bluuebunny/crossref_metadata_2025 huggingface dataset:
Stable carbon isotopes as indicators for micro-geomorphic changes in palsa peats
Authors: Alewell C. , Giesler R. , Klaminder J. , Leifeld J. , Rollog M.
Published: January 2011

Abstract. Palsa peats are unique northern ecosystems formed under an arctic climate and characterized by an unique biodiversity and ecology. The stability of the palsas are seriously threatened by climate warming which will change the permafrost dynamic and results in degradation of the mires. We used stable carbon isotope depth profiles in two palsa mires of Northern Sweden to track environmental change during the formation of the mires. Carbon isotope (δ13C) depth profile of the yet undisturbed mire Storflaket indicated very low to no degradation of the peat in the water saturated depressions (hollows) but increased rates of anaerobic degradation at the Stordalen site. The latter might be induced by degradation of the permafrost cores in the uplifted areas (hummocks) and subsequent braking and submerging of the hummock peat into the hollows due to climate warming. Carbon isotope depth profiles of hummocks indicated a turn from aerobic mineralisation to anaerobic degradation at a peat depth between 4 to 25 cm. The age of these turning point was 14C dated between 150 and 670 years and could thus not be caused by anthropogenically induced climate change. We found the uplifting of the hummocks due to permafrost heave the most likely explanation for our findings. We thus concluded that differences in carbon isotope profiles of the hollows might point to the disturbance of the mires due to climate warming or due to differences in hydrology. The characteristic profiles of the hummocks are indicators for micro-geomorphic change during permafrost up heaving.
Differences and implications in biogeochemistry from maximizing entropy production locally versus globally
Authors: Vallino J. J.
Published: January 2011

Abstract. In this manuscript we investigate the use of the maximum entropy production (MEP) principle for modeling biogeochemical processes that are catalyzed by living systems. Because of novelties introduced by the MEP approach, many questions need to be answered and techniques developed in the application of MEP to describe biological systems that are responsible for energy and mass transformations on a planetary scale. In previous work we introduce the importance of integrating entropy production over time to distinguish abiotic from biotic processes under transient conditions. Here we investigate the ramifications of modeling biological systems involving one or more spatial dimensions. When modeling systems with spatial dimensions, entropy production can be maximized either locally at each point in space asynchronously or globally over the system domain synchronously. We use a simple two-box model inspired by two-layer ocean models to illustrate the differences in local versus global entropy maximization. Synthesis and oxidation of biological structure is modeled using two autocatalytic reactions that account for changes in community kinetics using a single parameter each. Our results show that entropy production can be increased if maximized over the system domain rather than locally, which has important implications regarding how biological systems organize and supports the hypothesis for multiple levels of selection and cooperation in biology for the dissipation of free energy.
What Are Students Learning about Sustainability?
Authors: Yousey-Elsener Kimherly , Keith Diana Richter , Ripkey Staci Lynne
Published: January 2011

Kimherly Yousey-Elsener, Diana Richter Keith, and Staci Lynne Ripkey provide a model to integrate sustainability efforts, student learning, and assessment into one coherent process.
Highly Efficient Suzuki–Miyaura Coupling of Aryl Tosylates and Mesylates Catalyzed by Stable, Cost‐Effective [1,3‐Bis(diphenylphosphino)propane]nickel(II) Chloride [Ni(dppp)Cl2] with only 1 mol% Loading
Authors: Gao Han , Li You , Zhou Yi‐Guo , Han Fu‐She , Lin Ying‐Jie
Published: January 2011

We present a highly active, inexpensive, universally applicable, and markedly stable [1,3‐bis(diphenylphosphino)propane]nickel(II) chloride [Ni(dppp)Cl2] catalyst that is capable of effecting the Suzuki–Miyaura cross‐coupling of the inherently less reactive but readily available aryl tosylates and mesylates with only 1 mol% loading and in the absence of extra supporting ligand. Under the optimized reaction conditions, cross‐coupling of a wide range of activated, non‐activated, and deactivated, as well as sterically hindered and heteroaromatic substrates (36 examples) could proceed efficiently to afford the coupled products in 53–99% yields. Consequently, the results presented in this work provide a significant advance in Suzuki–Miyaura cross‐coupling in terms of generality, practicality, and cost which are key concerns in recent research regarding transition metal‐catalyzed cross‐couplings.
Polythiophene:Perylene Diimide Solar Cells – the Impact of Alkyl‐Substitution on the Photovoltaic Performance
Authors: Kamm Valentin , Battagliarin Glauco , Howard Ian A. , Pisula Wojciech , Mavrinskiy Alexey , Li Chen , Müllen Klaus , Laquai Frédéric
Published: January 2011

The photovoltaic parameters, i.e., the short‐circuit current, open‐circuit voltage and device fill factor, of bulk heterojunction solar cells that use perylene diimide (PDI) derivatives as electron acceptors are often far below the theoretically expected values for reasons still not entirely understood. This article demonstrates that the photovoltaic characteristics of blend films of regioregular poly(3‐hexylthiophene) (rr‐P3HT) and PDI molecules are improved upon using a core‐alkylated PDI derivative instead of the often used N‐alkylated PDI molecules. A doubling of the power conversion efficiency of P3HT:PDI solar cells by using the core‐alkylated PDI derivative is observed leading to an unprecedented power conversion efficiency of 0.5% for a P3HT:PDI solar cell under AM1.5 solar illumination. Furthermore, the optical properties of the novel PDI derivative are compared to two standard exclusively N‐alkylated PDI derivatives by steady‐state and time‐resolved photoluminescence spectroscopy in solution and solid state. The experiments reveal that aggregation in the solid state determines the photophysics of all PDI derivatives. However, the emission energy and excited state lifetime of the aggregates are clearly influenced by the alkyl‐substitution pattern through its effect on the packing of the PDI molecules. X‐ray diffraction experiments before and after thermal annealing of PDI:polystyrene and PDI:P3HT blends reveal subtle differences in the packing characteristics of the different PDI derivatives and, problematically, that P3HT ordering is suppressed by all of the PDI derivatives.
Single Material Solar Cells: the Next Frontier for Organic Photovoltaics?
Authors: Roncali Jean
Published: January 2011

An overview of various approaches for the realization of single‐material organic solar cells (SMOCs) is presented. Fullerene‐conjugated systems dyads, di‐block copolymers, and self‐organized donor‐acceptor molecules all represent different possible approaches towards SMOCs. Although each of them presents specific advantages and poses specific problems of design and synthesis, these different routes have witnessed significant progress in the past few years and SMOCs with efficiencies in the range of 1.50% have been realized. These performances are already higher than those of bi‐component bulk heterojunction solar cells some ten years ago, demonstrating that SMOCs can represent a credible approach towards efficient and simple organic solar cells. Possible directions for future research are discussed with the aim of stimulating further research on this exciting topic.
An Osteological and Histological Investigation of Cranial Joints in Geckos
Authors: Payne Samantha L. , Holliday Casey M. , Vickaryous Matthew K.
Published: January 2011

Cranial kinesis is a widespread feature of gekkotan lizards. Previous studies of kinesis in lizards often described the relevant, mobile joints as synovial, thus characterized by the presence of a synovial cavity lined with articular cartilage. To date however, detailed investigations of cranial joint histology are lacking. We examined eight cranial joints (quadrate–articular, quadrate–pterygoid, quadrate–otooccipital, quadrate–squamosal, epipterygoid–prootic, epipterygoid–pterygoid, basisphenoid–pterygoid, and frontal–parietal) in five gekkotan species (Oedura lesueuerii,Eublepharis macularius,Hemitheconyxcaudicinctus,Tarentola annularis,andChondrodactylous bibronii) using microcomputed tomography and serial histology. Particular focus was given to the relationship between the bony and soft‐tissue components of the joint. Our results demonstrate that only three of these joints are synovial: the quadrate–articular, epipterygoid–pterygoid, and basisphenoid–pterygoid joints. The frontal–parietal and quadrate–pterygoid joints are syndesmosis (fibrous), the epipterygoid–prootic and quadrate–otooccipital joints are synchondroses (cartilaginous without a synovial cavity) and the quadrate–squamosal joint was not present. Based on previous descriptions, we determine that the structure of some cranial joints is variable among lizard taxa. We caution that osteology does not necessarily predict cranial joint histology. Although the functional implications of these findings remain to be explored we note that the development of synovial joints appears to be associated with a neural crest origin for the elements involved. Anat Rec, 2011. © 2011 Wiley‐Liss, Inc.
Synthesis and antimicrobial evaluation of some cephem derivatives
Authors: Kalcheva Veneta , Mincheva Zoia
Published: January 2011

Two novel cephem derivative series were synthesized: 7‐(d‐α‐aminophenyl‐acetamido‐)‐3‐methyl‐3‐cephem‐4‐carboxylic acid monohydrate (Cephalexin) derivatives and those of 7‐amino‐3‐(1‐methyl‐1H‐tetrazol‐5‐yl)‐thio methyl‐3‐cephem‐4‐carboxylic acid (7‐AMTCA). The antimicrobial activity of the prepared compounds was studied and compared to that of known cephalosporin antibiotics of the first generation against 12 standard strains and 189 clinical isolates of Gram‐positive and Gram‐negative microorganisms. The Cephalexin derivatives 4a‐f show a narrow activity spectrum and are inactive while 5c and 5d are more active than the Cephalexin and Cephazolin antibiotics against clinically isolated S. aureus and S. epidermidis strains.
Cross‐conjugated and pseudo‐cross‐conjugated mesomeric betaines, XVIII: Bicyclic mesoionic pyrimidines with cardiovascular activity
Authors: Kappe C. Oliver , Kappe Thomas
Published: January 2011

Reaction of α‐Anilino‐azines 1a‐i with activated malonates (magic malonates) 2a‐e leads to bicyclic mesoionic systems 3–7. Out of these, pyrido[1,2‐a]pyrimidines 3b,d are active as cardiotonics, whereas pyrimido[1,2‐a]pyrimidines 4a‐g show significant anti‐anginal and anti‐hypertensive activity.
Heterocyclen, 67. Mitt.: Darstellung und Charakterisierung einiger 2‐(2‐Aryl‐thiazol‐4‐yl)‐3‐hydroxy‐chromone
Authors: Simiti Ioan , Zaharia Valentin , Mager Sorin , Horn Mihai , Köteles‐Popa Tiberiu
Published: January 2011

Bei der Kondensation des o‐Hydroxyacetophenons (1) mit einer Reihe von 2‐Aryl‐4‐formyl‐thiazolen 2 wurden die zugehörigen Heterochalcone 3 erhalten. Ihre Epoxydierung mit anschließender Cyclisierung und Oxidation liefert die 2‐(2‐Aryl‐thiazol‐4‐yl)‐3‐hydroxy‐chromone 5.
Untersuchungen an 1,3‐Thiazinen, 42. Mitt.: Carbazoylierungen und Thiocarbazoylierungen von 2‐Thioxo‐tetrahydro‐1,3‐thiazin‐Derivaten
Authors: Hanefeld Wolfgang , v. Gösseln Hans Joachim
Published: January 2011

Carbazoylchloride reagieren mit 2‐Thioxo‐tetrahydro‐1,3‐thiazinen 6 und 7 zu N‐Carbazoyl‐thiazinderivaten 9 und 11. Thiocarbazoylchloride greifen kinetisch kontrolliert am 2‐Thioxoschwefel an zu S‐Substitutionsprodukten 10 und 12, die thermisch intramolekular zu den stabileren N‐Substitutionsprodukten 9 und 11 umgelagert werden können.
Alterations in type I hemidesmosome components suggestive of epigenetic control in the salivary glands of patients with Sjögren's syndrome
Authors: González Sergio , Aguilera Sergio , Alliende Cecilia , Urzúa Ulises , Quest Andrew F. G. , Herrera Luisa , Molina Claudio , Hermoso Marcela , Ewert Patricia , Brito Mónica , Romo Rafael , Leyton Cecilia , Pérez Paola , González María‐Julieta
Published: January 2011

Objective

Acinar cells in the salivary glands of patients with Sjögren's syndrome (SS) display severe alterations in anchorage to the basal lamina. Bioinformatics analysis of the BP230 gene sequence has revealed the presence of CpG islands that might be involved in epigenetic control of gene expression, and methylation of the BP230 promotor region may be implicated as an epigenetic control mechanism in salivary gland damage. Thus, the present study was undertaken to evaluate the protein BP230, as well as proteins BP180, α6β4 integrin, and cytokeratin‐18, for their expression levels, localization, and ability to form hemidesmosome adhesion complexes.

Methods

Eighteen patients with primary SS and 14 healthy control subjects were studied. Levels of messenger RNA (mRNA) and protein were measured by reverse transcription–polymerase chain reaction and Western blotting, respectively. BP230 methylation was determined by methylation‐sensitive polymerase chain reaction. Protein complexes were analyzed by immunoprecipitation and assessed for localization by immunofluorescence.

Results

In patients with SS as compared with controls, BP230 mRNA levels were decreased while protein levels were increased, and the gene promotor region was hypermethylated. Augmented proteolysis of BP180 was detected, since levels of linear IgA disease fragment 1 were increased. The complex‐forming ability of BP230, BP180, α6β4 integrin, and cytokeratin‐18 was maintained in patients with SS, in contrast to that in controls. BP230 and BP180 colocalized at the basal membrane of acinar cells, and cleavage of BP180 coincided with a loss of colocalization.

Conclusion

The decrease in BP230 mRNA levels may be explained by gene hypermethylation. We postulate that local epigenetic modifications of BP230 are produced in response to factors present in the damaged salivary glands of patients with SS. Additionally, the paradoxical increase in BP230 protein levels and the formation of both normal and altered adhesion complexes may help avoid cell death induced by the loss of anchorage.
Maternal exposure to multi‐wall carbon nanotubes does not induce embryo–fetal developmental toxicity in rats
Authors: Lim Jeong‐Hyeon , Kim Sung‐Hwan , Shin In‐Sik , Park Na‐Hyeong , Moon Changjong , Kang Seong‐Soo , Kim Sung‐Ho , Park Seung‐Chun , Kim Jong‐Choon
Published: January 2011

BACKGROUND: Although the potential risk of carbon nanotubes (CNTs) to humans has recently increased due to expanding production and widespread use, the potential adverse effects of CNTs on embryo–fetal development have not yet been determined. METHODS: This study investigated the potential effects of multi‐wall CNTs (MWCNTs) on pregnant dams and embryo–fetal development in rats. MWCNTs were administered to pregnant rats by gavage at 0, 40, 200, and 1,000 mg/kg/day. All dams were subjected to Cesarean section on day 20 of gestation, and the fetuses were examined for any morphological abnormalities. RESULTS: All animals survived to the end of the study. A decrease in thymus weight was observed in the high dose group in a dose‐dependent manner. However, maternal body weight, food consumption, and oxidant–antioxidant balance in the liver were not affected by treatment with MWCNTs. No treatment‐related differences in gestation index, fetal deaths, fetal and placental weights, or sex ratio were observed between the groups. Morphological examinations of the fetuses demonstrated no significant difference in incidences of abnormalities between the groups. CONCLUSIONS: The results show that repeated oral doses of MWCNTs during pregnancy induces minimal maternal toxicity and no embryo–fetal toxicity at 1,000 mg/kg/day in rats. The no‐observed‐adverse‐effect level of MWCNTs is considered to be 200 mg/kg/day for dams and 1,000 mg/kg/day for embryo–fetal development. In this study, the dosing formulation was not analyzed to determine the degree of reaggregation (or not), nor were blood levels of CNT's measured in the dosed animals to verify or characterize absorption. Birth Defects Res (Part B) 92:69–76, 2011.  © 2011 Wiley‐Liss, Inc.
Risk factors for survival and local recurrence after particle radiotherapy for single small hepatocellular carcinoma
Authors: Komatsu S , Murakami M , Fukumoto T , Hori Y , Hishikawa Y , Ku Y
Published: January 2011

Background

Particle radiotherapy is a novel treatment for malignant tumours. The present study aimed to evaluate risk factors for overall survival and local control after particle radiotherapy of single small hepatocellular carcinoma (HCC), and to identify suitable candidates for this treatment.

Methods

All patients with a single HCC smaller than 5 cm in diameter treated by particle radiotherapy between 2001 and 2008 were identified retrospectively from a prospectively collected database. Clinical outcomes and prognostic factors were analysed.

Results

A total of 150 patients were included. Five-year overall survival and local control rates were 50·9 and 92·3 per cent respectively. Multivariable analysis revealed that several factors, including age and Child–Pugh classification, significantly influenced overall survival. Proximity to the digestive tract and Child–Pugh classification were independent risk factors for local recurrence. Other tumour factors including size, gross classification, previous treatment, macroscopic vascular invasion, and tumour location in relation to the diaphragm and large vessels did not influence local control rate.

Conclusion

Particle radiotherapy seems safe and effective, and may be a novel treatment for small HCC. Recurrences are more frequent when the tumour is located close to the gut.
Randomized clinical trial comparing polypropylene or polydioxanone for midline abdominal wall closure
Authors: Bloemen A , van Dooren P , Huizinga B F , Hoofwijk A G M
Published: January 2011

Background

Incisional hernia is a frequent complication of abdominal surgery, often requiring surgical intervention. This prospective randomized trial compared suture materials for closure of the fascia after abdominal surgery.

Methods

In 456 patients the abdominal fascia was closed with either non-absorbable (polypropylene; Prolene®) or absorbable (polydioxanone; PDS®) suture material. Follow-up was by clinical examination and ultrasonography at 6-month intervals. Outcome measures were incisional hernia, surgical-site infection and suture sinus.

Results

Some 223 patients were analysed after closure with Prolene® and 233 after PDS®. Median follow-up was 32 and 31 months respectively. There was no significant difference in the incidence of incisional hernia between the groups: 20·2 per cent (45 of 223) for Prolene® and 24·9 per cent (58 of 233) with PDS® (P = 0·229). Kaplan-Meier analysis showed a cumulative rate after 4 years of 23·7 and 30·2 per cent for Prolene® and PDS® respectively (P = 0·222). Secondary outcome measures showed no significant differences.

Conclusion

The incidence of incisional hernia in both groups was higher than expected from previous literature. There were no significant differences between the two suture methods. Registration number: ISRCTN65599814 (http://www.clinical-trials.com).
Radiation safety program for the cardiac catheterization laboratory
Authors: E. Chambers Charles , A. Fetterly Kenneth , Holzer Ralf , Paul Lin Pei‐Jan , C. Blankenship James , Balter Stephen , K. Laskey Warren
Published: January 2011

The Society of Cardiovascular Angiography and Interventions present a practical approach to assist cardiac catheterization laboratories in establishing a radiation safety program. The importance of this program is emphasized by the appropriate concerns for the increasing use of ionizing radiation in medical imaging, and its potential adverse effects. An overview of the assessment of radiation dose is provided with a review of basic terminology for dose management. The components of a radiation safety program include essential personnel, radiation monitoring, protective shielding, imaging equipment, and training/education. A procedure based review of radiation dose management is described including pre‐procedure, procedure and post‐procedure best practice recommendations. Specific radiation safety considerations are discussed including women and fluoroscopic procedures as well as patients with congenital and structural heart disease. © 2011 Wiley‐Liss, Inc.
Pore Structure and Surface Acidity Effects of Ordered Mesoporous Supports on Enantioselective Hydrogenation of Ethyl Pyruvate
Authors: Böttcher Stefan , Hoffmann Claudia , Räuchle Konstantin , Reschetilowski Wladimir
Published: January 2011

The enantioselective hydrogenation of ethyl pyruvate is studied using cinchonidine‐modified platinum supported on ordered mesoporous materials as a catalyst. The influence of different pore structures and hence, textural properties of the support on the enantiodifferentiation is investigated. The selected representative model supports are SBA‐15, SBA‐16, and KIT‐6. Depending on the pore structure, varying enantioselectivities are obtained. Furthermore, SBA‐15 is post‐synthetically aluminated to produce materials with different Si/Al ratios. An increase in Al content leads to an increased support surface acidity and enhanced enantioselectivity. The catalyst samples are characterized by small‐angle X‐ray scattering (SAXS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), temperature‐programmed desorption of ammonia (TPAD), and N2 and CO sorption techniques. Applying optimized reaction conditions resulted in enantiomeric excesses of (R)‐ethyl lactate of 90–94 % ee at total conversion.
Construction of Tetranuclear Macrocycles through CH Activation and Structural Transformation Induced by [2+2] Photocycloaddition Reaction
Authors: Yu Wei‐Bin , Han Ying‐Feng , Lin Yue‐Jian , Jin Guo‐Xin
Published: January 2011

A series of binuclear complexes [{Cp*Ir(OOCCH2COO)}2(pyrazine)] (1 b), [{Cp*Ir(OOCCH2COO)}2(bpy)] (2 b; bpy=4,4′‐bipyridine), [{Cp*Ir(OOCCH2COO)}2(bpe)] (3 b; bpe=trans‐1,2‐bis(4‐pyridyl)ethylene) and tetranuclear metallamacrocycles [{(Cp*Ir)2(OOC‐CC‐COO)(pyrazine)}2] (1 c), [{(Cp*Ir)2(OOC‐CC‐COO)(bpy)}2] (2 c), [{(Cp*Ir)2(OOC‐CC‐COO)(bpe)}2] (3 c), and [{(Cp*Ir)2[OOC(H3C6)‐NN‐(C6H3)COO](pyrazine)}2] (1 d), [{(Cp*Ir)2[OOC(H3C6)‐NN‐(C6H3)COO](bpy)}2] (2 d), [{(Cp*Ir)2[OOC(H3C6)‐NN‐(C6H3)COO](bpe)}2] (3 d) were formed by reactions of 1 a–3 a {[(Cp*Ir)2(pyrazine)Cl2] (1 a), [(Cp*Ir)2(bpy)Cl2] (2 a), and [(Cp*Ir)2(bpe)Cl2] (3 a)} with malonic acid, fumaric acid, or H2ADB (azobenzene‐4,4′‐chcarboxylic acid), respectively, under mild conditions. The metallamacrocycles were directly self‐assembled by activation of CH bonds from dicarboxylic acids. Interestingly, after exposure to UV/Vis light, 3 c was converted to [2+2] cycloaddition complex 4. The molecular structures of 2 b, 1 c, 1 d, and 4 were characterized by single‐crystal x‐ray crystallography. Nanosized tubular channels, which may play important roles for their stability, were also observed in 1 c, 1 d, and 4. All complexes were well characterized by 1H NMR and IR spectroscopy, as well as elemental analysis.
Optical probes and the applications in multimodality imaging
Authors: Liu Yang , Yu Gang , Tian Mei , Zhang Hong
Published: January 2011

Optical imaging essentially refers to in vivo fluorescence imaging and bioluminescence imaging. These types of imaging are widely used visualization methods in biomedical research and are important in molecular imaging. A new generation of imaging agents called multimodal probes have emerged in the past few years. These probes can be detected by two or more imaging modalities, which harnesses the strengths of the different modalities and enables researchers to obtain more information than can be achieved using only one modality. Owing to its low cost and the large number of probes available, the optical method plays an important role in multimodality imaging. In this mini‐review, we describe the available multimodal imaging probes for in vivo imaging that combine optical imaging with other modalities. Copyright © 2011 John Wiley & Sons, Ltd.
Enthalpy–Entropy Correlation for Hydrogen Adsorption on MOFs: Variable‐Temperature FTIR Study of Hydrogen Adsorption on MIL‐100(Cr) and MIL‐101(Cr)
Authors: Palomino Gemma Turnes , Cabello Carlos Palomino , Areán Carlos Otero
Published: January 2011

The thermodynamics of hydrogen interaction with the coordinatively unsaturated CrIII cationic sites in the metal–organic frameworks MIL‐100(Cr) and MIL‐101(Cr) was studied by variable‐temperature infrared (VTIR) spectroscopy. Simultaneous measurement of the equilibrium pressure of hydrogen and the integrated IR absorbance over the temperature range 79–105 K led to the determination of the corresponding values of standard adsorption enthalpy (ΔH0) and entropy (ΔS0). For MIL‐100(Cr) these values were ΔH0 = –6.9 kJ mol–1 and ΔS0 = –80 J mol–1 K–1, whereas for MIL‐101(Cr) the values ΔH0 = –9.5 kJ mol–1 and ΔS0 = –112 J mol–1 K–1were obtained. These thermodynamic quantities show a positive correlation between ΔH0 and ΔS0, which is analyzed in the broader context of the corresponding data available for hydrogen adsorption on other two MOFs and also on several cation‐exchanged zeolites. The implications for hydrogen storage and delivery by using MOFs are discussed.
Identification of gaps in knowledge concerning toxicology of 3‐MCPD and glycidol esters
Authors: Habermeyer Michael , Guth Sabine , Eisenbrand Gerhard
Published: January 2011

3‐Monochloropropane‐1,2‐diol (3‐MCPD), also named 3‐chloro‐propanediol or α‐chlorohydrin has long been known as a contaminant in certain heat‐processed foods, including cereal products, coffee, fish, meat products, dairy products, and sauces on the basis of acid hydrolyzed vegetable protein 1. There is convincing evidence that fatty acid esters of 3‐MCPD are also widespread in processed foods and that concentrations of these compounds exceed those of the corresponding chloropropanols. Whereas toxicology and biological effects of 3‐MCPD have been studied quite thoroughly, very little is known about 3‐MCPD esters of fatty acids. Recently, it has been reported that also esters of glycidol are formed during the refining of vegetable oils. There are no toxicological data available yet on glycidol esters but glycidol itself as an industrial chemical has been investigated and is known as genotoxic carcinogen found to induce tumors in different tissues after oral application. The following summary provides a condensed overview about gaps in knowledge concerning 3‐MCPD esters and glycidol esters and addresses questions concerning toxicological relevance.
Mechanism of action of mercury on sperm morphology, adenosine triphosphate content, and motility in Perca fluviatilis (Percidae; Teleostei)
Authors: Hatef Azadeh , Alavi Sayyed Mohammad Hadi , Butts Ian A. E , Policar Tomas , Linhart Otomar
Published: January 2011

The main objectives of the present study were to investigate the performance of mercury chloride (HgCl2) on sperm function and structure, identify sites of action of HgCl2, and investigate the mechanism of action of HgCl2 on fish (Perca fluviatilis L.) spermatozoa. Direct exposure of nonincubated sperm decreased sperm motility and velocity in a dose-dependent manner and was totally suppressed at 250 µM HgCl2. Adenosine-5′-triphosphate (ATP) content of sperm after activation in an activation medium (AM) containing more than 25 µM HgCl2 did not differ compared with nonactivated sperm. Motility and velocity of demembranated sperm decreased after activation in an AM containing 62 µM HgCl2, and was totally suppressed at 250 µM HgCl2. Incubation of sperm in an immobilizing medium (IM) containing HgCl2 enhanced HgCl2 effects after sperm activation in an AM containing HgCl2. Sperm motility of incubated sperm in an IM without HgCl2 was totally suppressed at 125 µM HgCl2 after 3 h incubation. In case of incubated sperm in an IM containing HgCl2, sperm motility was totally suppressed at 31 µM HgCl2. Adenosine-5′-triphosphate content of sperm was significantly lower in an IM containing HgCl2 greater than 3 µM compared with those of the control (no HgCl2) and lower HgCl2 concentrations. Damage to the plasma membrane and axoneme were observed in sperm incubated in an IM containing HgCl2 compared with the control, when HgCl2 concentration and incubation time increased. In conclusion, HgCl2 acts on sperm through disruption of function of the plasma membrane, axoneme, and ATP content. Environ. Toxicol. Chem. 2011; 30:905–914. © 2010 SETAC
A comparison of approaches to account for uncertainty in analysis of imputed genotypes
Authors: Zheng Jin , Li Yun , Abecasis Gonçalo R. , Scheet Paul
Published: January 2011

The availability of extensively genotyped reference samples, such as “The HapMap” and 1,000 Genomes Project reference panels, together with advances in statistical methodology, have allowed for the imputation of genotypes at single nucleotide polymorphism (SNP) markers that are untyped in a cohort or case‐control study. These imputation procedures facilitate the interpretation and meta‐analyses of genome‐wide association studies. A natural question when implementing these procedures concerns how best to take into account uncertainty in imputed genotypes. Here we compare the performance of the following three strategies: least‐squares regression on the “best‐guess” imputed genotype; regression on the expected genotype score or “dosage”; and mixture regression models that more fully incorporate posterior probabilities of genotypes at untyped SNPs. Using simulation, we considered a range of sample sizes, minor allele frequencies, and imputation accuracies to compare the performance of the different methods under various genetic models. The mixture models performed the best in the setting of a large genetic effect and low imputation accuracies. However, for most realistic settings, we find that regressing the phenotype on the estimated allelic or genotypic dosage provides an attractive compromise between accuracy and computational tractability. Genet. Epidemiol. 32:102–110, 2011. © 2011 Wiley‐Liss, Inc.
Reticulon 4B (Nogo-B) is a novel regulator of hepatic fibrosis
Authors: Zhang Dahai , Utsumi Teruo , Huang Hui-Chun , Gao Lili , Sangwung Panjamaporn , Chung Chuhan , Shibao Kazunori , Okamoto Kohji , Yamaguchi Koji , Groszmann Roberto J. , Jozsef Levente , Hao Zhengrong , Sessa William C. , Iwakiri Yasuko
Published: January 2011

Nogo-B, also known as Reticulon 4B, plays important roles in vascular injuries. Its function in the liver is not understood. The aim of this study was to characterize Nogo-B in liver fibrosis and cirrhosis. Nogo-B distribution was assessed in normal and cirrhotic human liver sections. We also determined the levels of liver fibrosis in wild-type (WT) and Nogo-A/B knockout (NGB KO) mice after sham operation or bile duct ligation (BDL). To investigate the mechanisms of Nogo-B's involvement in fibrosis, hepatic stellate cells were isolated from WT and NGB KO mice and transformed into myofibroblasts. Portal pressure was measured to test whether Nogo-B gene deletion could ameliorate portal hypertension. In normal livers, Nogo-B expression was found in nonparenchymal cells, whereas its expression in hepatocytes was minimal. Nogo-B staining was significantly elevated in cirrhotic livers. Fibrosis was significantly increased in WT mice 4 weeks after BDL compared with NGB KO mice. The absence of Nogo-B significantly reduced phosphorylation of Smad2 levels upon transforming growth factor β (TGF-β) stimulation. Reconstitution of the Nogo-B gene into NGB KO fibroblasts restored Smad2 phosphorylation. Four weeks after BDL, portal pressure was significantly increased in WT mice by 47%, compared with sham-operated controls (

P

= 0.03), whereas such an increase in portal pressure was not observed in NGB KO mice (

P

= NS).

Conclusion:

Nogo-B regulates liver fibrosis, at least in part, by facilitating the TGFβ/Smad2 signaling pathway in myofibroblasts. Because absence of Nogo-B ameliorates liver fibrosis and portal hypertension, Nogo-B blockade may be a potential therapeutic target in fibrosis/cirrhosis. (HEPATOLOGY 2011;)
Prediction of restraints among youth in a psychiatric hospital: application of translational action research
Authors: Tompsett Carolyn J. , Domoff Sarah , Boxer Paul
Published: January 2011

This study extends a translational action research program by applying a theoretically based measure of risk in predicting incidents of restraint among children and adolescents in a secure psychiatric hospital. Youth inpatients (N = 149, aged 5–17 years) were assessed at intake for the presence of selected individual and contextual risk factors, and their involvement in critical incidents was tracked (i.e., number of episodes in which restraint was applied) for the remainder of their hospitalization. Models including history of aggression or history of previous placements as well as combined models including several individual and contextual factors significantly predicted the likelihood of a youth becoming involved in at least one restraint. Unique predictors of restraint involvement included history of aggression against adults and history of previous psychiatric hospitalizations. None of the variables assessed predicted the extent of a youth's restraint involvement. The implications of these findings are discussed with respect to future research and empirically informed practice with high‐risk youth. © 2011 Wiley Periodicals, Inc. J Clin Psychol 00:1–15, 2011.
Mindfulness‐based approaches: are they all the same?
Authors: Chiesa Alberto , Malinowski Peter
Published: January 2011

Mindfulness‐based approaches are increasingly employed as interventions for treating a variety of psychological, psychiatric and physical problems. Such approaches include ancient Buddhist mindfulness meditations such as Vipassana and Zen meditations, modern group‐based standardized meditations, such as mindfulness‐based stress reduction and mindfulness‐based cognitive therapy, and further psychological interventions, such as dialectical behavioral therapy and acceptance and commitment therapy. We review commonalities and differences of these interventions regarding philosophical background, main techniques, aims, outcomes, neurobiology and psychological mechanisms. In sum, the currently applied mindfulness‐based interventions show large differences in the way mindfulness is conceptualized and practiced. The decision to consider such practices as unitary or as distinct phenomena will probably influence the direction of future research. © 2011 Wiley Periodicals, Inc. J Clin Psychol 67:1‐21, 2011.
Second‐order collision‐induced light scattering: a spherical tensor approach
Authors: Senchuk A. , Tabisz G. C.
Published: January 2011

Collision‐induced light scattering (CILS) is a rotational–translational Raman scattering occurring in pairs or larger clusters of interacting molecules. A general explicit expression for the dipole correlation function relevant to second‐order CILS is derived in the spherical tensor formalism. A Mathematica program is given to calculate this autocorrelation function and hence the scattered intensity and depolarization ratio. Some examples are given for interacting atoms and tetrahedral molecules. These developments will aid in the interpretation of the weak, high‐frequency wings of induced spectra. Copyright © 2011 John Wiley & Sons, Ltd.
Raman spectroscopy of laser‐induced oxidation of titanomagnetites
Authors: Bauer Michael , Davydovskaya Polina , Janko Marek , Kaliwoda Melanie , Petersen Nikolai , Gilder Stuart , Stark Robert W.
Published: January 2011

Titanomagnetites are important carriers of magnetic remanence in nature and can track redox conditions in magma. The titanium concentration in magnetite bears heavily on its magnetic properties, such as saturation moment and Curie temperature. On land and in the deep ocean, however, these minerals are prone to alteration which can mask the primary magnetic signals they once recorded. Thus, it is essential to characterize the cation composition and oxidation state of titanomagnetites that record the paleomagnetic field. Raman spectroscopy provides a unique tool for both purposes. Nonetheless, the heat generated by the excitation laser can itself induce oxidation. We show that the laser power threshold to produce oxidation decreases with increasing titanium content. With confocal Raman spectroscopy and magnetic force microscopy (MFM) on natural and synthetic titanomagnetites, a non‐destructive Raman imaging protocol was established. We applied this protocol to map out the composition and magnetization state within a single ex‐solved titanomagnetite grain in a deep‐sea basalt. Copyright © 2011 John Wiley & Sons, Ltd.
Synthesis of core‐shell molecularly imprinted polymer microspheres by precipitation polymerization for the inline molecularly imprinted solid‐phase extraction of thiabendazole from citrus fruits and orange juice samples
Authors: Barahona Francisco , Turiel Esther , Cormack Peter A. G. , Martín‐Esteban Antonio
Published: January 2011

In this work, the synthesis of molecularly imprinted polymer microspheres with narrow particle size distributions and core‐shell morphology by a two‐step precipitation polymerization procedure is described. Polydivinylbenzene (poly DVB‐80) core particles were used as seed particles in the production of molecularly imprinted polymer shells by copolymerization of divinylbenzene‐80 with methacrylic acid in the presence of thiabendazole (TBZ) and an appropriate porogen. Thereafter, polymer particles were packed into refillable stainless steel HPLC columns used in the development of an inline molecularly imprinted SPE method for the determination of TBZ in citrus fruits and orange juice samples. Under optimized chromatographic conditions, recoveries of TBZ within the range 81.1–106.4%, depending upon the sample, were obtained, with RSDs lower than 10%. This novel method permits the unequivocal determination of TBZ in the samples under study, according to the maximum residue levels allowed within Europe, in less than 20 min and without any need for a clean‐up step in the analytical protocol.
Analysis of anthocyanins in commercial fruit juices by using nano‐liquid chromatography‐electrospray‐mass spectrometry and high‐performance liquid chromatography with UV‐vis detector
Authors: Fanali Chiara , Dugo Laura , D'Orazio Giovanni , Lirangi Melania , Dachà Marina , Dugo Paola , Mondello Luigi
Published: January 2011

Nano‐LC and conventional HPLC techniques were applied for the analysis of anthocyanins present in commercial fruit juices using a capillary column of 100 μm id and a 2.1 mm id narrow‐bore C18 column. Analytes were detected by UV‐Vis at 518 nm and ESI‐ion trap MS with HPLC and nano‐LC, respectively. Commercial blueberry juice (14 anthocyanins detected) was used to optimize chromatographic separation of analytes and other analysis parameters. Qualitative identification of anthocyanins was performed by comparing the recorded mass spectral data with those of published papers. The use of the same mobile phase composition in both techniques revealed that the miniaturized method exhibited shorter analysis time and higher sensitivity than narrow‐bore chromatography. Good intra‐day and day‐to‐day precision of retention time was obtained in both methods with values of RSD less than 3.4 and 0.8% for nano‐LC and HPLC, respectively. Quantitative analysis was performed by external standard curve calibration of cyanidin‐3‐O‐glucoside standard. Calibration curves were linear in the concentration ranges studied, 0.1–50  and 6–50 μg/mL for HPLC‐UV/Vis and nano‐LC‐MS, respectively. LOD and LOQ values were good for both methods. In addition to commercial blueberry juice, qualitative and quantitative analysis of other juices (e.g. raspberry, sweet cherry and pomegranate) was performed. The optimized nano‐LC‐MS method allowed an easy and selective identification and quantification of anthocyanins in commercial fruit juices; it offered good results, shorter analysis time and reduced mobile phase volume with respect to narrow‐bore HPLC.
Role of endothelial nitric oxide synthase in remote ischemic preconditioning of the mouse liver
Authors: Abu-Amara Mahmoud , Yang Shi Yu , Quaglia Alberto , Rowley Peter , Fuller Barry , Seifalian Alexander , Davidson Brian
Published: January 2011

Hindlimb remote ischemic preconditioning (RIPC) reduces liver ischemia/reperfusion (IR) injury in wild-type mice. The underlying mechanisms of RIPC are currently unknown. In this study, we investigated the role of endothelial nitric oxide synthase (eNOS) in mediating the protective effects of RIPC. Endothelial nitric oxide synthase knockout (eNOS-/-) mice were divided into 4 groups: (1) a sham surgery group, (2) an RIPC group (6 cycles of 4 minutes of hindlimb ischemia and 4 minutes of hindlimb reperfusion), (3) an IR group [40 minutes of lobar (70%) hepatic ischemia and 2 hours of reperfusion], and (4) an RIPC+IR group (RIPC followed by the IR group procedures). Plasma liver aminotransferases, hepatic histopathological injury scores, transmission electron microscopy studies, and hepatic microcirculatory blood flow (MBF) were assessed. eNOS protein expression was analyzed in the livers and hindlimb muscles of wild-type mice. Hindlimb RIPC did not protect against subsequent liver IR injury in eNOS-/- mice; this was demonstrated by the lack of reduction in the plasma aminotransferase levels, histopathological scores, or ultrastructural features of IR injury in the RIPC+IR group versus the IR group. Hepatic MBF did not recover during liver reperfusion in the RIPC+IR group versus the IR group. eNOS protein expression was similar among all wild-type groups. In conclusion, eNOS is essential for the protective effects of hindlimb RIPC on liver IR injury. eNOS exerts its protective effects through the preservation of hepatic MBF. At 2 hours of reperfusion, eNOS protection is likely due to the increased activation of eNOS rather than increased expression. Liver Transpl 17:610-619, 2011. © 2011 AASLD.
Simultaneous Vapor‐Phase Polymerization of PEDOT and a Siloxane into Organic/Inorganic Hybrid Thin Films
Authors: Han Yong‐Hyeon , Travas‐Sejdic Jadranka , Wright Bryon , Yim Jin‐Heong
Published: January 2011

The co‐vaporization and simultaneous polymerization of EDOT and APTES on a FTS‐coated substrate resulting in a homogeneous PEDOT/ASSQ thin film is described. The physicochemical properties of the film, including surface hardness, solvent mechanical wear resistance, and resistance to scratch, were much better than those of pure PEDOT. A PEDOT/ASSQ hybrid film with homogeneous morphology resulted, as judged by AFM topography scans, surface roughness calculations, and SEM images. The ASSQ proportion in the hybrid films, as investigated by XPS and EDS, was strongly dependent on the content of FTS on the substrate. In addition, the simultaneous polymerization of a PEDOT/ASSQ hybrid film onto selective micropatterns was demonstrated and analyzed.

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High‐Mobility Conjugated Polymers Based on Fused‐Thiophene Building Blocks
Authors: Liu Yao , Liu Yunqi , Zhan Xiaowei
Published: January 2011

Organic field‐effect transistors (OFETs) are a promising cost‐effective alternative to silicon‐based field‐effect transistors, and possess low‐cost, light‐weight, and flexibility advantages. Conjugated polymers based on fused‐thiophene building blocks have received considerable attention in the emerging field of organic electronics. In this review the most recent developments in conjugated polymers based on fused‐thiophene rings for high‐performance OFETs are summarized. The focus is on correlations of polymer chemical structures with properties, such as energy levels, film‐forming property, film morphology, and OFET performance. This structure–property relationship analysis may guide rational structural design and evaluation of organic semiconductors.

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Homo and Block Copolymers of Poly(β‐benzyl‐L‐aspartate)s and Poly(γ‐benzyl‐L‐glutamate)s of Different Architectures
Authors: Brulc Blaž , Žagar Ema , Gadzinowski Mariusz , Słomkowski Stanisław , Žigon Majda
Published: January 2011

Homopolypeptides of linear and star‐like architectures were prepared by polymerizing benzylic‐protected L‐glutamic acid and L‐aspartic acid N‐carboxyanhydrides (Glu NCA, Asp NCA) in DMF. The polymerization rate of the Glu NCA is faster than that of Asp NCA. Using a simple monoamino initiator, its hydrochloride, di‐, tri‐, and tetraamino functional initiators, homopolypeptides with well‐defined structures and molar masses were obtained. The molar‐mass averages of the poly(γ‐benzyl‐L‐glutamate)s lie very close to calculated values, according to the initial [M]:[I] ratios, while those of the linear poly(β‐benzyl‐L‐aspartate)s were lower than the predicted ones. PBAs had somewhat broader molar‐mass distributions than PBGs.

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A Convenient Method for the Synthesis of the Amphiphilic Triblock Copolymer Poly(L‐lactic acid)‐block‐Poly(L‐lysine)‐block‐Poly(ethylene glycol) Monomethyl Ether
Authors: Xiang Li , Shen Lin‐Jing , Long Feng , Yang Ke , Fan Jun‐Bing , Li Ya‐Jing , Xiang Jiannan , Zhu Ming‐Qiang
Published: January 2011

The amphiphilic triblock copolymer PLA‐b‐PLL‐b‐MPEG is prepared in three steps through acylation coupling between the terminal amino groups of PLA‐b‐PZLL‐NH2 and carboxyl‐terminal MPEG, followed by the deprotection of amines. The block copolymers are characterized via FT‐IR, 1H NMR, DSC, GPC, and TEM. TEM analysis shows that the triblock polymers can form polymeric micelles in aqueous solution with a homogeneous spherical morphology. The cytotoxicity assay indicates that the final triblock polymer micelles after deprotection show low cytotoxicity against Bel7402 human hepatoma cells. MPEG and PLL were introduced into the main chain of PLA affording a kind of ideal bioabsorbable polymer materials, which is expected to be useful in drug and gene delivery.

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Biocompatible Poly(D,L‐lactide)‐block‐Poly(2‐methacryloyloxyethylphosphorylcholine) Micelles for Drug Delivery
Authors: Liu Gong‐Yan , Lv Li‐Ping , Chen Chao‐Jian , Hu Xiao‐Fen , Ji Jian
Published: January 2011

Well‐defined amphiphilic PLA‐b‐PMPC diblock copolymers were synthesized. Bimimetic micelles were prepared and applied for release of anti‐cancer drugs (DOX). TEM and DLS analysis revealed a regular spherical shape with small diameter (less than 50 nm) of the micelle. The biocompatibility of PLA‐b‐PMPC micelles was studied, and it was found that the micelles possessed excellent cytocompatibility due to the zwitterionic phosphorylcholine group. DOX could be efficiently loaded into the micelles with a loading efficiency of 44–67%. The DOX‐loaded micelles showed lower cytotoxicity than free drugs and efficiently delivered and released the drug into cancer cells. With these properties, the PLA‐b‐PMPC polymer micelles are attractive as drug carriers for pharmaceutical application.

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Percolation of Trace Amounts of Linear Polymers in Melts of Cyclic Polymers
Authors: Vasquez Rafael , Shanbhag Sachin
Published: January 2011

Melts of CPs, intentionally contaminated with small fractions of LPs, are studied using the bond fluctuation model to probe the extreme sensitivity of the rheology to trace amounts of linear chains. Using primitive path analysis to compute the number of entanglements on the molecules, the threshold concentration at which LPs percolate through the system is calculated using a mean‐field theory. It is found that the percolation threshold decreases with the molecular weight, and is approximately 25–30 times smaller than the overlap concentration of the linear chains for the longest polymers studied. These simulations help to understand and justify the approximations made in earlier theoretical investigations.

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