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Dearomative functionalization of heteroarenes offers an attractive and sustainable approach for the rapid construction of complex 3D heterocyclic scaffolds from planar structures. Despite progress in this field, dearomative amination of heteroarenes via a radical anion intermediate remains a challenge. Here, we report a photoredox-catalyzed dearomative hydroamination of heteroarenes with hydrazodiformates under mild and transition-metal-free reaction conditions. Various benzofurans and benzothiophenes can efficiently participate in this transformation. A series of mechanistic experiments revealed that heteroaryl radical anions are the crucial intermediates, generated through photo-induced electron transfer between the excited phenolate photocatalyst and heteroarenes.
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Direct carboxylation of C-H bonds with CO2 represents an attractive strategy to synthesize valuable carboxylic acids with high atom, step, and redox economy. Although great progress has been achieved in this field, catalytic carboxylation of tertiary C(sp3)-H bonds still remains challenging due to their inherent inertness and significant steric hindrance. Herein, we report a direct carboxylation of tertiary benzylic C(sp3)-H bonds with CO2 via visible-light photoredox catalysis. Various all-carbon quaternary carboxylic acids, which are of significant importance in medicinal chemistry, are successfully obtained with high yields. This direct carboxylation is characterized by good functional group tolerance, broad substrate scope, and mild operational conditions. Furthermore, our methodology enables the efficient and rapid synthesis of key drug or bioactive molecules, such as carbetapentane, caramiphen, and PRE-084 (σ1 receptor agonist), and facilitates various functionalizations of C(sp2)-H bonds using the directing ability of target carboxylic acids, thus highlighting its practical applications. Mechanistic studies indicate that a carbanion, which serves as the key intermediate to react with CO2, is catalytically generated via a single electron reduction of a benzylic radical through a consecutive photoinduced electron transfer process.
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Carbon emissions trading scheme (ETS) will change the internal and external operating environment of related companies, increase new carbon reduction costs, and may affect their investment behavior and decision-making. This study constructs the policy effect evaluation model to evaluate the net effect of China's ETS pilot policy on the investment efficiency of related companies in high-carbon industries. This study indicates that: first, China's ETS pilot policy has reduced the inefficient investment of related companies by 11.40% during the sample period. Second, innovation ability plays an enhanced moderating effect in the inhibitory effect of China's ETS pilot policy on the inefficient investment of related companies in the short term, but the effect is weakened in the long-term. Third, the policy effect is relatively obvious for non-state-owned companies and companies with more institutional shareholdings. This research has important reference value for the continuous improvement of China's national carbon market, and the steady transformation from simple investment-driven to investment-efficiency-driven economic development in China.
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Carbono , Investimentos em Saúde , China , Desenvolvimento Econômico , Poluição do Ar/prevenção & controleRESUMO
Curriculum is the core element of talent cultivation in universities, and its quality directly determines that of the talent cultivation. However, the efficiency of online course resource allocation in universities of China is unacceptable, and the corresponding driving mechanisms are unclear. Based on the data of iCourses platform for a top university (H University) of China, this paper develops the DEA-Malmquist index and Tobit regression model to evaluate the efficiency of university online course resource allocation and explore its main influencing factors. The empirical results indicate that, first of all, humanities and social sciences outperform natural sciences in the resource allocation efficiency of online courses. Compared with non-national premium online courses, the resource investment redundancy of national premium online courses appears relatively lower. Secondly, from the perspective of temporal changes, the total factor productivity of online course resource allocation generally has a downward trend. The innovation effect of technological progress is more significant, while the catch-up effect of technical efficiency is clearly insufficient. Scale efficiency is the main factor hindering its improvement. Finally, in terms of the factors affecting the efficiency of online course resource allocation, teachers' research guidance capability, teaching research skills, and the number of courses offered have significantly positive impact.
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Avaliação de Programas e Projetos de Saúde , Alocação de Recursos , China , Humanos , Universidades/organização & administração , Educação a Distância/organização & administração , Currículo , Internet , Ciências Humanas/educação , Ciências Sociais/educação , Disciplinas das Ciências Naturais/educaçãoRESUMO
Fowl adenovirus serotype 4 (FAdV-4) is the main pathogen of the acute infectious disease hepatitis-hydropericardium syndrome (HHS). Previous studies have focused on the mechanisms of FAdV-4 caused liver injury, while studies revealing potential mechanisms of inflammatory injury in FAdV-4-infected chicken cardiac cells remain scare. Here we found that FAdV-4 successfully infected chicken embryonic cardiac fibroblasts (CECF) cells in vitro and significantly upregulated production of inflammatory cytokines including IL-1ß, IL-6, IL-8, and TNF-α, suggesting induction of a strong inflammatory response. Mechanistically, FAdV-4 infection increased expression of phosphorylated Akt in a time-dependent manner, while phosphorylation of Akt and production of pro-inflammatory cytokines IL-1ß, IL-6, IL-8, and TNF-α were greatly reduced in FAdV-4-infected CECF cells after treatment with LY294002, a potent inhibitor of PI3K, indicating that the inflammatory response induced by FAdV-4 infection is mediated by the PI3K/Akt signaling pathway. Furthermore, FAdV-4 infection increased expression of phosphorylated IκBα, a recognized indicator of NF-κB activation, and treatment with the BAY11-7082, a selective IκBα phosphorylation and NF-κB inhibitor, significantly reduced IκBα phosphorylation and inflammatory cytokines (IL-1ß, IL-6, IL-8, and TNF-α) production in FAdV-4-infected CECF cells, suggesting a critical role of IκBα/NF-κB signaling in FAdV-4-induced inflammatory responses in CECF cells. Taken together, our results suggest that FAdV-4 infection induces inflammatory responses through activation of PI3K/Akt and IκBα/NF-κB signaling pathways in CECF cells. These results reveal potential mechanisms of inflammatory damage in chicken cardiac cells caused by FAdV-4 infection, which sheds new insight into clarification of the pathogenic mechanism of FAdV-4 infection and development of new strategies for HHS prevention and control.
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Infecções por Adenoviridae , Fibroblastos , NF-kappa B , Fosfatidilinositol 3-Quinases , Doenças das Aves Domésticas , Proteínas Proto-Oncogênicas c-akt , Transdução de Sinais , Animais , Fibroblastos/virologia , Embrião de Galinha , NF-kappa B/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Infecções por Adenoviridae/veterinária , Infecções por Adenoviridae/virologia , Infecções por Adenoviridae/imunologia , Doenças das Aves Domésticas/virologia , Inflamação , Aviadenovirus/fisiologia , Citocinas/metabolismo , Galinhas , Sorogrupo , Inibidor de NF-kappaB alfa/metabolismoRESUMO
Background and objective: To investigate the use of high-resolution magnetic resonance imaging (HR-MRI) to identify the characteristics of culprit plaques in intracranial arteries, and to evaluate the predictive value of the characteristics of culprit plaques combined with the modified Essen score for the recurrence risk of high-risk non-disabling ischemic cerebrovascular events (HR-NICE) patients. Methods: A retrospective analysis was conducted on 180 patients with HR-NICE at the First Affiliated Hospital of Xinxiang Medical University, including 128 patients with no recurrence (non-recurrence group) and 52 patients with recurrence (recurrence group). A total of 65 patients with HR-NICE were collected from the Sixth Affiliated Hospital of Shanghai Jiaotong University as a validation group, and their modified Essen scores, high-resolution magnetic resonance vessel wall images, and clinical data were collected. The culprit plaques were analyzed using VesselExplorer2 software. Univariate and multivariate logistic regression analyses were used to identify independent risk factors for recurrence, and a nomogram was constructed using R software to evaluate the discrimination of the model. The area under the curve (AUC) of the receiver operating characteristic curve (ROC) was used to evaluate the model performance. Calibration curves and Decision Curve Analysis (DCA) were used to evaluate the model efficacy. Results: Intra-plaque hemorrhage (OR = 3.592, 95% CI = 1.474-9.104, p = 0.006), homocysteine (OR = 1.098, 95% CI = 1.025-1.179, p = 0.007), and normalized wall index (OR = 1.114, 95% CI = 1.027-1.222, p = 0.015) were significantly higher in the recurrent stroke group than in the non-recurrent stroke group, and were independent risk factors for recurrent stroke. The performance of the nomogram model (AUC = 0.830, 95% CI: 0.769-0.891; PR-AUC = 0.628) was better than that of the modified Essen scoring model (AUC = 0.660, 95% CI: 0.583-0.738) and the independent risk factor combination model (AUC = 0.827, 95% CI: 0.765-0.889). The nomogram model still had good model performance in the validation group (AUC = 0.785, 95% CI: 0.671-0.899), with a well-fitting calibration curve and a DCA curve indicating good net benefit efficacy for patients. Conclusion: High-resolution vessel wall imaging combined with a modified Essen score can effectively assess the recurrence risk of HR-NICE patients, and the nomogram model can provide a reference for identifying high-risk populations with good clinical application prospects.
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Consumption of dietary fiber and anthocyanin has been linked to a lower incidence of colorectal cancer (CRC). This study scrutinizes the potential antitumorigenic attributes of a black rice diet (BRD), abundantly rich in dietary fiber and anthocyanin. Our results demonstrate notable antitumorigenic effects in mice on BRD, indicated by a reduction in both the size and number of intestinal tumors and a consequent extension in life span, compared to control diet-fed counterparts. Furthermore, fecal transplants from BRD-fed mice to germ-free mice led to a decrease in colonic cell proliferation, coupled with maintained integrity of the intestinal barrier. The BRD was associated with significant shifts in gut microbiota composition, specifically an augmentation in probiotic strains Bacteroides uniformis and Lactobacillus. Noteworthy changes in gut metabolites were also documented, including the upregulation of indole-3-lactic acid and indole. These metabolites have been identified to stimulate the intestinal aryl hydrocarbon receptor pathway, inhibiting CRC cell proliferation and colorectal tumorigenesis. In summary, these findings propose that a BRD may modulate the progression of intestinal tumors by fostering protective gut microbiota and metabolite profiles. The study accentuates the potential health advantages of whole-grain foods, emphasizing the potential utility of black rice in promoting health.
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As a potential alternative to antibiotics, hyperbranched poly(ionic liquid)s (HPILs) have demonstrated significant potential in combating bacterial biofilms. However, their high cation density poses a high risk of toxicity, greatly limiting their in vivo applications. In this study, we constructed a biocompatible HPIL (HPIL-Glu) from a hyperbranched polyurea core with modified terminals featuring charge-convertible ionic liquids. These ionic liquid moieties consist of an ammonium-based cation and a gluconate (Glu) organic counter. HPIL-Glu could form a homogeneous nanoassembly in water and exhibited a pH-responsive charge conversion property. Under neutral conditions, Glu shielded the positively charged surface, minimizing the toxicity. In a mildly acidic environment, Glu protonation exposes cationic moieties to biofilm eradication. Comprehensive antimicrobial assessments demonstrate that HPIL-Glu effectively kills bacteria and promotes the healing of bacteria-infected chronic wounds. Furthermore, prolonged exposure to HPIL-Glu does not induce antimicrobial resistance.
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Wound infections pose a major healthcare issue, affecting the well-being of millions of patients worldwide. Effective intervention and on-site detection are important in wound management. However, current approaches are hindered by time-consuming analysis and a lack of technology for real-time monitoring and prompt therapy delivery. In this study, a smart wound patch system (SWPS) designed for wireless closed-loop and in-situ wound management is presented. The SWPS integrates a microfluidic structure, an organic electrochemical transistor (OECT) based sensor, an electrical stimulation module, and a miniaturized flexible printed circuit board (FPCB). The OECT incorporates a bacteria-responsive DNA hydrogel-coated gate for continuous monitoring of bacterial virulence at wound sites. Real-time detection of OECT readings and on-demand delivery of electrical cues to accelerate wound healing is facilitated by a mobile phone application linked with an FPCB containing low-power electronics equipped with parallel sensing and stimulation circuitry. In this proof-of-concept study, the functionality of the SWPS is validated and its application both in vitro and in vivo is demonstrated. This proposed system expands the arsenal of tools available for effective wound management and enables personalized treatment.
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Tecnologia sem Fio , Cicatrização , Tecnologia sem Fio/instrumentação , Animais , Infecção dos Ferimentos/terapia , Desenho de Equipamento/métodos , Camundongos , Modelos Animais de Doenças , HumanosRESUMO
Semi-supervised learning (SSL), which aims to learn with limited labeled data and massive amounts of unlabeled data, offers a promising approach to exploit the massive amounts of satellite Earth observation images. The fundamental concept underlying most state-of-the-art SSL methods involves generating pseudo-labels for unlabeled data based on image-level predictions. However, complex remote sensing (RS) scene images frequently encounter challenges, such as interference from multiple background objects and significant intra-class differences, resulting in unreliable pseudo-labels. In this paper, we propose the SemiRS-COC, a novel semi-supervised classification method for complex RS scenes. Inspired by the idea that neighboring objects in feature space should share consistent semantic labels, SemiRS-COC utilizes the similarity between foreground objects in RS images to generate reliable object-level pseudo-labels, effectively addressing the issues of multiple background objects and significant intra-class differences in complex RS images. Specifically, we first design a Local Self-Learning Object Perception (LSLOP) mechanism, which transforms multiple background objects interference of RS images into usable annotation information, enhancing the model's object perception capability. Furthermore, we present a Cross-Object Consistency Pseudo-Labeling (COCPL) strategy, which generates reliable object-level pseudo-labels by comparing the similarity of foreground objects across different RS images, effectively handling significant intra-class differences. Extensive experiments demonstrate that our proposed method achieves excellent performance compared to state-of-the-art methods on three widely-adopted RS datasets.
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Introduction: It is known that patients with immune-abnormal co-pregnancies are at a higher risk of adverse pregnancy outcomes. Traditional pregnancy risk management systems have poor prediction abilities for adverse pregnancy outcomes in such patients, with many limitations in clinical application. In this study, we will use machine learning to screen high-risk factors for miscarriage and develop a miscarriage risk prediction model for patients with immune-abnormal pregnancies. This model aims to provide an adjunctive tool for the clinical identification of patients at high risk of miscarriage and to allow for active intervention to reduce adverse pregnancy outcomes. Methods: Patients with immune-abnormal pregnancies attending Sichuan Provincial People's Hospital were collected through electronic medical records (EMR). The data were divided into a training set and a test set in an 8:2 ratio. Comparisons were made to evaluate the performance of traditional pregnancy risk assessment tools for clinical applications. This analysis involved assessing the cost-benefit of clinical treatment, evaluating the model's performance, and determining its economic value. Data sampling methods, feature screening, and machine learning algorithms were utilized to develop predictive models. These models were internally validated using 10-fold cross-validation for the training set and externally validated using bootstrapping for the test set. Model performance was assessed by the area under the characteristic curve (AUC). Based on the best parameters, a predictive model for miscarriage risk was developed, and the SHapley additive expansion (SHAP) method was used to assess the best model feature contribution. Results: A total of 565 patients were included in this study on machine learning-based models for predicting the risk of miscarriage in patients with immune-abnormal pregnancies. Twenty-eight risk warning models were developed, and the predictive model constructed using XGBoost demonstrated the best performance with an AUC of 0.9209. The SHAP analysis of the best model highlighted the total number of medications, as well as the use of aspirin and low molecular weight heparin, as significant influencing factors. The implementation of the pregnancy risk scoring rules resulted in accuracy, precision, and F1 scores of 0.3009, 0.1663, and 0.2852, respectively. The economic evaluation showed a saving of ¥7,485,865.7 due to the model. Conclusion: The predictive model developed in this study performed well in estimating the risk of miscarriage in patients with immune-abnormal pregnancies. The findings of the model interpretation identified the total number of medications and the use of other medications during pregnancy as key factors in the early warning model for miscarriage risk. This provides an important basis for early risk assessment and intervention in immune-abnormal pregnancies. The predictive model developed in this study demonstrated better risk prediction performance than the Pregnancy Risk Management System (PRMS) and also demonstrated economic value. Therefore, miscarriage risk prediction in patients with immune-abnormal pregnancies may be the most cost-effective management method.
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INTRODUCTION: Although COPD may frequently co-exist with bronchiectasis [COPD-bronchiectasis associated (CBA)], little is known regarding the clinical heterogeneity. We aimed to identify the phenotypes and compare the clinical characteristics and prognosis of CBA. METHODS: We conducted a retrospective cohort study involving 2928 bronchiectasis patients, 5158 COPD patients, and 1219 patients with CBA hospitalized between July 2017 and December 2020. We phenotyped CBA with a two-step clustering approach and validated in an independent retrospective cohort with decision-tree algorithms. RESULTS: Compared with patients with COPD or bronchiectasis alone, patients with CBA had significantly longer disease duration, greater lung function impairment, and increased use of intravenous antibiotics during hospitalization. We identified five clusters of CBA. Cluster 1 (N=120, CBA-MS) had predominantly moderate-severe bronchiectasis, Cluster 2 (N=108, CBA-FH) was characterized by frequent hospitalization within the previous year, Cluster 3 (N=163, CBA-BI) had bacterial infection, Cluster 4 (N=143, CBA-NB) had infrequent hospitalization but no bacterial infection, and Cluster 5 (N=113, CBA-NHB) had no hospitalization or bacterial infection in the past year. The decision-tree model predicted the cluster assignment in the validation cohort with 91.8% accuracy. CBA-MS, CBA-BI, and CBA-FH exhibited higher risks of hospital re-admission and intensive care unit admission compared with CBA-NHB during follow-up (all P<0.05). Of the five clusters, CBA-FH conferred the worst clinical prognosis. CONCLUSION: Bronchiectasis severity, recent hospitalizations and sputum culture findings are three defining variables accounting for most heterogeneity of CBA, the characterization of which will help refine personalized clinical management.
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Bronquiectasia , Hospitalização , Fenótipo , Doença Pulmonar Obstrutiva Crônica , Humanos , Doença Pulmonar Obstrutiva Crônica/complicações , Masculino , Estudos Retrospectivos , Feminino , Idoso , Pessoa de Meia-Idade , Hospitalização/estatística & dados numéricos , Prognóstico , Árvores de Decisões , Antibacterianos/uso terapêutico , Análise por ConglomeradosRESUMO
The increasing antibiotic resistance poses a significant global health challenge, threatening our ability to combat infectious diseases. The phenomenon of collateral sensitivity, whereby resistance to one antibiotic is accompanied by increased sensitivity to another, offers potential avenues for novel therapeutic interventions against infections unresponsive to classical treatments. In this study, we elucidate the emergence of tobramycin (TOB)-resistant small colony variants (SCVs) due to mutations in the hemL gene, which render S. Typhimurium more susceptible to nitrofurantoin (NIT). Mechanistic studies demonstrate that the collateral sensitivity in TOB-resistant S. Typhimurium SCVs primarily stems from disruptions in haem biosynthesis. This leads to dysfunction in the electron transport chain (ETC) and redox imbalance, ultimately inducing lethal accumulation of reactive oxygen species (ROS). Additionally, the upregulation of nfsA/B expressions facilitates the conversion of NIT prodrug into its active form, promoting ROS-mediated bacterial killing and contributing to this collateral sensitivity pattern. Importantly, alternative NIT therapy demonstrates a significant reduction of bacterial load by more than 2.24-log10 cfu/g in the murine thigh infection and colitis models. Our findings corroborate the collateral sensitivity of S. Typhimurium to nitrofurans as a consequence of evolving resistance to aminoglycosides. This provides a promising approach for treating infections due to aminoglycoside-resistant strains.
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Antibacterianos , Nitrofurantoína , Salmonella typhimurium , Tobramicina , Nitrofurantoína/farmacologia , Animais , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/genética , Tobramicina/farmacologia , Camundongos , Antibacterianos/farmacologia , Testes de Sensibilidade Microbiana , Farmacorresistência Bacteriana/genética , Mutação , Feminino , Espécies Reativas de Oxigênio/metabolismo , Infecções por Salmonella/microbiologia , Infecções por Salmonella/tratamento farmacológico , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismoRESUMO
BACKGROUND: The traditional surgical procedures for upper lumbar disc herniation (ULDH) usually lead to frequent complications. We aim to investigate the clinical efficacy of the unilateral biportal endoscopy (UBE) technique in treating upper lumbar disc herniation (ULDH). METHODS: From January 2020 to December 2021, the clinical data of 28 patients with ULDH treated with the UBE technique were collected and analyzed for surgery time under UBE, postsurgical drainage, postsurgical hospital stay, and complications. The clinical efficacy was evaluated according to the modified MacNab score, Oswestry disability index (ODI), and visual analogue scale (VAS) of low back pain and lower limb pain before the surgery; one week, one month, and three months after the surgery; and at the last follow-up. RESULTS: All patients underwent the UBE surgery successfully. The surgery time under UBE for non-fusion cases was 47.50 ± 11.84 min (monosegment) and 75.00 ± 20.66 min (two segments), while that for fusion cases was 77.50 ± 21.02 min. The postsurgical drainage for non-fusion cases was 25.00 ± 13.94 mL (monosegment) and 38.00 ± 11.83 mL (two segments), while that for fusion cases was 71.25 ± 31.72 mL. The postsurgical hospital stay was 8.28 ± 4.22 days. The follow-up time was 15.82 ± 4.54 months. The VAS score for each time period after the surgery was significantly lower (P < 0.05), while the ODI was significantly higher than that before the surgery (P < 0.05). According to the modified MacNab scoring standard, the ratio of excellent to good was 96.43% at the last follow-up. Two patients experienced transient numbness and pain in their lower limbs and no activity disorder after the surgery, and they recovered after conservative treatment. CONCLUSIONS: The clinical effect of UBE technique in treating ULDH was reliable. According to the needs of the disease, the interlaminar approach or paraspinal approach of the UBE technique was selected. This technique took into account the effect of treatment, achieved the purpose of minimal invasiveness, and did not require special instruments. Therefore, it has the potential for clinical application.
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Endoscopia , Deslocamento do Disco Intervertebral , Vértebras Lombares , Humanos , Feminino , Masculino , Vértebras Lombares/cirurgia , Vértebras Lombares/diagnóstico por imagem , Pessoa de Meia-Idade , Deslocamento do Disco Intervertebral/cirurgia , Deslocamento do Disco Intervertebral/diagnóstico por imagem , Adulto , Endoscopia/métodos , Resultado do Tratamento , Estudos Retrospectivos , Duração da Cirurgia , Medição da Dor , Tempo de Internação , Complicações Pós-Operatórias/etiologiaRESUMO
BACKGROUND: Short-term poor uterine involution manifests as uterine contraction weakness. This is one of the important causes of postpartum hemorrhage, posing a serious threat to the mother's life and safety. The study aims to investigate whether low-intensity focused ultrasound (LIFUS) can effectively shorten lochia duration, alleviate postpartum complications, and accelerate uterine involution compared with the sham treatment. METHODS: A multicenter, concealed, randomized, blinded, and sham-controlled clinical trial was conducted across three medical centers involving 176 subjects, utilizing a parallel group design. Enrollment occurred between October 2019 and September 2020, with a 42-day follow-up period. Participants meeting the inclusion and exclusion criteria based on normal prenatal examinations were randomly divided into the LIFUS group or the sham operation group via computer-generated randomization. Patients in the LIFUS group received usual care with the LIFUS protocol, wherein a LIFUS signal was transmitted to the uterine site through coupling gel, or sham treatment, where no low-intensity ultrasound signal output was emitted. The primary outcome, lochia duration, was assessed via weekly telephonic follow-ups post-discharge. The involution of the uterus, measured by uterine fundus height, served as the secondary outcome. RESULTS: Among the 256 subjects screened for eligibility, 176 subjects were enrolled and randomly assigned to either the LIFUS group (n = 88) or the Sham group (n = 88). Data on the height of the uterine fundus were obtained from all the patients, with 696 out of 704 measurements (99%) successfully recorded. Overall, a statistically significant difference was noted in time to lochia termination (hazard ratio: 2.65; 95% confidence interval [CI]: 1.82-3.85; P < 0.001). The decline in fundal height exhibited notable discrepancies between the two groups following the second treatment session (mean difference: -1.74; 95% CI: -1.23 to -2.25; P < 0.001) and the third treatment session (mean difference: -3.26; 95% CI: -2.74 to -3.78; P < 0.001) after delivery. None of the subjects had any adverse reactions, such as skin damage or allergies during the treatment. CONCLUSIONS: This study found that LIFUS treatment can promote uterine involution and abbreviate the duration of postpartum lochia. Ultrasound emerges as a safe and effective intervention, poised to address further clinical inquiries in the domain of postpartum rehabilitation.
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Período Pós-Parto , Útero , Humanos , Feminino , Adulto , Útero/diagnóstico por imagem , Gravidez , Terapia por Ultrassom/métodos , Hemorragia Pós-Parto/terapia , Resultado do Tratamento , Contração Uterina/fisiologiaRESUMO
Ultrashort pulses, characterized by their short pulse duration, diverse spectral content, and high peak power, are widely used in fields including laser processing, optical storage, biomedical sciences, and laser imaging. The complex, highly-nonlinear process of ultrashort pulse evolution within fiber lasers is influenced by numerous aspects such as dispersion, loss, gain, and nonlinear effects. Traditionally, the split-step Fourier transforms method is employed for simulating ultrashort pulses in fiber lasers, which involves traversing multiple parameters within the fiber to attain the pulse's optimal state. The simulation is a significantly time-consuming process. Here, we use a neural network model to fit and predict the impact of multiple parameters on the pulse characteristics within fiber lasers, enabling parameter optimization through genetic algorithms to determine the optimal pulse duration, pulse energy, and peak power. Integrating artificial intelligence algorithms simplifies the acquisition of optimal pulse parameters and enhances our understanding of multiple parameters' impact on the pulse characteristics. The investigation of ultrashort pulse optimization based on artificial intelligence holds immense potential for laser design.
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Bronquiectasia , Fosfatos de Cálcio , Escarro , Humanos , Cor , Bronquiectasia/diagnóstico , Biomarcadores , Sistema de RegistrosRESUMO
Upgrading CO2 to value-added chiral molecules via catalytic asymmetric C-C bond formation is a highly important yet challenging task. Although great progress on the formation of centrally chiral carboxylic acids has been achieved, catalytic construction of axially chiral carboxylic acids with CO2 has never been reported to date. Herein, we report the first catalytic asymmetric synthesis of axially chiral carboxylic acids with CO2, which is enabled by nickel-catalyzed dynamic kinetic asymmetric reductive carboxylation of racemic aza-biaryl triflates. A variety of important axially chiral carboxylic acids, which are valuable but difficult to obtain via catalysis, are generated in an enantioconvergent version. This new methodology features good functional group tolerance, easy to scale-up, facile transformation and avoids cumbersome steps, handling organometallic reagents and using stoichiometric chiral materials. Mechanistic investigations indicate a dynamic kinetic asymmetric transformation process induced by chiral nickel catalysis.
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Radiofrequency ablation (RFA) is the treatment of choice for atrial fibrillation (AF). Additionally, the utilization of 3D printing for cardiac models offers an in-depth insight into cardiac anatomy and cardiovascular diseases. The study aims to evaluate the clinical utility and outcomes of RFA following in vitro visualization of the left atrium (LA) and pulmonary vein (PV) structures via 3D printing (3DP). Between November 2017 and April 2021, patients who underwent RFA at the First Affiliated Hospital of Xinxiang Medical University were consecutively enrolled and randomly allocated into two groups: the 3DP group and the control group, in a 1:1 ratio. Computed tomography angiography (CTA) was employed to capture the morphology and diameter of the LA and PV, which facilitated the construction of a 3D entity model. Additionally, surgical procedures were simulated using the 3D model. Parameters such as the duration of the procedure, complications, and rates of RFA recurrence were meticulously documented. Statistical analysis was performed using the t-test or Mann-Whitney U test to evaluate the differences between the groups, with a P-value of less than 0.05 considered statistically significant. In this study, a total of 122 patients were included, with 53 allocated to the 3DP group and 69 to the control group. The analysis of the morphological measurements of the LA and PV taken from the workstation or direct entity measurement showed no significant difference between the two groups (P > 0.05). However, patients in the 3DP group experienced significantly shorter RFA times (97.03 ± 28.39 compared to 120.51 ± 44.76 min, t = 3.05, P = 0.003), reduced duration of radiation exposure (2.55 [interquartile range 2.01, 3.24] versus 3.20 [2.28, 3.91] min, Z = 3.23, P < 0.001), and shorter modeling times (7.68 ± 1.03 compared to 8.89 ± 1.45 min, t = 5.38, P < 0.001). 3DP technology has the potential to enhance standard RFA practices by reducing the time required for intraoperative interventions and exposure to radiation.