Strengthening the mechanical characteristics and cathodic delamination resistance of fiber-reinforced polymer through chemical surface modification of glass fibers

This work aims to scrutinize the effect of the silanization of glass fibers (GF) on the mechanical properties and cathodic disbonding resistance of an epoxy composite coating. Successful silanization was approved based on different characterization techniques, including Fourier transform infrared spectra, field emission-scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy, and thermogravimetric analysis. Tensile strength measurement exhibited a significant effect of silanization on the mechanical performance of the fiber-reinforced polymer (FRP). FE-SEM cross-sectional images illustrated improved interfacial bonding between the epoxy matrix and GF upon silanization. Pull-off measurements revealed improved wet adhesion strength of the FRP to the mild steel surface after exposure to the salt spray chamber when the GF were silanized. In addition, silanization revealed enhanced resistance to cathodic delamination (CD). Electrochemical impedance spectroscopy and electrochemical noise assessments proved silanization's significant influence on the FRP's CD resistance.

Derivation and Validation of the UCAP-Q Case-finding Questionnaire to Detect Undiagnosed Asthma and COPD

BACKGROUND

Many people with asthma and COPD remain undiagnosed. We developed and validated a new case-finding questionnaire to identify symptomatic adults with undiagnosed obstructive lung disease.

METHODS

Adults in the community with no prior history of physician-diagnosed lung disease who self-reported respiratory symptoms were contacted via random-digit dialing. Pre- and post-bronchodilator spirometry was used to confirm asthma or COPD. Predictive questions were selected using multinomial logistic regression with backward elimination. Questionnaire performance was assessed using sensitivity, predictive values, and area under the receiver operating curve (AUC). The questionnaire was assessed for test-retest reliability, acceptability, and readability. External validation was prospectively conducted in an independent sample and predictive performance re-evaluated.

RESULTS

A 13-item UCAP-Q case-finding questionnaire to predict undiagnosed asthma or COPD was developed. The most appropriate risk cut-off was determined to be 6% for either disease. Applied to the derivation sample (N=1615), the questionnaire yielded a sensitivity of 92% for asthma and 97% for COPD, specificity of 17%, with an AUC of 0.69 (95% CI: 0.64-0.74) for asthma and 0.82 (95% CI: 0.78-0.86) for COPD. Prospective validation using an independent sample (n=471) showed sensitivities of 93% and 92% for asthma and COPD, respectively, specificity of 19%, with AUC's of 0.70 (95% CI: 0.62-0.79) for asthma and 0.81 (95% CI: 0.74-0.87) for COPD. AUC's for UCAP-Q were higher compared to AUC's for currently recommended case-finding questionnaires for asthma or COPD.Conclusions:The UCAP-Q demonstrated high sensitivities and AUC's for identifying undiagnosed asthma or COPD. A web-based calculator allows for easy calculation of risk probabilities for each disease.

Population-based case-finding to identify subjects with undiagnosed asthma or COPD

BACKGROUND

∼5-10% of adults may have undiagnosed airflow obstruction. The objective of this study was to develop a population-based case-finding strategy to assess the prevalence of undiagnosed airflow obstruction (asthma or COPD) amongst adults with respiratory symptoms in Canada.

METHODS

Adults without a previous history of asthma, COPD or lung disease were recruited using random digit-dialling and asked if they had symptoms of dyspnoea, cough, sputum or wheeze within the past 6 months. Those who answered affirmatively completed the Asthma Screening Questionnaire (ASQ), COPD-Diagnostic Questionnaire (COPD-DQ) and COPD Assessment Test (CAT). Those with an ASQ score of ≥6 or a COPD-DQ score of ≥20 underwent pre- and post-bronchodilator spirometry to diagnose asthma or COPD.

RESULTS

12 117 individuals were contacted at home and assessed for study eligibility. Of the 1260 eligible individuals, 910 (72%) enrolled and underwent spirometry. Ultimately, 184 subjects (20% of those enrolled) had obstructive lung disease (73 asthma and 111 COPD). Individuals found to have undiagnosed asthma or COPD had more severe respiratory symptoms and impaired quality of life compared with those without airflow obstruction. The ASQ, COPD-DQ, and CAT had ROC areas for predicting undiagnosed asthma or COPD of 0.49, 0.64 and 0.56, respectively. Four descriptive variables (age, BMI, sex and pack-years smoked) produced better receiver operating characteristic (ROC) values than the questionnaires (ROC area=0.68).

CONCLUSION

20% of randomly selected individuals who report respiratory symptoms in Canada have undiagnosed airflow obstruction due to asthma or COPD. Questionnaires could exclude subjects at low risk but lack the ability to accurately find subjects with undiagnosed disease.

Genetic associations in community context: a mixed model approach identifies a functional variant in the RBP4 gene associated with HDL-C dyslipidemia

Background

The objective of this study was to examine individual and community factors that influence high-density lipoprotein cholesterol (HDL-C) dyslipidemia in Newfoundland and Labrador (NL), a genetically isolated population in Canada with a high prevalence of HDL-C dyslipidemia.

Methods

First, a group of single nucleotide polymorphisms from 10 metabolic trait candidate genes was tested using a multivariate logistic regression model. The significant SNPs were entered into the second phase, where a mixed logistic model incorporated the community disease risk factors together with the individual factors as the fixed part of the model and the geographic region as a random effect.

Results

Analysis of 1489 subjects (26.9% HDL-C dyslipidemia) identified rs3758539, a non-coding variant in the 5’UTR of RBP4, to be associated with HDL-C dyslipidemia (odds ratio = 1.45, 95% confidence interval = 1.08–1.97, p = 0.01). The association remained significant, and the effect size did not change after the incorporation of individual and community risk factors from 17 geographic regions (odds ratio: 1.41, 95% confidence interval = 1.03–1.93, p = 0.03) in NL. Besides this variant, sex, BMI, and smoking also showed significant associations with HDL-C dyslipidemia, whereas no role was identified for the community factors.

Conclusions

This study demonstrates the use of community-level data in a genetic association testing. It reports a functional variant in the promoter of RBP4, a gene directly involved in lipoprotein metabolism, to be associated with HDL-C dyslipidemia. These findings indicate that individual factors are the main reason for a higher prevalence of HDL-C dyslipidemia in the NL population.

Six-year time-trend analysis of dyslipidemia among adults in Newfoundland and Labrador: findings from the laboratory information system between 2009 and 2014

Background

Dyslipidemia, an increased level of total cholesterol (TC), triglycerides (TG), low-density-lipoprotein cholesterol (LDL-C) and decreased level of high-density-lipoprotein cholesterol (HDL-C), is one of the most important risk factors for cardiovascular disease. We examined the six-year trend of dyslipidemia in Newfoundland and Labrador (NL), a Canadian province with a historically high prevalence of dyslipidemia.

Methods

A serial cross-sectional study on all of the laboratory lipid tests available from 2009 to 2014 was performed. Dyslipidemia for every lipid component was defined using the Canadian Guidelines for the Diagnosis and Treatment of Dyslipidemia. The annual dyslipidemia rates for each component of serum lipid was examined. A fixed and random effect model was applied to adjust for confounding variables (sex and age) and random effects (residual variation in dyslipidemia over the years and redundancies caused by individuals being tested multiple times during the study period).

Results

Between 2009 and 2014, a total of 875,208 records (mean age: 56.9 ± 14.1, 47.6% males) containing a lipid profile were identified. The prevalence of HDL-C and LDL-C dyslipidemia significantly decreased during this period (HDL-C: 35.8% in 2009 [95% CI 35.5-36.1], to 29.0% in 2014 [95% CI: 28.8-29.2], P = 0.03, and LDL-C: 35.2% in 2009 [95% CI: 34.9-35.4] to 32.1% in 2014 [95% CI: 31.9-32.3], P = 0.02). A stratification by sex, revealed no significant trend for any lipid element in females; however, in men, the previously observed trends were intensified and a new decreasing trend in dyslipidemia of TC was appeared (TC: 34.1% [95% CI 33.7-34.5] to 32.3% [95%CI: 32.0-32.6], p < 0.02, HDL-C: 33.8% (95%CI: 33.3-34.2) to 24.0% (95% CI: 23.7-24.3)], P < 0.01, LDL-C: 32.9% (95%CI:32.5-33.3) to 28.6 (95%CI: 28.3-28.9), P < 0.001). Adjustment for confounding factors and removing the residual noise by modeling the random effects did not change the significance.

Conclusion

This study demonstrates a significant downward trend in the prevalence of LDL-C, HDL-C, and TC dyslipidemia, exclusively in men. These trends could be the result of males being the primary target for cardiovascular risk management.

Identification of Dyslipidemic Patients Attending Primary Care Clinics Using Electronic Medical Record (EMR) Data from the Canadian Primary Care Sentinel Surveillance Network (CPCSSN) Database

The objective of this study was to define the optimal algorithm to identify patients with dyslipidemia using electronic medical records (EMRs). EMRs of patients attending primary care clinics in St. John's, Newfoundland and Labrador (NL), Canada during 2009-2010, were studied to determine the best algorithm for identification of dyslipidemia. Six algorithms containing three components, dyslipidemia ICD coding, lipid lowering medication use, and abnormal laboratory lipid levels, were tested against a gold standard, defined as the existence of any of the three criteria. Linear discriminate analysis, and bootstrapping were performed following sensitivity/specificity testing and receiver's operating curve analysis. Two validating datasets, NL records of 2011-2014, and Canada-wide records of 2010-2012, were used to replicate the results. Relative to the gold standard, combining laboratory data together with lipid lowering medication consumption yielded the highest sensitivity (99.6%), NPV (98.1%), Kappa agreement (0.98), and area under the curve (AUC, 0.998). The linear discriminant analysis for this combination resulted in an error rate of 0.15 and an Eigenvalue of 1.99, and the bootstrapping led to AUC: 0.998, 95% confidence interval: 0.997-0.999, Kappa: 0.99. This algorithm in the first validating dataset yielded a sensitivity of 97%, Negative Predictive Value (NPV) = 83%, Kappa = 0.88, and AUC = 0.98. These figures for the second validating data set were 98%, 93%, 0.95, and 0.99, respectively. Combining laboratory data with lipid lowering medication consumption within the EMR is the best algorithm for detecting dyslipidemia. These results can generate standardized information systems for dyslipidemia and other chronic disease investigations using EMRs.

Using Electronic Medical Record to Identify Patients With Dyslipidemia in Primary Care Settings: International Classification of Disease Code Matters From One Region to a National Database

Objective:

To assess the validity of the International Classification of Disease (ICD) codes for identifying patients with dyslipidemia in electronic medical record (EMR) data

Methods:

The EMRs of patients receiving primary care in St. John’s, Newfoundland and Labrador (NL), Canada, were retrieved from the Canadian Primary Care Sentinel Surveillance Network database. International Classification of Disease codes were first compared with laboratory lipid data as an independent criterion standard, and next with a “comprehensive criterion standard,” defined as any existence of abnormal lipid test, lipid-lowering medication record, or dyslipidemia ICD codes. The ability of ICD coding alone or combined with other components was evaluated against the two criterion standards using receiver operating characteristic (ROC) analysis, sensitivity, specificity, negative predictive value (NPV) and Kappa agreement. (No specificity was reported for the comparison of ICD codes against the comprehensive criterion standard as this naturally leads to 100% specificity.)

Results:

The ICD codes led to a poor outcome when compared with the serum lipid levels (sensitivity, 27%; specificity, 76%; PPV, 71%; NPV, 33%; Kappa, 0.02; area under the receiver operating characteristic curve (AUC), 0.51) or with the comprehensive criterion standard (sensitivity, 32%; NPV, 25%; Kappa, 0.15; AUC, 66%). International Classification of Disease codes combined with lipid-lowering medication data also resulted in low sensitivity (51.2%), NPV (32%), Kappa (0.28), and AUC (75%). The addition of laboratory lipid levels to ICD coding marginally improved the algorithm (sensitivity, 94%; NPV, 79%; Kappa, 0.85; AUC, 97%).

Conclusions:

The use of ICD coding, either alone or in combination with laboratory data or lipid-lowering medication records, was not an accurate indicator in identifying dyslipidemia.

Single and mixed dyslipidaemia in Canadian primary care settings: findings from the Canadian primary care sentinel surveillance network database

OBJECTIVES

Dyslipidaemia is a major risk factor to cardiovascular disease (CVD)--the leading cause of death worldwide. Limited data are available about the prevalence of various dyslipidaemia in Canada. The objective of this study is to describe the prevalence of various single and mixed dyslipidaemia within the Canadian population in a primary care setting.

SETTING

A cross-sectional study, using the Canadian Primary Care Sentinel Surveillance Network (CPCSSN), was undertaken.

PARTICIPANTS

Non-pregnant adults older than 20 years were included.

OUTCOME MEASURES

Canadian guidelines were used to define dyslipidaemia. Descriptive statistics and multivariate regression analyses were conducted to compare the prevalence of single/mixed dyslipidaemia.

RESULTS

134,074 individuals with a mean age of 59.2 (55.8% women) were identified. 34.8% of this population had no lipid abnormality, whereas 35.8%, 17.3% and 3.2% had abnormalities in one, two and three lipid components, respectively. Approximately 86% of these patients did not receive any lipid-lowering medication. Among the medication users (14%), approximately 12% were on statin monotherapy. Statin users (n=16,036) had a lower rate of low-density lipoprotein dyslipidaemia compared to non-medication users (3% vs 17%), whereas the prevalence of high-density lipoprotein (HDL) (20% vs 12%) and triglycerides (TG) (12% vs 7%) dyslipidaemia were higher in statin users. Statin users had a greater prevalence of HDL, TG and combined HDL-TG dyslipidaemia compared to non-medication users (OR 1.44, 95% CI 1.36 to 153), (OR 1.18, 95% CI 1.10 to 1.27) and (OR 1.30, 95% CI 1.22 to 1.38), respectively, (all p values<0.0001).

CONCLUSIONS

One of every five patients in primary care settings in Canada is suffering from mixed dyslipidaemia. The overall prevalence of dyslipidaemia remains the same between treated and untreated groups, although the type of abnormal lipid component is considerably different. Among the CVD risk factors, obesity has the greatest effect on the prevalence of all types of dyslipidaemia.

Low density lipoprotein cholesterol control status among Canadians at risk for cardiovascular disease: findings from the Canadian Primary Care Sentinel Surveillance Network Database

Background

To determine the prevalence of uncontrolled LDL-C in patients with high cardiovascular disease (CVD) risks across Canada and to examine its related factors.

Methods

Non-pregnant adults >20 years-old, who had a lipid test completed between January 1, 2009 and December 31, 2011 and were included in the Canadian Primary Care Surveillance Network (CPCSSN) database were studied. The Framingham-Risk-Score was calculated to determine the risk levels. A serum LDL-C level of >2.0 mmol/L was considered as being poorly controlled. Patients with a previous record of a cerebrovascular accident, peripheral artery disease, or an ischemic heart disease were regarded as those under secondary prevention. Logistic regression modeling was performed to examine the factors associated with the LDL-C control.

Results

A total of 6,405 high-risk patients were included in the study and, of this population, 68 % had a suboptimal LDL-C, which was significantly associated with the female gender (OR: 3.26; 95 % CI: 2.63–4.05, p < 0.0001) and no medication therapy (OR: 6.31, 95 % CI: 5.21–7.65, p < 0.0001). Those with comorbidities of diabetes, hypertension, obesity, and smokers had a better LDL-C control. Rural residents (OR: 0.64, 95 % CI: 0.52–0.78, p < 0.0001), and those under secondary prevention (OR: 0.42; 95 % CI: 0.35–0.51, p < 0.0001), were also more likely to have a better LDL-C control.

Conclusion

A high proportion of high-cardiac risk patients in Canadian primary care settings have suboptimal LDL-C control. A lack of medication therapy appears to be the major contributing factor to this situation.

Does the Prevalence of Dyslipidemias Differ between Newfoundland and the Rest of Canada? Findings from the Electronic Medical Records of the Canadian Primary Care Sentinel Surveillance Network

Introduction: Newfoundland and Labrador (NL) has the highest prevalence of cardiovascular disease (CVD) in Canada. Dyslipidemia is a risk factor for CVD. This study compares the prevalence of dyslipidemia in the NL population with the rest of Canada.

Methods: A cross-sectional study, using data from the Canadian Primary Care Sentinel Surveillance Network (CPCSSN), was undertaken. The study population included adults, excluding pregnant women, aged 20 years and older. Canadian guidelines were used for classifying dyslipidemia. Univariate and multivariate analyses were conducted to compare the lipid levels and prevalence of dyslipidemia between NL and the rest of Canada.

Results: About 128,825 individuals (NL: 7,772; rest of Canada: 121,053) were identified with a mean age of 59 years (55% females). Mean levels of total cholesterol (4.96 vs. 4.93, p = 0.03), low-density lipoprotein (LDL) (3.00 vs. 2.90 mmol/L, p < 0.0001), triglyceride (1.47 vs. 1.41 mmol/L, p < 0.0001), and high-density lipoprotein (HDL) (1.29 vs. 1.39 mmol/L, p < 0.0001) were significantly different in NL compared to the rest of Canada. Dyslipidemias of LDL (29 vs. 25% p < 0.0001), HDL (38 vs. 27%, p < 0.0001), and triglyceride (29 vs. 26%, p < 0.0001) were significantly more common in NL. After adjustment for confounding variables, NL inhabitants were more likely to have dyslipidemia of total cholesterol (OR: 1.16, 95% CI: 1.10–1.23, p < 0.0001), HDL (OR: 1.52, 95% CI: 1.44–1.60, p < 0.0001), LDL (OR: 1.38, 95% CI: 1.30–1.46, p < 0.0001), and ratio (OR: 1.53, 95% CI: 1.42–1.60, p < 0.0001).

Conclusion: The NL population has a significantly higher rate of dyslipidemia compared to the rest of Canada, and the mean levels of all lipid components are worse in NL. Distinct cultural and genetic features of the NL population may explain this, accounting for a higher rate of CVD in NL.

Evaluation of the corrosion protection properties of an epoxy coating containing sol–gel surface modified nano-zirconia on mild steel

In this study, corrosion protection of epoxy coating containing surface modified nano-zirconia was evaluated and compared to that containing unmodified nano-zirconia.

Brick by brick: metformin for gestational diabetes mellitus?

Evaluation of: Balani J, Hyer SL, Rodin DA, Shehata H. Pregnancy outcomes in women with gestational diabetes treated with metformin or insulin: a case-control study. Diabet. Med. 26(8), 798-802 (2009). This paper reviews a case-control study, reported by Balani et al., comparing maternal and neonatal outcomes of women treated for gestational diabetes mellitus with either metformin or insulin. A cohort of 100 women treated with metformin alone, without insulin rescue, was compared with a retrospective cohort of 100 women treated with insulin. Results favored metformin. This paper discusses issues related to the safety and efficiency of metformin treatment during pregnancy, the attitudes of pregnant women toward treatment options, public health policy and the worldwide gestational diabetes mellitus epidemic, as well as the financial burden of therapy, particularly for developing countries. It also looks at the pathophysiology of gestational diabetes mellitus and the need for clinical trial assessment of combination oral-hypoglycemic therapy.

Wound hypoxia and acidosis limit neutrophil bacterial killing mechanisms

BACKGROUND

"Respiratory burst" activity, ie, O2- production, is dependent on PO2, temperature, pH, and glucose concentrations within the physiologic range.

OBJECTIVES

To determine whether environmental conditions characteristic of wounds may limit human neutrophil respiratory burst metabolism and to clarify the degree to which bactericidal oxidant production depends on local PO2.

METHODS

Human blood and wound neutrophils were stimulated with phorbol myristate acetate. Oxygen consumption and superoxide production were measured over a range of 30 to 300 mm Hg PO2, 0 to 40 mmol/L glucose, pH 6.0 to 8.0, and 30 degrees C to 37 degrees C. The apparent Michaelis Menten constant for oxidant production with respect to PO2 was calculated.

RESULTS

Oxygen consumption and O2- production were dependent on PO2 throughout the range tested. Half-maximal oxidant production occurred in the range of 45 to 80 mm Hg PO2 and maximal at PO2 higher than 300 mm Hg. These data agree with the highest previous estimates. Oxidant generation was also dependent on pH, temperature, and glucose concentration, but to a lesser extent.

CONCLUSIONS

Leukocyte bacterial killing capacity as measured by oxygen consumption and superoxide production are substantially impaired at the low oxygen tensions often found in wounds. Changes in pH, temperature, and glucose concentration have lesser but nonetheless significant consequences. The data provide a plausible mechanism for the vulnerability of some wounds to infection and for the previous finding that increasing oxygen tension at wound sites enhances bactericidal function. Thus, the data serve as a basis for future studies on prevention of wound infection.

Lymphatic regeneration following microvascular limb replantation: a qualitative and quantitative animal study

Lymphatic regeneration following unilateral hindlimb autotransplantation was studied in 14 Lewis rats using Technetium-99 radiolabeled sulfur colloid (TC-99) lymphoscintigraphy and compared to the lymphatic pattern exhibited in four unoperated control rats. Control animals demonstrate a reproducible flow of lymph along the deep lymphatic system from the foot, draining into the ipsilateral inguinal nodes, and then up to the para-aortic nodes. Following replantation, lymphatic outflow from the replanted limb begins to occur within 3 to 6 days, reaching normal lymphatic clearance within 12 days. However, the pattern of lymphatic flow is ill-defined, relying on multiple small channels of the superficial lymphatic system. In contrast to controls, at 3 hr post TC-99 injection, lymphatic drainage in replanted rats is via the inguinal and axillary nodal regions bilaterally. This abnormal pattern persisted in the replanted animals for the duration of this study, 160 days. It is evident that lymphatic regeneration in this animal model is associated with a rapid return to normal levels of lymphatic clearance via collateral channels within the subcutaneous tissue. The rapidity with which lymphatic drainage is restored, and its localization within the subcutaneous tissue, can explain why replanted tissues and microvascular free flaps seldom develop lymphedema. In addition, the rat hindlimb replantation model may prove useful for studies of the general mechanisms and specific factors responsible for lymphangiogenesis.

Canine laryngeal transplantation: preliminary studies and a new heterotopic allotransplantation model

While transplantation of the larynx may eventually be useful in post-laryngectomy reconstruction, three criteria must first be met before human transplants can be attempted: transplant viability must be high, immunosuppression must be safe and effective and functional recovery of the larynx must occur. To study these first two criteria, a total of 11 canine larynx transplants were performed: 3 autografts, 6 orthotopic allografts and 2 heterotopic allografts. The rationale and technical performance of these different transplant procedures are reviewed in detail. Orthotopic transplant recipients received cyclosporin A (CsA) while the heterotopic allograft recipients received RS-61443 and methylprednisolone in addition to CsA. Overall, 9 of 11 of the transplants remained viable. In contrast, all 3 autografted animals developed esophageal-cutaneous fistulas; 2 developed sepsis and were sacrificed on post-operative days (POD) 5 and 28, respectively. The third survived for 91 days and demonstrated a high degree of regeneration in the recurrent and superior laryngeal nerves of the transplant. Orthotopically transplanted dogs also had a high morbidity and perioperative mortality (5 of 6 animals). The single "long-term" survivor was treated with CsA alone, but developed complete transplant rejection on POD 33. The two heterotopic transplant recipients had no perioperative morbidity and the combination of CsA, RS-61443 and methylprednisolone given these latter animals was effective in the long-term prevention of rejection. One of these heterotopic recipients died of sepsis on POD 68 while the other remained alive and well on POD 168. Our present findings show that currently available microsurgical techniques allow experimental canine laryngeal transplantation to be done with significantly high transplant viability rates. (ABSTRACT TRUNCATED AT 250 WORDS)