bluuebunny/crossref_metadata_2025_split huggingface dataset:
Conditional Power in Clinical Trial Monitoring
Authors: Tan Ming T. 
Published: September 2014

Abstract
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

Abstract
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

AbstractPlacebos 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.
Negative Binomial Distribution ‐ Applications
Authors: El‐shaarawi Abdel H. 
Published: September 2014

AbstractThe 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

Abstract

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

Abstract
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

Abstract

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

Abstract
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

AbstractA 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.
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

BackgroundA 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.MethodsA 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).ResultsOverall, 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.ConclusionFree 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

BackgroundPatients 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.MethodsThis 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.ResultsTreated 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.ConclusionThe 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

AbstractVolatile 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

AbstractBei 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

AbstractIn 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

AbstractFour 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

AbstractThree 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

BACKGROUNDWomen 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.METHODSOf 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.RESULTSThe 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).CONCLUSIONSIt 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

ABSTRACTAbout 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

AbstractThis 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

AbstractThe 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

AbstractBackgroundChronic 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.MethodsThis 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.ResultsIn 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.ConclusionParental 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.