bluuebunny/crossref_metadata_2025_split huggingface dataset:
Simple and sensitive determination of low‐molecular‐mass aromatic aldehydes in swimming pool water by LC‐diode array detector
Authors: Fernández‐Molina José María , Silva Manuel 
Published: August 2011

AbstractThis work reports the development of a simple method for the quantitative determination of aromatic and aliphatic low‐molecular‐mass aldehydes (LMMAs) as disinfection by‐products (DBPs) in indoor swimming pool waters after chlorination with a simplified SPE sample treatment. The method is based on the continuous in situ derivatization/preconcentration of the aldehydes with 2,4‐dinitrophenylhydrazine (DNPH) on a Lichrolut EN column in the presence of β‐CD. After elution, the 2,4‐dinitrophenylhydrazine derivatives were separated on an RP‐C18 analytical column using gradient of ACN–water at 60–80%. The optimized sample treatment described here allowed the direct analysis of large volumes of water in order to improve the sensitivity of the method; LODs in the 60–120 ng/L range were achieved for aromatic LMMAs by using a volume of 50 mL of water, precision being 7.5% or better at a concentration level of 5 μg/L. These results indicate that the ensuing method is a useful choice for the determination of LMMAs in water samples that provides better results than reported LC alternatives in terms of the LOD (except for MS/MS detection), sample requirements for analysis and cost.
Effects of freeze‐drying of samples on metabolite levels in metabolome analyses
Authors: Oikawa Akira , Otsuka Takao , Jikumaru Yusuke , Yamaguchi Shinjiro , Matsuda Fumio , Nakabayashi Ryo , Takashina Tadashi , Isuzugawa Kanji , Saito Kazuki , Shiratake Katsuhiro 
Published: August 2011

AbstractFreeze‐drying (FD) is a useful technique for removing water from biological tissues, such as food samples. Cellular components freeze at once, and the ice sublimates under conditions of high vacuum and low temperatures. Because biological activity is restricted during FD, the degradation of cellular metabolites is often believed to be limited. However, the cellular structure is damaged by several factors, such as the increase in cell volume during freezing, and this has serious effects on the levels of some cellular metabolites. We studied these effects of FD on metabolite levels when using it as a sample preparation step in metabolome analysis. We observed significant decreases in the levels of some metabolites, such as succinate and choline, in Arabidopsis and pear, respectively. We also found that the effects of FD on certain metabolite levels differed between Arabidopsis plants and pear fruits. These results suggest that it is necessary to confirm the metabolite recovery in each sample species when FD is used for sample preparation.
A new HPLC method with fluorescence detection for the determination of memantine in human plasma
Authors: Toker Sıdıka E. , Sağırlı Olcay , Çetin Sevil M. , Önal Armağan 
Published: August 2011

AbstractA sensitive, selective, simple and fast HPLC method based on the formation of derivative with fluorescamine was developed for the determination of memantine (ME) in human plasma. Separation was achieved on a CN column (200 mm×4.6 mm) using acetonitrile–10 mM orthophosphoric acid containing 1 mL/L triethylamine (45:55, v/v) at a flow rate of 1 mL/min. Emission and excitation wavelengths were 480 and 380 nm, respectively. Amantadine was used as an internal standard. Calibration graphs were rectilinear over the range of 1.0–100.0 ng/mL. Limit of detection and limit of quantification were found to be 0.3 and 1.0 ng/mL, respectively. Intra‐day and inter‐day relative standard deviation values were found to be <2.03%. Average recovery was also found to be around 94%. Proposed method was applied for the pharmacokinetic study in a healthy volunteer after a single oral administration of 20 mg of ME.
Application of centrifugal precipitation chromatography and high‐speed counter‐current chromatography equipped with a spiral tubing support rotor for the isolation and partial characterization of carotenoid cleavage‐like enzymes in Enteromorpha compressa (L.) Nees
Authors: Baldermann Susanne , Mulyadi Andriati N. , Yang Ziyin , Murata Ariaka , Fleischmann Peter , Winterhalter Peter , Knight Martha , Finn Thomas M. , Watanabe Naoharu 
Published: August 2011

AbstractCentrifugal precipitation chromatography and a high‐speed counter‐current chromatography system equipped with a spiral tubing support rotor (spHSCCC) were successfully applied for the identification and isolation of carotenoid cleavage‐like enzymes from Enteromorpha compressa (L.) Nees. This is the first study separating active enzymes from a complex natural matrix by spHSCCC. The target enzymes were identified after fractionation of the proteins in an acetone Tris‐buffer gradient by centrifugal precipitation chromatography. Also, an aqueous two‐phase solvent system consisting of PEG 1000 and mono‐ and dibasic potassium phosphate was used for the isolation of the enzymes by spHSCCC. The purified fractions contained two proteins of 65 and 72 kDa, respectively. The enzymes could cleave β‐carotene and β‐apo‐8′‐carotenal to produce β‐ionone.
Social constraints, genetic vulnerability, and mental health following collective stress
Authors: Holman E. Alison , Lucas‐Thompson Rachel G. , Lu Tammy 
Published: August 2011

AbstractA repeat‐length polymorphism of the serotonin promoter gene (5‐HTTLPR) has been associated with depression and posttraumatic stress disorder (PTSD) in trauma‐exposed individuals reporting unsupportive social environments. We examine the contributions of the triallelic 5‐HTTLPR genotype and social constraints to posttraumatic stress (PTS) symptoms in a national sample following the September 11, 2001 (9/11) terrorist attacks. Saliva was collected by mail from 711 respondents (European American subsample n = 463) of a large national probability sample of 2,729 adults. Respondents completed web‐based assessments of pre‐9/11 mental and physical health, acute stress 9 to 23 days post‐9/11, PTS symptoms, and social constraints on disclosure regarding fears of future terrorist attacks 2–3 years post‐9/11. Social constraints were positively associated with PTS symptoms 2–3 years post‐9/11. The triallelic 5‐HTTLPR genotype was not directly associated with PTS symptoms, but it interacted with social constraints to predict PTS symptoms 2‐3 years post‐9/11: Social constraints were more strongly associated with PTS symptoms for individuals with any s/lg allele than for homozygous la/la individuals. Constraints on disclosing fears about future terrorism moderate the 5‐HTTLPR genotype‐PTS symptom association even when indirectly exposed to collective stress.
The longitudinal course of PTSD among disaster workers deployed to the World Trade Center following the attacks of September 11th
Authors: Cukor Judith , Wyka Katarzyna , Mello Brittany , Olden Megan , Jayasinghe Nimali , Roberts Jennifer , Giosan Cezar , Crane Michael , Difede JoAnn 
Published: August 2011

AbstractThis study examined the long‐term mental health outcomes of 2,960 nonrescue disaster workers deployed to the World Trade Center site in New York City following the September 11, 2001 (9/11) terrorist attacks. Semistructured interviews and standardized self‐report measures were used to assess the prevalence of posttraumatic stress disorder (PTSD) and other psychopathology 4 and 6 years after the attacks. Clinician‐measured rates of PTSD and partial PTSD 4‐years posttrauma were 8.4% and 8.9%, respectively, in a subsample of 727 individuals. Rates decreased to 5.8% and 7.7% for full and partial PTSD 6 years posttrauma. For the larger sample, self‐report scores revealed probable PTSD and partial PTSD prevalence to be 4.8% and 3.6% at 4 years, and 2.4% and 1.8% at 6 years. Approximately 70% of workers never met criteria for PTSD. Although PTSD rates decreased significantly over time, many workers remained symptomatic, with others showing delayed‐onset PTSD. The strongest predictors of ongoing PTSD 6 years following 9/11 were trauma history (odds ratio (OR) = 2.27, 95% confidence interval (CI) [1.06, 4.85]); the presence of major depressive disorder 1–2 years following the trauma (OR = 2.80, 95% CI [1.17, 6.71]); and extent of occupational exposure (OR = 1.31, 95% CI [1.13, 1.51]). The implications of the findings for both screening and treatment of disaster workers are discussed.
Free‐radical scavenging activities of silybin and its analogues: A pulse radiolysis study
Authors: Fu Haiying , Lin Mingzhang , Katsumura Yosuke , Muroya Yusa 
Published: August 2011

AbstractThe flavonolignans (silybin and analogues) are important natural compounds with multiple biological activities operating at various cell levels. Many of these effects are connected with their radical scavenging activities. In the present study, free‐radical scavenging and antioxidant activities of four natural flavonoids, namely silybin, naringenin, naringin, and hesperetin, have been studied using nanosecond pulse radiolysis techniques. The kinetics and mechanisms of the reactions of silybin and analogues with various oxidizing radicals (such as •OH,N3•, CCl3OO•, SO4•−) have been investigated. Furthermore, the transient species has been assigned and radical scavenging rate constants have also been measured. Moreover, the structure–activity relationships between chemical structures of the flavonoids and their radical scavenging activities are further analayzed by theoretical calculation. Combined our previous observation of the fast reparation of DNA damage and efficient DNA protection against radiation damage in vitro, it can be confirmed that test flavonoids are promising molecules to be used for their potential antioxidant properties. © 2011 Wiley Periodicals, Inc. Int J Chem Kinet 43: 590–597, 2011
Factors Associated With the Postoperative Status of Donor Patients for Living Donor Liver Transplantation
Authors: Wakata Yoshufumi , Nakashima Naoki , Taketomi Akinobu , Shirabe Ken , Maehara Yoshihiko , Hagihara Akihito 
Published: August 2011

Abstract
Deceased donor liver transplantation has been an established surgical procedure since the 1960s. More recently, the technique of living donor liver transplantation (LDLT) was introduced, and it is being performed with increasing frequency. However, there is a paucity of information on the clinical outcomes of donor patients. In this study, which was conducted at a single university hospital, the relationship between potentially relevant factors (eg, patient characteristics, preoperative status, and operation characteristics) and postoperative developments in donor patients was examined. We used electronic critical pathways, which are charts of medical process that include favorable states (defined as outcomes) to be achieved during the hospital stay of a patient; predefined outcomes that are not achieved are recorded as variances. With the electronic critical pathway system, objective data about the conditions of patients and relevant clinical processes could be collected readily. Using data from the electronic critical pathways for LDLT donor patients and applying multiple logistic regression analysis, we examined factors that were related to the variance of each outcome measure for postoperative developments. Among the various donor characteristics, the duration of the operation was related to variance in 5 types of health outcomes, age and blood loss volume were related to variance in 2 types of health outcomes, and other characteristics (ie, sex, body surface area, operation urgency, and volume ratio of the remnant liver) were related to variance in 1 type of health outcome. In conclusion, the findings in this study may facilitate improvements in the postoperative status of LDLT donor patients. Further studies that incorporate analogous data from other medical facilities are necessary to verify these findings. Liver Transpl, 2011. © 2011 AASLD.
Properties of stationary distributions of a sequence of generalized Ornstein–Uhlenbeck processes
Authors: Lindner Alexander , Sato Ken‐iti 
Published: August 2011

AbstractThe infinite (in both directions) sequence of the distributions μ(k) of the stochastic integrals \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}$\int _0^{\infty -} c^{-N_{t-}^{(k)}} dL_t^{(k)}$\end{document} for integers k is investigated. Here c > 1 and (N(k)t, Lt(k)), t ≥ 0, is a bivariate compound Poisson process with Lévy measure concentrated on three points (1, 0), (0, 1), (1, c−k). The amounts of the normalized Lévy measure at these points are denoted by p, q, r. For k = 0 the process (N(0)t, Lt(0)) is marginally Poisson and μ(0) has been studied by Lindner and Sato (Ann. Probab. 37 (2009), 250–274). The distributions μ(k) are the stationary distributions of a sequence of generalized Ornstein–Uhlenbeck processes structurally related in a particular way. Continuity properties of μ(k) are shown to be the same as those of μ(0). The dependence on k of infinite divisibility of μ(k) is clarified. The problem to find necessary and sufficient conditions in terms of c, p, q, and r for μ(k) to be infinitely divisible is somewhat involved, but completely solved for every integer k. The conditions depend on arithmetical properties of c. The symmetrizations of μ(k) are also studied. The distributions μ(k) and their symmetrizations are c−1‐decomposable, and it is shown that, for each k ≠ 0, μ(k) and its symmetrization may be infinitely divisible without the corresponding factor in the c−1‐decomposability relation being infinitely divisible. This phenomenon was first observed by Niedbalska‐Rajba (Colloq. Math. 44 (1981), 347–358) in an artificial example. The notion of quasi‐infinite divisibility is introduced and utilized, and it is shown that a quasi‐infinitely divisible distribution on [0, ∞) can have its quasi‐Lévy measure concentrated on (− ∞, 0).
Tetrazine‐Norbornene Click Reactions to Functionalize Degradable Polymers Derived from Lactide
Authors: Barker Ian A. , Hall Daniel J. , Hansell Claire F. , Du Prez Filip E. , O'Reilly Rachel K. , Dove Andrew P. 
Published: August 2011

AbstractPost‐polymerization modification of polymers derived from sustainable resources using the click reaction between tetrazines and norbornenes is shown to provide a mild and efficient route for the synthesis of functional degradable polymers. Norbornene chain‐end functional poly(lactide) was synthesized using organocatalytic methods and functionalized by the addition of 3,6‐di‐2‐pyridyl‐1,2,4,5‐tetrazine without degradation of the polymer backbone. The versatility of this reaction was demonstrated by the application of analogues bearing amine and poly(ethylene oxide) groups to realize amine‐functional polymers and block copolymers. Poly(spiro[6‐methyl‐1,4‐dioxane‐2,5‐dione‐3,2′‐bicyclo[2.2.1]hept[5]ene]) was prepared from lactide. The pendant norbornene group on the backbone of the resultant polymer was modified in a similar manner to produce functional degradable polymers and graft co‐polymers.magnified image
Mass spectrometry in the proteome analysis of mature cereal kernels
Authors: Cunsolo Vincenzo , Muccilli Vera , Saletti Rosaria , Foti Salvatore 
Published: August 2011

AbstractIn the last decade, the improved performance and versatility of the mass spectrometers together with the increasing availability of gene and genomic sequence database, led the mass spectrometry to become an indispensable tool for either protein and proteome analyses in cereals. Mass spectrometric works on prolamins have rapidly evolved from the determination of the molecular masses of proteins to the proteomic approaches aimed to a large‐scale protein identification and study of functional and regulatory aspects of proteins. Mass spectrometry coupled with electrophoresis, chromatographic methods, and bioinformatics tools is currently making significant contributions to a better knowledge of the composition and structure of the cereal proteins and their structure–function relationships. Results obtained using mass spectrometry, including characterization of prolamins, investigation of the gluten toxicity for coeliac patients, identification of proteins responsible of cereal allergies, determination of the protein pattern and its modification under environmental or stress effects, investigation of genetically modified varieties by proteomic approaches, are summarized here, to illustrate current trends, analytical troubles and challenges, and suggest possible future perspectives. © 2011 Wiley Periodicals, Inc. Mass Spec Rev 31:448–465, 2012
NMR Investigations of Temperature‐Induced Phase Transition in Aqueous Polymer Solutions
Authors: Spěváček Jiří 
Published: August 2011

AbstractThe different dynamics of polymer segments forming phase‐separated globular structures in aqueous (D2O) solutions affects both the shape of NMR spectra and NMR relaxation times of polymer and solvent. Two types of the approach are discussed. The first one is based on the reduction of integrated intensities of polymer NMR lines in high‐resolution NMR spectra in the system undergoing the coil‐globule phase transition. The fraction p of phase‐separated units (units with significantly reduced mobility) and subsequently, e.g., thermodynamic parameters ΔH and ΔS characterizing the coil‐globule phase transition can be determined. The second approach is based on measurements of 1H NMR relaxation times of water (HDO) which provide information on behaviour of water during phase transition. The power of both approaches is demonstrated on results obtained with solutions of several thermoresponsive homopolymers and copolymers.
Hydrogen Bonding in Fluorinated Amides: FTIR, Two Dimensional Correlation Spectroscopy and DFT Calculations
Authors: Radice Stefano , Milani Alberto , Castiglioni Chiara 
Published: August 2011

AbstractFluorinated macromers with amidic functional groups are used as additives in several high tech applications. We show here how aggregation phenomena related to hydrogen bonding are one of the key factor determining their chemical/physical and macroscopic properties. IR spectra are analyzed depending on different external parameters such as the concentration of amide groups and temperature. The experimental findings have been interpreted by means of DFT (Density Functional Theory) calculations on suitable molecular models. Moreover, 2D correlation spectroscopy has been applied to different sets of data, considering concentration and temperature as perturbing variables. The two dimensional correlation approaches confirmed the computational results and give an overall interpretation of the effects due to concentration and temperature.
Analysis of Polymer Dynamics by NMR Modulated Gradient Spin Echo
Authors: Stepišnik Janez , Mohorič Aleš , Serša Igor , Lahajnar Gojmir 
Published: August 2011

AbstractNMR modulated gradient spin echo method, which allows the quantification of polymer segmental displacement via the measurement of the velocity autocorrelation, requires the formulation of theoretical predictions in the frequency domain in order to test their validity. We worked out the velocity autocorrelation spectrum of the segmental motion according to the Rouse and the tube/reptation model to compare it to the experimental results obtained by the new NMR technique. The analysis of polybutadiene shows the segmental velocity autocorrelation spectrum typical for the reptation‐like motion of polymer in a “tube”. The measurement of bulk water indicates a kind of Rouse motion in a network of hydrogen bonds.
Dynamics and Structure of Biopolyelectrolytes Characterized by Dielectric Spectroscopy
Authors: Tomić Silvia , Grgičin Danijel , Ivek Tomislav , Babić Sanja Dolanski , Vuletić Tomislav , Pabst Georg , Podgornik Rudi 
Published: August 2011

AbstractStructural properties of Na‐DNA and Na‐HA aqueous solutions can be quantified using dielectric spectroscopy in the frequency range 100 Hz–100 MHz. Two relaxation modes are typically detected that can be attributed to diffusive motion of polyion counterions. The overall study as a function of polyion length, concentration and added salt concentration demonstrates that the motion of polyion counterions detected at MHz frequencies probes collective properties, whereas the motion at kHz range probes single‐chain properties of polyelectrolytes. Fundamental length scales found to characterize the polyelectrolyte structure differ for the dilute and semidilute regime and also depend on the strength of electrostatic interactions and the flexibility. Characteristic length scales detected in the dielectric spectroscopy measurements compare well with the fundamental length scales predicted by theory and comply with those extracted from small‐angle X‐ray scattering.
High‐Resolution Tip‐Enhanced Raman Mapping
Authors: Hoffmann G. G. , Xue L. , Loos J. , de With G. 
Published: August 2011

AbstractTip‐enhanced Raman mapping (TERM) can be used to obtain chemical analysis of a sample with a topographical resolution down to 15 nm. A short review of this technique is given. Among other samples (e.g. carbon nanotubes and graphene), we recently measured a high resolution tip‐enhanced Raman map of a polymer for the first time. Using TERM, the phase separation behaviour of a polymer blend (PMMA/SAN) was monitored. In the early, incomplete state of phase separation an interface width of ∼200 nm was measured. A spatial resolution in the tens of nm range could be achieved.
Gracilis myocutaneous flap: Evaluation of potential risk factors and long‐term donor‐site morbidity
Authors: Papadopoulos Othon , Konofaos Petros , Georgiou Panos , Chrisostomidis Chrisostomos , Tsantoulas Zacharias , Karypidis Dimitrios , Kostakis Alkiviadis 
Published: August 2011

AbstractThis study reviewed our experience with the gracilis myocutaneous (GMC) flap, potential risk factors for flap necrosis, and long‐term morbidity at the donor‐site. From 1993 to 2002, 29 GMC flaps were harvested from 27 patients (pedicled n = 21 and free n = 8). The overall incidence of flap necrosis was 13.79% (partial (n = 2) and total (n = 2) necrosis). Flap necrosis was correlated with body mass index >25 (P = 0.022), with smoking (P = 0.04 9) and with radiation therapy at the recipient site (P = 0.020). The long‐term morbidity at the donor‐site was low, except for scar appearance (17.24%), thigh contour deformity (58.62%), and hypoesthesia (17.24%). Significant age and gender differences were seen for ranking of scar ugliness, with females (P = 0.0061) and younger patients (age ≤55) (P = 0.046) assigned higher values. Significant age differences were seen for ranking of thigh contour deformity, with younger patients assigned higher values (P = 0.0012). In conclusion, patient overweight, smoking, and previous radiation therapy at the recipient site may be the “potential risk factors” for flap necrosis. The long‐term morbidity at the donor‐site was low, which was in agreement with previous reported studies. A larger series would be the subject of a future study. © 2011 Wiley‐Liss, Inc. Microsurgery, 2011.