bluuebunny/crossref_metadata_2025_split huggingface dataset:
Active Transport of Amino Acids by a Guanidiniocarbonyl–Pyrrole Receptor
Authors: Urban Christian , Schmuck Carsten 
Published: May 2010

AbstractHerein we report the synthesis and characterization of a transporter 9 for N‐acetylated amino acids. Transporter 9 is a conjugate of a guanidiniocarbonyl pyrrole cation, one of the most efficient carboxylate binding motifs reported so far, and a hydrophobic tris(dodecylbenzyl) group, which ensures solubility in organic solvents. In its protonated form, 9 binds N‐acetylated amino acid carboxylates in wet organic solvents with association constants in the range of 104 M−1 as estimated by extraction experiments. Aromatic amino acids are preferred due to additional cation‐π‐interactions of the amino acid side chain with the guanidiniocarbonyl pyrrole moiety. U‐tube experiments established efficient transport across a bulk liquid chloroform phase with fluxes approaching 10−6 mol m−2 s−1. In experiments with single substrates, the release rate of the amino acid from the receptor–substrate complex at the interface with the receiving phase is rate determining. In contrast to this, in competition experiments with several substrates, the thermodynamic affinity to 9 becomes decisive. As 9 can only transport anions in its protonated form and has a pKa value of approximately 7, pH‐driven active transport of amino acids is also possible. Transport occurs as a symport of the amino acid carboxylate and a proton.
Affinity and selectivity of C2‐ and C5‐substituted “chiral‐box” PNA in solution and on microarrays
Authors: Manicardi Alex , Calabretta Alessandro , Bencivenni Mariangela , Tedeschi Tullia , Sforza Stefano , Corradini Roberto , Marchelli Rosangela 
Published: May 2010

AbstractTwo peptide nucleic acids (PNAs) containing three adjacent modified chiral monomers (chiral box) were synthesized. The chiral monomers contained either a C2‐ or a C5‐modified backbone, synthesized starting from D‐ and L‐arginine, respectively (2D‐ and 5L‐PNA). The C2‐modified chiral PNA was synthesized using a submonomeric strategy to avoid epimerization during solid‐phase synthesis, whereas for the C5‐derivative, the monomers were first obtained and then used in solid‐phase synthesis. The melting temperature of these PNA duplexes formed with the full‐match or with single‐mismatch DNA were measured both by UV and by CD spectroscopy and compared with the unmodified PNA. The 5L‐chiral‐box‐PNA showed the highest Tm with full‐match DNA, whereas the 2D‐chiral‐box‐PNA showed the highest sequence selectivity. The PNA were spotted on microarray slides and then hybridized with Cy5‐labeled full match and mismatched oligonucleotides. The results obtained showed a signal intensity in the order achiral >2D‐chiral box >5L‐chiral box, whereas the full‐match/mismatch selectivity was higher for the 2D chiral box PNA. Chirality, 2010. © 2010 Wiley‐Liss, Inc.
Enantioselective desymmetrization of meso‐epoxides with anilines catalyzed by polymeric and monomeric Ti(IV) salen complexes
Authors: Kureshy Rukhsana I. , Kumar Manish , Agrawal Santosh , Khan Noor‐Ul H. , Dangi Balchand , Abdi Sayed H. R. , Bajaj Hari C. 
Published: May 2010

AbstractThe active catalysts for the enantioselective ring opening (ARO) of meso‐stilbene oxide, cis‐butene oxide, cyclohexene oxide, cyclopentene oxide, and cyclooctene oxide with various substituted anilines were generated in situ by the reaction of Ti(OiPr)4 with poly‐[(R,R)‐N,N′‐bis‐{3‐(1,1‐dimethylethyl)‐5‐methylene salicylidene} cyclohexane‐1,2‐diamine]‐1 and (1R,2R)‐N,N′‐bis[3,5‐di(tert‐butyl)salicylidene] cyclohexane‐1,2‐diamine‐2. These catalysts in the presence of nonracemic imine as an additive provided β‐amino alcohol in excellent yield (99%) and chiral purity (enantiomeric excess (ee) up to 99%) for the ARO of meso‐stilbene oxide with aniline. The same protocol was less effective for the ARO of cyclic epoxides; however, when triphenylphosphine was used as an additive, there was a significant improvement in catalyst performance for the ARO of cyclohexene oxide (yield, 85–90%; ee, 63–67%). Both in situ generated polymeric and monomeric catalysts performed in a similar manner except that the polymeric catalyst Ti(IV)‐1 was more active and recycled several times with retention of enantioselectivity when compared with the monomeric catalyst Ti(IV)‐2, which was nonrecyclable. Chirality, 2011. © 2010 Wiley‐Liss, Inc.
Circular dichroism eigenspectra of polyproline II and β‐strand conformers of trialanine in water: Singular value decomposition analysis
Authors: Oh Kwang‐Im , Lee Kyung‐Koo , Park Eun‐Kyung , Yoo Dong‐Geun , Hwang Geum‐Sook , Cho Minhaeng 
Published: May 2010

AbstractDespite that a number of experimental and theoretical investigations have been carried out to determine the structure of trialanine in water, the reported populations of polyproline II (PPII) and β‐strand conformers vary and were found to be dependent on which spectroscopic method was used. Such discrepancies are due to limitations of different spectroscopic methods used. Here, the temperature‐ and pH‐dependent circular dichroism (CD) and NMR experiments have been carried out to develop a self‐consistent singular value decomposition procedure. The temperature‐dependent CD spectra indicate the presence of two conformers, but due to the two peptide bonds in a trialanine, one should take into consideration of four different conformers to fully interpret the NMR results. From the pH‐dependent NMR coupling constant measurements, the conformation of zwitterionic trialanine is little different from that of cationic one. The strong pH dependency of CD spectrum is likely due to charge transfer transitions between carboxylate and nearby peptide groups or internal field effects not to pH‐dependent conformational change. To simultaneously analyze the temperature‐dependent CD and NMR data, a self‐consistent procedure was used to newly determine the reference NMR coupling constants required to estimate one of the peptide dihedral angles. From the estimated enthalpy and entropy changes associated with the transition from enthalpically favorable PPII conformer to entropically favorable β‐strand conformer, the relative populations of the four possible conformers of trialanine were determined and compared with the previous experimental findings. We anticipate that the present experimental results and interpretation procedure would be of use in determining the solution structures of small oligopeptides in the future. Chirality, 2010. © 2010 Wiley‐Liss, Inc.
Heparin‐induced circular dichroism of an achiral, bicyclic species
Authors: Stanley Floyd E. , Warner Andrew M. , McWilliams Kayla M. , Stalcup Apryll M. 
Published: May 2010

AbstractAntimalarial drugs have shown potential in suppressing the role of glycosaminoglycans (GAGs) in the pathology of prion protein conformational disorders (e.g. “Mad Cow” disease) by competing for sites of electrostatic interaction. In this study, circular dichroism (CD) and UV/Visible (UV/Vis) absorption spectroscopy techniques were used to investigate the interactions between N‐methyl‐N′‐(7‐chloro‐4‐quinolyl)‐1,3‐diaminopropane (QD), an achiral, bicyclic compound similar to previously investigated antimalarial drugs, and heparin, a complex GAG that is frequently used as a clinical anticoagulant. Relatively intense heparin‐induced CD features were observed for QD and were noted to be radically different from previous studies using related chiral drugs, underscoring the importance of the Pfieffer effect on this and similar heparin research. Additionally, the induced CD for QD was observed to be highly dependent upon drug concentration, heparin concentration, system pH, equilibration time, and ionic strength. These results, in connection with recent work, provide new insight into the nature of the association between GAGs and antimalarial species. Chirality, 2011. © 2010 Wiley‐Liss, Inc.
Thiazolopyrimidine Inhibitors of 2‐Methylerythritol 2,4‐Cyclodiphosphate Synthase (IspF) from Mycobacterium tuberculosis and Plasmodium falciparum
Authors: Geist Julie G. , Lauw Susan , Illarionova Victoria , Illarionov Boris , Fischer Markus , Gräwert Tobias , Rohdich Felix , Eisenreich Wolfgang , Kaiser Johannes , Groll Michael , Scheurer Christian , Wittlin Sergio , Alonso‐Gómez José L. , Schweizer W. Bernd , Bacher Adelbert , Diederich François 
Published: May 2010

AbstractA library of 40 000 compounds was screened for inhibitors of 2‐methylerythritol 2,4‐cyclodiphosphate synthase (IspF) protein from Arabidopsis thaliana using a photometric assay. A thiazolopyrimidine derivative resulting from the high‐throughput screen was found to inhibit the IspF proteins of Mycobacterium tuberculosis, Plasmodium falciparum, and A. thaliana with IC50 values in the micromolar range. Synthetic efforts afforded derivatives that inhibit IspF protein from M. tuberculosis and P. falciparum with IC50 values in the low micromolar range. Several compounds act as weak inhibitors in the P. falciparum red blood cell assay.
Can we better select patients with metastatic renal cell carcinoma for cytoreductive nephrectomy?
Authors: Culp Stephen H. , Tannir Nizar M. , Abel E. Jason , Margulis Vitaly , Tamboli Pheroze , Matin Surena F. , Wood Christopher G. 
Published: May 2010

AbstractBACKGROUND:The benefits of cytoreductive nephrectomy (CN) in metastatic renal cell carcinoma (mRCC) should outweigh surgical morbidity. Even when the generally agreed upon selection criteria for CN are met, some patients do poorly after surgery. The objective of this study was to identify preoperative factors that were prognostic of outcome in patients who were being considered for CN.METHODS:The authors conducted a retrospective study to investigate the overall survival (OS) of patients who underwent CN using the OS of patients with mRCC who did not undergo CN as a referent group. Patients who underwent CN were divided into 2 groups based on when their OS diverged from that of nonsurgical patients. Chi‐square analysis was used to identify variables that differed between the 2 surgical groups. Multivariate Cox proportional hazards regression was used to analyze those variables for the entire CN cohort. Risk factors were defined as preoperative variables that remained significant on multivariate analysis. The median OS and the overall risk of death were calculated based on the number of risk factors.RESULTS:From 1991 to 2007, 566 patients who were eligible for or received systemic therapy underwent CN, and 110 patients received medical therapy alone. On multivariate analysis, independent preoperative predictors of inferior OS in surgical patients included a lactate dehydrogenase level greater than the upper limit of normal, an albumin level less than the lower limit of normal, symptoms at presentation caused by a metastatic site, liver metastasis, retroperitoneal adenopathy, supradiaphragmatic adenopathy, and clinical tumor classification ≥T3. Inferior OS and an increased risk of death were correlated positively with the number of risk factors. Surgical patients who had ≥4 risk factors did not appear to benefit from CN.CONCLUSIONS:The authors of this report identified 7 preoperative variables that permitted them to identify patients who were unlikely to benefit from CN. Cancer 2010. © 2010 American Cancer Society.
Trends in PSA, age and prostate cancer detection among black and white men from 1990‐2006 at a tertiary care center
Authors: Potts Jeannette M. , Lutz Megan , Walker Esteban , Modlin Charles , Klein Eric 
Published: May 2010

AbstractBACKGROUND:Prostate cancer is the most frequently diagnosed malignancy in men in the United States, with even higher prevalence and death rates among black men. The authors sought to compare trends in prostate‐specific antigen (PSA), age, and prostate‐cancer detection among black and white men in our region during a 16‐year period.METHODS:This was a retrospective study of patient archives between 1990 through 2006. Data collection was accomplished by examining patients' charts and electronic medical records. Data from 5570 patients, of whom 911 were black, were analyzed statistically by testing and comparing parameters over time.RESULTS:During this 16‐year period, mean age at the time of initial diagnostic prostate biopsy did not change in either group, despite what we had believed about the effects of patient education and screening campaigns. However, prostate‐cancer detection rates did decrease during the time period studied. Over time, the authors also observed significant decreases in the sensitivity and specificity of PSA as a screening tool. Indeed, analysis of more recent cases demonstrated a positive predictive value comparable to a coin toss. While Gleason scores remained relatively stable over time, reporting of prostate intraepithelial neoplasia (PIN) and inflammation increased.CONCLUSIONS:Using lower PSA thresholds, promoting younger screening age, and increasing efforts to educate the public have not seemed to influence age at time of diagnostic testing, which may reflect other factors such as usefulness of screening, physician referral patterns, patient compliance, and other sociodemographic issues. The usefulness of PSA as a screening tool appears to be diminishing. Cancer 2010. © 2010 American Cancer Society.
A survey of image‐guided radiation therapy use in the United States
Authors: Simpson Daniel R. , Lawson Joshua D. , Nath Sameer K. , Rose Brent S. , Mundt Arno J. , Mell Loren K. 
Published: May 2010

AbstractBACKGROUND:Image‐guided radiation therapy (IGRT) is a novel array of in‐room imaging modalities that are used for tumor localization and patient setup in radiation oncology. The prevalence of IGRT use among US radiation oncologists is unknown.METHODS:A random sample of 1600 radiation oncologists was surveyed by Internet, e‐mail and fax regarding the frequency of IGRT use, clinical applications, and future plans for use. The definition of IGRT included imaging technologies that are used for setup verification or tumor localization during treatment.RESULTS:Of 1089 evaluable respondents, 393 responses (36.1%) were received. The proportion of radiation oncologists using IGRT was 93.5%. When the use of megavoltage (MV) portal imaging was excluded from the definition of IGRT, the proportion using IGRT was 82.3%. The majority used IGRT rarely (in <25% of their patients; 28.9%) or infrequently (in 25%‐50% of their patients; 33.1%). The percentages using ultrasound, video, MV‐planar, kilovoltage (kV)‐planar, and volumetric technologies were 22.3%, 3.2%, 62.7%, 57.7%, and 58.8%, respectively. Among IGRT users, the most common disease sites treated were genitourinary (91.1%), head and neck (74.2%), central nervous system (71.9%), and lung (66.9%). Overall, 59.1% of IGRT users planned to increase use, and 71.4% of nonusers planned to adopt IGRT in the future.CONCLUSIONS:IGRT is widely used among radiation oncologists. On the basis of prospective plans of responders, its use is expected to increase. Further research will be required to determine the safety, cost efficacy, and optimal applications of these technologies. Cancer 2010. © 2010 American Cancer Society.
Breast cancer in men in the United States
Authors: Harlan Linda C. , Zujewski Jo Anne , Goodman Marc T. , Stevens Jennifer L. 
Published: May 2010

AbstractBACKGROUND:Breast cancer in men is rare, so clinical trials are not practical. Recommendations suggest treating men who are diagnosed with breast cancer using the guidelines for postmenopausal women; however, to date, no population‐based studies have evaluated patterns of care.METHODS:To examine characteristics, treatment, and survival among men with newly diagnosed breast cancer, in 2003 and 2004, 512 men were identified from the Surveillance, Epidemiology and End Results Program. Data were reabstracted and therapy was verified through the patients' treating physicians.RESULTS:The majority of men (79%) were diagnosed through discovery of a breast lump or other signs/symptoms. Among men who had invasive disease, 86% underwent mastectomy, 37% received chemotherapy, and 58% received hormone therapy. In multivariate analysis, tumor size (P = .01) and positive lymph node status (P < .0001) were associated positively with the use of chemotherapy, whereas age group (P < .0001) and current unmarried status (P = .01) had negative associations. Among men who had invasive, estrogen receptor (ER)‐positive/borderline tumors, the use of tamoxifen or aromatase inhibitors (AIs) was associated with age group (P = .05). Among men who had invasive disease, cancer mortality was associated with tumor size (P < .0001). Among men with ER‐positive/borderline disease, increased cancer mortality was associated with tumor size (P < .0001), current unmarried status (P = .04), and decreased mortality with tamoxifen (P = .04).CONCLUSIONS:Tumor characteristics and marital status were the primary predictors of therapy and cancer mortality among men with breast cancer. Although AIs are not currently recommended, they are commonly prescribed. However, their use did not result in a decrease in cancer mortality. Research must examine the efficacy of AIs with and without gonadotropin‐releasing hormone analogues. Cancer 2010. © 2010 American Cancer Society.
Readability of Corporate Social Responsibility communication in Malaysia
Authors: Abu Bakar Aishah Sheikh , Ameer Rashid 
Published: May 2010

AbstractThis study examines the readability of Corporate Social Responsibility (CSR) communication (disclosure) for a sample of listed companies in Malaysia. The study employs Readability Formulae and finds that the extent of syntactic complexity making it difficult to comprehend the CSR communication of the listed companies varies from very difficult to fairly difficult. There is a relationship between the readability of the CSR communication and companies' performance. Our findings imply that management of poorly performing companies deliberately choose difficult language in CSR communication which supports the obfuscation hypothesis. Our study contributes significantly to research in CSR literature by enumerating the syntactical difficulties in the corporate annual CSR communications. Copyright © 2010 John Wiley & Sons, Ltd and ERP Environment.
Application of a fuzzy hierarchical model to the assessment of corporate social and environmental sustainability
Authors: Kouikoglou Vassilis S. , Phillis Yannis A. 
Published: May 2010

AbstractCorporate responsibility has many facets. A corporation should organize its operations so that its environmental impact is minimal, its economic state is viable, labor conditions are good, and compliance with laws and regulations is satisfactory, among others. Corporate responsibility is intimately connected to corporate sustainability which expresses the economic, environmental, and social standing of a company. A responsible corporation embraces the principle of transparency of data pertaining to its performance and its policies and strives for strategies that enhance its sustainability. A model is presented that uses hierarchical fuzzy reasoning to assess corporate sustainability, given a number of inputs, called basic indicators. Inputs are normalized according to their sustainability status and then combined to obtain a sustainability index on [0, 1] for each facet of the corporation. A sensitivity analysis pinpoints the most important indicators affecting sustainability. Two case studies of multinational cement companies are presented in detail. Copyright © 2010 John Wiley & Sons, Ltd and ERP Environment.
Preparation and Li Storage Properties of Hierarchical Porous Carbon Fibers Derived from Alginic Acid
Authors: Wu Xing‐Long , Chen Li‐Li , Xin Sen , Yin Ya‐Xia , Guo Yu‐Guo , Kong Qing‐Shan , Xia Yan‐Zhi 
Published: May 2010

AbstractOne‐dimensional (1D) hierarchical porous carbon fibers (HPCFs) have been prepared by controlled carbonization of alginic acid fibers and investigated with scanning electron microscopy (SEM), transmission electron microscopy (TEM), X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), Raman spectroscopy, nitrogen adsorption–desorption isotherms, and electrochemical tests toward lithium storage. The as‐obtained HPCFs consist of a 3D network of nanosized carbon particles with diameters less than 10 nm and exhibit a hierarchical porous architecture composed of both micropores and mesopores. Electrochemical measurements show that HPCFs exhibit excellent rate capability and capacity retention compared with commercial graphite when employed as anode materials for lithium‐ion batteries. At the discharge/charge rate of 45 C, the reversible capacity of HPCFs is still as high as 80 mA h g−1 even after 1500 cycles, which is about five times larger than that of commercial graphite anode. The much improved electrochemical performances could be attributed to the nanosized building blocks, the hierarchical porous structure, and the 1D morphology of HPCFs.
Estimation of the location of dielectrics using a capacitor with widely spaced parallel electrodes and additional electrodes
Authors: Ohchi Masashi , Heigaku Sai , Tokushima Hisao , Furukawa Tatsuya 
Published: May 2010

AbstractWe have investigated the estimation of the location of a dielectric from the capacitance measured with widely spaced measurement electrodes provided with a shield and additional electrodes. In order to investigate the estimation method, a numerical technique was developed for calculating the capacitance between widely spaced measurement electrodes by finite element analysis. We discuss the new method for estimation of the locations of two dielectrics by using a capacitor with widely spaced parallel electrodes and additional electrodes. © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 172(3): 8–17, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20938
Decrease of primary electron number by NO, CO2, and SF6 mixing at breakdown in high‐pressure nitrogen
Authors: Kobayashi Fuminori , Hamano Syuichi , Iwao Toru , Yumoto Motoshige 
Published: May 2010

AbstractIt is reported that metastable excited particles affect the breakdown properties of nitrogen gas under low pressure extended over a long period. The purpose of this study is to confirm the influence of excited particles with the high‐pressure condition and to reduce the influence by excited particles. In the experiment, the delay time was measured and the number of primary electrons was evaluated. The test was carried out in N2/NO, N2/CO, N3/SP6, and N2/NO/SF6. The decrease rate of the primary electron number supplied by excited particles is higher in N2/NO than in N2/CO2. In N2/NO/SF6, it was more effective than two mixture gases. © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 172(3): 1–7, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20939
Modeling method for lead‐acid battery simulation using step changing current
Authors: Shimada Takae , Kurokawa Kosuke 
Published: May 2010

AbstractThis paper proposes a new simulation model of lead‐acid battery characteristics and a modeling method using step changing current. Battery simulation model is necessary to simulate the photovoltaic systems with batteries. The proposed model considers the nonlinearity of internal resistance and includes 36 constants that can be determined by only four cycles of charge–discharge tests. This paper offers a detailed description of the measurement method and modeling procedures of the battery characteristics. Results of verification tests using charge–discharge patterns of a hypothetical photovoltaic system show 1.0% of mean absolute error ratio of the simulated power at a battery temperature of $17 \ ^{\circ}\hbox{C}$. © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 172(3): 18–27, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20980