Dexmedetomidine vs Dexamethasone as an Adjuvant to Levobupivacaine in Ultrasound-Guided Transversus Abdominis Plane Block for Postoperative Analgesia in Patients Undergoing Total Abdominal Hysterectomies.

Background: In the postoperative period, open total abdominal hysterectomy (TAH) surgeries induce considerable pain. Multimodal strategies are being used to alleviate pain. Objectives: This study aimed to examine the efficacy and safety of dexamethasone and dexmedetomidine as an adjuvant to levobupivacaine in ultrasound-guided transversus abdominis plane (TAP) blocks for postoperative pain in TAH patients. Methods: A total of 72 patients with ASA grade I and grade II were randomly and equally assigned to two groups. After the completion of surgery with a subarachnoid block (SAB), patients in group 1 received a mixture of 20 mL of 0.25% levobupivacaine and 4 mg of dexamethasone on each side of the TAP block. Patients in group 2 received a mixture of 20 mL of 0.25% levobupivacaine and dexmedetomidine, with a total dose of 1 µg/kg body weight evenly distributed bilaterally in the TAP block. Patients were evaluated for pain using the Visual Analog Scale (VAS), total tramadol consumption as rescue analgesia, time to first rescue analgesia, any adverse effects, and patient satisfaction. Results: When comparing VAS scores for pain assessment, we observed that the mean VAS score was initially comparable between the two groups for the first hour. However, at 6, 9, and 12 h, VAS scores were significantly lower in group 2. The mean total tramadol consumption was higher in group 1 than in group 2 (213.33 ± 44.08 vs 161.11 ± 37.93 mg, P-value 0.027). The time to the first rescue analgesia after the TAP block in the postoperative period was significantly longer in group 2 (47.5 ± 62.76 vs 77.22 ± 56.14 min, P-value 0.002). No significant side effects were noted, and a greater proportion of patients in group 2 expressed satisfaction with their overall pain treatment. Conclusions: The addition of dexmedetomidine to levobupivacaine is superior to the addition of dexamethasone, as it prolongs the duration of the block in the dexmedetomidine group. However, the use of dexamethasone as an adjuvant is a good alternative option, particularly due to its lower cost and reduced incidence of adverse effects such as postoperative nausea and vomiting.

Precursor to Gas Sensor: A Detailed Study of the Suitability of Copper Complexes as an MOCVD Precursor and their Application in Gas Sensing.

There are very few p-type semiconductors available compared to n-type semiconductors for positive sensing response for oxidizing gases and other important electronic applications. Cupric oxide (CuO) is one of the few oxides that show p-type conductivity, useful for sensing oxidizing gases. Many researchers obtained CuO using the chemical and solid-state routes, but uniformity and large-area deposition have been the main issues. Chemical vapor deposition is one such technique that provides control on several deposition parameters, which allow obtaining thin films having crystallinity and uniformity over a large area for the desired application. However, CuO-chemical vapor deposition (CVD) is still unfathomed due to the lack of suitability of copper precursors based on vapor pressure, contamination, and toxicity. Here, to address these issues, we have taken four Cu complexes (copper(II) acetylacetonate, copper(II) bis(2,2,6,6-tetramethyl-3,5-heptanedionato), copper(II) ethylacetoacetate, and copper(II) tert-butylacetoacetate), which are evaluated using thermogravimetry for suitability as a CVD precursor. The decomposition behavior of the complexes was also experimentally confirmed by depositing CuO thin films via CVD. Phase purity, decomposition, volatility, growth rate, and morphological characteristics of the films are investigated in detail. Analysis suggests that copper(II) tert-butylacetoacetate has the highest vapor pressure and growth rate at a low temperature, making it the most suitable precursor for high-throughput CVD. Further, to investigate the role of these precursors, films deposited using Cu complexes were subjected to gas sensing. The CuO gas sensor fabricated on glass shows pronounced NO2 sensing. The sensing results of CuO films have been explained from the standpoint of roughness, morphology, and unpassivated bonds present on the surface of films and vapor pressure of precursors. The higher density of surface state and the lower resistivity of the Cu(tbaoac)2 film lead to a sensor with higher responsivity and sensitivity (down to 1 ppm). These precursors can probably be utilized to improve the performance of other metal oxide gas sensors, especially Cu2O and Cu-III-O2.

Growth-Temperature Dependent Unpassivated Oxygen Bonds Determine the Gas Sensing Abilities of Chemical Vapor Deposition-Grown CuO Thin Films.

CuO is a multifunctional metal oxide excellent for chemiresistive gas sensors. In this work, we report CuO-based NO2 sensors fabricated via chemical vapor deposition (CVD). CVD allows great control on composition, stoichiometry, impurity, roughness, and grain size of films. This endows sensors with high selectivity, responsivity, sensitivity, and repeatability, low hysteresis, and quick recovery. All these are achieved without the need of expensive and unscalable nanostructures, or heterojunctions, with a technologically mature CVD. Films deposited at very low temperatures (≤350 °C) are sensitive but slow due to traps and small grains. Films deposited at high temperatures (≥550 °C) are not hysteretic but suffer from low sensitivity and slow response due to lack of surface states. Films deposited at optimum temperatures (350-450 °C) combine the best aspects of both regimes to yield NO2 sensors with a response of 300 % at 5 ppm, sensitivity limit of 300 ppb, hysteresis of <20%, repeatable performance, and recovery time of ∼1 min. The work demonstrates that CVD might be a more effective way to deposit oxide films for gas sensors.

Chaperonin-catalyzed rescue of kinetically trapped states in protein folding.

GroEL and GroES form a chaperonin nano-cage for single protein molecules to fold in isolation. The folding properties that render a protein chaperonin dependent are not yet understood. Here, we address this question using a double mutant of the maltose-binding protein DM-MBP as a substrate. Upon spontaneous refolding, DM-MBP populates a kinetically trapped intermediate that is collapsed but structurally disordered. Introducing two long-range disulfide bonds into DM-MBP reduces the entropic folding barrier of this intermediate and strongly accelerates native state formation. Strikingly, steric confinement of the protein in the chaperonin cage mimics the kinetic effect of constraining disulfides on folding, in a manner mediated by negative charge clusters in the cage wall. These findings suggest that chaperonin dependence correlates with the tendency of proteins to populate entropically stabilized folding intermediates. The capacity to rescue proteins from such folding traps may explain the uniquely essential role of chaperonin cages within the cellular chaperone network.

Bispectrum of stator phase current for fault detection of induction motor.

A number of research studies has shown that faults in a stator or rotor generally show sideband frequencies around the mains frequency (50 Hz) and at higher harmonics in the spectrum of the Motor Current Signature Analysis (MCSA). However in the present experimental studies such observations have not been seen, but any fault either in the stator or the rotor may distort the sinusoidal response of the motor RPM and the mains frequency so the MCSA response may contain a number of harmonics of the motor RPM and the mains frequency. Hence the use of a higher order spectrum (HOS), namely the bispectrum of the MCSA has been proposed here because it relates both amplitude and phase of number of the harmonics in a signal. It has been observed that it not only detects early faults but also indicates the severity of the fault to some extent.

beta-Klotho and FGF-15/19 inhibit the apical sodium-dependent bile acid transporter in enterocytes and cholangiocytes.

beta-Klotho, a newly described membrane protein, regulates bile acid synthesis. Fibroblast growth factor-15 (FGF-15) and FGF receptor-4 (FGFR4) knockout mice share a similar phenotype with beta-Klotho-deficient mice. FGF-15 secretion by the intestine regulates hepatic bile acid biosynthesis. The effects of beta-Klotho and FGF-15 on the ileal apical sodium bile transporter (ASBT) are unknown. beta-Klotho siRNA treatment of the mouse colon cancer cell line, CT-26, and the human intrahepatic biliary epithelial cells (HIBEC) resulted in upregulation of endogenous ASBT expression that was associated with reduced expression of the farnesoid X receptor (FXR) and the short heterodimer partner (SHP). Silencing beta-Klotho activated the ASBT promoter in CT-26, Mz-ChA-1 (human cholangiocarcinoma), and HIBEC cells. Site-directed mutagenesis of liver receptor homolog-1 (mouse) or retinoic acid receptor/retinoid X receptor (RAR/RXR) (human) cis-elements attenuated the basal activity of the ASBT promoter and abrogated its response to beta-Klotho silencing. siSHP, siFXR, or dominant-negative FXR treatment also eliminated the beta-Klotho response. FGF-15 secretion into cell culture media by CT-26 cells was diminished after siFGF-15 or sibeta-Klotho treatment and enhanced by chenodeoxycholic acid. Exogenous FGF-19 repressed ASBT protein expression in mouse ileum, gallbladder, and in HIBEC and repressed ASBT promoter activity in Caco-2, HIBEC, and Mz-ChA-1 cells. Promoter repression was dependent on the expression of FGFR4. These results indicate that both beta-Klotho and FGF-15/19 repress ASBT in enterocytes and cholangiocytes. These novel signaling pathways need to be considered in analyzing bile acid homeostasis.

c-Fos is a critical mediator of inflammatory-mediated repression of the apical sodium-dependent bile acid transporter.

BACKGROUND & AIMS: Ileal bile acid malabsorption is present in Crohn's ileitis. The molecular mechanisms of regulation of the apical sodium-dependent bile acid transporter (ASBT) by inflammatory cytokines in vitro and in vivo are investigated. METHODS: Transient transfection studies of the human, mouse, and rat ASBT promoters and Northern analyses were performed in cells treated with the inflammatory cytokines and/or various activator protein-1 constructs. Rat ASBT promoter transgenic, wild-type, and c-fos-null mice were treated with indomethacin to assess the response to acute inflammation of the ileal mucosa. RESULTS: In Caco-2 cells, ASBT messenger RNA expression was reduced 65% after interleukin-1beta treatment, while c-fos and c-jun were up-regulated 2-fold. Human ASBT promoter activity was enhanced by c-jun and repressed by a dominant negative c-jun, c-fos, or a dominant negative c-fos. Meanwhile, c-fos antisense treatment activated the human ASBT promoter 5-fold and not only abrogated interleukin-1beta-mediated repression but led to a paradoxical increase in ASBT promoter activity. Indomethacin-induced acute ileitis led to repression of ASBT in wild-type mice and in the transgenic rat ASBT promoter reporter, while paradoxical activation of ASBT was seen in c-fos-null mice. Indomethacin-induced ileal injury was greater in the c-fos-null mice compared with the wild-type littermates. CONCLUSIONS: Human, rat, and mouse ASBT is inhibited by inflammatory cytokines via direct interactions of c-fos with the ASBT promoter.