ABSTRACT
As an emerging material in the field of environmental remediation, biochar produced by carbonisation of organic solid waste has been widely used in the remediation of antibiotic wastewater due to its environmental friendliness and excellent adsorption properties. This study analyses the current literature in the field in a comprehensive and scientific manner using CiteSpace and VOSviewer technologies. Between 2011 and 2023, a total of 1162 papers were published in this domain, spanning three distinct stages: applied methods, mechanism investigation, and enhanced improvement. The results of keyword clustering indicate that the remediation of antibiotics complexed with multiple pollutants by biochar is the main research topic, followed by the remediation of antibiotics by biochar in combination with other technologies. Furthermore, drawing from current research hotspots in antibiotic remediation using biochar, this study identified the pivotal mechanisms involved: (1) The primary mechanisms by which raw biochar remediates antibiotics include π-π electron donor-acceptor interactions, hydrophobic interactions, electrostatic interactions, hydrogen-bonding, and pore filling. (2) Steam activation, acid/base, metal salt/metal oxide, and clay mineral modification can improve the physical/chemical properties of biochar, enhancing its adsorptive removal of antibiotics. (3) Biochar activated persulfate and degraded antibiotics via free radical pathways (SO4-â¢, â¢OH and O2-â¢) as well as non-free radical pathways (1O2 and electron transfer). In addition, the challenge and prospect of biochar engineering applications for antibiotic remediation lies in improving the main mechanism of antibiotic remediation by biochar. The prospective utilization of biochar in enhancing the remediation of antibiotic-related pollutants holds tremendous value for the future.
Subject(s)
Anti-Bacterial Agents , Charcoal , Charcoal/chemistry , Anti-Bacterial Agents/chemistry , Adsorption , Environmental Restoration and Remediation/methods , Water Pollutants, Chemical/chemistry , Wastewater/chemistryABSTRACT
Raphani Semen, with both edible and medicinal values, is a typical Chinese herbal medicine with different effects before and after processing. The raw helps ascending and the cooked helps descending. This paper comprehensively summarizes the differences in chemical constituents and pharmacological effects between raw and processed Raphani Semen that are reported in recent years. Based on the principle of quality markers(Q-markers) of traditional Chinese medicines, the chemical constituent sources, chemical constituent detection techniques, and correlation between bidirectional regulatory efficacy and chemical constituents are compared between raw and processed Raphani Semen. The results suggest that sulforaphene and glucoraphanin could be used as candidate Q-markers of raw and processed Raphani Semen, respectively. This review is expected to provide a reference for further research on the processing, new drug development, and improvement of safety and effectiveness of Raphani Semen in clinical application.
Subject(s)
Drugs, Chinese Herbal , Drugs, Chinese Herbal/chemistry , Drugs, Chinese Herbal/analysis , Quality Control , Humans , Biomarkers/analysisABSTRACT
Atherosclerosis is a primary global health concern due to its high morbidity and mortality. This disease is characterized by a complex interplay of chronic inflammation, oxidative stress, and proteolytic enzymes. Traditional imaging techniques struggle to capture the dynamic biochemical processes within atherosclerotic plaques. Herein, we have developed a novel unimolecular photoacoustic probe (UMAPP) that combines specific recognition sites for neutrophil elastase (NE) and the redox pair O2â¢â/GSH into a cohesive molecular platform, allowing in vivo monitoring of oxidative stress and activated neutrophils within plaques. UMAPP features a boron-dipyrromethene (BODIPY) core linked to a hydrophilic NE-cleavable tetrapeptide, and dual oxidative stress-responsive catechol moieties, enabling NE-mediated modulation of photoinduced electron transfer, affecting the photoacoustic intensity at 685 nm (PA685), while oxidation and reduction of the catechol groups by O2â¢â and GSH lead to reversible, ratiometric changes in the photoacoustic spectrum. Preliminary applications of UMAPP have successfully differentiated between atherosclerotic and healthy mice, assessed the impact of pneumonia on plaque composition, and validated the probe's efficacy in drug-treatment studies, detecting molecular changes prior to observable histopathological alterations. UMAPP's integrated molecular imaging approach holds significant promise for advancing the diagnosis and management of atherosclerosis by enabling earlier and more precise detection of vulnerable plaques.
ABSTRACT
In photocatalysis, reducing the exciton binding energy and boosting the conversion of excitons into free charge carriers are vital to enhance photocatalytic activity. This work presents a facile strategy of engineering Pt single atoms on a 2D hydrazone-based covalent organic framework (TCOF) to promote H2 production coupled with selective oxidation of benzylamine. The optimised TCOF-Pt SA photocatalyst with 3 wt% Pt single atom exhibited superior performance to TCOF and TCOF-supported Pt nanoparticle catalysts. The production rates of H2 and N-benzylidenebenzylamine over TCOF-Pt SA3 are 12.6 and 10.9 times higher than those over TCOF, respectively. Empirical characterisation and theoretical simulation showed that the atomically dispersed Pt is stabilised on the TCOF support through the coordinated N1 -Pt-C2 sites, thereby induing the local polarization and improving the dielectric constant to reach the low exciton binding energy. These phenomena led to the promotion of exciton dissociation into electrons and holes and the acceleration of the separation and transport of photoexcited charge carriers from bulk to the surface. This work provides new insights into the regulation of exciton effect for the design of advanced polymer photocatalysts.
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BACKGROUND: The number of non-intubated general anesthesia outside the operating room is growing as the increasing demand for comfort treatment. Non-intubated general anesthesia outside the operating room requires rapid onset of anesthesia, smoothness, quick recovery, and few postoperative complications. Traditional anesthetic regimens (propofol alone or propofol and opioids/dezocine/midazolam, etc.) have severe respiratory and circulatory depression and many systemic adverse effects. In this paper, we compare the effectiveness and safety of propofol and subclinical doses of esketamine with other traditional regimens applied to non-intubated general anesthesia through a systematic review and meta-analysis. METHODS: We searched PubMed, Embase, Cochrane Library, Web of Science, CNKI, Wanfang, VIP, and Sinomed databases for the period from January 2000 to October 2022. We rigorously screened the literature according to predefined inclusion and exclusion criteria, while risk assessment of the studies was performed using The Cochrane Collaboration's tool, and statistical analysis of the data was performed using RevMan 5.4 software. The main outcome indicators we evaluated were the various hemodynamic parameters and incidence of various adverse effects between the experimental and control groups after induction of anesthesia. RESULTS: After a rigorous screening process, a total of 14 papers were included in the final meta-analysis. After risk bias assessment, three of the papers were judged as low risk and the others were judged as having moderate to high risk. Forest plots were drawn for a total of 16 indicators. Meta-analysis showed statistically significant differences in HR' WMD 3.27 (0.66, 5.87), MAP' WMD 9.68 (6.13, 13.24), SBP' WMD 5.42 (2.11, 8.73), DBP' WMD 4.02 (1.15, 6.88), propofol dose' SMD -1.39 (-2.45, -0.33), hypotension' RR 0.30 (0.20, 0.45), bradycardia' RR 0.33 (0.14, 0.77), hypoxemia or apnea' RR 0.45 (0.23, 0.89), injection pain' RR 0.28 (0.13, 0.60), intraoperative choking' RR 0.62 (0.50, 0.77), intraoperative body movements' RR 0.48 (0.29, 0.81) and overall incidence of adverse reactions' RR 0.52 (0.39, 0.70).The indicators that were not statistically different were time to wake up' WMD - 0.55 (-1.29, 0.19), nausea and vomiting 0.84' RR (0.43, 1.67), headache and dizziness' RR 1.57 (0.98, 2.50) and neuropsychiatric reaction' RR 1.05 (0.28, 3.93). The funnel plot showed that the vast majority of studies fell within the funnel interval, but the symmetry was relatively poor. CONCLUSION: In non-intubated general anesthesia, the combination of subclinical doses of esketamine and propofol did reduce circulatory and respiratory depression, injection pain, and other adverse effects, while the incidence of esketamine's own side effects such as neuropsychiatric reactions did not increase, and the combination of the two did not cause the occurrence of new and more serious adverse reactions, and the combination of the two was safe and effective. TRIAL REGISTRATION: PROSPREO registration number: CRD 42022368966.
Subject(s)
Drug-Related Side Effects and Adverse Reactions , Ketamine , Propofol , Humans , Propofol/adverse effects , Anesthesia, General/adverse effects , PainABSTRACT
The hazards caused by Pb pollution have received worldwide attention. Phosphogypsum (PG) and titanium gypsum (TG) have the disadvantage of limited adsorption capacity and poor dispersion when used as heavy metal adsorbents on their own. The excellent pore and electron transfer capacity of biochar makes it possible to combine with PG and TG to solidify/stabilize Pb2+. In this study, the mechanism of Pb2+ adsorption/immobilization by rice husk biochar (BC) combined with PG/TG was investigated in terms of both mineral formation and electron transfer rate. The removal rate of Pb2+ by BC composite PG (BC/PG-Pb) or TG (BC/TG-Pb) was as high as 97%-98%, an increase of 120.9% and 122.5% over BC. Adsorption kinetics and mineral precipitation results indicate that the main removal of Pb2+ from BC/PG-Pb and BC/TG-Pb is achieved by PG/TG induced Pb-sulfate and Pb-phosphate formation. The addition of PG/TG significantly enhances the formation of stable Pb-minerals on the biochar surface, with the proportion of non-bioaccessible forms exceeding 50%. The four-step extraction results confirm that P and F in PG/TG are key in facilitating the conversion of Pb minerals to pyromorphite. The rich pore structure of biochar not only disperses the easily agglomerated PG/TG onto the biochar surface, but also attracts Pb2+ for uniformly dispersed precipitation. Furthermore, the excellent electrical conductivity and smooth electron transfer channels of biochar facilitate the reaction rate of Pb2+ mineralization. Overall, the use of biochar in combination with PG/TG is a promising technology for the combination of solid waste resourceisation and Pb remediation.
Subject(s)
Calcium Sulfate , Titanium , Lead , Electrons , Charcoal/chemistry , Minerals , Adsorption , KineticsABSTRACT
Plumula nelumbinis, a widely used traditional Chinese medicine known for its calming and nerve-soothing properties, contains essential oil as a primary component. However, research on P. nelumbinis essential oil (PNEO) is limited. This study aimed to investigate PNEO components, network target analysis, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses, and antioxidant activity of P. nelumbinis from ten different habitats. GC-MS analysis identified 14 compounds in the essential oil, with CP12 (ß-Sitosterol) having the highest concentration. Five compounds were identified for the first time in P. nelumbinis, with three of them reported for the first time in the Nelumbo. Network target analysis revealed 185 potential targets for 11 compounds and GO and KEGG enrichment analyses showed that PNEO was mainly located in the plasma membrane and could regulate a variety of molecular functions. KEGG pathway enrichment analysis revealed that the essential oil was primarily enriched in pathways related to cancer and the nervous system. PNEO demonstrated strong antioxidant activity, with N8 (Fujiannanping) showing the highest ABTS scavenging capacity and N7 (Hunanxiangtan) showing the highest DPPH radical scavenging capacity. Cell experiments showed that CP4, CP5 and CP10 had protective effects against H2O2-induced oxidative damage. The study suggests that P. nelumbinis from different regions may have slightly different pharmacological effects due to the presence of unique compounds, and further research is necessary to explore the potential therapeutic benefits of PNEO.
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BACKGROUND: Retinopathy of prematurity (ROP) continues to be a major cause of visual impairment and blindness in premature infants and children. OBJECTIVES: To investigate the incidence of severe ROP receiving treatment in extremely preterm (EP) infants in China over time. The risk factors for ROP treatment were also assessed. METHODS: This was a multicentre retrospective study and a subanalysis of baseline data from the "Outcomes of EP infants in China 2010-2019" study. This study was conducted in 68 tertiary neonatal care centres from 31 provinces of China. Infants with a gestational age of 230 -276 weeks and admitted to a neonatal unit within the first 72 h of life between 2010 and 2019 were enrolled. Incidence of ROP was analysed in infants who survived to 32 weeks postmenstrual age and screened for ROP. Multivariable modified Poisson regression models were used to identify risk factors for ROP treatment. RESULTS: Among 7295 eligible infants, 4701 (64.5%) survived to 32 weeks postmenstrual age and met ROP screening criteria. Of the 3756 infants who screened and with ROP data, 2320 (61.8%) developed ROP of any stage. The overall incidence of ROP treatment was 12.6%, decreasing from 45.5% at 23 weeks to 8.3% at 27 weeks. During the 10-year period, the incidence of ROP treatment did not change, although the incidence of any ROP increased over time. Independent risk factors associated with ROP treatment included lower gestational age, small for gestational age, multiple birth, severe intraventricular haemorrhage, patent ductus arteriosus and supplemental oxygen duration. CONCLUSIONS: The incidence of EP infants receiving ROP treatment showed no change during this 10-year period in China. Prevention of prematurity and foetal growth restriction, judicious use of oxygen and reducing comorbidities are promising factors that may reduce the incidence of ROP needing treatment in these high-risk infants.
Subject(s)
Retinopathy of Prematurity , Birth Weight , Child , Gestational Age , Humans , Incidence , Infant , Infant, Extremely Premature , Infant, Newborn , Oxygen , Retinopathy of Prematurity/epidemiology , Retinopathy of Prematurity/therapy , Retrospective Studies , Risk FactorsABSTRACT
BACKGROUND: Coal dust particles (CDP), an inevitable by-product of coal mining for the environment, mainly causes coal workers' pneumoconiosis (CWP). Long-term exposure to coal dust leads to a complex alternation of biological processes during regeneration and repair in the healing lung. However, the cellular and complete molecular changes associated with pulmonary homeostasis caused by respiratory coal dust particles remain unclear. METHODS: This study mainly investigated the pulmonary toxicity of respirable-sized CDP in mice using unbiased single-cell RNA sequencing. CDP (< 5 µm) collected from the coal mine was analyzed by Scanning Electron Microscope (SEM) and Mass Spectrometer. In addition, western blotting, Elisa, QPCR was used to detect gene expression at mRNA or protein levels. Pathological analysis including HE staining, Masson staining, immunohistochemistry, and immunofluorescence staining were performed to characterize the structure and functional alternation in the pneumoconiosis mouse and verify the reliability of single-cell sequencing results. RESULTS: SEM image and Mass Spectrometer analysis showed that coal dust particles generated during coal mine production have been crushed and screened with a diameter of less than 5 µm and contained less than 10% silica. Alveolar structure and pulmonary microenvironment were destroyed, inflammatory and death (apoptosis, autophagy, and necrosis) pathways were activated, leading to pneumoconiosis in post 9 months coal dust stimulation. A distinct abnormally increased alveolar type 2 epithelial cell (AT2) were classified with a highly active state but reduced the antimicrobial-related protein expression of LYZ and Chia1 after CDP exposure. Beclin1, LC3B, LAMP2, TGF-ß, and MLPH were up-regulated induced by CDP, promoting autophagy and pulmonary fibrosis. A new subset of macrophages with M2-type polarization double expressed MLPH + /CD206 + was found in mice having pneumoconiosis but markedly decreased after the Vitamin D treatment. Activated MLPH + /CD206 + M2 macrophages secreted TGF-ß1 and are sensitive to Vitamin D treatment. CONCLUSIONS: This is the first study to reconstruct the pathologic progression and transcriptome pattern of coal pneumoconiosis in mice. Coal dust had obvious toxic effects on lung epithelial cells and macrophages and eventually induced pulmonary fibrosis. CDP-induced M2-type macrophages could be inhibited by VD, which may be related to the alleviation of the pulmonary fibrosis process.
Subject(s)
Coal Mining , Pneumoconiosis , Pulmonary Fibrosis , Adaptor Proteins, Signal Transducing , Animals , Coal/toxicity , Dust , Mice , Reproducibility of Results , Vitamin DABSTRACT
OBJECTIVES: To investigate the efficacy of intravitreal anti-vascular endothelial growth factor (anti-VEGF) injection in the treatment of retinopathy of prematurity (ROP) and the risk factors for recurrence. METHODS: A retrospective analysis was performed on the medical data of 159 infants with ROP who were born in the First Affiliated Hospital of Zhengzhou University and underwent anti-VEGF treatment from January 2016 to December 2021. According to the presence or absence of recurrence within the follow-up period after initial anti-VEGF treatment, they were divided into a recurrence group with 24 infants and a non-recurrence group with 135 infants. The medical data were compared between the two groups, and a multivariate logistic regression analysis was used to investigate the risk factors for the recurrence of ROP after anti-VEGF treatment. RESULTS: After one-time anti-VEGF treatment, all 159 infants showed regression of plus disease. Recurrence was observed in 24 infants (15.1%) after anti-VEGF treatment, with a mean interval of (8.4±2.6) weeks from treatment to recurrence. The multivariate logistic regression analysis showed that preoperative fundus hemorrhage and prolonged total oxygen supply time were risk factors for the recurrence of ROP (P<0.05), while gestational hypertension was a protective factor (P<0.05). CONCLUSIONS: Intravitreal anti-VEGF injection is effective for ROP. Preoperative fundus hemorrhage and long duration of oxygen therapy may increase the risk of ROP recurrence, and further studies are needed to investigate the influence of gestational hypertension on the recurrence of ROP.
Subject(s)
Hypertension, Pregnancy-Induced , Retinopathy of Prematurity , Female , Humans , Infant , Infant, Newborn , Pregnancy , Angiogenesis Inhibitors/adverse effects , Angiogenesis Inhibitors/therapeutic use , Endothelial Growth Factors/therapeutic use , Hemorrhage , Oxygen/therapeutic use , Retinopathy of Prematurity/drug therapy , Retrospective Studies , Risk Factors , Vascular Endothelial Growth Factor AABSTRACT
2D perovskites with chemical formula A'2 An-1 Bn X3n+1 have recently attracted considerable attention due to their tunable optical and electronic properties, which can be attained by varying the chemical composition. While high color-purity emitting perovskite nanomaterials have been accomplished through changing the halide composition, the preparation of single-phase, specific n-layer 2D perovskite nanomaterials is still pending because of the fast nucleation process of nanoparticles. We demonstrate a facile, rational and efficacious approach to synthesizing single-phase 2D perovskite nanoplates with a designated n number for both lead- and tin-based perovskites through kinetic control. Casting carboxylic acid additives in the reaction medium promotes selective formation of the kinetic product-multilayer 2D perovskite-in preference to the single-layer thermodynamic product. For the n-specific layered 2D perovskites, decreasing the number of octahedral layers per inorganic sheet leads to an increase of photoluminescence energy, radiative decay rate, and a significant boost in photostability.
ABSTRACT
The red yeast (Rhodotorula mucilaginosa: Rho) has abundant extracellular polymeric substances (EPS) and intracellular vesicles (Ves). This study explored the mechanisms of Rho to resist Cu toxicity from extracellular to intracellular, i.e., EPS, membrane, and Ves. The Cu2+ concentrations were set from 0 to 200 mg/L. In contrast to other heavy metals (e.g., Pb2+), low Cu2+ stress has no evident stimulation to EPS production. In particular, GSH content in EPS did not show significant changes. The Cu removal was decreased from ~ 35 to ~ 0% as Cu stress raised from 0 to 200 mg/L, which confirmed the low binding of Cu cations to EPS. Moreover, redox peaks at - 0.35 V (reduction) and - 0.02 V (oxidation) in EPS were observed based on electrochemical analysis. Subsequently, the potential Haber-Weiss reaction in EPS lowered fungal ability to shield against the Cu toxicity. Then, the contrast of Cu concentration between the extracellular and intracellular regions was enlarged. Moreover, the thickness of cell membrane decreased from 450 to 116 nm during the elevation of Cu stress. These accelerated the transport of Cu cations into intracellular, but the redox reaction in both cell membrane and intracellular region was limited. Under transmission electron microscopy, the intracellular Ves showed evident sorption of Cu cations (100 mg/L). However, the Ves started to deform and gradually lost their activity at 200 mg/L. Therefore, this study successfully elucidated the correlated extracellular and intracellular mechanisms of metal detoxification by yeast. KEY POINTS: â¢This study provides a comprehensive explanation for the invasion of Cu2+ into fungal (Rhodotorula mucilaginosa) cells based on microbial physiological and biochemical analysis, electrochemical analysis, and transmitted electron microscopy. â¢Cu nanoparticles are involved in redox reactions in the EPS, thus greatly reducing the prophase protection for fungal cells by EPS. â¢At 200 mg/L Cu2+ stress, deformation of cell membrane intensifies the contrast of Cu concentrations between extra- and intracellular regions. This further suppresses the transportation of Cu2+ by intracellular vesicles. Graphical abstract.
Subject(s)
Biological Products , Metals, Heavy , Rhodotorula , Extracellular Polymeric Substance MatrixABSTRACT
Tin perovskite nanomaterial is one of the promising candidates to replace organic lead halide perovskites in lighting applications. Unfortunately, the performance of tin-based systems is markedly inferior to those featuring toxic Pb salts. In an effort to improve the emission quantum efficiency of nanoscale 2D layered tin iodide perovskites through fine-tuning the electronic property of organic ammonium salts, we came to unveil the relationship between dielectric confinement and the photoluminescent properties of tin iodide perovskite nanodisks. Our results show that increasing the dielectric contrast for organic versus inorganic layers leads to a bathochromic shift in emission peak wavelength, a decrease of exciton recombination time, and importantly a significant boost in the emission efficiency. Under optimized conditions, a leap in emission quantum yield to a record high 21% was accomplished for the nanoscale thienylethylammonium tin iodide perovskite (TEA2SnI4). The as-prepared TEA2SnI4 also possessed superior photostability, showing no sign of degradation under continuous irradiation (10 mW/cm2) over a period of 120 h.
ABSTRACT
BACKGROUND: Coronary artery aneurysm (CAA) is a rare disease, and there are limited data on prescribing patterns for CAA. The aim of our study was to investigate prescribing patterns for CAA in Taiwan via the National Health Insurance Research Database (NHIRD). METHODS: We included all CAA patients in Taiwan from 2005 to 2011. Data from 1 year before and after the CAA diagnosis were used to analyze examinations, comorbidities and prescribing patterns. RESULTS: A total of 1397 patients diagnosed with CAA were enrolled in our study. Most pediatric patients with CAA were diagnosed with Kawasaki disease (95.7%). In pediatric CAA patients, the utilization rates of aspirin and gamma globulins were 82.9 and 53.6%, respectively, after CAA diagnosis. Among the antithrombotic agents, aspirin was used most commonly, followed by dipyridamole (16.9%), heparin (5.8%) and warfarin (4.6%). In adult CAA patients, common comorbidities included hypertension (63.4%), hyperlipidemia (39.6%), and diabetes mellitus (26.1%). Coronary atherosclerosis was identified in 72.5% of adult patients after CAA diagnosis. Antithrombotic agents, particularly aspirin, clopidogrel and heparin, were prescribed more frequently after CAA diagnosis. Among the prescribed medications, aspirin (75.8%), ß-blockers (48.3%), statins (47.6%), metformin (14.4%), sulfonylureas (14.4%) and isosorbide mononitrate (32.9%) were frequently observed in each category. CONCLUSIONS: Kawasaki disease was the main cause of CAA in pediatric patients, and coronary artery disease was the most common comorbidity in adult CAA patients. The most commonly used antithrombic agent after CAA diagnosis was aspirin in both adult and pediatric patients.
Subject(s)
Cardiovascular Agents/therapeutic use , Coronary Aneurysm/drug therapy , Coronary Artery Disease/drug therapy , Mucocutaneous Lymph Node Syndrome/drug therapy , Practice Patterns, Physicians'/trends , Adolescent , Adult , Age Factors , Aged , Child , Child, Preschool , Comorbidity , Coronary Aneurysm/diagnostic imaging , Coronary Aneurysm/epidemiology , Coronary Artery Disease/diagnosis , Coronary Artery Disease/epidemiology , Databases, Factual , Drug Prescriptions , Drug Utilization/trends , Female , Humans , Male , Middle Aged , Mucocutaneous Lymph Node Syndrome/diagnosis , Mucocutaneous Lymph Node Syndrome/epidemiology , Retrospective Studies , Risk Factors , Taiwan/epidemiology , Time Factors , Young AdultABSTRACT
Chiral aldehyde catalysis opens new avenues for the activation of simple amines. However, the lack of easy access to structurally diverse chiral aldehyde catalysts has hampered the development of this cutting-edge field. Herein, we report a Pd-catalyzed atroposelective C-H naphthylation with 7-oxabenzonorbornadienes for the preparation of axially chiral biaryls with excellent enantioselectivities (up to >99 %â ee). This reaction is scalable and robust, which serves as a key step to provide a rapid access to axially chiral aldehyde catalysts through a three-step C-H functionalization sequence. These chiral aldehydes exhibit better activities and enantioselectivities than the previously reported organocatalysts in the asymmetric activation of glycine derived amides and dipeptides. Moreover, preliminary investigation also discloses that the aldehyde catalyst can effectively override the intrinsic facial selectivity of chiral dipeptide substrates, showcasing the strong chiral induction ability of this type of novel aldehyde catalysts.
ABSTRACT
Biaryl atropisomers are of great importance in natural products, pharmaceuticals, and asymmteric synthesis. The efficient synthesis of these chiral scaffolds with full enantiocontrol and high diversity remains challenging. Reported herein is a Pd-catalyzed atroposelective C-H allylation with tert-leucine as an efficient catalytic chiral transient auxiliary. A wide range of enantioenriched biaryl aldehydes were prepared in synthetically useful yields with excellent enantioselectivity (up to >99 % ee) through ß-O elimination. The reaction could be carried out on a gram scale without erosion of the ee value. A variety of axially chiral carboxylic acids could be obtained with high enantiopurity. The resulting axially chiral biaryl aldehydes and carboxylic acids might be used in asymmetric synthesis as chiral ligands and/or organocatalysts.
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A palladium(II)-catalyzed direct alkenylation reaction of dihydropyranones was developed. Various substituted dihydropyranones could afford the desired products in reasonable yields. And different acrylates were found to be good coupling partners in this coupling reaction. A Pd(0)/Pd(II) catalytic pathway was proposed to be involved in this coupling reaction.
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Environmental and human health problems caused by Pb pollution have attracted much attention, and solidification and stabilization are effective means for its remediation. Improving the ability of biochar to remediate heavy metals through modification is the focus of current biochar research. This study used calcium-alginate gel (GB) and Fe3+ (magnetic) to encapsulate and improve sludge biochar (SB), and explored the adsorption behavior and passivation mechanism of Pb2+ on it from outside to inside. The magnetic-biochar (MB) in magnetic-biochar-gel microspheres (MBGB) showed a homogeneous dispersion and part of the Fe ion was detached from the MB into the three-dimensional pores of the gel. The results of kinetic, isothermal and pH adsorption experiments showed that the MBGB has 108.4 % and 200 % higher Pb2+ adsorption capacity and rate than SB and can be applied to pH 3-9. The adsorption of Pb2+ by MBGB is a multilayer adsorption with both physical and chemical mechanisms. Mineralogical and electrochemical results demonstrate that the cross-linking of the gel with magnetic-biochar (MB) can provide a directional diffusion channel for Pb2+ from the outside to the inside. The electron transfer rate of MBGB was significantly higher than that of SB (222.2 %) after the reaction. The dissolved cations and electrons on the MB guide Pb2+ from the MBGB surface to the internal MB quickly via accelerating the electron transfer and migration rate between Pb2+ and MB. Subsequently, the abundance of PO43- on the MB ensures stable mineral precipitation (Pyromorphite). Moreover, four-step extraction analysis confirmed that most of Pb2+ in MBGB was stable (36.2 % acid-soluble and 47.6 % non-bioavailable). Meanwhile, the Pb adsorption efficiency of MBGB was still >93.0 % after three cycles of adsorption-desorption. Excellent reuse performance and stability guarantee the environmental security of MBGB. The results of the study provide theoretical support for the efficient treatment of Pb2+ polluted water assisted by gel materials.
Subject(s)
Alginates , Charcoal , Lead , Sewage , Water Pollutants, Chemical , Charcoal/chemistry , Alginates/chemistry , Lead/chemistry , Adsorption , Sewage/chemistry , Water Pollutants, Chemical/chemistry , Hydrogen-Ion Concentration , Kinetics , Electrons , Water Purification/methodsABSTRACT
A difficult airway is a situation in which an anesthesiologist with more than 5 years of experience encounters difficulty with intubation or mask ventilation. According to the 2022 American Society of Anesthesiologists Practice Guidelines for the Management of Difficult Airway, difficult airways are subdivided into seven detailed categories. This condition can lead to serious adverse events and therefore must be diagnosed accurately and quickly. In this review, we comprehensively summarize and discuss the different methods used in clinical practice and research to assess difficult airways, including medical history, simple bedside assessment, comprehensive assessment of indicators, preoperative endoscopic airway examination, imaging, computer-assisted airway reconstruction, and 3D-printing techniques. We also discuss in detail the latest trends in difficult airway assessment through mathematical methods and artificial intelligence. With the continuous development of artificial intelligence and other technologies, in the near future, we will be able to predict whether a patient has a difficult airway simply by taking an image of the patient's face through a cell phone program. Artificial intelligence and other technologies will bring great changes to the development of airway assessment, and at the same time raise some new questions that we should think about.