We present a novel assay for rapid and highly sensitive detection of specific nucleic acid fragments in human serum. In a magnetic modulation biosensing (MMB) system, magnetic beads and fluorescently labeled probes are attached to the target analyte and form a "sandwich" complex.An alternating external magnetic field gradient condenses the magnetic beads (and hence the target molecules with the fluorescently labeled probes) to the detection volume and sets them in a periodic motion, in and out of a laser beam. A synchronous detection enables the removal of background signal from the oscillating target signal without complicated sample preparation. The high sensitivity of the MMB system, combined with the specificity of a sandwich hybridization assay, enables detection of DNA fragments without enzymatic signal amplification. Here, we demonstrate the sensitivity of the assay by directly detecting the EML4-ALK oncogenic translocation sequence spiked in human serum. The calculated limit of detection is 1.4 pM, which is approximately 150 times better than a conventional plate reader. In general, the MMB-assisted SHA can be implemented in many other applications for which enzymatic amplification, such as PCR, is not applicable and where rapid detection of specific nucleic acid targets is required.
It is well-established that physical exercise in humans improves cognitive functions, such as executive functions, pattern separation, and working memory. It is yet unknown, however, whether spatial learning, long known to be affected by exercise in rodents, is also affected in humans. In order to address this question, we recruited 20 healthy young male adults (18–30 years old) divided into exercise and control groups ( n = 10 in each group). The exercise group performed three sessions per week of mild-intensity aerobic exercise for 12 weeks, while the control group was instructed not to engage in any physical activity. Both groups performed maximal oxygen uptake (VO 2max ) tests to assess their cardiovascular fitness at baseline and every 4 weeks through the 12 weeks of the training program. The effects of mild aerobic exercise were tested on performance in two different virtual reality (VR)-based spatial learning tasks: (1) virtual Morris water maze (VMWM) and (2) virtual Radial arm water maze (VRAWM). Subjects were tested in both tasks at baseline prior to the training program and at the end of 12 weeks training program. While the mild-intensity aerobic exercise did not affect subjects' VO 2max parameters, mean time to anaerobic threshold increased for the exercise group compared with control. No effect was observed, however, on performance in the VMWM or VRAWM between the two groups. Based on these results, we suggest that mild-intensity aerobic exercise does not improve spatial learning and memory in young, healthy adults.
Background: Evidence regarding environmental exposure to green spaces and outcomes in coronary disease patients is lacking. We evaluated the association between residential exposure to greenness and mortality in patients undergoing percutaneous coronary interventions (PCI). Methods: Consecutive patients undergoing PCI at the Rabin Medical Center in Israel between 2004-2014 (n = 12,104) were studied. Clinical data at the time of hospitalization were extracted from medical records. Mortality data (through 2017) were obtained from the Ministry of Health. Patients with incomplete information on residential addresses were excluded. Exposure to greenness was estimated using normalized difference vegetation index (NDVI), a satellite-based index derived from Landsat 30 m spatial resolution imagery, with larger values indicating higher levels of vegetative density. NDVI was estimated within a buffer of 300 m around each patient’s home and as the point value of each 30 m pixel (immediate living environment). Additional residential-based environmental measures were obtained. Cox models assessed the hazard ratios (HRs) for mortality associated with greenness measures. Results: Among 11,262 patients analyzed [median age, 69 (IQR 61-78) y, 24% women], median NDVI-300 was 0.15 (IQR 0.13-0.17) and median NDVI-30 was 0.14 (IQR 0.11-0.17). Patients with higher NDVI-300 were slightly older; NDVI-30 was inversely correlated to ambient air pollution. During a median follow-up of 8.1 (IQR 5.1-10.6) years, 3,217 participants died. After adjustment for sociodemographic and clinical factors, NDVI-30 -but not NDVI-300- was associated with lower mortality (Figure), with an HR of 0.96 (95% CI: 0.92-0.99) per 1 SD increase. Conclusions: In this PCI registry, residential exposure to green spaces in the immediate living environment was associated with lower mortality. Results for the extended area of the living environment were inconclusive. This inconsistency between different spatial resolutions warrants further investigation
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