RESUMO
This paper outlines an innovative three-component coupling strategy for the 1,4-difunctionalization of 1,3-butadiene, utilizing sodium decatungstate (NaDT) as a hydrogen atom transfer (HAT) photocatalyst. The photoinduced process efficiently generates homoallylic amino acid esters with 100% atom economy, employing readily available components under mild reaction conditions. This light-induced protocol eliminates the need for an additional transition metal catalysts, additives, or equivalent reducing agents. The study explored various C(sp3)-H bearing partners, butadienes, and α-iminoesters, demonstrating the versatility and synthetic utility of this method.
RESUMO
The landfill is one of the most important sources of microplastics (MPs). The pretreatment method is a precondition of microplastics study for the presence of complex substances in landfills. Therefore, it is essential to examine the impact of different pretreatment methods on the microplastics detection. A literature review and a comparison experiment on digestion solutions were performed to establish a comprehensive identification method for MPs in landfills. When exposed to of 30 % H2O2, minimal mass reduction of PE, PP and PET were 4.00 %, 3.00 % and 3.00 % respectively, and the least surface damage was observed in MPs, while exhibiting the most optimal peak value for infrared spectral characteristics. It is demonstrated that the effect of 30 % H2O2 dissolution was superior compared to 10 % KOH and 65 % HNO3. The method was subsequently utilized to investigate the distribution of MPs in a landfill. The dominant MPs were polyethylene (PE, 18.56-23.91 %), polyethylene terephthalate (PET, 8.80-18.66 %), polystyrene (PS, 10.31-18.09 %), and polypropylene (PP, 11.60-14.91 %). The comprehensive identification method of "NaCl density separation + 30 % H2O2 digestion + NaI density separation + sampling microscope + Mirco-FTIR" is suitable for the detection of MPs in landfills.
Assuntos
Resíduos Sólidos , Instalações de Eliminação de Resíduos , Eliminação de Resíduos/métodos , Polietileno/análise , Polietilenotereftalatos/análise , Poliestirenos/análise , Polipropilenos/análiseRESUMO
Three-component diene carboaminations offer a potent means to access synthetically valuable allylic amines with rapid molecular complexity escalation. The existing literature primarily discloses racemic examples, necessitating the use of halides/pseudohalides as substrates. This paper introduces a photoinduced Pd-catalyzed enantioselective three-component carboamination of aryl-substituted 1,3-dienes, leveraging aliphatic C-H bonds for rapid synthesis. The reaction employs 10 mol % of chiral palladium catalyst and an excess aryl bromide as the HAT reagent. This approach yields diverse chiral allylamines with moderate to excellent enantioselectivities. Notably, it stands as the first instance of an asymmetric three-component diene carboamination reaction, directly utilizing abundant C(sp3)-H bearing partners, such as toluene-type substrates, ethers, amines, esters, and ketones. The protocol exhibits versatility across amines, encompassing aliphatic, aromatic, primary, and secondary derivatives. This method could serve as a versatile platform for stereoselective incorporation of various nucleophiles, dienes, and C(sp3)-H bearing partners.
RESUMO
The cycle of precipitation change is key to understanding the driving mechanism of the East Asian summer monsoon (EASM). However, the dominant cycles of EASM precipitation revealed by different proxy indicators are inconsistent, leading to the "Chinese 100 kyr problem". In this study, we examine a high-resolution, approximately 350,000-year record from a low-latitude loess profile in China. Our analyses show that variations in the ratio of dithionite-citrate-bicarbonate extractable iron to total iron are dominated by the ~20-kyr cycle, reflecting changes in precipitation. In contrast, magnetic susceptibility varies with the ~100-kyr cycle and may be mainly controlled by temperature-induced redox processes or precipitation-induced signal smoothing. Our results suggest that changes in the EASM, as indicated by precipitation in this region, are mainly forced by precession-dominated insolation variations, and that precipitation and temperature may have varied with different cycles over the past ~350,000 years.
RESUMO
BACKGROUND: Interstitial lung disease (ILD) represents a group of chronic heterogeneous diseases, and current clinical practice in assessment of ILD severity and progression mainly rely on the radiologist-based visual screening, which greatly restricts the accuracy of disease assessment due to the high inter- and intra-subjective observer variability. OBJECTIVE: To solve these problems, in this work, we propose a deep learning driven framework that can assess and quantify lesion indicators and outcome the prediction of severity of ILD. METHODS: In detail, we first present a convolutional neural network that can segment and quantify five types of lesions including HC, RO, GGO, CONS, and EMPH from HRCT of ILD patients, and then we conduct quantitative analysis to select the features related to ILD based on the segmented lesions and clinical data. Finally, a multivariate prediction model based on nomogram to predict the severity of ILD is established by combining multiple typical lesions. RESULTS: Experimental results showed that three lesions of HC, RO, and GGO could accurately predict ILD staging independently or combined with other HRCT features. Based on the HRCT, the used multivariate model can achieve the highest AUC value of 0.755 for HC, and the lowest AUC value of 0.701 for RO in stage I, and obtain the highest AUC value of 0.803 for HC, and the lowest AUC value of 0.733 for RO in stage II. Additionally, our ILD scoring model could achieve an average accuracy of 0.812 (0.736 - 0.888) in predicting the severity of ILD via cross-validation. CONCLUSIONS: In summary, our proposed method provides effective segmentation of ILD lesions by a comprehensive deep-learning approach and confirms its potential effectiveness in improving diagnostic accuracy for clinicians.
Assuntos
Aprendizado Profundo , Doenças Pulmonares Intersticiais , Humanos , Tomografia Computadorizada por Raios X/métodos , Doenças Pulmonares Intersticiais/diagnóstico por imagem , Pulmão/diagnóstico por imagem , Pulmão/patologia , Estudos RetrospectivosRESUMO
Background: Diverse representation in clinical trials is an important goal in the testing of a medical, diagnostic, or therapeutic intervention. To date, the desired level of trial equity and inclusivity has been unevenly achieved. Methods: Employing the US National Library of Medicine's Clinicaltrials.gov registry, we examined 481 clinical trials conducted - at least in part - in the state of New Jersey. These trials were initiated after the FDA-mandated Common Rule changes, i.e., between January 2017 and October 2022, were enacted, and had their results posted. We analyzed sex/race/ethnicity reporting as well as applicable enrollment. Using meta-analysis, we estimated group participation proportions of a subset of the 481 identified trials; specifically, the 229 studies that were conducted solely within the US (i.e., without international sites) and compared them to US census data. Findings: Within the 481 clinical trials analyzed, over 97% reported on the race and/or ethnicity of their enrollees; all included information on sex. Reporting was not affected by funding source or therapeutic area. Based on the 229 solely US-based studies, the participants overall were 76.7% White; 14.1% Black; 2.7% Asian; and 15% Hispanic. Inclusion of Black participants did not differ from the 2020 US census data; in contrast, the levels of Asian and Hispanic participation were below the corresponding census percentages. Interpretation: The past five years have seen an overall uptick in the equity of race/ethnicity reporting and inclusivity of clinical trials, as compared to previously reported data, presaging the potential acquisition of ever more powerful and meaningful results of such interventional studies going forward. Funding: Support for this study comes from the Hackensack Meridian Health Research Institute and the Hackensack Meridian School of Medicine. Research in context: Evidence before this studyClinical trials are a critical part of determining whether or not a medical (drug/device/biologic) or socio-behavioral intervention is safe and truly effective. Through their use, scientific understanding is advanced and, ideally, human health is improved. To gain the most impactful information from a clinical trial, it should be sufficiently representative, that is, should enroll an adequate number of participants, and include a diverse population. Without such inclusion, the study is of only limited generalizability. Efforts are underway by funders, sites, and other stakeholders, to enhance reporting and promote inclusive enrollment. The extent to which such attempts are yielding results - at least for clinical trials in the state of New Jersey - is the focus of this data-driven analysis. The ClinicalTrials.gov registry database was carefully mined for the information contained in this report.Added value of this studyOur analysis of clinical trials initiated in the state of New Jersey and conducted there or elsewhere in the US reveals several positive trends. Our 5-year snapshot reveals that a very large percentage of trials report on race/ethnicity - and inclusivity is improving. While there is still some way to go to have the demographic numbers in these trials match US census values, our results suggest that recent efforts are having an effect.Implications of all the available evidenceFor myriad reasons, clinical trials have not enjoyed the public's universal trust over the years. In many ways, medicine moves at the speed of trust - without it, the promise of modern healthcare is brought into question. Clinical trials must include a commitment to diverse enrollment pools and equitable reporting under the law. Creating a legacy of trust - through greater inclusivity in clinical trials and more transparent reporting of results - will begin to heal the divide and engender faith in modern medicine and today's healthcare system. It would also allow for the desired far-reaching generalizability of results across patient populations. To better appreciate what needs to be done going forward, we must truly understand the state of clinical trials reporting and demographic inclusion. This report initiates such an analysis, by carefully documenting how New Jersey's clinical trials are performing. By virtue of its location (e.g., proximity to the cities of New York and Philadelphia) the state is part of a large biopharma cluster and healthcare nexus; it is critical that it performs well with respect to adopting/adhering to updated clinical trial guideline mandates. This report provides a glimpse - an important first look - into the state of clinical trials in New Jersey - from 2017 through 2022.
RESUMO
Purpose: The COVID-19 pandemic has dramatically affected all aspects of people's lives and work, negatively impacting personal well-being and job satisfaction. Based on the conservation of resources theory, this study examines the relationship of organizational adaptive practices (OAP) responding to COVID-19 and psychological resilience (PR) with employee job satisfaction (JS) while incorporating the mediating role of emotional exhaustion (EE). Methods: We surveyed 340 employees from China through an online questionnaire, which was used under convenience sampling and finally recovered a valid sample size of 314. We used SPSS and AMOS to analyze the correlation and hypothesis testing of the collected data through structural equation modelling (SEM) and bootstrapping. Results: Both OAP and PR facilitate JS and inhibit employee EE. EE negatively predicted employee JS. EE mediated both the relationship between OAP and subordinate JS and the relationship between PR and subordinate JS. Conclusion: The study provides a new perspective on increasing JS during the COVID-19 pandemic, thereby expanding the scope of the antecedents of employee JS in crisis situations. It also reveals the mediating role of EE and deepens the research on the mechanism by which OAP and PR affect individuals, providing practical guidance for organizations to improve employee satisfaction in sudden public crisis situations.
RESUMO
OBJECTIVE: To explore the use of ChatGPT by educators and students in a medical school setting. METHOD: This study used the public version of ChatGPT launched by OpenAI on November 30, 2022 (https://openai.com/blog/chatgpt/). We employed prompts to ask ChatGPT to 1) generate a content outline for a session on the topics of cholesterol, lipoproteins, and hyperlipidemia for medical students; 2) produce a list of learning objectives for the session; and 3) write assessment questions with and without clinical vignettes related to the identified learning objectives. We assessed the responses by ChatGPT for accuracy and reliability to determine the potential of the chatbot as an aid to educators and as a "know-it-all" medical information provider for students. RESULTS: ChatGPT can function as an aid to educators, but it is not yet suitable as a reliable information resource for educators and medical students. CONCLUSION: ChatGPT can be a useful tool to assist medical educators in drafting course and session content outlines and create assessment questions. At the same time, caution must be taken as ChatGPT is prone to providing incorrect information; expert oversight and caution are necessary to ensure the information generated is accurate and beneficial to students. Therefore, it is premature for medical students to use the current version of ChatGPT as a "know-it-all" information provider. In the future, medical educators should work with programming experts to explore and grow the full potential of AI in medical education.
RESUMO
A highly enantio- and diastereoselective approach has been developed for the synthesis of chiral phosphono dihydropyranones. This approach is enabled by Pd/chiral isothiourea relay catalysis under mild reaction conditions, starting from readily available benzyl bromides, CO, and α-ketophosphonates. The cascade reaction involves the generation of a ketene intermediate from Pd-catalyzed carbonylation of benzyl bromide and subsequent chiral Lewis base catalyzed formal [4 + 2] reaction. Phosphono lactone products can also be transformed to chiral 1,5-diester products in good yield and high stereoselectivity.
RESUMO
In the face of an increasingly complex competitive environment, a company's ability to innovate is the key to a gaining sustainable competitive advantage. As the cornerstone of an organization's survival and development, employee innovative behavior is key to enhancing an organization's innovative capability. Based on a conservation of resources, this study investigates the mechanism of the role of superior-subordinate guanxi on employees' innovative behavior from both emotional and cognitive perspectives. Through the analysis of 305 full-time employees' research data, the results show that superior-subordinate guanxi can promote employees' innovative behavior by stimulating their work passion and reducing their dependence on superiors. Our research provides certain theoretical guidance and policy recommendations for enterprises to improve the innovation ability of employees by revealing the internal mechanism of superior-subordinate guanxi affecting the innovation behavior of employees.
RESUMO
Asymmetric Brønsted acid catalysis has been recognized as a powerful concept for asymmetric synthesis. In the process of pursuing more robust and highly effective chiral Brønsted acid catalysts, chiral bisphosphoric acids have received much attention in the last two decades. Their unique catalytic properties are mainly attributed to the inherent intramolecular hydrogen bonding interactions that could increase the overall acidity and tune the conformation property. Integrating hydrogen bonding into the catalyst design, quite a few structurally unique and effective bisphosphoric acids have been synthesized, which frequently exhibited superior selectivity in a broad range of asymmetric transformations. This review summarizes the status quo of chiral bisphosphoric acid catalysts and their applications in catalyzing asymmetric transformations.
RESUMO
The "trinitrogen" [ammonia nitrogen (NH4+ - N), nitrate nitrogen (NO3- - N), and nitrite nitrogen (NO2- - N)] from industrial or domestic wastewater can lead to eutrophication of water bodies. When ammonia nitrogen is converted into nitrate nitrogen, it will cause high nitrogen oxygen demand, which will also lead to hyperammonemia. High nitrite content in water bodies will increase the risk of human cancer. In this paper, Fe-Ce bimetallic-doped composites (Fe-Ce/SiO2 and Fe-Ce-SiO2/TiO2) were synthesized using SiO2 aerogel as a carrier for the adsorption and degradation of "three nitrogen."SiO2/TiO2 was prepared by dipping method, and Fe and Ce bimetals were loaded on the surface of SiO2/TiO2 material, and the effect of photo-Fenton oxidation on the degradation rate of three nitrogen under different materials was explored. The results showed that when the dosage of catalyst was 0.01 g, pH value was 11.0, and the concentration of H2O2 was 80 mmol/L, the photocatalytic efficiency was the best, and the degradation efficiency of three nitrogen remained above 70%.
Assuntos
Nitratos , Nitritos , Humanos , Nitritos/química , Nitratos/química , Amônia/química , Dióxido de Silício/química , Peróxido de Hidrogênio/química , Titânio/química , Água , Nitrogênio , CatáliseRESUMO
A highly enantioselective cascade carbonylation/annulation of benzyl bromides, CO, and vinyl benzoxazinanones under mild conditions has been established by Pd/chiral Lewis base relay catalysis, providing an efficient method to assemble chiral quinolinones from readily available starting materials in good yields with excellent diastereo- and enantioselectivities. The palladium catalyst plays two roles in this reaction, enabling both the carbonylation process and the generation of the zwitterionic π-allyl palladium intermediate.
RESUMO
The diverse functionalization of 1,3-butadiene provides wide applicability toward the synthesis of abundant and useful allylic compounds. Here, we describe a three-component and redox-neutral assembly of readily available CâX compounds, 1,3-butadiene, and various nucleophiles by merging photoredox and nickel catalysis, enabling the rapid synthesis of structurally diverse homoallyl amines and homoallylic alcohols.
Assuntos
Butadienos , Níquel , Oxirredução , CatáliseRESUMO
The first Municipal solid waste incineration (MSWI) plant in Lhasa, Tibet, the plateau region of China, started its operation in 2018. Considering the elevation and extreme climate (low pressure and low oxygen content) in Tibet, noticeable differences may be envisaged compared to MSWI elsewhere. The aim of this study is to evaluate the environmental impacts, economic benefits, and energy efficiency of this MSWI project with three representative MSWI case in plain region using Life cycle assessment (LCA), Cost-benefit analysis (CBA), and energy analysis methods. The result showed that enhancing blast volume and cross-sectional area of the boiler help adapt to the oxygen-deficient environment. GaBi model was employed based on the CML 2001 methodology to perform LCA. LCA shows that the Lhasa MSWI project has lower positive environment impacts than the projects in plain region. More attention is needed for the deficiencies in flue gas emissions of MSWI in the plateau region. CBA shows that the payback period is 11.97 years and the internal rate of return is 8.75%. The energy analysis indicates that the boiler energy efficiency is up to 81.92%. MSWI subject to minor changes seems suitable to Tibetan plateau, and can be deployed further.
Assuntos
Incineração , Eliminação de Resíduos , Resíduos Sólidos/análise , Tibet , Oxigênio , ChinaAssuntos
Técnicas de Imagem por Elasticidade , Hepatite B , Hipertensão Portal , Humanos , Baço/diagnóstico por imagem , Baço/patologia , Dureza , Fígado/diagnóstico por imagem , Fígado/patologia , Cirrose Hepática/complicações , Cirrose Hepática/diagnóstico por imagem , Hipertensão Portal/diagnóstico por imagem , Hipertensão Portal/etiologia , Hepatite B/complicações , Hepatite B/diagnósticoRESUMO
Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive neuromodulation technique, and it has been increasingly used as a nonpharmacological intervention for the treatment of various neurological and neuropsychiatric diseases, including depression. In humans, rTMS over the prefrontal cortex is used to induce modulation of the neural circuitry that regulates emotions, cognition, and depressive symptoms. However, the underlying mechanisms are still unknown. In this study, we investigated the effects of a short (5-day) treatment with high-frequency (HF) rTMS (15 Hz) on emotional behavior and prefrontal cortex morphological plasticity in mice. Mice that had undergone HF-rTMS showed an anti-depressant-like activity as evidenced by decreased immobility time in both the Tail Suspension Test and the Forced Swim Test along with increased spine density in both layer II/III and layer V apical and basal dendrites. Furthermore, dendritic complexity assessed by Sholl analysis revealed increased arborization in the apical portions of both layers, but no modifications in the basal dendrites branching. Overall, these results indicate that the antidepressant-like activity of HF-rTMS is paralleled by structural remodeling in the medial prefrontal cortex.
RESUMO
Purpose: Although social networking services (SNSs) have attracted billions of people to maintain and extend their social relationships online, more and more passive usage behaviors have been found during the daily SNS usage. The aim of this paper is to investigate how SNS users' continuance intention is affected by passive SNS use, subjective well-being, as well as perceived concern regarding privacy and impression management. Methods: A research model was developed according to the proposed hypotheses, and then partial least square (PLS) SEM was adopted to empirically assess the valid data collected from 389 WeChat users. Results: The findings show that passive SNS use cannot significantly undermine continuance intention, but it has a negative moderating effect on the relationship between subjective well-being and continuance intention. Besides, the results of empirical research also reveal the antecedents of passive SNS use and subjective well-being from the perspectives of privacy concern and impression management concern, and thereby present the mechanism underlying users' continuance intention. Conclusion: This study enriches the SNS literature by indicating the moderating role of passive SNS use in the process of SNS usage, which facilitates the understanding regarding how users' continuance intention can be influenced when they use SNSs passively. This study can help SNS providers to better understand the factors affecting users' continuance intention in the case of passive SNS use, and then formulating effective strategies for retaining users and avoiding passive usage behaviors.
RESUMO
Since emergency management capabilities with respect to COVID-19 differ across different regions of China, it is necessary to adopt a more comprehensive perspective to study the reasons for these differences and propose corresponding policies. By investigating 287 prefectural-level administrative regions, this study explores the reasons for different levels of COVID-19 prevention performance. The results lead to the following conclusions. The factors influencing pandemic prevention include both structural factors, such as economic and social factors, and the experiences and characteristics of prefectural-level government leaders (party secretaries and mayors), such as grassroots work experience and level of education, which are significantly positively correlated with the progress of pandemic prevention. Based on these findings, we propose suggestions to improve governance capacity in terms of three aspects: the improvement of emergency management capacity, the appointment of cadres in the context of new challenges and missions, and the establishment collocation of prefectural-level leader teams.