bluuebunny/crossref_metadata_2025_split huggingface dataset:
Efﬁciency of antidepressant drugs as monoamine reuptake inhibitors: analysis of the hydrophobicity inﬂuence using biopartitioning micellar chromatographic data
Authors: Quiñones‐Torrelo C. , Sagrado S. , Villanueva‐Camañas R. M. , Medina‐Hernández M. J. 
Published: August 2004

AbstractThe reuptake blockade of biogenic amines by antidepressants is related not only to their therapeutics effects, but also to their side effects and potential drug–drug interactions. As an alternative to classical quantitative structure–activity relationships studies, in this work we propose different quantitative retention–activity relationships (QRAR) models that are able to describe the monoamine reuptake inhibition by antidepressants. The retention of compounds is measured using a biopartitioning micellar chromatography (BMC) system that can simulate the same hydrophobic, electronic and steric molecular interactions as those that condition drug activity. Since all the compounds considered in this work are structurally related because all of them share the same molecular features as the corresponding basic pharmacophore, the results obtained show that there is a retention range in which antidepressants present the highest monoamine reuptake inhibitor potency. Copyright © 2003 John Wiley & Sons, Ltd.
Quantitation of normal and formaldehyde‐modiﬁed deoxynucleosides by high‐performance liquid chromatography/UV detection
Authors: Zhong Weiguang , Hee Shane Que 
Published: August 2004

AbstractA sensitive and selective method was developed for the ﬁrst time to quantify simultaneously the normal and formaldehyde (FA)‐modiﬁed bases in human placental DNA treated with 100 ppm FA for 20 h at 37°C. Digestion of DNA to deoxynucleosides with DNase I, phosphodiesterase and alkaline phosphatase occurred in that order with centrifugation steps. The normal and FA‐modiﬁed deoxynucleosides were then resolved from one another and reagent blank interferences to produce selective separation through high performance liquid chromatography–ultraviolet detection at 254 nm. A C18 reversed‐phase column facilitated the resolution using 5 mm ammonium acetate and a gradient of 0–6% methanol at ﬂow rates of 0.3–1.4 mL/min before column cleaning. The lower quantiﬁable limits for deoxyadenosine, deoxyguanosine, deoxycytidine, thymidine, N6‐hydroxymethyldeoxyadenosine (N6‐dA), N2‐hydroxymethyldeoxyguanosine (N2‐dG) and N4‐hydroxymethyldeoxycytidine (N4‐dC) were 11, 7.6, 12, 15, 10, 10 and 22 pmol, respectively. The abundance order of the modiﬁed deoxynucleosides was N6‐dA > N2‐dG > N4‐dC. dT did not form hydroxymethyl derivatives. The respective concentrations were about 6.0, 10.0 and 23 pmol of modiﬁed deoxynucleosides in 80 µg of human placental DNA after treatment with 100 µg/mL of formalin for 20 h at 37°C. The stabilities of N6‐dA and N2‐dG were much better at −20°C than at 25°C, where the respective halftimes were about 50.1 and 21.0 h. Copyright © 2004 John Wiley & Sons, Ltd.
An HPLC assay of hydroxyl radicals by the hydroxylation reaction of terephthalic acid
Authors: Linxiang Li , Abe Yoshihiro , Nagasawa Yukiko , Kudo Risa , Usui Noriko , Imai Kazuhiro , Mashino Tadahiko , Mochizuki Masataka , Miyata Naoki 
Published: August 2004

AbstractAn HPLC assay for hydroxyl radicals is described. The hydroxyl radical was trapped by terephthalic acid (non‐ﬂuorescent), and 2‐hydroxyl terephthalic acid (fluorescent) was quantitated by HPLC‐ﬂuorescence detection. At a terephthalic acid concentration of 4.25 mmol/L, the hydroxyl radical formed in the Fenton reaction was successfully assayed in the concentration range of hydrogen peroxide of 2.5–50 µmol/L, where the concentration of Fe(II) was 50 µmol/L. The ﬂuorescence of 2‐hydroxy terephthalate was stable at 24 h, and its detection limit by this method was 5 nmol/L (100 fmol). Copyright © 2004 John Wiley & Sons, Ltd.
A rapid and simple method for determination of halothane, isoﬂurane and sevoﬂurane in blood using gas chromatography
Authors: Atherley Richard J. , Antognini Joseph F. 
Published: August 2004

AbstractWe have developed a technique to determine the concentration of volatile anesthetics (halothane, isoﬂurane and sevoﬂurane) in blood that is a modiﬁcation of a method used for volatile anesthetics in Krebs solution. Methylene chloride was the internal standard and chloroform was used to extract the volatile anesthetic from blood. The congealed blood proteins were separated from the chloroform solvent (containing anesthetic) using a two‐compartment vial that ﬁltered out the proteinaceous material during centrifuging. Recovery averaged 102%. Linearity was excellent (r = 0.992–0.999) in the 50–600, 50–300 and 50–300 µg/mL range for halothane, isoﬂurane and sevoﬂurane, respectively. Intra‐day and inter‐day precisions were likewise excellent, with relative standard deviations <5.3 and <7.1%, respectively. Accuracy ranged from 0.8 to 9.5% of the estimated theoretical value. Extracted anesthetic in chloroform solvent was stable over 4–5 days, with <3% variability. The time from obtaining the blood sample to determination of the concentration from the chromatographic peak was 15 min or less. Copyright © 2004 John Wiley & Sons, Ltd.
A mathematical theory of strong emergence using multiscale variety
Authors: Bar‐Yam Yaneer 
Published: August 2004

AbstractWe argue conceptually and then demonstrate mathematically that it is possible to define a scientifically meaningful notion of strong emergence. A strong emergent property is a property of the system that cannot be found in the properties of the system's parts or in the interactions between the parts. The possibility of strong emergence follows from an ensemble perspective, which states that physical systems are only meaningful as ensembles rather than individual states. Emergent properties reside in the properties of the ensemble rather than of any individual state. A simple example is the case of a string of bits including a parity bit, i.e. the bits are constrained to have, e.g., an odd number of ON bits. This constraint is a property of the entire system that cannot be identified through any set of observations of the state of any or all subsystems of the system. It is a property that can only be found in observations of the state of the system as a whole. A collective constraint is a property of the system, however, the constraint is caused when the environment interacts with the system to select the allowable states. Although selection in this context does not necessarily correspond to biological evolution, it does suggest that evolutionary processes may lead to such emergent properties. A mathematical characterization of multiscale variety captures the implications of strong emergent properties on all subsystems of the system. Strong emergent properties result in oscillations of multiscale variety with negative values, a distinctive property. Examples of relevant applications in the case of social systems include various allocation, optimization, and functional requirements on the behavior of a system. Strongly emergent properties imply a global to local causality that is conceptually disturbing (but allowed!) in the context of conventional science, and is important to how we think about biological and social systems. © 2004 Wiley Periodicals, Inc. Complexity 9: 15–24, 2004
Sex promotes gamete selection: A quantitative comparative study of features favoring the evolution of sex
Authors: Jaffe Klaus 
Published: August 2004

AbstractExplaining the maintenance of sexual reproduction remains one of the greatest challenges in biology. The theoretical oddity of sex is based on at least three advantages that asexual organisms have over sexual ones: (1) Asexuals, by not producing males, have a twofold advantage over sexuals, regarding the number of reproductive individuals; (2) sexuals have an evolutionary disadvantage over asexuals, in that a rare alleles that increases fitness of one parent, for example, is not necessarily transmitted to the offspring, due to segregation; and (3) asexuals do not have to find a mate in order to reproduce. Here I present the results of evolutionary tournaments performed using the agent‐based computer simulation Biodynamica. The tournaments explored the relative merits of various features that have been proposed to affect the putative advantages of sexual reproduction, including ploidy, mate selection, large reproductive variance of males, low mutation rates, gamete selection, reduced cost for the production of males, thelytoky vs. parthenogenesis, variable environments, and complex genomes. The model allowed for a quantitative comparison of the effect of these features on the adaptive value of sex. The results showed that the production of large number of gametes (for example “masting” in massive flowering of trees or spermatozoa of most animals) inducing gamete selection, together with nonrandom mate selection, increased variance in male reproductive success and/or low mutation rates, allowed sexual agents to out‐breed asexual ones, despite the three disadvantages for sex cited above. The wok suggests that gamete cycles and alloiogenesis, common to most sexual plants, fungi, and animals, should be viewed as a new level for natural selection to work. Mate and gamete selection are more efficient in the use of biomass, energy, and time than natural selection at the level of organisms, helping to make sexual reproduction an evolutionary success. © 2004 Wiley Periodicals, Inc. Complexity 9: 43–51, 2004
The emergence of dynamical complexity: An exploration using elementary cellular automata
Authors: Mizraji Eduardo 
Published: August 2004

AbstractThis work concerns the interaction between two classical problems: the forecasting of the dynamical behaviors of elementary cellular automata (ECA) from its intrinsic mathematical laws and the conditions that determine the emergence of complex dynamics. To approach these problems, and inspired by the theory of reversible logical gates, we decompose the ECA laws in a “spectrum” of dyadic Boolean gates. Emergent properties due to interactions are captured generating another spectrum of logical gates. The combined analysis of both spectra shows the existence of characteristic bias in the distribution of Boolean gates for ECA belonging to different dynamical classes. These results suggest the existence of signatures capable to indicate the propensity to develop complex dynamics. Logical gates “exclusive‐or” and “equivalence” are among these signatures of complexity. An important conclusion is that within ECA space, interactions are not capable to generate signatures of complexity in the case these signatures are absent in the intrinsic law of the automaton. © 2004 Wiley Periodicals, Inc. Complexity 9: 33–42, 2004
Contextual regularity and complexity of neuronal activity: From stand‐alone cultures to task‐performing animals
Authors: Ayali A. , Fuchs E. , Zilberstein Y. , Robinson A. , Shefi O. , Hulata E. , Baruchi I. , Ben‐Jacob E. 
Published: August 2004

AbstractPrecursors of the superior information processing capabilities of our cortex can most probably be traced back to simple invertebrate systems. Using a unique set of newly developed neuronal preparations and state‐of‐the‐art analysis tools, we show that insect neurons have the ability to self‐regulate the information capacity of their electrical activity. We characterize the activity of a distinct population of neurons under progressive levels of structural and functional constraints: self‐formed networks of neuron clusters in vitro; isolated ex vivo ganglions; in vivo task‐free, and in vivotask‐forced neuronal activity in the intact animal. We show common motifs and identify trends of increasing self‐regulated complexity. This important principle may have played a key role in the gradual transition from simple neuronal motor control to complex information processing. © 2004 Wiley Periodicals, Inc. Complexity 9: 25–32, 2004
Application of signal‐adapted wavelet to on‐line partial discharge measurement
Authors: Su Jianshe , Xu Shuzhen , Chen Chen 
Published: August 2004

AbstractThis paper develops an approach for optimal selection of signal‐adapted wavelet in de‐noising. The new method employs Wu's elimination algorithm to construct compacted orthogonal wavelets. The threshold cost function is used as the objective function during choosing of the wavelet. The approach is validated by its application to de‐noising for on‐line partial discharge (PD) measurement. The physical experiments and field tests show that the method improves the suppression of noise for on‐line PD measurement with stronger robustness. Copyright © 2004 John Wiley & Sons, Ltd.
An empirical examination of the pricing of exchange‐traded barrier options
Authors: Easton Steve , Gerlach Richard , Graham Melissa , Tuyl Frank 
Published: August 2004

AbstractActively traded barrier options were introduced on the Australian Stock Exchange in 1998. This market provides a unique laboratory in which to empirically examine their pricing. This is particularly so given that, for a number of these options, otherwise identical standard European options were simultaneously traded. As a result, the pricing of barrier options may be compared both with their theoretical valuations and with the pricing of otherwise identical European options. © 2004 Wiley Periodicals, Inc. Jrl Fut Mark 24:1049–1064, 2004
Weather derivatives valuation and market price of weather risk
Authors: Cao Melanie , Wei Jason 
Published: August 2004

AbstractThis paper has two objectives: (1) to propose and implement a valuation framework for temperature derivatives (a specific class of weather derivatives); and (2) to study the significance of the market price of weather risk. The objectives are accomplished by generalizing the Lucas model of 1978 to include the weather as another fundamental source of uncertainty in the economy. Daily temperature is modeled by incorporating such key properties as seasonal cycles and uneven variations throughout the year. The temperature variable is related to the aggregate dividend or output through both contemporaneous and lagged correlations, as corroborated by the data. Numerical analysis shows that the market price of weather risk is significant for temperature derivatives. © 2004 Wiley Periodicals, Inc. Jrl Fut Mark 24:1065–1089, 2004
Hedging long‐term commodity risk: A comment
Authors: Lien Donald , Wang Yan 
Published: August 2004

AbstractY. V. Veld‐Merkoulova and F. A. de Roon (2003) adopted an encompassing model to demonstrate their linear yield assumption on the term structure of futures prices gains more empirical support than the linear price assumption proposed by A. Neuberger (1999). This comment points out the test procedure adopted is inappropriate and proposes an alternative non‐nested hypothesis testing method. Using the crude oil data, we find that the linear price assumption outperforms the linear yield assumption but is inferior to a generalized version of the linear yield assumption. © 2004 Wiley Periodicals, Inc. Jrl Fut Mark 24:1093–1099, 2004
Comparing alternative assumptions on the term structure of futures prices: Reply
Authors: De Roon Frans A. , Veld‐Merkoulova Yulia V. 
Published: August 2004

AbstractDonald Lien and Yan Wang (this issue) suggest an alternative test for different specifications of the term structure of futures prices, as used in our recently published paper in The Journal of Futures Markets. Our paper (Y. V. Veld‐Merkoulova and F. A. de Roon, 2003) focuses on developing optimal hedging strategies in case sufficiently long‐term futures contracts are not available (or not actively traded) on the exchange. One of the preliminary steps underlying this strategy was to compare linear and log‐linear term structures of futures prices in order to choose an appropriate specification. Although this is not the main issue of our paper, it is certainly important to use the correct econometric procedure in testing alternative model specifications. The results found by Lien and Wang do not contradict our conclusion that a linear term structure of futures yields is superior to a linear term structure of futures prices. However, as we point out here, the tests suggested by Lien and Wang are not without flaws. © 2004 Wiley Periodicals, Inc. Jrl Fut Mark 24:1101–1104, 2004
Downregulation of connexin 26 in human lung cancer is related to promoter methylation
Authors: Chen Yuan , Hühn Daniela , Knösel Thomas , Pacyna‐Gengelbach Manuela , Deutschmann Nicole , Petersen Iver 
Published: August 2004

AbstractCell‐Cell communication via gap junctions plays a key role in carcinogenesis and in growth control. One of the gap junction proteins, Connexin 26 (Cx26) was considered as tumor suppressor in various cancers. In our study, the expression of Cx26 was analyzed in human lung cancer. The reduced mRNA expression was observed in 17 lung cancer cell lines examined by Northern blot analysis and RT‐PCR. In 138 primary carcinomas comprising all subtypes analyzed by immunohistochemistry, 85 cases (62%) exhibited no expression of Cx26, whereas in other 53 cases the Cx26 staining was positive (38%). Additionally, an association between Cx26 protein expression and higher grading of tumors was found in whole tumor samples (p =0.028) but no statistically significant correlations could be observed with tumor stage, tumor size and node status. In squamous cell carcinoma, tumors with higher stage and grading were linked to higher expression of Cx26 (p = 0.015 and 0.017, respectively). To explore the mechanism responsible for the downregulation of Cx26, we treated 2 lung cancer cell lines H2170 and H226 with the demethylation agent 5‐aza‐2′‐deoxycytidine and found the reexpression of Cx26 mRNA. Methylation status of these 2 cell lines was further analyzed by PCR amplification of bisulfite modified DNA and sequencing. A heterogeneous methylation pattern turned out. Our results suggest the inactivation of Cx26 in lung cancer may be explained by promoter methylation.
p53 mutation profiling of multiple esophageal carcinoma using laser capture microdissection to demonstrate field carcinogenesis
Authors: Ito Shuhei , Ohga Takefumi , Saeki Hiroshi , Nakamura Toshihiko , Watanabe Masayuki , Tanaka Shinji , Kakeji Yoshihiro , Maehara Yoshihiko 
Published: August 2004

AbstractInactivation of the p53 tumor suppressor gene is one of the most frequent genetic alterations observed in human esophageal carcinomas. In patients with esophageal carcinoma, one of the significant pathological features of the tumor is the presence of multiple lesions within the esophagus. However, the molecular mechanisms involved in the occurrence of multiple lesions have remained elusive. To characterize p53 alterations in multiple esophageal carcinomas and to study their roles in carcinogenesis, we performed p53 immunohistochemical and p53 mutation analyses using laser capture microdissection on surgically resected human esophageal carcinomas from 11 patients: 9 patients with multiple esophageal carcinomas, 1 with an intramural metastasis lesion within the esophagus and 1 with an intraepithelial carcinoma lesion contiguous to the main lesion. In each of the patients with multiple esophageal carcinomas, we examined samples from 1 main lesion and 1 representative concomitant lesion. Molecular analyses of samples from fresh‐frozen normal tissues and tumor tissues of the main lesion (whole tumor) were also performed by the same method. p53 protein accumulation was observed in 16 (72.7%) of 22 lesions from the 11 cases. No p53 mutation was found in normal esophageal tissues. In the 9 cases of multiple esophageal carcinomas, point mutations were detected in the whole tumor in 1 (11.1%) case, in the microdissected tumor samples of main lesions in 3 (33.3%) cases and in the microdissected tumor samples of concomitant lesions in 3 (33.3%) cases. For the microdissected tumor samples, there was a 54.5% (12/22) concordance rate between the results of immunostaining and molecular analysis. In the 8 cases of whole tumors in which a p53 mutation was not observed, 2 cases revealed p53 mutation in the microdissected tumor samples of the main lesion. All 6 cases of multiple esophageal carcinomas that showed a p53 mutation in the microdissected tumor sample had a discordant p53 mutational status between the main and concomitant lesions. In contrast, both the intramural metastasis lesion and the intraepithelial carcinoma contiguous to the main lesion showed p53 mutational patterns identical to those of the main lesions. In conclusion, the analysis of microdissected DNA by laser capture microdissection is useful for characterizing the heterogeneity of the p53 gene mutation in multiple carcinoma lesions that cannot be accurately analyzed in whole esophageal tumor DNA. The finding of different p53 gene mutations among multiple esophageal carcinoma lesions suggest further evidence of multicentric or field carcinogenesis of the human esophagus.
HPV‐associated flat penile lesions in men of a non‐STD hospital population: Less frequent and smaller in size than in male sexual partners of women with CIN
Authors: Bleeker Maaike C.G. , Hogewoning Cornelis J.A. , Voorhorst Feja J. , van den Brule Adriaan J.C. , Berkhof Johannes , Hesselink Albertus T. , Lettink Marjolein , Starink Theo M. , Stoof Tom J. , Snijders Peter J.F. , Meijer Chris J.L.M. 
Published: August 2004

AbstractHuman papillomavirus (HPV) infections and HPV‐associated penile lesions are frequently found in male sexual partners of women with cervical intraepithelial neoplasia (CIN). To determine the significance of these findings, we studied the prevalence of HPV and HPV associated penile lesions in a male hospital population with non‐STD complaints. Penoscopy was performed after application of acetic acid to identify flat lesions, papular lesions, condylomata acuminata and pearly penile papules (PPPs). Presence of HPV DNA in penile scrapes was tested by GP5+6+ PCR. In case of HPV 16 positivity, viral loads were quantified using a LightCycler based real‐time PCR method. Comparing the non‐STD male hospital population (n = 118) with the male sexual partners of women with CIN (n = 238), flat penile lesions were found in 14% vs. 60% and penile HPV in 25% vs. 59% of the men, respectively. We found that the presence of penile HPV and, in case of HPV 16 positivity, higher viral loads were associated with the presence of flat penile lesions. Amongst the HPV‐positive men, flat penile lesions were more common and larger in size in male sexual partners of women with CIN than in the non‐STD hospital population. HPV infections and HPV‐associated flat penile lesions are commonly found in the non‐STD male population. However, these lesions are less frequently present and smaller in size than in male sexual partners of women with CIN. Higher viral loads in penile scrapes of male sexual partners of women with CIN are reflected by a higher prevalence of flat penile lesions and a larger size of these lesions.