Comparison of the recovery time of remimazolam besylate and propofol for gastrointestinal endoscopy sedation in elderly patients.

Background: Recovery time is a crucial factor in ensuring the safety and effectiveness of both patients and endoscopy centers. Propofol is often preferred due to its fast onset and minimal side effects. Remimazolam is a new intravenous sedative agent, characterized by its rapid onset of action, quick recovery and organ-independent metabolism. Importantly, its effect can be specifically antagonized by flumazenil. The primary goal of this study is to compare the recovery time of remimazolam besylate and propofol anesthesia during endoscopic procedures in elderly patients. Methods: 60 patients aged 65-95 years who underwent gastrointestinal endoscopy were randomly and equally assigned to two groups: the remimazolam group (Group R) and the propofol group (Group P). The primary measure was the recovery time, defined as the time from discontinuing remimazolam or propofol until reaching an Observer's Assessment of Alertness and Sedation scale (OAA/S) score of 5 (responds readily to name spoken in normal tone). The time required to achieve an OAA/S score of 3 (responds after name spoken loudly or repeatedly along with glazed marked ptosis) was also recorded and compared. Results: The recovery time for Group R (2.6 ± 1.6 min) was significantly shorter than that for Group P (10.8 ± 3.0 min), with a 95% confidence interval (CI): 6.949-9.431 min, p <0.001. Similarly, the time to attain an OAA/S score of 3 was significantly less in Group R (1.6 ± 0.9 min) compared to Group P (9.6 ± 2.6 min), with a 95% CI: 6.930-8.957 min, p <0.001. Conclusion: Our study demonstrated that remimazolam anesthesia combined with flumazenil antagonism causes a shorter recovery time for elderly patients undergoing gastrointestinal endoscopy compared to propofol. Remimazolam followed by flumazenil antagonism provides a promising alternative to propofol for geriatric patients, particularly during gastrointestinal endoscopy.

Relationship between age and remimazolam dose required for inducing loss of consciousness in older surgical patients.

Background: Remimazolam is a new ultra-short-acting benzodiazepine for procedural sedation and general anaesthesia, characterised by rapid onset of action, quick recovery, and organ-independent metabolism. Older patients tend to sustain more treatment-emergent adverse events (TEAEs) and worse perioperative prognoses after receiving remimazolam. However, few studies have investigated the appropriate dose of remimazolam for loss of consciousness (LOC) in geriatric patients. We designed this study to provide evidence for dose references and elucidate the relationship between age and remimazolam requirement for inducing LOC during anaesthesia induction. Methods: Exactly 120 patients scheduled for general surgery under general anaesthesia were included and divided into two groups: Group A (60 patients, 18-64 years) and Group B (60 patients, ≥ 65 years). LOC, defined as a Modified Observer's Assessment of Alertness and Sedation score at 1 had been reached, emerged after all participants received a continuous infusion of remimazolam at a rate of 0.05 mg/kg/min. Results: The remimazolam required for inducing LOC was 0.26 and 0.19 mg/kg in groups A and B, respectively, and the remimazolam dose in group B decreased by 26.9% compared to group A. According to the bivariate linear correlation analysis, remimazolam requirement was negatively correlated with age. Multivariable linear regression models and further adjustments for potential impact factors indicated that age was an independent factor for the remimazolam dose required for LOC. Conclusion: This study demonstrated that age was significantly and independently correlated with the remimazolam requirement for inducing LOC. To obtain haemodynamic stability during the induction of general anaesthesia, appropriately reducing the remimazolam dose is recommended for geriatric patients.

Microbial Communities Affected by Hydraulic Fracturing and Environmental Factors within an In Situ Coal Reservoir.

The rise of coalbed methane bioengineering enables the conversion and utilization of carbon dioxide through microbial action and the carbon cycle. The environment of underground coal reservoirs is the result of a comprehensive effort by microorganisms. Some studies on reservoir microorganisms have progressed in laboratory conditions. However, it does not replicate the interaction between microorganisms and the environment on site. Hydraulic fracturing is an engineering technology to improve the natural permeability of tight reservoirs and is also a prerequisite for increasing biomethane production. In addition to expanding the pore and fracture systems of coal reservoirs, hydraulic fracturing also improves the living conditions of microbial communities in underground space. The characteristics of microbial communities in the reservoir after hydraulic fracturing are unclear. To this end, we applied the 16S rRNA sequencing technique to coalbed methane production water after hydraulic fracturing south of the Qinshui Basin to analyze the microbial response of the hydraulic fracturing process in the coal reservoir. The diversity of microbial communities associated with organic degradation was improved after hydraulic fracturing in the coal reservoir. The proportion of Actinobacteria in the reservoir water of the study area increased significantly, and the abundance of Aminicenantes and Planctomycetes increased, which do not exist in non-fracturing coalbed methane wells or exist at very low abundance. There are different types of methanogens in the study area, especially in fracturing wells. Ecological factors also determine the metabolic pathway of methanogens in coal seams. After hydraulic fracturing, the impact on the reservoir's microbial communities remains within months. Hydraulic fracturing can strengthen the carbon circulation process, thereby enhancing the block's methane and carbon dioxide circulation. The study provides a unique theoretical basis for microbially enhanced coalbed methane.

Research Progress and Prospects on Microbial Response and Gas Potential in the Coal Gasification Process.

As an essential unconventional natural gas resource, China's coalbed methane resources are only commercially exploited in a few areas, such as the Qinshui Basin and the Ordos. The rise of coalbed methane bioengineering makes it possible to realize the conversion and utilization of carbon dioxide through microbial action and the carbon cycle. According to the metabolic behavior of the underground microbial community, if the coal reservoir is modified, it may stimulate the microorganism to continuously produce biomethane to prolong the production life of depleted coalbed methane wells. This paper systematically discusses the microbial response to promoting microbial metabolism by nutrients (microbial stimulation), introducing exogenous microorganisms or domestication of in situ microorganisms (microbial enhancement), pretreating coal to change its physical or chemical properties to improve bioavailability, and improving environmental conditions. However, many problems must be solved before commercialization. The whole coal reservoir is regarded as a giant anaerobic fermentation system. Some issues still need to be solved during the implementation of coalbed methane bioengineering. Firstly, the metabolic mechanism of methanogenic microorganisms should be clarified. Secondly, it is urgent to study the optimization of high-efficiency hydrolysis bacteria and nutrient solutions in coal seams. Finally, the research on the underground microbial community ecosystem and biogeochemical cycle mechanism must be improved. The study provides a unique theory for the sustainable development of unconventional natural gas resources. Furthermore, it provides a scientific basis for realizing the carbon dioxide reuse and carbon element cycle in coalbed methane reservoirs.

Pore Structure and Adsorption Characteristics of Maceral Groups: Insights from Centrifugal Flotation Experiment of Coals.

Coal has various types of macerals, which have different pore structures and adsorption properties that change with coal's thermal metamorphism. In-depth study of the characteristics of different coal macerals, especially the pore structure and adsorption properties, can better predict the coal reservoir gas storage capacity and migration ability. In this study, the sub-samples enriched in a specific maceral group with different coal ranks and particle sizes were obtained by centrifugal flotation experiments. Then, experiments containing low-temperature N2 isotherm adsorption (LT-N2GA), low-temperature CO2 isotherm adsorption (LT-CO2GA), and methane isothermal adsorption were carried out on the sub-samples to quantitatively analyze the evolution characteristics of pore structure and adsorption properties of different maceral groups. The results showed the following: (1) The separation effect of the light maceral groups by centrifugal flotation experiments increased with the decrease of particle sizes, which were treated with the heavy liquid of low and medium densities, while that of the heavy maceral groups had the relatively best separation effect in the particle sizes of 0.1-0.125 mm, which were treated with the heavy liquid of high densities. (2) The vitrinite-enriched samples had more ultra-micropores (mainly within the diameter range of 0.4-0.65 nm), while the inertinite enriched samples had more mesopores and transition pores (mainly within the diameter range of 40-50 nm). (3) For the low-rank coal, inertinite had more potential methane adsorption capacity. However, for the medium- and high-rank coal, vitrinite had more potential methane adsorption capacity. (4) For the low-rank coal, the adsorption potential and adsorption space increased with the increase of the inertinite content, while the adsorption potential, adsorption space, and surface free energy for the medium- and high-rank coal increased with the increase of vitrinite content. It is expected that the results can deepen the understanding about the gas storage capacity and migration ability and be used in the prevention of gas outburst and the reduction of carbon emission.

Microbiome of High-Rank Coal Reservoirs in the High-Production Areas of the Southern Qinshui Basin.

To study the distribution features of microorganisms in distinct hydrological areas of the southern Qinshui Basin, C-N-S microorganisms were studied using 16S RNA sequencing, metagenome sequencing and geochemical technologies, showing the high sensitivity of microorganisms to the hydrodynamic dynamics of coal. The hydrodynamic intensity of the #3 coal gradually decreased from the runoff areas to the stagnant areas. The stagnant zones have higher reservoir pressure, methane content, δ13CDIC and TDS and lower SO42-, Fe3+ and NO3- concentrations than the runoff areas. C-N-S-cycling microorganisms, including those engaged in methanogenesis, nitrate respiration, fermentation, nitrate reduction, dark oxidation of sulfur compounds, sulfate respiration, iron respiration, chlorate reduction, aromatic compound degradation, denitrification, ammonification and nitrogen fixation, were more abundant in the stagnant areas. The relative abundance of C-N-S functional genes, including genes related to C metabolism (e.g., mcr, mer, mtr, fwd and mtd), N metabolism (e.g., nifDKH, nirK, narGHI, nosZ, amoB, norC and napAB) and sulfur metabolism (e.g., dsrAB and PAPSS), increased in the stagnant zones, indicating that there was active microbiological C-N-S cycling in the stagnant areas. The degradation and fermentation of terrestrial plant organic carbon and coal seam organic matter could provide substrates for methanogens, while nitrogen fixation and nitrification can provide nitrogen for methanogens, which are all favorable factors for stronger methanogenesis in stagnant areas. The coal in the study area is currently in the secondary biogenic gas generation stage because of the rising of the strata, which recharges atmospheric precipitation. The random forest model shows that the abundance of C-N-S microorganisms and genes could be used to distinguish different hydrological zones in coal reservoirs. Since stagnant zones are usually high-gas-bearing zones and high-production areas of CBM exploration, these microbiological indicators can be used as effective parameters to identify high-production-potential zones. In addition, nitrate respiration and sulfate respiration microorganisms consumed NO3- and SO42-, causing a decrease in the content of these two ions in the stagnant areas.

Effect of different doses of dexmedetomidine on the median effective concentration of propofol during gastrointestinal endoscopy: a randomized controlled trial.

AIMS: Dexmedetomidine could be an ideal adjuvant to propofol during gastrointestinal endoscopy because it provides both analgesia and sedation without respiratory depression. This study investigates the effect of different doses of dexmedetomidine on the median effective concentration of propofol during gastrointestinal endoscopy. METHODS: Ninety adult patients were randomly assigned to Group Control, Group DEX0.5 (0.5 µg/kg dexmedetomidine) or Group DEX1.0 (1.0 µg/kg dexmedetomidine). Anaesthesia during endoscopy was implemented by plasma target-controlled infusion (TCI) of propofol with different doses of dexmedetomidine. TCI concentration of the first patient for each group was 2.5 µg/mL and the consecutive adjacent concentration gradient was 0.5 µg/mL. Median effective concentration (EC50 ) of propofol by TCI for gastrointestinal endoscopy was determined by using the modified Dixon's up-and-down method. Cardiovascular variables were also measured. RESULTS: EC50 of propofol by TCI and 95% confidence interval (CI) for gastrointestinal endoscopy were 3.77 (3.48-4.09), 2.51 (2.27-2.78) and 2.10 (1.90-2.33) µg/mL in Group Control, Group DEX0.5 and Group DEX1.0, respectively. The average percent change from heart rate (HR) baseline was 2.8 (8.9), -7.4 (7.7) and -10.5 (8.8) (P < .001), and the average percent change from mean arterial pressure (MAP) baseline was -10.6 [-24.7; 3.5], -9.5 [-29.2; 11.4] and -4.0 [-27.3; 15.5] (P = .034) in Group Control, Group DEX0.5 and Group DEX1.0, respectively. CONCLUSIONS: Dexmedetomidine reduced the EC50 of propofol by TCI. A 0.5-1 µg/kg dose of dexmedetomidine caused a decrease in HR without bradycardia. The decrease in dosage of propofol with increasing doses of dexmedetomidine caused more stable MAP. Dexmedetomidine is an ideal adjuvant drug to propofol during gastrointestinal endoscopy.

The Impact of Age on Propofol Requirement for Inducing Loss of Consciousness in Elderly Surgical Patients.

It is generally accepted that geriatric patients are more sensitive to propofol than adults; thus, a dose-adjusted propofol is recommended for these patients during the induction of anesthesia. However, for patients aged 75 years and over, established guidelines for propofol induction doses do not provide dose references. To this end, we observed 80 surgical patients (female 39, male 41, American Society of Anesthesiologists physical status score I ∼ II) to access the appropriate dose of propofol for inducing loss of consciousness (LOC). Accordingly, patients were subdivided into group A (20 patients, 45-64 years), group B (20 patients, 65-74 years), group C (20 patients, 75-84 years), and group D (20 patients, ≥ 85 years). All patients received propofol (at a rate of 0.3 mg/kg/min) alone for inducing LOC, which was defined by loss of both eyelash reflex and verbal response. Compared with group A, the propofol requirement for LOC in Group B, C and D decreased by 14.8, 25.2 and 38.5%, respectively. Bivariate linear correlation analysis showed that propofol requirement was negatively correlated with age. After adjusting for potential confounders, age was still an independent factor affecting propofol requirement. In conclusion, the propofol requirement for inducing LOC decreased significantly in elderly patients. We demonstrated that age was an independent factor impacting propofol requirement for LOC during the induction of general anesthesia, implying that the propofol dose for anesthesia induction should be further reduced in elderly surgical patients, especially those aged 75 years and over.

Biogeochemical Assessment of the Coalbed Methane Source, Migration, and Fate: A Case Study of the Shizhuangnan Block, Southern Qinshui Basin.

The exploration and exploitation of coalbed methane (CBM), an essential unconventional gas resource, have received much attention. In terms of shallow groundwater assessment during CBM production, biogenic methane natural formation in situ and methane migration from deep sources into shallow aquifers need to be of most concern. This study analyzes geochemical surveys including ions, isotopes, and dissolved methane concentrations in 75 CBM coproduced water samples in the southern Qinshui Basin. Most of these water samples are weakly alkaline. Some samples' negative oxidation/reduction potential (ORP) values reveal that the CBM reservoir water samples are mainly produced from reductive groundwater environments. Cl-, Na+, and HCO3 - are the dominant ionic constituents of the water samples, which are usually associated with dissolved methane concentrations. The biogeochemical parameters and isotopic features provide an opportunity to assess the origin, migration, and oxidation of biogenic or thermogenic methane. Some water samples suggest biogenic methane formation in situ characterized by negligible SO4 2- and NO3 - concentrations and low δ13CCH4. Only a few water samples indicate the migration of biogenic methane into shallow aquifers without oxidation based on elevated SO4 2-, NO3 -, and δ13CDIC and low δ13CCH4. A few cases characterized by elevated δ13CCH4, negative δ13CDIC values, and negligible SO4 2- and methane concentrations suggest the oxidation of biogenic methane rather than the migration of thermogenic methane. A significant number of cases mean methane migration to shallow aquifers. Partial oxidation of thermogenic or mixed methane is evaluated by negligible SO4 2-, NO3 -, and methane concentrations and elevated δ13CCH4. Dissolved methane isotopic compositions and aqueous biogeochemical features help study methane formation and potential migration in shallow groundwater.

Distribution Characteristics of C-N-S Microorganism Genes in Different Hydraulic Zones of High-Rank Coal Reservoirs in Southern Qinshui Basin.

Microbial decomposition of carbon and biogenic methane in coal is one of the most important issues in CBM exploration. Using metagenomic technologies, the microbial C-N-S functional genes in different hydraulic zones of high-rank coal reservoirs were systematically studied, demonstrating the high sensitivity of this ecosystem to hydrodynamic conditions. The results show that the hydrodynamic strength of coal reservoir #3 in the Shizhuangnan block gradually weakened from east to west, forming a transitional feature from a runoff area to a stagnant area. Compared with runoff areas, stagnant areas have higher reservoir pressure, gas content, and ion concentrations. The relative abundance of genes associated with C, N, and S cycling increased from the runoff area to the stagnant area, including cellulose-degrading genes (e.g., cellulose 1,4-beta-cellobiosidase), methane metabolism genes (e.g., mcr, fwd, mtd, mer, and mtr), N-cycling genes (e.g., nifDKH, amoB, narGHI, napAB, nirK, norC, and nosZ), and S-cycling genes (e.g., dsrAB, sir, cysN, sat, aprAB, and PAPSS). This indicates that the stagnant zone had a more active microbial C-N-S cycle. The machine learning model shows that these significantly different genes could be used as effective indices to distinguish runoff and stagnant areas. Carbon and hydrogen isotopes indicate that methane in the study area was thermally generated. Methanogens compete with anaerobic heterotrophic bacteria to metabolize limited substrates, resulting in a low abundance of methanogens. In addition, the existence of methane-oxidizing bacteria suggests that biogenic methane was consumed by methanotrophic bacteria, which is the main reason why biogenic methane in the study area was not effectively preserved. In addition, weakened hydrodynamic conditions increased genes involved in nutrient cycling, including organic matter decomposition, methanogenesis, denitrification, and sulfate reduction, which contributed to the increase in CO2 and consumption of sulfate and nitrate from runoff areas to stagnant areas.

Quantitative optimization of drainage strategy of coalbed methane well based on the dynamic behavior of coal reservoir permeability.

The development of coalbed methane (CBM) is not only affected by geological factors, but also by engineering factors, such as artificial fracturing and drainage strategies. In order to optimize drainage strategies for wells in unique geological conditions, the characteristics of different stages of CBM production are accurately described based on the dynamic behavior of the pressure drop funnel and coal reservoir permeability. Effective depressurization is achieved by extending the pressure propagation radius and gas desorption radius to the well-controlled boundary, in the single-phase water flow stage and the gas-water flow stage, respectively, with inter-well pressure interference accomplished in the single-phase gas flow stage. A mathematic model was developed to quantitatively optimize drainage strategies for each stage, with the maximum bottom hole flow pressure (BHFP) drop rate and the maximum daily gas production calculated to guide the optimization of CBM production. Finally, six wells from the Shizhuangnan Block in the southern Qinshui Basin of China were used as a case study to verify the practical applicability of the model. Calculation results clearly indicate the differences in production characteristics as a result of different drainage strategies. Overall, if the applied drainage strategies do not achieve optimal drainage results, the coal reservoir could be irreversibly damaged, which is not conducive to expansion of the pressure drop funnel. Therefore, this optimization model provides valuable guidance for rational CBM drainage strategy development and efficient CBM production.

Immunoassays for the rapid detection of gentamicin and micronomicin in swine muscle.

A monoclonal antibody (mAb)-based ELISA and strip test for gentamicin (GEN) and its analogue micronomicin (MIN), are reported in this study. The conjugate gentamicin-glutaraldehyde-bovine serum albumin (GEN-GDA-BSA) was used as an immunogen. The produced anti-GEN mAB exhibited high cross-reactivity with micronomicin (MIN; 131.2%) and slight or negligible crossreactivity with other aminoglycosides. Based on this mAB, an ELISA and a strip test for GEN and MIN were developed and evaluated. The ELISA showed a 50% inhibition concentration (IC50) of 0.75 ng/mL for GEN and 0.58 ng/mL for MIN. For GEN, the average recoveries at 25-200 microg/kg ranged from 73 to 91%, with intraday CVs of 9-16% and interday CVs of 8-15%. For MIN, the average recoveries ranged from 108 to 131%, with intraday CVs of 10-16% and interday CVs of 8-15%. In contrast, the strip test for GEN or MIN had a detection limit of 5 ng/mL in phosphate-buffered saline and 50 microg/kg in muscle (n=24), and the results could be judged within 10 min. The detection results of incurred samples analyzed by the strip test, ELISA, and HPLC indicated that the two immunoassays correlated well with the HPLC method and could be used as convenient tools for the rapid screening of GEN and MIN residues in swine muscle.