Advanced extraction of PV parameters' models based on electric field impacts on semiconductor conductivity using QIO algorithm.

This article presents a novel approach for parameters estimation of photovoltaic cells/modules using a recent optimization algorithm called quadratic interpolation optimization algorithm (QIOA). The proposed formula is dependent on variable voltage resistances (VVR) implementation of the series and shunt resistances. The variable resistances reduced from the effect of the electric field on the semiconductor conductivity should be included to get more accurate representation. Minimizing the mean root square error (MRSE) between the measured (I-V) dataset and the extracted (V-I) curve from the proposed electrical model is the main goal of the current optimization problem. The unknown parameters of the proposed PV models under the considered operating conditions are identified and optimally extracted using the proposed QIOA. Two distinct PV types are employed with normal and low radiation conditions. The VVR TDM is proposed for (R.T.C. France) silicon PV operating at normal radiation, and eleven unknown parameters are optimized. Additionally, twelve unknown parameters are optimized for a Q6-1380 multi-crystalline silicon (MCS) (area 7.7 cm2) operating under low radiation. The efficacy of the QIOA is demonstrated through comparison with four established optimizers: Grey Wolf Optimization (GWO), Particle Swarm Optimization (PSO), Salp Swarm Algorithm (SSA), and Sine Cosine Algorithm (SCA). The proposed QIO method achieves the lowest absolute current error values in both cases, highlighting its superiority and efficiency in extracting optimal parameters for both Single-Crystalline Silicon (SCS) and MCS cells under varying irradiance levels. Furthermore, simulation results emphasize the effectiveness of QIO compared to other algorithms in terms of convergence speed and robustness, making it a promising tool for accurate and efficient PV parameter estimation.

Biosynthesis of zinc oxide nanoparticles via neem extract and their anticancer and antibacterial activities.

In the present study, zinc oxide nanoparticles (ZnO-NPs) were synthesized using neem leaf aqueous extracts and characterized using transmission electron microscopy (TEM), ultraviolet visible spectroscopy (UV-Vis), and dynamic light scattering (DLS). Then compare its efficacy as anticancer and antibacterial agents with chemically synthesized ZnO-NPs and the neem leaf extract used for the green synthesis of ZnO-NPs. The TEM, UV-vis, and particle size confirmed that the developed ZnO-NPs are nanoscale. The chemically and greenly synthesized ZnO-NPs showed their optical absorbance at 328 nm and 380 nm, respectively, and were observed as spherical particles with a size of about 85 nm and 62.5 nm, respectively. HPLC and GC-MS were utilized to identify the bioactive components in the neem leaf aqueous extract employed for the eco-friendly production of ZnO-NPs. The HPLC analysis revealed that the aqueous extract of neem leaf contains 19 phenolic component fractions. The GC-MS analysis revealed the existence of 21 bioactive compounds. The antiproliferative effect of green ZnO-NPs was observed at different concentrations (31.25 µg/mL-1000 µg/mL) on Hct 116 and A 549 cancer cells, with an IC50 value of 111 µg/mL for A 549 and 118 µg/mL for Hct 116. On the other hand, the antibacterial activity against gram-positive and gram-negative bacteria was estimated. The antibacterial result showed that the MIC of green synthesized ZnO-NPs against gram-positive and gram-negative bacteria were 5, and 1 µg/mL. Hence, they could be utilized as effective antibacterial and antiproliferative agents.

Green synthesis, characterization, and hepatoprotective effect of zinc oxide nanoparticles from Moringa oleifera leaves in CCl4-treated albino rats.

Hepatotoxin carbon tetrachloride (CCl4) causes liver injury. This research aims to create ZnO-NPs using green synthesis from Moringa oleifera (MO) leaves aqueous extract, and chemically prepared and confirming the synthesis by specialized equipment analysis. The sizes formed of ZnO-NPs were 80 and 55 nm for chemical and green methods, respectively. In addition, to study their ability to protect Wistar Albino male rats against oxidative stress exposed to carbon tetrachloride. MO leaf aqueous extract, green synthesized ZnO-NPs, and ZnO-NPs prepared chemically at 100 and 200 mg/kg BW per day were investigated for their hepatoprotective effects on liver enzyme biomarkers, renal biomarkers, antioxidant enzymes, lipid peroxidation, hematological parameters, and histopathological changes. Compared to the control group, all liver and kidney indicators were considerably elevated after the CCl4 injection. However, the activity of antioxidant enzymes in the liver was significantly reduced after the CCl4 injection. These outcomes indicate that MO leaf aqueous extract, greenly synthesized ZnO-NPs, and ZnO-NPs chemically prepared can restore normal liver and kidney function and activity, as well as hematological and antioxidant enzymes. The highest impact on enhancing the hepatoprotective effect was recorded for rats that received green synthesized ZnO-NPs. The increased drug delivery mechanism of green synthesized ZnO-NPs resulted in a higher protective effect than that of MO leaf aqueous extract.

Reliability constrained dynamic generation expansion planning using honey badger algorithm.

Generation expansion planning (GEP) is a complex, highly constrained, non-linear, discrete and dynamic optimization task aimed at determining the optimum generation technology mix of the best expansion alternative for long-term planning horizon. This paper presents a new framework to study the GEP in a multi-stage horizon with reliability constrained. GEP problem is presented to minimize the capital investment costs, salvage value cost, operation and maintenance, and outage cost under several constraints over planning horizon. Added to that, the spinning reserve, fuel mix ratio and reliability in terms of Loss of Load Probability are maintained. Moreover, to decrease the GEP problem search space and reduce the computational time, some modifications are proposed such as the Virtual mapping procedure, penalty factor approach, and the modified of intelligent initial population generation. For solving the proposed reliability constrained GEP problem, a novel honey badger algorithm (HBA) is developed. It is a meta-heuristic search algorithm inspired from the intelligent foraging behavior of honey badger to reach its prey. In HBA, the dynamic search behavior of honey badger with digging and honey finding approaches is formulated into exploration and exploitation phases. Added to that, several modern meta-heuristic optimization algorithms are employed which are crow search algorithm, aquila optimizer, bald eagle search and particle swarm optimization. These algorithms are applied, in a comparative manner, for three test case studies for 6-year, 12-year, and 24-year of short- and long-term planning horizon having five types of candidate units. The obtained results by all these proposed algorithms are compared and validated the effectiveness and superiority of the HBA over the other applied algorithms.

Effect of Dexmedetomidine in Sub-Tenon's Block on Emergence Agitation in Pediatric Strabismus Surgery under Sevoflurane Anesthesia.

Background: Numerous unfavorable complications may occur with strabismus surgery as emergency agitation (EA), oculocardiac reflex (OCR), postoperative pain, and postoperative nausea and vomiting (PONV). Aims: This study was designed to evaluate the dexmedetomidine effect in sub-Tenon's block on EA in strabismus surgery in the pediatric population under sevoflurane anesthesia. Design: This was a prospective randomized double-blind clinical trial. Patients and Methods: Eighty American Society of Anesthesiologists (ASA) Physical Status Class I and II pediatric patients, in an age group ranging from 2 to 8 years of either sex, had strabismus surgery under sevoflurane anesthesia using laryngeal mask airway. Patients were divided randomly into two groups (each = 40). Sub-Tenon's block is performed in the operated eye with 0.5% bupivacaine (0.08 mL.kg-1) alone in Group B (bupivacaine group), and with 0.5% bupivacaine (0.08 mL.kg-1) and dexmedetomidine (0.5 µg.kg-1) in Group D (dexmedetomidine group). Hemodynamics were monitored, and OCR was recorded. Furthermore, postoperative EA (Pediatric Anesthesia Emergence Delirium and Cravero Scales), pain (Face, Legs, Activity, Cry, and Consolability), and incidence of PONV were recorded as well. Statistical Analysis: A prospective analysis of the collected data was performed using the SPSS program for Windows (version 26). Results: The dexmedetomidine group exhibited a lower EA incidence, pain, and PONV as compared to the bupivacaine group. No statistically significant differences regarding hemodynamics, OCR, or emergence time were found between both the groups. Conclusion: The addition of dexmedetomidine to bupivacaine in sub-Tenon's block can alleviate postoperative EA and nausea and vomiting with better pain management and hemodynamic stability in pediatric strabismus surgery under sevoflurane anesthesia.

High gain chopper supplied from PV system to fed synchronous reluctance motor drive for pumping water application.

Power generation for renewable energy sources increased rapidly during last few years. Similarly, the high gain dc-dc boost choppers are taking place of conventional power converters used for photovoltaic (PV) appliances. Researchers are developing different methods in order to provide high voltage gain, low ripple, reduced switch stress, low converter costs, and minimized variations of PV operating points. This study proposes a two-stage converter for a freestanding water pumping motor drive power by solar PV system. According to the proposed system, at first, a high gain (HG) cell and a DC-to-DC boost converter are combined to increase the PV voltage to high levels. Later on, the resulting dc voltage feds a three-phase synchronous reluctance motor drive that operates centrifugal pump load. The perturb and observe approach is utilized to get the maximum power out of the solar PV module. Moreover, indirect field-oriented control is implemented to accomplish smooth starting of synchronous reluctance motor. In order to validate the effectiveness of proposed technique, a MATLAB/Simulink environment-based simulation setup along with an experimental prototype is developed. Additionally, various cases are considered based on different operating conditions and irradiance levels to collect and analyse the results.

Simultaneous determination of ofloxacin and bromfenac in combined dosage form using four different spectrophotometric methods.

Four simple, precise, accurate and validated spectrophotometric methods have been developed for the simultaneous determination of ofloxacin (OFL) and bromfenac sodium (BROM). Firstly, first and second derivative spectrophotometric methods (1D &2D) using a zero-crossing technique utilizing 309.3 and 257.5 nm for OFL and 290.7 and 246.5 nm for BROM as optimum working wavelengths in a binary mixture, respectively. Secondly, the first derivative ratio spectrophotometric method (1DD) in which peak amplitudes at 297.3 nm and 260.7 nm were chosen to simultaneously estimate OFL and BROM, respectively. Thirdly, dual wavelength (DW) method based on two selected wavelengths for each drug in such a way that the difference in absorbance is zero for the second one. At wavelengths 296.4, 348.4 nm BROM has equal absorbance values, therefore, these two wavelengths have been used to determine OFL. Similarly, 271.7 nm and 313.1 nm were selected to determine BROM in the combined formulation. Finally, the fourth method depends on ratio difference spectrophotometry (RDSM), in which the difference between amplitudes at 305.6 nm and 326.5 nm on the ratio spectrum of the mixture was directly proportional to the concentration of OFL; independent of the interfering components. Similarly, the difference between amplitudes at 265.1 nm and 275.4 nm on the ratio spectrum was used for the determination of BROM. The linearity was confirmed in the range of 4 - 18 µg/ml for OFL and BROM for the four methods. The proposed methods were used to determine both drugs in their laboratory prepared mixture and combined formulation with mean percentage recoveries of 99.41 ± 1.35% for OFL and 99.98 ± 1.30 % for BROM in method (A). In method (B), the mean percentage recoveries were 101.70 ± 1.61% for OFL and 101.90 ± 1.45% for BROM. In method (C) OFL was 99.57 ± 1.61% and 100.90 ± 1.62% for BROM. Finally, in method (D) the mean percentage recoveries were 99.37 ± 1.67% for OFL and 100.70 ± 1.59% for BROM. The developed methods were successfully employed for determination of OFL and BROM in laboratory prepared mixtures and combined formulation showing satisfactory recoveries. Methods validation was performed according to the International Conference on Harmonization (ICH) guidelines. The obtained results conformed to the accepted ranges of recovery, precision and repeatability.

The fabrication of an innovative extremely sensitive nano green carbon paste electrode amended with the nanocomposite CuO/Y for electrochemical quantification of amprolium in sheep meat and liver samples.

In this work, carbon paste electrode (CPE) and modified CPE with copper oxide or copper yttrium oxide were prepared for determining amprolium hydrochloride (AMP) by differential pulse voltammetry. AMP has an antiprotozoal activity for treating coccidiosis in poultry; their retaining- in sheep meat and livers- induces adversative effects for the customer. XRD pattern was employed to define the fabricated nanostructured materials; the elemental composition of the nanocomposite was examined using EDX spectra. Over a pH ranging from 2 to 8, the oxidation process of AMP was studied using phosphate buffer. The scan rates were studied over a wide range (20 to 140 mV s-1) using cyclic voltammetry. The developed sensor shows a wide linear range (1.0 × 10-8-1.0 × 10-3 M) with a detection limit of 2.32 × 10-9 M. This method can quantify AMP in pharmaceutical form, sheep meat, and liver samples.

Relationship between Fragmented QRS and Microvascular Dysfunction in Masked Hypertension.

Aim: The aim of this study was to investigate the presence of fQRS and its association with subclinical systolic and microvascular dysfunction in patients with masked hypertension (MH). Methods: The study population consisted of 95 (mean age 48.9 ± 11.3, 61% males) subjects with MH and 80 age- and gender-matched healthy individuals who served as a control group. Coronary flow reserve (CFR) using transthoracic echocardiography and for left ventricular global longitudinal strain (LVGLS) using speckle-tracking strain imaging were performed. Patients with MH were stratified into two groups according to the presence of fQRS on surface electrocardiogram. Results: Fragmented QRS was more common among MH patients compared with controls (38.9% vs. 6.25%, p < 0.003). CFR was significantly lower in patients with fQRS compared with those without fQRS and controls (p < 0.001). Likewise, LVGLS values were lower in MH patients with fQRS (p < 0.001) compared with subjects without fQRS and controls. Fragmented fQRS was significantly correlated with systolic blood pressure, CFR, and LVGLS. Multivariate analysis showed that the presence of fQRS, number of leads, and CFR were independent predictors of subclinical systolic dysfunction. With ROC cure analysis, number of leads with fQRS ≥4 was the optimal value for predicting the presence of subclinical systolic dysfunction in subjects with MH. Conclusions: Fragmented QRS is more frequent among subjects with MH compared with controls. The presence of fQRS is related with pronounced subclinical left ventricular systolic dysfunction. Furthermore, CFR was significantly reduced in subjects with MH, a finding supposed that microvascular dysfunction to be a mechanistic link.

Usefulness of Stress-Derived E/e' Ratio in Asymptomatic Hypertensive Patients.

PURPOSE: We sought to investigate the usefulness of stress echocardiography-derived E/e' in predicting subclinical atherosclerosis in asymptomatic hypertensive patients. MATERIALS AND METHODS: 71 newly diagnosed untreated hypertensive patients (48 ± 13 years, 65% males) and 30 age- and sex-matched healthy controls were recruited. Resting and exercise echocardiography was performed to assess resting diastolic blood pressure and the diastolic stress parameters. Coronary flow reserve (CFR) was evaluated as well. RESULTS: Based on CFR values, newly diagnosed, untreated hypertensives were stratified into hypertensives with microvascular dysfunction (MVD; 34 patients had CFR <2.0) and those without MVD (37 patients had CFR ≥2.0). Patients with MVD had a significantly higher C-reactive protein level (p < 0.05) and lower metabolic equivalent values (p < 0.05). With resting echocardiography, only the left atrial volume index (LAVI) was significantly increased in those with MVD compared with those without MVD and controls (p < 0.05). With exercise echo, the E/e' was significantly increased in MVD patients compared with those without MVD and controls (p < 0.001). Importantly, the percentage of subjects with exercise E/e' ≥15 was 76.5% (26 patients in the group with MVD), 4.1% (3 patients in the group without MVD), and 0% in controls. At univariate analysis, high-sensitivity C-reactive protein (p < 0.05), LAVI (p < 0.05), and exercise E/e' (p < 0.001) were independently associated with reduced CFR. On the other hand, at multivariate analysis, only exercise E/e' was the independent predictor of reduced CFR in newly diagnosed hypertensives. CONCLUSION: We have demonstrated significant associations between exercise-derived raised left ventricular pressure and coronary MVD in newly diagnosed untreated hypertensive patients. Herein, we supposed that exercise-derived E/e' could predict subclinical atherosclerosis and might be a risk parameter for newly diagnosed untreated hypertensive patients.

Presence of Microvascular Dysfunction and CHA2DS2-VASc Score in Patients with ST-Segment Myocardial Infarction after Primary Percutaneous Coronary Intervention.

OBJECTIVE: We aimed to investigate the relation between CHA2DS2-VASc score and microvascular dysfunction (MVD) assessed by the index of microvascular resistance (IMR) immediately after primary percutaneous intervention (PPCI) for patients with ST-segment elevation myocardial infarction (STEMI). SUBJECTS AND METHODS: The study included 115 consecutive patients with STEMI who underwent successful PPCI. Angiographic results of reperfusion were inspected to evaluate the association of high CHA2DS2-VASc score and IMR. Also, we assessed echocardiographic changes with respect to CHA2DS2-VASc score. RESULTS: Subjects were stratified into 2 groups based on IMR

Resting Left Ventricular Dyssynchrony and Mechanical Reserve in Asymptomatic Normotensive Subjects with Early Type 2 Diabetes Mellitus.

BACKGROUND: Most diabetic patients have silent ischemia and cardiac dysfunction that is usually observed in the late phase of the disease when it becomes clinically obvious. We hypothesized that left ventricular dyssynchrony (LVdys) (or dispersion) is an early marker of myocardial involvement in asymptomatic early type 2 diabetes mellitus (T2DM) patients. Therefore, we aimed to detect early markers of myocardial dysfunction in early T2DM using LVdys and left ventricular mechanical reserve (LVMR). METHODS: We examined 91 consecutive subjects with early T2DM with speckle tracking imaging to evaluate LVdys and with dobutamine stress to evaluate LVMR (defined as left ventricular mechanical reserve global longitudinal strain [LVMRGLS] ≥2%). Our patients were divided into two groups according to LVdys: group 1 with LVdys (n = 49), and group 2 without LVdys (n = 42). RESULTS: We found that 49 (54%) subjects in our cohort had resting LVdys (standard deviation of tissue synchronization of the 12 left ventricular segments [Ts-SD-12] ≥34.2 ms). GLS and strain rate were comparable at rest between patients with and without LVdys. On the other hand, LVMR was blunted in those with LVdys (p < 0.001). We found that HbA1c, high-sensitivity C-reactive protein, and left atrial volume index were inversely correlated with LVMR. Multivariate analysis showed that LVdys was the strongest predictor (p < 0.001) of blunted LVMR. Using receiver operating characteristic curve analysis, we found that a Ts-SD-12 ≥36.5 ms was the best cutoff value to predict blunted LVMR (area under the curve = 0.89, p < 0.001). CONCLUSION: The LVdys (Ts-SD-12) cutoff ≥36.5 ms was the optimal value for prediction of impaired LVMR and might be an early marker of subclinical cardiac dysfunction and risk stratification of subjects with asymptomatic early T2DM with preserved left ventricular ejection fraction.

Blood Pressure Variability and Atrial Fibrillation in Patients with Acute ST Segment Elevation Myocardial Infarction: The Relation with Left Atrial Electromechanical Delay - A 1-Year Follow-Up Study.

PURPOSE: To investigate the association between 24-h blood pressure variability (BPV) and atrial electromechanical delay (EMD) in patients with ST segment elevation myocardial infarction (STEMI) who developed new-onset atrial fibrillation (NOAF). MATERIALS AND METHODS: A total of 175 STEMI patients (age 56.6 ± 10.5 years) who underwent primary percutaneous coronary intervention were subjected to in-hospital 24-h ambulatory BP monitoring, comprehensive echocardiography, and assessment of atrial EMD. The parameters of BPV analyzed were: (a) 24-h standard deviation (SD), (b) the coefficient of variation, and (c) the average of the daytime and nighttime SDs weighted for the duration of the daytime and nighttime interval (SDdn ). RESULTS: Based on the median of BPV index (SDdn) = 9.5 mm Hg of all participants, patients were stratified into low and high variability groups (SDdn: 7.1 ± 1.5 vs.13.5 ± 2.9; p < 0.001). Of the 175 patients with STEMI, 29 (16.7%) patients developed NOAF; 26 (28.9%) were in the high variability group and 3.5% were in the low variability group (p < 0.001). Echocardiographic data showed that the left atrial volume index (p < 0.01) and E/e' ratio (p < 0.001) were significantly higher in patients with high BPV. Inter and intra-atrial EMD were significantly increased in the high variability group compared to the low variability group (p < 0.001). With multiple linear analysis, there was significant correlation between SDdn and intra-left atrial and inter-atrial EMD (p < 0.001 and <0.01, respectively). Cox regression analysis revealed that SDdn and intra-atrial EMD were independent predictors for NOAF in patients with STEMI (OR = 3.75 and 02.72, respectively; p < 0.001). ROC analysis revealed that SDdn ≥12.8 was the optimal cut-off value for predicting NOAF during follow-up. CONCLUSIONS: Short-term BPV was associated with NOAF during the 1-year follow-up in patients with STEMI. In addition, BPV was correlated significantly with atrial EMD. Herein, BPV was predicted to be an early predictor of NOAF in patients with STEMI.

Validated Liquid Chromatography-Tandem Mass Spectroscopic Method for Simultaneous Determination of Certain Drugs Used in Cataract Surgery in Rabbit Aqueous Humor.

A sensitive, selective, accurate and precise ultra-high performance liquid chromatography-Tandem mass spectrometry (MS/MS) method was developed and validated for the simultaneous determination of drugs used as eye drops in cataract surgery in aqueous humor. Cataract surgery requires a powerful mydriatic eye drops combination such as cyclopentolate hydrochloride and phenylephrine hydrochloride to dilate the pupil and facilitate eye lens replacement and also requires strong fluoroquinolone antibiotic such as lomefloxacin hydrochloride. The method was performed with positive ion electrospray ionization and the analytes were quantified and monitored on a triple quadrupole mass spectrometer using multiple reaction monitoring scanning mode. Liquid-liquid extraction was used for the purification and preconcentration of analytes from rabbit aqueous humor matrix. Chromatographic elution was performed using an Phenomenex Luna® C18 (150 mm × 2.1 mm, 1.6 µm) column and moxifloxacin hydrochloride as internal standard with a mobile phase consisting of methanol:water:formic acid (70:29:1, by volume) at flow rate of 0.2 mL/min. Satisfactory results regarding linearity, recovery, stability, accuracy and precision of the analytes were obtained. Full validation of the procedure was performed according to the US Food and Drug Administration guidance for industry: bioanalytical method validation and European Medicines Agency (EMA) guideline on bioanalytical method validation.

Relation between left atrial strain and exercise tolerance in patients with mild mitral stenosis: An insight from 2D speckle-tracking echocardiography.

BACKGROUND: Mild mitral stenosis (MS) is a progressive disease but unfortunately, its clinical course is still unclearly studied. We aimed to study the left atrial (LA) deformation in such patients and how it is related to exercise intolerance. METHODS: Seventy-five patients with mitral valve area of 1.81 ± 0.13 cm2 and 40 healthy control subjects were enrolled. All participants had sinus rhythm, and they underwent conventional echocardiography and LA strain analysis with speckle-tracking study. The following parameters were obtained: left atrial reservoir strain (LAS-s), LA conduit strain (LAS-e), and LA contraction strain (LAS-a). All participants underwent symptoms limited stress ECG using modified Bruce protocol. RESULTS: Comparing with control subjects, patients with mild MS had significant lower LAS-s value (P < .01) and LAS-e (<0.03). Patients with exercise intolerance (METs < 8) had lower LAS-s (P < .001), LAS-e (P < .01), and LAS-a (P < .05) values compared to those with METs ≥ 8. We found that METs was significantly related to LAS-s (P < .001), brain natriuretic peptide (P < .001), and Δ TAPSE (P < .03). Multivariate analysis showed that LAS-s was an independent predictor of reduced exercise capacity. With ROC analysis, LAS-s ≤ 26.5% was the optimal value for prediction of exercise intolerance in patients with mild MS. CONCLUSION: A significant percentage of patients with mild mitral stenosis had exercise intolerance. We found that LAS-s was significantly associated with exercise capacity in patients with mild MS. Hence, we thought that LA deformation could be of great value in the follow-up of patients with mild MS.

Relation of microvascular dysfunction and exercise tolerance in patients with heart failure with preserved ejection fraction.

PURPOSE: We aimed to investigate the association of coronary flow reserve (CFR) with exercise tolerance (ET) in subjects with heart failure with preserved ejection fraction (HFpEF). MATERIALS AND METHODS: Seventy-seven patients with HFpEF were recruited for the study and compared with 30 healthy matched age and sex controls. All subjects underwent comprehensive echocardiographic evaluation. Exercise tolerance was assessed using 6-minute walking test (6 MWT). CFR was calculated with adenosine stress transthoracic Doppler echocardiography. RESULTS: Out of 77 patients with HFpEF, 51 (66%) had CFR < 2.0. Patients with CFR < 2.0 had lower 6 MWT distance (P < .001), increased E/e' ratio (P < .001), when compared to HFpEF patients with CFR ≥ 2.0 and controls. In subjects with HFpEF, CFR was significantly correlated with 6 MWTD (P < .001) and inversely correlated with E/e" (P < .01). With univariate analysis, the results showed that left ventricular mass index, left atrial volume index, E/e', and CFR were independent predictors for reduced exercise tolerance, whereas at multivariate analysis, reduced CFR was the only independent predictor (P < .001) for both reduced exercise tolerance in patients with HFpEF. CONCLUSION: The current study demonstrated that reduced CFR was an independent predictor for reduced exercise tolerance in patients with HFpEF. We supposed that microvascular dysfunction has an important role in pathogenesis and clinical course in subjects with HFpEF.

D-optimal design as a useful tool response surface methodology for the optimization of signals from synchronous fluorescence prior to simultaneous determination of avanafil and tadalafil.

A rapid, smart and sensitive first derivative spectrofluorimetric method has been carried out for the simultaneous estimation of avanafil and tadalafil either in their pure form, tablet dosage form or spiked human plasma. The measurements of normal emission spectra or synchronous fluorescence intensity of both drugs show severe overlap which hindered their determination using normal fluorescence or synchronous intensity. Therefore, a highly sensitive first derivative synchronous fluorescence procedure was used to resolve this overlap. The method is based upon measurement of the amplitude of the first derivative of synchronous fluorescence intensity of both drugs at Δλ = 70 nm and at suitable wavelength of 396 nm and 364 nm for avanafil and tadalafil, respectively. Under the optimum conditions, the linear determination ranges are 50-1800 and 5-400 ng mL-1 with a detection limit of 12.93 and 1.46 ng mL-1 for avanafil and tadalafil, respectively. A response surface methodology was used for optimization using D-optimal design which can be used for determination of the exact optimum parameters specifically designed for this method. In addition; it is a good way to graphically clarify the relationship between various experimental variables and the synchronous fluorescence intensity.

Ventricular Dyssynchrony based on echocardiographic variables and exercise tolerance After right ventricular pacing: Impact of alternative septal lead locations.

OBJECTIVE: We investigated the impact of alternative locations of right ventricular (RV) pacing on left ventricular function and its relation to exercise capacity. METHODS: Fifty patients who received a single lead pacemaker were divided according to RV pacing site into group 1 "high septum" (n = 15), group 2 "mid-septum" (n = 25), and group 3 "low septum" (n = 10) using a documented fluoroscopic method. Dyssynchrony parameters were obtained using different echocardiographic parameters. Their exercise tolerance was evaluated after 6 months of pacemaker implantation using 6 minutes walk test (6 MWT). RESULTS: We found a lesser degree of dyssynchrony in mid-location and high location compared with low location pacing (radial dyssynchrony: P < .001; maximum temporal difference: P < .01; inter-ventricular mechanical delay: P < .05, standard deviation of time-to-peak strain by tissue Doppler: P < .05). Sm was significantly increased 6 months following pacemaker implantation in group 1 and group 2 in contrast to group 3 patients (P < .05). Importantly, E/e' increased significantly (P < .001) in patients with low septal location pacing. Furthermore, 6 MWT distance was significantly improved (P < .001) in favor of groups 1 and 2. Importantly, the intra-ventricular dyssynchrony with speckle tracking was considerably less in group 1 and 2 patients. Tps-SL ≤ 120 ms was the optimal value to predict improvement in functional capacity following high to mid-septal pacing locations. CONCLUSION: There was significant improvement of functional capacity after RV pacing in high and mid-septal locations compared with low septal location. This was associated with a lesser degree of dyssynchrony in favor with mid- to high septal location.