bluuebunny/crossref_metadata_2025_split huggingface dataset:
An improved facile method for extraction and determination of steroidal saponins in Tribulus terrestris by focused microwave‐assisted extraction coupled with GC–MS
Authors: Li Tianlin , Zhang Zhuomin , Zhang Lan , Huang Xinjian , Lin Junwei , Chen Guonan 
Published: November 2009

AbstractAn improved fast method for extraction of steroidal saponins in Tribulus terrestris based on the use of focus microwave‐assisted extraction (FMAE) is proposed. Under optimized conditions, four steroidal saponins were extracted from Tribulus terrestris and identified by GC–MS, which are Tigogenin (TG), Gitogenin (GG), Hecogenin (HG) and Neohecogenin (NG). One of the most important steroidal saponins, namely TG was quantified finally. The recovery of TG was in the range of 86.7–91.9% with RSD<5.2%. The convention heating reflux extraction was also conducted in order to validate the reliability of this new FMAE method. The yield of total steroidal saponins was 90.3% in a one‐step FMAE, while the yield of 65.0% was achieved during heating reflux extraction, and the extraction time was reduced from 3 h to 5 min by using less solvent. The method was successfully applied to analyze the steroidal saponins of Tribulus terrestris from different areas of occurrence. The difference in chromatographic characteristics of steroidal saponins was proved to be related to the different areas of occurrence. The results showed that FMAE–GC–MS is a simple, rapid, solvent‐saving method for the extraction and determination of steroidal saponins in Tribulus terrestris.
Separation of tryptic peptides of native and glycated BSA using open‐tubular CEC with salophene–lanthanide–Zn2+ complex as stationary phase
Authors: Sedláková Pavla , Eckhardt Adam , Lacinová Kateřina , Pataridis Statis , Mikšík Ivan , Král Vladimír , Kašička Václav 
Published: November 2009

AbstractOpen‐tubular CEC (OT‐CEC) with a new stationary phase, salophene–lanthanide–Zn2+ complex, has been applied to the separation of tryptic peptides of native BSA and BSA glycated by glucose and ribose. Glycation of proteins (non‐enzymatic modification by sugars) significantly affects their properties and it is of great importance from a physiological point of view. Separation of tryptic peptides of glycated BSA by CZE was poor because of their strong adsorption to the bare fused silica capillary. An improved separation of tryptic peptides of both native and glycated BSA was achieved by OT‐CEC in the fused silica capillary non‐covalently coated with salophene–lanthanide–Zn2+ complex, which suppressed the adsorption of peptides to the capillary and via specific interactions with some (glyco)peptides enhanced selectivity of the separation. Significant differences have been found in OT‐CEC analyses of tryptic hydrolysates of native and glycated BSA. In OT‐CEC‐UV profile of tryptic peptides of native BSA, 44 peaks could be resolved, whereas a reduced number of 38 peaks were observed in the profile of tryptic peptides of glucose‐glycated BSA and only 30 peaks were found in the case of ribose‐glycated BSA. The developed OT‐CEC can be potentially used for monitoring of protein glycation.
The effect of interpersonal psychotherapy for depression on insomnia symptoms in a cohort of women with sexual abuse histories
Authors: Pigeon Wilfred R. , May Pamela E. , Perlis Michael L. , Ward Erin A. , Lu Naiji , Talbot Nancy L. 
Published: November 2009

AbstractInsomnia frequently occurs with trauma exposure and depression, but can ameliorate with improvements in depression. Insomnia was assessed by the insomnia subscale of the Hamilton Rating Scale for Depression in 106 women with childhood sexual abuse (CSA) and major depression receiving interpersonal psychotherapy (IPT) in an uncontrolled pilot (n = 36) and an immediately subsequent randomized controlled trial (n = 70) comparing IPT to treatment as usual. Depression improved in each study and in both treatment conditions; insomnia had smaller, nonsignificant improvements. Overall, 95 women (90%) endorsed insomnia on the Structured Clinical Interview for DSM‐IV at baseline and, of those, 90% endorsed insomnia following treatment. Despite improvements in depression, insomnia persists for most women with CSA.
Overview of research addressing ethical dimensions of participation in traumatic stress studies: Autonomy and beneficence
Authors: Newman Elana , Kaloupek Danny 
Published: November 2009

AbstractOne element of the design of human research studies is ethically informed decision‐making. Key issues include the safety, costs, and benefits of participation. Historically, much of this decision‐making was based on opinion rather than formal evidence. Recently, however, investigators in the traumatic stress field have begun to collect data that are relevant to these decisions. In this article, the authors focus on issues emanating from the ethical concepts of autonomy and respect for persons and beneficence and nonmaleficence, and then summarize relevant evidence from studies with trauma‐exposed individuals. Discussion addresses implications of this evidence for research practice and policy, and identifies some potentially informative data collections opportunities for future trauma studies.
Pilot testing of an assessment tool for competency in mastoidectomy
Authors: Laeeq Kulsoom , Bhatti Nasir I. , Carey John P. , Della Santina Charles C. , Limb Charles J. , Niparko John K. , Minor Lloyd B. , Francis Howard W. 
Published: November 2009

AbstractObjectives/Hypothesis:To determine the feasibility, validity, and reliability of an evaluation tool for the assessment of competency in mastoid surgery. This study tests the hypothesis that residents of dissimilar training levels differ in their technical performance as measured by this tool.Study Design:Cross‐sectional validation study.Methods:Two or more faculty otolaryngologists evaluated each resident performing a cortical mastoidectomy on a cadaveric temporal bone. Performance was rated using global and checklist components of a mastoidectomy assessment tool.Results:Fifteen internal and external faculty members evaluated 23 residents over 3 years resulting in 118 evaluations. Construct validity was observed as scores increased with clinical training year. These differences were greater for more complex tasks. There was a percentage agreement of 78.5% between evaluator pairs in the determination of pass (score 3–5) versus fail (score 1–2) for the checklist instrument, and an agreement of 74.4% for the global instrument. Although agreement was lower for the exact score on a scale of 1 to 5, differences of 1 or less occurred in over 80% of evaluator pairs. Regression analysis confirmed faculty perception that sharpening of the posterior external auditory canal cortex and opening of the antrum from posterior to anterior are strong predictors of overall surgical performance.Conclusions:Our results indicate that the tool we have developed is a feasible, valid, and reliable instrument for the assessment of competency in mastoidectomy. The instrument can be used to provide formative feedback and to identify procedural tasks for which additional training may be necessary. Laryngoscope, 2009
Gelatin Hydrogel Prepared by Photo‐initiated Polymerization and Loaded with TGF‐β1 for Cartilage Tissue Engineering
Authors: Hu Xiaohong , Ma Lie , Wang Chengchao , Gao Changyou 
Published: November 2009

AbstractGelatin is a nature‐derived protein having good cytocompatibility, and widely used in tissue engineering particularly in a form of a hydrogel. To obtain the hydrogel with good enough mechanical properties, however, measures are still need to be taken. In this work, the gelatin molecule was modified with methacrylic acid (MA) to obtain crosslinkable gelatin (GM), which formed a chemically crosslinked hydrogel by photoinitiating polymerization. The gelation time could be easily tuned and showed an inverse relationship with the GM concentration. After photo‐irradiation for 20 min there was no detectable double carbon bond in the hydrogen spectrum of high resolution magic angle spinning nuclear magnetic resonance spectroscopy (1H HR‐MAS NMR). With the increase of the GM concentration, storage modulus and loss modulus of the hydrogels increased, but their swelling ratio and mesh size decreased. Weight loss of the hydrogels was also affected by the polymer concentration. Transform growth factor‐β1 (TGF‐β1) was incorporated into the GM hydrogel to improve its bioactivity. In vitro chondrocyte culture showed that the GM hydrogel had indeed good performance to support chondrocyte growth and maintain chondrocytic phenotype. Incorporation of TGF‐β1 could further improve the biological activity in terms of cell proliferation and extracellular matrix secretion.magnified image
Self‐Assembly of Methacrylate‐Functionalized Phosphonate and Phosphate Amphiphiles and their Conversion into Nanospheres
Authors: Francová Denisa , Kickelbick Guido 
Published: November 2009

AbstractThe synthesis and micelle formation of methacrylate‐functionalized phosphate and phosphonate amphiphiles containing alkyl spacers of eight and eleven CH2 groups is studied. The CMC of these molecules in aqueous solutions was investigated by DLS and conductometry. The CMCs were dependent on the polarity of the phosphorus head groups as well as on the chain lengths of the spacers and were in the range 25 to 42 mmol · L−1. The resulting micelles were crosslinked by applying UV‐ or thermally initiated FRP, forming stable spherical nanospheres. Their size varied from 10 to 400 nm depending on the organophosphorus compound used. The particles were re‐dispersible in water and showed a core/shell structure containing a hydrophobic polymerized core and a hydrophilic shell.magnified image
Efficient Electrophosphorescence from a Platinum Metallopolyyne Featuring a 2,7‐Carbazole Chromophore
Authors: Ho Cheuk‐Lam , Chui Chung‐Hin , Wong Wai‐Yeung , Aly Shawkat M. , Fortin Daniel , Harvey Pierre D. , Yao Bing , Xie Zhiyuan , Wang Lixiang 
Published: November 2009

AbstractThe synthesis, thermal and emission properties of an electrophosphorescent platinum(II) metallopolyyne polymer consisting of 9‐butylcarbazole‐2,7‐diyl spacer P1 are described. The optical and electronic properties of P1 are compared to their molecular diplatinum(II) and digold(I) model complexes. The photophysical properties of P1 are somehow analogous to its 2,7‐fluorene‐linked congener but differs significantly from that for the 3,6‐carbazole derivative. Its optical band gap is notably reduced as compared to that for the 3,6‐carbazole analog. Multi‐layer polymer light‐emitting diodes (PLEDs) were fabricated with P1 as the emitting layer which gave a strong green‐yellow electrophosphorescence. The best PLED can reach the maximum current efficiency of 4.7 cd · A−1 at 5 wt.‐% doping level, corresponding to an external quantum efficiency of 1.5%. This represents the first literature example of efficient PLEDs exhibiting pure triplet emission under electrical excitation for metallopolyynes without the concomitant singlet emission. For safety concern, this metallopolymer was also tested for possible cytotoxicity and it does not show significant cytotoxic activity on liver and breast derived human cells at reasonable doses, rendering this functional material safe to use in practical devices.magnified image
Metaphor's validity in marketing research
Authors: Capelli Sonia , Jolibert Alain 
Published: November 2009

AbstractUsing metaphor is widespread in management and marketing because it provides creativity. However, metaphor's validity is seldom investigated. This article offers an analysis of the validity of metaphor using three steps: (1) analysis of the metaphor's source concept, (2) analysis of the metaphor's aptness, and (3) analysis of the process of metaphor generation. These three steps have been applied to investigate the validity of two very well‐known metaphors in marketing: product life cycle and brand personality. Results show these two metaphors lack validity when analyzed using the three steps. © 2009 Wiley Periodicals, Inc.
Effectiveness of price discounts and premium promotions
Authors: Palazon Mariola , Delgado‐Ballester Elena 
Published: November 2009

AbstractAlthough price discounts are by far the most common form of sales promotions employed by firms, the increasing use of premiums as a promotional strategy may imply that they are occupying a more important place in the promotional strategy. Since price discounts are quite costly and can reduce consumers' reference prices, undermine perception of quality, and hurt brand equity, it is crucial to know what type of promotion is the most preferred and valued by consumers. As the most recent works in the field have argued that the promotional benefit level is an important determinant of promotional effectiveness, this research reports the results of two experimental studies that investigated the interaction effect between promotional benefit level and promotion type across three levels of benefit (low, moderate, high). The results obtained suggest that at high benefit levels price discounts are more effective than premiums, while the opposite occurs at low levels. However, a similar evaluation of promotional tools was found at moderate benefit levels. The findings offer guidance to managers who might benefit from knowing what is the best strategy to promote their products and services. Our work also extends prior related research because, to this date, the effectiveness of price discounts and premiums across promotional benefit levels is an under‐researched issue. © 2009 Wiley Periodicals, Inc.
Covalently Scaffolded Inter‐π‐System Orientations in π‐Conjugated Polymers and Small Molecule Models
Authors: Smith Rhett C. 
Published: November 2009

AbstractOrganic π‐conjugated polymers have emerged as one of the most fascinating classes of materials as they have found utility in a host of plastic electronics technologies. The distance between π‐systems and their relative orientation dictate energy/charge transfer, conductivity, and photophysical properties of these materials in bulk. This Feature Article discusses π‐conjugated polymers and model compounds in which specific inter‐π‐system interactions are covalently enforced and the effect that the scaffolding has on optoelectronic properties.magnified image
Synthesis of a Macromonomer Library from High‐Temperature Acrylate Polymerization
Authors: Zorn Anna‐Marie , Junkers Tanja , Barner‐Kowollik Christopher 
Published: November 2009

AbstractThe auto‐initiated high temperature acrylate polymerization represents a versatile route for the synthesis of macromonomer building blocks. Various macromonomers were synthesized via this route based on methyl, ethyl, n‐butyl, t‐butyl, 2‐ethylhexyl, isobornyl and 2‐[[(butylamino)carbonyl]oxy]ethyl acrylate. The synthesis requires a temperature of 140 °C and is carried out in a 5 wt.‐% solution of hexyl acetate. The macromonomer library is fully characterized via electrospray ionization mass spectrometry (ESI‐MS). The amount of macromonomers containing the geminal double bond lies in between 82 and 95%, depending on the monomer type. The achievable molecular weight of the macromonomers is located between 800 and 2 000 g·mol−1 with a polydispersity of close to 1.6. In addition, it is demonstrated that radical initiators are useful add‐ons (to circumvent the inhibition time observed during initiator‐free synthesis) without interfering in the actual polymerization as no initiator‐fragment containing products are identified via high resolution mass spectrometry.magnified image
Surface‐Initiated PLP‐SEC of Butyl Acrylate and Styrene from Silica Nanoparticles
Authors: Rotzoll Robert , Vana Philipp 
Published: November 2009

AbstractThe pulsed‐laser polymerization size‐exclusion chromatography (PLP‐SEC) technique has been successfully applied to the measurement of the propagation rate coefficient, kp, of the surface‐initiated polymerizations of butyl acrylate (BA) and styrene, using the silica‐immobilized bipedal initiator 4,4′‐azobis(4‐cyano‐N‐(3″‐triethoxysilylpropyl)‐valeric amide) (ACTA). The molecular weight distribution (MWD) of grafted poly(BA) polymerized at 25 °C was structureless, whereas at 5 °C reaction temperature, the MWD exhibited a typical PLP structure with two inflection points. In case of styrene the SEC trace obtained at 26 °C is well structured and shows four inflection points. The propagation rate coefficients kp of the surface‐initiated polymerizations were about 22% higher in the case of BA and about 27–28% higher in the case of styrene compared to the IUPAC benchmark data.magnified image
A novel strategy to inhibit FAK and IGF‐1R decreases growth of pancreatic cancer xenografts
Authors: Zheng Donghang , Golubovskaya Vita , Kurenova Elena , Wood Cheng , Massoll Nicole A. , Ostrov David , Cance William G. , Hochwald Steven N. 
Published: November 2009

AbstractDeregulation of insulin‐like growth factor‐1 receptor (IGF‐1R) and focal adhesion kinase (FAK) signaling pathways plays an important role in cancer cell proliferation and metastasis. In pancreatic cancer cells, the crosstalk and compensatory mechanisms between these two pathways reduce the efficacy of the treatments that target only one of the pathways. Ablation of IGF‐1R signaling by siRNA showed minimal effects on the survival and growth of pancreatic cancer cells. An increased activity of FAK pathway was seen in these cells after IGF‐1R knockdown. Further inhibition of FAK pathway using Y15 significantly decreased cell survival, adhesion, and promoted apoptosis. The combination of Y15 treatment and IGF‐1R knockdown also showed significant antitumor effect in vivo. The current study demonstrates the importance of dual inhibition of both these signaling pathways as a novel strategy to decrease both in vitro and in vivo growth of human pancreatic cancer. © 2009 Wiley‐Liss, Inc.
Inhibition of focal adhesion kinase and src increases detachment and apoptosis in human neuroblastoma cell lines
Authors: Beierle Elizabeth A. , Ma Xiaojie , Trujillo Angelica , Kurenova Elena V. , Cance William G. , Golubovskaya Vita M. 
Published: November 2009

AbstractNeuroblastoma is the most common extracranial solid tumor of childhood. Focal adhesion kinase (FAK) is an intracellular kinase that is overexpressed in a number of human tumors including neuroblastoma, and regulates both cellular adhesion and survival. We have studied the effects of FAK inhibition upon neuroblastoma using adenovirus‐containing FAK‐CD (AdFAK‐CD). Utilizing an isogenic MYCN+/MYCN− neuroblastoma cell line, we found that the MYCN+ cells are more sensitive to FAK inhibition with AdFAK‐CD than their MYCN negative counterparts. In addition, we have shown that phosphorylation of Src is increased in the untreated isogenic MYCN− neuroblastoma cells, and that the decreased sensitivity of the MYCN− neuroblastoma cells to FAK inhibition with AdFAK‐CD is abrogated by the addition of the Src family kinase inhibitor, PP2. The results of the current study suggest that both FAK and Src play a role in protecting neuroblastoma cells from apoptosis, and that dual inhibition of these kinases may be important when designing therapeutic interventions for this tumor. © 2009 Wiley‐Liss, Inc.
Anti‐glycative and anti‐inflammatory effects of caffeic acid and ellagic acid in kidney of diabetic mice
Authors: Chao Che‐yi , Mong Mei‐chin , Chan Kung‐chi , Yin Mei‐chin 
Published: November 2009

AbstractProtective effects of caffeic acid (CA) and ellagic acid (EA) in kidney of diabetic mice were examined. CA or EA at 2.5 and 5% was mixed in diet and supplied to diabetic mice for 12 wk. Results showed that the intake of CA or EA increased renal content of these compounds, alleviated body weight loss, decreased urine output, increased plasma insulin and decreased blood glucose levels at weeks 6 and 12 (p<0.05). The intake of these compounds dose dependently reduced plasma blood urea nitrogen and elevated creatinine clearance (p<0.05). CA or EA at 5% significantly decreased the levels of plasma HbA1c, urinary glycated albumin, renal carboxymethyllysine, pentosidine, sorbitol and fructose (p<0.05), and significantly diminished renal activity of aldose reductase and sorbitol dehydrogenase, as well as suppressed renal aldose reductase mRNA expression (p<0.05). CA or EA dose dependently lowered renal levels of IL‐6, IL‐1β, tumor necrosis factor (TNF)‐α and monocyte chemoattractant protein 1 (MCP‐1) (p<0.05). Furthermore, CA or EA dose dependently down‐regulated tumor necrosis factor‐α and monocyte chemoattractant protein‐1 mRNA expression in kidney (p<0.05). Based on the observed anti‐glycative and anti‐inflammatory effects, the supplement of CA or EA might be helpful for the prevention or attenuation of diabetic kidney diseases.
Occurrence of urolithins, gut microbiota ellagic acid metabolites and proliferation markers expression response in the human prostate gland upon consumption of walnuts and pomegranate juice
Authors: González‐Sarrías Antonio , Giménez‐Bastida Juan A. , García‐Conesa María T. , Gómez‐Sánchez María B. , García‐Talavera Noelia V. , Gil‐Izquierdo Angel , Sánchez‐Álvarez Carmen , Fontana‐Compiano Luis O. , Morga‐Egea Juan P. , Pastor‐Quirante Francisco A. , Martínez‐Díaz Francisco , Tomás‐Barberán Francisco A. , Espín Juan Carlos 
Published: November 2009

AbstractEpidemiology supports the important role of nutrition in prostate cancer (PCa) prevention. Pomegranate juice (PJ) exerts protective effects against PCa, mainly attributed to PJ ellagitannins (ETs). Our aim was to assess whether ETs or their metabolites ellagic acid and urolithins reach the human prostate upon consumption of ET‐rich foods and to evaluate the effect on the expression of three proliferation biomarkers. Sixty‐three patients with BPH or PCa were divided into controls and consumers of walnuts (35 g walnuts/day) or pomegranate (200 mL PJ/day) for 3 days before surgery. Independently of the ETs source, the main metabolite detected was urolithin A glucuronide, (3,8‐dihydroxy‐6H‐dibenzo[b,d]pyran‐6‐one glucuronide) (up to 2 ng/g) together with the traces of urolithin B glucuronide, (3‐hydroxy‐6H‐dibenzo[b,d]pyran‐6‐one glucuronide) and dimethyl ellagic acid. The small number of prostates containing metabolites was likely caused by clearance of the compounds during the fasting. This was corroborated in a parallel rat study and thus the presence of higher quantities of metabolites at earlier time points cannot be discarded. No apparent changes in the expression of CDKN1A, MKi‐67 or c‐Myc were found after consumption of the walnuts or PJ. Our results suggest that urolithin glucuronides and dimethyl ellagic acid may be the molecules responsible for the beneficial effects of PJ against PCa.
Continuous ATRP Synthesis of Block‐Like Copolymers via Column Reactors: Design and Validation of a Kinetic Model
Authors: Dervaux Bart , Junkers Tanja , Barner‐Kowollik Christopher , Du Prez Filip E. 
Published: November 2009

AbstractA model for the block‐like copolymerization via continuous supported ATRP was developed, enabling the calculation of the sequence distributions of the different monomers as a function of chain length in continuous flow reactors. Polydispersity indices, copolymer compositions, and complete molecular weight distributions could be predicted. The model was extensively tested under a wide range of reaction conditions and the outcome was compared with experimental data. An almost perfect match between the simulated and experimental kinetic data (first order kinetic plots, conversions, and PDI) was observed. A reasonable fit for the composition data of the copolymers was obtained. The influence of the flow rate in the column reactor on the copolymer composition was studied.magnified image