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To improve the stability of pollock bone broth, compound emulsifiers were employed and evaluated in nano-emulsions from pollock bones (PBNs). The microstructure, creaming index, particle size, zeta potential, and viscosity of PBNs were characterized and the stability of PBNs was investigated. It revealed that the concentration of compound emulsifiers is one of the principal factors for particle size, zeta potential, and viscosity of PBNs, and 0.9% of sodium caseinate and sucrose fatty acid ester (CS-SE) can make the PBN display good stability. Its particle size changed from 81.17 ± 1.33 nm to 19.62 ± 0.21 nm when the temperature ranged from 40 °C to 80 °C, and its creaming index could reach a maximum (90.83%) among all PBNs in 4 months of freeze-thaw assays. PBN stability could be improved by the compound emulsifier (CS-SE), which offers a theoretical basis for the application of pollock bone broth.
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OBJECTIVE: To analyze the isolation rate, prevalence trends, species distribution, and drug sensitivity of non-tuberculous mycobacteria (NTM) in Anhui Province, providing a reference for diagnosis and treatment strategies. METHODS: Specimens from suspected mycobacterial infection patients at Anhui Chest Hospital (including outpatients and inpatients) from January 2021 to December 2023 were cultured. Identified NTM strains were analyzed for species distribution and drug sensitivity. RESULTS: Of 10,519 mycobacteria strains cultured, 1,589 were NTM (15.11%). The top four species were Mycobacterium intracellulare (75.36%), Mycobacterium abscessus (11.78%), Mycobacterium kansasii (7.09%), and Mycobacterium avium (2.85%). NTM strains showed high sensitivity to amikacin and clarithromycin (≥90%) and significant sensitivity to rifabutin, moxifloxacin, and rifampicin (89.03%-79.61%). They exhibited high resistance to imipenem/cilastatin, sulfamethoxazole, minocycline, and doxycycline (≥95%). CONCLUSION: NTM isolation rates in Anhui have remained stable, with the predominant species being M. intracellulare, M. kansasii, M. abscessus, and M. avium. NTM strains are highly sensitive to amikacin, clarithromycin, rifabutin, moxifloxacin, and rifampicin. These findings can guide diagnosis, treatment strategies, and drug selection for NTM disease in Anhui Province.
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Gallbladder cancer (GBC) is the most common malignant tumor of the biliary system, with poor response to current treatments. Abnormal alternative splicing has been associated with the development of a variety of tumors. Combining the GEO database and GBC mRNA-seq analysis, it is found high expression of the splicing factor polypyrimidine region- binding protein 3 (PTBP3) in GBC. Multi-omics analysis revealed that PTBP3 promoted exon skipping of interleukin-18 (IL-18), resulting in the expression of ΔIL-18, an isoform specifically expressed in tumors. That ΔIL-18 promotes GBC immune escape by down-regulating FBXO38 transcription levels in CD8+T cells to reduce PD-1 ubiquitin-mediated degradation is revealed. Using a HuPBMC mouse model, the role of PTBP3 and ΔIL-18 in promoting GBC growth is confirmed, and showed that an antisense oligonucleotide that blocked ΔIL-18 production displayed anti-tumor activity. Furthermore, that the H3K36me3 promotes exon skipping of IL-18 by recruiting PTBP3 via MRG15 is demonstrated, thereby coupling the processes of IL-18 transcription and alternative splicing. Interestingly, it is also found that the H3K36 methyltransferase SETD2 binds to hnRNPL, thereby interfering with PTBP3 binding to IL-18 pre-mRNA. Overall, this study provides new insights into how aberrant alternative splicing mechanisms affect immune escape, and provides potential new perspectives for improving GBC immunotherapy.
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BACKGROUND: Uniportal thoracoscopic right middle lobectomy (RML) poses greater technical challenges than other lobectomies. Although two-port thoracoscopy offers convenience, it results in heightened surgical trauma and scarring. The periareolar incision is rarely used in lobectomy while known for its cosmetic advantages. This study presents the periareolar access (combining a periareolar port and a 1-cm port) for video-assisted thoracoscopic surgery (VATS) in RML, comparing it with the traditional uniportal technique in both male and female patients. METHODS: Eighty patients who underwent RML were randomly divided into two groups: the periareolar VATS (PV) approach (n = 40) and the uniportal VATS (UV) approach (n = 40) from August 2020 to February 2023. All patients were followed up for 1 year and clinical data were collected and analyzed. RESULTS: No significant differences in complications, blood loss, duration of chest tube placement, and length of postoperative hospital stay were observed between two methods. However, the PV group exhibited significantly shorter operative time, reduced postoperative visible scarring and lower visual analogue scores (VAS) for postoperative pain (P < 0.05). Additionally, the PV group demonstrated significantly higher cosmetic and satisfaction scores at the 6-month postoperative assessment (P < 0.05). Notably, breast ultrasound follow-up revealed two cases injuries of the mammary glands in female patients, and sensory function of most nipple and areola remained intact except two cases in all PV group patients. CONCLUSIONS: Periareolar VATS emerges as a promising alternative approach for RML, providing clear benefits in pain management and cosmetic outcomes, while maintaining safety and convenience.
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The promoting effects of collagen and its derivatives on bone health have been uncovered. However, the structure and effects of type II collagen peptides from squid cartilage (SCIIP) on osteoarthritis still need to be clarified. In this study, SCIIP was prepared from squid throat cartilage with pretreatment by 0.2 mol/L NaOH at a liquid-solid ratio of 10:1 for 18 h and hydrolyzation using alkaline protease and flavourzyme at 50 °C for 4 h. The structure of SCIIP was characterized as a molecular weight lower than 5 kDa (accounting for 87.7 %), a high glycine level of 35.0 %, typical FTIR and CD features of collagen peptides, and a repetitive sequence of Gly-X-Y. GP(Hyp)GPD and GPAGP(Hyp)GD were separated and identified from SCIIP, and their binding energies with TLR4/MD-2 were - 8.4 and - 8.0 kcal/mol, respectively. SCIIP effectively inhibited NO production in RAW264.7 macrophages and alleviated osteoarthritis in rats through the TLR4/NF-κB pathway. Therefore, SCIIP exhibited the potential for application as an anti-osteoarthritis supplement.
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Cartilagem , Colágeno Tipo II , Decapodiformes , Osteoartrite , Animais , Decapodiformes/química , Osteoartrite/tratamento farmacológico , Colágeno Tipo II/metabolismo , Camundongos , Cartilagem/química , Cartilagem/metabolismo , Células RAW 264.7 , Ratos , Masculino , Peptídeos/química , Peptídeos/farmacologia , Ratos Sprague-Dawley , Óxido Nítrico/metabolismo , NF-kappa B/metabolismo , Receptor 4 Toll-Like/metabolismoRESUMO
We have successfully synthesized a series of bidentate ligands by utilizing 2-(trimethylsilyl)phenyl trifluorosulfonate as a precursor for the benzyl group. This method proceeded by inserting a polythiourea into the CâS π-bond, intramolecular ring proton migration, and ring opening. Salient features of this strategy are mild reaction conditions, a novel product structure, excellent stereochemistry, and a good functional group tolerance. Furthermore, a series of density functional theory calculations were performed to gain insights into the transfer mechanism.
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An efficient [3 + 2] cycloaddition reaction between in situ generated nitrile imines from hydrazonoyl halides and vinylsulfonium salts is developed. The nitrile imines are demonstrated to be a new class of reaction partner for vinylsulfonium salts to conduct the [3 + 2] cycloaddition reaction. The process provides a concise and efficient method for the construction of pyrazole derivatives under mild reaction conditions with broad substrate scope, good product yields, and high regioselectivity.
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Advancing the mechanistic understanding of absence epilepsy is crucial for developing new therapeutics, especially for patients unresponsive to current treatments. Utilizing a recently developed mouse model of absence epilepsy carrying the BK gain-of-function channelopathy D434G, here we report that attenuating the burst firing of midline thalamus (MLT) neurons effectively prevents absence seizures. We found that enhanced BK channel activity in the BK-D434G MLT neurons promotes synchronized bursting during the ictal phase of absence seizures. Modulating MLT neurons through pharmacological reagents, optogenetic stimulation, or deep brain stimulation effectively attenuates burst firing, leading to reduced absence seizure frequency and increased vigilance. Additionally, enhancing vigilance by amphetamine, a stimulant medication, or physical perturbation also effectively suppresses MLT bursting and prevents absence seizures. These findings suggest that the MLT is a promising target for clinical interventions. Our diverse approaches offer valuable insights for developing next generation therapeutics to treat absence epilepsy.
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Modelos Animais de Doenças , Epilepsia Tipo Ausência , Animais , Epilepsia Tipo Ausência/fisiopatologia , Camundongos , Tálamo/fisiopatologia , Neurônios/metabolismo , Neurônios/fisiologia , Optogenética , Canais de Potássio Ativados por Cálcio de Condutância Alta/metabolismo , Estimulação Encefálica Profunda/métodos , Masculino , Núcleos da Linha Média do Tálamo/fisiologiaRESUMO
Introduction: Premenstrual dysphoric disorder (PMDD), a severe form of premenstrual syndrome (PMS), is a serious health disorder that affects patient moods. It is caused by cyclic psychological symptoms and its pathogenesis is still unclear. Abnormalities in the basolateral amygdala (BLA) orexin system, which are important causes of the development of depressive mood, have not been reported in PMDD, so exploring its intrinsic mechanisms is meaningful for enriching the pathomechanisms of PMDD. Methods: High performance liquid chromatography was used for the determination of the active ingredients of Jingqianshu granules. Developing a rat model of premenstrual depression using the forced swimming test (FST). The experiment consisted of two parts. In Part 1, the rats were divided into the control group, the model group, the model + Jingqianshu group, and the model + fluoxetine group. The FST, open field test, and elevated plus maze test, were used to assess the behavior of the rats as well as to evaluate the effect of drug intervention. Immunofluorescence and RT-qPCR were used to detect the expression of orexin and its receptors OX1R and OX2R genes and proteins. The expression of Toll-like receptor 4, nuclear factor kappa-B, tumor necrosis factor-α, interleukin 6, and interleukin-1ß in the BLA brain region was detected by Western-Blot. In part 2, the rats were injected intracerebrally with orexin-A. Observe the behavioral activities of rats in the control group, model group, and model+orexin-A group. Immunofluorescence was used to detect microglia in the BLA area of rats, and the expression levels of the above inflammatory factors were detected by Western-Blot. Results: The five components of Jingqianshu granules are: paeoniflorin, erulic acid, liquiritin, hesperidin, and paeonol. During the estrous cycle, rats exhibited depressive-like behavior during the non-receptive phase of the behavioral test, which disappeared during the receptive phase. Immunofluorescence and RT-qPCR showed reduced gene and protein expression of orexin, OX1R, and OX2R in the BLA region of rats in the model group.WB showed elevated levels of inflammatory factors. All returned to control levels after drug treatment. In part 2, injection of orexin-A into the BLA brain region of model rats resulted in reduced immunoreactivity of microglia and decreased expression levels of inflammatory factors. Discussion: Jianqianshu granules can achieve the purpose of treating premenstrual depression by regulating orexin-mediated inflammatory factors, which provides a new idea for further research on the pathogenesis of PMDD. However, the current study is still preliminary and the pathogenesis of PMDD is complex. Therefore, more in-depth exploration is needed.
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This study investigated the effects of modified Fangji Huangqi Decoction on the expression of proteins related to epithelial-mesenchymal transition(EMT) in a mouse model of unilateral ureteral obstruction( UUO) and in a rat renal tubular epithelial cell(NRK-52E) model of fibrosis induced by transforming growth factor ß1(TGF-ß1). It aims to decipher the molecular mechanism by which modified Fangji Huangqi Decoction alleviates renal interstitial fibrosis. C57/BL mice were subjected to UUO.After the surgery, the mice were treated with 0. 5-fold and 2-fold concentrations of modified Fangji Huangqi Decoction and fosinopril sodium(positive control) for 7 days. The interstitial collagen deposition in the kidney was assessed by Masson staining. Western blot and RT-qPCR were employed to determine the expression levels of TGF-ß1, phosphorylated Smad2/3(p-Smad2/3), Smad2/3, Snail,epithelial cadherin(E-cadherin), alpha smooth muscle actin(α-SMA), and vimentin. The NRK-52E cell model induced by TGF-ß1was treated with the serum samples collected from SD rats treated with different concentrations of modified Fangji Huangqi Decoction.The CCK-8 assay was employed to examine the effects of the serum samples on NRK-52E cell proliferation. The cell morphology in different groups was observed under a microscope. Furthermore, the modeled cells were treated with the serum containing 1-fold decoction. Western blot and RT-qPCR were then employed to measure the expression levels of p-Smad2/3, Smad2/3, Snail,E-cadherin, α-SMA, and vimentin in the cells. Under the same conditions, sh RNA was used to silence the Snail gene, and measurements were repeated before and after treatment with the serum containing 1-fold decoction. The results indicated that modified Fangji Huangqi Decoction alleviated the fibrotic injury in the mouse model of UUO and the fibrosis in the NRK-52E cell model. The treatment with the decoction down-regulated the protein and m RNA levels of EMT-related indicators including p-Smad2/3, α-SMA,Snail, and vimentin, while it up-regulated the expression of E-cadherin. After sh RNA silencing of the Snail gene, the protein and m RNA levels of E-cadherin, α-SMA, and vimentin showed no significant differences before and after treatment with the serum containing the decoction. The results suggest that modified Fangji Huangqi Decoction may alleviate renal interstitial fibrosis by inhibiting the TGF-ß1/Smad/Snail signaling pathway and regulating the EMT process.
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Medicamentos de Ervas Chinesas , Transição Epitelial-Mesenquimal , Fibrose , Camundongos Endogâmicos C57BL , Transdução de Sinais , Proteínas Smad , Fatores de Transcrição da Família Snail , Fator de Crescimento Transformador beta1 , Animais , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Fator de Crescimento Transformador beta1/metabolismo , Fator de Crescimento Transformador beta1/genética , Camundongos , Medicamentos de Ervas Chinesas/farmacologia , Medicamentos de Ervas Chinesas/administração & dosagem , Fibrose/tratamento farmacológico , Fatores de Transcrição da Família Snail/metabolismo , Fatores de Transcrição da Família Snail/genética , Ratos , Transdução de Sinais/efeitos dos fármacos , Masculino , Proteínas Smad/metabolismo , Proteínas Smad/genética , Humanos , Rim/efeitos dos fármacos , Rim/metabolismo , Nefropatias/tratamento farmacológico , Nefropatias/metabolismo , Nefropatias/genéticaRESUMO
The aim of this study was to optimize the formation of sodium caseinate (CS) and gum arabic (GA) complexes through the Maillard reaction and to evaluate their effectiveness in improving the emulsification properties and stability of docosahexaenoic acid (DHA) nanoemulsions. First, the best target polysaccharides were selected, and the best modification conditions were determined using orthogonal experiments. Secondly, the response surface experiments were used to optimize the preparation process of the emulsion. The stability, in vitro digestion characteristics, and rheological characteristics of the emulsion prepared by means of CS-GA were compared with the emulsion prepared using a whey protein isolate (WPI). After the orthogonal test, the optimal modification conditions were determined to be a reaction time of 96 h, a CS-GA mass ratio of 1:2, a reaction temperature of 60 °C, and a degree of grafting of 44.91%. Changes in the infrared (IR), Raman, ultraviolet (UV), and endogenous fluorescence spectra also indicated that the complex structure was modified. The response surface test identified the optimal preparation process as follows: an emulsifier concentration of 5 g/L, an oil-phase concentration of 5 g/L, and a homogenization frequency of five, and the emulsion showed good stability. Therefore, the use of a nanoemulsion as a nanoscale DHA algal oil delivery system is very promising for extending the shelf life and improving the stability of food.
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TMEM16F (also known as ANO6), a Ca2+-activated lipid scramblase (CaPLSase) that dynamically disrupts lipid asymmetry, plays a crucial role in various physiological and pathological processes, such as blood coagulation, neurodegeneration, cell-cell fusion and viral infection. However, the mechanisms through which it regulates these processes remain largely elusive. Using endothelial cell-mediated angiogenesis as a model, here we report a previously unknown intracellular signaling function of TMEM16F. We demonstrate that TMEM16F deficiency impairs developmental retinal angiogenesis in mice and disrupts angiogenic processes in vitro. Biochemical analyses indicate that the absence of TMEM16F enhances the plasma membrane association of activated Src kinase. This in turn increases VE-cadherin phosphorylation and downregulation, accompanied by suppressed angiogenesis. Our findings not only highlight the role of intracellular signaling by TMEM16F in endothelial cells but also open new avenues for exploring the regulatory mechanisms for membrane lipid asymmetry and their implications in disease pathogenesis.
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Anoctaminas , Células Endoteliais , Transdução de Sinais , Animais , Anoctaminas/metabolismo , Anoctaminas/genética , Camundongos , Humanos , Células Endoteliais/metabolismo , Quinases da Família src/metabolismo , Quinases da Família src/genética , Neovascularização Fisiológica , Fosforilação , Caderinas/metabolismo , Antígenos CD/metabolismo , Antígenos CD/genética , Células Endoteliais da Veia Umbilical Humana/metabolismo , Membrana Celular/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Angiogênese , Proteínas de Transferência de FosfolipídeosRESUMO
A novel three-component cyclization carbonylation reaction of iodoarene-tethered propargyl ethers with amine and CO is reported. This palladium-catalyzed cascade reaction undergoes a sequence of oxidative addition, unsaturated bond migration, carbonyl insertion, and nucleophilic attack to deliver the benzofuran skeleton. Both aromatic amines and aliphatic amines could proceed smoothly in this transformation under one atm of CO.
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Liver metastasis is common in patients with gallbladder cancer (GBC), imposing a significant challenge in clinical management and serving as a poor prognostic indicator. However, the mechanisms underlying liver metastasis remain largely unknown. Here, we report a crucial role of tyrosine aminotransferase (TAT) in liver metastasis of GBC. TAT is frequently up-regulated in GBC tissues. Increased TAT expression is associated with frequent liver metastasis and poor prognosis of GBC patients. Overexpression of TAT promotes GBC cell migration and invasion in vitro, as well as liver metastasis in vivo. TAT knockdown has the opposite effects. Intriguingly, TAT promotes liver metastasis of GBC by potentiating cardiolipin-dependent mitophagy. Mechanistically, TAT directly binds to cardiolipin and leads to cardiolipin externalization and subsequent mitophagy. Moreover, TRIM21 (Tripartite Motif Containing 21), an E3 ubiquitin ligase, interacts with TAT. The histine residues 336 and 338 at TRIM21 are essential for this binding. TRIM21 preferentially adds the lysine 63 (K63)-linked ubiquitin chains on TAT principally at K136. TRIM21-mediated TAT ubiquitination impairs its dimerization and mitochondrial location, subsequently inhibiting tumor invasion and migration of GBC cells. Therefore, our study identifies TAT as a novel driver of GBC liver metastasis, emphasizing its potential as a therapeutic target.
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Movimento Celular , Neoplasias da Vesícula Biliar , Neoplasias Hepáticas , Ribonucleoproteínas , Ubiquitinação , Animais , Humanos , Camundongos , Linhagem Celular Tumoral , Neoplasias da Vesícula Biliar/patologia , Neoplasias da Vesícula Biliar/genética , Neoplasias da Vesícula Biliar/metabolismo , Regulação Neoplásica da Expressão Gênica , Neoplasias Hepáticas/secundário , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Camundongos Endogâmicos BALB C , Camundongos Nus , Mitofagia , Invasividade Neoplásica , Ribonucleoproteínas/metabolismo , Ribonucleoproteínas/genética , Tirosina TransaminaseRESUMO
Background: To analyze and evaluate the clinical outcomes of using high-viscosity bone cement compared to low-viscosity bone cement in percutaneous vertebroplasty (PVP) for treatment of Kummell's disease. Methods: From July 2017 to July 2019, 68 Kummell's disease patients who underwent PVP were chosen and separated into 2 groups: H group (n = 34), were treated with high-viscosity bone cement and L group (n = 34), treated with low-viscosity bone cement during treatment. The operation time, number of fluoroscopy tests done, and amount of bone cement perfusion were recorded for both groups. Clinical outcomes were compared, by measuring their Visual Analog Scale (VAS), Oswestry Disability Index (ODI), Kyphosis Cobb's angle, vertebral height compression rate, and other complications. Results: High-viscosity group showed less operation time and reduced number of fluoroscopy tests than the low-viscosity group (P < 0.05). When compared to preoperative period, both groups' VAS and ODI scores were significantly reduced at 1 day and 1 year postoperatively (P < 0.05). The vertebral height compression rate and Cobb's angle were significantly lower (P < 0.05) in both groups after surgery compared with those before surgery (P < 0.05). The cement leakage rate in group H was 26.5%, which was significantly lower than that in group L, which was 61.8% (P < 0.05). Conclusions: High-viscosity and low-viscosity bone cement in PVP have similar clinical efficacy in reducing pain in patients during the treatment, but in contrast, high-viscosity bone cement shortens the operative time, reduces number of fluoroscopy views and vertebral cement leakage and improves surgical safety.
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Purpose: Uniportal video-assisted thoracoscopic surgery (VATS) is recognized for its minimally invasive nature, widely adopted globally. However, the evident scarring it leaves often triggers psychological apprehension and resistance to surgery. Transareolar incision, known for its superior cosmetic outcome with no visible scars, poses challenges in women due to the risk of mammary gland damage. In this report, we present successful pulmonary ground glass nodule (GGN) resection using transareolar VATS in female patients, aiming to address these concerns. Materials and Methods: We retrospectively analyzed the clinical data of 35 female patients who underwent GGN resection through transareolar VATS between August 2020 and March 2022. Results: There were no serious complications or perioperative deaths in this cohort of 35 female patients undergoing GGN resection through transareolar VATS. The operations, including local resection or segmentectomy, had an average duration of 70.1 ± 26.4 minutes, with a tube duration of 4.7 ± 2.1 days and a hospitalization time of 7.2 ± 2.3 days. The surgical approach varied, with 21 cases using transareolar uniport, 8 cases assisted by a 3-mm tiny port, and 6 cases converted to two-port VATS. Scar outcomes varied, with 21 cases showing no scar, 8 cases displaying a microscar, and 6 cases presenting a dominant scar of 1.7 ± 0.5 cm. Postoperative pain scores at 1 week and 1 month were 1.9 ± 0.9 and 1.0 ± 0.9, respectively, and the wound numbness occurred in 2.86% (1/35) of cases. Regarding breast complications, 2 patients suffered delayed healing of the incision. No damage and inflammation of glands were detected by breast B-mode ultrasonography. Conclusions: The transareolar incision emerges as a novel approach for VATS in female patients, offering advantages in terms of pain management and cosmetic outcomes.
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Cirurgia Torácica Vídeoassistida , Humanos , Cirurgia Torácica Vídeoassistida/métodos , Feminino , Estudos Retrospectivos , Pessoa de Meia-Idade , Adulto , Nódulo Pulmonar Solitário/cirurgia , Idoso , Neoplasias Pulmonares/cirurgia , Neoplasias Pulmonares/patologia , Pneumonectomia/métodos , Mamilos/cirurgia , Duração da CirurgiaRESUMO
The interactions of the micro-mechanism of hydroxymethanesulfonic acid (HMSA) with the typical small organic molecule in atmospheric (X = methanol, formaldehyde, formic acid, methyl formate, dimethyl ether, acetone) has been investigated by density functional theory (DFT), quantum theory of atoms in molecules (QTAIM), Generalized Kohn-Sham Enery Decomposition Analysis (GKS-EDA) and the atmospheric clusters dynamic code (ACDC). The results of DFT show that the stable six- to eight-membered ring structures are easily formed in HMSA-X clusters. According to the topological analysis results of the AIM theory and the IRI method, a strong hydrogen bonding interaction is present in the complex. GKS-EDA results show that electrostatic energy is the main contributor to the interaction energy as it accounts for 51 %-55 % of the total attraction energy. The evaporation rates of HMSA-HMSA and HMSA-HCOOH clusters were much lower than those of the other HMSA complexes. In addition, the Gibbs energy of formation (ΔG) of HMSA-X dimers is investigated under atmosphere temperature T = 217-298 K and p = 0.19-1.0 atm, the ΔG decreased with decreasing of the atmosphere temperature and increased with the decrease of atmospheric pressure, indicating that the low temperature and high pressure may significantly facilitate to the formation of dimers.
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Atmosfera , Ligação de Hidrogênio , Atmosfera/química , Termodinâmica , Compostos Orgânicos/química , Modelos Moleculares , Teoria Quântica , Mesilatos/química , Eletricidade Estática , TemperaturaRESUMO
Atmospheric organic peroxides (POs) play a key role in the formation of O3 and secondary organic aerosol (SOA), impacting both air quality and human health. However, there still remain technical challenges in investigating the reactivity of POs in ambient aerosols due to the instability and lack of standards for POs, impeding accurate evaluation of their environmental impacts. In the present study, we conducted the first attempt to categorize and quantify POs in ambient PM2.5 through hydrolysis, which is an important transformation pathway for POs, thus revealing the reactivities of various POs. POs were generally categorized into hydrolyzable POs (HPO) and unhydrolyzable POs (UPO). HPO were further categorized into three groups: short-lifetime HPO (S-HPO), intermediate-lifetime HPO (I-HPO), and long-lifetime HPO (L-HPO). S-HPO and L-HPO are typically formed from Criegee intermediate (CI) and RO2 radical reactions, respectively. Results show that L-HPO are the most abundant HPO, indicating the dominant role of RO2 pathway in HPO formation. Despite their lower concentration compared to L-HPO, S-HPO make a major contribution to the HPO hydrolysis rate due to their faster rate constants. The hydrolysis of PM2.5 POs accounts for 19 % of the nighttime gas-phase H2O2 growth during the summer observation, constituting a noteworthy source of gas-phase H2O2 and contributing to the atmospheric oxidation capacity. Seasonal and weather conditions significantly impact the composition of POs, with HPO concentrations in summer being significantly higher than those in winter and elevated under rainy and nighttime conditions. POs are mainly composed of HPO in summer, while in winter, POs are dominated by UPO.
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Fusarium head blight (FHB) is a destructive disease that affects wheat production. Detecting FHB accurately and rapidly is crucial for improving wheat yield. Traditional models are difficult to apply to mobile devices due to large parameters, high computation, and resource requirements. Therefore, this article proposes a lightweight detection method based on an improved YOLOv8s to facilitate the rapid deployment of the model on mobile terminals and improve the detection efficiency of wheat FHB. The proposed method introduced a C-FasterNet module, which replaced the C2f module in the backbone network. It helps reduce the number of parameters and the computational volume of the model. Additionally, the Conv in the backbone network is replaced with GhostConv, further reducing parameters and computation without significantly affecting detection accuracy. Thirdly, the introduction of the Focal CIoU loss function reduces the impact of sample imbalance on the detection results and accelerates the model convergence. Lastly, the large target detection head was removed from the model for lightweight. The experimental results show that the size of the improved model (YOLOv8s-CGF) is only 11.7 M, which accounts for 52.0% of the original model (YOLOv8s). The number of parameters is only 5.7 × 106 M, equivalent to 51.4% of the original model. The computational volume is only 21.1 GFLOPs, representing 74.3% of the original model. Moreover, the mean average precision (mAP@0.5) of the model is 99.492%, which is 0.003% higher than the original model, and the mAP@0.5:0.95 is 0.269% higher than the original model. Compared to other YOLO models, the improved lightweight model not only achieved the highest detection precision but also significantly reduced the number of parameters and model size. This provides a valuable reference for FHB detection in wheat ears and deployment on mobile terminals in field environments.
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We introduce switchable chemoselectivity strategies based on the hydrazone phosphaketene intermediate to synthesize three classes of 1,2,4-diazaphosphol derivatives. First, the five-membered heterocyclic P and O anion intermediates acted as nucleophilic agents in the selective construction of C-P and C-O bonds. Second, the phosphinidene served as a phosphorus synthon, allowing for the formation of C-P and C-N bonds. Finally, a stepwise mechanism, supported by DFT calculations, was invoked to explain the reaction selectivity.