bluuebunny/crossref_metadata_2025 huggingface dataset:
Interactions between methylmercury and selenomethionine injected into mallard eggs
Authors: Klimstra Jon D. , Yee Julie L. , Heinz Gary H. , Hoffman David J. , Stebbins Katherine R.
Published: December 2011

Methylmercury chloride and seleno-L-methionine were injected separately or in combinations into mallard eggs (Anas platyrhynchos), and embryo mortality and teratogenic effects (deformities) were modeled using a logistic regression model. Methylmercury was injected at doses that resulted in concentrations of 0, 0.2, 0.4, 0.8, and 1.6 µg/g Hg in the egg on a wet weight basis and selenomethionine at doses that resulted in concentrations of 0, 0.1, 0.2, 0.4, and 0.6 µg/g Se in the egg, also on a wet weight basis. When selenomethionine and methylmercury were injected separately, hatching probability decreased in both cases. However, when methylmercury was injected at 1.6 µg/g in combination with selenomethionine at 0.2 µg/g, the presence of the methylmercury resulted in less embryo mortality than had been seen with 0.2 µg/g Se by itself, but it increased the number of deformed embryos and hatchlings. Selenomethionine appeared to be more embryotoxic than equivalent doses of methylmercury when injected into eggs, and both injected methylmercury and selenomethionine were more toxic to mallard embryos than when deposited naturally in the egg by the mother. The underlying mechanisms behind the interactions between methylmercury and selenomethionine and why methylmercury appeared to improve hatching probability of Se-dosed eggs yet increased deformities when the two compounds were combined are unclear. These findings warrant further studies to understand these mechanisms in both laboratory and field settings. Environ. Toxicol. Chem. 2012;31:579–584. © 2011 SETAC
Development of lateral meristem and pattern of secondary growth in stems and roots of Spinacia oleracea Linn (Amaranthaceae)
Authors: Rajput K. S. , Patil V. S. , Kapadane K. K.
Published: December 2011

Development of lateral meristem and pattern of secondary growth in the stems and roots of Spinacia oleracea Linn (Amaranthaceae) were studied anatomically. Maturing stems and roots increased in thickness by developing successive rings of cambia which produce secondary vascular elements embedded in the groundmass of thin walled parenchymatous conjunctive tissues. Second ring of the cambium was originated outside the first ring of the cambium and gave rise to parenchyma cells and sieve tube elements on the outer side whereas it gave rise to conjunctive tissue and secondary xylem on the inner side. Prior to the development of second ring of cambium, parenchyma cells located outside to the previous cambium dedifferentiated and acquired meristematic property which led to the formation of meristematic bands of radially arranged cells. Later on each successive ring of cambium developed in similar fashion as described above. The groundmass of the stems and roots was mostly composed of thin walled conjunctive tissue on both the outer and inner side of each cambium, whereas formation of thick walled conducting elements of secondary xylem and secondary phloem remained restricted to the small segments of the vascular cambium. Secondary xylem was composed of vessel elements, tracheids and libriform fibres whereas secondary phloem comprised of sieve tube elements, companion cells and axial parenchyma with no typical rays even in the mature stems. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The development of a rat in vitro model of spinal cord injury demonstrating the additive effects of rho and ROCK inhibitors on neurite outgrowth and myelination
Authors: Boomkamp Stephanie D. , Riehle Mathis O. , Wood Jenifer , Olson Michael F. , Barnett Susan C.
Published: December 2011

It is currently thought that treatment for spinal cord injury (SCI) will involve a combined pharmacological and biological approach; however, testing their efficacy in animal models of SCI is time‐consuming and requires large animal cohorts. For this reason we have modified our myelinating cultures as an in vitro model of SCI and studied its potential as a prescreen for combined therapeutics. This culture comprises dissociated rat embryonic spinal cord cells plated onto a monolayer of astrocytes, which form myelinated axons interspaced with nodes of Ranvier. After cutting the culture, an initial cell‐free area appears persistently devoid of neurites, accompanied over time by many features of SCI, including demyelination and reduced neurite density adjacent to the lesion, and infiltration of microglia and reactive astrocytes into the lesioned area. We tested a range of concentrations of the Rho inhibitor C3 transferase (C3) and ROCK inhibitor Y27632 that have been shown to promote SCI repair in vivo. C3 promoted neurite extension into the lesion and enhanced neurite density in surrounding areas but failed to induce remyelination. In contrast, while Y27632 did not induce significant neurite outgrowth, myelination adjacent to the lesion was dramatically enhanced. The effects of the inhibitors were concentration‐dependent. Combined treatment with C3 and Y27632 had additive affects with an enhancement of neurite outgrowth and increased myelination adjacent to the lesion, demonstrating neither conflicting nor synergistic effects when coadministered. Overall, these results demonstrate that this culture serves as a useful tool to study combined strategies that promote CNS repair. © 2011 Wiley Periodicals, Inc.
Nijmegen Observer‐Rated Depression scale for detection of depression in nursing home residents
Authors: Leontjevas Ruslan , Gerritsen Debby L. , Vernooij‐Dassen Myrra J. F. J. , Teerenstra Steven , Smalbrugge Martin , Koopmans Raymond T. C. M.
Published: December 2011

Objective

This study aims to test the accuracy of the Nijmegen Observer‐Rated Depression (NORD) scale, a new short scale for screening of depression in nursing home (NH) residents with and without dementia.

Methods

This cross‐sectional study with 103 residents with dementia (N = 19 depressed) and 72 residents without dementia (N = 10 depressed) was undertaken in 13 Dutch NH units. An elderly care physician and a psychologist of each unit assessed residents for the presence of clinical depression. Primary professional caregivers administered the NORD scale.

Results

Five of the six proposed items showed acceptable performance in screening for depression. Receiver operating characteristic analyses revealed significant areas under the empirical curve (AUC) for the 5‐item NORD scale in the total sample (AUC = 0.83, p < 0.001), as well as in residents with dementia (AUC = 0.84, p < 0.001) and without dementia (AUC = 0.84, p < 0.001). The cutoff score of >1 showed the highest sum of sensitivity (100) and specificity (69) in non‐dementia and >2 the highest sum of sensitivity (79) and specificity (77) in dementia. The cutoff score of >1 showed the lowest negative likelihood ratio of 0.0 in non‐dementia and of 0.2 in dementia. The highest positive likelihood ratios were found for the cutoff of >2 in non‐dementia (3.4) and for >4 in dementia (26.5).

Conclusion

The 5‐item NORD scale showed acceptable accuracy comparable with those of more extensive scales in other studies. It is easy and quick to administer and can be used for screening of depression in NH residents with or without dementia. Copyright © 2011 John Wiley & Sons, Ltd.
Latent class‐derived subgroups of depressive symptoms in a community sample of older adults: the Cache County Study
Authors: Lee Chien‐Ti , Leoutsakos Jeannie‐Marie , Lyketsos Constantine G. , Steffens David C. , Breitner John C. S. , Norton Maria C.
Published: December 2011

Objective

We sought to identify possible subgroups of elders that varied in depressive symptomatology and to examine symptom patterns and health status differences between subgroups.

Methods

The Cache County Memory Study is a population‐based epidemiological study of dementia with 5092 participants. Depressive symptoms were measured with a modified version of the Diagnostic Interview Schedule‐Depression. There were 400 nondemented participants who endorsed currently (i.e., in the past 2 weeks) experiencing at least one of the three “gateway” depressive symptoms and then completed a full depression interview. Responses to all nine current depressive symptoms were modeled using the latent class analysis.

Results

Three depression subgroups were identified: a significantly depressed subgroup (62%), with the remainder split evenly between a subgroup with low probability of all symptoms (21%), and a subgroup with primarily psychomotor changes, sleep symptoms, and fatigue (17%). Latent class analysis derived subgroups of depressive symptoms and Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition depression diagnostic group were nonredundant. Age, gender, education, marital status, early or late onset, number of episodes, current episode duration, and functional status were not significant predictors of depression subgroup. The first subgroup was more likely to be recently bereaved and had less physical health problems, whereas the third subgroup were less likely to be using antidepressants compared with the second subgroup.

Conclusions

There are distinct subgroups of depressed elders, which are not redundant with the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition classification scheme, offering an alternative diagnostic approach to clinicians and researchers. Future work will examine whether these depressive symptom profiles are predictive of incident dementia and earlier mortality. Copyright © 2011 John Wiley & Sons, Ltd.
Quasicrystals in Soft Matter
Authors: Dotera Tomonari
Published: December 2011

Two decades after the first publication on quasicrystals in aluminum manganese alloys by Shechtman et al., a “soft quasicrystal” was found in nature. Since then a number of materials successively joined the family of soft quasicrystals, including liquid crystals, polymers, nanoparticles, colloids, mesoporous silica, and even water and silicon. In this article, important experimental advances are reviewed to introduce readers to the emerging research front of soft quasicrystalline materials. The world of quasicrystals opened by Daniel Shechtman extends its reach into the twenty‐first century chemistry.
Control of mitochondrial activity by miRNAs
Authors: Li Peifeng , Jiao Jianqing , Gao Guifeng , Prabhakar Bellur S.
Published: December 2011

Mitochondria supply energy for physiological function and they participate in the regulation of other cellular events including apoptosis, calcium homeostasis, and production of reactive oxygen species. Thus, mitochondria play a critical role in the cells. However, dysfunction of mitochondria is related to a variety of pathological processes and diseases. MicroRNAs (miRNAs) are a class of small noncoding RNAs about 22 nucleotides long, and they can bind to the 3′‐untranslated region (3′‐UTR) of mRNAs, thereby inhibiting mRNA translation or promoting mRNA degradation. We summarize the molecular regulation of mitochondrial metabolism, structure, and function by miRNAs. Modulation of miRNAs levels may provide a new therapeutic approach for the treatment of mitochondria‐related diseases. J. Cell. Biochem. 113: 1104–1110, 2012. © 2011 Wiley Periodicals, Inc.
Leptin regulates estrogen receptor gene expression in ATDC5 cells through the extracellular signal regulated kinase signaling pathway
Authors: Wang Shan‐Jin , Li Xin‐Feng , Jiang Lei‐Sheng , Dai Li‐Yang
Published: December 2011

Both estrogen and leptin play an important role in the regulation of physiological processes of endochondral bone formation in linear growth. Estrogen receptors (ERα and ERβ) are known as members of the superfamily of nuclear steroid hormone receptors and are detected in all zones of growth plate chondrocytes. They can be regulated in a ligand‐independent manner. Whether leptin regulates ERs in the growth plate is still not clear. To explore this issue, chondrogenic ATDC5 cells were used in the present study. Messenger RNA and protein analyses were performed by quantitative PCR and Western blotting. We found that both ERα and ERβ were dynamically expressed during the ATDC5 cell differentiation for 21 days. Leptin (50ng/ml) significantly upregulated ERα and ERβ mRNA and protein levels 48 h after leptin stimulation (P < 0.05) at day 14. The up‐regulation of ERα and ERβ mRNA by leptin was shown in a dose‐dependent manner, but the most effective dose of leptin was different (100 and 1,000 ng/ml, respectively). Furthermore, we confirmed that leptin augmented the phosphorylation of ERK1/2 in a time‐dependent manner. A maximum eightfold change was observed at 15 min. Finally, a specific ERK1/2 inhibitor, UO126, blocked leptin‐induced ERs regulation in ATDC5 cells, indicating that ERK1/2 mediates, partly, the effects of leptin on ERs. These data demonstrate, for the first time, that leptin regulates the expression of ERs in growth plate chondrocytes via ERK signaling pathway, thereby suggesting a crosstalk between leptin and estrogen receptors in the regulation of bone formation. J. Cell. Biochem. 113: 1323–1332, 2012. © 2011 Wiley Periodicals, Inc.
MMP‐3 provokes CTGF/CCN2 production independently of protease activity and dependently on dynamin‐related endocytosis, which contributes to human dental pulp cell migration
Authors: Muromachi Koichiro , Kamio Naoto , Narita Takanori , Annen‐Kamio Motoyo , Sugiya Hiroshi , Matsushima Kiyoshi
Published: December 2011

Matrix metalloproteinase‐3 (MMP‐3) expression is promoted after pulpotomy, and application of MMP‐3 to dental pulp after pulpotomy accelerates angiogenesis and hard tissue formation. However, the mechanism by which MMP‐3 promotes dental pulp wound healing is still unclear. Connective tissue growth factor/CCN family 2 (CTGF/CCN2), a protein belonging to the CCN family, is considered to participate in wound healing, angiogenesis, and cell migration. In this study, we examined the involvement of CTGF/CCN2 in MMP‐3‐induced cell migration in human dental pulp (fibroblast‐like) cells. In human dental pulp cells, MMP‐3 promoted cell migration, but this effect was clearly blocked in the presence of anti‐CTGF/CCN2 antibody. MMP‐3 provoked mRNA and protein expression and secretion of CTGF/CCN2 in a concentration‐ and time‐dependent manner. The MMP‐3 inhibitor NNGH failed to suppress MMP‐3‐induced CTGF/CCN2 protein expression. The potent dynamin inhibitor dynasore clearly inhibited MMP‐3‐induced CTGF/CCN2 expression. These results strongly suggest that MMP‐3 induces CTGF/CCN2 production independently of the protease activity of MMP‐3 and dependently on dynamin‐related endocytosis, which is involved in cell migration in human dental pulp cells. J. Cell. Biochem. 113: 1348–1358, 2012. © 2011 Wiley Periodicals, Inc.
Procyanidins from grape pomace are suitable inhibitors of human endothelial NADPH oxidase
Authors: Álvarez Ezequiel , Rodiño‐Janeiro Bruno K. , Jerez María , Ucieda‐Somoza Rafael , Núñez María J. , González‐Juanatey José R.
Published: December 2011

Procyanidins have been associated with a reduced risk of cardiovascular diseases such as atherosclerosis. However, the molecular mechanisms underlying this benefit are not fully understood. Increased reactive oxygen species (ROS) production generated by nicotinamide adenine dinucleotide phosphate (NADPH) oxidase is a common problem in different cardiovascular diseases. Our objective was to evaluate the effects of procyanidin‐rich fractions from distilled grape pomace on NADPH oxidase activity in human umbilical vein endothelial cells (HUVEC). Three differently polymerized and galloylated procyanidin fractions were analyzed for their NADPH oxidase inhibitory activity in cell lysates and in HUVEC cultures. All of the three fractions, up to 1 µg/ml, equally inhibited isolated NADPH oxidase in HUVEC lysates in a concentration‐dependent manner and independently of any superoxide anion scavenging activities. The procyanidin fractions even blocked NADPH oxidase activity in intact HUVEC, inhibiting ROS production at both extra‐ and intracellular levels. The fractions achieved the same effects that known NADPH oxidase inhibitors, such as diphenylene iodonium and apocynin, but they presented better hydrosolubility. Our results demonstrated that procyanidin from grape pomace inhibit human endothelial NADPH oxidase regardless of their polymerization degree and galloylation percentage. Therefore, procyanidins are suitable NADPH oxidase inhibitors which could serve as models for therapeutic alternatives for cardiovascular diseases. J. Cell. Biochem. 113: 1386–1396, 2012. © 2011 Wiley Periodicals, Inc.
Hypoxia inhibits the spontaneous calcification of bone marrow‐derived mesenchymal stem cells
Authors: Huang Yong‐Can , Zhu Hong‐Ming , Cai Jia‐Qin , Huang Yi‐Zhou , Xu Jin , Zhou Yi , Chen Xiao‐He , Li Xiu‐Qun , Yang Zhi‐Ming , Deng Li
Published: December 2011

Bone marrow‐derived mesenchymal stem cells (BM‐MSCs) are the popular seed cells for regenerative medicine, and there has been a rapid increase in the number of BM‐MSC‐based clinical trials. However, the safety of these cells should also be closely studied. In this study, spontaneous calcification of BM‐MSCs from rats was evaluated in normoxia (20% O2) without osteogenic medium after continuous culture for 21 days; obvious mineralized nodules were observed, which were positive for Alizarin Red, collagen‐I (Col‐I), osteocalcin (OC) and alkaline phosphatase (ALP), and mainly consisted of C, O and Ca elements. Interestingly, hypoxia (2% O2) significantly inhibited this spontaneous calcification. In addition, the ALP and calcium content of rBM‐MSCs were sharply reduced. Based on RT‐PCR results, the expression of osteogenic genes (Cbfa1/Runx2, Col‐I, ALP, and OC) was reduced compared to that in normoxia. These results demonstrate a natural and unique characterization of rat BM‐MSCs in normoxia after continuous culture and highlight the inhibiting effects of hypoxia. Finally, this study contributes to the information regarding the application of BM‐MSCs in the regeneration of various tissues. J. Cell. Biochem. 113: 1407–1415, 2012. © 2011 Wiley Periodicals, Inc.
Rainbow connection number and connected dominating sets
Authors: Sunil Chandran L. , Das Anita , Rajendraprasad Deepak , Varma Nithin M.
Published: December 2011

The rainbow connection number of a connected graph is the minimum number of colors needed to color its edges, so that every pair of its vertices is connected by at least one path in which no two edges are colored the same. In this article we show that for every connected graph on n vertices with minimum degree δ, the rainbow connection number is upper bounded by 3n/(δ + 1) + 3. This solves an open problem from Schiermeyer (Combinatorial Algorithms, Springer, Berlin/Hiedelberg, 2009, pp. 432–437), improving the previously best known bound of 20n/δ (J Graph Theory 63 (2010), 185–191). This bound is tight up to additive factors by a construction mentioned in Caro et al. (Electr J Combin 15(R57) (2008), 1).

As an intermediate step we obtain an upper bound of 3n/(δ + 1) − 2 on the size of a connected two‐step dominating set in a connected graph of order n and minimum degree δ. This bound is tight up to an additive constant of 2. This result may be of independent interest.

We also show that for every connected graph G with minimum degree at least 2, the rainbow connection number, rc(G), is upper bounded by Γc(G) + 2, where Γc(G) is the connected domination number of G. Bounds of the form diameter(G)⩽rc(G)⩽diameter(G) + c, 1⩽c⩽4, for many special graph classes follow as easy corollaries from this result. This includes interval graphs, asteroidal triple‐free graphs, circular arc graphs, threshold graphs, and chain graphs all with minimum degree at least 2 and connected. We also show that every bridge‐less chordal graph G has rc(G)⩽3·radius(G). In most of these cases, we also demonstrate the tightness of the bounds.
The potential of greed for independence
Authors: Borowiecki Piotr , Göring Frank , Harant Jochen , Rautenbach Dieter
Published: December 2011

The well‐known lower bound on the independence number of a graph due to Caro (Technical Report, Tel‐Aviv University, 1979) and Wei (Technical Memorandum, TM 81 ‐ 11217 ‐ 9, Bell Laboratories, 1981) can be established as a performance guarantee of two natural and simple greedy algorithms or of a simple randomized algorithm. We study possible generalizations and improvements of these approaches using vertex weights and discuss conditions on so‐called potential functions pG: V(G)→ℕ0 defined on the vertex set of a graph G for which suitably modified versions of the greedy algorithms applied to G yield independent sets I with . We provide examples of such potentials, which lead to bounds improving the bound due to Caro and Wei. Furthermore, suitably adapting the randomized algorithm we give a short proof of Thiele's lower bound on the independence number of a hypergraph (T. Thiele, J Graph Theory 30 (1999), 213–221).
The structure of 4‐strong tournaments containing exactly three out‐arc pancyclic vertices
Authors: Guo Qiaoping , Li Shengjia , Li Ruijuan
Published: December 2011

Yao et al. (Discrete Appl Math 99 (2000), 245–249) proved that every strong tournament contains a vertex u such that every out‐arc of u is pancyclic and conjectured that every k‐strong tournament contains k such vertices. At present, it is known that this conjecture is true for k = 1, 2, 3 and not true for k⩾4. In this article, we obtain a sufficient and necessary condition for a 4‐strong tournament to contain exactly three out‐arc pancyclic vertices, which shows that a 4‐strong tournament contains at least four out‐arc pancyclic vertices except for a given class of tournaments. Furthermore, our proof yields a polynomial algorithm to decide if a 4‐strong tournament has exactly three out‐arc pancyclic vertices.
Late Pleistocene palaeolake in the interior of Oman: a potential key area for the dispersal of anatomically modern humans out‐of‐Africa?
Authors: Rosenberg Thomas M. , Preusser Frank , Blechschmidt Ingo , Fleitmann Dominik , Jagher Reto , Matter Albert
Published: December 2011

Relict fluvial and lacustrine deposits in the interior of Oman near Saiwan consist of waterlain breccias with pebble imbrications and current ripples, covered by algal laminites containing calcified reeds and charcoal pieces. Geomorphological evidence suggests that the palaeolake covered a maximum surface of 1400 km2 and had a maximum depth of about 25 m. Optically stimulated luminescence (OSL) and thermally transferred OSL dating indicate that this palaeolake existed sometime between 132 and 104 ka. The rich archaeological evidence in the area suggests substantial human occupation, possibly at the time when Palaeolake Saiwan existed. Interestingly, the lithic traditions of the archaeological material show no clear relation to coeval findings from neighbouring areas, putting a question mark on the origin of the culture found at Saiwan. This finding raises questions concerning the origin of the population inhabiting Saiwan, as the site lies along one possible route for the dispersal of anatomically modern humans out‐of‐Africa. Copyright © 2011 John Wiley & Sons, Ltd.
Current and projected abundance of potential nest sites for cavity‐nesting ducks in hardwoods of the north central United States
Authors: Denton John C. , Roy Charlotte L. , Soulliere Gregory J. , Potter Bradly A.
Published: December 2011

Clearing of hardwood forests was widespread in the north central region of the United States at the turn of the 20th century, but largely subsided by the 1920s. Hardwood trees in the region have since regenerated and matured into sizes capable of producing nest cavities suitable for cavity‐nesting ducks. We estimated regional nest‐site abundance for cavity‐nesting ducks during 2008, 2018, and 2028 from cavity density and tree‐abundance estimates obtained at 4 hardwood forest sites in conjunction with Forest Inventory and Analysis data and tree‐growth modeling software from the United States Forest Service (Forest Vegetation Simulator). Land cover data were used to determine area of hardwood forests ≤0.5 km, 0.5–1 km, 1–1.5 km, 1.5–2 km, and >2 km from wetlands and open water available to cavity‐nesting ducks. We estimated 13.2 million, 17.0 million, 19.0 million, and 20.1 million potential duck nest cavities available ≤0.5 km, ≤1 km, ≤1.5 km, and ≤2 km of water, respectively, in the region and predicted nest cavity abundance will increase 41% from 2008 to 2028. Hardwood forests in Indiana, Michigan, Ohio, and Wisconsin currently have the highest abundances of potential nest sites, but cavity‐bearing forests in Minnesota, Michigan, and Wisconsin were more commonly proximate to wetlands and open water. Because current and future estimates indicate sufficient nest sites to support growing cavity‐nesting duck populations in the north central United States, we recommend regional management efforts focus on protecting, restoring, and maintaining quality wetlands in proximity to hardwood forests. © 2011 The Wildlife Society.
Tunable Morphologies From Bulk Self‐Assemblies of Poly(acryloxypropyl triethoxysilane)‐b‐poly(styrene)‐b‐poly(acryloxypropyl triethoxysilane) Triblock Copolymers
Authors: Gamys Cé Guinto , Beyou Emmanuel , Bourgeat‐Lami Elodie , David Laurent , Alcouffe Pierre
Published: December 2011

Reactive poly(acryloxypropyl triethoxysilane)‐b‐poly(styrene)‐b‐poly(acryloxypropyl triethoxysilane) (PAPTES‐b‐PS‐b‐PAPTES) triblock copolymers are prepared through nitroxide‐mediated polymerization (NMP). The bulk morphologies formed by this class of copolymers cast into films are examined by small‐angle X‐ray scattering (SAXS) and transmission electron microscopy (TEM). The films morphology can be tuned from spherical structures to lamellar structures by increasing the volume fraction of PS in the copolymer. Thermal annealing at temperatures above 100 °C provides sufficient PS mobility to improve ordering.
Three‐Dimensionally Ordered Macroporous Nitroxide Polymer Brush Electrodes Prepared by Surface‐Initiated Atom Transfer Polymerization for Organic Radical Batteries
Authors: Lin Chun‐Hao , Chou Wei‐Jen , Lee Jyh‐Tsung
Published: December 2011

The synthesis and electrochemical performance of three‐dimensionally ordered macroporous (3DOM) nitroxide polymer brush electrodes for organic radical batteries are reported. The 3DOM electrodes are synthesized via polystyrene colloidal crystal templating with electropolymerization of polypyrrole, modification of surface initiator, and surface‐initiated atom transfer radical polymerization. The discharge capacity of the 3DOM electrodes is proportional to the thickness of the inverse opal. The discharge capacity of the 3DOM electrode at a discharge rate of 5 C is 40 times higher than that of the planar electrode; its cycle‐life performance exhibits 96.1% retention after 250 cycles.
Triblock Copolymer Based on Poly(propylene oxide) and Poly(1‐[11‐acryloylundecyl]‐3‐methyl‐imidazolium bromide)
Authors: Texter John , Vasantha Vivek Arjunan , Crombez Rene , Maniglia Rafael , Slater Lisa , Mourey Thomas
Published: December 2011

The controlled atom transfer radical polymerization of an ionic liquid, 1‐(11‐acryloylundecyl)‐3‐methyl imidazolium bromide (ILBr), from both ends of a telechelic poly(propylene oxide) (PPO) macroinitiator, end‐functionalized with bromoisobutyryloyl is reported. The resulting highly water‐soluble triblock, poly(ILBr‐b‐PO‐b‐ILBr) is multistimuli responsive. This new class of triblocks exhibits classical surface activity in lowering surface tension at the air–water interface and in modifying wetting in waterborne coatings. It also immunizes model colloids against coagulation induced by Debye–Hückel (indifferent electrolyte) electrostatic screening. Further, sol–gel thermoreversibility is unexpectedly found as an additional form of stimuli responsiveness.
Direct 3D Visualization of the Phase‐Separated Morphology in Chlorinated Polyethylene/Nylon Terpolyamide Based Thermoplastic Elastomers
Authors: Crisenza Tommaso , Butt Hans‐Jürgen , Koynov Kaloian , Simonutti Roberto
Published: December 2011

Blends of chlorinated polyethylene and nylon‐6/‐6,6/‐12 terpolyamide were prepared. The ratio of the two components was systematically varied within the blends. The mechanical behavior of the samples was analyzed with tensile tests and dynamical mechanical analysis showing that, for several ratios, materials with improved mechanical properties typical of thermoplastic elastomers were obtained. In such a mechanical regime, a co‐continuous phase‐separated morphology was clearly evidenced at the microscopic scale by 3D laser scanning confocal fluorescent microscopy (LSCFM). At blend compositions where plastic tensile behavior is observed, LSCFM reveals dispersed spheres of one component in the other.
Toward the Realization of A Practical Diketopyrrolopyrrole‐Based Small Molecule for Improved Efficiency in Ternary BHJ Solar Cells
Authors: Lee Junghoon , Yun Myoung Hee , Kim Jonggi , Kim Jin Young , Yang Changduk
Published: December 2011

An easily accessible DPP‐based small molecule (DMPA‐DTDPP) has been synthesized by a simple and efficient route. The resulting molecule, when incorporated into a P3HT:PCBM‐based BHJ solar cell, is found to significantly improve the efficiency. The utility of DMPA‐DTDPP as an additive yields an increase in the short circuit current density (Jsc) because DMPA‐DTDPP serves as an energy funnel for P3HT excitons at the P3HT:PCBM interfaces, resulting in an improved overall power conversion efficiency, compared to the P3HT:PCBM control device. Considering the trouble‐free and cost effective synthesis of DMPA‐DTDPP, it may prove very useful in high‐performance solar cells.
Optically Active Helical Substituted Polyacetylenes Showing Reversible Helix Inversion in Emulsion and Solution State
Authors: Huang Yingying , Zhang Yuanyuan , Yang Wantai , Deng Jianping
Published: December 2011

This Communication reports two substituted polyacetylenes that can adopt helical structures of preferential screw sense in both emulsion (nanoparticle) and solution; however, the handedness of the macromolecular helices is just opposite in the two states. More interestingly, the helical screw sense of the polymers demonstrated a reversible transition between the two states. The unprecedented findings are of significant importance for acquiring new insights into helical polymers and for developing novel advanced chiral materials.
Diffusion‐prepared fast imaging with steady‐state free precession (DP‐FISP): A rapid diffusion MRI technique at 7 T
Authors: Lu Lan , Erokwu Bernadette , Lee Gregory , Gulani Vikas , Griswold Mark A. , Dell Katherine M. , Flask Chris A.
Published: December 2011

Diffusion MRI is a useful imaging technique with many clinical applications. Many diffusion MRI studies have utilized echo‐planar imaging (EPI) acquisition techniques. In this study, we have developed a rapid diffusion‐prepared fast imaging with steady‐state free precession MRI acquisition for a preclinical 7T scanner providing diffusion‐weighted images in less than 500 ms and diffusion tensor imaging assessments in ∼1 min with minimal image artifacts in comparison with EPI. Phantom apparent diffusion coefficient (ADC) and fractional anisotropy (FA) assessments obtained from the diffusion‐prepared fast imaging with steady‐state free precession (DP‐FISP) acquisition resulted in good agreement with EPI and spin echo diffusion methods. The mean apparent diffusion coefficient was 2.0 × 10−3 mm2/s, 1.90 × 10−3 mm2/s, and 1.97 × 10−3 mm2/s for DP‐FISP, diffusion‐weighted spin echo, and diffusion‐weighted EPI, respectively. The mean fractional anisotropy was 0.073, 0.072, and 0.070 for diffusion‐prepared fast imaging with steady‐state free precession, diffusion‐weighted spin echo, and diffusion‐weighted EPI, respectively. Initial in vivo studies show reasonable ADC values in a normal mouse brain and polycystic rat kidneys. Magn Reson Med, 2012. © 2011 Wiley Periodicals, Inc.
Psychometric evaluation of the myasthenia gravis composite using rasch analysis
Authors: Sadjadi Reza , Conaway Mark , Cutter Gary , Sanders Donald B. , Burns Ted M. ,   the MG Composite MG‐QOL15 Study Group
Published: December 2011

Introduction: The MG Composite (MGC) is a validated outcome measure of the clinical manifestations of myasthenia gravis. Methods: We performed Rasch analyses of the MGC to investigate additional properties, including its unidimensionality and the appropriateness of the weights assigned to the response categories for the MGC items. Results: The fit statistics indicated that the 10 items belong together and can be summated for a total score. There was an overall absence of item order distortion between response categories. The Rasch model's expected category response values were compatible with item weights previously assigned. Conclusions: Our analysis suggests that: (1) the score can be summated to estimate an overall disease severity score; (2) the response options of the 10 items are not significantly distorted; and (3) the assigned weights of the response options are appropriate. Muscle Nerve 45: 820–825, 2012
Comparison of relative cerebral blood flow maps using pseudo‐continuous arterial spin labeling and single photon emission computed tomography
Authors: Liu Peiying , Uh Jinsoo , Devous Michael D. , Adinoff Bryon , Lu Hanzhang
Published: December 2011

Pseudo‐continuous arterial spin labeling (PCASL) MRI is a relatively new arterial spin labeling technique and has the potential to extend the cerebral blood flow (CBF) measurement to all tissue types, including white matter. However, the arterial transit time (δa) for white matter is not well established and a limited number of reports using multi‐delay methods have yielded inconsistent findings. In this study, we used a different approach and measured white matter δa (mean ± standard deviation, 1541 ± 173 ms) by determining the arrival times of exogenous contrast agent in a bolus tracking experiment. The data also confirmed δa of gray matter to be 912 ± 209 ms. In the second part of this study, we used these parameters in PCASL kinetic models and compared relative CBF (rCBF, with respect to the whole brain) maps with those measured using a single photon emission computed tomography (SPECT) technique. It was found that the use of tissue‐specific δa in the PCASL model was helpful in improving the correspondence between the two modalities. On a regional level, the gray/white matter CBF ratios were 2.47 ± 0.39 and 2.44 ± 0.18 for PCASL and SPECT, respectively. On a single‐voxel level, the variance between the modalities was still considerable, with an average rCBF difference of 0.27. Copyright © 2011 John Wiley & Sons, Ltd.
Equivalence of double and single wave vector diffusion contrast at low diffusion weighting
Authors: Jespersen Sune Nørhøj
Published: December 2011

Multiple pulsed field gradient diffusion sequences have received renewed interest in recent years as a potentially new type of MRI contrast. This attention is largely a result of the ability to measure pore sizes using low‐amplitude diffusion gradients, and to distinguish between macroscopically isotropic systems of anisotropic pores and systems of isotropic pores. In this article, it is shown that, under many circumstances, the same type of information can be obtained by combining two or more standard single pulse diffusion‐weighted experiments acquired at different diffusion times. Similarly, information from multiple pulsed field gradient diffusion can be reconstructed from several single pulsed diffusion experiments. This possibility is rooted in the information contained in the time dependence of the diffusion tensor, which provides a complete description of the diffusion‐weighted MR signal at low gradient amplitudes. The new information arising at the fourth order in the cumulant expansion is discussed. The coupling of the wave vectors at long mixing times is found to be controlled by the variance of the single pore mean displacement tensor. In particular, a discussion is given concerning the way in which the sensitivity of the fourth‐order term to the pore shape anisotropy is modulated by pore orientation anisotropy and vanishes in coherently oriented homogeneous ensembles. For macroscopically isotropic systems, a new index of pore shape anisotropy is proposed. Copyright © 2011 John Wiley & Sons, Ltd.
Computation of limit and shakedown loads using a node‐based smoothed finite element method
Authors: Nguyen‐Xuan H. , Rabczuk T. , Nguyen‐Thoi T. , Tran T.N. , Nguyen‐Thanh N.
Published: December 2011

This paper presents a novel numerical procedure for computing limit and shakedown loads of structures using a node‐based smoothed FEM in combination with a primal–dual algorithm. An associated primal–dual form based on the von Mises yield criterion is adopted. The primal‐dual algorithm together with a Newton‐like iteration are then used to solve this associated primal–dual form to determine simultaneously both approximate upper and quasi‐lower bounds of the plastic collapse limit and the shakedown limit. The present formulation uses only linear approximations and its implementation into finite element programs is quite simple. Several numerical examples are given to show the reliability, accuracy, and generality of the present formulation compared with other available methods. Copyright © 2011 John Wiley & Sons, Ltd.
Anisotropic mixed finite elements for elasticity
Authors: Pechstein A. , Schöberl J.
Published: December 2011

In this paper, we present a family of mixed finite elements, which are suitable for the discretization of slim domains. The displacement space is chosen as Nédélec's space of tangential continuous elements, whereas the stress is approximated by normal–normal continuous symmetric tensor‐valued finite elements. We show stability of the system on a slim domain discretized by a tensor product mesh, where the constant of stability does not depend on the aspect ratio of the discretization. We give interpolation operators for the finite element spaces, and thereby obtain optimal order a priori error estimates for the approximate solution. All estimates are independent of the aspect ratio of the finite elements. Copyright © 2011 John Wiley & Sons, Ltd.
PMLs: A direct approach
Authors: Kausel Eduardo , de Oliveira Barbosa João Manuel
Published: December 2011

This brief article outlines a new and rather simple method for obtaining the finite element matrices for a perfectly matched layer used for elastic wave propagation in the context of a frequency‐domain formulation. For this purpose, we introduce a fairly mild simplification, which allows applying the stretching functions directly to the mass and stiffness matrices obtained via conventional methods (i.e., elastic elements), a novel strategy that allows circumventing the use of integration via Gaussian quadrature. In essence, the technique proposed herein is equivalent to a direct application of the method of weighted residuals in stretched space, followed by a conversion of the linear dimensions into position‐dependent complex‐values. Most importantly, numerical tests demonstrate that the technique does work as intended, and in fact, splendidly so. Copyright © 2011 John Wiley & Sons, Ltd.
The taboo of cancer: the experiences of cancer disclosure by Iranian patients, their family members and physicians
Authors: Zamanzadeh Vahid , Rahmani Azad , Valizadeh Leila , Ferguson Caleb , Hassankhani Hadi , Nikanfar Ali‐Reza , Howard Fuchsia
Published: December 2011

Objective

The objective of this study is to describe the experiences of cancer disclosure by Iranian cancer patients, their family members and physicians.

Methods

Twenty cancer patients, ten family members and eight physicians participated in this study. Data were collected via semi‐structured, in‐depth interviews and analyzed using qualitative content analysis.

Results

Three categories were identified: cancer avoidance, a climate of non‐disclosure and mutual concern. The findings demonstrated that cancer is a taboo subject and the word cancer, as well as other indicative terms, was rarely used in daily communication. A climate of non‐disclosure predominated because patients were the last to know their diagnosis, they were unaware of their prognosis, and family members and physicians employed strategies to conceal this information. The mutual concern of patients, family members and physicians was the main reason that cancer was not discussed.

Conclusion

Cancer is a taboo subject in Iran that is maintained and reinforced primarily because of the mutual concern of patients, family members and physicians. The first step to address this taboo and inform cancer patients of their diagnosis would be to understand and help mitigate the individual, family and social consequences of disclosure. Copyright © 2011 John Wiley & Sons, Ltd.
Un Abrazo Para La Familia: Providing low‐income Hispanics with education and skills in coping with breast cancer and caregiving
Authors: Marshall Catherine A. , Badger Terry A. , Curran Melissa A. , Koerner Susan Silverberg , Larkey Linda K. , Weihs Karen L. , Verdugo Lorena , García Francisco A. R.
Published: December 2011

Objective

Un Abrazo Para La Familia (A Hug for the Family) is an intervention designed to increase the accessibility of cancer information to low‐income and medically underserved co‐survivors of cancer. Co‐survivors are family members or friends of an individual diagnosed with cancer. Our goal was to increase socio‐emotional support for these co‐survivors and improve skills in coping with cancer. The purpose of our pilot study was to explore the effectiveness of the intervention in increasing cancer knowledge and self‐efficacy among co‐survivors.

Methods

Un Abrazo consisted of three one‐hour sessions, in either Spanish or English. Sessions were delivered by a trained promotora (community health worker), in partnership with a counselor. Sixty participants completed measures of cancer knowledge and self‐efficacy preceding (pre‐test) and following the intervention (post‐test).

Results

From pre‐test to post‐test, the percentage of questions answered correctly about cancer knowledge increased (p < 0.001), as did ratings of self‐efficacy (p < 0.001). Decreases were seen in ‘Do not know’ responses for cancer knowledge (p < 0.01), with a negative correlation between number of ‘Do not knows’ on cancer knowledge at pre‐test and ratings of self‐efficacy at pre‐test (r = −0.47, p < 0.01).

Conclusions

When provided an accessible format, co‐survivors of cancer from underserved populations increase their cancer knowledge and self‐efficacy. This is notable because research indicates that family members and friends with increased cancer knowledge assume more active involvement in the cancer care of their loved ones. Copyright © 2011 John Wiley & Sons, Ltd.
Multi‐agent rotating consensus without relative velocity measurements in three‐dimensional space
Authors: Yang Tan , Jin Yuehui
Published: December 2011

In this paper, we study distributed rotating consensus in networks of second‐order agents using only local position information in three‐dimensional space. We propose a protocol to make the multi‐agent system finally move together around a common point and present corresponding conditions for rotating consensus of the system. Finally, a numerical example is provided to demonstrate the effectiveness of the theoretical results. Copyright © 2011 John Wiley & Sons, Ltd.
Surface morphology of a Cu substrate flattened by a 2″ photoemission‐assisted ion beam source
Authors: Ohtomo Yudai , Ogawa Shuichi , Takakuwa Yuji
Published: December 2011

Photoemission‐assisted plasma irradiation of a 2″ Cu substrate was performed to clarify the effect of ion impingement on the substrate. With the use of a photoemission‐assisted plasma apparatus, the photoemission‐assisted plasma was evaluated by optical emission spectroscopy and discharge characteristics. The density ratio of Ar ions and atoms increases with increasing the bias voltage of photoemission‐assisted plasma. Changes in the surface morphology of the substrate were investigated using atomic force microscopy. Sufficient ion density can be obtained in photoemission‐assisted Townsend discharge, and surface roughness of the Cu substrate decreased as the plasma irradiation time increased. This result indicates that ion impingement from photoemission‐assisted Townsend plasma can sputter the metal surfaces, leading to a decrease in surface roughness. Copyright © 2011 John Wiley & Sons, Ltd.
Organizational Design and Firm‐Wide Collaboration: Retrospective Appreciation of a Change‐Led Consulting Intervention in India within a Systems Thinking Paradigm
Authors: Chowdhury Rajneesh
Published: December 2011

This paper offers a retrospective appreciation of an organization design intervention of a Public Relations firm in India that was undertaken, keeping in mind productive collaboration within geographically spread out teams to support the organization's fast paced growth. It intends to highlight key insights from systems thinking that were used in designing and leading the intervention, and articulate the messages that surfaced during and at the end of the intervention. First, the Public Relations field is introduced in short, then the organization in focus is discussed, leading to a discussion of the need that arose for which the intervention was mandated, then the key concepts and implementation agenda are talked about, and it finally concludes with a retrospective appreciation of the nature of collaboration in the context, from a systems viewpoint. Copyright © 2011 John Wiley & Sons, Ltd.
Computational models for the study of heart–lung interactions in mammals
Authors: Ben‐Tal Alona
Published: December 2011

The operation and regulation of the lungs and the heart are closely related. This is evident when examining the anatomy within the thorax cavity, in the brainstem and in the aortic and carotid arteries where chemoreceptors and baroreceptors, which provide feedback affecting the regulation of both organs, are concentrated. This is also evident in phenomena such as respiratory sinus arrhythmia where the heart rate increases during inspiration and decreases during expiration, in other types of synchronization between the heart and the lungs known as cardioventilatory coupling and in the association between heart failure and sleep apnea where breathing is interrupted periodically by periods of no‐breathing. The full implication and physiological significance of the cardiorespiratory coupling under normal, pathological, or extreme physiological conditions are still unknown and are subject to ongoing investigation both experimentally and theoretically using mathematical models. This article reviews mathematical models that take heart–lung interactions into account. The main ideas behind low dimensional, phenomenological models for the study of the heart–lung synchronization and sleep apnea are described first. Higher dimensions, physiology‐based models are described next. These models can vary widely in detail and scope and are characterized by the way the heart–lung interaction is taken into account: via gas exchange, via the central nervous system, via the mechanical interactions, and via time delays. The article emphasizes the need for the integration of the different sources of heart–lung coupling as well as the different mathematical approaches.WIREs Syst Biol Med2012, 4:163–170. doi: 10.1002/wsbm.167

This article is categorized under:

Models of Systems Properties and Processes > Organismal Models