RESUMEN
Recent advancements have established quantum dots (QDs) as a promising alternative to conventional bulk materials in the fabrication of nanoscale integrated electronic devices. The appeal of QDs lies in their amenability to low-temperature processes and solution-based methodologies, facilitating the construction of devices with enhanced versatility and efficiency. The ternary metal chalcogenide CuInS2 QDs are one of the foremost, eco-friendly, and highly stable materials. In this study, CuInS2 QDs are employed as a functional layer in a memristive device featuring an Al/CuInS2/ITO configuration. The CuInS2 QDs have been synthesized by a hot injection method and characterized using X-ray diffraction (XRD) and transmission electron microscopy (TEM) to reveal their structural features. The Al/CuInS2/ITO device shows a unipolar resistive switching (RS) behaviour with a high on/off ratio of 105. The switching parameters have been studied for 100 cycles of SET/RESET. The SET and RESET voltages are found to be 1.66 ± 0.25 V and 0.69 ± 0.17 V. The spatial variability of switching parameters in the Al/CuInS2/ITO structure has also been studied for 9 different devices. The device also exhibits unipolar RS behaviour in the optimum temperature range of 0 °C to 50 °C. These outcomes demonstrate the impressive performance of CuInS2 QDs, indicating their potential for future energy-efficient and large-scale non-volatile memory applications.
RESUMEN
Background Caudal block is an efficient way to offer perioperative analgesia for painful sub-umbilical interventions. It enables early ambulation and periprocedural hemodynamic stability. These are important advantages over general anesthesia, notably in preterm babies and in children with cardiopulmonary comorbidities. In this study, we aimed to compare the effect of dexmedetomidine and clonidine to accentuate the perioperative analgesia of 0.25% isobaric levobupivacaine in pediatric caudal anesthesia. Methodology A prospective double-blind randomized control study was conducted on 60 patients with the American Society of Anesthesiologists (ASA) physical status I, between the ages of one to six undergoing infraumbilical abdominal surgery under caudal anesthesia in the Department of Anaesthesia, Sardar Patel Medical College, Bikaner. Patients were randomly allocated to the following three groups of 20 each: group L, 1 mL/kg of levobupivacaine 0.25%; group LD, 1 mL/kg of levobupivacaine 0.25% with 0.5 µg/kg of dexmedetomidine; and group LC, 1 mL/kg of levobupivacaine 0.25% with 0.5 µg/kg of clonidine. Intraoperative and postoperative hemodynamic parameters were recorded for 24 hours. Patients' pain scores, sedation scores, and Bromage scores were recorded. In our study, the main observation was the duration of analgesia and the total analgesic requirement for 24 hours. Results There was a significant difference in the duration of analgesia among the three groups (p < 0.001). Group LC had the highest duration of analgesia of 492.00 (50.01) minutes, followed by group LD 486.00 (54.71) minutes, and the lowest in group L 291.00 (40.25) minutes. There was a significant difference between the three groups in terms of the total dose of analgesics in 24 hours (p < 0.001), with the median total dose of analgesics being the highest in Group L. Three groups differed significantly in terms of motor block, which was limited to up to 180 minutes in groups LC and LD with no residual motor block. Conclusions The addition of α2 agonists such as clonidine or dexmedetomidine at a dose of 0.5 µg/kg as an adjuvant to caudal levobupivacaine (0.25%) at 1 mL/kg significantly prolongs the duration of opioid-free analgesia in children undergoing infraumbilical abdominal surgeries without prolonging the motor blockade and any side effects. Moreover, dexmedetomidine does not offer a significant advantage over clonidine regarding the analgesia duration.
RESUMEN
Background Non-invasive ventilation (NIV) is a well-established approach in the treatment of acute exacerbation of chronic obstructive pulmonary disease (COPD) with type 2 respiratory failure. Average volume-assured pressure support (AVAPS) mode integrates the characteristics of both volume and pressure-controlled modes of NIV. In bilevel positive airway pressure (BiPAP) mode, volume is the dependent variable, whereas in AVAPS mode, pressure is the dependent variable. In this study, we aimed to compare the role of AVAPS mode with BiPAP spontaneous/timed (S/T) mode for the management of patients with acute exacerbation of COPD with type 2 respiratory failure. Methodology A hospital-based comparative and analytical study was carried out on 100 patients with acute exacerbation of COPD with type 2 respiratory failure admitted to respiratory disease hospital, Sardar Patel Medical College, Bikaner (Rajasthan, India). Patients were randomly divided into two groups of 50 patients each. Group A patients were treated with AVAPS mode and group B patients with BiPAP (S/T) mode. Arterial blood gases, average duration of hospital stay, and need for invasive mechanical ventilation were compared between the two groups. Results There was a statistically significant difference in favor of group A in terms of improvement in pH and pCO2 as compared to group B at 6 h (pH, p=0.027; pCO2, p=0.012) and 24 h (pH, p=0.032; pCO2, p=0.013). The duration of hospital stay was found to be lower in group A (p=0.003). However, no significant difference was found in terms of need for invasive mechanical ventilation between both groups (p=0.338). Conclusion Application of AVAPS mode results in more rapid and steady improvement in patients of COPD as compared to BiPAP (S/T) mode. Thus, management through non-invasive ventilation AVAPS mode should be considered in patients with acute exacerbation of COPD with type 2 respiratory failure.
