bluuebunny/crossref_metadata_2025 huggingface dataset:
Muscle contractures in patients with cerebral palsy and acquired brain injury are associated with extracellular matrix expansion, pro‐inflammatory gene expression, and reduced rRNA synthesis
Authors: Von Walden Ferdinand , Gantelius Stefan , Liu Chang , Borgström Hanna , Björk Lars , Gremark Ola , Stål Per , Nader Gustavo A. , PontéN Eva
Published: March 2018

Introduction: Children with cerebral palsy (CP) and acquired brain injury (ABI) commonly develop muscle contractures with advancing age. An underlying growth defect contributing to skeletal muscle contracture formation in CP/ABI has been suggested. Methods: The biceps muscles of children and adolescents with CP/ABI (n = 20) and typically developing controls (n = 10) were investigated. We used immunohistochemistry, quantitative real‐time polymerase chain reaction, and Western blotting to assess gene expression relevant to growth and size homeostasis. Results: Classical pro‐inflammatory cytokines and genes involved in extracellular matrix (ECM) production were elevated in skeletal muscle of children with CP/ABI. Intramuscular collagen content was increased and satellite cell number decreased and this was associated with reduced levels of RNA polymerase I transcription factors, 45s pre‐rRNA and 28S rRNA. Discussion: The present study provides novel data suggesting a role for pro‐inflammatory cytokines and reduced ribosomal production in the development/maintenance of muscle contractures, possibly underlying stunted growth and perimysial ECM expansion. Muscle Nerve 58: 277–285, 2018
Survival and mortality of adult‐onset myasthenia gravis in the population of Belgrade, Serbia
Authors: Basta Ivana , PekmezoviĆ Tatjana , Peric Stojan , NikoliĆ Ana , RakoČeviĆ‐StojanoviĆ Vidosava , SteviĆ Zorica , LavrniĆ Dragana
Published: March 2018

Introduction: The objective of this study was to estimate mortality and survival in a large cohort of myasthenia gravis (MG) patients from Belgrade, Serbia, during the period 1979–2008. Methods: Data for all patients with MG were collected from hospital records and the Belgrade MG Registry. Results: Within the 30‐year study period, death occurred in 107 (20%) of 562 patients with MG, with MG‐related fatality below 2%. The average MG mortality rate was 1.76 per 1,000,000 population (1.26/1,000,000 women, 2.45/1,000,000 men). A statistically significant increase was recorded for the average standardized mortality rate for all patients (P < 0.01). The mean survival from disease onset was 34.3 ± 2.0 years. Significantly shorter survival was observed in men compared with women and in patients older than 50 years compared with younger ones (P < 0.01). Discussion: We observed long survival and low frequency of MG‐related fatalities but increasing average standardized mortality rate, most notably in older men with MG. Muscle Nerve 58: 708–712, 2018
Apigenin inhibits sciatic nerve denervation–induced muscle atrophy
Authors: Choi Won Hee , Jang Young Jin , Son Hyo Jeong , Ahn Jiyun , Jung Chang Hwa , Ha Tae Youl
Published: March 2018

Introduction: Apigenin (AP) has been reported to elicit anti‐inflammatory effects. In this study, we investigated the effect of AP on sciatic nerve denervation–induced muscle atrophy. Methods: Sciatic nerve–denervated mice were fed a 0.1% AP‐containing diet for 2 weeks. Muscle weight and cross‐sectional area (CSA), and the expression of atrophic genes and inflammatory cytokines in the gastrocnemius were analyzed. Results: Denervation significantly induced muscle atrophy. However, values for muscle weight and CSA were greater in the denervated muscle of the AP mice than the controls. AP suppressed the expression of MuRF1, but upregulated both myosin heavy chain (MHC) and MHC type IIb. AP also significantly suppressed expression of tumor necrosis‐alpha in the gastrocnemius and soleus muscles, and interleukin‐6 expression in the soleus muscle. Discussion: AP appears to inhibit denervation‐induced muscle atrophy, which may be due in part to its inhibitory effect on inflammatory processes within muscle. Muscle Nerve 58: 314–318, 2018
Micro‐inertia origin of instabilities in granular materials
Authors: Wautier Antoine , Bonelli Stephane , Nicot François
Published: March 2018

Within the framework of the second‐order work theory, the onset of instabilities is explored numerically in loose granular materials through three‐dimensional DEM simulations. Stress controlled directional analysis are performed in Rendulic's plane, and a particular attention is paid to transient evolutions at the microscale. Thanks to a micromechanical analysis, the onset and development of transient mechanical instabilities is explored. It is shown that these instabilities result from the unjamming and bending of a few force chains associated with a local burst of kinetic energy. This burst of kinetic energy propagates to the whole sample and provokes a generalized unjamming of force chains. As force chains buckle, a phase transition from a quasi‐static to an inertial regime is observed. At the macroscopic scale, this results in a transient softening and a loss of controllability. After the collapse of existing force chains, the development of plastic strain is eventually stopped as new stable force chains are built.
Work input for unsaturated soils considering interfacial effects
Authors: Liu Yan , Wei Chang‐Fu , Zhao Cheng‐Gang , Fang Qian , Li Jian
Published: March 2018

In this research, the interfacial energy is taken into account in the deformation work for unsaturated soils. Based on porous media theory, the thermodynamic balance equations for each phase and the interface are used to derive the work input for unsaturated soils. The work input equation serves as the basis and starting point for the choice of stress state variables, based on which the conjugate stresses and strain increments are derived. The influences of the interfaces on the effective stress and the constitutive law for the liquid phase are then discussed based on the work input equation. The effective stress can be expressed as Bishop's type, and the effective stress parameter is shown to be a function of both the degree of saturation and the interfacial area. The constitutive law for the liquid phase under dynamic condition is also presented. The relationship among interfacial area, saturation, and capillary pressure is proposed to calculate the value of the effective stress. Experimental data obtained from literature are used to validate the proposed model equations. Results show that our findings are in accordance with the existing research. Unlike the phenomenal study, our research has a rigorous theoretical basis, which lays a foundation for further research of unsaturated soils considering the interfacial effects.
Postoperative urinary retention after pelvic organ prolapse repair: Vaginal versus robotic transabdominal approach
Authors: Yune Junchan J. , Cheng Julie W. , Wagner Hillary , Kim Joo , Hardesty Jeffrey S. , Siddighi Sam
Published: March 2018

Aims

Postoperative urinary retention has been reported in 13–32% of patients that undergo pelvic organ prolapse (POP) repair. The purpose of our study was to compare rates of urinary retention between transvaginal and robotic transabdominal approaches and identify risk factors for postoperative urinary retention following POP repair.

Methods

Medical records of patients that underwent POP repair were reviewed. Surgeries included transvaginal high uterosacral ligament suspension (HUSLS) and robotic‐assisted sacral colpopexy (RASCP). All patients underwent a retrograde fill voiding trial (RGVT) postoperatively. Demographics, comorbidities, preoperative urodynamic findings, and surgical procedures were compared between women that passed their RGVT and those that did not.

Results

Out of 484 patients reviewed, 333 underwent POP repair with a transvaginal HUSLS and 151 underwent RASCP. Postoperative urinary retention was identified in 128 (26.4%) patients where 113 underwent transvaginal HUSLS and 15 underwent RASCP. The odds ratio (OR) of postoperative urinary retention following transvaginal HUSLS was 3.26 (CI 1.72‐6.18; P < 0.001) compared to RASCP. Older age was also a risk factor for postoperative urinary retention (OR 1.03, CI 1.01‐1.05; P = 0.012). While parity, preoperative post‐void residual (PVR), and rates of concomitant transvaginal anterior/posterior repair were significantly higher in patients that developed postoperative urinary retention on univariate analysis, these factors did not demonstrate significance on multivariate analysis.

Conclusions

Transvaginal HUSLS demonstrates a 3.26 OR for postoperative urinary retention compared to the robotic transabdominal approach. Older age is also a significant risk factor whereas parity, preoperative PVR, and rates of concomitant transvaginal anterior/posterior repair were not significant risk factors on multivariate analysis.
A novel discrete element method based on the distance potential for arbitrary 2D convex elements
Authors: Zhao Lanhao , Liu Xunnan , Mao Jia , Xu Dong , Munjiza Antonio , Avital Eldad
Published: March 2018

A new 2‐dimensional discrete element method, which is able to simulate a system involving a large number of arbitrary convex elements, is proposed. In this approach, a novel distance potential function is defined using a normalized format of the penetrated distance between contact couples, while a holonomic and precise algorithm for contact interaction is established, accounting for the influence of the tangential contact force. Furthermore, the new contact detection algorithm is well suited for nonuniform blocks unlike the common no binary search method that requires uniform elements. The proposed method retains the merit of the combined finite‐discrete element method and avoids its deficiencies. Compared with the existing finite‐discrete element method, the distance potential function has a clear physical meaning, where the calculation of contact interaction avoids the influence of the element shape. Accordingly, the new method completely gets rid of the restraint of uniform element type and can be applied to arbitrary convex elements. The new method is validated with well‐known benchmark examples, and the results are in very good agreement with existing experimental measurement and analytical solutions. Finally, the proposed method is applied to simulate the Tangjiashan landslide.
Fully coupled hydromechanical multiscale model with microdynamic effects
Authors: Khoei A.R. , Hajiabadi M.R.
Published: March 2018

In this paper, a multiscale finite element framework is developed based on the first‐order homogenization method for fully coupled saturated porous media using an extension of the Hill‐Mandel theory in the presence of microdynamic effects. The multiscale method is employed for the consolidation problem of a 2‐dimensional saturated soil medium generated from the periodic arrangement of circular particles embedded in a square matrix, which is compared with the direct numerical simulation method. The effects of various issues, including the boundary conditions, size effects, particle arrangements, and the integral domain constraints for the microscale boundary value problem, are numerically investigated to illustrate the performance of a representative volume element in the proposed computational homogenization method of fully coupled saturated porous media. This study is aimed to clarify the effect of scale separation and size dependence, and to introduce characteristics of a proper representative volume element in multiscale modeling of saturated porous media.
Exploring the link between government funding and efficiency in nonprofit colleges
Authors: Coupet Jason
Published: March 2018

Previous literature has suggested that federal funding can hinder the efficiency of nonprofit organizations, but this has yet not been empirically tested. This study used a two‐stage data envelopment analysis (DEA) model to measure the efficiency of a set of private nonprofit teaching‐oriented colleges, then estimate the impact of federal and state funding on organizational efficiency. The findings indicate that, on average, increases in neither state nor federal funding effect efficiency of nonprofit colleges. Increasing state funding negatively impacted the efficiency of public colleges (N = 799). This study suggests that the challenges for nonprofits that accompany government funding may not rise to a quantifiable negative effect on efficiency.
What do social entrepreneurs need to walk their talk? Understanding the attitude–behavior gap in social impact assessment practice
Authors: Grieco Cecilia
Published: March 2018

The topic of social impact assessment (SIA) is growing in importance, and this is especially true for social enterprises. The mission of solving social problems is the main feature of these organizations; thus, the need to assess the extent to which this mission is fulfilled becomes essential. The purpose of this paper is to propose a conceptual model that could explain the attitude–behavior gap in SIA practice through the development of a coherence/displacement matrix, to gauge if social entrepreneurs are coherent in “walking their talks.” The study is based on a mixed‐methods approach focused on the Italian context. An empirical quantitative analysis has been performed to identify the misalignment between attitude and behavior. The gaps that emerged are then analyzed through in‐depth interviews with social entrepreneurs, to provide a pilot case study that could test the model and gain further insights into how those gaps could be filled.
Living condition, weight loss and cognitive decline among people with dementia
Authors: Harsányiová Marcela , Prokop Pavol
Published: March 2018

Aims

The aim of this study was to investigate cognitive performance and BMI of patients with dementia living in their own homes with family members, nursing homes and alone.

Design

A prospective observational cohort study with a quantitative design.

Method

Mini–mental state examination (MMSE) scores and BMI were examined with a sample of Slovak patients (N = 428). Patients were followed up 12 months later after the first examination.

Results

Cognitive decline was significantly faster for patients living in nursing homes and for solitary patients. BMI consistently decreased in the follow‐up examination and this drop was stronger in patients living alone and in nursing homes. Patients with VaD manifested a stronger BMI decline as compared with AD patients. This study suggests that impoverished conditions such as nursing homes or social isolation of solitary people contribute to stronger progress in dementia. Healthcare professionals need to implement meaningful activities for institutionalized people and for people who are living alone to eliminate the negative impact of an impowerished environment on patient's cognitive functioning.
Finnish healthcare professionals' attitudes towards robots: Reflections on a population sample
Authors: Turja Tuuli , Van Aerschot Lina , Särkikoski Tuomo , Oksanen Atte
Published: March 2018

Aim

To answer the question: ‘How prepared healthcare professionals are to take robots as their assistants in terms of experience and acceptance?’

Background

The ageing population, increasing care needs and shortage of healthcare professionals pose major challenges in Western societies. Special service robots designed for care tasks have been introduced as one solution to these problems.

Design

A correlative design

Methods

Eurobarometer data (N = 969) and survey data of nurses and other healthcare professionals (N = 3800) were used to assess the relationship between robot acceptance and experiences with robots while controlling for the respondents’ age, gender, occupational status and managerial experience.

Results

Healthcare professionals had less experience with robots and more negative attitudes towards them than the general population. However, in healthcare, robot assistance was welcomed for certain tasks. These regarded, for example, heavy lifting and logistics. Previous experiences with robots were consistently correlated with robot acceptance.
Determination of space‐dependent coefficients from temperature measurements using the conjugate gradient method
Authors: Cao Kai , Lesnic Daniel
Published: March 2018

In this article, we consider coefficient identification problems in heat transfer concerned with the determination of the space‐dependent perfusion coefficient and/or thermal conductivity from interior temperature measurements using the conjugate gradient method (CGM). We establish the direct, sensitivity and adjoint problems and the iterative CGM algorithm which has to be stopped according to the discrepancy principle in order to reconstruct a stable solution for the inverse problem. The Sobolev gradient concept is introduced in the CGM iterative algorithm in order to improve the reconstructions. The numerical results illustrated for both exact and noisy data, in one‐ and two‐dimensions for single or double coefficient identifications show that the CGM is an efficient and stable method of inversion.
Seasonal variation in prey composition and digestion in small mammal predator assemblages
Authors: Andrews P. , Fernández‐Jalvo Y.
Published: March 2018

Many aspects of taphonomy have a time dimension which affects the way modifications develop. Weathering is an obvious aspect of this, and for this there is an added aspect of variations by geography or latitude. A long‐term taphonomy project in Wales was set up to investigate how small mammal assemblages may have changed in relation to seasonal and climatic variation. A collection of 304 pellets produced by a single pair of tawny owls (Strix aluco) spanned 40 months from 1982 to 1986, and pellets were collected from the roosting site on a monthly basis. The project ended in March 1986, when the owls left their roosting place, with a follow‐up collection from the same site but from a different owl individual in 1987. Both the species composition of the owls' prey, and the digestion of their prey, differed from month to month, with the major differences being between summer and winter and variations in the local climate. Earthworms were the most abundant prey, but they were more abundant during the summer months and during mild winters.Microtus agrestiswas the most abundant mammal species in the pellets and the next most common prey species, closely followed byApodemusand a large beetle species. Digestion of arvicolid teeth and post‐crania was greater during the winter months, but no difference was found for murid teeth between summer and winter collections because the summer sample was too small. Amphibian bones were also more digested in winter. Digestion ofApodemusmolars was about half that ofMicrotus, but digestion of incisors was the same, and where both occurred in the same pellets they were on average one stage behind that ofMicrotusmolars. It is concluded that seasonality and local climate are important factors both in the prey composition and the degrees of digestion of prey in tawny owl assemblages.
Examining the influence of hide processing on Native American upper limb morphology
Authors: Cameron M.E. , Lapham H. , Shaw C.
Published: March 2018

The commercial pelt trade between Native Americans and Europeans flourished in the 17th and 18th centuries. However, the impact of this economic change and increased hide processing efforts on Native American upper limb morphology is unknown. The hide scraping hypothesis, tested in living subjects, suggests that hide processing efforts may lead to significant changes in humeral morphology. Two modern human Native North American skeletal collections from south‐western Virginia, USA, were studied to test if intensive hide processing led to changes in humeral morphology. At the earlier Late Woodland Crab Orchard site, animal skins and furs were prepared for household use. During the occupation of the later early historic Trigg site, processing activities intensified to produce surplus hides for the commercial pelt trade. In this study, the cross‐sectional geometric properties at the mid‐distal humerus (35% of length) of Crab Orchard and Trigg adult males and females were examined. We assessed whether Trigg site individuals had increased humeral symmetry, changes to diaphyseal shape, and increased robusticity. Additionally, humerus morphological properties were compared between males and females to assess if there were sex‐based differences.

Trigg site males had greater humeral robusticity than Crab Orchard males. The humeri of females from the Trigg and Crab Orchard sites were both relatively anteroposterior strengthened and displayed quite low levels of bilateral asymmetry. This pattern suggests that females at both sites may have employed techniques that involved bimanual hide processing tools. The differences between the morphologies predicted and those observed in these Native American populations may indicate (a) adaptation to bimanual hide processing techniques or (b) adaptation to osteogenic tasks not involved in hide processing but associated with postcontact economic changes.
Zeolitic imidazolate frameworks‐8 modified graphene as a green flame retardant for reducing the fire risk of epoxy resin
Authors: Xu Baoling , Xu Wenzong , Wang Guisong , Liu Lvcheng , Xu Jie
Published: March 2018

A novel hybrid material of ZIF‐8/RGO (zeolitic imidazolate frameworks‐8 loaded the surface of graphene) was synthesised by a simple method and characterized. Then, ZIF‐8/RGO was added into epoxy resin (EP), and the flame retardancy and smoke suppression of the EP composites were studied. Compared with pure EP, the peak heat release rate and the total heat release of the EP composites were reduced remarkably, and their LOI and UL94 vertical burning rating were also improved. In addition, their smoke production rate and total smoke production were decreased drastically. The improved flame retardancy and smoke suppression were mainly attributed to the physical barrier effect of graphene. Meanwhile, the metal oxide decomposed from ZIF‐8 could contribute to the production of char residue and enhance the compactness of the char layer.
Microinjection molding of multiwalled carbon nanotubes (CNT)–filled polycarbonate nanocomposites and comparison with electrical and morphological properties of various other CNT‐filled thermoplastic micromoldings
Authors: Zhou Shengtai , Hrymak Andrew N. , Kamal Musa R.
Published: March 2018

A series of polycarbonate (PC)/multiwalled carbon nanotubes (CNT) nanocomposites were prepared by diluting a commercially available masterbatch using a neat PC resin in a lab‐scale batch mixer. The obtained nanocomposites were subjected to microinjection molding to fabricate microparts, which have a 3‐step decrease in thickness along the flow direction, under a defined set of processing conditions. The obtained microparts were mechanically divided into 3 different sections, namely, thick, middle, and thin sections, based on thickness. Morphology observations and electrical conductivity measurements were conducted to explore the evolution of microstructure within subsequent microparts. Additionally, a comparison of the electrical and morphological properties of stepped microparts of various thermoplastic polymers filled with CNT was studied. Results suggested that the selection of host polymers influences the dispersion of nanotubes within subsequent moldings, thereby affecting the electrical properties. The thermal stability of subsequent moldings deteriorated upon the addition of CNT, suggesting that the addition of CNT and the thermomechanical history experienced by the polymer melts in microinjection molding might cause a chain scission effect on PC. Raman spectroscopy analysis was used to study the orientation and properties of CNT in microparts.
Synthesis, characterization of layered double hydroxide‐poly(methylmethacrylate) graft copolymers via activators regenerated by electron transfer for atom transfer radical polymerization and its effect on the performance of poly(lactic acid)
Authors: Geng Zhongxing , Zhen Weijun , Song Zhongbo , Wang Xuefeng
Published: March 2018

Layered double hydroxide‐poly(methylmethacrylate) (LDH‐PMMA) graft copolymers were prepared via activators regenerated by electron transfer for atom transfer radical polymerization. The results showed that the hydrophobicity of LDH‐PMMA was improved by the incorporation of hydrophilic groups. Moreover, poly(lactic acid) (PLA)/LDH‐PMMA nanocomposites were prepared by melt blending to enhance the performances of PLA. The crystallization and mechanical properties of the PLA/LDH‐PMMA nanocomposites were studied by differential scanning calorimetry, tensile testing, and polarized optical microscopy, respectively. Results of mechanical testing showed that the tensile strength, elongation at break, and impact strength of PLA/LDH‐PMMA nanocomposites were increased by 5.64%, 37.95%, and 49.70%, respectively, compared with PLA. The differential scanning calorimetry results indicated that LDH‐PMMA eliminated the cold crystallization of PLA matrix and improved the crystallinity of PLA by 37.26%. The polarized optical microscopy of PLA/LDH‐PMMA nanocomposites demonstrated that LDH‐PMMA increased the crystallization rate of PLA. It was also found that the rheological behaviors of the PLA nanocomposites were significantly enhanced. Based on these results, a new choice for modified LDHs was provided and used as a nucleating agent to improve the properties of PLA.
Permanently antistatic and high transparent PMMA terpolymer: Compatilizer, antistatic agent, and the antistatic mechanism
Authors: Chen Si , Zhou Bo , Ma Meng , Shi Yanqin , Wang Xu
Published: March 2018

Permanently antistatic and high transparent PMMA terpolymer, P(MMA‐co‐HPA‐co‐SPMA), were reported in this paper, providing a new method to significantly improve the antistatic properties of PMMA without sacrificing transparency. 2‐Hydroxypropyl acrylate (HPA) was chosen as a kind of compatilizer because of the good compatibility with both methyl methacrylate (MMA) and sulfopropyl methacrylate potassium salt (SPMA), a potential antistatic agent with a strong hydrophilic group. The mechanical and optical properties of P(MMA‐co‐HPA‐co‐SPMA) terpolymer barely show any visibly differences compared to PMMA homopolymer, confirmed through Fourier transform infrared, dynamic mechanical analysis, and a haze meter. Furthermore, antistatic property analysis indicates that only a small amount of SPMA can significantly improve the antistatic properties of the obtained PMMA terpolymers. The surface resistivity of the P(MMA‐co‐HPA‐co‐SPMA) sheets could be reduced to 109 Ω sq−1 order of magnitude, while the SPMA content reached 0.72 wt%. The hydrophilic groups, the hydroxyl and acrylate sulfonate, on the surface contributed to attract the water molecules, which rendered it a reasonably good antistatic property. These selected terpolymers will provide more opportunities to develop high‐performance and antistatic products made from PMMA materials.
Electrospinning of carboxymethyl starch/poly(L‐lactide acid) composite nanofiber
Authors: Yusof Mohd Reusmaazran , Shamsudin Roslinda , Abdullah Yusof , Yalcinkaya Fatma , Yaacob Norzita
Published: March 2018

Carboxymethyl starch (CMS) is a natural polymer derived from sago starch that is obtained from sago palm (Metroxylon spp.). Herein, CMS was used as a polysaccharide source in preparations of composite nanofibers with poly(L‐lactide acid) (PLLA). The incorporation of CMS with PLLA in nanofiber form has great potential to be used in biomedical applications. The composite PLLA/CMS nanofibers were fabricated by electrospinning technique at various ratios of CMS, which were 5, 10, 15, and 20% vol/vol. The composite nanofibers were characterized according to their physical morphology, chemical interaction, wettability, water uptake, and thermal and mechanical behaviors. The result showed that uniform and bead‐free nanofibers were produced at the low ratio of CMS while fractal and discontinuing fiber was observed at a high ratio of CMS. A better mechanical strength was obtained at low CMS ratio as compared with higher one. Fourier transform infrared results showed that there was an interaction between CMS and PLLA after electrospinning. The surface hydrophilicity and water uptake increased with increasing ratio of CMS. The results from the differential scanning calorimeter analysis showed the decrease of the glass transition (Tg) and cold crystallization temperature (Tcc) of the nanofiber after addition of CMS in PLLA.
Solvent‐free ring‐opening polymerization of cyclohexene oxide catalyzed by palladium chloride
Authors: Chang Haibo , Li Dongdong , Cao Tingting , Li Qingshuo , Bu Zhanwei , Zhao Wenshan , Lin Tong
Published: March 2018

In this study, we have for the first time demonstrated that palladium chloride (PdCl2) is an efficient catalyst for ring‐opening polymerization of cyclohexene oxide in a solvent‐free condition. The polymerization product was in atactic structure, and reaction conditions, such as reaction temperature, time, and catalyst amount, showed effects on polymerization conversion yield, turnover number, and number‐average molecular weight of the resulting poly(cyclohexene oxide). PdCl2 catalysis follows a cationic ring‐opening mechanism. The polymerization result is highly determined by the chemical structure of the monomers.
Preparation and Investigation on Morphology, Thermal Stability and Crystallization Behavior of HDPE/EVA/Organo‐Modified Layered Double Hydroxide Nanocomposites
Authors: Wu Yifan , Tang Mengqi , Wang Na , Qin Jun , Chen Xiaolang , Zhang Kun
Published: March 2018

Organo‐modified MgAl layered double hydroxide (OLDH) was synthesized by anion exchange reaction and potassium monolauryl phosphate was used as organic anion modifier. High‐density polyethylene (HDPE)/ethylene vinyl acetate (EVA)/OLDH nanocomposites were prepared by melt blending from HDPE as polymer matrix with OLDH as filler and EVA as compatibilizer. The morphological structures, thermal stability and crystallization behaviors of the nanocomposites were investigated by Fourier transform infrared (FTIR) spectroscopy, X‐ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry. OLDH is synthesized from the appearance of P = O stretching vibration peak at 1,216 cm−1 of phosphate and P‐O‐C stretching vibration peak at 1,083 cm−1 in FTIR and the basal space is increased from 0.74 to 1.64 nm in XRD. When OLDH content is lower (<6 wt%), the exfoliated structure is formed. The dispersibility and compatibility between the fillers and matrix are improved. The results from TGA indicate that the thermal stability of HDPE/EVA/OLDH nanocomposites is better than HDPE/EVA and HDPE/EVA/LDH at high temperature. HDPE/EVA/OLDH nanocomposites with 4 wt% OLDH form exfoliated structure and acquire the most optimum thermal stability. In addition, the degree of crystallinity of HDPE in the nanocomposites is affected by OLDH. POLYM. COMPOS., 39:E1849–E1857, 2018. © 2018 Society of Plastics Engineers
Mechanical, electrical, and thermal properties of highly filled bamboo charcoal/ultra‐high molecular weight polyethylene composites
Authors: Li Suiyi , Wang Haiying , Chen Chuchu , Li Xiaoyan , Deng Qiaoyun , Li Dagang
Published: March 2018

Highly filled bamboo charcoal (BC)/ultra‐high molecular weight polyethylene (UHMWPE) composites were prepared using extrusion and hot‐compression molding methods. The addition of BC remarkably improved the tensile properties of UHMWPE composites. When the BC content reached 70 wt%, the tensile strength and Young's modulus rose from 28.0 and 326.6 MPa for the neat UHMWPE to 128.9 and 2,027.7 MPa, increasing by 360 and 520%, respectively. The incorporation of BC also significantly improved the creep resistance, especially at high temperature. The creep strains of the composites with 60, 70 and 80 wt% were reduced by 70.1, 78.3, and 85.2% compared to the neat UHMWPE at 80°C, respectively. To understand the mechanism, the Burger's model was employed to illustrate the influence of BC on the creep performance of the polymer composites. The addition of BC also increased the electrical conductivity of the composites: the composite with 80 wt% BC had a conductivity of 0.53 S/cm. Moreover, the thermal stability of BC/UHMWPE composites improved apparently with the increased charcoal loading. POLYM. COMPOS., 39:E1858–E1866, 2018. © 2018 Society of Plastics Engineers
Characterizing cardiac dysfunction in fetuses with left congenital diaphragmatic hernia
Authors: Cruz‐Lemini Mónica , Valenzuela‐Alcaraz Brenda , Granados‐Montiel Julio , Martínez Josep M. , Crispi Fátima , Gratacós Eduard , Cruz‐Martínez Rogelio
Published: March 2018

Objective

To evaluate cardiac function by conventional echocardiography and tissue Doppler imaging in fetuses with left congenital diaphragmatic hernia (CDH).

Methods

Conventional echocardiography (myocardial performance index, ventricular filling velocities, and E/A ratios) and tissue Doppler imaging (annular myocardial peak velocities, E/E′ and E′/A′ ratios) in mitral, septal, and tricuspid annulus were evaluated in a cohort of 31 left‐sided CDH fetuses and compared with 75 controls matched for gestational age 2:1.

Results

In comparison to controls, CDH fetuses had prolonged isovolumetric time periods (isovolumetric contraction time 35 ms vs 28 ms, P < .001), with higher myocardial performance index (0.49 vs 0.42, P < .001) and tricuspid E/A ratios (0.77 vs 0.72, P = .033). Longitudinal function assessed by tissue Doppler showed signs of impaired relaxation (mitral lateral A′ 8.0 vs 10.1 cm/s, P < .001 and an increased mitral lateral E′/A′ ratio 0.93 vs 0.78, P < .001) in the CDH fetuses as compared with controls, with preserved systolic function.

Conclusion

Left CDH fetuses show echocardiographic signs of diastolic dysfunction, probably secondary to fetal heart compression, maintaining a preserved systolic function.
Effects of water or alkali solution immersion on the water uptake and physicomechanical properties of polyurethane
Authors: Hong Bin , Xian Guijun , Li Hui
Published: March 2018

Polyurethane (PU) is an emerging resin matrix for fiber reinforced polymer (FRP) composites. In the present article, effects of immersion in water or alkaline solution on water uptake and thermomechanical properties of a PU were investigated. A traditional epoxy resin matrix was investigated for comparison. As found, unlike the epoxy (hydrolysis occurred in case of alkaline solution), water and alkaline solution immersion showed a similar effect for the PU resin. For both immersion, the water uptake of the PU system reached the equilibrium content of 2.5%–2.7%, in accordance with the Fick's law. Glass transition temperature (Tg) of the PU decreased rapidly after the first month of immersion and then leveled off. Both immersion for a short term (e.g., 1 month of immersion) led to an obvious decrease in the tensile strength, while long‐term immersion brought in obvious recovery. Remarkable increase in the elongation at break (up to 16.6%) due to immersion was found. The higher the immersion temperatures, the less the degradation of the tensile strength. The variations of the thermal–mechanical properties were attributed to the water‐induced plasticization and the postcuring‐induced increase of the crosslinkage. Compared with the common epoxy system, the PU system showed better resistance to the immersion. POLYM. ENG. SCI., 58:2276–2287, 2018. © 2018 Society of Plastics Engineers
Magnetic nanoparticles embedded in pectin‐based hydrogel for the sustained release of diclofenac sodium
Authors: Babaladimath Gangadhar , Badalamoole Vishalakshi
Published: March 2018

A supermagnetic polysaccharide‐based nanocomposite gel has been developed as a potential drug delivery system. The gel was made via graft copolymerization of 2‐acrylamido‐2‐methylpropanesulfonic acid on pectin using ammonium peroxodisulfate as an initiator and N,N‐methylenebisacrylamide as a crosslinker under microwave irradiation. The magnetic nanoparticles (MNPs) were incorporated within the gel network via an in situ method of diffusion of Fe2+/Fe3+ followed by reduction with ammonia solution. The graft copolymer gel and its nanocomposite were characterized using attenuated total reflection Fourier transform infrared spectroscopy, thermogravimetric analysis, powder X‐ray diffraction, field‐emission scanning electron microscopy, energy‐dispersive X‐ray spectroscopy and transmission electron microscopy. The magnetic properties of the nanocomposite were measured using a vibrating sample magnetometer and mechanical properties using a tensile compressive tester. The gel was evaluated for adsorption and release of the drug diclofenac sodium. The presence of MNPs is observed to enhance significantly the mechanical properties, swelling capacity, drug loading and release ability of the graft polymer gel. The increased porosity of the gel network and higher surface area of MNPs allowed for 20% higher adsorption of diclofenac sodium molecules compared to the parent nonmagnetic gel. About 95% of the loaded drug was released from the MNP‐containing gel. The drug release pattern followed first‐order kinetic model and the Higuchi square root model, indicating swelling‐controlled diffusion to be the mode of drug release. © 2018 Society of Chemical Industry
On the topology of highly branched polyethylenes prepared by amine−imine nickel and palladium complexes: the effect of ortho‐aryl substituents
Authors: Mundil Robert , Hermanová Soňa , Peschel Martin , Lederer Albena , Merna Jan
Published: March 2018

Series of nickel and palladium complexes bearing amine−imine ligands in various ortho‐aryl and backbone positions were prepared and investigated in ethene polymerization. Ethene polymerization initiated by symmetrically ortho‐substituted nickel and palladium amine−imine catalysts is controlled. Mono‐substitution in the ortho‐aryl positions of nickel complexes is not as efficient in protecting centers from chain transfer as di‐substitution. Both the central metal and the size of the ortho‐aryl substituent have a significant effect on the polyethylene (PE) topology. Based on detailed characterization by high temperature SEC‐IR‐η, SEC with multi‐angle laser light scattering and 13C NMR data, PEs prepared by nickel amine−imine complexes have a linear rather than dendritic topology. In contrast, palladium amine−imine complexes with small ortho‐aryl substituents at low ethene pressure were shown for the first time to form dendritic PEs with topology comparable to PEs formed by α‐diimine palladium catalyst. © 2018 Society of Chemical Industry
Study and development of rear‐emitter Si heterojunction solar cells and application of direct copper metallization
Authors: Yang Lifei , Zhong Sihua , Zhang Wenbin , Li Xingbing , Li Zhengping , Zhuang Yufeng , Wang Xin , Zhao Lei , Cao Xinmin , Deng Xunming , Wang Qi , Shen Wenzhong
Published: March 2018

We have presented a comprehensive study on the development of rear emitter silicon heterojunction (SHJ) solar cells, which shows more freedom for device optimization than the standard front emitter SHJ counterparts. The optimization of the p‐type hydrogenated amorphous silicon (a‐Si:H(p)) layer is liberated from the parasitic absorption issue, while the n‐type hydrogenated amorphous silicon (a‐Si:H(n)) layer is optimized considering the tradeoff between the light absorption loss and field‐effect passivation. The front transparent conductive oxide (TCO) layer can be designed stressing on its optical properties because the lateral transport of the majority carriers at the front side of the cell is supported by the Si substrate, while the rear TCO layer is free to be tuned for suppressing the TCO/a‐Si:H(p) contact resistance. A rear emitter SHJ solar cell (225.47 cm2) fabricated by industry compatible process has been achieved with an efficiency of over 22%. We have further demonstrated the replacement of screen‐printed silver metallization with a low cost direct copper metallization in the rear emitter SHJ solar cells. We report an exciting 22.06% cell efficiency which is comparable to that of the screen‐printed counterpart.
Motivational interviewing as a positive response to high‐school bullying
Authors: Cross Donna S. , Runions Kevin C. , Resnicow Ken A. , Britt Eileen F. , Gray Caitlin
Published: March 2018

Intervention approaches to bullying are largely preventive in nature, and even these have been shown to be ineffective, if not iatrogenic, with adolescents. Responses to bullying are limited to traditional punitive approaches or “no‐blame” approaches aiming to restore the relationship between the targeted students. Neither of these approaches may effectively engage the perpetrator of bullying at a motivational level, and we propose motivational interviewing (MI) as a means of promoting meaningful behavioral change among youths who bully. We provide a narrative review of MI and map its core features onto the extant literature on self‐reported motivations for bullying, highlighting the ways that MI fits with bullying and could serve as a potent solution that could be deployed by school psychologists and other student support staff members. Qualitative preliminary feedback and initial competency in MI from trained practitioners are presented as preliminary data from a cluster‐randomized control trial, documenting school staff perspectives on the integration of MI into their approach to bullying with recommendations for integrating MI into school settings.
Systematic Evaluation of Immobilized Trypsin‐Based Fast Protein Digestion for Deep and High‐Throughput Bottom‐Up Proteomics
Authors: Shen Xiaojing , Sun Liangliang
Published: March 2018

Immobilized trypsin (IM) has been recognized as an alternative to free trypsin (FT) for accelerating protein digestion 30 years ago. However, some questions of IM still need to be answered. How does the solid matrix of IM influence its preference for protein cleavage and how well can IM perform for deep bottom‐up proteomics compared to FT? By analyzing Escherichia coli proteome samples digested with amine or carboxyl functionalized magnetic bead–based IM (IM‐N or IM‐C) or FT, it is observed that IM‐N with the nearly neutral solid matrix, IM‐C with the negatively charged solid matrix, and FT have similar cleavage preference considering the microenvironment surrounding the cleavage sites. IM‐N (15 min) and FT (12 h) both approach 9000 protein identifications (IDs) from a mouse brain proteome. Compared to FT, IM‐N has no bias in the digestion of proteins that are involved in various biological processes, are located in different components of cells, have diverse functions, and are expressed in varying abundance. A high‐throughput bottom‐up proteomics workflow comprising IM‐N‐based rapid protein cleavage and fast CZE‐MS/MS enables the completion of protein sample preparation, CZE‐MS/MS analysis, and data analysis in only 3 h, resulting in 1000 protein IDs from the mouse brain proteome.
A randomized controlled trial of a group intervention for siblings of children with cancer: Changes in symptoms of anxiety in siblings and caregivers
Authors: Barrera Maru , Atenafu Eshetu G. , Schulte Fiona , Nathan Paul C. , Hancock Kelly , Saleh Amani
Published: March 2018

Objective

This study assessed the effects of a group intervention—Siblings Coping Together (SibCT)—on siblings' and caregivers' anxiety symptoms compared to controls, and potential moderators.

Methods

Seventy healthy siblings of children on or off treatment (7‐16 y old, 41 males) participated in a randomized controlled trial (RCT) with 2 arms/groups: SibCT (n = 41) and an attention control (CG) (n = 34). Both groups had eight 2‐hour weekly sessions. EG followed SibCT's educational, social, and problem‐solving activities. CG had planned games and crafts. Siblings and caregivers self‐reported on anxiety symptoms at baseline, intervention end, and 3 months later. Multivariable mixed model analyses examined the intervention effect over time, and potential moderators (gender, on/off ill child's treatment).

Results

No main effects of group or time were found in sibling scores. A group × gender interaction (P < .05) indicated that in the intervention group female siblings reported less total anxiety symptoms than male siblings, with no significant gender differences in the control group. Caregivers' total anxiety symptoms declined over time (P < .02). A group × on/off treatment interaction in physiological/panic subscale (P < .03) indicated that when ill child was on treatment, caregivers of siblings in SibCT reported less anxiety compared with caregivers of CG.

Conclusions

There was no clear SibCT intervention effect. SibCT may benefit female siblings, and caregivers whose ill child is on active treatment. Contextual factors (gender) seem to influence psychosocial intervention in this population.
Investigation of plasma‐induced chemistry in organic solutions for enhanced electrospun PLA nanofibers
Authors: Rezaei Fatemeh , Gorbanev Yury , Chys Michael , Nikiforov Anton , Van Hulle Stijn W. H. , Cos Paul , Bogaerts Annemie , De Geyter Nathalie
Published: March 2018

Electrospinning is a versatile technique for the fabrication of polymer‐based nano/microfibers. Both physical and chemical characteristics of pre‐electrospinning polymer solutions affect the morphology and chemistry of electrospun nanofibers. An atmospheric‐pressure plasma jet has previously been shown to induce physical modifications in polylactic acid (PLA) solutions. This work aims at investigating the plasma‐induced chemistry in organic solutions of PLA, and their effects on the resultant PLA nanofibers. Therefore, very broad range of gas, liquid, and solid (nanofiber) analyzing techniques has been applied. Plasma alters the acidity of the solutions. SEM studies illustrated that complete fiber morphology enhancement only occurred when both PLA and solvent molecules were exposed to pre‐electrospinning plasma treatment. Additionally, the surface chemistry of the PLA nanofibers was mostly preserved.
Quantification of Urinary Protein Biomarkers of Autosomal Dominant Polycystic Kidney Disease by Parallel Reaction Monitoring
Authors: Rauniyar Navin , Yu Xiaoqing , Cantley Jennifer , Voss Edward Z. , Belcher Justin , Colangelo Christopher M. , Stone Kathryn L. , Dahl Neera , Parikh Chirag , Lam TuKiet T. , Cantley Lloyd G.
Published: March 2018

Purpose

Autosomal dominant polycystic kidney disease (ADPKD) is a life‐long disease in which the genes responsible are known, but the pathogenesis of cyst formation and cyst growth are not understood. Cyst growth ultimately leads to end‐stage renal failure in most patients. Analysis of the urinary proteome offers the potential to identify proteins that indicate the presence of cysts (and thus provides diagnosis) as well as the rates of cyst growth (providing prognostic information).

Experimental design

A scheduled parallel reaction monitoring (sPRM) assay is performed on urine samples from 14 patients and 18 normal controls. For relative quantification, stable isotope‐labeled synthetic peptides are spiked in the urinary protein digests prior to data collection. The data are subsequently normalized to creatinine and protein concentration in the respective urine samples to control for variations in water intake between individuals.

Results

Out of the 143 urinary proteins targeted for sPRM assay, 69 proteins are observed to be significantly dysregulated in ADPKD. The dysregulated proteins are used to cluster ADPKD patients into those who are more or less similar to normal controls.

Conclusions and clinical relevance

This study shows that sPRM is a promising approach to rapidly screen large numbers of proteins in urine in order to provide earlier diagnosis and potentially better understand the pathogenesis of ADPKD development and progression.