bluuebunny/crossref_metadata_2025 huggingface dataset:
Bone tissue engineering: Adult stem cells in combination with electrospun nanofibrous scaffolds
Authors: Moradi Sadegh L. , Golchin Ali , Hajishafieeha Zahra , Khani Mohammad‐Mehdi , Ardeshirylajimi Abdolreza
Published: May 2018

Since bone tissue lesions caused by several reasons and has global outbreak without any attentions to the modernity level of the countries. In the other hands treatment of patients with this problem faced to the several limitations, in this because the future of the bone lesions treatments is related to the future of the bone tissue engineering. This review tries to cover the most suitable stem cells and materials from either natural or synthetic sources for bone tissue engineering. These understanding points would help researchers to further uncover the application of different adult stem cell sources in electrospinning scaffolds, promotion of nanofibrous composite construct design and adult stem cell type selection to enhance cell function and bone tissue engineering, and link laboratory investigations to clinical applications.
Subtrees of graphs
Authors: Chin Alex J. , Gordon Gary , MacPhee Kellie J. , Vincent Charles
Published: May 2018

We study a new graph invariant, the sequence of the number of k‐edge subtrees of a graph. We compute the mean subtree size for several classes of graphs, concentrating on complete graphs, complete bipartite graphs, and theta graphs, in particular. We prove that the ratio of spanning trees to all subtrees in approaches , and give a related formula for . We also connect the number of subtrees of that contain a given subtree to the hyperbinomial transform. For theta graphs, we find formulas for the mean subtree size (approximately ) and the mode (approximately ) of the unimodal sequence . The main tool is a subtree generating function.
Assessment of liver ischemia reperfusion injury in mice using hepatic T2 mapping: Comparison with histopathology
Authors: Hueper Katja , Lang Hannah , Hartleben Björn , Gutberlet Marcel , Derlin Thorsten , Getzin Tobias , Chen Rongjun , Abou‐Rebyeh Hassan , Lehner Frank , Meier Martin , Haller Hermann , Wacker Frank , Rong Song , Gueler Faikah
Published: May 2018

Background

Liver ischemia reperfusion injury (IRI) occurs during liver surgery or transplantation resulting in an inflammatory response, tissue damage, and functional impairment of the organ.

Purpose

To assess the feasibility of T2 mapping for noninvasive quantification of liver edema after partial liver IRI in mice.

Study Type

Prospective, experimental study.

Animal Model

Partial liver IRI was induced in C57BL/6‐mice by transient clamping of the left lateral and median liver lobes for 35 (n = 8), 45 (n = 6), 60 (n = 17), or 90 minutes (n = 5). For comparison, healthy C57BL/6‐mice were examined as controls (n = 9).

Field Strength/Sequence

Functional liver MRI was performed on a 7T scanner using a respiratory‐triggered multiecho spin‐echo sequence.

Assessment

Healthy control mice and mice with partial liver IRI on day 1 after surgery, and additionally on day 7 in a subgroup with 60 minutes IRI (n = 8) were examined. Maps of T2 relaxation time of liver tissue were used to assess distribution, severity of tissue edema (mean T2 time), and the percentage of edematous liver tissue.

Statistical Test

One‐way analysis of variance (ANOVA) with Tukey's honest significant difference (HSD), paired t‐tests, Pearson's test for correlation of MRI parameters with levels of liver enzymes, and histopathology, receiver operating characteristic (ROC) analysis.

Results

Significant tissue edema induced by liver IRI as compared to the control group was detected by increased mean T2 times in groups with 60 minutes (P < 0.001) and 90 minutes IRI (P < 0.001). The percentage of edematous liver tissue significantly increased with longer ischemia times (controls 3.4 ± 0.4%, 35 minutes 5.3 ± 0.6%, 45 minutes 23.3 ± 7.6%, 60 minutes 39.7 ± 3.6%, 90 minutes 51.3 ± 4.5%). Mean T2 times and the percentage of edematous liver tissue significantly correlated with elevation of liver enzymes (P < 0.001), histological evidence of liver injury (r = 0.80 and r = 0.82, P < 0.001), and neutrophil infiltration (r = 0.70 and r = 0.74, P < 0.001). In the subgroup with follow‐up, the severity (P < 0.01) and extent of liver edema decreased significantly over time (P < 0.01).

Data Conclusion

T2 mapping allows quantification and follow‐up of liver injury in mice.

Level of Evidence: 1

Technical Efficacy: Stage 2

J. Magn. Reson. Imaging 2018;48:1586–1594
A complex network analysis of global tourism flows
Authors: Lozano Sebastián , Gutiérrez Ester
Published: May 2018

In this paper, the global tourism network (GTN) is studied in order to gain insight about its structure and the interactions between source and destination markets. To concentrate on the main source and destination markets for each country, only its top k inbound and outbound flows are considered. The distribution of these most important ties in international tourism seems to be scale‐free, with some occurrence of reciprocity, large transitivity, and high‐degree centralization. The GTN shows a clustered structure determined by geographical as well as trade and cultural factors. Each major global and regional power seems to have a certain tourism sphere of influence. The network has a small world character and a high degree of geographic homophily, with more links within continents than between continents. Exponential random graph models have been fit to explain the observed global structure of the network based on its local interactions, and a number of significant motifs have been identified. The picture that results is a GTN that emerges from superimposed local processes in which tourism flows between countries is determined from multiple independent individual decisions made at the local level. This insight that global tourism patterns are driven by local processes is a major contribution of this research and can help develop strategic plans and cooperation partnerships at the national and regional levels, involving private and public stakeholders and targeting specific source and destination markets. The indicators computed using network analysis of global tourism flows can also be used to complement and enrich the information provided by current tourism statistics.
Visitor experience of the Hong Kong trams as an unconventional attraction
Authors: Xu Jing (Bill) , Yan Libo , Mak Connie K.Y.
Published: May 2018

The unconventional attractions failed to receive enough attention in academia. Although generally excluded from the tourism authority's highlight attractions, unconventional attractions, such as the Hong Kong trams, are appealing to the inquisitive tourists. Employing a netnography method, this study reveals 6 themes embedded in visitor experience of the Hong Kong trams: entertainment experience, people watching, historical experience, slow tourism, unique mobility, and social interaction. This study further contributes to the literature by introducing a 2‐dimension framework that incorporates the above themes. Tourism authorities are suggested reconsidering their marketing priorities to reflect the importance of unconventional attractions.
The paradox of cultural and media convergence. Segmenting the European tourist market by information sources and motivations
Authors: Almeida‐Santana Arminda , Moreno‐Gil Sergio , Boza‐Chirino Jose
Published: May 2018

The globalization of markets has led destination marketing organizations to question whether their marketing strategies should appeal to cultural convergence or divergence, both in the media to be used (information sources) and in the content to be communicated (related to travel motivations). The purpose of this study is to investigate the “cultural convergence” and “media convergence” using data from a computer‐assisted web interviewing survey on 17 European countries. The methodology uses multiple correspondence analysis, factor analysis, and cluster analysis to segment the market. The results identify both phenomenon (convergence and divergence) by culture (blocks of countries), media (set of information sources), and content (motivations). The 17 European countries were segmented by information sources into Ensurers, Ensurers with digital exploration, and Low‐social media users and by motivations into Adventures and Pleasure, Socializing, and Rest with Knowledge. An overall understanding of these segments and the paradoxical cultural and media convergence will serve as a tool for destination marketing organizations in the development of their segmenting and communication strategies, as they will be able to know what social media to use to best reach each culture and what content to communicate based on the European consumers' individual motivations.
Activity of an endangered bat increases immediately following prescribed fire
Authors: Braun de Torrez Elizabeth C. , Ober Holly K. , McCleery Robert A.
Published: May 2018

Spatiotemporal responses of bats to fire are not well understood. Fire can indirectly influence bat activity through changes to understory vegetation, insect prey availability, and roost tree abundance. High‐flying bats may be less influenced by fire‐induced changes to the understory because they forage above the forest canopy. Fire‐dependent forests are prevalent across the range of the endemic Florida bonneted bat (Eumops floridanus), a large, high‐flying, and critically endangered species, yet effects of fire management on this species are completely unknown. To investigate short‐term responses of these bats to fire, we conducted pre‐post‐treatment‐control experiments in 4 prescribed burns during 2 seasons (dry, wet). For 12 nights pre‐burn and 24 nights post‐burn, we surveyed bat activity acoustically at 3 sites within each burn (treatment) and 3 adjacent sites (control). Using mixed‐effects models to test the effect of treatment on bat activity, we found that bat activity significantly increased post‐burn in treatment sites relative to control sites, with more pronounced effects during dry season burns. We also detected significantly more feeding buzzes (foraging activity) in treatment sites than control sites, and a negative trend over time in the burn effect size post‐burn. We suggest that bats are attracted to increased availability of insect prey immediately following burns, particularly during the dry season when prey may be limited. Our results suggest that burns have short‐term positive effects on Florida bonneted bats and that restoring fire to fire‐dependent forests may improve foraging habitat for this species. © 2018 The Wildlife Society.
The effect of sample drying temperature on marine particulate organic carbon composition
Authors: Rosengard Sarah Z. , Lam Phoebe J. , McNichol Ann P. , Johnson Carl G. , Galy Valier V.
Published: May 2018

Compositional changes in marine particulate organic carbon (POC) throughout the water column trace important processes that underlie the biological pump's efficiency. While labor‐intensive, particle sampling efforts offer potential to expand the empirical POC archive at different stages in the water column, provided that organic composition is sufficiently preserved between sampling and analysis. The standard procedure for preserving organic matter composition in marine samples is to immediately store particles at −80°C to −20°C until they can be freeze‐dried for analysis. This report investigates the effect of warmer drying and storage temperatures on POC composition, which applies to the majority of POC samples collected in the field without intention for organic analysis. Particle samples collected off Woods Hole, Massachusetts were immediately dried at 56°C, at room temperature, or stored in a freezer until freeze‐drying. Results show that oven‐ and air‐drying did not shift the bulk composition (i.e., carbon and nitrogen content and stable isotope composition) of POC in the samples relative to freeze‐drying. Similarly, warmer drying temperatures did not affect POC thermal stability, as inferred by ramped pyrolysis/oxidation, a growing technique that uses a continuous temperature ramp to differentiate components of organic carbon by their decomposition temperature. Oven‐ and air‐drying did depress lipid abundances relative to freeze‐drying, the extent of which depended on compound size and structure. The data suggest that field samples dried at room temperatures and 56°C are appropriate for assessing bulk POC composition and thermal stability, but physical mechanisms such as molecular volatilization bias their lipid composition.
Glass Ceramic Phosphors: Towards Long‐Lifetime High‐Power White Light‐Emitting‐Diode Applications–A Review
Authors: Lin Hang , Hu Tao , Cheng Yao , Chen Mingxiang , Wang Yuansheng
Published: May 2018

With the technological advancements of high‐quality lightings and high‐end displays, white light‐emitting‐diodes (w‐LEDs) are quickly developing towards high energy density excitation, high output power and high device stability, which requires outstanding thermal properties of the phosphor color converters. In this connection, all‐inorganic luminescent glass ceramic (GC), exhibiting excellent physical/chemical stability to address the serious aging and yellowing issues of conventional phosphor/silicone composite, receives great attention recently and is regarded as a new generation color converter with longevity. Herein, a thorough survey of the research progress of this kind of material is made, with focus put on the design principle, microstructure‐property relationship, packaging technology and the burgeoning application direction. Some challenging issues are discussed and potential directions are suggested for further developing the phosphor‐glass composite fulfilling various requirements in practical application. This Review can promote rapid progress of long‐lifetime high‐power w‐LEDs.
Structures and corrosion properties of the AlCrFeNiMo0.5Tix high entropy alloys
Authors: Han Zhidong , Chen Na , Lu Siyuan , Luan Hengwei , Peng Ruixin , Xu Haotian , Shao Yang , Peng Zhen , Yao Kefu
Published: May 2018

The AlCrFeNiMo0.5Tix (x = 0, 0.25, 0.4, 0.5) high entropy alloys were prepared by copper mold suction casting, and the structures and aqueous corrosion behavior of the alloys were investigated in the present study. It shows that all of these alloys possess BCC + B2 structures at various Ti contents, while Ti element is enriched in ordered B2 phase. With increasing Ti content, the passive film becomes more protective. The charge transfer resistance (Rct) value increases from 229 kΩ · cm2 for the AlCrFeNiMo0.5 alloy to 635 kΩ · cm2 for the AlCrFeNiMo0.5Ti0.5 alloy. Meanwhile, the pitting potential (Epit) increases from 90 mV for the AlCrFeNiMo0.5 alloy to 410 mV for the AlCrFeNiMo0.5Ti0.5 alloy. The present results indicate that the corrosion resistance of the AlCrFeNiMo0.5Tix high entropy alloys has been significantly enhanced by Ti additions.
Proteasome‐mediated proteostasis: Novel medicinal and pharmacological strategies for diseases
Authors: Mishra Ribhav , Upadhyay Arun , Prajapati Vijay Kumar , Mishra Amit
Published: May 2018

Proteins actively participate in a wide range of cellular physiological functions. But aggregation of proteins results in cytotoxicity, and unwanted aggregation of misfolded proteins often causes many diseases. During abnormal protein aggregation events, cells try to cope against such deleterious consequences because of the remarkable functional attempts of two distinct proteolytic mechanisms. These tightly regulative and signaling mechanisms are autophagy pathway and ubiquitin proteasome system. Proteasome complex system holds the elimination capacity of intracellular aberrant protein aggregation. Despite the considerable progress that has been achieved, which elucidates wide function and diverse roles of proteasome system, still several crucial problems remain unanswered. For example, how the complex proteasomes assembly and their interactive pathways determine the precise sense of several proteotoxic insults, which can severely affect the cell survival and homeostasis? The specific degradation of various aberrant proteins that can disturb cellular homeostasis is achieved by proper proteasome functionality, which is yet another unclear and critical challenge. Therefore, a better understanding of the various cellular signaling mechanisms composing the proteasome machinery carries broad therapeutic implications linked with proteopathies. This article signifies the urgent need, which is now crucial for us to improve our understanding of the proteasome architecture, structure, and functions that span multiple level strategies from the molecular level to the cellular level. This systematic in‐depth information of proteasome may be helpful in the near future to design a new molecular framework based on intrinsic and extrinsic cellular mechanisms that drive the assembly of proteasome to induce cellular survival against proteostasis imbalance and disease conditions.
Diabetes is not associated with increased rates of free flap failure: Analysis of outcomes in 6030 patients from the ACS‐NSQIP database
Authors: Kantar Rami S. , Rifkin William J. , David Joshua A. , Cammarata Michael J. , Diaz‐Siso J. Rodrigo , Levine Jamie P. , Golas Alyssa R. , Ceradini Daniel J.
Published: May 2018

Background

Diabetes affects a significant proportion of the population in the United States. Microsurgical procedures are common in this patient population, and despite many conflicting reports in the literature, there are no large studies evaluating the direct association between diabetes and outcomes, specifically failure, following free flap reconstruction. In this study, we sought to determine the impact of diabetes on postoperative outcomes following free flap reconstruction using a national multi‐institutional database.

Methods

We reviewed the American College of Surgeons National Surgical Quality Improvement Program (ACS‐NSQIP) database to identify patients undergoing free flap reconstruction from 2010 to 2015. Preoperative variables and outcomes were compared between diabetic and nondiabetic patients. Univariate and multivariate analyses were performed to control for confounders.

Results

We identified 6030 eligible patients. No significant difference in flap failure rates was observed. However, diabetic patients presented significantly higher rates of wound complications, including deep incisional surgical site infection (SSI) (OR = 1.35; P = .01) and wound dehiscence (OR = 1.17; P = .03). Diabetic patients also presented a significantly longer hospital length of stay (LOS) (β = .62; P < .001).

Conclusions

Our study evaluated the largest national cohort of free flap procedures. These results suggest that diabetes is not associated with increased rates of flap failure. However, diabetic patients are at significantly higher risk of postoperative deep incisional SSI, wound dehiscence, and longer LOS. Our findings provide the most concrete evidence to date in support of free flap reconstruction in diabetic patients, but highlight the need for heightened clinical vigilance and wound care for optimal outcomes.
“You Don't Know That”: Refusals of Community Policing and Criminalization in California
Authors: Raschig Megan
Published: May 2018

When a community policing program named Why'd You Stop Me (WYSM) was implemented in Salinas, California, in 2016, a result of a series of police homicides of local Latino men 2 years prior, residents of this persistently criminalized Mexican‐American community insistently refused it. Rather than accepting WYSM's securitized logic and affirming their own potential criminality, in their refusals and a series of related public actions, residents rendered legible the program's role in the lethal process of criminalization. While community policing strategies are often upheld as viable and empathic solutions for repairing fraught relations between officers and distrustful communities, they form a critical part of counterinsurgency tactics and occupy a key surveillance role in America's militarized and racialized policing project. America's racial empathy gap, as black feminist epistemologists have argued, is better conceived as an epistemology gap, an ignorance and unwillingness to know or accept as legitimate the experiences of communities of color both underserved and under siege by the state. This paper thus considers Salinans’ refusals as epistemological interventions, activist attempts to make palpable the production of criminalization—including in its occasional masquerading as empathy—in the efforts of decriminalizing residents and building a healthy, livable community.
Zwitter zwischen anorganischer und organischer Chemie
Authors: Offermanns Heribert , Hohmeyer Andrea
Published: May 2018

Blausäure schlägt eine Brücke von der anorganischen zur organischen Chemie. Auch die Geschichte der industriellen Produktion und Verwertung des Stoffes spiegelt diese Besonderheit.
Kreislaufwirtschaft: Industrieabfall als Rohstoff
Authors: Köckinger Manuel , Kappe C. Oliver
Published: May 2018

Fluoroform, ein Treibhausgas, das bei der Polytetrafluorethylenproduktion anfällt, ist kostspielig zu entsorgen. Weitaus besser wäre, es für Arzneistoffe oder Industriechemikalien zu nutzen. Dies ist wegen seiner geringen Reaktivität schwierig. Kontinuierliche Prozessführung unterstützt solche Prozesse.
Sperrige Substituenten – Zwischen Attraktion und Repulsion
Authors: König Jonas , Breugst Martin
Published: May 2018

Viele Chemiker vermuten bei sperrigen Substituenten ausschließlich sterische Abstoßung. Häufig wird diese jedoch durch die anziehende London‐Dispersion kompensiert. Diese oft wenig beachtete Wechselwirkung beeinflusst zudem Struktur und Reaktivität.
Regionaltreffen der FCI‐Stipendiaten in Frankfurt
Authors: Hanft Anna , Lichtenberg Crispin
Published: May 2018

Mitte Dezember 2017 trafen sich an der Universität Frankfurt Stipendiaten des Fonds der Chemischen Industrie (FCI) aus Frankfurt, Darmstadt, Gießen, Göttingen und Würzburg. Organisiert hatte das Treffen Matthias Wagner, Professor für anorganische und analytische Chemie der Universität Frankfurt, der die Tagung auch eröffnete. In den Fachvorträgen der Stipendiaten ging es von Analysemethoden über Synthesechemie, Katalyse, Biochemie, nachhaltige Chemie und Energiespeicher bis hin zu großtechnischen Verfahren.
Long‐term urodynamic follow‐up after external sphincterotomy in patients with spinal cord injury
Authors: Takahashi Ryosuke , Kimoto Yasusuke , Eto Masatoshi
Published: May 2018

Aims

External sphincterotomy (ES) is a therapeutic option for male spinal cord injury patients with detrusor sphincter dyssynergia. However, some patients need to change their voiding management after ES. One of the potential causes of failure is reportedly detrusor dysfunction, but long‐term urodynamic follow‐up data after ES is limited. In the present study, we reviewed the urodynamic data before and after ES and analyzed it for possible causes of ES failure.

Methods

A total of 37 patients who were followed up at our center for at least 5 years after ES were included. Mean follow‐up period was 16.5 years. Urodynamic assessment was routinely performed every 2 or 3 years after ES, and the data were reviewed and analyzed.

Results

Of the 37 patients, 27 are still managed with reflex voiding to a condom catheter (success group), while 10 needed to change their bladder management. Mean maximum bladder pressure (MBP) was preserved at a low level after ES. However, after ES, there was a gradual increase over time in both the mean bladder volume at first neurogenic detrusor overactivity (NDO) and the percentage of patients without NDO. The mean preoperative MBP in the success group was significantly higher than that in the failure group.

Conclusions

MBP is maintained at a low level over 20 years after ES. However, NDO gradually decreases over time, which might be one of the reasons for failure after ES. In addition, low preoperative MBP would be a poor prognostic factor for ES.
Will cesarean section increase the risk of interstitial cystitis/painful bladder syndrome?
Authors: Chang Kun‐Min , Lee Ming‐Huei , Lin Hsuan‐Hung , Wu Shang‐Liang , Wu Huei‐Ching
Published: May 2018

Aims

A high number of patients with interstitial cystitis/painful bladder syndrome (IC/PBS) have a history of pelvic surgeries, and cesarean section is one of the most common pelvic surgeries in women. This study aimed to investigate if cesarean section increases the risk of IC/PBS.

Methods

Women who exclusively gave birth through cesarean section or vaginal delivery were identified from a nationwide database between 2002 and 2013. All were followed up during the study period to detect the event of IC/PBS. The IC/PBS hazard ratio (HR) in the cesarean cohort was compared with the vaginal delivery cohort with and without matching for confounding factors.

Results

The unmatched group included 22 158 cesarean deliveries and 40 214 vaginal deliveries. The IC/PBS HR in the cesarean cohort compared with that in the vaginal delivery cohort was 1.370 (95% confidence interval [CI], 0.903‐2.079; P = 0.139). In the matched group, 8368 women were matched in each cesarean and vaginal delivery cohort using propensity scores for age and comorbidities. The IC/PBS HR was 0.725 (95%CI, 0.358‐1.471; P = 0.373). Both HRs in these two groups were not significantly different. The incidence density of IC/PBS in delivered women, non‐delivery women, and the general female population were not significantly different either (0.310, 0.255, and 0.292 per 1000 person‐years, respectively; P = 0.549).

Conclusions

The risk of IC/PBS was not different between cesarean and vaginal delivery after controlling the confounding factors in this cohort study. Cesarean section has no causal effect on IC/BPS. Furthermore, delivery was not a risk factor for IC/PBS.
Nonprofit fundraising with virtual reality
Authors: Yoo Seung‐Chul , Drumwright Minette
Published: May 2018

An increasingly competitive fundraising environment and the new media ecosystem have prompted nonprofit organizations to strengthen their digital marketing capabilities. Recently, a few nonprofits have used virtual reality (VR) technology in fundraising, which raises questions about its effectiveness. Does VR work, and if so, through what psychological mechanisms? Through a lab experiment, the usefulness of VR as a digital fundraising tool was investigated. Specifically, we compared the media effects of experiencing the same fundraising video on two different devices: (a) a head‐mounted VR and (b) a tablet. The results revealed that donation intention, perceived vividness, perceived interactivity, and social presence were all significantly greater with the VR medium than with the tablet medium. Next, we tested and successfully verified the mediation effect of social presence on donation intention. Finally, we verified that a viewer's sensation‐seeking tendency served as a moderator when the device type influenced donation intention. Specifically, the media effects of VR were stronger for high sensation seekers than for low sensation seekers. This study contributes to theory and research by verifying the VR fundraising effect and identifying the key role of social presence, and it also provides important managerial guidelines for media design in VR fundraising campaigns.
Abdominal Subcutaneous Fat: A Favorable or Nonfunctional Fat Depot for Glucose Metabolism in Chinese Adults?
Authors: Hou Xuhong , Chen Peizhu , Hu Gang , Wei Li , Jiao Lei , Wang Hongmei , Liang Yebei , Bao Yuqian , Jia Weiping
Published: May 2018

Objective

The objective of this study was to assess the associations of abdominal visceral and subcutaneous adipose tissue with blood glucose and beta‐cell function.

Methods

In this study, 11,223 participants without known diabetes were selected for this cross‐sectional analysis. Visceral and subcutaneous fat area (VFA and SFA) were measured by magnetic resonance imaging. An oral glucose tolerance test was conducted, and beta‐cell function was evaluated.

Results

Men had significantly larger VFA but smaller SFA than women. After controlling for age, linear regression showed that SFA was adversely associated with 0‐minute, 30‐minute, and 2‐hour plasma glucose (PG) and early‐, first‐ and second‐phase disposition indices (DIs). After further adjustment for BMI and VFA, some associations of SFA with PG indices and DIs disappeared, while the other associations became significantly weaker in men (2‐hour PG: 0.05 and DI2nd: −0.05) or were reversed in women (0‐minute, 30‐minute, and 2‐hour PG: from −0.07 to −0.04; DI1st: 0.04, P < 0.05). After adjustment for age, BMI, and SFA, VFA was significantly and adversely associated with PG indices and DIs, with the largest standardized regression coefficients with 2‐hour PG.

Conclusions

The associations of SFA with blood glucose and beta‐cell function were clinically insignificant in Chinese adults. VFA had the strongest association with 2‐hour PG.
Fabrication‐controlled morphology of poly(butylene succinate) nano‐microcellular foams by supercritical CO2
Authors: Zhang Shuidong , Xu Yue , Wang Peng , Peng Xiangfang , Zeng Jianbing
Published: May 2018

Poly(butylene succinate) urethane ionomer (PBSUIs) foams with nano‐microcellular morphology were fabricated using supercritical CO2 (sc‐CO2) at different parameters. Effect of urethane ionic group (UIG) content (ranged from 1% to 5%) on the rheology and crystallization of PBSUIs were evaluated by intrinsic, dynamic rheological, X‐ray diffraction, and differential scanning calorimetry measurements. The results show that the complex viscosity of PBSUIs vastly improved, while their intrinsic viscosity and crystallinity decreased. They also evidenced that CO2 promoted the formation of crystallites in the amorphous and increased the Xc of PBSU and PBSUIs foams. Scanning electron microscope was employed to explore the influences of UIG content and foaming parameters on the morphologies of PBSUIs microcellular foams, and it revealed that UIG content was the dominated factor. The cell size and cell densities of PBSUIs microcellular foams were smaller than 5.0 micrometers and higher than 1.5 × 1010 cells/cm3, respectively, even foamed at diverse variations of foam temperature and pressure. Interestingly, PBSUIs with 3% and 5% UIG content achieved microcellular foams in nano‐cells, high‐stretched elliptical shape. The mechanism was ascribed that these PBSUIs with high melt viscosities could retard the CO2 bubbles to merge during the foam process and induce the cells to stretch and orient in depressururization direction. This study proposed a novel method for fabricating PBS nano‐microcellular foams.
Identification of relaxation processes in pure polyethylene oxide (PEO) films by the dielectric permittivity and electric modulus formalisms
Authors: Telfah Ahmad , Abdul‐Gader Jafar Mousa M. , Jum'h Inshad , Ahmad Mais Jamil A. , Lambert Jörg , Hergenröder Roland
Published: May 2018

The ac‐impedance of bulk‐like films of pure polyethylene oxide (PEO) polymer was measured as a function of frequency f in the range 0.1 to 107 Hz at various constant temperatures T (155 − 330 K). The as‐measured data were analyzed by electric permittivity and modulus formalisms to unveil which dielectric and conductive relaxation processes were responsible for their relaxation behavior below/above glass transition temperature Tg of pure PEO polymer. At T > Tg, none of the α‐, β‐, or γ‐relaxations could be inferred for studied pure PEO films from frequency variation of measured imaginary part ε′′(f, T) of complex dielectric permittivity
, as low‐frequency losses masked real dielectric contribution to the measured ε′′(f, T) at low frequencies and high temperatures. However, at T < Tg, a broad, relaxation process has been observed in the high‐frequency part of their isothermal ε′′(f, T) − f spectra, which can be related to the β‐ or γ‐dielectric relaxation process. Nonlinear regressions of the measured ε′′(f, T) − f data for T < Tg yielded moral fits to a simple addition of a Havriliak‐Negami function, and a Bergman‐loss Kohlrausch‐Williams‐Watts‐type function, with the relaxation time τmax(T) obtained from Havriliak‐Negami‐fitting parameters, was found to follow a thermally activated Arrhenius‐like relaxation behavior. Conversely, representation of the imaginary part M′′(f, T > Tg) − f spectra of complex electric modulus
was found to depict 2 overlapped relaxation processes, which were detached well by a nonlinear regression of a simple superposition of 2 different M′′(f) expressions having the form of the universal Bergman loss function, where it was found that the relaxation time is also thermally activated.
Fabrication of tragacanth and water soluble tragacanth nanoparticles through electrospraying
Authors: Javadi Zhinoos , Tavanai Hossein , Allafchian Alireza , Morshed Mohammad
Published: May 2018

This work reports the fabrication of tragacanth and water soluble tragacanth (WST) through electrospraying technique. Tragacanth is a biocompatible and biodegradable carbohydrate with a wide range of applications. Suspensions of tragacanth in water and water‐ethanol (70:30) were electrosprayed successfully. Moreover, deesterified tragacanth (WST), which is highly water soluble, was also successfully electrosprayed. The results showed that electrospraying technique is capable of producing tragacanth nanoparticles with an average size in the range of 30 to 50 nm, depending on the electrospraying conditions. Water soluble tragacanth gave rise to even smaller nanoparticles. It was also found that lowering feed rate, increasing nozzle‐ collector distance, and increasing voltage decrease the average size of the electrosprayed tragacanth nanoparticles. The molecular weight of tragacanth and WST was measured to be 610 and 301 KDa, respectively. The electrosprayed tragacanth and WST nanoparticles showed moisture regain of 50% and 75%, respectively. These values are much higher than that of their normal powder form. Fourier transform infrared proved the absence of ester groups in the WST as a result of deesterification. X‐ray diffraction studies showed an amorphous microstructure for both tragacanth and WST before electrospraying. After electrospraying, the amorphous structure of the 2 showed some orientation.
Enhancement of biocompatibility on aligned electrospun poly(3‐hydroxybutyrate) scaffold immobilized with laminin towards murine neuroblastoma Neuro2a cell line and rat brain‐derived neural stem cells (mNSCs)
Authors: Sangsanoh Pakakrong , Ekapakul Natjaya , Israsena Nipan , Suwantong Orawan , Supaphol Pitt
Published: May 2018

Electrospinning has been extensively used to construct tissue‐engineered scaffolds because of its ability to provide the fibrous scaffold with structurally analogous to the naturally occurring protein in the extracellular matrix of native tissues. In addition, the modification of scaffolds with bioactive molecules is beneficial as this can create an environment that consists of biochemical cues to further promote cell adhesion, proliferation, and differentiation. In the present contribution, we prepared and investigated the potential used of aligned electrospun poly(3‐hydroxybutyrate) (PHB) scaffold immobilized with bioactive molecule to serve as nervous scaffold. Laminin was successfully immobilized on the surface using covalent binding between functional groups of modified scaffolds and protein. The ability to use for neural regeneration was evaluated in vitro towards murine neuroblastoma Neuro2a cell line and mouse brain‐derived neural stem cells. The surface modification with laminin immobilized on the PHB fibrous scaffolds supported the attachment and promoted the proliferation of Neuro2a very wells. Despite the good attachment and proliferation of Neuro2a and mouse brain‐derived neural stem cells were not able to proliferate on the neat PHB, hydrolyzed PHB and laminin immobilized on hydrolyzed PHB fibrous scaffold.
The effect of MWCNT on dynamic mechanical properties and crystallinity of in situ polymerized polyamide 12 nanocomposite
Authors: Faridirad Farzaneh , Barmar Mohammad , Ahmadi Shervin
Published: May 2018

This work aims at investigating the dynamic mechanical properties of in situ anionic ring opening polymerized polyamide 12 in the presence of multi‐walled carbon nanotubes (MWCNT). According to the dynamic mechanical thermal analysis results, the addition of only 0.1 wt.% of MWCNTs led to 30% enhancement in modulus at room temperature which exhibited improved mechanical behavior of the nanocomposites. Test results showed that by the presence of 1.2% wt MWCNTs, the modulus is almost doubled, and it did not show any tangible changes by the addition of more nanotubes. Also, the effect of different frequencies on the viscoelastic behavior was investigated in order to determine the thermal transitions occurred in the synthesized nanocomposites. After that, the crystallinity of the samples has been studied using differential scanning calorimetry and X‐ray diffraction data in order to investigate the effect of MWCNT content on the crystals' dimension.
Mechanical reinforcement and creep resistance of coextruded wood flour/polyethylene composites by shell‐layer treatment with nano‐ and micro‐SiO2 particles
Authors: Hao Xiaolong , Zhou Haiyang , Xie Yanjun , Xiao Zefang , Wang Haigang , Wang Qingwen
Published: May 2018

Nano‐ and micro‐SiO2 particles (termed nSiO2 and mSiO2, respectively) were incorporated in the shell layer of a coextruded wood flour/high density polyethylene composite (WF/HDPE) to improve the mechanical properties and inhibit creep behavior. The effects of loading content, particle size, and surface treatment of the silica with vinyl trimethoxy silane (VTS) were investigated on the properties of the resulting coextruded WF/HDPE composites. Scanning electron microscopy revealed proper interfacial adhesion between the core and shell layers. nSiO2 exhibited higher reinforcement efficacy than that of mSiO2 for the shell‐layer materials. Incorporation of the VTS‐treated nSiO2 caused an increase in flexural‐ and impact strength of the coextruded composites by 29% and 57%, compared to the non‐silica filled coextruded WF/HDPE controls, respectively. Incorporation of nSiO2, either untreated or VTS‐treated, enhanced creep resistance of shell layer materials; however, only VTS‐nSiO2 worked for the coextruded composites. These findings demonstrate that filling with silica, particularly VTS‐treated nSiO2, in the shell layer substantially and economically reinforces coextruded shell/core‐structured WF/HDPE composites. POLYM. COMPOS., 40:1576–1584, 2019. © 2018 Society of Plastics Engineers
Uhren als Höhenmesser
Authors: Lisdat Christian , Schnatz Harald
Published: May 2018

Optische Atomuhren sind inzwischen so genau, dass sich die Gravitationsrotverschiebung von einigen Zentimetern Höhenunterschied signifikant auf ihren Gang auswirkt. Damit könnten sie als neuartige Messinstrumente in der Geodäsie genutzt werden, wenn sie nicht wie bisher nur in gut geschützten Laboren betrieben werden könnten. Jetzt wurde erstmals eine von der Physikalisch‐Technischen Bundesanstalt (PTB) in Braunschweig entwickelte, transportable optische Uhr in den Alpen zur Messung von Differenzen des Gravitationspotentials der Erde eingesetzt [1].
Bethe‐Strings: Exotische Anregungen in Spinsystemen
Authors: Wang Zhe , Loidl Alois
Published: May 2018

Hans Bethe sagte 1931 in einer fundamentalen Arbeit die Existenz von stark gebundenen Zuständen von Quasiteilchen voraus. Nun konnte eine internationale Kooperation erstmals derartige Bethe‐Strings in einem Kristall nachweisen.
Heiligenschein und Taubogen
Authors: Schlichting Hans‐Joachim
Published: May 2018

Wenn Sonnenlicht durch Tautropfen hindurch auf Pflanzenblättern reflektiert wird, kann ein Heiligenschein beobachtet werden. Unter günstigen Bedingungen kann durch Dispersion des Lichts auch ein schwer beobachtbarer Taubogen entstehen.
Newtonsche Dynamik mit Motion Track spielend verstehen
Authors: Wilhelm Thomas , Kuhn Jochen
Published: May 2018

Mit der App Motion Track lassen sich durch Simulationen spielerisch Erfahrungen mit Kräften auf einen bewegten Körper machen, die zu einem Verständnis der Newtonschen Axiome beitragen können.
Beizen: polare Wechselwirkungen und Wasserbindung
Authors: Vilgis Thomas
Published: May 2018

Beizen ist eine uralte Methode, Fisch zu konservieren. Dazu wird das Fischfilet großzügig mit Kräutern, Salz und Zucker bedeckt und für acht Stunden gebeizt, wobei je nach Rezeptur das Verhältnis von Salz und Zucker zwischen 1:1 bis 2:1 rangiert. Weniger bekannt sind die physikalischen Vorgänge auf molekularer Skala und die sich dabei offenbarende unterschiedliche Wirkung von Salz und Zucker.
A detailed DFT/TDDFT study on excited‐state intramolecular hydrogen bonding dynamics and proton‐transfer mechanism of 2‐phenanthro[9,10‐d]oxazol‐2‐yl‐phenol
Authors: Zhang Tianjie , Yang Guang , Jia Min , Song Xiaoyan , Zhang Qiaoli , Yang Dapeng
Published: May 2018

In this present work, using density functional theory and time‐dependent density functional theory methods, we theoretically study the excited‐state hydrogen bonding dynamics and the excited state intramolecular proton transfer mechanism of a new 2‐phenanthro[9,10‐d]oxazol‐2‐yl‐phenol (2PYP) system. Via exploring the reduced density gradient versus sign(λ2(r))ρ(r), we affirm that the intramolecular hydrogen bond O1‐H2⋯N3 is formed in the ground state. Based on photoexcitation, comparing bond lengths, bond angles, and infrared vibrational spectra involved in hydrogen bond, we confirm that the hydrogen bond O1‐H2⋯N3 of 2PYP should be strengthened in the S1 state. Analyses about frontier molecular orbitals prove that charge redistribution of 2PYP facilitates excited state intramolecular proton transfer process. Via constructing potential energy curves and searching transition state structure, we clarify the excited state intramolecular proton transfer mechanism of 2PYP in detail, which may make contributions for the applications of such kinds of system in future.
Light Scattering by Homogeneous Axisymmetric Particles for PDA Calculations to Measure Both Axes of Spheroidal Particles
Authors: Doicu Adrian , Wriedt Thomas , Bauckhage Klaus
Published: May 2018

Mathematical tools are provided for the computation of the scattered field produced by a non‐spherical particle moving through the measurement volume of a phase Doppler anemometer. The Doppler signal is modeled by using the rigorous extended boundary condition method and an approximate ray theory. The region of applicability of ray theory is discussed. In particular, a pure refraction model is considered for large particles. It is shown that under some circumstances the phase Doppler technique may be used for sizing of spheroidal particles.
Morphological Changes of Oxide Grains During Oxidation of Pure Iron in an Environmental Scanning Electron Microscope
Authors: Shao Manjun , Li Huijun , Kwauk Mooson
Published: May 2018

For modeling particles‐gas reactions in terms of the morphology of nascent solid reaction products, a technique using the environmental scanning electron microscope (ESEM) was developed to monitor the in situ oxidation of iron. Experimental conditions of the oxidation experiments were selected as the temperature range of 500–750°C and the oxygen partial pressure range 10–4–45 Pa. The evolution of nucleation and growth of oxide whiskers or grains on the surface of iron specimens under the ESEM was recorded. The characteristics of some specimens were further examined after oxidation by post‐analysis. Three sets of experimental results and other relative micrographs are shown. In the light of the surface morphology and textures of the oxide growths in the micrographs, their growth mechanism and reaction kinetics are discussed. Finally, a plausible physical model for oxidation of iron is suggested.
Rainbow Interferometry with Wire Diffraction for Simultaneous Measurement of Droplet Temperature, Size and Velocity
Authors: van Beeck Jeronimus P. A. J. , Riethmuller Michel L.
Published: May 2018

A rainbow measurement technique is presented which measures simultaneously the size, temperature and velocity of individual droplets in a spray. The technique is based on rainbow interferometry in combination with diffraction by a wire placed in the spatial filter of the scattered‐light detector. A photomultiplier detects the wire diffraction pattern superimposed on the rainbow interference pattern created by a droplet scattering laser light. The velocity is determined from the equivalent geometric wire shadow. The necessary sphericity validation is performed by comparing the Airy and the ripple droplet diameters, resulting from the respective interference structures. The temperature is recovered from the position of the wire diffraction pattern relative to the main rainbow maximum. The technique was applied to a water spray at ambient temperature. The results showed the importance of nonsphericity detection.
Classification of Crystal Shape Using Fourier Descriptors and Mathematical Morphology
Authors: Bernard‐Michel Bruno , Rohani Sohrab , Pons Marie‐Noelle , Vivier Herve , Hundal Harvinderjit S.
Published: May 2018

The performances of two image analysis methods for the classification of some randomly selected KCl crystals from a crystallization experiment into four two‐dimensional classes (nearly circular, square, rectangular and irregular) are compared. The first method uses the first 15 Fourier descriptors of the angular bend as a function of arc length of the periphery of the particles, whereas the second method is based on a combination of seven geometrical and morphological parameters of the crystals using a commercially available image analysis system (Visilog, Noesis, Orsay, France). The feedforward neural network with back‐propagation learning algorithm and discriminant factorial analysis (STATlab, SLP, Ivry sur Seine. France) were found to classify the crystals with similar success.
Significant Enhancement of Hydrogen Production in MoS2/Cu2ZnSnS4 Nanoparticles
Authors: Li Yulan , Zhou Zhihua , Lin Yuelai , Ji Haining , Li Handong , Wu Jiang , Ashalley Eric , Usman Muhammad , Bao Jiming , Niu Xiaobin , Wang Zhiming
Published: May 2018

Hydrogen produced from water splitting is a renewable and clean energy source. Great efforts have been paid in searching for inexpensive and highly efficient photocatalysts. Here, significant enhancement of hydrogen production has been achieved by introducing ≈1 mol% of MoS2 to Cu2ZnSnS4 nanoparticles. The MoS2/Cu2ZnSnS4 nanoparticles showed a hydrogen evolution rate of ≈0.47 mmol g−1 h−1 in the presence of sacrificial agents, which is 7.8 times that of Cu2ZnSnS4 nanoparticles (0.06 mmol g−1 h−1). In addition, the MoS2/Cu2ZnSnS4 nanoparticles exhibited high stability, and only ≈3% of catalytic activity was lost after a long time irradiation (72 h). Microstructure investigation on the MoS2/Cu2ZnSnS4 nanoparticles reveals that the intimate contact between the nanostructured MoS2 and Cu2ZnSnS4 nanoparticles provides an effective one‐way expressway for photogenerated electrons transferring from the conduction band of Cu2ZnSnS4 to MoS2, thus boosting the lifetime of charge carriers, as well as reducing the recombination rate of electrons and holes.