Effluent toxicity study using biomarkers for ciprofloxacin photoelectrocatalytic degradation by bismuth-doped titanium dioxide nanotubes.

Ciprofloxacin hydrochloride (CIP) is a broad-spectrum synthetic antibiotic often found in domestic sewage and industrial waste due to the inefficiency of conventional treatments. Given the potential risk of drug accumulation, this study presents coatings of titanium dioxide nanotubes (TiO2) doped with different bismuth (Bi) concentrations to degrade CIP through photocatalytic and photoelectrochemical processes. Characterization studies revealed that bismuth (Bi) doping affected the morphology of the materials, with concentrations of 0.01 and 0.05 mol L-1, resulting in collapsed materials with a smaller active surface area. Photocatalysis tests for all the materials exhibited a similar degree of efficiency to photolysis, approximately 33%. Ecotoxicity tests using the biomarkers Lactuca sativa L., Lemna minor, and Artemia salina indicated that, although they were similar to photolysis in terms of efficiency, the effluents generated when employing the doped catalysts showed lower levels of toxicity, with the best results achieved for the material doped with 0.005 mol L-1 of Bi, with a toxicity level approximately 40% lower. Photoelectrocatalysis proved to be the most efficient CIP degradation technique. The highest degradation rate was observed for materials doped with 0.005 mol L-1 of Bi, with an efficiency of 46%, which is 1.4 times more efficient than photolysis. These results demonstrate that materials doped with low amounts of Bi can be effectively used as photoanodes for drug degradation, as their performance is superior, and the final product generated exhibits low toxicity to living organisms.

Aerobic exercise prevents cardiomyocyte damage caused by oxidative stress in early cardiovascular disease by increasing vascularity while L-arginine supplementation prevents it by increasing activation of the enzyme nitric oxide synthase.

L-Arginine and chronic exercise reduce oxidative stress. However, it is unclear how they affect cardiomyocytes during cardiovascular disease (CVD) development. The aim of this research was to investigate the possible effects of L-arginine supplementation and aerobic training on systemic oxidative stress and their consequences on cardiomyocytes during cardiometabolic disease onset caused by excess fructose. Wistar rats were allocated into four groups: control (C), fructose (F, 10% fructose in water), fructose training (FT; moderate running, 50-70% of the maximal velocity), and fructose arginine (FA; 880 mg/kg/day). Fructose was given for two weeks and fructose plus treatments for the subsequent eight weeks. Body composition, blood glucose, insulin, lipid profile, lipid peroxidation, nitrite, metalloproteinase-2 (MMP-2) activity, left ventricle histological changes, microRNA-126, -195, and -146, eNOS, p-eNOS, and TNF-α expressions were analyzed. Higher abdominal fat mass, triacylglycerol level, and insulin level were observed in the F group, and both treatments reversed these alterations. Myocardial vascularization was impaired in fructose-fed groups, except in FT. Cardiomyocyte hypertrophy was observed in all fructose-fed groups. TNF-α levels were higher in fructose-fed groups than in the C group, and p-eNOS levels were higher in the FA than in the C and F groups. Lipid peroxidation was higher in the F group than in the FT and C groups. During CVD onset, moderate aerobic exercise reduced lipid peroxidation, and both training and L-arginine prevented metabolic changes caused by excessive fructose. Myocardial vascularization was impaired by fructose, and cardiomyocyte hypertrophy appeared to be influenced by pro-inflammatory and oxidative environments.

Aerobic exercise prevents cardiomyocyte damage caused by oxidative stress in early cardiovascular disease by increasing vascularity while L-arginine supplementation prevents it by increasing activation of the enzyme nitric oxide synthase

L-Arginine and chronic exercise reduce oxidative stress. However, it is unclear how they affect cardiomyocytes during cardiovascular disease (CVD) development. The aim of this research was to investigate the possible effects of L-arginine supplementation and aerobic training on systemic oxidative stress and their consequences on cardiomyocytes during cardiometabolic disease onset caused by excess fructose. Wistar rats were allocated into four groups: control (C), fructose (F, 10% fructose in water), fructose training (FT; moderate running, 50-70% of the maximal velocity), and fructose arginine (FA; 880 mg/kg/day). Fructose was given for two weeks and fructose plus treatments for the subsequent eight weeks. Body composition, blood glucose, insulin, lipid profile, lipid peroxidation, nitrite, metalloproteinase-2 (MMP-2) activity, left ventricle histological changes, microRNA-126, -195, and -146, eNOS, p-eNOS, and TNF-α expressions were analyzed. Higher abdominal fat mass, triacylglycerol level, and insulin level were observed in the F group, and both treatments reversed these alterations. Myocardial vascularization was impaired in fructose-fed groups, except in FT. Cardiomyocyte hypertrophy was observed in all fructose-fed groups. TNF-α levels were higher in fructose-fed groups than in the C group, and p-eNOS levels were higher in the FA than in the C and F groups. Lipid peroxidation was higher in the F group than in the FT and C groups. During CVD onset, moderate aerobic exercise reduced lipid peroxidation, and both training and L-arginine prevented metabolic changes caused by excessive fructose. Myocardial vascularization was impaired by fructose, and cardiomyocyte hypertrophy appeared to be influenced by pro-inflammatory and oxidative environments.

Coffea arabica and C. canephora discrimination in roasted and ground coffee from reference material candidates by real-time PCR.

To produce specific desirable coffee blends, Coffea arabica and C. canephora are mixed each other, in some cases to suit consumer preference, but in others to reduce production costs. In this scenario, the aim of this work was to evaluate standard candidate reference materials (RMc) for analysis of different blends of roasted and ground coffee. For this purpose, we analyzed different percentages of C. arabica and C. canephora (100:0; 50:50; 25:75; and 0:100, respectively). These RMc samples were developed in a previous study with green coffee beans submitted to medium roasting. In this work, coffee species differentiation (C. arabica and C. canephora) was analyzed by real-time PCR, using specific primers previously developed, called ARA primers. The RMc material with 100% C. canephora did not present amplification, in contrast with the samples containing C. arabica, which all presented amplification. These results indicate the specificity of ARA primers for C. arabica and that the detection system assay can be used as a promising molecular tool to identify and quantify percentages of C. arabica in different coffee blends.

Cardiovascular Adaptations Induced by Resistance Training in Animal Models.

In the last 10 years the number of studies showing the benefits of resistance training (RT) to the cardiovascular system, have grown. In comparison to aerobic training, RT-induced favorable adaptations to the cardiovascular system have been ignored for many years, thus the mechanisms of the RT-induced cardiovascular adaptations are still uncovered. The lack of animal models with comparable protocols to the RT performed by humans hampers the knowledge. We have used squat-exercise model, which is widely used by many others laboratories. However, to a lesser extent, other models are also employed to investigate the cardiovascular adaptations. In the subsequent sections we will review the information regarding cardiac morphological adaptations, signaling pathway of the cardiac cell, cardiac function and the vascular adaptation induced by RT using this animal model developed by Tamaki et al. in 1992. Furthermore, we also describe cardiovascular findings observed using other animal models of RT.

68(Ge+Ga) activity standardization by 4πß(LS)-γ(NaI(Tl)) anticoincidence counting measurements.

In this work, a 68(Ge+Ga) solution has been standardized at the National Institute of Ionizing Radiation Metrology (LNMRI), in Brazil, in the frame of an international key comparison CCRI(II)-K2.Ge-68 piloted by National Institute of Standards and Technology (NIST/USA). The 4πß(LS)-γ(NaI(Tl)) anticoincidence method with live-time and extended dead-time was used and its result was validated by 4πß(LS)-γ(NaI(Tl)) coincidence counting and liquid scintillation counting using the Triple to Double Coincidence Ratio (TDCR) method. The deviations of the activity concentration values of coincidence and TDCR measurements from the anticoincidence result were 1.7% and 0.63%, respectively, which were within experimental evaluated uncertainties at ~95% level of confidence (coverage factor k = 2). The combined relative standard uncertainties were 0.65%, 0.70% and 0.53% for anticoincidence, coincidence and TDCR methods, respectively. These values are consistent with the results reported by Cessna at the ICRM2017 conference.

Cardiac AT(1) receptor-dependent and IGF1 receptor-independent signaling is activated by a single bout of resistance exercise.

AT(1) receptor (AT1R) blockade prevents physiological cardiac hypertrophy induced by resistance training. Also, our group showed that a single bout of resistance exercise (RE) activates the AKT/mTOR which was also inhibited by AT1R blocker. Here, we investigated whether IGF1-receptor (IGF1-R) and MAPKs were also activated after a single bout of RE. Wistar rats were divided into Sedentary (Sed), Sedentary treated with losartan (Sed+LOS), Exercise (EX), and Exercise treated with losartan (EX+LOS). Cardiac tissue was obtained 5 and 30 min after 4 sets of 12 repetitions of squat exercise (80 % 1RM). We demonstrated that a single bout of RE did not induce IGF1-R tyrosine phosphorylation. ERK1/2 and P38 phosphorylation levels were elevated in the EX 5min and EX 30min groups however, only ERK1/2 was inhibited by losartan treatment (AT1R blocker). Next, we showed that beta-arrestin-2 expression increased 28 % in trained animals compared to sedentary group. Altogether, our results demonstrate that AT1R, but not IGF1-R, may exert the hypertrophic cardiac stimulus RE-induced. Also, activation of AKT/mTOR and ERK1/2 pathways may occur through the beta-arrestin-dependent pathway.

Resistance training attenuates salt overload-induced cardiac remodeling and diastolic dysfunction in normotensive rats.

Elevated salt intake induces changes in the extracellular matrix collagen, leading to myocardial stiffness and impaired relaxation. Resistance training (RT) has been used as a remarkably successful strategy in the treatment of heart disease. Therefore, the aim of this study was to investigate the effects of RT on preventing pathological adaptation of the left ventricle (LV) induced by salt overload. Male Wistar rats (10 weeks old) were distributed into four groups (n=8/group): control (CO), control+1% salt (CO+SALT), RT and RT+1% salt (RT+SALT). The RT protocol consisted of 4×12 bouts of squat training, 5/week for 8 weeks, with 80% of one repetition maximum (1RM). Echocardiographs were analyzed and interstitial collagen volume fraction (CVF) was determined in the LV. The 1RM tests in the RT and RT+SALT groups increased 145 and 137%, respectively, compared with the test performed before the training program. LV weight-to-body weight ratio and LV weight-to-tibia length ratio were greater in the RT and RT+SALT groups, respectively, compared with the CO group. Although there was no difference in the systolic function between groups, diastolic function decreased 25% in the CO+SALT group compared with the CO group measured by E/A wave ratio. RT partially prevented this decrease in diastolic function compared with the CO+SALT group. A 1% salt overload increased CVF more than 2.4-fold in the CO+SALT group compared with the CO group and RT prevented this increase. In conclusion, RT prevented interstitial collagen deposition in LV rats subjected to 1% NaCl and attenuated diastolic dysfunction induced by salt overload independent of alterations in blood pressure.

Intrauterine growth restriction-induced deleterious adaptations in endothelial progenitor cells: possible mechanism to impair endothelial function.

Intrauterine growth restriction (IUGR) can induce deleterious changes in the modulatory ability of the vascular endothelium, contributing to an increased risk of developing cardiovascular diseases in the long term. However, the mechanisms involved are not fully understood. Emerging evidence has suggested the potential role of endothelial progenitor cells (EPCs) in vascular health and repair. Therefore, we aimed to evaluate the effects of IUGR on vascular reactivity and EPCs derived from the peripheral blood (PB) and bone marrow (BM) in vitro. Pregnant Wistar rats were fed an ad libitum diet (control group) or 50% of the ad libitum diet (restricted group) throughout gestation. We determined vascular reactivity, nitric oxide (NO) concentration, and endothelial nitric oxide synthase (eNOS) protein expression by evaluating the thoracic aorta of adult male offspring from both groups (aged: 19-20 weeks). Moreover, the amount, functional capacity, and senescence of EPCs were assessed in vitro. Our results indicated that IUGR reduced vasodilation via acetylcholine in aorta rings, decreased NO levels, and increased eNOS phosphorylation at Thr495. The amount of EPCs was similar between both groups; however, IUGR decreased the functional capacity of EPCs from the PB and BM. Furthermore, the senescence process was accelerated in BM-derived EPCs from IUGR rats. In summary, our findings demonstrated the deleterious changes in EPCs from IUGR rats, such as reduced EPC function and accelerated senescence in vitro. These findings may contribute towards elucidating the possible mechanisms involved in endothelial dysfunction induced by fetal programming.

Traceability from governmental producers of radiopharmaceuticals in measuring (18)F in Brazil.

Since the inception of its proficiency test program to evaluate radionuclide measurement in hospitals and clinics, the National Metrology Laboratory of Ionizing Radiation-LNMRI, that represents Brazilian National Metrology Institute (NMI) for ionizing radiation has expanded its measurement and calibration capability. Requirements from the National Health Surveillance Agency from Ministry of Health (ANVISA), to producers of radiopharmaceuticals provided an opportunity to improve the full traceability chain to the highest level. Fluorodeoxyglucose (FDG-(18)F) is the only radiopharmaceutical simultaneously produced by all Brazilian radiopharmaceutical production centers (RPCs). By running this proficiency test, LNMRI began to provide them with the required traceability. For evaluation, the ratio of RPC to reference value results and ISO/IEC17043:2010 criteria were used. The reference value established as calibration factor on the secondary standard ionization chamber was obtained from three absolute measurements systems, and routinely confirmed in each round of proficiency test by CIEMAT/NIST liquid scintillation counting. The γ-emitting impurities were checked using a High-Purity Germanium (HPGe) detector. The results show that Brazilian RPCs are in accordance with (accuracy within ±10%) the Brazilian standard for evaluation of measurements with radionuclide calibrators (CNEN NN 3.05., 2013). Nevertheless, the RPCs should improve the methodology of uncertainty estimates, essential when using the statistical criteria of ISO/IEC 17043 standard, in addition to improving accuracy to levels consistent with their position in the national traceability chain.

Enchytraeid abundance in Araucaria Mixed Forest determined by cold and hot wet extraction.

Enchytraeids are small oligochaetes found worldwide in soils with sufficient moisture and organic matter, but scarcely studied in the Southern hemisphere. This is the third study on enchytraeid abundance in Brazil using wet extraction and the first carried out in Araucaria Mixed Forest (subtropical region). The sampling and extraction were based on the standard method ISO 23611-3/2007 using an adapted split soil corer and wet extraction with and without heat to assess the abundance of enchytraeids in a forest fragment at Embrapa Forestry in Colombo, Paraná State. The samplings were performed in 3 occasions between September 2011 and April 2012. The average numbers estimated by each method varied from appr. 2.000-12.000 (cold) and 5.000-12.000 ind./ m2 (hot), respectively, with a maximum of 44.000 ind./ m2 in one of the samples, the highest value reported so far in Brazil. The hot extraction was more advantageous, given the speed and preservation of the specimens in vivo, allowing taxonomic identification. Advantages and disadvantages of wet extractions compared to handsorting and formol methods are also discussed. Guaranidrilus, Hemienchytraeus, Enchytraeus, Fridericia and Achaeta were the genera identified in the samples.

Enchytraeid abundance in Araucaria Mixed Forest determined by cold and hot wet extraction

Abstract Enchytraeids are small oligochaetes found worldwide in soils with sufficient moisture and organic matter, but scarcely studied in the Southern hemisphere. This is the third study on enchytraeid abundance in Brazil using wet extraction and the first carried out in Araucaria Mixed Forest (subtropical region). The sampling and extraction were based on the standard method ISO 23611-3/2007 using an adapted split soil corer and wet extraction with and without heat to assess the abundance of enchytraeids in a forest fragment at Embrapa Forestry in Colombo, Paraná State. The samplings were performed in 3 occasions between September 2011 and April 2012. The average numbers estimated by each method varied from appr. 2.000-12.000 (cold) and 5.000-12.000 ind./ m2 (hot), respectively, with a maximum of 44.000 ind./ m2 in one of the samples, the highest value reported so far in Brazil. The hot extraction was more advantageous, given the speed and preservation of the specimens in vivo, allowing taxonomic identification. Advantages and disadvantages of wet extractions compared to handsorting and formol methods are also discussed. Guaranidrilus, Hemienchytraeus, Enchytraeus, Fridericia and Achaeta were the genera identified in the samples.

Resumo Os enquitreídeos são pequenos oligoquetas encontrados no mundo todo em solos com suficiente umidade e matéria orgânica, porém muito pouco estudados no hemisfério Sul. Este é o terceiro estudo sobre a abundância de enquitreídeos no Brasil utilizando o método de extração úmida e o primeiro realizado em Floresta Ombrófila Mista (região subtropical). A amostragem e extração foram baseadas no método padrão ISO 23611-3/2007, utilizando-se um trado desmontável adaptado e extração úmida com e sem aquecimento para acessar a abundância de enquitreídeo em um fragmento de floresta na Embrapa Florestas em Colombo, Paraná. As amostragens foram realizadas em três ocasiões entre setembro, 2011 e abril 2012. Os números médios estimados através de cada método variaram de 2.000-12.000 (frio) e 5.000-12.000 ind./ m2 (quente), respectivamente, e o máximo de 44.000 ind./ m2 em uma das amostras, o mais alto já relatado no Brasil. A extração quente foi a mais vantajosa, considerando a rapidez e preservação dos exemplares in vivo. As vantagens e desvantagens das extrações úmidas comparadas aos métodos de triagem manual e extração com formol foram discutidas. Os gêneros Guaranidrilus, Hemienchytraeus, Enchytraeus, Fridericia e Achaeta foram identificados nas amostras.

Enchytraeid abundance in Araucaria Mixed Forest determined by cold and hot wet extraction / Abundância de enquitreídeos na Floresta Ombrófila Mista determinada por extração úmida quente e fria

Abstract Enchytraeids are small oligochaetes found worldwide in soils with sufficient moisture and organic matter, but scarcely studied in the Southern hemisphere. This is the third study on enchytraeid abundance in Brazil using wet extraction and the first carried out in Araucaria Mixed Forest (subtropical region). The sampling and extraction were based on the standard method ISO 23611-3/2007 using an adapted split soil corer and wet extraction with and without heat to assess the abundance of enchytraeids in a forest fragment at Embrapa Forestry in Colombo, Paraná State. The samplings were performed in 3 occasions between September 2011 and April 2012. The average numbers estimated by each method varied from appr. 2.000-12.000 (cold) and 5.000-12.000 ind./ m2 (hot), respectively, with a maximum of 44.000 ind./ m2 in one of the samples, the highest value reported so far in Brazil. The hot extraction was more advantageous, given the speed and preservation of the specimens in vivo, allowing taxonomic identification. Advantages and disadvantages of wet extractions compared to handsorting and formol methods are also discussed. Guaranidrilus, Hemienchytraeus, Enchytraeus, Fridericia and Achaeta were the genera identified in the samples.

Resumo Os enquitreídeos são pequenos oligoquetas encontrados no mundo todo em solos com suficiente umidade e matéria orgânica, porém muito pouco estudados no hemisfério Sul. Este é o terceiro estudo sobre a abundância de enquitreídeos no Brasil utilizando o método de extração úmida e o primeiro realizado em Floresta Ombrófila Mista (região subtropical). A amostragem e extração foram baseadas no método padrão ISO 23611-3/2007, utilizando-se um trado desmontável adaptado e extração úmida com e sem aquecimento para acessar a abundância de enquitreídeo em um fragmento de floresta na Embrapa Florestas em Colombo, Paraná. As amostragens foram realizadas em três ocasiões entre setembro, 2011 e abril 2012. Os números médios estimados através de cada método variaram de 2.000-12.000 (frio) e 5.000-12.000 ind./ m2 (quente), respectivamente, e o máximo de 44.000 ind./ m2 em uma das amostras, o mais alto já relatado no Brasil. A extração quente foi a mais vantajosa, considerando a rapidez e preservação dos exemplares in vivo. As vantagens e desvantagens das extrações úmidas comparadas aos métodos de triagem manual e extração com formol foram discutidas. Os gêneros Guaranidrilus, Hemienchytraeus, Enchytraeus, Fridericia e Achaeta foram identificados nas amostras.

Electronic excitation of furfural as probed by high-resolution vacuum ultraviolet spectroscopy, electron energy loss spectroscopy, and ab initio calculations.

The electronic spectroscopy of isolated furfural (2-furaldehyde) in the gas phase has been investigated using high-resolution photoabsorption spectroscopy in the 3.5-10.8 eV energy-range, with absolute cross section measurements derived. Electron energy loss spectra are also measured over a range of kinematical conditions. Those energy loss spectra are used to derive differential cross sections and in turn generalised oscillator strengths. These experiments are supported by ab initio calculations in order to assign the excited states of the neutral molecule. The good agreement between the theoretical results and the measurements allows us to provide the first quantitative assignment of the electronic state spectroscopy of furfural over an extended energy range.

Intermediate energy electron impact excitation of composite vibrational modes in phenol.

We report differential cross section results from an experimental investigation into the electron impact excitation of a number of the low-lying composite (unresolved) vibrational modes in phenol (C6H5OH). The measurements were carried out at incident electron energies in the range 15-40 eV and for scattered-electron angles in the range 10-90°. The energy resolution of those measurements was typically ∼80 meV. Calculations, using the GAMESS code, were also undertaken with a B3LYP/aug-cc-pVDZ level model chemistry, in order to enable us to assign vibrational modes to the features observed in our energy loss spectra. To the best of our knowledge, the present cross sections are the first to be reported for vibrational excitation of the C6H5OH molecule by electron impact.

Neuromyelitis optica spectrum disorders: beyond longitudinally extensive transverse myelitis.

AIM: To describe the neuroradiological features and their prevalence in patients with neuromyelitis optica (NMO). MATERIALS AND METHODS: Two neuroradiologists independently reviewed 35 spinal cord and 37 brain MRI studies from patients with NMO. The examinations were analysed for the presence of lesion, topography, enhancement, and brain lesions suggestive of multiple sclerosis and/or NMO. RESULTS: Seventy percent of the spinal cord lesions involved over three or more vertebral segments. Seventy-eight percent of brain scans were abnormal, and the most prevalent findings were non-specific foci of T2 hyperintensities in the cerebral white matter (55%) and brainstem lesions (52%). One patient had lesions disseminated in space compatible with multiple sclerosis according to 2010 revised McDonald criteria. Brain lesions suggestive of NMO occurred at least once in 17 (59%) patients. CONCLUSION: Spinal cord lesions were often longitudinally extensive and brain lesions were common, with the majority of patients having at least one distinctive NMO lesion.

Differential cross sections for electron impact excitation of the electronic bands of phenol.

We report results from a joint theoretical and experimental investigation into electron scattering from the important organic species phenol (C6H5OH). Specifically, differential cross sections (DCSs) have been measured and calculated for the electron-impact excitation of the electronic states of C6H5OH. The measurements were carried out at energies in the range 15-40 eV, and for scattered-electron angles between 10° and 90°. The energy resolution of those experiments was typically ∼80 meV. Corresponding Schwinger multichannel method with pseudo-potentials calculations, with and without Born-closure, were also performed for a sub-set of the excited electronic-states that were accessed in the measurements. Those calculations were conducted at the static exchange plus polarisation (SEP)-level using a minimum orbital basis for single configuration interaction (MOBSCI) approach. Agreement between the measured and calculated DCSs was typically fair, although to obtain quantitative accord, the theory would need to incorporate even more channels into the MOBSCI.

Effect of exercise training on Ca2+ release units of left ventricular myocytes of spontaneously hypertensive rats

In cardiomyocytes, calcium (Ca2+) release units comprise clusters of intracellular Ca2+ release channels located on the sarcoplasmic reticulum, and hypertension is well established as a cause of defects in calcium release unit function. Our objective was to determine whether endurance exercise training could attenuate the deleterious effects of hypertension on calcium release unit components and Ca2+ sparks in left ventricular myocytes of spontaneously hypertensive rats. Male Wistar and spontaneously hypertensive rats (4 months of age) were divided into 4 groups: normotensive (NC) and hypertensive control (HC), and normotensive (NT) and hypertensive trained (HT) animals (7 rats per group). NC and HC rats were submitted to a low-intensity treadmill running protocol (5 days/week, 1 h/day, 0% grade, and 50-60% of maximal running speed) for 8 weeks. Gene expression of the ryanodine receptor type 2 (RyR2) and FK506 binding protein (FKBP12.6) increased (270%) and decreased (88%), respectively, in HC compared to NC rats. Endurance exercise training reversed these changes by reducing RyR2 (230%) and normalizing FKBP12.6 gene expression (112%). Hypertension also increased the frequency of Ca2+ sparks (HC=7.61±0.26 vs NC=4.79±0.19 per 100 µm/s) and decreased its amplitude (HC=0.260±0.08 vs NC=0.324±0.10 ΔF/F0), full width at half-maximum amplitude (HC=1.05±0.08 vs NC=1.26±0.01 µm), total duration (HC=11.51±0.12 vs NC=14.97±0.24 ms), time to peak (HC=4.84±0.06 vs NC=6.31±0.14 ms), and time constant of decay (HC=8.68±0.12 vs NC=10.21±0.22 ms). These changes were partially reversed in HT rats (frequency of Ca2+ sparks=6.26±0.19 µm/s, amplitude=0.282±0.10 ΔF/F0, full width at half-maximum amplitude=1.14±0.01 µm, total duration=13.34±0.17 ms, time to peak=5.43±0.08 ms, and time constant of decay=9.43±0.15 ms). Endurance exercise training attenuated the deleterious effects of hypertension on calcium release units of left ventricular myocytes.

Effect of exercise training on Ca²âº release units of left ventricular myocytes of spontaneously hypertensive rats.

In cardiomyocytes, calcium (Ca²âº) release units comprise clusters of intracellular Ca²âº release channels located on the sarcoplasmic reticulum, and hypertension is well established as a cause of defects in calcium release unit function. Our objective was to determine whether endurance exercise training could attenuate the deleterious effects of hypertension on calcium release unit components and Ca²âº sparks in left ventricular myocytes of spontaneously hypertensive rats. Male Wistar and spontaneously hypertensive rats (4 months of age) were divided into 4 groups: normotensive (NC) and hypertensive control (HC), and normotensive (NT) and hypertensive trained (HT) animals (7 rats per group). NC and HC rats were submitted to a low-intensity treadmill running protocol (5 days/week, 1 h/day, 0% grade, and 50-60% of maximal running speed) for 8 weeks. Gene expression of the ryanodine receptor type 2 (RyR2) and FK506 binding protein (FKBP12.6) increased (270%) and decreased (88%), respectively, in HC compared to NC rats. Endurance exercise training reversed these changes by reducing RyR2 (230%) and normalizing FKBP12.6 gene expression (112%). Hypertension also increased the frequency of Ca²âº sparks (HC=7.61 ± 0.26 vs NC=4.79 ± 0.19 per 100 µm/s) and decreased its amplitude (HC=0.260 ± 0.08 vs NC=0.324 ± 0.10 ΔF/F0), full width at half-maximum amplitude (HC=1.05 ± 0.08 vs NC=1.26 ± 0.01 µm), total duration (HC=11.51 ± 0.12 vs NC=14.97 ± 0.24 ms), time to peak (HC=4.84 ± 0.06 vs NC=6.31 ± 0.14 ms), and time constant of decay (HC=8.68 ± 0.12 vs NC=10.21 ± 0.22 ms). These changes were partially reversed in HT rats (frequency of Ca²âº sparks=6.26 ± 0.19 µm/s, amplitude=0.282 ± 0.10 ΔF/F0, full width at half-maximum amplitude=1.14 ± 0.01 µm, total duration=13.34 ± 0.17 ms, time to peak=5.43 ± 0.08 ms, and time constant of decay=9.43 ± 0.15 ms). Endurance exercise training attenuated the deleterious effects of hypertension on calcium release units of left ventricular myocytes.

An experimental and theoretical investigation into the excited electronic states of phenol.

We present experimental electron-energy loss spectra (EELS) that were measured at impact energies of 20 and 30 eV and at angles of 90° and 10°, respectively, with energy resolution ∼70 meV. EELS for 250 eV incident electron energy over a range of angles between 3° and 50° have also been measured at a moderate energy resolution (∼0.9 eV). The latter spectra were used to derive differential cross sections and generalised oscillator strengths (GOS) for the dipole-allowed electronic transitions, through normalization to data for elastic electron scattering from benzene. Theoretical calculations were performed using time-dependent density functional theory and single-excitation configuration interaction methods. These calculations were used to assign the experimentally measured spectra. Calculated optical oscillator strengths were also compared to those derived from the GOS data. This provides the first investigation of all singlet and triplet excited electronic states of phenol up to the first ionization potential.