bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

AbstractQuasi‐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

AbstractIn 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

AbstractEffect 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

AbstractA 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

AbstractBACKGROUND.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

AbstractBACKGROUND.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

AbstractBACKGROUND.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

AbstractWhen 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

AbstractEquilibrated 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.
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

AbstractEfficient 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

AbstractIn 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

AbstractA 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

AbstractTheta‐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

AbstractAlthough 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

AbstractPhospholipase 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

AbstractThe 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.