Search

Granular volcanic ash (GVA) is a volcanic activity material with low density, high porosity, and other undesirable properties that must be improved prior to use in any construction. This material can be considered an alternative for use in road building, given its availability in many locations and in large quantities in Yemen. This article aims to investigate the potential use of GVA for the construction of roads in Yemen when treated with cement stabilizer. Two types of GVA materials with different colors were selected and referred to as red and black GVA materials. Tests performed included the unconfined compressive strength (UCS), compaction, indirect tensile strength (ITS), wetting–drying durability test, and ultrasonic pulse velocity (UPV) test for samples curried for 7 and 28 days. For each GVA–cement mixture, the cement content varied as 2%, 5%, and 8% by dry weight of GVA. Test results revealed that the compaction energy applied during sample preparation led to a significant reduction in the finesse modulus for red and black coarse GVA materials, with reductions of 10% and 23%, respectively. In addition, the cement content and curing period had a significant effect on UCS, ITS, and UPV for cement-treated GVA. The applicable quantity of cement required stabilizing GVA and achieving the base course specification for strength and durability criteria in flexible pavement with low traffic is 8% cement. [ABSTRACT FROM AUTHOR]

Cardiovascular diseases (CVDs) are the leading cause of death worldwide. Therefore, the ability to monitor electrocardiogram (ECG) in the long term could save patients' lives by allowing early diagnosis and intervention. Dry electrodes are the best option to accomplish this task. 3D printing is one of the popular techniques currently used to construct dry electrodes. This project designs, builds, tests, and compares 3D printed ECG electrodes using four commercially available electrically conductive polylactic acid-based fuzed deposition modeling filaments. Also, this project uses these printed electrodes to acquire ECG raw signals. Then it compares these signals by calculating their signal-to-noise ratio (SNR) and their ability to measure heart rate using the Pan–Tompkins algorithm. Also, the resistance of these printed electrodes is measured. In conclusion, all printed electrodes in this experiment show acceptable efficiency with SNR values equal to or larger than 18.89 dB, and these electrodes prove their ability to measure heart rate using the Pan–Tompkins algorithm. However, according to the results of this experiment, one commercially available brand (Proto-Pasta) is more favorable to use. Proto-Pasta has the highest SNR value (20.71 dB), the second lower resistance values (∼ from 600 Ω to 2 kΩ), the lowest 60 Hz powerline and low-frequency noise, the most accurate printed electrodes (the printed electrodes have less shape deformity compared to other brands), and no any noticeable physical malfunction (no knops break from the electrodes during the test process). [ABSTRACT FROM AUTHOR]

Molybdenum disulfide (MoS2) is an actively pursuing material of the 2D family due to its semiconducting characteristics, making it a potential candidate for nano and optoelectronics application. MoS2 growth from molybdenum and sulphur precursors by chemical vapor depositions (CVD) is used widely, but molybdates' conversion into MoS2 via CVD is overlooked previously. Direct growth of MoS2 on the desired pattern not only reduces the interfacial defects but also reduces the complexities in device fabrication. In this work, we combine the wet synthesis and chemical vapor deposition method where sodium molybdate and L-cysteine are used to make a solution. With the dip coating, the mixture is coated on the substrates, and then, chemical vapor deposition is used to convert the chemicals into MoS2. Raman spectroscopy revealed the presence of oxysulphides (peaks number value) other than A 1 g and E 2 g 1 , where heat treatment was performed in the presence of Ar gas flow only. On the other hand, the films reducing in the presence of sulphur and argon gas promote only A 1 g and E 2 g 1 peaks of MoS2, which confirms complete transformation. XRD diffraction showed a very small change in the diffraction peaks and value of strain, whereas SEM imaging showed the flakes formation for MoS2 samples which were heated in the presence of sulphur. X-ray photoelectron spectroscopy is also performed for the chemical composition and to understand the valence state of Mo, S, and O and other species. [ABSTRACT FROM AUTHOR]

Reaction of metal salts CoCl2·6H2O,NiCl2·6H2O and Na2[PdCl4] with thymine bisdithiocarbamate and uracil bisthiocarbamate in molar ratio 2:1 (metal/ligand) affords the presumably tetrahedral complexes [M2(dtc)(H2O)4Cl2] M; Co, Ni and square planer complexes [Pd(dtc)(H2O)4Cl2] dtc=tdtc, utdc. Dithiocarbamates (dtcs) behave as monodentate ligands. Reaction of [M2 dtc (H2O)4Cl2] M; Co (II), Ni (II), and Pd(II) with 1,10‐Phen.″ or 2,2′‐BiPy. (two equivalents) affords tetrahedral complexes of type [M2dtc(Amin)2Cl2] M; Co, Ni and square planer complexes [Pd2dtc(Amin)2Cl2], bis(dithiocarbametes) acts as a monodentate ligand and binds to the metal center through the soft sulfur atoms. Antibacterial activity of ligands and complexes is evaluated with two types of bacteria Staphylococcus aurous (gram‐positive) and Escherichia coli (gram‐negative). The complexes are characterized by physico‐chemical and spectroscopic methods. [ABSTRACT FROM AUTHOR]

Objective. The present study was aimed at investigating the possible antiulcer activities of some natural phytochemicals Aloe perryi leaf extract (APLE) and flower extract (APFE) in addition to the date palm seed extract (DPSE) and the oily samples of DPSE in a pylorus ligation-induced ulcer model using ranitidine as a standard antiulcer drug. Background. Peptic ulcer is a prevalent gastrointestinal disorder due to hypersecretion of gastric acid. It affects four million people worldwide, and 2-10% of these ulcers are perforated and cause bleeding. This increases the risk of morbidity and mortality. So we aimed to introduce a primary study alternatively safe method for treating peptic ulcer. Materials and Methods. Forty-two Wistar Albino rats of either sex were randomly divided into seven groups (6/each). The pylorus ligation was done to induce ulcer in pretreated albino rats. The antiulcer activities of extracts were estimated at different dose levels (250 and 500 mg/kg) using ranitidine as a standard drug (50 mg/kg). Gastric volume, pH, and total and free acidity as well as ulcer index and percentage of ulcer inhibition were measured to elucidate the antiulcerogenic effects. Histological examination of gastric ulcer was also performed. Statistical analysis for the results was done where P < 0.05 was considered statistically significant. Results. Pylorus ligation for 6 h in control rats resulted in gastric ulcer which was indicated by the accumulation of gastric secretion and increased total acidity and decreased pH. The pretreatment of rats with APLE, APFE, and DPSE in addition to the oily samples of DPSE significantly inhibited the ulcers induced by pylorus ligation. These effects were attributed to significant reductions in total and free acidity, ulcer index, and gastric volume while there is a marked decrease in gastric pH (the antisecretory) as well as mucosal strengthening properties of these phytochemicals. Conclusion. These findings give these extracts the potential to be a promising tool for the management of gastric ulcer after performing further clinical and experimental studies. Our study demonstrated the promising antiulcer activity of extracts and oils in pyloric ligation-induced gastric ulcer. To the best of our knowledge, this is the first study to explore the antiulcer activity of these extracts; however, further investigations may be recommended for full details about this antiulcerogenic capacity. [ABSTRACT FROM AUTHOR]

Objectives: To assess the long-term safety and efficacy of the Occlutech® ACCELL® Flex II device used for atrial septal defect (ASD) closure. This device differs from the regular device by having two very thin patches that are made of polyethylene terephthalate (PET). These patches enhance faster sealing of the defect.Background: Transcatheter closure has become the method of choice to manage most patients with secundum ASDs. There are different types of devices. The regular Occlutech device used to close an ASD is called the Occlutech Figulla Flex II. A newer modification of this device (Occlutech® ACCELL® Flex II) has been designed to eliminate/reduce thrombus formation and to enhance faster sealing.Methods: Thirty patients were followed up after occlusion of secundum ASD using the Occlutech® ACCELL® Flex II Device. The follow-up period ranged from 5.2-5.5 years with median of 5.3 years. Detailed history and full clinical examination, twelve-lead electrocardiogram (ECG), plain chest radiograph, and full 2D transthoracic echocardiography (TTE) were performed at discharge, at one month, six months, and yearly thereafter.Results: The mean age of the study group at the last follow-up was 10.4 ± 4.6 years, with 63.3% (nineteen patients) females. There were no residual shunts or complications encountered immediately after the procedure and at the latest follow-up.Conclusion: This study confirmed the transcatheter closure (TCC) of secundum ASDs using the Occlutech® ACCELL® Flex II device to be safe and effective with no complications detected in children and adolescents. [ABSTRACT FROM AUTHOR]

The purpose of this research is to study the synchronization of two integrated nonlinear systems with time delay and disturbances. A nonlinear system is a system in which the difference in output is not relative to the difference in input. A new control methodology for synchronization of the two chaotic systems master and slave is recognized by means of the unique integrated chaotic synchronous observer and the integrated chaotic adaptive synchronous observer. The instantaneous approximation states of the master and slave systems are accomplished by means of methods for suggesting observers for every one of the master and slave systems and by the production of error signals between these approximated states. This approximated synchronization error signal and state approximation errors meet at the origin by means of methods involving a particular observer-based feedback control signal to ensure synchronization and state approximation. Using Lyapunov stability theory, adaptive and nonadaptive laws for control systems, and nonlinear properties, the intermingling conditions for state approximation errors and approximated synchronization errors are established as nonlinear matrix inequalities. A solution to the resulting inequality constraints using a two-step linear matrix inequality (LMI)-based approach is introduced, giving essential and adequate conditions to extract values from the controller gain and observer gain matrices. Simulation of the suggested synchronization procedure for FitzHugh–Nagumo neuronal systems is demonstrated to expand the viability of the suggested observer-based control techniques. [ABSTRACT FROM AUTHOR]

Introduction: The optimal management of scimitar syndrome remains incompletely defined. We (1) evaluated the impact of aortopulmonary collateral (APC) occlusion, (2) compared outcomes according to surgical approach for patients who underwent surgery, and (3) identified anatomic factors associated with longer survival time without scimitar vein repair.Methods: We conducted a single center, retrospective study of 61 patients diagnosed with scimitar syndrome between 1995 and 2019. Right pulmonary artery to total pulmonary artery cross-sectional area (RPA:PA CSA) quantitatively assessed right pulmonary artery size. Anatomical features were analyzed for association with longer survival time without scimitar vein repair.Results: Median follow-up time was 6 years (Q1-Q3, 2-12), with 96% 5-year survival. Twenty-three patients underwent APC occlusion, which significantly decreased symptoms of overcirculation (100%-46%; p = .001) and systolic pulmonary artery pressure (median, 34-29 mmHg; p = .004). Twenty-three patients underwent scimitar vein repair; 5-year freedom from scimitar vein stenosis was 90% among patients who underwent a reimplantation compared with 42% in patients with baffle repair (p = .1). Three patients underwent surgery before the first year of age, with lower 5-year freedom from scimitar vein stenosis (0% vs. 84%; p < .001). On multivariate analysis, a lower RPA:PA CSA was associated with longer survival time without scimitar vein repair (p = .003).Conclusions: APC occlusion improves the clinical status of young and hemodynamically unstable patients. Repair at an early age is associated with an increased risk of scimitar vein stenosis. Scimitar vein repair might be avoided in patients with a smaller right pulmonary artery. [ABSTRACT FROM AUTHOR]

Objectives. Aneurysmal bone cyst (ABC) is a benign but locally aggressive tumor. It has several challenging features. The aim of this study is to identify challenges in the diagnosis and treatment of ABC especially in patients with unusual features. Methods. This retrospective study involved medical record review of primary ABC patients with one or more of the following features: unusual clinical presentation with a mass or a pathological fracture especially at an unusual age, rare locations, radiological findings suggesting other diagnoses especially sarcoma, and a nondiagnostic histopathology of biopsy samples. Results. 25 patients (17 males and 8 females) were included. Most patients were either younger than 10 or older than 20 years. 10 patients presented with a mass or a pathological fracture. Unusual locations include the scapula, the olecranon, the hamate, the calcaneus, and the first metatarsal bone. Extension into the epiphysis occurred in 2 patients with proximal fibula and olecranon ABCs. Two separate synchronous cysts existed in the proximal epiphysis and middiaphysis of one humerus. Radiological imaging suggested other primary diagnoses in 8 patients. Core needle biopsy was diagnostic in only 2 of 7 patients. The main treatment was intralesional resection/curettage with bone grafting. Wide resection was performed in 4 patients. Recurrence rate was 28%. Recurrence risk factors included the following: age less than 10 years, male gender, and proximal femur location. Late recurrence occurred in 3/7 patients. One patient with asymptomatic radiological recurrence showed subsequent spontaneous resolution one year later. Conclusions. This study presented multiple unusual features of ABC including: unusual age, rare locations, and nondiagnostic radiological and histopathological findings. These features can complicate the diagnosis and management. Given these features, especially with pathological fractures, a well-planned incision, the use of frozen section examination, and the application of either external fixation or plate osteosynthesis for fracture fixation can be recommended. [ABSTRACT FROM AUTHOR]

Interruption of the aortic arch, aortopulmonary window, and anomalous origin of the right pulmonary artery from the ascending aorta are very rare congenital anomalies. It is even rarer to have all three anomalies in the same setting. We present a case of a newborn who was diagnosed with these lesions and describe the primary repair of these anomalies. [ABSTRACT FROM AUTHOR]

Circumflex aorta and double aortic arch are two forms of rare vascular rings. We present a case of an infant who was diagnosed with circumflex aorta and double aortic arch, and describe the surgical management of this rare anomaly. [ABSTRACT FROM AUTHOR]

We present a case of a 10-year-old female with a cervical aortic arch and distal transverse arch tortuosity causing coarctation and aneurysmal formation and describe the surgical repair of this rare congenital anomaly. [ABSTRACT FROM AUTHOR]

An editorial is presented, in which the author discusses percutaneous pulmonary valve implantation trough transcatheter pulmonary valve replacement. it mentions feasibility, safety and efficacy of tPVR. it also mentions armamentarium for the prevention and treatment of most conduit injuries.

Background Patients with free pulmonary regurgitation or mixed pulmonary stenosis and regurgitation and severely dilated right ventricles (RV) show little improvement in ventricular function after pulmonary valve replacement when assessed by traditional echocardiographic markers. We evaluated changes in right and left ventricular (LV) function using speckle tracking echocardiography in patients after SAPIEN transcatheter pulmonary valve (TPV) placement. Methods Echocardiograms were evaluated at baseline, discharge, 1 and 6 months after TPV placement in 24 patients from 4 centers. Speckle tracking measures of function included peak longitudinal strain, strain rate, and early diastolic strain rate. RV fractional area change, tricuspid annular plane systolic excursion, and left ventricular LV ejection fraction were assessed. Routine Doppler and tissue Doppler velocities were measured. Results At baseline, all patients demonstrated moderate to severe pulmonary regurgitation; this improved following TPV placement. No significant changes were detected in conventional measures of RV or LV function at 6 months. RV longitudinal strain (−16.9% vs. −19.6%, P < 0.01), strain rate (−0.87 s−1 vs. −1.16 s−1, P = 0.01), and LV longitudinal strain (−16.2% vs. −18.2%, P = 0.01) improved between baseline and 6 month follow-up. RV early diastolic strain rate, LV longitudinal strain rate and early diastolic strain rate showed no change. Conclusion Improvements in RV longitudinal strain, strain rate, and LV longitudinal strain are seen at 6 months post-TPV. Diastolic function does not appear to change at 6 months. Speckle tracking echocardiography may be more sensitive than traditional measures in detecting changes in systolic function after TPV implantation. [ABSTRACT FROM AUTHOR]

Graft rejection is the most common factor that limits graft survival after transplantation. During infancy, the humoral immune system is partially suppressed and humoral rejection of a cardiac allograft has not been reported in the absence of risk factors such as prior transplantation, blood transfusions, ventricular assist devices, and elevation of panel reactive antibodies. We present a case of an infant with dilated cardiomyopathy who developed multiple episodes of acute humoral rejection after heart transplantation in the absence of risk factors. [ABSTRACT FROM AUTHOR]

Background and Aim With the advancement of percutaneous coronary interventions (PCIs), more patients with diffuse coronary artery disease are referred for coronary artery bypass graft (CABG) surgery. The use of coronary endarterectomy may be useful in such cases. We reviewed our experience with left anterior descending artery endarterectomy as an adjunct to conventional CABG. Methods Between June 2005 and 2011, 58 consecutive patients underwent left anterior descending artery endarterectomy as an adjunct to CABG. These were matched to 58 cases based on age, gender, and Parsonnet score. All data were collected prospectively in a departmental database. Postoperative complications and in-hospital mortality were analyzed. Survival curves were produced. Results There was one death in the endarterectomy group (1.7%) from liver failure. There was no significant difference in postoperative complications (especially perioperative myocardial infarction) between the two groups with similar hospital mortality. Computed tomography (CT) angiography was performed in 24 patients with endarterectomy (41%), which showed 100% patency of the left internal mammary artery graft to the left anterior descending artery. Survival and freedom from intervention at a mean follow-up of 4.2 years were similar. Conclusions In patients with diffuse disease, the use of endarterectomy is a safe technique with no increase in short-term morbidity or mortality. Mid-term results are similar to nonendarterectomized patients. This technique is useful in patients with diffuse coronary artery disease. doi: 10.1111/jocs.12230 (J Card Surg 2014;29:1-7) [ABSTRACT FROM AUTHOR]

Objectives To evaluate echocardiographic changes after SAPIEN valve implantation in the pulmonary position. Background The feasibility of the SAPIEN transcatheter pulmonary valve ( TPV) has recently been demonstrated. We evaluated changes in pulmonary valve function and the right ventricle after SAPIEN TPV placement. Methods We evaluated echocardiograms at baseline, discharge, 1 and 6 months after TPV placement in 33 patients from 4 centers. Pulmonary insufficiency severity was graded 0-4. TPV peak and mean gradients were measured. Right ventricular ( RV) size and function were quantified using routine measures derived from color, spectral, and tissue Doppler indices and two-dimensional echocardiography. Results At baseline, 94% patients demonstrated pulmonary insufficiency grade 2-4. This decreased to 12% patients at 6 months (P < 0.01). TPV peak (P < 0.01) and mean gradient (P < 0.01) decreased. RV end-diastolic area indexed to body surface area (BSA) (P < 0.01), Tricuspid regurgitation ( TR) gradient (P < 0.01), and the ratio of TR jet area to BSA (P < 0.01) decreased. Tricuspid inflow peak E:A, tissue Doppler imaging ( TDI): septal E' and A', TDI: tricuspid A' improved between baseline and discharge, but trended back to baseline by 6-month follow-up. Tricuspid valve annulus z-score, RV area change, tricuspid annular plane systolic excursion ( TAPSE), RV dP/dt, tricuspid E:E', and TDI: tricuspid annulus E' showed no change. Conclusion Improvements in pulmonary insufficiency and stenosis, RV size, and TR gradient and severity are seen after SAPIEN TPV placement. Selected indices of RV diastolic function improve immediately after TPV implantation, but return to baseline by 6 months. RV systolic function is unchanged. [ABSTRACT FROM AUTHOR]

Introduction: The aim of this study is to assess the safety and the efficacy of radiofrequency ablation (RFA) of osteoid osteoma with Soloist monopolar electrode using tissue impedance, rather than temperature, as an indicator of osteonecrosis. Methods: The medical records and imaging studies of 30 patients (males 18, females 12) who underwent RFA of osteoid osteoma at our institution were reviewed. The mean age of the patients was 15.3 years (range 5-34 years) and the mean duration of follow up was 26.9 months (range 3-52 months). The lesions were located in the femur ( n = 6, 53%), tibia ( n = 8, 27%), hand ( n = 3, 10%), foot ( n = 2, 6%) and humerus ( n = 1, 3%). The procedure was performed with general anaesthesia under CT guidance. The nidus was accessed with 11-gauge bone biopsy needle and then the stylet was removed and replaced by monopolar 16.5G radiofrequency probe with a 9-mm active tip through the coaxial axis. Power delivery via the radiofrequency generator was started at 2 W and increased gradually until the end point of 450-500 Ω reached and 'Roll-Off' achieved indicating coagulation necrosis of the target lesion. Results: The procedure was technically successful in all patients. The mean procedure time was 72 min and the mean RFA time was 12.7 min. The clinical success rate was 93%. In one patient, the procedure was abandoned due to immature Roll-Off despite all measures. In one patient (3%), recurrence occurred 39 months after the procedure. No major complications were encountered. Two minor skin burns occurred that were resolved with conservative measures. Conclusion: RFA of osteoid osteoma using Soloist monopolar electrode is a safe and effective treatment. Tissue impedance could be used as an alternative to temperature to indicate osteonecrosis of osteoid osteoma during RFA. [ABSTRACT FROM AUTHOR]