bluuebunny/crossref_metadata_2025 huggingface dataset:
Design of flexure revolute joint based on double compliant curved beam
Authors: Zhang Jing , Guo Hong-wei , Zhang Zhan-ning
Published: February 2019

In view of the problems of low accuracy and large impact caused by flexure joints during the deployable process, design of an integrated flexure revolute joint for folding mechanisms is important. Using a double compliant curved beam as a flexible unit of a joint, the revolute joint is designed based on the method of compliance and stiffness ellipsoids. The geometrical constraints model of the curved beam is established to define the design range of the unit. The total error model, which is obtained by the analysis of single-parameter errors, is used to choose the size of the unit with the smallest error. The finite element models of the flexure joints are established to analyze the rotational stiffness, translational stiffness, and the maximum rotational angle of the joints. The rotational angle of one flexure revolute joint in one direction can reach 35.7°. The rotational angle of the series flexure revolute joint in one direction can achieve 51°. The experiments of single and series flexure joints are carried out to verify the correctness of the design and for the analysis of the flexure joint.
Polypharmacy and Utilization of Health Care Services: A Cohort Study of People Aged Over 50 Years in Taiwan
Authors: Li Ji-Wen , Hsieh Hui-Min , Weng Shih-Feng , Lee I-Chen
Published: February 2019

This study aimed to understand the changes and correlation in the long-term trends of polypharmacy and the utilization of health care services in a population over the age of 50 years through the use of a national database. A total of 2813 subjects who participated in surveys in 1999, 2003, and 2007 were selected as the samples. Each subject was followed-up for the period of 9 years. From 1999 to 2007, the proportion of mild and severe polypharmacy cases increased from 41.5% (1999) to 51.3% (2003) and 57.1% (2007), respectively. This study found that the more severe the polypharmacy was, the higher the risk of health care service utilization would be. The Generalized Estimating Equation model of multivariate analysis showed that the incidence rate ratio of medical utilization increased with the severity of polypharmacy, as did the use of advanced medical resources (ie, the number of hospitalizations). In particular, the increase in incidence rate ratio was more significant in 3 aspects: (1) number of pharmacy visits; (2) number of emergency room admissions; and (3) number of hospitalizations. The government should establish policies and guidance for the safe use of medicines to ensure reduced risk for older people.
Un-translatable? Interpreting customary laws in a western courtroom
Authors: Hannath Luke
Published: February 2019

This article observes interpretive issues that may arise when Aboriginal witnesses give evidence in western courtrooms. The author highlights this problem by observing native title claims in Australia. Two broad circumstances arise that present unique issues: first, when Aboriginal witnesses require interpreters for assistance in giving evidence, and second, when Aboriginal witnesses do not require such assistance. The clear difficulties that emerge for both Aboriginal witnesses and the judiciary are ultimately representative of a larger, fundamental disjunction between two legal systems.
Analytical solution for forced vibration of piezoelectrically actuated Timoshenko beam
Authors: Hosseini Seyedeh Marzieh , Al-Jumaily Adel
Published: February 2019

Forced vibrations of a Timoshenko beam covered with a piezoelectric actuator on its top surface were investigated in this article. As the proposed beam model complied with Timoshenko beam theory, the effects of both rotary inertia and shear deformation were considered. Hamilton principle in conjunction with the Galerkin procedure were applied to derive the governing equation of motion resulting in a second-order ordinary differential equation in time. A sinusoidal electric voltage was applied to the piezoelectric actuator, and a spatially distributed harmonic mechanical force was exerted to the beam. The response of the system to the force stimulation gave an analytical relation between natural frequency and amplitude of the vibration. Using the obtained analytical relation, the effects of different factors and material properties including the modulus of elasticity of the piezoelectric layer and the piezoelectric coefficient on the vibrational response of the beam were examined. The results indicated that the piezoelectric layer as an actuator provided an effective tool for active control of vibration. Increasing the piezoelectric coefficient as well as the electric voltage applied on the piezoelectric actuator increased the amplitude of vibration, while the amplitude decreased by increasing the modulus of elasticity of the piezoelectric actuator. The results were also verified by finite element analysis.
Socially Focused, Situationally Driven Practice: A Study of Distributed Leadership among School Principals and Counselors
Authors: Militello Matthew , Janson Chris
Published: February 2019

This study investigated how school counselors and principals perceive their professional relationship with each other. Specifically, it used Q methodology to develop 45 statements about the relationship between the school counselor and the principal. Subsequently, 39 professional school counselors and principals sorted the statements. Four factors emerged, each representing a distinct view of this relationship. The factors were analyzed using a distributed leadership framework. Although each factor contains constructive attributes of the school-counselor–principal relationship, one factor contains characteristics closely approximating the distributed leadership framework reflected in the literature and in the current school counselor and administrator professional standards.
Bridging Structure and Agency: Exploring the Role of Teacher Leadership in Teacher Collaboration
Authors: Szczesiul Stacy Agee , Huizenga Jessica L.
Published: February 2019

Building on York-Barr and Duke's (2004) conceptual framework for teacher leadership, this article explores teacher leadership as an informal influence that arises out of interactions and is exerted through group processes and norms. Through a 4-month qualitative study of two teacher teams’ work during structured teacher collaboration, we sought to understand how teachers’ informal action and interaction influence their colleagues’ sense of self-efficacy and motivation to engage in collaborative work. Given our findings, we theorize an emergent framework for teacher leadership to promote understanding and future investigation of teacher leadership as an informal, socially distributed phenomenon.
A Systematic Review Comparing Dose Response of Exercise on Cardiovascular and All-Cause Mortality
Authors: Moxley Elizabeth , Habtzghi Desale
Published: February 2019

It is well established that exercise improves cardiovascular and all-cause mortality, although an ideal dose of exercise is not known. The physical activity guidelines currently recommend 150 minutes per week of moderate-intensity exercise or 75 minutes of vigorous-intensity activity. Most individuals do not engage in adequate exercise, although a safe upper limit does not exist and a too much exercise hypothesis has recently emerged. This review of the literature analyzes studies that have evaluated exercise dose response on all-cause and cardiovascular mortality for the purpose of determining safe and effective exercise prescriptions. Searches were performed in PubMed and CINAHL between 2010 and 2018 to identify six studies that met inclusion criteria. Moderate-intensity exercise reduced all-cause mortality in five of six studies, whereas low-dose exercise most effectively improved all-cause mortality in three studies, and cardiovascular mortality in one study. Vigorous-intensity exercise or extreme doses demonstrated variable outcomes and remain controversial; two studies found vigorous-intensity exercise beneficial to improve health, two studies discouraged vigorous exercise, and two studies had less conclusive outcomes. It is not surprising that any amount of exercise improves health compared with none at all, with the greatest benefits observed when sedentary individuals began exercising. Low-dose exercise should be recommended to everyone with a goal of meeting the minimal requirements according to guidelines for decreased all-cause and cardiovascular mortality. Additional research to more thoroughly understand exercise dose response and motivate individuals to improve exercise engagement is currently warranted.
Change in cardiac troponin T level after intravitreal anti-vascular endothelial growth factor treatment: Prospective pilot study
Authors: Rebeiz Abdallah G , Mahfoud Ziyad , Abdul Fattah Maamoun , Saad Alain , Safar Ammar , Bashshur Ziad F
Published: February 2019

Background:

Evaluate subclinical myocardial injury associated with intravitreal anti-vascular endothelial growth factor therapy by measuring serum high-sensitivity cardiac troponin T.

Methods:

This is a prospective pilot comparative study conducted at American University of Beirut Medical Center, Beirut, Lebanon. In total, 40 consecutive patients were randomized to receive either intravitreal bevacizumab or ranibizumab. Patients received three consecutive monthly injections of the assigned drug, then continued treatment as needed. Systemic concentrations of high-sensitivity cardiac troponin T and vascular endothelial growth factor were obtained at baseline, week 9, and week 24. Primary endpoint measure was change in high-sensitivity cardiac troponin T levels compared to baseline. Secondary endpoint measure was change in systemic vascular endothelial growth factor levels.

Results:

There was no significant difference in high-sensitivity cardiac troponin T levels over time ( p = 0.227) within each treatment group and no significant difference between treatments at any time point ( p = 0.276). There was a significant decrease in plasma vascular endothelial growth factor levels at week 9 ( p = 0.001) and week 24 ( p < 0.001) compared to baseline. In the ranibizumab group, vascular endothelial growth factor levels were not significantly different at weeks 9 and 24 compared to baseline ( p = 0.708 and p = 0.117, respectively). There was a significant association between the number of bevacizumab injections from weeks 8 to 24 and the decrease in vascular endothelial growth factor levels at week 24 ( R = −0.67, p = 0.032). This correlation was not observed in the ranibizumab group ( R = −0.341, p = 0.141).

Conclusion:

Repeated intravitreal bevacizumab or ranibizumab did not influence serum high-sensitivity cardiac troponin levels. Intravitreal bevacizumab but not ranibizumab lowered free-systemic vascular endothelial growth factor levels, which was observed in this study to be inversely related to the number of bevacizumab injections.
Expression of platelet-derived growth factor-C in aqueous humor of patients with neovascular glaucoma and its correlation with vascular endothelial growth factor
Authors: Li Yujie , Hu Dan , Lv Peilin , Xing Minyan , Song Zejuan , Li Chan , Wang Yusheng , Hou Xu
Published: February 2019

Aim:

The aim of this study was to investigate the expression of platelet-derived growth factor-C in aqueous humor of patients with neovascular glaucoma and its correlation with vascular endothelial growth factor.

Methods:

This study involved 62 eyes of 62 patients with advanced neovascular glaucoma requiring transscleral cyclophotocoagulation. Aqueous humor was collected through paracentesis. Samples from 11 eyes of 11 patients with age-related cataract were collected as control. Concentrations of platelet-derived growth factor-C and vascular endothelial growth factor in aqueous humor were quantified by enzyme-linked immunosorbent assay. Meanwhile, the correlations between the concentrations of platelet-derived growth factor-C and vascular endothelial growth factor were analyzed. The elements including retinal photocoagulation treatment, iris neovascularization grade, and primary fundus disease were also studied to find out their roles in the concentrations of the two factors.

Results:

The vascular endothelial growth factor and platelet-derived growth factor-C concentrations in aqueous humor from controls were (679.54 ± 49.81) pg/mL and (18.60 ± 1.85) pg/mL, respectively. Both of them were significantly lower than neovascular glaucoma patients ( p < 0.001). The vascular endothelial growth factor and platelet-derived growth factor-C concentrations of neovascular glaucoma patients treated with retinal photocoagulation were (1095.99 ± 52.71) pg/mL and (28.55 ± 0.94) pg/mL, respectively, which were both significantly lower than those of untreated neovascular glaucoma patients, (1146.28 ± 69.57) pg/mL and (30.04 ± 1.64) pg/mL ( p = 0.008, p = 0.034). There was a weak correlation between the expression level of vascular endothelial growth factor and platelet-derived growth factor-C in aqueous humor with neovascular glaucoma ( r = 0.346, p = 0.006). However, iris neovascularization grade and primary fundus disease were not significant elements in the expression level of vascular endothelial growth factor and platelet-derived growth factor-C.

Conclusion:

Higher concentrations of vascular endothelial growth factor and platelet-derived growth factor-C were found in aqueous humor of patients with neovascular glaucoma compared with control, which could be lowered by retinal photocoagulation to some extent. Platelet-derived growth factor-C inhibitors may be another potential target for ocular neovascular diseases.
The feasibility of online video calling to engage patients with cystic fibrosis in exercise training
Authors: Tomlinson Owen W , Shelley James , Trott Jayne , Bowhay Ben , Chauhan Rohan , Sheldon Christopher D
Published: February 2019

Introduction

Physical activity, including structured exercise, is an essential component in the management of cystic fibrosis. The use of telehealth such as video-calling may be a useful method for the delivery of exercise and physical activity interventions, though the feasibility of this remains unknown.

Methods

Nine patients with cystic fibrosis (three female, six male, 30.9 ± 8.7 years) volunteered to participate. Participants completed an eight-week exercise training intervention conducted via Skype, using personalised exercises, with all sessions supervised by an exercise therapist. Feasibility was assessed by demand, implementation, practicality and acceptability. Changes in anthropometric, pulmonary, physical activity and quality of life variables were also assessed.

Results

Two male participants withdrew from the study, citing lack of available time. The remaining participants found use of Skype useful, with a mean satisfaction rating of 9/10, and three participants requesting to continue the sessions beyond the duration of the study. Mean compliance with sessions was 68%, with mean duration of sessions being 20 min. A total of 25% of calls suffered from technical issues such as video or audio lags. Anthropometric, pulmonary, physical activity and quality of life variables remained unchanged over the course of the study period.

Discussion

The use of Skype to deliver an exercise intervention to patients withcystic fibrosis was found to be technologically feasible, and acceptable among participants. Findings have implications for clinical practice and could allow care teams to engage patients remotely in exercise. Further research is required to assess the efficacy of this modality on increasing physical activity and associated health outcomes.
Crossing genre boundaries: H. J. Golakai's Afropolitan chick-lit mysteries
Authors: Fasselt Rebecca
Published: February 2019

Crime fiction by women writers across the globe has in recent years begun to explore the position of women detectives within post-feminist cultural contexts, moving away from the explicit refusal of the heterosexual romance plot in earlier feminist ‘hard-boiled’ fiction. In this article, I analyse Hawa Jande Golakai's The Lazarus Effect (2011) and The Score (2015) as part of the tradition of crime fiction by women writers in South Africa. Joining local crime writers such as Angela Makholwa, Golakai not only questions orthodox conceptions of gender and sexuality in traditional iterations of the crime novel, but also combines elements of chick-lit with the crime plot. Reading the archetypal quest structure of the two genres against the background of Sara Ahmed's cultural critique of happiness, I argue that Golakai inventively recasts the recent sub-genre of the chick-lit mystery from the perspective of an Afropolitan detective. Her detective tenaciously undercuts the future-directed happiness script that structures conventional chick-lit and detective novels with their respective focus on finding a fulfilling heterosexual, monogamous romantic relationship, and the resolution of the crime and restoration of order. In this way, the novels defy the frequently assumed apolitical nature of chick-lit texts and also allow us to reimagine the idea of Afropolitanism, outside of its dominant consumerist form, as a critical Afropolitanism that emerges from an openness to be affected by the unhappiness and suffering of others.
Self-Perceived Mate Value Is Poorly Predicted by Demographic Variables
Authors: Csajbók Zsófia , Havlíček Jan , Demetrovics Zsolt , Berkics Mihály
Published: February 2019

Mate value is a construct that can be measured in various ways, ranging from complex but difficult-to-obtain ratings all the way to single-item self-report measures. Due to low sample sizes in previous studies, little is known about the relationship between mate value and demographic variables. In this article, we tested the Mate Value Scale, a relatively new, short, 4-item self-report measure in two large samples. In the first sample of over 1,000, mostly college-age participants, the scale was found to be reliable and correlated with criterion variables in expected ways. In the second, larger sample, which included over 21,000 participants, we have tested for differences across demographics. Contrary to theoretical expectations and previous findings with smaller samples, the differences were either very small (sexual orientation, age, education) or small (sex, socioeconomic status, relationship status) in terms of their effect size. This suggests that the scale is not measuring “objective” mate value (as understood either in terms of fitness or actual mating decisions by potential partners on the “market”), but a self-perception of it, open to social comparison, relative standards, possibly even biases, raising questions about measuring self-perceived versus objective mate value.
A Nordic transition regime? Policies for school-to-work transitions in Sweden, Denmark and Finland
Authors: Helms Jørgensen Christian , Järvinen Tero , Lundahl Lisbeth
Published: February 2019

In recent decades, a range of policy measures to support young people’s school-to-work transitions has been initiated across Europe. However, these transition policies have rarely been studied systematically, particularly from a comparative perspective. Thus, the aim of this article is to compare Swedish, Danish and Finnish policies for supporting young people’s educational and school-to-work transitions. Synthesising and analysing recent research, the article critically draws on Walther’s (2006) classification of transition regimes that recognises a Nordic universalistic regime of youth transitions characterised by emphasis on collective social responsibility, individual motivation and personal development. We conclude that significant policy changes have occurred during the last two decades. Coercive measures have been adopted and social support reduced, making young people more individually responsible for the success of their transitions. Hence, current transition policies diverge in many respects from qualities traditionally ascribed to the Nordic transition regime. We also find significant differences between the three countries’ transition policies, which in some cases indicate policy trade-offs. In addition, we conclude that transition policies are generally weakly coordinated across policy domains, which increases the risk of unintended consequences of these policies.
Balancing ‘flexibility’ and ‘employability’: The changing role of general studies in the Finnish and Swedish VET curricula of the 1990s and 2010s
Authors: Nylund Mattias , Virolainen Maarit
Published: February 2019

This article analyses and compares the evolving role of general subjects in the curricula of initial upper secondary vocational education and training (VET) in Finland and Sweden during the 1990s and 2010s. The research illustrates how Bernstein’s concept of ‘pedagogic code’ supports comparative studies on principles guiding changes to curricula and how the role of general studies in VET has been redefined. The findings show that while a principle of ‘market relevance’ has been central to VET over the decades since the 1990s, it has been subject to varying interpretations. The shifts in interpretations have guided the organisation of VET in these two countries in different directions, including the role of general subjects within the curriculum. On a general level, the countries share some key similarities. Both countries emphasised lifelong learning and a broadening of VET in the 1990s, based on a core principle of ‘flexibility’. In the 2010s, the earlier promotion of flexibility and universal access to higher education was superseded by a stronger focus on employability and entrepreneurship in addition to students’ command of more specific vocational tasks.
In pursuit of community engagement: Unpacking the knowledge and skills associated with service-learning efforts
Authors: Lillo Sarah R
Published: February 2019

The study described in this article highlights the complexity of service-learning efforts and community engagement pursuits. It is based on 6.5 months of qualitative fieldwork in International Baccalaureate international schools in Kenya, Ethiopia, and South Africa. The article unpacks the understandings and skills involved in service-learning efforts through a framework developed by the research. The framework includes six knowledge domains: service-learning pedagogy, global issues, school contexts, local contexts, leadership/organizations, and communication. The author argues that related competencies in these domains support efforts, whereas related knowledge gaps impede efforts. Such a framework allows teams to be self-reflective and intentional, justifies related resources, and explains the strain that educators involved in these pursuits can feel. The author argues that facilitators need to have deep knowledge in far more than service-learning pedagogy.
Academic Success and 1 Year of Intramural Sports Participation by Freshmen Students
Authors: Vasold Kerri L. , Kosowski Lauren E. , Pivarnik James M.
Published: February 2019

The purpose of this study was to investigate differences in academic indicators among intramural sports participants and nonparticipants following their first year of college. Matched samples ( N = 1,796; 898 pairs) were generated based on demographic variables. Data were obtained from university databases. Paired sample t tests and logistic regression were used to assess differences between participants and nonparticipants. First-semester and first-year grade point average were significantly higher ( p < .001) for participants than nonparticipants. First-semester and first-year credit difference were significantly lower ( p < .001) for intramural sports participants than nonparticipants. Participants were more than twice as likely to be retained than nonparticipants and 40% more likely to achieve sophomore status. Results suggest that freshmen students participating in intramural sports during their first year of college achieve greater academic success than nonparticipants.
Vacuum for straightening the microcatheter after intra-aneurysmal looping: The “Lagman vacuum” technique
Authors: Lagios Konstantinos , Mantatzis Michalis
Published: February 2019

In many cases, an intra-arterial microcatheter loop is necessary to bypass the neck of wide-necked giant aneurysms for the placement of a stent across it. The removal of this loop is usually challenging, and many techniques have been described to achieve it. We describe a simple novel technique for straightening the microcatheter across the aneurysm’s neck, without the need for additional products/devices or complex exchanging techniques. The method has been successfully applied in two cases. We named this novel maneuver the “Lagman vacuum” technique.
Nerve injury elevates functional Cav3.2 channels in superficial spinal dorsal horn
Authors: Feng Xiao-Jin , Ma Long-Xian , Jiao Cui , Kuang Hai-Xia , Zeng Fei , Zhou Xue-Ying , Cheng Xiao-E , Zhu Meng-Ye , Zhang Da-Ying , Jiang Chang-Yu , Liu Tao
Published: February 2019

Cav3 channels play an important role in modulating chronic pain. However, less is known about the functional changes of Cav3 channels in superficial spinal dorsal horn in neuropathic pain states. Here, we examined the effect of partial sciatic nerve ligation (PSNL) on either expression or electrophysiological properties of Cav3 channels in superficial spinal dorsal horn. Our in vivo studies showed that the blockers of Cav3 channels robustly alleviated PSNL-induced mechanical allodynia and thermal hyperalgesia, which lasted at least 14 days following PSNL. Meanwhile, PSNL triggered an increase in both mRNA and protein levels of Cav3.2 but not Cav3.1 or Cav3.3 in rats. However, in Cav3.2 knockout mice, PSNL predominantly attenuated mechanical allodynia but not thermal hyperalgesia. In addition, the results of whole-cell patch-clamp recordings showed that both the overall proportion of Cav3 current-expressing neurons and the Cav3 current density in individual neurons were elevated in spinal lamina II neurons from PSNL rats, which could not be recapitulated in Cav3.2 knockout mice. Altogether, our findings reveal that the elevated functional Cav3.2 channels in superficial spinal dorsal horn may contribute to the mechanical allodynia in PSNL-induced neuropathic pain model.
Perioperative care of a patient with clam cystoileoplasty undergoing caesarean section: A case review
Authors: McGarry Jon R
Published: February 2019

This case report describes the care provided to a 35-year-old primagravida having an elective section who had undergone clam cystoileoplasty eight years prior. It examines the literature relating to this surgical technique and its implications for obstetric practice. It also examines anaesthetic considerations related to the surgery. Close involvement with urology surgeons is essential and the patient must be supported in their choices relating to ongoing management of continence.
Post-neoadjuvant treatment and the management of residual disease in breast cancer: state of the art and perspectives
Authors: Caparica Rafael , Lambertini Matteo , Pondé Noam , Fumagalli Debora , de Azambuja Evandro , Piccart Martine
Published: February 2019

Achieving a pathologic complete response after neoadjuvant treatment is associated with improved prognosis in breast cancer. The CREATE-X trial demonstrated a significant survival improvement with capecitabine in patients with residual invasive disease after neoadjuvant chemotherapy, and the KATHERINE trial showed a significant benefit of trastuzumab-emtansine (TDM1) in human epidermal growth factor receptor 2 (HER2)-positive patients who did not achieve a pathologic complete response after neoadjuvant treatment, creating interesting alternatives of post-neoadjuvant treatments for high-risk patients. New agents are arising as therapeutic options for metastatic breast cancer such as the cyclin-dependent kinase inhibitors and the immune-checkpoint inhibitors, but none has been incorporated into the post-neoadjuvant setting so far. Evolving techniques such as next-generation sequencing and gene expression profiles have improved our knowledge regarding the biology of residual disease, and also on the mechanisms involved in treatment resistance. The present manuscript reviews the current available strategies, the ongoing trials, the potential biomarker-guided approaches and the perspectives for the post-neoadjuvant treatment and the management of residual disease after neoadjuvant treatment in breast cancer.
Prognostic value of ALDH1 and Nestin in advanced cancer: a systematic meta-analysis with trial sequential analysis
Authors: Han Susu , Huang Tao , Wu Xing , Wang Xiyu , Li Wen , Liu Shanshan , Yang Wei , Shi Qi , Li Hongjia , Shi Kunhe , Hou Fenggang
Published: February 2019

Background:

Novel prognostic markers and therapeutic targets for advanced cancer are urgently needed. This report with trial sequential analysis (TSA) was first conducted to provide robust estimates of the correlation between aldehyde dehydrogenase 1 (ALDH1) and Nestin and clinical outcomes of advanced cancer patients.

Methods:

Hazard ratios (HRs) with 95% confidence intervals (CIs) were summarized for overall survival (OS), disease-free survival (DFS), progression-free survival (PFS), cancer-specific survival (CSS), relapse/recurrence-free survival (RFS), and metastasis-free survival (MFS) from multivariable analysis. TSA was performed to control for random errors.

Results:

A total of 20 studies with 2050 patients (ALDH1: 15 studies with 1557 patients and Nestin: 5 studies with 493 patients) were identified. ALDH1 (HR = 2.28, p < 0.001) and Nestin (HR = 2.39, p < 0.001) were associated with a worse OS, as confirmed by TSA. Nestin positivity was linked to a poor PFS (HR = 2.08, p < 0.001), but ALDH1 was not linked to DFS, RFS, MFS, or PFS, and TSA showed that more studies were needed. Subgroup analysis by tumor type indicated that ALDH1 positivity may be associated with shorter OS in breast, head and neck cancers, but there was no association with colorectal cancer. Subgroup analysis by study source showed that ALDH1 positivity was correlated with a worse OS for Japanese (HR = 1.94, p = 0.002) and European patients (HR = 4.15, p < 0.001), but there was no association for Chinese patients. Subgroup analysis by survival rate showed that ALDH1 positivity correlated with poor OS at ⩾ 5 years (HR = 2.33, p < 0.001) or 10 years (HR = 1.76, p = 0.038).

Conclusions:

ALDH1 may be more valuable as an effective therapeutic target than Nestin for improving the long-term survival rate of advanced cancer. Additional prospective clinical trials are needed across different cancer types.
Optimal mechanical properties of a scaffold for cartilage regeneration using finite element analysis
Authors: Koh Yong-Gon , Lee Jin-Ah , Kim Yong Sang , Lee Hwa Yong , Kim Hyo Jeong , Kang Kyoung-Tak
Published: February 2019

The development of successful scaffolds for bone tissue engineering requires concurrent engineering that combines different research fields. In previous studies, phenomenological computational models predicted the mechanical properties of a scaffold in a simple loading condition using the mechano-regulation theory. Therefore, the aim of this study is to predict the mechanical properties of an optimum scaffold required for cartilage regeneration using three-dimensional knee joint developed from medical imaging and mechano-regulation theory. It was predicted that the scaffold with optimal mechanical properties would result in greater amounts of cartilage tissue formation than without a scaffold. The results demonstrated the ability of the algorithms to design optimized scaffolds with target properties and confirmed the applicability of set techniques for bone tissue engineering. The scaffolds were optimized to suit the site-specific loading requirements, and the results reveal a new approach for computational simulations in tissue engineering.
Hypoxia‐induced pulmonary hypertension and chronic lung disease: caveolin‐1 dysfunction an important underlying feature
Authors: Huang Jing , Frid Maria , Gewitz Michael H. , Fallon John T. , Brown Dale , Krafsur Greta , Stenmark Kurt , Mathew Rajamma
Published: February 2019

Caveolin‐1 (cav‐1) has been shown to play a significant role in the pathogenesis of pulmonary hypertension (PH). In the monocrotaline model of PH, the loss of endothelial cav‐1 as well as reciprocal activation of proliferative and anti‐apoptotic pathways initiate the disease process and facilitate its progression. In order to examine the role of cav‐1 in hypoxia‐induced PH, we exposed rats and neonatal calves to hypobaric hypoxia and obtained hemodynamic data and assessed the expression of cav‐1 and related proteins eNOS, HSP90, PTEN, gp130, PY‐STAT3, β‐catenin, and Glut1 in the lung tissue. Chronic hypoxic exposure in rats (48 h–4 weeks) and calves (2 weeks) did not alter the expression of cav‐1, HSP90, or eNOS. PTEN expression was significantly decreased accompanied by PY‐STAT3 activation and increased expression of gp130, Glut1, and β‐catenin in hypoxic animals. We also examined cav‐1 expression in the lung sections from steers with chronic hypoxic disease (Brisket disease) and from patients with chronic lung disease who underwent lung biopsy for medical reasons. There was no cav‐1 loss in Brisket disease. In chronic lung disease cases, endothelial cav‐1 expression was present, albeit with less intense staining in some cases. In conclusion, hypoxia did not alter the cav‐1 expression in experimental models. The presence of cav‐1, however, did not suppress hypoxia‐induced activation of PY‐STAT3 and β catenin, increased gp130 and Glut1 expression, or prevent the PTEN loss, indicating cav‐1 dysfunction in hypoxia‐induced PH.
Parameters associated with outcome in pediatric patients with congenital heart disease and pulmonary hypertension subjected to combined vasodilator and surgical treatments
Authors: Thomaz Ana Maria , Kajita Luiz J. , Aiello Vera D. , Zorzanelli Leína , Galas Filomena Regina B.G. , Machado Cleide G. , Barbero‐Marcial Miguel , Jatene Marcelo B. , Rabinovitch Marlene , Lopes Antonio Augusto
Published: February 2019

Management of pediatric pulmonary hypertension associated with congenital heart disease (PHT‐CHD) is challenging. Some patients have persistently elevated pulmonary artery pressure (PAP) after cardiac surgery, an undesired condition that is difficult to predict. We investigated the value of clinical, hemodynamic, and histopathological data in predicting the outcome in a prospective cohort. Patients with PHT‐CHD received sildenafil orally pre‐ and postoperatively for six months and then were subjected to a catheter study. Thirty‐three patients were enrolled (age range = 4.6–37.0 months). Pulmonary vascular resistance (PVR) was 4.9 (range = 3.9–7.2) Wood units × m2 (median with IQR). Twenty‐two patients had a ≥ 20% decrease in PVR and pulmonary‐to‐systemic vascular resistance ratio (PVR/SVR) in response to inhaled nitric oxide (NO). The response was directly related to the degree of medial hypertrophy of pulmonary arterioles (P < 0.05) (morphometric analysis, intraoperative lung biopsy). Subsequently, five of the non‐responders had a ≥ 30% increase in pulmonary blood flow in response to sildenafil (3.0 [2.0–4.0] mg/kg/day). Six months after surgery, PAP and PVR were significantly lower (P < 0.001 vs. baseline), even in seven patients with Heath‐Edwards grade III/IV pulmonary vascular lesions (P = 0.018), but still abnormal in 12 individuals (>25 mmHg and >3.0 U × m2, respectively). A preoperative PVR/SVR of ≥24% during NO inhalation and a wall thickness of arteries accompanying respiratory bronchioli of ≥4.7 (Z score) were identified, respectively, as risk and protection factors for abnormal postoperative hemodynamics (hazard ratio [95% CI] = 1.09 [1.01–1.18], P = 0.036; and 0.69 [0.49–0.98], P = 0.040, respectively). Thus, in PHT‐CHD patients receiving oral sildenafil pre‐ and post‐surgical repair of cardiac lesions, mid‐term postoperative outcome is predictable to some extent.
Routine open abdomen treatment compared with on-demand open abdomen or direct closure following open repair of ruptured abdominal aortic aneurysms: A propensity score–matched study
Authors: Smidfelt Kristian , Nordanstig Joakim , Wingren Urban , Bergström Göran , Langenskiöld Marcus
Published: February 2019

Objective:

To investigate whether a strategy of treatment with a primarily open abdomen improves outcome in terms of mortality and major complications in patients treated with open repair for a ruptured abdominal aortic aneurysm compared to a strategy of primary closure of the abdomen.

Design:

Retrospective cohort study.

Methods:

Patients treated with a primarily open abdomen at a centre where this strategy was routine in most ruptured abdominal aortic aneurysm patients were compared to a propensity score–matched control group of patients who had the abdomen closed at the end of the primary operation in a majority of the cases.

Results:

In total, 79 patients treated with a primarily open abdomen after open repair for ruptured abdominal aortic aneurysm at Sahlgrenska University Hospital were compared to a propensity score–matched control group of 148 patients. The abdomen was closed at the end of the procedure in 108 (73%) of the control patients. There was no difference in 30-day mortality between patients treated with a primarily open abdomen at Sahlgrenska University Hospital and the controls, 21 (26.6%) versus 49 (33.1%), p = 0.37. The adjusted odds ratio for mortality at 30 days was 0.66 (95% confidence interval: 0.35–1.25) in patients treated with a primarily open abdomen at Sahlgrenska University Hospital compared to the controls. No difference was observed between the groups regarding 90-day mortality, postoperative renal failure requiring renal replacement therapy, postoperative intestinal ischaemia necessitating bowel resection or postoperative bleeding requiring reoperation.

Conclusions:

The study did not show any survival advantage or difference in major complications between patients treated with a primarily open abdomen after open repair for ruptured abdominal aortic aneurysm and propensity-matched controls where the abdomen was primarily closed in a majority of the cases.
A Nondiagnostic Assessment for Diagnostic Purposes: Q-Matrix Validation and Item-Based Model Fit Evaluation for the TIMSS 2011 Assessment
Authors: Terzi Ragip , Sen Sedat
Published: February 2019

Large-scale assessments are generally designed for summative purposes to compare achievement among participating countries. However, these nondiagnostic assessments have also been adapted in the context of cognitive diagnostic assessment for diagnostic purposes. Following the large amount of investments in these assessments, it would be cost-effective to draw finer-grained inferences about the attribute mastery. Nonetheless, the correctness of attribute specifications in the Q-matrix has not been verified, despite being designed by domain experts. Furthermore, the underlying process of TIMSS (Trends in International Mathematics and Science Study) assessment is unknown as it was not developed for diagnostic purposes. Thus, this study suggests an initial validating attribute specifications in the Q-matrix and thereafter defining specific reduced or saturated models for each item. In doing so, the two analyses were validated across 20 countries that were selected randomly for TIMSS 2011 data. Results show that attribute specifications can differ from expert opinions and the underlying model for each item can vary.
Critical Factors Influencing the Evolution of Companies’ Environmental Behavior: An Agent-Based Computational Economic Approach
Authors: Liu Yong , Li Fei , Su Yunpeng
Published: February 2019

Although a wealth of studies on companies’ environmental behavior exists, little is known about the factors with the greatest influence on the evolution of such behavior. Thus, employing empirical data on China and an agent-based simulation model, this study examines the evolution from defensive to preventive environmental behavior. The results show that community support is the most important factor in this process, followed by managers’ environmental awareness and companies’ financial ability. However, financial ability is the most significant factor in the evolution from preventive to enthusiastic environmental behavior, followed by managers’ environmental awareness and community support. Our identification of the most important factors can serve as a basis for decision makers to focus on improving the operational effectiveness of environmental policies.
Evaluating the buffering and acid-resistant properties of eggshell–titanium dioxide composite against erosive acids
Authors: Onwubu Stanley Chibuzor , Mdluli Phumlane Selby , Singh Shenuka
Published: February 2019

Objective:

This paper reports on the buffering and acid-resistant properties of a modified eggshell–titanium composite against citric acid attack.

Materials and Methods:

Eggshell–titanium EB-TiO2 was prepared by ball-milling eggshell powder and titanium dioxide. Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), and Transmission Electron Microscopy (TEM) were used to characterize EB-TiO2. The buffering property against citric acid at pH values of 2, 4, and 5 was measured using a pH meter. Five brands of toothpaste (Colgate, Colgate Sensitive, Aquafresh, Oralwise, and Sensodyne) were used to assess the acid-resistant properties of EB-TiO2. Enamel models were simulated by dissolving each brand of toothpaste with eggshell (control) and EB-TiO2. The samples were exposed to citric acid of pH 2. The average slope (kPa/s) was measured using a pressure sensor. An analysis of variance was used to analyze the kPa/s values (α =.05).

Results:

The FTIR and XRD analyses suggest the surface modification of EB-TiO2. The TEM image revealed spherical-shaped particles in EB-TiO2. The pH test results showed that the buffering properties of eggshell and EB-TiO2 were comparable. Significant differences were observed in the acid resistance properties of the samples exposed to citric acids ( P < .05). The Colgate toothpaste infused with eggshell powder had the highest mean kPa/s values, whereas Sensodyne infused with EB-TiO2 had the lowest kPa/s values.

Conclusion:

The salient features of this study indicate that modification of eggshell with titanium dioxide does not affect its carbonate buffering properties. Connecting the kPa/s values to acid-resistant properties, EB-TiO2 effectively reduces erosive attacks when added to toothpaste.
Investigation of load transfer process between external fixator and bone model by experimental and finite element methods
Authors: Zhao Xia , Li Jianfeng , Chen Ying , Tao Chunjing , Ji Run
Published: February 2019

Introduction:

Unilateral external fixators are widely used in orthopedics to stabilize fractured bones and to treat limb deformities. One of the main problems is that it is difficult to detect healing status. In addition, whether load transfer progress between the fixator and bone model are the same under axial, torsional, and bending loads has not been studied.

Methods:

Therefore the main purpose of this study was to detect the load transfer process between the fixator and a bone model by measuring strains on the fixator–bone system during four healing states using experimental and finite element methods. In the experimental method, 20 strain gauges were used to measure strain on the fixator and bone model under three load conditions. Polyacetal slice models with different material properties were used to simulate the callus model during four growth states.

Results:

The results indicate that strain on the bone model increased and strain on the fixator parts decreased with maturation of the callus under axial, bending, and torsional loads. Although all curves showed a similar changing trend, they were slightly different under the three loads.

Discussion and conclusions:

This study provides a useful method to monitor the fracture healing process, and identifies the healing endpoint, detects healing status, and provides useful information for the orthopedist.
Lime-cement textile reinforced mortar (TRM) with modified interphase
Authors: Signorini Cesare , Sola Antonella , Nobili Andrea , Siligardi Cristina
Published: February 2019

Background:

Lack of interphase compatibility between the fabric and the matrix significantly impairs the load-bearing capacity of textile reinforced mortar (TRM). In this study, we consider the application of two inorganic surface coatings for enhancing the interphase bond properties.

Methods:

Either of two silica-based coatings, namely nano- and micro-silica, were applied to alkali-resistant glass (ARG) and to hybrid carbon–ARG woven fabric. Mechanical performance of TRM reinforced with the uncoated and the coated fabric was compared in uniaxial tensile tests.

Results:

Mechanical testing provides evidence of a remarkable enhancement in terms of ultimate strength and deformability for the coated specimens. This effect can be ascribed to the improved hydrophilicity of the fibers’ surface and to the activation of pozzolanic reaction at the interphase. In addition, penetration of nano- and microparticles in the bundle of the textile yarns reduces the occurrence of telescopic failure.
Engineering biological gradients
Authors: Sardelli L , Pacheco DP , Zorzetto L , Rinoldi C , Święszkowski W , Petrini P
Published: February 2019

Biological gradients profoundly influence many cellular activities, such as adhesion, migration, and differentiation, which are the key to biological processes, such as inflammation, remodeling, and tissue regeneration. Thus, engineered structures containing bioinspired gradients can not only support a better understanding of these phenomena, but also guide and improve the current limits of regenerative medicine. In this review, we outline the challenges behind the engineering of devices containing chemical-physical and biomolecular gradients, classifying them according to gradient-making methods and the finalities of the systems. Different manufacturing processes can generate gradients in either in-vitro systems or scaffolds, which are suitable tools for the study of cellular behavior and for regenerative medicine; within these, rapid prototyping techniques may have a huge impact on the controlled production of gradients. The parallel need to develop characterization techniques is addressed, underlining advantages and weaknesses in the analysis of both chemical and physical gradients.
The effects of cryotherapy on quadriceps electromyographic activity and isometric strength in patient in the early phases following knee surgery
Authors: Loro William A , Thelen Mark D , Rosenthal Michael D , Stoneman Paul D , Ross Michael D
Published: February 2019

Purpose:

To determine the effects of cryotherapy on quadriceps electromyographic (EMG) activity and isometric strength in early postoperative knee surgery patients.

Methods:

Twenty-two volunteers with recent knee surgeries were included. EMG readings of the vastus medialis (VM), rectus femoris (RF), and vastus lateralis (VL) from the surgical leg were collected during a maximal voluntary quadriceps setting (QS) activity. Maximum isometric knee extension force measurements were also recorded. Subjects were randomly assigned to receive an ice bag or a sham room-temperature bag to the front of their postsurgical knee for 20 min. After treatment, the subjects repeated the above mentioned maximum QS and isometric knee extension force measurements. The subjects returned 24 h later to conduct the same test protocol but received the treatment (ice or sham) not applied during their first test session.

Results:

A 38% increase in VM EMG activity during QS and a 30% increase in maximum isometric knee extension strength were found after cryotherapy treatment. No significant differences were found in RF or VL EMG activity during QS after cryotherapy. No significant differences were found in any measurements after the sham treatment.

Conclusion:

Clinicians should consider applying ice to knee joints prior to exercise for patients following knee surgery with inhibited quadriceps.