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Unscrambling Structured Chirality with Structured Light at the Nanoscale Using Photoinduced Force
We show that the gradient force generated by the near field of a chiral nanoparticle carries information about its chirality. On the basis of this physical phenomenon we propose a new microscopy technique that enables the prediction of spatial features of chirality of nanoscale samples by exploiting the photoinduced optical force exerted on an achiral tip in the vicinity of the test specimen. The tip-sample interactive system is illuminated by structured light to probe both the transverse and longitudinal (with respect to the beam propagation direction) components of the sample's magnetoelectric polarizability as the manifestation of its sense of handedness, i.e., chirality. We specifically prove that although circularly polarized waves are adequate to detect the transverse polarizability components of the sample, they are unable to probe the longitudinal component. To overcome this inadequacy and probe the longitudinal chirality, we propose a judiciously engineered combination of radially and azimuthally polarized beams as optical vortices possessing pure longitudinal electric and magnetic field components along their vortex axis, respectively. The proposed technique may benefit branches of science such as stereochemistry, biomedicine, physical and material science, and pharmaceutics
Anthropometric indices in individuals infected with ascaris lumbericoids in Iran
Context: Ascaris Lumbericoids infection is more common in children and teenagers and in areas with poor sanitation or crowded living conditions. Largest of all the parasites inhabiting the human intestine it is also the most common of parasitic infections in developing countries. It has been reported to infect about one-fourth of the world population. Chronic ascariasis has been reported to adversely effect the growth rate and anthropometric indices in infected individuals of growing age. Aims: The goal of this research was to evaluate the anthropometric indices in individuals infected with Ascaris in Hamedan province of Iran. Settings and Design: This was a descriptive cross sectional study. Methods and Material: Six hundred fourteen randomly selected individuals who were inhabitants of Hamedan province of Iran were chosen for this study. Stool samples of these individuals were collected and then experimented with Formel-Ether method to determine Ascaris Lumbericoids infection. Height and weight of these individuals were measured and compared with the indices related to NCHS. Demographic information of these individuals was entered into questionnaires and ultimately was analyzed with SPSS software. Results: Out of the total study population, 16.5% of individuals were found to be infected with Ascaris. Out of the individuals infected with Ascaris, 1% were underweight. In the age groups of 6-10, 11-15, 16-20 years, 3.5%, 5.1% and 3.5% were found to be suffering from malnutrition, respectively. Conclusion: Malabsorption in children might result in malnutrition. In this study, few individuals infected with Ascaris had malnutrition, thus Ascaris infection may not be an important cause of malnutrition among children in our area
Evaluation of cranberry juice on bacteriuria and pyuria in spinal cord injured patient with neurogenic bladder
Background & aim: Urinary tract infections (UTIs) are the most common medical complication experienced by individuals living with SCI . Several factors are responsible for the high prevalence of UTIs in individual with SCI. Concerns regarding the overuse of antibiotics in individuals with SCI and emerge multi-drug-resistant bacteria , has prompted consideration for consumer –directed alternatives to improve urinary tract health. This study was designed to evaluation of cranberry juice on bacteriuria and pyuria and in spinal cord injured patients with neurogenic bladder in Shahrekord, Iran. Methods: This study was randomized, double-blind, placebo-controlled trial .60 patients (51 male and 9 female) with creatinine levels below 1.5 mg/dl and in the analysis of their urine white blood cell (WBC) counts were greater than 10 in a high-powered field (pyuria) or with a presence of bacteriuria (>= 104 cc/ml) in their urine culture selected in this study. Urine analysis and culture were carried out at before and after intervention.Samples was divided into two two groups of 30.The case patients were given a dose of 250 to 300 ml of cranberry juice cocktail with 30% concentration, daily with meals.The control group was fed the same amount of a placebo cocktail.After two weeks, first morning urine analysis and culture test were done.Data collected and analyzed using K-squared method using the SPSS software and Paired-T test technique. Results: Urine analysis and culture before and after interventions show , Urinary PH in case and control groups did not any significant statistical difference before and after intervention (P>0.05). A change in pyuria and bacteriuria levels in case patients was observed after the treatment which was statistically significant (P95٪). Conclusion: Consumption of cranberries can be effective in treating SCI patients with UTI under certain conditions. The effectiveness was most profound in patients with normal GFR who did not use urinary catheter for urination. The effectiveness was especially seen in short term reduction of pyuria and bacteriuria levels and in reduction of foul-smelling of patient's urine
Frequency-dependent anti arrhythmic effects of crataegus monogyna on the extracellular field potential recordings in the rabbit atrioventricular node, an experimental model of AF
Introduction: Despite extensive studies that have been performed on the effects of Crataegus monogyna in cardiovascular diseases, only few investigations have addressed the antiarrhythmic properties of this plant. Aims of the present study were: 1) To determine the protective role of methanolic extract of C. monogyna on the rate-dependent model and the concealed conduction of the AV node. 2) To explore the role of Na+-K+ ATPase in the protective role of C. monogyna Methods: Male New Zealand rabbits (1.5-2kg) were used in all experiments. Stimulation protocols were used to measure basic and rate-dependent AV nodal properties (recovery, atrial fibrilation and zone of concealment) in two groups (N=14). In the first group, all the stimulation protocols were performed before and after the administration of different concentrations of C. monogyna extract (n=7), while in the second group (n=7), all stimulation protocols were carried out in the presence of ouabaine (0.05 μM) and the plant extract. Results: Basic and rate-dependent properties of the AV node were inhibited after the addition of the extract of C. monogyna to Kerebs Henselite solution. At the maximum concentration of C. monogyna (30 mg/l), WBCL cycle length was significantly increased from 156.5±3.4 to 173±5.8 ms and the nodal functional refractory period was prolonged from 164.4±4.1 to 182.7±3.8 ms (P<0.05). Significant decreases of ventricular rhythm were recorded in both selective concentrations of the plant extract. The depressant electrophysiological effect of C. monogyna on the AV node was not abolished by ouabaine, a selective inhibitor of Na+-K+ ATPase enzyme. Conclusion: The results showed a potential anti-arrhythmic and protective effect for C. monogyna. The effect of the plant extract in increasing nodal refractory period and widening of the concealment zone might be the major mechanisms involved. The protective role of C. monogyna was not related to the Na+-K+ ATPase activity
Role of histaminegic and calcium channels in the inhibitory effects of hydroalcoholic extract of matricaria recutita L. on isolated rabbit jejunum
Introduction: Considering the long traditional history of anti-inflammatory and anti-spasmodic effects of Matricria spices on the gastrointestinal system, the present study aimed to investigate the role of calcium channels and Histamine receptors in the inhibitory effects of hydroalcoholic dry extract of German chamomile (Matricaria recutita L.) on the isolated rabbit jejunum. Methods: All experiments were done on the isolated jejunum of New Zealand rabbits (1.8-2.5 kg). Dry extract of aerial parts of M. recutita was obtained by the maceration technique. The study was performed on two groups (n=6 in each group). In the first group, the effects of cumulative concentrations of M. recutita (3×10-3-1×10-2 mg/ml) on normal and K+-induced contractions (50 mM) of isolated jejunum were studied. In the second group, the inhibitory role of M. recutita (3 – 13×10-3 mg/ml) was evaluated in the presence and absence of histamine and cetrizine. In the presence and absence of 10 μM certizine, a histamine H1-antagonist, a concentration-dependent inhibitory effect of M. recutita extract in the range of 3-13×10-3 mg/ml was recorded the rabbit jejunum. Results: Results showed that EC50 of M. recutita in the absence and presence of K+ was 6.3×10-3 and 6.5×10- 3mg/ml, respectively. IC50 values for two concentrations of M. recutita (8×10-3 , 1×10-2 ) to abrogated contractive phase of Histamine was 9.55 × 10-6 and 1.57 × 10-6 μM. Cetrizine (10 μM) abolished inhibitory effects of M. recutita (IC50=3.6×10-3), (p< 0.001). Conclusion: Dry extract of matricaria recutita had inhibitory effects on the contractions of isolated rabbit jejunum. Calcium channels and histamine were involved in these antispasmodic effects
Linear and non-linear simulation of joints contact surface using beam-like component
The joint modelling including non-linear effects needs accurate and precise study of their behaviors. When joints are under the dynamic loading, micro, macro- slip happens in contact surface which is non-linear reason of the joint contact surface. The non-linear effects of joint contact surface on total behavior of structure are measured by various criterions such as frequency response diagram and hysteresis loop. The objective of this research is first studying a two freedom degree system including non-linear component of hysterical valance to show its non-linear effects on structure behavior. Later, a non-linear contact model called beam-like component was simulated by ANSYS software was used amplitude to simulate joints contact surface of cantilever beam. Being linear or non-linear of this model was proved by various criterions such as frequency response diagram, hysteresis loop, and energy dissipation diagram with excitation force. The results show acceptable accuracy and modelling precision.Keywords: micro-slip, non-linear joints, finite elements, beam-like componen
Compare the effectiveness of face-to-face educationwithleaflet on preoperative knowledge of patients undergoing elective surgery- A randomized clinical trial
زمینه و هدف: طبق شواهد موجود بیماران از عدم دریافت اطلاعات لازم جهت آمادگی قبل از عمل و مراقبتهای پس از عمل رنج می برند. این مطالعه به مقایسه تأثیر دو روش آموزش کلامی چهره به چهره و آموزش از طریق پمفلت بر میزان دانش بیماران کاندیدای عمل جراحی غیراورژانس پرداخته است. روش بررسی: در این مطالعه کارآزمایی بالینی، 90 نفر بیمار کاندیدای عمل جراحی غیراورژانس با روش نمونه گیری تدریجی آسان وارد مطالعه گردیدند و به طور تصادفی و تدریجی دریک گروه کنترل و دو گروه آزمون (گروه آموزش کلامی چهره به چهره و گروه آموزش از طریق پمفلت) توزیع شدند. متغیر وابسته پژوهش را سطح دانش بیمار در مورد آمادگی های قبل، حین و پس از جراحی تشکیل می داد که با استفاده از آزمون دانش چند گزینه ای قبل و پس از مداخله مورد سنجش قرار گرفت.. یافته ها: دانش قبل از عمل بیماران پس از انجام مداخله در گروه های آزمون بطور معنی داری بالاتر از گروه شاهد بود (05/0>(P ولی بین دو گروه آزمون تفاوت معنی داری بدست نیامد (05/
Protective role of cyclosporine on the model simulated the rotational nodal arrhythmia (AVNRT) by using extracellular field potential recordings of isolated atrioventricular-node of rabbit
Introduction: Recent studies have shown acute cardioprotective effects of cyclosporine. The aim of the present study was to determine the protective role of cyclosporine on the model simulated the rotational nodal arrhythmia (AVNRT) by using extracellular field potential recordings of isolated atrioventricular-node (AV-node) of rabbit. Methods: This study was performed on isolated double-perfused AV-node of male New Zealand rabbits (1.5-2.5 kg) in one group (n=7). Basic and rate-dependent stimulation protocols (recovery, facilitation, fatigue) and arrhythmia threshold (index of refractoriness) and % Gap incidence were measured for assessment of electrophysiological properties of the AV- node. All stimulation protocols were repeated in control step and in the presence of various cumulative concentrations of cyclosporine (0.5 - 10 μm). Results: Cyclosporine prolonged the effective refractory period from 114.3±7.9 to 142±7.3 msec at the concentration of 10 μm. It also prolonged the functional refractory period from 162±3.3 to 178.6±5 msec and increased the time of Wenckebach at the concentrations of 5 - 10 μM. Various concentrations of cyclosporine increased fatigue and reached a significant level at 10 μm. Gap incidence was 82%, 16.6% and 20% in the control and treatments with 0.5 and 10 μm of cyclosporine, respectively. Conclusion: Block of MPTP by cyclosporine caused inhibition of basic and rate-dependent properties of atrioventricular node. Cyclosporine, by raising the threshold of arrhythmia, could be possibly considered as an anti- AVNRT drug
Role of nitric oxide on the electrophysiological properties of isolated rabbit atrioventricular node by extracellular field potential during atrial fibrillation
Introduction: The aim of the present study was to determine direct effects of NO modulation on protective electrophysiological properties of atrioventricular node (AV node) in the experimental model of AF in rabbit. Methods: Isolated perfused rabbit AV nodal preparations were used in two groups. In the first group (N=7), LNAME (50μM) was applied. In the second group (N=12), different concentrations of L - argenine (250 μM - 5000 μM) were added to the solution. Programmed stimulation protocols were used to quantify AV nodal conduction time, refractoriness and zone of concealment. AF protocol was executed by software with coupling intervals (ranging from 75–125 msec). Results: L-NAME had depressive effects on basic AV nodal properties. L-Arginine (250μM) had direct inhibitory effects on nodal conduction time, Wenckebach and refractoriness. Significant increases in the number of concealed beats were induced by L-Arginine (500 μM). Number of concealed beats were increased from 700.7±33.7 to 763±21 msec (P<0.05). Trend of zone of concealment prolongation in a frequency-dependent model was abrogated by Larginine (250, 5000 μM). Conclusion: NO at low concentration (in the presence of L-NAME) had facilitatory role on AV nodal properties, but at high concentration (in the presence of L-arginine) enhanced protective role of AV node during AF. Biphasic modulatory role of NO may affect protective behavior of AV node during AF. © 2011, Iranian Society of Physiology and Pharmacology. All rights reserved
Switching Strategy Development, Dynamic Model, and Small Signal Analysis of Current-Fed Cockcroft-Walton Voltage Multiplier
High voltage generation, is one of the main applications of the Cockcroft-Walton voltage multiplier (CWVM), however recently this structure is investigated to be used for high step-up DC-DC applications. This paper discusses dynamic behaviour and small-signal modelling of a CWVM based DC-DC converter and investigates how switching strategy can affect the dynamic performance of the converter. This study firstly presents, a new switching method, the steady-state relations are derived and compared to the conventional switching strategy, which shows that the proposed method equilibrates the voltage and current stress of the switches and decreases the current ripple of the input inductor. Then, the converter is dynamically modelled and analyzed using the pole-zero map. The analysis shows that the proposed switching strategy improves the dynamic behaviour of the converter. The effect of the passive elements on dynamic performance is also discussed. Experimental results are presented for a 160 W prototype to validate the evaluated performance and the dynamic analysis.©2021 Authors. Published by IEEE. This work is licensed under a Creative Commons Attribution 4.0 License. For more information, see https://creativecommons.org/licenses/by/4.0/fi=vertaisarvioitu|en=peerReviewed
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