bluuebunny/crossref_metadata_2025 huggingface dataset:
A Novel Xanthone from Garcinia oligantha
Authors: Gao Xue‐Mei , Cui Ming‐Zhu , Yu Ting , Hu Qiu‐Fen , Pu Jian‐Xin , Du Xue , Liu Tian‐Cheng , Qian Luo Kathy
Published: March 2013

One novel xanthone, oliganthone A (1), was isolated from the stems of the plant Garcinia oligantha. It features the O‐bearing C(3)‐atom and absence of C(4) compared with the structures of related known xanthones, which have never been reported before. The structure of this compound was elucidated by spectroscopic analysis. Compound 1 showed strong HeLa cell growth‐inhibiting effects with IC50 values below 10 μM.
Two New Pentacyclic Triterpenes from Abelmoschus esculentus
Authors: Zhou Yonghui , Jia Xin , Shi Jinmin , Xu Yinpeng , Jing Linlin , Jia Lu
Published: March 2013

Two new pentacyclic triterpenes, (3β,21β)‐19,21‐epoxylup‐20(29)‐en‐3‐yl acetate (1) and (3β)‐9,18‐dihydroxyolean‐12‐en‐3‐yl acetate (2), were isolated from Abelmoschus esculentus (L.) Moench. Their structures were determined on the basis of detailed analyses of their 1D‐ and 2D‐NMR‐spectroscopic and MS data.
New Selenosemicarbazides Derived from Imidazole‐Based Carbohydrazides
Authors: Pieczonka Adam M. , Ciepielowski Krzysztof , Cebulska Zofia , Mlostoń Grzegorz , Linden Anthony , Heimgartner Heinz
Published: March 2013

Imidazole‐based carbohydrazides, i.e., 3‐oxidoimidazole‐4‐carbohydrazides 1 and 2‐[(imidazol‐2‐yl)sulfanyl]acetohydrazides 6, react with aryl isoselenocyanates 4 in MeOH at room temperature to give the corresponding selenosemicarbazides 5 and 7, respectively, in good yields. On heating 7b in DMF in the presence of air to 100°, 1,3,4‐oxadiazole 8a was formed via cyclization and formal elimination of H2Se. Product 8a was also obtained after heating of a mixture of 4a and 6b under the same conditions. On the other hand, on heating of a solution of 7c in MeOH at reflux, a cyclization occurred to give the corresponding 1,2,4‐triazole‐3‐selone 9b. Again, the same product was formed when a mixture of 4b and 6b was heated in MeOH. Surprisingly, analogous cyclizations of selenosemicarbazides of type 5 under the same conditions failed, and only decomposition was observed. The structures of 7a, 7d, and 9b have been established by X‐ray crystallography.
Sensitivity to First‐Order Relations of Facial Elements in Infant Rhesus Macaques
Authors: Paukner Annika , Bower Seth , Simpson Elizabeth A. , Suomi Stephen J.
Published: March 2013

Faces are visually attractive to both human and nonhuman primates. Human neonates are thought to have a broad template for faces at birth and prefer face‐like to non‐face‐like stimuli. To better compare developmental trajectories of face processing phylogenetically, here, we investigated preferences for face‐like stimuli in infant rhesus macaques using photographs of real faces. We presented infant macaques aged 15–25 days with human, macaque and abstract faces with both normal and linear arrangements of facial features and measured infants' gaze durations, number of fixations and latency to look to each face using eye‐tracking technology. There was an overall preference for normal over linear facial arrangements for abstract and monkey faces but not human faces. Moreover, infant macaques looked less at monkey faces than at abstract or human faces. These results suggest that species and facial configurations affect face processing in infant macaques, and we discuss potential explanations for these findings. Further, carefully controlled studies are required to ascertain whether infant macaques' face template can be considered as broad as human infants' face template. Copyright © 2013 John Wiley & Sons, Ltd.
A China data set of soil properties for land surface modeling
Authors: Shangguan Wei , Dai Yongjiu , Liu Baoyuan , Zhu Axing , Duan Qingyun , Wu Lizong , Ji Duoying , Ye Aizhong , Yuan Hua , Zhang Qian , Chen Dongdong , Chen Ming , Chu Jianting , Dou Youjun , Guo Jianxia , Li Haiqin , Li Junjia , Liang Lu , Liang Xiao , Liu Heping , Liu Shuyan , Miao Chiyuan , Zhang Yizhou
Published: March 2013

A comprehensive 30×30 arc‐second resolution gridded soil characteristics data set of China has been developed for use in the land surface modeling. It includes physical and chemical attributes of soils derived from 8979 soil profiles and the Soil Map of China (1:1,000,000). We used the polygon linkage method to derive the spatial distribution of soil properties. The profile attribute database and soil map are linked under the framework of the Genetic Soil Classification of China which avoids uncertainty in taxon referencing. Quality control information (i.e., sample size, soil classification level, linkage level, search radius and texture) is included to provide “confidence” information for the derived soil parameters. The data set includes 28 attributes for 8 vertical layers at the spatial resolution of 30×30 arc‐seconds. Based on this data set, the estimated storage of soil organic carbon in the upper 1 m of soil is 72.5 Pg, total N is 6.6 Pg, total P is 4.5 Pg, total K is 169.9 Pg, alkali‐hydrolysable N is 0.55 Pg, available P is 0.03 Pg, and available K is 0.61 Pg. These estimates are reasonable compared with previous studies. The distributions of soil properties are consistent with common knowledge of Chinese soil scientists and the spatial variations over large areas are well represented. The data set can be incorporated into land models to better represent the role of soils in hydrological and biogeochemical cycles in China.
Enantiomer‐specific profenofos‐induced cytotoxicity and DNA damage mediated by oxidative stress in rat adrenal pheochromocytoma (PC12) cells
Authors: Lu Xianting , Yu Cheng
Published: March 2013

Recent studies have shown that chiral pesticides could enantioselectively induce cytotoxicity and genotoxicity. However, investigations on molecular mechanisms of enantioselective toxicity of pesticides are limited. In this study, the role of oxidative stress in enantiomer‐specific, profenofos (PFF)‐induced cytotoxicity and genotoxicity was investigated using PC12 cells. The results demonstrated that PFF enantioselectively reduced cell viability and induced DNA damage in PC12 cells. A concentration‐ and time‐dependent significant induction of reactive oxygen species (ROS), malondialdehyde and gene expression encoding antioxidant enzyme (Cu‐ZnSOD, GST and CAT) and stress protein (HSP 70 and HSP 90) was observed in (−)­PFF, whereas (+)­PFF and rac‐PFF exhibited these effects to lesser degrees. Pre‐treatment with vitamin E (600 μM) caused a significant attenuation in the toxic effect; reversing subsequent PFF‐induced elevation of ROS and malondialdehyde (MDA) levels, further strengthening the involvement of oxidative stress in PFF‐mediated toxicity. In addition, the results also showed that PFF‐dependent ROS accumulation, MDA release and oxidative stress gene expression preceded the loss of cell viability and induction of DNA damage, and already significantly changed at concentrations which are not yet cytotoxic or genotoxic. These results indicate that oxidative stress may contribute to PFF‐induced toxicity and that it was not a consequence of it. Copyright © 2013 John Wiley & Sons, Ltd.
Multispectral fluorescence lifetime imaging system for intravascular diagnostics with ultrasound guidance: in vivo validation in swine arteries
Authors: Bec Julien , Ma Dinglong M. , Yankelevich Diego R. , Liu Jing , Ferrier William T. , Southard Jeffrey , Marcu Laura
Published: March 2013

Fluorescence lifetime technique has demonstrated potential for analysis of atherosclerotic lesions and for complementing existing intravascular imaging modalities such as intravascular ultrasound (IVUS) in identifying lesions at high risk of rupture. This study presents a multimodal catheter system integrating a 40 MHz commercial IVUS and fluorescence lifetime imaging (FLIm) using fast helical motion scanning (400 rpm, 0.75 mm/s), able to acquire in vivo in pulsatile blood flow the autofluorescence emission of arterial vessels with high precision (5.08 ± 0.26 ns mean average lifetime over 13 scans). Co‐registered FLIm and IVUS data allowed 3D visualization of both biochemical and morphological vessel properties. Current study supports the development of clinically compatible intravascular diagnostic system integrating FLIm and demonstrates, to our knowledge, the first in vivo intravascular application of a fluorescence lifetime imaging technique. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Architecture of the osteocyte network correlates with bone material quality
Authors: Kerschnitzki Michael , Kollmannsberger Philip , Burghammer Manfred , Duda Georg N , Weinkamer Richard , Wagermaier Wolfgang , Fratzl Peter
Published: March 2013

In biological tissues such as bone, cell function and activity crucially depend on the physical properties of the extracellular matrix which the cells synthesize and condition. During bone formation and remodeling, osteoblasts get embedded into the matrix they deposit and differentiate to osteocytes. These cells form a dense network throughout the entire bone material. Osteocytes are known to orchestrate bone remodeling. However, the precise role of osteocytes during mineral homeostasis and their potential influence on bone material quality remains unclear. To understand the mutual influence of osteocytes and extracellular matrix, it is crucial to reveal their network organization in relation to the properties of their surrounding material. Here we visualize and topologically quantify the osteocyte network in mineralized bone sections with confocal laser scanning microscopy. At the same region of the sample, synchrotron small-angle X-ray scattering is used to determine nanoscopic bone mineral particle size and arrangement relative to the cell network. Major findings are that most of the mineral particles reside within less than a micrometer from the nearest cell network channel and that mineral particle characteristics depend on the distance from the cell network. The architecture of the network reveals optimization with respect to transport costs between cells and to blood vessels. In conclusion, these findings quantitatively show that the osteocyte network provides access to a huge mineral reservoir in bone due to its dense organization. The observed correlation between the architecture of osteocyte networks and bone material properties supports the hypothesis that osteocytes interact with their mineralized vicinity and thus, participate in bone mineral homeostasis.
Expression and function of K(ATP) channels in normal and osteoarthritic human chondrocytes: Possible role in glucose sensing
Authors: Rufino Ana T. , Rosa Susana C. , Judas Fernando , Mobasheri Ali , Lopes M. Celeste , Mendes Alexandrina F.
Published: March 2013

ATP‐sensitive potassium [K(ATP)] channels sense intracellular ATP/ADP levels, being essential components of a glucose‐sensing apparatus in various cells that couples glucose metabolism, intracellular ATP/ADP levels and membrane potential. These channels are present in human chondrocytes, but their subunit composition and functions are unknown. This study aimed at elucidating the subunit composition of K(ATP) channels expressed in human chondrocytes and determining whether they play a role in regulating the abundance of major glucose transporters, GLUT‐1 and GLUT‐3, and glucose transport capacity. The results obtained show that human chondrocytes express the pore forming subunits, Kir6.1 and Kir6.2, at the mRNA and protein levels and the regulatory sulfonylurea receptor (SUR) subunits, SUR2A and SUR2B, but not SUR1. The expression of these subunits was no affected by culture under hyperglycemia‐like conditions. Functional impairment of the channel activity, using a SUR blocker (glibenclamide 10 or 20 nM), reduced the protein levels of GLUT‐1 and GLUT‐3 by approximately 30% in normal chondrocytes, while in cells from cartilage with increasing osteoarthritic (OA) grade no changes were observed. Glucose transport capacity, however, was not affected in normal or OA chondrocytes. These results show that K(ATP) channel activity regulates the abundance of GLUT‐1 and GLUT‐3, although other mechanisms are involved in regulating the overall glucose transport capacity of human chondrocytes. Therefore, K(ATP) channels are potential components of a broad glucose sensing apparatus that modulates glucose transporters and allows human chondrocytes to adjust to varying extracellular glucose concentrations. This function of K(ATP) channels seems to be impaired in OA chondrocytes. J. Cell. Biochem. 114: 1879–1889, 2013. © 2013 Wiley Periodicals, Inc.
Regulation of selective PPARγ modulators in the differentiation of osteoclasts
Authors: Wu Haochen , Li Long , Ma Yong , Chen Yongjun , Zhao Jingfa , Lu Yan , Shen Pingping
Published: March 2013

Diabetes is the most common chronic disease in the world and causes complications with many diseases, such as heart disease and osteoporosis. Osteoporosis is a systemic bone disease characterized by imbalance in bone resorption and bone formation. Osteoclast is type of bone cell that functions in bone resorption and plays a critical role in bone remodeling. Rosiglitazone and pioglitazone, which belong to Thiazolidinediones(TZDs), are commonly used antidiabetic drugs. As PPARγ full agonists, they can activate PPARγ in a ligand‐dependent way. Recent studies indicate that these PPARγ full agonists have some side effects, such as weight gain and bone loss, which may increase the risk of osteoporosis. In contrast, selective PPARγ Modulators (SPPARγMs) are novel PPARγ ligands that can activate PPARγ in different ways and lead to distinct downstream genes. Mice bone marrow cells were stimulated with recombinant mouse RANKL and M‐CSF to generate osteoclasts. To determine the effect on osteoclasts formation, PPARγ ligands (Rosiglitazone, Fmoc‐L‐Leu, and Telmisartan) were added at the beginning of the culture. Rosiglitazone significantly increased the differentiation of multinucleated osteoclasts, while osteoclasts formation triggered by SPPARγMs was much less than that displayed by rosiglitazone. We found that the enhancement of PPARγ ligands may be associated with TRAF6 and downstream ERK signal pathway. We also demonstrated osteoclasts show characteristic M2 phenotype and can be further promoted by PPARγ ligands, especially rosiglitazone. In conclusion, reduced osteoclasts differentiation characteristic of SPPARγMs highlights SPPARγMs potential as therapeutic targets in diabetes, versus traditional antidiabetic drugs. J. Cell. Biochem. 114: 1969–1977, 2013. © 2013 Wiley Periodicals, Inc.
Sclerostin is expressed in osteoclasts from aged mice and reduces osteoclast‐mediated stimulation of mineralization
Authors: Ota Kuniaki , Quint Patrick , Ruan Ming , Pederson Larry , Westendorf Jennifer J. , Khosla Sundeep , Oursler Merry Jo
Published: March 2013

Osteoclast‐mediated bone resorption precedes osteoblast‐mediated bone formation through early adulthood, but formation fails to keep pace with resorption during aging. We previously identified several factors produced by osteoclasts that promote bone formation. In this study, we determined if osteoclast‐produced factors contribute to the impaired bone formation with aging. We previously found that mice between the ages of 18 and 22 months develop age‐related bone loss. Bone marrow‐derived pre‐osteoclasts were isolated from 6‐week, 12‐month, and 18‐ to 24‐month‐old mice and differentiated into osteoclasts in vitro. Conditioned media were collected and compared for osteoblast mineralization support. Conditioned medium from osteoclasts from all ages was able to support mineralization of bone marrow stromal cells. Concentrating the conditioned medium from 6‐week‐old and 12‐month‐old mouse marrow cells‐derived osteoclasts enhanced mineralization support whereas concentrated conditioned medium from 18‐ to 24‐month‐old mouse marrow‐derived osteoclasts repressed mineralization compared to base medium. This observation suggests that an inhibitor of mineralization was secreted by aged murine osteoclasts. Gene and protein analysis revealed that the Wnt antagonist sclerostin was significantly elevated in the conditioned media from 24‐month‐old mouse cells compared to 6‐week‐old mouse cells. Antibodies directed to sclerostin neutralized the influences of the aged mouse cell concentrated conditioned media on mineralization. Sclerostin is primarily produced by osteocytes in young animals. This study demonstrates that osteoclasts from aged mice also produce sclerostin in quantities that may contribute to the age‐related impairment in bone formation. J. Cell. Biochem. 114: 1901–1907, 2013. © 2013 Wiley Periodicals, Inc.
Mechanisms of ceramide‐induced COX‐2‐dependent apoptosis in human ovarian cancer OVCAR‐3 cells partially overlapped with resveratrol
Authors: Lin Hung‐Yun , Delmas Dominique , Vang Ole , Hsieh Tze‐Chen , Lin Sharon , Cheng Guei‐Yun , Chiang Hsiao‐Ling , Chen Chiao En , Tang Heng‐Yuan , Crawford Dana R. , Whang‐Peng Jacqueline , Hwang Jaulang , Liu Leroy F. , Wu Joseph M.
Published: March 2013

Ceramide is a member of the sphingolipid family of bioactive molecules demonstrated to have profound, diverse biological activities. Ceramide is a potential chemotherapeutic agent via the induction of apoptosis. Exposure to ceramide activates extracellular‐signal‐regulated kinases (ERK)1/2‐ and p38 kinase‐dependent apoptosis in human ovarian cancer OVCAR‐3 cells, concomitant with an increase in the expression of COX‐2 and p53 phosphorylation. Blockade of cyclooxygenase‐2 (COX‐2) activity by siRNA or NS398 correspondingly inhibited ceramide‐induced p53 Ser‐15 phosphorylation and apoptosis; thus COX‐2 appears at the apex of the p38 kinase‐mediated signaling cascade induced by ceramide. Induction of apoptosis by ceramide or resveratrol was inhibited by the endocytosis inhibitor, cytochalasin D (CytD); however, cells exposed to resveratrol showed greater sensitivity than ceramide‐treated cells. Ceramide‐treated cells underwent a dose‐dependent reduction in trans‐membrane potential. Although both ceramide and resveratrol induced the expressions of caspase‐3 and ‐7, the effect of inducible COX‐2 was different in caspase‐7 expression induced by ceramide compared to resveratrol. In summary, resveratrol and ceramide converge on an endocytosis‐requiring, ERK1/2‐dependent signal transduction pathway and induction of COX‐expression as an essential molecular antecedent for subsequent p53‐dependent apoptosis. In addition, expressions of caspase‐3 and ‐7 are observed. However, a p38 kinase‐dependent signal transduction pathway and change in mitochondrial potential are also involved in ceramide‐induced apoptosis. J. Cell. Biochem. 114: 1940–1954, 2013. © 2013 Wiley Periodicals, Inc.
Modeling in Engineering: The Role of Representational Fluency in Students' Conceptual Understanding
Authors: Moore Tamara J. , Miller Ronald L. , Lesh Richard A. , Stohlmann Micah S. , Kim Young Rae
Published: March 2013

Background

Modeling abilities play an important role in engineering. The creation and use of representations is a central aspect of modeling, and students who are learning to model often use a variety of representations to express, test, revise, and communicate their own thinking. Consequently, model development often depends on representational fluency and the ability to translate between and within different representational forms.

Purpose

This study investigates the role that representations and representational fluency play in conceptual understanding during a complex modeling task related to heat transfer.

Design/Method

This study involved 16 teams of 3 or 4 college students in a first‐semester heat transfer course participating in a complex modeling task. The task of the student teams was to develop a model to predict the interface temperature and the sensation felt by human skin when touching a utensil made of a given material at a given temperature. Data sources included audio recordings of student teams, as well as student‐generated artifacts.

Results

The results show teams thinking about their model through multiple representations and through translations within and among representations. Students' early ways of thinking used a variety of interacting representations but were often unstable and involved incomplete notions of the system to be modeled. Model development involved increasing representational fluency as well as parallel and interacting progress along a variety of dimensions.

Conclusions

This study furthers the understanding of representational fluency in undergraduate engineering students in a heat transfer setting and how representational fluency contributes to conceptual and application understanding.
Analysis of the morphogenesis and cell proliferation in the retina of a pleuronectiform fish, the turbot psetta maxima (Pleuronectiformes: Teleostei)
Authors: Cid Patricia , Doldán María Jesús , Rodríguez María Soledad , Prego Benjamin , de Miguel Encarnación
Published: March 2013

The morphogenesis and cell proliferation in the retina of turbot (Psetta maxima, Pleuronectiformes: Teleostei) from embryo through metamorphosis have been examined by using proliferating cell nuclear antigen (PCNA)‐immunohistochemistry and general histological procedures. In the embryonic retina, cell proliferation and spatial cell reorganization form the anlage of the pigment epithelium and neural retina. Neurogenesis begins around hatching in the temporal retina, dorsal to the optic nerve exit, and then a wave of cell differentiation spreads to the nasal retina to yield a laminated retina by the end of the prolarval turbot stage. Germinal zones in the differentiated retina persist as a rim at the retinal margin, as well as surrounding the optic fissure in premetamorphic and metamorphic turbot larvae. In these zones, progenitor cells with different morphologies show a similar spatial arrangement, which suggests that they have a similar retinogenic potential. During metamorphosis, asymmetric proliferative activity in turbot germinal zones is associated with a marked expansion of the retinal tissue. Scattered stem cells in the laminated retina, related to the lineage of rod photoreceptors, were also observed both in large premetamorphic larvae and metamorphic turbots. The proliferative activity of these cells increases considerably during metamorphosis, when rod photoreceptors become morphologically differentiated. Microsc. Res. Tech. 76:588–597, 2013. © 2013 Wiley Periodicals, Inc.
Does Low Gas Permeability of Rigid‐Shelled Gekkotan Eggs Affect Embryonic Development?
Authors: ANDREWS ROBIN M. , THOMPSON MICHAEL B. , GREENE VIRGINIA W.
Published: March 2013

Parchment‐shelled eggs are characteristic of most squamates, including the basal clades of gekkotan lizards. The majority of gekkotan lizards, however, produce rigid‐shelled eggs that are highly impermeable to gas exchange; eggs are laid in dry sites and experience a net loss of water during incubation. We tested the hypothesis that the 1,000‐fold lower rate of oxygen diffusion through the shells of rigid‐ compared to parchment‐shelled eggs imposes a physiological cost on development. To do this, we contrasted species with rigid and with parchment shells with regards to (1) rates of embryonic metabolism and (2) rates and patterns of development of the yolk sac and chorioallantois, the vascularized extra‐embryonic membranes that transport oxygen to embryonic tissues. Metabolic rates of embryos from the rigid‐shelled eggs of Gehyra variegata did not differ from those of the parchment‐shelled eggs of Oedura lesueurii. Moreover, maximum metabolic rates of gekkotans with rigid shells did not differ from those of gekkotan or scincid lizards with parchment shells. In contrast, the yolk sac covered more of the surface area of the egg at oviposition, and the chorioallantois reached its full extent earlier for the species with rigid shelled eggs (Chondrodactylus turneri, G. variegata) than for the species with parchment‐shelled eggs (Eublepharis macularius, O. lesueurii). Differences in the temporal patterns of yolk sac and chorioallantois development would thus serve to compensate for low rates of oxygen diffusion through rigid shells of gekkotans. J. Exp. Zool. 319A:259–267, 2013. © 2013 © 2013 Wiley Periodicals, Inc.
Simulation of six years of carbon fluxes for a sedge‐dominated oligotrophic minerogenic peatland in Northern Sweden using the McGill Wetland Model (MWM)
Authors: Wu Jianghua , Roulet Nigel T. , Sagerfors Jorgen , Nilsson Mats B.
Published: March 2013

Northern peatlands store ~30% of the global soil carbon, despite covering only 3% of the land. To understand the carbon balance of these systems and predict their response to changes in climate, robust and reliable models are needed. The McGill Wetland Model (MWM), originally developed to simulate the carbon dynamics of ombrotrophic bogs, was modified to simulate the CO2 biogeochemistry of sedge‐dominated oligotrophic minerogenic peatlands, a prominent peatland type in boreal and subarctic landscapes. Three modifications were implemented: (1) a function to describe the impact of soil moisture on the optimal gross primary production, (2) a scheme to partition the peat profile into oxic and anoxic compartments based on the “effective root depth” as a function of daily sedge net primary production, and (3) a function to describe the “fen” moss water dynamics. The modified MWM was evaluated using eddy‐covariance net ecosystem production (NEP) from Degero Stormyr in northern Sweden. The root mean square error for daily NEP was ~0.46 g C m−2 d−1, and the index of agreement was 84%. This model adequately captures the magnitude and direction of the CO2 fluxes and simulates the seasonal and inter‐annual variability reasonably well (r2 > 0.8). Sensitivity analysis confirms that specifically water table depth (WTD) and moss water content are key biogeochemical hydrology processes for the carbon biogeochemistry of a sedge‐dominated oligotrophic minerogenic peatland. An increase of WTD by 15 cm or air temperature by 3°C could decrease NEP by up to 200% and make the peatland become a source of CO2.
Satellite observations of terrestrial water storage provide early warning information about drought and fire season severity in the Amazon
Authors: Chen Yang , Velicogna Isabella , Famiglietti James S. , Randerson James T.
Published: March 2013

Fire risk in the Amazon can be predicted several months before the onset of the dry season using sea surface temperatures in the tropical north Atlantic and tropical Pacific. The lead times between ocean state and the period of maximum burning (4–11 months) may enable the development of forecasts with benefits for forest conservation, yet the underlying physical and biological mechanisms responsible for these temporal offsets are not well known. Here, we examined the hypothesis that year‐to‐year variations in soil water recharge during the wet season modify atmospheric water vapor and fire behavior during the following dry season. We tested this hypothesis by analyzing terrestrial water storage observations from the Gravity Recovery and Climate Experiment (GRACE), active fires from the Moderate Resolution Imaging Spectroradiometer (MODIS), and several other satellite and atmospheric reanalysis datasets during 2002–2011. We found that terrestrial water storage deficits preceded severe fire seasons across the southern Amazon. The most significant relationships between monthly terrestrial water storage and the sum of active fires during the dry season occurred during April–August (p < 0.02), corresponding to 1–5 month lead times before the peak month of burning (September). Analysis of other datasets provided evidence for a cascade of processes during drought events, with lower cumulative precipitation (and higher cumulative evapotranspiration) in the wet season substantially reducing terrestrial water storage, and subsequently, surface and column atmospheric water vapor. Our results suggest that terrestrial water storage observations from GRACE have the potential to improve fire season forecasts for the southern Amazon.
A facile synthesis of deuterium labeled 2,2‐dimethyl‐[2H6]‐succinic acid and its anhydride
Authors: Srinivas G. , Unny V. K. P. , Mukkanti K. , Choudary B. M.
Published: March 2013

Deuterium labeled 2,2‐dimethyl‐[2H6]‐succinic anhydride by a sequence of reactions involving Knoevenagel condensation of [2H6]‐acetone with ethyl cyanoacetate in the presence of piperidine, Michael addition of cyanide, HCl hydrolysis, simultaneous decarboxylation, and subsequent dehydration using acetic anhydride in an overall yield of 34.23% based on [2H6]‐acetone utilized in the reaction is reported. The title compounds were characterized and confirmed spectroscopically by Fourier transform infrared, 1H‐NMR, and Mass. The chemical purity as determined by HPLC was 99%. To the best of our knowledge, the synthesis of these specifically deuterium labeled compounds has not been reported so far.
Degrees of freedom effect on fragmentation in tandem mass spectrometry of singly charged supramolecular aggregates of sodium sulfonates
Authors: Indelicato Serena , Bongiorno David , Indelicato Sergio , Drahos Laszlo , Turco Liveri Vincenzo , Turiák Lilla , Vékey Karoly , Ceraulo Leopoldo
Published: March 2013

The characteristic collision energy (CCE) to obtain 50% fragmentation of positively and negatively single charged noncovalent clusters has been measured. CCE was found to increase linearly with the degrees of freedom (DoF) of the precursor ion, analogously to that observed for synthetic polymers. This suggests that fragmentation behavior (e.g. energy randomization) in covalent molecules and clusters are similar. Analysis of the slope of CCE with molecular size (DoF) indicates that activation energy of fragmentation of these clusters (loss of a monomer unit) is similar to that of the lowest energy fragmentation of protonated leucine–enkephalin. Positively and negatively charged aggregates behave similarly, but the slope of the CCE versus DoF plot is steeper for positive ions, suggesting that these are more stable than their negative counterparts. Copyright © 2013 John Wiley & Sons, Ltd.
Positive and negative‐mode laser desorption/ionization‐mass spectrometry (LDI‐MS) for the detection of indigoids in archaeological purple
Authors: Ribechini Erika , Pérez‐Arantegui Josefina , Colombini Maria Perla
Published: March 2013

Laser‐based ionization techniques have demonstrated to be a valuable analytical tool to study organic pigments by mass spectrometric analyses. Though laser‐based ionization techniques have identified several natural and synthetic organic dyes and pigments, they have never been used in the characterization of purple.

In this work, positive and negative‐mode laser desorption/ionization mass spectrometry (LDI‐MS) was used for the first time to detect indigoids in shellfish purple. The method was used to study organic residues collected from archaeological ceramic fragments that were known to contain purple, as determined by a classical high‐performance liquid chromatography‐based procedure.

LDI‐MS provides a mass spectral fingerprint of shellfish purple, and it was found to be a rapid and successful tool for the identification of purple. In addition, a comparison between positive and negative mode ionization highlighted the complementarity of the two ionization modes. On the one hand, the negative‐ion mode LDI‐MS showed a better selectivity and sensitivity to brominated molecules, such as 6,6'‐dibromoindigo, 6‐monobromoindigo, 6,6'‐dibromoindirubin, 6‐ and 6’‐monobromoindirubin, thanks to their electronegativity, and produced simpler mass spectra. On the other hand, negative‐ion mode LDI‐MS was found to have a lower sensitivity to non‐brominated compounds, such as indigo and indirubin, whose presence can be established in any case by collecting the complementary positive‐ion LDI mass spectrum. Copyright © 2013 John Wiley & Sons, Ltd.
Methods for uncertainty assessment of climate models and model predictions over East Asia
Authors: Heo Ki‐Young , Ha Kyung‐Ja , Yun Kyung‐Sook , Lee Sun‐Seon , Kim Hyung‐Jin , Wang Bin
Published: March 2013

Model performance and uncertainty have been assessed using simulations of the climate in the 20th century based on the 21 models of the Intergovernmental Panel on Climate Change's Fourth Assessment Report (IPCC AR4) and NCEP/NCAR reanalysis data. To evaluate the fidelity and reliability of the simulations of East Asian climate change, the following approaches are compared to assess the uncertainty of East Asian monsoon and climate projection in conjunction with global warming: Taylor diagrams using correlation and standard deviation of model results over East Asia (100°E–150°E, 20°N–45°N), signal‐to‐noise ratio (SNR), and principal‐mode comparison identified by empirical orthogonal function (EOF) analysis. On the basis of the Taylor diagram and SNR results, good performance models with statistically high fidelity produce higher values of warming over East Asia and an enhancement of the northwest–southeast temperature gradient between the land and ocean. This enhanced temperature gradient may strengthen the East Asian summer monsoon flow, resulting in a greater increase in precipitation along the East Asian summer rain band on the continental side of East Asia. However, the good performance models as determined by the principal‐mode comparison produce lower values of warming over the East Asia region during winter; these values are clearly different from the corresponding values obtained from the Taylor diagram and SNR approaches. These results suggest that the models that give priority to the signal associated with the first leading mode of EOF or the principal mode may predict less warming than other models. The models that predict an El Niño‐like state in response to greenhouse warming produce less warming over East Asia, corresponding to the results of the principal‐mode comparison.
Locally injection of cell sheet fragments enhances new bone formation in mandibular distraction osteogenesis: A rabbit model
Authors: Ma Dongyang , Ren Liling , Yao Hong , Tian Wenyan , Chen Fulin , Zhang Junrui , Liu Yanpu , Mao Tianqiu
Published: March 2013

Effective methods to shorten the treatment period of distraction osteogenesis (DO) are needed. To investigate whether injections of osteogenic bone marrow stromal cell (BMSC) sheet fragments could be used to facilitate new bone formation during DO, 30 rabbits underwent bilateral mandibular osteotomy and their mandibles were lengthened at a rate of 0.75 mm/12 h for 6 days after a 5‐day latency period. There were three treatment groups (n = 10 for each group): Serum‐free medium, dissociated BMSCs, and BMSC sheet fragments. A local injection was conducted with a needle directly into the distracted areas immediately after distraction. Rabbits were sacrificed for examination at 3 and 6 weeks after injection. Gross examination, radiographic evaluation, and micro‐CT scanning indicated a significant increase in bony union in the BMSC sheet fragment group, compared with the medium group and the dissociated cell group. The histomorphometric analysis showed more intensive bone formation in the sheet fragment group than the other two groups at each time point. Additionally, the peak load was significantly higher in the fragment group than those in the others. The results show that injection of BMSC sheet fragments promotes bone formation in DO and indicate a promising approach to shorten the treatment period of osteodistraction. © 2013 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 31:1082–1088, 2013
Impingement and stability of total hip arthroplasty versus femoral head resurfacing using a cadaveric robotics model
Authors: Colbrunn R.W. , Bottros J.J. , Butler R.S. , Klika A.K. , Bonner T.F. , Greeson C. , van den Bogert A.J. , Barsoum W.K.
Published: March 2013

We identified and compared the impingent‐free range of motion (ROM) and subluxation potential for native hip, femoral head resurfacing (FHR), and total hip arthroplasty (THA). These constructs were also compared both with and without soft tissue to elucidate the role of the soft tissue. Five fresh‐frozen bilateral hip specimens were mounted to a six‐degree of freedom robotic manipulator. Under load‐control parameters, in vivo mechanics were recreated to evaluate impingement free ROM, and the subluxation potential in two “at risk” positions for native hip, FHR, and THA. Impingement‐free ROM of the skeletonized THA was greater than FHR for the anterior subluxation position. For skeletonized posterior subluxations, stability for THA and FHR constructs were similar, while a different pattern was observed for specimens with soft tissues intact. FHR constructs were more stable than THA constructs for both anterior and posterior subluxations. When the femoral neck is intact the joint has an earlier impingement profile placing the hip at risk for subluxation. However, FHR design was shown to be more stable than THA only when soft tissues were intact. © 2013 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 31:1108–1115, 2013
Genotypic variation for potassium efficiency in wild and domesticated watermelons under ample and limited potassium supply
Authors: Fan Molin , Bie Zhilong , Xie Huiying , Zhang Fang , Zhao Shuang , Zhang Hongyan
Published: March 2013

Potassium (K) is an important nutrient for watermelon (Citrullus lanatus Thunb. Matsum. & Nakai). However, there is little knowledge about genetic variations in K efficiency in watermelon. Sixty‐four watermelon genotypes were grown under conditions of ample (6 mM) and limited (0.1 mM) K supply in a glasshouse. Thirty‐eight wild genotypes (C. lanatus var. citroide) and 26 domesticated genotypes (C. lanatus var. lanatus) were cultivated hydroponically for 30 d. Shoot dry weight, shoot K concentration, K uptake, K‐use index (shoot dry weight / shoot K concentration), relative shoot dry weight (shoot dry weight under limited K / shoot dry weight under ample K), and relative shoot K concentration (shoot K concentration under limited K / shoot K concentration under ample K) were determined. Significant differences were observed among genotypes. The K efficiency was classified based on a medium‐efficiency interval which is equivalent to the 95% confidence interval of the mean relative shoot dry weight and relative shoot K concentration. Genotypic data above or below this interval were classified as either K‐efficient or K‐inefficient. We identified eight K‐efficient genotypes, of which four were wild types. Thus, wild watermelons can be used in breeding programs to improve the K efficiency of domesticated watermelons.
Additive Prozesskette zur Instandsetzung von Bauteilen
Authors: Bergmann André , Grosser Henrik , Graf Benjamin , Uhlmann Eckart , Rethmeier Michael , Stark Rainer
Published: March 2013

Komplexe Bauteile ohne Fügestellen sind die Spezialität additiver Verfahren. Immer deutlicher wird der Wert dieser Technologie für den Turbomaschinenbau, etwa bei der Fertigung von Turbinenschaufeln mit inneren Kühlstrukturen. Wichtig für vorbildgetreue Turbinenkomponenten: Die Technologie ermöglicht die Fertigung von Freiformen und Hinterschnitten, von außen‐ und innenliegenden filigranen, komplexen Strukturen als Einzelteil – und das in einem einzigen Arbeitsschritt. Des Weiteren benötigen additive Verfahren keine formgebenden Werkzeuge und weisen demnach kürzere Prozessketten im Vergleich zu konventionellen Herstellungsverfahren auf. Wirtschaftliche Vorteile kommen vor allem bei kleinen Losgrößen und Bauteilabmessungen zur Geltung.

In diesem Artikel werden am Beispiel einer Turbinenschaufel Schlüsseltechnologien einer additiven Prozesskette gezeigt. Zunächst erfolgt die additive Fertigung einer Turbinenschaufel mittels Selective Laser Melting (SLM). Das Verfahren ermöglicht die Integration innenliegender Kühlkanäle. An dieser Schaufel wird anschließend mittels Laser‐PulverAuftragschweißen (LPA) die Reparatur unterschiedlicher Beschädigungen demonstriert. Im nächsten Schritt der Prozesskette bietet ein optischer 3D‐Scan der Schaufel die Möglichkeit zur Qualitätskontrolle und zum Vergleich der Bauteilabmessungen mit der Sollgeometrie.
Dauerfestigkeit nach dem Laserstrahlbeschichten
Authors: Köhler Henry , Seefeld Thomas , Vollertsen Frank
Published: March 2013

Das Laserstrahlbeschichten wird seit langem erfolgreich für eine Vielzahl von Anwendungen eingesetzt, um beispielsweise funktionale Randschichten bzw. schadhafte Ausgangsgeometrien wiederherzustellen. Einem großen Feld steht das Verfahren jedoch bis heute nicht bzw. nur sehr eingeschränkt zur Verfügung: Bauteile, die dynamischen Lasten ausgesetzt sind. Grund dafür ist, dass bisher wenige Untersuchungen systematisch nachweisen, inwiefern der Schweißprozess entsprechende Bauteileigenschaften beeinflusst.
High prevalence of vitamin A deficiency and vitamin D deficiency in patients evaluated for liver transplantation
Authors: Venu Mukund , Martin Eric , Saeian Kia , Gawrieh Samer
Published: March 2013

Deficiencies in vitamins A, D, and E have been linked to night blindness, bone health, and post–liver transplant reperfusion injury. The aim of this study was to determine the prevalence and predictive factors of fat-soluble vitamin deficiencies in liver transplant candidates. We reviewed the medical records of liver transplant candidates at our center from January 2008 to September 2011. The etiology of cirrhosis, Model for End-Stage Liver Disease score, Child-Pugh class, body mass index (BMI), and vitamin A, vitamin E, and vitamin 25-OH-D levels were recorded. Patients were excluded for incomplete laboratory data, short gut syndrome, celiac disease, pancreatic insufficiency, or prior liver transplantation. Sixty-three patients were included. The most common etiologies of liver disease were alcohol (n = 23), hepatitis C virus (n = 19), and nonalcoholic steatohepatitis (n = 5). Vitamin A and D deficiencies were noted in 69.8% and 81.0%, respectively. Only 3.2% of the patients were vitamin E–deficient. There were no documented cases of night blindness. Twenty-five of the 55 patients with bone density measurements had osteopenia, and 10 had osteoporosis. Four patients had vertebral fractures. There was 1 case of posttransplant reperfusion injury in a patient with vitamin E deficiency. In a multivariate analysis, there were no statistically significant predictors for vitamin D deficiency. The Child-Pugh class [odds ratio (OR) = 6.84, 95% confidence interval (CI) = 1.52-30.86, P = 0.01], elevated total bilirubin level (OR = 44.23, 95% CI = 5.02-389.41, P < 0.001), and elevated BMI (OR = 1.17, 95% CI = 1.00-1.36, P = 0.045) were found to be predictors of vitamin A deficiency. In conclusion, the majority of liver disease patients evaluated for liver transplantation at our center had vitamin A and D deficiencies. The presence or absence of cholestatic liver disease did not predict deficiencies, whereas Child-Pugh class, bilirubin level, and elevated BMI predicted vitamin A deficiency. Liver Transpl 19:627–633, 2013. © 2013 AASLD.
Selective Detection of NADPH among Four Pyridine‐Nucleotide Cofactors by a Fluorescent Probe Based on Aggregation‐Induced Emission
Authors: Noguchi Takao , Dawn Arnab , Yoshihara Daisuke , Tsuchiya Youichi , Yamamoto Tatsuhiro , Shinkai Seiji
Published: March 2013

A fluorescent sensor based on guanidinium‐tethered tetraphenylethene (TPE) has been investigated toward the differentiation of pyridine nucleotide cofactors (NAD+, NADH, NADP+, and NADPH). TPE selectively recognizes NADPH possessing the higher tetra‐anionic net‐charge, resulting in the steep “turn‐on” fluorescence increase. The comparative aggregation behaviors and fluorescence response studies of TPE on the four cofactors reveal that the critical aggregate concentration of TPE against NADPH correlates directly with the concentration threshold for the fluorescence response. These results establish that TPE can selectively differentiate NADPH over the other three cofactors by the steep aggregation‐induced fluorescence response accompanied by the high signal‐to‐background contrast.

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Photoluminescent Toroids Formed by Temperature‐Driven Self‐Assembly of Rhodamine B End‐Capped Poly(N‐isopropylacrylamide)
Authors: Hsu Chih‐Yuan , Chang Shih‐Chieh , Hsu Keh‐Ying , Liu Ying‐Ling
Published: March 2013

In this paper, self‐assembled polymeric toroids formed by a temperature‐driven process are reported. Rhodamine B (RhB) end‐capped poly(N‐isopropylacrylamide) (PNIPAAm) demonstrating a lower critical solution temperature (LCST) is prepared. In a two‐phase system, the polymer in the aqueous phase could move to the chloroform phase on raising the temperature above its LCST. This temperature‐driven process results in the formation of polymeric toroids in the chloroform phase, and the strategy affords a new pathway to toroidal self‐assembly of polymers. Moreover, the photoluminescent behavior of the RhB end‐capped PNIPAAm species formed by the process is also studied and discussed.

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Magnetoresistance of multi‐walled carbon nanotubes modified with iron
Authors: Ovsienko I. V. , Matzui L.Y. , Yatsenko I. V. , Khrapatiy S. V. , Prylutskyy Y. I. , Ritter U. , Scharff P. , Le Normand F.
Published: March 2013

The dependence of the magnetoresistance of iron‐doped multi‐walled carbon nanotubes (Fe‐MWCNTs) on the carbon nanotubes arrangement, the temperature, the relative orientation of the magnetic field, and the current was investigated. The findings show that the magnetoresistance of partially‐oriented Fe‐MWCNTs is due to a combination of two mechanisms: (1) the giant magnetoresistance (GMR) that takes place in layered or cluster systems consisting of magnetic and nonmagnetic materials, and (2) the anisotropic magnetoresistance which is characteristic of ferromagnetic metals. For array‐oriented Fe‐MWCNTs the dominant mechanism of magnetoresistance depends on the relative orientation of the magnetic field and current through the sample, namely it depends on the localization mechanism at the mutually perpendicular orientation of the magnetic field and current and the GMR effect in mutual parallel orientation of the magnetic field and current.
The role of band structure in electron transfer kinetics in low‐dimensional carbon
Authors: Szroeder P. , Górska A. , Tsierkezos N. , Ritter Uwe , Strupiński W.
Published: March 2013

The role of band structure in heterogeneous electron transfer kinetics at graphene and carbon nanotube electrodes is discussed within Gerischer‐Marcus model. Raman spectroscopy was used to estimate the averaged density of defects in anodized epitaxial graphene, single‐walled carbon nanotube mats, and multi‐walled carbon nanotube carpets. Comparison of the density of defects with cyclic voltammetry data reveals correlation between the defect induced electronic states near the Fermi level and electrochemical efficiency. Electron transfer at low dimensional carbon electrodes is additionally enhanced by layer curvature and doping. Results show that defect induced states are responsible for large dispersion of heterogeneous electron transfer rate constant at different graphitic nanocarbon electrodes.
Physical properties of C60 fullerene nanostructures
Authors: Kolyadina E. Y. , Matveeva L. A. , Neluba P. L. , Shlapatskaya V. V.
Published: March 2013

Nanoheterostructures of C60 fullerenes were obtained by thermal vacuum sublimation of a C60 fullerene powder onto non‐heated silicon, mica, quartz, and Ti6Al4V alloy substrates. The composition, structure, electronic and optical properties and the internal mechanical stresses of the heterostructures were studied by Raman spectroscopy, atomic force microscopy, electroreflectance modulation spectroscopy, light absorption spectroscopy, photoluminescence, and measurements of the heterostructure bending. The effects of the film sublimation temperature and external actions (γ‐irradiation, helium plasma) on the physical properties were studied. Mainly, the appearance of new carbon (graphite‐ and diamond‐like) phases after the decomposition of C60 molecules was observed at increased film sublimation temperature and after γ‐irradiation or helium plasma.