparum Cell-Traversal Protein for Ookinetes and Sporozoites as a Candidate for Preerythrocytic and Transmission-Blocking Vaccines
Authors: Espinosa Diego A. , Vega-Rodriguez Joel , Flores-Garcia Yevel , Noe Amy R. , Muñoz Christian , Coleman Russell , Bruck Torben , Haney Keith , Stevens Alex , Retallack Diane , Allen Jeff , Vedvick Thomas S. , Fox Christopher B. , Reed Steven G. , Howard Randall F. , Salman Ahmed M. , Janse Chris J. , Khan Shahid M. , Zavala Fidel , Gutierrez Gabriel M. 
Published: November 2016

ABSTRACT

Recent studies have shown that immune responses against the cell-traversal protein for
Plasmodium
ookinetes and sporozoites (CelTOS) can inhibit parasite infection. While these studies provide important evidence toward the development of vaccines targeting this protein, it remains unknown whether these responses could engage the
Plasmodium falciparum
CelTOS
in vivo
. Using a newly developed rodent malaria chimeric parasite expressing the
P. falciparum
CelTOS (PfCelTOS), we evaluated the protective effect of
in vivo
immune responses elicited by vaccination and assessed the neutralizing capacity of monoclonal antibodies specific against PfCelTOS. Mice immunized with recombinant
P. falciparum
CelTOS in combination with the glucopyranosyl lipid adjuvant-stable emulsion (GLA-SE) or glucopyranosyl lipid adjuvant-liposome-QS21 (GLA-LSQ) adjuvant system significantly inhibited sporozoite hepatocyte infection. Notably, monoclonal antibodies against PfCelTOS strongly inhibited oocyst development of
P. falciparum
and
Plasmodium berghei
expressing PfCelTOS in
Anopheles gambiae
mosquitoes. Taken together, our results demonstrate that anti-CelTOS responses elicited by vaccination or passive immunization can inhibit sporozoite and ookinete infection and impair vector transmission.
The Predicted Lytic Transglycosylase HpaH from Xanthomonas campestris pv. vesicatoria Associates with the Type III Secretion System and Promotes Effector Protein Translocation
Authors: Hausner Jens , Hartmann Nadine , Jordan Michael , Büttner Daniela 
Published: November 2016

ABSTRACT

The pathogenicity of the Gram-negative plant-pathogenic bacterium
Xanthomonas campestris
pv. vesicatoria depends on a type III secretion (T3S) system, which spans both bacterial membranes and translocates effector proteins into plant cells. The assembly of the T3S system presumably involves the predicted lytic transglycosylase (LT) HpaH, which is encoded adjacent to the T3S gene cluster. Bacterial LTs degrade peptidoglycan and often promote the formation of membrane-spanning macromolecular protein complexes. In the present study, we show that HpaH localizes to the bacterial periplasm and binds to peptidoglycan as well as to components of the T3S system, including the predicted periplasmic inner rod proteins HrpB1 and HrpB2 as well as the pilus protein HrpE.
In vivo
translocation assays revealed that HpaH promotes the translocation of various effector proteins and of early substrates of the T3S system, suggesting a general contribution of HpaH to type III-dependent protein export. Mutant studies and the analysis of reporter fusions showed that the N-terminal region of HpaH contributes to protein function and is proteolytically cleaved. The N-terminally truncated HpaH cleavage product is secreted into the extracellular milieu by a yet-unknown transport pathway, which is independent of the T3S system.
The Pathogenic Potential of Proteus mirabilis Is Enhanced by Other Uropathogens during Polymicrobial Urinary Tract Infection
Authors: Armbruster Chelsie E. , Smith Sara N. , Johnson Alexandra O. , DeOrnellas Valerie , Eaton Kathryn A. , Yep Alejandra , Mody Lona , Wu Weisheng , Mobley Harry L. T. 
Published: November 2016

ABSTRACTUrinary catheter use is prevalent in health care settings, and polymicrobial colonization by urease-positive organisms, such asProteus mirabilisandProvidencia stuartii, commonly occurs with long-term catheterization. We previously demonstrated that coinfection withP. mirabilisandP. stuartiiincreased overall urease activityin vitroand disease severity in a model of urinary tract infection (UTI). In this study, we expanded these findings to a murine model of catheter-associated UTI (CAUTI), delineated the contribution of enhanced urease activity to coinfection pathogenesis, and screened for enhanced urease activity with other common CAUTI pathogens. In the UTI model, mice coinfected with the two species exhibited higher urine pH values, urolithiasis, bacteremia, and more pronounced tissue damage and inflammation compared to the findings for mice infected with a single species, despite having a similar bacterial burden within the urinary tract. The presence ofP. stuartii, regardless of urease production by this organism, was sufficient to enhanceP. mirabilisurease activity and increase disease severity, and enhanced urease activity was the predominant factor driving tissue damage and the dissemination of both organisms to the bloodstream during coinfection. These findings were largely recapitulated in the CAUTI model. Other uropathogens also enhancedP. mirabilisurease activityin vitro, including recent clinical isolates ofEscherichia coli,Enterococcus faecalis,Klebsiella pneumoniae, andPseudomonas aeruginosa. We therefore conclude that the underlying mechanism of enhanced urease activity may represent a widespread target for limiting the detrimental consequences of polymicrobial catheter colonization, particularly byP. mirabilisand other urease-positive bacteria.
Risk of obstructive sleep apnoea in patients with rheumatoid arthritis: a nationwide population-based retrospective cohort study
Authors: Shen Te-Chun , Hang Liang-Wen , Liang Shinn-Jye , Huang Chien-Chung , Lin Cheng-Li , Tu Chih-Yen , Hsia Te-Chun , Shih Chuen-Ming , Hsu Wu-Huei , Sung Fung-Chang 
Published: November 2016

ObjectiveSleep disorders are prevalent medical disorders in patients with rheumatoid arthritis (RA). However, whether patients with RA are at an increased risk of developing obstructive sleep apnoea (OSA) is unclear.DesignUsing population-based retrospective cohort study to examine the risk of OSA in patients with RA.SettingWe used claims data of the National Health Insurance Research Database (NHIRD) of Taiwan.ParticipantsWe identified a RA cohort with 33 418 patients newly diagnosed in 2000–2010 and a randomly selected non-RA comparison cohort with 33 418 individuals frequency matched by sex, age and diagnosis year.Primary and secondary outcome measuresIncident OSA was estimated by the end of 2011. The HRs of OSA were calculated using the Cox proportional hazards regression analysis.ResultsThe overall incidence rate of OSA was 75% greater in the RA cohort than in the non-RA cohort (3.04 vs 1.73/10 000 person-years, p<0.001), with an adjusted HR (aHR) of 1.75 (95% CI 1.18 to 2.60). Stratified analyses by sex, age group and comorbidity revealed that the incidence rates of OSA associated with RA were higher in all subgroups.ConclusionsThis population-based retrospective cohort study suggested that patients with RA should be monitored for the risk of developing OSA.
Protocol of the Swiss Longitudinal Cohort Study (SWICOS) in rural Switzerland
Authors: Schoenenberger Andreas W , Muggli Franco , Parati Gianfranco , Gallino Augusto , Ehret Georg , Suter Paolo M , Schoenenberger-Berzins Renate , Resink Therese J , Erne Paul 
Published: November 2016

IntroductionIncreased longevity and consequent major changes in demographics and population lifestyles necessitate new approaches to reduce the burden of ageing-related diseases (including cardiovascular disease) and maintain an optimal quality of life. This study aims to examine and longitudinally follow health status and disease risk factors in a Swiss rural cohort, evaluating all health-related research and practice disciplines to assure development of new implementable and successful preventive strategies for healthy ageing.Methods and objectivesSmall Swiss villages with low migration rates will be selected for this study. 2 villages (Cama/Lostallo) have already been selected as initial study sites. All residents (age ≥6 years, no upper age limit) are eligible. The target enrolment number per village is 300. Examinations and measurements encompass medical history, anthropometry, cardiac and vascular health, pulmonary function, physical performance, nutritional, mental and emotional status, biochemical and molecular analyses. Follow-up examinations (identical to baseline) will be performed after 5 and 10 years, and in 10-year intervals thereafter. The major objective is to assess, and observe change in, health status over time in a prospective manner. Secondary objectives are to: (1) identify ‘hidden’ (asymptomatic and/or unrecognised) health problems which enhance risk for chronic diseases; (2) identify barriers to accessing healthcare and adapting health behaviours; (3) evaluate efficacy of present preventive strategies and recommendations; (4) evaluate knowledge and attitude towards ongoing health programmes and public health recommendations; (5) monitor change and progress towards the national health objectives; (6) formulate new preventive strategies and recommendations based on the findings and knowledge base of the past 10 years; (7) formulate models for successful prevention of chronic diseases and for healthy ageing.Ethics and disseminationThe Ethics Committee of Nordwest-und Zentralschweiz approved this study (EKNZ 2014-209). It is registered at ClinicalTrials.gov (NCT02282748). Findings will be disseminated through scientific articles/presentations and public events.
Impact of a dedicated cancer-associated thrombosis service on clinical outcomes: a mixed-methods evaluation of a clinical improvement exercise
Authors: Noble Simon , Pease Nikki , Sui Jessica , Davies James , Lewis Sarah , Malik Usman , Alikhan Raza , Prout Hayley , Nelson Annmarie 
Published: November 2016

ObjectivesCancer-associated thrombosis (CAT) complex condition, which may present to any healthcare professional and at any point during the cancer journey. As such, patients may be managed by a number of specialties, resulting in inconsistent practice and suboptimal care. We describe the development of a dedicated CAT service and its evaluation.SettingSpecialist cancer centre, district general hospital and primary care.ParticipantsPatients with CAT and their referring clinicians.InterventionA cross specialty team developed a dedicated CAT service , including clear referral pathways, consistent access to medicines, patient's information and a specialist clinic.Primary and secondary outcome measuresThe service was evaluated using a mixed-methods evaluation , including audits of clinical practice, clinical outcomes, staff surveys and qualitative interviewing of patients and healthcare professionals.ResultsData from 457 consecutive referrals over an 18-month period were evaluated. The CAT service has led to an 88% increase in safe and consistent community prescribing of low-molecular-weight heparin, with improved access to specialist advice and information. Patients reported improved understanding of their condition, enabling better self-management as well as better access to support and information. Referring clinicians reported better care standards for their patients with improved access to expertise and appropriate management.ConclusionsA dedicated CAT service improves overall standards of care and is viewed positively by patients and clinicians alike. Further health economic evaluation would enhance the case for establishing this as the standard model of care.