Background
One of the most common problems in parturients receiving regional anesthesia during cesarean section is shivering. It usually interferes with the readings of the oxygen plethysmography ...(SpO
2
) and electrocardiogram (ECG). It expands the needs for oxygen and increases creation of carbon dioxide about four folds.
The aim of this work is to compare the efficacy of dexamethasone and dexmedetomidine in prevention of perioperative shivering when added to hyperbaric bupivacaine intrathecally in cesarean sections (CS) and their effect on the intraoperative hemodynamics, intensity of the block, sedation, and postoperative analgesic requirement.
Results
Study included 60 obstetric patients who fulfilled all the inclusion criteria and were randomized into 2 equal groups, each consisting of 30 patients, namely group A (dexmedetomidine group) and B (dexamethasone group).
Group A patients received 5 μg dexmedetomidine with 12.5 mg hyperbaric bupivacaine 0.5% intrathecally.
Group B patients received 8 mg dexamethasone then 12.5 mg hyperbaric bupivacaine 0.5% intrathecally.
The comparison included assessment of intra- and postoperative hemodynamics, duration of surgery, assessment of sensory and motor block, assessment for shivering and sedation, and assessment of adverse events.
This study showed that there were a small number of patients complaining of shivering (five patients in group A and seven patients in group B) with no statistical difference between both groups in the incidence and intensity of shivering. Time to two segment regression (minutes) was longer in group B compared to group A, and also, time to first analgesic rescue was longer in group B compared to group A. For sedation intensity, there was statistical difference between both groups as all patients in group A were sedated compared to six patients only in group B. There was no statistical difference between both groups as regards incidence of adverse effects.
Conclusion
We concluded that both drugs can be added safely to bupivacaine, and both dexmedetomidine and dexamethasone decreased the incidence and the intensity of shivering. Dexamethasone was found to prolong the duration of sensory block and delay opioid requirements post-operatively, while dexmedetomidine is more effective in sedating the patients intra- and postoperatively.
The success rate of fractured instrument retrieval varies because it is dependent mainly on several factors including the visibility of the fractured instrument, the length of the fractured ...instrument in relation to the curvature of the canal and the techniques applied to each case. This review aims to update the present status on removal of fractured instruments to identify factors and variables that could affect the success of fractured instrument retrieval based on both the preparation techniques and the instrument retrieval techniques. On the other hand, future directions of fractured instrument retrieval should focus on management of nonvisible fractured instruments since the removal of those instruments is deemed unpredictable with the current techniques, whereas the removal of visible fractured instruments is considered predictable now. Another possible direction of it is that there might be no more instrument fracture due to possible significant changes in the root canal preparation technique which may dispense with the use of rotary instruments.
A comparative study of volatile constituents, antioxidant activity, and molecular docking was conducted between essential oils from Mentha longifolia L., Mentha spicata L., and Origanum majorana L., ...widely cultivated in Madinah. The investigation of volatile oils extracted by hydrodistillation was performed using Gas Chromatography-Mass Spectrometry (GC-MS). A total number of 29, 42, and 29 components were identified in M. longifolia, M. spicata, and O. majorana representing, respectively, 95.91, 94.62, and 98.42, of the total oils. Pulegone (38.42%), 1,8-cineole (15.60%), menthone (13.20%), and isopulegone (9.81%) were the dominant compounds in M. longifolia oil; carvone (35.14%), limonene (27.11%), germacrene D (4.73%), and β-caryophyllene (3.02%) were dominant in M. spicata oil; terpin-4-ol (42.47%), trans-sabinene hydrate (8.52%), γ-terpinene (7.90%), α-terpineol (7.38%), linalool (6.35%), α-terpinene (5.42%), and cis-sabinene hydrate (3.14%) were dominant in O. majorana oil. The antioxidant activity, assessed using DPPH free radical–scavenging and ABTS assays, was found to be the highest in O. majorana volatile oil, followed by M. spicata and M. longifolia, which is consistent with the differences in total phenolic content and volatile constituents identified in investigated oils. In the same context, molecular docking of the main identified volatiles on NADPH oxidase showed a higher binding affinity for cis-verbenyl acetate, followed by β-elemene and linalool, compared to the control (dextromethorphan). These results prove significant antioxidant abilities of the investigated oils, which may be considered for further analyses concerning the control of oxidative stress, as well as for their use as possible antioxidant agents in the pharmaceutical industry.
The concentrations of eight heavy metals (As, Cd, Cr, Cu, Mn, Ni, Pb and Zn) were measured in the sediment, the isolated microplastics from the sediment and the body wall of sea cucumbers from farms ...in China. Accordingly, the heavy metal concentrations in the sediment were below the class I upper limit of Chinese sediment quality guidelines. Among heavy metals, the median concentrations of Cd and As were higher in the body wall than in the corresponding sediment. Additionally, the median concentrations of Cd, Pb, and Zn were higher on the microplastics than in the corresponding sediment. Furthermore, there was no significant correlation among heavy metals in sediment, sea cucumber and microplastics. This study contributes to the understanding of the heavy metal accumulation in the sediment, the microplastics and the body wall of the sea cucumber.
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•Microplastics may serve as a vector of heavy metals in the sea cucumber farms.•Sea cucumber may have a strategy accumulating some heavy metals in the body wall.•Sea cucumber A. japonicus might be considered as a bio-monitor for Cd.
The treatment of triple‐negative breast cancer (TNBC) remains a major challenge. The present study aimed to throw more light on the role of copper (I)‐nicotinate complex (CNC) as an antitumor as well ...as a proapoptotic agent. In this study, the HCC‐1806 cell line was used as a model for TNBC. Cell cycle, apoptosis assay, and programmed cell death protein‐1 were investigated by flowcytometry. Besides, the comet assay was performed using a fluorescence microscope. The enzyme‐linked immunosorbent assay technique was used for the detection of phospho‐Chk1 at ser 317 and caspase‐3. Moreover, the gene expression of survivin was identified by real‐time polymerase chain reaction. Finally, superoxide dismutase (SOD) was calorimetrically assayed. The viability of HCC‐1806 cells treated with CNC was decreased in a dose‐dependent manner. The tendency for apoptotic machinery was observed through the increase in the sub G0 peak, the percentage of early and late apoptotic phases, and the elevation in caspase‐3 levels associated with a downregulation of the survivin gene expression. The antioxidant property of the complex, reflected by elevated SOD activity, may contribute to mediate the cell death pathways. Low concentrations of CNC were found to favor the apoptotis‐mediated mechanism. However, one cannot neglect the abundance of cell necrosis–mediated death of cells via CNC, especially at higher concentrations.
The present study aimed to throw more light on the role of copper (I)‐nicotinate complex (CNC) as an antitumor and a proapoptotic agent. Based on the results of the present study, it could be concluded that the treatment of HCC‐1806 cells, triple‐negative breast cancer (TNBC), with CNC resulted in increased tendency for apoptotic and necrotic mechanisms; the tendency to the first at low concentrations and the latter at high levels.
•This work focuses on the viability of using liquid metal (LM) bonded gap instead of He-gap.•The obtained results show a slight difference in the various neutronic parameters.•In the ...thermal–hydraulic results, a great reduction in the fuel centerline temperature takes place.•The LM bonded gap reduces the fuel outer surface displacement and the Von-Mises stress.•The UO2 overheating problems using He-gap can be solved by applying LM bonded gap.
This work focuses on the viability of using liquid metal bonded gap instead of the traditional helium (He)-gap through investigating its effects on the neutronic, thermal–hydraulic, and solid mechanics analyses. The shortcoming of using a He-gap is the high thermal resistance of helium, which causes overheating and much heat accumulation inside the fuel, and hence causes many problems with the fuel‘s solid mechanics behavior. To reduce both the heat accumulation and overheating inside the fuel material, LM boned gap was applied. The obtained results showed a slight difference in the various neutronic parameters, while in the thermal–hydraulic analysis, an excellent enhancement in the maximum fuel temperature happened, which reduced the heat accumulation in the fuel material. Also, in solid mechanics analysis, the enhancement that came from decreasing the fuel temperature decreased both the thermal expansion of the fuel and the von-Mises stress that acts on it.
•Neutronic, thermal-hydraulic, and solid mechanics analyses of different burnable absorber materials.•The standard BPs (ZrB2, Pyrex rods) used in AP-1000 are not optimum in all cases.•Different ...burnable absorbers have been investigated to reach the most optimum one.•WABA rods and Er2O3 presented excellent results in AP-1000 compared to the standard BPs.
Because of the importance of absorber materials in regulating the reactivity of AP-1000, several materials with varied designs have been investigated to find the most optimum absorber materials from the neutronic, thermal-hydraulic, and solid mechanics perspectives. In this work, ZrB2, Er2O3, (SiO2-B2O3) and (Al2O3-B4C) were investigated as burnable absorbers (BAs) and H3BO3, Ag–In–Cd, and SS-304 as non-burnable absorbers. For the investigated BAs, the main neutronic parameters such as the fuel burn-up, axial thermal neutron flux distribution and the pin by pin distribution have been simulated. For the non-burnable absorbers, the control rod worth (CRW) and the boron concentration coefficient have been calculated. In the thermal-hydraulic analysis, the temperature distribution of the fuel, clad, coolant and the minimum departure from nucleate boiling ratio (MDNBR) have been studied. The BAs’ effects on solid mechanics analysis have emerged on both the von-Mises stress and the maximum fuel outer surface displacement.
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