bluuebunny/crossref_metadata_2025 huggingface dataset:
Interleukin‐6 limits influenza‐induced inflammation and protects against fatal lung pathology
Authors: Lauder Sarah N. , Jones Emma , Smart Kathryn , Bloom Anja , Williams Anwen S. , Hindley James P. , Ondondo Beatrice , Taylor Philip R. , Clement Mathew , Fielding Ceri , Godkin Andrew J. , Jones Simon A. , Gallimore Awen M.
Published: July 2013

Balancing the generation of immune responses capable of controlling virus replication with those causing immunopathology is critical for the survival of the host and resolution of influenza‐induced inflammation. Based on the capacity of interleukin‐6 (IL‐6) to govern both optimal T‐cell responses and inflammatory resolution, we hypothesised that IL‐6 plays an important role in maintaining this balance. Comparison of innate and adaptive immune responses in influenza‐infected wild‐type control and IL‐6‐deficient mice revealed striking differences in virus clearance, lung immunopathology and generation of heterosubtypic immunity. Mice lacking IL‑6 displayed a profound defect in their ability to mount an anti‐viral T‐cell response. Failure to adequately control virus was further associated with an enhanced infiltration of inflammatory monocytes into the lung and an elevated production of the pro‐inflammatory cytokines, IFN‐α and TNF‐α. These events were associated with severe lung damage, characterised by profound vascular leakage and death. Our data highlight an essential role for IL‐6 in orchestrating anti‐viral immunity through an ability to limit inflammation, promote protective adaptive immune responses and prevent fatal immunopathology.
FCRL3 promotes TLR9‐induced B‐cell activation and suppresses plasma cell differentiation
Authors: Li Fu Jun , Schreeder Daniel M. , Li Ran , Wu Jiongru , Davis Randall S.
Published: July 2013

Fc receptor‐like (FCRL) molecules are preferentially expressed by B lymphocytes and possess tyrosine‐based immunoregulatory function. Although they generally inhibit B‐cell receptor signaling, their influence on other activation pathways remains largely unexplored. In humans, FCRL3 encodes a type I transmembrane protein harboring both cytoplasmic ITAM and ITIM elements that can repress B‐cell receptor activation. Despite this inhibitory property, mounting associations for FCRL3 with autoimmune and lympho‐proliferative disorders imply a role for it in promoting B‐cell pathogenesis. Here, we explore the influence of FCRL3 on B‐cell responses to innate TLR9 stimulation. A detailed survey of blood B‐cell populations found that FCRL3 expression increased as a function of differentiation and was higher among memory subsets with innate‐like features. FCRL3 ligation augmented CpG oligodeoxynucleotide TLR9‐mediated B‐cell proliferation, activation, and survival, but surprisingly, abrogated plasma cell differentiation and antibody production. Although FCRL3 amplified the NF‐κB and mitogen‐activated protein kinase signaling cascades, it halted CpG triggered BLIMP1 induction in an ERK‐dependent fashion. These findings indicate that FCRL3 differentially modulates innate signaling in B cells and provide new insight into the potential of this disease‐associated receptor to counter‐regulate adaptive and innate immunity.
Crystallization and polymorphic behavior of shea stearin and the effect of removal of polar components
Authors: Ray Joydeep , Smith Kevin W. , Bhaggan Krishnadath , Nagy Zoltan K. , Stapley Andrew G. F.
Published: July 2013

The crystallization of shea stearin was investigated both before and after pre‐treatment with silica to remove a small amount (0.7 wt%) of diacylglycerols (DAGs) and oxidized material. NMR (for solid fat content), X‐ray diffraction (XRD), polarized light microscopy, confocal Raman microscopy, and non‐isothermal, isothermal and “stop‐and‐return” differential scanning calorimetry (DSC) techniques were used. Four major polymorphs previously found with 1,3‐distearoyl‐2‐oleoyl‐sn‐glycerol (StOSt) were detected: α, γ, β′, and β; whilst evidence for a further (δ) polymorph was found by DSC and possibly XRD but not Raman spectroscopy. Isothermal crystallization of shea stearins by DSC at 20°C produced α and δ forms within 5 min which then transformed to γ. Microscope images showed that after 1 day these had transformed into β′ with a few crystals of β, with further conversion to β after one week. Silica treated samples showed a faster initial crystallization, with faster transformation or direct crystallization into δ and then γ and β′ forms. Non‐isothermal DSC also showed a faster transformation into γ from α on the subsequent remelt. However, further transformation into β appeared to occur at reasonably similar rates for both types, suggesting that DAGs have less influence on this transformation and may be excluded from higher forms.

Practical applications: This paper has two main practical applications: (i) Provides knowledge and understanding of the crystallization and polymorphic behavior of commercial shea stearin, which is a widely used fat in the confectionery, cosmetic, and pharmaceutical industries. (ii) The presence of small amounts of DAGs significantly delays the crystallization process of shea stearin, particularly of the lower polymorphs.
Practical methods to reduce impurities for gram‐scale amounts of acidic sophorolipid biosurfactants
Authors: Baccile Niki , Cuvier Anne‐Sophie , Valotteau Claire , Van Bogaert Inge N. A.
Published: July 2013

Raw sophorolipids, a variety of bioderived glycolipid biosurfactants produced by the yeast Candida bombicola, generally present themselves as a mixture of acetylated acidic and lactonic forms mixed with residual fatty acids. To recover the acidic form alone in large amounts, e.g., tens of grams, which is interesting for various applications in cleaning technologies, material science, medicine, one must either purify the mixture through column chromatography, thus tremendously reducing the final yield, or remove the fatty acids via hot hexane extraction followed by alkaline hydrolysis and a liquid–liquid extraction process; in the latter, pentanol, used as extraction medium, is a high boiling point solvent and, consequently, difficult to remove under standard vacuum extraction conditions. Here, we compare, quantify, and draw the positive and negative aspects of the typical hexane/pentanol extraction route compared to two additional ones, never reported for this system: a cold extraction from a pentanol/alkane mixture and a consecutive filtration on inverse C18‐modified silica phase and silica gel in, respectively, water/acetonitrile and methanol/dichloromethane mixtures. The first one generates highly pure products but quantitative extraction is quite long (up to several days) while the second is an extremely handy and rapid (few hours) way but less quantitative as it provides a product with not less than 6% impurities.
Quantitative analysis of thymosin β4 in whole saliva by capillary electrophoresis–mass spectrometry using multiple ions monitoring (CE‐MIM‐MS)
Authors: Rossetti Diana Valeria , Martelli Claudia , Longhi Renato , Iavarone Federica , Castagnola Massimo , Desiderio Claudia
Published: July 2013

Thymosin β4 (Tβ4) is a peptide present in almost any tissue and in extracellular media in mammals, having multiple amazing functions as wound healing, stimulation of angiogenesis, and suppression of inflammation. This study describes its determination in saliva through CE‐MS using multiple ions monitoring scan mode by isolating the four most intense multicharged ions present in the MS spectra of the peptide. This scan modality, by reducing the baseline noise and interferences, increases the sensitivity and specificity in biological matrices. The CE‐MS separation was optimized by studying different parameters influencing CE analysis, sample injection, and MS ionization, that is, the nebulizer gas flow, the sheath liquid, and BGE composition. The proposed technique can unambiguously identify in short time Tβ4 in saliva after a very fast and reduced sample pretreatment procedure. The method was validated for quantitation showing linearity of the response in the range 0.25 (lower limit of quantification) to 4 μM (average R2 0.996 ± 0.005) and intra‐ and interassay precision and accuracy at three different concentrations with RSD values in the range of 7–16%. It was successfully applied to the analysis of Tβ4 in whole saliva showing a variable peptide content from individual to individual (in the range of 0.3–1.4 μM) and in different days from the same individual. CE‐MS in multiple ions monitoring scan mode provides a fast, selective, and economic method requiring only very few microliters of sample.
High‐throughput deterministic single‐cell encapsulation and droplet pairing, fusion, and shrinkage in a single microfluidic device
Authors: Schoeman Rogier M. , Kemna Evelien W.M. , Wolbers Floor , van den Berg Albert
Published: July 2013

In this article, we present a microfluidic device capable of successive high‐yield single‐cell encapsulation in droplets, with additional droplet pairing, fusion, and shrinkage. Deterministic single‐cell encapsulation is realized using Dean‐coupled inertial ordering of cells in a Yin‐Yang‐shaped curved microchannel using a double T‐junction, with a frequency over 2000 Hz, followed by controlled droplet pairing with a 100% success rate. Subsequently, droplet fusion is realized using electrical actuation resulting in electro‐coalescence of two droplets, each containing a single HL60 cell, with 95% efficiency. Finally, volume reduction of the fused droplet up to 75% is achieved by a triple pitchfork structure. This droplet volume reduction is necessary to obtain close cell–cell membrane contact necessary for final cell electrofusion, leading to hybridoma formation, which is the ultimate aim of this research.
Utilization of paramagnetic microparticles for automated isolation of free circulating mRNA as a new tool in prostate cancer diagnostics
Authors: Fojtu Michaela , Gumulec Jaromir , Balvan Jan , Raudenska Martina , Sztalmachova Marketa , Polanska Hana , Smerkova Kristyna , Adam Vojtech , Kizek Rene , Masarik Michal
Published: July 2013

Determination of serum mRNA gained a lot of attention in recent years, particularly from the perspective of disease markers. Streptavidin‐modified paramagnetic particles (SMPs) seem an interesting technique, mainly due to possible automated isolation and high efficiency. The aim of this study was to optimize serum isolation protocol to reduce the consumption of chemicals and sample volume. The following factors were optimized: amounts of (i) paramagnetic particles, (ii) oligo(dT)20 probe, (iii) serum, and (iv) the binding sequence (SMPs, oligo(dT)20, serum vs. oligo(dT)20, serum and SMPs). RNA content was measured, and the expression of metallothionein‐2A as possible prostate cancer marker was analyzed to demonstrate measurable RNA content with ability for RT‐PCR detection. Isolation is possible on serum volume range (10–200 μL) without altering of efficiency or purity. Amount of SMPs can be reduced up to 5 μL, with optimal results within 10–30 μL SMPs. Volume of oligo(dT)20 does not affect efficiency, when used within 0.1–0.4 μL. This optimized protocol was also modified to fit needs of automated one‐step single‐tube analysis with identical efficiency compared to conventional setup. One‐step analysis protocol is considered a promising simplification, making RNA isolation suitable for automatable process.
Properties of the thundercloud discharges responsible for terrestrial gamma‐ray flashes
Authors: Dwyer Joseph R. , Liu Ningyu , Rassoul Hamid K.
Published: July 2013

The source of terrestrial gamma‐ray flashes (TGFs) has been an active area of research since their discovery by Compton Gamma‐Ray Observatory/Burst and Transient Source Experiment in 1994. These intense bursts of gamma rays originate within thunderclouds via the rapid production of relativistic runaway electrons, accelerated by thundercloud/lightning electric fields to multi‐MeV energies. Recent studies have shown that electrical discharges within thunderclouds caused by these runaway electrons can generate currents that rival those of lightning and so could serve as an alternative discharge path for thunderclouds. In particular, the discharges responsible for TGFs produce some of the largest amplitude VLF‐LF radio pulses from thunderstorms and, indeed, were previously misidentified as lightning. In this article, we shall provide a brief review of TGFs and present calculations of their electrical properties inside thunderclouds and their gamma‐ray and optical emissions. We shall show that the lightning‐like events responsible for TGFs emit relatively little visible light and, thus, are inherently dark.
The rarity of absent growth rings in Northern Hemisphere forests outside the American Southwest
Authors: George Scott St. , Ault Toby R. , Torbenson Max C. A.
Published: July 2013

We present a synthesis of locally absent (or “missing”) growth rings across the Northern Hemisphere based on 2359 publicly available tree ring‐width records. During the last millennium, widespread absent rings have been observed only in the southwestern United States and were associated with severe drought. Absent rings were uncommon during the growing seasons that followed major volcanic eruptions, including A.D. 1259 and 1816. Because these features have occurred so rarely in high‐latitude and high‐elevation tree ring‐width records, the hypothesis that the Northern Hemisphere tree ring‐width network is compromised by dating errors due to unrecognized absent rings would require that many temperature‐limited forest stands in the network exhibited a reaction to cold temperatures that have essentially never been observed anywhere. If however absent‐ring formation were to increase in forests outside of the American Southwest, that behavior would represent an unprecedented response to environmental stress.
Effects of Weight-Bearing Activities on Bone Mineral Content and Density in Children and Adolescents: A Meta-Analysis
Authors: Behringer Michael , Gruetzner Sebastian , McCourt Molly , Mester Joachim
Published: July 2013

Osteoporosis and associated fractures are a major health concern in Western industrialized nations. Exercise during growth is suggested to oppose the involutional bone loss later in life by increasing peak bone mass. The primary aim of the present meta-analysis was to provide a robust estimate of the effect of weight-bearing activities (WBAs) on bone mineral content (BMC) and areal bone mineral density (aBMD), during childhood and adolescence. To locate relevant studies up to June 2012, computerized searches of multiple bibliographic databases and hand searches of key journals and reference lists were performed. Results were extracted by two independent reviewers. The quality of the included trials was assessed via the Physiotherapy Evidence Database (PEDro) score. The study group effect was defined as the difference between the standardized mean change for the treatment and control groups divided by the pooled pretest SD. From 109 potentially relevant studies, only 27 met the inclusion criteria. The analyzed training programs were capable of significantly increasing BMC and aBMD during growth. However, the weighted overall effect sizes (ESs) for changes in BMC (ES 0.17; 95% confidence interval [CI], 0.05–0.29; p < 0.05) and aBMD (ES 0.26; 95% CI, 0.02–0.49) were small. Stepwise backward regression revealed that more than one-third of the observed variance (r2 = 0.35) between subgroups of the BMC dataset could be explained by differences in the amount of habitual calcium intake per day (beta 0.54, p < 0.01) and the maturational stage (beta −0.28, p < 0.01) at baseline. No significant moderators were identified for aBMD, possibly due to the small number of trials investigating WBAs on aBMD. The results of this meta-analysis conclude that WBAs alongside high calcium intake provide a practical, relevant method to significantly improve BMC in prepubertal children, justifying the application of this exercise form as an osteoporosis prophylaxis in this stage of maturity. © 2014 American Society for Bone and Mineral Research.
High-Sensitivity CRP Is an Independent Risk Factor for All Fractures and Vertebral Fractures in Elderly Men: The MrOS Sweden Study
Authors: Eriksson Anna L , Movérare-Skrtic Sofia , Ljunggren Östen , Karlsson Magnus , Mellström Dan , Ohlsson Claes
Published: July 2013

Epidemiological studies have shown low-grade inflammation measured by high-sensitivity C-reactive protein (hs-CRP) to be associated with fracture risk in women. However, it is still unclear whether hs-CRP is also associated with fracture risk in men. We therefore measured serum levels of hs-CRP in 2910 men, mean age 75 years, included in the prospective population-based MrOS Sweden cohort. Study participants were divided into tertile groups based on hs-CRP level. Fractures occurring after the baseline visit were validated (average follow-up 5.4 years). The incidence for having at least one fracture after baseline was 23.9 per 1000 person-years. In Cox proportional hazard regression analyses adjusted for age, hs-CRP was related to fracture risk. The hazard ratio (HR) of fracture for the highest tertile of hs-CRP, compared with the lowest and the medium tertiles combined, was 1.48 (95% CI, 1.20–1.82). Multivariate adjustment for other risk factors for fractures had no major effect on the associations between hs-CRP and fracture. Results were essentially unchanged after exclusion of subjects with hs-CRP levels greater than 7.5 mg/L, as well as after exclusion of subjects with a first fracture within 3 years of follow-up, supporting that the associations between hs-CRP and fracture risk were not merely a reflection of a poor health status at the time of serum sampling. Femoral neck bone mineral density (BMD) was not associated with hs-CRP, and the predictive role of hs-CRP for fracture risk was essentially unchanged when femoral neck BMD was added to the model (HR, 1.37; 95% CI, 1.09–1.72). Exploratory subanalyses of fracture type demonstrated that hs-CRP was clearly associated with clinical vertebral fractures (HR, 1.61; 95% CI, 1.12–2.29). We demonstrate, using a large prospective population-based study, that elderly men with high hs-CRP have increased risk of fractures, and that these fractures are mainly vertebral. The association between hs-CRP and fractures was independent of BMD. © 2014 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals, Inc. on behalf of the American Society for Bone and Mineral Research. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
Delayed Bone Regeneration Is Linked to Chronic Inflammation in Murine Muscular Dystrophy
Authors: Abou-Khalil Rana , Yang Frank , Mortreux Marie , Lieu Shirley , Yu Yan-Yiu , Wurmser Maud , Pereira Catia , Relaix Frédéric , Miclau Theodore , Marcucio Ralph S , Colnot Céline
Published: July 2013

Duchenne muscular dystrophy (DMD) patients exhibit skeletal muscle weakness with continuous cycles of muscle fiber degeneration/regeneration, chronic inflammation, low bone mineral density, and increased risks of fracture. Fragility fractures and associated complications are considered as a consequence of the osteoporotic condition in these patients. Here, we aimed to establish the relationship between muscular dystrophy and fracture healing by assessing bone regeneration in mdx mice, a model of DMD with absence of osteoporosis. Our results illustrate that muscle defects in mdx mice impact the process of bone regeneration at various levels. In mdx fracture calluses, both cartilage and bone deposition were delayed followed by a delay in cartilage and bone remodeling. Vascularization of mdx fracture calluses was also decreased during the early stages of repair. Dystrophic muscles are known to contain elevated numbers of macrophages contributing to muscle degeneration. Accordingly, we observed increased macrophage recruitment in the mdx fracture calluses and abnormal macrophage accumulation throughout the process of bone regeneration. These changes in the inflammatory environment subsequently had an impact on the recruitment of osteoclasts and the remodeling phase of repair. Further damage to the mdx muscles, using a novel model of muscle trauma, amplified both the chronic inflammatory response and the delay in bone regeneration. In addition, PLX3397 treatment of mdx mice, a cFMS (colony stimulating factor receptor 1) inhibitor in monocytes, partially rescued the bone repair defect through increasing cartilage deposition and decreasing the number of macrophages. In conclusion, chronic inflammation in mdx mice contributes to the fracture healing delay and is associated with a decrease in angiogenesis and a transient delay in osteoclast recruitment. By revealing the role of dystrophic muscle in regulating the inflammatory response during bone repair, our results emphasize the implication of muscle in the normal bone repair process and may lead to improved treatment of fragility fractures in DMD patients. © 2014 American Society for Bone and Mineral Research.
Grcarma: A fully automated task‐oriented interface for the analysis of molecular dynamics trajectories
Authors: Koukos Panagiotis I. , Glykos Nicholas M.
Published: July 2013

We report the availability of grcarma, a program encoding for a fully automated set of tasks aiming to simplify the analysis of molecular dynamics trajectories of biological macromolecules. It is a cross‐platform, Perl/Tk‐based front‐end to the program carma and is designed to facilitate the needs of the novice as well as those of the expert user, while at the same time maintaining a user‐friendly and intuitive design. Particular emphasis was given to the automation of several tedious tasks, such as extraction of clusters of structures based on dihedral and Cartesian principal component analysis, secondary structure analysis, calculation and display of root‐mean‐square deviation (RMSD) matrices, calculation of entropy, calculation and analysis of variance–covariance matrices, calculation of the fraction of native contacts, etc. The program is free‐open source software available immediately for download. © 2013 Wiley Periodicals, Inc.
Usefulness of Thiopurine Metabolites in Predicting Azathioprine Resistance in Pediatric IBD Patients
Authors: Nguyen Thi‐Van‐Anh , Nguyen Thi‐Mai‐Hoang , Lachaux Alain , Boulieu Roselyne
Published: July 2013

Few data on azathioprine (AZA) therapy for inflammatory bowel disease (IBD) exist for children. We evaluated whether the 6‐thioguanine nucleotides (6‐TGN) level predicts AZA refractoriness in children with IBD and whether children benefit an AZA dose escalation. Seventy‐eight children with IBD initially treated with an AZA dose of 1.5–2.5 mg/kg/day were retrospectively included. The dose was adjusted based on the clinical status. The receiver operating characteristic curve and logistic regression were used to determine predictors for AZA resistance. Initially, 18 of 40 (45%) patients receiving a dose of <2 mg/kg/day and 11 of 38 (28.9%) patients receiving a dose of 2–2.5 mg/kg/day achieved remission. The 6‐TGN level above 250 pmol/8.108 RBCs was associated with a higher remission rate, though non‐significant. Among 35 patients with a dose escalation due to treatment failure, 12 (34.3%) achieved remission (the median 6‐TGN level increased from 260 to 394 pmol/8.108 RBCs [P = .002]), 23 (67.6%) were AZA refractory. A 6‐TGN level above 405 pmol/8.108 RBCs was the only predictor for AZA resistance (sensitivity 78.3%, specificity 75%, OR 10.8 [95% CI: 2.1–55.7, P = .004]). Serial metabolite monitoring is useful to identify children with IBD resistant to AZA. Children who cannot achieve remission despite a 6‐TGN level above 405 pmol/8.108 RBCs should receive alternative therapies than dose increase.
Relationships between the large‐scale atmosphere and the small‐scale convective state for Darwin, Australia
Authors: Davies L. , Jakob C. , May P. , Kumar V. V. , Xie S.
Published: July 2013

A persistent problem for numerical weather and climate models is the representation of tropical convective precipitation which for the most part occurs on spatial and temporal scales too small and too short to be explicitly resolved. Given that model parameterizations represent this subgrid convection as a function of the large‐scale atmospheric state, an understanding of the strongest relationships between the two scales is needed. This study introduces a method to create two concurrent long‐term data sets that describe both the large‐scale atmosphere and the characteristics of the small‐scale convection. Important relationships between these two scales are then investigated. It is found that convective precipitation, through convective precipitation area, has the strongest relationship with dynamical variables such as moisture convergence and vertical velocity at midlevels. The magnitude of the fluctuations of convective strength about the mean is found to be anticorrelated with the strength of the large‐scale variables, indicating a more stochastic behavior of tropical convection in weakly than strongly forced regimes, respectively. Atmospheric stability related variables are not found to be positively related to either convective precipitation area or convective precipitation intensity, which is often an assumption made in convective parameterization. On the contrary, in a more unstable atmosphere, there is lower convective precipitation.
A general route for 13C‐labeled fluorenols and phenanthrenols via palladium‐catalyzed cross‐coupling and one‐carbon homologation
Authors: Wu Ruilian , ‘Pete’ Silks L. A. , Olivault‐Shiflett Morgane , Williams Robert F. , Ortiz Erick G. , Stotter Philip , Kimball David B. , Martinez Rodolfo A.
Published: July 2013

A series of 13C‐labeled polyaromatic hydrocarbons (PAHs), fluorenols and phenanthrenols were synthesized from commercially available 13C‐labeled starting material giving rise to M + 6 isotopomers. This was accomplished using key palladium‐catalyzed cross‐coupling and one‐carbon homologation strategies. The conditions for these reactions were optimized, and the new chemical routes are efficient in the number of chemical steps, can be scaled to afford gram quantities and occur in good yields based on the 13C label. These labeled compounds as precursors for more complex PAHs and are useful as internal standards in mass spectrometry and NMR spectroscopy studies for monitoring environmental contamination and biological exposure to PAHs and their metabolites.
Synthetic approach for unsaturated precursors for parahydrogen induced polarization of choline and its analogs
Authors: Shchepin Roman V. , Chekmenev Eduard Y.
Published: July 2013

Reported here are (i) a new synthetic approach for preparation of (ii) a new compound class, of –OH, for example, an –OH group is replaced with acetyl protecting group, protected 1,2‐dehydrocholine analogs and (iii) a new synthetic route for betaine aldehyde. The CC bond of 1,2‐dehydrocholine moiety can be used for molecular addition of parahydrogen producing –OH protected hyperpolarized choline by parahydrogen‐induced polarization (PHIP). The reported synthetic approach allows for incorporation of 15N and deuterium labels, which are necessary for preparation of highly polarized PHIP contrast agents. Isotope labeling with 15N and/or deuterium was conducted. Hyperpolarized 15N‐choline enabled by the reported synthetic approach can be potentially used as an imaging biomarker of cancer similar to choline positron emission tomography tracers.
Modeling DCE‐MRI at low temporal resolution: A case study on rheumatoid arthritis
Authors: Ledsam Joseph R. , Hodgson Richard , Moots Robert J. , Sourbron Steven P.
Published: July 2013

Purpose

To identify the optimal tracer‐kinetic modeling strategy for dynamic contrast‐enhanced magnetic resonance imaging (DCE‐MRI) data acquired at low temporal resolution.

Materials and Methods

DCE‐MRI was performed on 13 patients with rheumatoid arthritis of the hand before and after anti‐tumor necrosis factor alpha (TNFα) therapy, using a 3D sequence with a temporal resolution of 13 seconds, imaging for 4 minutes postcontrast injection. Concentration–time curves were extracted from regions of interest (ROIs) in enhancing synovium and fitted to the 3‐parameter modified Tofts model (MT) and the 4‐parameter two‐compartment exchange model (2CXM). To assist the interpretation of the data, the same analysis was applied to simulated data with similar characteristics.

Results

Both models fitted the data closely, and showed similar therapy effects. The MT plasma volume was significantly lower than with 2CXM, but the differences in permeability and interstitial volume were not significant. 2CXM was less precise than MT, with larger standard deviations relative to the mean in most parameters. The additional perfusion parameter determined with 2CXM did not provide a statistically significant trend due to low precision.

Conclusion

The standard MT model is the optimal modeling strategy at low temporal resolution. Advanced models improve the accuracy and generate an additional parameter, but these benefits are offset by low precision. J. Magn. Reson. Imaging 2013;38:1554–1563. © 2013 Wiley Periodicals, Inc.
Noncovalent Chiral Functionalization of Graphene with Optically Active Helical Polymers
Authors: Ren Chonglei , Chen Yu , Zhang Haiyang , Deng Jianping
Published: July 2013

Optically active helical substituted (co)polyacetylenes containing pendent pyrene groups are prepared and then noncovalently immobilized on graphene via π–π interactions. The resulting graphene composite is characterized by XRD, FTIR, Raman, circular dichroism, UV‐vis absorption, TEM, TGA, and fluorescent spectroscopy techniques. The helical polyacetylene endows graphene with the desired optical activity. Also interestingly, the dispersibility of the functionalized graphene in tetrahydrofuran is remarkably improved due to the presence of the helical polymer chains. The present methodology opens new opportunities and serves as a versatile platform toward preparing novel graphene‐based materials.

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Adaptive responses of TRPC1 and TRPC3 during skeletal muscle atrophy and regrowth
Authors: Zhang Bao‐Ting , Yeung Simon S. , Cheung Kwok‐Kuen , Chai Zacary Y. , Yeung Ella W.
Published: July 2013

Introduction: We assessed the time‐dependent changes of transient receptor potential canonical type 1 (TRPC1) and TRPC3 expression and localization associated with muscle atrophy and regrowth in vivo. Methods: Mice were subjected to hindlimb unloading for 7 or 14 days (7U, 14U) followed by 3, 7, or 14 days of reloading (3R, 7R, 14R). Results: Soleus muscle mass and tetanic force were reduced significantly at 7U and 14U and recovered by 14R. Recovery of muscle fiber cross‐sectional area was observed by 28R. TRPC1 mRNA was unaltered during the unloading‐reloading period. However, protein expression remained depressed through 14R. Decreased localization of TRPC1 to the sarcolemma was observed. TRPC3 mRNA and protein expression levels were decreased significantly during the early phase of reloading. Conclusions: Given the known role of these channels in muscle development, changes observed in TRPC1 and TRPC3 may relate closely to muscle atrophy and remodeling processes. Muscle Nerve 49: 691–699, 2014