bluuebunny/crossref_metadata_2025 huggingface dataset:
The Influence of Size and Shape of Pd Nanoparticles on the Performances of Pd/Beta Catalysts for n‐Heptane Hydroisomerization
Authors: Chen Huimin , Liu Suyao , Yin Junqing , Gao Xiang , Tao Zhichao , Wu Baoshan , Xiang Hongwei , Yang Yong , Li Yongwang
Published: June 2019

Several Pd/Beta catalysts with cubic (9 nm, 12 nm, 16 nm) and truncated‐octahedral (18 nm) Pd nanoparticles (NPs) were prepared to investigate the effect of size and shape of Pd NPs for n‐heptane hydroisomerization. Characterizations confirmed that the cubic Pd NPs solely exposed {100} crystal plane and truncated‐octahedral Pd NPs were enclosed by {100} and {111} crystal planes, and that the desorption temperature of subsurface hydrogen on Pd NPs showed size and shape dependence. Hydroisomerization results exhibits that the catalyst with 9 nm cubic Pd NPs displayed the higher isomers selectivity compared to the catalyst with 12 nm cubic NPs, 18 nm truncated octahedral NPs and 16 nm cubic NPs at similar conversion. This result suggested the size and shape dependence of (de)hydrogenation activity of Pd NPs, and further revealed the key role of subsurface hydrogen in determining the (de)hydrogenation activity.
Flow Pattern and Pressure Drop for Small Long‐Cylinder Cyclones Operating at High Flow Rates
Authors: Wang Dongshen , Zhao Bingtao , Su Yaxin
Published: June 2019

To address the gas flow pattern and pressure drop characteristics for small long‐cylinder cyclones (SLCCs) in the high operating flow rate range, experimental investigation and computational fluid dynamics (CFD)‐based simulation were performed. The pressure drop coefficient depends insignificantly on the Reynolds number at high flow rates. The tangential and axial velocities present the Rankine vortex and the roughly inverted V‐shaped distribution, respectively, similar to those in typical cyclones. The CFD simulation approximated well the experimental data of pressure drop. The pressure drop caused by vortex loss, turbulent energy loss, and resistance loss accounted for 72.5 % of the total pressure drop. The Stairmand model was found to be relatively accurate among the classical pressure drop models for the proposed cyclone. The results may help in the design and applications of cyclone separators and reactors.
Residential Energy Supply Concept with Integration of Renewable Energies and Energy Storage
Authors: Pauksztat Anja , Saliger Rainer , Boyanov Neven
Published: June 2019

Renewable energies are gaining importance in urban management and in the planning of new residential and mixed‐use areas. Attention is also paid to self‐sufficiency, as the public electrical grid is strained through the integration of renewables. Here, an energy supply concept for an urban residential area in the planning phase is discussed to meet both economic and ecologic criteria. Based on the demand, different technical options are analyzed. The integration of renewables is coupled with energy storage to increase the self‐sufficiency of the residential area. The economic feasibility of the energy supply concept depends on the requirements to be met as well as the regulatory framework. With the currently available technology and the regulatory framework in place, self‐sufficiency and economic feasibility are opposing targets.
A SINS‐aided two‐step fast acquisition method for GNSS signal based on compressive sensing
Authors: Cheng Junbing , Li Dengao
Published: June 2019

The Global navigation satellite system (GNSS) multi‐mode compatible and multi‐frequency information not only improves information redundancy but also eliminates errors such as ionospheric delays to improve positioning performance. However, multi‐mode and multi‐frequency observation information increases the hardware overhead and computational complexity, especially the signal acquisition. In this contribution, according to the strong complementarity between GNSS and Strapdown inertial navigation system (SINS) and the sparsity of the GNSS signal spreading code in the autocorrelation domain, a SINS‐aided fast acquisition method for GNSS signals based on Compressive sensing (CS) is proposed. First, the inertia information of SINS narrows the Doppler frequency search range; then, the CS is applied to measure compressively the GNSS signal in two steps, ie, the first step is to narrow down the code phase search range, and the second step is to determine the code phase of the half chip accuracy. Finally, the proposed method and the other two typical acquisition methods are compared by the detection probability and the Mean acquisition time (MAT). Theoretical analysis and experimental results show that the proposed method can not only reduce the number of correlators and computational complexity but also improve the detection probability and reduce the MAT.
The role of networks and sustainable intrapreneurship as interactive drivers catalyzing the adoption of sustainable innovation
Authors: Pellegrini Chiara , Annunziata Eleonora , Rizzi Francesco , Frey Marco
Published: June 2019

This paper explores which are the drivers and their interactions that can lead organizations to adopt radical sustainable innovation (SI) in unfavorable contexts. We identify external and internal drivers of SI adoption, and we conceptualize sustainable intrapreneurship as an additional driver. We report and discuss the findings from a case study in the water sector based on interviews and secondary data collected among eleven water utilities in Israel, Italy, and Spain. We provide new insights on how interactions between external and internal drivers can generate dynamic cycles that gradually shift utilities from a reactive to an embedding and system change approach in adopting SI. Within this process, networks and sustainable intrapreneurship act as interactive drivers that catalyze internal and external drivers. The study links testable propositions in a conceptual model describing the dynamics triggering SI adoption and argues for the relevance of sustainable intrapreneurship for addressing the systemic nature, complexity, and ambiguity of SI adoption.
Visible‐Light Photocatalytic Reduction of CO2 to Formic Acid with a Ru Catalyst Supported by N,N′‐Bis(diphenylphosphino)‐2,6‐diaminopyridine Ligands
Authors: Hameed Yasmeen , Rao Gyandshwar Kumar , Ovens Jeffrey S. , Gabidullin Bulat , Richeson Darrin
Published: June 2019

Visible‐light photocatalytic CO2 reduction is carried out by using a RuII complex supported by N,N′‐bis(diphenylphosphino)‐2,6‐diaminopyridine (“PNP”) ligands, an unprecedented molecular architecture for this reaction that breaks the longstanding domination of α‐diimine ligands. These competent catalysts transform CO2 into formic acid with high selectivity and turnover number. A proposed mechanism, with combined electron transfer and catalytic cycles, models the experimental rate of formic acid production.
Distribution of cervical lesions in young and older women
Authors: Díaz del Arco Cristina , Jiménez Ayala Beatriz , García Dolores , Sanabria Carmen , Fernández Aceñero Mª Jesús
Published: June 2019

Introduction

Age range for cervical screening varies widely between countries. In addition, sexual behavior has changed, life expectancy is increasing, and new insights have been gained into the pathogenesis of HPV infection. Our aim is to evaluate the distribution of cervical lesions in young and older patients.

Methods

Review of all cervical smears diagnosed in a public institution (2010‐2017) and a private institution (2016‐2017) in Madrid, Spain. We have included all women aged younger than 30 and older than 65 years with atypical smears (n = 1573).

Results

Women younger than 30 years were diagnosed with ASCUS, ASC‐H, LSIL, and HSIL in 47%, 5.3%, 45.17%, and 2.6% of atypical cases, respectively. Women older than 65 years were diagnosed with ASCUS, ASC‐H, LSIL, HSIL, and SCC in 38%, 12.39%, 16.8%, 13.27%, and 19.5% of atypical cases, respectively. Medical records of patients from the public institution were reviewed. Of note, 76.3% of young women showed negative smears at follow‐up and 14.1% showed high‐grade dysplasia (HGD). Mean ages for low‐grade and HGD were 24.7 and 25.7 years, respectively. HGD was found in 37.9% of women with histological examination (33.5%). As for older patients, 25% of them had no Pap smears performed before age 65, and in 60% of the previously screened women, the screening program had not been used adequately. Mean age of first smear was 69.5 years. Carcinoma was subsequently detected in 20.7% of patients.

Conclusions

Current guidelines seem to be adequately preventing carcinoma in young women. However, screening adherence should be encouraged to detect important lesions in both age groups, especially among older women.
Development of high‐frequency‐type MEMS ultrasonic array sensor using P(VDF/TrFE) thin films
Authors: Tanaka Tsunehisa , Murakami Shuichi , Uno Mayumi
Published: June 2019

MEMS (microelectromechanical systems) ultrasonic array sensors were fabricated using the poly (vinylidene fluoride‐trifluoroethylene) [P(VDF/TrFE)] copolymer thin films having multilayer diaphragm structures. For an increased resonant frequency of sensor, we developed a new diaphragm structure. The resonant frequency and sensitivity of new MEMS ultrasonic array sensor was estimated to be on the order of 376 kHz and −75 dBV (1V/Pa = 0 dBV), respectively. This MEMS ultrasonic array sensor can be adapted for ultrasonic 3D imaging and nondestructive ultrasonic testing systems.
Sustained safe and effective anticoagulation using Edoxaban via percutaneous endoscopic gastrostomy
Authors: Galli Mattia , D'Amario Domenico , Andreotti Felicita , Porto Italo , Vergallo Rocco , Sabatelli Mario , Lancellotti Stefano , Meleo Emiliana , De Cristofaro Raimondo , Crea Filippo
Published: June 2019

Extensive data support the safety of direct oral anticoagulants compared with vitamin K antagonists in patients with non‐valvular atrial fibrillation, leading to a significantly increase in the use of these compounds in clinical practice. However, there is no compelling evidence supporting the use of direct oral anticoagulant in individuals who are intubated or have a percutaneous endoscopic gastrostomy (PEG): patients with several co‐morbidities are underrepresented in clinical trials, so the best long‐term strategy for anticoagulation is difficult to ascertain. The aim of the present report was to evaluate the safety and efficacy of edoxaban administered via PEG in a patient with heart failure and a history of atrial fibrillation affected by amyotrophic lateral sclerosis (ALS). A 71‐year‐old man with atrial fibrillation, advanced ALS, type II diabetes mellitus, and hypertension presented to the emergency department with dyspnoea and tachycardia. Because vitamin K antagonist and rivaroxaban 15 mg were dropped because of difficult international normalized ratio control (time in therapeutic range <30%) and severe haematuria, respectively, edoxaban 30 mg (crushed pill) daily was administered based on the patient's weight of 58 kg. Mean edoxaban plasma concentration–time profiles were measured, as anti‐Xa activity, 2 h before and at 2, 6, and 22 h after drug administration and then compared with the pharmacokinetic profile of edoxaban 30 mg in healthy subjects. An additional testing of steady‐state peak plasma concentration of edoxaban after 10 days and a 30 day follow‐up were evaluated. The values of the pharmacokinetic parameters, analysed with a non‐compartmental analysis by PKSolver module, showed that Cmax and AUC0→t were only slightly higher than those observed in healthy subjects, while the half‐life and observed clearance were significantly longer and lower, respectively, than in normal subjects. Steady‐state peak plasma concentration of edoxaban was very similar to the levels reported in healthy subjects, and neither relevant bleeding nor thromboembolic event was reported at a 30 day follow‐up. These results support safe and effective anticoagulation with edoxaban 30 mg but suggest caution with the use of full dose of edoxaban (60 mg daily) in this kind of patients. We report, for the first time, a safe and effective anticoagulation based on the administration of edoxaban 30 mg daily through PEG in a patient with advanced ALS, acute respiratory, and heart failure, presenting with Takotsubo syndrome and atrial fibrillation.
MitraClip improves cardiopulmonary exercise test in patients with systolic heart failure and functional mitral regurgitation
Authors: Benito‐González Tomás , Estévez‐Loureiro Rodrigo , Garrote‐Coloma Carmen , Iglesias Garriz Ignacio , Gualis Javier , Álvarez‐Roy Laura , Rodriguez‐Santamarta Miguel , Pérez de Prado Armando , Fernández‐Vázquez Felipe
Published: June 2019

Aims

The aim of this study is to evaluate changes in cardiopulmonary exercise test (CPET) after percutaneous mitral valve repair (PMVR) with MitraClip in patients with heart failure with reduced ejection fraction who are potentially candidates for heart transplantation or destination left ventricular assist device.

Methods and results

Prospective registry of all consecutive patients with heart failure with reduced ejection fraction and functional mitral regurgitation (MR) underwent elective PMVR between October 2015 and March 2018 in our institution. Patients with preserved or mid‐range left ventricular ejection fraction (>40%), advanced age (>75 years old), or severe co‐morbidities (end‐stage organ damage) were not included. Treadmill exercise testing with respiratory gas exchange analysis was carried out in 11 patients (male, 72.7%; median age, 67 years old) within the month prior to the procedure and at 6 month follow‐up. PMVR was successfully performed in all patients. At 6 month follow‐up, PMVR was associated with an improvement in New York Heart Association functional class (P = 0.021) and a reduction in MR severity (P = 0.013) and N‐terminal pro‐brain natriuretic peptide levels (2805 [1878–5022] vs. 1485 [654–3032] pg/mL; P = 0.012). All patients completed pre‐procedural and post‐procedural CPET, and all the studies showed a respiratory exchange ratio ≥1 and were consistent with sufficient exercise effort. Compared with pre‐procedural CPET, patients showed a significant increase in exercise time (295 [110–335] vs. 405 [261–540] s; P = 0.047), VO2 (9.8 [9.1–13.4] vs. 13.5 [12.1–16.8] mL/kg/min; P = 0.033), ventilatory anaerobic threshold (510 [430–950] vs. 850 [670–1070] mL/kg/min; P = 0.033), peak O2 pulse (7.2 [4.3–8.6] vs. 8.3 [6.2–11.8] mL/beat; P = 0.033), and workload (5 [3–6] vs. 6 [5–8] metabolic equivalents; P = 0.049).

Conclusions

Percutaneous mitral valve repair with MitraClip was associated with an enhancement in cardiopulmonary performance in patients with systolic heart failure and secondary MR.
Potassium tert‐Butoxide Prompted Highly Efficient Transamidation and Its Coordination Radical Mechanism
Authors: Tan Zhiyong , Li Zhenhua , Ma Yao , Qin Jinjing , Yu Chuanming
Published: June 2019

A simple and highly efficient protocol was developed for the transamidation of N,N‐disubstituted amides with primary amines in the presence of tBuOK, affording desired products in good to excellent yields. This reaction proceeded under nitrogen atmosphere and featured extensive substrate tolerance. Experimental investigation suggested that a coordination radical process enhanced this transformation.
Assessment of municipal solid waste for valorization into biofuels
Authors: Thompson Vicki S. , Ray Allison E. , Hoover Amber , Emerson Rachel , Hartley Damon , Lacey Jeffrey A. , Yancey Neal , Thompson David N.
Published: June 2019

Almost 36 million tons of paper and yard trimmings are not currently being recycled or composted annually and likely end up in landfills. One approach to valorize these resources would be for biofuels production. Nonrecyclable municipal solid waste (MSW) paper and yard trimmings were assessed for their suitability as feedstocks to produce biofuels from sugars. Both materials met the cost target of less than $85.51/ton ($2016) with MSW paper ranging from $36.40 to $62.18/dry ton and grass clippings from $25.64 to $45.86/dry ton. MSW paper exceeded the carbohydrate requirement of 59% while grass clippings had significantly lower amounts of carbohydrates (30%). However, both types of MSW had ash contents significantly above the required 5% total ash with paper at 22% ash and grass clippings at 16%. While neither waste material was individually found to be suitable for biofuels production based on compositional requirements, it was determined that blending either waste with corn stover would produce materials that met carbohydrate, ash, and cost targets. The higher carbohydrate and lower ash stover compensated for the lower carbohydrates and high ash of the waste materials, while the lower cost waste materials offset the higher cost of corn stover.
Gaussian mixture–based equivalent linearization method (GM‐ELM) for fragility analysis of structures under nonstationary excitations
Authors: Yi Sang‐ri , Wang Ziqi , Song Junho
Published: June 2019

Gaussian mixture–based equivalent linearization method (GM‐ELM) is a recently developed stochastic dynamic analysis approach which approximates the random response of a nonlinear structure by collective responses of equivalent linear oscillators. The Gaussian mixture model is employed to achieve an equivalence in terms of the probability density function (PDF) through the superposition of the response PDFs of the equivalent linear system. This new concept of linearization helps achieve a high level of estimation accuracy for nonlinear responses, but has revealed some limitations: (1) dependency of the equivalent linear systems on ground motion intensity and (2) requirements for stationary condition. To overcome these technical challenges and promote applications of GM‐ELM to earthquake engineering practice, an efficient GM‐ELM‐based fragility analysis method is proposed for nonstationary excitations. To this end, this paper develops the concept of universal equivalent linear system that can estimate the stochastic responses for a range of seismic intensities through an intensity‐augmented version of GM‐ELM. Moreover, the GM‐ELM framework is extended to identify equivalent linear oscillators that could capture the temporal average behavior of nonstationary responses. The proposed extensions generalize expressions and philosophies of the existing response combination formulations of GM‐ELM to facilitate efficient fragility analysis for nonstationary excitations. The proposed methods are demonstrated by numerical examples using realistic ground motions, including design code–conforming nonstationary ground motions.
Nonlinear analysis of masonry structures using fiber‐section line elements
Authors: Peruch Matteo , Spacone Enrico , Camata Guido
Published: June 2019

For seismic analysis of unreinforced masonry (URM) buildings characterized by a box‐like behavior, a widely accepted model is based on the equivalent frame idealization of walls. The equivalent frame model uses 1D elements to represent the vertical piers and horizontal spandrels which are connected by rigid nodes. The mechanical characterization of the elements is one of the crucial aspects to predict reasonably the building seismic behavior. Through the comparison with pseudo‐static and dynamic experimental tests performed on two‐story full‐scale buildings, this paper validates the frame modeling in the OpenSees framework, which includes a fiber‐section force‐based beam element for the axial‐flexural behavior, coupled with a cyclic shear‐deformation phenomenological law.
Eradication of Hepatitis C Virus Is Associated With Reduction in Hematologic Malignancies: Major Differences Between Interferon and Direct‐Acting Antivirals
Authors: Ioannou George N. , Green Pamela K. , Berry Kristin , Graf Solomon A.
Published: June 2019

It is unclear whether eradication of hepatitis C virus (HCV) leads to a reduction in the risk of hematologic malignancies. We aimed to determine the impact of sustained virologic response (SVR) induced by either direct‐acting antivirals (DAAs) or interferon (IFN) on the risk of hematologic malignancies. We identified 69,581 patients who initiated antiviral treatment in the Veterans Affairs national health care system from January 1, 1999, to December 31, 2015, including 40,410 (58%) IFN‐only regimens, 4,546 (6.5%) DAA + IFN regimens, and 24,625 (35%) DAA‐only regimens. We retrospectively followed patients to identify incident cases of hematologic malignancies or monoclonal gammopathy of unknown significance (MGUS), a premalignant precursor of multiple myeloma. Among patients treated with IFN, SVR was significantly associated with a reduction in the risk of lymphoma (adjusted hazard ratio [AHR], 0.70; 95% confidence interval [CI], 0.51‐0.97), multiple myeloma (AHR, 0.40; 95% CI, 0.20‐0.77), MGUS (AHR, 0.65; 95% CI, 0.42‐0.99), or all hematologic malignancies and MGUS combined (AHR, 0.67; 95% CI, 0.53‐0.84) over a mean follow‐up of 10.6 years. In contrast, among patients treated with DAA, SVR was not associated with the risk of lymphoma, multiple myeloma, MGUS, or all hematologic malignancies and MGUS combined (AHR, 1.08; 95% CI, 0.66‐1.78) during a mean follow‐up of 2.9 years. Neither IFN‐induced SVR nor DAA‐induced SVR was associated with risk of colon cancer or prostate cancer, which were chosen a priori as comparison/control malignancies. Conclusion: We describe novel strong associations between IFN‐induced SVR and lymphoma, multiple myeloma, MGUS, and all hematologic malignancies combined. Surprisingly, these associations were not observed with DAA‐induced SVR.
Molecular docking explores heightened immunogenicity and structural dynamics of acetaldehyde human immunoglobulin G adduct
Authors: Waris Sana , Habib Safia , Khan Shifa , Kausar Tasneem , Naeem Shahid M. , Siddiqui Shahid A. , Moinuddin  , Ali Asif
Published: June 2019

Acetaldehyde is a metabolite of ethanol, an important constituent of tobacco pyrolysis and the aldehydic product of lipid peroxidation. Acetaldehyde induced toxicity is mainly due to its binding to cellular macromolecules resulting in the formation of stable adducts accompanied by oxidative stress. The aim of this study was to characterize structural and immunological alterations in human immunoglobulin G (IgG) modified with acetaldehyde in the presence of sodium borohydride, a reducing agent. The IgG modifications were studied by various physicochemical techniques such as fluorescence and CD spectroscopy, free amino group estimation, 2,2‐azobis 2‐amidinopropane (AAPH) induced red blood cell hemolysis as well as transmission electron microscopy. Molecular docking was also employed to predict the preferential binding of acetaldehyde to IgG. The immunogenicity of native and acetaldehyde‐modified IgG was investigated by immunizing female New Zealand white rabbits using native and modified IgG as antigens. Binding specificity and cross reactivity of rabbit antibodies was screened by competitive inhibition ELISA and band shift assays. The modification of human IgG with acetaldehyde results in quenching of the fluorescence of tyrosine residues, decrease in free amino group content, a change in the antioxidant property as well as formation of cross‐linked structures in human IgG. Molecular docking reveals strong binding of IgG to acetaldehyde. Moreover, acetaldehyde modified IgG induced high titer antibodies (>1:12800) in the experimental animals. The antibodies exhibited high specificity in competitive binding assay toward acetaldehyde modified human IgG. The results indicate that acetaldehyde induces alterations in secondary and tertiary structure of IgG molecule that leads to formation of neo‐epitopes on IgG that enhances its immunogenicity.
LINC00261 suppresses human colon cancer progression via sponging miR‐324‐3p and inactivating the Wnt/β‐catenin pathway
Authors: Yan Dongsheng , Liu Weidong , Liu Yeliu , Luo Man
Published: June 2019

Growing evidence indicates long noncoding RNAs (lncRNAs) are significant regulators in the progression of various malignant tumors including colon cancer. Dysregulation of lncRNA LINC00261 has been identified in many cancers. Investigations on LINC00261 function have revealed that LINC00261 could act as a crucial tumor suppressor in various cancers. But, the biological involvement of LINC00261 in colon cancer is still barely known. Here, we found LINC00261 was reduced in colon cancer cells. Meanwhile, overexpressed LINC00261 repressed colon cancer cell viability and proliferation capacity. In addition, colony cancer cell colony formation was inhibited and apoptosis was enhanced by upregulation of LINC00261. Also, colon cancer cell migration and invasion both were restrained by LINC00261. miR‐324‐3p can exert important functions in several carcinomas, but its role in colon cancer is uninvestigated. In the current study, miR‐324‐3p was examined and miR‐324‐3p was greatly increased in colon cancer cells. Moreover, the association between miR‐324‐3p and LINC00261 was confirmed via performing RNA immunoprecipitation and RNA‐pull‐down experiments. In cancer biology, aberrant modulation of the Wnt signaling pathway remains a prevalent theme. Overexpression of LINC00261 obviously impaired colon cancer progression via inactivating the Wnt pathway. Furthermore, in the xenograft model assay, an increase of LINC00261 could suppress colon tumor growth via sponging miR‐324‐3p and inactivating the Wnt pathway. Overall, our results showed that LINC00261 repressed colon cancer progression via regulating miR‐324‐3p and the Wnt pathway. LINC00261 could be established as a novel therapeutic target for colon cancer.
Population Pharmacokinetics of Pregabalin Extended‐Release in Healthy Volunteers and Patients With Postherpetic Neuralgia, Fibromyalgia, and Partial‐Onset Seizures
Authors: Chew Marci , Ma Guangli , Xie Rujia , Bockbrader Howard , Chapel Sunny , Marshall Scott
Published: June 2019

A population pharmacokinetic (PK) model was developed to characterize the properties of pregabalin extended‐release (ER) in healthy volunteers and was subsequently applied to patient data from efficacy/safety studies investigating pregabalin ER for postherpetic neuralgia, fibromyalgia, and partial‐onset seizures. The impact of demographic and other covariates on PK was assessed, and various dosing scenarios were simulated to inform pregabalin ER dosing/administration instructions. Phase 1 and 3 models were developed using data from 14 phase 1 studies (12 627 samples from 335 participants receiving pregabalin immediate‐release [IR] or ER) and 3 phase 3 studies (2591 samples from 1235 patients receiving pregabalin ER), respectively. Final phase 1 and 3 models adequately characterized the data. Several covariates were statistically significant, but renal function (creatinine clearance) was considered the only clinically relevant covariate. The relationship between creatinine clearance and pregabalin clearance was reasonably consistent between phase 1 and 3 models and with that reported previously with pregabalin IR data alone. Patients with moderate renal impairment who received pregabalin ER 82.5 mg once daily (QD) had similar predicted area under the plasma concentration–time curve and peak plasma concentration values as patients with normal/mild renal impairment who received 165 mg QD. Ranges in predicted PK parameters after switching from pregabalin IR administered in the morning to ER after a meal at 3, 6, or 9 pm were similar. Administration of a missed evening dose at bedtime with food or the next morning with food did not result in clinically important changes in predicted PK parameters.
Design by taking perspectives: How engineers explore problems
Authors: Murray Jaclyn K. , Studer Jaryn A. , Daly Shanna R. , McKilligan Seda , Seifert Colleen M.
Published: June 2019

Background

Problem exploration includes identifying, framing, and defining design problems and bounding problem spaces. Intentional and unintentional changes in problem understanding naturally occur as designers explore design problems to create solutions. Through problem exploration, new perspectives on the problem can emerge along with new and diverse ideas for solutions. By considering multiple problem perspectives varying in scope and focus, designers position themselves to increase their understandings of the “real” problem and engage in more diverse idea generation processes leading to an increasing variety of potential solutions.

Purpose/Hypothesis

The purpose of this study was to investigate systematic patterns in problem exploration in the early design phases of mechanical engineers.

Design/Method

Thirty‐five senior undergraduate students and experienced designers with mechanical engineering backgrounds worked individually following a think‐aloud protocol. They explored problems and generated solutions for two of four randomly assigned design problems. After generating solutions, participants framed and rewrote problem statements to reflect their perspectives on the design problem their solutions addressed. Thematic analysis and a priori codes guided the identification of problem exploration patterns within and across problems.

Results

The set of patterns in engineers' problem exploration that emerged from the analysis documents alternative strategies in exploring problems to arrive at solutions. The results provide evidence that engineering designers, working individually, apply both problem‐specific and more general strategies to explore design problems.

Conclusions

Our study identified common patterns in the explorations of presented problems by individual engineering designers. The observed patterns, described as Problem Exploration Perspectives, capture alternative approaches to discovering problems and taking multiple problem perspectives during design. Learning about Problem Exploration Perspectives may be helpful in creating alternative perspectives on a design problem, potentially leading to more varied and innovative solutions. This paper concludes with an extended example illustrating the process of applying Problem Exploration Perspectives to move between problem perspectives to generate varied design outcomes.
Coupled Si and O isotope measurements of meteoritic material by laser fluorination isotope ratio mass spectrometry
Authors: Hill Patrick J. A. , Banerjee Neil R. , Ali Arshad , Jabeen Iffat , Osinski Gordon R. , Longstaffe Fred J.
Published: June 2019

We present a procedure for the determination of the isotopic ratios of silicon and oxygen from the same aliquot of anhydrous silicate material. The sample is placed in a bromine pentafluoride atmosphere as it is heated with a CO2 laser system releasing silicon tetrafluoride and oxygen gasses. The oxygen gas is then purified to remove other reaction by‐products through several liquid nitrogen traps before being captured onto a molecular sieve and transferred to an isotope ratio mass spectrometer. The silicon tetrafluoride gas is then purified using a supplementary line by repeatedly freezing to −196°C with liquid nitrogen and then thawing with an ethanol slurry at −110°C through a series of metal and Pyrex traps. The purified gas is then condensed into a Pyrex sample tube before it is transferred to an isotope ratio mass spectrometer for silicon isotope ratio measurements. This system has silicon yields of greater than 90% for pure quartz, olivine, and garnet standards and has a reproducibility of ±0.1‰ (2σ) for pure quartz for both oxygen and silicon isotope measurements. Meteoritic samples were also successfully analyzed to demonstrate this system's ability to measure the isotopic ratio composition of bulk powders with precision. This unique technique allows for the fluorination of planetary material without the need for wet chemistry. Though designed to analyze small aliquots of meteoritic material (1.5 to 3 mg), this approach can also be used to investigate refractory terrestrial samples where traditional fluorination is not suitable.
Analysis of spatiotemporal variability in temperature extremes in the Yellow and Yangtze River basins during 1961–2014 based on high‐density gauge observations
Authors: Niu Zigeng , Wang Lunche , Fang Lulu , Li Jiarui , Yao Rui
Published: June 2019

The Yellow and Yangtze River basins are the most important basins in China due to their environment and natural and socioeconomic conditions, and they are highly sensitive to extreme climate events. In this study, we used daily maximum and minimum temperature data gathered from 892 meteorological stations to analyse the spatiotemporal variations in temperature extremes in the Yellow and Yangtze River basins during 1961–2014 and identified correlations with the geographic location and atmospheric circulation patterns. The results indicated that annual mean maximum and minimum temperatures (TXmandTNm), most warm extremes and some cold extremes (minimum of the minimum temperature and maximum temperature,TNnandTXn) generally showed low values in the northwestern region of the Yellow and Yangtze basins, while the diurnal temperature range (DTR) and some cold extremes (ice days,ID0and frost days,FD0) were generally higher in the northwest of the two basins.TXm,TNm, all warm extremes and some cold extremes (TNnandTXn) showed significant increasing trends in both basins. The increase in the extreme temperature was between 0.17–0.38°C/decade in the Yellow basin, while the interval was 0.15–0.38°C/decade in the Yangtze basin. DTR decreased by −0.07 days/decade in the former and −0.05 days/decade in the latter. Furthermore, warm event days increased by 1.38–3.52 and 1.42–2.65 days/decade in the Yellow and Yangtze basins, respectively. At the same time, the cold event days decreased by −1.90 to −3.47 and −0.20 to −2.70 days/decade in the respective basins. In terms of the spatial patterns, most stations that displayed significant trends were located over the Loess Plateau in the Yellow River basins; Sichuan basin and the lower reaches of the Yangtze River basins. Moreover, almost all of the temperature extremes exhibited the largest trends in spring and winter in the two basins. Most temperature extremes showed strong correlations with longitude and altitude and the Atlantic Multidecadal Oscillation (AMO) displayed significant correlations with almost all of the temperature extremes, except DTR,TNnandTXn; the East Atlantic/Western Russia (EA/WR) was also related to many temperature extremes. Finally, most temperature observations showed abrupt changes in the 1990s, and the timing in the Yangtze River basin was generally later than that in the Yellow River basin.
Implementing new technologies for complex care: The role of embeddedness factors in team learning
Authors: Stevens Merieke , van Schaik Jan
Published: June 2019

Bearing the rising health care costs of our aging global population is one of the most urgent challenges society is facing. We study the implementation of new medical technologies as one way to increase the effectiveness of care, particularly in the area of aortic disease—a condition that affects an increasing number of patients globally. Our research focus is the implementation of complex endovascular treatment techniques by a multidisciplinary aortic treatment group, in addition to their traditional open treatment of aortic disease. We find that relational and cognitive embeddedness factors support team learning, which in turn enables the team to achieve its self‐set goals of treating more patients; offering more tailor‐made care; and providing endovascular treatment in emergency situations. At the end of our data collection period, the first steps toward the team's ultimate goal of offering patient‐centered care were also taken.
Effects of ganciclovir treatment in a murine model of cytomegalovirus‐induced hearing loss
Authors: Haller Travis J. , Price Melissa S. , Lindsay Spencer R. , Hillas Elaine , Seipp Michael , Firpo Matthew A. , Park Albert H.
Published: June 2019

Objective

To determine whether ganciclovir (GCV) treatment reduces sensorineural hearing loss in cytomegalovirus (CMV)‐infected mice. The effects of GCV on viral load, absolute neutrophil count (ANC), and outer hair cell (OHC) integrity were also investigated.

Methods

Infected BALB/c mice were inoculated with murine CMV on postnatal day 3. Those treated with GCV received an intraperitoneal injection twice a day for 14 days. Auditory thresholds were assessed using distortion product otoacoustic emission (DPOAE) and auditory brainstem response (ABR) testing 4 weeks after inoculation. Temporal bones were used for determination of viral load by quantitative polymerase chain reaction and hair cell quantification by scanning electron microscopy. ANCs were completed by an automated hematology analyzer, with manual review for confirmation.

Results

GCV‐treated CMV‐infected mice had lower ABR (P < 0.0001, Kruskal‐Wallis test) and DPOAE (P < 0.0001) thresholds compared to CMV‐infected untreated mice, indicating that GCV protected mice from CMV‐induced hearing loss. Viral load in infected populations undergoing GCV treatment was significantly decreased (P = 0.03) relative to untreated mice. GCV treatment alone had no effect on ABR and DPOAE compared to untreated, uninfected controls (P = 0.1, P = 0.24, respectively). GCV‐treated mice received increased protection from OHC loss when compared to untreated groups, with total OHC losses of approximately 7% and 14%, respectively (P < 0.05). Neutropenia was absent after 7 days of GCV treatment.

Conclusion

Ganciclovir effectively ameliorated SNHL and partially protected from OHC loss in a preclinical model of congenital CMV infection, seemingly by reducing viral load.

Level of Evidence

NA Laryngoscope, 130:1064–1069, 2020
Lead Halide Perovskite‐Based Dynamic Metasurfaces
Authors: Zhang Chen , Xiao Shumin , Wang Yuhan , Gao Yisheng , Fan Yubin , Huang Can , Zhang Nan , Yang Wenhong , Song Qinghai
Published: June 2019

Lead halide perovskites CH3NH3PbX3 (MAPbX3) are known to have high refractive index and controllable bandgap, making them attractive for all‐dielectric and tunable metasurfaces. Till now, perovskite metasurfaces have only been used in structural colors. More interesting meta‐devices with 2π phase control are still absent. Here, MAPbX3‐perovskite‐based metasurfaces are experimentally demonstrated with a complete control of phase shift in a reflection mode. By utilizing MAPbBr3 cut‐wires as meta‐atoms on a ground metal film, it is found that the MAPbBr3 perovskite metasurface can produce full phase control from 0 to 2π and high reflection efficiency simultaneously. Consequently, high‐efficiency polarization conversion, anomalous reflection, and meta‐holograms are successfully produced. Most interestingly, the bandgap of the MAPbX3 perovskite can be post‐synthetically and reversibly tuned via anion exchange, providing a new approach to dynamically control of the all‐dielectric meta‐devices with novel function such as anomalous reflection and hologram.
X‐ray micro‐computed tomography analysis of accumulated corrosion products in deep‐water shipwrecks
Authors: Albahri Mohammed , Barifcani Ahmed , Dwivedi Deepak , Iglauer Stefan , Lebedev Maxim , MacLeod Ian D. , Machuca Laura L.
Published: June 2019

Accumulated corrosion products from two different shipwrecks which had lain on the seabed (2.5 km depth) for 73 years were systematically analysed by three‐dimensional imaging at high resolution using X‐ray micro‐computed tomography. Complementary surface and chemical characterization experiments were conducted to identify the morphological structure of the corrosion products. Goethite was observed as the main corrosion phase found in both the wreck's corrosion products. However, other corrosion products such as silica, lepidocrocite, maghemite, magnetite, benyacarite, jarosite and amorphous materials were noticed using Fourier transform infrared spectroscopy, Raman spectroscopy and X‐ray diffraction. In addition, mineralized microbial structures were also observed as significant constituents of the corrosion products. However, there were significant differences between samples from the two shipwrecks including porosity, distribution and volume percent of the corrosion products components. The mechanism of different corrosion products formation was proposed and discussed in detail.
Global strong solutions to the Shliomis system for ferrofluids in a bounded domain
Authors: Xie Chuangen
Published: June 2019

We consider the partial differential equations proposed by Shliomis to model the dynamics of an incompressible viscous ferrofluid submitted to an external magnetic field. The Shliomis system consists of the incompressible Navier‐Stokes equations, the magnetization equations, and the magnetostatic equations. The magnetization equations is of Bloch type, and no regularizing term is added. We prove the global existence of unique strong solution to the initial boundary value problem for the system in a bounded domain, with the small initial data and external magnetic field but without any restrictions on the physical parameters. The novelty of the analysis is to introduce a linear combination of magnetic fields.
A novel cylindrical dielectric resonator antenna based on Fibonacci series approach
Authors: Chauhan Monika , Pandey Ajay K. , Mukherjee Biswajeet
Published: June 2019

A novel cylindrical dielectric resonator antenna based on Fibonacci series approach is presented in this letter. Because of the presence of major and minor axis, the antenna characteristics resemble an Elliptical DRA. Optimized radius to height ratio (a/h) of the antenna and probe feed at an offset position (x = 10 mm, y = 1 mm) from the center is responsible to excite the orthogonal modes and generate quadrature phase shift in polarization of wave, that is, achieving circular polarization. Impedance bandwidth (|S11| < −10 dB) and 3‐dB axial ratio bandwidth achieved are 106.5% (6.1‐12.6 GHz) and 18.9% (10.6‐12.6 GHz), respectively. Fundamental HE11δ and HE12δ modes are excited at 9.1 and 10.8 GHz resonant frequency respectively and maximum gain attained is 7.6 dBi at 8.7 GHz. Peak radiation efficiency of 90% at 7.2 GHz is attained by the proposed dielectric resonator antennas. This antenna supports C, X, and Ku band applications like satellite communication, amateur radio (10‐10.5 GHz), weather monitoring and so on. Simulated and experimental results are in close agreement for fabricated proposed structure.
Non‐Cartesian GRAPPA and coil combination using interleaved calibration data – application to concentric‐ring MRSI of the human brain at 7T
Authors: Moser Philipp , Bogner Wolfgang , Hingerl Lukas , Heckova Eva , Hangel Gilbert , Motyka Stanislav , Trattnig Siegfried , Strasser Bernhard
Published: June 2019

Purpose

Proton MR spectroscopic imaging (MRSI) benefits from B0 ≥ 7T and multichannel receive coils, promising substantial resolution improvements. However, MRSI acquisition with high spatial resolution requires efficient acceleration and coil combination. To speed up the already‐fast sampling via concentric rings, we implemented additional, non‐Cartesian, hybrid through‐time/through‐k‐space (tt/tk)‐generalized autocalibrating partially parallel acquisition (GRAPPA). A new multipurpose interleaved calibration scan (interleaved MUSICAL) acquires reference data for both coil combination and PI. This renders the reconstruction process (especially PI) less sensitive to instabilities.

Methods

Six healthy volunteers were scanned at 7T. Three calibration datasets for coil combination and PI were recorded: a) iMUSICAL, b) static MUSICAL as prescan, c) moved MUSICAL as prescan with misaligned head position. The coil combination performance, including motion sensitivity, of iMUSICAL was compared to MUSICAL for single‐slice free induction decay (FID)‐MRSI. Through‐time/through‐k‐space‐GRAPPA with constant/variable‐density undersampling was evaluated on the same data, comparing the three calibration datasets. Additionally, the proposed method was successfully applied to 3D whole‐brain FID‐MRSI.

Results

Using iMUSICAL for coil combination yielded the highest signal‐to‐noise ratio (SNR) (+9%) and lowest Cramer‐Rao lower bounds (CRLBs) (‐6%) compared to both MUSICAL approaches, with similar metabolic map quality. Also, excellent mean g‐factors of 1.07 and low residual lipid aliasing were obtained when using iMUSICAL as calibration data for two‐fold, variable‐density undersampling, while significantly degraded metabolic maps were obtained using the misaligned MUSICAL calibration data.

Conclusion

Through‐time/through‐k‐space‐GRAPPA can accelerate already time‐efficient non‐Cartesian spatial‐spectral 2D/3D‐MRSI encoding even further. Particularly promising results have been achieved using iMUSICAL as a robust, interleaved multipurpose calibration for MRSI reconstruction, without extra calibration prescan.
Robust Synthesis of Gold Nanotriangles and their Self‐Assembly into Vertical Arrays
Authors: Szustakiewicz Piotr , González‐Rubio Guillermo , Scarabelli Leonardo , Lewandowski Wiktor
Published: June 2019

We report an efficient, seed‐mediated method for the synthesis of gold nanotriangles (NTs) which can be used for controlled self‐assembly. The main advantage of the proposed synthetic protocol is that it relies on using stable (over the course of several days) intermediate seeds. This stability translates into increasing time efficiency of the synthesis and makes the protocol experimentally less demanding (‘fast addition’ not required, tap water can be used in the final steps) as compared to previously reported procedures, without compromising the size and shape monodispersity of the product. We demonstrate high reproducibility of the protocol in the hands of different researchers and in different laboratories. Additionally, this modified seed‐mediated method can be used to produce NTs with edge lengths between ca. 45 and 150 nm. Finally, the high ‘quality’ of NTs allows the preparation of long‐range ordered assemblies with vertically oriented building blocks, which makes them promising candidates for future optoelectronic technologies.
Catalytic Chain Transfer Copolymerization of Propylene Oxide and CO2 using Zinc Glutarate Catalyst
Authors: Marbach Jakob , Höfer Theresa , Bornholdt Nick , Luinstra Gerrit A.
Published: June 2019

Oligo and poly(propylene ether carbonate)‐polyols with molecular weights from 0.8 to over 50 kg/mol and with 60–92 mol % carbonate linkages were synthesized by chain transfer copolymerization of carbon dioxide (CO2) and propylene oxide (PO) mediated by zinc glutarate. Online‐monitoring of the polymerization revealed that the CTA controlled copolymerization has an induction time which is resulting from reversible catalyst deactivation by the CTA. Latter is neutralized after the first monomer additions. The outcome of the chain transfer reaction is a function of the carbonate content, i. e. CO2 pressure, most likely on account of differences in mobility (diffusion) of the various polymers. Melt viscosities of poly(ether carbonate)diols with a carbonate content between 60 and 92 mol % are reported as function of the molecular weight, showing that the mobility is higher when the ether content is higher. The procedure of PO/CO2 catalytic chain copolymerization allows tailoring the glass temperature and viscosity.