C2 C3 Research Articles

An Atypical Manifestation of Lateral Medullary Syndrome (P12-5.011)

<h3>Objective:</h3> To describe a case of lateral medullary syndrome (LMS) presenting with ipsilateral hemiparesis and upper motor neuron (UMN)-type facial palsy. <h3>Background:</h3> LMS is a classical vascular syndrome involving the posterior inferior cerebellar artery, which presents typically with ipsilateral Horner syndrome, ipsilateral ataxia, and contralateral hemianesthesia. Motor weakness and facial palsy are not traditionally presented in LMS. <h3>Design/Methods:</h3> Case report. <h3>Results:</h3> A 62-year-old male with poorly controlled hypertension presented with sudden onset left hemiparesis. On presentation, initial blood pressure was 178/95 mmHg. The neurological exam showed dysarthria, left facial palsy sparing the forehead, left facial hypoesthesia, and left hemiparesis (NIHSS 8). Diffusion-weighted MR Brain showed acute infarct in the left lateral medulla. FLAIR sequence showed chronic infarct in the right thalamus. CT arteriogram revealed non-opacification of the left vertebral artery at the level of C2–C3 with opacification of the distal left V4 via retrograde flow, severe stenosis of the right M1 segment, and multifocal atherosclerosis of the bilateral internal carotid arteries. Initial labs showed elevated LDL (213 mg/dl) and normal hemoglobin A1c. Right hemianesthesia was reported during his hospitalization; dysphagia, frequent hiccups, and left dysmetria out of proportion to weakness were noted during the recovery. After acute interventions, he was started on dual antiplatelet treatments for 90 days and a single antiplatelet afterward given concerns of large vessel disease as stroke etiology. <h3>Conclusions:</h3> Atypical clinical presentation in this LMS case included the combination of ipsilateral hemiparesis and ipsilateral UMN-type facial palsy. LMS with ipsilateral hemiparesis is known as Opalski’s syndrome, which is explained by involving the post-decussating pyramidal tract at the lower medulla and upper cervical spine. The explanation of ipsilateral UMN-type facial palsy in our case remains unclear. One possible explanation is the aberrant caudal looping of facial corticobulbar fibers into medulla oblongata prior to synapsing with the pontine facial nucleus. <b>Disclosure:</b> Dr. Yu has nothing to disclose. Mr. Bluntson has nothing to disclose. Dr. Sharma has nothing to disclose.

Electrosynthesis of methyl 2-ureidobenzoates via a C2–C3 bond cleavage of isatins

A facile and efficient ring opening of isatin has been achieved by electrochemical anodic oxidation directly at room temperature. The results show that a constant current electrolysis of isatins in an undivided cell affords both the ester group and the urea group simultaneously. This reaction opens a new avenue for the synthesis of methyl 2-ureidobenzoates, enriches the research on the reactions of isatins involving the cleavage of the C2–C3 bond and shows a good range of substrates for both isatin and simple organic amine in an acidic buffer solutions of HOAc and Cu(OAc)2. In addition, this electrochemical C2–C3 bond cleavage reaction could be scaled up.

Dissolved organic matter composition and fluorescence characteristics of the river affected by coal mine drainage

Coal mine drainage (CMD) discharged into surface waters results in serious environmental pollution risk to rivers, lakes, and reservoirs. Coal mine drainage generally contains a variety of organic matter and heavy metals due to coal mining activities. Dissolved organic matter (DOM) plays an important role in the physicochemical and biological processes of many aquatic ecosystems. In this study, the investigations were carried out in the dry and wet seasons in 2021 to assess the characteristics of DOM compounds in coal mine drainage and the CMD-affected river. The results indicated that the pH of CMD-affected river pressed close to coal mine drainage. Besides, coal mine drainage lowered DO by 36% and increased total dissolved solids by 19% in the CMD-affected river. Coal mine drainage decreased absorption coefficient a(350) and absorption spectral slope S275-295 of DOM in the CMD-affected river; hence, DOM molecular size increased with decreasing S275-295. Three-dimensional fluorescence excitation-emission matrix spectroscopy and parallel factor analysis identified humic-like C1, tryptophan-like C2, and tyrosine-like C3 in the CMD-affected river and coal mine drainage. DOM in the CMD-affected river mainly originated from microbial and terrestrial sources, with strong endogenous characteristics. The ultra-high-resolution Fourier transform ion cyclotron resonance mass spectrometry analysis revealed that coal mine drainage had a higher relative abundance of CHO (44.79%), with a higher unsaturation degree of DOM. Coal mine drainage decreased the AImod,wa, DBEwa (double bond equivalents), Owa, Nwa, and Swa values and increased the relative abundance of the O3S1 species with DBE of 3 and carbons number range of 15-17 at the CMD inlet to the river channel. Moreover, coal mine drainage with the higher protein content increased the protein content of water at the CMD inlet to the river channel and the downstream river. DOM compositions and proprieties in coal mine drainage were investigated to further understand the influence of organic matter on heavy metals in future study.

Analysis of the clinical characteristics and predisposing factors for neurological deficit with Hangman fractures

BackgroundHangman fracture is the second most common injury of the upper cervical spine, and neurological deficit with Hangman fracture is not rare. To our knowledge, few reports have statistically analyzed the predisposing factors for this injury. The objective of this study was to describe the clinical characteristics of neurological deficit associated with Hangman fracture and evaluate its risk factors.MethodsIn this retrospective study, 97 patients with Hangman fractures were included. Data on the age, sex, injury etiology, neurological deficits, and associated injuries were obtained and evaluated. The pretreatment parameters, anterior translation and angulation of C2/3, presence of the posterior vertebral wall (PVW) fractures of C2, and presence of spinal cord signal changes were measured. Twenty-three patients with neurological deficits after Hangman fractures comprised group A, and 74 patients without neurological deficit comprised group B. Student’s t-test or a nonparametric test and the chi-square test were used to evaluate the differences between groups. Binary logistic regression analysis was used to identify the risk factors for neurological deficit.ResultsAmong the 23 patients in group A, 2 were American Spinal Injury Association (ASIA) scale B, 6 were C, and 15 were D, and spinal cord magnetic resonance imaging signal change was observed at the level of C2–C3 disc, C2, or both. Patients with the combination of PVW fractures and ≥ 50% significant translation or angulation of C2/3 were significantly more likely to have a neurological deficit. Both factors remained significant in binary logistic regression analysis.ConclusionsNeurological deficit after Hangman fractures always presents clinically as a partial neurological impairment. The combination of PVW fractures with ≥ 1.8 mm of translation or ≥ 5.5° of angulation of C2/3 was the predisposing factor for neurological deficit with Hangman fractures.

Potential of derivation of a series of C6–C14 1-alkene skeletal oxidation mechanisms on the basis of reaction rate rules

Olefins, accounting for one-fifth proportion of gasoline fuel, are also essential intermediates in the combustion of large hydrocarbons and vital precursors of large polycyclic aromatic hydrocarbons and soot. The unsaturated C = C bond of alkenes renders a more complex low-temperature reaction scheme compared with their corresponding n-alkanes. Thus, it is of great necessity to obtain a thorough knowledge of the chemical kinetics of alkenes. However, the studies on the chemical kinetics of long-chain olefins are far from sufficient. In this work, a collection of skeletal oxidation mechanisms for 1-alkenes from 1-hexene (C6H12-1) to 1-tetradecene (C14H28-1) were constructed in light of recent advances in skeletal mechanism construction for fuels sharing similar structures based on reaction rate rules. For each 1-alkene, the skeletal mechanism includes ∼54 species and ∼216 reactions. Meanwhile, the effect of the C = C double bond was evaluated by conducting a bond dissociation energy calculation to assist the skeletal mechanism construction and derivation. It is discovered that the allylic position is preferred for H-atom abstraction reactions owing to its lowest bond dissociation energy among different locations for all heavy 1-alkenes. Furthermore, the reactions of OH addition to the C = C bond become important at low temperatures, which competes with the H-atom abstraction reactions. This results in the lower reactivity of 1-alkenes compared with corresponding n-alkanes at low temperatures. The acquired skeletal mechanisms were validated against extensive experimental data including laminar flame speeds, ignition delay times in shock tubes, and key species concentrations in jet-stirred reactors, flow reactors, and premixed laminar flames. The good agreements between experiments and simulations demonstrate the prediction capability of all the skeletal mechanisms of 1-alkenes although minor discrepancies exist in the concentration predictions for C2–C3 species, which might stem from a highly reduced C2–C3 sub-mechanism being utilized in the present mechanism.

Identification of the furanose ring conformations and the factors driving their adoption

Three groups of furanoses with restricted freedom of rotation on the C3–C4, C2–C3, and C1–C2 bonds, respectively, are presented. Conformational analysis of these furanoses is conducted based on the proton nuclear magnetic resonance (1H NMR) spectroscopy, density functional theory (DFT) calculations, and X-ray analysis. It is shown that the particular group of the presented furanoses is locked in the specific conformation. These are the 1T2-like, the 0E-like, and the 3T4-like conformation, respectively. Characteristic 1H NMR spectra of these three conformations are presented and the factors influencing the conformational preferences of the analyzed furanoses are discussed.

In silico study of CYP450 inhibitor activity of (E)-1-(3-((4-chlorophenyl) diazenyl)-4-hydroxyphenyl)ethanone

Molecular docking and single crystal study of azo dye (E)-1-(3-((4-chlorophenyl)diazenyl)-4-hydroxyphenyl)ethanone (3) is reported here. It has been synthesized by diazotization of 4-chloroaniline followed by coupling with 4-hydroxyacetophenone. Molecule is almost planar with acetyl as well as azo groups only slightly deviating from the plane of C3–C8 phenyl ring as evident by C1–C2–C3–C8 and N2–N1–C7–C6 torsion angles of –3.6(3)° and –3.9(3)°, respectively. Torsion angle N1–N2–C9–C14 between azo group and chlorophenyl ring is somewhat larger being –13.1(3)° leading to torsion angle between phenyl C3–C8 and chlorophenyl C9–C14 ring of 17.26(11)°. Intramolecular O2–H2···N2 hydrogen-bonding is observed here. Pillars along b-axis are formed due to π∙∙∙π stacking interactions of parallel molecules in head-to-head fashion with centroid-to-centroid distance of 3.8829(14) Å and ring slippage of 1.416 Å. Title compound shows good binding affinity towards six enzymes of CYP450 family. Both nitrogens of the azo bond show significant involvement in bonding interactions with proteins in case of all the six enzymes.

Clinical effect of different doses of ciprofol for induction of general anesthesia in elderly patients: A randomized, controlled trial.

Ciprofol is a newly developed intravenous anesthetic agent with improved pharmacokinetic properties. Compared to propofol, ciprofol exhibits stronger binding to the GABAA receptor and elicits a greater enhancement of GABAA receptor-mediated neuronal currents in vitro. The aims of the present clinical trials were to examine the safety and efficacy of different doses of ciprofol for induction of general anesthesia in elderly patients. A total of 105 elderly patients undergoing elective surgery were randomized, in a 1:1:1 ratio, to receive one of three sedation regimens: (1) the C1 group (0.2mg/kg ciprofol), (2) the C2 group (0.3mg/kg ciprofol), (3) the C3 group (0.4mg/kg ciprofol). The primary outcome was the incidence of various adverse events, including hypotension, hypertension, bradycardia, tachycardia, hypoxemia, and injection pain. The secondary outcomes of efficacy were the success rate of general anesthesia induction, the time to anesthesia induction, and the frequency of remedial sedation was recorded in each group. Adverse events occurred in 13 patients (37%) in group C1, 8 patients (22%) in group C2, and 24 patients (68%) in group C3. Compared with group C2, the total incidence of adverse events was significantly higher in group C1 and group C3 (p < .001).The success rate of general anesthesia induction in the three groups was 100%. Compared with group C1, the frequency of remedial sedation was significantly lower in group C2 and group C3. The outcomes demonstrated that ciprofol at a dose of 0.3mg/kg has good safety and efficacy in the induction of general anesthesia in elderly patients. Overall, ciprofol is a new and viable option for the induction of general anesthesia in elderly patients undergoing elective surgery.

Effects of anti-cyclooxygenases (COX-1 and COX-2), structure activity relationship, molecular docking and in silico ADMET of some synthesized chalcones

Purpose: To develop effective cancer chemopreventive and anti-inflammatory agents, a series of chalcones were prepared by reacting suitable aromatic aldehyde with appropriate acetophenones.&#x0D; Methods: Twenty-four synthesized chalcones (namely, 1 - 24) were assessed for their in vitro anti-cyclooxygenase-1 (COX-1) and anti-cyclooxygenase-2 (COX-2) activity in a COX catalyzed prostaglandin synthesis bioassay. Molecular docking was done to investigate the ligand-protein interactions, and selectivity on both enzymes. ADMET (absorption, distribution, metabolism, excretion, toxicity) modeling and software were also used.&#x0D; Results: The compounds inhibited both COX-1 and COX-2. Two compounds (3 and 19) demonstrated more marked COX-2 inhibition than compound 1. Indomethacin as a standard anti-cyclooxygenase shows unselective inhibition of 81.44 ± 6.5 and 91 ± 9.5, respectively. The in silico data revealed that a chalcone skeleton with C=O at 4-position, C2–C3 double bond and OH at 5-position are necessary properties for anti-cyclooxygenase effects. It was also revealed that the propenone moiety comprises of an appropriate scaffold which proposes a new acyclic 1,3-diphenylprop-2-en-1-ones with selective anti-COX effects. A molecular modeling investigations where these chalcones 1, 3 and 19 were docked in the active site of COX-2 depicted that the p-CH3 substituent on the C-4- phenyl ring A are oriented in the vicinity of the COX-2 secondary pocket Phe381, Gly526, Tyr385 and Val349.&#x0D; Conclusion: Based on the screening for oral bioavailability, in silico ADMET, and toxicity risk assessment, this study shows that these compounds could be a cornerstone for the development of new pharmaceuticals in the battle against COX-associated inflammatory disorders.

Enhanced hydrogen production via staged catalytic gasification of rice husk using Ca(OH)2 adsorbent and Ce–Ni/γAl2O3 catalyst in a fluidized bed

Hydrogen production from rice husk was carried out via a two-stage system combining CLG (calcium looping gasification) using Ca(OH)2 adsorbent in a bubbling fluidized bed and catalytic reforming with Ce–Ni/γAl2O3 catalyst in a connected fixed bed. The results show that the maximum H2 concentration (69.16 vol%) and H2 yield (11.86 mmol g−1rice husk) are achieved at Ca/C (Ca(OH)2 to carbon molar ratio) = 1.5, H2O/C (H2O to carbon molar ratio) = 1.5, Tg (gasification temperature) = 500 °C, Tc (catalytic temperature) = 800 °C. The supplementation of fresh Ca(OH)2 at Ca/C of 0.5 during calcination helps to activate the regenerated CaO by hydration, maintaining its carbonation activity and CO2 adsorption. Ce–Ni/γAl2O3 catalyst promotes water gas shift (WGS), steam methane reforming (SMR), and C2–C3 hydrocarbons reforming, also exhibits excellent activity stability to maintain H2 concentration and H2 yield above 67.21 vol% and 11.67 mmol g−1rice husk, respectively, during 5 lifetime tests.

Trace Analysis Method Based on UPLC-MS/MS for the Determination of (C2-C18) Per-and Polyfluoroalkyl Substances and Its Application to Tap Water and Bottled Water.

As the usage of long-chain perfluoroalkyl and polyfluoroalkyl substances (PFASs) may be gradually restricted, short-chain and even ultra-short-chain PFASs have been widely produced and used, which has put forward new requirements for the simultaneous analysis of the above substances. Using solid phase extraction two-fraction elution and ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS), an experimental method was established for the simultaneous analysis of ultrashort-chain, short-chain, and long-chain PFASs and the precursor perfluorohexanesulfonamide (FHxSA) in low-concentration water, such as tap water and bottled water. By optimizing the volume of methanol in the first-fraction elution, the concentration of ammonia in the second-fraction elution, and the concentration of ammonium acetate in the mobile phase, the high recovery and low detection limit (0.01-3 ng/L) were obtained. In addition, this method was used to measure nine tap water samples and six bottled water samples for validation, and the results showed that the concentration of PFASs in bottled water was lower than that in tap water. This study first reported the trifluoroacetic acid concentration in bottled water (6.61 ± 9.60 ng/L), which was lower than that in tap water (1712 ± 174 ng/L). The main substances in tap water and bottled water are both ultrashort-chain PFASs (C2-C3), accounting for more than 50%. There are few reports on the simultaneous analysis of ultrashort-chain, short-chain, and long-chain PFASs (C2-C18) and the precursor FHxSA in low-concentration water samples, and the new method can be further developed for different environmental media.

SENSORY CHARACTERISATION OF EMULSIFIED SAUSAGES INCORPORATING CELERY POWDER AND OBTAINED WITH DIFFERENT TECHNOLOGICAL PARAMETERS

This study aimed to evaluate and sensorily describe membrane-emulsified poultry and pork meat products (frankfurter sausages) manufactured in the USV Iași Meat Processing Workshop, products to which celery powder was added. Six technology sheets were developed to obtain six batches of products (three chicken and three pork): C1 (66% chicken breast, 17% pork backfat, 1.8% celery powder) and P1 (66% pork, 17% pork backfat, 1.8% celery powder), C2 (56% chicken breast, 24% pork backfat, 3.5% celery powder) and P2 (56% pork, 24% pork backfat, 3.5% celery powder) and C3 (48% chicken breast, 31% pork backfat, 4.5% celery powder) and P3 (48% pork, 31% pork backfat, 4.5% celery powder). The samples were evaluated in terms of instrumental colour and sensory evaluation (acceptability test and CATA – check-all-that-apply). The results showed significant differences (p &lt; 0.05) between the samples regarding the instrumental colour, chicken meat frankfurter sausages having significantly higher lightness values (L*) compared to pork frankfurter sausages, and in terms of the proportion of raw materials: the lightness increased significantly in direct proportion to the percentage of fat added. According to the CATA analysis, the evaluators associated a pink colour and meaty flavour with batch 1 products and attributes such as uniformity of colour, characteristic flavour, the right amount of seasoning and smooth texture were identified in all six batches of products. However, the batches with the highest scores on the hedonic scale, considered acceptable by the evaluators, were C1, P1 and C2.

Reaction characteristics of maximizing light olefins and decreasing methane in C5 hydrocarbons catalytic pyrolysis

When converting C5 hydrocarbons to light olefins by catalytic pyrolysis, the generation of low value-added methane will affect the atomic utilization efficiency of C5 hydrocarbons. To improve the atomic utilization efficiency, different generation pathways of light olefins and methane in the catalytic pyrolysis of C5 hydrocarbons were analyzed, and the effects of reaction conditions and zeolite types were investigated. Results showed that light olefins were mainly formed by breaking the C2–C3 bond in the middle position, while methane was formed by breaking the C1–C2 bond at the end. Meanwhile, it was discovered that the hydrogen transfer reaction could be reduced by about 90% by selecting MTT zeolite with 1D topology and FER zeolite with 2D topology under high weight hourly space velocity (WHSV) and high temperature operations, thus leading to the improvement of the light olefins selectivity for the catalytic pyrolysis of n-pentane and 1-pentene to 55.12% and 74.60%, respectively. Moreover, the fraction ratio of terminal C1–C2 bond cleavage was reduced, which would reduce the selectivity of methane to 6.63% and 1.83%. Therefore, zeolite with low hydrogen transfer activity and catalytic pyrolysis process with high WHSV will be conducive to maximize light olefins and to decrease methane.

FUNCTIONAL OUTCOMES OF DISTAL RADIUS FRACTURES MANAGED WITH 2.7MM VARIABLE ANGLE VOLAR LOCKING COMPRESSION PLATES

Objective: About 15 to 17 % of all fractures presenting to emergency department constitutes the distal radius fracture. Intra-articular fracture of distal radius remains one of the most challenging fractures to be reduced over decades for orthopedic surgeons. Objective is to demonstrate the functional outcomes of 2.7mm variable angle volar locking compression plate using Mayo’s wrist score in distal radius fracture.&#x0D; Methodology: A Quasi experimental study was conducted in the Department of Orthopedics &amp; Trauma, CMH Rawalpindi from 20th October 2020 to 19th April 2021. A total of 120 patients with distal radius fracture AO Classification A1 C2 C3, 19 to 69 years of age of both genders were included. Outcome of 2.7mm Variable angle Volar Locking Compression Plates using Mayo’s wrist score was calculated. Data was entered in SPSS version 25. Descriptive analysis was done for age. Gender and mayo wrist scoring criteria were presented as frequencies and percentages. To analyze association of the outcome with age and gender chi-square test was applied.&#x0D; Results: Mean age in the study was 40.34 ± 8.01 years. Majority of the patients 71 (59.17%) were between 19 to 40 years of age. Out of 120 patients, 82 (68.33%) were males and 38 (31.67%). 51 (42.50%) patients had excellent functional outcome, 47 (29.17%) had good outcome, 13 (10.83%) had fair outcome and 09 (7.50%) had poor outcome.&#x0D; Conclusion: The functional outcomes of 2.7mm volar locking compression plate using Mayo’s wrist score in distal radius fracture is very good.

Cervical spine movements during laryngoscopy and orotracheal intubation: a systematic review and meta-analysis

BackgroundAirway management is challenging in trauma patients because of the fear of worsening cervical spinal cord damage. Video-integrated and optic-integrated devices and intubation laryngeal mask airways have been proposed as...

From a Metal-Organic Square to a Robust and Regenerable Supramolecular Self-assembly for Methane Purification.

Porous supramolecular assemblies constructed by noncovalent interactions are promising for adsorptive purification of methane because of their easy regeneration. However, the poor stability arising from the weak noncovalent interactions has obstructed their practical applications. Here, we report a robust and easily regenerated polyhedron-based cationic framework assembled from a metal-organic square. This material exhibits a very low affinity for CH4 and N2 , but captures other competing gases (e.g. C2 H6 , C3 H8 , and CO2 ) with a moderate affinity. These results underpin highly selective separation of a range of gas mixtures that are relevant to natural gas and industrial off-gas. Dynamic breakthrough studies demonstrate its practical separation for C2 H6 /CH4 , C3 H8 /CH4 , CO2 /N2 , and CO2 /CH4 . Particularly, the separation time is ≈11 min g-1 for the C2 H6 /CH4 (15/85 v/v) mixture and ≈49 min g-1 for the C3 H8 /CH4 (15/85 v/v) mixture (under a flow of 2.0 mL min-1 ), respectively, enabling its capability for CH4 purification from light alkanes.

Flavonoids as Antidiabetic and Anti-Inflammatory Agents: A Review on Structural Activity Relationship-Based Studies and Meta-Analysis.

Flavonoids are a group of naturally occurring polyphenolic secondary metabolites which have been reported to demonstrate a wide range of pharmacological properties, most importantly, antidiabetic and anti-inflammatory effects. The relationship between hyperglycaemia and inflammation and vascular complications in diabetes is now well established. Flavonoids possessing antidiabetic properties may alleviate inflammation by reducing hyperglycaemia through different mechanisms of action. It has been suggested that the flavonoids’ biochemical properties are structure-dependent; however, they are yet to be thoroughly grasped. Hence, the main aim of this review is to understand the antidiabetic and anti-inflammatory properties of various structurally diverse flavonoids and to identify key positions responsible for the effects, their correlation, and the effect of different substitutions on both antidiabetic and anti-inflammatory properties. The general requirement of flavonoids for exerting both anti-inflammatory and antidiabetic effects is found to be the presence of a C2–C3 double bond (C-ring) and hydroxyl groups at the C3’, C4’, C5, and C7 positions of both rings A and B of a flavonoid skeleton. Furthermore, it has been demonstrated that substitution at the C3 position of a C-ring decreases the anti-inflammatory action of flavonoids while enhancing their antidiabetic activity. Correlation is discussed at length to support flavonoids possessing essential pharmacophores to demonstrate equipotent effects. The consideration of these structural features may play an important role in synthesizing better flavonoid-based drugs possessing dual antidiabetic and anti-inflammatory effects. A meta-analysis further established the role of flavonoids as antidiabetic and anti-inflammatory agents.

Automated Detection of Cervical Carotid Artery Calcifications in Cone Beam Computed Tomographic Images Using Deep Convolutional Neural Networks.

The aim of this study was to determine if a convolutional neural network (CNN) can be trained to automatically detect and localize cervical carotid artery calcifications (CACs) in CBCT. A total of 56 CBCT studies (15,257 axial slices) were utilized to train, validate, and test the deep learning model. The study comprised of two steps: Step 1: Localizing axial slices that are below the C2–C3 disc space. For this step the openly available Inception V3 architecture was trained on the ImageNet dataset of real-world images, and retrained on 40 CBCT studies. Step 2: Detecting CACs in slices from step 1. For this step, two methods were implemented; Method A: Segmentation neural network trained using small patches at random coordinates of the original axial slices; Method B: Segmentation neural network trained using two larger patches at fixed coordinates of the original axial slices with an improved loss function to account for class imbalance. Our approach resulted in 94.2% sensitivity and 96.5% specificity. The mean intersection over union metric for Method A was 76.26% and Method B improved this metric to 82.51%. The proposed CNN model shows the feasibility of deep learning in the detection and localization of CAC in CBCT images.

Design and control of fraction cutting for the separation of mixed alcohols from the Fischer–Tropsch aqueous by-products

Since the minimum-boiling azeotropes of C2–C8 alcohols with water and high-water content (up to 95% (mass)) in the Fischer–Tropsch aqueous by-products, the separation is energy-intensive and challenging. The energy-saving strategy for the complete separation of the Fischer–Tropsch aqueous by-products has received massive attention in recent decades. In this study, a stripper-sidestream decanter process is proposed by exploiting homogeneous azeotropes (C2–C3 alcohols–water) and heterogeneous azeotropes (C4–C8 alcohols–water). The introduction of the stripping column for pre-dehydration avoids the re-vaporization of the mixture, and energy carried by the overhead vapor is conserved instead of being removed in a condenser. The precise fraction cutting of C1–C3 alcohol–water mixture, C4–C8 alcohols, and water is realized by the sidestream distillation column. The C4–C8 alcohols rich mixture withdrawn from the sidestream flows into the decanter to break the distillation boundary, where the organic phase returns to the sidestream distillation column to obtain the dehydrated C4–C8 alcohols, and the aqueous phase enters the stripping column. Steady-state optimization based on total annual cost (TAC) minimization shows that the stripper-sidestream decanter process reduces TAC by 17.00% and saves energy by 21.27% compared with the conventional three-column distillation process. Further, a control structure of the process is established, and dynamic simulations show that the control structure combining a differential controller with a low-selector exhibits robust control. This study provides a novel design scheme and deepens the insights into the efficient separation of aqueous by-products of the Fischer–Tropsch synthesis.

Toward abiotic sugar synthesis from CO2 electrolysis

Toward abiotic sugar synthesis from CO2 electrolysis