bluuebunny/crossref_metadata_2025 huggingface dataset:
Serial Dilution Assay
Authors: Ridout Martin
Published: September 2014

Serial dilution assays are used to estimate concentrations of bacteria in samples of food, water, soil, and so on. Key assumptions are that the bacteria are distributed randomly throughout the medium, and that the presence or absence of bacteria in subsamples can be ascertained reliably. The concentration of bacteria can then be estimated based on the presence or absence of bacteria in subsamples of different volumes. Essentially, the same method can be used to estimate the proportion of individuals in a population that have some characteristic, for example, in immunology, the proportion of cells that are immunocompetent. The term limiting dilution assay is often used for this type of application. This article considers point and interval estimation of concentration, including bias correction, tests of the underlying assumptions, and issues of experimental design for dilution assays.
Coherence Between Time Series
Authors: Pawitan Yudi
Published: September 2014

Association between time series is a complex phenomenon that may involve a leading or lagging relationship. This entry is concerned with coherence, which is an approach to measuring the strength of the relationship and is, in some sense, the time series analogue of the standard correlation coefficient.
Noise and White Noise
Authors: Lawrence Clive J.
Published: September 2014

Noise and white noise arise in the description of time series data. Both are defined in this entry.
Time Series Similarity Measures
Authors: Gunopulos Dimitrios
Published: September 2014

A distance or similarity function measures the extent to which different time series display different behavior, and can be used to define clusters of time series or to classify a new time series.
O
blimin Rotation
Authors: Jackson J. Edward
Published: September 2014

Oblimin rotation
is a general form for obtaining oblique rotations used to transform vectors associated with principal component analysis or factor analysis to
simple structure
. Oblimin is similar to the
Orthomax rotation
procedures used in orthogonal rotation in that it, too, includes an arbitrary constant used to obtain different rotational properties. A numerical example is included. While most orthogonal rotations use some form of Orthomax rotation, this is no longer the case with Oblimin rotation for the oblique case.
Orthoblique Rotation
Authors: Jackson J. Edward
Published: September 2014

Orthoblique rotation
is a two‐stage procedure for obtaining
oblique rotations
used to transform vectors associated with
principal component analysis
or
factor analysis
to
simple structure
. The first stage will usually be an orthogonal rotation such as
Varimax
. The nature of the second stage will depend to some extent on the degree of obliqueness desired. A numerical example is included with two second‐stage options. This technique is sometimes referred to as the
Harris–Kaiser rotation
.
Varimax Rotation
Authors: Jackson J. Edward
Published: September 2014

Varimax rotation
is the most common form of
orthogonal rotation
used to transform vectors associated with
principal component analysis
or
factor analysis
to
simple structure
. It is a special case of
orthomax rotation
, which maximizes the sums of squares of the coefficients within each of the resultant vectors as opposed to
Quartimax
, which maximizes the sums of squares of the coefficients across the vectors for each of the original variables. A numerical example is included.
Multistage Sampling
Authors: Shimizu Iris
Published: September 2014

Multistage sampling is an extension of cluster sampling in which sampling is done in stages with smaller units being defined and selected at each stage within the units selected at the prior stage. Multistage sampling is used to reduce data collection costs. However, its use usually results in larger sampling errors than would result from simple random samples of the same size. The article illustrates how to apply multistage sampling in terms of two‐stage samples. Formulas are given for calculating estimates and their variances for aggregates and ratios under different situations. Procedures for determining optimum sample sizes and allocation between primary and secondary sampling stages are discussed. Some methods are also given for controlling the effects of variation in sizes of primary sampling units on sampling errors.
Foundations of Probability
Authors: Lindley Dennis V.
Published: September 2014

Probability, as a mathematical subject, is essentially unique and its formal rules are described. There are many different interpretations, of which three are mentioned: classical, frequentist, and in terms of belief. The many and varied justifications for thinking that beliefs should conform to the rules of probability, the Bayesian view, are described. The connections with decision‐making, the concept of utility, and the role of subjectivity are discussed. It is pointed out that the frequentist and Bayesian interpretations lead to distinct, practical implications of probability, especially in connection with the likelihood principle, and illustrations are provided. The role of exchangeability, which links the two views, is developed. Alternatives to probability are briefly mentioned.
Mean Square Error
Authors: Schluchter Mark D.
Published: September 2014

If is an estimator of a parameter θ, then the mean‐square(d) error (MSE) of the estimator is defined as the expectation of the squared deviation of from θ: . The MSE is a measure of closeness of the estimator to the true value. It can be shown that

That is, MSE reflects both the bias (accuracy) of the estimator, that is, how much its expected value deviates systematically from the true value, as well as the variance (precision) of the estimator, which indicates how much it varies about its expected value due to sampling variability.
Bayesian Item Response Theory Estimation
Authors: Swaminathan Hariharan
Published: September 2014

The problem of fundamental importance in item response theory is the accurate estimation of the parameters that characterize the items and the ability or the proficiency levels of examinees. While in general, likelihood‐based approaches such as joint, conditional, and marginal maximum likelihood procedures provide reasonable estimates of the item parameters, more often than not these procedures yield estimates in the two‐ and three‐parameter models that are inadmissible in the sense that the estimates of the ability and item parameters fall outside acceptable ranges. Bayesian approaches, by taking into account prior and collateral information, overcome the problems encountered by likelihood‐based approaches.
Exact Methods for Categorical Data
Authors: Hershberger Scott L.
Published: September 2014

Exact tests evaluate the significance of a test statistic by using the test statistic's empirically derived sampling distribution instead of a theoretical sampling distribution. Preference for exact tests may occur in situations in which the sample size is small, or when the data have distributional deficiencies. Two well‐known exact tests, Pitman's test and Fisher's test, are described.
z

Scores
Authors: Clark‐Carter David
Published: September 2014

A
z
‐score is the difference between a score or statistic and the mean for that score or statistic divided by the standard deviation for that score or statistic. It can be used to form inferential statistics, to find the proportion of a population that has a given score, and to identify possible outliers in a set of scores.
Scatterplots
Authors: Williams Siân E. , Wright Daniel B.
Published: September 2014

Scatterplots display the relationship between two variables. Most statistical and graphics packages allow a number of extra options to be added to provide more information about the bivariate relationship, the univariate information, and the characteristics of individual cases.
Rater Bias Models
Authors: Saudino Kimberly J.
Published: September 2014

Raters' response tendencies, standards, or expectations can result in the tendency to consistently overestimate or underestimate the behavior of targets. Such rater biases can influence the outcomes of behavioral genetic studies. Quantitative genetic models allow researchers to determine the significance of rater biases and estimate genetic and environmental influences on behaviors controlling for bias.
Scales of Measurement
Authors: Wuensch Karl L.
Published: September 2014

Scales of measurement, as conceived by S. S. Stevens, are defined with respect to (1) the extent to which empirical relationships among the measured objects correspond to numerical relationships among the measurements, and (2) the types of transformations that can be applied to the scale without distorting the structure of the scale. Stevens argued that whether or not a particular statistical analysis is ‘permissible’ depends upon the scale of measurement of the data being analyzed. While this assertion has been defended by some statisticians, it has been attacked by others. Many statistical textbooks for social scientists are organized around the assertion that scale of measurement is a critical factor in determining which statistical analysis is appropriate. Here, the authors argue that parametric statistical methods are appropriate only for interval level data and that nonparametric methods should be employed with noninterval data. One's attitude about the relationship between scale of measurement and choice of statistical analysis may follow from one's more basic ideas about measurement and the nature of reality. Ultimately, the distinction between interval and ordinal scales depends on whether one believes the relationship between the measurements and the true amounts of the measured attribute is positive linear (interval) or merely positive monotonic (ordinal), and such beliefs are largely a matter of faith.
Recursive Models
Authors: Cortina Lilia M.
Published: September 2014

Recursive statistical models only include unidirectional effects – that is, causality flows in only one direction. These models do not permit reciprocal causation or feedback loops, nor do they allow variables that are linked in a causal chain to have correlated disturbance terms. If all criteria for being recursive are met, then the model is identified.
Eigenvalues and eigenvectors in statistics
Authors: Jolliffe Ian
Published: September 2014

The words eigenvalue and eigenvector often appear in computer output for multivariate statistical techniques. An explanation is given of what is meant by these terms for some specific techniques and more generally.
Multitrait–Multimethod Analyses
Authors: Pardy Susan A. , Fabrigar Leandre R. , Visser Penny S.
Published: September 2014

The multitrait‐multimethod (MTMM) framework originally proposed by Campbell and Fiske has long guided efforts to assess the discriminant and convergent validity of measures. Numerous statistical approaches for analyzing MTMM matrices have been proposed. Surprisingly, little consensus has developed on the most appropriate method for analyzing these matrices or what criteria should be used as a basis for choosing the most appropriate method. We provide a nontechnical review of statistical approaches for analyzing MTMM matrices. We conclude with a set of general recommendations regarding the analysis of MTMM data.
F
riedman's Test
Authors: Sawilowsky Shlomo , Fahoome Gail
Published: September 2014

The nonparametric Friedman test expands the Sign (
S
) test to
k
related samples. The null hypothesis is that the samples come from the same population, which is tested against the alternative that at least one of the samples comes from a different population.
Ethics in Research
Authors: Miller Richard
Published: September 2014

This review of research ethics provides a history of the regulation of research ethics and a summary of ethical issues including the recruitment of human participants, informed consent, debriefing, deception, avoiding harm, confidentiality, risk/benefit assessment, vulnerable populations, methodological issues, the use of animals, and ethical publication standards.
Clinical Trials and Intervention Studies
Authors: Lesaffre Emmanuel , Verbeke Geert
Published: September 2014

Intervention studies are experimental studies that evaluate the effect of an intervention on humans. There are many different types of intervention, including medical, social, psychological, and so on. In all of these cases, interventions seek to improve the condition of the individual. In an epidemiological context, an intervention study is a specific type of a cohort study. When a medical intervention is involved, one speaks of a clinical trial. Clinical trials take a prominent place in clinical research, as they are pivotal for the registration of new medical treatments.

We give a brief overview of the types of intervention studies, but special attention will be paid to clinical trials. Aspects of designing and analyzing an intervention study will be presented.
Logistic Regression in Practice
Authors: Lemeshow Stanley , W. Hosmer David
Published: September 2014

This article deals with the use of logistic regression to model data, where the response variable is binary and there are potentially numerous explanatory or predictor variables. Methods of estimating the coefficients in the model and procedures for hypothesis testing are considered. The correspondence of the coefficients of the logistic regression model to the odds ratio is noted along with methods for computing point estimates and confidence intervals for the odds ratio. Interpretation of coefficients for dichotomous, polytomous, and continuous independent variables is carefully developed. Confounding and effect modification are easily dealt with through the use of this modeling technique. All these concepts are illustrated through the analysis of low birth weight data.
Repository
Authors: Winkler Cheryl A , Groover Kathleen H.
Published: September 2014

Repositories for the acquisition, storage/archival, and distribution of biosamples are essential to the success of clinical trials and biomedical research. In the current era of genomics and proteomics, the banking of human biosamples and associated phenotypes for the discovery of genetic factors underpinning rare and common diseases has expanded the role and impact of repositories and biobanks. Today's repositories are banking an unprecedented number of biosamples and data for molecular‐based research. This article provides an overview of repository models, the core function and management of repositories, and issues that pertain to the protection of donor rights and confidentiality.
Conditional Power in Clinical Trial Monitoring
Authors: Tan Ming T.
Published: September 2014

For ethical, economical, and scientific reasons, clinical trials may be terminated early for treatment efficacy or the lack thereof. In addition to group sequential tests and type I error‐spending functions, another approach is to ask more directly whether the accumulated evidence is sufficiently convincing for efficacy. Or, if evidence is lacking, one would ask whether the trial should continue to the planned end and whether the conventional fixed sample (nonsequential) test should be employed. Conditional power is one way to quantify this evidence. It is the power of the conventional nonsequential test conditional on interim data. This article introduces the versatile conditional power and related stochastic curtailment approaches in the monitoring of clinical trials.
Change/Percent Change From Baseline
Authors: Vickers Andrew J.
Published: September 2014

Many clinical trials involve baseline and follow‐up assessment of a continuous outcome, such as pain, blood pressure, or weight. Different methods are available to analyze the results of such trials, which include between‐group two‐sample comparisons of the follow‐up measure, change score or percentage change, and linear regression of treatment on the follow‐up measure with the baseline measure as a covariate [analysis of covariance (ANCOVA)]. Each method provides a statistic that may have greater or less clinical applicability, depending on the particular trial involved. ANCOVA has greatest statistical power irrespective of the correlation between baseline and follow‐up measure, the nature of the treatment effect (shift or ratio), whether the control group also experiences change, and the distribution of the follow‐up measure. ANCOVA has additional advantages including control for chance baseline differences and incorporation of randomization strata as covariates. If trials results are best expressed in terms other than ANCOVA, such as a percentage change, then the preferred approach is to analyze the trial using ANCOVA and then convert the results into statistics that can be readily understood by clinicians.
Placebos
Authors: Holbrook Anne , Goldsmith Charles H. , Leung Mova
Published: September 2014

Placebos have a long and controversial history in clinical research and in practice. In this chapter, we review the meaning, the pharmacology, effectiveness, safety, influences on, and ethical issues involving placebos. Various international guidelines for the use of placebos in research are available and evolving. We then suggest novel factorial designs to allow a full assessment of efficacy and safety of a new therapy while minimizing patient exposure to placebo alone.
Repeatability and Reproducibility
Authors: Connett John E.
Published: September 2014

Repeatability and reproducibility are defined, the distinction between them is described, and examples are provided. The use of these measures in quantifying the precision of laboratory procedures is discussed. The role of reproducibility in the estimation of sample size for clinical trials with quantitative outcomes is explained.
Negative Binomial Distribution ‐ Applications
Authors: El‐shaarawi Abdel H.
Published: September 2014

The negative binomial distribution is widely used to analyze count data. In environmentrics, one is frequently interested in summarizing the changes in the abundance of particular organisms in the environment either for protection or impact assessment. For example, monitoring the safety of a drinking water source is based on the estimation of the density of an indicator bacteria from the number of organisms found in several water samples. Another example is the estimation of the abundance of threatened species and the impact of habitat changes on their numbers in ecological conservation.
Extra Risk
Authors: West R. Webster
Published: September 2014

To properly quantify the toxic effect of a toxin, the
background risk
of no exposure to the toxin,
R
(0), must first be specified. The excess risk incurred by exposure to a dose,
d
, of the toxin is then viewed as the added risk at this dose relative to the rate of nonadverse responses, 1 − 
R
(0), in the unexposed population.
Historical Controls: Example
Authors: Ryan Louise
Published: September 2014

Because development toxicity, carcinogenicity, and other toxicological studies are typically conducted in genetically homogeneous animal strains, the large historical database that builds up over time can often prove useful in interpreting results from current experiments. For instance, if a certain defect has only rarely appeared among control animals, then its appearance among even a few exposed animals may indicate strong cause for concern even though statistical tests may not yield a significant dose effect for that current study. Of course, the use of historical control information requires caution. It is important that the current and historical studies are similar with respect to study design, animal species, quality assurance and review procedures, as well as diagnostic and nomenclature conventions.
Groundwater Monitoring, Detection, and Compliance
Authors: Gibbons Robert D. , Bhaumik Dulal K. , Aryal Subhash
Published: September 2014

An overview of statistical issues and methods is provided relevant to the analysis of groundwater detection and compliance‐monitoring problems. The rich methodology that has been used in this area goes well beyond groundwater monitoring applications to many other areas of interest in environmental monitoring and statistics. First, we provide an overview of statistical prediction limits for normal, lognormal, and gamma random variables, as well as nonparametric alternatives. Issues related to multiple comparisons, censored data, nonnormality, and verification sampling (i.e., sequential testing) are considered in the statistical developments. Second, we provide an overview of statistical methods that are relevant for compliance monitoring, where interest is often focused on whether on‐site average concentrations exceed a health‐based regulatory standard. This leads to discussion of a variety of statistical approaches based on confidence limits for normal and nonnormal distributions and nonparametric alternatives. A distinction is made between assessment monitoring where the null hypothesis is that contamination
is not
present and corrective action monitoring where the null hypothesis is that contamination
is
present.
Life‐Stage Analysis
Authors: Young Linda J.
Published: September 2014

For animals with well‐defined life stages, life stage analysis may be used to estimate properties of the stages, such as the total number of individuals that enter the stage, the mean time spent in a life stage, the probability of surviving each life stage, the mean time to entering each life stage, or the unit time survival rate. In life tables, population survival and mortality are displayed in a systematic manner and may be either age specific or time specific. The Kiritani–Nakasuji–Manly method is perhaps the most widely used method for estimating time unit and stage survival rates and stage duration. Key stages may be defined to be those life stages exhibiting the most variation or those having the greatest effect on the variation in the numbers entering the final stage. Given the structure of a continuously reproducing population in one time period, matrix population models are used to estimate the numbers in each life stage during the next time period or at some more distant time.
Point Processes, Spatial‐Temporal
Authors: Schoenberg Frederic Paik , Brillinger David R. , Guttorp Peter
Published: September 2014

A spatial–temporal point process (also called space–time or spatio‐temporal point process) is a random collection of points, where each point represents the time and location of an event. Examples of events include incidence of disease, sightings or births of a species, or the occurrences of fires, earthquakes, lightning strikes, tsunamis, or volcanic eruptions. Typically the spatial locations are recorded in three spatial coordinates, e.g. longitude, latitude, and height or depth, though sometimes only one or two spatial coordinates are available or of interest.
Laser‐Activatible PLGA Microparticles for Image‐Guided Cancer Therapy In Vivo
Authors: Sun Yang , Wang Yanjie , Niu Chengcheng , Strohm Eric M. , Zheng Yuanyi , Ran Haitao , Huang Rongzhong , Zhou Di , Gong Yuping , Wang Zhigang , Wang Dong , Kolios Michael C.
Published: September 2014

Poly(lactide‐co‐glycolic acid) (PLGA) particles are biocompatible and bio­degradable, and can be used as a carrier for various chemotherapeutic drugs, imaging agents and targeting moieties. Micrometer‐sized PLGA particles were synthesized with gold nanoparticles and DiI dye within the PLGA shell, and perfluorohexane liquid (PFH) in the core. Upon laser irradiation, the PLGA shell absorbs the laser energy, activating the liquid core (liquid conversion to gas). The rapidly expanding gas is expelled from the particle, resulting in a microbubble; this violent process can cause damage to cells and tissue. Studies using cell cultures show that PLGA particles phagocytosed by single cells are consistently vaporized by laser energies of 90 mJ cm−2, resulting in cell destruction. Rabbits with metastasized squamous carcinoma in the lymph nodes are then used to evaluate the anti‐cancer effects of these particles in the lymph nodes. After percutaneous injection of the particles and upon laser irradiation, through the process of optical droplet vaporization, ultrasound imaging shows a significant increase in contrast in comparison to the control. Histology and electron microscopy confirm damage with disrupted cells throughout the lymph nodes, which slows the tumor growth rate. This study shows that PLGA particles containing PFC liquids can be used as theranostic agents in vivo.
Polysaccharide‐Coated PCL Nanofibers for Wound Dressing Applications
Authors: Croisier Florence , Atanasova Ganka , Poumay Yves , Jérôme Christine
Published: September 2014

Polysaccharide‐based nanofibers with a multilayered structure are prepared by combining electrospinning (ESP) and layer‐by‐layer (LBL) deposition techniques. Charged nanofibers are firstly prepared by electrospinning poly(ε‐caprolactone) (PCL) with a block‐copolymer bearing carboxylic acid functions. After deprotonation of the acid groups, the layer‐by‐layer deposition of polyelectrolyte polysaccharides, notably chitosan and hyaluronic acid, is used to coat the electrospun fibers. A multilayered structure is achieved by alternating the deposition of the positively charged chitosan with the deposition of a negatively charged polyelectrolyte. The construction of this multilayered structure is followed by Zeta potential measurements, and confirmed by observation of hollow nanofibers resulting from the dissolution of the PCL core in a selective solvent. These novel polysaccharide‐coated PCL fiber mats remarkably combine the mechanical resistance typical of the core material (PCL)—particularly in the hydrated state—with the surface properties of chitosan. The control of the nanofiber structure offered by the electrospinning technology, makes the developed process very promising to precisely design biomaterials for tissue engineering. Preliminary cell culture tests corroborate the potential use of such system in wound healing applications.
In Situ Morphology Studies of the Mechanism for Solution Additive Effects on the Formation of Bulk Heterojunction Films
Authors: Richter Lee J. , DeLongchamp Dean M. , Bokel Felicia A. , Engmann Sebastian , Chou Kang Wei , Amassian Aram , Schaible Eric , Hexemer Alexander
Published: September 2014

The most successful active film morphology in organic photovoltaics is the bulk heterojunction (BHJ). The performance of a BHJ arises from a complex interplay of the spatial organization of the segregated donor and acceptor phases and the local order/quality of the respective phases. These critical morphological features develop dynamically during film formation, and it has become common practice to control them by the introduction of processing additives. Here, in situ grazing incidence X‐ray diffraction (GIXD) and grazing incidence small angle X‐ray scattering (GISAXS) studies of the development of order in BHJ films formed from the donor polymer poly(3‐hexylthiophene) and acceptor phenyl‐C61‐butyric acid methyl ester under the influence of two common additives, 1,8‐octanedithiol and 1‐chloronaphthalene, are reported. By comparing optical aggregation to crystallization and using GISAXS to determine the number and nature of phases present during drying, two common mechanisms by which the additives increase P3HT crystallinity are identified. Additives accelerate the appearance of pre‐crystalline nuclei by controlling solvent quality and allow for extended crystal growth by delaying the onset of PCBM‐induced vitrification. The glass transition effects vary system‐to‐system and may be correlated to the number and composition of phases present during drying.
An immunologic test for chronic rhinosinusitis based on free intranasal eosinophilic major basic protein
Authors: Ponikau Jens U. , Winter Laurie A. , Kephart Gail M. , Squillace Diane L. , Hershcovitch Matt D. , Moon Seo , Sherris David A. , Kern Eugene B. , Gleich Gerald J. , Kita Hirohito
Published: September 2014

Background

A histologic hallmark of chronic rhinosinusitis (CRS) is an eosinophilic inflammation, present with and without nasal polyposis and independent of atopy. Eosinophils migrate through nasal tissue including the epithelium into the nasal airway mucus, where they form clusters and degranulate, releasing granule proteins including the toxic major basic protein (MBP). Specific biomarkers for CRS, which could be used as a diagnostic test for CRS with a high sensitivity and specificity, are presently lacking. Recently, an enzyme‐linked immunosorbent assay (ELISA)‐based test for MBP in nasal airway mucus received regulatory approval.

Methods

A new assay was specifically developed to detect released MBP in airway mucus. MBP levels in nasal mucus of 85 randomly selected CRS patients diagnosed by endoscopy, computed tomography (CT) scans and symptoms were compared to 13 healthy controls and 5 disease controls (allergic rhinitis).

Results

Overall, 92% (78/85) of CRS patients’ mucus were positive for MBP (mean 7722 ng/mL) vs none of 13 healthy controls and none of 5 allergic rhinitis patients (<7.8 ng/mL; p < 0.000000000002). In this study, the MBP ELISA had a 92% sensitivity and 100% specificity for CRS.

Conclusion

Free MBP in nasal mucus can be used as a biomarker to diagnose CRS. The MBP ELISA represents the first immunologically‐based test to potentially distinguish CRS from the eosinophilic inflammation in allergic rhinitis.
RESOLVE: a randomized, controlled, blinded study of bioabsorbable steroid‐eluting sinus implants for in‐office treatment of recurrent sinonasal polyposis
Authors: Han Joseph K. , Forwith Keith D. , Smith Timothy L. , Kern Robert C. , Brown William J. , Miller Steven K. , Ow Randall A. , Poetker David M. , Karanfilov Boris , Matheny Keith E. , Stambaugh James , Gawlicka Anna K.
Published: September 2014

Background

Patients with recurrent sinonasal polyposis after endoscopic sinus surgery (ESS) have limited treatment options. This study evaluated the safety and efficacy of a bioabsorbable steroid‐eluting implant with 1350 μg of mometasone furoate for its ability to dilate obstructed ethmoid sinuses, reduce polyposis, and reestablish sinus patency.

Methods

This was a randomized, controlled, blinded study including 100 patients chronic rhinosinusitis with nasal polyposis (CRSwNP) refractory to medical therapy and considered candidates for revision ESS. Follow‐up included endoscopic grading by investigators and patient‐reported outcomes.

Results

Treated patients (n = 53; age as mean ± standard deviation [SD] 47.8 ± 12.6 years; 55% male) underwent in‐office bilateral placement. Control patients (n = 47; age 51.6 ± 13.1 years; 66% male) underwent a sham procedure. At 3 months, treated patients experienced a significant reduction in bilateral polyp grade (p = 0.0269) and ethmoid sinus obstruction (p = 0.0001) compared to controls. Treated patients also experienced a 2‐fold improvement in the mean nasal obstruction/congestion score (−1.33 ± 1.47 vs −0.67 ± 1.45; p = 0.1365). This improvement reached statistical significance (p = 0.025) in patients with greater polyp burden (grade ≥2 bilaterally; n = 74). At 3 months, 53% of treated patients compared to only 23% of controls were no longer indicated for repeat ESS. There was no serious adverse event or clinically significant increases in intraocular pressure or cataract formation.

Conclusion

The symptomatic improvement and statistically significant reduction in polyp grade and ethmoid sinus obstruction supported the efficacy of the steroid‐eluting implant for in‐office treatment of CRS patient with recurrent polyposis after ESS. The study results demonstrated that the steroid‐eluting implant represents a safe and effective alternative to current management for this patient population.
Volatile fatty acids derived from waste organics provide an economical carbon source for microbial lipids/biodiesel production
Authors: Park Gwon Woo , Fei Qiang , Jung Kwonsu , Chang Ho Nam , Kim , Yeu‐Chun , Kim Nag‐jong , Choi Jin‐dal‐rae , Kim Sangyong , Cho Jaehoon
Published: September 2014

Volatile fatty acids (VFAs) derived from organic waste, were used as a low cost carbon source for high bioreactor productivity and titer. A multi‐stage continuous high cell density culture (MSC‐HCDC) process was employed for economic assessment of microbial lipids for biodiesel production. In a simulation study we used a lipid yield of 0.3 g/g‐VFAs, cell mass yield of 0.5 g/g‐glucose or wood hydrolyzates, and employed process variables including lipid contents from 10–90% of cell mass, bioreactor productivity of 0.5–48 g/L/h, and plant capacity of 20000–1000000 metric ton (MT)/year. A production cost of USD 1.048/kg‐lipid was predicted with raw material costs of USD 0.2/kg for wood hydrolyzates and USD 0.15/kg for VFAs; 9 g/L/h bioreactor productivity; 100, 000 MT/year production capacity; and 75% lipids content. The variables having the highest impact on microbial lipid production costs were the cost of VFAs and lipid yield, followed by lipid content, fermenter cost, and lipid productivity. The cost of raw materials accounted for 66.25% of total operating costs. This study shows that biodiesel from microbial lipids has the potential to become competitive with diesels from other sources.
Advanced TEMKIN Reactor: Testing of Industrial Egg‐Shell Catalysts in Lab Scale
Authors: Kuhn Martin , Lucas Martin , Claus Peter
Published: September 2014

Bei vielen Reaktionen in der chemischen Industrie werden Schalenkatalysatoren mit einer dünnen aktiven Schicht eingesetzt, die für Laboruntersuchungen häufig zerkleinert werden. Die Zerstörung der Schale kann durch ein spezielles Reaktordesign verhindert werden. Der hier vorgestellte Advanced‐TEMKIN‐Reaktor ist eine Weiterentwicklung des von Temkin 1969 vorgeschlagenen Reaktorsystems zur Testung von Schalenkatalysatoren im Labormaßstab. Er eignet sich für kinetische Studien ebenso wie für die detaillierte Untersuchung von Desaktivierungsvorgängen, wie anhand der Selektivhydrierung von Acetylen gezeigt wird.
Co2(CO)8‐mediated Selective Reductions of Propargyl Alcohol Derivatives to Alkenes
Authors: Dou Ying , Xing Ping , Huang Zuogang , Jiang Biao
Published: September 2014

In the presence of Co2(CO)8 and additives, propargyl alcohol derivatives could be reduced to alkenes in moderate to good yield. The selectivity of this reaction could be controlled by adding different additives: with H2O as the additive, the major configuration of product is Z‐alkene; with CF3COOH as the additive, the major configuration of product is E‐alkene.
Efficient and Practical Syntheses of Enantiomerically Pure (S)‐(−)‐Norcryptostyline I, (S)‐(−)‐Norcryptostyline II, (R)‐(+)‐Salsolidine and (S)‐(−)‐Norlaudanosine via a Resolution‐Racemization Method
Authors: Zhu Ruiheng , Xu Zhangli , Ding Wei , Liu Shiling , Shi Xiaoxin , Lu Xia
Published: September 2014

Four racemic tetrahydroisoquinolines (RS)‐(±)‐1–4 were prepared from homoveratrylamine via amidation, Bischler‐Napieralski reaction and the subsequent reduction. The enantiomerically pure tetrahydroisoquinolines (S)‐ (−)‐norcryptostyline I [(S)‐(−)‐1], (S)‐(−)‐norcryptostyline II [(S)‐(−)‐2], (R)‐(+)‐salsolidine [(R)‐(+)‐3] and (S)‐(−)‐norlaudanosine [(S)‐(−)‐4] were then obtained in 45%, 40%, 41% and 38% yields, respectively, via resolution of the racemic compounds (RS)‐(±)‐1–4 with half equivalent of chiral acids. In addition, the enantiomerically enriched compounds (R)‐(+)‐1, (R)‐(+)‐2, (S)‐(−)‐3 and (R)‐(+)‐4 from the mother liquors were efficiently racemized via a one‐pot redox method in almost quantitative yields.
Tuning the Charge Transport Property of Naphthalene Diimide Derivatives by Changing the Substituted Position of Fluorine Atom on Molecular Backbone
Authors: Zhang Xiao , Wang Zhongli , Chen Shiyan , Zhao Zheng , Yuan Wei , Wang Huaping , Gao Xike
Published: September 2014

Three naphthalene diimides (2, 3 and 4) fused with 2‐(1,3‐dithiol‐2‐ylidene)‐2‐fluorophenylacetonitrile moieties were designed and synthesized. Due to the different substituted positions of fluorine atom on the phenyl group, the solution‐processed thin films of 2 and 3 operated in air as n‐channel transistors, while the films of 4 performed as ambipolar transistors, indicating that the variation of substituted position of fluorine atom on molecular backbone may tune the material's charge transport behavior.
Influence of knowledge of human immunodeficiency virus serostatus on accuracy of cervical cytologic diagnosis
Authors: van Bogaert Louis‐Jacques
Published: September 2014

BACKGROUND

Women who are infected with the human immunodeficiency virus (HIV) are at high risk of human papillomavirus‐persistent infections. Invasive cervical cancer is listed among the illnesses associated with the acquired immunodeficiency syndrome. The objective of the current study was to investigate whether, in South Africa, the accuracy of abnormal cytology confirmed by a histological diagnosis using loop electrosurgical excision procedure (LEEP) is affected by knowledge of the woman's HIV serostatus.

METHODS

Of 7648 biopsy specimens, 941 were LEEPs indicated by a cytology report of low‐grade squamous intraepithelial lesion or high‐grade squamous intraepithelial lesion. A total of 618 specimens (65.7%) were from HIV‐uninfected women and 323 specimens (34.3%) were from HIV‐infected women. Those women with an unknown pre‐LEEP cytological diagnosis were excluded from the study.

RESULTS

The total prevalence of HIV infection among the 7648 patients was 18.6%, reflecting its prevalence in the general population of women aged 15 to 49 years. The rate of HIV infection among 3462 women with invasive cervical cancer was 10.7%. The overall prevalence of preinvasive lesions was 73.9% in HIV‐infected women compared with 50.3% in women not infected with HIV (P<.0001). The concordance and discordance rates between cytology and histology were similar in uninfected and infected women (P =.93 and P =.18, respectively). Among HIV‐infected women, 79.1% of discordant results were due to cytological overdiagnosis; among HIV‐negative women, 86.5% of discordant results were due to underdiagnosis (P<.0001).

CONCLUSIONS

It appears that the finding of a higher prevalence of preinvasive lesions combined with the knowledge of a patient's HIV‐positive serostatus prompts more cytological overdiagnosis, thereby resulting in avoidable LEEP interventions. Cancer (Cancer Cytopathol) 2014;122:909–913. © 2014 American Cancer Society.
Analysis of bipolar and amacrine populations in marmoset retina
Authors: Weltzien Felix , Percival Kumiko A. , Martin Paul R. , Grünert Ulrike
Published: September 2014

About 15 parallel ganglion cell pathways transmit visual signals to the brain, but the interneuron (bipolar and amacrine) populations providing input to ganglion cells remain poorly understood in primate retina. We carried out a quantitative analysis of the inner nuclear layer in the retina of the marmoset (Callithrix jacchus). Vertical Vibratome sections along the horizontal meridian were processed with immunohistochemical markers. Image stacks were taken with a confocal microscope, and densities of cell populations were determined. The density of flat midget bipolar cells fell from 15,746 cells/mm2 at 1 mm (8 deg) to 7,827 cells/mm2 at 3 mm (25 deg). The rod bipolar cell density fell from 8,640 cells/mm2 at 1 mm to 4,278 cells/mm2 at 3 mm, but the ratio of the two bipolar cell types did not change with eccentricity. The amacrine cell density ranged from 30,000 cells/mm2 at 8 deg to less than 15,000 cells/mm2 at 25 deg, but throughout the retina, the ratio of glycinergic to γ‐aminobutyric acid (GABA)ergic to amacrine cells remained relatively constant. The fractions of rod bipolar, cone bipolar, amacrine, Müller, and horizontal cells of all cells in the inner nuclear layer were comparable in central and peripheral retina. Marmosets had lower proportions of midget bipolar and rod bipolar in comparison with macaque. These differences were correlated with differences in rod and cone densities between the two species and did not reflect fundamental differences in the wiring between the two species. J. Comp. Neurol. 523:313–334, 2015. © 2014 Wiley Periodicals, Inc.
Constitutional Hybrid Materials – Toward Selection of Functions
Authors: Barboiu Mihail
Published: September 2014

This microreview reveals a new strategy to transcribe supramolecular architectures in self‐organized constitutional hybrids. In particular, the use of communicating reversible‐covalent and supramolecular hydrophobic interfaces between organic/supramolecular and inorganic/siloxane networks represents a useful approach for improving their compatibility. Interpenetrated hybrid components lead, after the sol–gel process, to materials in which the features of supramolecular and inorganic networks are expressed through cross‐over and linear processing schemes. Such a “dynamic marriage” between the processes of supramolecular self‐assembly and inorganic sol–gel polymerization, which communicate synergistically, leads to higher self‐organized hybrid materials on increased micrometric scale. Considering the simplicity of this strategy, possible applications in membranes and sensors are effective, reaching close to novel expressions of complex matter.
Rhodium‐Catalyzed Oxidative Perfluoroalkenylation by Carbonyl Group Directed C–H Bond Activation
Authors: Kathiravan Subban , Nicholls Ian A.
Published: September 2014

The selective activation of C–H bonds under mild RhIII catalytic conditions has been developed for the perfluoroalkenylation of various cyclic and acyclic aromatic ketones. This protocol uses versatile reagents and mild conditions. It requires a very low catalyst loading and has exceptional functional group tolerance as well as provides products in good to excellent yields. An application of this approach was described for the preparation of perfluoroethyl acrylate derivatives of biologically active substances.
Neck/upper back and low back pain in parents and their adult offspring: Family linkage data from the Norwegian HUNT Study
Authors: Lier R. , Nilsen T.I.L. , Vasseljen O. , Mork P.J.
Published: September 2014

Background

Chronic pain in the neck and low back is highly prevalent. Although heritable components have been identified, knowledge about generational transmission of spinal pain between parents and their adult offspring is sparse.

Methods

This study examined the intergenerational association of spinal pain using data from 11,081 parent–offspring trios participating in the population‐based HUNT Study in Norway. Logistic regression was used to calculate adjusted odds ratios (ORs) with 95% confidence intervals (CIs) for offspring spinal pain associated with parental spinal pain.

Results

In total, 3654 (33%) offspring reported spinal pain at participation. Maternal and paternal spinal pain was consistently associated with higher ORs for offspring spinal pain. The results suggest a slightly stronger association for parental multilevel spinal pain (i.e., both neck/upper back pain and low back pain) than for pain localized to the neck/upper back or low back. Multilevel spinal pain in both parents was associated with ORs of 2.6 (95% CI, 2.1–3.3), 2.4 (95% CI, 1.9–3.1) and 3.1 (95% CI, 2.2–4.4) for offspring neck/upper back, low back and multilevel spinal pain, respectively.

Conclusion

Parental chronic spinal pain was consistently associated with increased occurrence of chronic spinal pain in their adult offspring, and this association was particularly strong for multilevel spinal pain.
Evaluation of sulfated maltodextrin as a novel anionic chiral selector for the enantioseparation of basic chiral drugs by capillary electrophoresis
Authors: Tabani Hadi , Mahyari Mojtaba , Sahragard Ali , Fakhari Ali Reza , Shaabani Ahmad
Published: September 2014

Introducing a new class of chiral selectors is an interesting work and this issue is still one of the hot topics in separation science and chirality. In this study, for the first time, sulfated maltodextrin (MD) was synthesized as a new anionic chiral selector and then it was successfully applied for the enantioseparation of five basic drugs (amlodipine, hydroxyzine, fluoxetine, tolterodine, and tramadol) as model chiral compounds using CE. This chiral selector has two recognition sites: a helical structure and a sulfated group which contribute to three corresponding driving forces; inclusion complexation, electrostatic interaction, and hydrogen binding. Under the optimized condition (buffer solution: 50 mM phosphate (pH 3.0) and 2% w/v sulfated MD; applied voltage: 18 kV; temperature: 20°C), baseline enantioseparation was observed for all mentioned chiral drugs. When instead of sulfated MD neutral MD was used under the same condition, no enantioseparation was observed which means the resolution power of sulfated MD is higher than neutral MD due to the electrostatic interaction between sulfated groups and protonated chiral drugs. Also, the countercurrent mobility of negatively charged MD (sulfated MD) allows more interactions between the chiral selector and chiral drugs and this in turn results in a successful resolution for the enantiomers. Furthermore, a higher concentration of neutral MD (approximately five times) is necessary to achieve the equivalent resolution compared with the negatively charged MD.
A fully implicit scheme for simulating ionized gas flows using the gas dynamics electrodynamics coupled system
Authors: Panourgias Konstantinos T. , Ekaterinaris John A.
Published: September 2014

The flow of ionized gases under the influence of electromagnetic fields is governed by the coupled system of the compressible flow equations and the Maxwell equations. In this system, coupling of the flow with the electromagnetic field is obtained through nonlinear and stiff source terms, which may cause difficulties with the numerical solution of the coupled system. The discontinuous Galerkin finite element method is used for the numerical solution of this system. For the magnetic field vector, discontinuous Galerkin discretization is performed using a divergence‐free vector base for the magnetic field to preserve zero divergence in the element and retain the implicit constraint of a divergence‐free magnetic field vector down to very low level both globally and locally. To circumvent difficulties resulting from the presence of the stiff source terms, implicit time marching is used for the fully coupled system to avoid wrong wave shapes and propagation speeds that are obtained when the coupling source terms are lagged in time or by using splitting iterative schemes. Numerical solutions for benchmark problems computed on collocated meshes for the flow and electromagnetic field variables with this fully coupled monolithic approach showed good agreement with other numerical solutions and exact results. Copyright © 2014 John Wiley & Sons, Ltd.
Dysregulated serum response factor triggers formation of hepatocellular carcinoma
Authors: Ohrnberger Stefan , Thavamani Abhishek , Braeuning Albert , Lipka Daniel B. , Kirilov Milen , Geffers Robert , Authenrieth Stella E. , Römer Michael , Zell Andreas , Bonin Michael , Schwarz Michael , Schütz Günther , Schirmacher Peter , Plass Christoph , Longerich Thomas , Nordheim Alfred
Published: September 2014

The ubiquitously expressed transcriptional regulator serum response factor (SRF) is controlled by both Ras/MAPK (mitogen‐activated protein kinase) and Rho/actin signaling pathways, which are frequently activated in hepatocellular carcinoma (HCC). We generated SRF‐VP16iHep
mice, which conditionally express constitutively active SRF‐VP16 in hepatocytes, thereby controlling subsets of both Ras/MAPK‐ and Rho/actin‐stimulated target genes. All SRF‐VP16iHep
mice develop hyperproliferative liver nodules that progresses to lethal HCC. Some murine (m)HCCs acquire Ctnnb1 mutations equivalent to those in human (h)HCC. The resulting transcript signatures mirror those of a distinct subgroup of hHCCs, with shared activation of oncofetal genes including Igf2, correlating with CpG hypomethylation at the imprinted Igf2/H19 locus. Conclusion: SRF‐VP16iHep
mHCC reveal convergent Ras/MAPK and Rho/actin signaling as a highly oncogenic driver mechanism for hepatocarcinogenesis. This suggests simultaneous inhibition of Ras/MAPK and Rho/actin signaling as a treatment strategy in hHCC therapy. (Hepatology 2015;61:979–989)