bluuebunny/crossref_metadata_2025 huggingface dataset:
Prior exercise and standing as strategies to circumvent sitting-induced leg endothelial dysfunction
Authors: Morishima Takuma , Restaino Robert M. , Walsh Lauren K. , Kanaley Jill A. , Padilla Jaume
Published: April 2017

We have previously shown that local heating or leg fidgeting can prevent prolonged sitting-induced leg endothelial dysfunction. However, whether physical activity prevents subsequent sitting-induced leg endothelial dysfunction remains unknown. Herein, we tested the hypothesis that sitting-induced leg endothelial dysfunction would be prevented by prior exercise. We also examined if, in the absence of exercise, standing is an effective alternative strategy to sitting for conserving leg endothelial function. Fifteen young healthy subjects completed three randomized experimental trials: (1) sitting without prior exercise; (2) sitting with prior exercise; and (3) standing without prior exercise. Following baseline popliteal artery flow-mediated dilation (FMD) measurements, subjects maintained a supine position for 45 min in the sitting and standing trials, without prior exercise, or performed 45 min of leg cycling before sitting (i.e. sitting with prior exercise trial). Thereafter, subjects were positioned into a seated or standing position, according to the trial, for 3 h. Popliteal artery FMD measures were then repeated. Three hours of sitting without prior exercise caused a significant impairment in popliteal artery FMD (baseline: 3.8±0.5%, post-sitting: 1.5±0.5%, P<0.05), which was prevented when sitting was preceded by a bout of cycling exercise (baseline: 3.8±0.5%, post-sitting: 3.6±0.7%, P>0.05). Three hours of standing did not significantly alter popliteal artery FMD (baseline: 4.1±0.4%, post-standing: 4.3±0.4%, P>0.05). In conclusion, prolonged sitting-induced leg endothelial dysfunction can be prevented by prior aerobic exercise. In addition, in the absence of exercise, standing represents an effective substitute to sitting for preserving leg conduit artery endothelial function.
Word Learning Deficits in Children With Dyslexia
Authors: Alt Mary , Hogan Tiffany , Green Samuel , Gray Shelley , Cabbage Kathryn , Cowan Nelson
Published: April 2017

Purpose

The purpose of this study is to investigate word learning in children with dyslexia to ascertain their strengths and weaknesses during the configuration stage of word learning.

Method

Children with typical development (
N
= 116) and dyslexia (
N
= 68) participated in computer-based word learning games that assessed word learning in 4 sets of games that manipulated phonological or visuospatial demands. All children were monolingual English-speaking 2nd graders without oral language impairment. The word learning games measured children's ability to link novel names with novel objects, to make decisions about the accuracy of those names and objects, to recognize the semantic features of the objects, and to produce the names of the novel words. Accuracy data were analyzed using analyses of covariance with nonverbal intelligence scores as a covariate.

Results

Word learning deficits were evident for children with dyslexia across every type of manipulation and on 3 of 5 tasks, but not for every combination of task/manipulation. Deficits were more common when task demands taxed phonology. Visuospatial manipulations led to both disadvantages and advantages for children with dyslexia.

Conclusion

Children with dyslexia evidence spoken word learning deficits, but their performance is highly dependent on manipulations and task demand, suggesting a processing trade-off between visuospatial and phonological demands.
A Diagnostic Marker to Discriminate Childhood Apraxia of Speech From Speech Delay: III. Theoretical Coherence of the Pause Marker with Speech Processing Deficits in Childhood Apraxia of Speech
Authors: Shriberg Lawrence D. , Strand Edythe A. , Fourakis Marios , Jakielski Kathy J. , Hall Sheryl D. , Karlsson Heather B. , Mabie Heather L. , McSweeny Jane L. , Tilkens Christie M. , Wilson David L.
Published: April 2017

Purpose

Previous articles in this supplement described rationale for and development of the pause marker (PM), a diagnostic marker of childhood apraxia of speech (CAS), and studies supporting its validity and reliability. The present article assesses the theoretical coherence of the PM with speech processing deficits in CAS.

Method

PM and other scores were obtained for 264 participants in 6 groups: CAS in idiopathic, neurogenetic, and complex neurodevelopmental disorders; adult-onset apraxia of speech (AAS) consequent to stroke and primary progressive apraxia of speech; and idiopathic speech delay.

Results

Participants with CAS and AAS had significantly lower scores than typically speaking reference participants and speech delay controls on measures posited to assess representational and transcoding processes. Representational deficits differed between CAS and AAS groups, with support for both underspecified linguistic representations and memory/access deficits in CAS, but for only the latter in AAS. CAS–AAS similarities in the age–sex standardized percentages of occurrence of the most frequent type of inappropriate pauses (
abrupt
) and significant differences in the standardized occurrence of appropriate pauses were consistent with speech processing findings.

Conclusions

Results support the hypotheses of core representational and transcoding speech processing deficits in CAS and theoretical coherence of the PM's pause-speech elements with these deficits.
Planning of Hiatus-Breaking Inserted /ɹ/ in the Speech of Australian English–Speaking Children
Authors: Yuen Ivan , Cox Felicity , Demuth Katherine
Published: April 2017

Purpose

Non-rhotic varieties of English often use /ɹ/ insertion as a connected speech process to separate heterosyllabic V
1
.V
2
hiatus contexts. However, there has been little research on children's development of this strategy. This study investigated whether children use /ɹ/ insertion and, if so, whether hiatus-breaking /ɹ/ can be considered planned, as evidenced by F3 lowering on V
1
.

Method

Thirteen Australian English–speaking children (7 girls, 6 boys; mean age 6;1 [years;months]) participated in an elicited production task. The stimuli included carrier sentences containing 4 test words (linking /ɹ/ context:
door, floor
; intrusive /ɹ/ context:
paw, claw
) followed by
of
(e.g., “This is the
paw of
the cat”). After familiarization containing auditory and picture prompts, children produced test sentences upon presentation of picture prompts alone.

Results

Eight children produced /ɹ/ insertion; the others used (some) glottalization. The incidence of /ɹ/ did not vary across linking or intrusive contexts, and inserted /ɹ/ was associated with F3 lowering at V
1
onset relative to control items without /ɹ/.

Conclusion

Six-year-old Australian English–speaking children who use /ɹ/ insertion show evidence of planning ahead and inserting /ɹ/ as a segment. The implications for the development of speech-planning processes and phonological and lexical representations are discussed.
Robust spectrum sensing based on spectral flatness measure
Authors: Gurugopinath S. , Muralishankar R. , Shankar H.N.
Published: April 2017

The authors investigate the spectral flatness measure (SFM)‐based spectrum sensing technique for cognitive radios. This scheme exploits the fact that under Gaussian noise, the noise‐only observations have flattened spectrum, i.e. more white, when compared with that of the observations containing the incumbent or primary signal; hence, an increased SFM under the null hypothesis. Under the null hypothesis, the authors derive the asymptotic distribution of the test statistic, and the asymptotically optimal detection threshold, with a constraint on the probability of false‐alarm. Furthermore, the authors show that this test is robust to the noise variance uncertainty (NVU) and is related to a test based on the entropy in the observed sequence. Through extensive Monte‐Carlo simulations, the authors show that the test based on SFM performs better than the existing energy detector and the blind detector, under realistic signal and fading models, all in the presence of NVU. The authors also highlight the practical utility of this technique based on experimental results.
Power efficient noise‐coupled ΔΣ ADC with simple delay cells
Authors: Jung Y. , Temes G.C.
Published: April 2017

A power efficient noise‐coupled ΔΣ analogue‐to‐digital converter (ADC) is proposed. The new architecture can effectively implement double‐noise coupling with simple digital delay cells. For performance improvement, one more input feed‐forward path is added to reduce the output swing of an integrator. Zero optimisation technique was also applied to the proposed modulator to increase the signal to quantisation noise ratio (SQNR). A third‐order ΔΣ ADC using new configuration was designed and simulated. The results verify the advantages of the proposed architecture.
Hundred gigahertz spacing Si arrayed‐waveguide grating using rib‐waveguide multimode interference coupler at slab–array interface
Authors: Okayama H. , Onawa Y. , Shimura D. , Takahashi H. , Yaegashi H. , Sasaki H.
Published: April 2017

Silicon arrayed‐waveguide grating using rib‐waveguide multimode interference coupler at the array and slab waveguide interface is reported. A 100 GHz channel spacing 8ch device showing 2.8 dB insertion loss is obtained. The insertion loss was improved compared with a device using simple width taper.
Radar measurement accuracy associated with target RCS fluctuation
Authors: Shin S.‐J.
Published: April 2017

Radar measurement accuracy is mainly dependent on the signal‐to‐noise ratio (SNR). SNR variation of the same target is related to fluctuating target radar cross‐section (RCS) that is known as Swerling RCS model. Radar measurement accuracy is an important parameter to design a radar system or to analyse its performance. More useful measurement accuracy formula than the previous research that is sensitive to the detection threshold is proposed. To investigate the measurement accuracy affected by Swerling model, the relative standard deviation is defined to compare the value of the previous research with the proposed value.
Automatic disease diagnosis using optimised weightless neural networks for low‐power wearable devices
Authors: Cheruku Ramalingaswamy , Edla Damodar Reddy , Kuppili Venkatanareshbabu , Dharavath Ramesh , Beechu Nareshkumar Reddy
Published: April 2017

Low‐power wearable devices for disease diagnosis are used at anytime and anywhere. These are non‐invasive and pain‐free for the better quality of life. However, these devices are resource constrained in terms of memory and processing capability. Memory constraint allows these devices to store a limited number of patterns and processing constraint provides delayed response. It is a challenging task to design a robust classification system under above constraints with high accuracy. In this Letter, to resolve this problem, a novel architecture for weightless neural networks (WNNs) has been proposed. It uses variable sized random access memories to optimise the memory usage and a modified binary TRIE data structure for reducing the test time. In addition, a bio‐inspired‐based genetic algorithm has been employed to improve the accuracy. The proposed architecture is experimented on various disease datasets using its software and hardware realisations. The experimental results prove that the proposed architecture achieves better performance in terms of accuracy, memory saving and test time as compared to standard WNNs. It also outperforms in terms of accuracy as compared to conventional neural network‐based classifiers. The proposed architecture is a powerful part of most of the low‐power wearable devices for the solution of memory, accuracy and time issues.
Klein Heidelberg: new information and further insight
Authors: Griffiths Hugh
Published: April 2017

Klein Heidelberg (KH) was a German WW2 bistatic radar system that used the British Chain Home radars as its illumination source. A paper published in 2010 presented information from previously classified sources on its origins and performance. Subsequently, some further information has been found, in particular concerning the dates by which the different KH stations become operational and their performance. This study summarises this new information, and discusses the dates by which each KH station was operational, the evidence for its effectiveness and the countermeasures considered by the British against KH.
Statistical simulations of the dust foreground to cosmic microwave background polarization
Authors: Vansyngel F. , Boulanger F. , Ghosh T. , Wandelt B. , Aumont J. , Bracco A. , Levrier F. , Martin P. G. , Montier L.
Published: April 2017

The characterization of the dust polarization foreground to the cosmic microwave background (CMB) is a necessary step toward the detection of the B-mode signal associated with primordial gravitational waves. We present a method to simulate maps of polarized dust emission on the sphere that is similar to the approach used for CMB anisotropies. This method builds on the understanding of Galactic polarization stemming from the analysis of Planck data. It relates the dust polarization sky to the structure of the Galactic magnetic field and its coupling with interstellar matter and turbulence. The Galactic magnetic field is modeled as a superposition of a mean uniform field and a Gaussian random (turbulent) component with a power-law power spectrum of exponent αM. The integration along the line of sight carried out to compute Stokes maps is approximated by a sum over a small number of emitting layers with different realizations of the random component of the magnetic field. The model parameters are constrained to fit the power spectra of dust polarization EE, BB, and TE measured using Planck data. We find that the slopes of the E and B power spectra of dust polarization are matched for αM = −2.5, an exponent close to that measured for total dust intensity but larger than the Kolmogorov exponent − 11/3. The model allows us to compute multiple realizations of the Stokes Q and U maps for different realizations of the random component of the magnetic field, and to quantify the variance of dust polarization spectra for any given sky area outside of the Galactic plane. The simulations reproduce the scaling relation between the dust polarization power and the mean total dust intensity including the observed dispersion around the mean relation. We also propose a method to carry out multifrequency simulations, including the decorrelation measured recently by Planck, using a given covariance matrix of the polarization maps. These simulations are well suited to optimize component separation methods and to quantify the confidence with which the dust and CMB B-modes can be separated in present and future experiments. We also provide an astrophysical perspective on our phenomenological modeling of the dust polarization spectra.
Preparation of Nonradioactive Standards and a Precursor for a Hypoxia 18F PET Tracer Derived from 1-(β-d-Galactopyranosyl)-2-nitroimidazole
Authors: Hammerschmidt Friedrich , Schweifer Anna , Malová Križková Petra , Mereiter Kurt
Published: April 2017

Acetyl-protected 1-(β-d-galactopyranosyl)-2-nitroimidazole was converted to a potential precursor for a fluorine-18 labeled hypoxia tumor marker. Two nonradioactive standards, the 6′-deoxy-6′-fluorogalactosyl and the 4′-deoxy-4′-fluoroglucosyl analogue were also prepared. These 2-nitroimidazole nucleosides were prepared by a modified Vorbrüggen coupling.
Safety of 2-Octyl Cyanoacrylate in Spreader Grafting
Authors: Standlee Aurora , Hohman Marc
Published: April 2017

Cyanoacrylate adhesives can make the placement of spreader grafts in open septorhinoplasty technically easier, but its use is off-label beneath the skin. There is a theoretical risk of toxicity from cyanoacrylate breakdown products, but this risk has not been thoroughly studied in rhinoplasty. The objective was to evaluate the effects of subcutaneous cyanoacrylate use during spreader graft placement in rhinoplasty in a retrospective review of open septorhinoplasties in which 2-octyl cyanoacrylate was used to aid placement of spreader grafts. The review was carried out in a tertiary care military academic medical center. A total of 140 adults underwent open septorhinoplasty between September 2013 and May 2016 with spreader graft placement. The authors excluded patients in whom 2-octyl cyanoacrylate was not used to aid graft placement and those who did not follow up postoperatively in our clinic. 108 (85 males and 23 females) patients were included in the final analysis. Nine (8.3%) patients had inflammatory reactions possibly attributable to 2-octyl cyanoacrylate toxicity. The overall rate of postoperative inflammation possibly attributable to 2-octyl cyanoacrylate was 17% among females and 5.9% among males, and this difference was not statistically significant (p = 0.07). However, the rate of postoperative inflammation attributable to 2-octyl cyanoacrylate that required an intervention (incision and drainage or antibiotics) was 2.7% overall, 13% among women and 0% among men, and this difference was significant based on chi-square testing (p < 0.001). Further, revision cases were significantly more likely to develop abnormal postoperative inflammation than initial cases (p = 0.02). Herein, the authors present the largest series of patients in whom 2-octyl cyanoacrylate was used to assist placement of cartilage spreader grafts during open septorhinoplasty. While 2-octyl cyanoacrylate is an effective adjunct to facilitate graft placement, they recommend against its use, as the risk of postoperative inflammation is significant.
Cartilage Scales Embedded in Fibrin Gel
Authors: Kovacevic Milos , Riedel Frank , Wurm Jochen , Bran Gregor
Published: April 2017

Multiple techniques have been described for dorsal nasal augmentation in rhinoplasty. In this article, we review common surgical techniques for raising the dorsum or eliminating dorsal irregularities, by highlighting inherent advantages and disadvantages of each method. Within the past few years, the use of diced cartilage grafts has become the workhorse in this field of interest. To overcome drawbacks of methods based on diced cartilage, we present a new concept for autologous augmentation, using regenerative medicine protocols. A mix of cartilage scales with cartilage pâté was embedded in platelet-rich fibrin (PRF). Since December 2015, a total of 48 patients were treated with this technique. Based on our preliminary results, cartilage scales in PRF appear to be a promising and reliable alternative to existing procedures for dorsal nasal augmentation.
Dorsal Augmentation-Diced Cartilage Techniques: The Diced Cartilage Glue Graft
Authors: Tasman Abel-Jan
Published: April 2017

The quest for the ideal method for augmenting the nasal dorsum continues to be a matter of debate, with both most surgeons and patients preferring autologous tissue. This article reviews the current use of diced cartilage for nasal augmentation, emphasizing the diced cartilage in fibrin glue (DCG) graft. It offers the first collation of unfavorable outcomes and complications of the DCG graft seen in a series of 108 patients treated at the author's institution. The DCG graft continues to be a versatile graft that is stable over time and combines unique features. It has proved to be particularly well suited for segmental augmentations of the dorsum. Resorption of the graft has been rare and infrequent unfavorable outcomes have all been amenable to successful minor surgical revisions.
Dorsal Augmentation Using Autologous Costal Cartilage or Microfat-Infused Soft Tissue Augmentation
Authors: Toriumi Dean
Published: April 2017

Costal cartilage grafting is increasing in popularity with increased demand for augmentation rhinoplasty and increased need for grafting material for structure rhinoplasty techniques. Use of costal cartilage for dorsal grafting is both art and science. The art is demonstrated in the act of carving a dorsal graft that will reflect the actual contour of the nasal dorsum. The science is linked to the methodology of how the grafts are contoured to match the patient's desires and how the graft is fixed to the bony dorsum to minimize the risk of warping and displacement. Variations in dorsal graft design and methods of fixation are described. Use of the perichondrial interface between dorsal graft and perforated/rasped nasal dorsum acts to ossify the dorsal graft to the underlying bone, creating an immobile and natural appearing nasal dorsum. The fixation of the dorsal graft limits movement and hence decreases the likelihood of warping or deformity. Use of microfat in rhinoplasty has tremendous potential for camouflage and to promote healing of compromised tissues. Using microfat-infused soft tissue augmentation (MISTA), the surgeon is able to deliver microfat to an open surgical field, promote healing, and provide soft tissue augmentation. In this technique, microfat is injected into soft tissue carriers (perichondrium, temporalis fascia, etc.) and then implanted into the surgical field. MISTA has tremendous potential utility in many areas of cosmetic and reconstructive surgery.
Riboflavin-Responsive Multiple Acyl-CoA Dehydrogenase Deficiency Associated with Hepatoencephalomyopathy and White Matter Signal Abnormalities on Brain MRI
Authors: Myllynen Päivi , Perhomaa Marja , Tuominen Hannu , Keski-Filppula Riikka , Rytky Seppo , Risteli Leila , Uusimaa Johanna , Vieira Päivi
Published: April 2017

Multiple acyl-CoA dehydrogenase deficiency (MADD) is a rare inborn error of metabolism affecting both fatty acid and amino acid oxidation. It can manifest at any age, but riboflavin-responsiveness has mainly been described in less severely affected patients. We describe an infant with severe MADD presenting with profound hypotonia and hepatomegaly. Treatment with riboflavin improved his muscle strength, liver size, and biochemical markers. A homozygous mutation of electron transfer flavoprotein dehydrogenase (ETFDH) was found. His motor skills continued to progress until a fatal infection-triggered deterioration at the age of 34 months. We show changes in brain magnetic resonance imaging over the course of the disease, with profound white matter abnormalities during the deterioration phase. Aggregates of mitochondria with abnormal cristae in muscle electron microscopy were noticed already in infancy. An unusual lactate dehydrogenase (LDH) isoenzyme pattern with LDH-1 predominance was additionally observed. This case demonstrates riboflavin-responsiveness in a severely affected infant with both muscular and extramuscular involvement and further underlines the variable nature of this disease.
The Reliability and Validity of the 3-min All-out Cycling Critical Power Test
Authors: Wright James , Bruce-Low Stewart , Jobson Simon
Published: April 2017

Research suggests that critical power (CP) can be estimated from a single 3-min bout of all-out cycling. The purpose of this study was to investigate the reliability and validity of the 3-min all-out cycling test when carried out at a constant cadence (isokinetic) and against a fixed resistance (linear). 12 participants completed 8 tests: 1) a ramp test; 2–4) 3 fixed power tests to calculate CP and W′ using the 1/time mathematical model; 5–8) four 3-min all-out tests to calculate EP and WEP; 2 isokinetic and 2 linear tests. There was no significant difference between EP-isokinetic and CP (P=0.377). There were significant differences between EP-linear and CP (P=0.004), WEP-isokinetic and W′ (P<0.001) and WEP-linear and W′ (P<0.001). The coefficient of variation in EP-isokinetic, EP-linear, WEP-isokinetic and WEP-linear was 1.93, 1.17, 8.44 and 5.39%, respectively. The 3-min all-out isokinetic test provides a reliable estimate of EP and a valid estimate of CP. The 3-min all-out linear test provides a reliable estimate of EP, but not a valid estimate of CP. Furthermore, these results suggest that the 3-min all-out test should not be used to estimate W′.
Antidiabetic Activities of an LC/MS Fingerprinted Aqueous Extract of Fagonia cretica L. in Preclinical Models
Authors: Nazir Imran , ur Rahman Nisar , Alvi Zunaira , Hafizur Rahman M. , Sendker Jandirk , Zhang Tao , Frankish Neil , Sheridan Helen
Published: April 2017

Diabetes mellitus is a chronic disease and one of the most important public health challenges facing mankind. Fagonia cretica is a medicinal plant used widely in the Punjab in Pakistan. A recent survey has demonstrated that traditional healers and herbalists frequently use this plant to treat diabetes. In the current study, the traditional medicine was prepared as a tea, and the profile of the main metabolites present in the traditional medicine was analysed via LC/MS/MS. The extract was shown to contain a number of phenolic glycosides including quercetin-3-O-rutinoside, kaempferol-3-O-rutinoside, kaempferol-3-O-glycoside, kaempferol-3(6′-malonylglucoside), isorhamnetin-3-O-rutinoside, and isorhamnetin 3-(6″-malonylglucoside) in addition to two unidentified sulphonated saponins. The traditional medicine inhibits α-glucosidase in vitro with an IC50 of 4.62 µg/mL. The hypoglycaemic effect of the traditional medicine was evaluated in normoglycaemic and streptozotocin-treated diabetic rats, using glibenclamide as an internal control. The preparation (250 or 500 mg/kg body weight) was administered once a day for 21 consecutive days. The dose of 500 mg/kg was effective in the management of the disease, causing a 45 % decrease in the plasma glucose level at the end of the experimental period. Histological analysis of pancreatic sections confirmed that streptozotocin/nictotinamide treatment caused destruction of pancreatic islet cells, while pancreatic sections from the treatment groups showed that both the extract and glibenclamide partially prevented this deterioration. The mechanism of this protective effect is unclear. However, such a finding suggests that ingestion of the tea could confer additional benefits and should be investigated further.
Beta-Ecdysone Protects Mouse Osteoblasts from Glucocorticoid-Induced Apoptosis In Vitro
Authors: Dai Wei-Wei , Wang Li-Bo , Jin Guo-Qin , Wu Hong-Jin , Zhang Jie , Wang Cheng-Long , Wei Yuan-Ji , Lee Joon-Ho , Lay Yu-An , Yao Wei
Published: April 2017

Glucocorticoid-induced osteoporosis is a common form of secondary osteoporosis. Glucocorticoids affect both bone formation and resorption, and prolonged glucocorticoid exposure can suppress osteoblast activities. beta-Ecdysone, found in many plants, is involved in protein synthesis, carbohydrate and lipid metabolism, and immunologic modulation. Here, we evaluated the effects of beta-ecdysone on osteoblast viability by assessing apoptosis following treatment with excess glucocorticoids. Mouse bone marrow stromal cells were induced to differentiate and grow into osteoblasts, and then treated with 10 µM glucocorticoid and 10, 1, or 0.1 µM beta-ecdysone. The expression levels of osteoblast growth and differentiation factors (runt-related transcription factor 2, osteogenic protein-1, and alkaline phosphatase), apoptosis-related genes (transformation-related protein 53, ataxia telangiectasia mutated protein, caspase-3, and caspase-8), and Akt1 and phospho-Akt (Thr308) were then assessed via alkaline phosphatase staining, acridine orange-propidium iodide staining, annexin V/PI apoptosis assay, real-time RT-PCR, and Western blot analyses. Notably, treatment with 10 µM glucocorticoid resulted in reduced osteoblast viability and the specific activity of alkaline phosphatase as well as reduced runt-related transcription factor 2, osteogenic protein-1, and alkaline phosphatase mRNA expression in vitro, indicating that glucocorticoid inhibited osteogenic differentiation. Moreover, glucocorticoid treatment yielded increased transformation-related protein 53, ataxia telangiectasia mutated protein, caspase-3, and caspase-8 expression and decreased Akt1 and phospho-Akt levels, indicating glucocorticoid-induced apoptosis. Meanwhile, beta-ecdysone inhibited glucocorticoid function, preserving the expression of Akt1 and phospho-Akt and reducing the expression of transformation-related protein 53, ataxia telangiectasia mutated protein, caspase-3, and caspase-8. Thus, beta-ecdysone prevented glucocorticoid-induced osteoblast apoptosis in vitro. These data highlight the potential for beta-ecdysone as a treatment for preventing the effects of glucocorticoid on bone growth.
Metabolism of Curcumin in Human Breast Cancer Cells: Impact of Sulfation on Cytotoxicity
Authors: Jamil Qurrat , Jaerapong Natharath , Zehl Martin , Jarukamjorn Kanokwan , Jäger Walter
Published: April 2017

Curcumin is a natural polyphenol with promising anticancer properties that undergoes pronounced metabolism in humans. In order to determine whether metabolism of curcumin also occurs in tumor cells and whether biotransformation has any impact on cytotoxicity, metabolism experiments were conducted with hormone-dependent ZR-75-1 and hormone-independent MDA-MB-231 human breast cancer cells. By using HPLC-ESI-Qq-TOF-MS, it was possible to identify one main metabolite, namely curcumin sulfate, in both cell lines. Its concentration in the cytoplasm and culture medium was 1.6- to 1.7-fold higher in ZR-75-1 cells than in MDA-MB-231 cells, concomitant with a 2-fold higher IC50 value in the ZR-75-1 cell line (14 µM compared to 7.3 µM). The net result of sulfation seems to lower the intracellular concentration of curcumin, thereby decreasing its growth inhibitory activity. Interestingly, for the first time, we also found the formation of a curcumin dimer in the cytoplasm but not in the cellular medium of both cell lines. Compared to curcumin sulfate, however, its maximal intracellular concentrations were up to 4-fold lower, indicating only a minor contribution to the overall curcumin clearance. In conclusion, our data elucidated the metabolism of curcumin in breast cancer cells, which must be considered in humans following oral uptake of dietary curcumin as a chemopreventive agent.
Polynomial functors and combinatorial Dyson–Schwinger equations
Authors: Kock Joachim
Published: April 2017

We present a general abstract framework for combinatorial Dyson–Schwinger equations, in which combinatorial identities are lifted to explicit bijections of sets, and more generally equivalences of groupoids. Key features of combinatorial Dyson–Schwinger equations are revealed to follow from general categorical constructions and universal properties. Rather than beginning with an equation inside a given Hopf algebra and referring to given Hochschild 1-cocycles, our starting point is an abstract fixpoint equation in groupoids, shown canonically to generate all the algebraic structures. Precisely, for any finitary polynomial endofunctor P defined over groupoids, the system of combinatorial Dyson–Schwinger equations X = 1 + P(X) has a universal solution, namely the groupoid of P-trees. The isoclasses of P-trees generate naturally a Connes–Kreimer-like bialgebra, in which the abstract Dyson–Schwinger equation can be internalised in terms of canonical B+-operators. The solution to this equation is a series (the Green function), which always enjoys a Faà di Bruno formula, and hence generates a sub-bialgebra isomorphic to the Faà di Bruno bialgebra. Varying P yields different bialgebras, and cartesian natural transformations between various P yield bialgebra homomorphisms and sub-bialgebras, corresponding for example to truncation of Dyson–Schwinger equations. Finally, all constructions can be pushed inside the classical Connes–Kreimer Hopf algebra of trees by the operation of taking core of P-trees. A byproduct of the theory is an interpretation of combinatorial Green functions as inductive data types in the sense of Martin-Löf type theory (expounded elsewhere).
Energy consumption and low carbon development strategies of three global cities in Asian developing countries
Authors: Zhang Jing , Li Fengting
Published: April 2017

With the rise of Asia in the global economy, it is important for developing countries in Asia to break away from energy and resource intensive growth models and explore low carbon pathways. In this process, urban energy policies are crucial and pioneering cities should play a leading role. The change in energy consumption patterns in three cities, i.e., Beijing, Shanghai, and Bangkok, was studied, and these cities' low carbon development strategies were reviewed. It was found that total energy consumption in the three cities has shown a tendency towards being stable or even started to decrease. The energy consumption by industry has started to decrease or stopped increasing. Service sectors became the most important energy consumers in all three cities, particularly the transport sector in Bangkok. Household energy consumption gradually increased in Beijing and Shanghai. Electricity use at home and energy for vehicles are becoming more important with urbanization and changes in lifestyles. All three cities have adopted a variety of low carbon development strategies, such as transition towards a lower carbon economy, developing a low carbon transportation system, and adopting cleaner and renewable substitutes for electricity to disengage from the dependency on coal and petroleum products. However, most low carbon strategies have focused on industrial and service sectors. Those cities should also explore and lead more sustainable lifestyles, which are important for system-wide energy savings.
H+ ion-induced damage and etching of multilayer graphene in H2 plasmas
Authors: Davydova A. , Despiau-Pujo E. , Cunge G. , Graves D. B.
Published: April 2017

H+ ion-induced damage of multilayer graphene (MLG) is investigated using Molecular Dynamics simulations as H2 plasmas could provide a possible route to pattern graphene. Low-energy (5–25 eV) H+ cumulative bombardment of ABA-stacked MLG samples shows an increase of the hydrogenation rate with the ion dose and ion energy. At 5 eV, the H coverage grows with the ion fluence only on the upper-side of the top layer but saturates around 35%. Hydrogenation of multi-layers and carbon etching are observed at higher energies. Layer-by-layer peeling/erosion of the MLG sample is observed at 10 eV and occurs in two phases: the MLG sample is first hydrogenated before carbon etching starts via the formation of CHx (∼60%) and C2Hx (∼30%) by-products. A steady state is reached after an ion dose of ∼5 × 1016 H+/cm2, as evidenced by a constant C etch yield (∼0.02 C/ion) and the saturation of the hydrogenation rate. At 25 eV, an original etching mechanism—lifting-off the entire top layer—is observed at low fluences due to the accumulation of H2 gas in the interlayer space and the absence of holes/vacancies in the top layer. However, as the underneath layers contain more defects and holes, this Smartcut-like mechanism cannot be not repeated and regular ion-assisted chemical etching is observed at higher fluences, with a yield of ∼0.05 C/ion.
Turbulence modeling for flows in wall bounded porous media: An analysis based on direct numerical simulations
Authors: Jin Y. , Kuznetsov A. V.
Published: April 2017

Various models are available for simulating turbulent flows in porous media. Models based on the eddy viscosity assumption are often adopted to close the Reynolds stress term. In order to validate the assumptions behind such turbulence models, we studied the dynamics of macroscopic momentum and turbulence kinetic energy in porous media flows by utilizing Direct Numerical Simulation (DNS). The generic porous matrix is composed of regularly arranged spheres. The resulting periodic porous medium is bounded by two walls. The DNS analyses with a Lattice Boltzmann method were performed for various values of the applied pressure gradient, pore size to channel width ratio, and porosity. The DNS results were averaged over time and volume to obtain macroscopic results. The results show that the macroscopic shear Reynolds stress in all Representative Elementary Volumes (REVs), independent of their location, is negligibly small, although the mean velocity gradient takes nonzero values near the wall. The turbulence kinetic energy production rate is generally balanced by the dissipation rate in each REV. The DNS results support a zero-equation turbulence model that accounts for the fact that turbulent structures are restricted in size by the pore scale. The DNS results also suggest that the Brinkman term, which expresses the diffusion of momentum, has an important effect near the wall where the gradient of the shear stress is large. Therefore, the Brinkman term should be taken into account in the macroscopic momentum equation as a component of the total drag. A preliminary macroscopic model for calculating turbulent porous media flows has been proposed and compared with our DNS results.
Optimizing the formation of solid solutions with components of different shapes
Authors: Escobedo Fernando A.
Published: April 2017

A key challenge to engineer ordered solids from the co-assembly of two differently shaped building blocks is to predict the key particle characteristics that lead to maximal mutual ordered-phase compatibility (MaxOC). While both entropy disparity, as captured by the relative size of the components, and energetic inter-species selectivity affect MaxOC, it is the former whose effect is less intuitive and the main focus of this work. Such MaxOC predictive rules are formulated and validated by using Monte Carlo simulation results for hard-core mixtures of octahedra and spheres and of other previously studied mixtures. Specifically, it is proposed that component size ratios should maximize their “substitutional symmetry” and hence minimize the combined free-energy cost associated with mutating a host-particle into a guest-particle in each of the solid phases. For the hard-core mixtures examined, packing entropy stabilizes substitutionally disordered solid solutions but not stoichiometric compounds. Additional molecular simulations were hence used to demonstrate, consistent with recent experimental findings, that such compounds can be formed by strengthening the inter-species compatibility via orientation-dependent attractions.
High-β equilibrium and ballooning stability of the low aspect ratio CNT stellarator
Authors: Hammond K. C. , Lazerson S. A. , Volpe F. A.
Published: April 2017

The existence and ballooning-stability of low aspect ratio stellarator equilibria is predicted for the Columbia Neutral Torus (CNT) with the aid of 3D numerical tools. In addition to having a low aspect ratio, CNT is characterized by a low magnetic field and small plasma volume. Also, highly overdense plasmas were recently heated in CNT by means of microwaves. These characteristics suggest that CNT might attain relatively high values of plasma beta and thus be of use in the experimental study of stellarator stability to high-beta instabilities such as ballooning modes. As a first step in that direction, here the ballooning stability limit is found numerically. Depending on the particular magnetic configuration we expect volume-averaged β limits in the range 0.9%–3.0%, and possibly higher, and observe indications of a second region of ballooning stability. As the aspect ratio is reduced, stability is found to increase in some configurations and decrease in others. Energy-balance estimates using stellarator scaling laws indicate that the lower β limit may be attainable with overdense heating at powers of 40 to 100 kW. The present study serves the additional purpose of testing VMEC and other stellarator codes at high values of β and at low aspect ratios. For this reason, the study was carried out both for free boundary, for maximum fidelity to experiment, as well as with a fixed boundary, as a numerical test.
Interface formation during silica encapsulation of colloidal CdSe/CdS quantum dots observed by in situ Raman spectroscopy
Authors: Biermann Amelie , Aubert Tangi , Baumeister Philipp , Drijvers Emile , Hens Zeger , Maultzsch Janina
Published: April 2017

We investigate the encapsulation of CdSe/CdS quantum dots (QDs) in a silica shell by in situ Raman spectroscopy and find a distinct shift of the CdS Raman signal during the first hours of the synthesis. This shift does not depend on the final silica shell thickness but on the properties of the initial core-shell QD. We find a correlation between the Raman shift rate and the speed of the silica formation and attribute this to the changing configuration of the outermost layers of the QD shell, where an interface to the newly formed silica is created. This dependence of Raman shift rate on the speed of silica formation process will give rise to many possible studies concerning the growth mechanism in the water-in-oil microemulsion, rendering in situ Raman a valuable instrument in monitoring this type of reaction.
From 2D to 3D: Critical Casimir interactions and phase behavior of colloidal hard spheres in a near-critical solvent
Authors: Tasios Nikos , Dijkstra Marjolein
Published: April 2017

Colloids dispersed in a binary solvent mixture experience long-ranged solvent-mediated interactions (critical Casimir forces) upon approaching the critical demixing point of the solvent mixture. The range of the interaction is set by the bulk correlation length of the solvent mixture, which diverges upon approaching the critical point. This presents a great opportunity to realize the reversible self-assembly of colloids by tuning the proximity to the critical point of the solvent. Here, we develop a rejection-free geometric cluster algorithm to study the full ternary mixture of colloidal hard spheres suspended in an explicit three-dimensional lattice model for the solvent mixture using extensive Monte Carlo simulations. The phase diagram displays stable colloidal gas, liquid, and crystal phases, as well as broad gas-liquid and gas-crystal phase coexistence, and pronounced fractionation of the solvent in the coexisting colloid phases. The topology of the phase diagram in our three-dimensional study shows striking resemblance to that of our previous studies carried out in two dimensions.
Laboratory and numerical study of intense envelope solitons of water waves: Generation, reflection from a wall, and collisions
Authors: Slunyaev A. , Klein M. , Clauss G. F.
Published: April 2017

The investigation of dynamics of intense solitary wave groups of collinear surface waves is performed by means of numerical simulations of the Euler equations and laboratory experiments. The processes of solitary wave generation, reflection from a wall, and collisions are considered. Steep solitary wave groups with characteristic steepness up to kAcr ≈ 0.3 (where k is the dominant wavenumber and Acr is the crest amplitude) are concerned. They approximately restore the structure after the interactions. In the course of the interaction with the wall and collisions, the maximum amplitude of the wave crests is shown to enhance up to 2.5 times. A standing-wave-like structure occurs in the vicinity of the wall, with certain locations of nodes and antinodes regardless the particular phase of the reflecting wave group. A strong asymmetry of the maximal wave groups due to an anomalous setup is shown in situations of collisions of solitons with different frequencies of the carrier. In some situations of head-on collisions, the amplitude of the highest wave is larger than in overtaking collisions of the same solitons. The discovered effects in interactions of intense wave groups are important in the context of mechanisms and manifestations of oceanic rogue waves.
High-pressure rotational deformation apparatus to 135 GPa
Authors: Nomura Ryuichi , Azuma Shintaro , Uesugi Kentaro , Nakashima Yuki , Irifune Tetsuo , Shinmei Toru , Kakizawa Sho , Kojima Yohei , Kadobayashi Hirokazu
Published: April 2017

A large-strain, torsional deformation apparatus has been developed based on diamond anvil cells at high pressures, up to 135 GPa with a help of hard nano-polycrystalline diamond anvils. These pressure conditions correspond to the base of the Earth’s mantle. An X-ray laminography technique is introduced for high-pressure in situ 3D observations of the strain markers. The technique developed in this study introduces the possibility of the in situ rheological measurements of the deep Earth materials under ultrahigh-pressure conditions.
Crossing the dividing surface of transition state theory. IV. Dynamical regularity and dimensionality reduction as key features of reactive trajectories
Authors: Lorquet J. C.
Published: April 2017

The atom-diatom interaction is studied by classical mechanics using Jacobi coordinates (R, r, θ). Reactivity criteria that go beyond the simple requirement of transition state theory (i.e., PR* > 0) are derived in terms of specific initial conditions. Trajectories that exactly fulfill these conditions cross the conventional dividing surface used in transition state theory (i.e., the plane in configuration space passing through a saddle point of the potential energy surface and perpendicular to the reaction coordinate) only once. Furthermore, they are observed to be strikingly similar and to form a tightly packed bundle of perfectly collimated trajectories in the two-dimensional (R, r) configuration space, although their angular motion is highly specific for each one. Particular attention is paid to symmetrical transition states (i.e., either collinear or T-shaped with C2v symmetry) for which decoupling between angular and radial coordinates is observed, as a result of selection rules that reduce to zero Coriolis couplings between modes that belong to different irreducible representations. Liapunov exponents are equal to zero and Hamilton’s characteristic function is planar in that part of configuration space that is visited by reactive trajectories. Detailed consideration is given to the concept of average reactive trajectory, which starts right from the saddle point and which is shown to be free of curvature-induced Coriolis coupling. The reaction path Hamiltonian model, together with a symmetry-based separation of the angular degree of freedom, provides an appropriate framework that leads to the formulation of an effective two-dimensional Hamiltonian. The success of the adiabatic approximation in this model is due to the symmetry of the transition state, not to a separation of time scales. Adjacent trajectories, i.e., those that do not exactly fulfill the reactivity conditions have similar characteristics, but the quality of the approximation is lower. At higher energies, these characteristics persist, but to a lesser degree. Recrossings of the dividing surface then become much more frequent and the phase space volumes of initial conditions that generate recrossing-free trajectories decrease. Altogether, one ends up with an additional illustration of the concept of reactive cylinder (or conduit) in phase space that reactive trajectories must follow. Reactivity is associated with dynamical regularity and dimensionality reduction, whatever the shape of the potential energy surface, no matter how strong its anharmonicity, and whatever the curvature of its reaction path. Both simplifying features persist during the entire reactive process, up to complete separation of fragments. The ergodicity assumption commonly assumed in statistical theories is inappropriate for reactive trajectories.