Respuesta fisiológica de Euglena gracilis al estrés por cobre

The objective of this study was to evaluate the toxic effect of Cu2 + in the physiological development of E. gracilis. The results showed that E. gracilis had an effect on the dose-dependent growth to the concentration of metal. The exposure of E. gracilis metal at doses of 0.8 and 1.6 mM of Cu2+ showed a significant negative effect on the stability of DNA and photosynthetic pigments involved in capturing light in the antenna complex after 144 h of exposure to the metal.

Vibration analysis for Bearing outer race condition diagnostics

This paper investigates defect detection methodologies for rolling element bearings through vibration analysis. Specifically, the utility of a new signal processing scheme combining the High Frequency Resonance Technique (HFRT) and Adaptive Line Enhancer (ALE) is investigated. The accelerometer is used to acquire data for this analysis, and experimental results have been obtained for outer race defects. Results show the potential effectiveness of the signal processing technique to determine both the severity and location of a defect. The HFRT utilizes the fact that much of the energy resulting from a defect impact manifests itself in the higher resonant frequencies of a system. Demodulation of these frequency bands through use of the envelope technique is then employed to gain further insight into the nature of the defect while further increasing the signal to noise ratio. If periodic, the defect frequency is then present in the spectra of the enveloped signal. The ALE is used to enhance the envelope spectrum by reducing the broadband noise. It provides an enhanced envelope spectrum with clear peaks at the harmonics of a characteristic defect frequency. It is implemented by using a delayed version of the signal and the signal itself to decorrelate the wideband noise. This noise is then rejected by the adaptive filter that is based upon the periodic information in the signal. Results have been obtained for outer race defects. They show the effectiveness of the methodology to determine both the severity and location of a defect. In two instances, a linear relationship between signal characteristics and defect size is indicated.

High pressure near infrared study of the mutated light-harvesting complex LH2

The pressure sensitivities of the near infrared spectra of the light-harvesting (LH2) complex and a mutant complex with a simplified BChl-B850 binding pocket were compared. In the mutant an abrupt change in the spectral properties occurred at 250 MPa, which was not observed with the native sample. Increased disorder due to collapse of the chromophore pocket is suggested.

Prevalence of low trauma fractures in long-term kidney transplant patients with preserved renal function

We evaluated the prevalence of low bone mineral density (BMD) and osteoporotic fractures in kidney transplantation (KT) patients and determined risk factors associated with osteoporotic fractures. The study was conducted on 191 patients (94 men and 97 women) with first KT for 3 years or more presenting stable and preserved renal function (serum creatinine levels lower than 2.5 mg/dl). KT patients were on immunosuppressive therapy and the cumulative doses of these drugs were also evaluated. BMD was determined by dual-energy X-ray absorptiometry at multiple sites (spine, femur and total body). Quantitative ultrasound of the calcaneus (broadband ultrasound attenuation, speed of sound, and stiffness index, SI) was also performed. Twenty-four percent (46) of all patients had either vertebral (29/46) or appendicular (17/46) fractures. We found osteoporosis and osteopenia in 8.5-13.4 and 30.9-35.1% of KT patients, respectively. Women had more fractures than men. In women, prevalent fractures were associated with diabetes mellitus [OR = 11.5, 95% CI (2.4-55.7)], time since menopause [OR = 3.7, 95% CI (1.2-11.9)], femoral neck BMD [OR = 1.99, 95% CI (1.4-2.8)], cumulative dose of steroids [OR = 1.1, 95% CI (1.02-1.12)] and low SI [OR = 1.1, 95% CI (1.0-1.2)]. In men, fractures were associated with lower lumbar spine BMD [OR = 1.75, 95% CI (1.1-2.7)], lower SI [OR = 1.1, 95% CI (1.03-1.13)], duration of dialysis [OR = 1.3, 95% CI (1.13-2.7)], and lower body mass index [OR = 1.24, 95% CI (1.1-1.4). Our results demonstrate high prevalence of low BMD and osteoporotic fractures in patients receiving a successful kidney transplant and indicate the need for specific intervention to prevent osteoporosis in this population.