Comparison of Long-Term Strength Development of Steel Fiber Shotcrete with Cast Concrete Based on Accelerator Type

This study analyzed the effect of accelerating agents, such as aluminate, cement mineral, and alkali-free accelerators, on the long-term performance of steel-fiber-reinforced shotcrete. The shotcrete performance was studied based on the type and amount of steel fiber added. Performance tests were performed to identify the accelerator providing better long-term performance to the steel-fiber-reinforced shotcrete. Changes in strength and flexural performance over time were investigated. The compressive strength and flexural strength tests on 1-, 3-, 6-, 12-, and 24-month-old test specimens were performed, wherein 37 kg of steel fiber was added to the cement mineral and aluminate mixes, and 40 kg of steel fiber was added to the alkali-free mix. The 1-month compressive strength result of all the test variables satisfied the Korea Expressway Corporation standard. The compressive strength of the cast concrete and shotcrete specimens increased with age, demonstrating a strength reduction, particularly in the 24-month-old shotcrete specimens. Thus, the shotcrete performance may deteriorate in the long-term. In the 24-month-old specimen, substantial flexural strength reduction was observed, particularly in the aluminate and alkali-free specimens. The relative strength of the specimens was compared with that of the cast concrete mold specimens. The results suggest the use of alkali-free accelerators, considering the long-term performance of tunnels and safety of workers. Moreover, increasing the steel fiber performance rather than the amount of low-performance steel fiber must be considered.     

Incidence of and Risk Factors for Hospital-Acquired Diarrhea in Three Tertiary Care Public Hospitals in Bangladesh

During April 2007–April 2010, surveillance physicians in adult and pediatric medicine wards of three tertiary public hospitals in Bangladesh identified patients who developed hospital-acquired diarrhea. We calculated incidence of hospital-acquired diarrhea. To identify risk factors, we compared these patients to randomly selected patients from the same wards who were admitted > 72 hours without having diarrhea. The incidence of hospital-acquired diarrhea was 4.8 cases per 1,000 patient-days. Children < 1 year of age were more likely to develop hospital-acquired diarrhea than older children. The risk of developing hospital-acquired diarrhea increased for each additional day of hospitalization beyond 72 hours, whereas exposure to antibiotics within 72 hours of admission decreased the risk. There were three deaths among case-patients; all were infants. Patients, particularly young children, are at risk for hospital-acquired diarrhea and associated deaths in Bangladeshi hospitals. Further research to identify the responsible organisms and transmission routes could inform prevention strategies.     

Lipoprotein status among urban populations in Bangladesh

ObjectiveSerum lipoprotein is the most important predictor for microvascular diseases, and may be influenced by rapid urbanization. Currently available data are limited, particularly regarding age-specific lipoprotein status in urban Bangladeshi populations.MethodsBlood lipoprotein levels of 51,353 male and female individuals primarily residing in urban Bangladesh were analyzed. De-identified data (collected between January 2005 and December 2011) were extracted from the Clinical Biochemistry Laboratory Data Archive of International Centre for Diarrheal Disease Research, Bangladesh (icddr,b). For analyses, six age categories were created: (i) <20 years, n = 481; (ii) 20–29 years, n = 1602; (iii) 30–39 years, n = 7272; (iv) 40–49 years, n = 13,582; (v) 50–59 years, n = 15,890; and (vi) 60 years and more, n = 12,526.ResultsMean serum levels of TC, LDL, TG, LDL:HDL and TC:HDL were significantly higher among adults 30–39 years old compared to other age groups, regardless of sex. The proportion of high TC and LDL from 2005 to 2011 among individuals aged 30–39 years old varied widely (p < 0.01 for trend and all pairwise tests).Conclusion30–39 years old individuals had higher concentration of lipoprotein, which increases microvascular disease risk. Further population-based studies are needed to validate our observations in rural areas of Bangladesh.     

The determinants of chronic bronchitis in Aboriginal children and youth

BACKGROUND:

There is limited knowledge concerning chronic bronchitis (CB) in Canadian Aboriginal peoples.

OBJECTIVE:

To determine the prevalence (crude and adjusted) of CB and its associated risk factors in Canadian Aboriginal children and youth six to 14 years of age.

METHODS:

Data from the cross-sectional Aboriginal Peoples Survey were analyzed in the present study. Logistic regression analysis was used to determine risk factors influencing the prevalence of CB among Aboriginal children and youth. The balanced repeated replication method was used to compute standard errors of regression coefficients to account for clustering inherent in the study design. The outcome of interest was based on the question: “Have you been told by a doctor, nurse or other health professional that you have chronic bronchitis?” Demographics, environment and population characteristics (predisposing and enabling resources) were tested for an association with CB.

RESULTS:

The prevalence of CB was 3.1% for boys and 2.8% for girls. Other significant risk factors of CB were age (OR 1.38 [95% CI 1.24 to 1.52] for 12 to 14 year olds versus six to eight year olds), income (OR 2.28 [95% CI 2.02 to 2.59] for income category <$25,000/year versus ≥$85,000/year), allergies (OR 1.96 [95% CI 1.78 to 2.16] for having allergies versus no allergies), asthma (OR 7.61 [ 95% CI 6.91 to 8.37] for having asthma versus no asthma) and location of residence (rural/urban and geographical location). A significant two-way interaction between sex and body mass index indicated that the relationship between the prevalence of CB and body mass index was modified by sex.

DISCUSSION:

The prevalence of CB was related to well-known risk factors among adults, including older age and lower annual income.     

Is discontinuation of clopidogrel necessary for intracapsular hip fracture surgery? Analysis of 102 hemiarthroplasties

Background

An increasing number of elderly patients are managed with long-term antiplatelet therapy. Such patients often present with hip fracture requiring surgical intervention and may be at increased risk of perioperative bleeding and complications. The aim of this study was to ascertain whether it is necessary to stop clopidogrel preoperatively to avoid postoperative complications following hip hemiarthroplasty surgery in patients with intracapsular hip fracture.

Materials and methods

A retrospective review of 102 patients with intracapsular hip fracture with either perioperative clopidogrel therapy [clopidogrel group (CG)] or no previous clopidogrel exposure [no clopidogrel group (NCG)] who underwent hip hemiarthroplasty surgery was undertaken. Statistical comparison on pre- and postoperative haemoglobin, American Society of Anesthesiologists (ASA) grade, comorbidities, operative time, transfusion requirements, hospital length of stay (LOS), wound infection, haematoma and reoperation rate between the two groups was undertaken. Regression analysis was undertaken to ascertain the risk ratios (RR) of complications and transfusion associated with clopidogrel.

Results

There was no difference with respect to ASA grade, comorbidities (except cardiac comorbidities), pre- and postoperative haemoglobin levels, operation time, age or gender between the two groups. Four and two patients, respectively, required transfusion postoperatively in the CG and NCG (p = 0.37). There was no difference with respect to LOS, wound infection, haematoma or reoperation rate between the two groups postoperatively. The covariate-adjusted RR for complications and transfusion while being on clopidogrel were 0.43 [95 % confidence interval (CI) 0.07–2.60] and 3.96 (95 % CI 0.40–39.68), respectively.

Conclusion

Continuing clopidogrel therapy throughout the perioperative period in patients with intracapsular hip fracture is not associated with an increased risk of complications following hip hemiarthroplasty surgery.