bluuebunny/crossref_metadata_2025 huggingface dataset:
MiR‐291a‐3p regulates the BMSCs differentiation via targeting DKK1 in dexamethasone‐induced osteoporosis
Authors: Li Zhe‐Hai , Hu He , Zhang Xiao‐Yan , Liu Guo‐Dong , Ran Bo , Zhang Pei‐Guang , Liao Ming‐Mei , Wu Yu‐Chi
Published: November 2019

Osteoporosis is a skeleton disease affecting 55% of people over age 60, and the number is still increasing due to an ageing population. One method to prevent osteoporosis is to increase the formation of new bone while preventing the resorption of older bone. Thus, osteogenic differentiation of bone marrow‐derived mesenchymal stem cells (BMSCs) is of great importance in improving the treatment of osteoporosis. On the other hand, glucocorticoids (GCs) are widely used to treat the chronic inflammatory disorders, but long‐term exposure to GCs can induce osteoporosis. In present study, we treated BMSCs with dexamethasone (DEX) to simulate GC‐induced osteoporosis. MTT assay, ALP activity, and Alizarin Red were used to evaluate the role miRNA‐291a‐3p in the DEX‐induced osteogenic differentiation suppression. Further, we used qPCR and western blot to investigate the mechanisms of miRNA‐291a‐3p affecting BMSCs differentiation. The results showed that miRNA‐291a‐3p could improve the cell viability, osteogenic differentiation, and ALP activity, which are suppressed by DEX in BMSCs. Furthermore, we found that the osteogenesis genes Runx2, DMP1, and ALP were upregulated whereas the lipogenic genes C/EBPα and PPARγ were downregulated when miRNA‐291a‐3p mimics were transfected. Additionally, we demonstrated that miRNA‐291a‐3p promoted BMSCs' osteogenic differentiation by directly suppressing DKK1 mRNA and protein expression and subsequently activating Wnt/β‐catenin signaling pathway. Our study suggests that miR‐291a‐3p plays an important role in preventing osteoporosis and may serve as a potential miRNA osteoporosis biomarker.
Successive straw biochar amendments reduce nitrous oxide emissions but do not improve the net ecosystem economic benefit in an alkaline sandy loam under a wheat–maize cropping system
Authors: Liu Yujuan , Bi Yucui , Xie Yingxin , Zhao Xu , He Dexian , Wang Shenqiang , Wang Chenyang , Guo Tiancai , Xing Guangxi
Published: November 2019

Crop straw is converted to biochar with subsequent applications to soils as a multi‐benefit strategy for greenhouse gas (GHG) emission mitigation, carbon sequestration, and straw disposal and utilization in intensive agriculture. However, tradeoffs between agronomic, economic, and environmental performance of long‐term agricultural biochar use remain unclear. Using a case study of biochar‐amended alkaline sandy loamy soil, we investigated the effects of field application of straw biochar at 0, 2.25, 6.75, and 11.25 Mg ha−1 to 10 successive wheat and maize crop seasons over five rotation years on crop yield, nitrous oxide (N2O) emissions, soil total organic carbon (TOC), and soil carbon pool (SCP). The net global warming potential (net GWP) and net ecosystem economic benefit (NEEB) were assessed to examine the tension between balancing economic returns and environmental benefits. Results indicated that biochar treatments slightly increased total crop grain yields and greatly reduced the total N2O emissions over five rotation years. The soil total organic carbon content was enhanced while the CO2 emissions during biochar production almost offset the increase in the soil carbon pool. Economic assessment showed that the net ecosystem economic benefit was lowered with enhanced costs of the increasing biochar use under the current low C trade market. These results highlight the promotion of the use of straw biochar in successive applications as a strategy to effectively offset greenhouse gas emissions from agriculture requires optimization of the straw pyrolysis system to reduce the energy consumption and overall biochar costs, and price enhancement of C trade.
Mn‐promoting formation of a long‐period stacking‐ordered phase in laser‐melted Mg alloys to enhance degradation resistance
Authors: Shuai Cijun , Liu Long , Gao Chengde , Yang Wenjing , Zhao Zhenyu , Tan Ying , Liao Weiwei
Published: November 2019

Magnesium (Mg) alloys are promising candidates for use as biomedical implant materials. However, their very fast degradation rate greatly restricts their application. A rare earth phase possessed with a long‐period stacking‐ordered (LPSO) structure was in favor of enhancing the degradation resistance of Mg alloys. In fact, the formation of the LPSO phase in Mg alloys depends on their stacking fault energy. The lower the stacking fault energy, the more the LPSO phase formed. In this study, manganese (Mn) was alloyed to Mg alloy ZK30–10Gd (containing 3 wt.% Zn and 10 wt.% Gd) via selective laser melting to promote the formation of the LPSO phase. As an alloying element, Mn could be in favor of reducing stacking fault energy due to the fact that the large difference between the atomic radius of Mn and that of Mg induced large lattice distortion to facilitate forming stacking faults. The results showed that as the Mn content increased from 0 to 1.2 wt.%, the area fraction of LPSO phase increased from 12.22% to 22.37%, meanwhile the area fraction of (Mg,Zn)3Gd phase decreased from 9.31% to 2.32%. The ZK30–10Gd–0.6Mn possessed the highest degradation resistance (weight loss rate 0.38 mg · cm−2 · day−1). The enhancement of degradation resistance had two reasons. On the one hand, more LPSO phase provided more sites for nucleation of degradation products, which could promote the formation of a homogeneous and compact degradation product film to protect the Mg matrix. On the other hand, the inhibition of (Mg,Zn)3Gd phase precipitation could reduce galvanic corrosion.
Cooperation with a multiproduct corporation in a strategic managerial delegation
Authors: Garcia Arturo , Leal Mariel , Lee Sang‐Ho
Published: November 2019

We consider an industry composed of a multiproduct corporation that adopts corporate social responsibility (CSR) as a strategic managerial delegation and examine the profit‐incentive to form a cooperative group. We find that competition is an equilibrium for any degree of substitutability and yields the highest CSR, which is increasing in the degree of substitutability. We also show that full cooperation is an equilibrium for lower substitutability but induces no CSR, whereas partial cooperation with one uniplant firm is an equilibrium for higher substitutability but yields lower CSR than that under competition. Therefore, cooperation might reduce strategic CSR activities, whereas competition will encourage higher CSR but yield lower industry profits.
Variable neurodevelopmental and morphological phenotypes of carriers with 12q12 duplications
Authors: Myers Lynnea , Blyth Moira , Moradkhani Kamran , Hranilović Dubravka , Polesie Sam , Isaksson Johan , Nordgren Ann , Bucan Maja , Vincent Marie , Bölte Sven , Anderlid Britt‐Marie , Tammimies Kristiina
Published: November 2019

Background

Variable size deletions affecting 12q12 have been found in individuals with neurodevelopmental disorders (NDDs) and distinct facial and physical features. For many genetic loci affected by deletions in individuals with NDDs, reciprocal duplications have been described. However, for the 12q12 region, there are no detailed descriptions of duplication cases in the literature.

Methods

We report a phenotypic description of a family with monozygotic twins diagnosed with NDDs, carrying a 9 Mb duplication at 12q12, and five other individuals with overlapping duplications ranging from 4.54 Mb up to 15.16 Mb.

Results

The duplication carriers had language delays, cognitive delays, and were diagnosed with autism spectrum disorder. Additionally, distinct facial features (e.g., high foreheads, deeply set eyes, short palpebral fissures, small ears, high nasal bridges, abnormalities of the nose tip, thin lips), large feet, and abnormalities in the digits were noted. We also describe incomplete penetrance of the NDD phenotypes among the individuals with 12q12 duplication.

Conclusion

This case series expands our knowledge on this rare genetic aberration and suggests that large 12q12 duplications may increase the risk for developing NDDs.
Simple models for biological control of crop pests and their application
Authors: Vela‐Arevalo Luz Vianey , Ku‐Carrillo Roberto Alejandro , Delgadillo‐Aleman Sandra Elizabeth
Published: November 2019

In this work, we construct simple models in terms of differential equations for the dynamics of pest populations and their management using biological pest control. For the first model used, the effect of the biological control is modelled by a function of repeated infinite impulses. And, our second model uses a periodic function proportional to the population to model the effect of biological control. In both cases, we present analytical solutions and derive a discrete version of them. Moreover, convergence conditions are given for periodic solutions. Finally, an application of such models is described for diamondback moth in a plot of broccoli to be controlled by the application of biological pesticides and beneficial parasitoids.
Passivity and passification of quaternion‐valued memristive neural networks
Authors: Wei Hongzhi , Wu Baowei , Tu Zhengwen
Published: November 2019

In this paper, a class of memristive neural networks with quaternion‐valued connection weights is studied. By starting from some basic quaternion‐valued algorithms, the quaternion‐valued memristive system is obtained; then, some passivity criteria for the memristive neural networks are presented based on some appropriate auxiliary functions. Furthermore, to tackle with the passification problem, two kinds of control protocols are designed. What should be mentioned is that, in the above derived conclusions, the partial order is employed, which can be employed to compare the “magnitude” of two different quaternions, and thus, the closed convex hull consisted by quaternion can be derived correspondingly. In the end, the analytical design are substantiated with two numerical results.
A time domain hybrid method for the coupling of two wires above the ground excited by electromagnetic pulses
Authors: Huan Rui , Liao Cheng , Ye Zhihong , Luo Jie
Published: November 2019

To efficiently solve the coupling problems of two wires above the ground excited by incident electromagnetic pulses, a time domain hybrid method consisting of transmission line (TL) equations, finite difference time domain (FDTD) method, and a fast calculation approach to the excitation fields of the wires is presented. In this hybrid method, a novel coupling model of the two wires is established by the TL equations firstly, which is suitable for arbitrary heights of the two wires and for considering influences of the ground on distributed parameters of the two wires. Then, due to the obviously infinite dimension of the ground, a fast calculation approach is utilized to obtain the excitation fields of the wires to avoid modeling the ground directly. Finally, the FDTD method is adopted to discretize the TL equations to calculate the transient responses at the termination loads of the two wires. Numerical examples are given to demonstrate the accuracy and efficiency of this hybrid method. It shows that this method can tremendously decrease the memory requirement and computation time, compared with the full‐wave method. The applicability of this method in fast coupling analysis of long two wires with arbitrary heights above the ground excited by multiple electromagnetic pulses is verified.
Microdosimetric characterization of clinical carbon‐ion beams using synthetic diamond detectors and spectral conversion methods
Authors: Magrin Giulio , Verona Claudio , Ciocca Mario , Marinelli Marco , Mastella Edoardo , Stock Marcus , Verona‐Rinati Gianluca
Published: November 2019

Purpose

To investigate for the first time the potentialities of obtaining microdosimetric measurements in scanned clinical carbon‐ion beams using synthetic single crystal diamond detector and to verify the spectral conversion methods.

Methods

Microdosimetric measurements were performed at different depths in a water phantom at the therapeutic scanned carbon‐ion beam of the National Center of Oncological Hadrontherapy (CNAO) in Pavia, using waterproof encapsulated diamond microdosimeter developed at “Tor Vergata” University. A monoenergetic carbon‐ion beam of 195 MeV/μ scanned over a square field of 2 × 2 cm2 was used. Experimental microdosimetric spectra were compared with those obtained with a propane‐filled Tissue Equivalent Proportional Counters (TEPCs) microdosimeter in the same facility at the same conditions. To this purpose, the spectra in diamond were converted to the spectra that would have been collected with a propane‐filled cylindrical sensitive volume by means of a novel analytic methodology, recently developed at MedAustron.

Results

The microdosimetric spectra acquired by the diamond microdosimeter show different shapes in the 10 keV µm−1 ÷ 103 keV µm−1 lineal‐energy range at different water depths. In spite of the high counting rate, no spectral distortion, due to pile‐up events and polarization effects, were observed. The experimental spectra have a low detection threshold of about 6 keV µm−1 due to the electronic noise in the irradiation room. The comparison between the spectra converted to propane from diamond detector and the spectra collected directly with propane‐filled TEPC shows a good agreement in the whole lineal‐energy range. Furthermore this comparison confirms that diamond detector response is LET independent. The frequency‐ and dose‐mean lineal energy values were also assessed for all spectra. The frequency‐mean values obtained with diamond microdosimeter at different depths scales rather well with the absorbed dose values.

Conclusions

Microdosimetric characterization of a synthetic single crystal diamond detector in high‐energy scanned carbon‐ion beams was performed. The results of the present study showed that this detector is suitable for microdosimetry of clinical carbon ion beams. In addition, the good agreement between the converted diamond spectra and those obtained with TEPC provides the first experimental validation of the spectra conversion methodologies as valuable tools for the comparison of spectra collected with different detectors.
Lactate measurement by neurochemical profiling in the dorsolateral prefrontal cortex at 7T: accuracy, precision, and relaxation times
Authors: Dehghani Masoumeh , Do Kim Q. , Magistretti Pierre , Xin Lijing
Published: November 2019

Purpose

This assesses the potential of measuring lactate in the human brain using three non‐editing MRS methods at 7T and compares the accuracy and precision of the methods.

Methods

1H MRS data were measured in the right dorsolateral prefrontal cortex using a semi‐adiabatic spin‐echo full‐intensity acquired localized sequence with three different protocols: (I) TE = 16 ms, (II) TE = 110 ms, and (III) TE = 16 ms, TI = 300 ms. T1 and T2 relaxation times of lactate were also measured. Simulated spectra were generated for three protocols with known concentrations, using a range of spectral linewidths and SNRs to assess the effect of data quality on the measurement precision and accuracy.

Results

Lactate was quantified in all three protocols with mean Cramér‐Rao lower bound of 8% (I), 13% (II), and 7% (III). The T1 and T2 relaxation times of lactate were 1.9 ± 0.2 s and 94 ± 13 ms, respectively. Simulations predicted a spectral linewidth‐associated underestimation of lactate measurement. Simulations, phantom and in vivo results showed that protocol II was most affected by this underestimation. In addition, the estimation error was insensitive to a broad range of spectral linewidth with protocol I. Within‐session coefficient of variances of lactate were 6.1 ± 7.9% (I), 22.3 ± 12.3% (II), and 5.1 ± 5.4% (III), respectively.

Conclusion

We conclude that protocols I and III have the potential to measure lactate at 7T with good reproducibility, whereas the measurement accuracy and precision depend on spectral linewidth and SNR, respectively. Moreover, simulation is valuable for the optimization of measurement protocols in future study design and the correction for measurement bias.
MiRNAs as biomarkers of phenotype in neutral lipid storage disease with myopathy
Authors: Pegoraro Valentina , Missaglia Sara , Marozzo Roberta , Tavian Daniela , Angelini Corrado
Published: November 2019

Background

Neutral lipid storage disease with myopathy (NLSDM) is a rare lipid metabolism disorder. In this study, we evaluated some circulating miRNAs levels in serum samples and the MRI of three affected siblings.

Methods

Three members of one NLSDM family were identified: two brothers and one sister. Muscles of lower and right upper extremities were studied by MRI. Expression profile of miRNAs, obtained from serum samples, was detected using qRT‐PCR.

Results

Two brothers presented with progressive skeletal myopathy, while the sister had severe hepatosteatosis and diabetes. NLSDM patients showed a significant increase of muscle‐specific miRNAs expression compared with healthy subjects. We found a correlation between hepatic damage and elevation of miRNAs expression profile of liver origin.

Conclusions

The dysregulation of miRNAs might represent an indicator of skeletal and hepatic damage and it might be useful to monitor the progression of NLSDM.
Enuretic children have a higher variability in REM sleep when comparing their sleep parameters with nonenuretic control children using a wearable sleep tracker at home
Authors: Collier Ellen , Varon Carolina , Van Huffel Sabine , Bogaert Guy
Published: November 2019

Purpose

That children with nocturnal enuresis (“bedwetting”) are deep sleepers is a fact that their parents often state when asking for advice. However, until today no clear difference in sleep has been observed between children who do and do not wet the bed. This study investigates the difference in sleep parameters and heart rate variability (HRV) between enuretic and control children in their home setting by using a wearable sleep tracker during a long observation period.

Methods

Twenty‐one enuretic and 18 control children, aged 6 to 12 years old, slept with a wearable sleep tracker device, a Fitbit Charge 2, for 14 consecutive days. In addition, nocturnal urine production (voided volumes and/or weight of the diaper) were measured. The HRV was calculated using the standard time and frequency domain parameters. The Kruskal‐Wallis test was applied to evaluate the differences in the sleep and HRV parameters between both groups.

Results

Compared with healthy controls, enuretic children showed a higher standard deviation (P = .0209) of minutes spent in rapid eye movement (REM) sleep among the different nights. In addition, they showed the tendencies to fewer awakenings (P = .1161), although this was not significant. Analyzing the wet nights of the enuretic children, they showed higher autonomic activity, lower sleep efficiency and a higher restlessness compared with their dry nights and to the control group.

Conclusion

This 2‐weeks sleep‐study, using a wrist‐worn sleep tracker device Fitbit Charge 2, in the normal home environment has shown that enuretic children have a larger variation in their REM sleep and sleepless efficiently during a wet night when compared with non‐bedwetting children.
A coupled thermo‐chemo‐mechanical reduced‐order multiscale model for predicting process‐induced distortions, residual stresses, and strength
Authors: Yuan Zifeng , Aitharaju Venkat , Fish Jacob
Published: November 2019

We study residual stresses and part distortion induced by a manufacturing process of a polymer matrix composite and its effect on the component strength. Unlike most of the thermo‐chemo‐mechanical models in the literature where governing multiphysics equations are directly formulated on the macroscale, we present a multiscale‐multiphysics approach. To address the enormous computational complexity involved, a reduced‐order homogenization was originally developed for a single physics problem is employed. The proposed reduced‐order two‐scale thermo‐chemo‐mechanical model has been validated for predicting part distortion beam strength in three‐point bending test. It is shown that while macroscopic stresses are relatively low, and therefore often ignored in practice, stresses at the scale of microconstituents are significant and may have an effect on the overall composite component strength.
Proteome analysis of formalin‐fixed paraffin‐embedded colorectal adenomas reveals the heterogeneous nature of traditional serrated adenomas compared to other colorectal adenomas
Authors: Sohier Pierre , Sanson Romain , Leduc Marjorie , Audebourg Anne , Broussard Cédric , Salnot Virginie , Just Pierre‐Alexandre , Pasmant Eric , Mayeux Patrick , Guillonneau François , Romagnolo Béatrice , Perret Christine , Terris Benoît
Published: November 2019

Traditional serrated adenoma (TSA) remains the least understood of all the colorectal adenomas, although these lesions have been associated with a significant cancer risk, twice that of the conventional adenoma (CAD) and of the sessile serrated adenoma (SSA/P). This study was performed to investigate the proteomic profiles of the different colorectal adenomas to better understand the pathogenesis of TSA. We performed a global quantitative proteome analysis using the label‐free quantification (LFQ) method on 44 colorectal adenoma (12 TSAs, 15 CADs, and 17 SSA/Ps) and 17 normal colonic mucosa samples, archived as formalin‐fixed paraffin‐embedded blocks. Unsupervised consensus hierarchical clustering applied to the whole proteomic profile of the 44 colorectal adenomas identified four subtypes: C1 and C2 were well‐individualized clusters composed of all the CADs (15/15) and most of the SSA/Ps (13/17), respectively. This is consistent with the fact that CADs and SSA/Ps are homogeneous and distinct colorectal adenoma entities. In contrast, TSAs were subdivided into C3 and C4 clusters, consistent with the more heterogeneous entity of TSA at the morphologic and molecular levels. Comparison of the proteome expression profile between the adenoma subtypes and normal colonic mucosa further confirmed the heterogeneous nature of TSAs, which overlapped either on CADs or SSA/Ps, whereas CADs and SSAs formed homogeneous and distinct entities. Furthermore, we identified LEFTY1 a new potential marker for TSAs that may be relevant for the pathogenesis of TSA. LEFTY1 is an inhibitor of the Nodal/TGFβ pathway, which we found to be one of the most overexpressed proteins specifically in TSAs. This finding was confirmed by immunohistochemistry. Our study confirms that CADs and SSA/Ps form homogeneous and distinct colorectal adenoma entities, whereas TSAs are a heterogeneous entity and may arise from either SSA/Ps or from normal mucosa evolving through a process related to the CAD pathway. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Factors of importance for discontinuation of thiazides associated with hyponatremia in Sweden: A population‐based register study
Authors: Fahlén Bergh Cecilia , Toivanen Susanna , Johnell Kristina , Calissendorff Jan , Skov Jakob , Falhammar Henrik , Nathanson David , Lindh Jonatan D. , Mannheimer Buster
Published: November 2019

Purpose

In a patient with clinically significant hyponatremia without other clear causes, thiazide treatment should be replaced with another drug. Data describing to which extent this is being done are scarce. The aim of this study was to investigate sociodemographic and socioeconomic factors that may be of importance for the withdrawal of thiazide diuretics in patients hospitalized due to hyponatremia.

Methods

The study population was sampled from a case‐control study investigating individuals hospitalized with a main diagnosis of hyponatremia. For every case, four matched controls were included. In the present study, cases (n = 5204) and controls (n = 7425) that had been dispensed a thiazide diuretic prior to index date were identified and followed onward regarding further dispensations. To investigate the influence of socioeconomic and sociodemographic factors, multiple logistic regression was used.

Results

The crude prevalence of thiazide withdrawal for cases and controls was 71.9% and 10.8%, respectively. Thiazide diuretics were more often withdrawn in medium‐sized towns (adjusted OR, 1.52; 95% CI, 1.21‐1.90) and rural areas (aOR, 1.81; 95% CI, 1.40‐2.34) compared with metropolitan areas and less so among divorced (aOR, 0.72; 95% CI, 0.53‐0.97). However, education, employment status, income, age, country of birth, and gender did not influence withdrawal of thiazides among patients with hyponatremia.

Conclusions

Thiazide diuretics were discontinued in almost three out of four patients hospitalized due to hyponatremia. Educational, income, gender, and most other sociodemographic and socioeconomic factors were not associated with withdrawal of thiazides.
Synthesis, electrochemistry, and electrochromic properties of branched thiophene polymers with different conjugation lengths
Authors: Li Weijun , Luo Feifei , Zhang Ling , Yan Shuanma , Zhao Ruiyang , Ren Ning , Wu Yizhao , Chen Yuliang , Dong Yujie , Ouyang Mi , Zhang Cheng
Published: November 2019

Here the authors designed and synthesized three branched thiophene polymers with different effective conjugation lengths of thiophene groups, pTPBT, pTPTT, and pTPQT, mainly based on bithiophene, trithiophene, and quadruple thiophene. The electrochemical curves and theoretical calculation results reflect that the oxidation potential of polymers decreased gradually as the conjugation lengths of thiophene groups increased, which is favorable for the appearance of electrochromism. Electrochromic properties demonstrate that pTBTT displays no electrochromism, pTPTT exhibits an unstable one, while pTPQT shows an obvious stable electrochromism between yellow‐orange and blue‐violet colors. These results indicate that thiophene polymers with effective electrochromism should be the smallest conjugation length of quadruple thiophene at least. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 2340–2348
Synthesis and cationic ring‐opening polymerization of oxetane monomer containing five‐membered cyclic carbonate moiety via highly chemoselective addition of CO2
Authors: Aoyagi Naoto , Endo Takeshi
Published: November 2019

The bicyclic amidinium iodide effectively catalyzed the reaction of carbon dioxide and the epoxy‐containing oxetane under ordinary pressure and mild conditions with high chemoselectivity to give the corresponding oxetane monomer containing five‐membered cyclic carbonate quantitatively. The cationic ring‐opening polymerization of the obtained monomer by boron trifluoride diethyl ether proceeded to give linear polyoxetane bearing five‐membered cyclic carbonate pendant group in high yield. The molecular weight of the polyoxetane was higher than that of polyepoxide obtained by the cationic ring‐opening polymerization of epoxide monomer containing five‐membered cyclic carbonate. The cyclic carbonate functional crosslinked polyoxetanes were also synthesized by the cationic ring‐opening copolymerization of cyclic carbonate having oxetane and commercially available bisoxetane monomers. Analyses of the resulting polyoxetanes were performed by proton nuclear magnetic resonance, size exclusion chromatography, thermogravimetric analysis, and differential scanning calorimetry. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 2606–2615
Predicting the location of weld line in microinjection‐molded polyethylene via molecular orientation distribution
Authors: Liao Tao , Zhao Xintong , Yang Xiao , Whiteside Ben , Coates Phil , Jiang Zhiyong , Men Yongfeng
Published: November 2019

The microstructure and molecular orientation distribution over both the length and the thickness of microinjection‐molded linear low‐density polyethylene with a weld line were characterized as a function of processing parameters using small‐angle X‐ray scattering and wide‐angle X‐ray diffraction techniques. The weld line was introduced via recombination of two separated melt streams with an angle of 180° to each other in injection molding. The lamellar structure was found to be related to the mold temperature strongly but the injection velocity and the melt temperature slightly. Furthermore, the distributions of molecular orientation at different molding conditions and different positions in the cross section of molded samples were derived from Hermans equation. The degree of orientation of polymeric chains and the thickness of oriented layers decrease considerably with an increase of both mold temperature and melt temperature, which could be explained by the stress relaxation of sheared chains and the reduced melt viscosity, respectively. The level of molecular orientation was found to be lowest in the weld line when varying injection velocity, mold temperature, and melt temperature, thus providing an effective means to identify the position of weld line induced by flow obstacles during injection‐molding process. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019, 57, 1705–1715
Impact of drug distribution into adipose on tissue function: The cholesteryl ester transfer protein (CETP) inhibitor anacetrapib as a test case
Authors: Johns Douglas G. , Wang Sheng‐Ping , Rosa Raymond , Hubert James , Xu Suoyu , Chen Ying , Bateman Thomas , Blaustein Robert O.
Published: November 2019

Anacetrapib is an inhibitor of cholesteryl ester transfer protein (CETP) previously under development as a lipid‐modifying agent that reduces LDL‐cholesterol and increases HDL‐cholesterol in hypercholesterolemic patients. Anacetrapib demonstrates a long terminal half‐life and accumulates in adipose tissue, which contributes to a long residence time of anacetrapib. Given our previous report that anacetrapib distributes into the lipid droplet of adipose tissue, we sought to understand whether anacetrapib affected adipose function, using a diet‐induced obese (DIO) mouse model. Following 20 weeks of treatment with anacetrapib (100 mg/kg/day), levels of the drug increased to approximately 0.6 mmol/L in white adipose tissue. This level of anacetrapib was not associated with any impairment in adipose functionality as evidenced by a lack of any reduction in biomarkers of adipose functionality (plasma adiponectin, leptin, insulin; adipose adiponectin, leptin mRNA). In DIO wild‐type (WT) mice treated with anacetrapib for 2 weeks and then subjected to 30% food restriction during washout to induce weight loss (18%) and fat mass loss (7%), levels of anacetrapib in adipose and plasma were not different between food restricted and ad lib‐fed mice. These data indicate that despite deposition and long‐term residence of ~0.6 mmol/L levels of anacetrapib in adipose tissue, adipose tissue function appears to be unaffected in mice. In addition, these data also indicate that even with severe caloric restriction and acute loss of fat mass, anacetrapib does not appear to be mobilized from the fat depot, thereby solidifying the role of adipose as a long‐term storage site of anacetrapib.
A review of the extensions of the geometric process, applications, and challenges
Authors: Wu Di , Peng Rui , Wu Shaomin
Published: November 2019

Modelling the failure process of a repairable system is vitally important in many industrial sectors such as the offshore industry and the transport industry, in which properly maintaining assets is needed. Among the various models, the geometric process (GP) has been widely applied, mainly in the reliability and maintenance engineering, since its introduction. A book on the GP was published in 2007 and included the GP‐related research by that year. However, since then, much research has been conducted, which creates a necessity to review the existing publications relating to the GP, its various extensions and applications since 2007. This paper serves for this purpose.
Ionized water clusters , n = 2 to 6: A high‐accuracy study of structures and energetics
Authors: Ünal Aslı , Bozkaya Uğur
Published: November 2019

Ionized water clusters, , have been of remarkable interest owing to their crucial roles in many chemical and biological processes. Small cationic water clusters , n = 2 to 6 serve as reasonable models for understanding the nature of the ionized water. In this study, employing high‐level ab initio quantum chemical methods, such as the density‐fitted orbital‐optimized linearized coupled‐cluster doubles (DF‐OLCCD), coupled‐cluster singles and doubles (CCSD), and coupled‐cluster singles and doubles with perturbative triples [CCSD(T)], a high‐accuracy study of structures and energetics for cationic water clusters [, n = 2‐6] is presented. In this study, 2 dimer, 8 trimer, 18 tetramer, 23 pentamer, and 25 hexamer clusters are reported. Most of the structures considered are reported for the first time. Relative, binding, and vertical attachment energies (VAEs), for the first time, are presented at the complete basis set (CBS) limit, extrapolating energies of the aug‐cc‐pVTZ and aug‐cc‐pVQZ basis sets, to provide the most accurate energetics to date. Our results demonstrate that as cluster size increases, the VAE value decreases, which indicates that large‐size clusters better compensate for the electron deficiency compared with small‐size clusters. The VAE values for pentamer and hexamer clusters are 118.5 to 165.5 and 121.9 to 153.7 kcal mol−1, respectively. Further, our binding energy results, at the CCSD(T)/CBS level, indicate strong bindings in cationic clusters due to hydrogen bond interactions. The average binding energy per water molecule varies from −16.6 to −21.8 kcal mol−1 for the clusters considered. Hence, we present the most extensive and accurate study on ionized water clusters to date. Further, our results indicate that the DF‐OLCCD method is very promising for ionic molecular clusters, and its accuracy approaches the CCSD(T) quality. The inexpensive analytic gradients of DF‐OLCCD, compared with CCSD(T), make it very helpful for high‐accuracy studies of molecular geometries.
Mass spectrometry and ion mobility study of poly(ethylene glycol)‐based polyurethane oligomers
Authors: Harris Rachel A. , Picache Jaqueline A. , Tomlinson Ian D. , Zlibut Emanuel , Ellis Berkley M. , May Jody C. , McLean John A. , Hercules David M.
Published: November 2019

Rationale

Commercial‐grade polymer synthesis is performed via melt polymerization, which leads to polydispersion. The work reported herein provides a synthetic strategy to produce mono‐dispersive polyurethane oligomers and an analytical strategy to distinguish these oligomers, providing chemists with the tools necessary to synthesize and identify specific polymer structures that exhibit a desired property.

Methods

Three isomeric poly(ethylene glycol)–polyurethane (PEG‐PUR) oligomers were synthesized and analyzed via flow‐injection ion mobility mass spectrometry (IM‐MS). Each polymer oligomer was injected and run independently via flow injection at 100 μL•min−1 and analyzed in positive ion mode on a drift tube quadrupole time‐of‐flight (QTOF) instrument. Mobility measurements were determined using a single‐field approach. For tandem mass spectrometry (MS/MS) experiments, the sodium‐adducted singly charged precursor ion was isolated in the quadrupole and subjected to a range of collision energies.

Results

In MS experiments, both +1 and +2 sodium‐adducted species were observed for each oligomer at m/z 837.4 and 430.2, respectively. When isolated and fragmented via MS/MS, the +1 precursor yielded distinct product ions for each of the three isomeric oligomers. Fragmentation generally occurred at urethane linkages via 1,3‐ and 1,5‐H shift mechanisms. IM was also used to distinguish the three isomers, with greater IM separation observed for the +2 versus the +1 species.

Conclusions

Mono‐disperse PEG‐PUR oligomers were synthesized and analyzed. Although the polymeric oligomers analyzed in this study are quite small and structurally simple, this work serves as a model system for the synthesis and structural characterization of larger, more complex block copolymers.
Missing data and sensitivity analysis for binary data with implications for sample size and power of randomized clinical trials
Authors: Cook Thomas , Zea Ryan
Published: November 2019

Despite our best efforts, missing outcomes are common in randomized controlled clinical trials. The National Research Council's Committee on National Statistics panel report titled The Prevention and Treatment of Missing Data in Clinical Trials noted that further research is required to assess the impact of missing data on the power of clinical trials and how to set useful target rates and acceptable rates of missing data in clinical trials. In this article, using binary responses for illustration, we establish that conclusions based on statistical analyses that include only complete cases can be seriously misleading, and that the adverse impact of missing data grows not only with increasing rates of missingness but also with increasing sample size. We illustrate how principled sensitivity analysis can be used to assess the robustness of the conclusions. Finally, we illustrate how sample sizes can be adjusted to account for expected rates of missingness. We find that when sensitivity analyses are considered as part of the primary analysis, the required adjustments to the sample size are dramatically larger than those that are traditionally used. Furthermore, in some cases, especially in large trials with small target effect sizes, it is impossible to achieve the desired power.
Learn how FERPA and HIPAA apply to student records
Authors: Gelpi Aileen
Published: November 2019

Does your college or university offer health services to students, employees, and their family members? If the answer is yes, take this opportunity to review how the Health Insurance Portability and Accountability Act and the Family Educational Rights and Privacy Act apply to the records created and maintained by university health services.
Dermatophilus congolensis associated bronchopneumonia in an alpaca
Authors: Horadagoda Neil U. , Biasutti Sara , Gimeno Marina , Dart Andrew
Published: November 2019

A severe, chronic, locally extensive granulomatous bronchopneumonia was diagnosed on post‐mortem and histopathological examination of an adult alpaca. Dermatophilus congolensis organisms were isolated from the lungs and genotypic identification of aerobic culture was confirmed by sequence analysis of the entire 16S rDNA gene. This is the first report of D. congolensis‐associated bronchopneumonia in any species.
The zero limit of thermal diffusivity for the 2D density‐dependent Boussinesq equations with vacuum
Authors: Ye Xia , Zhu Mingxuan
Published: November 2019

This paper is concerned with the initial boundary problem to the two‐dimensional density‐dependent Boussinesq equations with vacuum. The global solution of the density‐dependent Boussinesq equations with zero thermal diffusivity will be obtained. We also show the asymptotic behavior of the solutions of the Boussinesq equations as the thermal diffusivity tends to zero. If the initial data , the solutions of the Boussinesq equations converge to those of zero thermal diffusivity Boussinesq equations as the thermal diffusivity tends to zero.
Little strings, long strings, and fuzzballs
Authors: Martinec Emil J. , Massai Stefano , Turton David
Published: November 2019

Abstract

At high energy densities, fivebranes are populated by a Hagedorn phase of so- called little strings, whose statistical mechanics underlies black fivebrane thermodynamics. A particular limit of this phase yields BTZ black holes in AdS3, leading us to the idea that in this context fuzzballs and highly excited little strings are one and the same. We explore these ideas through an analysis of D-brane probes of fivebrane supertube backgrounds. String theory dynamics on these backgrounds is described by an exactly solvable null- gauged WZW model. We develop the formalism of null gauging on worldsheets with boundaries, and find that D-branes wrapping topology at the bottom of the supertube throat are avatars of the “long string” structure that dominates the thermodynamics of the black hole regime, appearing here as excitations of supertubes lying near but slightly outside the black hole regime.
Gravitational collapse in SYK models and Choptuik-like phenomenon
Authors: Dhar Avinash , Gaikwad Adwait , Joshi Lata Kh , Mandal Gautam , Wadia Spenta R.
Published: November 2019

Abstract

SYK model is a quantum mechanical model of fermions which is solvable at strong coupling and plays an important role as perhaps the simplest holographic model of quantum gravity and black holes. The present work considers a deformed SYK model and a sudden quantum quench in the deformation parameter. The system, as in the undeformed case, permits a low energy description in terms of pseudo Nambu Goldstone modes. The bulk dual of such a system represents a gravitational collapse, which is characterized by a bulk matter stress tensor whose value near the boundary shows a sudden jump at the time of the quench. The resulting gravitational collapse forms a black hole only if the deformation parameter ∆𝜖 exceeds a certain critical value ∆𝜖c and forms a horizonless geometry otherwise. In case a black hole does form, the resulting Hawking temperature is given by a fractional power Tbh∝ (∆𝜖 − ∆ 𝜖c)1/2, which is reminiscent of the ‘Choptuik phenomenon’ of critical gravitational collapse.
APS η-invariant, path integrals, and mock modularity
Authors: Dabholkar Atish , Jain Diksha , Rudra Arnab
Published: November 2019

Abstract

We show that the Atiyah-Patodi-Singer η-invariant can be related to the temperature-dependent Witten index of a noncompact theory and give a new proof of the APS theorem using scattering theory. We relate the η-invariant to a Callias index and compute it using localization of a supersymmetric path integral. We show that the η-invariant for the elliptic genus of a finite cigar is related to quantum modular forms obtained from the completion of a mock Jacobi form which we compute from the noncompact path integral.
Doped holographic superconductor in an external magnetic field
Authors: Correa Diego , Grandi Nicolás , Hernández Alejo
Published: November 2019

Abstract

We add the magnetic field axis to the holographic model for a doped superconductor proposed by Kiritsis and Li. We explore the resulting superconducting dome, in a particular region of parameters in which the equations for the superconductor can be mapped into the previously known undoped case.
Linearizability on hardware weak memory models
Authors: Smith Graeme , Winter Kirsten , Colvin Robert J.
Published: November 2019

Linearizability is a widely accepted notion of correctness for concurrent objects. Recent research has investigated redefining linearizability for particular hardware weak memory models, in particular for TSO. In this paper, we provide an overview of this research and show that such redefinitions of linearizability are not required: under an interpretation of specification behaviour which abstracts from weak memory effects, the standard definition of linearizability is sound and complete on
all
hardware weak memory models.We prove our result with respect to a definition of object refinement which takes a weak memory model as a parameter. The main consequence of our findings is that we can leverage the range of existing techniques and tools for standard linearizability when verifying concurrent objects running on hardware weak memory models.
How to accurately assess surfactant biodegradation-impact of sorption on the validity of results
Authors: Cierniak Dorota , Woźniak-Karczewska Marta , Parus Anna , Wyrwas Bogdan , Loibner Andreas P. , Heipieper Hermann J. , Ławniczak Łukasz , Chrzanowski Łukasz
Published: November 2019

Surfactants not only are widely used in biotechnological processes but also constitute significant contaminants of the modern world. Among many reports, there is a shortage of works which summarize the issue of surfactant sorption to biomass in a way that would elucidate the biological factors for analysts and analytical factors for microbiologists. The main factor, which is not as obvious as one would expect, is associated with the susceptibility of analytical approaches to errors resulting from incorrect handling of biomass. In case of several publications reviewed in the framework of this study, it was not possible to establish whether the decrease of the analytical signal observed by the authors actually resulted from biodegradation of the surfactant. This review emphasizes the necessity to consider the possibility of surfactant sorption to microbial cells, which may result in significant detection errors as well as conceptual inconsistency. In addition, a reference study regarding representative surfactants (cationic, anionic and non-ionic) as well as yeast, Gram-negative, Gram-positive bacteria, and activated sludge was provided to highlight the possible errors which may arise from disregarding sorption processes when determining degradation of surfactants. This particularly applies to systems which include ionic surfactants and activated sludge as sorption may account for 90% of the observed depletion of the surfactant. Therefore, a systematic approach was proposed in order to improve the credibility of the obtained results. Finally, the need to employ additional procedures was highlighted which may be required in order to verify that the decrease of surfactant concentration results from biodegradation processes.
Effect of fine particles on strength and stiffness of cement treated sand
Authors: Moon Sung-Woo , Vinoth Ganapathiraman , Subramanian Sathya , Kim Jong , Ku Taeseo
Published: November 2019

Naturally available sands are always found with finer particles of varying sizes and proportions which are generally not accounted for in the geotechnical design of a cemented soil system. This paper explores the behavior of cemented sand with fine particles in smaller proportions. Two types of cements: (1) ordinary portland cement (OPC), (2) calcium sulfoaluminate cement (CSA); three cement contents: 3%, 5%, 7% and four fine (kaolin powder) contents: 0%, 1%, 3%, 5% are considered in this study. The ultrasonic pulse velocity (UPV), shear wave velocity ($$V_{s}$$Vs) and unconfined compressive strength (UCS) are measured to investigate the effects of fine particles on the cemented sand. The results show that fine particles do affect quite significantly the mechanical properties of cement-treated sand, even at negligent proportions. The strength and stiffness increase with fine content in both types of cement. The increase in strength and stiffness with increasing fine contents is attributed to the increased density with kaolin acting as a filler material facilitating more contact points among the particles. The results also show that the effect of fine particles on cemented sand depends not only on their relative volume and mineralogy but also on the type of the binding material.