bluuebunny/crossref_metadata_2025 huggingface dataset:
The Performance of Small‐Pore Microporous Aluminophosphates in Low‐Temperature Solar Energy Storage: The Structure–Property Relationship
Authors: Ristić Alenka , Logar Nataša Zabukovec , Henninger Stefan K. , Kaučič Venčeslav
Published: February 2012

The utilization of the reversible chemical and physical sorption of water on solids provides a new thermal energy storage concept with a great potential for lossless long‐term storage. The performance of microporous aluminophosphates in heat storage applications is highlighted by a comparative thermogravimetric and calorimetric study of three known materials (SAPO‐34, AlPO4‐18, APO‐Tric) and is correlated with their structural features. The maximum water sorption capacity is similar for all three samples and results in a stored energy density of 240 kWh m−3 in the 40–140 °C range. The elemental composition influences the gradual (silicoaluminophosphate SAPO‐34) or sudden (aluminophosphates AlPO4‐18, APO‐Tric) water uptake, with the latter being favourable in storage systems. The driving force for the determined sorption process is the formation of highly ordered water clusters in the pores, which is enabled by rapid and reversible changes in the Al coordination and optimal pore diameters. The ease with which changes in the Al coordination can occur in APO‐Tric is related to the use of the fluoride route in the synthesis. The understanding of these fundamental structure/sorption relationships forms an excellent basis for predicting the storage potential of numerous known or new microporous aluminophosphates and other porous materials from their crystal structures.
Hyposplenism: Comparison of different methods for determining splenic function
Authors: Lammers A.J. Jolanda , de Porto Alexander P.N.A. , Bennink Roelof J. , van Leeuwen Ester M.M. , Biemond Bart J. , Goslings J. Carel , van Marle Jan , ten Berge Ineke J.M. , Speelman Peter , Hoekstra Joost B.L.
Published: February 2012

Asplenic patients are at risk for pneumococcal sepsis. Patients with hyposplenic function, such as associated with sickle cell disease (SCD), are also at risk. However, tests to assess splenic function are either unavailable or lacking standardization. The aim of this study was to compare different methods for determining splenic function. Eighteen patients with SCD (i.e., 10 heterozygous (SC) and 8 homozygous (SS) SCD patients), and eight splenectomized patients were compared to 10 controls. All subjects underwent spleen scintigraphy, after which functional splenic volumes (FSV) were calculated. FSV was compared to immunological function and B cell‐subsets, as well as phagocytic function represented by the presence of Howell Jolly bodies (HJB) and percentages of pitted red cells (PIT). Heterozygous SCD (SC) patients had increased splenic volumes, but diminished FSV, homozygous SCD (SS) patients were asplenic. Splenectomized and SS patients had a strongly reduced phagocytic and immunological function. SC patients had reduced anti‐polysaccharide responses without an increase in PIT. FSV correlated significantly with phagocytic and immunological function. HJB were indicative of splenic dysfunction, HJB absence was not indicative of normal functioning splenic tissue. Although visualizing HJB is methodologically advantageous to PIT, both are valid biomarkers of splenic dysfunction. The amount of non‐switched memory B cells is strongly correlated to FSV. Am. J. Hematol. 87:484–489, 2012. © 2012 Wiley Periodicals, Inc.
Mutations inNRXN1in a family multiply affected with brain disorders:NRXN1mutations and brain disorders
Authors: Duong Linh , Klitten Laura L. , Møller Rikke S. , Ingason Andrés , Jakobsen Klaus D. , Skjødt Celina , Didriksen Michael , Hjalgrim Helle , Werge Thomas , Tommerup Niels
Published: February 2012

Mutation of the neurexin1‐gene,NRXN1, interrupting the expression of neurexin1 has been associated with schizophrenia, autism, and intellectual disability. We have identified a family multiply affected with psychiatric, neurological, and somatic disorders along with an intricate co‐segregation ofNRXN1mutations. The proband suffered from autism, mental retardation, and epilepsy and on genotyping it was revealed that he carried a compound heterozygous mutation in theNRXN1consisting of a 451 kb deletion, affecting the promoter and first introns in addition to a point mutation, predicted to be deleterious toNRXN1. The deletion was passed on from the patient's mother who was clinically characterized by sub‐diagnostic autistic traits in addition to type 1 diabetes mellitus. The point mutation was subsequently found in the patient's brother, suffering from a psychotic disorder, which implies that the point mutation was inherited from the deceased father, who was diagnosed with schizophrenia. The observations suggest a possible gene‐dose effect ofNRXN1mutations on type and severity of mental illness and support the notion that the penetrance and pleiotropy of pathogenic CNVs in general are determined by additional genetic variants in the genome. Finally the findings also propose a linkage ofNRXN1neurobiology to epilepsy and possibly to type 1 diabetes. © 2012 Wiley Periodicals, Inc.
Patterns of dural involvement in sinonasal tumors: prospective correlation of magnetic resonance imaging and histopathologic findings
Authors: McIntyre John B. , Perez Carlos , Penta Mrudula , Tong Liyue , Truelson John , Batra Pete S.
Published: February 2012

Background:

The presence of dural invasion serves as an important negative predictive factor for survival in sinonasal and skull‐base neoplasms. The objective of this study was to prospectively correlate preoperative magnetic resonance imaging (MRI) findings with intraoperative surgical findings and histopathology to establish key correlates for dural involvement in sinonasal tumors.

Methods:

Prospective blinded MRI review of 50 sinonasal and anterior skull‐base neoplasms was performed by a staff neuroradiologist. Retrospective chart review was performed to accrue salient patient and tumor data.

Results:

The mean patient age was 54.6 years with a male:female ratio of 1.8:1. The most common tumor histology included adenocarcinoma (18%), squamous cell carcinoma (18%), mucosal melanoma (8%), and olfactory neuroblastoma (8%). MRI demonstrated dural enhancement in 20 patients (40%), with 1 mm and ≥2 mm thickening being noted in 14 (70%) and 6 (30%) cases, respectively. Spectrum of MR findings in these 20 patients included linear enhancement in 15 (75%), nodular thickening in 5 (25%), and loss of hypointense zone in 13 (65%) cases. Intraoperative findings and histology confirmed dural invasion in 12 of 20 cases (60%). Positive predictive value (PPV) of linear and nodular dural enhancement for dural invasion was 46.7% and 100%, respectively. One millimeter (1 mm) and ≥2 mm of dural thickening demonstrated PPV of 42.9% and 100%, respectively. Loss of the hypointense zone had PPV of 92.3% for dural invasion. Fisher's exact test demonstrated that loss of hypointense zone and dural thickening ≥2 mm were statistically associated with dural involvement (p < 0.05).

Conclusion:

The presence of ≥2 mm of dural thickening, loss of hypointense zone, and nodular dural enhancement were highly predictive for presence of dural invasion by sinonasal malignant tumors. Preoperative knowledge of these MRI patterns may better guide surgical planning and patient counseling. © 2012 ARS‐AAOA, LLC.
Bioflavonoid profile of citrus juices from Greece
Authors: Anagnostopoulou Maria A. , Kefalas Panagiotis
Published: February 2012

High‐performance liquid chromatography with confirmation by UV–visible photodiode array detector–positive electrospray ionization–mass spectrometry [HPLC‐UV–vis‐DAD‐(+ESI)‐MS] with enhanced fragmentation by appropriate adjustment of the cone voltage was used to determine bioflavonoid content of five citrus species (tangerine, sanguine, sour orange, lemon and grapefruit) cultivated in Greece which come from citrus varieties analyzed for the first time. The main groups of bioflavonoids found in the juice of the citrus species according to HPLC retention times, spectral data and literature references were O‐glycosylated flavanones and flavones, C‐glucosylated flavones, O‐glucosylated flavones, O‐C‐glucosylated flavones like saponarin and a phenolic derivative. Copyright © 2012 John Wiley & Sons, Ltd.
Practical determination of methotrexate in serum of rheumatic patients by LC‐MS/MS
Authors: Sonemoto Emi , Kono Narumi , Ikeda Rie , Wada Mitsuhiro , Ueki Yukitaka , Nakashima Kenichiro
Published: February 2012

A rapid and simple liquid chromatography tandem mass spectrometry method for determination of methotrexate (MTX) in rheumatic patients' serum is described. Serum spiked with pterin as an internal standard was deproteinized with methanol. The separation of MTX from interfering peaks in matrix was achieved on a Luna 3 µm C18 (100 × 4.6 mm i.d.) column with a mixture of 1% acetic acid and acetonitrile (88:12, v/v) within 5 min. Multiple reaction monitoring transitions monitored for MTX were m/z 455.2–308.1. The calibration curve of MTX in serum showed a good linearity (r = 0.999). Limits of detection and quantification of MTX at a signal‐to‐noise ratio of 3 and 10 were 3.0 n m (4.4 fmol/injection) and 10.0 n m (14.5 fmol/injection), respectively. The accuracy and precision for intra‐ and inter‐day assays were 94.6–106.5% and <5.5 and <5.1%, respectively. Furthermore, the proposed method was successfully applied to the sera nine rheumatic patients receiving MTX treatment. Copyright © 2012 John Wiley & Sons, Ltd.
Identification of modification sites on human serum albumin and human hemoglobin adducts with houttuynin using liquid chromatography coupled with mass spectrometry
Authors: Deng Zhipeng , Zhong Dafang , Chen Xiaoyan
Published: February 2012

Houttuynin, a β‐keto aldehyde compound, is the major active ingredient in herba houttuyniae injection. The injection was once used as an anti‐inflammatory drug associated with occasional serious hypersensitivity reactions in the clinic, which were proposed to be related to the formation of protein adducts. Nα‐Boc‐lysine, FEEM and IVTNTT were used as model amino acids or peptides containing one nucleophilic residue to investigate adduct types by liquid chromatography coupled with ion trap mass spectrometry (LC/MSn) and high‐resolution quadrupole time‐of‐flight mass spectrometry (Q‐TOF MS). These adducts were respectively characterized as Schiff bases formed by 1:1 reaction of houttuynin with lysine or N‐terminal residue and pyridinium adducts by 2:1 reaction. LC/MSn analysis of trypsin digests of HSA/Hb incubations with houttuynin revealed that houttuynin‐modified HSA adducts were formed mainly at N‐terminal amino acid and lysine residues, specifically at Lys‐212, Lys‐414 and Lys‐525 for Schiff base adducts, and at Lys‐414 and Lys‐432 for pyridinium adducts, and houttuynin adducted more readily with N‐terminal valine of the α‐ and β‐chains in Hb and lysine amine (Lys‐62) of the β‐chain for Schiff base adducts. The results showed the direct modification of houttuynin to HSA/Hb in vitro, which was speculated to be responsible for the adverse reactions induced by houttuyniae injection. Copyright © 2012 John Wiley & Sons, Ltd.
Simple batch distillation of a binary mixture
Authors: Binous Housam , Al‐Harthi Mamdouh A.
Published: February 2012

A simple experiment such as the batch distillation of an ethanol–water binary mixture can be performed in a 3‐h laboratory session using a very rudimentary apparatus consisting of a still pot and two thermocouples. Yet, the results can lead to very interesting insights to distillation and chemical engineering thermodynamics. The present article describes how one can exploit this simple laboratory experiment to teach these various aspects of chemical engineering. In addition, several simple calculations using computer software such as Mathematica® are performed to explain, interpret and reproduce theoretically all the gathered experimental data during the laboratory session.© 2012 Wiley Periodicals, Inc. Comput Appl Eng Educ 22:649–657, 2014; View this article online at wileyonlinelibrary.com/journal/cae; DOI 10.1002/cae.21556
Enzyme‐Regulated Activation of DNAzyme: A Novel Strategy for a Label‐Free Colorimetric DNA Ligase Assay and Ligase‐Based Biosensing
Authors: He Kaiyu , Li Wang , Nie Zhou , Huang Yan , Liu Zhuoliang , Nie Lihua , Yao Shouzhuo
Published: February 2012

The DNA nick repair catalyzed by DNA ligase is significant for fundamental life processes, such as the replication, repair, and recombination of nucleic acids. Here, we have employed ligase to regulate DNAzyme activity and developed a homogeneous, colorimetric, label‐free and DNAzyme‐based strategy to detect DNA ligase activity. This novel strategy relies on the ligation‐trigged activation or production of horseradish peroxidase mimicking DNAzyme that catalyzes the generation of a color change signal; this results in a colorimetric assay of DNA ligase activity. Using T4 DNA ligase as a model, we have proposed two approaches to demonstrate the validity of the DNAzyme strategy. The first approach utilizes an allosteric hairpin‐DNAzyme probe specifically responsive to DNA ligation; this approach has a wide detection range from 0.2 to 40 U mL−1 and a detection limit of 0.2 U mL−1. Furthermore, the approach was adapted to probe nucleic acid phosphorylation and single nucleotide mismatch. The second approach employs a “split DNA machine” to produce numerous DNAzymes after being reassembled by DNA ligase; this greatly enhances the detection sensitivity by a signal amplification cascade to achieve a detection limit of 0.01 U mL−1.
Surface Diels–Alder Reactions as an Effective Method to Synthesize Functional Carbon Materials
Authors: Kaper Helena , Grandjean Agnes , Weidenthaler Claudia , Schüth Ferdi , Goettmann Frédéric
Published: February 2012

The post‐synthesis chemical modification of various porous carbon materials with unsaturated organic compounds is reported. By this method, amine, alcohol, carboxylate, and sulfonic acid functional groups can be easily incorporated into the materials. Different carbonaceous materials with surface areas ranging from 240 to 1500 m2 g−1 and pore sizes between 3.0 and 7.0 nm have been studied. The resulting materials were analyzed by elemental analysis, nitrogen sorption, FTIR spectroscopy, zeta‐potential measurements, thermogravimetric analysis, photoelectron spectroscopy, and small‐angle X‐ray scattering. These analyses indicated that the degree of functionalization is dependent on the nature of the dienophile (reactivity, steric hindrance) and the porosity of the carbon material. As possible applications, the functionalized carbonaceous materials were studied as catalysts in the Knoevenagel reaction and as adsorbents for Pb2+ from aqueous solution.
A Simple Polyoxometallate for Selective Oxidation of Benzyl Alcohol to Benzaldehyde with Hydrogen Peroxide
Authors: Tian Wei , Hou Yang , Wang Xiaoguang , Lu Bin , Zhao Jingxiang , Cai Qinghai
Published: February 2012

A series of Keggin‐type polyoxometallates, M3(PW12O40)2 [M=Ni, Zn, Co, Mn, Cu], FePW12O40, Ni3(PMo12O40)2 and Ni2SiW12O40, were prepared and used as catalysts for selective oxidation of benzyl alcohol into benzaldehyde with H2O2 as an oxidant under solvent‐free condition. Ni3(PW12O40)2·26H2O afforded high catalytic activity with TON of 550.6 mol/(mol cat.) and 87.3% selectivity. However, this catalyst can be easily recovered and reused.
Synthesis and Bioactivity of Substituted Benzoylguanidine Derivatives as Potent Na+/H+ Exchanger Inhibitors
Authors: Jin Ning , Yang Yun , Xu Wenting , Yang Xiaozhi , Gong Guoqing , Xu Yungen
Published: February 2012

A novel series of substituted benzoylguanidine derivatives were designed and synthesized in order to evaluate their NHE1 inhibitory activity. Most of them were found to inhibit NHE1‐mediated platelet swelling in a concentration‐dependent manner, and eight compounds showed more potent NHE1 inhibitory activity than Cariporide. Compound 6f with an IC50 value of 1.08×10−10 mol·L−1, was 39 times more potent than lead compound CPU‐X‐050420 in vitro tests.
An Efficient Four‐component Synthesis of Spiro[indoline‐pyrazolo[4′,3′:5,6]pyrido[2,3‐d]pyrimidine]triones
Authors: Ghahremanzadeh Ramin , Moghaddam Mojtaba Mirhosseini , Bazgir Ayoob , Akhondi Mohammad Mehdic
Published: February 2012

A four‐component reaction in the presence of Alum [KAl(SO4)2·12H2O] as an inexpensive and reusable catalyst using the ionic liquid as an effective green reaction media is reported.
Preparation of Ultrafine TATB and the Technology for Crystal Morphology Control
Authors: Yang Li , Ren Xiaoting , Li Tiecheng , Wang Shiwei , Zhang Tonglai
Published: February 2012

The ultrafine 1,3,5‐triamino‐2,4,6‐trinitrobenzene (TATB) has been prepared by using solvent and non‐solvent method, and the influencing factors in close relationship with the grain size and crystal morphology control such as categories and dosage of surfactants, volume ratio of solvent to non‐solvent have also been considered in this paper. It showed that these factors had remarkable effect on the crystal morphology, particle size and agglomeration during the crystallization process. By using 0.095% (mass percentage) ionic surfactant (S) as the additive and using spray‐drops feeding device as the dropping equipment, 1.06 g TATB raw materials have been refined into free‐running ellipsoid and spherical TATB grains with the grain size from 30 to 50 nm. By using 0.014% (mass percentage) non‐ionic surfactant (P) as the additive, spherical TATB grains with the particle diameter of 50 nm and with narrow particle‐size distribution have also been obtained. It was shown by the characterizations that the ultrafine particle of TATB had better heat resisting evenness and its 5 seconds ignition point is advanced by 7.5 K.
Selective and Sensitive Fluorescent Chemosensors for Cu2+ Ion Based upon Bis‐1,8‐naphthalimide Dyads
Authors: Dai Huiling , Xu Hui
Published: February 2012

A series of new fluorescent chemosensors 5a–5e, composed of two aminonaphthalimide fluorophores and 2,6‐bis((N‐aminoalkyl)aminocarboxy)pyridines, were prepared, characterized, and their fluorescent properties towards heavy and transition metal (HTM) ions were investigated. Chemosensors 5c–5e exhibited high selectivity and sensitivity for Cu2+ ion over other HTM ions with fluorescent quenching (green to colourless). It clearly demonstrated that the length of the linkers (diamines) between the aminonaphthalimides and 2,6‐dicarboxypyridine of 5a–5e was very important for their sensitivity and selectivity for Cu2+ ion over other HTM ions.
Potassium tert‐Butoxide Catalyzed Synthesis and Characterization of Novel 3‐Aryl‐3‐(phenylthio)‐1‐(thiophen‐3‐yl)propan‐1‐one Derivatives
Authors: Budak Yakup
Published: February 2012

A series of thiophenyl‐containing 3‐thiophene derivatives (4a–4i) were prepared via the reaction of chalcone‐analogua compounds (3a–3i) and thiophenol in the presence of catalytic amount of KOBu‐t in CH2Cl2 with moderate to high yields. The mechanistic pathway of the reaction was explained by the Michael‐type addition of thiophenol to chalcone derivatives (3a–3i).
Electrochemical Property of Manganese Oxide Nanobelt Bundles with Layered Structure
Authors: Kang Liping , Jiang Yishu , Tang Xiuhua , Yang Mingyang , Liu Zonghuai
Published: February 2012

One‐dimensional manganese oxide nanobelt bundles with birnessite‐type structure have been synthesized by a hydrothermal process in a NaOH solution employing K‐type layered manganese oxide as a precursor. The obtained manganese oxide nanobelt bundles exhibit excellent discharge properties and cycle stability. The initial capacity is 376 mAh·g−1 and the reversible capacity of 243 mAh·g−1 is maintained after the 50th cycle at a current density of 20 mA·g−1. Meanwhile, the manganese oxide nanobelt bundles show an excellent cycle performance even if at relative high current density.
Asymmetric Synthesis of All Four Isomers of an Unusual Heterocycle‐Containing Amino Acid: 2‐Amino‐3‐furan‐2‐yl‐pentanoic Acid
Authors: Nie Lei , Yang Rui , Zhang Conghai , Yin Haichuan , Yan Shengjiao , Lin Jun
Published: February 2012

All four isomers of a novel β‐branched unusual amino acid were designed and synthesized with high stereoselectivity (>90% de) and in 33% –44% overall yields by the use of 4(R/S)‐5,5‐dimethyl‐4‐phenyl‐oxazolidin‐2‐one as the chiral auxiliary via asymmetric 1,4‐Michael addition, direct or indirect azidation, hydrolysis and hydrogenation reactions.
Fluorescence Properties of Carba Nicotinamide Adenine Dinucleotide for Glucose Sensing
Authors: von Ketteler Alexa , Herten Dirk‐Peter , Petrich Wolfgang
Published: February 2012

Carba nicotinamide adenine dinucleotide (cNAD) may serve as a stable cofactor for the enzyme‐based detection of glucose. Many characteristics of cNAD and its reduced form cNADH resemble those of NAD and NADH, respectively. The fluorescence lifetimes of cNADH are determined to be 0.32(2) ns and 0.66(3) ns compared to 0.28(2) ns and 0.60(3) ns for NADH, and the temperature dependence of these lifetimes hints towards identical processes for quenching. The maximum emission occurs at 464 nm for both cNADH and NADH and absorbance maxima are found at 360 nm and 340 nm, respectively. In contrast to previous suggestions the respective maximum extinction coefficient of cNADH equals that of NADH and amounts to 6.2(2) mM−1 cm−1. When changing from NADH to cNADH we observe a ∼50 % increase in quantum efficiency, which—together with the larger excitation wavelength and the higher stability—should make cNAD a well suited alternative as coenzyme for robust glucose detection.
Ultrasound and Microstructures—A Promising Combination?
Authors: Hübner S. , Kressirer S. , Kralisch D. , Bludszuweit‐Philipp C. , Lukow K. , Jänich I. , Schilling A. , Hieronymus H. , Liebner C. , Jähnisch K.
Published: February 2012

Short diffusion paths and high specific interfacial areas in microstructured devices can increase mass transfer rates and thus accelerate multiphase reactions. This effect can be intensified by the application of ultrasound. Herein, we report on the design and testing of a novel versatile setup for a continuous ultrasound‐supported multiphase process in microstructured devices on a preparative scale. The ultrasonic energy is introduced indirectly into the microstructured device through pressurized water as transfer medium. First, we monitored the influence of ultrasound on the slug flow of a liquid/liquid two‐phase system in a channel with a high‐speed camera. To quantify the influence of ultrasound, the hydrolysis of p‐nitrophenyl acetate was utilized as a model reaction. Microstructured devices with varying channel diameter, shape, and material were applied with and without ultrasonication at flow rates in the mL min−1 range. The continuous procedures were then compared and evaluated by performing a simplified life cycle assessment.
In vivo visualization of the lymphatic vessels in pFLT4‐EGFP transgenic medaka
Authors: Deguchi Tomonori , Fujimori Kazuhiro E. , Kawasaki Takashi , Maruyama Kouichi , Yuba Shunsuke
Published: February 2012

Feline McDonough Sarcoma (FMS)‐like tyrosine kinase 4 (FLT4) is a marker for lymphatic vessels and some high endothelial venules in human adult tissues. We generated a transgenic medaka fish in which the lymphatic vessels and some blood vessels are visible in vivo by transferring the promoter of medaka flt4 driving the expression of enhanced green fluorescent protein (EGFP) using a see‐through medaka line. To do this, we identified and cloned medaka flt4 and generated a construct in which the promoter was the 4‐kb region upstream of the translation initiation site. The fluorescent signal of EGFP could be observed with little background, and the expression pattern correlated well with that of flt4 determined by whole‐mount RNA in situ hybridization. Because a see‐through medaka line is transparent until adult, the model is useful for visualizing the lymphatic vessels not only in embryo and fry but also in adult. This model will be a useful tool for analyzing lymphatic development. genesis 50:625–634, 2012. © 2012 Wiley Periodicals, Inc.
Population‐based resequencing revealed an ancestral winter group of cultivated flax: implication for flax domestication processes
Authors: Fu Yong‐Bi
Published: February 2012

Cultivated flax (Linum usitatissimum L.) is the earliest oil and fiber crop and its early domestication history may involve multiple events of domestication for oil, fiber, capsular indehiscence, and winter hardiness. Genetic studies have demonstrated that winter cultivated flax is closely related to oil and fiber cultivated flax and shows little relatedness to its progenitor, pale flax (L. bienne Mill.), but winter hardiness is one major characteristic of pale flax. Here, we assessed the genetic relationships of 48 Linum samples representing pale flax and four trait‐specific groups of cultivated flax (dehiscent, fiber, oil, and winter) through population‐based resequencing at 24 genomic regions, and revealed a winter group of cultivated flax that displayed close relatedness to the pale flax samples. Overall, the cultivated flax showed a 27% reduction of nucleotide diversity when compared with the pale flax. Recombination frequently occurred at these sampled genomic regions, but the signal of selection and bottleneck was relatively weak. These findings provide some insight into the impact and processes of flax domestication and are significant for expanding our knowledge about early flax domestication, particularly for winter hardiness.
Cholesterol versus other sterols: How do they compare as physiological regulators of cholesterol homeostasis?
Authors: Brown Andrew J.
Published: February 2012

There is a growing body of work indicating that maintaining cholesterol homeostasis involves oxysterol‐derivatives and sterol precursors of cholesterol. Their importance relative to cholesterol itself is a contentious area, which is difficult to address experimentally. In this review, the molecular basis of cholesterol homeostasis is briefly described, some of the major putative sterol regulators introduced, and the evidence that they may indeed serve as physiological regulators is discussed, along with caveats of this research. This review will also briefly address some recent literature ascribing physiological roles of non‐cholesterol sterols beyond cholesterol metabolism.
On the treatment of transient area variation in 1D discontinuous Galerkin simulations of train‐induced pressure waves in tunnels
Authors: Biotto C. , Proverbio A. , Ajewole O. , Waterson N. P. , Peiró J.
Published: February 2012

To simulate the pressure wave generated by a train travelling through a tunnel, we implement a discontinuous Galerkin (DG) method for the solution of the one‐dimensional equations of variable area flow. This formulation uses a spatial discretisation via Legendre polynomials of arbitrary degree, and the resulting semi‐discrete system is integrated using an explicit Runge–Kutta scheme. A simulation of subsonic steady flow in a nozzle shows that the scheme produces stable solutions, without the need for artificial dissipation, and that its performance is optimal for polynomial degrees between 5 and 7. However, when dealing with an unsteady area, we report the presence of numerical oscillations that are not due to the steep pressure fronts in the flow but rather to the projection of a moving area, with piecewise continuous derivatives onto a fixed grid. We propose a reformulation of the DG method to eliminate these oscillations that, put in simple terms, amount to splitting the integrals where the derivatives of the cross‐sectional area are discontinuous into subintegrals where they are continuous. The resulting method does not exhibit oscillations, and it is applied here to two practical cases involving train‐induced pressure waves in a tunnel. The first application is a validation of the DG method through comparison of its computational results with pressure data measured during transit at the Patchway tunnel near Bristol (UK). The second application is a study of the influence of the nose shape and length on the pressure wave gradients responsible for sonic boom at tunnel exit portals to show that the proposed modification is able to deal with realistic train shapes. Copyright © 2012 John Wiley & Sons, Ltd.
Localized DNA cleavage secondary to genotoxic exposure adjacent to an Alu inverted repeat
Authors: Ho Bay , Baker Pamela M. , Singh Sheetal , Shih Shyh‐Jen , Vaughan Andrew T.
Published: February 2012

Radiation is a potent inducer of DNA damage leading to both random DNA loss and mutation. As part of a study focused on the mechanism whereby cells undergo loss of heterozygosity (LOH), a region of common LOH telomeric termination at 11q24 was observed in clones of H292 mucoepidermoid cells established after irradiation (IR). A 10‐kbp region including the telomeric extent of LOH termination was analyzed after IR using six sets of ligation‐mediated polymerase chain reaction (PCR) primers to detect the presence of DNA breaks. A cluster of DNA breaks was detected that closely mapped to the telomeric extent of LOH and which were observed up to 8 hr after IR. Repeating the experiment in the presence of the inhibitor of apoptosis, zVAD.fmk, did not change the location or amount of cleavage. A similar distribution of breaks was also seen in the MCF‐10A breast cancer cell line after IR. Further inspection of the involved region showed that 22/32 and 7/7 DNA breaks found in H292 and MCF‐10A cells, respectively, were located either in or immediately adjacent to an AluSx1 sequence, itself ∼1 kbp 5′ to an AluSq2 that was in an inverted orientation to the AluSx1. The region between the inverted Alu repeats was notable for both DNAse hypersensitivity and an open chromatin conformation inferred from histone modification data. These factors may contribute to genomic instability at this location. © 2012 Wiley Periodicals, Inc.
Segmental chromosome aberrations converge on overexpression of mitotic spindle regulatory genes in high‐risk neuroblastoma
Authors: Ooi Wen Fong , Re Angela , Sidarovich Viktoryia , Canella Valentina , Arseni Natalia , Adami Valentina , Guarguaglini Giulia , Giubettini Maria , Scaruffi Paola , Stigliani Sara , Lavia Patrizia , Tonini Gian Paolo , Quattrone Alessandro
Published: February 2012

Integration of genome‐wide profiles of DNA copy number alterations (CNAs) and gene expression variations (GEVs) could provide combined power to the identification of driver genes and gene networks in tumors. Here we merge matched genome and transcriptome microarray analyses from neuroblastoma samples to derive correlation patterns of CNAs and GEVs, irrespective of their genomic location. Neuroblastoma correlation patterns are strongly asymmetrical, being on average 10 CNAs linked to 1 GEV, and show the widespread prevalence of long range covariance. Functional enrichment and network analysis of the genes covarying with CNAs consistently point to a major cell function, the regulation of mitotic spindle assembly. Moreover, elevated expression of 14 key genes promoting this function is strongly associated to high‐risk neuroblastomas with 1p loss and MYCN amplification in a set of 410 tumor samples (P < 0.00001). Independent CNA/GEV profiling on neuroblastoma cell lines shows that increased levels of expression of these genes are linked to 1p loss. By this approach, we reveal a convergence of clustered neuroblastoma CNAs toward increased expression of a group of prognostic and functionally cooperating genes. We therefore propose gain of function of the spindle assembly machinery as a lesion potentially offering new targets for therapy of high‐risk neuroblastoma. © 2012 Wiley Periodicals, Inc.
Disease‐associated patterns of disomic chromosomes in hyperhaploid neoplasms
Authors: Mandahl Nils , Johansson Bertil , Mertens Fredrik , Mitelman Felix
Published: February 2012

The chromosome number of human tumors varies widely, from near‐haploidy to more than decaploidy. Overt hyperhaploid (24–34 chromosomes) tumors constitute a small minority (0.2–0.3% of cytogenetically investigated lesions), but occur in many different disease entities. In these karyotypes, most chromosomes are present in one copy; one or a few chromosomes are disomic. Published reports on 141 strictly hyperhaploid tumors, supplemented with nine previously unpublished cases, were used for evaluating the pattern of disomic chromosomes. Only one tumor type, acute lymphoblastic leukemia (ALL), was sufficiently common (n = 75) to allow proper evaluation; other neoplasms were lumped together in as reasonably logical groups as possible, including 10 myeloid leukemias (ML), nine plasma cell neoplasms (PCN), 13 chondrosarcomas (CS), 11 soft tissue tumors (STT), nine adeno‐ or squamous cell carcinomas (ASC), and eight tumors of the nervous system (TNS); the remaining 15 tumors could not be grouped. It was evident that the pattern of disomies is nonrandom. Moreover, unique signatures for each tumor group were detected. Among ALL, most disomies were independent of age and gender, except for disomy 10, which was overrepresented in females. Chromosome 21 was invariably disomic, whereas chromosome 17 was always monosomic. The most frequent disomies were two gonosomes in ML, chromosomes 7, 9, 11, 3, 18, and 19 in PCN, 7, 5, 20, 19, and 21 in CS, 20 in STT, 7 in ASC, and 1, 7, and 9 in TNS. Chromosome 1 was often partially disomic, due to unbalanced structural rearrangements, with segment 1q21–31 in common. Doubling of the hyperhaploid clone was found in at least one‐third of the cases, apart from in ML where only one of 10 cases showed chromosome doubling. The present findings indicate that retention of disomy for some chromosomes is pathogenetically important and that the chromosome(s) maintained in two copies is related to cell type or histological context. © 2012 Wiley Periodicals, Inc.
Establishment of myelinating schwann cells and barrier integrity between central and peripheral nervous systems depend on Sox10
Authors: Fröb Franziska , Bremer Magdalena , Finzsch Markus , Kichko Tatjana , Reeh Peter , Tamm Ernst R. , Charnay Patrick , Wegner Michael
Published: February 2012

The transcription factor Sox10 is expressed throughout Schwann cell development and has already been shown to be essential for specification and for the identity and further development of immature Schwann cells. Here, we show that Sox10 is also required in Schwann cells for establishing the myelinating state. This is concluded from the fact that a peripheral neuropathy develops in mice in which Sox10 is deleted by a Cre recombinase whose expression is under control of Krox20 regulatory elements. This neuropathy is characterized by altered marker gene expression along the peripheral nerve, decreased conductivity, and severe persistent hypomyelination. As the Cre recombinase is additionally active in boundary cap cells, we also analyzed the role of Sox10 during embryogenesis in establishment and maintenance of the boundary between central and peripheral nervous systems. Sox10 deletion did not affect establishment or survival of boundary cap cells but appeared to compromise barrier function as cells expressing oligodendrocyte and astrocyte markers were no longer restricted to the central nervous system, and instead found in peripheral nerves. We infer that in addition to its many roles in Schwann cells, Sox10 is also important for the integrity of the boundary between central and peripheral nervous systems. © 2012 Wiley Periodicals, Inc.
What predicts whether caregivers of people with dementia find meaning in their role?
Authors: Quinn Catherine , Clare Linda , Woods Robert T.
Published: February 2012

Background

Informal dementia caregiving has traditionally been perceived as an extremely stressful process; however, more recent research has started to focus on the positive aspects of providing care. Studies indicate that caregivers who derive something positive out of caregiving have better well‐being. However, there has been little exploration of the factors linked to caregivers identifying positive aspects of providing care. The aim of the current study was to explore the predictors of finding meaning in caregiving.

Methods

This was a cross‐sectional questionnaire study in which the respondents were 447 caregivers of people with dementia who were in receipt of a specialist nursing service. The questionnaire contained measures of meaning, relationship quality, caregivers' motivations to provide care, role captivity and caregiving competence.

Results

Correlational analyses showed that higher meaning was associated with being a spousal caregiver, providing greater hours of care, higher religiosity, a better pre‐caregiving and current relationship quality, higher competence, lower role captivity, higher intrinsic motivations and higher extrinsic motivations. Hierarchical regression analyses indicated that variance in finding meaning was significantly predicted by high religiosity, high competence, high intrinsic motivations and low role captivity.

Conclusion

From these findings, it is recommended that interventions should help caregivers focus on positive aspects of providing care and enhance their feelings of competence. Copyright © 2012 John Wiley & Sons, Ltd.
Predictors of comprehensive stimulation program efficacy in patients with cognitive impairment. Clinical practice recommendations
Authors: Binetti Giuliano , Moretti Davide V. , Scalvini Chiara , di Giovanni Giuseppina , Verzeletti Chiara , Mazzini Filippo , Valent Silvia , Ghidoni Roberta , Benussi Luisa
Published: February 2012

Background

The aim of the present study was to identify which factors may predict the best response to a comprehensive stimulation program in patients with dementia and mild cognitive impairment (MCI) as well as in their caregivers.

Methods

A six‐month longitudinal study has been performed on 145 patients (55 with MCI and 90 with dementia), participating to a cognitive motor rehabilitation program, and their 131 caregivers, attending informational/psychoeducational interventions. Mini mental state examination, Alzheimer's Disease Assessment Scale—Cognition, and Clinician's Interview‐Based Impression of Change‐plus were used as primary outcome measures.

Results

Sixty‐eight (46.9%) of the 145 subjects were classified as clinical responders. At baseline, responders had a significant less insight impairment, larger functional ability as well as less delusions, euphoria, and aberrant motor behaviors than the non‐responder. After 6 months along with an improvement in cognition, responders showed decrease in behavioral disturbances and severity of the disturbances. During the 6 months of analysis, stability has been observed in caregiver's burden distress. After 6 months, the caregivers of MCI responders have their burden reduced.

Conclusions

The high level of insight, the preserved functional abilities as well as the lack of severe delusions, euphoria, and aberrant motor behaviors are significant predictors of responsiveness to stimulation program. Copyright © 2012 John Wiley & Sons, Ltd.
Analysis of channel transmission losses in a dryland river reach in north‐eastern Brazil using streamflow series, groundwater level series and multi‐temporal satellite data
Authors: Costa Alexandre Cunha , Foerster Saskia , de Araújo José Carlos , Bronstert Axel
Published: February 2012

Scarcity of hydrological data, especially streamflow discharge and groundwater level series, restricts the understanding of channel transmission losses (TL) in drylands. Furthermore, the lack of information on spatial river dynamics encompasses high uncertainty on TL analysis in large rivers. The objective of this study was to combine the information from streamflow and groundwater level series with multi‐temporal satellite data to derive a hydrological concept of TL for a reach of the Middle Jaguaribe River (MJR) in semi‐arid north‐eastern Brazil. Based on this analysis, we proposed strategies for its modelling and simulation. TL take place in an alluvium, where river and groundwater can be considered to be hydraulically connected. Most losses certainly infiltrated only through streambed and levees and not through the flood plains, as could be shown by satellite image analysis. TL events whose input river flows were smaller than a threshold did not reach the outlet of the MJR. TL events whose input flows were higher than this threshold reached the outlet losing on average 30% of their input. During the dry seasons (DS) and at the beginning of rainy seasons (DS/BRS), no river flow is expected for pre‐events, and events have vertical infiltration into the alluvium. At the middle and the end of the rainy seasons (MRS/ERS), river flow sustained by base flow occurs before/after events, and lateral infiltration into the alluvium plays a major role. Thus, the MJR shifts from being a losing river at DS/BRS to become a losing/gaining (mostly losing) river at MRS/ERS. A model of this system has to include the coupling of river and groundwater flow processes linked by a leakage approach. Copyright © 2012 John Wiley & Sons, Ltd.
A hydro‐economic modelling framework for flood damage estimation and the role of riparian vegetation
Authors: Kourgialas Nektarios N. , Karatzas George P.
Published: February 2012

A modelling framework for the quick estimate of flood inundation and the resultant damages is developed in this paper. The model, called the flood economic impact analysis system (FEIAS), can be applied to a river reach of any hydrogeological river basin. For the development of the integrated modelling framework, three models were employed: (1) a modelling scheme based on the Hydrological Simulation Program FORTRAN model that was developed for any geomorphological river basin, (2) a river flow/floodplain model, and (3) a flood loss estimation model. The first sub‐model of the flood economic impact analysis system simulates the hydrological processes for extended periods of time, and its output is used as input to a second component, the river/floodplain model. The hydraulic model MIKE 11 (quasi‐2D) is the river/floodplain model employed in this study. The simulated flood parameters from the hydraulic model MIKE 11 (quasi‐2D) are passed, at the end of each time step, to a third component, the flood loss model for the estimation of flood damage. In the present work, emphasis was given to the seasonal variation of Manning's coefficient (n), which is an important parameter for the determination of the flood inundation in hydraulic modelling. High values of Manning's coefficient for a channel indicate high flow resistance. The riparian vegetation can have a large impact on channel resistance. The modelling framework developed in this paper was used to investigate the role of riparian vegetation in reducing flood damage. Moreover, it was used to investigate the influence of cutting riparian vegetation scenarios on the flow characteristics. The proposed framework was applied to the downstream part of the Koiliaris River basin in Crete, Greece, and was tested and validated with historical data. Copyright © 2012 John Wiley & Sons, Ltd.
Observing lingering hyporheic storage using electrical resistivity: variations around stream restoration structures, Crabby Creek, PA
Authors: Toran Laura , Nyquist Jonathan E. , Fang Allison C. , Ryan Robert J. , Rosenberry Donald O.
Published: February 2012

Time‐lapse geophysical surveys can map lingering hyporheic storage by detecting changes in response to saline tracer. Tracer tests were conducted in Crabby Creek, an urban stream outside Philadelphia, to examine the influence of stream restoration structures and variable sediment thickness. We compared electrical resistivity surveys with extensive well sampling (57 wells) in two 13.5‐m‐long reaches, each with a step drop created by a J‐hook. The two step drops varied in tracer behaviour, based on both the well data and the geophysical data. The well data showed more variation in arrival time where the streambed sediment was thick and was more uniform where sediment was thin. The resistivity in the reach with thin sediment showed lingering tracer in the hyporheic zone both upstream and downstream from the J‐hook. In the second reach where the sediment was thicker, the lingering tracer in the hyporheic zone was more extensive downstream from the J‐hook. The contrasting results between the two reaches from both methods suggested that sediments influenced hyporheic exchange more than the step at this location. Resistivity inversion differed from well data in both reaches in that it showed evidence for tracer after well samples had returned to background, mapping lingering tracer either upstream or downstream of a step. We conclude that resistivity surveys may become an important tool for hyporheic zone characterization because they provide information on the extent of slow moving fluids in the hyporheic zone, which have the potential to enhance chemical reactions. Copyright © 2012 John Wiley & Sons, Ltd.
Autophagy in toxicology: self‐consumption in times of stress and plenty
Authors: Bolt Alicia M. , Klimecki Walter T.
Published: February 2012

Autophagy is a critical cellular process orchestrating the lysosomal degradation of cellular components in order to maintain cellular homeostasis and respond to cellular stress. A growing research effort over the last decade has proven autophagy to be essential for constitutive protein and organelle turnover, for embryonic/neonatal survival and for cell survival during conditions of environmental stress. Emphasizing its biological importance, dysfunctional autophagy contributes to a diverse set of human diseases. Cellular stress induced by xenobiotic exposure typifies environmental stress, and can result in the induction of autophagy as a cytoprotective mechanism. An increasing number of xenobiotics are notable for their ability to modulate the induction or the rate of autophagy. The role of autophagy in normal cellular homeostasis, the intricate relationship between cellular stress and the induction of autophagy, and the identification of specific xenobiotics capable of modulating autophagy, point to the importance of the autophagic process in toxicology. This review will summarize the importance of autophagy and its role in cellular response to stress, including examples in which consideration of autophagy has contributed to a more complete understanding of toxicant‐perturbed systems. Copyright © 2012 John Wiley & Sons, Ltd.
3‐(3,4‐Dihydroxyphenyl)adenine, a urinary DNA adduct formed in mice exposed to high concentrations of benzene
Authors: Mikeš Petr , Šístek Václav , Krouželka Jan , Králík Antonín , Frantík Emil , Mráz Jaroslav , Linhart Igor
Published: February 2012

Metabolism of benzene, an important environmental and industrial carcinogen, produces three electrophilic intermediates, namely, benzene oxide and 1,2‐ and 1,4‐benzoquinone, capable of reacting with the DNA. Numerous DNA adducts formed by these metabolites in vitro have been reported in the literature, but only one of them was hitherto identified in vivo. In a search for urinary DNA adducts, specific LC‐ESI‐MS methods have been developed for the determination in urine of six nucleobase adducts, namely, 7‐phenylguanine, 3‐phenyladenine, 3‐hydroxy‐3,N4‐benzethenocytosine, N2‐(4‐hydroxyphenyl)guanine, 7‐(3,4‐dihydroxyphenyl)guanine and 3‐(3,4‐dihydroxyphenyl)‐adenine (DHPA), with detection limits of 200, 10, 260, 50, 400 and 200 pg ml−1, respectively. Mice were exposed to benzene vapors at concentrations of 900 and 1800 mg m−3, 6 h per day for 15 consecutive days. The only adduct detected in their urine was DHPA. It was found in eight out of 30 urine samples from the high‐exposure group at concentrations of 352 ± 146 pg ml−1 (mean ± SD; n = 8), whereas urines from the low‐exposure group were negative. Assuming the DHPA concentration in the negative samples to be half of the detection limit, conversion of benzene to DHPA was estimated to 2.2 × 10−6% of the absorbed dose. Thus, despite the known high mutagenic and carcinogenic potential of benzene, only traces of a single DNA adduct in urine were detected. In conclusion, DHPA is an easily depurinating adduct, thus allowing indication of only high recent exposure to benzene, but not long‐term damage to DNA in tissues. Copyright © 2012 John Wiley & Sons, Ltd.