bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of high temperature fatigue lifetime of GH4133B superalloy used in turbine disk of aero-engine
Authors: Ren C L , Zhao R G , Liu Y F , Ji N , Deng L Y , Li X M 
Published: September 2019

Abstract
Based on the S-H cavity model theory and the thermodynamic diffusion equation, the high temperature fatigue lifetime equation is deduced, and the influence of stress amplitude and mean stress on fatigue lifetime is quantitatively analyzed. At high temperature of 650°C, according to the test data of fatigue lifetime of GH4133B superalloy under different stress ratios or alternatively at various maximum stress levels, the nonlinear regression analysis method is applied to identify the material parameters in the fatigue lifetime equation, and a 3D N
f-σm-σa curve surface is plotted. The comparison between theoretic fatigue lifetime N
fp and test one N
ft indicates that the fatigue lifetime equation derived from the microstructure evolution of metallic materials can accurately predict the fatigue lifetime of GH4133B superalloy under different cyclic loading parameters. Finally, a parameter γ is introduced to characterize the effect of mean stress σm and stress amplitude σa on fatigue lifetime N
f of GH4133B superalloy. It is suggested that the effect of mean stress σm on N
f is larger than that of stress amplitude σa on N
f under the condition of tensile-tensile fatigue loading.
Nonlinear dynamics and parameter control for metamaterial plate with negative Poisson’s ratio
Authors: Zhu S T , Li J , Zhou J , Quan T T 
Published: September 2019

Abstract
The metamaterial with negative Poison’s ratio is widely used due to its special mechanical and physical properties. Based on the theory of periodic solution and bifurcation of nonlinear dynamics, we mainly focus on the nonlinear vibration behaviors and parameter control of a simply supported concave hexagonal composite sandwich plate with negative Poisson’s ratio in auxetic honeycombs subjected to in-plane and transverse excitation. The Melnikov function is improved by introducing the curvilinear coordinate frame and Poincaré map to detect the existence and number of the periodic solutions. The effects of the forcing excitation coefficient on nonlinear dynamics as well as the parameter control conditions are presented. Numerical method is performed to obtain the phase portraits of the number and corresponding positions of multiple periodic orbits.
Integrated design of structure and anisotropic material based on the BESO method
Authors: Yan X L , Xu Q W , He J , Huang D F , Huang X D 
Published: September 2019

Abstract
An Integrated structural and material topology optimization method considering optimal material orientation is presented based the on bi-direction evolutionary structural optimization (BESO) method. It is assumed that the macrostructure is composed of uniform cellular material but with different orientation. The homogenization method is used to calculate the effective material properties which builds a connection between material and structure. The continuous material orientation design variables and the discrete topology design variables are treated hierarchically in an iteration. The principal stress method is adopted and embedded to determine the optimal material orientation, meanwhile the topologies of the macrostructure and its material microstructure are concurrently optimized by using the BESO method. Numerical examples are conducted to demonstrate the effectiveness of the proposed optimization algorithm.
Low-velocity impact response of 3D-printed lattice sandwich panels
Authors: Wang Sheng , Xu Yingjie , Zhang Weihong 
Published: September 2019

Abstract
This paper investigates the low velocity response of sandwich panels with four different lattice cores by conducting drop-weight impact tests. Sandwich panels are made of galvanized sheet and 3D-printed lattice cores in this study. Four different types of lattice, including body-centered cubic (BCC), z-reinforced body-centered-cubic (BCCz), gyroid lattice and Schwarz P lattice, are selected for the cores of sandwich panels respectively. Functional graded versions of these lattices are also examined, which features a density gradient along impact direction. Low-velocity impact response of a solid sandwich panel with the same quality is tested as a comparison. Experimental results show that lattice sandwich panels absorb more energy compared with solid sandwich panels. In addition, the graded lattice cores can further improve the energy absorption capacity of sandwich panels.
Failure analysis of composite tube hinge and optimization design
Authors: Li Bowen , Ye Hongling , Zhang Yang 
Published: September 2019

Abstract
Composite materials with intriguing mechanical properties are introduced into special deployable structure. The tube hinge in this research is investigated, which has a base tube structure with one slot. However, due to large rotation and large nonlinearity, the composite tube hinge has material failure, thus leading to deployment failure. To overcome the problem, Hashin failure criterion is used for checking the extent to which the material is damaged in folding processes. The optimal model is established base on response surface methodology, which aimed at maximizing the strain energy and minimizing the peak moment to ensure full deployment stably. The failure index during folding processes are subjected (less than 1) to avoid material damage. The length of slot L, width of slot D, diameter R and thickness T of tube hinge are chosen as the design variables. Using the non-dominated sorting genetic algorithm, the optimum parameters are obtained by solving the multi-objective optimal model. The proposed method has significance on designing novel deployable structures with high stability and reliability.
Concurrent wind and base vibration energy harvesting with a broadband bistable aeroelastic energy harvester
Authors: Zhao Liya 
Published: September 2019

Abstract
This paper presents a novel energy harvesting device driven by concurrent aeroelastic vibration and base vibratory excitation. The harvester undergoes flow-induced limit-cycle oscillation under galloping instability, and at the same time, inertia force induced vibration is present due to the base vibratory excitation. A limitation with a traditional linear aeroelastic energy harvester is that effective energy harvesting from combined sources is only achievable within a narrow frequency range. To overcome this issue, bistability is introduced by exploiting nonlinear restoring force. A lumped aero-electro-mechanical model is established to incorporate the mutual coupling between the wind flow, piezoelectric element, nonlinear structure and circuit. Dynamic responses are investigated for different bistable configurations. Results show that the proposed harvester achieves a significantly widened bandwidth over which the two excitation frequencies are forced to lock into each other, and both vibratory and aeroelastic energy are effectively harnessed.
The lightweight topology optimization of plate/shell structures with different mechanical performance constraints
Authors: Wang W W , Ye H L , Sui Y K 
Published: September 2019

Abstract
The plate/shell structures are popular among in engineering because they show great potential in lightweight design under pressure loads. This paper develops a lightweight topology optimization method of plate/shell structures considering different mechanical performances based on independent, continuous and mapping (ICM) method. A mathematical formulation is established to describe the plate/shell topology optimization problem with minimum volume or mass as objective, the critical buckling load and nodal displacement as constraints. The finite element model is employed to subdivide the design domain and the existing state of each element is described as a topology design variable. In addition, linear buckling and static analyses are used to get the critical buckling load and nodal displacement of plate/shell structures and relevant information of elements and nodes used in the process of topology optimization. The filter functions are introduced to recognize element properties and map the 0-1 integer programming model into a formulation with continuous variables. Sensitivity analysis and Taylor expansion are applied to achieve a standard quadratic programming model. Finally, numerical examples are provided to test the effectiveness and feasibility of the theory above, and discuss the influence of constraints on optimal structures. This study can provide a theoretical basis for the lightweight topology optimization of plate/shell structures.
The Photoacoustic Effect of Multilayered Graphene Films
Authors: Yang Nizi , Li Shuang , Li Cheng , Fan Xueliang 
Published: September 2019

Abstract
This paper presents a theoretical model of the photoacoustic effect for mutilayered graphene films based on the photoacoustic theory of solids and the thermoacoustic theory of graphene films. The expression of sound pressure of the photoacoustic signal from a mutilayered graphene film is therefore derived according to the theoretical formula. An acoustic platform is built to measure the output sound pressure generated by graphene film on a polyethylene terephthalate (PET) substrate, and the experimental values are compared with the corresponding theoretical values. The results show that the trends of the two in the frequency domain are identical, thereby validating the proposed theoretical model. The graphene film speaker has a wide range of frequency response, and the output sound pressure of the film varies linearly with the input optical power. In the far-field region below 17000 Hz, the output sound pressure of the film gradually rises with an increase of the incident light frequency under constant incident light power. The frequency response of the film is relatively stable in the near-field region by comparison.
Linker length affects photostability of protein-targeted sensor of cellular microviscosity
Authors: Kubánková Markéta , Chambers Joseph E , Huber Roland G , Bond Peter J , Marciniak Stefan J , Kuimova Marina K 
Published: September 2019

Abstract
Viscosity sensitive fluorophores termed ‘molecular rotors’ represent a convenient and quantitative tool for measuring intracellular viscosity via Fluorescence Lifetime Imaging Microscopy (FLIM). We compare the FLIM performance of two BODIPY-based molecular rotors bound to HaloTag protein expressed in different subcellular locations. While both rotors are able to penetrate live cells and specifically label the desired intracellular location, we found that the rotor with a longer HaloTag protein recognition motif was significantly affected by photo-induced damage when bound to the HaloTag protein, while the other dye showed no changes upon irradiation. Molecular dynamics modelling indicates that the irradiation-induced electron transfer between the BODIPY moiety and the HaloTag protein is a plausible explanation for these photostability issues. Our results demonstrate that binding to the targeted protein may significantly alter the photophysical behaviour of a fluorescent probe and therefore its thorough characterisation in the protein bound form is essential prior to any in vitro and in cellulo applications.
Prevalence of Chlamydia psittaci, Chlamydia pneumoniae, and Chlamydia trachomatis Determined by Molecular Testing in Ocular Adnexa Lymphoma Specimens
Authors: Travaglino Antonio , Pace Mirella , Varricchio Silvia , Della Pepa Roberta , Iuliano Adriana , Picardi Marco , Pane Fabrizio , Staibano Stefania , Mascolo Massimo 
Published: September 2019

AbstractObjectivesTo assess the prevalence of Chlamydia psittaci, Chlamydia pneumoniae, and Chlamydia trachomatis in ocular adnexa lymphoma (OAL) determined by molecular testing in different countries and the potential association of Chlamydia infection with mucosa-associated lymphoid tissue (MALT) histotype by performing a systematic review and meta-analysis.MethodsElectronic databases were searched for studies assessing the presence of Chlamydia in OAL. Pooled prevalence of the three Chlamydia species was calculated in each country. An odds ratio was calculated for the association between Chlamydia and MALT histotype, with a significant P &lt; .05.ResultsThirty-seven studies with 1,188 OALs were included. Pooled prevalence of C psittaci, C pneumoniae, and C trachomatis by country was done. Chlamydia infection was significantly associated with MALT histotype (odds ratio, 2.183; P = .027).ConclusionsThe involvement of C psittaci in OAL is highly variable, with the highest prevalence in Italy and Korea. Chlamydia is associated with MALT histotype.
The Role of Pornography, Physical Symptoms, and Appearance in Labiaplasty Interest
Authors: Sorice-Virk Sarah , Li Alexander Y , Canales Francisco L , Furnas Heather J 
Published: September 2019

Abstract

Background
With the American College of Obstetricians and Gynecologists reaffirming its 2007 opposition to labiaplasty in 2019, the procedure continues to be controversial. Particular emphasis on pornography as a major influencer on women seeking labiaplasty contributes to its controversy and distracts from other motivations. Few articles have established pornography’s influence relative to functional and appearance-related symptoms.

Objectives
The objective of this study was to investigate the relative influence of pornography on women’s decision to seek labiaplasty relative to other factors compared with a control cohort.

Methods
In this prospective study, 124 consecutive patients consulting about labiaplasty and a control cohort of 50 women were questioned about 11 labia-related symptoms and the possible influence of pornography.

Results
The mean age was 34.2 and 38.9 years in the labiaplasty and control cohorts, respectively. Women in the labiaplasty cohort had on average 2.8 of the 6 queried physical symptoms and 3.2 of the 5 queried appearance-related symptoms compared with control patients who reported an average of 0.3 of the 6 queried physical symptoms and 0.2 of the 5 queried appearance-related symptoms (P &lt; 0.001). Less than one-half (47% of the labiaplasty and 42% of the control cohort) never viewed pornography. Pornography was not an influential factor to seek labiaplasty in 42% of the labiaplasty cohort and 54% of the control cohort. A minority (11% in the labiaplasty cohort and 4% in the control cohort) said that pornography influenced them to seek labiaplasty. There were no statistically significant differences between these 2 groups.

Conclusion
Pornography influences some women to seek labiaplasty, but relative to other motivating factors its role is minor.
Regularized calibrated estimation of propensity scores with model misspecification and high-dimensional data
Authors: Tan Z 
Published: September 2019

SummaryPropensity scores are widely used with inverse probability weighting to estimate treatment effects in observational studies. We study calibrated estimation as an alternative to maximum likelihood estimation for fitting logistic propensity score models. We show that, with possible model misspecification, minimizing the expected calibration loss underlying the calibrated estimators involves reducing both the expected likelihood loss and a measure of relative errors between the limiting and true propensity scores, which governs the mean squared errors of inverse probability weighted estimators. Furthermore, we derive a regularized calibrated estimator by minimizing the calibration loss with a lasso penalty. We develop a Fisher scoring descent algorithm for computing the proposed estimator and provide a high-dimensional analysis of the resulting inverse probability weighted estimators, leveraging the control of relative errors of propensity scores for calibrated estimation. We present a simulation study and an empirical application to demonstrate the advantages of the proposed methods over maximum likelihood and its regularization. The methods are implemented in the R package RCAL.
Measurement errors in the binary instrumental variable model
Authors: Jiang Zhichao , Ding Peng 
Published: September 2019

Summary
Instrumental variable methods can identify causal effects even when the treatment and outcome are confounded. We study the problem of imperfect measurements of the binary instrumental variable, treatment and outcome. We first consider nondifferential measurement errors, that is, the mismeasured variable does not depend on other variables given its true value. We show that the measurement error of the instrumental variable does not bias the estimate, that the measurement error of the treatment biases the estimate away from zero, and that the measurement error of the outcome biases the estimate toward zero. Moreover, we derive sharp bounds on the causal effects without additional assumptions. These bounds are informative because they exclude zero. We then consider differential measurement errors, and focus on sensitivity analyses in those settings.
Carpellary appendages in Nymphaea and Victoria (Nymphaeaceae): evidence of their role as osmophores based on morphology, anatomy and ultrastructure
Authors: Zini Lucía Melisa , Galati Beatriz Gloria , Gotelli Marina , Zarlavsky Gabriela , Ferrucci María Silvia 
Published: September 2019

Abstract
In flowers of Nymphaea and Victoria, carpellary appendages are regarded as structures related to pollination by deceit of night-blooming species. In this study, the anatomy, histochemistry and ultrastructure of carpellary appendages were analysed to investigate their possible role in the production of volatile compounds in nocturnal species Nymphaea amazonum, N. gardneriana, N. prolifera (Nymphaea subgenus Hydrocallis) and Victoria cruziana, and in diurnal species N. caerulea (Nymphaea subgenus Brachyceras). Carpellary appendages were studied using light microscopy and scanning and transmission electron microscopy from pre-anthesis to the second day of anthesis. Anatomical and ultrastructural features are characteristic of osmophores. In all species, the most frequent components in secretory cells are amyloplasts, lipid bodies, mitochondria, rough endoplasmic reticulum and elaioplasts. The epidermis and multilayered parenchyma accumulate abundant starch grains and lipophilic substances, both of which vanish during anthesis. Amorphous substances are deposited between the plasmalemma and the outer cell wall of epidermal cells, and are then released by cuticular diffusion. Odour production in carpellary appendages might be an ancient role of primary importance both in diurnal and nocturnal species that are pollinated by deceit. Olfactory and visual cues of small carpellary appendages in Nymphaea subgenus Brachyceras correspond to bee pollination, and large carpellary appendages in subgenus Hydrocallis and Victoria represent parallel functional specializations of the flowers to the attraction and reward for exclusive beetle pollination.
Real-world Effectiveness of Advanced Therapies Among Patients With Moderate to Severe Ulcerative Colitis in the United States
Authors: Long Millie D , Smith Timothy W , Dibonaventura Marco , Gruben David , Bargo Danielle , Salese Leonardo , Quirk Daniel 
Published: September 2019

Abstract

Background
Ulcerative colitis (UC) treatment aims to induce response and maintain steroid-free remission. For patients with moderate to severe UC and/or nonresponse to conventional treatment, advanced therapies (immunosuppressants and biologics) are available. We assessed real-world effectiveness of advanced UC therapies.

Methods
This retrospective analysis of claims data included adult patients with UC initiating immunosuppressant or biologic therapy, with 12 months’ continuous enrollment pre- and postinitiation. Patients had no prescription for biologic therapy (and/or immunosuppressant if initiating immunosuppressant) in the previous 12 months. Proportion of patients remaining steroid-free (excluding 14-week tapering period), hospitalizations, and costs in the 12 months postinitiation were assessed.

Results
In total, 3562 patients were included in the analysis. Most patients (83.0%) used steroids in the 12 months before initiating advanced therapy. Overall, 47.8% remained steroid-free after 12 months (excluding tapering). After adjusting for patient characteristics, remaining steroid-free was significantly more likely with infliximab (43.9%) than with adalimumab (39.4%; P &lt; 0.05); golimumab (38.2%) and vedolizumab (41.4%) were not significantly different vs adalimumab. Overall, 12.2% of patients had a UC-related hospitalization within 12 months of initiation, with a mean (SD) total length of stay of 8.2 (8.9) days and no significant differences between biologic therapies. Mean, unadjusted, UC-related costs in the 12 months postinitiation were $42,579 and were similar between therapies.

Conclusions
Patients with UC initiating advanced therapy frequently continued using steroids for at least a year. Some patients experienced extended UC-related hospitalizations, with high UC-related costs overall. This suggests an ongoing challenge in managing patients with moderate to severe UC.
Utilization of Diagnostic Imaging and Ionization Radiation Exposure Among an Inflammatory Bowel Disease Inception Cohort
Authors: Nguyen Geoffrey C , Low Daniel , Chong Rachel Y , Diong Christina , Chawla Tanya 
Published: September 2019

Abstract

Background
Abdominal imaging is important in managing inflammatory bowel disease (IBD). We characterized utilization of imaging and exposure to ionizing radiation.

Methods
We enumerated abdominal diagnostic imaging in a population-based cohort of IBD patients between 1994 and 2016. Trends in utilization of abdominal computed tomography (CT), magnetic resonance imaging (MRI), and ultrasound were characterized. Cumulative doses of ionizing radiation were compared between IBD patients and non-IBD controls and between Crohn’s disease (CD) and ulcerative colitis (UC) patients. Regression models were constructed to assess predictors of high ionizing radiation exposure.

Results
There were 72,933 incident cases of IBD. During the first 5 years of diagnosis, IBD patients were exposed to nearly 6-fold higher exposure to cumulative ionizing radiation attributable to abdominal imaging compared with non-IBD controls (18.6 mSv vs 2.9 mSv). Cumulative ionizing radiation exposure was higher in CD than UC (26.0 mSv vs 12.0 mSv; P &lt; 0.001). Crohn’s disease patients were more than twice as likely as UC patients to exceed 50 mSv (15.6% vs 6.2%; P &lt; 0.001) and 100 mSV (5.0% vs 2.1%; P &lt; 0.001). There was geographic variation in ionizing radiation exposure, and individuals of lower income were more likely to have high exposure. Utilization of abdominal MRI has increased substantially, peaking between 2007 and 2012 and increasing annually at 34%, which coincided with an annual 2% decline in the use of abdominal CT.

Conclusions
Crohn’s disease patients are at highest risk for high exposure to ionizing radiation, with a subgroup receiving potentially harmful levels. Increasing utilization and access to abdominal MRI may alleviate exposure.