2,158 research outputs found
High Quality Bioreplication of Intricate nanostructures from a Fragile Gecko Skin Surface with Bactericidal Properties
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Unusual cause of a painful right testicle in a 16-year-old man: a case report
<p>Abstract</p> <p>Introduction</p> <p>Urgent surgical exploration of the scrotum of a child or teenager who presents with a painful and swollen testicle is paramount if testicular torsion is not to be missed. It is extremely rare for a non-scrotal pathology to present with acute scrotal signs. Here we present such a rare case and emphasize the importance of being aware of this potential clinical pitfall.</p> <p>Case presentation</p> <p>A 16-year-old Caucasian man presented as a surgical emergency with a five to six hour history of a painful, red, and swollen right hemiscrotum. He also complained of vague lower abdominal pain, vomiting, and watery diarrhea. He had a temperature of 38.5Β°C and a tender, red, and swollen right hemiscrotum. The right testicle appeared elevated. He was mildly tender in his central and upper abdomen and less so in the lower abdomen. No convincing localizing abdominal signs were noted. He had an increased white cell count (15 Γ 10<sup>9</sup>/L) and C-reactive protein (CRP; 300 mg/L). Urgent right hemiscrotal exploration revealed about 5 ml of pus in the tunica vaginalis and a normal testicle. A right iliac fossa incision identified the cause: a perforated retrocecal appendix. Appendectomy was performed, and both the abdomen and scrotum washed copiously with saline before closure. The patient made an uneventful recovery.</p> <p>Conclusion</p> <p>Acute appendicitis presenting with scrotal signs due to a patent processus vaginalis is an extremely rare clinical entity. To date, fewer than five such cases have been reported in the medical literature. It is, therefore, extremely important to be aware of this unusual clinical scenario, as only a high index of suspicion will enable prompt, successful management of both the appendicitis and the scrotal abscess.</p
Nongenomic mechanisms of physiological estrogen-mediated dopamine efflux
<p>Abstract</p> <p>Background</p> <p>Neurological diseases and neuropsychiatric disorders that vary depending on female life stages suggest that sex hormones may influence the function of neurotransmitter regulatory machinery such as the dopamine transporter (DAT).</p> <p>Results</p> <p>In this study we tested the rapid nongenomic effects of several physiological estrogens [estradiol (E<sub>2</sub>), estrone (E<sub>1</sub>), and estriol (E<sub>3</sub>)] on dopamine efflux via the DAT in a non-transfected, NGF-differentiated, rat pheochromocytoma (PC12) cell model that expresses membrane estrogen receptors (ERs) Ξ±, Ξ², and GPR30. We examined kinase, ionic, and physical interaction mechanisms involved in estrogenic regulation of the DAT function. E<sub>2</sub>-mediated dopamine efflux is DAT-specific and not dependent on extracellular Ca<sup>2+</sup>-mediated exocytotic release from vesicular monoamine transporter vesicles (VMATs). Using kinase inhibitors we also showed that E<sub>2</sub>-mediated dopamine efflux is dependent on protein kinase C and MEK activation, but not on PI3K or protein kinase A. In plasma membrane there are ligand-independent associations of ERΞ± and ERΞ² (but not GPR30) with DAT. Conditions which cause efflux (a 9 min 10<sup>-9 </sup>M E<sub>2 </sub>treatment) cause trafficking of ERΞ± (stimulatory) to the plasma membrane and trafficking of ERΞ² (inhibitory) away from the plasma membrane. In contrast, E<sub>1 </sub>and E<sub>3 </sub>can inhibit efflux with a nonmonotonic dose pattern, and cause DAT to leave the plasma membrane.</p> <p>Conclusion</p> <p>Such mechanisms explain how gender biases in some DAT-dependent diseases can occur.</p
Wave Intensity Analysis Provides Novel Insights Into Pulmonary Arterial Hypertension and Chronic Thromboembolic Pulmonary Hypertension.
BACKGROUND: In contrast to systemic hypertension, the significance of arterial waves in pulmonary hypertension (PH) is not well understood. We hypothesized that arterial wave energy and wave reflection are augmented in PH and that wave behavior differs between patients with pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH). METHODS AND RESULTS: Right heart catheterization was performed using a pressure and Doppler flow sensor-tipped catheter to obtain simultaneous pressure and flow velocity measurements in the pulmonary artery. Wave intensity analysis was subsequently applied to the acquired data. Ten control participants, 11 patients with PAH, and 10 patients with CTEPH were studied. Wave speed and wave power were significantly greater in PH patients compared with controls, indicating increased arterial stiffness and right ventricular work, respectively. The ratio of wave power to mean right ventricular power was lower in PAH patients than CTEPH patients and controls. Wave reflection index in PH patients (PAH: β25%; CTEPH: β30%) was significantly greater compared with controls (β4%), indicating downstream vascular impedance mismatch. Although wave speed was significantly correlated to disease severity, wave reflection indexes of patients with mildly and severely elevated pulmonary pressures were similar. CONCLUSIONS: Wave reflection in the pulmonary artery increased in PH and was unrelated to severity, suggesting that vascular impedance mismatch occurs early in the development of pulmonary vascular disease. The lower wave power fraction in PAH compared with CTEPH indicates differences in the intrinsic and/or extrinsic ventricular load between the 2 diseases
A Study of Problem Solving Using Blocks Vehicle in a STEAM Course for Lower Elementary Levels
STEAM education is currently one of the most important parts of the elementary school curriculum. If STEAM learning can cultivate good problem-solving ability, it will also help improve judgment and thinking abilities. Several voices in the literature have argued for cooperative learning in STEAM courses. Although the effectiveness of course learning often is evaluated using course feedback forms, there is comparatively little emphasis on whether a course succeeds in realizing cooperative learning. For a course involving self-propelled toy-brick cars, there is little research on the application of low-grade pupils. Therefore, based on the integration of STEAM courses into self-propelled toy-brick car learning, this study applied two learning strategies of cooperative learning and individual learning to low-grade pupils in the second grade in elementary schools. After completing the course problem-solving ability indicators were measured and analyzed using the problem-solving ability test. The results show that the mean score of the experimental group in the problem-solving ability test was higher than that of the control group. In the problem-solving ability test, the scores of the two groups were also significantly different, which suggests that cooperative learning is more effective than individual learning strategies.acceptedVersio
Massless D-strings and moduli stabilization in type I cosmology
We consider the cosmological evolution induced by the free energy F of a gas
of maximally supersymmetric heterotic strings at finite temperature and weak
coupling in dimension D>=4. We show that F, which plays the role of an
effective potential, has minima associated to enhanced gauge symmetries, where
all internal moduli can be attracted and dynamically stabilized. Using the fact
that the heterotic/type I S-duality remains valid at finite temperature and can
be applied at each instant of a quasi-static evolution, we find in the dual
type I cosmology that all internal NS-NS and RR moduli in the closed string
sector and the Wilson lines in the open string sector can be stabilized. For
the special case of D=6, the internal volume modulus remains a flat direction,
while the dilaton is stabilized. An essential role is played by light D-string
modes wrapping the internal manifold and whose contribution to the free energy
cannot be omitted, even when the type I string is at weak coupling. As a
result, the order of magnitude of the internal radii expectation values on the
type I side is (lambda_I alpha')^{1/2}, where lambda_I is the ten-dimensional
string coupling. The non-perturbative corrections to the type I free energy can
alternatively be described as effects of "thermal E1-instantons", whose
worldsheets wrap the compact Euclidean time cycle.Comment: 39 pages, 1 figur
Developing an algorithm for pulse oximetry derived respiratory rate (RRoxi): a healthy volunteer study
Objective The presence of respiratory information within the pulse oximeter signal (PPG) is a well-documented phenomenon. However, extracting this information for the purpose of continuously monitoring respiratory rate requires: (1) the recognition of the multi-faceted manifestations of respiratory modulation components within the PPG and the complex interactions among them; (2) the implementation of appropriate advanced signal processing techniques to take full advantage of this information; and (3) the post-processing infrastructure to deliver a clinically useful reported respiratory rate to the end user. A holistic algorithmic approach to the problem is therefore required. We have developed the RROXI algorithm based on this principle and its performance on healthy subject trial data is described herein
The impact of point mutations in the human androgen receptor : classification of mutations on the basis of transcriptional activity
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A pilot dose-response study of the acute effects of haskap berry extract (Lonicera caerulea L.) on cognition, mood and blood pressure in older adults
Purpose
Haskap (Lonicera caerulea L. or blue honeysuckle) is a plant native to the low-lying wet areas and mountains of Siberia and northeastern Asia, but is now cultivated in Canada. The dark blue berries are rich in anthocyanins, particularly cyanidin-3-O-glucoside. Previously, anthocyanin-rich fruits have been observed to benefit cognitive performance during the immediate postprandial period following a single acute dose. However, no study has currently examined the potential for haskap berries to influence cognitive performance. Here, we investigate the acute cognitive benefits of an anthocyanin-rich haskap berry extract.
Methods
A double-blind, counterbalanced, crossover intervention study compared the acute effects of three separate haskap berry extract doses, containing 100mg, 200mg, and 400mg anthocyanins, with a sugar-matched placebo. Participants were an opportunity sample of 20 older adults, aged 62-81 years. Measures of cognition, mood, and blood pressure were recorded at baseline and 1.5 hours postprandially.
Results
Compared to placebo, the 400mg dose elicited significantly lower diastolic blood pressure and heart rate. Both 200mg and 400mg doses elicited significantly higher word recall, with the 400mg dose also significantly improving word recognition scores, on an episodic memory task. However, mood, working memory and executive function task results were more equivocal.
Conclusions
The findings provide evidence for improvements in episodic memory and blood pressure following acute supplementation with haskap berry extract, with higher doses appearing most effective. The cognitive findings concur with previous literature that suggests episodic memory effects, and not executive function effects, are most prevalent in older adults following anthocyanin-rich berry supplementation. The blood pressure outcome is consistent with a vasodilatory mechanism of action
Proton Radiation Hardness of Perovskite Solar Cells Utilizing a Mesoporous Carbon Electrode
Funder: Airbus Endeavr WalesFunder: Alexander von Humboldt FoundationWhen designing spacefaring vehicles and orbital instrumentation, the onboard systems such as microelectronics and solar cells require shielding to protect them from degradation brought on by collisions with highβenergy particles. Perovskite solar cells (PSCs) have been shown to be much more radiation stable than Si and GaAs devices, while also providing the ability to be fabricated on flexible substrates. However, even PSCs have their limits, with higher fluences being a cause of degradation. Herein, a novel solution utilizing a screenβprinted, mesoporous carbon electrode to act biβfunctionally as an encapsulate and the electrode is presented. It is demonstrated that the carbon electrode PSCs can withstand proton irradiation up to 1 Γ 1015 protons cmβ2 at 150 KeV with negligible losses (<0.07%) in power conversion efficiency. The 12 ΞΌm thick electrode acts as efficient shielding for the perovskite embedded in the mesoporous TiO2. Through Raman and photoluminescence spectroscopy, results suggest that the structural properties of the perovskite and carbon remain intact. Simulations of the device structure show that superior radiation protection comes in conjunction with good device performance. This work highlights the potential of using a carbon electrode for future space electronics which is not limited to only solar cells
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