Ultrasonic Preparation of Nano-CaCO3 Templates and Hollow Mesoporous SiO2 Nanoparticles for Voriconazole Loading.

CaCO3 nanoparticles (nano-CaCO3) as nano-templates were prepared using CaCl2 and Na2CO3 solutions under controlled sonication (19.5 kHz). Using the same ultrasonic device, subsequently, hollow mesoporous silica nanoparticles (HMSNs) were obtained by the hard template of nano-CaCO3. HMSNs were selected as carriers for the antifungal drug voriconazole (VOR) loading to overcome poor water solubility. Three-dimensional CaCO3 nanosheets HMSNs were obtained under gentle sonication. Three-dimensional CaCO3 nanosheets of 24.5 nm (hydrodynamic diameter) were obtained under 17.6 W for 3 min. HMSNs were synthesized by double-template method with nano-CaCO3 as the hard template. Transmission electron microscopy measurements showed that the prepared HMSNs possess hollow structures with particle size between 110 and 120 nm. Nitrogen physisorption at -196 °C revealed that the HMSNs had high surface area (401.57 m2/g), high pore volume (0.11 cm3/g), and uniform pore size (2.22 nm) that facilitated the effective encapsulation of VOR in the HMSNs. The loading capacity of VOR (wt%) on the HMSNs was 7.96%, and the total VOR release amount of VOR-HMSNs material was 71.40% at 480 min. The kinetic model confirmed that the release mechanism of HMSNs nanoparticles followed Fickian diffusion at pH = 7.4 and 37 °C. Moreover, the cumulative VOR release at 42 °C (86.05%) was higher than that at 37 °C (71.40%). The cumulative release amount of VOR from the VOR-HMSNs material was 92.37% at pH = 5.8 at the same temperature. Both nano-CaCO3 templates and HMSNs were prepared by sonication at 19.5 kHz. The as-prepared HMSNs can effectively encapsulate VOR and released drug by Fickian diffusion.

Bailout intracranial angioplasty or stenting following thrombectomy for acute large vessel occlusion in China (ANGEL-REBOOT): a multicentre, open-label, blinded-endpoint, randomised controlled trial.

BACKGROUND: Unsuccessful recanalisation or reocclusion after thrombectomy is associated with poor outcomes in patients with large vessel occlusion (LVO) acute ischaemic stroke (LVO-AIS). Bailout angioplasty or stenting (BAOS) could represent a promising treatment for these patients. We conducted a randomised controlled trial with the aim to investigate the safety and efficacy of BAOS following thrombectomy in patients with LVO. METHODS: ANGEL-REBOOT was an investigator-initiated, multicentre, prospective, randomised, controlled, open-label, blinded-endpoint clinical trial conducted at 36 tertiary hospitals in 19 provinces in China. Participants with LVO-AIS 24 h after symptom onset were eligible if they had unsuccessful recanalisation (expanded Thrombolysis In Cerebral Infarction score of 0-2a) or risk of reocclusion (residual stenosis >70%) after thrombectomy. Eligible patients were randomly assigned by the minimisation method in a 1:1 ratio to undergo BAOS as the intervention treatment, or to receive standard therapy (continue or terminate the thrombectomy procedure) as a control group, both open-label. In both treatment groups, tirofiban could be recommended for use during and after the procedure. The primary outcome was the change in modified Rankin Scale score at 90 days, assessed in the intention-to-treat population. Safety outcomes were compared between groups. This trial was completed and registered at ClinicalTrials.gov (NCT05122286). FINDINGS: From Dec 19, 2021, to March 17, 2023, 706 patients were screened, and 348 were enrolled, with 176 assigned to the intervention group and 172 to the control group. No patients withdrew from the trial or were lost to follow-up for the primary outcome. The median age of patients was 63 years (IQR 55-69), 258 patients (74%) were male, and 90 patients (26%) were female; all participants were Chinese. After random allocation, tirofiban was administered either intra-arterially, intravenously, or both in 334 [96%] of 348 participants. No between-group differences were observed in the primary outcome (common odds ratio 0·86 [95% CI 0·59-1·24], p=0·41). Mortality was similar between the two groups (19 [11%] of 176 vs 17 [10%] of 172), but the intervention group showed a higher risk of symptomatic intracranial haemorrhage (eight [5%] of 175 vs one [1%] of 169), parenchymal haemorrhage type 2 (six [3%] of 175 vs none in the control group), and procedure-related arterial dissection (24 [14%] of 176 vs five [3%] of 172). INTERPRETATION: Among Chinese patients with unsuccessful recanalisation or who are at risk of reocclusion after thrombectomy, BAOS did not improve clinical outcome at 90 days, and incurred more complications compared with standard therapy. The off-label use of tirofiban might have affected our results and their generalisability, but our findings do not support the addition of BAOS for such patients with LVO-AIS. FUNDING: Beijing Natural Science Foundation, National Natural Science Foundation of China, National Key R&D Program Beijing Municipal Administration of Hospitals Incubating Program, Shanghai HeartCare Medical Technology, HeMo (China) Bioengineering, Sino Medical Sciences Technology.

Anesthesia, Anesthetics, and Postoperative Cognitive Dysfunction in Elderly Patients.

Postoperative cognitive dysfunction (POCD) remains a major issue that worsens the prognosis of elderly surgery patients. This article reviews the current research on the effect of different anesthesia methods and commonly utilized anesthetics on the incidence of POCD in elderly patients, aiming to provide an understanding of the underlying mechanisms contributing to this condition and facilitate the development of more reasonable anesthesia protocols, ultimately reducing the incidence of POCD in elderly surgery patients.

Antisolvent fabrication of monodisperse liposomes using novel ultrasonic microreactors: Process optimization, performance comparison and intensification effect.

Liposomes as drug carriers for the delivery of therapeutic agents have triggered extensive research but it remains a grand challenge to develop a novel technology for enabling rapid and mass fabrication of monodisperse liposomes. In this work, we constructed a novel ultrasonic microfluidic technology, namely ultrasonic microreactor (USMR) with two different conjunction structure (co-flow and impinge flow, corresponding to USMR-CF and USMR-IF, respectively), to prepare uniform liposomes by antisolvent precipitation method. In this process, the monodisperse liposomes with tunable droplet sizes (DS) in 60-100 nm and a polydispersity index (PDI) less than 0.1 can easily be achieved by tuning the total flow rate, flow rate ratio, ultrasonic power, and lipid concentration within the two USMRs. Impressively, the USMR-IF is superior for reducing the PDI and tuning DS of the liposomes over the USMR-CF. More importantly, the ultrasonic can effectively reduce DS and PDI at the low TFR and support the IF-micromixer in reducing the PDI even at a high TFR. These remarkable performances are mainly due to the rapid active mixing, fouling-free property and high operation stability for USMR-IF. In addition, diverse lipid formulations can also be uniformly assembled into small liposomes with narrow distribution, such as the prepared HSPC-based liposome with DS of 59.6 nm and PDI of 0.08. The liposomes show a high stability and the yield can reach a high throughput with 108 g/h by using the USMR-IF at an initial lipid concentration of 60 mM. The results in the present work highlight a novel ultrasonic microfluidic technology in the preparation of liposomes and may pave an avenue for the rapid, fouling-free, and high throughput fabrication of different and monodisperse nanomedicines with controllable sizes and narrow distribution.

Compression properties and constitutive model of short glass fiber reinforced poly-ether-ether-ketone (PEEK).

To analyze the deformation behavior of short glass fiber-reinforced poly-ether-ether-ketone (SGFR-PEEK) under various conditions through numerical simulations, it is crucial to construct a constitutive model that can describe its stress-strain behavior over a wide range of strain rates and temperatures. In this study, quasi-static compression tests were conducted on SGFR-PEEK composites with varying mass fractions, and dynamic tests were performed using a Split Hopkinson Pressure Bar to acquire the material's compressive stress-strain response under quasi-static and dynamic conditions. The results indicate that, under compression, the yield stress of SGFR-PEEK composites increases with an augmentation in glass fiber content, rises with increasing strain rate, and decreases with elevated temperature. Based on experimental findings, a modified Johnson-Cook constitutive model was established to characterize the mechanical performance of SGFR-PEEK. In comparison to the traditional Johnson-Cook intrinsic structure model, the modified model takes into account the glass fiber mass fraction as comprehensively as possible and better predicts the material's flow behavior at high strain rates. Finally, this modified constitutive model was implemented in the ABAQUS software using the user-defined subroutine VUMAT to simulate the compression behavior of SGFR-PEEK composites under different loading conditions, and the model was validated. This research provides valuable insights for the practical application of SGFR-PEEK composites in engineering.

Analgesic Efficacy of Nalbuphine as an Adjuvant to Ropivacaine in Erector Spinae Plane Block for Percutaneous Nephrolithotomy: A Randomized, Double-Blinded, Clinical Trial.

Background: Erector spinae plane block (ESPB) is an easy and safe method for postoperative analgesia. However its effect lasts only for several hours. This trial was to investigate the effectiveness of different doses of nalbuphine as an adjuvant to ropivacaine in ESPB for patients undergoing percutaneous nephrolithotomy (PCNL). Methods: Patients scheduled for PCNL were randomized into three groups and received ultrasound-guided ESPB at T10 level for postoperative analgesia. Each subject received 28 mL of 100 mg ropivacaine solution mixed with 2 mL of normal saline (Group R), 2 mL of 10 mg nalbuphine (Group RNL), or 2 mL of 20 mg nalbuphine (Group RNH). Primary outcome was the time to first opioid demand. Secondary outcomes were morphine consumption, VAS scores within 24 h postoperatively, rescue analgesic requirements, and length of hospital stay. Results: The median [interquartile range, IQR] time to first opioid demand was significantly longer in group RNH (8.70 [6.90,14.85] h) than that of group R and group RNL (2.90 [2.00,6.30] h and 5.80 [2.95,7.00] h, respectively). VAS scores (either resting or active) within 24 h postoperatively were comparable between the three groups, with the most significant differences especially at 4, 6, 8 h. Morphine consumption at 24 h postoperatively was significant for R group vs RNH group (median difference, 9; 95% confidence interval [CI], 1.57 to 16.43; p = 0.02). Conclusions: Adding 20mg nalbuphine to ropivacaine in ESPB could significantly improve the effect of analgesia and prolong the duration of nerve blocks for PCNL.

Sonolytic degradation kinetics and mechanisms of antibiotics in water and cow milk.

Antibiotics (ABX) residues frequently occurred in water and cow milk. This work aims to understand the kinetics and mechanisms of sonolytic degradation of four ABX, i.e. ceftiofur hydrochloride (CEF), sulfamonomethoxine sodium (SMM), marbofloxacin (MAR), and oxytetracycline (OTC) in water and milk. In both water and milk, the sonolytic degradation of ABX follows pseudo-first order (PFO) kinetics well (R2: 0.951-0.999), with significantly faster ABX degradation in water (PFO kinetics constants (k1): 1.5 × 10-3-1.2 × 10-1 min-1) than in milk (k1: 3.5 × 10-4-5.6 × 10-2 min-1). The k1 values for SMM degradation in water increased by 118% with ultrasonic frequency (40-120 kHz), 174% with ultrasonic frequency (80-500 kHz), 649% with ultrasonic power (73-259 W), 22% with bulk temperature (12-40℃), and by 68% with reaction volume (50-250 mL), respectively, in other things being equal. The relevant k1 values in milk increased by 326%, 231%, 122%, 10% as well as 82% with the above same effective factors, respectively. The oxidation by free radicals generated in situ dominates ABX degradation, and the hydrophobic CEF (54.0-971.7 nM min-1) and SMM (39.2-798.4 nM min-1) underwent faster degradation than the hydrophilic MAR (33.9-751.9 nM min-1) and OTC (33.8-545.3 nM min-1) in both water and milk. Adding an extra 0.5 mM H2O2 accelerated SMM degradation by 19% in water and 33% in milk. After 130-150 min sonication of 100 mL of 2.0 mg L-1 (6.62 µM) SMM in various milk with 500 kHz and 259 W, the residue concentrations (52.9-96.3 µg L-1) can meet the relevant maximum residue limit (100 µg L-1).

Nanoemulsification of soybean oil using ultrasonic microreactor: Process optimization, scale-up and numbering-up in series.

Ultrasonically-induced nanoemulsions have been widely investigated for the development of functional food, cosmetics, and pharmaceuticals due to ideal droplet sizes (DS), low polydispersity index (PDI), and superior physical stability. However, a series of frequently-used ultrasonic set-ups mainly suffered from a low ultrasonic energy efficiency caused by the large acoustic impedance and energy consumption, subordinately confronted with a low throughput, complicated fabrication with complex structure and weak ultrasonic cavitation. Herein, we employed a typical ultrasonic microreactor (USMR) that ensured the high-efficient energy input and generated intense cavitation behavior for efficient breakage of droplets and continuous production of unified oil-in-water (O/W) nanoemulsions in a single cycle and without any pre-emulsification treatment. The emulsification was optimized by tuning the formula indexes, technological parameters, and numerical analysis using Response Surface Methodology (RSM), followed by a comparison with the emulsification by a traditional ultrasonic probe. The USMR exhibited superior emulsification efficiency and easy scale-up with remarkable uniformity by series mode. In addition, concurrent and uniform nanoemulsions with high throughput could also be achieved by a larger USMR with high ultrasonic power. Based on RSM analysis, uniform DS and PDI of 96.4 nm and 0.195 were observed under the optimal conditions, respectively, well consistent with the predicted values. Impressively, the optimal nanoemulsions have a uniform spherical morphology and exhibited superior stability, which held well in 45 days at 4℃ and 25℃. The results in the present work may provide a typical paradigm for the preparation of functional nanomaterials based on the novel and efficient emulsification tools.

Mechanisms and implications in gene polymorphism mediated diverse reponses to sedatives, analgesics and muscle relaxants.

Responses to sedatives, analgesics and muscle relaxants vary among patients under general anesthesia, which could be ascribed to the disparities of clinical characteristics and genetic factors of individuals. Accumulating researches have indicated that gene polymorphisms of the receptors, transporters and metabolizing enzymes associated with anesthetics play a considerable role in their efficacy. However, a systematically summarized study on the mechanisms of gene polymorphisms on pharmacodynamics and pharmacokinetics of anesthetics is still lacking. In this paper, the recent researches on pharmacogenomics of sedatives, analgesics and muscle relaxants are comprehensively reviewed, and the contributions and mechanisms of polymorphisms to the differences of individual efficacy of these drugs are discussed, so as to provide guidance for the formulation of a rational anesthesia regimen for patients with various genotypes.

Electrocatalytic three-component synthesis of 4-halopyrazoles with sodium halide as the halogen source.

The first example of the electrocatalytic multicomponent synthesis of 4-chloro/bromo/iodopyrazoles from hydrazines, acetylacetones and sodium halides under chemical oxidant- and external electrolyte-free conditions has been developed. Sodium halides played a dual role as a halogenation reagent and a supporting electrolyte. Mechanism studies revealed that the bromination reaction proceeded via an ionic pathway, whereas both chlorination and iodination proceeded via a radical pathway.

Medium-high frequency sonication dominates spherical-SiO2 nanoparticle size.

Spherical SiO2 nanoparticles (SSNs) have been inventively synthesized using the Stöber method with sonication at medium-high frequencies (80, 120, and 500 kHz), aiming to control SSN size and shorten reaction time. Compared to the conventional method, such sonication allowed the Stöber reaction complete in 20-60 min with a low molar ratio of NH4OH/tetraethyl orthosilicate (0.84). The hydrodynamic diameters of 63-117 nm of SSNs were obtained under sonication with 80, 120, and 500 kHz of ultrasonic frequencies. Moreover, the SSNs obtained were smaller at 120 kHz than at 80 kHz in a multi-frequencies ultrasonic reactor, and the SSN size decreased with increasing ultrasonic power at 20 °C, designating the sonochemical unique character, namely, the SSN-size control is associated with the number of microbubbles originated by sonication. With another 500 kHz ultrasonic bath, the optimal system temperature for producing smaller SSNs was proven to be 20 °C. Also, the SSN size decreased with increasing ultrasonic power. The smallest SSNs (63 nm, hydrodynamic diameter by QELS, or 21 nm by FESEM) were obtained by sonication at 207 W for 20 min at 20 °C. Furthermore, the SSN size increased slightly with increasing sonication time and volume, favoring the scale-up of SSNs preparation. The mechanisms of controlling the SSN size were further discussed by the radical's role and effects of ammonia and ethanol concentration.

Alfentanil and propofol induced anesthesia for patients with huge endotracheal tumor undergoing fiberoptic bronchoscopic interventional therapy: case report.

Background: There is a high risk of hypoxia or apnea for patients with huge tracheal tumor during general anesthesia. Here we reported two cases of extremely huge endotracheal tumors undergoing fiberoptic bronchoscopic interventional therapy under general anesthesia. We hope the experience will be of reference value for formulating reasonable anesthesia scheme for such critically ill patients. Case Description: The two patients were accompanied with severe respiratory distress. And fiberoptic bronchoscopy revealed that the trachea cavity was blocked nearly completely by extremely huge tracheal tumor. Tracheal tumors were scheduled to be removed with fiberoptic bronchoscopic interventional therapy. General anesthesia was inducted with alfentanil and propofol. Then a laryngeal mask was inserted and spontaneous breath was preserved. During the operation, complete airway obstruction occurred, but it was effectively handled by using the fiberoptic bronchoscope to push the tumor and reopen the gap between the mass and the tracheal wall. After the therapy, the patients' symptom of respiratory distress was relieved significantly. Conclusions: For patients with huge tracheal tumor that to be handled with fiberoptic bronchoscopic interventional therapy, general anesthesia with spontaneous breath induced by alfentanil and propofol is preferable. The most important, when complete airway blockade occurs during the process, pushing the tumor and reopening the respiratory tract with fiberoptic bronchoscope is a fairly effective solution to enable patients to be reoxygenated.

Amelioration of myocardial ischemia/reperfusion injury in diabetes: A narrative review of the mechanisms and clinical applications of dexmedetomidine.

Mechanisms contributing to the pathogenesis of myocardial ischemia-reperfusion (I/R) injury are complex and multifactorial. Many strategies have been developed to ameliorate myocardial I/R injuries based on these mechanisms. However, the cardioprotective effects of these strategies appear to diminish in diabetic states. Diabetes weakens myocardial responses to therapies by disrupting intracellular signaling pathways which may be responsible for enhancing cellular resistance to damage. Intriguingly, it was found that Dexmedetomidine (DEX), a potent and selective α2-adrenergic agonist, appears to have the property to reverse diabetes-related inhibition of most intervention-mediated myocardial protection and exert a protective effect. Several mechanisms were revealed to be involved in DEX's protection in diabetic rodent myocardial I/R models, including PI3K/Akt and associated GSK-3ß pathway stimulation, endoplasmic reticulum stress (ERS) alleviation, and apoptosis inhibition. In addition, DEX could attenuate diabetic myocardial I/R injury by up-regulating autophagy, reducing ROS production, and inhibiting the inflammatory response through HMGB1 pathways. The regulation of autonomic nervous function also appeared to be involved in the protective mechanisms of DEX. In the present review, the evidence and underlying mechanisms of DEX in ameliorating myocardial I/R injury in diabetes are summarized, and the potential of DEX for the treatment/prevention of myocardial I/R injury in diabetic patients is discussed.

Five-Year Outcomes After Endovascular Treatment for Large Vessel Occlusion Stroke.

Background: The long-term outcomes of acute large vessel occlusion (LVO) in anterior circulation treated by endovascular treatment (EVT) remains to be determined. The aim of this study was to assess the 5-year outcomes of patients with LVO who underwent EVT. Methods: This study was an observational, nationwide registry of consecutive patients with acute LVO who received EVT in 28 comprehensive stroke centers in China. The primary outcome was the proportion of favorable outcome [modified Rankin Scale score (mRS) 0-2] at 5 years. Secondary outcomes included proportions of patients with excellent outcome (mRS 0-1), all-cause mortality and risk of stroke recurrence at 5 years. Results: A total of 807 patients were included into the study and had 90-day follow-up data, 657 patients had 5-year follow-up data. At 90 days, 218 patients (27.0%) had an excellent outcome, 349 patients (43.2%) had a favorable functional outcome. 199 patients (24.7%) died. At 5 years, 190 patients (28.9%) had an excellent outcome, 261 patients (39.7%) had a favorable functional outcome, 317 patients (48.2%) died and 129 (28.2%) had stroke recurrence. Because of missing 5-year follow-up data, among available 269 patients who achieved functional independence at 90 days, 208 (77.3%) maintained favorable outcome, 19 (7.1%) had disability (mRS 3-5) and 42 (15.6%) died at 5 years. Furthermore, among available 189 patients with mRS 3-5 at 90 days, 53 (28.0%) patients achieved favorable functional outcome, 60 (31.7%) patients maintained unfavorable functional outcome and 76 (40.2%) patients died within 5 years. Multivariate analyses identified that younger age [odds ratio (OR): 0.96; 95% CI, 0.93-0.99; P = 0.009], lower mRS at 90 days (OR: 0.15; 95% CI, 0.10-0.23; P < 0.001) and absence of stroke recurrence (OR: 0.001; 95% CI, 0.000-0.006; P < 0.001) were significantly associated with favorable outcome at 5 years. Advanced age (OR: 1.06, 95% CI, 1.04-1.08; P < 0.001), higher mRS at 90 days (OR: 0.84; 95% CI, 0.73-0.98; P = 0.021) and atrial fibrillation (OR: 1.63; 95% CI, 1.02-2.60; P = 0.04) were independent factors for stroke recurrence. Conclusion: Our results indicated that the beneficial effect of EVT in patients with acute LVO can be sustained during the course of at least 5 years. Reducing the risk of stroke recurrence by anticoagulation for atrial fibrillation may be a crucial strategy to improve long-term outcome.

Removal of antibiotics from milk via ozonation in a vortex reactor.

Antibiotics (ABX) residues occur frequently in milk, causing considerable wastage of medicated milk and serious economic losses, and making the issue a burden for the dairy industry. Improper disposal of medicated milk harms dairy production, animal welfare, and the environment. This work studies the use of ozonation in a vortex reactor for removing ceftiofur hydrochloride (CEF), sulfamonomethoxine sodium (SMM), marbofloxacin (MAR) and oxytetracycline (OTC) from milk. In terms of residual concentration, O3 efficiency and the degradation kinetics of the various O3-involving processes in the vortex reactor, ABX removal via ozonation is better using stronger vortexing, which induces hydrodynamic cavitation. CEF undergoes the fastest degradation, followed by SMM, MAR, and OTC. High ABX hydrophobicity favors ABX degradation via ozonation, O3/H2O2, and O3/Na2S2O8. ABX oxidation by •OH at the O3 gas-bubble/milk interface is the principle degradation pathway, except for MAR. ABX degradation follows pseudo-first-order kinetics and is affected by initial ABX concentration, O3 concentration/flow rate, reaction temperature, and milk components to varying degrees. Under optimal ozonation conditions, ABX residues meet the maximum limits as set by the European Commission and no antimicrobial activity was observed. The decontaminated milk was therefore suggested to be reused as calf food, animal feed, organic fertilizer, etc.

Synergistic Effect of Melatonin and Selenium Improves Resistance to Postharvest Gray Mold Disease of Tomato Fruit.

Melatonin (MT) is a ubiquitous hormone molecule that is commonly distributed in nature. MT not only plays an important role in animals and humans but also has extensive functions in plants. Selenium (Se) is an essential micronutrient for animals and humans, and is a beneficial element in higher plants at low concentrations. Postharvest diseases caused by fungal pathogens lead to huge economic losses worldwide. In this study, tomato fruits were treated with an optimal sodium selenite (20 mg/L) and melatonin (10 µmol/L) 2 h and were stored for 7 days at room temperature simulating shelf life, and the synergistic effects of Se and MT collectively called Se-Mel on gray mold decay in tomato fruits by Botrytis cinerea was investigated. MT did not have antifungal activity against B. cinerea in vitro, while Se significantly inhibited gray mold development caused by B. cinerea in tomatoes. However, the interaction of MT and Se showed significant inhibition of the spread and growth of the disease, showing the highest control effect of 74.05%. The combination of MT with Se treatment enhanced the disease resistance of fruits by improving the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), as well as increasing the gene expression level of pathogenesis-related (PR) proteins. Altogether, our results indicate that the combination of MT and Se would induce the activation of antioxidant enzymes and increase the expression of PR proteins genes that might directly enhance the resistance in tomato fruit against postharvest pathogenic fungus B. cinerea.

Mechanism Analysis of Rock Failure Process under High-Voltage Electropulse: Analytical Solution and Simulation.

This work aims to investigate and analyse the mechanism of rock failure under high-voltage electropulses in order to evaluate and increase the efficiency of high-voltage pulse technology in geological well drilling, tunnel boring, and other geotechnical engineering applications. To this end, this paper discusses the equivalent circuit of electric pulse rock breaking, the model of shock wave in electro channel plasma, and, particularly, the model of rock failure in order to disclose the rock failure process when exposed to high-voltage electropulse. This article uses granite as an example to present an analytical approach for predicting the mechanical behaviour of high-voltage electropulses and to analyse the damage that occurs. A numerical model based on equivalent circuit, shock wave model, and elasto-brittle failure criterion is developed for granite under electropulse to further examine the granite failure process. Under the conditions described in this study, and using granite as an example, the granite is impacted by a discharge device (Marx generator) with an initial voltage U0 that is 10 kV and a capacitance F that is 5 µF before it begins to degrade at about 40 µs after discharge, with the current reaching its peak at approximately 50 µs. The shock wave pressure then attains a peak at about 70 µs. Dense short cracks form around granite and the dominant cracks grow to an average length of about 20 cm at around 200 µs. The crack width dcr is predicted to be approximately 1.6 mm. This study detects dense cracks in a few centimetres surrounding the borehole, while around seven dominant cracks expand outward. The distribution of the length of the dominating cracks can be inhomogeneous because of the spatial heterogeneity of granite's tensile strength, however the heterogeneity has an insignificant effect on the crack growth rate, total cracked area, or the number of main cracks. The mechanism of rock failure under electropulse can be well supported by the findings of numerical simulations and analytical studies.

A Semi-Analytical Solution for Shock Wave Pressure and Radius of Soil Plastic Zone Induced by Lightning Strikes.

A semi-analytical solution for forecasting the soil behavior induced by lightning strikes is of great engineering significance to calculate the radius of the soil plastic zone. In this paper, a simplified two-stage method is employed to solve the shock wave pressure and the radius of the soil plastic zone. The solution is verified against experimental data. Using the present model, the major factors dominating the shock wave pressure and the radius of the soil plastic zone are investigated. The results show that (1) the radius of the soil plastic zone (rp) induced by lightning decreases monotonically with cohesion (c) and internal friction angle (φ), while c has a better effect on soil properties than φ does; (2) increasing the initial radius of the plasma channel (ri0) can reduce the pressure (P) and increasing ri0 has a nonnegligible effect on rp; with ri0 increasing by 100%, the radius of the soil plastic zone increases by 47.9-59.7%; (3) the plasma channel length (L) has a significant influence on P and rp, especially when L is at a relatively low level; (4) the rp induced by lightning decreases exponentially with attenuation coefficient (a); (5) the wavefront time is a major factor while the half-value time is a minor factor for the shock wave pressure induced by plasma explosives.

Determination of trace antibiotics in water and milk via preconcentration and cleanup using activated carbons.

CPAC-SPE-HPLC (coconut powdered activated carbon -SPE- HPLC) has been developed for the determination of antibiotic (ABX), sulfamonomethoxine sodium (SMM), oxytetracycline (OTC), ceftiofur hydrochloride (CEF) and marbofloxacin (MAR), in water and milk. Over 99.0% SMM and OTC were recovered from 20 mL of 0.5 µg/mL ABX solution using 10 mg-CPAC for adsorption and 2 mL of 30% NH4OH/EtOH (1/19 v/v) for elution. Similarly, over 99.0% CEF and MAR were recovered using 15 mg-CPAC and 2 mL of 30% NH4OH/n-PrOH (1/19 v/v). Moreover, the recovery efficiencies of various ABX from 5 to 80 mL of 0.02-2.00 µg/mL medicated milk containing 10 mM EDTA are ordered as follows: OTC (99.3%), SMM (99.1%) > CEF (68.9%) > MAR (61.4%). No interference towards HPLC analysis were observed with elution using 2 mL of 30% NH4OH/EtOH (1/19 v/v). Furthermore, much lower limit of detections (0.02 µg/mL) than the maximum residual limits from European Commission (0.075-0.100 µg/mL) were obtained.

Evaluation of the Efficacy of Dexmedetomidine as a Local Anesthetic Adjuvant in Children: A Meta-Analysis of Randomized Controlled Trials.

Dexmedetomidine has been identified as a useful adjunct to improve the effect of nerve blocks in adults; however, its effect for children has not yet been fully investigated. This meta-analysis aimed to evaluate the reliability and efficacy of dexmedetomidine as a local anesthetic adjunct for pediatric surgeries. Eligible studies were searched in Cochrane, Embase, PubMed, and CBM. RevMan 5.4 was used to assess the risk of bias of each study and perform statistical analysis. Stata 15.0 was used to evaluate the publication bias of primary outcomes. Thirteen randomized controlled trial (RCTs) involving 722 patients aged 6 months to 12 years were harvested. Statistical analysis showed that dexmedetomidine resulted in: a significantly longer duration of analgesia (standardized mean difference [SMD], 7.16; 95% confidence interval [95%CI], 4.88 to 9.43; P < .001; I2  = 98%); a reduction in the 1-hour pain score (mean difference [MD], -0.27; 95%CI, -0.47 to -0.06; P = .01; I2  = 28%); cumulative doses of rescue analgesic required of 2 doses (risk ratio [RR], 0.26; 95%CI, 0.14 to 0.49; P < .001; I2  = 0) or 3 doses (RR, 0.04; 95%CI, 0.01 to 0.16; P < .001; I2  = 4%); the frequency of emergence agitation (RR, 0.44; 95%CI, 0.22 to 0.91; P = .03; I2  = 0); and a reduction in the onset time of blocks (mean difference -3.56; 95%CI, -6.39 to -0.74; P = .01; I2  = 90%). However, the incidence of some side effects, including hypotension, bradycardia, nausea and vomiting, pruritis, urinary retention, and respiratory depression, did not significantly differ between the dexmedetomidine group and the placebo group. Therefore, dexmedetomidine is a reliable and efficient adjunct to local anesthetics in children.