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Recently, there has been a growing interest in variable selection for causal inference within the context of high-dimensional data. However, when the outcome exhibits a skewed distribution, ensuring the accuracy of variable selection and causal effect estimation might be challenging. Here, we introduce the generalized median adaptive lasso (GMAL) for covariate selection to achieve an accurate estimation of causal effect even when the outcome follows skewed distributions. A distinctive feature of our proposed method is that we utilize a linear median regression model for constructing penalty weights, thereby maintaining the accuracy of variable selection and causal effect estimation even when the outcome presents extremely skewed distributions. Simulation results showed that our proposed method performs comparably to existing methods in variable selection when the outcome follows a symmetric distribution. Besides, the proposed method exhibited obvious superiority over the existing methods when the outcome follows a skewed distribution. Meanwhile, our proposed method consistently outperformed the existing methods in causal estimation, as indicated by smaller root-mean-square error. We also utilized the GMAL method on a deoxyribonucleic acid methylation dataset from the Alzheimer's disease (AD) neuroimaging initiative database to investigate the association between cerebrospinal fluid tau protein levels and the severity of AD.
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Doença de Alzheimer , Humanos , Doença de Alzheimer/genética , Simulação por Computador , Bases de Dados Factuais , Modelos Lineares , Processamento de Proteína Pós-TraducionalRESUMO
Hydrogen spillover widely occurs in a variety of hydrogen-involved chemical and physical processes. Recently, metal-organic frameworks have been extensively explored for their integration with noble metals toward various hydrogen-related applications, however, the hydrogen spillover in metal/MOF composite structures remains largely elusive given the challenges of collecting direct evidence due to system complexity. Here we show an elaborate strategy of modular signal amplification to decouple the behavior of hydrogen spillover in each functional regime, enabling spectroscopic visualization for interfacial dynamic processes. Remarkably, we successfully depict a full picture for dynamic replenishment of surface hydrogen atoms under interfacial hydrogen spillover by quick-scanning extended X-ray absorption fine structure, in situ surface-enhanced Raman spectroscopy and ab initio molecular dynamics calculation. With interfacial hydrogen spillover, Pd/ZIF-8 catalyst shows unique alkyne semihydrogenation activity and selectivity for alkynes molecules. The methodology demonstrated in this study also provides a basis for further exploration of interfacial species migration.
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Importance: Sibling death is a highly traumatic event, but empirical evidence on the association of sibling death in childhood and early adulthood with subsequent risk of incident cardiovascular disease (CVD) remains limited. Objective: To evaluate the association between sibling death in the early decades of life and subsequent risk of incident early-onset CVD. Design, Setting, and Participants: This population-based cohort study included 2â¯098â¯659 individuals born in Denmark from 1978 to 2018. Follow-up started at age 1 year or the date of the first sibling's birth, whichever occurred later, and it ended at the first diagnosis of CVD, the date of death, emigration, or December 31, 2018, whichever came first. Data analyses were conducted from November 1, 2021, through January 10, 2022. Exposures: The death of a sibling. Main Outcomes and Measures: The outcome was early-onset CVD. Cox models were used to estimate hazard ratios (HRs) with 95% CIs. Results: This study included 2â¯098â¯659 individuals (1â¯076â¯669 [51.30%] male; median [IQR] age at death of sibling, 11.48 [4.68-21.32] years). During the median (IQR) follow-up of 17.52 (8.85-26.05) years, 1286 and 76â¯862 individuals in the bereaved and nonbereaved groups, respectively, were diagnosed with CVD. Sibling death in childhood and early adulthood was associated with a 17% increased risk of overall CVD (HR, 1.17; 95% CI, 1.10-1.23; cumulative incidence in bereaved individuals, 1.96% [1.61%-2.34%]; cumulative incidence in nonbereaved individuals at age 41 years, 1.35% [1.34%-1.37%]; cumulative incidence difference: 0.61% [95% CI, 0.24%-0.98%]). Increased risks were also observed for most type-specific CVDs, in particular for myocardial infarction (HR, 1.66; 95% CI, 1.12-2.46), ischemic heart disease (HR, 1.52; 95% CI, 1.22-1.90), and heart failure (HR, 1.50; 95% CI, 1.00-2.26). The association was observed whether the sibling died due to CVD (HR, 2.54; 95% CI, 2.04-3.17) or non-CVD (HR, 1.13; 95% CI, 1.06-1.19) causes. The increased risk of CVD was more pronounced for individuals who lost a twin or younger sibling (HR, 1.25; 95% CI, 1.15-1.36) than an elder sibling (HR, 1.11; 95% CI, 1.03-1.20). Conclusions and Relevance: In this cohort study of the Danish population, sibling death in childhood and early adulthood was associated with increased risks of overall and most type-specific early-onset CVDs, with the strength of associations varying by cause of death and age difference between sibling pairs. The findings highlight the need for extra attention and support to the bereaved siblings to reduce CVD risk later in life.
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Doenças Cardiovasculares , Sistema Cardiovascular , Insuficiência Cardíaca , Masculino , Humanos , Feminino , Adulto , Idoso , Lactente , Pré-Escolar , Criança , Adolescente , Adulto Jovem , Irmãos , Doenças Cardiovasculares/epidemiologia , Estudos de CoortesRESUMO
BACKGROUND: When estimating the causal effect on survival outcomes in observational studies, it is necessary to adjust confounding factors due to unbalanced covariates between treatment and control groups. There is no study on multiple robust method for estimating the difference in survival functions. In this study, we propose a multiply robust (MR) estimator, allowing multiple propensity score models and outcome regression models, to provide multiple protection. METHOD: Based on the previous MR estimator (Han 2014) and pseudo-observation approach, we proposed a new MR estimator for estimating the difference in survival functions. The proposed MR estimator based on the pseudo-observation approach has several advantages. First, the proposed estimator has a small bias when any PS and OR models were correctly specified. Second, the proposed estimator considers the advantage pf the pseudo-observation approach, which avoids proportional hazards assumption. A Monte Carlo simulation study was performed to evaluate the performance of the proposed estimator. And the proposed estimator was used to estimate the effect of chemotherapy on triple-negative breast cancer (TNBC) in real data. RESULTS: The simulation studies showed that the bias of the proposed estimator was small, and the coverage rate was close to 95% when any model for propensity score or outcome regression is correctly specified regardless of whether the proportional hazard assumption holds, finite sample size and censoring rate. And the simulation results also showed that even though the propensity score models are misspecified, the bias of the proposed estimator was still small when there is a correct model in candidate outcome regression models. And we applied the proposed estimator in real data, finding that chemotherapy could improve the prognosis of TNBC. CONCLUSIONS: The proposed estimator, allowing multiple propensity score and outcome regression models, provides multiple protection for estimating the difference in survival functions. The proposed estimator provided a new choice when researchers have a "difficult time" choosing only one model for their studies.
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Neoplasias de Mama Triplo Negativas , Humanos , Simulação por Computador , Modelos Estatísticos , Método de Monte Carlo , Pontuação de Propensão , Tamanho da Amostra , FemininoRESUMO
BACKGROUND: When data is distributed across multiple sites, sharing information at the individual level among sites may be difficult. In these multi-site studies, propensity score model can be fitted with data within each site or data from all sites when using inverse probability-weighted Cox regression to estimate overall hazard ratio. However, when there is unknown heterogeneity of covariates in different sites, either approach may lead to potential bias or reduced efficiency. In this study, we proposed a method to estimate propensity score based on covariate balance-related criterion and estimate the overall hazard ratio while overcoming data sharing constraints across sites. METHODS: The proposed propensity score was generated by choosing between global and local propensity score based on covariate balance-related criterion, combining the global propensity score fitted in the entire population and the local propensity score fitted within each site. We used this proposed propensity score to estimate overall hazard ratio of distributed survival data with multiple sites, while requiring only the summary-level information across sites. We conducted simulation studies to evaluate the performance of the proposed method. Besides, we applied the proposed method to real-world data to examine the effect of radiation therapy on time to death among breast cancer patients. RESULTS: The simulation studies showed that the proposed method improved the performance in estimating overall hazard ratio comparing with global and local propensity score method, regardless of the number of sites and sample size in each site. Similar results were observed under both homogeneous and heterogeneous settings. Besides, the proposed method yielded identical results to the pooled individual-level data analysis. The real-world data analysis indicated that the proposed method was more likely to find a significant effect of radiation therapy on mortality compared to the global propensity score method and local propensity score method. CONCLUSIONS: The proposed covariate balance-related propensity score in multi-site distributed survival data outperformed the global propensity score estimated using data from the entire population or the local propensity score estimated within each site in estimating the overall hazard ratio. The proposed approach can be performed without individual-level data transfer between sites and would yield the same results as the corresponding pooled individual-level data analysis.
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Disseminação de Informação , Humanos , Pontuação de Propensão , Modelos de Riscos Proporcionais , Simulação por Computador , Disseminação de Informação/métodos , ViésRESUMO
BACKGROUND: In observational studies, double robust or multiply robust (MR) approaches provide more protection from model misspecification than the inverse probability weighting and g-computation for estimating the average treatment effect (ATE). However, the approaches are based on parametric models, leading to biased estimates when all models are incorrectly specified. Nonparametric methods, such as machine learning or nonparametric double robust approaches, are robust to model misspecification, but the efficiency of nonparametric methods is low. METHOD: In the study, we proposed an improved MR method combining parametric and nonparametric models based on the previous MR method (Han, JASA 109(507):1159-73, 2014) to improve the robustness to model misspecification and the efficiency. We performed comprehensive simulations to evaluate the performance of the proposed method. RESULTS: Our simulation study showed that the MR estimators with only outcome regression (OR) models, where one of the models was a nonparametric model, were the most recommended because of the robustness to model misspecification and the lowest root mean square error (RMSE) when including a correct parametric OR model. And the performance of the recommended estimators was comparative, even if all parametric models were misspecified. As an application, the proposed method was used to estimate the effect of social activity on depression levels in the China Health and Retirement Longitudinal Study dataset. CONCLUSIONS: The proposed estimator with nonparametric and parametric models is more robust to model misspecification.
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Aprendizado de Máquina , Modelos Estatísticos , Humanos , Estudos Longitudinais , Simulação por Computador , ProbabilidadeRESUMO
We report the use of polymer N-heterocyclic carbenes (NHCs) to control the microenvironment surrounding metal nanocatalysts, thereby enhancing their catalytic performance in CO2 electroreduction. Three polymer NHC ligands were designed with different hydrophobicity: hydrophilic poly(ethylene oxide) (PEO-NHC), hydrophobic polystyrene (PS-NHC), and amphiphilic block copolymer (BCP) (PEO-b-PS-NHC). All three polymer NHCs exhibited enhanced reactivity of gold nanoparticles (AuNPs) during CO2 electroreduction by suppressing proton reduction. Notably, the incorporation of hydrophobic PS segments in both PS-NHC and PEO-b-PS-NHC led to a twofold increase in the partial current density for CO formation, as compared to the hydrophilic PEO-NHC. While polymer ligands did not hinder ion diffusion, their hydrophobicity altered the localized hydrogen bonding structures of water. This was confirmed experimentally and theoretically through attenuated total reflectance surface-enhanced infrared absorption spectroscopy and molecular dynamics simulation, demonstrating improved CO2 diffusion and subsequent reduction in the presence of hydrophobic polymers. Furthermore, NHCs exhibited reasonable stability under reductive conditions, preserving the structural integrity of AuNPs, unlike thiol-ended polymers. The combination of NHC binding motifs with hydrophobic polymers provides valuable insights into controlling the microenvironment of metal nanocatalysts, offering a bioinspired strategy for the design of artificial metalloenzymes.
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Efficient C-C bond cleavage and oxidation of alcohols to CO2 is the key to developing highly efficient alcohol fuel cells for renewable energy applications. In this work, we report the synthesis of core/shell Au/Pt nanowires (NWs) with stepped Pt clusters deposited along the ultrathin (2.3 nm) stepped Au NWs as an active catalyst to effectively oxidize alcohols to CO2. The catalytic oxidation reaction is dependent on the Au/Pt ratios, and the Au1.0/Pt0.2 NWs have the largest percentage (â¼75%) of stepped Au/Pt sites and show the highest activity for ethanol electro-oxidation, reaching an unprecedented 196.9 A/mgPt (32.5 A/mgPt+Au). This NW catalyst is also active in catalyzing the oxidation of other primary alcohols, such as methanol, n-propanol, and ethylene glycol. In situ X-ray absorption spectroscopy and infrared spectroscopy are used to characterize the catalyst structure and to identify key reaction intermediates, providing concrete evidence that the synergy between the low-coordinated Pt sites and the stepped Au NWs is essential to catalyze the alcohol oxidation reaction, which is further supported by DFT calculations that the C-C bond cleavage is indeed enhanced on the undercoordinated Pt-Au surface. Our study provides important evidence that a core/shell structure with stepped core/shell sites is essential to enhance electrochemical oxidation of alcohols and will also be central to understanding electro-oxidation reactions and to the future development of highly efficient direct alcohol fuel cells for renewable energy applications.
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Subgroup analysis has become an important tool to characterize the treatment effect heterogeneity, and finally towards precision medicine. On the other hand, longitudinal study is widespread in many fields, but subgroup analysis for this data type is still limited. In this article, we study a partial linear varying coefficient model with a change plane, in which the subgroups are defined based on linear combination of grouping variables, and the time-varying effects in different subgroups are estimated to capture the dynamic association between predictors and response. The varying coefficients are approximated by basis functions and the group indicator function is smoothed by kernel function, which are included in the generalized estimating equation for estimation. Asymptotic properties of the estimators for the varying coefficients, the constant coefficients and the change plane coefficients are established. Simulations are conducted to demonstrate the flexibility, efficiency and robustness of the proposed method. Based on the Standard and New Antiepileptic Drugs study, we successfully identify a subgroup in which patients are sensitive to the newer drug in a specific period of time.
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Algoritmos , Humanos , Estudos Longitudinais , Modelos LinearesRESUMO
Anisotropy is an important and widely present characteristic of materials that provides desired direction-dependent properties. In particular, the introduction of anisotropy into magnetic nanoparticles (MNPs) has become an effective method to obtain new characteristics and functions that are critical for many applications. In this review, we first discuss anisotropy-dependent ferromagnetic properties, ranging from intrinsic magnetocrystalline anisotropy to extrinsic shape and surface anisotropy, and their effects on the magnetic properties. We further summarize the syntheses of monodisperse MNPs with the desired control over the NP dimensions, shapes, compositions, and structures. These controlled syntheses of MNPs allow their magnetism to be finely tuned for many applications. We discuss the potential applications of these MNPs in biomedicine, magnetic recording, magnetotransport, permanent magnets, and catalysis.
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Polymer N-heterocyclic carbenes (NHCs) are a class of robust surface ligands to provide superior colloidal stability for metal nanoparticles (NPs) under various harsh conditions. We report a general method to prepare polymeric NHCs and demonstrate that these polymer NHC-AgNPs are stable against oxidative etching and show high peroxidase activity. We prepared three imidazolium-terminated poly(methyl methacrylate) (PMMA), polystyrene (PS), and poly(2-(2-methoxyethoxy)ethyl methacrylate) (PMEO2MA) through atom-transfer radical polymerization with an imidazole-containing initiator. The imidazolium end group was further converted to NHC-Ag(I) in the presence of Ag2O at room temperature. Polymer NHC-Ag(I) can transmetalate to AgNPs through ligand exchange at the interface of oil/water within 2 min. All the three polymers can modify metal NPs, such as AgNPs, Ag nanowires, and AuNPs, providing excellent thermal, oxidative, and chemical stabilities for AgNPs. As an example, in the presence of hydrogen peroxide, AgNPs modified by polymer NHCs were resistant against oxidative etching with a rate of â¼700 times slower than those grafted with thiolates. AgNPs modified by polymer NHCs also showed higher peroxidase activity, 4 times more active than those capped by citrate and polyvinylpyrrolidone (PVP) and 2 times more active than those with polymer thiolate. Our studies demonstrate a great potential of using polymer NHCs to stabilize metallic NPs for various applications.
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BACKGROUND: Estimating the average effect of a treatment, exposure, or intervention on health outcomes is a primary aim of many medical studies. However, unbalanced covariates between groups can lead to confounding bias when using observational data to estimate the average treatment effect (ATE). In this study, we proposed an estimator to correct confounding bias and provide multiple protection for estimation consistency. METHODS: With reference to the kernel function-based double-index propensity score (Ker.DiPS) estimator, we proposed the artificial neural network-based multi-index propensity score (ANN.MiPS) estimator. The ANN.MiPS estimator employed the artificial neural network to estimate the MiPS that combines the information from multiple candidate models for propensity score and outcome regression. A Monte Carlo simulation study was designed to evaluate the performance of the proposed ANN.MiPS estimator. Furthermore, we applied our estimator to real data to discuss its practicability. RESULTS: The simulation study showed the bias of the ANN.MiPS estimators is very small and the standard error is similar if any one of the candidate models is correctly specified under all evaluated sample sizes, treatment rates, and covariate types. Compared to the kernel function-based estimator, the ANN.MiPS estimator usually yields smaller standard error when the correct model is incorporated in the estimator. The empirical study indicated the point estimation for ATE and its bootstrap standard error of the ANN.MiPS estimator is stable under different model specifications. CONCLUSIONS: The proposed estimator extended the combination of information from two models to multiple models and achieved multiply robust estimation for ATE. Extra efficiency was gained by our estimator compared to the kernel-based estimator. The proposed estimator provided a novel approach for estimating the causal effects in observational studies.
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Algoritmos , Modelos Estatísticos , Humanos , Pontuação de Propensão , Simulação por Computador , Redes Neurais de ComputaçãoRESUMO
OBJECTIVE: To examine the association of maternal hypertensive disorder of pregnancy (HDP) with overall and cause specific mortality in offspring from birth to young adulthood. DESIGN: Nationwide population based cohort study. SETTING: Danish national health registers. PARTICIPANTS: All 2 437 718 individuals live born in Denmark, 1978-2018, with follow-up from date of birth until date of death, emigration, or 31 December 2018, whichever came first. MAIN OUTCOME MEASURES: The primary outcome was all cause mortality. Secondary outcomes were 13 specific causes of death in offspring from birth to young adulthood (age 41 years). Cox regression was used to assess the association, taking into consideration several potential confounders. The role of timing of onset and severity of pre-eclampsia, maternal history of diabetes, and maternal education were also studied. RESULTS: 102 095 mothers had HDP: 67 683 with pre-eclampsia, 679 with eclampsia, and 33 733 with hypertension. During follow-up to 41 years (median 19.4 (interquartile range 9.7-28.7) years), deaths occurred in 781 (58.94 per 100 000 person years) offspring born to mothers with pre-eclampsia, 17 (133.73 per 100 000 person years) born to mothers with eclampsia, 223 (44.38 per 100 000 person years) born to mothers with hypertension, and 19 119 (41.99 per 100 000 person years) born to mothers with no HDP. The difference in cumulative incidence in overall mortality between cohorts exposed and unexposed to maternal HDP was 0.37% (95% confidence interval 0.11% to 0.64%), and the population attributable fraction for maternal HDP was estimated as 1.09% (95% confidence interval 0.77% to 1.41%). Maternal HDP was associated with a 26% (hazard ratio 1.26, 95% confidence interval 1.18 to 1.34) higher risk of all cause mortality in offspring. The corresponding estimates for maternal pre-eclampsia, eclampsia, and hypertension were 1.29 (1.20 to 1.38), 2.88 (1.79 to 4.63), and 1.12 (0.98 to 1.28). Increased risks were also observed for several cause specific mortalities, such as deaths from conditions originating in the perinatal period (2.04, 1.81 to 2.30), cardiovascular diseases (1.52, 1.08 to 2.13), digestive system diseases (2.09, 1.27 to 3.43), and endocrine, nutritional, and metabolic diseases (1.56, 1.08 to 2.27). The increased risks were more pronounced among offspring of mothers with early onset and severe pre-eclampsia (6.06, 5.35 to 6.86) or with both HDP and diabetes history (1.57, 1.16 to 2.14) or HDP and low education level (1.49, 1.34 to 1.66). CONCLUSION: Maternal HDP, particularly eclampsia and severe pre-eclampsia, is associated with increased risks of overall mortality and various cause specific mortalities in offspring from birth to young adulthood.
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Diabetes Mellitus , Eclampsia , Hipertensão Induzida pela Gravidez , Pré-Eclâmpsia , Gravidez , Feminino , Humanos , Adulto Jovem , Adulto , Pré-Eclâmpsia/epidemiologia , Eclampsia/epidemiologia , Estudos de Coortes , Hipertensão Induzida pela Gravidez/epidemiologiaRESUMO
Given the continuous and excessive CO2 emission into the atmosphere from anthropomorphic activities, there is now a growing demand for negative carbon emission technologies, which requires efficient capture and conversion of CO2 to value-added chemicals. This review highlights recent advances in CO2 capture and conversion chemistry and processes. It first summarizes various adsorbent materials that have been developed for CO2 capture, including hydroxide-, amine-, and metal organic framework-based adsorbents. It then reviews recent efforts devoted to two types of CO2 conversion reaction: thermochemical CO2 hydrogenation and electrochemical CO2 reduction. While thermal hydrogenation reactions are often accomplished in the presence of H2, electrochemical reactions are realized by direct use of electricity that can be renewably generated from solar and wind power. The key to the success of these reactions is to develop efficient catalysts and to rationally engineer the catalyst-electrolyte interfaces. The review further covers recent studies in integrating CO2 capture and conversion processes so that energy efficiency for the overall CO2 capture and conversion can be optimized. Lastly, the review briefs some new approaches and future directions of coupling direct air capture and CO2 conversion technologies as solutions to negative carbon emission and energy sustainability.
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We report the synthesis of Cu2O nanoparticles (NPs) by controlled oxidation of Cu NPs and the study of these NPs as a robust catalyst for ammonia borane dehydrogenation, nitroarene hydrogenation, and amine/aldehyde condensation into Schiff-base compounds. Upon investigation of the size-dependent catalysis for ammonia borane dehydrogenation and nitroarene hydrogenation using 8-18 nm Cu2O NPs, we found 13 nm Cu2O NPs to be especially active with quantitative conversion of nitro groups to amines. The 13 nm Cu2O NPs also efficiently catalyze tandem reactions of ammonia borane, diisopropoxy-dinitrobenzene, and terephthalaldehyde, leading to a controlled polymerization and the facile synthesis of polybenzoxazole (PBO). The highly pure PBO (Mw = 19 kDa) shows much enhanced chemical stability than the commercial PBO against hydrolysis in boiling water or simulated seawater, demonstrating a great potential of using noble metal-free catalysts for green chemistry synthesis of PBO as a robust lightweight structural material for thermally and mechanically demanding applications.
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Identifying subpopulations that may be sensitive to the specific treatment is an important step toward precision medicine. On the other hand, longitudinal data with dropouts is common in medical research, and subgroup analysis for this data type is still limited. In this paper, we consider a single-index threshold linear marginal model, which can be used simultaneously to identify subgroups with differential treatment effects based on linear combination of the selected biomarkers, estimate the treatment effects in different subgroups based on regression coefficients, and test the significance of the difference in treatment effects based on treatment-subgroup interaction. The regression parameters are estimated by solving a penalized smoothed generalized estimating equation and the selection bias caused by missingness is corrected by a multiply robust weighting matrix, which allows multiple missingness models to be taken account into estimation. The proposed estimator remains consistent when any model for missingness is correctly specified. Under regularity conditions, the asymptotic normality of the estimator is established. Simulation studies confirm the desirable finite-sample performance of the proposed method. As an application, we analyze the data from a clinical trial on pancreatic cancer.
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Modelos Estatísticos , Projetos de Pesquisa , Simulação por Computador , Humanos , Modelos Lineares , Viés de SeleçãoRESUMO
It has been a long-standing challenge to create and identify the active sites of heterogeneous catalysts, because it is difficult to precisely control the interfacial chemistry at the molecular level. Here we report the synthesis and catalysis of a heteroleptic gold trihydride nanocluster, [Au22H3(dppe)3(PPh3)8]3+ [dppe = 1,2-bis(diphenylphosphino)ethane, PPh3 = triphenylphosphine]. The Au22H3 core consists of two Au11 units bonded via six uncoordinated Au sites. The three H atoms bridge the six uncoordinated Au atoms and are found to play a key role in catalyzing electrochemical reduction of CO2 to CO with a 92.7% Faradaic efficiency (FE) at -0.6 V (vs RHE) and high reaction activity (134 A/gAu mass activity). The CO current density and FECO remained nearly constant for the CO2 reduction reaction for more than 10 h, indicating remarkable stability of the Au22H3 catalyst. The Au22H3 catalytic performance is among the best Au-based catalysts reported thus far for electrochemical reduction of CO2. Density functional theory (DFT) calculations suggest that the hydride coordinated Au sites are the active centers, which facilitate the formation of the key *COOH intermediate.
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Aim: We aimed to develop a new signature based on immune-related genes to predict prognosis and response to immune checkpoint inhibitors in patients with triple-negative breast cancer (TNBC). Materials & methods: Single-sample gene set enrichment was used to develop an immune-based prognostic signature (IPRS) for TNBC patients. We conducted multivariate Cox analysis to evaluate the prognosis value of the IPRS. Result: An IPRS based on 66 prognostic genes was developed. Multivariate Cox analysis indicated that the IPRS was an independent factor for prognosis. PD-1, PD-L1, PD-L2 and CTLA4 gene expression was higher in the low-risk group, suggesting IPRS could predict the response to immune checkpoint inhibitors. Conclusion: The IPRS might be a reliable signature to predict TNBC patients' prognosis and response to immune checkpoint inhibitors, but needs prospective validation.
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Regulação Neoplásica da Expressão Gênica , Inibidores de Checkpoint Imunológico/uso terapêutico , Prognóstico , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Biomarcadores Tumorais , Feminino , Humanos , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/mortalidadeRESUMO
Electrosynthesis is to use electricity to drive chemical reactions for chemical synthesis and is potentially a green approach to fuel and energy sustainability. Nanostructured catalysts play an important role in promoting electrochemical reactions under green chemistry conditions. This perspective first provides a brief tutorial on electrosynthesis and the roles the nanocatalysts play in the synthesis. It then outlines the common strategies used to develop nanocatalysts for hydrogen evolution reaction, CO2 reduction reaction, and biomass upgrading. The perspective further summarizes the current methodologies that have been developed for scaling-up synthesis of nanocatalysts, which will be essential for the electrosynthesis to become a viable industry approach.
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While nanoscale mimics of peroxidase have been extensively developed over the past decade or so, their catalytic efficiency as a key parameter has not been substantially improved in recent years. Herein, we report a class of highly efficient peroxidase mimic-nickel-platinum nanoparticles (Ni-Pt NPs) that consist of nickel-rich cores and platinum-rich shells. The Ni-Pt NPs exhibit a record high catalytic efficiency with a catalytic constant (Kcat) as high as 4.5 × 107 s-1, which is â¼46- and 104-fold greater than the Kcat values of conventional Pt nanoparticles and natural peroxidases, respectively. Density functional theory calculations reveal that the unique surface structure of Ni-Pt NPs weakens the adsorption of key intermediates during catalysis, which boosts the catalytic efficiency. The Ni-Pt NPs were applied to an immunoassay of a carcinoembryonic antigen that achieved an ultralow detection limit of 1.1 pg/mL, hundreds of times lower than that of the conventional enzyme-based assay.