A novel method for the measurement of the number of positrons contained in intense positron bunches is presented. The technique is based on the Poisson distribution of the number of gamma rays ...emitted by many simultaneous positron–electron annihilations in a small solid angle. The results have been found in good agreement with those achieved with a calibrated CsI(Tl) detector coupled to a photodiode. The small dimension of the required equipment and the reduced constraints of the technique open the possibility of monitoring, in complex positrons systems, the number of positrons at different positions that are too difficult to reach with other devices.
•A new method to assess the absolute concentration of metabolites in the absence of chemically synthetized authentic standard was developed.•The method was based on the determination for a given ...metabolite of a response factor that is obtained by combining two different analytical methodologies namely, LC-radioactivity and LC-diode array detection.•A stepwise process of metabolite generation from biological source and quantification using the radiolabeled and non-radiolabeled parent compound was defined.•The method was applied to the quantification of pharmacokinetic samples and the results were compared with those obtained with an authentic chemically synthetized standard.
A new method for the quantification of metabolites in the absence of a chemically synthetized authentic standard is described herein. Metabolites to be used as reference standards were obtained biologically from microsomes incubation. The method is a stepwise process in which, only the radiolabeled (14C) and non-radiolabeled parent compound are required. Briefly, the separation and principles of equimolar detection of LC-radioactivity were applied and, a calibration curve of the 14C-parent compound was used to quantify the formation of its 14C-metabolite. In turn, serial dilutions of this 14C-metabolite were the base for the calibration curve that allowed the quantification of the non-radiolabeled metabolite.
This method was applied in plasma samples obtained from a dog pharmacokinetic study in which, a PharmaMar compound (lurbinectedin) and its N-desmethylated metabolite were quantified and, the results compared to those obtained by the classical approach (with the chemically synthetized N-desmethylated metabolite). Plasma concentrations obtained with the two methods were very similar, with standard relative errors between −11% to −4%. Similar, main pharmacokinetic parameters were calculated with the concentrations obtained either thru this method or by using a chemically synthetized authentic standard
Dynamic and efficient resuscitation strategies are now being implemented in severely injured hemodynamically unstable (HU) patients as blood products become readily and more immediately available in ...the trauma room. Our ability to maintain aggressive resuscitation schemes in HU patients allows us to complete diagnostic imaging studies before rushing patients to the operating room (OR). As the criteria for performing computed tomography (CT) scans in HU patients continue to evolve, we decided to compare the outcomes of immediate CT versus direct admission to the OR and/or angio suite in a retrospective study at a government-designated regional Level I trauma center in Cali, Colombia.
During a 2-year period (2012-2013), blunt and penetrating trauma patients (≥ 15 years) with an Injury Severity Score (ISS) greater than 15 who met criteria of hemodynamic instability (systolic blood pressure SBP <100 mm Hg and/or heart rate >100 beats/min and/or ≥ 4 U of packed red blood cells transfused in the trauma bay) were included. Isolated head trauma and patients who experienced a prehospital cardiac arrest were excluded. The main study outcome was mortality.
We reviewed 171 patients. CT scans were performed in 80 HU patients (47%) immediately upon arrival (CT group); the remaining 91 patients (53%) went directly to the OR (63 laparotomies, 20 thoracotomies) and/or 8 (9%) to the angio suite (OA group). Of the CT group, 43 (54%) were managed nonoperatively, 37 (46%) underwent surgery (15 laparotomies, 3 thoracotomies), and 2 (5%) underwent angiography (CT OA subgroup). None of the mortalities in the CT group occurred in the CT suite or during their intrahospital transfers.
There was no difference in mortality between the CT and OA groups in HU patients. CT scan was attainable in 47% of HU patients and avoided surgery in 54% of the cases. Furthermore, CT scan was helpful in deciding definitive/specific surgical management in 46% scanned HU patients who necessitated surgery after CT.
Therapy/care management study, level IV.
The aims of the current study were to assess the inclusion levels of grape byproduct replacing jiggs hay in lambs diets and to evaluate signs of copper poisoning. Thirty-four Texel and Corriedale ...crossbred female lambs were used in a randomized block experimental design. The treatments comprised four levels of grape byproduct (0; 100; 200 and 300 g/kg DM) in replacement of jiggs hay. The diets were adjusted to the same ZnCu ratio (6:1) of the basal diet. Grape byproduct consumption at up to 30%, led to similar weight gain in the different treatments (P = .92), which was suitable for growing lambs. Grape byproduct in the diet had linear effect on GGT (P < .001) and AST (P < .0001) enzymes as well as on total bilirubin (P = .05). In addition, the highest grape byproduct addition showed the highest consumption of hay (P < .01). Hay replacement by grape byproduct at up to 300 g/kg in the DM was satisfactory to weight gain and did not negatively affect feed intake and weight gain of growing lambs. Maintaining zinc:copper ratio in sheep diets is not effective in preventing liver damage caused by increased dietary copper concentrations over a period of 70 days.
•A new by-product with a potential utilization in ruminant diets•Jiggs hay replacement by grape byproduct in the sheep diet is satisfactory.•Zinc:copper balance ratio in sheep diets is not effective in preventing liver damage.
Identification of RF-amide-related peptides (RFRP), as putative mammalian orthologs of the avian gonadotropin-inhibitory hormone, has drawn considerable interest on its potential effects and ...mechanisms of action in the control of gonadotropin secretion in higher vertebrates. Yet, these analyses have so far relied mostly on indirect approaches, while direct assessment of their physiological roles has been hampered by the lack of suitable antagonists. RF9 was recently reported as a selective and potent antagonist of the receptors for RFRP (RFRPR) and the related neuropeptides, neuropeptide FF (NPFF) and neuropeptide AF (NPFF receptor). We show here that RF9 possesses very strong gonadotropin-releasing activities in vivo. Central administration of RF9 evoked a dose-dependent increase of LH and FSH levels in adult male and female rats. Similarly, male and female mice responded to intracerebroventricular injection of RF9 with robust LH secretory bursts. In rats, administration of RF9 further augmented the gonadotropin-releasing effects of kisspeptin, and its stimulatory effects were detected despite the prevailing suppression of gonadotropin secretion by testosterone or estradiol. In fact, blockade of estrogen receptor-α partially attenuated gonadotropin responses to RF9. Finally, systemic administration of RF9 modestly stimulated LH secretion in vivo, although no direct effects in terms of gonadotropin secretion were detected at the pituitary in vitro. Altogether, these data are the first to disclose the potent gonadotropin-releasing activity of RF9, a selective antagonist of RFRP (and NPFF) receptors. Our findings support a putative role of the RFRP/gonadotropin-inhibitory hormone system in the central control of gonadotropin secretion in mammals and have interesting implications concerning the potential therapeutic indications and pharmacological effects of RF9.
The very potent gonadotropin-releasing activity of RF9, a selective antagonist of the receptors for the RF-amide peptides, RFRP (putative GnIH in mammals), and NPFF, is discussed.
Superconducting nanocomposites are the best material choice to address the performance required in power applications and magnets working under high magnetic fields. However, it is still challenging ...to sort out how to achieve the highest superconducting performance using attractive and competitive manufacturing processes. Colloidal solutions have been recently developed as a novel and very promising low cost route to manufacture nanocomposite coated conductors. Well dispersed and stabilized preformance nanoparticle solutions are first prepared with high concentrations and then mixed with the YBa2Cu3O7 metalorganic precursor solutions to generate colloidal solutions to grow the nanocomposite films. Here we demonstrate, for the first time, that non-reactive BaZrO3 and BaHfO3 perovskite preformed nanoparticles are suitable for growing high quality thin and thick films, and coated conductors with a homogeneous distribution and controlled particle size using this fabrication method. Additionally, we extend the nanoparticle content of the nanocomposites up to 20%-25% mol without any degradation of the superconducting properties. Thick nanocomposite films, up to 0.8 m, have been prepared with a single deposition of low-fluorine solutions using an ink jet printing dispenser and we demonstrate that the preformed nanoparticles display only a very limited coarsening during the growth process and so high critical current densities Jc(B) under high magnetic fields. These films show the highest critical currents achieved so far based on the colloidal solution approach, Ic = 220 A/cm-w at 77 K and self-field, and they still have a high potential for further increase in the film thickness. Finally, we also show that nanocomposite YBa2Cu3O7-BaZrO3 coated conductors based on an alternating beam assisted deposited YSZ buffer layer on stainless steel metallic substrates can be developed based on these novel colloidal solutions. Non-reactive preformed oxide perovskite nanoparticles are therefore very promising elements to further advance the colloidal solution approach in the implementation of low cost and high performance coated conductors for high magnetic field applications.
Peripheral neuropathy, which can include axonal degeneration and/or demyelination, impacts adipose tissues with obesity, diabetes, and aging. However, the presence of demyelinating neuropathy had not ...yet been explored in adipose. Both demyelinating neuropathies and axonopathies implicate Schwann cells (SCs), a glial support cell that myelinates axons and contributes to nerve regeneration after injury. We performed a comprehensive assessment of SCs and myelination patterns of subcutaneous white adipose tissue (scWAT) nerves, and changes across altered energy balance states. We found that mouse scWAT contains both myelinated and unmyelinated nerves and is populated by SCs, including SCs that were associated with synaptic vesicle-containing nerve terminals. BTBR ob/ob mice, a model of diabetic peripheral neuropathy, exhibited small fiber demyelinating neuropathy and alterations in SC marker gene expression in adipose that were similar to obese human adipose. These data indicate that adipose SCs regulate the plasticity of tissue nerves and become dysregulated in diabetes.
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•Mouse scWAT is densely innervated by myelinated and unmyelinated nerves•Mouse scWAT is populated by multiple Schwann cells (SC) subtypes•SCs are located near synaptic vesicle-containing neuro-adipose nexus (NAN)•BTBR ob/ob scWAT has demyelinating neuropathy; downregulation of SC markers
Biological sciences; Cellular physiology; Cell biology; Cell
The most used thermal energy storage material in concentrated solar power plants is a binary salt of 60%NaNO3 + 40%KNO3. However, the relatively high melting point of this mixture (222 °C) represents ...a significant risk of local solidification in the operation of these plants during stand-by periods. This research proposes the use of a novel mixture composed by 30%LiNO3 + 57%KNO3 + 13%NaNO3 with a low melting point of 127 °C. The transient cooling process of a molten salt tank working with a considerable amount of 616 kg of the proposed ternary mixture was studied experimentally in a pilot-scale tank for the first time. A computational fluid dynamics (CFD) model was then developed and validated with the experimental data with a maximum temperature relative error below 4 %. Simulation of the cooling process to obtain crystallization times for the proposed ternary salt, solar salt and Hitec molten salts were performed, and it was obtained a higher crystallization time for the proposed ternary salt 125.4 h in comparison with solar salt (56.4 h) and Hitec (124.2 h). Finally, using the model developed, new simulations were performed for a scaled-up model of a state-of-the-art cold tank of a two-tank molten salt CSP thermal storage system. Results revealed that crystallization risk is minimized with the use of the proposed ternary mixture for both considered scenarios of minimum and medium height levels, with crystallization times of 24 days and 7 h and 277 days and 5 h respectively.
•A considerable amount of 616 kg of the proposed ternary mixture was studied experimentally in a pilot-scale tank.•Lithium nitrate is one of the most promising additives in TES materials under study for application in CSP plants.•Cooling process of the ternary mixture of 30%LiNO3+57%KNO3+13% NaNO3 in the molten salt tank of the pilot plant•CFD model of the pilot-scale storage tank is experimentally validated•The novel ternary mixture showed a much lower risk of crystallization in comparison with solar salt
Lin28 and Lin28b are related RNA-binding proteins that inhibit the maturation of miRNAs of the let-7 family and participate in the control of cellular stemness and early embryonic development. ...Considerable interest has arisen recently concerning other physiological roles of the Lin28/let-7 axis, including its potential involvement in the control of puberty, as suggested by genome-wide association studies and functional genomics. We report herein the expression profiles of Lin28 and let-7 members in the rat hypothalamus during postnatal maturation and in selected models of altered puberty. The expression patterns of c-Myc (upstream positive regulator of Lin28), mir-145 (negative regulator of c-Myc), and mir-132 and mir-9 (putative miRNA repressors of Lin28, predicted by bioinformatic algorithms) were also explored. In male and female rats, Lin28, Lin28b, and c-Myc mRNAs displayed very high hypothalamic expression during the neonatal period, markedly decreased during the infantile-to-juvenile transition and reached minimal levels before/around puberty. A similar puberty-related decline was observed for Lin28b in monkey hypothalamus but not in the rat cortex, suggesting species conservation and tissue specificity. Conversely, let-7a, let-7b, mir-132, and mir-145, but not mir-9, showed opposite expression profiles. Perturbation of brain sex differentiation and puberty, by neonatal treatment with estrogen or androgen, altered the expression ratios of Lin28/let-7 at the time of puberty. Changes in the c-Myc/Lin28b/let-7 pathway were also detected in models of delayed puberty linked to early photoperiod manipulation and, to a lesser extent, postnatal underfeeding or chronic subnutrition. Altogether, our data are the first to document dramatic changes in the expression of the Lin28/let-7 axis in the rat hypothalamus during the postnatal maturation and after different manipulations that disturb puberty, thus suggesting the potential involvement of developmental changes in hypothalamic Lin28/let-7 expression in the mechanisms permitting/leading to puberty onset.
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