bluuebunny/crossref_metadata_2025_split huggingface dataset:
Simultaneous determination of methylxanthines in different types of tea by a newly developed and validated TLC method
Authors: Cimpoiu Claudia , Hosu Anamaria , Seserman Liana , Sandru Mihaela , Miclaus Vasile 
Published: October 2010

AbstractThe aim of this paper is to develop a new simple, fast and economical method for simultaneous quantitative determination of methylxanthine compounds based on TLC combined with image analysis. To obtain certain results, both extraction and chromatographic separation were optimized. The optimum extraction conditions were maceration in ethanol–water 8:2, v/v. The chromatographic separations were done on the silica gel F254 TLC plates developed with chloroform–dichloromethane–isopropanol, 4:2:1 v/v/v. Detection was performed under UV lamp at 254 nm and the evaluation of the chromatographic plate was based on digital processing of chromatographic images. The developed TLC method was validated for parameters such as specificity, linearity and range, LOD and LOQ, precision, robustness and accuracy. This method was then applied for determination of caffeine, theobromine and theophylline in different types of tea, commercially available. Moreover, the content of methylxanthines detected and determined in commercial tea samples can be used as chemical marker in quality control.
An overview of matrix effects in liquid chromatography–mass spectrometry
Authors: Trufelli Helga , Palma Pierangela , Famiglini Giorgio , Cappiello Achille 
Published: October 2010

AbstractMatrix‐dependent signal suppression or enhancement represents a major drawback in quantitative analysis with liquid chromatography coupled to atmospheric pressure ionization mass spectrometry (LC–API‐MS). Because matrix effects (ME) might exert a detrimental impact on important method parameters (limit of detection, limit of quantification, linearity, accuracy, and precision), they have to be tested and evaluated during validation procedure. This review gives a detailed description on when these phenomena might be expected, and how they can be evaluated. The major sources of ME are discussed and illustrated with examples from bioanalytical, pharmaceutical, environmental, and food analysis. Because there is no universal solution for ME, the main strategies to overcome these phenomena are described in detail. Special emphasis is devoted to the sample‐preparation procedures as well as to the recent improvements on chromatographic and mass spectrometric conditions. An overview of the main calibration techniques to compensate for ME is also presented. All these solutions can be used alone or in combination to retrieve the performance of the LC–MS for a particular matrix–analyte combination. © 2010 Wiley Periodicals, Inc., Mass Spec Rev 30:491–509, 2011
Clinical application and outcome of the internal mammary artery perforator (IMAP) free flap for soft tissue reconstructions of the upper head and neck region in three patients
Authors: Schellekens Pascal P.A. , Hage J. Joris , Paes Emma C. , Kon Moshe 
Published: October 2010

AbstractBackground: The fasciocutaneous internal mammary artery perforator (IMAP) island flap allows for superior esthetical and functional skin cover in the head and neck region in combination with limited donor site morbidity. Its modification as a free flap allows reconstruction of more cranial defects. Patients and methods: Three IMAP free flaps varying from 7 × 4 cm2 to 10 × 6 cm2 were transplanted in three patients with a mean age of 59 years (range, 54–69 years). Enhancement of the flap's vascular pedicle at least doubles the diameter of the internal mammary vessels to be anastomosed. Results: Coverage with excellent texture and color match was uneventfully obtained and the flaps' donor sites were primarily closed in all three cases. Conclusions: Our experience proves the consistent feasibility of successful transplantation of the IMAP free flap. Because of its characteristics, we suggest contemplating the use of this flap in the upper head and neck region. © 2010 Wiley‐Liss, Inc. Microsurgery, 2010.
Estimation of Acid Dissociation Constants Using Graph Kernels
Authors: Rupp Matthias , Körner Robert , Tetko Igor V. 
Published: October 2010

AbstractThe biopharmaceutical profile of a compound depends directly on the dissociation constants of its acidic and basic groups. We estimate these constants using kernel ridge regression and graph kernels. The performance of our approach is similar to that of a semi‐empirical model (Tehan et al, QSAR & Comb. Sci. 21(5): 457–472, 473–485) based on frontier electron theory, but uses only the annotated structure graph. In particular, no structure optimization is necessary. We discuss advantages and shortcomings of our approach.
Neue Regelung zur Verordnung besonderer Arzneimittel. “Zweitmeinungsverfahren”: Sparbüchse oder Qualitätsinstrument?
Authors: Briswalter Stéphanie , Heigl Andreas 
Published: October 2010

AbstractDie Indikation der Pulmonal Arteriellen Hypertonie dient als Testlauf für die seit 1. April 2009 neu eingeführte Regelung zur Verordnung besonderer Arzneimittel (“Zweitmeinungsverfahren”). Das Ziel ist die Verbesserung der Versorgungsqualität einerseits und zugleich die Sicherstellung der Wirtschaftlichkeit andererseits. Begründet wird dies mit den stark variierenden, zum Teil hohen Jahrestherapiekosten der verschiedenen Therapiemöglichkeiten der PAH. Problematisch ist dabei die Beurteilung der Arzneimittelverordnung bezüglich Zweckmäßigkeit und Wirtschaftlichkeit, die der “Zweitmeinungsarzt” vorzunehmen hat.Die Umsetzung in der Richtlinie des Gemeinsamen Bundesausschusses deutet jedoch darauf hin, dass damit Ärzte und Patienten eher verunsichert werden und der bürokratische Aufwand höher erscheint als der potenzielle Nutzen des Verfahrens.
Modulation of color change and photocyclization of diarylethene with metal complex
Authors: Liu Huan‐Huan , Chen Yi 
Published: October 2010

AbstractModulation of color change and photocyclization of diarylethene with metal complex is described. A diarylethene derivative with 4‐(ethylideneamino) phenol group 1a is prepared and photochromic behavior is investigated. It is found that 1a exhibits ring‐opening and ring‐closing photoisomerization with UV/Vis light irradiation in solution. Addition of Cu(OAc)2 to the solution of 1a produces a metal complex 1a–Cu, which generates not only marked color change but also significant promotion in photocyclization. Copyright © 2010 John Wiley & Sons, Ltd.
Structural and property comparison between the di‐piperidinyl‐ and di‐pyrrolidinyl‐substituted perylene tetracarboxylic diimides
Authors: Feng Junqian , Wang Delou , Wang Hailong , Zhang Daopeng , Zhang Liangliang , Li Xiyou 
Published: October 2010

AbstractFour compounds 1–4 connected with cyclic amino groups at the bay positions of perylenetetracarboxylic diimide (PDI) have been prepared and the isomers with 1,7‐ and 1,6‐substituted PDIs were successfully separated by conventional column chromatography. The structures of 1,7‐dipyrrolidinyl‐substituted PDI (1) and 1,7‐dipiperidinyl‐substituted PDI (3) were further characterized by single crystal X‐ray diffraction experiments. The crystal structure revealed that the small difference in the molecular structure has caused significant difference on the absorption and emission spectra as well as the electrochemical properties. The shorter bond length of C1N3, together with the more sp2 hybrid atomic orbital characteristics of the nitrogen atom in pyrrolidine relative to those in piperidine is found to be responsible for this large property difference between 1 and 3. Copyright © 2010 John Wiley & Sons, Ltd.
Morphologies and crystalline forms of polyvinylidene fluoride membranes prepared in different diluents by thermally induced phase separation
Authors: Yang Jian , Wang Xiao‐Lin , Tian Ye , Lin Yakai , Tian Feng 
Published: October 2010

AbstractWe have studied the morphologies and crystalline forms of polyvinylidene fluoride (PVDF) membranes separately prepared in four different diluents bearing >CO groups, namely 1,2‐propylene glycol carbonate (PGC), dimethyl phthalate (DMP), diphenyl ketone (DPK), and dibutyl phthalate (DBP), by the thermally induced phase separation (TIPS) method. The permittivities of the diluents and PVDF were measured to compare the different PVDF–diluent systems. The results showed the permittivity of PGC to be much greater than that of PVDF, and those of DMP and DBP to be lower than that of PVDF. The permittivity difference between DPK and PVDF was not apparent above 120 °C. On cooling mixtures with a PVDF concentration of 10 wt %, PVDF crystallization was observed in the PVDF–DMP, PVDF–DBP, and PVDF–PGC systems, while liquid–liquid phase separation occurred in the PVDF–DPK system. A cross‐section of the PVDF–PGC membrane presented smooth PVDF particles in the β‐phase crystalline form. Those of the PVDF–DMP and PVDF–DBP membranes presented PVDF particles consisting of a fibrillar network in the α‐phase. The PVDF–DPK membrane preferentially adopted an α‐phase bicontinuous channel structure. When the concentration of PVDF was 60 wt %, the cross‐sections of the above four membranes revealed PVDF polyhedra, among which the PVDF–DMP, PVDF–DBP, and PVDF–DPK membranes retained the α‐phase crystalline form, and the diffraction peak of the α‐phase became visible in the X‐ray diffraction (XRD) spectrum of the PVDF–PGC membrane. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2010
Effects of microcrystallites on swelling behavior in chemically crosslinked poly(vinyl alcohol) gels
Authors: Otsuka Emiko , Kudo Shuhei , Sugiyama Masaaki , Suzuki Atsushi 
Published: October 2010

AbstractWe report the swelling ratio and network structure of a poly(vinyl alcohol) (PVA) gel chemically crosslinked by glutaraldehyde with different degrees of crosslinks. Microcrystallites were formed in a chemical PVA gel during a drying process and were confirmed by X‐Ray diffraction (XRD) measurements and Fourier transform infrared (FTIR) spectroscopy. The formation of microcrystallites in the dried gels was suppressed by increasing the degrees of chemical crosslinks. When the dried samples were immersed in pure water at 25 °C, the swelling ratio depended on the degree of chemical crosslinks resulting from the destruction of physical crosslinks by microcrystallites. On the other hand, when the dried samples were immersed in a poor solvent of a mixture of dimethyl sulfoxide and water at 8 °C, the gels did not swell and stayed in the collapsed state. Starting from the collapsed state, the equilibrium swelling ratios were measured while the temperature was increased to 90 °C and then decreased to 8 °C. As a result, irreversible swelling behaviors were observed for all gels with different degrees of crosslinks, which were attributed to the destruction of microcrystallites. The swelling behavior is discussed in terms of the formation and destruction of additional physical crosslinks in the chemical PVA gels. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011
Psychological outcomes of siblings of cancer survivors: a report from the Childhood Cancer Survivor Study
Authors: Buchbinder David , Casillas Jacqueline , Krull Kevin R. , Goodman Pam , Leisenring Wendy , Recklitis Christopher , Alderfer Melissa A. , Robison Leslie L. , Armstrong Gregory T. , Kunin‐Batson Alicia , Stuber Margaret , Zeltzer Lonnie K. 
Published: October 2010

AbstractObjective: To identify risk factors for adverse psychological outcomes among adult siblings of long‐term survivors of childhood cancer.Methods: Cross‐sectional, self‐report data from 3083 adult siblings (mean age 29 years, range 18–56 years) of 5 + year survivors of childhood cancer were analyzed to assess psychological outcomes as measured by the Brief Symptom Inventory‐18 (BSI‐18). Sociodemographic and health data, reported by both the siblings and their matched cancer survivors, were explored as risk factors for adverse sibling psychological outcomes through multivariable logistic regression.Results: Self‐reported symptoms of psychological distress, as measured by the global severity index of the BSI‐18, were reported by 3.8% of the sibling sample. Less than 1.5% of siblings reported elevated scores on two or more of the subscales of the BSI‐18. Risk factors for sibling depression included having a survivor brother (OR 2.22, 95% CI 1.42–3.55), and having a survivor with impaired general health (OR 2.15, 95% CI 1.18–3.78). Siblings who were younger than the survivor reported increased global psychological distress (OR 1.81, 95% CI 1.05–3.12), as did siblings of survivors reporting global psychological distress (OR 2.32, 95% CI 1.08–4.59). Siblings of sarcoma survivors reported more somatization than did siblings of leukemia survivors (OR 2.07, 95% CI 1.05–3.98).Conclusions: These findings suggest that siblings of long‐term childhood cancer survivors are psychologically healthy in general. There are, however, small subgroups of siblings at risk for long‐term psychological impairment who may benefit from preventive risk‐reduction strategies during childhood while their sibling with cancer is undergoing treatment. Copyright © 2010 John Wiley & Sons, Ltd.
Study of dyadic communication in couples managing prostate cancer: a longitudinal perspective
Authors: Song Lixin , Northouse Laurel L. , Zhang Lingling , Braun Thomas M. , Cimprich Bernadine , Ronis David L. , Mood Darlene W. 
Published: October 2010

AbstractObjective: Cancer patients and partners often report inadequate communication about illness‐related issues, although it is essential for mutual support and informal caregiving. This study examined the patterns of change in dyadic communication between patients with prostate cancer and their partners, and also determined if certain factors affected their communication over time.Method: Using multilevel modeling, this study analyzed longitudinal data obtained from a randomized clinical trial with prostate cancer patients and their partners, to examine their communication over time. Patients and partners (N=134 pairs) from the usual‐care control group independently completed baseline demographic assessment and measures of social support, uncertainty, symptom distress, and dyadic communication at baseline, and 4‐, 8‐, and 12‐month follow‐ups.Results: The results indicated that (1) patients and partners reported similar levels of open communication at the time of diagnosis. Communication reported by patients and partners decreased over time in a similar trend, regardless of phase of illness; (2) phase of illness affected couples' open communication at diagnosis but not patterns of change over time; and (3) couples' perceived communication increased as they reported more social support, less uncertainty, and fewer hormonal symptoms in patients. Couples' demographic factors and general symptoms, and patients' prostate cancer‐specific symptoms did not affect their levels of open communication.Conclusions: Perceived open communication between prostate cancer patients and partners over time is affected by certain baseline and time‐varying psychosocial and cancer‐related factors. The results provide empirical evidence that may guide the development of strategies to facilitate couples' interaction and mutual support during survivorship. Copyright © 2010 John Wiley & Sons, Ltd.
Plasma Functionalization of MWCNTs in He Followed by NH3 Treatment and its Application in PMMA Based Nanocomposites
Authors: Pourfayaz Fathollah , Khodadadi Abbas Ali , Mortazavi Yadollah , Jafari Seyed‐Hassan 
Published: October 2010

AbstractWe report treatment of multi‐walled carbon nanotubes (MWCNTs) by dielectric barrier discharge plasma followed by their exposure to NH3, which are to be used for making poly(methyl methacrylate) (PMMA) based nanocomposites. First MWCNTs were treated by He plasma and then exposed to NH3. Fourier transform infrared and Raman spectroscopy showed presence of nitrogen‐containing functional groups attached to the MWCNTs surface. Influence of the functionalized nanotubes (F‐MWCNTs) on surface electrical resistivity of the PMMA‐based nanocomposites was determined and compared with those of pristine (not functionalized) and acid‐treated MWCNTs. The results revealed that F‐MWCNTs decrease the surface electrical resistivity of the nanocomposites better than those of pristine and acid‐treated MWCNTs. This was attributed to better dispersion state of F‐MWCNTs confirmed by optical microscopy and scanning electron microscopy images. magnified image
Satellite link performance under rain and external interferences: Constraints to be imposed on the statistical behavior of the external interferences
Authors: Fortes José Mauro P. , Baptista Antonio José S. 
Published: October 2010

AbstractThis paper concerns an environment in which several communication systems share a common frequency band and, therefore, each system operates subject to the interference generated by the others. More specifically, the paper addresses the problem of establishing the limits that should be imposed on the transmitted interfering signals so that all systems sharing the band are able to operate adequately and none of them experiences harmful interferences. This is a well‐known problem for those working in the telecommunication regulation and standardization areas. Its solution requires studies and analysis that are usually complex and strongly depend on the technical characteristics of the systems involved. This paper presents a new technique that is able to determine, in a systematic way, the constraints to be imposed on the statistical behavior of the external interferences affecting a satellite link to guarantee that the link performance requirements are satisfied. The proposed technique considers the joint effect of the degradations due to rain and due to external interferences. In the method, a series expansion on the basis of orthonormal functions is used to represent the probability density function of the degradation due to external interferences and the limiting mask is obtained by solving a conveniently defined constrained optimization problem. The method is flexible enough to allow for the use of the rain attenuation models that are usually employed in link calculations. Two example applications are presented: one involving a satellite downlink in 19 GHz and the other an uplink in 29 GHz using power control. Copyright © 2010 John Wiley & Sons, Ltd.
In vivo kinetics of [F‐18]MEFWAY: A comparison with [C‐11]WAY100635 and [F‐18]MPPF in the nonhuman primate
Authors: Wooten D.W. , Moraino J.D. , Hillmer A.T. , Engle J.W. , DeJesus O.J. , Murali D. , Barnhart T.E. , Nickles R.J. , Davidson R.J. , Schneider M.L. , Mukherjee J. , Christian B.T. 
Published: October 2010

Abstract[F‐18]Mefway was developed to provide an F‐18 labeled positron emission tomography (PET) neuroligand with high affinity for the serotonin 5‐HT1A receptor to improve the in vivo assessment of the 5‐HT1A system. The goal of this work was to compare the in vivo kinetics of [F‐18]mefway, [F‐18]MPPF, and [C‐11]WAY100635 in the rhesus monkey. Methods: Each of four monkeys were given bolus injections of [F‐18]mefway, [C‐11]WAY100635, and [F‐18]MPPF and scans were acquired with a microPET P4 scanner. Arterial blood was sampled to assay parent compound throughout the time course of the PET experiment. Time activity curves were extracted in the high 5‐HT1A binding areas of the anterior cingulate cortex (ACG), mesial temporal cortex, raphe nuclei, and insula cortex. Time activity curves were also extracted in the cerebellum, which was used as a reference region. The in vivo kinetics of the radiotracers were compared based on the nondisplaceable distribution volume (VND) and binding potential (BPND). Results: At 30 min, the fraction of radioactivity in the plasma due to parent compound was 19%, 28%, and 29% and cleared from the arterial plasma at rates of 0.0031, 0.0078, and 0.0069 (min−1) ([F‐18]mefway, [F‐18]MPPF, [C‐11]WAY100635). The BPND in the brain regions were mesial temporal cortex: 7.4 ± 0.6, 3.1 ± 0.4, 7.0 ± 1.2, ACG: 7.2 ± 1.2, 2.1 ± 0.2, 7.9 ± 1.2; raphe nuclei: 3.7 ± 0.6, 1.3 ± 0.3, 3.3 ± 0.7; and insula cortex: 4.2 ± 0.6, 1.2 ± 0.1, 4.7 ± 1.0 for [F‐18]mefway, [F‐18]MPPF, and [C‐11]WAY100635 respectively. Conclusions: In the rhesus monkey, [F‐18]mefway has similar in vivo kinetics to [C‐11]WAY100635 and yields greater than 2‐fold higher BPND than [F‐18]MPPF. These properties make [F‐18]mefway a promising radiotracer for 5‐HT1A assay, providing higher counting statistics and a greater dynamic range in BPND. Synapse, 2011. © 2010 Wiley‐Liss, Inc.
How do we ensure that everyone graduates? An integrated prevention and tiered intervention model for schools and districts
Authors: Mac Iver Martha Abele , Mac Iver Douglas J. 
Published: October 2010

AbstractSchools with large numbers of students falling off the graduation path need comprehensive reforms that create a solid foundation of high‐quality instruction and positive behavioral supports for all students. They also need data‐driven response systems that provide targeted and intensive interventions for students who need additional academic and social supports. This article offers a systematic plan for dropout prevention at the district and school levels that integrates research‐based recommendations into a coherent, three‐tiered model. The model provides a way to coordinate all types of interventions and replace the patchwork of fragmented programs that often allows students to fall through the cracks.
Using technology to engage and educate youth
Authors: Martinez Monica , Schilling Susan 
Published: October 2010

AbstractGiven that information age technologies are as natural to the Net generation as breathing, it is time to provide learning experiences that maximize their use in schools. The authors argue that integrating technology into learning is central to creating the meaningful learning opportunities needed to engage and motivate youth today. To achieve this potential, however, technology must support a new paradigm of teaching and learning. This chapter discusses common elements and challenges to implementing pioneering high school reform models that promote one‐to‐one student‐computer ratios, collaborative learning environments, problem‐ and project‐based instruction, and interdisciplinary teaching.
The Mobile story: Data‐driven community efforts to raise graduation rates
Authors: Newell Jeremiah , Akers Carolyn 
Published: October 2010

AbstractThrough sustained community organizing and strategic partnerships, the Mobile (Alabama) County Public School System is improving achievement and creating beat‐the‐odds schools that set and achieve high academic expectations despite the challenges of poverty and racial disparity. The authors chart how Mobile's Research Alliance for Multiple Pathways, funded through the U.S. Department of Labor's Multiple Pathways Blueprint Initiative, is identifying gaps in services throughout the community, analyzing the data about dropouts, benchmarking other communities, studying best practices, and mobilizing the community to expect and demand higher graduation rates. These activities are resulting in early identification of off‐track students and coordination of school‐ and community‐based reforms.