bluuebunny/crossref_metadata_2025 huggingface dataset:
Knowledge transfer for sustainability
Authors: Alzubi Yazan
Published: June 2018

Purpose

Knowledge is a fundamental source for sustainability and transfer as it plays a vital role in gaining and maintaining competitive advantage; thus it is imperative to investigate the factors that might impact knowledge transfer (KT). Therefore, the purpose of this paper is to investigate the association between knowledge enablers (organizational culture (OC), information technology (IT) knowledge leadership (KL) and knowledge strategy (KS)) and KT in the Jordanian construction industry.

Design/methodology/approach

A quantitative research approach was adopted, and structured questionnaire was sent to the employees in the construction industry. An aggregate of 250 surveys were distributed and out of them 195 were obtained, which represented a response rate of 78 percent.

Findings

The results of this paper showed that KS, OC, IT and KL has positive and significant impact on KT.

Originality/value

The study contributes to the literature by empirically testing the antecedents of KT in the Jordanian construction industry. To the best of authors’ knowledge, there are not many studies that incorporate these factors in single model, especially in Jordan.
Identification of new diagnostic biomarkers for Mycobacterium tuberculosis and the potential application in the serodiagnosis of human tuberculosis
Authors: Ren Ningning , JinLi Jingfang , Chen Yingyu , Zhou Xia , Wang Jieru , Ge Pan , Khan Farhan Anwar , Zhang Li , Hu Changmin , Robertson Ian D. , Chen Huanchun , Guo Aizhen
Published: June 2018

Mycobacterium tuberculosis (M. tuberculosis) regions of difference (RD) encode proteins which are potentially useful as diagnostic reagents for tuberculosis (TB). In this study, 75 genes from M. tuberculosis RD1‐RD16 were successfully cloned from which 68 proteins were expressed and purified. Three serum pools from patients with pulmonary TB (PTB), extra‐pulmonary tuberculosis (EPTB) and healthy controls (HC) were used to preliminarily screen individual RD proteins. The OD630 ratio of the PTB or EPTB to the HC group ≥ 2‐fold was positive. As a result, 29 proteins were obtained. The serological response to the identified antigens was further verified using 58 PTB samples with 38 sera from smear‐positive PTB (PTB‐SP) patients and 20 sera from smear‐negative PTB (PTB‐SN) patients, 16 EPTB samples, 42 latent M. tuberculosis infection samples and 40 HCs by indirect ELISA. With respect to the PTB diagnosis, receiver operating characteristic analysis showed that Rv0222 [area under the curve (AUC), 0.8129; 95% confidence interval (CI), 0.7280–0.8979] and Rv3403c (AUC, 0.8537; 95% CI, 0.7779–0.9294) performed better than ESAT6/CFP10 (AUC, 0.7435; 95% CI, 0.6465–0.8406). Rv0222 and Rv3403c demonstrated the highest diagnostic ability in the PTB‐SP group (sensitivity, 86.8%; specificity, 80%), while Rv3403c demonstrated the highest diagnostic ability in the PTB‐SN group (sensitivity, 70%; specificity, 80%). With respect to the EPTB diagnosis, Rv0222 exhibited the highest diagnostic value (AUC, 0.7523; sensitivity, 68.8%; specificity, 87.5%). In addition, the combination of Rv0222 and Rv3403c improved the test for PTB‐SN. These results indicate that Rv0222 and Rv3403c would be potential diagnostic biomarkers for active TB serodiagnosis. Mouse experiments demonstrated that Rv0222 and Rv3403c elicited specific cellular and humoral responses which were characterized by production of IFN‐γ, IgG1, and IgG2a, but a higher level of IgG1 than IgG2a.
Changing board behaviour: The role of the ‘Two Strikes’ rule in improving the efficacy of Australian Say‐on‐Pay
Authors: Borthwick James , Jun Aelee , Ma Shiguang
Published: June 2018

This article analyses whether the transition from the 2004 CLERP 9 advisory Say‐on‐Pay regime to the ‘Two Strikes’ rule in 2012 influenced CEO pay in Australian firms. Analysing a panel of 2,074 firm‐years (2005–2015), we find that (i) CEO pay is a positive predictor of shareholder dissent; (ii) firm performance has a reducing effect on shareholder dissent; (iii) excessive shareholder dissent moderated CEO pay under the ‘Two Strikes’ rule relative to the CLERP 9 regime, and (iv) the market responded favourably to the introduction of the ‘Two Strikes’ rule and negatively to ‘strike’ instances after its introduction.
When Did the Swahili Become Maritime?: A Reply to Fleisher et al. (2015), and to the Resurgence of Maritime Myopia in the Archaeology of the East African Coast
Authors: Kusimba Chapurukha M. , Walz Jonathan R.
Published: June 2018

In this article, we respond to an article by Jeffrey Fleisher et al. (2015) in which they pose the question: When did the Swahili become maritime? We draw from our research findings in coastal and inland Eastern Africa to show that inland African societies were an essential component in the development of Swahili urbanism and maritimity. To understand change in any part of the East African coast requires understanding the entire context of economic, political, and social interaction across the diverse dimensions of this society. By excluding inland Eastern Africa from their analysis, Fleisher et al. omit the interactions between land and sea that were the basis of this society's development. We conclude that Swahili society resulted from intercommunity interaction, socioeconomic networks, and exploitation of diverse regional resources. [trade, maritime, mosaics, urbanism, Swahili]
Association between the frequency of bedwetting and late preterm birth in children aged ≥5 years
Authors: Nishizaki Naoto , Obinata Kaoru , Kantake Masato , Yoshida Noboru , Ohtomo Yoshiyuki , Niijima Shinichi , Yanagisawa Naotake , Nishizaki Yuji , Shoji Hiromichi , Shimizu Toshiaki
Published: June 2018

Aim

We examined the associations between late preterm (LPT) birth children aged ≥5 years and the frequency of bedwetting. Moreover, those who were born full‐term/low birthweight (BW), LPT/low BW, LPT/normal BW and LPT/low BW were compared.

Methods

In total, we evaluated 614 patients who underwent assessments for frequent bedwetting at the three hospitals from January 2014 to December 2016. Data at the initial visit were collected from the electronic medical records. We assessed the patients’ bladder diaries and questionnaires containing detailed information on demographics and frequency of bedwetting per month. Neonatal data were collected from the Maternal and Child Health Handbook.

Results

Frequency of bedwetting in the LPT/low BW group was higher than in the term/low BW group (28 vs. 22.5, p < 0.05). However, the frequency between the LPT/normal BW group and the LPT/low BW group was not significantly different (28 vs. 28, p = 1.00). Multiple regression analyses were conducted to eliminate potential confounding factors, attention‐deficit/hyperactivity disorder and intellectual disability, but results were not changed.

Conclusion

This study revealed that LPT/low BW was associated with increased frequency of bedwetting in children. The results suggest that gestational age should be considered when examining patients with severe bedwetting.
Interferon‐free therapy in hepatitis C virus mixed cryoglobulinaemia: a prospective, controlled, clinical and quality of life analysis
Authors: Gragnani L. , Cerretelli G. , Lorini S. , Steidl C. , Giovannelli A. , Monti M. , Petraccia L. , Sadalla S. , Urraro T. , Caini P. , Xheka A. , Simone A. , Arena U. , Matucci‐Cerinic M. , Vergani D. , Laffi G. , Zignego A. L.
Published: June 2018

Background

Cryoglobulinaemic vasculitis (CV) is a lymphoproliferative disorder related to hepatitis C virus (HCV) infection; anti‐viral therapy is the first therapeutic option. CV can be incapacitating, compromising the patients’ quality of life (QoL). In a controlled study, interferon‐based therapy was associated with a lower virological response in vasculitic patients than in patients without vasculitis. Limited, uncontrolled data on direct‐acting anti‐virals are available.

Aim

To evaluate safety, clinical efficacy, virological response and the impact of interferon‐free treatment on QoL in HCV patients with and without mixed cryoglobulinaemia (MC).

Methods

We prospectively studied HCV patients with cryoglobulinaemia (with vasculitis‐CV‐ and without vasculitis‐MC‐) and without cryoglobulinaemia (controls), treated with direct‐acting anti‐virals. Hepato‐virological parameters, CV clinical response and impact on QoL were assessed.

Results

One hundred and eighty‐two HCV patients were recruited (85 with CV, 54 with MC and 43 controls). A sustained virological response at 12 weeks (SVR12) was achieved in 166 (91.2%) patients (77/85 CV, 48/54 MC, 41/43 controls). In CV SVR patients, cryocrit levels progressively decreased and clinical response progressively improved, reaching 96.7%, 24 weeks after treatment. QoL, baseline physical and mental component summaries were lower in the CV group compared to the other groups (P < 0.05). Scores improved in all groups, and significantly in CV patients after SVR.

Conclusions

No significant differences in SVR rates were recorded between cryoglobulinaemic patients and controls and a high clinical and immunological efficacy was confirmed in CV, supporting the role of interferon‐free therapy as the first therapeutic option. Interestingly, CV patients had worse baseline QoL than other HCV‐positive groups and interferon‐free therapy was effective in significantly increasing QoL, suggesting the important role of direct‐acting anti‐viral‐based therapy in improving CV's individual and social burden.
“Girls Are as Good as Boys at Math” Implies That Boys Are Probably Better: A Study of Expressions of Gender Equality
Authors: Chestnut Eleanor K. , Markman Ellen M.
Published: June 2018

Although “Girls are as good as boys at math” explicitly expresses equality, we predict it could nevertheless suggest that boys have more raw talent. In statements with this subject‐complement structure, the item in the complement position serves as the reference point and is thus considered more typical and prominent. This explains why “Tents are like houses,” for instance, sounds better than “Houses are like tents”—people generally think of houses as more typical. For domains about ability, the reference point should be the item that is typically more skilled. We further propose that the reference point should be naturally more skilled. In two experiments, we presented adults with summaries of actual scientific evidence for gender equality in math (Experiment 1) or verbal ability (Experiment 2), but we manipulated whether the reference point in the statements of equality in the summaries (e.g., “Boys’ verbal ability is as good as girls’”) was girls or boys. As predicted, adults attributed more natural ability to each gender when it was in the complement rather than subject position. Yet, in Experiment 3, we found that when explicitly asked, participants judged that such sentences were not biased in favor of either gender, indicating that subject‐complement statements must be transmitting this bias in a subtle way. Thus, statements such as “Girls are as good as boys at math” can actually backfire and perpetuate gender stereotypes about natural ability.
Microwave‐assisted preparation of pyrite and its sensitisation of titanium dioxide in self‐cleaning aramid fabrics
Authors: Zheng Chenghui , Zhou Chang‐E , Qi Zhenming , Zhou Qingqing , Wang Chaoxia
Published: June 2018

Titanium dioxide (TiO2) dispersions were obtained by neutralising anatase nano‐titanium dioxide sols prepared by hydrolysing tetrabutyl titanate in acidic aqueous media. Pyrite was initially prepared via the microwave‐assisted method with a mixed solvent of ethylene glycol and small amounts of water, and was then used in sensitising micron‐sized titanium dioxide particles to obtain aramid fabrics with self‐cleaning properties. X‐ray diffraction demonstrated the crystalline structure of pyrite, and ultraviolet‐visible (UV‐vis) spectrum and energy‐dispersive X‐ray spectroscopy characterised the band gaps, surface status on fabrics and the distribution of the pyrite compound's titanium dioxide particles. The contact angle, UV protection factor (UPF) and photocatalytic degradation of methylene blue (MB) were used to evaluate the performance of treated aramid fabrics. Results show that pyrite‐sensitised titanium dioxide compounds obtained at pH 5 have smaller band gap energies and relatively poor wetting abilities, higher UPF values, and perform well in the photocatalytic degradation of MB. The pseudo‐first kinetic model was used to analyse elaborate sections of the curve for the degradation of MB.
The structural formation of closely packed colloidal crystals on fibre and the effect of fibre surface functionality on crystalline structure
Authors: Hirogaki Kazumasa , Nakamura Daichi , Sekiguchi Kazushi , Satake Tomohiro , Tabata Isao
Published: June 2018

The effect of hydrophilicity and the charge of the fibre surface upon the formation of colloidal crystals on the fibre was investigated. Surface‐modified polyester fibre was prepared either by oxygen plasma treatment or with a sol‐gel method using 3‐aminopropyltriethoxysilane (APS). The surface‐modified polyester fibre was dip‐coated with 20 wt.% water suspension of uniform‐sized silica particles with a diameter of 300 nm and then it was dried. Hexagonal and square arrangements were observed for the particles deposited on the fibre surface by scanning electron microscopy (SEM). The crystallinity of deposited particles was estimated with the number ratio of arranged particles to all particles in the SEM image. On the plasma‐treated fibre, the crystallinity of deposited particles was 82% and the ratio of hexagonal arrangement to square arrangement was 3:1. On the APS‐treated fibre, crystallinity was 56% and the ratio was 1:8. The fibre‐fabricated colloidal crystal exhibited red colour on its surface and it had a peak wavelength of 637 nm in the reflection spectrum.
The Inner Life of Democracy: Learning in Deliberation between the Police and Communities of Color
Authors: Wahl Rachel
Published: June 2018

Deliberation has become a defining ideal of democratic theory, and learning is central to robust deliberation. It is challenging for people to learn from each other, however, in contexts of inequality and deep social cleavages — though this is precisely when such learning is most needed. The political theorist Danielle Allen has argued that the cultivation of “political friendships” and the development of verbal empowerment can mitigate the negative effects of difference and inequality in such settings. In this essay, Rachel Wahl uses her fieldwork on deliberation between police and communities of color to illuminate the challenges that are frequently encountered in efforts to adhere to Allen's aims and prescriptions, and also to consider the kind of learning that might make political friendship possible in the most challenging circumstances. Wahl shows how, in the context of divisive and unequal settings, people must develop the capacity not only to learn from those who are different from themselves but even from their sharpest critics. This requires a prior education that cultivates a kind of receptivity that can complement the long‐standing focus on agency and self‐expression in education for democratic citizenship. Her detailed account of the deliberative dynamics observed at a series of police–community fora reveals the political importance of inner life and of receiving an education that cultivates in individuals the disposition of receptive listening. Complicating deeply ingrained distinctions between the public and private spheres within a liberal society, it points to the value not only of cultivating skills, but also of shaping the person.
Whats and Hows of Family Financial Socialization: Retrospective Reports of Emerging Adults, Parents, and Grandparents
Authors: LeBaron Ashley B. , Hill E. Jeffrey , Rosa Christina M. , Marks Loren D.
Published: June 2018

Objective

To qualitatively explore the whats and hows of financial socialization in families, as reported by emerging adults and their parents and grandparents.

Background

Previous research has examined the positive impact of financial socialization in families as well as the negative consequences of a lack of sufficient financial education. However, there is a need to explore the breadth of parent–child financial socialization methods and topics.

Method

A convenience sample of 90 emerging adults (18–30 years of age), 17 of their parents, and eight of their grandparents (N = 115) were interviewed at three diverse universities regarding what and how their parents taught them about money. Parents and grandparents were also interviewed regarding what and how they taught their children about money.

Results

Thematic content coding revealed three core how themes (modeling, discussion, and experiential learning) and four core what themes (financial planning, work ethic, money management, and sharing). The themes coded most often were discussion and money management.

Conclusion

The findings provide a starting point for gaining insight about how and what parents teach children about money but leave many questions unanswered that future research will need to address to build efficient and effective evidence‐based approaches for parental financial socialization in future generations.

Implications

Family life educators and others can use our findings to better understand how financial socialization occurs in families as a necessary step in ultimately improving financial socialization and increasing the financial capability and independence of emerging adults.
A conservative approach for mode I‐II fatigue analysis under residual stresses:The RSIF proportionality conjecture
Authors: Ruiz Muñoz G. A. , Eder M. A.
Published: June 2018

Residual stresses are a crucial aspect of fatigue life predictions of welded structures. However, their implementation in fatigue crack growth simulations can be tedious. In this paper, a novel approach is proposed that considers the effects of residual stresses in a worst‐case scenario by applying themaximum tangential stress criterionand maximising the crack growth rate. Results demonstrate that computationally demanding analysis of residual stresses can be avoided by assuming the residual stress intensity factors are proportional to the stress intensity factors induced by the externally applied cyclic load. This approach is referred to as theresidual stress intensity factors proportionality conjecture, which is particularly useful for inspection planning of complex structures subject to mixed‐mode crack propagation situations, where the computational recovery of current residual stress states by consideration of their temporal evolvement is cumbersome.
Beyond serum creatinine: which tools to evaluate renal function in cirrhotic patients?
Authors: Carrier Paul , Debette‐Gratien Marilyne , Essig Marie , Loustaud‐Ratti Véronique
Published: June 2018

In cirrhotic patients, a high serum creatinine value is an independent mortality factor. Similarly, it is predictive of renal insufficiency after liver transplantation. In these cases, chronic kidney disease is also an independent mortality factor. A relevant evaluation of glomerular filtration rate is crucial, particularly in cases of end‐stage liver disease or liver transplantation, and is key for the decision to undertake dual liver–kidney transplantation. Serum creatinine or creatinine‐based equations are the most used tools in clinical practice but they significantly overestimate renal function. Equilibrium inulin renal clearance remains the gold standard but is time consuming and expensive. Cystatin C and cystatin C‐based equations are less influenced by muscle mass or bilirubin value, but their dosage is not standardized and they are expensive. Pharmacological models using exogenous markers, new kidney biomarkers, Doppler coupled with ultrasounds, and kidney histology could be interesting tools but their indications need to be specified.
Infants Discriminate the Affective Expressions of their Peers: The Roles of Age and Familiarization Time
Authors: Flom Ross , Bahrick Lorraine E. , Pick Anne D.
Published: June 2018

Research examining infants’ discrimination of affect often uses unfamiliar faces and voices of adults. Recently, research has examined infant discrimination of affect in familiar faces and voices. In much of this research, infants were habituated to the affective expressions using a “standard” 50% habituation criterion. We extend this line of research by examining infants’ discrimination of unfamiliar peers’, that is, 4‐month‐olds, dynamic, facial, and vocal affective expressions and assessing how discrimination is affected by changing the habituation criterion. In two experiments, using an infant‐controlled habituation design, we explored 3‐ and 5‐month‐olds’ discrimination of their peers’ dynamic audiovisual displays of positive and negative expressions of affect. Results of Experiment 1, using a 50% habituation criterion, revealed that 5‐month‐olds, but not 3‐month‐olds discriminated the affective expressions of their peers. In Experiment 2, we examined whether 3‐month‐olds’ lack of discrimination in Experiment 1 was a result of insufficient habituation (i.e., familiarization). Specifically, 3‐month‐olds were habituated using a 70% habituation criterion, providing them with longer familiarization time. Results revealed that using the more stringent habituation criterion, 3‐month‐olds showed longer habituation times, that is increased familiarization, and discriminated their peers’ affective expressions. Results are discussed in terms of infants’ discrimination of affect, the role of familiarization time, and limitations of the 50% habituation criterion.
Controlling lead times and minor ordering costs in the joint replenishment problem with stochastic demands under the class of cyclic policies
Authors: Braglia Marcello , Castellano Davide , Santillo Liberatina , Song Dongping
Published: June 2018

In this paper, we consider the periodic review joint replenishment problem under the class of cyclic policies. For each item, the demand in the protection interval is assumed stochastic. Moreover, a fraction of shortage is lost, while the other quota is backordered. We suppose that lead times and minor ordering costs are controllable. The problem concerns determining the cyclic replenishment policy, the lead times, and the minor ordering costs in order to minimize the long‐run expected total cost per time unit. We established several properties of the cost function, which permit us to derive a heuristic algorithm. A lower bound on the minimum cost is obtained, which helps us to evaluate the effectiveness of the proposed heuristic. The heuristic is also compared with a hybrid genetic algorithm that is specifically developed for benchmarking purposes. Numerical experiments have been carried out to investigate the performance of the heuristic.
Fabrication and microstructure characterizations of transparent Er:CaF2 composite ceramic
Authors: Liu Zuodong , Jia Mengying , Yi Guoqiang , Mei Bingchu , Jing Qiangshan , Liu Peng
Published: June 2018

A novel layered transparent Er:CaF2 composite ceramic was proposed in the present study. Er:CaF2 nanoparticles were synthesized by a chemical coprecipitation method. The crystal structures and morphologies of synthesized nanoparticles were performed by X‐ray diffraction (XRD) and field emission scanning electron microscope (FE‐SEM) measurements, respectively. Transparent composite ceramic was fabricated by the combination of multistep dry pressing and hot‐pressed sintering method without any sintering aids or binders. The average grain size of 2% Er‐doped and 5% Er‐doped layers were about 30 and 55 μm, respectively. The thickness of interfacial between two different Er‐doped layers was 150‐200 μm. For a 1.5 mm thickness transparent Er:CaF2 composite ceramic, the optical transmittance reached 44.9% at 500 nm and 53.6% at 1200 nm. The luminescence spectra and thermal conductivities of transparent ceramic specimens were also discussed.
Vitamin D3supplementation improves testicular function in diabetic rats through peroxisome proliferator‐activated receptor‐γ/transforming growth factor‐beta 1/nuclear factor‐kappa B
Authors: Liu Yang , He Yanyan , Wang Qingzhu , Guo Feng , Huang Fengjuan , Ji Linlin , An Tingting , Qin Guijun
Published: June 2018

Aims/Introduction

Vitamin D3deficiency can lead to male hypogonadism in diabetes mellitus, but the target organs and the mechanism driving the disorder are unclear. This experiment was designed to study the relationship between vitamin D3deficiency and hypogonadism in diabetes mellitus.

Materials and Methods

Rats with streptozotocin‐induced diabetes were randomly divided into four groups and treated with different doses of vitamin D3: blank (no vitamin D3), low (0.025 μg/kg/day), high (0.1 μg/kg/day), high (0.1 μg/kg/day) and with bisphenol A diglycidyl ether (peroxisome proliferator‐activated receptor gamma inhibitor 30 mg/kg/day). They were compared with wild‐type rats.

Results

After 12 weeks, the vitamin D3supplements had partially restored testicular pathological changes, as shown by reduced testicular fibrosis related to downregulation transforming growth factor beta 1 and apoptosis related to downregulation of nuclear factor kappa B, but not the pituitary gland. The expression of peroxisome proliferator‐activated receptor gamma, which can inhibit transforming growth factor beta 1 and nuclear factor kappa B, was significantly increased after treatment with vitamin D3.

Conclusions

These results suggest that treatment with vitamin D3can improve testicular function in diabetic rats through the peroxisome proliferator‐activated receptor gamma/transforming growth factor beta 1/nuclear factor kappa B signaling pathway.
Reid's Rules: Filibusters, the Nuclear Option, and Path Dependence in the US Senate
Authors: Wawro Gregory J. , Schickler Eric
Published: June 2018

The recent moves by senators to impose majority cloture for nominations provides a unique opportunity for advancing our understanding of the evolution of the Senate into a supermajoritarian institution. We integrate discussion of alternative theoretical perspectives on Senate development and path dependence to shed new light on mechanisms of stability and change, concluding that the perspective that Senate majorities have generally maintained supermajority procedures because they preferred them to the alternative of majority rule has more explanatory power than does the perspective that Senate majorities were “locked in” to these procedures by previous institutional choices.
Molecular Photoacoustic Contrast Agents: Design Principles & Applications
Authors: Borg Raymond E. , Rochford Jonathan
Published: June 2018

Photoacoustic imaging (PAI) is a rapidly growing field which offers high spatial resolution and high contrast for deep‐tissue imaging in vivo. PAI is nonionizing and noninvasive and combines the optical resolution of fluorescence imaging with the spatial resolution of ultrasound imaging. In particular, the development of exogenous PA contrast agents has gained significant momentum of late with a vastly expanding complexity of dye materials under investigation ranging from small molecules to macromolecular proteins, polymeric and inorganic nanoparticles. The goal of this review is to survey the current state of the art in molecular photoacoustic contrast agents (MPACs) for applications in biomedical imaging. The fundamental design principles of MPACs are presented and a review of prior reports spanning from early‐to‐current literature is put forth.
Photocrosslinkable Type-I Collagen for In Situ Material Modification
Authors: Gaudet Ian D. , Shreiber David I.
Published: June 2018

Hydrogels are attractive materials for use as tissue engineering scaffolds [1]. Natural hydrogels, such as collagen, are both cytocompatible and highly biofunctional. However, they have somewhat constrained material properties and have an inherently large variability in composition due to their biological origin, making them more difficult to work with from an engineering viewpoint[2–4]. Here, we aim to use type 1 collagen — the most abundant protein in the body that maintains excellent cytocompatibility and can self assemble into a fibrillar network — as a base component for a photocrosslinkable biomaterial. One main advantage of this system over previous studies attempting to photocrosslink collagen is that the collagen retains its ability to self assemble, which provides a stable environment into which localized modifications can be made to the stiffness, porosity, and biochemical properties of the hydrogel scaffold. By taking advantage of the spatial control provided by the system, we can create complex 3-dimensional hydrogel scaffolds that have non-homogenous microenvironments.
Prestress as an Optimal Biomechanical Parameter for Needle Penetration and Formulation Injection
Authors: Griebel Adam , Novak Tyler , Butz Kent D. , Harris Kevin , Kornokovich Amy , Chiappetta Michael , Neu Corey P.
Published: June 2018

Intradermal and subcutaneous needle injections have long been used as a means to deliver vital medication subcutaneously across a range of applications from vaccines to insulin [1]. In order to optimize the efficacy of these injections, the needle must penetrate precisely to a targeted depth. However, the actual net penetration of the needle beneath the surface of the skin is confounded by the deflection of the skin. With the rise of the use of auto-injectors in such fields as diabetes care, achieving the actual required penetration becomes exceedingly important. There have been previous attempts to characterize this deflection [2–4], but these were limited in that they did not account for a range of factors that play a role in the penetration mechanics, and many were based on mathematical models, synthetic skin substitutes, or other tissues. The purpose of our work was to investigate the multiple factors that govern needle penetration and injection, including velocity, needle gauge, depth of insertion, and skin prestress.
Development and Validation of an In-Vivo Finite Element Pelvis Model With Cortical Thickness Mapped From a Cadaver
Authors: Kim Young Ho , Kim Jong-Eun , Eberhardt Alan W.
Published: June 2018

Pelvis fracture and associated injuries from motor vehicle accidents or falls are often life threatening [1]. Cadaveric experiments and finite element (FE) models have been widely used to investigate biomechanical properties, structural responses, and injury tolerances of the pelvis. In FE model development, the geometry of the bone structures is commonly constructed from computed tomography (CT) scans of cadavers. The use of live human subjects, however, has been limited due to low CT resolution resulting from mandatory low radiation doses and involuntary movements of the subject. The Global Human Body Models Consortium (GHBMC) elected to use a living 50th percentile male for its full body FE model development; however, cortical bone thickness was not accurately imaged for the pelvis, where it is believed to play an important role in absorbing strain energy during lateral impact [2].
Fluid Structure Interaction (FSI) Methodology for Evaluation of a Passive Endovascular Carotid Implant for Hypertension Treatment
Authors: Peter Dinesh A. , Alemu Yared , Xenos Michalis , Weisberg Ori , Avnery Itzik , Bluestein Danny
Published: June 2018

Drug-resistant hypertensive patients may be treated by stimulating baroreceptors located in the arterial walls of the internal carotid artery, specifically in the sinus region of the carotid artery bifurcation. To assess the ability of a custom implant design to stimulate baroreceptors by triggering them to fire and thereby reduce hypertension, the design was deployed within a patient based carotid bifurcation and FSI simulations were conducted. Results demonstrate the effect of such an implant on the arterial wall region where the baroreceptors are located. Localized wall contact and pulsatile stretch due to the implant are depicted by elevated wall stresses in the corresponding regions. These FSI simulations indicate that such a device would trigger baroreceptor firing and thus may effectively reduce hypertension in patients who do not respond to medication.
The Effect of Inlet Flow Profile Simplifications in Computational Fluid Dynamics of the Carotid Bifurcation
Authors: Ries Jared , Campbell Ian C. , Dhawan Saurabh S. , Quyyumi Arshed A. , Taylor W. Robert , Oshinski John N.
Published: June 2018

Computational fluid dynamics (CFD) is emerging as a powerful tool for researching the role of blood flow in disease processes. Modern clinical imaging technology such as magnetic resonance (MR) angiography and computed tomography (CT) can provide very high resolution information about the geometry of patients’ vasculature for such modeling. However, in many situations, patient-specific inlet velocity information is not available. In these situations, a simplified velocity profile must be selected. In this study, we sought to identify how idealized inlet velocity profiles (blunt flow, parabolic flow, and Womersley flow) affect patient-specific CFD results when compared to simulations employing the real measured velocity profile for each patient. Focusing on the carotid bifurcation, a site prone to atherosclerosis because of its branching geometry and oscillatory flow patterns, we investigated the effect of inlet flow assumptions on hemodynamic parameters known to be associated with atherosclerosis and vascular disease, namely mean wall shear stress (WSS) and oscillatory shear index (OSI) [1].
Endothelial Cell Injury Under High Frequency Vibration in the Rat-Tail Model
Authors: Goenka Shilpi , Peelukhana Srikara V. , Kim Jay , Stringer Keith F. , Banerjee Rupak K.
Published: June 2018

Hand-Arm Vibration Syndrome (HAVS) consists of vascular, sensorineural and musculoskeletal disorders and affects around 1.7–5.8% of industrial workers. In this study, a rat-tail vibration injury model is used to assess early vascular damage due to HAVS, manifested in the form of endothelial cell vacuolation and oxidative injury. Tails were vibrated at two frequencies 125Hz and 250Hz for 4hr/day for 1 and 5 days (49m/s2). Hematoxylin and Eosin (H&E) staining was done to assess gross changes in artery sections and toluidine blue stain was done for vacuole counting. Immunohistochemical (IHC) methods were used to detect Nitrotyrosine, a potent biomarker of cell inflammation and oxidative stress. The vacuole count in Endothelial Cells (ECs) was not statistically significant after 1 and 5 days for any frequency. However IHC images showed significant oxidative damage in Endothelial Cells (ECs) with considerable oxidative damage being induced as early as 1 day for both 125Hz and 250Hz frequencies, with more EC damage induced by 250Hz frequency after 5 days. These findings indicate that higher frequency vibrations can cause severe oxidative damage to EC.
Precise Patterning of Mouse Embryonic Stem Cells on Glass Cover Slips for High-Throughput Analysis Using Laser Direct-Write
Authors: Dias Andrew D. , Schiele Nathan R. , Carr Brendan M. , Raof Nurazhani Abdul , Xie Yubing , Chrisey Douglas B. , Corr David T.
Published: June 2018

Engineering a microenvironment where the growth substrate and distance between cells are controlled is highly desirable to understand how cellular interactions affect stem cell differentiation. Laser direct-write (LDW) allows rapid and precise placement of living cells via computer-aided design/computer-aided manufacturing (CAD/CAM) control. Application of this technique to study the effects of various stem cell microenvironments on differentiation requires a high-throughput experimental setup [1]. Recently, our lab has developed a gelatin-based LDW method for the precise patterning of sensitive cell types, such as mouse embryonic stem cells (mESCs), at a resolution of about 5 μm [2]. Although viable mESCs were successfully printed with maintained pluripotency, this technique required cells to be patterned onto polystyrene Petri dishes [2,3], which may limit high-throughput efficiency. Moreover, the use of polystyrene Petri dishes requires large quantities of culture medium and is not convenient for biological analysis of mESC differentiation. Therefore, the objective of this study was to adapt the LDW method, without altering its prior success, to transfer patterns of viable mESCs to glass cover slips. However, this adaptation to cover slips could not be achieved through simple downscaling due to the unique challenges of providing sufficient moisture for viable cell transfer while maintaining pattern registry on a cover slip. Once cells have been laser patterned, cover slips can then be moved to a 24-well plate so that separate sets of laser patterned cells can be analyzed in parallel for higher experimental throughput utilizing fewer resources to maintain the cells.
Effect of Strain Rate on the Bending Properties of Human Ribs
Authors: Feuer Gavriel , Saha Subrata
Published: June 2018

To fully characterize the mechanical behavior of bones under various loading conditions, it is important to determine the effect of strain rate on the load carrying capacit and fracture behavior of various members of our skeletal system. In this study embalmed human ribs were tested in a three-point bending mode under deformation rates of 0.05 mm/s, 0.5 mm/s, and 8 mm/s. Mechanical parameters such as maximum bending moment, maximum deformation, bending stiffness, and energy absorption capacity were determined. The maximum bending moment and stiffness showed an increase by 53 and 8 percent, respectively, at the highest rate of deformation compared to the lowest. The ultimate deformation and energy absorbed also increased by 26 and 66 per cent, respectively, in this range of deformation rate. This data confirms that bone is visco-elastic in nature and exhibits different mechanical properties that depend on the deformation rate.
The Effect of Return to Overuse Activity After a Supraspinatus Tear on Joint Function and Biceps Mechanical Properties in a Rat Model
Authors: Thomas Stephen J. , Sarver Joseph J. , Tucker Jennica , Reuther Katherine , Edelstein Lena , Ilkhani-Pour Sarah , Gray Chancellor , Lee Chang Soo , Glaser David L. , Soslowsky Louis J.
Published: June 2018

Rotator cuff tendon tears are one of the most common shoulder injuries and are most prevalent in populations performing repetitive overhead activities [1]. In addition, long head of the biceps (LHB) tendon injuries occur secondary to cuff tears and may or may not lead to functional deficits [2]. Previous animal model studies have found that in the presence of a cuff tear, the biceps has decreased mechanical properties at 8 weeks [3]. Such studies, however, did not examine the effect of repetitive overhead activity on biceps properties and shoulder function in the presence of a cuff tear. Therefore, the objective of this study was to evaluate the effect of returning to overuse activity after a supraspinatus tendon tear on shoulder function and biceps structural and mechanical properties. We hypothesized that overuse activity following a supraspinatus tendon tear would not alter shoulder function, when compared to cage activity, but would decrease biceps structural and mechanical properties, particularly at the insertion site.
Dynamic Compression Promotes Cartilage-Like Functional Properties in MSC-Seeded Hyaluronic Acid Hydrogels
Authors: Erickson Isaac E. , Zellars Kilief H. , Kestle Sydney R. , Burdick Jason A. , Mauck Robert L.
Published: June 2018

The specialized function of articular cartilage in distributing stresses during normal joint movement must be recapitulated in a successful engineered cartilage repair. Chondrocytes can generate in vitro cartilage constructs with mechanical properties at or near native levels [1–3] when cultured in specialized media formulations. While these advances in chondrocyte-based tissue engineering are highly instructive, the difficulty of obtaining sufficient numbers of healthy autologous chondrocytes represents a considerable challenge. To circumvent this limitation, many have evaluated mesenchymal stem cells (MSCs), an autologous cell type that can be expanded in vitro and with a demonstrated capacity for chondrogenic differentiation. Despite their potential, MSC-based engineered cartilage has yet to achieve functional properties comparable to those produced by chondrocytes in 3D culture [4–6].
Cryo-Mechanics of Ex Vivo Porcine Femoral Artery
Authors: Thomas Margaret A. , Barocas Victor H.
Published: June 2018

CryoPlasty is a therapeutic technique which combines cryo-therapy with angioplasty [1]. The technique helps to make angioplasty more effective by limiting dissection, vessel recoil, and restenosis [2]. Cryotherapy uses a gas to freeze the tissue to about −10 to −20°C at the balloon inflation site [1]. Another benefit is that it does not leave a foreign object implanted in the body [2]. Cryopreservation is also used to keep whole tissues for extended periods of time. Whole artery sections are preserved in this manner at approximately −80 to −190°C to be used as grafts [3]. Prior experiments have examined total cryofreeze-thaw afftect on the mechanical behavior of arteries [3]. Further studies are needed to determine if cryo-damaging an artery has adverse affects on the regional properties of arteries which could lead to changes in how the artery functions mechanically.
Evaluation of Globe Rupture Injury Mechanisms and Pressure Response of the Eye During Projectile Impact
Authors: Desharnais Kelly , Clark Samantha , Kennedy Eric
Published: June 2018

In the United States, over 1.9 million civilian eye injuries occur annually [1]. Furthermore, with the recent conflict, the military has experienced a dramatic 17%–26% increase in rate of injury to the eyes [2]. Risk functions for various eye injuries, particularly globe rupture, have already been developed and show area-normalized energy (based on the mass, size, and velocity of the projectile) to be most highly correlated to injury [3–5]. However, it remains desirable to further investigate the relationship between area-normalized energy and the eye injury mechanism.
Nanostructure Processed on Culture Plate Improves Cell Adhesion
Authors: Suganuma Lisa , Fujie Hiromichi , Sudama Hiroki , Sato Yoshihide , Nakamura Norimasa , Suzuki Kenji , Tanaka Yasuhiro , Moronuki Nobuyuki
Published: June 2018

Ligaments and tendons have superior functions, but their healing capacities are limited. We have been developing a novel tissue-engineering technique for the repair of ligaments and tendons which involve stem cell-based self-assembled tissues (scSAT) derived from synovium[1]. For biological reconstruction of soft tissues, it is required for the scSAT to have high tensile strength. Our previous study indicted that, when the scSAT was cultured under high cell density condition, the tensile strength of the scSAT become higher than that cultured under low density condition[2]. However, the scSAT had a significant tendency to detach naturally from the culture dish with increasing cell density. Therefore, we expect that the mechanical property of the scSAT improves by enhancing the cell adhesion to culture plates. Previous studies suggested that nanostructure processed on culture dish affected cell adhesion [3, 4]. In the present study, nanostructure was processed on a silicon wafer using a nanoprocessing technology, and the structure was replicated to a polydimethylsiloxane (PDMS) plate. Human synovium-derived mesenchymal stem cells were cultured on the plate, and cell adhesion and morphological observation were performed.
Mechanisms of Platelet Capture Under Very High Shear
Authors: Wellings P. J. , Ku D. N.
Published: June 2018

Arterial thrombus forms from the capture and accumulation of circulating platelets on a stenotic arterial wall. As the thrombus grows, the lumen becomes further stenotic with resulting elevated shear rates of up to 500,000 s−1 as the blood velocities increase through the narrowed cross-section [1]. Increased blood velocities impart greater forces on platelets binding to a thrombus. These forces can increase to 100 times the strength of an individual GPIbα-vWFA1 bond (∼100 pN) [2]. The increased shear rates also require that the capture bonds be formed quickly before the platelet is swept away. Thus, the hemodynamic conditions require that a platelet be able to form bonds in very short timescales in order to adhere. In this study, we estimate the bond forces and capture times for platelet capture under high shear considering the biophysics of bonding at the micromechanics scale.
Deformable Image Registration Between Cardiac PET Images Encompassing a Range of Physical Heart Sizes
Authors: Coleman Benjamin R. , Veress Alexander I.
Published: June 2018

Cardiac mechanical performance depends upon myocardial tissue elongation and contraction. Deformation, stress and strain within the myofibers provide valuable information about potential tissue adaptation [1]. Specifically, the stress state of the tissue is believed to drive remodeling of the myocardium. Because it is not possible to measure in-vivo stress in the human heart, considerable research has gone into developing patient specific, mathematical models of the heart based on finite element (FE) analysis and cardiac imaging [2, 3]. Stress estimates from these models could yield valuable information about of the material behavior of the myocardium that would provide valuable information for research into cardiac pathologies.
Simplifying Cell Traction Forces Using Fibronectin Patterned Polyacrylamide Gels
Authors: Polio Samuel R. , Rothenberg Katheryn E. , Stamenović Dimitrije , Smith Michael L.
Published: June 2018

Cells inhabit highly dynamic environments which greatly influence cell behavior. One of the ways in which a cell interacts with its environment is through its membrane by focal adhesion complexes. These protein complexes form an intermediary between the cytoskeleton and the extracellular matrix. Tension generated within the contractile cytoskeleton results in cellular traction forces (CTFs) at the adhesion sites, which can greatly affect cell shape, adhesion, and function (1).
The Role of Nonmuscle Myosin IIA Regulation in Platelet Forces Using Microposts and Multiphysics Modeling
Authors: Feghhi Shirin , Sniadecki Nathan J.
Published: June 2018

A multi-physics model has been developed that closely matches with the biochemical regulation of platelet forces. The model is based on measurements of platelet forces using arrays of microposts. Different concentrations of thrombin or myosin inhibitors were added to the platelets to reduce their forces on the posts. The platelet forces obtained from the model have good agreement with those measured in the inhibition studies.
Cellular Dynamics on Aligned Fibrous PLGA Scaffolds
Authors: Ng Colin , Nain Amrinder
Published: June 2018

Understanding cellular dynamics is fundamental to increasing the healing and regenerative capacity of biomedical scaffolds. The ability to investigate environmental cues and cell-cell interactions in vitro with successful translation to in vivo therapies will enhance many tissue engineering technologies. Understanding the dynamics of a cell in response to external mechanical stimuli can help achieve directed cellular migration by varying cellular environment geometries. Customized scaffolds can then be designed to achieve desired cellular migration rates, cell-cell interaction pathways, increased proliferation and directed cellular differentiation platforms to achieve tissue engineering specific goals. In this study, a unique fiber manufacturing platform known as STEP (Spinneret-based Tunable Engineered Parameters) is used to create and manipulate geometrical cues for cellular migration. The cell’s reaction to these geometric cues provides valuable insight into cellular behavior, which can be used to determine the optimal engineered microenvironment. We envision that studying cellular behavior on STEP enabled customized scaffolds will aid in the design and fabrication of accurate mechanistic environments for different cell types which can then be coupled with chemical cues to achieve desired results.