Commonly used antiemetics for prophylaxis of postoperative nausea and vomiting after Caesarean delivery with neuraxial morphine: a network meta-analysis.

BACKGROUND: Dopamine antagonists, 5-HT3 antagonists, and dexamethasone are frequently used in obstetrics to prevent postoperative nausea and vomiting (PONV). However, the superiority of any drug class is yet to be established. This network meta-analysis aimed to compare the efficacy of these antiemetics for PONV prophylaxis in women receiving neuraxial morphine for Caesarean delivery. METHODS: We searched PubMed, Embase, CENTRAL, Web of Science, and Wanfang Data for eligible randomised controlled trials. Primary outcomes were the incidences of postoperative nausea (PON) and postoperative vomiting (POV) within 24 h after surgery. We used a Bayesian random-effects model and calculated odds ratios with 95% credible intervals for dichotomous data. We performed sensitivity and subgroup analyses for primary outcomes. RESULTS: A total of 33 studies with 4238 women were included. In the primary analyses of all women, 5-HT3 antagonists, dopamine antagonists, dexamethasone, and 5-HT3 antagonists plus dexamethasone significantly reduced PON and POV compared with placebo, and 5-HT3 antagonists plus dexamethasone were more effective than monotherapy. In the subgroup analyses, similar results were seen in women receiving epidural morphine or intrathecal morphine alone but not in women receiving intrathecal morphine with fentanyl or sufentanil. However, most included studies had some concerns or a high risk of bias, and the overall certainty of the evidence was low or very low. CONCLUSIONS: Combined 5-HT3 antagonists plus dexamethasone are more effective than monotherapy in preventing PONV associated with neuraxial morphine after Caesarean delivery. Future studies are needed to determine the role of prophylactic antiemetics in women receiving intrathecal morphine and lipophilic opioids. SYSTEMATIC REVIEW PROTOCOL: PROSPERO CRD42023454602.

Effects of different neuraxial analgesia modalities on the need for physician interventions in labour: A network meta-analysis.

BACKGROUND: Neuraxial labour analgesia can be initiated with epidural (EPL), combined spinal epidural (CSE) or dural puncture epidural (DPE) and maintained with continuous epidural infusion (CEI), patient-controlled epidural analgesia (PCEA) or programmed intermittent epidural bolus (PIEB), but the optimal analgesia modality is still controversial. OBJECTIVE: To compare the effects of commonly used neuraxial analgesia modalities on the proportion of women needing physician interventions, as defined by the need for physician-administered epidural top-ups for inadequate analgesia in labour. DESIGN: Bayesian network meta-analysis. DATA SOURCES: PubMed, Embase, CENTRAL, Web of Science and Wanfang Data were searched from January 1988 to August 2023 without language restriction. ELIGIBILITY CRITERIA: Randomised controlled trials comparing two or more modalities of the following six neuraxial analgesia modalities in healthy labouring women: EPL+CEI+PCEA, EPL+PIEB+PCEA, CSE+CEI+PCEA, CSE+PIEB+PCEA, DPE+CEI+PCEA and DPE+PIEB+PCEA. RESULTS: Thirty studies with 8188 women were included. Compared with EPL+CEI+PCEA, EPL+PIEB+PCEA [odds ratio (OR) = 0.44; 95% credible interval (CrI), 0.22 to 0.86], CSE+PIEB+PCEA (OR = 0.29; 95% CrI, 0.12 to 0.71) and DPE+PIEB+PCEA (OR = 0.19; 95% CrI, 0.08 to 0.42) significantly reduced the proportion of women needing physician interventions. DPE+PIEB+PCEA had fewer women needing physician interventions than all other modalities, except for CSE+PIEB+PCEA (OR = 0.63; 95% CrI, 0.25 to 1.62). There were no significant differences in local anaesthetic consumption, maximum pain score, and the incidence of instrumental delivery between the different neuraxial modalities. CONCLUSIONS: PIEB+PCEA is associated with a lower risk of physician interventions in labour than CEI+PCEA. DPE or CSE and PIEB+PCEA may be associated with a lower likelihood of physician interventions than other neuraxial modalities. Otherwise, the new neuraxial analgesia techniques do not appear to offer significant advantages over traditional techniques. However, these results should be interpreted with caution due to limited data and methodological limitations. TRIAL REGISTRATION: PROSPERO (CRD42023402540).

Prevalence of risk stomach in laboring women allowed to unrestrictive oral intake: a comparative cross-sectional study.

BACKGROUND: Although restricting food intake during labor is recommended by guidelines, intrapartum starvation has not been popular in some regions. We conducted this comparative cross-sectional study to determine the prevalence of risk stomach in non-fasted laboring women compared with fasted non-laboring women using gastric ultrasound. METHODS: Ultrasound examination of the antrum was performed in 50 term fasted non-laboring women before elective cesarean delivery and 50 laboring women allowed to eat and drink during active labor. Examinations consisted of the qualitative (antral grades, 0-3) and quantitative evaluation (antral cross-sectional area and calculated gastric volume) in the supine and right lateral decubitus (RLD) position. A risk stomach was defined as an antral grade ≥ 2 or grade 1 with gastric volume ≥ 1.5 ml· kg- 1. RESULTS: No non-laboring women had grade ≥ 2, while 34 (68%) laboring women had grade ≥ 2. Nine (18%) non-laboring and 40 (80%) laboring women presented risk stomach (P < 0.001) (risk ratio: 4.4, 95% CI 2.4-8.2). Compared with non-laboring women, laboring women had larger antral area at "empty" stomach (grade 0) (437 mm2 vs.350 mm2 in supine, 571 mm2 vs.480 mm2 in RLD, P < 0.05) and cut-off values of antral area to discriminate a risk stomach (510 mm2 vs. 453 mm2 in supine, 670 mm2 vs. 605 mm2 in RLD). CONCLUSIONS: This study confirms a higher prevalence of risk stomach presents in laboring women under a liberal eating policy, gastric ultrasound is therefore useful for this risk population if general anesthesia is required unexpectedly.

A Domestic Trash Detection Model Based on Improved YOLOX.

Domestic trash detection is an essential technology toward achieving a smart city. Due to the complexity and variability of urban trash scenarios, the existing trash detection algorithms suffer from low detection rates and high false positives, as well as the general problem of slow speed in industrial applications. This paper proposes an i-YOLOX model for domestic trash detection based on deep learning algorithms. First, a large number of real-life trash images are collected into a new trash image dataset. Second, the lightweight operator involution is incorporated into the feature extraction structure of the algorithm, which allows the feature extraction layer to establish long-distance feature relationships and adaptively extract channel features. In addition, the ability of the model to distinguish similar trash features is strengthened by adding the convolutional block attention module (CBAM) to the enhanced feature extraction network. Finally, the design of the involution residual head structure in the detection head reduces the gradient disappearance and accelerates the convergence of the model loss values allowing the model to perform better classification and regression of the acquired feature layers. In this study, YOLOX-S is chosen as the baseline for each enhancement experiment. The experimental results show that compared with the baseline algorithm, the mean average precision (mAP) of i-YOLOX is improved by 1.47%, the number of parameters is reduced by 23.3%, and the FPS is improved by 40.4%. In practical applications, this improved model achieves accurate recognition of trash in natural scenes, which further validates the generalization performance of i-YOLOX and provides a reference for future domestic trash detection research.

A prediction model using machine-learning algorithm for assessing intrathecal hyperbaric bupivacaine dose during cesarean section.

BACKGROUND: The intrathecal hyperbaric bupivacaine dosage for cesarean section is difficult to predetermine. This study aimed to develop a decision-support model using a machine-learning algorithm for assessing intrathecal hyperbaric bupivacaine dose based on physical variables during cesarean section. METHODS: Term parturients presenting for elective cesarean section under spinal anaesthesia were enrolled. Spinal anesthesia was performed at the L3/4 interspace with 0.5% hyperbaric bupivacaine at dosages determined by the anesthesiologist. A spinal spread level between T4-T6 was considered the appropriate block level. We used a machine-learning algorithm to identify relevant parameters. The dataset was split into derivation (80%) and validation (20%) cohorts. A decision-support model was developed for obtaining the regression equation between optimized intrathecal 0.5% hyperbaric bupivacaine volume and physical variables. RESULTS: A total of 684 parturients were included, of whom 516 (75.44%) and 168 (24.56%) had block levels between T4 and T6, and less than T6 or higher than T4, respectively. The appropriate block level rate was 75.44%, with the mean bupivacaine volume [1.965, 95%CI (1.945,1.984)]ml. In lasso regression, based on the principle of predicting a reasonable dose of intrathecal bupivacaine with fewer physical variables, the model is "Y=0.5922+ 0.055117* X1-0.017599*X2" (Y: bupivacaine volume; X1: vertebral column length; X2: abdominal girth), with λ 0.055, MSE 0.0087, and R2 0.807. CONCLUSIONS: After applying a machine-learning algorithm, we developed a decision model with R2 0.8070 and MSE due to error 0.0087 using abdominal girth and vertebral column length for predicting the optimized intrathecal 0.5% hyperbaric bupivacaine dosage during term cesarean sections.

Shift of DNRA bacterial community composition in sediment cores of the Pearl River Estuary and the impact of environmental factors.

Dissimilatory nitrate reduction to ammonia (DNRA) process, competing with denitrification and anaerobic ammonia oxidation (anammox) for nitrate, is an important nitrogen retention pathway in the environment. Previous studies on DNRA bacterial diversity and composition focused on the surface sediments in estuaries, but studies on the deep sediments are limited, and the linkage between DNRA community structure and complex estuarine environment remains unclear. In this study, through high-throughput sequencing of nrfA gene followed by high-resolution sample inference, we examined spatially and temporally the composition and diversity of DNRA bacteria along a salinity gradient in five sediment cores of the Pearl River Estuary (PRE). We found a higher diversity and richness of DNRA bacteria in sediments with lower organic carbon, where sea water intersects fresh water. Moreover, the DNRA bacterial communities had the specific spatially distribution coupling with their metabolic difference along the salinity gradient of the Pearl River Estuary, but no obvious difference along the sediment depth. The distribution of DNRA bacteria in the PRE was largely driven by various environmental factors, including salinity, Oxidation-Reduction Potential (ORP), ammonium, nitrate and Corg/NO3-. Furthermore, dominant DNRA bacteria were found to be the key populations of DNRA communities in the PRE sediments by network analysis. Collectively, our results showed that niche difference of DNRA bacteria indeed occurs in the Pearl River Estuary.

A Prospective, Randomized, Double-Blinded Study of the Effect of Intravenous Ondansetron on the Effective Dose in 50% of Subjects of Prophylactic Phenylephrine Infusions for Preventing Spinal Anesthesia-Induced Hypotension During Cesarean Delivery.

BACKGROUND: Ondansetron has been shown to reduce the incidence of hypotension and vasopressor requirement during spinal anesthesia for obstetric and nonobstetric surgery. However, the magnitude of this effect has not been fully quantified. In this parallel-group, randomized, double-blinded study, we determined the effective dose in 50% of subjects (ED50) of a prophylactic phenylephrine infusion for preventing hypotension in patients who received a single dose of intravenous ondansetron 4 mg or saline control before combined spinal-epidural anesthesia for elective cesarean delivery. ED50 values obtained were compared to estimate the effect of ondansetron versus placebo on vasopressor requirement. METHODS: Sixty parturients were randomly assigned to receive ondansetron (group O) or saline control (group C) 10 minutes before positioning for induction of spinal anesthesia. A prophylactic phenylephrine infusion was used to prevent hypotension. The first patient in each group received a phenylephrine infusion at the rate of 0.5 µg/kg/min. The infusion rate for each subsequent patient was varied with increments or decrements of 0.05 µg/kg/min based on the response of the previous patient, and the effective dose of the phenylephrine infusion for preventing hypotension in 50% of patients (ED50) was calculated for each group and compared using up-down sequential analysis. Probit regression was applied as a backup and sensitivity analysis was used to compare ED50 values for phenylephrine between groups by comparing calculated relative mean potency. RESULTS: The ED50 (mean [95% confidence interval (CI)]) of the rate of phenylephrine infusion was lower in group O (0.24 µg/kg/min [0.10-0.38 µg/kg/min]) compared with group C (0.32 µg/kg/min [0.14-0.47 µg/kg/min]) (P < .001). The total consumption of phenylephrine (mean ± standard deviation [SD]) until delivery was lower in group O (316.5 ± 25.9 µg) than in group C (387.7 ± 14.7 µg, P = .02). The estimate of relative median potency for phenylephrine for group O versus group C was 0.74 (95% CI, 0.37-0.95). CONCLUSIONS: Under the conditions of this study, intravenous ondansetron 4 mg reduced the ED50 of a prophylactic phenylephrine infusion by approximately 26% in patients undergoing cesarean delivery under combined spinal-epidural anesthesia.

The effect of intrathecal dexmedetomidine on the dose requirement of hyperbaric bupivacaine in spinal anaesthesia for caesarean section: a prospective, double-blinded, randomized study.

BACKGROUND: Studies have shown that dexmedetomidine (Dex) can prolong the duration of analgesia when added to local anaesthetic as an adjuvant in a central or peripheral nerve block. We hypothesized that intrathecal Dex can reduce the ED95 of spinal hyperbaric bupivacaine. Therefore, we conducted this prospective, double-blinded, randomized study to verify our hypothesis. METHODS: Ninety patients were allocated into the Dexmedetomidine group (received bupivacaine + 5 mcg dexmedetomidine) and the Control group (received bupivacaine + the same volume of saline) using a double-blinded and randomized method. The first patient in each group received 5 mg of IT hyperbaric bupivacaine, and the next dose for the following patient was determined by the probability of successful anaesthesia of the previous neighbouring dose. An improved up-down sequence allocated method combined with probit analysis was used to determine the ED95 of intrathecal hyperbaric bupivacaine for the two groups. RESULTS: The ED95 and 95% confidence intervals (95% CI) of IT hyperbaric bupivacaine of the Dex group and Control group were 8.4 mg (95% CI, 6.5~ 13.8 mg) and 12.1 mg (95% CI, 8.3~ 312.8 mg), respectively. The duration of sensory block was longer in the Dex group than in the Control group (110.3 ± 35.3 vs 67.5 ± 26.2). The duration of analgesia was also longer in the Dex group than in the Control group (224.9 ± 45.4 vs 155.1 ± 31.6). The consumption of postoperative rescued sufentanil was significantly higher in the Control group than in the Dex group. CONCLUSION: Intrathecal 5 mcg dexmedetomidine potentiated hyperbaric bupivacaine antinociception by 31% in spinal anaesthesia for patients undergoing caesarean section. TRIAL REGISTRATION: We registered this study in a Chinese Clinical Trial Registry (ChiCTR) centre on Nov 1st 2016 and received the registration number: ChiCTR-IPR-16009699 .

Determination of carbonyl pollutants adsorbed on ambient particulate matter of type PM2.5 by using magnetic molecularly imprinted microspheres for sample pretreatment and capillary electrophoresis for separation and quantitation.

The authors describe a method for the determination of carbonyl pollutants adsorbed on ambient particulate matter (diameter < 2.5 µm; PM2.5). 2,4-Dinitrophenylhydrazine (DNPH) was used to derivatize carbonyl compounds. Magnetic molecularly imprinted polymers (MMIPs) selective for 2,4-DNPH were synthesized to remove excess of the derivatization reagent 2,4-DNPH. Micellar electrokinetic chromatography (MEKC) was then applied to the separation of DNPH-derivatized carbonyl compounds. The increased sensitivity of MEKC with UV detection and the sample cleanup resulted in drastically reduced sampling times (15 min) with detection limits ranging from 0.005-0.068 µg·m-3 for different carbonyls. The method was applied to continuous monitoring of carbonyl compounds on ambient PM 2.5 for two consecutive months. The concentrations and gas-to-particle ratios of carbonyls were determined, and a statistical method was used to evaluate the correlation among different carbonyls. It was observed that the total concentration of carbonyls, especially of multi-carbon carbonyls, increases with the level of air pollution. The level of isovaleraldehyde rises sharply and accounts for 37% of total carbonyls on days with extremely humid haze. The ratio of acetaldehyde to propionaldehyde (C2/C3) decreases with the duration and heaviness of haze conditions. Results indicate that anthropogenic emissions and the characteristics of the atmosphere (e.g. temperature, sunlight, and relative humidity) are the main factors that lead to abnormally high levels of isovaleraldehyde and other carbonyls in ambient PM 2.5. Graphical abstract Schematic of a method for the determination of carbonyl pollutants adsorbed on ambient fine particle of type PM2.5. Magnetic molecularly imprinted polymers (MMIPs) were synthesized to remove the excess derivatization reagent (2,4-DNPH) in air sample prior to CE separation.

Source analysis of municipal solid waste in a mega-city (Guangzhou): Challenges or opportunities?

Rapid economic development accelerates the generation of municipal solid waste (MSW), and thereby calls for an effective and reliable waste management strategy. In the present work, we systematically investigated the status of MSW management in a mega-city of China (Guangzhou). The data were collected from literatures, government statistics and field sampling work. It can be found that a combination of waste sorting by individual residents and a necessary quantity of sanitation workers is one of the most feasible strategies to achieve a sustainable waste management. With implementation of that integrated strategy, approximately 0.03 million tons of metal, 0.24 million tons of paper, as well as 0.46 million tons of plastics can be recycled/recovered for further processing. A cost reduction of 70 million US$ is achieved in comparison with the un-optimized system due to the sale revenue of recyclable materials and the saving from waste disposal fees. The values of environmental assessment were expressed as environmental load units. The developed scenarios could decrease the environmental cost, namely, 0.66 million US$. Based on the studies, waste sorting is urgently needed in Guangzhou. However, to make the proposed strategy to be more economically feasible, the sorting should be performed individually as well as with public participation. The establishment of a win-win situation for all stakeholders is an effective path for the improvement of the integrated waste management system.

Development of a simple cataluminescence sensor system for detecting and discriminating volatile organic compounds at different concentrations.

The detection and identification of volatile organic compounds (VOCs) is one of the most serious subjects in the field of chemical sensing, but it remains an enormous challenge. Usually, during the sensing of gases involved in chemical reactions, the residual gas of that reaction (including undecomposed analytes and reaction products) are considered waste gases and released into the air. Here, a novel cataluminescence (CTL) sensing method based on detection of the luminescent intensities of both the analyte (I(A)) and its products (I(R)) was developed and used to identify VOCs at different concentrations. After the analyte gas passed through the first sensing material, the product gas was treated as a new reactant and passed through the second sensing material (which could be the same as or different from the first material). The luminescent signals of I(A) and I(R) were recorded over a short period of time using one photomultiplier. We found the ratio of I(A) to I(R) (I(A)/I(R)) to be a unique characteristic of a given analyte within a wide range of concentrations. To illustrate the new method, 11 kinds of organic gases were successfully identified using I(A)/I(R) values. The most distinct feature of this method is that it allows the user to obtain many more luminescent signals from the sensing materials than common methods. It does so by allowing different flow channels of the analyte gas. This simple method here was used to discriminate different species, homologous series, and isomers in different concentrations. This method could be applied to chemical sensing arrays to increase the discrimination ability or decrease the number of sensing units required.

A randomized comparison of caudal block by sacral hiatus injection under ultrasound guidance with traditional sacral canal injection in children.

BACKGROUND: There is a risk of inadvertent dural or vascular puncture for the traditional single-shot caudal block performed by inserting the needle into the sacral canal through the sacral hiatus. This prospective, randomized study was to evaluate the clinical feasibility of the hiatus injection under ultrasound guidance for caudal block in children. METHODS: 140 ASA I-II children undergoing inguinal hernia repair were randomly allocated to one of two groups (Group C or Group H, n = 70). 1 ml·kg(-1) of 0.25% ropivacaine was injected after the needle was inserted into the sacral canal in Group C, or after the needle pierced the sacrococcygeal ligament under a transverse ultrasound view in Group H. Success rate of block, puncture frequency, complications, and durations of block were recorded. RESULTS: The success rate of block was similar between two groups (95.7% in Group C vs 92.8% in Group H, P > 0.05). The first puncture success rate was higher, and the durations of block were shorter in Group H than in Group C (92.8% vs 60% and 145 ± 23s vs 164 ± 31s, respectively P < 0.05). Bloody puncture had an incidence of 18.6% in Group C and 5.7% in Group H (P < 0.05). Subcutaneous bulging occurred in six patients (7.1%) in Group C but none in Group H (P < 0.05). CONCLUSIONS: Sacral hiatus injection offers a reliable caudal block for pediatric inguinal hernia repair with the advantages of easier performance and fewer complications compared with traditional sacral canal injection.

Efficacy and safety of epidural clonidine by continuous infusion or patient-controlled analgesia in labor: A meta-analysis of randomized controlled trials.

BACKGROUND: Epidural clonidine improves analgesia but may induce adverse effects in labor. OBJECTIVE: To evaluate the efficacy and safety of epidural clonidine as local anesthetics (LA) adjuvant by continuous infusion or patient-controlled epidural analgesia (PCEA) in labor. SEARCH STRATEGY: PubMed, Embase, Web of Science, and CENTRAL were searched from inception to May 10, 2022 without language restriction; references of the retrieved studies were hand searched. SELECTION CRITERIA: Randomized controlled trials (RCTs) comparing epidural LA with and without clonidine using continuous infusion or PCEA in labor were included. DATA COLLECTION AND ANALYSIS: A random effects model was used to pool the data on analgesia and adverse effects. MAIN RESULTS: Eight RCTs were included. Clonidine did not reduce the incidence of parturients requiring additional epidural boluses but reduced LA consumption and pain scores without increasing adverse effects, except for a higher incidence of instrumental delivery when clonidine was combined with LA and opioid (risk ratio 2.38, 95% confidence interval 1.26-4.50). Clonidine offered similar analgesia to opioids but had reduced opioid-related adverse effects. Trial sequential analysis showed that the evidence was insufficient. CONCLUSIONS: Epidural clonidine by continuous infusion or PCEA does not increase significant adverse effects and offers similar analgesia to opioids in labor. PROSPERO registration no. CRD42022306565.

Study on the Regulation Mechanism of Quality Deterioration Due to Chilling Stress and Dry Exposure during Anhydrous Storage and Transportation of Yesso Scallop Patinopecten yessoensis.

In this paper, the quality change of Yesso scallop (Patinopecten yessoensis) in the process of anhydrous storage and transportation after cold acclimation and induced dormancy was studied, and the regulation mechanism of quality degradation during storage and transportation in the process of gradient chilling stress and drying exposure was further explored. The results show that, when transferred from hydrous to anhydrous states, the breathing pattern of the scallops changed from aerobic to anaerobic. Their gill filaments were altered and their apparent vitality constantly declined, which was reflected by the edge shrinkage of the pallium and the direct proportions of the edge reduction rate and the stimulus response period. After being in the anhydrous state for 4 d, the AEC value dropped to 67.59%. At this time, if they were placed under hydration again, the scallops resumed a good growth state. By proteomics analysis, it was revealed that cold acclimation and dry exposure mainly led to changes in biological functions and pathways, such as mitochondrial inner membrane and ATP hydrolysis activity. In addition, it can be seen from the functional annotation and enrichment analysis of the metabolite KEGG that cold acclimation promoted the purine metabolism of scallops, while dry exposure inhibited the metabolism of saturated fatty acids. In this study, the infrared sensing mode was used for the first time, too, in order to record the heart-rate changes of the scallops during circulation, which shows that non-destructive vitality monitoring of Lamellibranchia is feasible.

Effect of Alkylation Chain Length on Inhibiting Performance of Soluble Ionic Liquids in Water-Based Drilling Fluids.

This work investigated the effect of the alkyl chain length of soluble methylimidazolium bromide ionic liquids (ILs) on their inhibition performance. The IL with a shorter alkyl chain length showed superior inhibition performance by suppressing clay swelling, mitigating clay dispersion, at room temperature. Particularly, the IL with an alkyl chain length of two (EmBr) reduced the sodium bentonite (Na-BT) swelling degree to 89% and achieved a cutting recovery of 81.9% after being rolled at room temperature, performing the best among all ILs. To systematically analyze the inhibition mechanism of ILs, X-ray diffraction (XRD), ζ potential, and particle size distribution have been carried out. The results revealed that the methylimidazolium with shorter alkyl chain length had better ability to enter the interlayer void by ion exchange and decrease interlayer distance, suppress the electrical double layer of the Na-BT particles and decrease the ζ potential, and promote the aggregation of Na-BT in water. It is also observed that high hot rolling temperature reduced the shale inhibiting performance of all ILs, and ILs with longer alkyl chain length had better ability to prevent cutting disintegration at high temperature. It is attributed to the variation of the hydrophilic characteristic of Na-BT at high temperature where EmBr no longer adsorbed the most on the surface and entered the interlayer voids of Na-BT. This study can be used as a reference to systematically explore the effect of the structure of shale inhibitors on their inhibiting performance and develop effective shale inhibitors.

Desulfurization of hydrophilic and hydrophobic volatile reduced sulfur with elemental sulfur production in denitrifying bioscrubber.

Volatile reduced sulfur compounds were odor and irritating toxic gas, which were commonly produced during waste and wastewater treatment. The autotrophic sulfide denitrifiers converted sulfide as alternative electron acceptor to reduce nitrate, which achieved simultaneous denitrification and sulfur oxidation. In this study, to investigate the effect of sulfur compounds solubility, S/N and oxygen on sulfur and nitrogen removal, a bioscrubber was studied for treatment of hydrophilic H2S and hydrophobic CS2. Both H2S and CS2 could be efficiently removed (99%), with the highest sulfide loading of 46.9 gS/m3·d. The elemental sulfur production was strongly correlated to S/N ratio (r = 0.969, p = 0.03), the highest elemental sulfur production efficiency achieved 92.0% under S/N ratio of 2.0 for treatment of H2S. Thiobacillus sp. bacteria was the pre-dominated sulfide-dependent denitrifiers (78.2%) before exposing to oxygen, while abundance of Cryseobacterium and unclassified Xanthomonadaceae aerobic sulfide oxidizer dramatically increased up to 40% and 7.3% after aeration. Remarkably increasing production of extracellular polymeric substance (197%) was observed after treatment of CS2, which might promote the hydrolysis of CS2 and stabilization of elemental sulfur. This study demonstrated the possibility to apply sulfide-dependent denitrification process for treatment of both hydrophilic and hydrophobic volatile reduced sulfur waste gas with elemental sulfur recovery.

Biomonitoring trace metal contamination in Guangzhou urban parks using Asian tramp snails (Bradybaena similaris).

Anthropogenic activities have caused environmental metal contamination in urban areas. Biomonitoring using organisms such as invertebrates can evaluate metal pollution, supplementing chemical monitoring, which cannot comprehensively reflect how metals influence organisms in the urban environment. To assess metal contamination in Guangzhou urban parks and its source, Asian tramp snails (Bradybaena similaris) were collected from ten parks in Guangzhou in 2021. The metal concentrations (Al, Cd, Cu, Fe, Mn, Pb, and Zn) were measured by ICP-AES and ICP-MS. We evaluated the metal distribution characteristics and correlations among metals. The probable sources of metals were determined by the positive matrix factorization (PMF) model. The metal pollution levels were analysed using the pollution index and the Nemerow comprehensive pollution index. The mean metal concentrations were ranked Al > Fe > Zn > Cu > Mn > Cd > Pb; metal pollution level in the snails was ranked Al > Mn > CuFe > Cd > Zn > Pb. Pb-Zn-Al-Fe-Mn and Cd-Cu-Zn were positively correlated in all samples. Six major metal sources were identified: an Al-Fe factor corresponding to crustal rock and dust, an Al factor related to Al-containing products, a Pb factor indicative of traffic and industries, a Cu-Zn-Cd factor dominated by the electroplating industry and vehicle sources, an Mn factor reflecting fossil fuel combustion, and a Cd-Zn factor related to agricultural product use. The pollution evaluation suggested heavy Al pollution, moderate Mn pollution, and light Cd, Cu, Fe, Pb, and Zn pollution in the snails. Dafushan Forest Park was heavily polluted; Chentian Garden and Huadu Lake National Wetland Park were not widely contaminated. The results indicated that B. similaris snails can be used as effective biomarkers for monitoring and evaluating environmental metal pollution in megacity urban areas. The findings show that snail biomonitoring provides a valuable understanding of the migration and accumulation pathways of anthropogenic metal pollutants in soil‒plant-snail food chains.

Application of transcranial doppler in patients after stent-assisted coil embolization.

BACKGROUND AND PURPOSE: Patients with intracranial aneurysms treated with stent-assisted coil embolization (SACE) require radiological and clinical follow-up in view of in-stent stenosis (ISS). The aim of the study was to evaluate transcranial Doppler (TCD) as an alternative to more invasive digital subtraction angiography (DSA) in monitoring patients with SACE. METHODS: Over the course of 72 months, from January 2016 to December 2021, we analyzed 49 patients treated with SACE because of internal carotid artery (ICA) aneurysms (C6 ophthalmic segment or C7 communicating segment). DSA was performed in all patients at 24-months and TCD was examined preoperatively and at 3, 6, 12, and 24-months postoperatively. The degree of stenosis found on TCD was compared with the results of DSA. Preoperative and postoperative blood flow velocities, including peak systolic blood flow velocity (Vs), end diastolic velocity (Vd), and mean velocity (Vm), were compared and the optimal cutoff velocities for detecting stenosis were calculated. RESULTS: Pre-embolization middle cerebral artery (MCA) and intracranial terminal internal cerebral arteries (TICA) velocities and pulsatility index (PI) did not significantly differ between the ipsilateral and contralateral sides. The blood flow velocities, Vs, Vd, and Vm, on the operation side significantly increased after SACE (P < 0.05). Over the 24-month study period, 7 of the 49 patients (14.3%) exhibited angiographic ISS. ISS of TCD and DSA results at 24-months were compared and found to correlate well; the Cohen's κ coefficient was 0.851 (95% CI 0.651-1.051). The optimal cutoff velocity for detecting ISS was MCA Vs = 173.5 cm/s. CONCLUSIONS: TCD is a potentially useful adjunct for evaluating ISS after SACE.

A new method for identifying compounds by luminescent response profiles on a cataluminescence based sensor.

Rapid identification of different compounds has been proven to be one of the most dynamic fields in analytical chemistry. Herein, a very simple cataluminescence-sensor-based (CTL-based) method suitable for rapid identification of compounds is reported. The oxidation of analytes was catalyzed in a closed reaction cell (CRC) containing enough air to facilitate complete luminescent response profiles with several peaks. The multipeaked response profiles are characteristic of analytes and can be used for identifying compounds. In existing CTL-based sensors, CTL reactions take place in an airstream flow reaction cell (AFRC) in which a continuous airstream carries the analytes flow across the catalyst's surface. The luminescent response profiles obtained are transitory and lack characteristic features, so they cannot be used to identify different compounds. To illustrate the new method, 12 medicines and 4 organic gases were examined in CRC sensors. Results showed that these compounds could be successfully identified through their unique luminescent response profiles. The response was rapid and the system was inexpensive and easy to handle. We believe that it has great potential for real-world use.