bluuebunny/crossref_metadata_2025 huggingface dataset:
The influence of iatrogenic interatrial septum leaks after left atrial appendage closure on cardiac function test results
Authors: Mitrega Katarzyna , Streb Witold , Szymala Magdalena , Podolecki Tomasz , Leopold‐Jadczyk Anna , Morawski Stanislaw , Kalarus Zbigniew
Published: June 2018

Aim

Left atrial appendage occlusion (LAAO) is a technique for preventing thromboembolism in patients with atrial fibrillation and a high risk of irreversible bleeding. In some patients, a spontaneous iatrogenic transseptal leak (ITL) remains after LAAO. The aim of this study was to assess the correlation between ITL incidence and the results of cardiac function tests in patients who underwent LAAO.

Methods and Results

LAOO was performed in 62 consecutive patients using the Amplatzer Amulet. Before and 3 months after LAA occlusion, the 6‐min walking distance (6MWD) test was performed in all patients and oxygen consumption assessment (VO2max) was performed in 32. All patients had transesophageal echocardiography before and 3 months after LAAO to assess ITL incidence. The patients were divided according to the presence and absence of ITL and the subgroup of patients with heart failure (HF) were further analyzed. In patients with HF and ITL, an increased VO2max (12.8 ± 5.2 vs 15.3 ± 4.7; P < 0.05) and 6MWD (350.1 ± 77.4 vs 414.3 ± 70.6; P < 0.05) was observed after the procedure comparing to the results before the procedure. The 6MWD was also significantly higher in the patients with transseptal leaks in comparison to those without (P < 0.0001).

Conclusion

The presence of transseptal leaks after LAAO does not influence overall cardiac function test results. However, in patients with HF, there is an increase in oxygen consumption and 6MWD. These results indicate that ITLs in patients with HF decrease left atrial pressure, which is the key contributor to the symptoms of heart failure during physical activity.
Periodic limb movements during sleep are associated with cardiovascular diseases: A systematic review and meta‐analysis
Authors: Huang Tien‐Chi , Tseng Ping‐Tao , Wu Meng‐Ni , Stubbs Brendon , Carvalho André F. , Lin Pao‐Yen , Chen Yen‐Wen , Chen Tien‐Yu , Hsu Chung‐Yao
Published: June 2018

Periodic limb movements during sleep present with repetitive movements, typically in the lower limbs, during sleep. Periodic limb movements during sleep have been proposed to be associated with increased risk of heart diseases. The aim of this study was to examine the co‐morbidity rates of heart disease, including acute myocardial infarction, coronary artery disease and cardiovascular disease, in subjects with or without periodic limb movements during sleep through a meta‐analysis. An electronic review of PubMed, Embase, ScienceDirect, Cochrane Library, ProQuest, Web of Science, ClinicalKey and ClinicalTrials.gov was performed. Clinical studies, case‐controlled trials and cohort studies were all included in the search. Case reports or series, and non‐clinical studies were excluded. A meta‐analysis of the results of six studies comparing the prevalence of coronary artery disease/acute myocardial infarction/cardiovascular disease in subjects with/without periodic limb movements during sleep was performed. There were significantly higher co‐morbidity rates of coronary artery disease (odds ratio = 1.568, 95% confidence interval: 1.187–2.073, p = 0.002) and cardiovascular disease (odds ratio = 1.279, 95% confidence interval: 1.095–1.494, p = 0.002), but not acute myocardial infarction (odds ratio = 1.272, 95% confidence interval = 0.942–1.718, p = 0.117), in the periodic limb movements during sleep group than in the non‐periodic limb movements during sleep group. This meta‐analysis highlights the importance of a significantly high prevalence of coronary artery disease and cardiovascular disease in subjects with periodic limb movements during sleep. Further studies should be focused on the potential pathophysiology, and whether treatment for periodic limb movements during sleep can improve the outcome of heart disease.
Dantu's mineralogical properties – A view into the composition of Ceres' crust
Authors: Stephan K. , Jaumann R. , Wagner R. , De Sanctis M. C. , Palomba E. , Longobardo A. , Williams D. A. , Krohn K. , Tosi F. , McFadden L. A. , Carrozzo F. G. , Zambon F. , Ammannito E. , Combe J.‐P. , Matz K.‐D. , Schulzeck F. , von der Gathen I. , Roatsch T. , Raymond C. A. , Russell C. T.
Published: June 2018

Impact crater Dantu not only exhibits a very complex geological history but also shows an exceptional heterogeneity of its surface composition. Because of its location within a low‐lying region named Vendimia Planitia, which has been proposed to represent an ancient impact basin, Dantu possibly offers a window into the composition of Ceres’s deeper crust, which apparently is enriched in ammonia. Local concentration of carbonates within Dantu or its ejecta blanket may be either exposed or their emplacement induced by the Dantu impact event. Because carbonates can be seen along Dantu's crater walls, exposed due to recent slumping, but also as fresh spots or clusters of spots scattered across the surface, the deposition/formation of carbonates took place over a long time period. The association of several bright spots enriched in carbonates with sets of fractures on Dantu's floor might be accidental. Nevertheless, its morphological and compositional similarity to the faculae in Ceres’s prominent impact crater Occator including its hydrated state does not exclude a cryo‐volcanic origin, i.e., upwelling of carbonate‐enriched brines influenced by H2O ice in the subsurface. Indeed, an isolated H2O ice spot can be identified near Dantu, which shows that ice still exists in Ceres’s subsurface at midlatitudes and that it can exist on the surface for a longer period of time.
The efficiency of light‐emitting diode suction traps for the collection of South African livestock‐associated Culicoides species
Authors: Venter G. J. , Boikanyo S. N. B. , De Beer C. J.
Published: June 2018

Culicoides biting midges (Diptera: Ceratopogonidae) are vectors of a range of orbiviruses that cause important veterinary diseases such as bluetongue and African horse sickness. The effective monitoring of Culicoides species diversity and abundance, both at livestock and near potential wildlife hosts, is essential for risk management. The Onderstepoort 220‐V ultraviolet (UV) light trap is extensively used for this purpose. Reducing its power requirements by fitting low‐energy light‐emitting diodes (LEDs) can lead to greater flexibility in monitoring. A comparison of the efficiency of the 220‐V Onderstepoort trap (8‐W fluorescent UV light) with the efficiency of the 220‐V or 12‐V Onderstepoort traps fitted with red, white, blue or green LEDs or a 12‐V fluorescent Onderstepoort trap demonstrated the 220‐V Onderstepoort trap to be the most efficient. All the results showed nulliparous Culicoides imicola Kieffer females to be the dominant grouping. Despite the lower numbers collected, 12‐V traps can be used in field situations to determine the most abundant species.
Role of pannexin 1 channels in load‐induced skeletal response
Authors: Seref‐Ferlengez Zeynep , Urban‐Maldonado Marcia , Sun Hui B. , Schaffler Mitchell B. , Suadicani Sylvia O. , Thi Mia M.
Published: June 2018

The pannexin 1 (Panx1) channel is a mechanosensitive channel that interacts with P2X7 receptors (P2X7R) to form a functional complex that has been shown in vitro to play an essential role in osteocyte mechanosignaling. While the participation of P2X7R in skeletal responses to mechanical loading has been demonstrated, the role of Panx1 and its interplay with P2X7R still remain to be determined. In this study, we use a global Panx1−/− mouse model and in vivo mechanical loading to demonstrate that Panx1 channels play an essential role in load‐induced skeletal responses. We found that absence of Panx1 not only disrupts the P2X7R–Panx1 signaling complex, but also alters load‐induced regulation of P2X7R expression. Moreover, lack of Panx1 completely abolished load‐induced periosteal bone formation. Load‐induced regulation of β‐catenin and sclerostin expression was dysregulated in Panx1−/−, compared to wild‐type, bone. This finding suggests that Panx1 deficiency disrupts Wnt/β‐catenin signaling by lowering β‐catenin while favoring inhibition of bone formation by increasing load‐induced sclerostin expression. This study demonstrates the existence of a Panx1‐dependent mechanosensitive mechanism that not only modulates ATP signaling but also coordinates Wnt/β‐catenin signaling that is essential for proper skeletal response to mechanical loading.
Coexistence of atrioventricular accessory pathways and drug‐induced type 1 Brugada pattern
Authors: Hasdemir Can , Juang Jimmy Jyh‐Ming , Kose Sedat , Kocabas Umut , Orman Mehmet N. , Payzin Serdar , Sahin Hatice , Celen Candan , Ozcan Emin E. , Chen Ching‐Yu Julius , Gunduz Ramazan , Turan Oguzhan E. , Senol Oktay , Burashnikov Elena , Antzelevitch Charles
Published: June 2018

Background

Atrial arrhythmias, particularly atrioventricular nodal reentrant tachycardia, can coexist with drug‐induced type 1 Brugada electrocardiogram (ECG) pattern (DI‐Type1‐BrP). The present study was designed to determine the prevalence of DI‐Type1‐BrP in patients with atrioventricular accessory pathways (AV‐APs) and to investigate the clinical, electrocardiographic, electrophysiologic, and genetic characteristics of these patients.

Methods

One‐hundred twenty‐four consecutive cases of AV‐APs and 84 controls underwent an ajmaline challenge test to unmask DI‐Type1‐BrP. Genetic screening and analysis was performed in 55 of the cases (19 with and 36 without DI‐Type1‐BrP).

Results

Patients with AV‐APs were significantly more likely than controls to have a Type1‐BrP unmasked (16.1 vs 4.8%, P = 0.012). At baseline, patients with DI‐Type1‐BrP had higher prevalence of chest pain, QR/rSr’ pattern in V1 and QRS notching/slurring in V2 and aVL during preexcitation, rSr’ pattern in V1‐V2, and QRS notching/slurring in aVL during orthodromic atrioventricular reentrant tachycardia (AVRT) compared to patients without DI‐Type1‐BrP. Abnormal QRS configuration (QRS notching/slurring and/or fragmentation) in V2 during preexcitation was present in all patients with DI‐Type1 BrP. The prevalence of spontaneous preexcited atrial fibrillation (AF) and history of AF were similar (15% vs 18.3%, P = 0.726) in patients with and without DI‐Type1‐BrP, respectively. The prevalence of mutations in Brugada‐susceptibility genes was higher (36.8% vs 8.3%, P = 0.02) in patients with DI‐Type1‐BrP compared to patients without DI‐Type1‐BrP.

Conclusions

DI‐Type1‐BrP is relatively common in patients with AV‐APs. We identify 12‐lead ECG characteristics during preexcitation and orthodromic AVRT that point to an underlying type1‐BrP, portending an increased probability for development of malignant arrhythmias.
Cryoablation of the right anteroseptal or midseptal accessory pathways in children: A 2‐year single‐center experience
Authors: Jiang He , Li Xiaomei
Published: June 2018

Background

Radiofrequency catheter ablation (RFCA) in the septum close to the atrioventricular node or His bundle has an increased risk of irreversible complications. Cryothermal energy has the advantages of reversible cryomapping and increased catheter stability. The study aims to evaluate the efficacy and safety of cryoablation of the right anteroseptal or midseptal accessory pathways (APs) in pediatric patients.

Method

A retrospective review was performed with 26 pediatric patients (16 males and 10 females; median age 6.0 years and average body weight 24.9 kg) with paroxysmal supraventricular tachycardia (PSVT) in our Pediatric Heart Center from 2014 to 2016. Half of them had manifest APs. All the children underwent cryoablation for the treatment of PSVT because of the right anteroseptal or midseptal APs (16 cases had right anteroseptal APs and 10 cases had right midseptal APs).

Results

Acute cryoablation success was achieved in 23 cases (88%, 23/26). Atrioventricular block (AVB) occurred in eight cases (31%, 8/26) during the procedures and normal atrioventricular conduction recovered in seven cases except a case with I°AVB. During follow‐up, three cases recurred (13%, 3/23) and no permanent high degree AVB was found.

Conclusion

Cryoablation of the right anteroseptal or midseptal APs in pediatric patients is both safe and effective.
Journeys through discrete‐character morphospace: synthesizing phylogeny, tempo, and disparity
Authors: Lloyd Graeme T.
Published: June 2018

Palaeontologists have long employed discrete categorical data to capture morphological variation in fossil species, using the resulting character–taxon matrices to measure evolutionary tempo, infer phylogenies and capture morphological disparity. However, to date these have been seen as separate approaches despite a common goal of understanding morphological evolution over deep time. Here I argue that there are clear advantages to considering these three lines of enquiry in a single space: the phylomorphospace. Conceptually these high‐dimensional spaces capture how a phylogenetic tree explores morphospace and allow us to consider important process questions around evolutionary rates, constraints, convergence and directional trends. Currently the literature contains fundamentally different approaches used to generate such spaces, with no direct comparison between them, despite the differing evolutionary histories they imply. Here I directly compare five different phylomorphospace approaches, three with direct literature equivalents and two that are novel. I use a single empirical case study of coelurosaurian theropod dinosaurs (152 taxa, 853 characters) to show that under many analyses the literature‐derived approaches tend to reflect introduced phylogenetic (rather than the intended morphological) signal. The two novel approaches, which produce limited ancestral state estimates prior to ordination, are able to minimize this phylogenetic signal and thus exhibit more realistic amounts of phylogenetic signal, rate heterogeneity, and convergent evolution.
Widening the genetic base of cultivated gene pool following introgression from wild Lens taxa
Authors: Singh Mohar , Sharma Shyam K. , Singh Badal , Malhotra Nikhil , Chandora Rahul , Sarker Ashutosh , Singh Kuldeep , Gupta Dorin
Published: June 2018

Wild Lens taxa are a reservoir of useful rare genes/alleles for widening the genetic base and synthesis of a new gene pool of lentil. To maximize and sustain lentil production, new gene sources are needed to be identified and incorporated into cultivated background. This needs a comprehensive approach to accumulate favourable alleles from distantly related germplasm for widening of the cultivated gene pool and would be the most appropriate strategy to solve the various problems associated with stressed crop production and plateaued yields. Furthermore, expansion of deeper understanding of lentil genomics along with extensive research undertaken in other crop species can provide suitable guidelines to cover the distribution of Lens genus and component gene pools for further remarkable progress in lentil genetic improvement. This review aims at the genus Lens distribution and gene pools, crop germplasm conserved in ex‐situ and in‐situ collection, wild species characterization and evaluation for useful traits of interest to solve production‐related problems, highlight useful gene sources present in different gene pools and the progress achieved for widening the genetic base of cultivated varieties of lentil through wide hybridization and exploring lentil genomics.
The relationship between naevus count, memory function and telomere length in the Twins UK cohort
Authors: Masi Stefano , Georgiopoulos Georgios , Ribero Simone , Taddei Stefano , Bataille Veronique , Steves Claire J.
Published: June 2018

The presence of a skin–brain connection whereby alterations in the skin can inform on mechanisms underlying neurodegenerative diseases is increasingly recognized. In this study, we used a discovery (n = 321) and replication (n = 147) sample from the Twins UK population to test the association between naevus count and memory function, and its mediation by telomeres. Memory function was assessed in 1999 and 2009 using the paired associates learning test (PAL), while naevus count and leucocyte telomere length (LTL, assessed by the terminal restriction fragment assay) were measured once. Higher baseline naevus count was significantly associated with fewer errors at the baseline and follow‐up PAL, as well as with change in PAL score over 10 years. This association was significantly attenuated after adjustment for LTL. The significant association between naevus count and PAL score was reproduced in the replication sample. These findings suggest that melanocytes might be used as model system to study the biological ageing pathways involved in neurodegeneration.
The intrinsic probability of theism
Authors: Miller Calum
Published: June 2018

In this paper, I explore one of the most important but least discussed components of an evidentialist case for or against theism: its intrinsic plausibility and simplicity as a theory aside from the evidence. This is a crucial consideration in any inductive framework, whether Inference to the Best Explanation, probabilism, or another. In the context of Bayesian reasoning, this corresponds to an assessment of theism's intrinsic probability. I offer a survey of how philosophers of science have attempted to evaluate the intrinsic plausibility and simplicity of scientific theories more generally, before applying these considerations to the question of God's existence.
The potato transcription factor StbZIP61 regulates dynamic biosynthesis of salicylic acid in defense against Phytophthora infestans infection
Authors: Zhou Xin‐Tong , Jia Li‐Jia , Wang Hai‐Yun , Zhao Pan , Wang Wen‐Yan , Liu Ning , Song Shuang‐Wei , Wu Yao , Su Lei , Zhang Jie , Zhong Nai‐Qin , Xia Gui‐Xian
Published: June 2018

Salicylic acid (SA) signalling plays an essential role in plant innate immunity. In this study, we identified a component in the SA signaling pathway in potato (Solanum tuberosum), the transcription factor StbZIP61, and characterized its function in defence against Phytophthora infestans. Expression of StbZIP61 was induced upon P. infestans infection and following exposure to the defense signaling hormones SA, ethylene and jasmonic acid. Overexpression of StbZIP61 increased the tolerance of potato plants to P. infestans while RNA interference (RNAi) increased susceptibility. Yeast two‐hybrid and pull down experiments revealed that StbZIP61 could interact with an NPR3‐like protein (StNPR3L) that inhibited its DNA‐binding and transcriptional activation activities. Moreover, StNPR3L interacted with StbZIP61 in an SA‐dependent manner. Among candidate genes involved in SA‐regulated defense responses, StbZIP61 had a significant impact on expression of StICS1, which encodes a key enzyme for SA biosynthesis. StICS1 transcription was induced upon P. infestans infection and this responsive expression to the pathogen was reduced in StbZIP61 RNAi plants. Accordingly, StICS1 expression was remarkably enhanced in StbZIP61‐overexpressing plants. Together, our data demonstrate that StbZIP61 functions in concert with StNPR3L to regulate the temporal activation of SA biosynthesis, which contributes to SA‐mediated immunity against P. infestans infection in potato.
Amazonian struggles for recognition
Authors: Fraser James Angus
Published: June 2018

Since the 1988 Constitution, forest peoples of Brazilian Amazonia have been struggling for territorial recognition. Yet studies of recognition in post colonial contexts, based on cases with clear settler/indigenous distinctions, are highly critical of recognition, seeing it as a form of “neoliberal multiculturalism,” a co‐option of subaltern identities with limited emancipatory potential. I question these critiques by examining struggles for legal and intersubjective recognition of subaltern identity categories “Índio” and “Agroextractivista” and corresponding territories of the “Terra Indigena” and “Reserva Extractivista” on the Madeira and Tapajós Rivers in Brazilian Amazonia, where heterogeneous origins of forest peoples belie simple settler/indigenous distinctions. I engage a key question, the relationships of subaltern peoples with state institutions, and highlight a finding, the relevance of the state's “proximity,” often underestimated in the literature. I build a theory of decolonial recognition combining Axel Honneth's idea of recognition as love, rights and solidarity with David Scott's late‐Foucauldian reworking of Frantz Fanon. Herein, the Fanonian colonised subjectivity is shaped by the negation of love, rights and solidarity, that is to say, misrecognition. The subject requires legal and intersubjective recognition in order to positively incorporate love, rights and solidarity into their “practices of techniques of the self.” On the Tapajós, territorial struggles are more successful owing to a stronger sphere of legal recognition – the presence of state institutions – and a history of Church and union grassroots organisation, both supporting greater intersubjective recognition among forest peoples. On the Madeira, a much weaker sphere of legal recognition has resulted in a situation of intractable conflict around territorial struggles which have correspondingly less intersubjective recognition. I conclude that a theory of decolonial recognition is of considerable utility in elucidating the dynamics of subaltern emancipatory struggles for territory.
Reviewer Acknowledgements
Authors: Smith Robert
Published: June 2018

Journal of Education and Training Studies (JETS) would like to acknowledge the following reviewers for their assistance with peer review of manuscripts for this issue. Many authors, regardless of whether JETS publishes their work, appreciate the helpful feedback provided by the reviewers. Their comments and suggestions were of great help to the authors in improving the quality of their papers. Each of the reviewers listed below returned at least one review for this issue.Reviewers for Volume 6, Number 7 Alperen Yandı, Abant İzzet Baysal University, TurkeyFatma Ozudogru, Usak University, TurkeyHatice Öztürk, Artvin Çoruh University, Turkeyİbrahim Yaşar Kazu, Firat University, TurkeyJohn Cowan, Edinburgh Napier University, UKJon S. Turner, Missouri State University, USALaima Kyburiene, Kaunas University of Applied Sciences, LithuaniaMan-fung Lo, The Hong Kong Polytechnic University, Hong KongMaria Pavlis Korres, Hellenic Open University, GreeceMaurizio Sajeva, Pellervo Economic Research PTT, FinlandMin Gui, Wuhan University, ChinaNuran Bayram, Uludag Universtiy, TurkeyOzgur Demirtas, Inonu University, TurkeyRichard H. Martin, Mercer University, USASayim Aktay, Mugla Sitki Kocman University, TurkeySenem Seda Şahenk Erkan, Marmara University, TurkeySeyfullah Tingir, Florida State University, USASirin Akbulut Demirci, Uludag University, TurkeyYalçın Dilekli, Aksaray University, Turkey      Robert SmithEditorial AssistantOn behalf of,The Editorial Board of Journal of Education and Training StudiesRedfame Publishing9450 SW Gemini Dr. #99416Beaverton, OR 97008, USAURL: http://jets.redfame.com
Influence of Vortex-Induced Loads on the Motion of SPAR-Type Wind Turbine: A Coupled Aero-Hydro-Vortex-Mooring Investigation
Authors: Li Yan , Liu Liqin , Zhu Qiang , Guo Ying , Hu Zhiqiang , Tang Yougang
Published: June 2018

The nonlinear coupling effect between degree-of-freedom (DOFs) and the influence of vortex-induced loads on the motion of SPAR-type floating offshore wind turbine (FOWT) are studied based on an aero-hydro-vortex-mooring coupled model. Both the first- and second-order wave loads are calculated based on the three-dimensional (3D) potential theory. The aerodynamic loads on the rotor are acquired with the blade element momentum (BEM) theory. The vortex-induced loads are simulated with computational fluid dynamics (CFD) approach. The mooring forces are solved by the catenary theory and the nonlinear stiffness provided by the SPAR buoy is also considered. The coupled model is set up and a numerical code is developed for calculating the dynamic response of a Hywind SPAR-type FOWT under the combined sea states of wind, wave, and current. It shows that the amplitudes of sway and roll are dominated by lift loads induced by vortex shedding, and the oscillations in roll reach the same level of pitch in some scenarios. The mean value of surge is changed under the drag loads, but the mean position in pitch, as well as the oscillations in surge and pitch, is little affected by the current. Due to the coupling effects, the heave motion is also influenced by vortex-induced forces. When vortex-shedding frequency is close to the natural frequency in roll, the motions are increased. Due to nonlinear stiffness, super-harmonic response occurs in heave, which may lead to internal resonance.
Tissue Oxygen Transfer During Reperfusion and Post-Conditioning
Authors: La Barck Anthony J. , Akers Jennifer E. , Merrill Thomas L.
Published: June 2018

Heart disease is the leading cause of death in the United States. Ischemic heart disease occurs when coronary blood flow to the heart is reduced, limiting the amount of oxygen and nutrients the heart receives. When blood flow is restored after a percutaneous transluminal coronary intervention (PCI), rapid reperfusion from sudden balloon deflation can cause further injury to oxygen-starved tissue, leading to increased cell injury and cell death. Studies in animal models with ischemic heart disease have shown that reperfusion injury may account for up to 50% of the final infarct size [1]. Post-conditioning (PC) may reduce the amount of reperfusion injury by applying intermittent periods of ischemia during the early moments of reperfusion. This procedure periodically occludes blood vessels during reperfusion by periodically inflating and deflating an angioplasty balloon according to a specific algorithm. Zhao et al. showed that PC reduced reperfusion injury in a canine model by applying 3 cycles of 30 seconds of reperfusion followed by 30 seconds of ischemia (re-occlusion) at the onset of reperfusion. PC in this study reduced tissue AN/AAR (area of necrosis/area at risk) by 48% [2]. In 2008, Gao et al. demonstrated that the effectiveness of PC in rats was dependent on the number of cycles in the PC algorithm, as well as the durations of the ischemia/reperfusion phases [3].
Treatment of Severe Aortic Stenosis: Development and Feasibility Testing of an Aortic Valve Bypass Apical Cannula
Authors: Graham Joel D. , Sharp M. Keith , Koenig Steven C. , Giridharan Guruprasad , Sobieski Michael A. , Slaughter Mark S.
Published: June 2018

Treatment of aortic stenosis through surgical replacement has been one of the most successful advances in cardiovascular medicine (1), though use in certain patient populations, specifically in the elderly, has been associated with increased mortality rates (2). A growing alternative surgery is Aortic Valve Bypass (AVB). This therapy offers decreased surgical risk because it does not require cardiopulmonary bypass, aortic crossclamping, aortotomy, or cardioplegic cardiac arrest (3). A one-way conduit between the apex of the left ventricle and the descending aorta increases flow by reducing afterload (Fig. 1, LEFT). Systolic blood from the left ventricle is ejected via both the native stenotic aortic valve and the AVB circuit. In this feasibility study, an apical cannula was developed and tested.
The Effect of Selective Breeding for Body Weight on Geometric Properties in Turkey Femurs
Authors: Muckley Matthew , Agcaoglu Serife , Zhong Ziwei , Zhao Hansi , Grisham Morgan , Karcher Darrin , Orth Michael , Lilburn Michael , Akkus Ozan
Published: June 2018

Crespo et al. (1999) was the first to identify the problem of turkey femoral fractures in breeding farms [3]. It was suggested that this type of failure was the result of fatigue under daily activities as opposed to acute trauma [1]. There are a number of factors that can lead to decreased bone integrity including ineffective bone mineralization, microcrack propagation and changes in collagen fibril orientation [1, 4, 5].
Incorporation of a Decorin Biomimetic Enhances the Mechanical Properties of Electrochemically Aligned Collagen Threads
Authors: Kishore Vipuil , Paderi John E. , Akkus Anna , Panitch Alyssa , Akkus Ozan
Published: June 2018

Damaged tendons often do not heal completely and lack full functionality. Tissue engineering employing collagen based biomaterials is a viable option to repair damaged tendons. However, most existing constructs lack the desired mechanical strength needed to reconstruct such load bearing tissues. We have previously reported a novel methodology to synthesize highly ordered electrochemically aligned collagen (ELAC) threads that are mechanically stronger and more amenable to cell migration compared to randomly oriented collagen constructs. While the ELAC mimics the orientational anisotropy of tendon it can be further improved by the incorporation of small leucine rich proteoglycans like decorin. Decorin consists of a protein core that binds to collagen and a glycosaminoglycan (GAG) chain. The GAG chains of adjacent collagen fibrils associate with one another to form crosslinks and are suggested to enhance the mechanical properties of tendon by allowing fibrillar slippage. Based on the structure of natural decorin, we have previously synthesized a novel peptidoglycan (DS-SILY) containing a collagen binding peptide (SILY) and a dermatan sulfate (DS) GAG chain. DS-SILY mimics decorin both structurally and functionally. In this study, we investigated the effects of the incorporation of DS-SILY on the mechanical properties and structural organization of ELAC threads by monotonic mechanical testing, swelling ratio and differential scanning calorimetry.
Cell-Matrix Interactions Modulate Mesenchymal Stem Cell Response to Dynamic Compression
Authors: Thorpe Stephen D. , Buckley Conor T. , Steward Andrew J. , Kelly Daniel J.
Published: June 2018

Unconfined cyclic compressive loading has been shown to promote the chondrogenic differentiation of agarose encapsulated mesenchymal stem cells (MSCs) in the absence of chondrogenic growth factors [1, 2]. However, in general robust chondrogenesis has not been reported as a result of mechanical stimulation alone; with biochemical stimulation through TGF-β supplementation yielding a more potent pro-chondrogenic effect [2, 3].
Size Based Particle Separation Method by Zero Diffusivity
Authors: Han Chungmin , Park Jaesung
Published: June 2018

Separation is one of the most basic and frequently using techniques for biological research. Researchers have been using gel-electrophoresis for DNA separation and also using various chromatography techniques for protein and bio-molecule separations. Recently, as micro and nano fabrication techniques have developed, interest in miniaturized micro scale biology research tools has also increased. According to this trend, micro scale devices for separating various sized of particles such as cells, organelles, proteins, lipids and vesicles play an important role in a total system. Therefore, separation devices based on various methods are suggested. Widely used separation methods for micro devices are electro-kinetics with special channel geometries and laminar flow control. In electro-kinetic methods, micro channel electrophoresis and DEP (dielectrophoresis) are commonly used.[1] These separation methods, however, can only be used in very narrow range because their working conditions, high voltage and charge dependence, are not compatible with many biomaterials.
Directional Solidification Stage With Dynamically Variable Speeds: Assessment of Cell Viability After Interrupted Cooling
Authors: LaFountain Josh , Devireddy Ram V.
Published: June 2018

A two-step directional freezing method was utilized to assess the membrane integrity in frozen/thawed adult stem cells (ASCs). Using a custom built directional solidification stage (DSS) we determined that cells cooled at two different rates (i.e., a slower rate between room temperature, 27 °C and −10 °C and a higher rate between −10 °C and −60 °C) experienced significantly higher loss of cell viability when compared with those cooled at a single and uniform slower cooling rate between 27 °C and −60 °C. Specifically, the cells cooled using the two-step freezing method exhibited a post-thaw cell viability of ∼17% while those that were cooled using the traditional method exhibited a cell viability of 49%. We also found that varying the cooling rate between 27 °C and −10 °C did not significantly affect the post-thaw viability of ASCs, suggesting that they are not susceptible to supra-zero cooling injury.
Prediction of Metatarsal Stress Fracture Location: Parametric Analysis of the Foot Using FEA
Authors: Chen Raymond G. , Edelhauser Adam , Gatt Charles J. , Langrana Noshir A.
Published: June 2018

Metatarsal stress fractures occur in 1.0–2.6% of all NCAA athletes and 1.0–1.7% of all soldiers in the military (1). The metatarsal bones are susceptible to stress fractures due to repeated musculoskeletal loading from running, jumping and sudden movements during sports activity and extreme training conditions for military personnel. The loads create bending stresses on the metatarsals at sub-ultimate strength values that create microcracks on the bones, which may propagate into stress fractures (2) if proper precautions are not taken.
Wrapping of the Medial Ulnar Collateral Ligament
Authors: Motlagh Amin M. , Miller Mark Carl
Published: June 2018

The multi-bundle structure of the medial ulnar collateral ligament (mUCL) has been documented [1] and it is known that the anterior bundle of the mUCL is the primary restraint to valgus stress of the elbow [2–5]. It has also been documented that the anterior band of this bundle becomes taut in extension whereas the posterior band becomes taut in flexion [1]. The mUCL is frequently injured in the throwing athlete due to over use or extreme valgus load. In order to reconstruct the ligament, surgical repair may be required. It has been experimentally observed in our lab and in other labs that the UCL wraps around the medial epicondyle. One of the parameters to ensure achievement of a successful surgical reconstruction may be the re-establishment of the natural wrapping behavior of UCL around the epicondyle. Previous studies [6] also suggest that soft-tissue wrapping constraints have substantial impact on joint stability. This study begins to characterize the wrapping of the two bands in the anterior bundle of UCL in terms of the location along the ligament’s length and flexion angle to establish native behavior.
Geometric Measurement of Wear in Tibial Inserts Through an Autonomous Reconstruction of the Original Surface
Authors: Knowlton Christopher B. , Hanson George , Orozco Diego , Laurent Michel P. , Wimmer Markus A.
Published: June 2018

Wear of the polyethylene tibial components in total knee replacements remains a limiting factor of implant life. Studies have used coordinate measuring machines (CMM) to estimate volumetric wear in retrieved components. This technique requires knowledge of the original pre-worn surfaces. Pre-worn surfaces have been successfully approximated in literature by nominal computer-aided design (CAD) models or, more commonly, size-matched unused inserts [1,2]. However, models and drawings of implants are proprietary, and many design parameters can have large tolerances. Unworn components are costly, often unattainable for obsolete implants and subject to deviation between batches.
Beneficial Effects of Chondroitinase ABC Release From Lipid Microtubes Encapsulated in Chondrocyte-Seeded Hydrogel Constructs
Authors: O’Connell Grace D. , Gollnick Clare , Ateshian Gerard A. , Bellamkonda Ravi V. , Hung Clark T.
Published: June 2018

Tissue-engineered cartilage using a hydrogel scaffold is capable of achieving native compressive properties and glycosaminglycan (GAG) content [1]; however, promoting collagen growth towards native values has been challenging. As the cells in the cartilage constructs deposit matrix over time in culture, transport of nutrients to the construct center becomes increasingly hindered [2]. Digestion of mature tissue engineered constructs with chondroitinase (chABC) temporarily suppresses the GAG content, allowing an increase in the collagen content and eventually improving the mechanical properties after GAG content recovers [1]. However, adding chABC into the feeding media limits its effectiveness to the construct’s periphery, reflecting enzyme diffusion gradients. Additionally, long-term use of chABC, without re-application, is limited since its enzymatic activity degrades within 5 days at 37°C [3]. Lee and co-workers have developed a method for delivering thermostabilized chABC using sugar trehalose and hydrogel-microtubes for applications desiring extended enzyme release [4]. Lipid microtubes loaded with thermostabilized chABC may be incorporated into an agarose hydrogel scaffold to provide long-term release of the enzyme uniformly throughout the construct [3]. The objective of this study was to test the hypothesis that chABC-filled microtubes will enhance in vitro development of engineered cartilage.
Transient Exposure to TGF-β3 Improves the Functional Properties of MSC-Seeded Photocrosslinked Hyaluronic Acid Hydrogels
Authors: Kim Minwook , Erickson Isaac E. , Burdick Jason A. , Mauck Robert L.
Published: June 2018

Articular cartilage is the primary compressive load bearing soft tissue in diarthrodial joints. While the tissue can function remarkably well in a demanding environment over a lifetime of use, focal defects and other trauma can initiate progressive degeneration. Cartilage tissue engineering approaches have been developed with the goal of forming biologic replacement materials with functional mechanical properties [1]. While chondrocytes are a popular cell source for such approaches, and can produce constructs with near-native functional properties [2], mesenchymal stem cells (MSCs) derived from bone marrow have emerged as an attractive alternative cell type. MSCs are multi-potent and easy to expand, and so are available in a nearly unlimited supply, and in an autologous fashion. While MSCs can undergo functional chondrogenesis in a variety of 3D contexts [3], we are particularly interested in the translational capacity of hyaluronic acid (HA). Hydrogels formed from this natural constituent of the cartilage extracellular matrix provide a biologically relevant interface for encapsulated cells and gel properties are readily tunable [4, 5]. Indeed, using a methacrylated (and so photo-crosslinkable) HA macromer, we have optimized gel formation and functional matrix production by MSCs with variations in both macromer (1%, [5]) and MSC (∼60 million cells/mL, [6]) concentration, consistently producing cartilage-like constructs with near native compressive properties. Additionally, we have reported that transient exposure of TGF-β3 (for three weeks) to MSCs in agarose constructs at a high-density induced a stable chondrogenic phenotype, with functional properties at six weeks greater than continual exposure to this pro-chondrogenic factor [7]. Transient exposure presents an interesting paradigm with clinical relevance, in vivo defect filling will require robust maturation of the engineered tissue driven by TGF-β3 delivered from the material itself in a controlled and sustained fashion. The purpose of this study was to determine the minimal TGF-β3 dosage and duration of exposure required to promote the most robust chondrogenesis and functional maturation of MSCs in this HA hydrogel system.
High-Speed Imaging of Intra-Embryonic Phase Transformation Events During Rapid Freezing of Zebrafish Embryos
Authors: Bommer Kathleen M. , DiBenedetto Angela , Karlsson Jens O. M.
Published: June 2018

The zebrafish (Danio rerio) represents an increasingly popular vertebrate animal model valuable for genetic and developmental biology research, due to its rapid rate of reproduction and the ability to directly observe the growing embryos, which are optically clear and develop ex vivo. However, the need to maintain live stock of each genetic strain (the number of which is growing exponentially) is risky and prohibitively costly. Although long-term banking of frozen embryos would solve this problem, to date, no adequate method for cryopreservation of zebrafish embryos has been found (Hagedorn et al., 2004).
Near Side Lateral Impacts and Aortic Injury: A Parametric Study
Authors: Belwadi Aditya , Yang King H.
Published: June 2018

Traumatic rupture of the aorta (TRA) remains the second most common cause of death associated with motor vehicle crashes after brain injury. On an average, nearly 8,000 people die annually in the United States due to blunt injury to the aorta. It is observed that more than 80% of occupants who suffer an aortic injury die at the scene due to exsanguination into the chest cavity. TRA and blunt aortic injury (BAI) are leading causes of death in high-speed blunt impact trauma. More specific injuries that fall under these classifications include myocardial contusion (MC), traumatic aortic disruption (TAD), sternal fracture (SF), flail chest (FC) and tracheobronchial disruption (TBD) (Swan et al. 2001). Smith and Chang (1986) reported on 387 cases of blunt traumatic death in vehicular crashes and found that aortic injury was second only to head injury as the leading cause of death. Burkhart et al. (2001) reviewed 242 autopsy cases with fatal BAI and concluded that in most cases aortic injury was accompanied by head injury, rib fractures and/or hepatic trauma.
Plasma polymerization of styrene using an argon-fed atmospheric pressure plasma jet
Authors: Tan Paolo Edward C. , Mahinay Christian Lorenz S. , Culaba Ivan B. , Streeter Oliver Kevin M. , Hilario Miguel Ricardo A.
Published: June 2018

In this paper, the authors describe an alternative polymerization process of styrene monomer. Styrene, placed in a Plexiglas crucible to minimize splattering, was treated with an argon-atmospheric plasma jet, at a gas flow rate of 12.5 standard cubic feet per hour for 12 min, using a 450-W neon sign transformer power supply. Treated samples were transferred from the crucible to glass substrates and allowed to dry at room temperature. Solvent washing analysis showed an average product retention of 66.59% proving that polymerization occurred. Contact angle measurements of the treated samples showed an increase in hydrophobicity from 78.12° for untreated styrene to 88.14° for plasma-treated styrene. Fourier transform infrared analysis revealed the absence of the C=C, C=C-H and the presence of the C=O and C-O-C functional groups upon treatment. It was concluded that styrene was polymerized successfully through the use of an argon fed atmospheric pressure plasma jet, and that hydrophobic plasma-polymerized polystyrene coatings were successfully deposited onto glass substrates.
Hard TiN2 dinitride films prepared by magnetron sputtering
Authors: Musil Jindřich , Jaroš Martin , Kos Šimon , Čerstvý Radomír , Haviar Stanislav
Published: June 2018

This letter reports on the formation of hard TiN2 dinitride films prepared by magnetron sputtering. TiN2 films were reactively sputtered in an Ar + N2 gas mixture using a pulsed dual magnetron with a closed magnetic field B. The principle of the formation of TiN2 films by magnetron sputtering is briefly described. The stoichiometry x = N/Ti of the TiNx films was controlled by deposition parameters, and its maximum value of x = 2.3 was achieved. For the first time, a possibility to form the TiN2 dinitride films by magnetron sputtering has been demonstrated. The mechanical properties of sputtered films were investigated in detail.
Training Periodization Over an Elite Rugby Sevens Season: From Theory to Practice
Authors: Marrier Bruno , Le Meur Yann , Leduc Cédric , Piscione Julien , Lacome Mathieu , Igarza Germain , Hausswirth Christophe , Morin Jean-Benoît , Robineau Julien
Published: June 2018

Purpose: To describe the training periodization in rugby sevens players competing in the World Rugby Sevens Series during a non-Olympic season. Methods: Workload data were collected over a 33-wk period in 12 male players participating in a full competitive season. Workload was quantified using session rating of perceived exertion and global positioning system–derived data during training and competition. Self-reported well-being was assessed using a questionnaire. Each variable was analyzed weekly and through 5 mesocycles (preseason, in-season 1–4), each of which ended with competition blocks. Results: The perceived load decreased throughout the season for the full squad (−68% [26%] between preseason and final competitive block, large effect) and when unavailable players were removed from the analysis (−38% [42%], moderate). Weekly perceived load was highly variable, with a typical periodization in 4 phases during each mesocycle (regeneration, training overload, taper, and competition). During the preseason, the workload was higher during the overload training phase than during the competitive period (range: +23% to +59%, large to very large, for the distance covered above individual maximal aerobic speed and the number of accelerations). This observation no longer persisted during the season. The well-being score decreased almost certainly from in-season 3 (moderate). Conclusions: These results highlighted the apparent difficulty in maintaining high-load training periods throughout the season in players engaged on the World Rugby Sevens Series despite ∼4–7 training weeks separating each competitive block. This observation was likely explained by the difficulties inherent to the World Rugby Sevens Series (risk of contact injury, calendar, and multiple long-haul travel episodes) and potentially by limited squad-rotation policies.
Polarized Versus High-Intensity Multimodal Training in Recreational Runners
Authors: Carnes Andrew J. , Mahoney Sara E.
Published: June 2018

Purpose: This study longitudinally compared changes in running performance (5-km time trial) and fitness (maximal oxygen uptake [VO2max] and body composition [BC]) between polarized training and CrossFit Endurance (CFE) in recreational runners. Methods: Participants (N = 21) completed 12 wk of CFE or polarized endurance training (POL). Both groups trained 5 d·wk−1. POL ran 5 d·wk−1, whereas CFE ran 3 d·wk−1 and performed CrossFit 3 d·wk−1 (run + CrossFit 1 d·wk−1). Intensity was classified as low, moderate, or high (zone 1, 2, or 3) according to ventilatory thresholds. POL was prescribed greater volume (295 [67] min·wk−1), distributed as 85%/5%/10% in Z1/Z2/Z3. CFE emphasized a lower volume (110 [18] min·wk−1) distribution of 48%/8%/44%. Results: POL ran 283 (75.9) min·wk−1 and 47.3 (11.6) km·wk−1, both exceeding the 117 (32.2) min·wk−1 and 19.3 (7.17) km·wk−1 in CFE (P < .001). The POL distribution (74%/11%/15%) had greater total and percentage Z1 (P < .001) than CFE (46%/15%/39%), which featured higher percentage Z3 (P < .001). Time trial improved −93.8 (40.4) s (−6.21% [2.16%]) in POL (P < .001) and −84.2 (65.7) s (−5.49% [3.56%]) in CFE (P = .001). BC improved by −2.45% (2.59%) fat in POL (P = .02) and −2.62% (2.53%) in CFE (P = .04). The magnitude of improvement was not different between groups for time trial (P = .79) or BC (P = .88). Both groups increased VO2max (P ≤ .01), but with larger magnitude (P = .04, d = 0.85) in POL (4.3 [3.6] mL·kg·min−1) than CFE (1.78 [1.9] mL·kg·min−1). Conclusions: Recreational runners achieved similar improvement in 5-km performance and BC through polarized training or CFE, but POL yielded a greater increase in VO2max. Extrapolation to longer distances requires additional research.