Effect of anesthetics on postoperative nausea and vomiting after peripheral vascular surgery in end-stage renal disease patients: A retrospective observational study.

Background: Propofol-based total intravenous anesthesia (TIVA) is considered a prophylactic approach to decrease postoperative nausea and vomiting (PONV). Despite general anesthesia commonly being performed in end-stage renal disease (ESRD) patients, PONV in ESRD patients has not been well-described. We investigated PONV in peripheral vascular surgery under general anesthesia in ESRD patients. Methods: To compare PONV between propofol-based TIVA and anesthesia with volatile anesthetics, we collected retrospective data from patients who underwent peripheral vascular surgery under general anesthesia from July 2018 to April 2020. We performed univariable and multivariable analyses, including factors that could be associated with PONV and those previously shown to affect PONV. Result: A total of 1,699 peripheral vascular surgeries under general anesthesia in ESRD patients were eligible for analysis. Based on the multivariable analysis, TIVA (odds ratio [OR], 0.45; 95% confidence interval [CI], 0.35-0.60; P < 0.001) significantly decreased PONV. Female sex (OR, 1.85; 95% CI, 1.44-2.38; P < 0.001) and anesthetic duration (OR, 1.01; 95% CI, 1.00-1.01; P < 0.001) were associated with increased PONV. Conclusion: Propofol-based TIVA is the most influential factor decreasing PONV after peripheral vascular surgery in ESRD patients. Anesthesiologists can apply propofol-based TIVA as an alternative to anesthesia with volatile anesthetics.

Comparison of bispectral index and phase lag entropy during general anesthesia: Sevoflurane or propofol anesthesia.

BACKGROUND: Phase-lag entropy (PLE) based on functional connectivity between different regions of the brain may be superior to conventional depth of anesthesia (DoA) methods for monitoring changes in consciousness. However, few studies have compared the PLE and bispectral index (BIS) methods for monitoring consciousness during clinical anesthesia, such as total intravenous anesthesia (TIVA) or anesthesia via inhalation. Therefore, we evaluated differences between the PLE and BIS methods in clinical anesthesia, including TIVA using propofol and anesthesia with sevoflurane. METHODS: The observational trial included 60 patients scheduled for elective surgery under general anesthesia. The BIS and PLE electrodes were placed together on the left temporal-frontal area of all patients. During anesthesia, anesthetic levels were adjusted using the BIS values, which are generally used to monitor the DoA; the level of anesthesia was maintained at between 40 and 60. BIS- and PLE-derived values were recorded continuously. Anesthetic events, the concentration of each anesthetic, and standard monitoring values were recorded. The patients included were divided into 2 groups, the TIVA and sevoflurane groups, with 30 patients in each. For the TIVA group, anesthesia was induced and maintained using propofol and remifentanil target-controlled infusion. For the sevoflurane group, anesthesia was induced using propofol and maintained using sevoflurane and remifentanil. RESULTS: From loss of consciousness until the anesthetic maintenance period, PLE values were higher than BIS values at several time points. During the recovery period, BIS values were higher than PLE values (all P < .001). Spaghetti plots showed that there was more variation among the BIS values than among the PLE values. CONCLUSIONS: For monitoring DoA during general anesthesia and surgery, PLE values vary less than BIS values; thus, PLE may be more reliable for monitoring changes in consciousness. However, further studies are needed to evaluate the clinical application of these methods in general anesthesia.

Postoperative mortality in patients with end-stage renal disease according to the use of sugammadex: a single-center retrospective propensity score matched study.

BACKGROUND: Clearance of the sugammadex-rocuronium complex is limited to renal excretion. There are restrictions on the use of sugammadex in patients with severe renal impairment. A paucity of data supports the clinical safety of sugammadex in patients with renal impairment. We analyzed mortality after using sugammadex in patients with end-stage renal disease to establish evidence of safety for sugammadex. METHODS: We retrospectively collected the medical records of 2,134 patients with end-stage renal disease who were dependent on hemodialysis and underwent surgery under general anesthesia between January 2018 and December 2019. Propensity score matching was used. The primary outcome was the 30-day mortality rate, and secondary outcomes were the 1-year mortality rate and causes of death. RESULTS: A total of 2,039 patients were included in the study. Sugammadex was administered as a reversal agent for rocuronium in 806 (39.5%) patients; the remaining 1,233 (60.5%) patients did not receive sugammadex. After matching, 1,594 patients were analyzed; 28 (3.5%) of the 797 patients administered sugammadex, and 28 (3.5%) of the 797 patients without sugammadex, died within 30 days after surgery (P > 0.99); 38 (4.8%) of the 797 patients administered sugammadex, and 45 (5.7%) of the 797 patients without sugammadex, died within 1 year after surgery (P = 0.499). No significant differences in the causes of 30-day mortality were observed between the two groups after matching (P = 0.860). CONCLUSIONS: In this retrospective study, sugammadex did not increase the 30-day and 1-year mortality rate after surgery in end-stage renal disease patients.

Protection and Installation of FBG Strain Sensor in Deep Boreholes for Subsurface Faults Behavior Monitoring.

Fiber optic sensors are gradually replacing electrical sensors in geotechnical applications owing to their immunity to electrical interference, durability, and cost-effectiveness. However, additional protective measures are required to prevent loss of functionality due to damage to the sensors, cables, or connection parts (splices and/or connectors) during installation and completion processes in borehole applications. We introduce two cases of installing fiber Bragg grating (FBG) strain sensors in 1 km boreholes to monitor the behavior of deep subsurface faults. We present our fiber-reinforced plastic (FRP) forming schemes to protect sensors and splices. We also present uniaxial load test and post-completion monitoring results for assessing the effects and performance of the protective measures. The uniaxial load test and post-completion monitoring show that FBG sensors are well protected by FRP forming without significant impact on sensor performance itself and that they are successfully installed in deep boreholes. In addition to summarizing our learning from experiences, we also suggest several points for consideration to improve the applicability of FBG sensors in borehole environment of the geotechnical field.

Distributed Temperature Sensing Monitoring of Well Completion Processes in a CO2 Geological Storage Demonstration Site.

The Distributed Temperature Sensing (DTS) profiles obtained during well completion of a CO2 monitoring well were analyzed to characterize each well completion process in terms of temperature anomalies. Before analysis, we corrected the depth by redistributing the discrepancy, and then explored three temperature calibration methods. Consequently, we confirmed the depth discrepancy could be well corrected with conventional error redistribution techniques. Among three temperature calibration methods, the conventional method shows the best results. However, pointwise methods using heat coil or in-well divers also showed reliable accuracy, which allows them to be alternatives when the conventional method is not affordable. The DTS data revealed that each well completion processes can be characterized by their own distinctive temperature anomaly patterns. During gravel packing, the sand progression was monitorable with clear step-like temperature change due to the thermal bridge effect of sand. The DTS data during the cementing operation, also, clearly showed the progression up of the cement slurry and the exothermic reaction associated with curing of cement. During gas lift operations, we could observe the effect of casing transition as well as typical highly oscillating thermal response to gas lifting.

Twisted Dual-Cycle Fiber Optic Bending Loss Characteristics for Strain Measurement.

The intensity-based fiber optic sensor (FOS) head using twisted dual-cycle bending loss is proposed and experimentally demonstrate. The bending loss characteristics depend on the steel wire radius, number, and distance. To determine the effects of these parameters, two samples in each of seven configuration cases of the proposed FOS head were bonded to fiber reinforced plastics coupons, and tensile and flexural strain tests were repeated five times for each coupon. The bending loss of the manufactured FOS heads was measured and converted to the tensile and flexural strain as a function of configuration cases. The measurement range, sensitivity, and average measurement errors of the tensile load and flexural strain were 4.5 kN and 1,760 µÎµ, 0.70 to 3.99 dB/kN and 0.930 to 6.554 dB/mm, and 57.7 N, and 42.6 µÎµ, respectively. The sensing range of FOS head were 82 to 138 mm according to configuration cases. These results indicate that it is possible to measure load, tensile strain, and flexural strain using the proposed FOS head, and demonstrate that the sensitivities, the operating ranges, and the sensing range can be adjusted depending on the deformation characteristics of the measurement target.

Directed evolution of the 3-hydroxypropionic acid production pathway by engineering aldehyde dehydrogenase using a synthetic selection device.

3-Hydroxypropionic acid (3-HP) is an important platform chemical, and biological production of 3-HP from glycerol as a carbon source using glycerol dehydratase (GDHt) and aldehyde dehydrogenase (ALDH) has been revealed to be effective because it involves a relatively simple metabolic pathway and exhibits higher yield and productivity than other biosynthetic pathways. Despite the successful attempts of 3-HP production from glycerol, the biological process suffers from problems arising from low activity and inactivation of the two enzymes. To apply the directed evolutionary approach to engineer the 3-HP production system, we constructed a synthetic selection device using a 3-HP-responsive transcription factor and developed a selection approach for screening 3-HP-producing microorganisms. The method was applied to an ALDH library, specifically aldehyde-binding site library of alpha-ketoglutaric semialdehyde dehydrogenase (KGSADH). Only two serial cultures resulted in enrichment of strains showing increased 3-HP production, and an isolated KGSADH variant enzyme exhibited a 2.79-fold higher catalytic efficiency toward its aldehyde substrate than the wild-type one. This approach will provide the simple and efficient tool to engineer the pathway enzymes in metabolic engineering.

Engineering an aldehyde dehydrogenase toward its substrates, 3-hydroxypropanal and NAD+, for enhancing the production of 3-hydroxypropionic acid.

3-Hydroxypropionic acid (3-HP) can be produced via the biological route involving two enzymatic reactions: dehydration of glycerol to 3-hydroxypropanal (3-HPA) and then oxidation to 3-HP. However, commercial production of 3-HP using recombinant microorganisms has been hampered with several problems, some of which are associated with the toxicity of 3-HPA and the efficiency of NAD+ regeneration. We engineered α-ketoglutaric semialdehyde dehydrogenase (KGSADH) from Azospirillum brasilense for the second reaction to address these issues. The residues in the binding sites for the substrates, 3-HPA and NAD+, were randomized, and the resulting libraries were screened for higher activity. Isolated KGSADH variants had significantly lower Km values for both the substrates. The enzymes also showed higher substrate specificities for aldehyde and NAD+, less inhibition by NADH, and greater resistance to inactivation by 3-HPA than the wild-type enzyme. A recombinant Pseudomonas denitrificans strain with one of the engineered KGSADH variants exhibited less accumulation of 3-HPA, decreased levels of inactivation of the enzymes, and higher cell growth than that with the wild-type KGSADH. The flask culture of the P. denitrificans strain with the mutant KGSADH resulted in about 40% increase of 3-HP titer (53 mM) compared with that using the wild-type enzyme (37 mM).

An Optical Fiber Displacement Sensor Using RF Interrogation Technique.

We propose a novel non-contact optical fiber displacement sensor. It uses a radio frequency (RF) interrogation technique which is based on bidirectional modulation of a Mach-Zehnder electro-optical modulator (MZ-EOM). The displacement is measured from the free spectral range (FSR) which is determined by the dip frequencies of the modulated MZ-EOM transfer function. In experiments, the proposed sensor showed a sensitivity of 456 kHz/mm or 1.043 kHz/V in a measurement range of 7 mm. The displacement resolution of the proposed sensor depends on the linewidth and the power of the optical source. Resolution better than 0.05 µm would be achieved if an optical source which has a linewidth narrower than 1.5 nm and a received power larger than -36 dBm is used. Also, the multiplexing characteristic of the proposed sensor was experimentally validated.

A self-referencing intensity-based fiber optic sensor with multipoint sensing characteristics.

A self-referencing, intensity-based fiber optic sensor (FOS) is proposed and demonstrated. The theoretical analysis for the proposed design is given, and the validity of the theoretical analysis is confirmed via experiments. We define the measurement parameter, X, and the calibration factor, ß, to find the transfer function, , of the intensity-based FOS head. The self-referencing and multipoint sensing characteristics of the proposed system are validated by showing the measured and relative error versus the optical power attenuation of the sensor head for four cases: optical source fluctuation, various remote sensing point distances, fiber Bragg gratings (FBGs) with different characteristics, and multiple sensor heads with cascade and/or parallel forms. The power-budget analysis and limitations of the measurement rates are discussed, and the measurement results of fiber-reinforced plastic (FRP) coupon strain using the proposed FOS are given as an actual measurement. The proposed FOS has several benefits, including a self-referencing characteristic, the flexibility to determine FBGs, and a simple structure in terms of the number of devices and measuring procedure.

Novel RF interrogation of a fiber Bragg grating sensor using bidirectional modulation of a Mach-Zehnder electro-optical modulator.

We propose and experimentally demonstrate the novel radio-frequency (RF) interrogation of a fiber Bragg grating (FBG) sensor using bidirectional modulation of a Mach-Zehnder electro-optical modulator (MZ-EOM). Based on the microwave photonic technique and active detection, the transfer function of the proposed system was obtained, and the time delay was calculated from the change in the free spectral range (FSR) at different wavelengths over the optimal measuring range. The results show that the time delay and the wavelength variation have a good linear relationship, with a gradient of 9.31 ps/nm. An actual measurement taken with a sensing FBG for temperature variation shows the relationship with a gradient of 0.93 ps/10 °C. The developed system could be used for FBG temperature or strain sensing and other multiplexed sensor applications.

Effect of span length on the fit of zirconia framework fabricated using CAD/CAM system.

PURPOSE: The purpose of this study was to evaluate the effect of the span length on the fit of zirconia framework fabricated using CAD/CAM system. MATERIALS AND METHODS: Abutments for single, 4-unit and 6-unit fixed partial prostheses were fabricated. Ten zirconia frameworks were fabricated for each group. The marginal and internal gap were presented by means of replica technique and measured by measuring microscope (AXIO®, Carl Zeiss, Rochester, NY) and software (I-solution®, IMT i-solution Inc., Vancouver, BC, Canada). The results were statistically analyzed by multivariate analysis test and Dunnett T3 test for post hoc test (α=.05). RESULTS: There were statistically significant differences at 2, 4, 7, 8 points (mesio-distal section) and b, d, e, f, g (labio-lingual section). In some marginal reference points of 6-unit group (P<.05), the marginal gap were larger than 120 µm. CONCLUSION: Span length of zirconia core may have an influence on marginal and internal fit. Within the limitation of this study, the increase of span length of zirconia framework of 6 or more-unit fixed partial denture may decrease the marginal and internal fit.

Effects of a polyacetylene from Panax ginseng on Na+ currents in rat dorsal root ganglion neurons.

The root of ginseng (Panax ginseng) has been used as a traditional medicine in the far east countries since ancient times. Ginseng extracts produce analgesia among other various biologically beneficial effects. A polyacetylenic compound, (9R,10S)-epoxyheptadecan-4,6-diyn-3-one (EHD), has been isolated from ginseng extract, whose biological activity is largely unknown. Voltage-gated Na(+) channels in primary sensory neurons play important roles in pain perception. We investigated the effects of EHD on tetrodotoxin-sensitive (TTX-S) and tetrodotoxin-resistant (TTX-R) Na(+) currents in acutely dissociated rat dorsal root ganglion neurons. EHD inhibited both Na(+) currents in a concentration-dependent manner with an equal potency (K(d) values were both 14.3 microM). The activation voltage was not affected by EHD in either type of Na(+) current. However, EHD accelerated the inactivation of both Na(+) currents and produced a hyperpolarizing shift of the steady-state inactivation curve. In addition EHD suppressed the maximal Na(+) current at negative holding potentials at which the channels are relieved from inactivation. Thus EHD appears to bind both resting and inactivated channels. The recovery from inactivation of both Na(+) currents was also slowed by EHD. EHD inhibition of TTX-S Na(+) current but not TTX-R Na(+) current was frequency-dependent. This is the first report that a polyacetylene from ginseng inhibits Na(+) currents in primary sensory neurons. EHD by inhibiting Na(+) currents may contribute to the ginseng analgesia.