Sensitivity and specificity of single-tube osmotic fragility test and its different methods as screening test for thalassemia trait: an alternative to expensive laboratory tests for resource-limited countries.

OBJECTIVE: To determine the sensitivity and specificity of single-tube osmotic fragility (SOFT) and its different methods as screening test for thalassemia trait. METHODS: A cross-sectional study was conducted at Omair Sana Foundation. A total of 400 participants were included in the study. Three hundred were known thalassemia carriers (parents with at least one child with thalassemia major), while 100 were healthy blood donors. SOFT was performed on all 400 participants. Serum iron, ferritin, and DNA tests were performed on 100 participants (donors). ARMS technique was used for detecting thalassemia mutations. RESULTS: Sensitivity and specificity of SOFT (venous method) were found to be 99.6% and 86%, respectively, while with EDTA method, sensitivity was 95% and specificity was 96%. For venous and EDTA methods, positive predictive values were 95.5% and 98.6%, respectively, while negative predictive values were 98.8% and 86.6%, respectively. Use of EDTA and storage had an effect on the results. Sensitivity of SOFT was 95% at 5 min, while it decreased to 87% with EDTA method at 240 min. Sensitivity of SOFT for iron deficiency anemia was found to be 14%. CONCLUSION: SOFT can be used as screening test for thalassemia trait in a cost-effective way. Moreover, we also found that SOFT should be performed on venous blood without adding preservatives (EDTA) that can interfere with the results.

A featureless approach for object detection and tracking in dynamic environments.

One of the challenging problems in mobile robotics is mapping a dynamic environment for navigating robots. In order to disambiguate multiple moving obstacles, state-of-art techniques often solve some form of dynamic SLAM (Simultaneous Localization and Mapping) problem. Unfortunately, their higher computational complexity press the need for simpler and more efficient approaches suitable for real-time embedded systems. In this paper, we present a ROS-based efficient algorithm for constructing dynamic maps, which exploits the spatial-temporal locality for detecting and tracking moving objects without relying on prior knowledge of their geometrical features. A two-prong contribution of this work is as follows: first, an efficient scheme for decoding sensory data into an estimated time-varying object boundary that ultimately decides its orientation and trajectory based on the iteratively updated robot Field of View (FoV); second, lower time-complexity of updating the dynamic environment through manipulating spatial-temporal locality available in the object motion profile. Unlike existing approaches, the snapshots of the environment remain constant in the number of moving objects. We validate the efficacy of our algorithm on both V-Rep simulations and real-life experiments with a wide array of dynamic environments. We show that the algorithm accurately detects and tracks objects with a high probability as long as sensor noise is low and the speed of moving objects remains within acceptable limits.

Comparative analysis of the relative potential of silver, Zinc-oxide and titanium-dioxide nanoparticles against UVB-induced DNA damage for the prevention of skin carcinogenesis.

Sunscreen formulations containing UVB filters, such as Zinc-oxide (ZnO) and titanium-dioxide (TiO2) nanoparticles (NPs) have been developed to limit the exposure of human skin to UV-radiations. Unfortunately, these UVB protective agents have failed in controlling the skin cancer incidence. We recently demonstrated that silver nanoparticles (Ag-NPs) could serve as novel protective agents against UVB-radiations. Here our goal was to perform comparative analysis of direct and indirect UVB-protection efficacy of ZnO-, TiO2- and Ag-NPs. Sun-protection-factor calculated based on their UVB-reflective/absorption abilities was the highest for TiO2-NPs followed by Ag- and ZnO-NPs. This was further confirmed by studying indirect protection of UVB radiation-induced death of HaCaT cells. However, only Ag-NPs were active in protecting HaCaT cells against direct UVB-induced DNA-damage by repairing bulky-DNA lesions through nucleotide-excision-repair mechanism. Moreover, Ag-NPs were also effective in protecting HaCaT cells from UVB-induced oxidative DNA damage by enhancing SOD/CAT/GPx activity. In contrast, ZnO- and TiO2-NPs not only failed in providing any direct protection from DNA-damage, but rather enhanced oxidative DNA-damage by increasing ROS production. Together, these findings raise concerns about safety of ZnO- and TiO2-NPs and establish superior protective efficacy of Ag-NPs.