bluuebunny/crossref_metadata_2025_split huggingface dataset:
Differences in DNA curvature-related sequence periodicity between prokaryotic chromosomes and phages, and relationship to chromosomal prophage content
Authors: Abel Jacob , Mrázek Jan 
Published: May 2012

Abstract

Background
Periodic spacing of A-tracts (short runs of A or T) with the DNA helical period of ~10–11 bp is characteristic of intrinsically bent DNA. In eukaryotes, the DNA bending is related to chromatin structure and nucleosome positioning. However, the physiological role of strong sequence periodicity detected in many prokaryotic genomes is not clear.

Results
We developed measures of intensity and persistency of DNA curvature-related sequence periodicity and applied them to prokaryotic chromosomes and phages. The results indicate that strong periodic signals present in chromosomes are generally absent in phage genomes. Moreover, chromosomes containing prophages are less likely to possess a persistent periodic signal than chromosomes with no prophages.

Conclusions
Absence of DNA curvature-related sequence periodicity in phages could arise from constraints associated with DNA packaging in the viral capsid. Lack of prophages in chromosomes with persistent periodic signal suggests that the sequence periodicity and concomitant DNA curvature could play a role in protecting the chromosomes from integration of phage DNA.
Enhanced magnetic-field-induced optical properties of nanostructured magnetic fluids by doping nematic liquid crystals
Authors: Wang Xiang , Pu Shengli , Ji Hongzhu , Yu Guojun 
Published: May 2012

Abstract
Ferronematic materials composed of 4-cyano-4′-pentylbiphenyl nematic liquid crystal and oil-based Fe3O4 magnetic fluid were prepared using ultrasonic agitation. The birefringence (Δn) and figure of merit of optical properties (Q = Δn/α, where α is the extinction coefficient) of pure magnetic fluids and the as-prepared ferronematic materials were examined and compared. The figure of merit of optical properties weighs the birefringence and extinction of the materials and is more appropriate to evaluate their optical properties. Similar magnetic-field- and magnetic-particle-concentration-dependent properties of birefringence and figure of merit of optical properties were obtained for the pure magnetic fluids and the ferronematic materials. For the ferronematic materials, the values of Q increase with the volume fractions of nematic liquid crystal under certain fixed field strength and are larger than those of their corresponding pure magnetic fluids at high field region. In addition, the enhancement of Q value increases monotonously with the magnetic field and becomes remarkable when the applied magnetic field is beyond 50 mT. The maximum relative enhanced value of Q
R exceeds 6.8% in our experiments. The results of this work may conduce to extend the pragmatic applications of nanostructured magnetic fluids in optical field.
Potential Usefulness of Single Nucleotide Polymorphisms to Identify Persons at High Cancer Risk: An Evaluation of Seven Common Cancers
Authors: Park Ju-Hyun , Gail Mitchell H. , Greene Mark H. , Chatterjee Nilanjan 
Published: May 2012

PurposeTo estimate the likely number and predictive strength of cancer-associated single nucleotide polymorphisms (SNPs) that are yet to be discovered for seven common cancers.MethodsFrom the statistical power of published genome-wide association studies, we estimated the number of undetected susceptibility loci and the distribution of effect sizes for all cancers. Assuming a log-normal model for risks and multiplicative relative risks for SNPs, family history (FH), and known risk factors, we estimated the area under the receiver operating characteristic curve (AUC) and the proportion of patients with risks above risk thresholds for screening. From additional prevalence data, we estimated the positive predictive value and the ratio of non–patient cases to patient cases (false-positive ratio) for various risk thresholds.ResultsAge-specific discriminatory accuracy (AUC) for models including FH and foreseeable SNPs ranged from 0.575 for ovarian cancer to 0.694 for prostate cancer. The proportions of patients in the highest decile of population risk ranged from 16.2% for ovarian cancer to 29.4% for prostate cancer. The corresponding false-positive ratios were 241 for colorectal cancer, 610 for ovarian cancer, and 138 or 280 for breast cancer in women age 50 to 54 or 40 to 44 years, respectively.ConclusionForeseeable common SNP discoveries may not permit identification of small subsets of patients that contain most cancers. Usefulness of screening could be diminished by many false positives. Additional strong risk factors are needed to improve risk discrimination.
Forschungsfeld Learning Analytics
Authors: Chatti Mohamed Amine , Dyckhoff Anna Lea , Schroeder Ulrik , Thüs Hendrik 
Published: May 2012

Summary
Learning analytics has attracted a great deal of attention in technology enhanced learning (TEL) in recent years as educational institutions and researchers are increasingly seeing the potential that learning analytics has to support the learning process. Learning analytics has been identified as a possible key future trend in learning and teaching (Johnson et al., 2011). Analytics can be a powerful tool to support learning. There are, however, a number of issues that need to be addressed before starting analytics projects. In this paper, we identify various challenges and research opportunities in the emerging area of learning analytics.
Effect of Intensive Versus Standard Blood Pressure Control on Depression and Health-Related Quality of Life in Type 2 Diabetes
Authors: O’Connor Patrick J. , Narayan K.M. Venkat , Anderson Roger , Feeney Patricia , Fine Larry , Ali Mohammed K. , Simmons Debra L. , Hire Don G. , Sperl-Hillen JoAnn M. , Katz Lois Anne , Margolis Karen L. , Sullivan Mark D. 
Published: May 2012

OBJECTIVE
We tested the hypothesis that intensive (systolic blood pressure [SBP] &lt;120 mmHg) rather than standard (SBP 130–139 mmHg) blood pressure (BP) control improves health-related quality of life (HRQL) in those with type 2 diabetes.

RESEARCH DESIGN AND METHODS
Subjects were 1,028 ACCORD (Action to Control Cardiovascular Risk in Diabetes) BP trial HRQL substudy participants who completed baseline and one or more 12-, 36-, or 48-month HRQL evaluations. Multivariable linear regression assessed impact of BP treatment assignment on change in HRQL.

RESULTS
Over 4.0 years of follow-up, no significant differences occurred in five of six HRQL measures. Those assigned to intensive (vs. standard) BP control had statistically significant worsening of the Medical Outcomes Study 36-item short-form health survey (SF36) physical component scores (−0.8 vs. −0.2; P = 0.02), but magnitude of change was not clinically significant. Findings persisted across all prespecified subgroups.

CONCLUSIONS
Intensive BP control in the ACCORD trial did not have a clinically significant impact, either positive or negative, on depression or patient-reported HRQL.
18F-fluorodeoxyglucose PET/CT findings in pleural effusions of patients with known cancer
Authors: Letovanec I. , Allenbach G. , Mihaescu A. , Nicod Lalonde M. , Schmidt S. , Stupp R. , Fitting J.-W. , Boubaker A. , Ris H.-B. , Prior J. O. 
Published: May 2012

SummaryAim: Pleural effusion is common in cancer patients and to determine its malignant origin is of huge clinical significance. PET/CT with 18F-FDG is of diagnostic value in staging and follow-up, but its ability to differentiate between malignant and benign effusions is not precisely known. Patients, methods: We examined 50 PET/CT from 47 patients (29 men, 18 women, 60 ± 16 years) with pleural effusion and known cancer (24 NSCLC, 7 lymphomas, 5 breasts, 4 GIST, 3 mesotheliomas, 2 head and neck, 2 malignant teratoma, 1 colorectal, 1 oesophageal, 1 melanoma) for FDG uptake in the effusions using SUVmax. This was correlated to cytopathology performed after a median of 21 days (interquartile range –3 to 23), which included pH, relative distribution (macrophages, neutrophils, eosinophils, basophils, lymphocytes, plasmocytes), and absolute cell count. Results: Malignant cells were found in 17 effusions (34%) (6 NSCLC, 5 lymphomas, 2 breasts, 2 mesotheliomas, 2 malignant teratomas). SUV in malignant effusions were higher than in benign ones [3.7 (95%CI 1.8–5.6) vs. 1.7 g/ml (1.5–1.9), p = 0.001], with a correlation between malignant effuUntersion and SUV (Spearman coefficient ρ = 0.50, p = 0.001), but not with other cytopathological or radiological parameters (ROC area 0.83 ± 0.06). Using a 2.2-mg/l SUV threshold, 12 PET/CT studies were positive and 38 negative with sensitivity, specificity, positive and negative predictive values of 53%, 91%, 75% and 79%, respectively. For NSCLC only (n = 24), ROC area was 0.95 ± 0.04, 7 studies were positive and 17 negative with a sensitivity, specificity, positive and negative predictive values of 83%, 89%, 71 and 94%, respectively. Conclusion: PET/CT may help to differentiate the malignant or benign origin of a pleural effusion with a high specificity in patients with known cancer, in particular NSCLC.
Comparison of Dynamic and Locked Compression Plates for Treating Midshaft Clavicle Fractures
Authors: Lai Yu-Cheng , Tarng Yih-Wen , Hsu Chien-Jen , Chang Wei-Ning , Yang Shan-Wei , Renn Jenn-Huei 
Published: May 2012

The purpose of this study was to compare the parameters of perioperative course and cost-effectiveness for patients with midshaft clavicle fractures treated by dynamic compression plates or locked compression plates.
This retrospective, case-controlled study involved 54 patients with midshaft clavicle fractures who received dynamic compression plates (n=21) or locked compression plates (n=33) between January 2002 and December 2008. Indications for surgery included displacement or shortening >2 cm, comminuted fractures, and skin tenting. Patients with previous malunion, nonunion, multiple injuries of the shoulder girdle, or open fractures were excluded. Preoperative demographics showed no statistically significant differences between the 2 groups. Eighteen patients with dynamic compression plates and 28 patients with locked compression plates with postoperative follow-up >1 year were included for comparison. Statistical analyses for operative time, blood loss, complication rate, hospital stay, and union rate demonstrated no statistically significant difference between the 2 groups. The only statistically significant difference was a higher rate of plate removal requests in the dynamic compression plate group. Considering medical expenditure, locked compression plates cost 6 times more than dynamic compression plates in the authors’ institution (US $600 vs $100, respectively).
Other than more plate removal requests in the dynamic compression plate group and greater expense in the locked compression plate group, dynamic compression plates and locked compression plates achieved satisfactory operative outcomes in treating midshaft clavicle fractures, with no statistically significant difference between perioperative course and eventual fracture union observed between the 2 groups.
Femtosecond Laser–assisted LASIK Improves Quality of Life
Authors: Meidani Alexandra , Tzavara Chara , Dimitrakaki Christina , Pesudovs Konrad , Tountas Yannis 
Published: May 2012

PURPOSE:
To investigate the quality of life (QOL) outcomes of femtosecond laser–assisted LASIK using the Quality of Life Impact of Refractive Correction (QIRC) questionnaire.

METHODS:
Translation of the QIRC questionnaire from English to Greek followed standard international protocols. The questionnaire was completed by 190 individuals, aged 18 to 39 years with myopia (range: −0.75 to −8.50 diopters) and corrected distance visual acuity (CDVA) of logMAR 0.2 or better (Snellen equivalent 20/32) in the worse eye. Half of this sample underwent LASIK with femtosecond laser flap creation and ablation with the Visx Star S4 IR excimer laser (Abbott Medical Optics). The questionnaire was scored with Rasch analysis. Validity was tested by internal consistency reliability (Cronbach’s α) and repeatability by intraclass correlation coefficient (ICC) and Bland-Altman limits of agreement, convergent validity was examined with inter-item correlations, and construct validity was evaluated by known groups comparison analysis.

RESULTS:

The total QIRC score improved with femtosecond laser–assisted LASIK from mean 38.9±5.7 preoperatively to 53.7±5.1 postoperatively (
P
<.001). Among the pre-treatment and control groups, QIRC score was greater for those wearing contact lenses than those wearing spectacles (
P
<.01). The Greek version of the QIRC had good internal consistency reliability. Inter-item correlations were all significant (
P
<.001), ranging from 0.32 to 0.79. Repeatability was high (Bland-Altman limits of agreement were −6.72 to +5.41 and ICC for the total score was 0.98).

CONCLUSIONS:
Femtosecond laser–assisted LASIK leads to marked improvements in refractive error–related quality of life. This study also provides evidence for the reliability and validity of the Greek version of the QIRC questionnaire.
Bioengineered Myocardium Derived from Induced Pluripotent Stem Cells Improves Cardiac Function and Attenuates Cardiac Remodeling Following Chronic Myocardial Infarction in Rats
Authors: Miki Kenji , Uenaka Hisazumi , Saito Atsuhiro , Miyagawa Shigeru , Sakaguchi Taichi , Higuchi Takahiro , Shimizu Tatsuya , Okano Teruo , Yamanaka Shinya , Sawa Yoshiki 
Published: May 2012

Abstract
Cell-based therapies are promising strategies for myocardial repair following myocardial infarction. Induced pluripotent stem (iPS) cells have the potential to generate many cardiomyocytes, and they hold significant promise for the application of regenerative medicine to heart failure. Here, we developed cardiac tissue sheets, termed bioengineered myocardium (BM), from mouse iPS cells and measured cardiac performance following BM implantation in a rat chronic myocardial infarction model. Immunostaining analyses revealed that the α-actinin+ cell population was isolated with more than 99% purity under specific culture conditions. To evaluate the contribution of BM to the improvements in cardiac performance, we induced myocardial infarction in 30 F344/NJcl-rnu/rnu rats by left anterior descending coronary ligation. The rats were randomly divided into two groups, 2 weeks after ligation: a BM implantation group (n = 15) and a sham group (n = 15). Echocardiography and catheter examination showed that the BM implantation significantly improved cardiac function and attenuated cardiac remodeling compared with the sham group. Histological analyses demonstrated that the implanted BM survived at the epicardial implantation site 4 weeks after implantation. The implanted BM survived and attenuated left ventricular remodeling in the rat chronic myocardial infarction model. Thus, BM derived from iPS cells might be a promising new treatment for heart failure.
Disposition of Biological Therapeutics: Monoclonal Antibodies, Proteins, and Peptides
Authors: Rock Dan A. , Wienkers Larry C. , Retter Marc W. 
Published: May 2012

AbstractOver the past decade, advances in molecular biology and immunology has brought about a significant growth in the number of biotherapeutic agents, including peptides, proteins, and monoclonal antibodies, available for clinical use to treat a variety of diseases. Similar to traditional small‐molecule drugs, the role of pharmacokinetics (PK) and drug metabolism contributes to the clinical success of a large‐molecule therapeutic drug candidate. However, while underlying PK principles are consistent between large‐molecule biotech drugs and small‐molecule drugs, the mechanisms that govern processes of absorption, distribution, metabolism, and excretion (ADME) of large‐molecule drugs are quite different from that of small‐molecule drugs. To this end, a good understanding of the ADME processes of large‐molecule drugs is essential in support of the development of therapeutic biologics. The focus of this chapter is to highlight various aspects and dispositional features that govern the PK of large‐molecule therapeutics.
Bioactivation by Phase‐II‐Enzyme‐Catalyzed Conjugation of Xenobiotics
Authors: Grillo Mark P. 
Published: May 2012

AbstractPhase‐II‐enzyme‐catalyzed conjugation of xenobiotics with endogenous cofactors leads to hydrophilic derivatives that, in most cases, functions in the elimination and detoxification of xenobiotics from the body. However, this process can also mediate their bioactivation to chemically‐reactive and hence potentially toxic metabolites. The major conjugation reactions known to be involved in xenobiotic bioactivation are glucuronidation, sulfonation, acetylation, GSH conjugation, and acyl‐S‐CoA formation. Chemically‐reactive metabolites of xenobiotics can lead to covalent binding to protein and/or nucleic acids which some cases leads to intrinsic and/or idiosyncratic toxicity and carcinogenicity. This chapter will cover the known mechanisms of xenobiotic bioactivation by phase‐II‐drug‐conjugating enzymes.
Ligand‐Binding Assays
Authors: Verch Thorsten , Bakhtiar Ray 
Published: May 2012

AbstractLigand‐binding assays (LBAs) or immunoassays are the analytical method of choice for pharmacokinetic (PK) and immunogenicity assessment for biopharmaceuticals. As pipelines for this class of drugs are expanding, immunoassays are revisited to address current scientific questions with this classic technology. Although formats and technologies are ever expanding, the basic principle remains the same: analytes of interest are captured and/or detected in unpurified samples using specific antibodies. The technology of choice often depends on the balance between sensitivity, life cycle, and cost. Regardless of assay technologies, close attention should be paid to reagent quality and potential matrix effects. PK measurements in particular rely on LBAs to detect biologic drugs in unpurified patient sera. A combination of white papers and evolving regulatory guidelines governs the use and validation of LBAs to measure both therapeutic drugs for PK and anti‐drug antibodies for immunogenicity during preclinical and clinical development.
Leveraging Advances inHPLCand Sample Preparation to MaximizeDMPKData Quality
Authors: Hayes Roger N. 
Published: May 2012

AbstractHigh throughput bioanalytical methods are essential to support the rapid discovery and development of drugs in the pharmaceutical industry. Liquid chromatography coupled with tandem mass spectrometric detection (LC‐MS/MS) is considered the benchmark analytical methodology to be employed for the quantification of new chemical entities in biological fluids. Because of the high sensitivity and selectivity of LC‐MS/MS, the time required for method development and subsequent sample analysis is dramatically reduced. Rigorous chromatographic resolutions of analytes and/or tedious sample extraction protocols are typically not required even when complex biological matrices are used. Nevertheless, effective sample preparation and appropriate chromatographic separation of endogenous matrix components is required to ensure the quality of the data. The importance of sample preparation stems from three major concerns: removing interferences from the biological sample matrices, concentrating analyte(s) of interest, and improving analytical system performance. The choice of sample preparation method should be dependent on the quality of the data required.
Iron‐Catalyzed Efficient Synthesis of Amides from Aldehydes and Amine Hydrochloride Salts
Authors: Ghosh Subhash Chandra , Ngiam Joyce S. Y. , Chai Christina L. L. , Seayad Abdul M. , Dang Tuan Thanh , Chen Anqi 
Published: May 2012

AbstractA practical and efficient method for the synthesis of amides has been developed by iron‐catalysed oxidative amidation of aldehydes with amine hydrochloride salts. A wide range of amides have been obtained in good to excellent yields under mild conditions. The application of this novel amide formation reaction to the synthesis of pharmaceutical compounds has been successfully demonstrated.
The use of gamma irradiation to induce the miscibility between urea‐formaldehyde and vinyl acetate versatic ester copolymer latex blend
Authors: Taha Ahmed A. , Magida M. M. , Shehata Eman M. 
Published: May 2012

AbstractThe objective of this research was to investigate the miscibility behavior of urea‐formaldehyde (UF) resin and vinyl acetate versatic ester copolymer latex (VAcVe) blends. Blend of various compositions of UF resin as thermoset polymer and VAcVe as thermoplastic polymer were prepared. This study shows how the addition of VAcVe latex can alter the behavior of UF resin toward hardness, press‐ability, and inhibition of cracks occurred in the UF resin films and moulds. After that, these blends (UF/VAcVe) were irradiated with gamma rays in different doses. Physical properties such as solubility percent, water absorption behavior in water, and effect of dilute acid and dilute alkali were studied. Thermogravimetric analysis shows that VAcVe is more stable against thermal decomposition than UF resin over the entire temperature range studied. Also, the thermal stability of polymer blends (UF/VAcVe) increases with increasing the ratio of VAcVe component in the blend. The influence of addition of VAcVe on compressive strength was studied. The results showed an improvement with a decrease in compressive strength due to the flexibility, this improvement is related to the amount of VAcVe. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Ionic conductivity, dielectric behavior, and HATR–FTIR analysis onto poly(methyl methacrylate)–poly(vinyl chloride) binary solid polymer blend electrolytes
Authors: Ramesh S. , Liew Chiam–Wen , Ramesh K. 
Published: May 2012

AbstractSolid polymer electrolytes comprising blends of poly(vinyl chloride) (PVC) and poly(methyl methacrylate) (PMMA) as host polymers and lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) as dopant salt were prepared by solution‐casting technique. The ionic conductivity and dielectric behavior were investigated by using AC‐impedance spectroscopy in the temperature range of 298–353 K. The highest ionic conductivity of (1.11 ± 0.09)×10−6 S cm−1 is obtained at room temperature. The temperature dependence of ionic conductivity plots showed that these polymer blend electrolytes obey Arrhenius behavior. Conductivity–frequency dependence, dielectric relaxation, and dielectric moduli formalism were also further discussed. Apart from that, the structural characteristic of the polymer blend electrolytes was characterized by means of horizontal attenuated total reflectance–Fourier transform infrared (HATR–FTIR) spectroscopy. HATR–FTIR spectra divulged the interaction between PMMA, PVC, and LiTFSI. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Dynamic Mixtures: Challenges and Opportunities for the Amplification and Sensing of Scents
Authors: Herrmann Andreas 
Published: May 2012

AbstractNature generates compounds as complicated mixtures, but surprisingly little is known about the synergies or inhibitory effects of compound mixtures, which is likely to become an important research area in life sciences in the near future. Some recently developed concepts in dynamic combinatorial/covalent chemistry (DCC) have been applied to amplify (increase the intensity and long‐lastingness of perception) and sense (selectively detect and discriminate) individual bioactive volatile molecules in compound mixtures. This Concept article focuses on the potential of DCC to impact and modulate the biological and chemical properties of mixtures of bioactive volatile compounds to gain a more fundamental understanding of the properties of compound mixtures in molecular recognition.