bluuebunny/crossref_metadata_2025 huggingface dataset:
Medical Cannabis: Effects on Opioid and Benzodiazepine Requirements for Pain Control
Authors: O’Connell Megan , Sandgren Megan , Frantzen Leah , Bower Erika , Erickson Brian
Published: May 2019

Background: There is currently little evidence regarding the use of medical cannabis for the treatment of intractable pain. Literature published on the subject to date has yielded mixed results concerning the efficacy of medical cannabis and has been limited by study design and regulatory issues. Objective: The objective of this study was to determine if the use of medical cannabis affects the amount of opioids and benzodiazepines used by patients on a daily basis. Methods: This single-center, retrospective cohort study evaluated opioid and benzodiazepine doses over a 6-month time period for patients certified to use medical cannabis for intractable pain. All available daily milligram morphine equivalents (MMEs) and daily diazepam equivalents (DEs) were calculated at baseline and at 3 and 6 months. Results: A total of 77 patients were included in the final analysis. There was a statistically significant decrease in median MME from baseline to 3 months (−32.5 mg; P = 0.013) and 6 months (−39.1 mg; P = 0.001). Additionally, there was a non–statistically significant decrease in median DE at 3 months (−3.75 mg; P = 0.285) and no change in median DE from baseline to 6 months (−0 mg; P = 0.833). Conclusion and Relevance: Over the course of this 6-month retrospective study, patients using medical cannabis for intractable pain experienced a significant reduction in the number of MMEs available to use for pain control. No significant difference was noted in DE from baseline. Further prospective studies are warranted to confirm or deny the opioid-sparing effects of medical cannabis when used to treat intractable pain.
Eating Disorder Recovery: A Metaethnography
Authors: Eaton Carrie Morgan
Published: May 2019

BACKGROUND: Eating disorders seriously affect both physical health and psychosocial functioning. Breaking the confines of an eating disorder requires engagement in a multifaceted recovery process. OBJECTIVE: This article provides a synthesis of 12 qualitative research studies with various eating disordered populations (anorexia nervosa, bulimia nervosa, binge eating disorder, eating disorder not otherwise specified, and other specified feeding and eating disorders) to elucidate the recovery process from the perspective of those who have overcome the disease. METHOD: A metasynthesis of qualitative studies was conducted using Noblit and Hare’s metaethnographic methodology. RESULTS: Five overarching themes emerged from the data: (1) the eating disorder as a life jacket, (2) drowning: recognizing consequences, (3) treading the surface: contemplating recovery, (4) swimming: the path toward recovery, and (5) reaching recovery: a sense of freedom. CONCLUSIONS: Eating disorder treatment often entails a cycle of transitions before recovery occurs. Synthesizing the experiences from the perspective of individuals who have overcome an eating disorder presents a unique understanding of the treatment and recovery process.
Effective properties of hierarchical fiber-reinforced composites via a three-scale asymptotic homogenization approach
Authors: Ramírez-Torres Ariel , Penta Raimondo , Rodríguez-Ramos Reinaldo , Grillo Alfio
Published: May 2019

The study of the properties of multiscale composites is of great interest in engineering and biology. Particularly, hierarchical composite structures can be found in nature and in engineering. During the past decades, the multiscale asymptotic homogenization technique has shown its potential in the description of such composites by taking advantage of their characteristics at the smaller scales, ciphered in the so-called effective coefficients. Here, we extend previous works by studying the in-plane and out-of-plane effective properties of hierarchical linear elastic solid composites via a three-scale asymptotic homogenization technique. In particular, the approach is adjusted for a multiscale composite with a square-symmetric arrangement of uniaxially aligned cylindrical fibers, and the formulae for computing its effective properties are provided. Finally, we show the potential of the proposed asymptotic homogenization procedure by modeling the effective properties of musculoskeletal mineralized tissues, and we compare the results with theoretical and experimental data for bone and tendon tissues.
Understanding Replication: Trust But Verify
Authors: Suter W. Newton , Suter Paula M.
Published: May 2019

Replication as a pillar of science is described in the context of the replication crisis that first struck psychology but spread quickly to other science-based fields. Empirical evidence suggests that the crisis is real but not well understood. We explain why replication often fails in science and how research in home health can be strengthened by a greater understanding of the value of replication and current thinking about replication success or failure decisions. We conclude with a call for replication in home health nursing that couples original research and replication in the same report.
Loss of Placental P-Glycoprotein May Be a Common Pathophysiologic Pathway for First Trimester Spontaneous Miscarriages
Authors: Lanjewar Sonali , Jayakumar Rajeswari , Axiotis Constantine A
Published: May 2019

Introduction

P-glycoprotein the highly conserved mammalian adenosine triphosphate-binding cassette transmembrane multidrug protein transporter is involved in peri-implantation events and fetal placental development. Greater expression in early versus late pregnancy and localization in both syncytio- and cytotrophoblast indicate that P-glycoprotein transports substances across the uterine epithelium during early pregnancy and protects the conceptus from toxic substances during implantation and early embryogenesis. We hypothesized that P-glycoprotein is involved in the physiologic maintenance of early pregnancy and that P-glycoprotein dysregulation may be involved in early pregnancy pathologies.

Methods

First trimester dilation and curettage specimens were selected retrospectively from the archives of the Department of Pathology from spontaneous miscarriages (n = 36) and elective termination of pregnancy (n = 20). Two P-glycoprotein specific monoclonal antibodies JSB1and C219 were used on formalin-fixed, paraffin-embedded 5µ tissue sections. The location, intensity, and percentage of P-glycoprotein chorionic villous immunostaining were semiquantitated.

Results

Spontaneous miscarriages demonstrated absence or significant reduction in P-glycoprotein compared to elective terminations; 75% (27/36) showed total absence of P-glycoprotein, 19% (7/36) showed only rare villi with discontinuous immunostaining, and 6% (2/36) showed weak immunostaining. In contrast, 90% of elective terminations (18/20) showed positive immunostaining for P-glycoprotein and only 10% (2/20) showed loss of P-glycoprotein expression ( P < .0001).

Discussion

We report a dramatic loss/decrease of P-glycoprotein in first trimester spontaneous miscarriages. This finding in conjunction with the known high expression of P-glycoprotein in normal first trimester placental tissues suggests an important role of P-glycoprotein in the maintenance of early pregnancy.
Experimental and numerical analysis of the dynamic behavior of a bio-based sandwich with an auxetic core
Authors: Essassi Khawla , Rebiere Jean-Luc , Mahi Abderrahim EL , Souf Mohamed Amine Ben , Bouguecha Anas , Haddar Mohamed
Published: May 2019

This paper presents the experimental and numerical analysis results of the damping properties of a bio-based sandwich with an auxetic core. The skins and core of the sandwich structure are made from the same material which is a polylactic acid reinforced with flax fibers. A 3D printing technique was used to produce the sandwich structures. Experimental tests were conducted on the skins, the auxetic structure and the sandwich beams to evaluate their damping properties. Vibration tests were performed in a clamped-free configuration. Those tests were carried out on two different configurations and four core densities of the auxetic structures in order to investigate their effect on the damping factors and dynamic stiffness. Furthermore, finite element analysis was used to validate the experimental results. The resonance frequencies and the loss factor obtained from experimental and numerical analysis were in close agreement. Finally, a study of the effect of each sandwich component on energy dissipation was carried out in order to understand the dynamic response of such beams.
Drug-coated balloon angioplasty in failing haemodialysis arteriovenous shunts: 12-month outcomes in 200 patients from the Aperto Italian registry
Authors: Tozzi Matteo , Franchin Marco , Savio Daniele , Comelli Simone , Di Maggio Luca , Carbonari Luciano , Ebrahimi Reza , Fontana Federico , Piacentino Filippo , Cervarolo Maria Cristina , Palermo Vincenzo , Piffaretti Gabriele
Published: May 2019

Background:

We evaluated the safety and technical and clinical outcomes of angioplasty with a drug-coated balloon for the management of venous stenosis in arteriovenous grafts and arteriovenous fistulas in patients undergoing haemodialysis.

Methods:

Data were obtained from an ongoing prospective, non-randomised registry conducted at three Italian centres. Patients were treated with a drug-coated balloon according to standard procedures in each participating centre. Evaluation was by colour Doppler imaging every 3 months. The primary end-point was primary assisted patency. The secondary end-point was the rate of assisted patency of the vascular access.

Results:

A total of 311 angioplasty procedures in 200 patients, (60.4% male), were analysed. The procedural success rate was 100%. A total of 192 treatments of restenosis were necessary in 81 patients during average 21 ± 8 months follow-up. Kaplan–Meier estimates indicated that 88.0%, 64.2% and 40.6% of treated lesions were free from restenosis at 6, 12 and 24 months, respectively. Including multiple angioplasty, circuit patency rates were 99.2%, 92.5% and 84.8% at 6, 12 and 24 months, respectively. Primary patency rates were highest in shunts treated de novo with drug-coated balloons. Risk of restenosis was associated with circuit age (p = 0.017), history of treatment with conventional angioplasty (p < 0.001) and the kind of balloon used during pre-dilation (p = 0.001).

Conclusion:

The results suggest that favourable long-term patency rates can be achieved with the drug-coated balloon in a varied population of patients with failing haemodialysis arteriovenous shunts treated under conditions of actual care.
Analysis of magnetohydrodynamic partial slip laser bump texture slider and journal bearing
Authors: Rao TVVLN , Rani Ahmad Majdi Abdul , Mohamed Norani Muti , Ya Hamdan Haji , Awang Mokhtar , Hashim Fakhruldin Mohd
Published: May 2019

A model of magnetohydrodynamic partial slip laser texture bearing (slider and journal) is developed. The influence of laser bump texture and slip laser texture partial configuration on the magnetohydrodynamic performance analysis of bearing is presented. An electrically conducting fluid is confined to bearing surfaces under uniform magnetic field perpendicular to slider bearing and inclined to the line of maximum film thickness to journal bearing. A one-dimensional analysis based on the narrow groove theory is considered to evaluate the nondimensional pressure distribution in bearing. Results of the nondimensional load capacity and coefficient of friction of magnetohydrodynamic partial laser bump texture and partial slip laser texture bearing configurations are analyzed. Partial slip configuration under MHD lubrication without laser bump texture brings in the performance improvement.
Is your online identity different from your offline identity? – A study on the college students’ online identities in China
Authors: Qin Yue , Lowe John
Published: May 2019

This study took innovative perspectives in studying the college students’ online identities in China. Three modes of online identities were found to satisfy the participants’ different needs, which indicate the principle of what is lacking tends to appear online. The logic of ‘imagination–reflection circle’ explains these online behaviours and show the ‘rationality’ in choosing among different identities to fulfill the users’ different needs according to different online settings. The college students showed a better control of themselves compared with their period of adolescences. Under this situation, most of the online experiments are beneficial to these college students, except when the transition between different identities is difficult.
Mahi a Atua: A Māori approach to mental health
Authors: Maree Kopua Diana , Kopua Mark A , Bracken Patrick J
Published: May 2019

Māori are the indigenous people of Aotearoa New Zealand. European colonisation had a devastating effect on their communities and their way of life. While there is some evidence of a renaissance of Māori culture in recent years, like other indigenous people across the world, they continue to be massively overrepresented in their country’s figures for poor mental and physical health. In this paper, we briefly review the literature on the Movement for Global Mental Health and review the case that has been made for the use of indigenous psychologies in place of approaches based on Western psychiatry and psychology. We present two case histories where an intervention based on an indigenous Māori approach to negotiating emotional conflicts and dealing with mental health problems was used. This approach, called Mahi a Atua, was developed by two of the authors over a number of years. We conclude that indigenous approaches to mental health offer not just an adjunct to, but a real alternative to, the interventions of Western psychiatry. They provide a framework through which individuals and families can negotiate their journeys through mental health crises and difficulties. However, such approaches can also work on a socio-cultural level to promote a positive identity for indigenous communities by celebrating the power of indigenous deities, narratives, and healing practices that were marginalised and suppressed by the forces of colonisation.
Sensorless adaptive rotor flux direct vector-controlled induction motor drive based on fuzzy logic control flux estimator
Authors: Kuo Ying-Piao , Ji Yan-Chen
Published: May 2019

In this paper, we propose the application of a speed estimation strategy to a fuzzy logic control flux estimator for a sensorless adaptive rotor flux direct-vector-controlled (RFDVC) induction motor drive. The RFDVC induction motor drive was established using the stator current and rotor flux, with the stator current being obtained from the induction motor. The model reference adaptive system (MRAS) theory was utilized to develop an adaptive rotor flux estimator based on voltage-model and current-model flux estimators. The estimated rotor speed and synchronous angle position are derived from the adaptive flux estimator. The adjustment mechanism of this estimator was designed using the fuzzy logic control strategy because this scheme is simple, easy to implement, and requires no precise information about the mathematical model. The MATLAB/Simulink® toolbox was used to simulate this system, and all the control algorithms were realized using a TI 6713-and-F2812 DSP card to validate this approach. Both the simulation and experimental results (including the estimated rotor speed, electromagnetic torque, and stator flux locus) confirmed the effectiveness of the proposed system and thereby validate the proposed approach.
Intelligent fault diagnosis of rotating machinery based on deep learning with feature selection
Authors: Han Dongying , Liang Kai , Shi Peiming
Published: May 2019

In the absence of a priori knowledge, manual feature selection is too blind to find the sensitive features which can effectively classify the different fault features. And it is difficult to obtain a large number of typical fault samples in practice to train the intelligent classifier. A novel intelligent fault diagnosis method based on feature selection and deep learning is proposed for rotating machine mechanical in the paper. In this method, the deep neural network is not only used for feature extraction but also for fault diagnosis. First, the deep neural network 1 is used to extract feature from the spectral signal of the original signal. In addition, the original vibration signal is decomposed to a series of intrinsic mode function components by empirical mode decomposition, and the statistical features of each intrinsic mode function component are extracted by the deep neural network 2 in time domain and frequency domain. Second, the extraction features of the original signal spectrum and the extraction features of each intrinsic mode function component are evaluated, respectively. After features evaluation, the selected sensitive features are combined together to construct a joint feature. Finally, the joint feature is put into the deep neural network 3 to realize the automatic recognition of different fault states of rotating machinery. The experimental results show that the method proposed in this paper which integrated time-domain, frequency-domain statistical characteristics, empirical mode decomposition, feature selection, and deep learning methods can obtain the fault information in detail and can select sensitive features from a large number of fault features. The method can reduce the network size, improve the mechanical fault diagnosis classification accuracy, and has strong robustness.
The effects of journalistic transparency on credibility assessments and engagement intentions
Authors: Curry Alexander L , Stroud Natalie Jomini
Published: May 2019

Transparency is an oft-cited remedy for the public’s lack of confidence in the news media. Yet scant empirical evidence exists to support this claim. This article presents a test of the relationship between increased journalistic transparency and credibility evaluations of a news organization. Experimental results suggest that increasing transparency (by providing news consumers with information about why and how a story was written, details about the story’s author, etc.) leads to an increase in credibility evaluations and intentions to engage with news. These results hold across the three different article topics used in our experiment and regardless of the participants’ political ideology. Implications for news organizations and contributions to theory are discussed.
Hear–Communicate–Remember: Feasibility of delivering an integrated intervention for family caregivers of people with dementia and hearing impairment via telehealth
Authors: Meyer Carly J , Koh Sheena SH , Hill Annie J , Conway Erin R , Ryan Brooke J , McKinnon Eril R , Pachana Nancy A
Published: May 2019

Purpose

To evaluate the feasibility of Hear–Communicate–Remember, a training programme developed for family caregivers of people with dementia and hearing impairment that integrated hearing, communication and memory strategies, which was intended to be delivered via telehealth.

Materials and methods

Participants included six dyads consisting of adults with dementia and hearing impairment and their family caregivers. Data collection involved a combination of semi-structured interviews, self-report questionnaires and field notes.

Results

Analysis of the qualitative interviews revealed four themes: appropriateness of intervention resources, considerations for the delivery of intervention via telehealth, knowledge and application of intervention strategies, and impact of the intervention on day-to-day life. Results from the satisfaction survey indicated that caregiver participants were mostly satisfied with all aspects of the intervention except the use of some technological components. The field notes described challenges with implementation via telehealth.

Conclusions

Future research involving a cohort comparison study with a larger cohort of dyads is needed to establish treatment efficacy.
Real-time distortion monitoring during fused deposition modeling via acoustic emission
Authors: Li Feng , Yu Zhonghua , Yang Zhensheng , Shen Xuanwei
Published: May 2019

Fused deposition modeling is a popular technique for three-dimensional prototyping since it is cost-effective, convenient to operate, and environment-friendly. However, the low quality of its printed products jeopardizes its future development. Distortion, also known as warping deformation, which is caused by many factors such as inappropriate process parameters and process drifts, is one of the most common defects in the fused deposition modeling process. Rapid detection of such part distortion during the printing process is beneficial for improving the production efficiency and saving materials. In this article, a real-time part distortion monitoring method based on acoustic emission is presented. Our work is to identify distortion defects and understand the condition of the distortion area through sensing and digital signal processing techniques. In our experiments, both the acoustic emission hits and original signals were acquired during the fused deposition modeling process. Then, the acoustic emission hits were analyzed. Ensemble empirical mode decomposition was utilized to eliminate noise and extract features from the original acoustic emission signal to further analyze the acoustic emission signal in the case of part distortion. Furthermore, the root mean square of the reconstructed signals was calculated, and the prediction results are strongly correlated with the ground truth printing states. This work provides a promising method for the quality diagnosis of printing parts.
Impact of Somatic Yoga and Meditation on Fall Risk, Function, and Quality of Life for Chemotherapy-Induced Peripheral Neuropathy Syndrome in Cancer Survivors
Authors: Galantino Mary Lou , Tiger Robyn , Brooks Jennifer , Jang Shera , Wilson Kim
Published: May 2019

Objective. Chemotherapy-induced peripheral neuropathy (CIPN) syndrome causes significant pain as an adverse effect of treatment, with few nonpharmacological interventions tested. A somatic yoga and meditation (SYM) intervention on functional outcomes and quality of life (QOL) was investigated. Design and methods. Individuals diagnosed with CIPN were enrolled in an open-label, single-arm, mixed-methods feasibility trial. Participants and Setting. In an outpatient rehabilitation center, ten participants with median age 64.4 years (47-81) attended 61% of the sessions with no adverse events. Intervention. SYM twice a week for 8 weeks for 1.5 hours, with home program and journaling. Main outcome measures. Primary functional outcomes included Sit and Reach (SR), Functional Reach (FR), and Timed Up and Go (TUG). Self-reported Patient Neurotoxicity Questionnaire (PNQ) and Functional Assessment of Cancer Therapy—Neurotoxicity (FACT-GOG-NTX) were secondary CIPN outcomes. Biomarkers included salivary cortisol (stress) and bioesthesiometer (vibration). Results: Quantitative findings. Significant improvements were found in flexibility (SR; P = .006); balance (FR; P = .001) and fall risk (TUG; P = .004). PNQ improved significantly ( P = .003) with other measures improving non-significantly. Qualitative findings. Five themes emerged: (1) vacillation of CIPN pain perception over time; (2) transferability of skills to daily activities; (3) improvement in physical function; (4) perceived relaxation as an effect of SYM; and (5) group engagement provided a social context for not feeling isolated with CIPN. Conclusion. Preliminary data suggest SYM may improve QOL, flexibility, and balance in cancer survivors with CIPN, with a fully powered randomized controlled trial indicated.

Trial registration: NCT03786055
Functional OCT angiography reveals early physiological dysfunction of hyaloid vasculature in developing mouse eye
Authors: Kim Tae-Hoon , Son Taeyoon , Yao Xincheng
Published: May 2019

Hyaloid vascular system (HVS) is a transient capillary network nourishing developing eye. Better study of the HVS regression correlated with eye development is essential for in-depth understanding of the nature of vision system. In this study, we demonstrate the feasibility of longitudinal optical coherence tomography (OCT) and OCT angiography (OCTA) monitoring of the HVS in C57BL/6J mice. OCT enables morphological monitoring of the HVS regression, and OCTA allows physiological assessment of the HVS involution correlated with eye development. Functional OCTA reveals early physiological dysfunction before morphological regression of the hyaloid vasculature in developing mouse eye. We anticipate that noninvasive, simultaneous OCT/OCTA observation of morphological regression and physiological degradation in normal and diseased animal models will be valuable to unravel the complex mechanisms of the HVS regression correlated with normal eye development and abnormal persistent hyaloid conditions.

Impact statement

Hyaloid vascular system (HVS) is known to have an essential role in the eye development. However, established knowledge of the HVS largely relies on end-point studies with biochemically fixed tissues, lacking a full description of the natural dynamics of the HVS correlated with eye development. An imaging methodology for noninvasive, longitudinal, and high-resolution monitoring of the HVS is important not only for better understanding of the nature of the vision system and is also valuable for better study of abnormal eye conditions. Here, we report the feasibility of in vivo optical coherence tomography (OCT) and OCT angiography (OCTA) imaging of the HVS regression in developing mouse eye. OCT enables morphological imaging of the HVS structure, and OCTA allows functional assessment of the HVS physiology correlated with eye development.
Long-Dose Intensive Therapy Is Necessary for Strong, Clinically Significant, Upper Limb Functional Gains and Retained Gains in Severe/Moderate Chronic Stroke
Authors: Daly Janis J. , McCabe Jessica P. , Holcomb John , Monkiewicz Michelle , Gansen Jennifer , Pundik Svetlana
Published: May 2019

Background. Effective treatment methods are needed for moderate/severely impairment chronic stroke. Objective. The questions were the following: (1) Is there need for long-dose therapy or is there a mid-treatment plateau? (2) Are the observed gains from the prior-studied protocol retained after treatment? Methods. Single-blind, stratified/randomized design, with 3 applied technology treatment groups, combined with motor learning, for long-duration treatment (300 hours of treatment). Measures were Arm Motor Ability Test time and coordination-function (AMAT-T, AMAT-F, respectively), acquired pre-/posttreatment and 3-month follow-up (3moF/U); Fugl-Meyer (FM), acquired similarly with addition of mid-treatment. Findings. There was no group difference in treatment response ( P ≥ .16), therefore data were combined for remaining analyses (n = 31; except for FM pre/mid/post, n = 36). Pre-to-Mid-treatment and Mid-to-Posttreatment gains of FM were statistically and clinically significant ( P < .0001; 4.7 points and P < .001; 5.1 points, respectively), indicating no plateau at 150 hours and benefit of second half of treatment. From baseline to 3moF/U: (1) FM gains were twice the clinically significant benchmark, (2) AMAT-F gains were greater than clinically significant benchmark, and (3) there was statistically significant improvement in FM ( P < .0001); AMAT-F ( P < .0001); AMAT-T ( P < .0001). These gains indicate retained clinically and statistically significant gains at 3moFU. From posttreatment to 3moF/U, gains on FM were maintained. There were statistically significant gains in AMAT-F ( P = .0379) and AMAT-T P = .003.
Research on improved indoor positioning algorithm based on WiFi–pedestrian dead reckoning
Authors: Zhang Guanghua , Sun Xue , Ren Jingqiu , Lu Weidang
Published: May 2019

In order to improve the positioning accuracy and reduce the impact of indoor complex environment on WiFi positioning results, an improved fusion positioning algorithm based on WiFi–pedestrian dead reckoning is proposed. The algorithm uses extended Kalman filter as the fusion positioning filter of WiFi–pedestrian dead reckoning. Aiming at the problem of WiFi signal strength fluctuation, Bayesian estimation matching algorithm based on K-nearest neighbor is proposed to reduce the impact of the dramatic change of received signal strength indicator value on the positioning result effectively. For the cumulative error problem in pedestrian dead reckoning positioning algorithm, a post-correction module is used to reduce the error. The experimental results show that the algorithm can improve the shortcomings of these two algorithms and control the positioning accuracy within 1.68 m.
A dynamical tool adjustment method for computer numerical control abrasive belt grinding
Authors: Zhang Mingde , Chen Tianning , Cao Silin , Zheng Fangyan , Tan Yining
Published: May 2019

Blisk, as the key component in the aero-engine, is hard to be fabricated for the complexity geometry in comparison with separable impeller. In the process, cutter interference is easy to occur because of the narrow groove between adjacent blades. To solve this problem, the paper proposed a dynamic adjustment method for the cutter, through which a cutter interference can be avoided dynamically realized when the cutter approach to the potential interference zone and a smooth transition between two adjacent cutter traces can be realized instantly. Finally, with the proposed method, a polish experiment is conducted, showing its effectiveness in improving the precise and reducing the roughness.
Double-arc harmonic gear profile design and meshing analysis for multi-section conjugation
Authors: Chen Guangsheng , Li Huanhuan , Liu Yang
Published: May 2019

Harmonic gear with double-circular-arc tooth profile has great advantage in the meshing performance. However, only the single cross section meshing or the adjustment of the flexible gear structure is considered to design the conjugate profile in the current research, which leads to the increase of the machining difficulty and is not consistent with the actual working condition of the harmonic gear transmission. Considering the cone deformation of the flexible gear shell, in the direction perpendicular to the axis, the conjugate of the flexible gear teeth is different from that of the rigid gear. Therefore, based on the envelope theory, a double circular arc tooth profile of rigid gear can be designed to achieve multi-section conjugation. Then MATLAB programming is used to simulate the flexible teeth in multi-section. At the same time, according to the assembly simulation, it is shown that the different parts of the flexible gear are engaged with the rigid gear continuously in the meshing process. The results show that on the premise of not adjusting the structure of the gear, this method is more consistent with the actual working condition of the harmonic gear compared with the method of only designing the tooth profile of the middle section conjugate. During the meshing process, there is a double conjugate phenomenon in some regions. By means of parameter adjustment, effective conjugation can be realized in a wider range. When the wave generator cam rotates 67.13°, the tooth profile of the middle section is separated from the rigid gear, and the pairs of meshing teeth are increased and the load capacity is strong. Through the finite element analysis, the dynamic characteristics of the harmonic gear device under normal working conditions are studied, and it is proved that the design parameters of the device can fully meet the strength requirements. A prototype of the double circular arc harmonic gear reducer is manufactured. And by means of assembly and dynamic performance test, the accuracy error of return is 105.2 s. The continuous conjugate meshing with multiple sections can improve the stability and bearing capacity of the transmission and is suitable for actual production and processing. The continuous conjugate meshing with multiple sections can improve the stability and bearing capacity of the transmission, and this is suitable for actual production and processing of rigid gear.
A mathematical model of a bolted connection based on Florida contact theory to study the influence of the friction coefficient on structural performance
Authors: Xu Wenxiang , Liu Zhifeng , Cheng Qiang , Chen Huaxiong , Zhao Yongsheng , Li Ying
Published: May 2019

Bolted joints are widely used for the mechanical assembly of engineering structures and friction coefficient of the contact surface of a bolted connection is the main factor that influences its structural performance. This article presents a mathematical model based on the Florida contact model to obtain the friction coefficient for the contact surface of a bolted joint. The pressure distribution function of the bolted joint is introduced into the mathematical model and elastic, elastic–plastic, and full plastic deformation of asperities at the microscale is also considered. By varying the peak height of asperities, an improved exponential distribution function was constructed. In addition, the proposed model was verified by comparing simulation results to experimental values obtained using a CETR UMT-5 high-precision ball-on-disk friction and wear tester. Then the theoretical friction coefficient was used in the finite element model of the bolted joint, and through numerical simulation, the state of the contact surface of the tightened bolted connection was analyzed. Increasing the friction coefficient was shown to improve the structural performance of the bolted joint. The results provide a theoretical basis for designing uniform preloading of bolted joints and reducing micro-slip at the joint interface.
A study of the transient shear flow behavior of the incompressible and isothermal thermoplastic polymer materials
Authors: Liu Donglei , Fang Kun
Published: May 2019

In this article, a feasible mathematical method was proposed to describe the instantaneous shear flow behavior of the incompressible and isothermal thermoplastic materials. Based on the molecular kinetics, thermodynamics, and continuum mechanics method, a viscoelastic model was presented about the intricate rheological phenomena of polymer macromolecules, which is simplified as the generalized Newton’s law. The rheological experiments were carried out with the isotactic polypropylene material. The analysis of variance method was performed to determine the fitness of the model. By comparing with the Ostwald–de Waele power law model and Cross model, the theoretical model was studied. The experimental results reveal that the theoretical model is more accurate than the Ostwald–de Waele power law model and shows a roughly equivalent fitness with the Cross model, which indicates that the theoretical model is effective and robust. Moreover, the results of this study may have potential industrial applications and benefit the users of certain plastic components.
Investigation of the hysteresis behavior of a convex column brace based on buckling mode transition mechanism
Authors: Zhang Yuan , Wang Shuqing , Fang Hui , Zhang Zhaode , Yuan Xinyan
Published: May 2019

Brace structures with nonlinear stiffness are attractive in vibration mitigation. A new brace consisting of a novel convex column, which is characterized by the addition of a bulge structure compared to a column with constant cross-section, is proposed as a hysteresis brace structure with great applicability for mitigation of low-frequency vibration. The negative stiffness and D-shaped hysteresis damping of the proposed convex column brace generated by the buckling mode transition are verified theoretically and numerically. Comparisons of hysteresis characteristics of the proposed convex column brace and the one with the constant cross-section column are carried out to testify the outperformances of the proposed brace. The results demonstrate that the convex column brace can provide stronger bearing capacity with a smaller deflection and realize hysteresis damping within a shorter displacement range. In addition, a full parametric study is conducted to clarify the effects of geometric properties on hysteresis behavior. The investigation performed in this study not only demonstrates the great applicability of the proposed convex column brace, but also provides guidance on brace design for mitigation in practical application.
Embolic strokes of undetermined source: theoretical construct or useful clinical tool?
Authors: Tsivgoulis Georgios , Katsanos Aristeidis H. , Köhrmann Martin , Caso Valeria , Lemmens Robin , Tsioufis Konstantinos , Paraskevas George P. , Bornstein Natan M. , Schellinger Peter D. , Alexandrov Andrei V. , Krogias Christos
Published: May 2019

In 2014, the definition of embolic strokes of undetermined source (ESUS) emerged as a new clinical construct to characterize cryptogenic stroke (CS) patients with complete vascular workup to determine nonlacunar, nonatherosclerotic strokes of presumable embolic origin. NAVIGATE ESUS, the first phase III randomized-controlled, clinical trial (RCT) comparing rivaroxaban (15 mg daily) with aspirin (100 mg daily), was prematurely terminated for lack of efficacy after enrollment of 7213 patients. Except for the lack of efficacy in the primary outcome, rivaroxaban was associated with increased risk of major bleeding and hemorrhagic stroke compared with aspirin. RE-SPECT ESUS was the second phase III RCT that compared the efficacy and safety of dabigatran (110 or 150 mg, twice daily) to aspirin (100 mg daily). The results of this trial have been recently presented and showed similar efficacy and safety outcomes between dabigatran and aspirin. Indirect analyses of these trials suggest similar efficacy on the risk of ischemic stroke (IS) prevention, but higher intracranial hemorrhage risk in ESUS patients receiving rivaroxaban compared to those receiving dabigatran (indirect HR = 6.63, 95% CI: 1.38–31.76). ESUS constitute a heterogeneous group of patients with embolic cerebral infarction. Occult AF represents the underlying mechanism of cerebral ischemia in the minority of ESUS patients. Other embolic mechanisms (paradoxical embolism via patent foramen ovale, aortic plaque, nonstenosing unstable carotid plaque, etc.) may represent alternative mechanisms of cerebral embolism in ESUS, and may mandate different management than oral anticoagulation. The potential clinical utility of ESUS may be challenged since the concept failed to identify patients who would benefit from anticoagulation therapy. Compared with the former diagnosis of CS, ESUS patients required thorough investigations; more comprehensive diagnostic work-up than is requested in current ESUS diagnostic criteria may assist clinicians in uncovering the source of brain embolism in CS patients and individualize treatment approaches.
Go into school, get a cushy job, move to a better area: Male primary school teachers and neoliberal regimes of value
Authors: Pulsford Mark
Published: May 2019

This article uniquely employs Beverley Skeggs’ ‘hierarchies of personhood’ as a means to explore the iconographies of teacherhood in neoliberal times. Drawing on the narratives of three male primary school teachers in England, it examines and critiques the neoliberal ‘subject of value’ that is acquisitional, performative and self-propelling. ‘Self-projection’, ‘self-protection’ and ‘self-separation’ are identified as a trio of self-care practices that invite normative identity claims as they articulate with embodiments of value found in gendered, classed and raced discourses in contemporary cultural and political domains. The article is therefore about how, within school communities, conditions of personhood are established through regimes of value, and how these regimes are bound by the logic of commodity and exchange. In addressing the limited attention given to the localised formation of masculinities within neoliberalism, the article contributes to an emerging area of scholarship via its innovative engagement with sociological conceptions of personhood and value. The article thereby seeks to mark a shift in the academic and public discourses framing ‘male primary school teachers’, as it critically examines how such an identity category hinges on regimes of value conditioned by interlocking technologies of neoliberal educational governance, patriarchy and classism.
Acute myocardial infarction: Does survival depend on geographical location and social background?
Authors: Kjærulff Thora Majlund , Bihrmann Kristine , Zhao Jinfeng , Exeter Daniel , Gislason Gunnar , Larsen Mogens Lytken , Ersbøll Annette Kjær
Published: May 2019

Aims

This study described the interplay between geographical and social inequalities in survival after incident acute myocardial infarction (AMI) and examined whether geographical variation in survival exists when accounting for sociodemographic characteristics of the patients and their neighbourhood.

Methods

Ringmap visualization and generalized linear models were performed to study post-AMI mortality. Three individual-level analyses were conducted: immediate case fatality, mortality between days 1 and 28 after admission and 365-day survival among patients who survived 28 days after admission.

Results

In total, 99,013 incident AMI cases were registered between 2005 and 2014 in Denmark. Survival after AMI tended to correlate with sociodemographic indicators at the municipality level. In individual-level models, geographical inequality in immediate case fatality was observed with high mortality in northern parts of Jutland after accounting for sociodemographic characteristics. In contrast, no geographical variation in survival was observed among patients who survived 28 days. In all three analyses, odds and rates of mortality were higher among patients with low educational level (odds ratio (OR) (95% credible intervals) of 1.20 (1.12–1.29), OR of 1.12 (1.01–1.24) and mortality rate ratio of 1.45 (1.30–1.61)) and low income (OR of 1.24 (1.15–1.33), OR of 1.33 (1.20–1.48) and mortality rate ratio of 1.25 (1.13–1.38)).

Conclusion

Marked geographical inequality was observed in immediate case fatality. However, no geographically unequal distribution of survival was found among patients who survived 28 days after AMI. Results additionally showed social inequality in survival following AMI.
Developing age-friendly city readiness: A case study from Depok City, Indonesia
Authors: Fatmah Fatmah , Dewi Vita Priantina , Priotomo Yudarini
Published: May 2019

Depok, as one of the largest cities in Indonesia, has great potential to be an age-friendly city. Before the formation of age-friendly city is established, eight dimensions of age-friendly cities had been studied by the World Health Organization in 2013, but since 2013 these dimensions have not been assessed. The study aimed to assess the preparedness of Depok to be an age-friendly city with a qualitative approach from the stakeholders’ point of view. This study used a qualitative design involving 50 informants through in-depth interviews and focus group discussion techniques using purposive sampling. The findings indicate that Depok was deemed not yet prepared to be an age-friendly city due to an abundance of infrastructure deficiencies. There were not many changes in the facilities, such as infrastructure improvements in age-friendly city indicators and existing Regional Regulations of age-friendly cities, except for buildings and open green spaces. In general, Depok still needs time to achieve the age-friendly city where the community will have a good place to live, grow, and age in it.
The prediction of colorectal cancer using anthropometric measures: A Swedish population‐based cohort study with 22 years of follow‐up
Authors: Andreasson Anna , Hagström Hannes , Sköldberg Filip , Önnerhag Kristina , Carlsson Axel C , Schmidt Peter T , Forsberg Anna M
Published: May 2019

Background

Obesity is a risk factor for colorectal cancer (CRC).

Objective

The objective of this article is to investigate whether anthropometric measures reflecting visceral obesity are better predictors of CRC than body mass index (BMI).

Methods

Data were analysed from the Malmö Diet and Cancer study in Sweden, comprising 16,669 women and 10,805 men (median age 56.6 and 59.1 years) followed for a median 21.5 years. Diagnoses of CRC were identified using Swedish national registers. Cox regression was used to test the associations of BMI, waist circumference (WC), waist‐hip ratio, waist‐to‐height ratio, waist‐to‐hip‐to‐height ratio, A Body Shape Index (ABSI) and percentage body fat with the development of CRC adjusted for age, alcohol consumption, smoking, education and physical activity in men and women.

Results

None of the measures were significantly associated with an increased risk for CRC in women. WC was the strongest predictor of colon cancer (CC) in men and the only measure that was independent of BMI. ABSI was the only measure significantly associated with the risk of rectal cancer in men.

Conclusions

Visceral obesity, best expressed as WC, is a risk factor for CC in men but a poor predictive marker for CRC in women.
Genres as Social Affect: Cultivating Moods and Emotions through Playlists on Spotify
Authors: Siles Ignacio , Segura-Castillo Andrés , Sancho Mónica , Solís-Quesada Ricardo
Published: May 2019

This article bridges work on media technologies and affect theories through an analysis of how users appropriate playlists on Spotify. Our study draws on 30 interviews with users of music streaming services in Costa Rica and an analysis of their accounts on these platforms. We discuss how users create playlists as a means to cultivate affect. The notion of cultivation stresses the dynamic and ritual work involved in producing, capturing, and exploring moods and emotions. We argue that playlists work as “genres”—fusions of musical substance, sociotechnological assemblages, and sociomaterial practices—to respond to the exigencies of affect. This helps turning the platform into an obligatory intermediary in the establishment of a utilitarian relationship between users and music. We draw on Berlant’s notion of “intimate public” to analyze how playlists form the basis of collective experiences that serve Spotify’s political-economic project. As material embodiments of cultivated affect, playlists offer a promise of identification and belonging to “intimate publics” formed by strangers through the specific bonds between music, technology, and affect they enact (as genres). Our analysis concludes with a discussion of the implications of our study for rethinking the relationship between technology, affect, and genre.
Social Media Usage Patterns: Research Note Regarding the Lack of Universal Validated Measures for Active and Passive Use
Authors: Trifiro Briana M. , Gerson Jennifer
Published: May 2019

The existing literature regarding social media use provides extant evidence supporting the claim that usage patterns ultimately have the capability of impacting users. However, the vast majority of the literature is based upon experimental laboratory settings where participants are observed by researchers. The current article asserts that there is a significant deficiency within the discipline regarding the validated measurement of usage patterns of social networking sites (SNSs) and offers guidance for those who may want to develop a general measure.