bluuebunny/crossref_metadata_2025 huggingface dataset:
Engineered heart tissue enables study of residual undifferentiated embryonic stem cell activity in a cardiac environment
Authors: Dengler Jana , Song Hannah , Thavandiran Nimalan , Massé Stéphane , Wood Geoffrey A. , Nanthakumar Kumaraswamy , Zandstra Peter W. , Radisic Milica
Published: October 2010

Embryonic stem cell (ESC) derivatives are a promising cell source for cardiac cell therapy. Mechanistic studies upon cell injection in conventional animal models are limited by inefficient delivery and poor cell survival. As an alternative, we have used an engineered heart tissue (EHT) based on neonatal rat cardiomyocytes (CMs) cultivated with electrical field stimulation as an in vitro model to study cell injection. We injected (0.001, 0.01, and 0.1 million) and tracked (by qPCR and histology) undifferentiated yellow‐fluorescent protein transgenic mouse ESCs and Flk1 + /PDGFRα+ cardiac progenitor (CPs) cells, to investigate the effect of the cardiac environment on cell differentiation, as well as to test whether our in vitro model system could recapitulate the formation of teratoma‐like structures commonly observed upon in vivo ESC injection. By 8 days post‐injection, ESCs were spatially segregated from the cardiac cell population; however, ESC injection increased survival of CMs. The presence of ESCs blocked electrical conduction through the tissue, resulting in a 46% increase in the excitation threshold. Expression of mouse cardiac troponin I, was markedly increased in CP injected constructs compared to ESC injected constructs at all time points and cell doses tested. As early as 2 weeks, epithelial and ganglion‐like structures were observed in ESC injected constructs. By 4 weeks of ESC injection, teratoma‐like structures containing neural, epithelial, and connective tissue were observed in the constructs. Non‐cardiac structures were observed in the CP injected constructs only after extended culture (4 weeks) and only at high cell doses, suggesting that these cells require further enrichment or differentiation prior to transplantation. Our data indicate that the cardiac environment of host tissue and electrical field stimulation did not preferentially guide the differentiation of ESCs towards the cardiac lineage. In the same environment, injection of CP resulted in a more robust cardiac differentiation than injection of ESC. Our data demonstrate that the model‐system developed herein can be used to study the functional effects of candidate stem cells on the host myocardium, as well as to measure the residual activity of undifferentiated cells present in the mixture. Biotechnol. Bioeng. 2011; 108:704–719. © 2010 Wiley Periodicals, Inc.
Preparation of stimulus responsive multiple emulsions by membrane emulsification using con a as biochemical sensor
Authors: Piacentini Emma , Drioli Enrico , Giorno Lidietta
Published: October 2010

In this work, a novel strategy for the controlled fabrication of biomolecular stimulus responsive water‐in‐oil‐in‐water (W/O/W) multiple emulsion using the membrane emulsification process was investigated. The emulsions interface was functionalized with a biomolecule able to function as a receptor for a target compound. The interaction between the biomolecular receptor and target stimulus activated the release of bioactive molecules contained within the structured emulsion. A glucose sensitive emulsion was investigated as a model study case. Concanavalin A (Con A) was used as the biomolecular glucose sensor. Various physicochemical strategies for stimulus responsive materials formulation are available in literature, but the preparation of biomolecule‐responsive emulsions has been explored for the first time in this paper. The development of novel drug delivery systems requires advanced and highly precise techniques to obtain their particular properties and targeting requirements. The present study has proven the flexibility and suitability of membrane emulsification for the preparation of stable and functional multiple emulsions containing Con A as interfacial biomolecular receptor able to activate the release of a bioactive molecule as a consequence of interaction with the glucose target molecule. The influence of emulsion interfacial composition and membrane emulsification operating conditions on droplets stability and functional properties have been investigated. The release of the bioactive molecule as a function of glucose stimulus and its concentration has been demonstrated. Biotechnol. Bioeng. 2011; 108:913–923. © 2010 Wiley Periodicals, Inc.
Preoperative inflammation is a prognostic factor for gallbladder carcinoma
Authors: Han H-S , Cho J Y , Yoon Y-S , Ahn K S , Kim H
Published: October 2010

Background

Inflammation frequently accompanies gallbladder carcinoma (GBC), but its impact on outcome is unclear. The present study investigated the impact of concomitant inflammation on survival of patients with GBC.

Methods

All patients undergoing surgery for GBC between October 2003 and May 2009 were identified retrospectively from a prospectively collected database. Patients were classified according to whether preoperative inflammation was present (65 patients) or not (23).

Results

A total of 88 patients were enrolled. There were no differences in sex, mean age, tumour node metastasis (TNM) stage and radicality of resection between the two groups. The overall 3-year survival rate was lower in patients with preoperative inflammation than in those without (33 versus 73 per cent; P = 0·001). In univariable analysis, preoperative inflammation, T, N and M category, TNM stage, radicality of surgery and tumour differentiation were significant prognostic factors. The presence of preoperative inflammation (hazard ratio (HR) 2·38, 95 per cent confidence interval 1·04 to 5·43), lymph node metastases (HR 5·23, 1·05 to 26·09) and R1 or R2 resection (HR 3·77, 1·47 to 9·72) were independent prognostic factors for poor survival.

Conclusion

The presence of preoperative inflammation is an independent prognostic factor for poor survival in patients with GBC.
The morphometry of patella and patellar ligament during the fetal period
Authors: Koyuncu Esra , Cankara Neslihan , Sulak Osman , Özgüner Gulnur , Albay Soner
Published: October 2010

This study aims to determine the development and morphology of the patella and patellar tendon and to obtain morphometric data about these structures during the fetal period. One hundred five human fetuses (55 males and 50 females) aged 9–40 weeks were used in this study. Fetuses were divided into four groups between gestational weeks; Group I (9–12 weeks), Group II (13–25 weeks), Group III (26–37 weeks), and Group IV (38–40 weeks). The patella and patellar ligament were exposed via anatomical dissection; the dimensions (length, width, thickness) and the width of the lateral and medial articular surfaces of the patella, and the length and width of the patellar ligament, were measured using a Vernier's caliper. No significant differences were observed between genders or sides for any of the parameters (P > 0.05), and a significant correlation was found between gestational age and all parameters (P < 0.001). All parameters of the patella and patellar ligament were found to be different statistically between trimesters (P < 0.05). This study reveals the development, morphological changes, and the morphometric measurements of the patella and patellar ligament during the fetal period. We hope that the present results can be useful for future studies. Clin. Anat. 24:225–231, 2011. © 2010 Wiley‐Liss, Inc.
A rare case of a complete left inferior vena cava associated with the symptoms of Dunbar syndrome
Authors: Wartmann Christopher T. , Kinsella Christopher R. , Tubbs R. Shane , Loukas Marios
Published: October 2010

We report a case of an 82‐year‐old female with an anomalous left inferior vena cava. The left inferior vena cava ascends parallel and to the left of the descending abdominal aorta. At the level of the celiac trunk, the inferior vena cava courses anteriorly and to the right to reach the posterior surface of the liver. The patient also suffers from chronic mild postprandial abdominal pain. It is possible that position of inferior vena cava anterior to the aorta, at the level of the celiac trunk, may lead to intermittent celiac artery compression syndrome (Dunbar syndrome). Clin. Anat. 24:262–265, 2011. © 2010 Wiley‐Liss, Inc.
Fluoroscopic angiography in the gross anatomy dissection laboratory: Visualizing the aortic arch and its branches in a cadaver
Authors: Vogt Keith M. , Kauh Courtney Y. , Holder David M. , DePhilip Robert M.
Published: October 2010

We present fluoroscopic images of the aortic arch and its branches obtained in a first year medical gross anatomy teaching laboratory after an aberrant right subclavian artery was discovered during dissection. The aortic arch and its branches in the cadaver were filled with contrast medium in molten agar. After the agar solidified, a portable fluoroscope was used to obtain radiographic images. These post‐mortem images were then compared with computed tomography images obtained while the individual was living. The embryology, prevalence, and clinical findings of this arterial variation are reviewed, and the importance of recognizing the presence of an aberrant right subclavian artery before performing various procedures is discussed. This exercise gave students the unique opportunity to compare the three‐dimensional anatomy seen in the dissection laboratory with the two‐dimensional presentation of that same anatomy in the radiographic images that they will see in clinical practice. Clin. Anat. 24:253–257, 2011. © 2010 Wiley‐Liss, Inc.
The third time is the charm—Anastomosis between the celiac trunk and the left colic artery
Authors: Stimec Bojan V. , Terraz Sylvain , Fasel Jean H.D.
Published: October 2010

An atypical case of abdominal vasculature, found in a 58‐year‐old woman is presented. The multidetector computed tomography angiogram revealed a large tortuous anastomotic vessel between the stem of the celiac trunk and the left colic artery, supplying branches for the left colon and pancreatic body and tail. We propose a simple embryological explanation for the development of this aberrant artery—the longitudinal ventral anastomosis, which connects the precursors of principal visceral arteries in a loop‐like manner, loses its direct communication with the superior mesenteric artery but maintains its continuity above and below this level. This variation could pose a problem for radiological interpretation and affect surgical approaches to the aorta, left colon, and the pancreas. Clin. Anat. 24:258–261, 2011. © 2010 Wiley‐Liss, Inc.
Mediating between international knowledge and local knowledge: The critical role of local field officers in an HIV prevention intervention
Authors: Aveling Emma‐Louise
Published: October 2010

The outcomes of health interventions are co‐constructed through negotiation between the competing knowledges of different stakeholders. In such a context, local implementing partners – who mediate between international donors/programme managers and local beneficiary communities – have a critical ‘knowledge brokering’ role to play. With appropriate support, they can facilitate integration of internationally established knowledge with local beliefs and practices in ways that support health‐enhancing behaviour change. This paper focuses on the local field officers of an HIV prevention programme with Cambodian military couples. The paper asks: (1) what are the outcomes of knowledge encounters between international organizations and local field officers, as expressed in field officers' interpretation of programme goals, strategies and messages? (2) To what extent does the intervention context support the field officers' knowledge brokering efforts? Data collected includes semi‐structured interviews, observations of programme meetings and activities, and textual materials. The findings demonstrate that field officers privilege international knowledge, particularly in interactions with international manager–partners. However, in the field, they both hybridize programme messages and struggle to resolve dilemmas provoked by conflicting international and local knowledges. Material and symbolic asymmetries within the intervention context are shown to undermine their knowledge brokering efforts, as field officers attempt to claim identities and futures as health development professionals. Implications for programme practices and accountability systems are discussed. Copyright © 2010 John Wiley & Sons, Ltd.
Cytoprotective effects of catechin 7‐O‐β‐Dglucopyranoside against mitochondrial dysfunction damaged by streptozotocin in RINm5F cells
Authors: Kim Ki Cheon , Kim Jin Sook , Ah Kang Kyoung , Kim Jong Min , Won Hyun Jin
Published: October 2010

The protective effects of catechin 7‐O‐β‐Dglucopyranoside (C7G) against streptozotocin (STZ)‐induced mitochondrial damage in rat pancreatic β‐cells (RINm5F) were investigated. A marked increase in mitochondrial reactive oxygen species (ROS) was observed in STZ‐treated cells; this increase was restricted by C7G treatment. C7G also scavenged superoxide anions and hydroxyl radicals generated by xanthine/xanthine oxidase (xanthine/XO) and the Fenton reaction (FeSO4 + H2O2), respectively. C7G restored activity and expression of both mitochondrial manganese superoxide dismutase (MnSOD) and catalase (CAT), which were suppressed by STZ treatment. In addition, C7G prevented STZ‐induced mitochondrial lipid peroxidation, protein carbonyl, and DNA base modification. C7G restored the loss of mitochondrial membrane potential (Δψ) that was disrupted by STZ treatment, and prevented cell death via inhibition of apoptosis. These results suggest that C7G has a protective effect against STZ‐induced cell damage by its antioxidant effects and the attenuation of mitochondrial dysfunction. Copyright © 2010 John Wiley & Sons, Ltd.
Enhancement of osteoblast biocompatibility on titanium surface with Terrein treatment
Authors: Lee Young‐Hee , Lee Nan‐Hee , Bhattarai Govinda , Oh Young‐Taek , Yu Mi‐Kyung , Yoo Ick‐Dong , Jhee Eun‐Chung , Yi Ho‐Keun
Published: October 2010

Titanium is biocompatible with bodily tissues. However, the formation of ROS on the titanium surfaces might have negative response of the activity of the surroundings cells. Terrein was isolated from Penicullium sp. 20135 and found to reduce the effects of LPS‐induced inflammation. This study examined the role of Terrein on the biocompatibility of titanium to determine if it can help improve osseointegration. MC‐3T3 E1 cells were grown on titanium surfaces. The biocompatibility of Terrein was examined by adding it directly to the culture media at the indicated concentration. The cells on the titanium surface produced excessive ROS and decreased the activity of Cu/Zn SOD and Mn SOD. Moreover, the cells had higher activity towards oxidative stress molecules, such as MAPK, FAK and iNOS expression. In addition, MC‐3T3 E1 osteoblast‐like cells promoted osteoclast differentiation but reduced osteoblast differentiation and mineralization on the titanium surface. Interestingly, the cells given the Terrein treatment showed higher resistance towards oxidative stress through the up‐regulation of ERK1/2 and FAK activity but the down‐regulation of SAPK/JNK and iNOS activity. Moreover, Terrein promoted osteoblast differentiation and bone mineralization to elevate the activity of ALP, SPARC and down‐regulate RANKL expression after blocking NF‐κB translocation from the cytosol to the nucleus. In conclusion, the presence of Terrein on titanium surfaces increases osteoblast cell growth without inflammation. Moreover, Terrein, as a putative antioxidant agent, may enhance osseointegration by decreasing the level of ROS and having a potentially synergistic effect on osteoblast differentiation. Copyright © 2010 John Wiley & Sons, Ltd.
Dynamic Interplay between Histone H3 Modifications and Protein Interpreters: Emerging Evidence for a “Histone Language”
Authors: Oliver Samuel S. , Denu John M.
Published: October 2010

Histone proteins organize DNA into dynamic chromatin structures and regulate processes such as transcription, repair, and replication. Control of chromatin function and structure is mediated in part by reversible post‐translational modifications (PTMs) on histones. The most N‐terminal region of histone H3 contains a high density of modifiable residues. Here we focus on the dynamic interplay between histone modification states on the H3 N terminus and the binding modules that recognize these states. Specifically, we discuss the effect of auxiliary modifications to H3K4unmod/me3 binding modules (specifically H3R2 methylation, H3T3 phosphorylation, and H3T6 phosphorylation). Emerging evidence suggests that histone PTMs behave less like a strict “code”, but more like a “language”, which better illustrates the importance of context. Using androgen‐receptor‐mediated gene activation as an example, we propose a model of how the combinatorial natures of PTMs on the H3 N terminus and the complexes that recognize these epigenetic modifications control gene expression.
Removal of Cr(VI) from Aqueous Solutions by a Bacterial Biofilm Supported on Zeolite: Optimisation of the Operational Conditions and Scale‐Up of the Bioreactor
Authors: Pazos M. , Branco M. , Neves I. C. , Sanromán M. A. , Tavares T.
Published: October 2010

The aim of this study was to investigate the feasibility of a bioreactor system and its scale‐up to remove Cr(VI) from solution. The bioreactor is based on an innovative process that combines bioreduction of Cr(VI) to Cr(III) by the bacterium Arthrobacter viscosus and Cr(III) sorption by a specific zeolite. Batch studies were conducted in a laboratory‐scale bioreactor, taking into account different operating conditions. Several variables, such as biomass concentration, pH and zeolite pre‐treatment, were evaluated to increase removal efficiency. The obtained results suggest that the Cr removal efficiency is improved when the initial biomass concentration is approximately 5 g L–1 and the pH in the system is maintained at an acidic level. Under the optimised conditions, approximately 100 % of the Cr(VI) was removed. The scale‐up of the developed biofilm process operating under the optimised conditions was satisfactorily tested in a 150‐L bioreactor.
Preparation of Zirconia Promoted Sulfated Titania System with High Catalytic Activity
Authors: Wu M. , Ni J. B. , Yang Z. H. , Li C. L. , Bu C. F. , Sun Y. M.
Published: October 2010

SO42–/TiO2‐ZrO2 (STZ) solid superacid catalysts were prepared using the coprecipitation‐impregnation method and characterized by FT‐IR, XRD, NH3‐TPD, N2 adsorption‐desorption isotherms, and SEM. It was observed that the sulfur content and the specific surface area of STZ changes with the ZrO2 content, and passes through a maximum at Zr/Ti = 1/4. The results indicate that the molar ratio of Zr/Ti and nonionic surfactant, PEG, were helpful for increasing the surface areas and stabilizing the sulfate species on the surfaces of the catalysts. The catalytic activity results were supported by the hydrolysis reaction rate of 2‐methyl‐1,3‐dioxane (2MD) that was strongly dependent on the sulfur content in the zirconia promoted sulfated titania catalyst.
High Hole Mobility for a Side‐Chain Liquid‐Crystalline Smectic Polysiloxane Exhibiting a Nanosegregated Structure with a Terthiophene Moiety
Authors: Matsui Aya , Funahashi Masahiro , Tsuji Toru , Kato Takashi
Published: October 2010

Side‐chain liquid‐crystalline siloxane polymers bearing terthiophene moieties as mesogenic pendant groups have been synthesized. An alkenylterthiophene derivative was treated with poly(hydrogenmethylsiloxane) and poly(dimethylsiloxane‐co‐hydrogenmethylsiloxane)s in Me2SiO/MeHSiO ratios of 1:1 and 7:3, respectively, in the presence of the Karstedt catalyst, to produce pale yellow polymers. The degrees of introduction of the mesogenic unit were 100, 50, and 30 %, respectively. The polymers exhibit ordered smectic phases at room temperature. The copolymers with dimethylsiloxane units form smectic phases as a consequence of nanosegregation between the mesogenic units and siloxane backbones with the alkylene spacers. Time‐of‐flight measurement reveals that the hole mobility exceeds 1×10−2 cm2 V−1 s−1 in the ordered smectic phase of the copolymer with a degree introduction of the mesogenic units of 50 %. This value is comparable to that of the highly ordered mesophases of low‐molecular‐weight derivatives of phenylnaphthalene and terthiophene. Because of the segregation behavior induced by the flexible backbone, a closer molecular packing structure favorable for fast carrier transport may be formed in the smectic phase of the copolymer in spite of the low density of the mesogenic groups.
Magnetic, Luminescent Eu‐Doped Mg–Al Layered Double Hydroxide and Its Intercalation for Ibuprofen
Authors: Wang Jun , Zhou Jideng , Li Zhanshuang , Song Yanchao , Liu Qi , Jiang Zhaohua , Zhang Milin
Published: October 2010

A magnetic, luminescent Eu‐doped Mg–Al layered double hydroxide with ibuprofen (IBU) intercalated in the gallery has been successfully prepared by a simple coprecipitation method. The physicochemical properties of the samples were well characterized by powder XRD, TEM, FTIR, TGA, inductively coupled plasma MS (ICP‐MS), vibrating sample magnetometry (VSM), and fluorospectrophotometry. The results revealed that Fe3O4 nanoparticles are coated on the surface of layered double hydroxides and the obtained (Mg2Al0.95Eu0.05)Fe–(IBU) sample exhibits both superparamagnetic and luminescent properties, with a saturation magnetization value of 1.86 emu g−1 and a strong emission band at 610 nm, respectively. Additionally, it was found that the ibuprofen loading amount is about 31 % (w/w), and the intercalated ibuprofen possesses sustained release behavior when the magnetic, luminescent composite is immersed in simulated body fluid (SBF).
Generation and Reactions of Oxiranyllithiums by Use of a Flow Microreactor System
Authors: Nagaki Aiichiro , Takizawa Eiji , Yoshida Jun‐ichi
Published: October 2010

A flow microreactor system consisting of micromixers and microtubes provides an effective reactor for the generation and reactions of aryloxiranyllithiums without decomposition by virtue of short residence time and efficient temperature control. The deprotonation of styrene oxides with sBuLi can be conducted by using the flow microreactor system at −78 or −68 °C (whereas much lower temperatures (<−100 °C) are needed for the same reactions conducted under macrobatch conditions). The resulting α‐aryloxiranyllithiums were allowed to react with electrophiles in the flow microreactor system at the same temperature. The sequential introduction of various electrophiles onto 2,3‐diphenyloxiranes was also achieved by using an integrated flow microreactor, which serves as a powerful system for the stereoselective synthesis of tetrasubstituted epoxides.
Dynamic Octopus Amphiphiles as Powerful Activators of DNA Transporters: Differential Fragrance Sensing and Beyond
Authors: Montenegro Javier , Bonvin Pauline , Takeuchi Toshihide , Matile Stefan
Published: October 2010

We report the design, synthesis and evaluation of dynamic “octopus” amphiphiles with emphasis on their efficiency as activators in synthetic membrane‐based sensing systems. Previously, we found that the in situ treatment of charged hydrazides with hydrophobic aldehydes or ketones gives amphiphilic counterion activators of polyion transporters in lipid bilayers, and that their efficiency increases with the number of their hydrophobic tails. Herein, we expand this series to amphiphiles with one cationic head (guanidinium or ammonium) and four exchangeable hydrophobic tails. These results, with the highest number of tails reported to date, confirm that dynamic octopus amphiphiles provide access to maximal activity and selectivity. Odorants, such as muscone, carvone, or anisaldehyde are used to outline their usefulness in differential sensing systems that operate based on counterion‐activated DNA transporters in fluorogenic vesicles. The enhanced ability of octopus amphiphiles to enable the discrimination of enantiomers as well as that of otherwise intractable ortho, meta, and para isomers and short cyclo‐/alkyl tails is demonstrated. These findings identify dynamic octopus amphiphiles as being promising for application to differential sensing, “fragrant” cellular uptake, and slow release.
Integrated Palladium‐Catalyzed Arylation of Heavier Group 14 Hydrides
Authors: Lesbani Aldes , Kondo Hitoshi , Yabusaki Yusuke , Nakai Misaki , Yamanoi Yoshinori , Nishihara Hiroshi
Published: October 2010

A convenient procedure has been developed for the preparation of Group 14 compounds by integrated palladium‐catalyzed cross‐coupling of aromatic iodides with the corresponding Group 14 hydrides in the presence of a base. The reaction conditions can be applied to the cross‐coupling of tertiary, secondary, and primary Group 14 compounds. In most cases, the desired arylated products were obtained in synthetically useful yields. Even in the case of aryl iodides containing OH, NH2, CN, or CO2R groups, the reactions proceeded with good to high yields with tolerance of these reactive functional groups. A possible application of this method is the unique synthesis of a fungicidal diarylmethyl(1H‐1,2,4‐triazol‐1‐ylmethyl)silane derivative.
A Highly Efficient and Extensively Reusable “Dip Catalyst” Based on a Silver‐Nanoparticle‐Embedded Polymer Thin Film
Authors: Hariprasad E. , Radhakrishnan T. P.
Published: October 2010

Achieving a harmonious combination of the efficiency of homogeneous catalysts with the reusability of heterogeneous catalysts is a fundamental and challenging problem. Metal nanoparticles in a suitable matrix offer a potential solution. However an ideal design is yet to be realized, because the critical requirements of facile access to the catalyst, its durability, and ease of retrieval and reuse are difficult to reconcile. We report herein a multilayer free‐standing thin‐film catalyst based on silver nanoparticles, generated in situ inside poly(vinyl alcohol) by using a facile protocol, which shows excellent efficiency and extensive reusability in the prototypical reaction, the reduction of 4‐nitrophenol by sodium borohydride. The “dip catalyst” film, which can start/stop the reaction instantaneously by mere insertion/removal, is used 30 times leading to a total turnover number (TON) of ≈3390, which is unprecedented for this reaction. The efficiency of the catalyst is reduced only marginally at the end of these runs, promising further extended usage. The unique advantage of convenient catalyst monitoring is illustrated by the periodic spectroscopic and microscopic examinations of the thin film, which revealed the basis of its durability. The demonstrated potential of metal‐nanoparticle‐embedded polymer thin films, coupled with their versatility and ease of fabrication, promises extensive applications in chemical catalysis.
Rotaxanes Capable of Recognising Chloride in Aqueous Media
Authors: Hancock Laura M. , Gilday Lydia C. , Carvalho Sílvia , Costa Paulo J. , Félix Vítor , Serpell Christopher J. , Kilah Nathan L. , Beer Paul D.
Published: October 2010

A new, versatile chloride‐anion‐templating synthetic pathway is exploited for the preparation of a series of eight new [2]rotaxane host molecules, including the first sulfonamide interlocked system. 1H NMR spectroscopic titration investigations demonstrate the rotaxanes’ capability to selectively recognise the chloride anion in competitive aqueous solvent media. The interlocked host’s halide binding affinity can be further enhanced and tuned through the attachment of electron‐withdrawing substituents and by increasing its positive charge. A dicationic rotaxane selectively binds chloride in 35 % water, wherein no evidence of oxoanion binding is observed. NMR spectroscopy, X‐ray structural analysis and computational molecular dynamics simulations are used to account for rotaxane formation yields, anion binding strengths and selectivity trends.
Characterization, Synthesis and Self‐Aggregation of (−)‐Alternarlactam: A New Fungal Cytotoxin with Cyclopentenone and Isoquinolinone Scaffolds
Authors: Zhang Ai Hua , Jiang Nan , Gu Wen , Ma Jing , Wang Yu Rong , Song Yong Chun , Tan Ren Xiang
Published: October 2010

(−)‐Alternarlactam [(−)‐1], a new promising cytotoxin against two human cancer cell lines, was isolated from an endophyte culture and synthesized (along with (+)‐1) from readily available starting materials. The absolute configuration, chirality–activity relevance and self‐aggregation of (−)‐1 were assigned by a combination of synthetic, spectroscopic and computational approaches. The full characterization of the new fungal cytotoxin may provide valuable information in the discovery of new antitumor agents.
Reactivity of C1 Surface Species Formed in Methane Activation on Zn‐Modified H‐ZSM‐5 Zeolite
Authors: Wu Jian Feng , Wang Wei David , Xu Jun , Deng Feng , Wang Wei
Published: October 2010

Solid‐state 13C magic angle spinning (MAS) NMR spectroscopy investigations identified zinc methyl species, formate species, and methoxy species as C1 surface species formed in methane activation on the zeolite Zn/H‐ZSM‐5 catalyst at T≤573 K. These C1 surface species, which are possible intermediates in further transformations of methane, were prepared separately by adsorption of 13C‐enriched methane, carbon monoxide, and methanol onto zinc‐containing catalysts, respectively. Successful isolation of each surface species allowed convenient investigations into their chemical nature on the working catalyst by solid‐state 13C MAS NMR spectroscopy. The reactivity of zinc methyl species with diverse probe molecules (i.e., water, methanol, hydrochloride, oxygen, or carbon dioxide) is correlated with that of organozinc compounds in organometallic chemistry. Moreover, surface formate and surface methoxy species possess distinct reactivity towards water, hydrochloride, ammonia, or hydrogen as probe molecules. To explain these and other observations, we propose that the C1 surface species interconvert on zeolite Zn/H‐ZSM‐5. As implied by the reactivity information, potential applications of methane co‐conversion on zinc‐containing zeolites might, therefore, be possible by further transformation of these C1 surface species with rationally designed co‐reactants (i.e., probe molecules) under optimized reaction conditions.
The binding of flavopiridol to blood serum albumin
Authors: Myatt Daniel , Johnson Louise , Baumli Sonja , Siligardi Giuliano
Published: October 2010

Flavopiridol is a potent cyclin‐dependant kinase (CDK) inhibitor and is in clinical trials for anticancer treatment. A limiting factor in its drug development has been the high dosage required in human clinical trials. The high dosage is suggested to be necessary because of significant flavopiridol binding to human blood serum. Albumin is the major protein component of blood serum and has been suggested as a likely high affinity binding target. We characterized the binding of human serum albumin to flavopiridol using circular dichroism (hereafter CD). Flavopiridol bound to human serum albumin has a diagnostic CD binding peak at 284 nm. The diagnostic CD binding peak was unobservable for flavopiridol with bovine serum albumin, using the same experimental conditions. However, under higher albumin concentrations a small CD signal is observed confirming, flavopiridol binds to bovine serum albumin as well. Chirality 22:E40–E43, 2010. © 2010 Wiley‐Liss, Inc.
Development of New Electrochemical Surfaces for the Detection of Metals in Waste Water
Authors: Oztekin Yasemin , Yazicigil Zafer , Duran Tolga , Dumrul Hakan , Guler Ersin , Kocyigit Ozcan
Published: October 2010

In this study, electrochemical experiments were performed in non‐aqueous media in order to determine electrochemical behavior of some of the glyoxime derivatives (GDs). Phenylglyoxime (PG), p‐chloro‐phenylglyoxime (p‐CPG), and 1,2‐phenylendiamino‐p‐chlorophenylglyoxime (PACPG) were chosen as GDs. Pt wire, Ag/Ag+ (in 0.01 M AgNO3) and glassy carbon (GC) electrode were used as counter, reference, and working electrode, respectively. The multiscan cyclic voltammograms (CVs) of these compounds were registered in acetonitrile (MeCN) containing 0.1 M tetrabutylammonium tetrafluoroborat (TBATFB) at scan rate of 100 mV/s. The potential was swept from 0 to +2.0 V versus Ag/Ag+ (0.01 M). The CVs of GDs were compared with each other and the electrochemical behaviors of the compounds were investigated depending on the functional groups in their structures. The electrochemical characterization of these modified surfaces was performed and characterizations were compared with the chatacterization results of bare GC surfaces. The application areas for new surfaces were investigated. These results will be active in the disciplines of electrochemistry and industrial physical chemistry, and in related industrial fields at the dissemination of new information for scientific area.
Statistical Optimization of Anaerobic Biological Processes for Dye Treatment
Authors: Khalili Zahra , Bonakdarpour Babak
Published: October 2010

In the present study both the synthetic media composition as well as some process parameters in the anaerobic decolorization of Reactive Black 5 (RB5) by activated sludge were studied and optimized using statistical design of experiments (DOEs). Statistical analysis of the results of Plackett–Burman DOE showed that the addition of Mn or Fe, or increase in concentration of Mg, had a positive effect on the anaerobic decolorization efficiency whereas the effect of increase in concentration of glucose, ammonium chloride, and calcium chloride was negative. The effect of change in the concentration of glucose, mixed liquor suspended solid (MLSS), and RB5 on the anaerobic decolorization efficiency and rate and chemical oxygen demand (COD) removal was studied using central composite design methodology. Statistical analysis of the data showed that all the factors had significant effect on both the dye decolorization efficiency and rate. The interaction of glucose with MLSS and with dye and the interaction of MLSS with glucose and with dye were significant when the response was decolorization efficiency and rate, respectively. When COD removal was the response, the effect of change in glucose and MLSS concentration and the interaction between these two factors had statistically significant effect on the response.
Machine Learning Approach to Predict Sediment Load – A Case Study
Authors: Azamathulla Hazi Md. , Ghani Aminuddin Ab. , Chang Chun Kiat , Hasan Zorkeflee Abu , Zakaria Nor Azazi
Published: October 2010

In this study, a novel machine learning technique called the support vector machine (SVM) method is proposed as a new predictive model to predict sediment loads in three Malaysian rivers. The SVM is employed without any restriction to an extensive database compiled from measurements in the Muda, Langat, and Kurau rivers. The SVM technique demonstrated a superior performance compared to other traditional sediment‐load methods. The coefficient of determination, 0.958, and the mean square error, 0.0698, of the SVM method are higher than those of the traditional method. The performance of the SVM method demonstrates its predictive capability and the possibility of the generalization of the model to nonlinear problems for river engineering applications.
Probing Small‐Molecule Binding to Cytochrome P450 2D6 and 2C9: An In Silico Protocol for Generating Toxicity Alerts
Authors: Rossato Gianluca , Ernst Beat , Smiesko Martin , Spreafico Morena , Vedani Angelo
Published: October 2010

Drug metabolism, toxicity, and their interaction profiles are major issues in the drug‐discovery and lead‐optimization processes. The cytochromes P450 (CYPs) 2D6 and 2C9 are enzymes involved in the oxidative metabolism of a majority of marketed drugs. Therefore, the prediction of the binding affinity towards CYP2D6 and CYP2C9 would be beneficial for identifying cytochrome‐mediated adverse effects triggered by drugs or chemicals (e.g., toxic reactions, drug–drug, and food–drug interactions). By identifying the binding mode by using pharmacophore prealignment, automated flexible docking, and by quantifying the binding affinity by multidimensional QSAR (mQSAR), we validated a model family of 56 compounds (46 training, 10 test) and 85 compounds (68 training, 17 test) for CYP2D6 and CYP2C9, respectively. The correlation with the experimental data (cross‐validated r2=0.811 for CYP2D6 and 0.687 for CYP2C9) suggests that our approach is suited for predicting the binding affinity of compounds towards CYP2D6 and CYP2C9. The models were challenged by Y‐scrambling and by testing an external dataset of binding compounds (15 compounds for CYP2D6 and 40 for CYP2C9). To assess the probability of false‐positive predictions, datasets of nonbinders (64 compounds for CYP2D6 and 56 for CYP2C9) were tested by using the same protocol. The two validated mQSAR models were subsequently added to the VirtualToxLab (VTL, http://www.virtualtoxlab.org).
Biocompatible blood pool MRI contrast agents based on hyaluronan
Authors: Zhu Wenlian , Artemov Dmitri
Published: October 2010

Biocompatible gadolinium blood pool contrast agents based on a biopolymer, hyaluronan, were investigated for magnetic resonance angiography application. Hyaluronan, a non‐sulfated linear glucosaminoglycan composed of 2000–25,000 repeating disaccharide subunits of D‐glucuronic acid and N‐acetylglucosamine with molecular weight up to 20 MDa, is a major component of the extracellular matrix. Two gadolinium contrast agents based on 16 and 74 kDa hyaluronan were synthesized, both with R1 relaxivity around 5 mM−1 s−1 per gadolinium at 9.4 T at 25°C. These two hyaluronan based agents show significant enhancement of the vasculature for an extended period of time. Initial excretion was primarily through the renal system. Later uptake was observed in the stomach and lower gastrointestinal tract. Macromolecular hyaluronan‐based gadolinium agents have a high clinical translation potential as hyaluronan is already approved by FDA for a variety of medical applications. Copyright © 2010 John Wiley & Sons, Ltd.
Chemical neuroanatomy of the Drosophila central complex: Distribution of multiple neuropeptides in relation to neurotransmitters
Authors: Kahsai Lily , Winther Åsa M.E.
Published: October 2010

The central complex of the insect brain is an integration center, receiving inputs from many parts of the brain. In Drosophila it has been associated with the control of both locomotor and visually correlated behaviors. The central complex can be divided into several substructures and is comprised of a large number of neuronal types. These neurons produce classical neurotransmitters, biogenic amines, and different neuropeptides. However, the distribution of neurotransmitters and neuromodulators in central‐complex circuits of Drosophila is poorly known. By immunolabeling and GAL4‐directed expression of marker proteins, we analyzed the distribution of acetylcholine, glutamate, GABA, monoamines, and eight different neuropeptides; Drosophila tachykinin, short neuropeptide F, myoinhibitory peptide, allatostatin A, proctolin, SIFamide, neuropeptide F, and FMRFamide. All eight neuropeptides were localized to the fan‐shaped body, the largest substructure of the central complex, and were mapped to different layers within this structure. Several populations of peptide‐immunoreactive tangential and columnar neurons were identified, of which some colocalized acetylcholine. Fewer peptides were found to be expressed in the other substructures: the ellipsoid body, the protocerebral bridge, and the noduli. The ellipsoid body and the protocerebral bridge were innervated by extrinsic peptide expressing neurons. Our findings reveal that numerous neuropeptides are expressed in the central complex and that each peptide has a distinct distribution pattern, suggesting important roles for neuropeptides as neuromediators and cotransmitters in this brain area. J. Comp. Neurol. 519:290‐315, 2011. © 2010 Wiley‐Liss, Inc.
Topography and morphology of the inhibitory projection from superior olivary nucleus to nucleus laminaris in chickens (Gallus gallus)
Authors: Tabor Kathryn M. , Wong Rachel O.L. , Rubel Edwin W
Published: October 2010

The avian nucleus laminaris (NL) is involved in computation of interaural time differences (ITDs) that encode the azimuthal position of a sound source. Neurons in NL are bipolar, with dorsal and ventral dendritic arbors receiving input from separate ears. NL neurons act as coincidence detectors that respond maximally when input from each ear arrives at the two dendritic arbors simultaneously. Computational and physiological studies demonstrated that the sensitivity of NL neurons to coincident inputs is modulated by an inhibitory feedback circuit via the superior olivary nucleus (SON). To understand the mechanism of this modulation, the topography of the projection from SON to NL was mapped, and the morphology of the axon terminals of SON neurons in NL was examined in chickens (Gallus gallus). In vivo injection of AlexaFluor 568 dextran amine into SON demonstrated a coarse topographic projection from SON to NL. Retrogradely labeled neurons in NL were located within the zone of anterogradely labeled terminals, suggesting a reciprocal projection between SON to NL. In vivo extracellular physiological recording further demonstrated that this topography is consistent with tonotopic maps in SON and NL. In addition, three‐dimensional reconstruction of single SON axon branches within NL revealed that individual SON neurons innervate a large area of NL and terminate on both dorsal and ventral dendritic arbors of NL neurons. The organization of the projection from SON to NL supports its proposed functions of controlling the overall activity level of NL and enhancing the specificity of frequency mapping and ITD detection. J. Comp. Neurol. 519:358‐375, 2011. © 2010 Wiley‐Liss, Inc.
Experiments on the Temperature Dependence of Heterogeneous Nucleation on Nanometer‐Sized NaCl and Ag Particles
Authors: Schobesberger Siegfried , Winkler Paul M. , Pinterich Tamara , Vrtala Aron , Kulmala Markku , Wagner Paul E.
Published: October 2010

Experimental investigations on the activation of NaCl and Ag aerosol particles by heterogeneous nucleation of n‐propanol vapor at well‐defined vapor saturation ratios are presented. Particular emphasis is placed on the temperature dependence of this process from −11 to +14 °C. Aerosols are generated in a tube furnace and electrostatically classified at mean geometric mobility equivalent diameters between 3.6 and 11 nm. Activation probabilities are measured by means of expansion chamber experiments, and onset n‐propanol saturation ratios are subsequently determined. The experiments with Ag particles do not produce any unexpected results. The results for NaCl particles, however, show a temperature trend of the onset saturation ratios that is opposite to that predicted by classical nucleation theory. This stresses the important role that surface properties play in heterogeneous nucleation processes. By tentatively assuming a temperature‐dependent contact angle, we are able to theoretically reproduce this reversed temperature trend. In addition, the shrinkage of NaCl condensation particles is investigated for varying amounts of n‐propanol vapor, and contact angle measurements are performed at temperatures ranging from −7 to +30 °C.
Organosilica Spheres Covalently Functionalized with Diphenylanthracene and Viologen Units
Authors: Álvaro Mercedes , Bizzoca Giorgia , Ferrer Belén , García Hermenegildo , de Miguel Maykel , Teruel Laura
Published: October 2010

Organosilica spheres functionalized with two different photoactive units, diphenylanthracene, DPA@SPH, and viologen, VIO@SPH, covalently linked to the silica framework are prepared. These new materials have a uniform diameter, 300 nm for the DPA@SPH and 550 nm for the VIO@SPH, and exhibit the typical photochemical response of the organic moieties. It is observed that organic radical cations incorporated in the structure of the functionalized silica spheres are remarkably persistent. Due to their morphology and regular diameter DPA@SPH do not tend to aggregate and they form a highly regular, ordered and homogeneous multilayer film of high surface coverage which is employed as the active layer for the preparation of an electroluminescence cell.
Plasma‐dependent, antibody‐ and Fcγ receptor‐mediated translocation of CD8 molecules from T cells to monocytes
Authors: Iwasaki Sari , Masuda Sakiko , Baba Tomohisa , Tomaru Utano , Katsumata Kazuaki , Kasahara Masanori , Ishizu Akihiro
Published: October 2010

CD8αβ heterodimers are mainly expressed on cytotoxic T lymphocytes. This study demonstrated the detection of CD8αβ heterodimers on human monocytes by whole blood erythrocyte lysis method in flow cytometry. Results revealed that CD8αβ heterodimers were not produced by monocytes themselves, but were transferred from T cells to monocytes when these cells were coincubated in plasma and with anti‐CD8 monoclonal antibody (mAb). For completion of CD8 translocation from T cells to monocytes, cell‐to‐cell contact between T cells and monocytes, as well as binding of the Fc portion of the anti‐CD8 mAb and Fcγ receptor II (FcγRII) on monocytes were required. Furthermore, the dynamism of cell membrane and cytoskeleton were involved in the mechanism of CD8 translocation. Interestingly, CD3 and αβT cell receptor (TCR) were also transferred from T cells to monocytes accompanied by CD8. These phenomena are consistent with Ab‐dependent and FcγR‐mediated trogocytosis, which is recently recognized as one of the intercellular communication processes of the immune system. Trogocytosis means exchange of plasma membrane including cell surface molecules in conjugates formed between immune cells. Results of this study could provide another model of trogocytosis and clearly indicated that putative plasma factors were critically implicated in the mechanism of Ab‐dependent and FcγR‐mediated trogocytosis. © 2010 International Society for Advancement of Cytometry
The role of cortisol reactivity in children's and adults' memory of a prior stressful experience
Authors: Quas Jodi A. , Yim Ilona S. , Edelstein Robin S. , Cahill Larry , Rush Elizabeth B.
Published: October 2010

The purpose of this study was to identify whether cortisol reactivity to a stressful laboratory event was related to children's memory of that event and to determine whether this relation was comparable to that observed in adults. Nine‐ to 12‐year‐olds and young adults completed an impromptu speech and math task during which repeated cortisol samples and self‐reported stress ratings were collected. Two weeks later, participants' memory for the tasks was examined. Greater cortisol reactivity was associated with enhanced memory, most prominently in children. Self‐reported stress was unrelated to memory. Findings reveal that an important mechanism underlying the association between emotion and memory in adults, namely activation of the hypothalamic pituitary adrenal axis, appears to operate similarly in late childhood. Findings also demonstrate that positive associations between cortisol reactivity and memory are evident when the event that actually elicited that reactivity serves as the to‐be‐remembered event. © 2010 Wiley Periodicals, Inc. Dev Psychobiol 53:166–174, 2011
The changing epidemiology of type 1 diabetes: why is it going through the roof?
Authors: Vehik Kendra , Dabelea Dana
Published: October 2010

The incidence of type 1 diabetes is increasing and this may double the burden of disease in our youngest by 2020. The recent increase in incidence is mostly happening in the very young and those with moderate genetic susceptibility. Many environmental factors have been implicated, but no major determinants have been clearly identified, and the mechanisms of involvement remain elusive. This review summarizes current research efforts directed at understanding the possible reasons for this increase, including the role of viruses, gut microbiota, early life feeding patterns, perinatal factors and childhood growth patterns. It also provides a road map for future research directions. Copyright © 2010 John Wiley & Sons, Ltd.