bluuebunny/crossref_metadata_2025 huggingface dataset:
Análisis microscópico de la industria lítica: la traceología.
Authors: Martín Lerma Ignacio
Published: April 2015

El objetivo de este trabajo es divulgar el protocolo habitual de la Traceología, abordando cuestiones metodológicas y algunas aplicaciones realizadas, hasta el momento, en diversos yacimientos arqueológicos.

The aim of this work is to communicate and popularize the usual protocol in Traceology, while discussing on methodological issues and on some practical applications which have been essayed in several sites up-to-date.
Deception Reality: Street Magic from Blaine to Dynamo
Authors: Sexton Max
Published: April 2015

Television has, throughout its history, used a mode that was founded on liveness as an assertion of its ability to relay an untransformed event. This essay explores the tension between the unmediated ‘reality’ suggested by the television reality show, and the deception of ‘street magic’, popularised by the American David Blaine and the British magician, Dynamo. This tension can be understood as a sign of the intermediate space between fact and fiction, and, in turn, the parataxis of live and mediated forms within television.
Unravelling a can of worms
Authors: Sánchez Alvarado Alejandro
Published: April 2015

Understanding the evolutionary relationships between species could help researchers select better model organisms to study in the laboratory.
Effects of northern and southern components of the East Asian winter monsoon variability on SST changes in the western North Pacific
Authors: Chen Zhang , Wu Renguang , Chen Wen
Published: April 2015

The present study investigates the impacts of the two components of the East Asian winter monsoon (EAWM) variability on sea surface temperature (SST) changes in the western North Pacific. When the EAWM is stronger than normal, significant negative SST anomalies form in the East Asian marginal seas and subtropical western North Pacific and persist from winter to the following spring. It is found that winter‐spring SST anomalies in the Yellow Sea and the Japan Sea have a close association with the northern component of the EAWM variability, whereas the southern component has a large impact on SST changes in subtropical western North Pacific. The two components induce SST anomalies through both surface heat flux and oceanic advection changes. The surface latent heat flux is predominantly responsible for SST changes. The oceanic advection has a secondary contribution to the SST change in subtropical western North Pacific associated with the northern component and in the Japan Sea associated with the southern component. The surface latent heat flux anomalies associated with the northern component are induced through changes in both wind speed and sea‐air humidity difference, and those associated with the southern component are induced mainly through changes in sea‐air humidity difference north of 20°N. The SST anomalies induced by the northern component are mostly independent of El Niño–Southern Oscillation (ENSO). While ENSO has a large effect on the SST anomalies in open oceanic regions, the southern component has a dominant contribution independent of ENSO to the SST anomalies in the marginal seas.
Contraception
Authors: Aengst Jennifer C.
Published: April 2015

Contraception—the devices and techniques used to prevent pregnancy—has broad social significance in the shaping of attitudes toward fertility, sexual responsibility, and women's health. While many methods of contraception are available, method effectiveness varies and can depend on correct and consistent use. Economic factors and social concerns are additional factors that influence contraceptive decision making. Though knowledge and use of contraception are prevalent, there are notable disparities between the privileged and the marginalized. Despite having a long history, contraception remains controversial, with religious and political opposition centering on issues of availability, safety, and sexual norms.
Craft specialization
Authors: Costin Cathy Lynne
Published: April 2015

A gendered division of labor in craft production is found in virtually all human societies. Rarely do women and men perform the same tasks and produce the same goods in any given culture. However, there is no universal pattern or structure to the assignment of specific tasks to females or males among cultures; therefore, societies need to be studied individually in order to identify and explain the unique combinations of task allocation we find. Archaeologists use analyses of ethnography, mortuary remains (both bioarchaeological and grave goods), textual data, and visual representations to reconstruct ancient gendered divisions of labor.
Dominatrix
Authors: Prior Emily E.
Published: April 2015

The Dominatrix, also known as a Pro‐Domme, Professional Domme, Domina, and Femme Domme, is an iconic figure in mainstream film and television, as well as in pornography and erotica. Even the femme fatale of
film noir
has similar qualities of a woman in charge of her sexuality, and the men around her. Dressed in a leather or latex catsuit and wielding a whip, the Dominatrix is a strong, sexy figure who takes control of those around her, usually for her own enjoyment and amusement.
Drag queens
Authors: Tyler Carole‐Anne
Published: April 2015

Drag queens are gay men who cross‐dress as women, who may adopt a feminine voice and mannerisms, with various effects: glamorous, burlesque, or—when in combination with signs of masculinity—gender queer or androgynous. They may engage in professional impersonation, imitating or parodying stars whose personas are associated with female sexuality, power, or tragedy. Drag has a long theatrical history, since many cultures have prohibited women on the professional stage, and boys or men have played female parts, as has been the case in all‐male organizations too. Drag has been key for the gay community from the community's birth in the early modern period, even if some shows have catered to straight audiences. The politics of drag have been much debated. It has been both praised and critiqued for imitating or parodying feminine norms. More recently, it has been claimed as the very mechanism of the social construction of gender, which it exposes and denaturalizes.
Erection
Authors: Hall Timothy M.
Published: April 2015

Erection, or penile erection, is the physiological process whereby a male's penis becomes larger, firmer, and engorged with blood. It is necessary for intromission. Erectile dysfunction (ED) has both psychological and physiological potential causes. Its treatment is a significant focus of traditional healing systems and a lucrative pharmaceutical market involving PDE5 inhibitors in allopathic medicine. Peyronie's disease is an abnormal curvature of the penis which interferes with erection. Priapism is a sustained, sometimes painful erection lasting more than four hours, which can cause permanent damage to sexual function.
Fertility and fecundity
Authors: Shenk Mary K.
Published: April 2015

Fertility is the number of children born to a woman, while fecundity is her physiological potential to bear children. Fertility is often used as measure of fitness, and fecundity is related to reproductive value. Key topics in the study of fertility include
natural fertility
societies in which no conscious efforts are made to limit fertility, understanding the
demographic transition
in which mortality and fertility have declined globally in the last 200 years, and the study of reproductive physiology or variation in fecundity. Demographers generally focus on the proximate determinants of fertility, with the goal of calculating and/or forecasting population size and fertility rates. In contrast, economics and evolutionary demography study fertility from a theoretical perspective with the goal of generating and testing hypotheses about fertility patterns, drawn, respectively, from rational choice theory and life history theory.
Flo family (chimpanzee)
Authors: Goodall Jane , Pusey Anne
Published: April 2015

Observations of female chimpanzee Flo and her family in Gombe National Park, Tanzania, provided the first information on chimpanzee sexuality across the lifespan in the wild. Like other female chimpanzees, Flo continued to breed into old age and was immensely popular with males during her sexual swellings. All the young and adult males except her sons mated with her repeatedly, while infant daughter Fifi, like other infants, “interfered” by hurling herself at the mating male and pushing him. Flo's daughter and granddaughters avoided inbreeding with their maternal brothers, and one avoided the mating attempts of her father. Young males start mating attempts by their third year, but stop mating with their mothers before adolescence. Flo family members formed enduring family bonds, supporting each other against non‐family members. Most of the males attained alpha status. The females exhibited high dominance rank, short inter‐birth intervals, and exceptional reproductive success.
Fluctuating asymmetry
Authors: Grammer Karl , Pflüger Lena S.
Published: April 2015

Fluctuating asymmetry is one of three biological asymmetries that occur within bilateral structures. Unlike other types of asymmetry it is unlikely to be adaptive but rather reflects the inability of an organism to undergo stable development under a range of environmental conditions. The role of fluctuating asymmetry in human mate choice is emphasized by means of studies on physical attractiveness.
Foot‐binding
Authors: Yen‐Wei Miao
Published: April 2015

The millennium‐long practice of foot‐binding in traditional China embodied various positive cultural values, such as beauty, femininity, sexuality, morality, higher social status, and Han ethnicity. Infused with these positive meanings, the practice of foot‐binding, in spite of its obvious pain and cruelty, became increasingly popular before the mid‐nineteenth century. The practice declined during the Republican era.
Gay men's communities
Authors: Whittier David
Published: April 2015

Gay men's communities, social networks, and strategic action fields consider the interconnectivity of gay men. These concepts are discussed. Overall the concern is to describe how gay men coalesce, engage in concerted action, and experience categorical oppression. We can realistically speak of separate, somewhat overlapping, communities of gay men or gay men's communities encompassing territory (the gay ghettos of Wilton Manors and the Castro for example), ethnic‐like enclaves, friendship groups, institutions, social venues, fictive kin‐like relations, value or even interest, imagined, symbolic, referential, or aspiration groups, and so forth. Clearly, in late modernity there is nothing like a “total” community of gay men. There have been and in some cases today are gay men's communities of mollies, S&M, leather, drag, clones, house ball scenes (or communities), political and voluntary groups, party, sport and recreational, sexual scenes and networks, “bears,” social scenes (both commercial and noncommercial), gendered, raced, medicalized, capitalized, activist, resistant, marketed to, subaltern, secretive, professional associations (and professional groups permeated by same‐sex sexually interested and active men), Radical Faeries, queers, Act Up‐ers, Internet‐ and electronic‐based networks, groups, venues or communities, and so on. There clearly are, however, subgroups or social networks of gay men. Social movements’ analysis has some utility herese (Adam 1987). Field theory also appears to have the potential to assist with our understanding of the aggregated lives of gay men; that is, if we are interested in the birth, ebb, flow, impacts, outcomes, and possible death(s) of these gay communities, social networks or fields of culture, structure and action.
Gräfenberg, Ernst (1881–1957)
Authors: Jannini Emmanuele A.
Published: April 2015

Ernst Gräfenberg (1881–1957) was a German gynecologist who theorized mechanisms of metastasis in cancer, developed an efficient contraceptive, identified the role of the urethra in female orgasm, and hypothesized that female ejaculatory fluid was different from urine. The G spot positioned within the anterior vaginal wall has been named after him as a result of his work.
Hair removal
Authors: Fahs Breanne
Published: April 2015

Though hair removal practices vary in meaning and symbolism throughout the world, hair removal for Euro‐American women often symbolizes powerlessness and women's lower social status. Studies find that over 90 percent of Euro‐American women routinely remove their body hair, while far fewer men routinely remove body hair. As a pervasive social norm in many Euro‐American cultures, women remove their body hair for many reasons: achieving femininity, feeling attractive, confirming to pressures, or emphasizing one's less‐than‐fully‐adult status. For men, hair removal carries less significance than other elements of body image such as penis size and muscularity, though men's hair removal is far more pervasive outside Euro‐American cultures (e.g., Muslim cultures).
Hymen reconstruction
Authors: Essén Birgitta
Published: April 2015

Hymenal anatomy and vaginal bleeding are not secure indicators of past sexual intercourse. Since the state of the hymen has little to say about sexual activities, and surgical procedures intended to “restore virginity” are not based on evidence, hymenoplasty is a questionable medical solution to a cultural issue.
Synthesis, Structure, and Properties of Core‐modified Pentaphyrins Containing Six meso Carbons
Authors: Ganapathi Emandi , Chatterjee Tamal , Lee Way‐Zen , Ravikanth Mangalampalli
Published: April 2015

Our successful synthesis of nonaromatic 24π core‐modified pentaphyrins containing six meso carbons is reported. The pentaphyrins were prepared by [3+2] condensation of butane‐2,3‐diyl‐bisthiophene‐2,5‐diyl‐bis(p‐methoxyphenylmethanol) with different meso‐aryl tripyrromethanes under mild acid‐catalyzed conditions. By using this method, we obtained two stable, core‐modified pentaphyrins containing six meso carbons in acceptable yields. The pentaphyrins were characterized by HR‐MS, 1D, 2D NMR, absorption and electrochemical techniques, and also by X‐ray crystallography for one of the pentaphyrin macrocycles. The crystal structure revealed that the macrocycle is almost planar and one of the thiophene rings, which is positioned opposite to the ethene bridged meso‐carbons, is inverted. Our studies revealed that the macrocycles in their protonated form have specific sensing ability for CH3COO− ions.
Process improvement for fermentation coupling with foam separation: a convenient strategy for cell recycle
Authors: Zhang Da , Dong Kai , Xu Dandan , Zheng Huijie , Wu Zhaoliang , Xu Xin
Published: April 2015

Applications of fermentation coupling with foam separation technology show great advantages in many natural biosurfactants fermentation such as nisin, surfactin, and polymyxin E. However, only a few reports focus on process improvement, i.e. cells overflowing with foam. Because the cells also have hydrophobicity, it will overflow during foam separation, which decrease the productivity and contaminate the environment. Therefore, it is important to prevent cell from overflowing. In this study, a new approach was proposed to increase yield, using fermentation coupling with foam separation technology. Meanwhile, we tried to prevent cell from overflowing. This strategy was characterized by enrichment, recovery percentage, and inactivity percentage for product and cells. The results indicated pH was the most important factor in foam separation of polymyxin E. The optimal condition for fermentation coupling with foam separation was determined. The maximum total titer of polymyxin E reached 917 932.31 U (1147.4 U/mL) using coupling strategy that was 1.36 times more than total titer in shaken‐flask culture. Additionally, the adsorption mechanism for polymyxin E and cells was studied. The results indicated polymyxin E were mainly adsorbed on bubble, while the cells were partly in liquid form and partly adsorbed on undesired protein. Undesired protein can be considered as a stabilizer in foam separation of polymyxin E. Copyright © 2015 Curtin University of Technology and John Wiley & Sons, Ltd.
Kinetics and crystallization in pH‐sensitive free‐radical crosslinking polymerization of acrylic acid
Authors: Kim Byungsoo , Hong Daesun , Chang Wenji V.
Published: April 2015

Free‐radical crosslinking polymerization and crystallization of acrylic acid (AAc) were investigated by shear storage modulus (G′) measurements in pH 2, as well as in pH 6 and pH 10, by varying the molar ratio of crosslinking agent (N,N′‐methylene bis‐acrylamide; MBAAm) to AAc (0.583 × 10−3, 1.169 × 10−3, 1.753 × 10−3, and 2.338 × 10−3). Our results showed that the pre‐gelation time was the same at pH 2, regardless of the concentration of MBAAm. The propagation time was determined by the initial feed concentration of AAc, and the length of the linear curve in the propagation was proportional to the concentration of MBAAm. The Avrami exponent (n), as an indicative of growing pattern of an infinite molecule, in the crystallization was increased in proportional to the concentration of MBAAm, and generally low at pH 2. In the deceleration phase, n was observed near 1.0 throughout the all specimens. These results indicated that (1) the length of the pre‐gelation period was determined by the ionization of AAc (or pH), (2) the polymerization rate of AAc was not affected by the concentration of MBAAm, and (3) the inhomogeneity of hydrogel was determined by the growing pattern of infinite molecule in propagation phase. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42195.
Biosynthesis of Sesterterpenes, Head‐to‐Tail Triterpenes, and Sesquarterpenes in Bacillus clausii: Identification of Multifunctional Enzymes and Analysis of Isoprenoid Metabolites
Authors: Ueda Daijiro , Yamaga Hiroaki , Murakami Mizuki , Totsuka Yusuke , Shinada Tetsuro , Sato Tsutomu
Published: April 2015

We performed functional analysis of recombinant enzymes and analysis of isoprenoid metabolites in Bacillus clausii to gain insights into the biosynthesis of rare terpenoid groups of sesterterpenes, head‐to‐tail triterpenes, and sesquarterpenes. We have identified an (all‐E)‐isoprenyl diphosphate synthase (E‐IDS) homologue as a trifunctional geranylfarnesyl diphosphate (GFPP)/hexaprenyl diphosphate (HexPP)/heptaprenyl diphosphate (HepPP) synthase. In addition, we have redefined the function of a tetraprenyl‐β‐curcumene synthase homologue as that of a trifunctional sesterterpene/triterpene/sesquarterpene synthase. This study has revealed that GFPP, HexPP, and HepPP, intermediates of two isoprenoid pathways (acyclic terpenes and menaquinones), are biosynthesized by one trifunctional E‐IDS. In addition, GFPP/HexPP and HepPP are the primary substrates for the biosynthesis of acyclic terpenes and menaquinone‐7, respectively.
Postsynthetic Metal and Ligand Exchange in MFU‐4l: A Screening Approach toward Functional Metal–Organic Frameworks Comprising Single‐Site Active Centers
Authors: Denysenko Dmytro , Jelic Jelena , Reuter Karsten , Volkmer Dirk
Published: April 2015

The isomorphous partial substitution of Zn2+ ions in the secondary building unit (SBU) of MFU‐4l leads to frameworks with the general formula [MxZn(5–x)Cl4(BTDD)3], in which x≈2, M=MnII, FeII, CoII, NiII, or CuII, and BTDD=bis(1,2,3‐triazolato‐[4,5‐b],[4′,5′‐i])dibenzo‐[1,4]‐dioxin. Subsequent exchange of chloride ligands by nitrite, nitrate, triflate, azide, isocyanate, formate, acetate, or fluoride leads to a variety of MFU‐4l derivatives, which have been characterized by using XRPD, EDX, IR, UV/Vis‐NIR, TGA, and gas sorption measurements. Several MFU‐4l derivatives show high catalytic activity in a liquid‐phase oxidation of ethylbenzene to acetophenone with air under mild conditions, among which Co‐ and Cu derivatives with chloride side‐ligands are the most active catalysts. Upon thermal treatment, several side‐ligands can be transformed selectively into reactive intermediates without destroying the framework. Thus, at 300 °C, CoII‐azide units in the SBU of Co‐MFU‐4l are converted into CoII‐isocyanate under continuous CO gas flow, involving the formation of a nitrene intermediate. The reaction of CuII‐fluoride units with H2 at 240 °C leads to CuI and proceeds through the heterolytic cleavage of the H2 molecule.
Non‐Invasive Salivary Electrochemical Quantification of Paraquat Poisoning Using Boron Doped Diamond Electrode
Authors: Selva Thiago Matheus Guimarães , Reis de Araujo William , Cesar da Paixão Thiago Regis Longo
Published: April 2015

The present work describes the first electrochemical method for quantifying paraquat herbicide poisoning in human saliva samples. Paraquat shows two couples of well‐defined peaks in aqueous solution using a boron doped diamond (BDD) electrode. By using square wave voltammetry (SWV) technique under optimum experimental conditions, a linear analytical curve was obtained for paraquat concentrations ranging from 0.800 to 167 µmol L−1, with a detection limit of 70 nmol L−1. This method was applied to quantify paraquat spikes in human saliva samples and in two different water samples (tap and river). The recovery values obtained ranged from 83.0 to 104 % and 99.1 to 105 %, respectively, which highlight the accuracy of the proposed method.
Polyion‐Sensitive Polymeric Membrane‐Based Pulstrode as a Potentiometric Detector in Liquid Chromatography
Authors: Wang Xuewei , Balijepalli Anant S. , Meyerhoff Mark E.
Published: April 2015

Potentiometric polyion‐sensitive polymeric membrane electrodes are capable of detecting a wide variety of polyionic macromolecules. Herein, we utilize this lack of selectivity to report the first application of this sensor technology as a detector in liquid chromatography (LC). A reversible polycation pulstrode based on tridodecylmethylammonium‐dinonylnaphthalene sulfonate doped within a polymeric membrane is employed as the LC detector. Poly‐arginines/protamine mixtures are separated by cation‐exchange/affinity chromatography on an immobilized heparin column, with eluted polycation peptide bands clearly observed via the pulstrode detector. The LC‐pulstrode system is further applied to follow the production of different polycation peptides derived from thermolysin catalyzed protamine digestion.
Polyketides and Meroterpenoids from Neosartorya glabra
Authors: Liu Wen‐Hong , Zhao Hong , Li Rong‐Qun , Zheng Hong‐Bin , Yu Qin
Published: April 2015

Two new polyketides, neosarphenols A and B (1 and 2, resp.), were isolated from Neosartorya glabra, together with six known polyketides, 3–8, and two meroterpenoids, 9 and 10. The structures of the new compounds were elucidated by comprehensive spectroscopic analysis, especially by HR‐ESI‐MS and NMR experiments. All compounds were evaluated for their cytotoxic activities against MDA‐MB‐231, MCF‐7, and PANC‐1 tumor cell lines; 1 and 6 exhibited selective and moderate cytotoxicities against PANC‐1 cell line.
Selenophen‐2‐yl‐Substituted Thiocarbonyl Ylides – at the Borderline of Dipolar and Biradical Reactivity
Authors: Mlostoń Grzegorz , Urbaniak Katarzyna , Linden Anthony , Heimgartner Heinz
Published: April 2015

The reactions of aryl (selenophen‐2‐yl) thioketones with CH2N2 occur with spontaneous elimination of N2, even at low temperature (−65°), to give regioselectively sterically crowded 4,4,5,5‐tetrasubstituted 1,3‐dithiolanes and/or a novel type of twelve‐membered dithia‐diselena heterocycles as dimers of the transient thiocarbonyl S‐methanides. The ratio of these products depends on the type of substituent located at C(4) of the phenyl ring. Whereas the formation of the 1,3‐dithiolanes corresponds to a [3+2] cycloaddition of an intermediate thiocarbonyl ylide with the starting thioketone, the twelve‐memberd ring has to be formed via dimerization of the ‘thiocarbonyl ylide’ with an extended biradical structure.
Studies on the Reactions of Thiocarbonyl S‐Methanides with Hetaryl Thioketones
Authors: Mlostoń Grzegorz , Pipiak Paulina , Linden Anthony , Heimgartner Heinz
Published: April 2015

Dihetaryl thioketones react with thiocarbonyl ylides to give 1,3‐dithiolanes in high yields. No competitive side reactions of the thiocarbonyl ylides were observed, evidencing the ‘superdipolarophilic’ character of this less‐known group of thioketones. Depending on the type of substituents present in both the thiocarbonyl ylide and the thioketone, formal [3+2] cycloadditions occur with complete regioselectivity or with formation of a mixture of both regioisomers. Regioselective formation of the sterically more crowded 1,3‐dithiolanes is explained via a mechanism involving stabilized 1,5‐biradicals. In systems with less‐efficient radical stabilization, e.g., in the case of adamantanethione S‐methanide, substantial violation of the regioselectivity was observed as a result of steric hindrance.
A Facile Synthesis of Face “D” Quinolino Annulated Benzazepinone Analogues with Its Quinoline Framework Appended To Oxadiazole, Triazole and Pyrazole Heterocycles
Authors: Kaur Navjeet , Anand Aditi , Kishore Dharma
Published: April 2015

An exceedingly facile protocol to the hetero‐annulation of face “d” of benzazepinone with quinoline nucleus has been developed. The synthesis proceeded with the formation of the key intermediate 7‐fluoro‐benzazepin‐2,5‐dione (2), which resulted from the acylation of p‐fluoroaniline with succinyl chloride followed by treatment with PPA. Compound 2 underwent a very smooth Pfitzinger reaction with isatin to furnish the acid 3, the hydrazide of which reacted rapidly with reagents indicated in Schemes  and to afford the corresponding oxadiazole, triazole, and pyrazole incorporated analogues 5, 6, 7, 8, 9, respectively, in acceptable yields.
Behavioral abnormalities are common and severe in patients with distal 22q11.2 microdeletions and microduplications
Authors: Lindgren Valerie , McRae Anne , Dineen Richard , Saulsberry Alexandria , Hoganson George , Schrift Michael
Published: April 2015

We describe six individuals with microdeletions and microduplications in the distal 22q11.2 region detected by microarray. Five of the abnormalities have breakpoints in the low‐copy repeats (LCR) in this region and one patient has an atypical rearrangement. Two of the six patients with abnormalities in the region between LCR22 D–E have hearing loss, which has previously been reported only once in association with these abnormalities. We especially note the behavioral/neuropsychiatric problems, including the severity and early onset, in patients with distal 22q11.2 rearrangements. Our patients add to the genotype–phenotype correlations which are still being generated for these chromosomal anomalies.
Impact of Preoperative ERCP on Laparoscopic Cholecystectomy: A Case‐Controlled Study with Propensity Score Matching
Authors: Ahn Keun Soo , Kim Yong Hoon , Kang Koo Jeong , Kim Tae‐Seok , Cho Kwang Bum , Kim Eun Soo
Published: April 2015

Background

Although inflammation induced by endoscopic retrograde cholangiopancreatography (ERCP) may affect laparoscopic cholecystectomy (LC), making the procedure more difficult, clinical impact of ERCP on LC is unclear. The aim of this study was to evaluate the effects of ERCP on LC and to determine appropriate time of LC after ERCP.

Methods

Six hundred twenty‐one patients who underwent LC for gallstone disease were enrolled. These patients were divided into two groups; patients with preoperative ERCP prior to LC (ERCP group) and patients who underwent LC without ERCP (non‐ERCP group). Among these patients, patients who had shown acute cholecystitis or cholangitis were excluded. To control for different demographic factors in the two groups, propensity score case matching was used at a 1:1 ratio. Finally, 142 patients were matched with 71 patients of the ERCP group and 71 patients of the non‐ERCP group. Intraoperative inflammation degree, technical difficulty, and postoperative outcome were analyzed.

Results

In the ERCP group, the degree of inflammation was severe and operations were more difficult than those of the non‐ERCP group. The operation time was longer, and rates of open conversion were higher in the ERCP group. On multivariate analysis, preoperative ERCP was significant factor for difficult operations. The difficulty of operation was not different according to the operation timing after ERCP.

Conclusion

Preoperative ERCP is a significant factor in difficult LC. Therefore, experienced surgeons should perform LC after preoperative ERCP. Since operation difficulty was similar according to the timing of cholecystectomy after ERCP, there is no reason to delay LC after ERCP.
A NOTE ON ENVIRONMENT-DEPENDENT TIME PREFERENCES
Authors: Chu Hsun , Lai Ching-chong , Liao Chih-hsing
Published: April 2015

In this paper we investigate the growth effect of environmental taxes when time preference is endogenously determined by environmental quality. We find that if people become more patient because of a cleaner environment, raising the environmental tax may reduce pollution and stimulate growth. Moreover, the Pigouvian principle may be inefficient in the presence of endogenous time preference.
Emergence of californium as the second transitional element in the actinide series
Authors: Cary Samantha K. , Vasiliu Monica , Baumbach Ryan E. , Stritzinger Jared T. , Green Thomas D. , Diefenbach Kariem , Cross Justin N. , Knappenberger Kenneth L. , Liu Guokui , Silver Mark A. , DePrince A. Eugene , Polinski Matthew J. , Van Cleve Shelley M. , House Jane H. , Kikugawa Naoki , Gallagher Andrew , Arico Alexandra A. , Dixon David A. , Albrecht-Schmitt Thomas E.
Published: April 2015

A break in periodicity occurs in the actinide series between plutonium and americium as the result of the localization of 5f electrons. The subsequent chemistry of later actinides is thought to closely parallel lanthanides in that bonding is expected to be ionic and complexation should not substantially alter the electronic structure of the metal ions. Here we demonstrate that ligation of californium(III) by a pyridine derivative results in significant deviations in the properties of the resultant complex with respect to that predicted for the free ion. We expand on this by characterizing the americium and curium analogues for comparison, and show that these pronounced effects result from a second transition in periodicity in the actinide series that occurs, in part, because of the stabilization of the divalent oxidation state. The metastability of californium(II) is responsible for many of the unusual properties of californium including the green photoluminescence.
Insights into perfluorooctane sulfonate photodegradation in a catalyst-free aqueous solution
Authors: Lyu Xian-Jin , Li Wen-Wei , Lam Paul K. S. , Yu Han-Qing
Published: April 2015

Photodegradation in the absence of externally added chemicals could be an attractive solution for the removal of perfluorooctane sulfonate (PFOS) in aqueous environment, but the low decomposition rate presents a severe challenge and the underlying mechanisms are unclear. In this study, we demonstrated that PFOS could be effectively degraded in a catalyst-free aqueous solution via a reduction route. Under appropriate pH and temperature conditions, a rapid PFOS photodegradation, with a pseudo-first-order decomposition rate constant of 0.91 h−1, was achieved. In addition, hydrated electrons were considered to be the major photo-generated reductive species responsible for PFOS photodegradation in this system. Its production and reduction ability could be significantly affected by the environmental conditions such as pH, temperature and presence of oxidative species. This study gives insights into the PFOS photodegradation process and may provide useful information for developing catalyst-free photodegradation systems for decomposing PFOS and other persistent water contaminants.
Enzymatically generated long polyT-templated copper nanoparticles for versatile biosensing assay of DNA-related enzyme activity
Authors: Peng Feifei , Liu Zhuoliang , Li Wang , Huang Yan , Nie Zhou , Yao Shouzhuo
Published: April 2015

Terminal deoxynucleotidyl transferase-generated long poly(thymine) DNA can be used as an efficient template to synthesize fluorescent copper nanoparticles, providing a versatile method for detecting various enzymes with low background noise and high sensitivity.
Investigation of thermal evolution of copper nanoclusters encapsulated in carbon nanotubes: a molecular dynamics study
Authors: Akbarzadeh Hamed , Abbaspour Mohsen , Salemi Sirous , Abroodi Mousareza
Published: April 2015

We have simulated the heating and cooling processes of CuN nanoclusters encapsulated in CNTs with different diameters and chiralities.
The effects of thermal and electric fields on the electronic structures of silicene
Authors: Lian Chao , Ni Jun
Published: April 2015

We have investigated the effects of thermal and electric fields on the electronic properties of silicene.
Synthesis of mixed-valence hexanuclear Mn(ii/iii) clusters from its Mn(ii) precursor: variations of catecholase-like activity and magnetic coupling
Authors: Kar Paramita , Ida Yumi , Kanetomo Takuya , Drew Michael G. B. , Ishida Takayuki , Ghosh Ashutosh
Published: April 2015

A pyrazine bridged 1D coordination polymer of Mn(ii) has been oxidized with n-Bu4NMnO4 to hexanuclear Mn(ii/iii) complexes. Their catecholase-like activities and magnetic interactions have been studied.
Polyacrylonitrile/lignin sulfonate blend fiber for low-cost carbon fiber
Authors: Dong Xiaozhong , Lu Chunxiang , Zhou Pucha , Zhang Shouchun , Wang Liyong , Li Denghua
Published: April 2015

Polyacrylonitrile/lignin sulfonate blend fiber spun via wet spinning process could be stabilized rapidly, and thus suitable to produce a low-cost carbon fiber.
Electrically conductive polymers and composites for biomedical applications
Authors: Kaur Gagan , Adhikari Raju , Cass Peter , Bown Mark , Gunatillake Pathiraja
Published: April 2015

This paper provides a review of the recent advances made in the field of electroactive polymers and composites for biomedical applications.
Metallo-supramolecular grid-type architectures for highly and selectively efficient adsorption of dyes in water
Authors: Qin Xiaoting , Zhang Guonan , Gao Yanfei , Liu Houting , Du Chunfang , Liu Zhiliang
Published: April 2015

This work reports fascinating MOFs which can efficiently and selectively adsorb organic dye methyl orange (MO) and develop a new class of materials for the adsorption of dyes in water.
Synthesis of a flower-like CuS/ZnS nanocomposite decorated on reduced graphene oxide and its photocatalytic performance
Authors: Guan Xiao-Hui , Yang Liu , Guan Xin , Wang Guang-Sheng
Published: April 2015

CZS/rGO composites with enhanced photocatalytic activity have been synthesized. The results demonstrate that the CZS/rGO composites have enormous potential for photodegradation of organic pollutants. The enhanced mechanism was also explained.
Ceric ammonium nitrate (CAN): an efficient and eco-friendly catalyst for the one-pot synthesis of alkyl/aryl/heteroaryl-substituted bis(6-aminouracil-5-yl)methanes at room temperature
Authors: Brahmachari Goutam , Banerjee Bubun
Published: April 2015

Ceric ammonium nitrate (CAN)-catalyzed one-pot synthesis of alkyl/aryl/heteroaryl-substituted bis(6-aminouracil-5-yl)methane scaffolds (3a–3u) has been developedviaapseudothree-component reaction in aqueous ethanol at room temperature.
An effective dipping method for coating activated carbon catalyst on the cathode electrodes of microbial fuel cells
Authors: Ge Zheng , He Zhen
Published: April 2015

A dipping method is developed to coat activated carbon catalysts for microbial fuel cells with better control of distribution and loading.
Novel visible-light sensitive vanadate photocatalysts for water oxidation: implications from density functional theory calculations
Authors: Li Peng , Umezawa Naoto , Abe Hideki , Ye Jinhua
Published: April 2015

New vanadate photocatalysts, Ag2Sr(VO3)4 and Sr(VO3)2, are theoretically designed for water oxidation reactions. The calculations have shown that the new photocatalysts possess desirable electronic structures. Our experiments demonstrated that these vanadates efficiently oxidize water to O2 under irradiation of visible light.
Au nanoparticle-coated, PLGA-based hybrid capsules for combined ultrasound imaging and HIFU therapy
Authors: Xi Juqun , Qian Xiaodong , Qian Kehong , Zhang Wanying , He Wen , Chen Yan , Han Jie , Zhang YuZhen , Yang XiangJun , Fan Lei
Published: April 2015

A simple method to prepare AuNPs@PDA/PLGA hybrid capsules for combined ultrasound imaging and HIFU therapy was presented.
Energy‐optimal base station density considering traffic dynamics
Authors: Chen Zheng , Qiu Ling , Liang Xiaowen
Published: April 2015

Optimal base station (BS) density, to minimise network energy consumption, is studied. Contrary to previous works, both the spatial randomness of the network topology and the wireless traffic dynamics are taken into consideration. With the technology of cell discontinuous transmission, network energy consumption depends on the average transmission probability of BSs. On the basis of stochastic geometry, it is found that the BS transmission probability and BS density satisfy a nonlinear equation. To reduce overall energy consumption, an iteration algorithm that can converge to the global optimal BS density is proposed.
Reconstructing the feedback polynomial of a linear scrambler with the method of hypothesis testing
Authors: WenJia He
Published: April 2015

Blind identification of the feedback polynomial in a linear scrambler is an important component in the wireless communication systems which have the function of automatic standard recognition and parameter estimation. The following research contains three parts. In the first part, promotion model is deduced based on Cluzeau's model. Comparative analysis shows the advantage of computational complexity by use of the promotion model. In the second part, the improved method of estimation for the normalised standard deviation is proposed, which plays an important role for the computation time and precision. In the final part, simulation results explain the better practical application of my algorithm compared with Cluzeau's algorithm and XiaoBei‐Liu's algorithm.
Energy‐efficient packet transmission with unidirectional‐valve scheduling
Authors: Liu Siping , Zhang Changming , Liu Xiaoxin , Zhou Yuezhi , Zhang Yaoxue
Published: April 2015

This study proposes a unidirectional‐valve (UDV) algorithm for energy‐efficient transmission, where the packets arrived at different times must be transmitted before a common deadline. The UDV algorithm divides the total transmission time into a series of segments. For a newly arrived packet, it is regarded as a new segment and its rate is compared with that of the former adjacent one, then the two segments are combined into one if the new segment has a lower or an equal rate. The comparison and combination are alternately performed until the rate on the whole actually becomes non‐decreasing. In the offline case that the sizes and arrival times of all packets are learned at the beginning, it has been demonstrated that the UDV scheduling achieves the optimal energy‐efficient transmission; while in the online case that only the mean size and mean interval of future packets are known, UDV achieves the energy efficiency approaching the optimality. In addition, the proposed UDV scheduling has a low computational complexity, and thus can be readily implemented in the system.
Improved finite‐length Luby‐transform codes in the binary erasure channel
Authors: Hayajneh Khaled F. , Yousefi Shahram , Valipour Mehrdad
Published: April 2015

Fountain codes were introduced to provide high reliability and scalability and low complexities for networks such as the Internet. Luby‐transform (LT) codes, which are the first realisation of Fountain codes, achieve the capacity of the binary erasure channel (BEC) asymptotically and universally. Most previous work on single‐layer Fountain coding targets the design via the right degree distribution. The left degree distribution of an LT code is left as a Poisson to protect the universality. For finite lengths, this is no longer an issue; thus, the author's focus is on designing better codes for the BEC at practical lengths. Their left degree shaping provides codes outperforming LT codes and all other competing schemes in the literature. At a bit error rate of 10−7 and packet length k = 256, their scheme provides a realised rate of 0.6 which is 23.5% higher than that of Sorensen et al.’s decreasing‐ripple‐size scheme.
Energy‐efficient joint routing and power allocation optimisation in bit error rate constrained multihop wireless networks
Authors: Gupta Sabyasachi , Bose Ranjan
Published: April 2015

Energy efficiency is a crucial design issue in energy‐constrained wireless networks to ensure uninterrupted information exchange. With the requirement of average end‐to‐end bit error rate (BER), the problem of joint routing and power allocation optimisation in multihop wireless network is studied here for two network power management policies: one is to minimise overall transmit power and the other is to maximise network lifetime. The proposed minimum total power strategy is optimal for minimising the overall transmit power consumption in the network and is preferable in network with tethered energy resources. To maximise the lifetime of a network with battery‐operated nodes, the authors have developed two residual energy‐aware joint routing and power allocation strategies: path lifetime maximisation (PLM) strategy and minimum weighted total power (MWTP) strategy. A distributed implementation for these strategies is also presented. Simulation results demonstrate that the proposed strategies achieve significant power saving and prolong network lifetime considerably over traditional routing algorithm with individual link BER constraint. It has also been shown that at reasonably low route refresh interval, the MWTP strategy performs best in terms of network lifetime, whereas at very high route refresh interval, the PLM strategy is optimal for network lifetime maximisation.
Spread spectrum high performance techniques for a long haul high frequency link
Authors: Alsina‐Pagès Rosa Maria , Salvador Martí , Hervás Marcos , Bergadà Pau , Pijoan Joan Lluís , Badia David
Published: April 2015

Skywave ionospheric communication systems offer a good choice to satellite communications when transmitting from the poles. For the last 10 years the authors have been sounding and testing modulations through a 12 700 km high frequency link from the Spanish Antarctic Station to Spain. Previous tests comparing direct sequence spread spectrum (DS‐SS) and orthogonal frequency division multiplexing (OFDM) showed that spread spectrum bit rate error (BER) results outperformed OFDM at the expense of lower bit rates. In this study the authors present three spread spectrum techniques for this long haul link that increase the bit rate and the spectral efficiency of the direct sequence while keeping the good BER performance obtained. Tests have been performed with several symbol periods as well as different bandwidth for each technique, hence the authors can conclude which combination best suits this channel.
Differential successive relaying scheme for fast and reliable data delivery in vehicular ad hoc networks
Authors: Ren Chao , Chen Jian , Kuo Yonghong , Yang Long
Published: April 2015

The high‐speed mobility of modern transportation worsens the situation of unstable direct links and imprecise channel estimation, which poses challenges on fast and reliable data delivery in vehicular ad hoc networks (VANETs). The goal of the proposed scheme is to provide high‐speed full‐duplex relaying connectivity for unstable direct links, and reliable information detection without precise channel state information (CSI) in VANETs. In the proposed scheme, full‐duplex relaying connectivity is provided by differential successive relays (DSRs) at roadside or inside other vehicles. To improve robustness of DSR without specific CSI, efficient blind interference cancellation is presented to mitigate inter‐relay interference. Meanwhile, reliable information detection without precise CSI is enabled by superposition coding with differential modulation. Furthermore, the advantages, applications of DSR and complexities for real‐world implementation are discussed, and the decision rule, bit error probability and ergodic capacity are theoretically obtained. Numerical results verify significant improvements in the performance of the proposed scheme when compared with conventional schemes with half‐duplex relays and frequent channel estimation in VANETs.
Sparsity‐aware, channel order‐blind pilot placement with channel estimation in orthogonal frequency division multiplexing systems
Authors: Peng Xiaoqing , Wu Weimin , Sun Jun , Liu Yingzhuang , Li Frank Yong
Published: April 2015

Equispaced pilot arrangement is the most popular scheme for pilot‐aided transmission in orthogonal frequency division multiplexing systems. In this study, the authors argue that a non‐equispaced pilot pattern may outperform its equispaced counterpart, if they fully take into account the sparsity of the channel impulse response which is inherent in wireless channels. More specifically, a sparsity‐aware pilot arrangement scheme based on the coherence criterion is investigated in this study. To address the resulting non‐deterministic polynomial (NP)‐hard combinatorial optimisation problem, they propose an efficient local search algorithm. For channel estimation, they convert it to a sparse recovery problem. To enhance the applicability of the authors scheme, that is, when there is no prior knowledge about the channel order, they propose to employ the Bayesian information criterion to estimate the channel order first and then recover the sparse channel vector via existing low‐complexity methods, for example, orthogonal matching pursuit. By combining the above pilot arrangement scheme with channel estimation, their scheme exhibits substantially better performance in comparison with the conventional equispaced schemes with linear (or spline) interpolation, in terms of total number of pilot symbols and bit error rate.
Economic evaluation of maintenance strategies for wind turbines: a stochastic analysis
Authors: Kerres Bertrand , Fischer Katharina , Madlener Reinhard
Published: April 2015

The authors develop a stochastic model for assessing the life‐cycle cost and availability of wind turbines resulting from different maintenance scenarios, with the objective to identify the most cost‐effective maintenance strategy. Using field‐data‐based reliability models, the wind turbine – in terms of reliability – is modelled as a serial connection of the most critical components. Both direct cost for spare parts, labour and access to the turbine, as well as indirect cost from production losses are explicitly taken into account. The model is applied to the case of a Vestas V44–600 kW wind turbine. Results of a reliability‐centred maintenance analysis of this wind turbine are used to select the most critical wind turbine components and to identify possible maintenance scenarios. This study reveals that corrective maintenance is the most cost‐effective maintenance strategy for the gearbox and the generator of the V44 turbine, while the cost benefit of condition‐based maintenance using online condition‐monitoring systems increases with higher electricity price, turbine capacity and remoteness of sites.