A Comparison of the Effects of Epidural Levobupivacaine and Morphine for Postoperative Analgesia Following Major Abdominal Surgery: A Randomized Controlled Trial.

Objectives Epidural analgesia remains the cornerstone of pain management following laparotomy. Local anesthetics used in epidural analgesia provide good analgesia but may result in hypotension and/or motor blockade. Morphine, a long-acting opioid, can also be used epidurally to provide analgesia. Morphine used epidurally will cause fewer hemodynamic disturbances and no motor blockade. Hence, we compared the efficacy, hemodynamic parameters, and motor blockade between epidural levobupivacaine and morphine for postoperative analgesia following laparotomy. Materials and methods This is a prospective, double-blind, randomized controlled study registered in the Clinical Trials Registry of India (CTRI/2021/04/033102). Ninety patients undergoing elective major abdominal surgery were randomly divided into two groups: levobupivacaine (0.125%/mL) and morphine (0.032 mg/mL) group. All patients received epidural infusion at 6 mL/hour. The visual analog scale (VAS) score at rest and during cough was observed for 24 hours. Heart rate and blood pressure were monitored continuously for 24 hours postoperatively. Additional analgesic requirements, postoperative sedation score, and motor blockade were also compared between the two groups. Statistical analysis was done using the chi-square test, unpaired T-test, and Mann-Whitney test. The sample size estimation was based on a pilot study. Results The demographic data and duration of the procedure were comparable in both groups. The initial median VAS score at rest in the levobupivacaine group was high (interquartile range (IQR): 2-4) when compared to the morphine group (IQR: 1-3) at the fourth, sixth, and eighth hour with a P value of <0.05. The initial median VAS score at coughing in the levobupivacaine group was 4 (IQR: 3-5) and in the morphine group was 3 (IQR: 3-4). The VAS score at rest and at coughing was significantly higher in the levobupivacaine group. Heart rate was stable in both groups, and a significant fall in mean arterial blood pressure was observed in the levobupivacaine group. The sedation score was significantly higher in the morphine group (IQR: 2-2) when compared to the levobupivacaine group (IQR: 1-2) at the fourth hour postoperatively with a P value of <0.05. Motor blockade was found to be stronger in the levobupivacaine group (IQR: 0-2) when compared to the morphine group (IQR: 0-0) at the fourth, sixth, and eighth hour postoperatively with a P value of <0.05. An additional dose of fentanyl was required by 6.7% of the patients in the levobupivacaine group and 8.9% of the patients in the morphine group. In the levobupivacaine group, 11.1% reported headaches, 2.2% reported vomiting, and 4.4% reported hypotension, and no pruritus was reported. In the morphine group, 11.1% reported tachycardia, 6.7% reported nausea and vomiting, 6.4% reported pruritus, and 2.2% reported hypotension. Conclusion We conclude that patients receiving epidural morphine had better pain scores with better hemodynamic stability than the epidural levobupivacaine group following laparotomy. The morphine group had less motor blockade. Sedation was observed in the morphine group. Additional analgesics were required in both groups. The adverse effects observed in the epidural morphine group were tachycardia, nausea, pruritus, and itching. The epidural levobupivacaine group reported headache, vomiting and fever, and hypotension.

Novel Insight into the Concept of Favorable Combination of Electrodes in High Voltage Supercapacitors: Toward Ultrahigh Volumetric Energy Density and Outstanding Rate Capability.

Most of the biomass-derived carbon-based supercapacitors using organic electrolytes exhibit very low energy density due to their low operating potential range between 2.7 and 3.0 V. A novel insight into the concept of the different porous architecture of electrode materials that is employed to extend a device's operating potential up to 3.4 V using TEABF4 in acetonitrile, is reported. The combination of two high surface area activated carbons derived from abundant natural resources such as industrial waste cotton and wheat flour as sustainable and green carbon precursors is explored as an economical and efficient supercapacitor carbon electrode. Benefitting from the simultaneous achievement of the higher potential window (3.4 V) with higher volumetric capacitance (101 F cm-3), the supercapacitor electrodes exhibit higher volumetric energy density (42.85 Wh L-1). Bimodal pore size distribution of carbon with a tuned pore size and high specific surface area of the electrode can promote the fast transport of cations and anions. Hence, it exhibits a high rate capability even at 30 A g-1. In addition, the electrodes remain stable during operation cell voltage at 3.4 V upon 15 000 charging-discharging cycles with 90% capacitance retention.

Metal chalcogenide-based core/shell photocatalysts for solar hydrogen production: Recent advances, properties and technology challenges.

Metal chalcogenides play a vital role in the conversion of solar energy into hydrogen fuel. Hydrogen fuel technology can possibly tackle the future energy crises by replacing carbon fuels such as petroleum, diesel and kerosene, owning to zero emission carbon-free gas and eco-friendliness. Metal chalcogenides are classified into narrow band gap (CdS, Cu2S, Bi2S3, MoS2, CdSe and MoSe2) materials and wide band gap materials (ZnS, ZnSe and ZnTe). Composites of these materials are fabricated with different architectures in which core-shell is one of the unique composites that drastically improve the photo-excitons separation, where chalcogenides in the core can be well protected for sustainable uses. Thus,the core-shell structures promote the design and fabrication of composites with the required characteristics. Interestingly, the metal chalcogenides as a core-shell photocatalyst can be classified into type-I, reverse type-I, type-II and S-type nanocomposites, which can effectively influence and significantly enhance the rate of hydrogen production. In this direction, this review is undertaken to provide a comprehensive overview of the advanced preparation processes, properties of metal chalcogenides, and in particular, photocatalytic performance of the metal chalcogenides as a core-shell photocatalysts for solar hydrogen production.

Conversion of Solar Energy into Electrical Energy Storage: Supercapacitor as an Ultrafast Energy-Storage Device Made from Biodegradable Agar-Agar as a Novel and Low-Cost Carbon Precursor.

Solar cells hold promise as energy conversion devices but intermittent sunlight limits their continuous applications. The self-powering integrated solar cells and electrical energy storage devices can be an alternative to resolve this problem. This study demonstrates the integration of solar cell with supercapacitor (SC) device and evaluates its performance for energy conversion and storage for practical validity. SC carbon is derived from agar-agar as low-cost carbon precursor and a high-performance SC electrode is utilized for the first time. The fabricated SC shows an excellent specific capacitance of 170 F g-1 and retains 85% of its original value up to 15 000 charge/discharge cycles at 1 A g-1, and it holds a maximum energy density of 17.7 Wh kg-1. The integration of SCs (three cells in series with 5.4 V) with a commercial solar lantern for a self-sustaining power pack is demonstrated. The SC is charged by solar cells in a few seconds and powers a solar lantern with 40 light-emitting diodes without sunlight, demonstrates its potential for efficient conversion of solar energy into electrical energy storage. This result highlights that solar SC can be considered as an ultrafast next-generation energy-storage device that can mitigate the energy demand in the near future.

Development of regenerative dye impregnated mesoporous silica materials for assessing exposure to ammonia.

The mesostructured materials MCM-41 and SBA-15 were studied as possible supports of bromocresol green (BG) dye impregnation for the ammonia gas detection because of their large surface area, high regenerative property, and high thermal stability. X-ray diffraction, transmission electron microscopy, scanning electron microscope, and N2 adsorption analysis were used to characterize the prepared materials. These materials could sense ammonia via visible color change from yellowish-orange to blue color. The color change process of the nanostructured materials was fully reversible during 10 cyclic tests. The results indicated that the ammonia absorption responses of the two nanostructured materials were both very sensitive, and high linear correlation and high precision were achieved. As the gaseous ammonia concentrations were 50 and 5 ppmv, the response times for the SBA-15/BG were only 1 and 5 min, respectively. Moreover the BG dye-impregnated SBA-15 was less affected by the variation in the relative humidity. It also had faster response for the detection of NH3, as well as lower manufacturing price as compared to that of the dye-impregnated MCM-41. Such feature enables SBA-15/BG to be a very promising material for the detection of ammonia gas.

Titanium dioxide/zeolite catalytic adsorbent for the removal of NO and acetone vapors.

This study delineates a simple and versatile approach for the removal of nitrogen monoxide (NO) and volatile organic vapors over composites of titanium dioxide (TiO2) catalyst/zeolite adsorbent under ultraviolet (UV) irradiation at ambient temperature. The catalytic adsorbents with different TiO2/H-ZSM-5 zeolite ratios were prepared by a simple insipient wetness impregnation method. It was found that a 60%/40% weight ratio of TiO2/H-ZSM-5 composite is most effective and can achieve over 90% efficiency for the removal of NO and acetone vapors. This composite also showed a better long-term activity than that of bulk TiO2 photocatalyst or zeolite adsorbent. The experimental results revealed that photocatalytic decomposition of NO was dramatically enhanced in the presence of acetone. NO also promoted the acetone oxidation under humid conditions. Furthermore, the co-existence of acetone and NO in the gaseous stream could reduce acid accumulation on the surface of the catalyst as confirmed by Fourier-transform infrared spectroscopy. Thus, the TiO2/zeolite catalytic adsorbent could have a high potential for the removal of multiple air pollutants in the indoor air environment.