The 50th percentile was also slightly upwards biased. For all variables, bias was more severe with shorter sampling durations, and it correlated significantly with the true full-shift value for the 10th and 90th percentiles and the percentile range. As expected, shorter samples led to decreased precision of the estimate; sample standard deviations correlated strongly with true full-shift exposure values.
Conclusions: The documented risk of pronounced bias and low precision of percentile estimates obtained from short posture samples presents a concern in ergonomics research and practice, and suggests that alternative, unbiased exposure variables should be considered if data collection resources are restricted.”
“Purpose:
To evaluate the cytotoxic activity of Hibiscus rosa sinensis against K-562
cancer selleck cell line.
Methods: The crude CT99021 solubility dmso petroleum ether, ethyl acetate and methanol extracts of the leaf and stem of Hibiscus rosa sinensis were prepared using cold extraction method. The in vitro cytotoxic activity of the extracts (20 -100 mu g/ml) was evaluated on leukaemic cancer cell line (K-562) and Mardin-Darby kidney cell line (MDBK) (control) using 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)- 2H-tetrazolium (MTS) and 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assays, followed by morphological detection with Hoeschst staining.
Results: The methanol leaf selleck chemicals extracts showed higher activity (IC50 value: 30.9
+/- 1.1 mu g/ml) against K-562 cells than petroleum ether and ethyl acetate extracts which exhibited IC50 of 87.6 +/- 0.91 and 57.6 +/- 0.61 mu g/ml (p < 0.05), respectively. Meanwhile, stem extracts from methanol showed IC50 of 79.80 mu g/ml against K-562. MDBK cells (positive control) showed IC50 > 100 mu g/ml for all the extracts. On treating K-562 cells with methanol leaf extract (30 mu g/ml), the former were observed to undergo apoptosis with nuclear segmentation after 24 h incubation. The methanol leaf extract produced cell death on K-562 cells by apoptosis.
Conclusion: Hibiscus rosa sinensis extracts possess potentials as effective cytotoxic agents against K562 cells.”
“Older adults with chronic pain who seek treatment often are in a health care environment that emphasizes patient-directed care, a change from the patriarchal model of care to which many older adults are accustomed.
To explore the experiences of older adults seeking treatment for chronic pain, with respect to patient-directed care and the patient-provider relationship.
In-depth interviews with 15 Caucasian older adults with chronic pain who had been evaluated at a university-based pain clinic. All interviews were audiotaped and the transcripts were analyzed using a grounded theory based approach.
Older adults with chronic pain vary in their willingness to be involved in their treatment decisions.