An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
<b>Copyright information:</b>Taken from "Should tumor VEGF expression influence ... more <b>Copyright information:</b>Taken from "Should tumor VEGF expression influence decisions on combining low-dose chemotherapy with antiangiogenic therapy? Preclinical modeling in ovarian cancer"http://www.translational-medicine.com/content/6/1/2Journal of Translational Medicine 2008;6():2-2.Published online 8 Jan 2008PMCID:PMC2235830. , Estimated difference between the observed mean tumor volume in animals receiving combined paclitaxel/SU5416 therapy and a predicted tumor volume assuming additive effects for the two individual drugs with 95% confidence intervals.
In many experiments, time series data can be collected from multiple units and multiple time seri... more In many experiments, time series data can be collected from multiple units and multiple time series segments can be collected from the same unit. This article introduces a mixed effects Cramér spectral representation which can be used to model the effects of design covariates on the second-order power spectrum while accounting for potential correlations among the time series segments collected from the same unit. The transfer function is composed of a deterministic component to account for the population-average effects and a random component to account for the unit-specific deviations. The resulting log-spectrum has a functional mixed effects represen-tation where both the fixed effects and random effects are functions in the frequency domain. It is shown that, when the replicate-specific spectra are smooth, the log-periodograms converge to a functional mixed effects model. A data-driven iterative estimation procedure is offered for the periodic smoothing spline estimation of the ...
Zhonghua liu xing bing xue za zhi = Zhonghua liuxingbingxue zazhi, 2009
OBJECTIVE To analyze the characteristics and trend of Japanese encephalitis (JE) in Henan provinc... more OBJECTIVE To analyze the characteristics and trend of Japanese encephalitis (JE) in Henan province. METHODS Adopting descriptive epidemiological method to analyze the data on the epidemic situation of JE from 1950 to 2008, and on mosquitoes and host animals at disease surveillance points. The host serum JE IgG antibody was detected by ELISA. Data was analyzed using SPSS 12.0 and Excel 2003 software. RESULTS The incidence of JE in Henan province had a fluctuant downward trend. Peak of the incidence fell in July to September, accounting for 88.09% of total cases. The scope of geographical distribution was increasing from northern to southern parts of the province. Cases mainly concentrated in the southern and south-eastern parts of the province. 0 - 14 year-old group had the highest incidence (81.95%). In Luoyang city, there was a significant increase in children at 15-years or older (58.93%). Most patients were farmers (42.33%). The positive-times for half of the antibodies of JE in ...
Neurologic injury is a leading cause of morbidity and mortality following pediatric cardiac arres... more Neurologic injury is a leading cause of morbidity and mortality following pediatric cardiac arrest. In this study, we assess the feasibility of quantitative, non-invasive, frequency-domain diffuse optical spectroscopy (FD-DOS) neuromonitoring during cardiopulmonary resuscitation (CPR), and its predictive utility for return of spontaneous circulation (ROSC) in an established pediatric swine model of cardiac arrest. Cerebral tissue optical properties, oxy- and deoxy-hemoglobin concentration ([HbO2], [Hb]), oxygen saturation (StO2) and total hemoglobin concentration (THC) were measured by a FD-DOS probe placed on the forehead in 1-month-old swine (8–11 kg; n = 52) during seven minutes of asphyxiation followed by twenty minutes of CPR. ROSC prediction and time-dependent performance of prediction throughout early CPR (< 10 min), were assessed by the weighted Youden index (Jw, w = 0.1) with tenfold cross-validation. FD-DOS CPR data was successfully acquired in 48/52 animals; 37/48 achi...
Journal of the American Society of Nephrology, 2002
ABSTRACT. To evaluate the impact of parenteral iron administration on the survival and rate of ho... more ABSTRACT. To evaluate the impact of parenteral iron administration on the survival and rate of hospitalization of US hemodialysis patients, a nonconcurrent cohort study of 10,169 hemodialysis patients in the United States in 1994 was conducted. The main outcome measures were patient survival and rate of hospitalization. After adjusting for 23 demographic and comorbidity characteristics among 5833 patients included in multivariable analysis, bills for ≤10 vials of iron over 6 mo showed no adverse effect on survival (adjusted relative risk [RR] = 0.93; 95% confidence interval [CI], 0.84 to 1.02;P= 0.14) when compared with none, but bills for >10 vials showed a statistically significant elevated rate of death (adjusted RR = 1.11; 95% CI, 1.00 to 1.24;P= 0.05). Bills for ≤10 vials of iron over 6 mo also showed no significant association with hospitalization (adjusted RR = 0.92; 95% CI, 0.83 to 1.03;P= 0.15), but bills for >10 vials showed statistically significant elevated risk (a...
Since the Covid-19 outbreak, researchers have been predicting how the epidemic will evolve, espec... more Since the Covid-19 outbreak, researchers have been predicting how the epidemic will evolve, especially the number in each country, through using parametric extrapolations based on the history. In reality, the epidemic progressing in a particular country depends largely on its policy responses and interventions. Since the outbreaks in some countries are earlier than United States, the prediction of US cases can benefit from incorporating the similarity in their trajectories. We propose an empirical Bayesian time series framework to predict US cases using different countries as prior reference. The resultant forecast is based on observed US data and prior information from the reference country while accounting for different population sizes. When Italy is used as prior in the prediction, which the US data resemble the most, the cases in the US will exceed 300,000 by the beginning of April unless strong measures are adopted.
Journal of Cerebral Blood Flow & Metabolism, 2019
Obstructive sleep apnea (OSA) is characterized by intermittent obstruction of the airways during ... more Obstructive sleep apnea (OSA) is characterized by intermittent obstruction of the airways during sleep. Cerebrovascular reactivity (CVR) is an index of cerebral vessels' ability to respond to a vasoactive stimulus, such as increased CO2. We hypothesized that OSA alters CVR, expressed as a breath-hold index (BHI) defined as the rate of change in CBF or BOLD signal during a controlled breath-hold stimulus mimicking spontaneous apneas by being both hypercapnic and hypoxic. In 37 OSA and 23 matched non sleep apnea (NSA) subjects, we obtained high temporal resolution CBF and BOLD MRI data before, during, and between five consecutive BH stimuli of 24 s, each averaged to yield a single BHI value. Greater BHI was observed in OSA relative to NSA as derived from whole-brain CBF (78.6 ± 29.6 vs. 60.0 ± 20.0 mL/min2/100 g, P = 0.010) as well as from flow velocity in the superior sagittal sinus (0.48 ± 0.18 vs. 0.36 ± 0.10 cm/s2, P = 0.014). Similarly, BOLD-based BHI was greater in OSA in wh...
While adolescent–adult connections have been shown to be protective against violence perpetration... more While adolescent–adult connections have been shown to be protective against violence perpetration and victimization, mechanisms through which these connections confer protection from violence are poorly understood. We assessed whether adolescent–adult connections protected youth in lower resource urban neighborhoods from exposure to environmental risk factors for violence during daily activities. We overlaid on the city landscape minute-by-minute activity paths from 274 randomly sampled predominantly African American male youth, ages 10 to 24, enrolled in a population-based study of daily activities in Philadelphia, PA, to calculate environmental exposures and to compare exposures along actual versus shortest potential travel routes. Adolescent–adult connections were defined using brief survey questions and detailed family genograms. Analyses demonstrated that youth’s selected travel routes resulted in significantly lower exposure to several types of crime, including vandalism, narc...
American Journal of Physiology-Lung Cellular and Molecular Physiology, 2019
The effects of e-cigarette (e-cig) aerosol inhalation by nonsmokers have not been examined to dat... more The effects of e-cigarette (e-cig) aerosol inhalation by nonsmokers have not been examined to date. The present study was designed to evaluate the acute response to aerosol inhalation of non-nicotinized e-cigarettes in terms of oxidative stress and indices of endothelial activation in human pulmonary microvascular endothelial cells (HPMVEC). Ten smoking-naïve healthy subjects (mean age ± SD = 28.7 ± 5.5 yr) were subjected to an e-cig challenge, following which their serum was monitored for markers of inflammation [C-reactive protein (CRP) and soluble intercellular adhesion molecule (sICAM)] and nitric oxide metabolites (NOx). The oxidative stress and inflammation burden of the circulating serum on the vascular network was also assessed by measuring reactive oxygen species (ROS) production and induction of ICAM-1 expression on HPMVEC. Our results show that serum indices of oxidative stress and inflammation increased significantly ( P < 0.05 as compared with baseline), reaching a p...
Diffuse correlation spectroscopy (DCS) noninvasively permits continuous, quantitative, bedside me... more Diffuse correlation spectroscopy (DCS) noninvasively permits continuous, quantitative, bedside measurements of cerebral blood flow (CBF). To test whether optical monitoring (OM) can detect decrements in CBF producing cerebral hypoxia, we applied the OM technique continuously to probe brain-injured patients who also had invasive brain tissue oxygen (PbO) monitors. Comatose patients with a Glasgow Coma Score (GCS) < 8) were enrolled in an IRB-approved protocol after obtaining informed consent from the legally authorized representative. Patients underwent 6-8 h of daily monitoring. Brain PbO was measured with a Clark electrode. Absolute CBF was monitored with DCS, calibrated by perfusion measurements based on intravenous indocyanine green bolus administration. Variation of optical CBF and mean arterial pressure (MAP) from baseline was measured during periods of brain hypoxia (defined as a drop in PbO below 19 mmHg for more than 6 min from baseline (PbO > 21 mmHg). In a secondary ...
Journal of urban health : bulletin of the New York Academy of Medicine, Jan 26, 2018
Strengths-based strategies to reduce youth violence in low-resource urban communities are urgentl... more Strengths-based strategies to reduce youth violence in low-resource urban communities are urgently needed. Supportive adolescent-adult relationships may confer protection, but studies have been limited by self-reported composite outcomes. We conducted a population-based case-control study among 10- to 24-year-old males in low-resource neighborhoods to examine associations between supportive adult connection and severe assault injury. Cases were victims of gunshot assault injury (n = 143) and non-gun assault injury (n = 206) from two level I trauma centers. Age- and race-matched controls (n = 283) were recruited using random digit dial from the same catchment. Adolescent-adult connections were defined by: (1) brief survey questions and (2) detailed family genograms. Analysis used conditional logistic regression. There were no significant associations between positive adult connection, as defined by brief survey questions, and either gunshot or non-gun assault injury among adolescents...
Clinical journal of the American Society of Nephrology : CJASN, Jan 15, 2018
Despite colistin's longstanding reported association with nephrotoxicity, the attributable ri... more Despite colistin's longstanding reported association with nephrotoxicity, the attributable risk and timing of toxicity onset are still unknown. Whether substantial toxicity occurs during the initial 72 hours of exposure has important implications for early treatment decisions. The objective of this study was to compare colistin-exposed patients with a matched control group given other broad spectrum antibiotics. We conducted a retrospective cohort study in patients treated for multidrug-resistant,, orspp. Colistin-exposed patients were matched to unexposed controls using propensity scores. AKI was defined according to the Kidney Disease Improving Global Outcomes creatinine criteria. Incidence rate ratios and risk differences of AKI in the matched cohort were estimated with the generalized estimating equation Poisson regression model. Risk factors for AKI were tested for effect modification in the matched cohort. The study included 150 propensity-matched pairs with similar types ...
This paper uses data from a population-based case control study of daily activities and assault i... more This paper uses data from a population-based case control study of daily activities and assault injury to examine residence-based versus actual path-based approaches to measuring environmental exposures that pose risks for violence among adolescents. Defining environmental exposures based on participant home address resulted in significant misclassification compared to gold standard daily travel path measures. Dividing participant daily travel paths into origin-destination segments, we explore a method for defining spatial counterfactuals by comparing actual trip path exposures to shortest potential trip path exposures. Spatial methods explored herein can be utilized in future research to more accurately quantify environmental exposures and associations with health outcomes.
Dysfunctions in stress biology are hypothesized to contribute to anxiety disorders, and to be ame... more Dysfunctions in stress biology are hypothesized to contribute to anxiety disorders, and to be ameliorated during successful treatment, but limited clinical data exist to support this hypothesis. We evaluated whether increases in morning cortisol and the diurnal cortisol slope, markers of stress biology, are associated with clinical response to chamomile therapy among subjects with generalized anxiety disorder (GAD). Among 45 subjects with DSM-IV diagnosed GAD in an open-label clinical trial of chamomile, salivary cortisol was assessed for three days each pre- and post-treatment, at 8am, 12pm, 4pm, and 8pm. Mixed model analyses assessed whether GAD symptom change predicted the degree to which cortisol levels changed during treatment. Symptom improvement during treatment was significantly associated with pre-to-post treatment changes in cortisol. Subjects who experienced more symptomatic improvement experienced significant increases in their morning salivary cortisol (β = 0.48, p <...
A nested case-control is a case-control study within a cohort. An advantage of the nested case-c... more A nested case-control is a case-control study within a cohort. An advantage of the nested case-control design is the number of subjects for whom outcome measures are needed are small compared to the cohort size, which is ideal when acquisition of outcomes is costly and time consuming and prevalence of cases is small. Existing selection schemes such as 1:1, 1:m, and m:n have been implemented in various studies. Upon choice of scheme, implementation requires consistent implementation across all strata, which is usually too restrictive in nested case-control studies. To maximize the usage of the available information, we propose a flexible cluster matching algorithm, in which multiple cases are matched to a group of selected controls. This may lead to unbalanced designs and induce complicated correlation structures. Mixed Effects models provide a flexible modeling framework to account for the clustering structure together with other study designs, such as repeated measures. An illustration from a nested case-control study consisting of longitudinal data is presented.
Fourth International Conference on Thin Film Physics and Applications, 2000
SiC material is of intense interest because of its unique properties. Two samples were prepared b... more SiC material is of intense interest because of its unique properties. Two samples were prepared by carbon ion implantation into silicon substrates with a metal vapor vacuum arc ion source at an energy of 65 keV and a dose of 1.0 X 1018 cm-2. Following implantation, one sample was annealed in nitrogen ambient at 1250 degree(s)C for 10 hours. Spectroscopic
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
<b>Copyright information:</b>Taken from "Should tumor VEGF expression influence ... more <b>Copyright information:</b>Taken from "Should tumor VEGF expression influence decisions on combining low-dose chemotherapy with antiangiogenic therapy? Preclinical modeling in ovarian cancer"http://www.translational-medicine.com/content/6/1/2Journal of Translational Medicine 2008;6():2-2.Published online 8 Jan 2008PMCID:PMC2235830. , Estimated difference between the observed mean tumor volume in animals receiving combined paclitaxel/SU5416 therapy and a predicted tumor volume assuming additive effects for the two individual drugs with 95% confidence intervals.
In many experiments, time series data can be collected from multiple units and multiple time seri... more In many experiments, time series data can be collected from multiple units and multiple time series segments can be collected from the same unit. This article introduces a mixed effects Cramér spectral representation which can be used to model the effects of design covariates on the second-order power spectrum while accounting for potential correlations among the time series segments collected from the same unit. The transfer function is composed of a deterministic component to account for the population-average effects and a random component to account for the unit-specific deviations. The resulting log-spectrum has a functional mixed effects represen-tation where both the fixed effects and random effects are functions in the frequency domain. It is shown that, when the replicate-specific spectra are smooth, the log-periodograms converge to a functional mixed effects model. A data-driven iterative estimation procedure is offered for the periodic smoothing spline estimation of the ...
Zhonghua liu xing bing xue za zhi = Zhonghua liuxingbingxue zazhi, 2009
OBJECTIVE To analyze the characteristics and trend of Japanese encephalitis (JE) in Henan provinc... more OBJECTIVE To analyze the characteristics and trend of Japanese encephalitis (JE) in Henan province. METHODS Adopting descriptive epidemiological method to analyze the data on the epidemic situation of JE from 1950 to 2008, and on mosquitoes and host animals at disease surveillance points. The host serum JE IgG antibody was detected by ELISA. Data was analyzed using SPSS 12.0 and Excel 2003 software. RESULTS The incidence of JE in Henan province had a fluctuant downward trend. Peak of the incidence fell in July to September, accounting for 88.09% of total cases. The scope of geographical distribution was increasing from northern to southern parts of the province. Cases mainly concentrated in the southern and south-eastern parts of the province. 0 - 14 year-old group had the highest incidence (81.95%). In Luoyang city, there was a significant increase in children at 15-years or older (58.93%). Most patients were farmers (42.33%). The positive-times for half of the antibodies of JE in ...
Neurologic injury is a leading cause of morbidity and mortality following pediatric cardiac arres... more Neurologic injury is a leading cause of morbidity and mortality following pediatric cardiac arrest. In this study, we assess the feasibility of quantitative, non-invasive, frequency-domain diffuse optical spectroscopy (FD-DOS) neuromonitoring during cardiopulmonary resuscitation (CPR), and its predictive utility for return of spontaneous circulation (ROSC) in an established pediatric swine model of cardiac arrest. Cerebral tissue optical properties, oxy- and deoxy-hemoglobin concentration ([HbO2], [Hb]), oxygen saturation (StO2) and total hemoglobin concentration (THC) were measured by a FD-DOS probe placed on the forehead in 1-month-old swine (8–11 kg; n = 52) during seven minutes of asphyxiation followed by twenty minutes of CPR. ROSC prediction and time-dependent performance of prediction throughout early CPR (< 10 min), were assessed by the weighted Youden index (Jw, w = 0.1) with tenfold cross-validation. FD-DOS CPR data was successfully acquired in 48/52 animals; 37/48 achi...
Journal of the American Society of Nephrology, 2002
ABSTRACT. To evaluate the impact of parenteral iron administration on the survival and rate of ho... more ABSTRACT. To evaluate the impact of parenteral iron administration on the survival and rate of hospitalization of US hemodialysis patients, a nonconcurrent cohort study of 10,169 hemodialysis patients in the United States in 1994 was conducted. The main outcome measures were patient survival and rate of hospitalization. After adjusting for 23 demographic and comorbidity characteristics among 5833 patients included in multivariable analysis, bills for ≤10 vials of iron over 6 mo showed no adverse effect on survival (adjusted relative risk [RR] = 0.93; 95% confidence interval [CI], 0.84 to 1.02;P= 0.14) when compared with none, but bills for >10 vials showed a statistically significant elevated rate of death (adjusted RR = 1.11; 95% CI, 1.00 to 1.24;P= 0.05). Bills for ≤10 vials of iron over 6 mo also showed no significant association with hospitalization (adjusted RR = 0.92; 95% CI, 0.83 to 1.03;P= 0.15), but bills for >10 vials showed statistically significant elevated risk (a...
Since the Covid-19 outbreak, researchers have been predicting how the epidemic will evolve, espec... more Since the Covid-19 outbreak, researchers have been predicting how the epidemic will evolve, especially the number in each country, through using parametric extrapolations based on the history. In reality, the epidemic progressing in a particular country depends largely on its policy responses and interventions. Since the outbreaks in some countries are earlier than United States, the prediction of US cases can benefit from incorporating the similarity in their trajectories. We propose an empirical Bayesian time series framework to predict US cases using different countries as prior reference. The resultant forecast is based on observed US data and prior information from the reference country while accounting for different population sizes. When Italy is used as prior in the prediction, which the US data resemble the most, the cases in the US will exceed 300,000 by the beginning of April unless strong measures are adopted.
Journal of Cerebral Blood Flow & Metabolism, 2019
Obstructive sleep apnea (OSA) is characterized by intermittent obstruction of the airways during ... more Obstructive sleep apnea (OSA) is characterized by intermittent obstruction of the airways during sleep. Cerebrovascular reactivity (CVR) is an index of cerebral vessels' ability to respond to a vasoactive stimulus, such as increased CO2. We hypothesized that OSA alters CVR, expressed as a breath-hold index (BHI) defined as the rate of change in CBF or BOLD signal during a controlled breath-hold stimulus mimicking spontaneous apneas by being both hypercapnic and hypoxic. In 37 OSA and 23 matched non sleep apnea (NSA) subjects, we obtained high temporal resolution CBF and BOLD MRI data before, during, and between five consecutive BH stimuli of 24 s, each averaged to yield a single BHI value. Greater BHI was observed in OSA relative to NSA as derived from whole-brain CBF (78.6 ± 29.6 vs. 60.0 ± 20.0 mL/min2/100 g, P = 0.010) as well as from flow velocity in the superior sagittal sinus (0.48 ± 0.18 vs. 0.36 ± 0.10 cm/s2, P = 0.014). Similarly, BOLD-based BHI was greater in OSA in wh...
While adolescent–adult connections have been shown to be protective against violence perpetration... more While adolescent–adult connections have been shown to be protective against violence perpetration and victimization, mechanisms through which these connections confer protection from violence are poorly understood. We assessed whether adolescent–adult connections protected youth in lower resource urban neighborhoods from exposure to environmental risk factors for violence during daily activities. We overlaid on the city landscape minute-by-minute activity paths from 274 randomly sampled predominantly African American male youth, ages 10 to 24, enrolled in a population-based study of daily activities in Philadelphia, PA, to calculate environmental exposures and to compare exposures along actual versus shortest potential travel routes. Adolescent–adult connections were defined using brief survey questions and detailed family genograms. Analyses demonstrated that youth’s selected travel routes resulted in significantly lower exposure to several types of crime, including vandalism, narc...
American Journal of Physiology-Lung Cellular and Molecular Physiology, 2019
The effects of e-cigarette (e-cig) aerosol inhalation by nonsmokers have not been examined to dat... more The effects of e-cigarette (e-cig) aerosol inhalation by nonsmokers have not been examined to date. The present study was designed to evaluate the acute response to aerosol inhalation of non-nicotinized e-cigarettes in terms of oxidative stress and indices of endothelial activation in human pulmonary microvascular endothelial cells (HPMVEC). Ten smoking-naïve healthy subjects (mean age ± SD = 28.7 ± 5.5 yr) were subjected to an e-cig challenge, following which their serum was monitored for markers of inflammation [C-reactive protein (CRP) and soluble intercellular adhesion molecule (sICAM)] and nitric oxide metabolites (NOx). The oxidative stress and inflammation burden of the circulating serum on the vascular network was also assessed by measuring reactive oxygen species (ROS) production and induction of ICAM-1 expression on HPMVEC. Our results show that serum indices of oxidative stress and inflammation increased significantly ( P < 0.05 as compared with baseline), reaching a p...
Diffuse correlation spectroscopy (DCS) noninvasively permits continuous, quantitative, bedside me... more Diffuse correlation spectroscopy (DCS) noninvasively permits continuous, quantitative, bedside measurements of cerebral blood flow (CBF). To test whether optical monitoring (OM) can detect decrements in CBF producing cerebral hypoxia, we applied the OM technique continuously to probe brain-injured patients who also had invasive brain tissue oxygen (PbO) monitors. Comatose patients with a Glasgow Coma Score (GCS) < 8) were enrolled in an IRB-approved protocol after obtaining informed consent from the legally authorized representative. Patients underwent 6-8 h of daily monitoring. Brain PbO was measured with a Clark electrode. Absolute CBF was monitored with DCS, calibrated by perfusion measurements based on intravenous indocyanine green bolus administration. Variation of optical CBF and mean arterial pressure (MAP) from baseline was measured during periods of brain hypoxia (defined as a drop in PbO below 19 mmHg for more than 6 min from baseline (PbO > 21 mmHg). In a secondary ...
Journal of urban health : bulletin of the New York Academy of Medicine, Jan 26, 2018
Strengths-based strategies to reduce youth violence in low-resource urban communities are urgentl... more Strengths-based strategies to reduce youth violence in low-resource urban communities are urgently needed. Supportive adolescent-adult relationships may confer protection, but studies have been limited by self-reported composite outcomes. We conducted a population-based case-control study among 10- to 24-year-old males in low-resource neighborhoods to examine associations between supportive adult connection and severe assault injury. Cases were victims of gunshot assault injury (n = 143) and non-gun assault injury (n = 206) from two level I trauma centers. Age- and race-matched controls (n = 283) were recruited using random digit dial from the same catchment. Adolescent-adult connections were defined by: (1) brief survey questions and (2) detailed family genograms. Analysis used conditional logistic regression. There were no significant associations between positive adult connection, as defined by brief survey questions, and either gunshot or non-gun assault injury among adolescents...
Clinical journal of the American Society of Nephrology : CJASN, Jan 15, 2018
Despite colistin's longstanding reported association with nephrotoxicity, the attributable ri... more Despite colistin's longstanding reported association with nephrotoxicity, the attributable risk and timing of toxicity onset are still unknown. Whether substantial toxicity occurs during the initial 72 hours of exposure has important implications for early treatment decisions. The objective of this study was to compare colistin-exposed patients with a matched control group given other broad spectrum antibiotics. We conducted a retrospective cohort study in patients treated for multidrug-resistant,, orspp. Colistin-exposed patients were matched to unexposed controls using propensity scores. AKI was defined according to the Kidney Disease Improving Global Outcomes creatinine criteria. Incidence rate ratios and risk differences of AKI in the matched cohort were estimated with the generalized estimating equation Poisson regression model. Risk factors for AKI were tested for effect modification in the matched cohort. The study included 150 propensity-matched pairs with similar types ...
This paper uses data from a population-based case control study of daily activities and assault i... more This paper uses data from a population-based case control study of daily activities and assault injury to examine residence-based versus actual path-based approaches to measuring environmental exposures that pose risks for violence among adolescents. Defining environmental exposures based on participant home address resulted in significant misclassification compared to gold standard daily travel path measures. Dividing participant daily travel paths into origin-destination segments, we explore a method for defining spatial counterfactuals by comparing actual trip path exposures to shortest potential trip path exposures. Spatial methods explored herein can be utilized in future research to more accurately quantify environmental exposures and associations with health outcomes.
Dysfunctions in stress biology are hypothesized to contribute to anxiety disorders, and to be ame... more Dysfunctions in stress biology are hypothesized to contribute to anxiety disorders, and to be ameliorated during successful treatment, but limited clinical data exist to support this hypothesis. We evaluated whether increases in morning cortisol and the diurnal cortisol slope, markers of stress biology, are associated with clinical response to chamomile therapy among subjects with generalized anxiety disorder (GAD). Among 45 subjects with DSM-IV diagnosed GAD in an open-label clinical trial of chamomile, salivary cortisol was assessed for three days each pre- and post-treatment, at 8am, 12pm, 4pm, and 8pm. Mixed model analyses assessed whether GAD symptom change predicted the degree to which cortisol levels changed during treatment. Symptom improvement during treatment was significantly associated with pre-to-post treatment changes in cortisol. Subjects who experienced more symptomatic improvement experienced significant increases in their morning salivary cortisol (β = 0.48, p <...
A nested case-control is a case-control study within a cohort. An advantage of the nested case-c... more A nested case-control is a case-control study within a cohort. An advantage of the nested case-control design is the number of subjects for whom outcome measures are needed are small compared to the cohort size, which is ideal when acquisition of outcomes is costly and time consuming and prevalence of cases is small. Existing selection schemes such as 1:1, 1:m, and m:n have been implemented in various studies. Upon choice of scheme, implementation requires consistent implementation across all strata, which is usually too restrictive in nested case-control studies. To maximize the usage of the available information, we propose a flexible cluster matching algorithm, in which multiple cases are matched to a group of selected controls. This may lead to unbalanced designs and induce complicated correlation structures. Mixed Effects models provide a flexible modeling framework to account for the clustering structure together with other study designs, such as repeated measures. An illustration from a nested case-control study consisting of longitudinal data is presented.
Fourth International Conference on Thin Film Physics and Applications, 2000
SiC material is of intense interest because of its unique properties. Two samples were prepared b... more SiC material is of intense interest because of its unique properties. Two samples were prepared by carbon ion implantation into silicon substrates with a metal vapor vacuum arc ion source at an energy of 65 keV and a dose of 1.0 X 1018 cm-2. Following implantation, one sample was annealed in nitrogen ambient at 1250 degree(s)C for 10 hours. Spectroscopic
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Papers by Wensheng Guo