bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ontogeny of the Shell Bones of Embryos of Podocnemis unifilis (Troschel, 1848) (Testudines, Podocnemididae)
Authors: Lima Fabiano Campos , Santos André Luiz Quagliatto , Vieira Lucélia Gonçalves , Da Silva‐Junior Luiz Martins , Romão Mariluce Ferreira , De Simone Simone Borges Salgueiro , Hirano Líria Queiroz Luz , Silva Juliana Macedo Magnino , Montelo Kennedy Mota , Malvásio Adriana 
Published: March 2011

AbstractThe aim of the present study was to investigate the sequence of shell bone formation in the embryos of the Pleurodira, Podocnemis unifilis. Their bones and cartilage were collected and cleared before staining. The shell was also examined by obtaining a series of histological slices. All the bony elements of the plastron have independent ossification centers, which subsequently join together and retain two fontanelles until the period of hatching. This turtle has a mesoplastra, which is characteristic of the Podocnemididae. The carapace begins to form concurrently with the ossification of the ribs at the beginning of stage 20. All the plates, except the suprapygal, initiate ossification during the embryonic period. The main purpose of the histological investigation was to highlight the relationship between the formation of the carapace and ribs with that of the neural plates. The costal and neural plates were found not to independent ossification centers, but to be closely related to components of the endoskeleton, originating as expansions of the perichondral collar of the ribs and the neural arches, respectively. Considering the ribs as an endoskeletal element of the carapace, the carapace and plastron begin ossification at the same stage in P. unifilis. This pattern reveals similarities with other Pleurodira, as well as evident variations, such as the presence of the seven neural bones and the presence of only one ossification center in the nuchal plate. Anat Rec, 2011. © 2011 Wiley‐Liss, Inc.
Resident perceptions of anatomy education: A survey of medical school alumni from two different anatomy curricula and multiple medical specialties
Authors: Bohl Michael A. , Gest Thomas R. 
Published: March 2011

AbstractIn 2004, the University of Michigan Medical School reduced its gross anatomy curriculum. To determine the effect of this reduction on resident perceptions of their clinical preparedness, we surveyed alumni that included residents from the original and new shortened curricula. A Likert‐scale survey was sent to four classes of alumni. Respondents were compared in old curriculum (OC) and new curriculum (NC) groups, surgical specialty (SS) and nonsurgical specialty (NS) groups, and subgroups of SS and NS were compared for differences between OC and NC. Mean response scores were compared using independent samples T‐tests. As a single population (n = 110), respondents felt their anatomy education prepared them well for residency, that a more robust anatomy curriculum would be helpful, that dissection was important to their residency preparation, and that a 4th year anatomy elective was effective in expanding their anatomy education and preparing them for residency. No significant difference existed between OC and NC groups, neither as a whole nor as SS and NS subgroups. The SS group felt dissection was more important to their residency preparation than the NS group (P = 0.001) and that a more robust anatomy curriculum would have better prepared them for residency (P = 0.001). Thirty percent of SS respondents who did not take a 4th year elective commented that they wish they had. Fourth year anatomy electives were highly valued by residents, and respondents felt that they should be offered to students as a way of revisiting anatomy following the 1st year of clinical training. Anat Sci Educ 4:126–131, 2011. © 2011 American Association of Anatomists.
Paper 4: EUROCAT statistical monitoring: Identification and investigation of ten year trends of congenital anomalies in Europe
Authors: Loane Maria , Dolk Helen , Kelly Alan , Teljeur Conor , Greenlees Ruth , Densem James ,   and a EUROCAT Working Group
Published: March 2011

AbstractBACKGROUNDAs part of EUROCAT's surveillance of congenital anomalies in Europe, a statistical monitoring system has been developed to detect recent clusters or long‐term (10 year) time trends. The purpose of this article is to describe the system for the identification and investigation of 10‐year time trends, conceived as a “screening” tool ultimately leading to the identification of trends which may be due to changing teratogenic factors.METHODSThe EUROCAT database consists of all cases of congenital anomalies including livebirths, fetal deaths from 20 weeks gestational age, and terminations of pregnancy for fetal anomaly. Monitoring of 10‐year trends is performed for each registry for each of 96 non‐independent EUROCAT congenital anomaly subgroups, while Pan‐Europe analysis combines data from all registries. The monitoring results are reviewed, prioritized according to a prioritization strategy, and communicated to registries for investigation. Twenty‐one registries covering over 4 million births, from 1999 to 2008, were included in monitoring in 2010.CONCLUSIONSSignificant increasing trends were detected for abdominal wall anomalies, gastroschisis, hypospadias, Trisomy 18 and renal dysplasia in the Pan‐Europe analysis while 68 increasing trends were identified in individual registries. A decreasing trend was detected in over one‐third of anomaly subgroups in the Pan‐Europe analysis, and 16.9% of individual registry tests. Registry preliminary investigations indicated that many trends are due to changes in data quality, ascertainment, screening, or diagnostic methods. Some trends are inevitably chance phenomena related to multiple testing, while others seem to represent real and continuing change needing further investigation and response by regional/national public health authorities. Birth Defects Research (Part A), 2011.© 2011 Wiley‐Liss, Inc.
Long‐term effect of inoculum pretreatment on fermentative hydrogen production by repeated batch cultivations: Homoacetogenesis and methanogenesis as competitors to hydrogen production
Authors: Luo Gang , Karakashev Dimitar , Xie Li , Zhou Qi , Angelidaki Irini 
Published: March 2011

AbstractLong‐term effects of inoculum pretreatments (heat, acid, loading‐shock) on hydrogen production from glucose under different temperatures (37°C, 55°C) and initial pH (7 and 5.5) were studied by repeated batch cultivations. Results obtained showed that it was necessary to investigate the long‐term effect of inoculum pretreatment on hydrogen production since pretreatments may just temporarily inhibit the hydrogen consuming processes. After long‐term cultivation, pretreated inocula did not enhance hydrogen production compared to untreated inocula under mesophilic conditions (initial pH 7 and pH 5.5) and thermophilic conditions (initial pH 7). However, pretreatment could inhibit lactate production and lead to higher hydrogen yield under thermophilic conditions at initial pH 5.5. The results further demonstrated that inoculum pretreatment could not permanently inhibit either methanogenesis or homoacetogenesis, and methanogenesis and homoacetogenesis could only be inhibited by proper control of fermentation pH and temperature. Methanogenic activity could be inhibited at pH lower than 6, both under mesophilic and thermophilic conditions, while homoacetogenic activity could only be inhibited under thermophilic condition at initial pH 5.5. Microbial community analysis showed that pretreatment did not affect the dominant bacteria. The dominant bacteria were Clostridium butyricum related organisms under mesophilic condition (initial pH 7 and 5.5), Thermoanaerobacterium sp. related organisms under thermophilic condition (initial pH 7), and Thermoanaerobacterium thermosaccharolyticum related organisms under thermophilic condition (initial pH 5.5). Results from this study clearly indicated that the long‐term effects of inoculum pretreatments on hydrogen production, methanogenesis, homoacetogenesis and dominant bacteria were dependent on fermentation temperature and pH. Biotechnol. Bioeng. 2011; 108:1816–1827. © 2011 Wiley Periodicals, Inc.
Determination of metformin and other biguanides in forensic whole blood samples by hydrophilic interaction liquid chromatography–electrospray tandem mass spectrometry
Authors: Sørensen Lambert K. 
Published: March 2011

ABSTRACTMetformin is an anti‐diabetic drug in the biguanide class which also includes phenformin and buformin. Because of the potential adverse effects of the biguanides, a reliable liquid chromatography–tandem mass spectrometry method using pneumatically assisted electrospray ionization was developed for the quantification of the drugs in both live and post‐mortem human whole blood. The blood proteins were precipitated by the addition of a mixture of methanol and acetonitrile, and the extract was cleaned up by cation‐exchange solid‐phase extraction to eliminate ion suppression effects. The separation was performed by hydrophilic interaction liquid chromatography. Matrix‐matched calibrants combined with isotope dilution of metformin were used for calibration. The detection limits were 0.01 mg/L for metformin and phenformin and the relative intra‐laboratory reproducibility standard deviations were less than 6% at concentrations of 1–10 mg/L. The mean true recoveries were greater than 86%.
Combination of microwave‐assisted micellar extraction with liquid chromatography tandem mass spectrometry for the determination of fluoroquinolone antibiotics in coastal marine sediments and sewage sludges samples
Authors: Montesdeoca‐Esponda Sarah , Sosa‐Ferrera Zoraida , Santana‐Rodríguez José Juan 
Published: March 2011

ABSTRACTIn this work, a method for the analysis of fluoroquinolone antibiotics using microwave‐assisted micellar extraction combined with liquid chromatography–mass spectrometry detection has been developed. Different surfactants were tested for use as extractants in the isolation of the analytes from solid samples, and several experimental designs were evaluated for the determination and optimization of the variables that affect recovery from the matrix. Under optimal conditions, we obtained recoveries greater than 73% with relative standard deviations below 8%. Compounds were detected by liquid chromatography–electrospray ionization tandem mass spectrometry with detection limits between 0.15 and 0.55 ng g−1 and quantification limits between 0.49 and 1.85 ng g−1. Finally, the optimized method was applied in the determination of antibiotics in real solid samples. Four fluoroquinolones (levofloxacin, norfloxacin, ciprofloxacin and enrofloxacin) were found in coastal marine sediments taken close to a marine outfall and in sewage sludge samples from a wastewater treatment plant. Concentrations ranged between 0.81 and 34.3 ng g−1 in the sediments and 3.43 and 206.1 ng g−1 in the sludge. Copyright © 2011 John Wiley & Sons, Ltd.
Unusual Transglycosylation Activity of Flavobacterium meningosepticum Endoglycosidases Enables Convergent Chemoenzymatic Synthesis of Core Fucosylated Complex N‐Glycopeptides
Authors: Huang Wei , Li Jie , Wang Lai‐Xi 
Published: March 2011

AbstractStructurally well defined, homogeneous glycopeptides and glycoproteins are indispensable tools for functional glycomics studies. By screening of various endo‐β‐N‐acetylglucosaminidases through the use of appropriate synthetic donor and acceptor substrates, we have found that the Flavobacterium meningosepticum endo‐β‐N‐acetyl‐glucosaminidases (GH family 18), including Endo‐F2 and Endo‐F3, were able to glycosylate α‐1,6‐fucosylated GlcNAc derivative to provide natural, corefucosylated complex‐type N‐glycopeptides. The Endo‐F2 and Endo‐F3 were efficient for transferring both sialylated and asialylated glycans and were highly specific for an α‐1,6‐fucosylated GlcNAc‐peptide as acceptor for transglycosylation, showing only marginal activity with non‐fucosylated GlcNAc‐peptides. In contrast, we found that the commonly used endoglycosidases such as Endo‐A and Endo‐M, which belong to GH family 85, were unable to take α‐1,6‐fucosyl‐GlcNAc derivative as acceptors for transglycosylation. The novel activity of Endo‐F2 and Endo‐F3 was successfully applied for a highly convergent chemoenzymatic synthesis of a full‐sized CD52 glycopeptide antigen carrying both terminal sialic acid and core fucose. This is the first report on endoglycosidases that are able to glycosylate α‐1,6‐fucosylated GlcNAc derivatives to form natural core‐fucosylated glycopeptides.
The Cooperative Effect in Ion‐Pair Recognition by a Ditopic Hemicryptophane Host
Authors: Perraud Olivier , Robert Vincent , Martinez Alexandre , Dutasta Jean‐Pierre 
Published: March 2011

AbstractThe heteroditopic hemicryptophane 1, which bears a tripodal anion binding site and a cation recognition site in the molecular cavity, proved to be an efficient ion‐pair receptor. The hemicryptophane host binds anions selectively depending on shape and hydrogen‐bond‐accepting ability. It forms an inclusion complex with the Me4N+ ion, which can simultaneously bind anionic species to provide anion@[1⋅Me4N+] complexes. The increased affinity of [1⋅Me4N+] for anionic species is attributed to a strong cooperative effect that arises from the properly positioned binding sites in the hemicryptophane cavity, thus allowing the formation of the contact ion pair. Density functional theory calculations were performed to analyze the Coulomb interactions of the ion pairs, which compete with the ion‐dipole ones, that originate in the ion–hemicryptophane contacts.
Switching Micellization of Pluronics in Water by CO2
Authors: Zhang Jianling , Han Buxing , Zhao Yueju , Li Jianshen , Yang Guanying 
Published: March 2011

AbstractThe micellization of amphiphilic molecules is an interesting topic from both theoretical and practical points of view. Herein we have studied the effects of compressed CO2 on the micellization of Pluronics in water by means of fluorescence, UV/Vis spectra, and small‐angle X‐ray scattering. It was found that CO2 can induce the micellization of Pluronics in water, and the micelle can return to the initial state of molecular dispersion after depressurization. Therefore, the micellization of Pluronics in water can be switched through the easy control of pressure. Different from the common micelles with hydrophobic cores, interestingly, this CO2‐induced micelle has an amphiphilic core, in which hydrophobic and hydrophilic domains coexist. On account of the ability to dissolve both polar and nonpolar components in the micellar core, the CO2‐induced micelles can improve the reagent compatibilities frequently encountered in various applications. In an attempt to address this advantage, this micelle was utilized as template to the one‐step synthesis of Au/silica core–shell composite nanoparticles. Furthermore, the underlying mechanism for the CO2‐induced micellization of Pluronics in water was investigated by a series of experiments.
Homoleptic Organometallic Anions of Ti, Zr, Hf, and Nb
Authors: El‐Kurdi Said , Seppelt Konrad 
Published: March 2011

AbstractReactions of C6H5Li and 4‐CH3C6H4Li with halides of Ti, Ir, Hf, and Nb lead to the formation of homoleptic organometallic anions of these metals. Owing to their thermal instability and their sensitivity towards H2O and O2, these compounds are characterized by single‐crystal structure determinations at low temperature, whereas other physical data could only be obtained occasionally. Three pentacoordinate complex anions [Ti(C6H5)5]−, [Ti(4‐CH3C6H4)5]−, and [Zr(C6H5)5]− have square‐pyramidal structures that display only slight deviations from the ideal geometry, in contrast to the already known structures of [Ti(CH5)5]−. The hexacoordinate complex anions [Zr(C6H5)6]2−, [Zr(4‐CH3C6H4)6]2−, [Nb(C6H5)6]2−, and [Nb(4‐CH3C6H4)6]2− all have trigonal‐prismatic structures, in accord with the known hexamethyl complex dianions. In contrast, the hexacoordinate complex anion [Hf(C6H5)6]2− has an octahedral or close to octahedral structure, in contrast to the known trigonal‐prismatic structures of [Ta(C6H5)6]− and [Ta(4‐CH3C6H4)6]−. A qualitative explanation for this structural variability is given.
Scale‐up and Detailed Process Analysis of a Membrane Assisted Esterification Reaction
Authors: Roth Tim , Hoffmann Achim , Kreis Peter , Lauterbach Sebastian 
Published: March 2011

AbstractDie Kombination zwischen Reaktion und Pervaporation am Beispiel der Veresterung zu Propylpropionat wird untersucht. Eine Validierung des Prozessmodells erfolgt mit experimentellen Untersuchungen und es wird ein Scale‐up in den Technikumsmaßstab durchgeführt. Ausgehend von einer detaillierten Prozessanalyse werden optimale Bereiche für die Betriebs‐ und Strukturvariablen festgelegt und zwei mögliche Produktaufreinigungssequenzen vorgeschlagen.
Slip flow in doubly connected ducts
Authors: Wang C. Y. 
Published: March 2011

AbstractThe slip flows in a polygonal duct with a circular core and in an eccentric annular duct are studied by eigenfunction expansion and point match. It is found that the velocity distributions are quite different from those of no‐slip flow. The resistance (Poisueille number) decreases dramatically with increased slip.On a étudié, par expansion de la fonction propre et par corrélation par points, les écoulements glissants dans une tuyère polygonale avec un cœur circulaire et dans une tuyère à anneaux excentriques. Les résultats montrent que la distribution des vitesses est différente par rapport aux écoulements non glissants. La résistance (en poiseuille) diminue considérablement avec un glissement accru. © 2011 Canadian Society for Chemical Engineering
Discovery and Biological Activity of 6BrCaQ as an Inhibitor of the Hsp90 Protein Folding Machinery
Authors: Audisio Davide , Messaoudi Samir , Cegielkowski Lukasz , Peyrat Jean‐François , Brion Jean‐Daniel , Methy‐Gonnot Délphine , Radanyi Christine , Renoir Jack‐Michel , Alami Mouâd 
Published: March 2011

AbstractHeat shock protein 90 (Hsp90) is a significant target in the development of rational cancer therapy, due to its role at the crossroads of multiple signaling pathways associated with cell proliferation and viability. Here, a novel series of Hsp90 inhibitors containing a quinolein‐2‐one scaffold was synthesized and evaluated in cell proliferation assays. Results from these structure–activity relationships studies enabled identification of the simplified 3‐aminoquinolein‐2‐one analogue 2 b (6BrCaQ), which manifests micromolar activity against a panel of cancer cell lines. The molecular signature of Hsp90 inhibition was assessed by depletion of standard known Hsp90 client proteins. Finally, processing and activation of caspases 7, 8, and 9, and the subsequent cleavage of PARP by 6BrCaQ, suggest stimulation of apoptosis through both extrinsic and intrinsic pathways.
Oxidatively Activated DNA‐Modifying Agents for Selective Cytotoxicity
Authors: Li Guorui , Bell Tiffany , Merino Edward J. 
Published: March 2011

AbstractDNA‐modifying agents are stalwarts of chemotherapeutic cancer treatments, but require significant design improvements to improve selectivity, minimize side effects, and for their widespread use to continue. Herein we present a novel design strategy in which DNA‐modifying agents contain an oxidizable leaving group and a nitrogen mustard. The agents form strong electrophiles specifically when oxidized. Activation, measured by hydrolysis, illustrates that oxidants increase reactivity 1700‐fold. Reaction in the presence of 2′‐deoxyguanosine leads to the formation of lesions. Cytotoxicity measured in HeLa cells showed that low IC50 values require an oxidizable hydroquinone and a nitrogen mustard fragment. Cytotoxicity measurements in 15 cancer cell lines demonstrates that oxidatively activated DNA‐modifying agents are highly selective, as the analogue tested has IC50 values less than 10 μM for only three of the 15 cell lines; in contrast, cisplatin is highly toxic to 13 of the 15 cell lines. The selective cytotoxicity of oxidatively activated DNA‐damaging agents could be useful against kidney cancer cells, as the 786‐O cell line model assay resulted in an IC50 value of 5 μM.
Parallel isosurface extraction for 3D data analysis workflows in distributed environments
Authors: D'Agostino D. , Clematis A. , Gianuzzi V. 
Published: March 2011

AbstractIn this paper we discuss the issues related to the development of efficient parallel implementations of the Marching Cubes algorithm, one of the most used methods for isosurface extraction, which is a fundamental operation for 3D data analysis and visualization. We present three possible parallelization strategies and we outline the pros and cons of each of them, considering isosurface extraction as stand‐alone operation or as part of a dynamic workflow. Our analysis shows that none of these implementations represents the most efficient solution for arbitrary situations. This is a major issue, because in many cases the quality of the service provided by a workflow depends on the possibility of selecting dynamically the operations to perform and, consequently, the more efficient basic building block for each stage. In this paper we present a set of guidelines that permits to achieve the highest performance for the extraction of isosurface in the most common situations, considering the characteristics of the data to process and of the workflow. These guidelines represent a suitable example to support the efficient configurations of workflows for 3D data processing in a dynamic and complex computing environment. Copyright © 2011 John Wiley & Sons, Ltd.
Detailed Characterization of the Dynamics of Ibuprofen in the Solid State by a Multi‐Technique NMR Approach
Authors: Carignani Elisa , Borsacchi Silvia , Geppi Marco 
Published: March 2011

AbstractThe internal rotations and interconformational jumps of ibuprofen in the solid state are fully characterized by the simultaneous analysis of a variety of low‐ and high‐resolution NMR experiments for the measurement of several 13C and 1H spectral and relaxation properties, performed at different temperatures and, in some cases, frequencies. The results are first qualitatively analyzed to identify the motions of the different molecular fragments and to assign them to specific frequency ranges (slow, <103 Hz; intermediate, 103–106 Hz; and fast, >106 Hz). In a second step, a simultaneous fit of the experimental data sets most sensitive to each frequency range is performed by means of suitable motional models to obtain, for each motion, values of correlation times and activation energies. The rotations of the three methyl groups around their ternary symmetry axes, which occur in the fast regime, are characterized by slightly different activation energies. Thanks to the simultaneous analysis of 1H and 13C data, the π‐flip of the dimeric structure made by the acidic groups is also identified and seen to occur in the fast regime. On the contrary, the π‐flip of the phenyl ring is found to occur in the slow motional regime, while the rotations of the isobutyl and propionic groups are frozen. The approach used appears to be of general applicability for studying the dynamics of small organic molecules.