bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optimizing the amount of simulation training used to teach vaginal delivery skills to medical students
Authors: Nitsche Joshua F. , Butler Timberly R. , Shew Alison W. , Jin Sha , Brost Brian C. 
Published: September 2017

AbstractObjectiveTo determine the amount of simulation training required for students to attain minimal competence and mastery of a vaginal delivery.MethodsAn observational study was conducted at a US medical school between May 11, 2015, and May 8, 2016. Using a modified Angoff method, 10 members of the Obstetrics and Gynecology faculty evaluated a vaginal delivery procedural checklist and established cutoff scores for minimal competence and mastery. During a 5‐week period, all third‐year students received between two and five 45‐minute vaginal delivery simulation sessions; performance was assessed during week 6. Performance according to the checklist was compared.ResultsThe cutoff score was 20 and 26 out of 30 for minimal competence and mastery, respectively. Among 115 students, mean checklist scores in final assessment rose with increasing number of simulations: 23.6, 25.1, 27.5, and 27.6 points for two, three, four, and five training sessions, respectively (P<0.001). The proportion of patients achieving mastery also increased with number of simulations: 34%, 59%, 73%, and 93% for two, three, four, and five training sessions, respectively (P<0.001). Two or three training sessions were sufficient to attain minimal competence in most students; however, no significant between‐group difference was found.ConclusionSimulation training exerts an increasing effect on performance with each additional session that students receive.
Ultrafiltration of whey: membrane performance and modelling using a combined pore blocking–cake formation model
Authors: Corbatón‐Báguena María‐José , Álvarez‐Blanco Silvia , Vincent‐Vela María‐Cinta 
Published: September 2017

AbstractBACKGROUNDUltrafiltration has been considered as a ‘green’ technique to treat different industrial wastewaters, such as whey in the dairy industry. However, fouling is one of the major drawbacks in the industrial implementation of this process. Thus, in this work, the performance of ultrafiltration membranes was investigated in terms of permeate flux and protein rejection when treating different whey model solutions. Modelling of permeate flux was performed combining two main fouling mechanisms (complete pore blocking and cake formation) by a time‐dependent pore blocking parameter.RESULTSResults demonstrated that high protein concentration and the presence of calcium salts in the feed solution favoured permeate flux decline. The combined model was appropriate to describe the main fouling mechanisms, with fitting accuracies higher than 0.960. Model parameters were correlated with both calcium and protein concentration and the developed model was successfully validated with an additional fouling test.CONCLUSIONAll the membranes tested were suitable for carrying out whey protein separation, with rejection indexes greater than 99%. The combined model and the statistical correlation of model parameters with calcium and protein concentrations were useful to predict permeate flux decline when the ultrafiltration of a new whey model solution was performed. © 2017 Society of Chemical Industry
Is real‐time elastography helpful to differentiate acute from subacute deep venous thrombosis? A preliminary study
Authors: Aslan Ahmet , Barutca Hakan , Ayaz Ercan , Aslan Mine , Kocaaslan Cemal , Inan Ibrahim , Sahin Sinan , Yıkılmaz Ali 
Published: September 2017

AbstractPurposeTo detect and characterize changes in stiffness of thrombus in patients with acute and subacute deep venous thrombosis (DVT) by using real‐time elastography (RTE).MethodsFifty‐eight patients with acute or subacute DVT were prospectively evaluated by B‐mode sonography (US), color Doppler US (CDUS), and RTE. Two radiologists evaluated the thrombus echogenicity, compressibility, and recanalization of the affected vein, and thrombus stiffness in consensus. The thrombi were classified into 3 groups as soft, intermediate, and hard on RTE images.ResultsThe final study group consisted of 30 patients with acute DVT, among whom 10 were women (33%), and 19 patients with subacute DVT, among whom 6 were women (32%). The presence of hypoechoic thrombus, incompressible vein, and absence of recanalization on US and CDUS were significantly associated with acute DVT (P < .001 for all variables). The differences in elasticity pattern of the thrombi between acute and subacute DVT were not significant (P = .202).ConclusionVenous thrombus hardens with age; however, elastography pattern on RTE, in its present form, may not be able to differentiate acute DVT from subacute DVT.
Wear testing of a canine hip resurfacing implant that uses highly cross‐linked polyethylene
Authors: Warburton Kevin J. , Everingham John B. , Helms Jillian L. , Kazanovicz Andrew J. , Hollar Katherine A. , Brourman Jeff D. , Fox Steven M. , Lujan Trevor J. 
Published: September 2017

ABSTRACTHip resurfacing offers advantages for young, active patients afflicted with hip osteoarthritis and may also be a beneficial treatment for adult canines. Conventional hip resurfacing uses metal‐on‐metal bearings to preserve bone stock, but it may be feasible to use metal‐on‐polyethylene bearings to reduce metal wear debris while still preserving bone. This study characterized the short‐term wear behavior of a novel hip resurfacing implant for canines that uses a 1.5 mm thick liner of highly cross‐linked polyethylene in the acetabular component. This implant was tested in an orbital bearing machine that simulated canine gait for 1.1 million cycles. Wear of the liner was evaluated using gravimetric analysis and by measuring wear depth with an optical scanner. The liners had a steady‐state mass wear rate of 0.99 ± 0.17 mg per million cycles and an average wear depth in the central liner region of 0.028 mm. No liners, shells, or femoral heads had any catastrophic failure due to yielding or fracture. These results suggest that the thin liners will not prematurely crack after implantation in canines. This is the first hip resurfacing device developed for canines, and this study is the first to characterize the in vitro wear of highly cross‐linked polyethylene liners in a hip resurfacing implant. The canine implant developed in this study may be an attractive treatment option for canines afflicted with hip osteoarthritis, and since canines are the preferred animal model for human hip replacement, this implant can support the development of metal‐on‐polyethylene hip resurfacing technology for human patients. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1196–1205, 2018.
Morbidity and mortality associated with preclinical tracheostomy models
Authors: Dion Gregory R. , Benedict Peter A. , Amin Milan R. , Branski Ryan C. 
Published: September 2017

Objectives/HypothesisA secure airway is critical to study obstructive disorders of the larynx and trachea in preclinical models. Tracheostomy has been described in rabbits, swine, canines, and other mammals using tracheostomy tubes or permanent stomas. No studies specifically evaluated morbidity and mortality associated with these models, and existing studies using tracheostomy make little mention of tracheostomy‐related complications. We assessed the management, complications, and mortality associated with tracheostomy in a rabbit model that has recently gained significant attention.Study DesignIn vivo.MethodsTwenty‐two female rabbits underwent tubeless tracheotomy. Rabbits were monitored hourly for the first 8 hours, with progressively increasing intervals between evaluations up to 7 days. A suctioning and tracheal moisture protocol was employed, and animals with signs of crusting or impending airway compromise underwent therapeutic bronchoscopy.ResultsNine of 22 (41%) rabbits succumbed to tracheostomy‐related complications, ranging from 1 to 7 days after tracheotomy. The experiment consisted of two study groups. The preliminary group of 10 rabbits studied over a 4‐day period had 40% mortality. After implementing modified preventive therapy guidelines and a new humidification system, the second group of 12 rabbits studied over a 7‐day period had 42% mortality. Average time to unrecoverable complication was 2.2 days (median = 2 days). Cause of death was airway obstruction in four animals and respiratory depression in three animals, and two animals were found unresponsive.ConclusionTracheostomy in preclinical rabbit models should be temporally limited, and investigators should anticipate tracheostomy‐related complications during study design.Level of EvidenceNA. Laryngoscope, 128:E68–E71, 2018
Influence of cyanobacteria, mixotrophic flagellates, and virioplankton size fraction on transcription of microcystin synthesis genes in the toxic cyanobacterium Microcystis aeruginosa
Authors: Scherer Pia I. , Absmeier Carolin , Urban Maria , Raeder Uta , Geist Juergen , Zwirglmaier Katrin 
Published: September 2017

AbstractToxic cyanobacteria such as Microcystis aeruginosa are a worldwide concern in freshwater reservoirs. Problems associated with their mass occurrence are predicted to increase in the future due to global warming. The hepatotoxic secondary metabolite microcystin is of particular concern in this context. This study aimed to determine whether co‐occurring microorganisms influence the expression of microcystin biosynthesis genes. To this end, we performed cocultivation experiments and measured mcyB and mcyD transcripts in M. aeruginosa using RT‐qPCR. We utilized representatives from three different plankton groups: the picocyanobacterium Synechococcus elongatus, the unicellular flagellate grazer Ochromonas danica, and virioplankton from two different lakes. The presence of S. elongatus significantly increased mcyB and mcyD transcription in M. aeruginosa. Cocultivation with the mixotrophic chrysophyte O. danica did not increase the transcription of mcyB and mcyD; in fact, mcyD transcripts decreased significantly. The virioplankton size fraction of environmental water samples induced a significant increase in mcyB and mcyD transcription when obtained from lakes with cyanobacterial blooms. Our results show that co‐occurring microorganisms influence the expression of microcystin biosynthesis genes in M. aeruginosa.
A new method for analysing transition to psychosis: Joint modelling of time‐to‐event outcome with time‐dependent predictors
Authors: Yuen Hok Pan , Mackinnon Andrew , Nelson Barnaby 
Published: September 2017

AbstractAn active area in psychosis research is the identification of predictors of transition to a psychotic state among those who are assessed as being at high risk of psychosis. Many of the potential predictors are time dependent in the sense that they may change over time and are measured at a number of assessment time points. Examples are various psychopathological measures such as negative symptoms, positive symptoms, depression, and anxiety. Most research in transition to psychosis has not made use of the dynamic nature of these measures, probably because suitable statistical methods and software have not been easily available. However, a relatively new statistical methodology is well suited to include such time‐dependent predictors in transition to psychosis analysis. This methodology is called joint modelling and has recently been incorporated in mainstream statistical software. This paper describes this methodology and demonstrates its usefulness using data from one of the pioneering studies on transition to psychosis.
Whole brain inhomogeneous magnetization transfer (ihMT) imaging: Sensitivity enhancement within a steady‐state gradient echo sequence
Authors: Mchinda Samira , Varma Gopal , Prevost Valentin H. , Le Troter Arnaud , Rapacchi Stanislas , Guye Maxime , Pelletier Jean , Ranjeva Jean‐Philippe , Alsop David C. , Duhamel Guillaume , Girard Olivier M. 
Published: September 2017

PurposeTo implement, characterize, and optimize an interleaved inhomogeneous magnetization transfer (ihMT) gradient echo sequence allowing for whole‐brain imaging within a clinically compatible scan time.Theory and MethodsA general framework for ihMT modelling was developed based on the Provotorov theory of radiofrequency saturation, which accounts for the dipolar order underpinning the ihMT effect. Experimental studies and numerical simulations were performed to characterize and optimize the ihMT‐gradient echo dependency with sequence timings, saturation power, and offset frequency. The protocol was optimized in terms of maximum signal intensity and the reproducibility assessed for a nominal resolution of 1.5 mm isotropic. All experiments were performed on healthy volunteers at 1.5T.ResultsAn important mechanism driving signal optimization and leading to strong ihMT signal enhancement that relies on the dynamics of radiofrequency energy deposition has been identified. By taking advantage of the delay allowed for readout between ihMT pulse bursts, it was possible to boost the ihMT signal by almost 2‐fold compared to previous implementation. Reproducibility of the optimal protocol was very good, with an intra‐individual error < 2%.ConclusionThe proposed sensitivity‐boosted and time‐efficient steady‐state ihMT‐gradient echo sequence, implemented and optimized at 1.5T, allowed robust high‐resolution 3D ihMT imaging of the whole brain within a clinically compatible scan time. Magn Reson Med 79:2607–2619, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
Synthesis of self‐matting waterborne polyurethane coatings with excellent transmittance
Authors: Sun Zhe , Fan Haojun , Chen Yi , Huang Junjiang 
Published: September 2017

AbstractThe effect of structural factors, including the type of diisocyanates and glycols, degree of crosslinking, hard‐segment content, crystallinity and hydrophilic group content, on optical properties of waterborne polyurethane (WPU) was investigated. Based on the relationship between structure and properties, a series of self‐matting WPUs with excellent transmittance were synthesized. Results demonstrated that refractive index of constituent groups was an important factor to influence the optical properties of coatings. For multiphase polyurethane, aromatic ring, ester bond, NHCOO and urea groups with high refractive index could decrease the matting effect and transmittance. Higher hard‐segment content resulting in an increase of the number of NHCOO or urea bonds also decreased the matting effect and transmittance. The aggregation structure of WPU was another factor to influence the optical properties of coatings. Crystalline soft and hard segment domains could decrease the transmittance and matting effect, whilst non‐crystalline segments, pendent groups and crosslinking destroyed the regularity or crystallinity of macromolecules, behaving as an auxiliary function to improve the transmittance. The particle size of WPU was of great importance for the matting effect. Smaller particle size (<5.0 µm) would endow the coating with a smoother surface and higher reflected light ratio, and thus the expected matting effect was hard to be achieved. A larger particle size could improve the matting effect but impart to the coating a coarse surface and hand‐feel. When the 2,2‐bis(hydroxymethyl)propionic acid content was 1.6 wt%, spherical particles with a size distribution of 7–8 µm were aggregated on the coating surface, giving the coating an excellent matting effect and hand‐feel. © 2017 Society of Chemical Industry
Tyrosine hydroxylase coordinates larval–pupal tanning and immunity in oriental fruit fly (Bactrocera dorsalis)
Authors: Chen Er‐Hu , Hou Qiu‐Li , Wei Dan‐Dan , Dou Wei , Liu Zhao , Yang Pei‐Jin , Smagghe Guy , Wang Jin‐Jun 
Published: September 2017

AbstractBACKGROUNDThe oriental fruit fly Bactrocera dorsalis (Hendel), a notorious world pest infesting fruits and vegetables, has evolved a high level of resistance to many commonly used insecticides. In this study, we investigate whether tyrosine hydroxylase (TH) that is required for cuticle tanning (sclerotization and pigmentation) in many insects, could be a potential target in controlling B. dorsalis.RESULTSWe cloned TH cDNA (BdTH) of B. dorsalis. The complete open reading frame of BdTH (KY911196) was 1737 bp in length, encoding a protein of 578 amino acids. Quantitative real‐time PCR confirmed that BdTH was highly expressed in the epidermis of 3rd instar larvae, and its expression increased prior to pupation, suggesting a role in larval–pupal cuticle tanning. When we injected dsBdTH or 3‐iodo‐tyrosine (3‐IT) as a TH inhibitor or fed insect diet supplemented with 3‐IT, there was significant impairment of larval–pupal cuticle tanning and a severe obstacle to eclosion in adults followed by death in most. Furthermore, injection of Escherichia coli into larvae fed 3‐IT resulted in 92% mortality and the expressions of four antimicrobial peptide genes were significantly downregulated.CONCLUSIONThese results suggest that BdTH might play a critical role in larval–pupal tanning and immunity of B. dorsalis, and could be used as a potential novel target for pest control. © 2017 Society of Chemical Industry
Effects of fluorine‐containing usnic acid and fungus Beauveria bassiana on the survival and immune–physiological reactions of Colorado potato beetle larvae
Authors: Kryukov Vadim Yu , Tomilova Oksana G , Luzina Olga A , Yaroslavtseva Olga N , Akhanaev Yuriy B , Tyurin Maksim V , Duisembekov Bahytzhan A , Salakhutdinov Nariman F , Glupov Viktor V 
Published: September 2017

AbstractBACKGROUNDThe search for compounds that interact synergistically with entomopathogenic fungi is aimed at enhancing the efficacy and stability of biological products against pest insects, for example, against the Colorado potato beetle (CPB). We hypothesized that fluorine‐containing derivatives of usnic acid (FUA) might be candidates for the development of multicomponent bio‐insecticides. The aim of this study was to analyze the co‐influence of FUA and Beauveria bassiana on the survival and immune–physiological reactions of CPB larvae.RESULTSSynergy between FUA and B. bassiana was observed after treatment of second, third and fourth larvae instars under laboratory conditions. Furthermore, synergy was observed in field trials in continental climate conditions in southeastern Kazakhstan. In a field experiment, the median lethal time was shortened three‐fold, and cumulative mortality for 15 days increased by 36% in the combined treatment compared with a fungal infection alone. FUA treatment delayed larval development, decreased the total hemocyte count, and increased both the phenoloxidase activity in integuments and the detoxification enzyme rate in hemolymph. A combined treatment with fungus and FUA led to increases in the aforementioned changes.CONCLUSIONToxicosis caused by FUA provides a stable synergistic effect between FUA and B. bassiana. The combination can be promising for the development of highly efficient products against CPB. © 2017 Society of Chemical Industry
Design of conjugated microporous polymer nanotubes for efficient benzene molecular adsorptions
Authors: Fan Wen‐Jie , Zhao Yan‐Ling , Hu Yu‐Cai , Shi Hua , Tan Da‐Zhi , Zhang Rui‐Qin 
Published: September 2017

AbstractSingle‐walled conjugated microporous polymer (CMP) nanotubes containing alternative phenylene and ethynylene units were described computationally for the first time in this work. The electronic structures and adsorption properties were studied by the density‐functional tight‐binding method augmented with a van der Waals dispersion term. Our calculations show that the morphology of CMP influences the benzene‐adsorption performance significantly. The tubes show smaller binding energies to benzene molecule than the film counterparts, consistent with the observation of low adsorption capacities of tubular materials in our experiments. Enlarging the linker or adding substituents in the node can both reduce the tube's band gap. The introduction of OH or NH2 substituents in the tube node increases the binding strength between the adsorbent and the adsorbate, which is energetically favorable to enhance the adsorption capacity. Our results are expected to provide theoretical insights into the rational design of novel CMP nanotubes with improved adsorption capacities for organics.
Network coding for system‐level throughput improvement in satellite systems
Authors: Alegre‐Godoy R. , Vázquez‐Castro M. Ángeles 
Published: September 2017

SummaryIn this paper, we introduce 2 designs based on network coding (NC) for system‐level throughput improvement in satellite systems. The first design is applied to the forward downlink of multibeam satellite systems using an adaptive physical layer. In this type of systems, user terminals (UTs) receiving a satellite channel happen to also be able to receive physical links transmitted towards other UTs in other geographical areas. Hence, if UTs were able to tune other physical channels, they could access and decode all such signals. Assuming such multilink reception, the overall system would have an enormous increase of useful throughput, and moreover, multiple paths would become available to every UT. NC can then be naturally used to optimally mix the traffic towards the users through such multiple physical paths. The proposed full design targets multicast applications and achieves throughput improvements of up to the 88% with regard to state‐of‐the‐art schemes. The second design applies to systems where multiple sources transmitting to one or more satellites experience severe packet losses (eg, forward uplink through multiple gateways). Nowadays, system availability is achieved by transmitting the same packets in different spatial channels, ie, using spatial diversity. Using NC to encode the data across users, and introducing novel cognitive elements, the system outage probability can be reduced, thus increasing the throughput. The design is shown to achieve more than one order of magnitude system outage probability advantage for a sufficient number of UTs. Furthermore, a methodology determining the optimal number of transmitting UTs and code rate is derived.
Retracted: Pulmonary fibrosis of mice and its molecular mechanism following chronic inhaled exposure to TiO2 nanoparticles
Authors: Hong Fashui , Ji Li , Zhou Yingjun , Wang Ling 
Published: September 2017

AbstractNanoparticulate titanium dioxide (nano–TiO2) has been widely used in industry, medicine and daily life. However, assessment of nano–TiO2 toxicity on health is an important occupational safety issue. Numerous studies have demonstrated that nano‐TiO2 can induced sustained pulmonary inflammation, but whether chronic exposure to nano–TiO2 results in pulmonary fibrosis is unclear. In this study, therefore, nano–TiO2 was administered to the male mice by nasal administration for six consecutive months, the inflammatory and/or fibrogenic responses induced by nano–TiO2 were investigated. The results showed that chronic inhaled nano–TiO2 induced pulmonary inflammation and firosis, increased expression of inflammatory cytokines and fibrotic cytokines including nuclear factor‐κB, interleukin‐1β, tumor necrosis factor–α, monocyte chemotactic protein 1, macrophage inflammatory protein–2, intercellular adhesion molecule 1, vascular cell adhesion molecule 1, transform growth factor –β1, osteopontin, matrix metalloproteinase–1, −2, −3, and −9, tissue inhibitors of metalloproteinase‐1, collagen, platelet derived growth factor, and connective tissue growth factor in mouse lung. Taken together, nano‐TiO2‐induced pulmonary inflammation and fibrosis are closely associated with increased expression of inflammatory and/or fibrotic cytokines, an imbalanced production of MMPs and TIMP–1 that favors fibrosis in mice, implying that nano–TiO2 may lead to potential health effects.