bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydrogenation of Furfural to Furfuryl Alcohol over Co‐B Amorphous Catalysts Prepared by Chemical Reduction in Variable Media
Authors: Li Hui , Chai Wei‐Mei , Luo Hong‐Shan , Li He‐Xing
Published: December 2006

Five Co‐B amorphous alloy catalysts were prepared by chemical reduction in different media, including pure water and pure ethanol as well as the mixture of ethanol and water with variable ethanol content. Their catalytic properties were evaluated using liquid phase furfural hydrogenation to furfuryl alcohol as the probe reaction. It was found that the reaction media had no significant influence on either the amorphous structure of the Co‐B catalyst or the electronic interaction between metallic Co and alloying B. This could successfully account for the fact that all the as‐prepared Co‐B catalysts exhibited almost the same selectivity to furfuryl alcohol and the same activity per surface area (RSH), which could be considered as the intrinsic activity, since the nature of active sites remained unchanged. However, the activity per gram of Co (RmH) of the as‐prepared Co‐B catalysts increased rapidly when the ethanol content in the water‐ethanol mixture used as the reaction medium for catalyst preparation increased. This could be attributed to the rapid increase in the surface area possibly owing to the presence of more oxidized boron species which could serve as a support for dispersing the Co‐B amorphous alloy particles.
Glucose‐lowering Activity of Amino Acid‐N‐phosphonic Acid Oxovanadium Complexes and Its Interaction with DNA
Authors: Liu Ju‐Tao , Fan Sheng‐Di , Li Chuan‐Bi , Li De‐Qian
Published: December 2006

Vanadium has well‐documented lowering glucose properties both in vitro and in vivo. The design of new oxovanadium(IV) coordination compounds, intended for use as insulin‐enhancing agents in the treatment of diabetes mellitus, can potentially benefit from a synergistic approach, in which the whole complex has more than an additive effect from its component parts. Biological testing with oxovanadium(IV) organic phosphonic acid, for insulin‐enhancing potential included acute administration, by oral gavage in streptozotocin (STZ) diabetic rats. The complexes of oxovanadium(IV) amino acid‐N‐phosphonic acid exhibit higher lowering glucose activity in vivo. The interaction of the complexes of oxovanadium(IV) amino acid‐N‐phosphonic acid with DNA was investigated by agarose gel electrophoresis. The results indicated that these complexes have strong interaction with DNA.
Forming and Gathering of SnO2 Nanoparticles on External Surface of High Silica TON, MFI and FAU Type Zeolites
Authors: Xu Xiao‐Wen , Wang Jing , Long Ying‐Cai
Published: December 2006

Tin dioxide (SnO2) nano‐particles were prepared on high silica TON, MFI and FAU type zeolites by impregnation of SnCl2 solution and subsequent calcination at 873 K. XRD and SAED were used to characterize the crystalline phase, and TEM was used to characterize the morphology, the particle size and the agglomerative state of the formed nano‐materials. The nano‐particles, which possess 8 nm, 10–80 nm and 6 nm in size, were found to form on the outer surface of TON, MFI and FAU zeolites, respectively. SnO2 microcapsules and SnO2 netlike nanostructure were obtained by decomposition of SnO2‐TON and SnO2‐MFI in 40% hydrofluoric acid at room temperature. Compared with the nano‐particles formed on NaY zeolite, the special morphology and the agglomerative state of SnO2 nanostructures on TON and MFI type zeolites with one and two dimension channel system indicate that the heterogeneous framework, surface structure and property perform important function for forming and growing SnO2 nanostructure on the outer surface of the zeolites.
Ionic Liquid Based Electrolyte with Mesoporous Silica SBA‐15 as Framework for Quasi‐solid‐state Dye‐sensitized Solar Cells
Authors: Xiao Qin , Yang Hong , Cheng Yun‐Fei , Zhou Zhi‐Guo , Chen Zhi‐Gang , Li Fu‐You , Yi Tao , Huang Chun‐Hui
Published: December 2006

Quasi‐solid‐state electrolytes were fabricated with mesoporous silica SBA‐15 as a framework material. Ionic conductivity measurements revealed that SBA‐15 can enhance the conductivity of the quasi‐solid‐state electrolyte. The diffusion coefficients of polyiodide ions such as I−3 and I−5 which were confirmed by Raman spectroscopic measurement, were about twice larger than that of I−. The optimized photoenergy conversion efficiency of dye‐sensitized solar cells (DSSC) with the quasi‐solid‐state electrolyte was 4.3% under AM 1.5 irradiation at 75 mW·cm−2 light intensity.
Capillary Electrophoresis for the Simultaneous Determination of Metals by Using Ethylenediamine Tetraacetic Acid as Complexing Agent and Vancomycin as Complex Selector
Authors: Threeprom Jirasak , Som‐aum Waraporn , Lin Jin‐Ming
Published: December 2006

A new separation system of capillary electrophoresis for the simultaneous determination of metals by using ethylenediamine tetraacetic acid (EDTA) as complexing agent and employing vancomycin as complex selector was described. The Z‐shape cell capillary electrophoresis was used to enhance the sensitivity for the determination of the complexes of Cu(II), Ni(II), Co(II) and Fe(III) with EDTA. The partial filling method (co‐current mode) was used in order to increase the selectivity of the electrophoretic method, meanwhile vancomycin was not present at the detector path during the detection of metal‐EDTA complexes. The vancomycin concentration, phosphate concentration and pH of the buffer strongly influenced mobility, resolution and selectivity of the studied analytes. Under the optimal condition, the relative standard deviations (n=5) of the migration time and the peak area were less than 3.14% and 7.35%, respectively. Application of the Z‐shape cell capillary electrophoresis method with UV detection and vancomycin loading led to the reliable determination of these metal ions in tap water and the recoveries were97%–101%. The detection limits based on a signal to noise ratio of 3:1 were found in the range of 2–10 µg·L−1.
Rod‐like Schiff Base Magnetic Liquid Crystals Bearing Organic Radical
Authors: Zheng Min‐Yan , An Zhong‐Wei
Published: December 2006

4 novel rod‐like Schiff base magnetic liquid crystals have been prepared in which trans‐bicyclohexyl or trans‐cyclohexyl phenyl and biphenyl carboxylic acid phenol ester mesogenic cores with n‐propyl and n‐pentyl substituents were terminated by 4‐amino‐TEMPO (TEMPO=2,2,6,6‐tetramethylpiperidine‐1‐oxyl). Of these compounds the silk‐like and schlieren textures were found from 4c and 4d by POM (Polarizing Optical Microscope). DSC (Differential Scanning Calorimeter) measurements show that the mesophase exists from 4–6 °C. EPR spectra reveal their paramagnetic properties.
Development of Monoclonal Antibody‐based Enzyme‐linked Immunosorbent Assay to the Estrogen Diethylstilbestrol
Authors: Wang Wen‐Jun , Li Ji , Zhao Ji‐Xun , Zhang Guo‐Zhong , Xu Ting , Sheng Wei
Published: December 2006

Diethylstilbestrol (DES) is a synthetic estrogen that has ever been used worldwide. Polyclonal antibodies (PAbs) were used in immunoassay for detection of DES residues in environmental and agricultural samples in previous paper. In this paper, an indirect competitive enzyme‐linked immunosorbent assay (icELISA) was developed based on monoclonal antibody (MAb) for the determination of diethylstilbestrol. Mono‐o‐carboxypropyldiethylstilbestrol (DES‐CP) and mono‐o‐carboxymethyldiethylstilbestrol (DES‐CME) were synthesized to be haptens. DES‐CP was coupled to bovine serum albumin (BSA) to be an immunogen in BALB/c female mouse for MAb production. The MAb was characterized for specificity and affinity to DES in icELISA. Under the optimum condition, the icELISA showed an IC50 of 9.8 ng/mL, the limit of detection (IC20) of 2.3 ng/mL and a working range of 2–42 ng/mL. Hexestrol and dienestrol exhibited cross‐reactivity values were 44% and 27%, respectively. Cross‐reactivity of natural estrogen 17β‐estradiol was less than 0.1%. The influences of some factors such as salt concentration, pH and organic solvent concentration on the assay were evaluated. The concentrations of DES in the fortified water samples determined by the assay were correlated well with the fortification levels. The results were confirmed with analysis by HPLC.
Further Study on Separation of DNA Fragments by Capillary Electrophoresis by Quasi‐interpenetrating Network of Polyacryamide and Polyvinylpyrrolidone with UV Detection
Authors: Wang Qian , Xu Xu , Dai Li‐Xin
Published: December 2006

Quasi‐interpenetrating network of polyacrylamide (PAA) and polyvinylpyrrolidone (PVP) had been successfully used for single‐base resolution of double‐stranded DNA (0.76 for 123 bp/124 bp) and single‐stranded DNA fragments (0.97 for 123 b/124 b) with UV detection. This quasi‐IPN (interpenetrating network) sieving matrix showed low viscosity (23.5 mPa·s at 25 °C) and decreased with increasing temperature. This polymer also exhibited dynamically coating capacity and could be used in the uncoated capillary. The effects of temperature and electric field strength on the DNA separation of quasi‐IPN matrix were also investigated and found that the temperature and electric field strength could markedly affected the mobility behavior of DNA fragments. This polymer matrix has also applied to separate the bigger DNA fragments by capillary electrophoresis with UV detection. Under the denaturing conditions, this matrix separated the samples with last fragment of 1353 base in 40 min, in which the doublet of 309/310 base was partial separated and the resolution was 0.88.
Constituents from the Roots of Semiaquilegia adoxoides
Authors: Niu Feng , Cui Zheng , Chang Hai‐Tao , Jiang Yong , Chen Fa‐Kui , Tu Peng‐Fei
Published: December 2006

In present literature search, some cyano‐containing compounds, which are very rare in plants, from the traditional anticancer herb Tiankuizi were reported. To find more cyano‐containing compounds in the important plant Semiaquilegia adoxoides (DC) Makino (Chinese name Tiankuizi), the isolation of the chemical constituents was investigated for advancing the research. Two new compounds, a new alkaloid, 1,2,3,4‐tetrahydro‐6‐hydroxy‐1‐ [(3,4‐dihydroxyphenyl)methyl]‐7‐methoxy‐2,2‐dimethyl‐isoquinolinium, named Semiaquilegine A (1), and a new ester, 3‐(4′‐hydroxyphenyl)‐2‐propenoic acid (4′′‐carboxyl)‐phenyl ester (2), and four cyano‐containing compounds, (Z)‐6α‐(β‐D‐glucosyloxy)‐4α,5α‐dihydroxy‐2‐cyclohexene‐Δ1,α‐acetonitrile (3), (Z)‐6α‐(β‐D‐glucosyloxy)‐4α‐hy‐droxy‐2‐cyclohexene‐Δ1,α‐acetonitrile (4), lithospermoside (5), ehretioside B (6), as well as eleven known compounds, were isolated from the roots of Semiaquilegia adoxoides. The structures of new compounds 1 and 2 were elucidated mainly by 1D/2D‐NMR techniques. Very unusual cyano‐containing compounds 3 and 4 were first isolated from Ranunculaceae family. Hitherto, there were six cyano‐containing compounds found in the herb.
Studies on Effect of Tri(2‐hydroxypropyl), Tri(2‐hydroxybutyl) and Tri(hydroxythiodiethylene) Borates on Thermal and Heat Properties of Rigid Polyurethane‐Polyisocyanurate Foams
Authors: Czupryński Bogusław , Paciorek‐sadowska Joanna , Liszkowska Joanna
Published: December 2006

Effect of tri(2‐hydroxypropyl), tri(2‐hydroxybutyl) and tri(hydroxythiodiethylene) borates (BT2HB, BT2HP and BTHET) on the thermal and heat properties of the rigid polyurethane‐polyisocyanurate (PUR‐PIR) foams was investigated. Increasing amounts of BT2HB and BT2HP in the foam composition, from 0.05 to 0.4 of chemical equivalent, caused increases in the softening point, the temperature of the first mass loss, the extrapolated temperature of the main mass loss foam and temperature of the highest rate of the mass loss. In the case when BTHTE was added to the foam compositions, the lower increase in the mentioned above characteristic temperatures was observed as compared to those of standard foam (without borate added).
Design and Synthesis of a Selective Chemosensor for Zn2+
Authors: Xie Nan , Chen Yi
Published: December 2006

A hydroxyl substituted phenolic Schiff base 1, used as sensor for detection of Zn2+, was synthesized and investigated. It was found that a strong fluorescence emission was observed when 1 bound to Zn2+ in acetonitrile, whereas no fluorescence emission was detected when 1 bound to other metal ions (Fe2+, Co2+, Ni2+, Cu2+, Cd2+, Hg2+, Mg2+, Pb2+, Ca2+, Ba2+, Sr2+) except for Mg2+, for which a weak fluorescence emission was detected in the same condition. Competition experiment showed that no obvious interference was observed in its fluorescence while 1 performed the titration with Zn2+ in the different mixtures of metal ions. To understand the site where Zn2+coordinated to the ligand and the mechanism of binding, three other hydroxyl substituted phenolic Schiff bases 2–4 were synthesized and their binding reactions with Zn2+were also investigated.
Efficacy and safety of first‐ or second‐line irinotecan, cisplatin, and mitomycin in mesothelioma
Authors: Fennell Dean A. , Steele Jeremy P.C. , Shamash Jonathan , Evans Marie T. , Wells Paula , Sheaff Michael T. , Rudd Robin M. , Stebbing Justin
Published: December 2006

BACKGROUND.

Malignant pleural mesothelioma (MPM) is a rapidly progressive lethal tumor. Treatment options remain limited and the outcome in recurrent disease is poor.

METHODS.

A Phase II open‐label noncomparative study was conducted to assess the safety and efficacy of the triplet combination irinotecan, cisplatin, and mitomycin‐C (IPM) chemotherapy in untreated patients and in those with previous exposure to chemotherapy.

RESULTS.

In 62 patients an objective response rate of 25% was observed. In the first‐line setting progression‐free survival measured 6.4 months (95% confidence interval [CI]: 4.5–7.3) and overall survival was 10.8 months (95% CI: 7.9–13.7). In the second‐line setting progression‐free survival was 7.3 months (95% CI: 3.4–11.2) and overall survival was also 7.3 months (95% CI: 4.8–9.8). Psychosocial well‐being improved during chemotherapy and the main toxicity observed was neutropenia (40%).

CONCLUSIONS.

IPM appeared to have a reasonable response rate with an acceptable toxicity profile in the first‐ and second‐line treatment of MPM. Cancer 2007. © 2006 American Cancer Society.
Prognostic markers in triple‐negative breast cancer
Authors: Rakha Emad A. , El‐Sayed Maysa E. , Green Andrew R. , Lee Andrew H. S. , Robertson John F. , Ellis Ian O.
Published: December 2006

BACKGROUND.

Triple‐negative breast cancer (estrogen receptor‐negative, progesterone receptor‐negative, and HER2‐negative) is a high risk breast cancer that lacks the benefit of specific therapy that targets these proteins.

METHODS.

In this study, the authors examined a large and well characterized series of invasive breast carcinoma (n = 1944) with a long‐term clinical follow‐up (median, 56 months) by using tissue microarray. The series were also stained with concurrent immunohistochemical prognostic panels (estrogen receptor, progesterone receptor, HER‐2, androgen receptor, epidermal growth factor receptor (EGFR), P‐cadherin, E‐cadherin, and basal (CK5/6, CK14), and p53), to characterize this specific subgroup of breast cancer and to identify prognostic markers that can identify tumors with more aggressive behavior.

RESULTS.

Of informative cases, 16.3% were of the triple‐negative phenotype. The majority of these tumors were grade 3, ductal/no‐specific‐type carcinomas. There were positive associations with larger size, pushing margins, poorer Nottingham Prognostic Index, development of recurrence and distant metastasis, and poorer outcome. In addition, associations were found with loss of expression of androgen receptor and E‐cadherin, and positive expression of basal cytokeratins (basal phenotype), P‐cadherin, p53, and EGFR. In all tumors, tumor size, lymph node stage, and androgen receptor were the most useful prognostic markers. In the lymph node‐positive subgroup, both size and androgen receptor retained their prognostic significance. However, in the lymph node‐negative tumors, basal phenotype was the sole prognostic marker identified in this subgroup. Other parameters including age, histological grade, tumor size, vascular invasion or other biomarkers included in the current study were not significant.

CONCLUSIONS.

The authors concluded that assessment of androgen receptor and basal phenotype, in addition to the established pathologic variables, mainly lymph node status and tumor size, can be used to select high‐risk and low‐risk patients at the time of primary surgery and can provide valuable information on treatment options in these triple‐negative tumors. Cancer 2007. © 2006 American Cancer Society
Detection of interval distant metastases
Authors: Bruzzi John F. , Swisher Stephen G. , Truong Mylene T. , Munden Reginald F. , Hofstetter Wayne L. , Macapinlac Homer A. , Correa Arlene M. , Mawlawi Osama , Ajani Jaffer A. , Komaki Ritsuko R. , Fukami Norio , Erasmus Jeremy J.
Published: December 2006

BACKGROUND.

The objective of the study was to determine the utility of integrated computed tomography / positron emission tomography (CT‐PET) imaging for detecting interval distant metastases and assessing therapeutic response in patients with locally advanced, potentially resectable esophageal carcinoma after neoadjuvant therapy.

METHODS.

A retrospective study was performed of 88 patients with potentially resectable esophageal carcinoma who received neoadjuvant therapy before planned surgical resection. CT‐PET before and after completion of neoadjuvant was used for evaluating therapeutic response; response criteria were based on qualitative and semiquantitative analyses.

RESULTS.

Neoadjuvant therapy comprised chemoradiotherapy in 85 patients, with prior induction chemotherapy in 39 patients. Fifty‐five patients proceeded to esophagectomy. Repeat CT‐PET was performed after induction chemotherapy (n = 23) and after completing chemoradiotherapy (n = 85). CT‐PET identified the interval appearance of metastatic disease in 7 (8%) patients. For assessment of locoregional therapeutic response, CT‐PET was unable to predict pathological response to neoadjuvant therapy in the primary tumor or locoregional lymph nodes. CT‐PET had sensitivity, specificity, and positive and negative predictive values of 57%, 46%, 39%, and 64%, respectively, for detection of residual macroscopic malignancy within the primary tumor; and sensitivity, specificity, and positive and negative predictive values of 0%, 90%, 0%, and 69% for detection of residual malignancy within resected lymph nodes.

CONCLUSIONS.

CT‐PET performed after neoadjuvant therapy in patients with potentially resectable esophageal carcinoma is important for detecting interval metastases that preclude surgical resection, but is of limited utility for assessing locoregional therapeutic response. Cancer 2007. © 2006 American Cancer Society
DC capacitor simulation by the boundary element method
Authors: Kirkup Stephen
Published: December 2006

When the direct current (DC) metallized thin film capacitor is fully charged the electromagnetic fields can be considered to have reached a steady state in which the governing equation is Laplace's equation. It is the computational analysis of the electrostatic state that is considered in this paper.

The capacitor is modelled as a stack made up of infinitesimally thin layers of metal on polymer. An integral equation method from the BEMLAP package (www.boundary‐element‐method.com (Introduction to the Boundary Element Method for Scientists and Engineers: The BEMLAP Fortran Library for Laplace Problems)) for modelling the electric field, based on the methods described in Kirkup (Fortran codes for computing the discrete Helmholtz integral operators; Adv. Comput. Math. 1998; 9:391–409). The method is applied to a typical capacitor structure and encouraging results are obtained. Copyright © 2006 John Wiley & Sons, Ltd.
Hybrid equilibrium hexahedral elements and super‐elements
Authors: Pereira O. J. B. Almeida
Published: December 2006

Equilibrated solutions, locally satisfying all the equilibrium conditions, may be obtained by using a special case of the hybrid finite element formulation. Unlike simplicial super‐elements in 2D and 3D, which are free from spurious kinematic modes, and the quadrilateral super‐element with diagonal subdivision, which has exactly one internal spurious kinematic mode, no hexahedral super‐element free of external spurious kinematic modes is yet known as far as the author is aware. Copyright © 2006 John Wiley & Sons, Ltd.
Cover Picture: Identification of the D3h Isomer of Carbon Trioxide (CO3) and Its Implications for Atmospheric Chemistry (ChemPhysChem 12/2006)
Authors: Jamieson Corey S. , Mebel Alexander M. , Kaiser Ralf I.
Published: December 2006

The cover picture shows the D3h isomer of carbon trioxide and the overlapping vibrational modes of different acyclic CO3 isotopomers. The D3h isomer of carbon trioxide is an important intermediate in atmospheric reactions between O and CO2. It has been experimentally detected for the first time by infrared spectroscopy after irradiating a carbon dioxide ice with energetic electrons. In their Article on page 2508 Jamieson et al. combine experiment with electronic structure calculation to identify the D3h isomer of carbon trioxide. The cloudy background photograph is a courtesy of Steve Hudson (www.hudsonphoto.com).
A general framework for evaluating nonlinearity, noise and dynamic range in continuous‐time OTA‐C filters for computer‐aided design and optimization
Authors: Koziel S. , Ramachandran A. , Szczepanski S. , Sánchez‐Sinencio E.
Published: December 2006

Efficient procedures for evaluating nonlinear distortion and noise valid for any OTA‐C filter of arbitrary order are developed based on matrix description of a general OTA‐C filter model. Since those procedures use OTA macromodels, they allow us to obtain the results significantly faster than transistor‐level simulation. On the other hand, the general OTA‐C filter model allows us to apply matrix transforms that manipulate (rescale) filter element values and/or change topology without changing its transfer function. Due to this, the proposed procedures can be used in direct optimization of OTA‐C filters with respect to important characteristics such as noise performance, THD, IM3, DR or SNR. As an example, a simple optimization procedure using equivalence transformations is discussed. An application example of the proposed approach to optimal block sequencing and gain distribution of 8th order cascade Butterworth filter is given. Accuracy of the theoretical tools has been verified by comparing to transistor‐level simulation results and to experimental results. Copyright © 2006 John Wiley & Sons, Ltd.
An approach to model high‐frequency distortion in negative‐feedback amplifiers
Authors: Cannizzaro S. O. , Palumbo G. , Pennisi S.
Published: December 2006

In this paper, we present an analytical approach to study the harmonic distortion in the frequency domain of operational amplifiers (opamps) embedded in a nonlinear feedback network. The analysis is based on a frequency‐domain block scheme that models the opamp with one block and the feedback network with two blocks, but it is demonstrated that only one feedback block needs to be characterized for the two basic inverting and non‐inverting configurations. The obtained closed‐form expressions extend our understanding of nonlinear frequency behaviour in feedback opamp circuits. Indeed, they give the contribution of each network component to the output distortion. As an instructive example, we analysed second‐ and third‐order harmonic distortion of an active‐RC inverting lossy integrator having all the components nonlinear. The accuracy of the proposed method is confirmed by comparison with computer simulations at transistor level. Copyright © 2006 John Wiley & Sons, Ltd.
A Middle Ordovician cephalopod fauna from Cuzco Province, southern Perú and its palaeobiogeographical significance
Authors: Evans David H.
Published: December 2006

A small cephalopod assemblage collected during the 1930s by J. A. Douglas from the Middle Ordovician San José Formation of Cuzco Province is redescribed. Although small in number (four taxa) and poorly preserved, this assemblage contains a representative of the ellesmerocerid family Eothinoceratidae and a probable member of the Arionoceratidae (Orthocerida). One taxon may be closely related toProtocycloceras harringtoniCecioni from northern Argentina. The presence of a particular group of eothinoceratids, here and elsewhere in South America indicate a link with western Gondwana. The relatively diminutive size of the arionoceratids suggests homeomorphy with those Silurian forms associated with a pelagic habitat and indicates a relatively offshore site for this assemblage. Copyright © 2006 John Wiley & Sons, Ltd.
Cholinergic suppression of excitatory synaptic responses in layer II of the medial entorhinal cortex
Authors: Hamam Bassam N. , Sinai Marco , Poirier Guillaume , Chapman C. Andrew
Published: December 2006

Theta‐frequency (4–12 Hz) electroencephalographic activity is thought to play a role in mechanisms mediating sensory and mnemonic processing in the entorhinal cortex and hippocampus, but the effects of acetylcholine on excitatory synaptic inputs to the entorhinal cortex are not well understood. Field excitatory postsynaptic potentials (fEPSPs) evoked by stimulation of the piriform (olfactory) cortex were recorded in the medial entorhinal cortex during behaviors associated with theta activity (active mobility) and were compared with those recorded during nontheta behaviors (awake immobility and slow wave sleep). Synaptic responses were smaller during behavioral activity than during awake immobility and sleep, and responses recorded during movement were largest during the negative phase of the theta rhythm. Systemic administration of cholinergic agonists reduced the amplitude of fEPSPs, and the muscarinic receptor blocker scopolamine strongly enhanced fEPSPs, suggesting that the theta‐related suppression of fEPSPs is mediated in part by cholinergic inputs. The reduction in fEPSPs was investigated using in vitro intracellular recordings of EPSPs in Layer II neurons evoked by stimulation of Layer I afferents. Constant bath application of the muscarinic agonist carbachol depolarized membrane potential and suppressed EPSP amplitude in Layer II neurons. The suppression of EPSPs was not associated with a substantial change in input resistance, and could not be accounted for by a depolarization‐induced reduction in driving force on the EPSP. The GABAA receptor‐blocker bicuculline (50 μM) did not prevent the cholinergic suppression of EPSPs, suggesting that the suppression is not dependent on inhibitory mechanisms. Paired‐pulse facilitation of field and intracellular EPSPs were enhanced by carbachol, indicating that the suppression is likely due to inhibition of presynaptic glutamate release. These results indicate that, in addition to well known effects on postsynaptic conductances that increase cellular excitability, cholinergic activation in the entorhinal cortex results in a strong reduction in strength of excitatory synaptic inputs from the piriform cortex. © 2006 Wiley‐Liss, Inc.
Effects of serotonin on the intrinsic membrane properties of layer II medial entorhinal cortex neurons
Authors: Ma Li , Shalinsky Mark H. , Alonso Angel , Dickson Clayton T.
Published: December 2006

Although serotonin (5‐HT) is an important neuromodulator in the superficial layers of the medial entorhinal cortex (mEC), there is some disagreement concerning its influences upon the membrane properties of neurons within this region. We performed whole cell recordings of mEC Layer II projection neurons in rat brain slices in order to characterize the intrinsic influences of 5‐HT. In current clamp, 5‐HT evoked a biphasic response consisting of a moderately short latency and large amplitude hyperpolarization followed by a slowly developing, long lasting, and small amplitude depolarization. Correspondingly, in voltage clamp, 5‐HT evoked a robust outward followed by a smaller inward shift of holding current. The outward current evoked by 5‐HT showed a consistent current/voltage (I/V) relationship across cells with inward rectification, and demonstrating a reversal potential that was systematically dependent upon the extracellular concentration of K+, suggesting that it was predominantly carried by potassium ions. However, the inward current showed a less consistent I/V relationship across different cells, suggesting multiple independent ionic mechanisms. The outward current was mediated through activation of 5‐HT1Areceptors via a G‐protein dependent mechanism while inward currents were evoked in a 5‐HT1A‐independent fashion. A significant proportion of the inward current was blocked by the Ihinhibitor ZD7288 and appeared to be due to 5‐HT modulation of Ihas 5‐HT shifted the activation curve of Ihin a depolarizing fashion. Serotonin is thus likely to influence, in a composite fashion, the information processing of Layer II neurons in the mEC and thus, the passage of neocortical information via the perforant pathway to the hippocampus. © 2006 Wiley‐Liss, Inc.
Phospholipase D1 activation through Src and Ras is involved in basic fibroblast growth factor‐induced neurite outgrowth of H19‐7 cells
Authors: Oh Doo‐Yi , Park Shin‐Young , Cho Ju Hwan , Lee Ki Sung , Min Do Sik , Han Joong‐Soo
Published: December 2006

Phospholipase D (PLD) is implicated in a variety of physiological processes that reveal it to be a member of the signal transducing phospholipases. We found that PLD1 is activated when basic fibroblast growth factor (bFGF) stimulates neurite outgrowth of an immortalized hippocampal cell line (H19‐7). Overexpression of PLD1 in H19‐7 cells dramatically elongated bFGF‐induced neurite outgrowth and increased PLD activity. Transfection of DN‐rPLD1 blocked bFGF‐induced PLD activation and completely inhibited neurite outgrowth induced by bFGF, suggesting that PLD1 activation is important in bFGF‐induced neurite outgrowth of H19‐7 cells. PLD activation and neurite outgrowth induced by bFGF was dependent on phospholipase C gamma (PLC‐γ) and Ca2+, but not protein kinase C (PKC). Furthermore, inhibition of Src and Ras partially blocked bFGF‐induced PLD activation and neurite outgrowth, respectively. Coinhibition of Src and Ras completely blocked bFGF‐induced PLD activation, suggesting that Src and Ras independently regulate PLD1 activation. Interestingly, bFGF‐induced PLD activation and neurite outgrowth did not require ERK1/2 activated by Ras. Taken together, this study demonstrates that bFGF activates PLD1 through PLC‐γ activation, which leads to neurite outgrowth in H19‐7 cells. Furthermore, our results show that PLD1 activation by bFGF is regulated by Src and Ras independently. J. Cell. Biochem. 101: 221–234, 2007. © 2006 Wiley‐Liss, Inc.
BRCA1 does not paint the inactive X to localize XIST RNA but may contribute to broad changes in cancer that impact XIST and Xi heterochromatin
Authors: Pageau Gayle J. , Hall Lisa L. , Lawrence Jeanne B.
Published: December 2006

The BRCA1 tumor suppressor involved in breast and ovarian cancer is linked to several fundamental cell regulatory processes. Recently, it was reported that BRCA1 supports localization of XIST RNA to the inactive X chromosome (Xi) in women. The apparent cytological overlap between BRCA1 and XIST RNA across the Xi raised the possibility a direct role of BRCA1 in localizing XIST. We report here that BRCA1 does not paint the Xi or XIST territory, as do markers of Xi facultative heterochromatin. A smaller BRCA1 accumulation abuts Xi, although this is not exclusive to Xi. In BRCA1 depleted normal and tumor cells, or BRCA1 reconstituted cells, BRCA1 status does not closely correlate with XIST localization, however in a BRCA1 inducible system over‐expression correlated strongly with enhanced XIST expression. We confirm frequent loss of an Xi in tumor cells. In addition to mitotic loss of Xi, we find XIST RNA expression or localization frequently become compromised in cultured breast cancer cells, suggesting Xi heterochromatin may not be fully maintained. We demonstrate that complex epigenetic differences between tumor cell subpopulations can have striking effects on XIST transcription, accumulation, and localization, but this does not strictly correlate with BRCA1. Although BRCA1 can have indirect effects that impact XIST, our results do not indicate a direct and specific role in XIST RNA regulation. Rather, regulatory factors such as BRCA1 that have broad effects on chromatin or gene regulation can impact XIST RNA and the Xi. We provide preliminary evidence that this may occur as part of a wider failure of heterochromatin maintenance in some cancers. J. Cell. Biochem. 100: 835–850, 2007. © 2006 Wiley‐Liss, Inc.
Differential gene expression in skeletal muscle cells after membrane depolarization
Authors: Juretić Nevenka , Urzúa Ulises , Munroe David J. , Jaimovich Enrique , Riveros Nora
Published: December 2006

Skeletal muscle is a highly plastic tissue with a remarkable capacity to adapt itself to challenges imposed by contractile activity. Adaptive response, that include hypertrophy and activation of oxidative mechanisms have been associated with transient changes in transcriptional activity of specific genes. To define the set of genes regulated by a depolarizing stimulus, we used 22 K mouse oligonucleotide microarrays. Total RNA from C2C12 myotubes was obtained at 2, 4, 18, and 24 h after high K+ stimulation. cDNA from control and depolarized samples was labeled with cyanine 3 or 5 dyes prior to microarray hybridization. Loess normalization followed by statistical analysis resulted in 423 differentially expressed genes using an unadjusted P‐value ≤ 0.01 as cut off. Depolarization affects transcriptional activity of a limited number of genes, mainly associated with metabolism, cell communication and response to stress. A number of genes related to Ca2+ signaling pathways are induced at 4 h, reinforcing the potential role of Ca2+ in early steps of signal transduction that leads to gene expression. Significant changes in the expression of molecules involved in muscle cell structure were observed; K+‐depolarization increased Tnni1 and Acta1 mRNA levels in both differentiated C2C12 and rat skeletal muscle cells in primary culture. Of these two, depolarization induced slow Ca2+ transients appear to have a role only in the regulation of Tnni1 transcriptional activity. We suggest that depolarization induced expression of a small set of genes may underlie Ca2+ dependent plasticity of skeletal muscle cells. J. Cell. Physiol. 210: 819–830, 2007. © 2006 Wiley‐Liss, Inc.
An automated tracking system to measure the dynamic properties of vesicles in living cells
Authors: Ku Tien‐Chuan , Huang Yun‐Nih , Huang Chien‐Chang , Yang De‐Ming , Kao Lung‐Sen , Chiu Tai‐Yu , Hsieh Chung‐Fan , Wu Pei‐Yo , Tsai Yuh‐Show , Lin Chung‐Chih
Published: December 2006

Recent technological improvements have made it possible to examine the dynamics of individual vesicles at a very high temporal and spatial resolution. Quantification of the dynamic properties of secretory vesicles is labor‐intensive and therefore it is crucial to develop software to automate the process of analyzing vesicle dynamics. Dual‐threshold and binary image conversion were applied to enhance images and define the areas of objects of interest that were to be tracked. The movements, changes in fluorescence intensity, and changes in the area of each tracked object were measured using a new software system named the Protein Tracking system (PTrack). Simulations revealed that the system accurately recognized tracked objects and measured their dynamic properties. Comparison of the results from tracking real time‐lapsed images manually with those automatically obtained using PTrack revealed similar patterns for changes in fluorescence intensity and a high accuracy (<89%). According to tracking results, PTrack can distinguish different vesicular organelles that are similar in shape, based on their unique dynamic properties. In conclusion, the novel tracking system, PTrack, should facilitate automated quantification of the dynamic properties of vesicles that are important when classifying vesicular protein locations. Microsc. Res. Tech. 2007. © 2006 Wiley‐Liss, Inc.
The composition of capital flows to South Africa
Authors: Ahmed Faisal , Arezki Rabah , Funke Norbert
Published: December 2006

Unlike in most other emerging markets, capital flows to South Africa since the mid 1990s have been heavily biased toward portfolio flows. In this context, the objective of the paper is twofold: to identify the determinants of the level and composition of capital flows to emerging markets and to draw policy conclusions for South Africa. The empirical results suggest that further trade and capital control liberalisation would increase the share of FDI in South Africa. Additionally, a reduction in exchange rate volatility would affect the composition of capital flows in favour of FDI. Copyright © 2006 John Wiley & Sons, Ltd.
Morphological changes in pedal phalanges through ornithopod dinosaur evolution: A biomechanical approach
Authors: Moreno Karen , Carrano Matthew T. , Snyder Rebecca
Published: December 2006

The evolution of ornithopod dinosaurs provides a well‐documented example of the transition from digitigrady to subunguligrady. During this transition, the ornithopod pes was drastically altered from the plesiomorphic dinosaurian morphology (four digits, claw‐shaped unguals, strongly concavo‐convex joints, phalanges longer than wide, excavated collateral ligament fossae, presence of sagittal ridge, and prominent processes for the attachment of tendons) to a more derived condition (tridactyly, modification of the unguals into hooves, phalanges wider and thinner than long, lack of collateral ligament fossae, loss of sagittal ridge and tendon attachment processes, relatively flattened articular surfaces). These changes are particularly noteworthy given the overall conservatism in pedal morphology seen across Dinosauria. But what are the functional consequences of these specific morphological transitions? To study them, we examine a wide range of pedal morphologies in four non‐avian dinosaurs and two birds. Our analyses of the external morphology, two‐dimensional models (using Finite Element Analysis), and internal bone structure demonstrate that this evolutionary shift was accompanied by a loss of digit mobility and flexibility. In addition, pedal posture was modified to better align the pes with the main direction of the ground reaction force, thus becoming well suited to support high loads. These conclusions can be applied to other, parallel evolutionary changes (in both dinosaurs and mammals) that involved similar transitions to a subunguligrade posture. J. Morphol, 2006. © 2006 Wiley‐Liss, Inc.
Reproductive morphology of Brittanichthys axelrodi (Teleostei: Characidae), a miniature inseminating fish from South America
Authors: Javonillo Robert , Burns John R. , Weitzman Stanley H.
Published: December 2006

Light and electron microscopy were used to investigate the morphology of reproductive characters in a characid fish, Brittanichthys axelrodi. Spermatozoa were found in ovaries of females, thereby confirming insemination in this species. Bony hooks can be found on the fourth unbranched ray and branched rays 1–4 of the anal fin and the unique sigmoidally‐curved ray of the caudal fin in mature males. Testes have three distinct regions: an anterior spermatogenic region, an aspermatogenic middle region lined with a simple squamous epithelium and used for storage of mature spermatozoa, and a posterior region of coiled chambers lined with a high simple cuboidal epithelium. The most posterior region appears to be instrumental in the formation and storage of spermatozeugmata, unencapsulated sperm packets. Thus far, this tripartite testis morphology is unique among characids. The mature spermatozoon has an elongate nucleus (∼5 μm in length). A striated rootlet originates at the anterior end of the distal centriole and continues to the anterior tip of the cell. The striated rootlet wraps around the entire ventral area of the anterior part of the nucleus and appears to continue around the anterior tip of the nucleus and down the dorsal side as electron‐dense material. Several large, spherical mitochondria (∼0.6 μm in diameter) with lamellar cristae overlap the posterior end of the nucleus and continue beyond together with the cytoplasmic collar that contains the flagellum which lacks axonemal fins. Each spermatozeugma is lanceolate in shape when sectioned mid‐sagitally, with the core staining positively for mucopolysaccharides. In both sexes, the gonopore opens posterior to the anus, with the urinary pore having a separate opening posterior to the gonopore. Bands of skeletal muscle were found in the area of the male gonopore. These morphological features are likely linked to the reproductive mode of insemination, a trait that is so far as known, relatively rare among teleost fishes, but is proving increasingly frequent among certain groups of characid fishes. J. Morphol, 2006. © 2006 Wiley‐Liss, Inc.
Direct laser desorption/ionization time‐of‐flight mass spectrometry of conjugated polymers
Authors: Ma Zhun , Qiang Liang‐Liang , Fan Qu‐Li , Wang Yan‐Yan , Pu Kan‐Yi , Yin Rong , Huang Wei
Published: December 2006

Two conjugated polymers (CPs), poly(9,9‐dioctylfluorene) (PF) and poly(3‐octylthiophene) (PT) were analyzed by direct laser desorption/ionization time‐of‐flight mass spectrometry (LDI‐ToF MS). Because of their strong absorption near the wavelength of the laser (337 nm), easy and transient energy transfer properties and sufficient thermal stability, CPs can be desorbed and ionized directly without a matrix. For comparison, these two polymers were also analyzed using matrix‐assisted laser desorption/ionization (MALDI)‐ToF MS in the positive reflectron mode. The results revealed that they are very similar in terms of quality and resolution. All results demonstrate that LDI‐ToF MS is an alternative method for the mass characterization of some conjugated systems, thereby simplifying the process of sample preparation and result analysis. Copyright © 2006 John Wiley & Sons, Ltd.
Detection and identification of arginine modifications on methylglyoxal‐modified ribonuclease by mass spectrometric analysis
Authors: Brock Jonathan W. C. , Cotham William E. , Thorpe Suzanne R. , Baynes John W , Ames Jennifer M.
Published: December 2006

Analysis of the broad range of trace chemical modifications of proteins in biological samples is a significant challenge for modern mass spectrometry. Modification at lysine and arginine residues, in particular, causes resistance to digestion by trypsin, producing large tryptic peptides that are not readily sequenced by mass spectrometry. In this work, we describe the analysis of ribonuclease (RNase) modified by methylglyoxal (MGO) under physiological conditions. For detection of modifications, we use comparative analysis of the single combined spectra extracted from the full‐scan MS data of the tryptic digests from native and modified proteins. This approach revealed 11 ions unique to MGO‐modified RNase, including a 32‐amino acid peptide containing a modified Arg‐85 residue. Sequential digestion of MGO‐modified RNase by endoproteinase Glu‐C and trypsin was required to obtain peptides that were amenable to sequencing analysis. Arg‐39 was identified as the main site of modification (35% modification) on MGO‐modified Rnase, and the dihydroxyimidazolidine and hydroimidazolone derivatives were the main adducts formed, with minor amounts of the tetrahydropyrimidine and argpyrimidine derivatives. For identification of these products, we used variations in source voltage and collision energy to obtain the dehydration and decarboxylation products of the tetrahydropyrimidine‐containing peptides and dehydration of the dihydroxyimidazoline‐containing peptides. The resultant spectra were dependent on the cone voltage and collision energy, and analysis of spectra at various settings permitted structural assignments. These studies illustrate the usefulness of single combined mass spectra extracted from full‐scan data and variations in source and collision cell voltages for detection and structural characterization of chemical adducts on proteins. Copyright © 2006 John Wiley & Sons, Ltd.
Simulated changes in active/break spells during the Indian summer monsoon due to enhanced CO2 concentrations: assessment from selected coupled atmosphere–ocean global climate models
Authors: Mandke Sujata K. , Sahai A. K. , Shinde M. A. , Joseph Susmitha , Chattopadhyay R.
Published: December 2006

The simulations by ten coupled GCMs under the Intergovernmental Panel on Climate Change Assessment Report‐4 are used to study the implication of possible global climate change on active/break spells of the Indian summer monsoon (ISM). The validation of the mean daily cycle of the summer monsoon precipitation over the Indian core region and the spatial pattern of the ISM precipitation climatology with observation suggest that six models simulate fairly well, whereas four models differ from observation. Thus, the identification of active/break spells is confined to six models.

The sensitivity to climate change has been assessed from two experiments, namely, 1% per year CO2 increase to doubling and 1% per year CO2 increase to quadrupling. The changes in the daily mean cycle and the standard deviation of precipitation, frequency, and duration of active/break spells in future climate change are uncertain among the models and at times among two experiments. The break composite precipitation anomalies strengthen and spread moderately (significantly) in the doubled (quadrupled) CO2 experiment. Copyright © 2006 Royal Meteorological Society
Simulation of seasonal precipitation and raindays over Greece: a statistical downscaling technique based on artificial neural networks (ANNs)
Authors: Tolika K. , Maheras P. , Vafiadis M. , Flocas H. A. , Arseni‐Papadimitriou A.
Published: December 2006

A statistical downscaling technique based on artificial neural network (ANN) was employed for the estimation of local changes on seasonal (winter, spring) precipitation and raindays for selected stations over Greece. Empirical transfer functions were derived between large‐scale predictors from the NCEP/NCAR reanalysis and local rainfall parameters. Two sets of predictors were used: (1) the circulation‐based 500 hPa and (2) its combination along with surface specific humidity and raw precipitation data (nonconventional predictor). The simulated time series were evaluated against observational data and the downscaling model was found efficient in generating winter and spring precipitation and raindays. The temporal evolution of the estimated variables was well captured, for both seasons. Generally, the use of the nonconventional predictors are attributed to the improvement of the simulated results. Subsequently, the present day and future changes on precipitation conditions were examined using large‐scale data from the atmospheric general circulation model HadAM3P to the statistical model. The downscaled climate change signal for both precipitation and raindays, partly for winter and especially for spring, is similar to the signal from the HadAM3P direct output: a decrease of the parameters is predicted over the study area. However, the amplitude of the changes was different. Copyright © 2006 Royal Meteorological Society