bluuebunny/crossref_metadata_2025 huggingface dataset:
Pharmacokinetics of high‐dose intravenous melatonin in humans
Authors: Andersen Lars P. H. , Werner Mads U. , Rosenkilde Mette M. , Fenger Andreas Q. , Petersen Marian C. , Rosenberg Jacob , Gögenur Ismail
Published: July 2015

This crossover study investigated the pharmacokinetics and adverse effects of high‐dose intravenous melatonin. Volunteers participated in 3 identical study sessions, receiving an intravenous bolus of 10 mg melatonin, 100 mg melatonin, and placebo. Blood samples were collected at baseline and 0, 60, 120, 180, 240, 300, 360, and 420 minutes after the bolus. Quantitative determination of plasma melatonin concentrations was performed using a radioimmunoassay technique. Pharmacokinetic parameters were estimated by a compartmental pharmacokinetic analysis. Adverse effects included assessments of sedation and registration of other symptoms. Sedation, evaluated as simple reaction times, was measured at baseline and 120, 180, 300, and 420 minutes after the bolus. Twelve male volunteers completed the study. Median (IQR) Cmax after the bolus injections of 10 mg and 100 mg of melatonin were 221,500.0 (185,637.5–326,175.0) pg/mL and 1,251,500.0 (864,375.0–1,770,500.0) pg/mL, respectively; mean (SD) t1/2 was 42.3 (5.6) minutes and 46.2 (6.2) minutes; mean (SD) Vd was 1.6 (0.9) L/kg and 2.0 (0.8) L/kg; mean (SD) CL was 0.0253 (0.0096) L/min · kg and 0.0300 (0.0120) L/min · kg; and median (IQR) AUC0‐∞, 8,997,633.0 (6,071,696.2–11,602,811.9) pg · min/mL and 54,685,979.4 (36,028,638.6–105,779,612.0) pg · min/mL. High‐dose intravenous melatonin did not induce sedation, evaluated as simple reaction times. No adverse effects were reported in the study.
The Political Economy of Africa's Emergent Middle Class: Retrospect and Prospects
Authors: Resnick Danielle
Published: July 2015

This special issue introduction provides a historical perspective in order to contextualize the political economy of Africa's emergent middle class. In doing so, three overarching research questions are discussed to better understand the middle class' transformative potential. First, who constitute Africa's middle class and how has this concept changed over time? Second, what dynamics explain the growth of this group? Third, what are the implications of the middle class for good governance and pro‐poor policies? The contributions of each of the articles in the special issue to answering these specific questions for Africa's contemporary middle class are then briefly discussed. © 2015 The Authors. Journal of International Development published by John Wiley & Sons, Ltd.
Feasibility of a reduced field‐of‐view diffusion‐weighted (rFOV) sequence in assessment of myometrial invasion in patients with clinical FIGO stage I endometrial cancer
Authors: Bhosale Priya , Ma Jingfei , Iyer Revathy , Ramalingam Preetha , Wei Wei , Soliman Pamela , Frumovitz Michael , Kundra Vikas
Published: July 2015

Purpose

To compare the clinical usefulness of reduced field‐of‐view diffusion‐weighted imaging (rFOV) with other imaging techniques in determining the depth of myometrial invasion (DMI) in endometrial cancer.

Materials and Methods

In this prospective study we reviewed 3T magnetic resonance images of 51 patients with clinical Stage I endometrial cancer who underwent total abdominal hysterectomy with bilateral salphingoopherectomy within 3 days after imaging. rFOV with apparent diffusion coefficient reconstruction was obtained in three standard planes followed by sagittal T2‐weighted (T2WI) images and 3D dynamic T1‐weighted and contrast‐enhanced imaging (DCE MRI). Two radiologists with expertise in imaging gynecologic cancers evaluated images independently. The DMI was recorded on imaging and correlated with surgical pathology results. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for DMI were calculated (<50% vs. >50%).

Results

Compared with sagittal T2WI + DCE MRI, rFOV imaging yielded greater specificity (82.2% vs. 90.0%, positive predictive value (42.8% vs. 60.0%), and accuracy (84.0% vs. 92%) for DMI determined by reader 1 and greater the sensitivity (83.3% vs. 100%) for DMI determined by reader 2. The error of measurement of DMI as a continuous variable in millimeters did not differ significantly between the rFOV and pathology results (P < 0.21). However, there was a statistically significant difference for the DMI measured on the dynamic sequence. The DMI on DCE was greater than that seen on pathology at P = 0.02.

Conclusion

rFOV can be used to assess DMI in clinical Stage I endometrial cancer. J. Magn. Reson. Imaging 2016;43:316–324.
Apparent diffusion coefficient (ADC) measurements in pancreatic adenocarcinoma: A preliminary study of the effect of region of interest on ADC values and interobserver variability
Authors: Ma Chao , Liu Li , Li Jing , Wang Li , Chen Lu‐guang , Zhang Yong , Chen Shi‐yue , Lu Jian‐ping
Published: July 2015

Purpose

To assess the influence of region of interest (ROI) on tumor apparent diffusion coefficient (ADC) measurements and interobserver variability in pancreatic ductal adenocarcinoma (PDAC).

Materials and Methods

Twenty‐two patients recruited with pathology‐proven PDAC underwent diffusion‐weighted imaging (DWI, 3.0T) prior to the surgical resection. Two independent readers measured tumor ADCs according to three ROI methods: whole‐volume, single‐slice, and small solid sample of tumor. Minimum and mean ADCs were obtained. The interobserver variability for each of the three methods was analyzed using interclass correlation coefficient (ICC) and Bland–Altman analysis. The minimum and mean ADCs among the ROI methods were compared using nonparametric tests.

Results

The single‐slice ROI method showed the best reproducibility in the minimum ADC measurements (mean difference ± limits of agreement between two readers were 0.025 ± 0.25 × 10−3 mm2/s; ICC, 0.92) among the three ROI methods. For the solid tumor sample ROI, both minimum ADC and mean ADC measurements reproducibility were the worst, with limits of agreement up to ±0.50 × 10−3 mm2/s and ±0.32 × 10−3 mm2/s, respectively (ICCs, 0.41/0.58). Both the minimum and mean ADCs demonstrated significant differences among the three ROI methods (both P < 0.001). The post‐hoc analyses results showed no significant difference with regard to the mean ADCs between whole‐volume and single‐slice ROI methods (P = 0.14).

Conclusion

The ROI method had a considerable influence on both the minimum and mean ADC values and the interobserver variability in PDAC. The worst interobserver variability was observed for both the minimum and mean ADCs derived from small solid‐sample ROI. J. Magn. Reson. Imaging 2016;43:407–413.
Potential for Southern Hemisphere climate surprises
Authors: MAYEWSKI P. A. , BRACEGIRDLE T. , GOODWIN I. , SCHNEIDER D. , BERTLER N. A. N. , BIRKEL S. , CARLETON A. , ENGLAND M. H. , KANG J‐H. , KHAN A. , RUSSELL J. , TURNER J. , VELICOGNA I.
Published: July 2015

Climate model results suggest that future climate change in Antarctica will be accompanied by continued strengthening and poleward contraction of the Southern Ocean westerly wind belt. Paleoclimate records suggest past changes in the westerly winds can be abrupt and that healing of the Antarctic ozone hole could lead to poleward contraction of the westerlies and increased meridional atmospheric transport of warm air regionally into Antarctica. An abrupt shift to more meridional circulation could lead to notable changes in moisture availability for extra‐Antarctic regions, increased Antarctic ice sheet disintegration and more rapid sea‐level rise.
Conidia survival of Aspergillus section Nigri, Flavi and Circumdati under UV‐A and UV‐B radiation with cycling temperature/light regime
Authors: García‐Cela Maria Esther , Marín Sonia , Reyes Monica , Sanchis Vicent , Ramos Antonio J
Published: July 2015

BACKGROUND

Bio‐geographical differences in fungal infection distribution have been observed around the world, confirming that climatic conditions are decisive in colonization. This research is focused on the impact of ultraviolet radiation (UV) on Aspergillus species, based on the consideration that an increase in UV‐B radiation may have large ecological effects.

RESULTS

Conidia of six mycotoxigenic Aspergillus species isolated from vineyards located in the northeast and south of Spain were incubated for 15 days under light/dark cycles and temperatures between 20 and 30 °C per day. Additionally, 6 h of exposure to UV‐A or UV‐B radiation per day were included in the light exposure. UV irradiance used were 1.7 ± 0.2 mW cm−2 of UV‐A (peak 365 nm) and 0.10 ± 0.2 mW cm−2 of UV‐B (peak 312 nm). The intrinsic decrease in viability of conidia over time was accentuated when they were UV irradiated. UV‐B radiation was more harmful.

CONCLUSION

Conidial sensitivity to UV light was marked in Aspergillus section Circumdati. Conidia pigmentation could be related to UV sensitivity. Different resistance was observed within species belonging to sections Flavi and Nigri. An increase in UV radiation could lead to a reduction in the Aspergillus spp. inoculum present in the field (vineyards, nuts, cereal crops). In addition, it could unbalance the spore species present in the field, leading to a higher predominance of dark‐pigmented conidia. © 2015 Society of Chemical Industry
KCl‐induced high temperature corrosion of selected commercial alloys
Authors: Kiamehr S. , Dahl K. V. , Montgomery M. , Somers M. A. J.
Published: July 2015

Laboratory testing of selected chromia‐forming alloys was performed to rank the materials and gain further knowledge on the mechanism of KCl‐induced high temperature corrosion. The investigated alloys were stainless steels EN1.4021, EN1.4057, EN1.4521, TP347H (coarse‐grained), TP347HFG (fine‐grained), Sanicro 28 and the nickel‐based alloys 625, 263 and C276. Exposure was performed at 600 °C for 168 h in flowing N2(g)+5%O2(g)+15% H2O(g) (vol.%). Samples were covered with KCl powder prior to exposure. A salt‐free exposure was also performed for comparison. Corrosion morphology and products were studied with scanning electron microscopy (SEM), energy dispersive X‐ray spectroscopy (EDS) and X‐ray diffractometry (XRD). It was observed that in the salt‐free exposure, stainless steels TP347H (coarse‐grained) and EN1.4521 failed to form a thin protective oxide layer compared to the oxide formed on the other alloys. In the presence of solid KCl, all the alloys showed significant corrosion. Measurement of corrosion extent indicated that alloys EN1.4057, Sanicro 28 and 625 show a better performance compared to the industrial state of the art material TP347HFG under laboratory conditions. An additional test was performed with KCl vapor in static air for the same duration and at the same temperature. This was undertaken to investigate the role of the vapor phase and revealed that KCl vapor at 600 °C can initiate attack.
Music‐based magnetic resonance fingerprinting to improve patient comfort during MRI examinations
Authors: Ma Dan , Pierre Eric Y. , Jiang Yun , Schluchter Mark D. , Setsompop Kawin , Gulani Vikas , Griswold Mark A.
Published: July 2015

Purpose

Unpleasant acoustic noise is a drawback of almost every MRI scan. Instead of reducing acoustic noise to improve patient comfort, we propose a technique for mitigating the noise problem by producing musical sounds directly from the switching magnetic fields while simultaneously quantifying multiple important tissue properties.

Theory and Methods

MP3 music files were converted to arbitrary encoding gradients, which were then used with varying flip angles and repetition times in a two‐ and three‐dimensional magnetic resonance fingerprinting (MRF) examination. This new acquisition method, named MRF‐Music, was used to quantify T1, T2, and proton density maps simultaneously while providing pleasing sounds to the patients.

Results

MRF‐Music scans improved patient comfort significantly during MRI examinations. The T1 and T2 values measured from phantom are in good agreement with those from the standard spin echo measurements. T1 and T2 values from the brain scan are also close to previously reported values.

Conclusions

MRF‐Music sequence provides significant improvement in patient comfort compared with the MRF scan and other fast imaging techniques such as echo planar imaging and turbo spin echo scans. It is also a fast and accurate quantitative method that quantifies multiple relaxation parameters simultaneously. Magn Reson Med 75:2303–2314, 2016. © 2015 Wiley Periodicals, Inc.
A case of neuromyotonia and axonal motor neuropathy: A report of a HINT1 mutation in the United States
Authors: Jerath Nivedita U. , Shy Michael E. , Grider Tiffany , Gutmann Ludwig
Published: July 2015

Introduction: HINT1 mutations cause an autosomal recessive distal hereditary motor axonal neuropathy with neuromyotonia. This is a case report of a HINT1 mutation in the United States. Methods: A 30‐year‐old man of Slovenian heritage and no significant family history presented with scoliosis as a child and later developed neuromyotonia and distal weakness. Electrodiagnostic testing revealed an axonal motor neuropathy and neuromyotonic discharges. Previous diagnostic work‐up, including testing for Cx32, MPZ, PMP‐22, NF‐L, EGR2, CLCN1, DM1, DM2, SMN exon 7/8, emerin, LMNA, MPK, SCNA4, acid maltase gene, paraneoplastic disorder, and a sural nerve biopsy, was negative. Results: Genetic testing for a HINT1 mutation was performed and revealed a homozygous mutation at p.Arg37Pro. Conclusion: This entity should be distinguished clinically and genetically from myotonic dystrophy and channelopathies with the clinical features of neuromyotonia and an axonal neuropathy. This case illustrates the importance of identifying the correct phenotype to avoid unnecessary and costly evaluations. Muscle Nerve 52: 1110–1113, 2015
A statistical clustering approach to discriminating perfusion from conduit vessel signal contributions in a pulmonary ASL MR image
Authors: Walker Shane C. , Asadi Amran K. , Hopkins Susan R. , Buxton Richard B. , Prisk G. K.
Published: July 2015

The measurement of pulmonary perfusion (blood delivered to the capillary bed within a voxel) using arterial spin labeling (ASL) magnetic resonance imaging is often complicated by signal artifacts from conduit vessels that carry blood destined for voxels at a distant location in the lung. One approach to dealing with conduit vessel contributions involves the application of an absolute threshold on the ASL signal. While useful for identifying a subset of the most dominant high signal conduit image features, signal thresholding cannot discriminate between perfusion and conduit vessel contributions at intermediate and low signal. As an alternative, this article discusses a data‐driven statistical approach based on statistical clustering for characterizing and discriminating between capillary perfusion and conduit vessel contributions over the full signal spectrum. An ASL flow image is constructed from the difference between a pair of tagged magnetic resonance images. However, when viewed as a bivariate projection that treats the image pair as independent measures (rather than the univariate quantity that results from the subtraction of the two images), the signal associated with capillary perfusion contributions is observed to cluster independently of the signal associated with conduit vessel contributions. Analyzing the observed clusters using a Gaussian mixture model makes it possible to discriminate between conduit vessel and capillary‐perfusion‐dominated signal contributions over the full signal spectrum of the ASL image. As a demonstration of feasibility, this study compares the proposed clustering approach with the standard absolute signal threshold strategy in a small number of test images. Copyright © 2015 John Wiley & Sons, Ltd.
Genome‐wide analysis of the oxyntic proliferative isthmus zone reveals ASPM as a possible gastric stem/progenitor cell marker over‐expressed in cancer
Authors: Vange Pål , Bruland Torunn , Beisvag Vidar , Erlandsen Sten Even , Flatberg Arnar , Doseth Berit , Sandvik Arne K , Bakke Ingunn
Published: July 2015

The oxyntic proliferative isthmus zone contains the main stem/progenitor cells that provide for physiological renewal of the distinct mature cell lineages in the oxyntic epithelium of the stomach. These cells are also proposed to be the potential cells‐of‐origin of gastric cancer, although little is known about their molecular characteristics and specific biological markers are lacking. In this study, we developed a method for serial section‐navigated laser microdissection to isolate cells from the proliferative isthmus zone of rat gastric oxyntic mucosa for genome‐wide microarray gene expression analysis. Enrichment analysis showed a distinct gene expression profile for the isthmus zone, with genes regulating intracellular processes such as the cell cycle and ribosomal activity. The profile was also related to stem cell transcriptional networks and stomach neoplasia. Genes expressed uniquely in the isthmus zone were associated with E2F transcription factor 1 (E2F1), which participates in the self‐renewal of stem cells and in gastric carcinogenesis. One of the unique genes was Aspm [Asp (abnormal spindle) homologue, microcephaly‐associated (Drosophila)]. Here we show ASPM in single scattered epithelial cells located in the proliferative isthmus zone of rat, mouse and human oxyntic mucosa, which do not seem to be actively dividing. The ASPM‐expressing cells are mainly mature cell marker‐deficient, except for a limited overlap with cells with neuroendocrine and tuft cell features. Further, both ASPM and E2F1 were expressed in human gastric cancer cell lines and increased and correlated in human gastric adenocarcinomas compared to non‐tumour mucosa, as shown by expression profile analyses and immunohistochemistry. The association between ASPM and the transcription factor E2F1 in gastric tissue is relevant, due to their common involvement in crucial cell fate‐regulatory mechanisms. Our results thus introduce ASPM as a novel possible oxyntic stem/progenitor cell marker that may be involved in both normal gastric physiology and gastric carcinogenesis. © 2015 Authors. Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.
Effects of a 6‐Month, Group‐Based, Therapeutic Exercise Program for Childhood Cancer Outpatients on Motor Performance, Level of Activity, and Quality of Life
Authors: Beulertz Julia , Prokop Aram , Rustler Vanessa , Bloch Wilhelm , Felsch Moritz , Baumann Freerk T.
Published: July 2015

Background

Exercise interventions in pediatric oncology are feasible and safe. However, scarce data are available with regard to the effectiveness of outpatient, group‐based exercise interventions. As well, the potential role of exercise to improve motor performance has not been adequately explored despite being a meaningful outcome during childhood with important implications for physical activity behavior. No study has yet demonstrated significant changes in motor performance after an exercise intervention.

Procedures

This explorative, prospective study was designed to evaluate the effects of a 6‐month, group‐based, therapeutic exercise program for a mixed childhood cancer population on motor performance, level of activity, and quality of life. After cessation of inpatient medical treatment, childhood cancer outpatients aged 4–17 years exercised once a week during a 6‐month period (IG). Comparison groups included childhood cancer outpatients receiving care as usual (CG1), as well as healthy peers (matched to IG by age and gender) (CG2).

Results

Overall motor performance, various motor dimensions, activity in sport clubs and school sports, as well as physical and emotional well‐being were significantly reduced in the IG at baseline. Significant differences between the IG and CG1 and/or CG2 were identified in the change of overall motor performance, single motor dimensions, overall level of activity, and emotional well‐being from baseline to post‐intervention.

Conclusions

The exercise intervention was beneficial in terms of motor performance, level of activity, and emotional well‐being. As such, this study provides support for group‐based exercise as a potential strategy to improve these outcomes after inpatient medical treatment. Pediatr Blood Cancer © 2015 Wiley Periodicals, Inc.
Effect of chemical treatment on the properties of coir fiber reinforced polypropylene and polyethylene composites
Authors: Sultana Mir Samia , Hasan Mahbub , Hasan Syed M.N. , Hossain Md. Jahangir , Nafsin Nazia
Published: July 2015

Chemical treatment of reinforcement material is one of the main ways of improving the mechanical properties of natural fiber reinforced polymer composites. In the present study, coir fiber was used as reinforcement material, while polypropylene (PP) and polyethylene (PE) polymer were used as matrix material. Before reinforcing with polymer, raw coir fiber was chemically treated with basic chromium sulfate and sodium bicarbonate in a sieve shaker. Hot‐pressed method was used for composite manufacturing during which the fiber loading was varied at 0, 5, 10, 15, and 20 wt%. Comparison of the properties of raw and chemically treated coir fiber reinforced PP and PE was conducted. Mechanical characteristics of the composites were evaluated using tensile, flexural, impact, and hardness tests. Water absorption test was conducted to know water uptake characteristics. Microstructural analysis using a scanning electron microscope was performed to observe the adhesiveness between the matrix and the fiber. Thermogravimetric analysis was done to observe the physical and chemical changes in fiber and composites. The results showed that chemical treatment improved the physical, mechanical, and thermal properties of the manufactured composites. PP composites had better properties as compared to PE composites, while higher fiber loading resulted in better mechanical properties of the resultant composites. POLYM. COMPOS., 38:1259–1265, 2017. © 2015 Society of Plastics Engineers
Polypropylene/nTiO2 nanocomposites using melt mixing and its investigation on mechanical and thermal properties
Authors: Shimpi Navinchandra , Shirole Sharada , Mishra Satyendra
Published: July 2015

This study investigates the preparation of nTiO2 particle using green chemistry approach and its subsequent effect on the properties of isotactic polypropylene (iPP) nanocomposites, which is one of the most suited thermoplastic polymer. The nanocomposite of iPP with TiO2 nanoparticle (0.5, 1, 1.5, 2, and 2.5 wt%) were prepared on Brabender plasticorder, which was then subjected to injection molding to get a dumbbell‐shape specimens. Meanwhile, TiO2 nanoparticles (nTiO2) were prepared using ultrasonic cavitation technique using leaf extract of Murraya koenigii. The extraction of leaf was carried out using distilled water as a solvent. The size and shape of nTiO2 particle was confirmed using transmission electron microscope and found to be spherical shape of diameter ∼10–45 nm. The mechanical properties of nTiO2 reinforced iPP composites were studied using universal testing machine. Moreover, thermal properties were studied using Vicat softening temperature, thermogravimetric analyzer, and differential scanning calorimeter. The extent of dispersion of nTiO2 in iPP matrix was studied using field‐emission scanning electron microscope and X‐ray diffractometer. The mechanical and thermal properties of nTiO2‐iPP composites were found to be improved significantly with increasing amount of nTiO2 particles except elongation at break, which is a marginal increment. This improvement in properties (mechanical and thermal) was due to the uniform dispersion of nTiO2 in iPP matrix, which means that chains of polymers were well adhered with the spherical shaper particles. POLYM. COMPOS., 38:1273–1279, 2017. © 2015 Society of Plastics Engineers
Experimental investigation and numerical simulation of granite powder filled polymer composites for wind turbine blade: A comparative analysis
Authors: Pawar M.J. , Patnaik Amar , Nagar Ravindra
Published: July 2015

This paper describes the mechanical, thermo‐mechanical, and thermal behavior of unfilled E‐glass fiber (10–50 wt%) reinforced polymer (GFRP) composites and granite powder filled (8–24 wt%) GFRP composite in different weight percentages, respectively. The void fraction of unfilled glass epoxy composite is decreased from 7.71% to 3.17% with the increase in fiber loading from 10 to 50 wt%. However, void fraction for granite powder filled GFRP composites show reverse in trend. The granite powder addition in glass‐epoxy composites show significant improvement in hardness (37–47 Hv), impact strength (31.56–37.2 kJ/m2), and stress intensity factor (by 14.29% for crack length of 5 mm) of the composites. The thermo‐mechanical analyses also show strong correlation with the mechanical performance of the composites. The minimum difference of 0.17 GPa in storage and flexural moduli are observed for unfilled 20 wt% glass epoxy composite; whereas, maximum difference of 0.71 GPa is recorded for unfilled 50 wt% glass epoxy composite. Moreover, the numerical and experimentally measured thermal conductivity of unfilled and granite powder filled epoxy composites are within the lower and upper bound values. Hence, a successful attempt is presented for mechanical analysis of full scale model by finite element analysis. The results show that finite element analysis predicted reasonably actual stress value and tip deflection of wind turbine blade. POLYM. COMPOS., 38:1335–1352, 2017. © 2015 Society of Plastics Engineers
Influence of alkali treatment on flax fiber for use as reinforcements in polylactide stereocomplex composites
Authors: Zhang Huihui , Ming Ruihao , Yang Gesheng , Li Yuzeng , Li Qiao , Shao Huili
Published: July 2015

The flax and equivalent proportion of poly(l‐lactic acid)/poly(d‐lactic acid) (PLLA/PDLA) were melt compounded and injection molded to prepare flax‐reinforced polylactide stereocomplex (sc‐PLA) bio‐composite, and the effect of alkali treatment on the structure and properties of flax as well as the flax/sc‐PLA composite was investigated. SEM and FTIR results showed hemicellulose in flax was almost completely removed after alkali treatment and the treated flax (ALK‐flax) bundles were more separated with a cleaner surface than untreated flax (UN‐flax). DSC results showed homo‐crystallites (hc, Tm = 160–170°C) and stereocomplex crystallites (sc, Tm ∼210°C) coexisted in sc‐PLA and flax/sc‐PLA composites. Compared with sc‐PLA, the total crystallinity and sc‐crystallinity of flax/sc‐PLA composite increased regardless of whether the flax were treated with alkali, whereas ALK‐flax/sc‐PLA composite showed a little higher crystallinity than UN‐flax/sc‐PLA composite. TGA results confirmed ALK‐flax/sc‐PLA composite had a higher thermal degradation temperature than UN‐flax/sc‐PLA composite. The mechanical tests indicated although the mechanical properties of sc‐PLA increased significantly by reinforcing with flax, the ALK‐flax/sc‐PLA composite showed little lower mechanical properties than UN‐flax/sc‐PLA composite. The alkali treatment of flax had no obvious influence on the Vicat softening temperature (VST) of flax/sc‐PLA composites, a higher heat resistance with VST at ∼155°C could be obtained for flax/sc‐PLA composite. POLYM. ENG. SCI., 55:2553–2558, 2015. © 2015 Society of Plastics Engineers
Quantification of SAA1 and SAA2 in lung cancer plasma using the isotype‐specific PRM assays
Authors: Kim Yeoun Jin , Gallien Sebastien , El‐Khoury Victoria , Goswami Panchali , Sertamo Katriina , Schlesser Marc , Berchem Guy , Domon Bruno
Published: July 2015

The quantification of plasma proteins using the high resolution and accurate mass (HR/AM)‐based parallel reaction monitoring (PRM) method provides an immediate benefit over the conventional SRM‐based method in terms of selectivity. In this study, multiplexed PRM assays were developed to analyze isotypes of serum amyloid A (SAA) proteins in human plasma with a focus on SAA1 and SAA2. Elevated plasma levels of these proteins in patients diagnosed with lung cancer have been reported in previous studies. Since SAA1 and SAA2 are highly homologous, the available immunoassays tend to overestimate their concentrations due to cross‐reactivity. On the other hand, when mass spectrometry (MS)‐based assays are used, the presence of the several allelic variants may result in a problem of underestimation. In the present study, eight peptides that represent the target proteins at three different levels: isotype‐specific (SAA1α,  SAA 1β,  SAA1γ,  SAA2α,  SAA2β), protein‐specific (SAA1 or SAA2), and pan SAA (SAA1 and SAA2) were chosen to differentiate SAAs in lung cancer plasma samples using a panel of PRM assays. The measurement of specific isotypes, leveraging the analytical performance of PRM, allowed to quantify the allelic variants of both target proteins. The isotypes detected were corroborated with the genetic information obtained from the same samples. The combination of SAA2α and SAA2β assays representing the total SAA2 concentration demonstrated a superior analytical outcome than the previously used assay on the common peptide when applied to the detection of lung cancer.
Hydroxylamine synthesis by oxygen insertion into ReNH2 bond via Baeyer–Villiger oxidation: a Theoretical study
Authors: Baskaran Sambath , Sivasankar Chinnappan
Published: July 2015

A novel scheme has been proposed by computational methods (B3LYP and CCSD(T)) to produce hydroxylamine under normal experimental conditions using [O3Re‐(NH2)] and H2O2 under basic conditions. This particular reaction may proceed similar to Baeyer–Villiger oxidation and μ‐peroxo type pathways to insert oxygen into the ReNH2 bond to yield NH2OH; nevertheless, Baeyer–Villiger type oxidation is seems to be more viable. The calculated energy barriers further revealed that the introduction of different solvent medium does not affect significantly the energies of intermediates and transition state molecules. The calculated Gibbs free energies show that this reaction is perhaps viable experimentally to produce NH2OH from the our choice of reagents. Copyright © 2015 John Wiley & Sons, Ltd.
Electrostatics, structure prediction, and the energy landscapes for protein folding and binding
Authors: Tsai Min‐Yeh , Zheng Weihua , Balamurugan D. , Schafer Nicholas P. , Kim Bobby L. , Cheung Margaret S. , Wolynes Peter G.
Published: July 2015

While being long in range and therefore weakly specific, electrostatic interactions are able to modulate the stability and folding landscapes of some proteins. The relevance of electrostatic forces for steering the docking of proteins to each other is widely acknowledged, however, the role of electrostatics in establishing specifically funneled landscapes and their relevance for protein structure prediction are still not clear. By introducing Debye‐Hückel potentials that mimic long‐range electrostatic forces into the Associative memory, Water mediated, Structure, and Energy Model (AWSEM), a transferable protein model capable of predicting tertiary structures, we assess the effects of electrostatics on the landscapes of thirteen monomeric proteins and four dimers. For the monomers, we find that adding electrostatic interactions does not improve structure prediction. Simulations of ribosomal protein S6 show, however, that folding stability depends monotonically on electrostatic strength. The trend in predicted melting temperatures of the S6 variants agrees with experimental observations. Electrostatic effects can play a range of roles in binding. The binding of the protein complex KIX‐pKID is largely assisted by electrostatic interactions, which provide direct charge‐charge stabilization of the native state and contribute to the funneling of the binding landscape. In contrast, for several other proteins, including the DNA‐binding protein FIS, electrostatics causes frustration in the DNA‐binding region, which favors its binding with DNA but not with its protein partner. This study highlights the importance of long‐range electrostatics in functional responses to problems where proteins interact with their charged partners, such as DNA, RNA, as well as membranes.
Diffusion accessibility as a method for visualizing macromolecular surface geometry
Authors: Tsai Yingssu , Holton Thomas , Yeates Todd O.
Published: July 2015

Important three‐dimensional spatial features such as depth and surface concavity can be difficult to convey clearly in the context of two‐dimensional images. In the area of macromolecular visualization, the computer graphics technique of ray‐tracing can be helpful, but further techniques for emphasizing surface concavity can give clearer perceptions of depth. The notion of diffusion accessibility is well‐suited for emphasizing such features of macromolecular surfaces, but a method for calculating diffusion accessibility has not been made widely available. Here we make available a web‐based platform that performs the necessary calculation by solving the Laplace equation for steady state diffusion, and produces scripts for visualization that emphasize surface depth by coloring according to diffusion accessibility. The URL is http://services.mbi.ucla.edu/DiffAcc/.
Evaluating the dynamics and electrostatic interactions of folded proteins in implicit solvents
Authors: Hua Duy P. , Huang He , Roy Amitava , Post Carol Beth
Published: July 2015

Three implicit solvent models, namely GBMVII, FACTS, and SCPISM, were evaluated for their abilities to emulate an explicit solvent environment by comparing the simulated conformational ensembles, dynamics, and electrostatic interactions of the Src SH2 domain and the Lyn kinase domain. This assessment in terms of structural features in folded proteins expands upon the use of hydration energy as a metric for comparison. All‐against‐all rms coordinate deviation, average positional fluctuations, and ion‐pair distance distribution were used to compare the implicit solvent models with the TIP3P explicit solvent model. Our study shows that the Src SH2 domains solvated with TIP3P, GBMVII, and FACTS sample similar global conformations. Additionally, the Src SH2 ion‐pair distance distributions of solvent‐exposed side chains corresponding to TIP3P, GBMVII, and FACTS do not differ substantially, indicating that GBMVII and FACTS are capable of modeling these electrostatic interactions. The ion‐pair distance distributions of SCPISM are distinct from others, demonstrating that these electrostatic interactions are not adequately reproduced with the SCPISM model. On the other hand, for the Lyn kinase domain, a non‐globular protein with bilobal structure and a large concavity on the surface, implicit solvent does not accurately model solvation to faithfully reproduce partially buried electrostatic interactions and lobe‐lobe conformations. Our work reveals that local structure and dynamics of small, globular proteins are modeled well using FACTS and GBMVII. Nonetheless, global conformations and electrostatic interactions in concavities of multi‐lobal proteins resulting from simulations with implicit solvent models do not match those obtained from explicit water simulations.
Enhancement of light absorption by using light scattering and emitting dyes in organic photovoltaics
Authors: Kim Kangmin , Jung Buyoung , Eom Yoomin , Kim Woochul
Published: July 2015

To enhance the power conversion efficiency of organic photovoltaics (OPVs), sufficient light absorption in the active layer is necessary to generate a greater number of excitons. We propose incorporating luminescent dyes into hole transport layer of OPVs as a route of enhancing light absorption, minimizing changes in the morphology and structure of the active layer; dyes scatter incoming collimated light isotropically, thereby increasing the distance light travels in the active layer, which leads to enhanced light absorption. In addition, dyes can absorb light in the portion of the spectrum where the active layer is transparent and re‐emit light in the portion of the spectrum corresponding to the absorption peak of the active layer. Coumarin 102 (C102) is a dye that has an absorption wavelength of 389 nm, which corresponds to the weakest absorption region of P3HT:PCBM blends. C102 is then able to isotropically re‐emit visible light, in the region that corresponds to the absorption spectrum of P3HT, into the active layer. Based on this effect, we demonstrate that the short circuit current density can be increased by 22.8% compared to the reference sample without any dye.
Design of networked freeway traffic controllers based on event‐triggered control concepts
Authors: Ferrara Antonella , Sacone Simona , Siri Silvia
Published: July 2015

In this paper, an event‐triggered model predictive networked scheme is proposed to control traffic in freeway networks. The freeway network is a spatially distributed system in which sensors and actuators act locally on portions of the overall system; measurements and control actions are transmitted to/from the feedback controllers via a shared communication network. In this sense, the considered plant can be properly controlled by relying on a design framework typical of networked control systems, a major feature of which is the necessity of taking care of both the computational effort and the communication effort. The proposed control scheme allows to reduce the computational load with a feedback model predictive controller in which suitable triggering conditions are defined. As for the communication effort, local triggering conditions are included in sensors, inducing transmissions of the system state only when such conditions are verified. The robustness properties of the controlled system are investigated in the paper by analyzing the input‐to‐state practical stability of the plant under the action of the proposed control strategy. The effectiveness of this proposal is also analyzed via simulation. Copyright © 2015 John Wiley & Sons, Ltd.
Joint estimation of multiple disease‐specific sensitivities and specificities via crossed random effects models for correlated reader‐based diagnostic data: application of data cloning
Authors: Withanage Niroshan , de Leon Alexander R. , Rudnisky Christopher J.
Published: July 2015

We present a model for describing correlated binocular data from reader‐based diagnostic studies, where the same group of readers evaluates the presence or absence of certain diseases on binocular organs (e.g., fellow eyes) of patients. Multiple random effects are incorporated to meaningfully delineate various associations in the data including crossed random effects to account for reader‐specific variability and to incorporate cross correlations. To overcome the computational complexity involved in the evaluation and maximization of the marginal likelihood, we adopt the data cloning approach, which calculates maximum likelihood estimates under the Bayesian paradigm. The bias and efficiency of the estimates are assessed in two simulation studies. We apply our model to data from a diabetic retinopathy study. Copyright © 2015 John Wiley & Sons, Ltd.
Joint multiple imputation for longitudinal outcomes and clinical events that truncate longitudinal follow‐up
Authors: Hu Bo , Li Liang , Greene Tom
Published: July 2015

Longitudinal cohort studies often collect both repeated measurements of longitudinal outcomes and times to clinical events whose occurrence precludes further longitudinal measurements. Although joint modeling of the clinical events and the longitudinal data can be used to provide valid statistical inference for target estimands in certain contexts, the application of joint models in medical literature is currently rather restricted because of the complexity of the joint models and the intensive computation involved. We propose a multiple imputation approach to jointly impute missing data of both the longitudinal and clinical event outcomes. With complete imputed datasets, analysts are then able to use simple and transparent statistical methods and standard statistical software to perform various analyses without dealing with the complications of missing data and joint modeling. We show that the proposed multiple imputation approach is flexible and easy to implement in practice. Numerical results are also provided to demonstrate its performance. Copyright © 2015 John Wiley & Sons, Ltd.
Effects of wind shear on wind turbine rotor loads and planetary bearing reliability
Authors: Gould B. J. , Burris D. L.
Published: July 2015

Recent studies suggest that wind shear and the resulting pitch moments increase bearing loads and thereby contribute to premature wind turbine gearbox failure. In this paper, we use momentum‐based modeling approaches to predict the pitch moments from wind shear. The non‐dimensionalized results, which have been validated against accepted aeroelastic results, can be used to determine thrust force, pitch moment and power of a general rotor as a function of the wind shear exponent. Even in extreme wind shear (m = 1), the actual thrust force and power for a typical turbine (R* < 0.5) were within 8% and 20% of the nominal values (those without wind shear), respectively. The mean pitch moment increased monotonically with turbine thrust, rotor radius and wind shear exponent. For extreme wind shear (m = 1) on a typical turbine (R* = 0.5), the mean pitch moment is ~25% the product of thrust force and rotor radius. Analysis of wind shear for a typical 750 kW turbine revealed that wind shear does not significantly affect bearing loads because it counteracts the effects of rotor weight. Furthermore, even though general pitch moments did significantly increase bearing loads, they were found to be unlikely to cause bearing fatigue. Analyses of more common low wind‐speed cases suggest that bearing under‐loading and wear are more likely to contribute to premature bearing failure than overloading and classical surface contact fatigue. Copyright © 2015 John Wiley & Sons, Ltd.
The motion induced by a radially stretching membrane in a rotating fluid system
Authors: Weidman Patrick D.
Published: July 2015

The flow induced above an impermeable sheet undergoing linear radial stretching in a system rotating at angular velocity Ω is investigated. The problem is governed by the single parameter , where a is the stretching rate of the membrane. A similarity reduction of the Navier‐Stokes equations leads to a pair of nonlinearly‐coupled ordinary differential equations which are numerically solved over the range . Coriolis forces acting on the radially stretching flow in the vicinity of the wall induces azimuthal flow in the boundary layer. A large‐σ analysis of the system leads to the Ekman equations describing the balance of Coriolis and viscous forces for which an exact solution is presented. Numerical results for the radial and azimuthal shear stresses, along with the magnitude of the velocity induced into the boundary layer, are shown to be in good agreement with the large‐σ asymptotic results.
Medical education in the United States: do residents feel prepared?
Authors: Chen Chen (Amy) , Kotliar Dylan , Drolet Brian C.
Published: July 2015

Background Medical schools face a growing challenge in providing a comprehensive educational experience. Students must graduate with not only the medical knowledge but also the requisite skills to care for patients and serve as physicians-in-training.

Objective To assess whether residents felt prepared by their medical school training.

Method We developed a questionnaire to assess resident attitudes towards various aspects of their medical school training and electronically distributed it among 107 United States training institutions.

Results A total of 2287 residents responded. Overall, a majority (53.8 %) agreed that ‘medical school prepared me well to be a resident.’ Most residents felt very well or mostly prepared in medical knowledge and clinical skills such as collecting a history (92.3 %), presenting a physical exam (86.1 %), or pathophysiology (81.6 %), but not for applied medical and psychosocial practices including end-of-life care (41.7 %), dealing with a patient death (46.3 %), and considering cost-effective care (28.7 %). Additionally, many residents reported feeling underprepared for time and fatigue management, debt, and medical-legal issues.

Conclusions Medical school graduates generally feel well prepared for residency. However, they may be less prepared to face important psychosocial, cultural and professional issues. Ultimately, a greater emphasis on skills and psychosocial experience may yield graduates who feel better prepared for today's residency challenges.
Studying learning in the healthcare setting: the potential of quantitative diary methods
Authors: Yvette Ciere Yvette , Jaarsma Debbie , Visser Annemieke , Sanderman Robbert , Snippe Evelien , Fleer Joke
Published: July 2015

Quantitative diary methods are longitudinal approaches that involve the repeated measurement of aspects of peoples’ experience of daily life. In this article, we outline the main characteristics and applications of quantitative diary methods and discuss how their use may further research in the field of medical education. Quantitative diary methods offer several methodological advantages, such as measuring aspects of learning with great detail, accuracy and authenticity. Moreover, they enable researchers to study how and under which conditions learning in the health care setting occurs and in which way learning can be promoted. Hence, quantitative diary methods may contribute to theory development and the optimization of teaching methods in medical education.
It is time to progress beyond the System 1 versus System 2 dichotomy
Authors: Rotgans Jerome I.
Published: July 2015

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International note: Are Emirati parents' attitudes toward mathematics linked to their adolescent children's attitudes toward mathematics and mathematics achievement?
Authors: Areepattamannil Shaljan , Khine Myint Swe , Melkonian Michael , Welch Anita G. , Al Nuaimi Samira Ahmed , Rashad Fatimah F.
Published: July 2015

Drawing on data from the 2012 Program for International Student Assessment (PISA) and employing multilevel modeling as an analytic strategy, this study examined the relations of adolescent children's perceptions of their parents' attitudes towards mathematics to their own attitudes towards mathematics and mathematics achievement among a sample of 5116 adolescents from 384 schools in the United Arab Emirates. The results of this cross‐sectional study revealed that adolescents who perceived that their parents liked mathematics and considered mathematics was important for their children not only to study but also for their career tended to report higher levels of intrinsic and instrumental motivation to learn mathematics, mathematics self‐concept and self‐efficacy, and mathematics work ethic. Moreover, adolescents who perceived that their parents liked mathematics and considered mathematics was important for their children's career tended to report positive intentions and behaviors toward mathematics. However, adolescents who perceived that their parents considered mathematics was important for their children's career tended to report higher levels of mathematics anxiety. Finally, adolescents who perceived that their parents considered mathematics was important for their children to study performed significantly better on the mathematics assessment than did their peers whose parents disregarded the importance of learning mathematics.