bluuebunny/crossref_metadata_2025 huggingface dataset:
Overlooking Terris: A Speculative Reconsideration of a Curious Spot-Blindness in the History of Alcohol-Control Science
Authors: Roizen Ron , Fillmore Kaye Middleton , Kerr William
Published: July 2017

The authors argue that the overlooking or forgetting of a beverage-specific element of Milton Terris's classic 1967 paper linking per capita alcohol consumption with cirrhosis mortality trends sheds new light on the subsequent paradigmatic history of alcohol epidemiology. The historical standing and subsequent citation of Terris's paper are re-examined, and Terris's reasons for not reminding the alcohol epidemiology literature of this aspect of his paper are explored. Aspects of presentation and content of the 1967 paper are also discussed with respect to the explanation of the subsequently lost beverage-specific element of Terris's article. The authors suggest that an evolutionary aspect of the relationship and competition between the modern alcoholism and alcohol controls paradigms in alcohol epidemiology may offer the key to accounting for this historical-forgetting puzzle.
Measuring Social Model in California: How Much has Changed?
Authors: Kaskutas Lee Ann , Keller John W. , Witbrodt Jane
Published: July 2017

To examine the prevalence of social model philosophy in programs today and to study ways in which the philosophy may have eroded in recent years, a survey was mailed in 1998 to all state-licensed alcohol and drug residential programs in California (83% response rate). Analysis of the survey (Social Model Philosophy Scale, n=311) also identified specific ways in which social model programs differ from other types of programs such as medical/clinical model programs or therapeutic communities (e.g., by exhibiting more active 12-step community involvement). Results reveal that social model programs adhere decreasingly to social model principles in their philosophy and operation; for example, they now are more likely than not to keep complete case management files on all participants. Possible causes of this erosion, such as the growing dominance of managed care in the health-care world, are also discussed.
Studies on the Modification of Thermoplastic Polyolefins (TPOs)—Part I. Effect of Various Modifiers on the Adhesion of a Two-Component (2K) Polyurethane Coating to the Modified TPOs
Authors: Hailat M. , Xiao H. X. , Frisch K. C.
Published: July 2017

Thermoplastic polyolefins (TPOs) have low energy surfaces, therefore, they are difficult to be adhered to with adhesive and coating systems. Various modifiers, namely, polycaprolactone, polyvinyl acetate, poly(oxy-ethylene)glycol and polyamides were incorporated into the matrix of TPOs to modify and enhance their surface energy in order to improve adhesion of two component (2K) urethane coatings to their surface. Adhesion was investigated by using the crosshatch adhesion test. Good adhesion of 2K polyurethane coatings to the modified TPOs was achieved by using polyamides based on maleated polypropylene (MPP) and polyetheramine (PEA) (ED4000). The adhesion was found to be dependent on the modifier percentage and the equivalent ratio of MPP to PEA (ED4000).
Studies on the Effect of Waste Dipped and Calendered Nylon Short Fibre on Farm/Tractor Tyre Tread Formulation
Authors: Chandra A. K. , Nizar K. M. A. , Mukhopadhyay R.
Published: July 2017

The effective utilisation of waste and dipped calendered Nylon fabric in Farm/Tractor tyre tread to improve the tearing and chunking resistance has been studied. Short fibres are made from the waste dipped and calendered nylon fabric and mixed with a standard Farm/Tractor tyre tread formulation in different concentrations. Physical and mechanical properties of the mixes in the longitudinal as well as in the transverse directions, i.e., mill direction and perpendicular to mill direction, were studied. Abrasion resistance, hardness and modulus increase while the tensile strength and fatigue life decreased on increasing the fibre concentration. Tear strength and crack growth resistance are found optimum at 5 phr of fibre loading. A laboratory Banbury trial with 5 phr of calendered fabric, which substituted an equal amount of carbon black, has been found to enhance most of the physical properties without affecting the processability.

The positive results obtained in this study point to the potential utilization of this waste fabric, generated by the rubber industry, thereby, providing a substantial improvement in the economy of the industry.
A Study on the Relationships between Network Structure and Mechanical Properties of Interpenetrating Polymer Networks-Part I: A New Molecular Theory of Viscoelasticity for Thermoplastic Polyurethane Elastomers
Authors: Song M. S. , Chen H. , Hu C. J.
Published: July 2017

A new molecular theory of nonlinear viscoelasticity for crystallizable thermoplastic polyurethane elastomers (CTPUE) possessing the capability of characterizing the mechanical properties both at small and at large deformations is presented and verified by experimental data. Based on the proposed structure for CTPUE and the mechanism of large deformation, the probability distribution functions of the end-to-end vectors for five kinds of constituent chains were calculated. Also, the free energy of deformation for the microstructures including three kinds of networks and induced crystallites was calculated. The theory successfully related the viscoelastic behaviors to molecular constitution by three important network parameters (C,100, C020 and C200). The constitutive equations for various types of deformation were obtained and the relation of modulus to relaxation time was derived. It provides a theoretical foundation for studying the relations between the structure of networks and the mechanical properties of CTPUE at large deformations.
Effect of Ionizing Radiation on the Properties of Ultrahigh Molecular Weight Polyethylene Fibers
Authors: Shaker Manal , Kamel Ihab , Abdel-Bary E. M.
Published: July 2017

Ultrahigh molecular weight polyethylene UHMW-PE fibers intended to be used as reinforcing fillers in elastomers were subjected to ionizing radiation vulcanization to avoid the deleterious effect of conventional sulfur vulcanization conditions, i.e., vulcanization temperature on the properties of polyethylene fibers. Thus, UHMW-PE fibers (Spectra™ 1000) were subjected to both gamma as well as electron beam radiation in absence of air and up to 250 kGy. Changes in melting (Tm) and crystallization temperature (Tc) enthalpy of melting and crystallization depending on the type and dose of radiation were followed up using differential scanning calorimetry (DSC). In addition to the observed decrease in tensile strength, decrease in fiber diameter and increase in modulus depending on radiation dose were correlated with the changes in fiber morphology.
Rheological, Thermal, and Tensile Properties of LLDPE/EPDM Blends
Authors: Kim K. H. , Cho W. J. , Ha C. S. , Kang T. K. , Kim Y.
Published: July 2017

Melt blends of linear low density polyethylene (LLDPE) and ethylene-propylene-diene terpolymer (EPDM) have been prepared. Rheological properties, thermal properties, and mechanical properties of the blends were investigated by using Rheometric Dynamic Spectroscopy (RDS), differential scanning calorimetry (DSC), and tensile tests, respectively. Crystalline structure and morphology of the blends were also investigated by X-ray diffractometer and scanning electron microscopy (SEM), respectively. The properties and morphology of the blends were dependent on the blend compositions. It was concluded that the LLDPE/EPDM blends of 90/10 composition by weight% show miscibility in the theological sense.
Scanning Electron Microscopic Studies of PP/EPDM/NR Ternary Blends
Authors: Ashalatha P. V. , George K. E. , Francis D. Joseph
Published: July 2017

The morphological properties of PP/EPDM/NR blends were investigated. A double layered morphological structure was observed for the compression moulded PP/EPDM/NR blends. Blends with low levels of elastomer content show a particulate distribution in the elastomer phase. For the 80/10/10 blend an interpenetrating co-continuous network is observed. The same blend shows the highest impact strength.
Rheological Study of Phenolic-Urethane-Amine Process
Authors: Bakhtiyarov Sayavur I. , Overfelt Ruel A.
Published: July 2017

The flow dynamics of phenolic-urethane-amine process in a core box of an inverted "U" configuration was studied experimentally using a Laempe LI Core Shooter. The effects of reduction in area of the vents were evaluated by manual reduction of the active vent areas. In addition, experimental data on the pressure drop and friction factor for the vents were obtained as a function of the amounts of sand deposited in vent area. The experimental data are compared with the predictions of the Blake-Kozeny and Ergun porous flow equations and good agreement was found.
Polyolefins Containing Reactive p-Methylstyrene Groups: From High Tm Thermoplastics to Low Tg Elastomers
Authors: Chung T. C.
Published: July 2017

This paper summarizes the experimental results in a new class of polyolefin co- and terpolymers containing "reactive" p-methylstyrene (p-MS) groups, which includes the materials from high T m thermoplastics to low T g elastomers. Due to the extraordinary copolymerization capability of metallocene catalysts with constrained ligand geometry, p-MS can be effectively copolymerized with α-olefins (i.e., ethylene, propylene, 1-octene, etc.) to form co- and terpolymers having narrow molecular weight and composition distributions. Comparing with other relative styrenic comonomers, i.e., styrene, o-methylstyrene and m-methylstyrene, p-MS shows significantly higher reactivity in metallocene catalysis. In turn, the incorporated p-MS units in polyolefins are very versatile, which not only can be interconverted to various functional groups, such as -OH, -COOH, anhydride, silane and halides, but also can be conveniently transformed to "stable" anionic initiators for "living" anionic graft-from polymerization reactions. Many new functional polyolefin graft co-polymers have been prepared, containing polyolefin backbone (PE, EP, EO, etc.) and functional polymer side chains, such as PMMA, PAN, PS, etc.
Modification of a Bitumen with Various Polymers for Use in Built-Up Roofing Membranes
Authors: Fawcett A. H. , Mcnally T. , Mcnally G. M.
Published: July 2017

Bitumen, a mixture of aromatics, paraffins, asphaltenes and resins that remain after crude oil has been fractionally distilled, finds applications in blends with a proportion of a polymer, in built up membranes for the roofing industry. Blends of three commercially used polymers with a 100 penetration grade Nynas bitumen at levels between 9% and 29% w/w were prepared using a Z-blade mixer. The morphology, thermal and dynamic mechanical properties of these blends were examined using fluorescence optical microscopy, differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA). The blends prepared with these polymers displayed low temperature flexibility and an onset of flow at high temperatures. The former characteristic is required for use in cold environments the latter feature being a critical property when the membrane is manufactured and later when applied by the torching process on a roof. It may be seen how the different blends function in a manner that makes them suitable for the production of built-up roofing membranes.
Smooth switching linear parameter-varying fault detection filter design for morphing aircraft with asynchronous switching
Authors: Cheng Haoyu , Dong Chaoyang , Wang Qing , Jiang Weilai
Published: July 2017

This article deals with the problem of fault detection filters design for morphing aircraft with asynchronous switching. Considering time delay and intermittent measurements in the network environment, the morphing aircraft can be modeled as a switched linear parameter-varying (LPV) system. There always exists asynchronous switching phenomenon owing to time delay and data missing, which will lead to performance degradation. The parameter-dependent filters are established to generate the residual signal. In order to ensure the transient response of the morphing aircraft, the smooth switching LPV fault detection filters are designed by dividing the whole scheduling parameter set into subsets with overlaps. Meanwhile, the stability and prescribed performance of the system are guaranteed by combining multiple Lyapunov functional method and mode-dependent average dwell time method. The existing conditions and solution of filters are derived by linear matrix inequalities. Furthermore, an automatic partition method is proposed for the convenience of designing process. Simulation in the end demonstrates the superiority and effectiveness of the proposed method.
A comparison of UK domestic water services sizing methods with each other and with empirical data
Authors: Tindall Jess , Pendle Jamie
Published: July 2017

Evidence suggests that domestic cold water service sizing methods in many countries around the world tend to overestimate the actual peak water volume flow rate. Oversizing domestic water service systems does waste materials and money, but it also increases the length of time that it takes for water to pass through the system which can increase water temperatures with the associated risks that presents. This paper compares the three commonly used UK domestic cold water service sizing methods and reveals variance in the methods, the design flow rates calculated and the amount of diversity applied by each method. BS EN 806 returns the lowest design flow rates of the three methods and also applies significantly greater diversity. Empirical domestic cold water service volume flow rate data from two case study buildings revealed that all three UK sizing methods significantly overestimated the peak water volume flow rates but that BS EN 806 was the closest. Additional empirical data from seven more buildings have been used to validate the data from this study and add confidence to the findings. This research provides useful evidence to help engineers select the most appropriate UK domestic cold water service sizing method and to anticipate the likely range and fluctuation of domestic cold water service flow rates.

Practical application: Engineers tend to be conservative by nature and generally err on the side of caution to ensure that there is never any cause for customer complaint about their designs. This is understandable but there can be negative consequences if the full implications of such decisions are not fully understood. This paper reveals significant oversizing compared to empirical data from each of the three UK domestic water service sizing methods and highlights the reasons for this. The practical application of this paper lies in the presented results data and analysis which will help engineers make this important choice between the available sizing methods.
Nitrogen Balance and Electrolyte Requirements in Intralipid‐Based Hyperalimentation
Authors: Van Way Charles W. , Buerk Charles A. , Peterson Rod , Dresler Carolyn
Published: July 2017

The present study was directed at determining whether or not a relatively low‐calorie regimen in which 40 to 50% of the calories are provided as fat will produce positive nitrogen balance in most patients, and at establishing the electrolyte requirements for such a regimen. Clearly, the recommended regimen is successful in promoting nitrogen balance and provides adequate electrolytes. Further experience will be necessary to determine the place of intravenous fat emulsions in the clinical practice of total parenteral nutrition.
Intravenous Protein‐sparing Therapy in Patients with Gastrointestinal Disease
Authors: Greenberg Gordon R. , Jeejeebhoy Khursheed N.
Published: July 2017

Two groups (each of 6 moderately ill, protein‐depleted patients) were infused daily for 7 days. Mean 7 day nitrogen (N) balances with infusions of 0.83 and 1.83 g of a defined amino acid mixture (containing further nutrients but no other source of energy)/kg ideal body wt/day were −3.66 and +1.54 g/day, respectively (P < 0.025) when adjusted for changes in body urea and estimated miscellaneous N losses. Concentrations of plasma free fatty acids, immunoreactive insulin and glucagon, and of blood glucose, pyruvate, lactate and glycerol were indistinguishable on corresponding treatment days in the 2 groups but blood ketone bodies were lower in the 1.83 g/kg group. Blood amino acid concentrations of alanine, valine, leucine, and isoleucine were similar, whereas those of phenylalanine, histidine, serine, and arginine were higher, and glutamine lower, in the 1.83 g/kg group. The data confirm that not only can body protein mass be maintained, but a net positive N retention achieved, in such patients, through provision of exogenous amino acids and concurrent mobilization of endogenous energy stores. Of note is that this fat mobilization can occur without plasma free fatty acids and/or significant blood ketone body elevations. An infusion of 2, rather than 1 g/kg/day seems suitable in the situation examined.
Why and What They Read When They Don’t Have to: Factors Influencing the Recreational Reading Habits of Gifted Students in Singapore
Authors: Garces-Bacsal Rhoda M. , Yeo Sulyn Denise
Published: July 2017

This study examined the recreational reading habits of 10- to 12-year-old students enrolled in one of the nine Gifted Education Program (GEP) schools in Singapore. A total of 125 students were surveyed regarding the time they spent on recreational reading, and the top and bottom 10% were labeled Highly Avid Readers (HAR) and Less Avid Readers (LAR), respectively. The 24 readers from the HAR and LAR groups subsequently participated in Focus Group Discussions (FGDs), which revealed that the two groups differ considerably in terms of their ideations about reading, perception of themselves as readers, and the time they devote to reading, as well as parental influences in reading. Results, which are interpreted using Bronfenbrenner’s Ecological Theory framework, indicate more can be done in both home and school settings to encourage recreational reading. Insights and recommendations are offered in light of this.
Accumulation of the p53 Tumor‐Suppressor Gene Product in Oral Leukoplakia
Authors: Wood Mark W. , Medina Jesus E. , Thompson Glenn C. , Houck John R. , Min Kyung‐Whan
Published: July 2017

OBJECTIVES:

(1) To determine whether the protein of the suppressor gene p53 accumulates in leukoplakia of the oral cavity in individuals who use snuff; and (2) to determine whether a correlation exists between the accumulation of p53 protein and the degree of epithelial dysplasia present in oral leukoplakia.

DESIGN:

Retrospective analysis of archival tissue specimens.

SETTING:

The University Hospital, a tertiary referral hospital affiliated with the Oklahoma University Medical Center, Oklahoma City, Oklahoma.

PATIENTS:

In the first part of the study, biopsy specimens of leukoplakia from 12 persons who used snuff were compared with specimens from uninvolved oral mucosa of the same persons and with biopsy specimens from 12 nontobacco‐using persons. In the second part of the study, accumulation of p53 protein was determined in 42 archival paraffin‐embedded specimens from oral leukoplakia and correlated with the degree of epithelial dysplasia.

METHODS:

Accumulation of p53 protein was assessed by immunoperoxidase staining with four different primary antibodies. Positive cells were counted in five consecutive high‐power fields.

RESULTS:

In part one, the average number of positive cells in the leukoplakia of snuff‐users (21.89 ± 4.33; mean ± SE) was higher than that of normal‐appearing mucosa (4.00 ± 1.0; p < 0.05) and that of nontobacco‐using controls (7.00 ± 5.04). In part two, the average number of positive cells was higher in the moderately dysplastic (140.36 ± 30.03) and severely dysplastic lesions (232.86 ± 26.85) than in the mildly dysplastic lesions (14.53 ± 3.33; p < 0.05). The correlation between the degree of epithelial dysplasia and the number of cells positive is strong (Spearman's correlation coefficient = 0.853).

CONCLUSIONS:

The accumulation of p53 protein in leukoplakia of snuff‐users is higher than in normal‐appearing oral mucosa from both snuff‐users and nontobacco‐using controls. A strong correlation exists between the degree of epithelial dysplasia present in oral leukoplakia and the number of cells staining positive for p53. The accumulation of p53 protein holds potential as an intermediate end point in studies of chemoprevention of oral cancer.
Race, Statistics and Italian Eugenics: Alfredo Niceforo’s Trajectory from Lombroso to Fascism (1876–1960)
Authors: Caglioti Angelo Matteo
Published: July 2017

This article traces the development of Italian eugenics and scientific racism from their origins in nineteenth-century positivist anthropology to the 1938 Manifesto of Racial Scientists. I follow the biographical trajectory of the Sicilian racial thinker Alfredo Niceforo (1876–1960), the last member of Cesare Lombroso’s positivist school, a founding father of Italian eugenics and a prominent statistician throughout the fascist regime. I argue that the peculiarity of the Italian path to eugenics was its ‘internal orientalism’, caused by the poverty and perceived backwardness of the Italian South. Blending Niceforo’s biography with his ideas, I chart the social and intellectual history of Italian scientific racism from the transformation of Lombroso’s school to the fascist ‘Aryanization’ of Italians.
Adding Events to a Markov Model Using DICE Simulation
Authors: Caro J. Jaime , Möller Jörgen
Published: July 2017

Background. Health care decisions are often made under uncertainty and modeling is used to inform the choices and possible consequences. State-transition (“Markov”) models are commonly used but they represent the problem solely in terms of states; events are not explicitly considered. Methods. Discretely integrated condition event (DICE) simulation provides for both aspects that persist over time (“conditions”) and for those happening at a point in time (“events”). A Markov model can be specified in DICE by representing states as conditions with a recurrent transition event processing transition probabilities, and other events added explicitly. Results. The DICE specification of a Markov model is compact because transitions are enumerated only once; it is very transparent, as these specifications are tabulated rather than programmed in code; and flexibility is enhanced by the ease with which alternative structures are specified. Events can be added to represent clinical occurrences, treatment features, health care activities, and any other relevant aspect of this type. They may coincide with the transition event or occur at their own times. Varying cycle times and structural sensitivity analyses are easy to implement. Limitations. Execution of a DICE simulation using a macro in spreadsheet software can be slow, especially for complex models requiring stochastic analyses replicated thousands of times. Modelers wishing to use other software can still use the tabular specification ideas to expand their Markov models, but the descriptions provided here may not be entirely applicable. Another limitation is the inability of these simulations to handle constrained resources or interactions among patients. Conclusions. With DICE simulation, it is possible to expand the Markov formulation to include explicitly many events occurring at various times.
Robert F. Lusch—One of a Kind Scholar and a Macromarketer
Authors: Peterson Mark
Published: July 2017

Robert F. Lusch spoke in a plenary session at the 2015 Macromarketing Conference in Chicago and shared four ideas he felt will have importance to macromarketing scholars in the future. His essay “The Long Macro View” follows. In it, he highlights humans’ innate propensity for 1) engaging in exchange, 2) creating technology, 3) encountering choices with unseen costs, and 4) developing institutions to coordinate interactions with each other. Four macromarketers offer their own comments on this essay: 1) Gene R. Laczniak (who also organized the set of commentaries on “The Long Macro View”), 2) Olga Kravets, 3) Clifford J. Shultz, II, and 4) Roger A. Layton. These commentaries were authored and edited shortly before Bob Lusch passed away.
Breath-hold black-blood T1rho mapping improves liver T1rho quantification in healthy volunteers
Authors: Wáng Yì Xiáng J , Deng Min , Lo Gladys G , Liang Dong , Yuan Jing , Chen Weitian
Published: July 2017

Background

Recent researches suggest that T1rho may be a non-invasive and quantitative technique for detecting and grading liver fibrosis.

Purpose

To compare a multi-breath-hold bright-blood fast gradient echo (GRE) imaging and a single breath-hold single-shot fast spin echo (FSE) imaging with black-blood effect for liver parenchyma T1rho measurement and to study liver physiological T1rho value in healthy volunteers.

Material and Methods

The institutional Ethics Committee approved this study. 28 healthy participants (18 men, 10 women; age = 29.6 ± 5.1 years) underwent GRE liver T1rho imaging, and 20 healthy participants (10 men, 10 women; age = 36.9 ± 10.3 years) underwent novel black-blood FSE liver T1rho imaging, both at 3T with spin-lock frequency of 500 Hz. The FSE technique allows simultaneous acquisition of four spin lock times (TSLs; 1 ms, 10 ms, 30 ms, 50msec) in 10 s.

Results

For FSE technique the intra-scan repeatability intraclass correlation coefficient (ICC) was 0.98; while the inter-scan reproducibility ICC was 0.82 which is better than GRE technique’s 0.76. Liver T1rho value in women tended to have a higher value than T1rho values in men (FSE: 42.28 ± 4.06 ms for women and 39.13 ± 2.12 ms for men; GRE: 44.44 ± 1.62 ms for women and 42.36 ± 2.00 ms for men) and FSE technique showed liver T1rho value decreased slightly as age increased.

Conclusion

Single breath-hold black-blood FSE sequence has better scan–rescan reproducibility than multi-breath-hold bright-blood GRE sequence. Gender and age dependence of liver T1rho in healthy participants is observed, with young women tending to have a higher T1rho measurement.
Multiparametric MRI in men with clinical suspicion of prostate cancer undergoing repeat biopsy: a prospective comparison with clinical findings and histopathology
Authors: Boesen Lars , Nørgaard Nis , Løgager Vibeke , Balslev Ingegerd , Thomsen Henrik S
Published: July 2017

Background

Multiparametric magnetic resonance imaging (mpMRI) can improve detection of clinically significant prostate cancer (csPCa).

Purpose

To compare mpMRI score subgroups to systematic transrectal ultrasound-guided biopsies (TRUSbx) and prostate-specific antigen (PSA)-based findings for detection of csPCa in men undergoing repeat biopsies.

Material and Methods

MpMRI was performed prior to re-biopsy in 289 prospectively enrolled patients. All underwent repeat TRUSbx followed by targeted biopsies (MRITB) of any mpMRI-identified lesion. MpMRI suspicion grade, PSA level, and density (PSAd) were compared with biopsy results and further matched to the radical prostatectomy (RP) specimen if available.

Results

PCa was detected in 128/289 (44%) patients with median age, PSA, and prior negative TRUSbx of 64 (interquartile range [IQR] = 59–67), 12.0 ng/mL (IQR = 8.3–19.1), and 2 (IQR = 1–3), respectively. TRUSbx detected PCa in 108/289 (37%) patients, of which 49 (45%) had insignificant cancer. MRITB was performed in 271/289 (94%) patients and detected PCa in 96 (35%) with 78 (81%) having csPCa. MpMRI scores showed a high association between suspicion level and biopsy results on both lesion and patient level ( P < 0.001). MpMRI was better than PSA and PSAd ( P < 0.001) to identify patients with missed csPCa. In total, 64/128 (50%) patients underwent RP; 60/64 had csPCa. MpMRI was significantly better in predicting csPCa on RP compared with TRUSbx ( P = 0.019) as MRITB and TRUSbx correctly identified 47/60 (78%) and 35/60 (58%) patients, respectively.

Conclusion

MpMRI improves detection of missed csPCa and suspicion scores correlate well with biopsy and RP results on both patient and lesion level.
Altered brain network centrality in patients with adult comitant exotropia strabismus: A resting-state fMRI study
Authors: Tan Gang , Dan Zeng-Renqing , Zhang Ying , Huang Xin , Zhong Yu-Lin , Ye Lin-Hong , Rong Rong , Ye Lei , Zhou Qiong , Shao Yi
Published: July 2017

Objective

To investigate the underlying functional network brain-activity changes in patients with adult comitant exotropia strabismus (CES) and the relationship with clinical features using the voxel-wise degree centrality (DC) method.

Methods

A total of 30 patients with CES (17 men, 13 women), and 30 healthy controls (HCs; 17 men, 13 women) matched in age, sex, and education level participated in the study. DC was used to evaluate spontaneous brain activity. Receiver operating characteristic (ROC) curve analysis was conducted to distinguish CESs from HCs. The relationship between mean DC values in various brain regions and behavioral performance was examined with correlation analysis.

Results

Compared with HCs, CES patients exhibited decreased DC values in the right cerebellum posterior lobe, right inferior frontal gyrus, right middle frontal gyrus and right superior parietal lobule/primary somatosensory cortex (S1), and increased DC values in the right superior temporal gyrus, bilateral anterior cingulate, right superior temporal gyrus, and left inferior parietal lobule. However, there was no correlation between mean DC values and behavioral performance in any brain regions.

Conclusions

Adult comitant exotropia strabismus is associated with abnormal brain network activity in various brain regions, possibly reflecting the pathological mechanisms of ocular motility disorders in CES.
Impairments in the Visual Processing of Global Biological Motion Cues in Down Syndrome
Authors: Riddell Hugh , Tolentino-Castro J. Walter , Wagner Heiko , Lappe Markus
Published: July 2017

Down syndrome (DS) is one of the most common chromosomal disorders and is often associated with a number of motor and cognitive impairments. Little research has been dedicated to investigating the perceptual abilities of individuals with DS. The visual processing of biological motion has been shown to be impaired in DS. It has been proposed that these impairments may stem from an inability to process the global patterns of full-body motion produced by a moving actor; however, this has not been explicitly investigated. We tested groups of participants with and without DS on a task requiring the visual discrimination of point-light walkers from spatially scrambled versions of point-light walkers. Participants with DS demonstrated poorer performance and slower reaction times on the task than healthy controls. From these results, we conclude that biological motion processing is impaired in DS and that this deficit is related to an inability to integrate global configural cues. In a second experiment, individuals with DS were able to discriminate the direction in which laterally translating walkers moved, suggesting that the global motion processing deficit observed in Experiment 1 is specific to biological motion recognition and does not generalise to other types of global motion.
The pathophysiology of episodic cluster headache: Insights from recent neuroimaging research
Authors: Yang Fu-Chi , Chou Kun-Hsien , Kuo Chen-Yuan , Lin Yung-Yang , Lin Ching-Po , Wang Shuu-Jiun
Published: July 2017

Background

Cluster headache is a disorder characterized by intermittent, severe unilateral head pain accompanied by cranial autonomic symptoms. Most cases of CH are episodic, manifesting as “in-bout” periods of frequent headache separated by month-to-year-long “out-of-bout” periods of remission. Previous imaging studies have implicated the hypothalamus and pain matrix in the pathogenesis of episodic CH. However, the pathophysiology driving the transition between in- and out-of-bout periods remains unclear.

Methods

The present study provides a narrative review of previous neuroimaging studies on the pathophysiology of episodic CH, addressing alterations in brain structures, metabolism, and structural and functional connectivity occurring between bout periods.

Results

Although the precise brain structures responsible for episodic CH are unknown, major roles are indicated for the posterior hypothalamus (especially in acute attacks), the pain neuromatrix with an emphasis on central descending pain modulation, and non-traditional pain processing networks including the occipital, cerebellar, and salience networks. These areas are potentially related to dynamic transitioning between in- and out-of-bout periods.

Conclusion

Recent progress in magnetic resonance imaging of episodic CH has provided additional insights into dynamic bout-associated structural and functional connectivity changes in the brain, especially in non-traditional pain processing network areas. These areas warrant future investigations as targets for neuromodulation in patients with CH.
Headache in pediatric and adolescent patients with chronic kidney disease, with and without hemodialysis: A comparative cohort study
Authors: Davidovits Miriam , Eidlitz Markus Tal
Published: July 2017

Background

Several studies have reported dialysis-related headache in adults. We investigated headache and its characteristics in pediatric and adolescent patients with chronic kidney disease and patients treated with dialysis, and compared characteristics of patients with and without headache in the entire cohort and separately among dialysis and among chronic kidney disease patients.

Methods

Patients and their parents who attended a nephrology clinic and hemodialysis unit were interviewed regarding the existence of headache and its characteristics. We reviewed hospital files for medical history, blood test results, and pharmacologic treatment. Headache was defined according to International Headache Society criteria.

Results

The cohort comprised 60 patients: 39 with chronic kidney disease without hemodialysis and 21 treated with hemodialysis; 39 were males, mean age 11.9 ± 5.3 years. Twenty-six (43.3%) reported experiencing headaches. The hemodialysis group had a higher rate of headache than the chronic kidney disease patients, at 76.2% vs. 25.5%, p < 0.001. In the hemodialysis group, 15 out of 16 reported dialysis-related headache; 14 (87.5%) of these had migraine characteristics. For the entire cohort, headache was associated with hemodialysis, chronic kidney disease grade, lower glomerular filtration rate anemia and a higher parathyroid hormone level. In logistic regression analysis, glomerular filtration rate was significantly associated with headache, odds ratio 2.74 (95% CI 1.56–4.82, p < 0.001).

Conclusions

A high rate of headache, mostly migraine type, was reported by hemodialysis patients. Hemodialysis, anemia, higher parathyroid hormone levels, phosphate, and lower glomerular filtration rate are strongly associated with headache among chronic kidney disease pediatric and adolescent patients.
Role of adipocytokines in the pathophysiology of migraine: A cross-sectional study
Authors: Domínguez Clara , Vieites-Prado Alba , Pérez-Mato María , Sobrino Tomás , Rodríguez-Osorio Xiana , López Ana , Campos Francisco , Martínez Francisco , Castillo José , Leira Rogelio
Published: July 2017

Background

Obesity is a risk factor for migraine and headache chronification. Adipocytokines may be involved in this correlation.

Objective

To relate serum adipocytokine levels to clinical and biochemical parameters associated with migraine.

Methods

We measured levels of leptin, adiponectin and other inflammatory (interleukin 6, interleukin 10, tumor necrosis factor α, high sensitivity C-reactive protein) and endothelial (pentraxin 3, soluble TNF-like weak inducer of apoptosis) molecules potentially related to migraine pathophysiology in a group of migraine patients (IHS 2013) and healthy controls.

Results

One hundred and eleven patients (mean age 39.7 years, 93% female) and 24 healthy controls (mean age 35.9 years, 90% female) were included. Fifty-six patients were diagnosed with episodic migraine (mean age 35.1 years, 98.2% female) and 55 patients with chronic migraine (mean age 44.4 years, 89.5% female). Leptin serum levels (15.2 ng/mL, SD = 10.5 vs . 3.1 ng/mL, SD = 0.9; p < 0.001) and adiponectin serum levels (72.3 µg/mL, SD = 38.5 vs . 37.7 µg/mL, SD = 16.9; p < 0.001) were significantly increased in migraine patients. Leptin serum levels (15.5 ng/mL, SD = 9.7 vs . 10.8 ng/mL, SD = 6.0; p < 0.001) and adiponectin serum levels (65.8 µg/mL, SD = 42.9 vs . 33.2 µg/mL, SD = 31.0; p < 0.001) were significantly higher in chronic compared to episodic migraine patients. We found a positive correlation between leptin levels and inflammatory biomarkers: IL6 (r = 0.498; p < 0.001), TNF-α (r = 0.389; p < 0.001), and hs-CRP (r = 0.422; p < 0.001).

Conclusions

Leptin and adiponectin are increased in migraineurs. There is a correlation between adipocytokine levels and other inflammation-related molecules. This suggests a potential role of adipocytokines in migraine pathophysiology and chronification.
Design optimization of molds for autoclave process of composite manufacturing
Authors: Wang Qing , Wang Lingyun , Zhu Weidong , Xu Qiang , Ke Yinglin
Published: July 2017

Autoclave process is widely used in manufacturing processes for thermosetting matrix composite materials. During the process, the non-uniformity of temperature distribution in autoclave may result in non-synchronous curing of composite, which in turn reduces the mechanical properties of composite parts. In order to improve the curing performance, design optimization of autoclave molds has to be performed. In this paper, a finite volume method based numerical model is established to simulate the temperature distribution inside an autoclave and it is verified by known experimental data. Then, a typical mold structure, which is covered with composites and simplified auxiliary materials, is introduced to the numerical model. Moreover, a method which combines the numerical model with the genetic algorithm is presented to optimize design parameters of the substructure of mold with an aim of improving the synchronism of curing. The maximum standard deviation of degree of cure in composite parts is adopted as the objective, while the deformation of the mold under hoisting situation is considered as the constraint. The result shows that the maximum standard deviation of degree of cure in composite parts is improved as much as 17.21%, which indicates that better synchronism of curing is achieved with the presented method.
A review on the polymeric laminates reinforced with natural fibers
Authors: Vinayagamoorthy R
Published: July 2017

The use of composites in industries has become inevitable due to the enhancement in properties, reduction in the manufacturing cost and suitability to several applications. Among the different classifications, polymeric composites are majorly focused for their use as structural components. In a polymeric composite, the selection and composition of reinforcement play a vital role in deciding the characteristics of the composite. Although composites are developed with man-made reinforcement in the beginning stage, in the present scenario, natural reinforcements have proved consummate results in terms of properties. Hence, present day researches are mainly focused on the use of different natural fibers in different forms as reinforcements in polymeric composite. The present study gives a clear picture of various available natural fibers and how they are made in the form of reinforcement for composites. The study also explains the diverse pre-treatment methods used by the researchers for the enhancement of fiber quality. In addition, this review also gives a detailed insight of how the natural fibers are used in the hybrid form for the improvement of composite property.
The Method of Solution of Boundary Three-Dimensional Problems of the Elasticity Theory of Isotropic and Orthotropic Bodies
Authors: Skalozub S. L.
Published: July 2017

The approach described is to solve equation of motion in migrations of elastic orthotropic and isotropic bodies with regard to boundary problems of steady-state oscillations. Assumed equations are trnsformed into Helmholtz equations, to obtain solutions by the method of separation of variables. The comparison is given of the results of determining longitudinal acoustic speed in a thin plate made of isotropic material performing planar resonance oscillations, on the basis of experiments and calculations on wellknown and suggested theories.
Local Fracture and Crack Growth Behavior in a Particulate Composite Material
Authors: Liu C. T. , Ravi-Chandar K.
Published: July 2017

In this study, centrally cracked sheet specimens made from polybutadiene rubber embedded with hard particles were used in crack propagation tests. The precracked specimens were tested at two constant crosshead speeds, 0.58 mm/min and 50.8 mm/min, at room temperature. The effect of crosshead speed on the local fracture and the crack behaviors were investigated and the results are discussed.
Determination of Temperature Variable Properties of Composite Materials: Methodology and Experimental Results
Authors: Bailleul J. -L. , Delaunay D. , Jarny Y.
Published: July 2017

In the present article we discuss a method for the determination of temperature variable properties of composite materials. The method involves thermophysical properties (specific heat and thermal conductivity) and rate of cure. The method is general and based on the combined analysis of heat transfer in thin and thick pieces of material.

A simulation model is then developed to predict the cure response and heat transfer that occur in composite material during fabrication. It is validated by experimental results obtained with an epoxy resin/glass fiber composite.
Symmetric Deformation Analysis of Symmetric Sandwich Plates Including Transverse Shear and Normal Effects
Authors: He Ji-Fan
Published: July 2017

Symmetric deformation analysis of sandwich plates with symmetric and balanced laminated faces and an orthotropic core is presented here. The transverse shear and normal strain and stress effects on symmetric deformation of such sandwich plates are considered. A set of twelfth-order governing equations and consistent boundary conditions are given from a mixed variational theorem. The symmetric deformation of square sandwich plates with fully simple supports subjected to symmetric sinusoidal loading on both surfaces is evaluated. The numerical results are compared with elasticity solutions. The present theory is found to agree approximately with three-dimensional elasticity solutions.
The Influence of Interlaminar Stresses on Fatigue Behaviour of Notched Composite Laminates
Authors: Barboni Renato , Carbonaro Rolando , Scarponi Claudio
Published: July 2017

The influence of the interlaminar stresses on the fatigue behaviour of composite laminates is studied. The present paper is comprised of experimental results and comparison with theoretical results on the delamination onset and propagation. Numerical results are obtained by a specialized computer code which has shown the points where the high intensity of the interlaminar stress tensor components can produce a delamination.

Several tension-tension fatigue tests have been performed on angle-ply and cross-ply centrally holed composite specimens which present the major sensitivity to the interlaminar stresses in order to verify the onset and the propagation of delaminations in the same points revealed by the static analysis.

For the identification of the presence of delaminations an ultrasonic NDI equipment in the form of reflection has been utilized; this system provides a 3D positioning of the delaminations inside the laminates. The experimental results are in good agreement with the theoretical previsions for both the stacking sequences.
The Use of Evanescent Wave Fluorescence Spectroscopy for Control of the Liquid Molding Process
Authors: Woerdeman Dara L. , Flynn Kathleen M. , Dunkers Joy P. , Parnas Richard S.
Published: July 2017

Fluorescence has been demonstrated to be an accurate measurement of resin cure and is measured using an evanescent wave fiber-optic sensor. An economical optical fiber sensor has been developed with a refractive index in excess of 1.6, permitting evanescent wave monitoring of epoxy resins. In this work, the fluorescence wavelength-shift, which has been correlated with monomer conversion, is monitored during the liquid molding process.

A hierarchical control strategy is being developed for liquid molding processes that will use the cure measurement provided by the evanescent wave fluorescence sensor. Single input/single output control loops are implemented at the base level to regulate the mold temperature, the vacuum pressure in the mold, either the inlet flow or pressure during injection, and the final mold pressure. A model-based feedback controller is implemented to control the chemical cure and manipulates the setpoint of the temperature controller to achieve cure control. A general high-level controller is under development to optimize the process under a wide range of operating conditions.
Forced Vibration Analysis of Composite Laminates Using a Discrete Layer Stress Based Model
Authors: Chang C.-J. , Butalia T. S. , Wolfe W. E.
Published: July 2017

Although modern displacement based plate theories are capable of predicting the deflected shape and lower frequencies of a loaded plate with a high degree of precision, their ability to predict stresses, particularly interlaminar stresses, has been poor. A discrete layer stress based theory for composite laminates that assumes a linear distribution of in-plane stresses across each lamina was presented and showed good prediction of interlaminar stresses. The present study extends that work to forced vibration response of a composite plate subjected to a time varying transverse load.
Sublaminate Buckling and Compression Strength of Stitched Uniweave Graphite/Epoxy Laminates
Authors: Sharma S. K. , Sankar B. V.
Published: July 2017

Effects of through-the-thickness stitching on the sublaminate buckling and residual compression strength (often referred as compression-after-impact or CAI strength) of graphite/epoxy uniweave laminates are experimentally investigated. Primarily, three stitching variables: type of stitch yarn, linear density of stitch yarn and stitch density were studied. Delaminations were created by implanting teflon inserts during processing. The improvement in the CAI strength of the stitched laminates was up to 400% compared to the unstitched laminates. Stitching was observed to effectively restrict sublaminate buckling failure of the laminates. The CAI strength increases rapidly with increase in stitch density. It reaches a peak CAI strength that is very close to the compression strength of the undamaged material. All the stitch yarns in this study demonstrated very close performance in improving the CAI strength. It appears that any stitch yarn with adequate breaking strength and stiffness successfully restricts the sublaminate buckling.
Acid Resistance of Glass Fibre Composites with Different Layup Sequencing Part II: Degradation Studies
Authors: Pai Raghavendra , Kamath M. S. , RAO R. M. V. G. K.
Published: July 2017

The degradative effects of sulphuric acid on glass fibre composites with different layup sequencing were studied by monitoring the changes in the Inter Laminar Shear Strength (ILSS) using short beam shear specimens. The composite specimens used for the diffusion studies in Part I were chosen for the degradation studies. The results of the studies indicated that isopthalic polyester resin composites retained maximum percentage of Inter Laminar Shear Strength, while those of the General Purpose Resin showed higher degradation. The degradation increased as the concentration of the sulphuric acid was increased, indicating that degradation was a dominant phenomenon at higher concentrations. The weave compactness of woven roving type glass reinforcement which formed the face skin in the case of composites of sequential layup C accounted for better performance of these composites in Sulphuric acid environment, while the presence of a loosely bonded chopped strand mat as the skin in composites of sequential layup A caused higher degradation.