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Atrial fibrillation in the elderly: Is ablation ready for prime time ?

作者： (美)乔治·j. 塞拉斯(george j. Searles)

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j.urnal of Geriatric Cardiology 2005年第2期2卷 101-102页

作者： Allen j. Solomon george Washington University Hospital

Atrial fibrillation is the most common sustained arrhythmia and results in significant morbidity, especially in the elderly. The prevalence of atrial fibrillation increases dramatically with advancing age to almost 6% in individuals older than 65 years. In fact, 84% of people with atrial fibrillation are over 65 years of age.1 Additionally, the risk of stroke increases with advancing age, such that one-third of strokes in patients over the age of 65 are caused by atrial fibrillation.

关键词： Is ablation ready for prime time Atrial fibrillation in the elderly

Analytical Modeling to Predict the Strain Energy of Circular GLARE Fiber-Metal Laminates Under Lateral Indentation

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材料科学与工程（中英文A版） 2013年第8期3卷 569-583页

作者： george j. Tsamasphyros george S. E. Bikakis Strength of Materials Laboratory National Technical University of Athens Athens 157 73 GR Greece

This article deals with the strain energy calculation of thin circular clamped Glass Reinforced (GLARE) fiber-metal laminates subj.cted to static indentation by a lateral hemispherical indentor. Using one-, two- and three-parameter Ritz approximations, analytical equations of the strain energy as a function of the central plate deflection are derived. Previously published analytical formulas, concerning the load-indentation response of circular GLARE plates, are used in order to determine the Ritz parameters and the first failure load and deflection due to tensile fracture of glass-epoxy layers. In this study, the membrane and bending strain energy components of aluminum and prepreg layers are determined. Also, the elastic and plastic strain energy absorbed during the indentation loading are calculated. The derived formulas are applied successfully for GLARE 2-2/1-0.3, GLARE 3-3/2-0.4 and GLARE 3I (special lay-up) circular plates subj.cted to lateral indentation. The strain energy results converge satisfactorily in all examined cases. The predicted strain energy-indentation response is compared with published experimental data and a good agreement is found. No other solution of this problem is known to the authors.

关键词：纤维金属层板弯曲应变能压痕预测建模解析公式金属层压板塑性应变能

The Study of a Simple Pine-Oil Based Laboratory Prepared and Commercial Detergents Using Conductivity Measurements

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American j.urnal of Analytical Chemistry 2015年第12期6卷 957-964页

作者： Mosotho j. george Ts’ukulu Motsamai Department of Chemistry and Chemical Technology National University of Lesotho Roma Lesotho

Detergents are very important substances in everyday life as they are used in laundry services. This manuscript reports the study of the commercial and laboratory prepared pine oil-based detergents employing the critical micelle concentration (CMC) phenomenon using conductivity measurements. The two samples showed the CMC values of 0.0725 g/cm3 and 0.0920 g/cm3 for laboratory and commercial samples respectively. The effect of ionic strength was investigated using NaCl and it demonstrated a drop of CMC value of about CMC by 40% (laboratory sample) and 70% (commercial sample) while the equi-molar naphthalene increased the CMC values by about 50% (laboratory sample) and 12% (commercial sample) relative to their corresponding values under distilled water. The combined effect of equi-molar NaCl and naphthalene lowered the CMC by 5% (laboratory sample) and 30% (commercial sample). These differences could signify the superiority of the laboratory sample in that it is somehow buffered against drastic changes in the CMC under different conditions. The relationship between conductivity and the CMC values does not show sufficient linearity (R2 < 0.8403) suggesting different mechanisms of interactions between NaCl and naphthalene. Overall, the results are gratifying to the small-scale manufacturer who supplied the preparation protocol for laboratory sample preparation, in two respects: they inspire some degree of confidence in his product as well as enabling the manufacturer to employ the same protocol for his quality control practices as such improve product consistency and hence profitability.

关键词： Detergent Pine Gel Critical Micelle Concentration Conductivity Ionic Strength Small-Scale Manufacturer

An Analysis of Specific Categories of Birth Defects and Developmental Disabilities for Children of Participants of the Air Force Health Study

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Open j.urnal of Epidemiology 2024年第2期14卷 312-330页

作者： george j. Knafl School of Nursing University of North Carolina at Chapel Hill Chapel Hill NC USA

Background: The Air Force Health Study collected reproductive outcomes for live-born children of male Air Force veterans of the Vietnam War. Methods: Dioxin values for participants were obtained from blood samples. Analyses were conducted of occurrence of 16 specific categories of birth defects and developmental disabilities. Children were categorized as conceived before and after the start of participants’ Vietnam War service. Children conceived before the start of Vietnam War service were treated as being conceived when their fathers had unquantifiable dioxin values. Children conceived after the start of Vietnam War service for participants with missing dioxin values were excluded from primary analyses, but were used to assess the impact of their exclusion on conclusions. Correlation between values for specific categories for multiple children fathered by the same participant was accounted for. The dose-response relationship was treated as a step function increasing for dioxin values larger than adaptively identified individual thresholds changing with the specific category. Results: For 15 of 16 specific categories, the probability of occurrence increased substantially for a sufficiently high dioxin level above identified thresholds. Exclusion of children due to missing dioxin likely did not affect these results. Conclusions: Results supported the conclusion of substantial adverse effects on a wide variety of specific categories of birth defects and developmental disabilities due to sufficiently high exposures to dioxin, a toxic contaminant of Agent Orange used for herbicide spraying in the Vietnam War. Results may hold more generally, but might also have been affected by a variety of limitations.

关键词： Agent Orange Air Force Health Study Birth Defects Developmental Disabilities Dioxin Dose-Response Relationship Vietnam War

Adaptive Random Effects/Coefficients Modeling

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Open j.urnal of Statistics 2024年第2期14卷 179-206页

作者： george j. Knafl School of Nursing University of North Carolina at Chapel Hill Chapel Hill USA

Adaptive fractional polynomial modeling of general correlated outcomes is formulated to address nonlinearity in means, variances/dispersions, and correlations. Means and variances/dispersions are modeled using generalized linear models in fixed effects/coefficients. Correlations are modeled using random effects/coefficients. Nonlinearity is addressed using power transforms of primary (untransformed) predictors. Parameter estimation is based on extended linear mixed modeling generalizing both generalized estimating equations and linear mixed modeling. Models are evaluated using likelihood cross-validation (LCV) scores and are generated adaptively using a heuristic search controlled by LCV scores. Cases covered include linear, Poisson, logistic, exponential, and discrete regression of correlated continuous, count/rate, dichotomous, positive continuous, and discrete numeric outcomes treated as normally, Poisson, Bernoulli, exponentially, and discrete numerically distributed, respectively. Example analyses are also generated for these five cases to compare adaptive random effects/coefficients modeling of correlated outcomes to previously developed adaptive modeling based on directly specified covariance structures. Adaptive random effects/coefficients modeling substantially outperforms direct covariance modeling in the linear, exponential, and discrete regression example analyses. It generates equivalent results in the logistic regression example analyses and it is substantially outperformed in the Poisson regression case. Random effects/coefficients modeling of correlated outcomes can provide substantial improvements in model selection compared to directly specified covariance modeling. However, directly specified covariance modeling can generate competitive or substantially better results in some cases while usually requiring less computation time.

关键词： Adaptive Regression Correlated Outcomes Extended Linear Mixed Modeling Fractional Polynomials Likelihood Cross-Validation Random Effects/Coefficients

Efficacy of Hilbert-Huang Transform (HHT) in the Analysis of Instantaneous Low Frequency Waves of Magnetosheath

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International j.urnal of Geosciences 2016年第1期7卷 11-19页

作者： Ekong U. Nathaniel Nyakno j. george j.wel I. Ibanga Aniekan M. Ekanem Department of Physics Akwa Ibom State University Ikot Akpaden Nigeria

The flow of supersonic plasma is accompanied by a highly thermalized region called the Magnetoshealth found after the bow shock. Enclosed within this region are different wave modes associated with classes of boundaries which have been determined by different methods. The efficacy of Hilbert-Huang transform (HHT) is based on the conditionality of allowing for the local analysis of frequencies, which presents the physical meaning of the original signal at that instant. The observed data have been taken from Cluster II Fluxgate Magnetometer (FGM) instrument that provides advantage for the analysis in three dimensions. The result compares favourably with instantaneous frequencies computed using simple Hilbert transform (SHT) with electric field measurements of Cluster II mission already carried out in literatures. The result of this study has shown that HHT provides the best applicability in the magnetosheath data analysis than the wavelet and Fast Fourier Transform (FFT). The application of HHT based on its advantages over other methods is viewed to be very critical in the analysis of multi-frequency signals where different frequencies could be determined distinctively at a point.

关键词： Plasma Waves Instantaneous Frequency Empirical Mode Decomposition (EMD) Hilbert-Huang Transform (HHT)

Examining the“revisability”benefit of hip resurfacing arthroplasty

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World j.urnal of Orthopedics 2024年第6期15卷 554-559页

作者： j.se george Adam j.Taylor Thomas P Schmalzried Department of Orthopedics Harbor UCLA Medical CenterTorranceCA 90509United States

BACKGROUND Hip resurfacing arthroplasty(HRA)is an alternative to total hip arthroplasty(THA)that is typically reserved for young active patients because it preserves ***,the benefits of HRA only hold true if conversion THA after failed HRA provides acceptable *** To compare patient reported outcomes for conversion THA after HRA failure to primary *** A retrospective review of 36 patients(37 hips)that underwent conversion THA for failed HRA between October 2006 and May 2019 by a single surgeon was *** reported outcomes[modified Harris Hip Score(mHHS),University of California Los Angeles(UCLA)activity score]were obtained via an email-based responder-anonymous *** were compared to normative data of a primary THA cohort with similar *** analysis was performed comparing outcomes of conversion THA for adverse local tissue reaction(ALTR)vs all other causes for *** The study group had a lower mHHS than the control group(81.7±13.8 vs 90.2±11.6,P<0.01);however,both groups had similar UCLA activity levels(7.5±2.3 vs 7.2±1.6,P=0.51).Patients that underwent conversion for non-ATLR causes had similar mHHS(85.2±11.5 vs 90.2±11.6,P=0.11)and higher UCLA activity levels(8.5±1.8 vs 7.2±1.6,P<0.01)compared to the control *** that underwent conversion for ATLR had worse mHHS(77.1±14.5 vs 90.2±11.6,P<0.01)and UCLA activity levels(6.1±2.3 vs 7.2±1.6,P=0.05)when compared to the control *** Patient outcomes equivalent to primary THA can be achieved following HRA conversion to ***,inferior outcomes were demonstrated for ALTR-related HRA *** selection and perhaps further studies examining alternative HRA bearing surfaces should be considered.

关键词： Total hip arthroplasty Hip resurfacing arthroplasty Conversion total hip arthroplasty Adverse local tissue reaction Patient reported outcome measures

Genetics of Gallstone Disease and Their Clinical Significance: A Narrative Review

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j.urnal of Clinical and Translational Hepatology 2024年第3期12卷 316-326页

作者： Christopher j.Costa Minh Thu T.Nguyen Haleh Vaziri george Y.Wu Department of Medicine University of Connecticut Health CenterFarmingtonCTUSA Division of Gastroenterology and Hepatology University of Connecticut Health CenterFarmingtonCTUSA

Gallstone(GS)disease is common and arises from a combination of genetic and environmental *** genetic abnormalities specifically leading to cholesterol GSs are rare,there are clinically significant gene variants associated with cholesterol *** contrast,most bilirubin GSs can be attributed to genetic *** pathogenesis of cholesterol and bilirubin GSs differs *** GSs are notably influenced by genetic variants within the ABC protein superfamily,including ABCG8,ABCG5,ABCB4,and ABCB11,as well as genes from the apolipoprotein family such as ApoB100 and ApoE(especially the E3/E3 and E3/E4 variants),and members of the MUC ***,bilirubin GSs are associated with genetic variants in highly expressed hepatic genes,notably UGT1A1,ABCC2(MRP2),ABCC3(MRP3),CFTR,and MUC,alongside genetic defects linked to hemolytic anemias and conditions impacting *** genetic cases constitute a small portion of GS disease,recognizing genetic predisposition is essential for proper diagnosis,treatment,and genetic counseling.

关键词： Gallstones Cholelithiasis ATP-binding cassette transporters ABCG8 protein Human UDP-glucuronosyltransferase A1

Thermal Degradation and Decomposition Kinetics of Freeze Dried Cow and Camel Milk as well as Their Constituents

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j.urnal of Food Science and Engineering 2011年第2期1卷 77-84页

作者： K. V. Sunooj.j. george V. A. Saj.ev Kumar K. Radhakrishna A. S. Bawa Department of Food Science and Technology Pondicherry University R. Venkataraman Nagar Pondicherry 605014 India De fence Food Research Laboratory Siddarthanagar Mysore 570011 India

A study was conducted to evaluate thermal properties and degradation kinetic parameters of FD cow milk and camel milk powder. FT-IR was used to confirm the fat removal from the whole milk powder. Differential Scanning Calorimetry （DSC） was used to study the thermal transitions. DSC thermograms of WMP showed a two-step endotherm, the former at lower temperatures （cow milk 16-35 ℃, camel milk 25-60 ℃） and the later at higher temperatures （cow milk 75-125 ℃, camel milk 90-160 ℃）. The main difference observed between cow and camel milk was peak maximum temperature for fat melting, AH and other decomposition temperatures. The enthalpy of fat melting was 2.314 j.g and 3.397 j.g for cow and camel milk respectively. Thermogravimetric Analysis （TGA）/derivative thermogravimetric analysis （DTG） also showed two steps degradation. The first step involves lactose degradation and second step corresponds to combined degradation of protein and fat. Hence logβ vs 1000/T was plotted separately for individual components to determine cumulative value of activation energy using Flynn-Wall-Osawa method.

关键词： Thermal degradation differential scanning calorimetry thermogravimetric analysis FT-IR Flynn-Wall-Osawa method.