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The study aims to execute machine learning (ML) method for building an intelligent prediction system for catalytic activities of a relatively big dataset of 1056 transition metal complex precatalysts in ethylene polymerization. Among 14 different algorithms, the CatBoost ensemble model provides the best prediction with the correlation coefficient (R2 ) values of 0.999 for training set and 0.834 for external test set. The interpretation of the obtained model indicates that the catalytic activity is highly correlated with number of atom, conjugated degree in the ligand framework, and charge distributions. Correspondingly, 10 novel complexes are designed and predicted with higher catalytic activities. This work shows the potential application of the ML method as a high-precision tool for designing advanced catalysts for ethylene polymerization.
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In anticipation of the correlations between catalyst structures and their properties, the catalytic activities of 2-imino-1,10-phenanthrolyl iron and cobalt metal complexes are quantitatively investigated via linear machine learning (ML) algorithms. Comparatively, the Ridge Regression (RR) model has captured more robust predictive performance compared with other linear algorithms, with a correlation coefficient value of R2= 0.952 and a cross-validation value of Q2= 0.871. It shows that different algorithms select distinct types of descriptors, depending on the importance of descriptors. Through the interpretation of the RR model, the catalytic activity is potentially related to the steric effect of substituents and negative charged groups. This study refines descriptor selection for accurate modeling, providing insights into the variation principle of catalytic activity.
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The clinical data of 246 patients with acute pancreatitis who met the inclusion and exclusion criteria in our hospital from May 2018 to May 2020 were collected as the modeling group, and 96 patients were used as the model validation group. To observe the expression of mir-25-3p, CARD9 and Survivin in patients with acute pancreatitis. To analyze the prognostic factors of acute pancreatitis by univariate and multivariate analysis, and to establish and validate the prognostic model of acute pancreatitis. Results: There was no significant difference in general data between the two groups (P>0.05). Of 246 AP patients, 217 survived and 29 died. The APACHEI score, BISAP score, CRP, lipase, lactate, mir-25-3p, CARD9 and Survivin in the survival group were lower than those in the death group, and the differences were statistically significant (P<0.05). There was no significant difference in other indexes (P>0.05). APACHEI score, BISAP score, CRP, lipase, lactate, mir-25-3p, CARD9 and Survivin were included in multivariate logistic regression analysis. Survival =1 and death =0 were the dependent variables. BISAP score, CRP, lipase, lactate, mir-25-3p, CARD9 and Survivin were all protective factors for the survival of AP patients. Log(P)=-1.648×BISAP score -0.045×CRP-0.013× lipase-0.205 × lactate-1.339 × Mir-25-3P-2.701 ×CARD9-1.663×Survivin+43.925. The survival protective factors of AP patients were incorporated into R software to establish the nomogram prediction model.
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MicroRNAs , Pancreatite , Humanos , Pancreatite/genética , Survivina/genética , Índice de Gravidade de Doença , Doença Aguda , Lactatos , Estudos Retrospectivos , Proteínas Adaptadoras de Sinalização CARD , MicroRNAs/genéticaRESUMO
Interfacial active water molecule-induced parasitic reactions and stochastic Zn2+ transport-caused dendrite issue significantly impede the implementation of aqueous Zn-ion batteries. Herein, three positively charged amino acids, namely arginine, histidine, and lysine, were utilized as adsorption-type electrolyte additives to enhance the stability and reversibility of Zn anodes. Combined theoretical and experimental analyses verified that these amino acid cations can synergistically modulate the interfacial microenvironment and promote orientational Zn deposition. The adsorbed amino acid cations reconfigured the interfacial electric double layer structure, forming SO42-- and H2O-poor interfaces, thereby retarding hydrogen evolution and corrosion side reactions. Simultaneously, the preferential adsorption of the amino acid cations at specific facets induced crystallographic orientational Zn deposition along unterminated facets. Three deposition architectures, namely planar texture, subvertical alignment, and vertical erection, were obtained, all effectively inhibiting dendrite formation. Consequently, symmetric cells with the three amino acid cations exhibited high stripping/plating reversibility of over 2000 cycles at 5 mA cm-2. Moreover, MnO2-based full cells exhibited markedly improved stabilities compared with their additive-free counterparts.
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In recent years, researchers have put much attention on the improvements and upgrades of novel wet strength agent in the papermaking fields, especially in the usage of household paper. Herein, PEIM-KH560 by polyethyleneimine (PEI) and γ-glycidyl ether propyl trimethoxysilane (KH560) was synthesized with five molecular weights (Mw) of PEI at 600, 1800, 10,000, 70,000 and 750,000. Results showed that the molecular weight greatly influenced the physicochemical properties of PEI-KH560, such as the size and thermal stability. The intrinsic cationic charge of PEI-KH560 provided the bonding sites with the paper fibers, forming strengthened fiber-fiber joints. It was shown that the dry, wet strength and hydrophobicity of cellulosic paper sheets were obviously improved. When the m (PEI):m(KH560) is 1:2, the strength of papers after sizing by Mw of PEI at 600 and 1800 is the most obvious, with the dry strength increased by 227.9 % and 187.5 %, and the wet strength increased by 183.8 % and 207.8 %, respectively. The maximum hydrophobicity was found at the PEI1800-KH560 with the contact angle value of 130.6°. The resultant environmental-friendly agent (PEI-KH560) obtained in this work provides valuable significance for the preparation of household and food packaging paper.
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Interações Hidrofóbicas e Hidrofílicas , Peso Molecular , Papel , Polietilenoimina , Polietilenoimina/química , Silanos/química , Propriedades de SuperfícieRESUMO
BACKGROUND: Patients with myocardial infarction (MI) can have disturbed sleep, but little is known about the efficacy of light therapy on sleep and prognosis of patients with MI. We conducted a randomized controlled study to investigate its efficacy. MATERIAL AND METHODS: This preliminary study included 34 patients with MI. They were randomized into the blue light and the white light groups during their stay in intensive care unit. 17 age and gender matched healthy controls were also enrolled. Actigraphy was used to evaluate objective sleep since enrollment. Delirium scales were used to screen delirium. Lab work-up including vitamin D level was performed at the baseline and discharge. We used Mann-Whitney U test or Wilcoxon signed-rank test to compare the difference between the MI group and the healthy control group, and the group difference after receiving light therapy. RESULTS: Patients with MI had significantly lower vitamin D level than healthy controls (p<0.001). They also had significantly poorer sleep, as indicated by actigraphy parameters including sleep onset latency (p=0.01), sleep efficiency (p=0.002), wake after sleep onset (p<0.001) and awake times (p=0.002). No significant group difference was found by actigraphy after light therapy except a non-significant higher relative amplitude of the blue light group (p=0.061). Besides, vitamin D level of the blue light group increased significantly (p1=0.047, p2=0.045). CONCLUSIONS: Patients with MI had poorer sleep, highlighting the needs to develop interventions. Significantly increased vitamin D level and a non-significant better rest-active rhythm after light therapy suggest its potential with sleep and prognosis which warrants further investigation.
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Lignin, which is rich in phenolic hydroxyl/methoxy groups as redox active groups, is a potential electrolyte material for aqueous redox flow batteries (ARFBs). This work demonstrated to the synthesis of lignin-derived electrolytes via cyclization with 1,4-dihydroxyanthraquinone (1,4-DHAQ), in the absence of hazardous or noble metal catalysts in mild conditions (0 °C, 1 atm). The structure of lignin anthraquinone derivatives (LAQDs) cyclized in basis alkaline solution was experimentally determined. An exhaustive comparative study was conducted with respect to the electrochemical properties, charging-discharging tests and cycling performances. The initially volumetric capacitance, the capacity retention rate and coulombic efficiency of two LAQDs were determined to be 148.0 mAh.L-1, 89.3 % and 99.0 % for coniferaldehyde-anthraquinone derivative [LAQD(G)], and 132.1 mAh.L-1, 81.2 % and 99.0 % for sinusaldehyde-anthraquinone derivative [LAQD(S)], respectively. The theoretical value calculated by DFT is consistent with the actual value. Such LAQDs can be used as organic electrolyte materials, which can overcome poor chemical stability of anthraquinone, while improving the electrochemical activity of lignin-based electrolyte materials. This technology provides a pathway to prepare organic electrolyte for the development of environment friendly and better energy storage performance electrolytes for ARFBs.
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Antraquinonas , Lignina , Oxirredução , EletrólitosRESUMO
BACKGROUND: Parkinson's disease (PD) is a common degenerative nervous system disease. At present, there are certain limitations in various treatment options aimed at preventing or delaying the progression of PD. Therefore, the exploration of new drugs for PD is beneficial. Mendelian randomization (MR) analysis can be used to explore the association between drugs and diseases. In this study, MR analysis was adopted to investigate the causal relationship between 23 drugs and PD. These drugs have been approved for the treatment of different diseases, such as salicylic acid and derivatives (collectively called salicylates, e.g., aspirin, used for fever and pain relief), antithrombotic agents (e.g., warfarin, aspirin, used for preventing thrombotic events). METHODS: The GWAS data for the 23 drugs were obtained from the UK Biobank (UKB) project, while the GWAS data for PD were sourced from FinnGen. Single-Nucleotide Polymorphisms (SNPs) were selected as instrumental variables (IVs). We first performed a series of quality control steps (including MR-PRESSO) to select the appropriate SNPs. Two-sample MR analysis was performed using five different methods, including inverse variance weighting (IVW) with random-effects model, weighted median, MR-Egger, simple model, and weighted model. At the same time, sensitivity analysis was carried out using the MR-Egger and Cochran's Q test to ensure the authenticity and reliability of the results. RESULTS: In MR-PRESSO, salicylates and antithrombotic agents showed statistically significant associations with PD, respectively. In the main MR analysis (IVW), there was a negative causal relationship between salicylates and PD (OR = 0.73, 95% CI = 0.54-0.98, p = .039). Similarly, there was a negative causal relationship between antithrombotic agents and PD (OR = 0.70, 95%CI = 0.52-0.96, p = .027). No statistically significant association was found between the remaining 21 drugs and PD. CONCLUSION: This MR study demonstrated that salicylates and antithrombotic agents can reduce the risk of PD, thus providing a novel avenue for future drug exploration in PD.
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Doença de Parkinson , Humanos , Doença de Parkinson/tratamento farmacológico , Doença de Parkinson/genética , Fibrinolíticos , Análise da Randomização Mendeliana , Reprodutibilidade dos Testes , Aspirina/efeitos adversos , Ácido Salicílico , Estudo de Associação Genômica AmplaRESUMO
Developing renewable and biodegradable materials derived from cellulose is an attractive strategy to replace petroleum-derived plastics. In this study, metal ions (Cu2+, Fe3+, and Al3+) were added as a green binder into carboxymethyl cellulose (CMC) films to improve their mechanical properties and water resistance capacity. The tensile strengths of CMCAl3+ films were 133 MPa and 99 MPa at 43 % and 97 % humidity, respectively, which were comparable to or greater than those of the majority of commercially available plastics. Additionally, we proposed an interfacial adhesion-assisted molding strategy for forming cellulose-based films, avoiding film wrinkles and unevenness during drying and metal-coordination formation. The resultant films exhibited high transparency, excellent mechanical properties, water resistance capacity, ultraviolet light (UV) shielding, and antibacterial activity. In summary, the biodegradable, eco-friendly, excellent application performance, and adaptability of CMCMn+ (Mn+: polyvalent metal ions) films open new prospects as a viable alternative to non-biodegradable plastics.
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Carboximetilcelulose Sódica , Petróleo , Antibacterianos/farmacologia , Celulose , Plásticos , ÁguaRESUMO
Cathodic catalytic activity and interfacial mass transfer are key factors for efficiently generating hydrogen peroxide (H2O2) via a two-electron oxygen reduction reaction (ORR). In this work, a carbonized carboxymethyl cellulose (CMC)-reduced graphene oxide (rGO) synthetic fabric cathode was designed and constructed to improve two-electron ORR activity and interfacial mass transfer. Carbonized CMC exhibits abundant active carboxyl groups and excellent two-electron ORR activity with an H2O2 selectivity of approximately 87%, higher than that of rGO and other commonly used carbonaceous catalysts. Carbonizing CMC and the agglomerates formed from it restrain the restacking of rGO sheets and thus create abundant meso/macroporous channels for the interfacial mass transfer of oxygen and H2O2. Thus, the as-constructed carbonized CMC-rGO synthetic fabric cathode exhibits exceptional H2O2 electrosynthesis performance with 11.94 mg·h-1·cm-2 yield and 82.32% current efficiency. The sufficient active sites and mass-transfer channels of the cathode also ensure its practical application performance at high current densities, which is further illustrated by the rapid organic pollutant degradation via the H2O2-based electro-Fenton process.
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When old corrugated cardboard (OCC) is returned to the paper mill for repulping and reuse, the starch, which is added to the paper surface as a reinforcement agent, is dissolved into the pulping wastewater. Most of the OCC pulping wastewater is recycled to save precious water resources; however, during the water recycling process, the accumulation of dissolved starch stimulates microbial reproduction, which causes poor water quality and putrid odor. This problem seriously affects the stability of the papermaking process and product quality. In this study, phosphomolybdic acid (H3PMo12O40, abbreviated as PMo12) was utilized to catalyze the waste starch present in papermaking wastewater to monosaccharides, realizing the resource utilization of waste starch. The results showed that the optimized yield of total reducing sugar (78.68 wt%) and glycolic acid (12.83 wt%) was achieved at 145 °C with 30 wt% PMo12 at pH 2, which is equivalent to 91.51 wt% starch recovered from wastewater for resource utilization. In addition, the regeneration of the reduced PMo12 was realized by applying a potential of 1 V for 2 h. Overall, this study has theoretical significance and potential application value for resource utilization of waste starch in OCC pulping process and cleaner management of OCC waste paper.
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Amido , Águas Residuárias , Catálise , Resíduos Industriais/análise , Molibdênio , Ácidos Fosfóricos , ReciclagemRESUMO
Cellulose-based aerogels are considered to be carriers that can absorb oils and organic solvents owing to the merits of low density and high surface area. However, the natural hydrophility and poor mechanical strength often obstruct their widespread applications. In this work, Miscanthus-based dual cross-linked lignocellulosic nanofibril (LCNF) aerogels were prepared by gas phase coagulation and methylene diphenyl dissocyanate (MDI) modification. Due to physical and chemical cross-linking strategies, the optimally 4 M-LCNF aerogels had high surface area of 157.9 m2/g, water contact angle of 138.1°, and enhanced compression properties. Moreover, the modified aerogels exhibited absorption performance for various organic solvents, and the maximal absorption capacity of chloroform was 42 g/g aerogel. Because LCNF was directly produced from Miscanthus without using bleaching reagents, this research provided a more sustainable methodology to utilize lignocelluloses to design robust aerogels to deal with the leakage of oil and organic solvents in industrial applications.
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Lignina/química , Nanofibras/química , Géis/síntese química , Géis/química , Lignina/síntese química , Estrutura Molecular , Solventes/químicaRESUMO
Laparoscopic incisional hernia repair using intraperitoneal onlay mesh (IPOM) is one of the most widely used minimally invasive methods for repairing incisional hernias. The laparoscopic IPOM involves implanting the mesh into the abdominal cavity through laparoscopy to repair an abdominal wall hernia. In the IPOM surgery, after the closure of the hernia ring, an anti-adhesion mesh is placed laparoscopically. The correct placement of this mesh is critical to the success of the method, and surgical skills are required to achieve perfect placement. If the mesh placement is not mastered properly, the operation and anesthesia time will be prolonged. In addition, improper placement of the mesh can lead to serious consequences, such as intestinal obstruction and mesh infection. A "contraposition and alignment" mesh fixation method is described in this study, which involves pre-marking the fixation position of the mesh to reduce the difficulty of mesh placement. A properly placed mesh is completely flat on the peritoneum, the edges are not curled or wrapped, and the mesh is adhered firmly such that there is no displacement after removing the pneumoperitoneum pressure. The "contraposition and alignment" mesh fixation technique offers the advantages of reliable placement of the mesh and fewer complications than other techniques, and it is easy to learn and master. It also allows for positioning the nail gun in advance based on the anatomy of the incisional hernia. This enables the use of the minimum number of nails possible while still ensuring good fixation, which can reduce the occurrence of complications and reduce the cost of surgery. Thus, the mesh fixation method described here is highly suitable for clinical applications based on the aforementioned advantages.
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Hérnia Ventral , Hérnia Incisional , Laparoscopia , Humanos , Hérnia Incisional/cirurgia , Herniorrafia/métodos , Telas Cirúrgicas , Hérnia Ventral/cirurgia , Laparoscopia/métodosRESUMO
BACKGROUND: Cuproptosis has recently been considered a novel form of programmed cell death. To date, long-chain non-coding RNAs (lncRNAs) crucial to the regulation of this process remain unelucidated. AIM: To identify lncRNAs linked to cuproptosis in order to estimate patients' prognoses for hepatocellular carcinoma (HCC). METHODS: Using RNA sequence data from The Cancer Genome Atlas Live Hepatocellular Carcinoma (TCGA-LIHC), a co-expression network of cuproptosis-related genes and lncRNAs was constructed. For HCC prognosis, we developed a cuproptosis-related lncRNA signature (CupRLSig) using univariate Cox, lasso, and multivariate Cox regression analyses. Kaplan-Meier analysis was used to compare overall survival among high- and low-risk groups stratified by median CupRLSig risk score. Furthermore, comparisons of functional annotation, immune infiltration, somatic mutation, tumor mutation burden (TMB), and pharmacologic options were made between high- and low-risk groups. RESULTS: Three hundred and forty-three patients with complete follow-up data were recruited in the analysis. Pearson correlation analysis identified 157 cuproptosis-related lncRNAs related to 14 cuproptosis genes. Next, we divided the TCGA-LIHC sample into a training set and a validation set. In univariate Cox regression analysis, 27 LncRNAs with prognostic value were identified in the training set. After lasso regression, the multivariate Cox regression model determined the identified risk equation as follows: Risk score = (0.2659 × PICSAR expression) + (0.4374 × FOXD2-AS1 expression) + (-0.3467 × AP001065.1 expression). The CupRLSig high-risk group was associated with poor overall survival (hazard ratio = 1.162, 95%CI = 1.063-1.270; P < 0.001) after the patients were divided into two groups depending upon their median risk score. Model accuracy was further supported by receiver operating characteristic and principal component analysis as well as the validation set. The area under the curve of 0.741 was found to be a better predictor of HCC prognosis as compared to other clinicopathological variables. Mutation analysis revealed that high-risk combinations with high TMB carried worse prognoses (median survival of 30 mo vs 102 mo of low-risk combinations with low TMB group). The low-risk group had more activated natural killer cells (NK cells, P = 0.032 by Wilcoxon rank sum test) and fewer regulatory T cells (Tregs, P = 0.021) infiltration than the high-risk group. This finding could explain why the low-risk group has a better prognosis. Interestingly, when checkpoint gene expression (CD276, CTLA-4, and PDCD-1) and tumor immune dysfunction and rejection (TIDE) scores are considered, high-risk patients may respond better to immunotherapy. Finally, most drugs commonly used in preclinical and clinical systemic therapy for HCC, such as 5-fluorouracil, gemcitabine, paclitaxel, imatinib, sunitinib, rapamycin, and XL-184 (cabozantinib), were found to be more efficacious in the low-risk group; erlotinib, an exception, was more efficacious in the high-risk group. CONCLUSION: The lncRNA signature, CupRLSig, constructed in this study is valuable in prognostic estimation of HCC. Importantly, CupRLSig also predicts the level of immune infiltration and potential efficacy of tumor immunotherapy.
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Background: Accumulating evidence suggests that cellular senescence promotes tumor formation and that long non-coding RNAs (lncRNAs) expression predicts tumor prognosis. However, senescence-related variables, particularly lncRNAs, are still largely unknown. Therefore, the present study developed a novel senescence-associated lncRNA signature to predict colorectal cancer (CRC) prognosis. Methods: A co-expression network of senescence-associated mRNAs and lncRNAs was built using RNA-sequence data from The Cancer Genome Atlas (TCGA). By using the prognosis outcomes data of overall survival (OS) and disease-free survival (DFS) from TCGA, we constructed a prognostic senescence-associated lncRNA signature (SenALSig). The OS and DFS were compared between the low- and high- risk groups defined by SenALSig. A single-sample gene set enrichment analysis (ssGSEA) and CIBERSORT algorithm were used to investigate the relationship between the predictive signature and immune status. Finally, the relationship between SenALSig and drug treatment options was investigated. An independent CRC cohort and three CRC cell lines were recruited to perform real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR) analysis to validate the results discovered in silico. Results: A prognostic risk model consisting of six senescence-associated lncRNAs was constructed, including SNHG16, AL590483.1, ZEB1-AS1, AC107375.1, AC068580.3, and AC147067.1. High-risk scores according to the SenALSig were significantly associated with poor OS (hazard ratio =1.218, 95% confidence interval: 1.140-1.301; P<0.001). The model's accuracy was further supported by receiver operating characteristic (ROC) curves (the area under the curve is 0.714) and a principal component analysis (PCA). In univariate and multivariate Cox regression analyses, SenALSig was further found to be a prognostic factor independent of other clinical factors. Furthermore, we discovered that immune checkpoint expression and response to chemotherapy and targeted therapy differed significantly between the SenALSig-stratified high- and low-risk groups. Finally, the qPCR results revealed that the expression levels of the six senescence-associated lncRNAs differed significantly between tumor and normal tissues and between the CRC cell lines and a normal human colon mucosal epithelial cell line. Conclusions: SenALSig can better predict survival and risk in CRC patients, as well as help develop new anti-cancer treatment strategies for CRC.
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Background: The epigenetic regulators of cellular senescence, especially long non-coding RNAs (lncRNAs), remain unclear. The expression levels of lncRNA were previously known to be prognostic indicators for tumors. We hypothesized that lncRNAs regulating cellular senescence could also predict prognosis in patients with hepatocellular carcinoma (HCC) and developed a novel lncRNA predictive signature. Methods: Using RNA sequencing data from The Cancer Genome Atlas Liver Hepatocellular Carcinoma (TCGA-LIHC) database, a co-expression network of senescence-related messenger RNAs (mRNAs) and lncRNAs was constructed. Using univariate Cox regression analysis and a stepwise multiple Cox regression analysis, we constructed a prognostic HCC senescence-related lncRNA signature (HCCSenLncSig). Kaplan-Meier analysis was used to compare the overall survival (OS) of high- and low-risk groups stratified by the HCCSenLncSig. Furthermore, the HCCSenLncSig risk score and other clinical characteristics were included to develop an HCC prognostic nomogram. The accuracy of the model was evaluated by the time dependent receiver operating characteristic (ROC) and calibration curves, respectively. Results: We obtained a prognostic risk model consisting of 8 senescence-related lncRNAs: AL117336.3, AC103760.1, FOXD2-AS1, AC009283.1, AC026401.3, AC021491.4, AC124067.4, and RHPN1-AS1. The HCCSenLncSig high-risk group was associated with poor OS [hazard ratio (HR) =1.125, 95% confidence interval (CI): 1.082-1.169; P<0.001]. The accuracy of the model was further supported by ROC curves (the area under the curve is 0.783, sensitivity of 0.600, and specificity of 0.896 at the cut-off value of 1.447). The HCCSenLncSig was found to be an independent prognostic factor from other clinical factors in both univariate and multivariate Cox regression analyses. The prognostic nomogram shows HCCSenLncSig has a good prognostic effect for survival risk stratification. Finally, we found that a higher number of immunosuppressed Treg cells infiltrate in high-risk patients (P<0.001 compared to low-risk patients), possibly explaining why these patients have a poor prognosis. On the other hand, the expression of immunotherapy markers, such as CD276, PDCD1, and CTLA4, was also up-regulated in the high-risk patients, indicating potential immunotherapy response in these patients. Conclusions: The development of HCCSenLncSig allows us to better predict HCC patients' survival outcomes and disease risk, as well as contribute to the development of novel HCC anti-cancer therapeutic strategies.
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Hydrolysis of polyethylene terephthalate (PET) is an efficient strategy for the depolymerization of waste PET to terephthalic acid (TPA), which can be used as a fundamental building block for the repolymerization of PET or for the synthesis of biodegradable plastics and metal-organic frameworks. However, most of the reported hydrolysis catalysts are strong acids or bases, which are soluble in reaction media and difficult to separate after the reaction, leading to high production costs and a profound influence on the environment. Herein, we propose the use of TPA, the basic unit of PET, as an acid catalyst to promote the hydrolysis of PET. Under optimized conditions, i.e., 2.5 g of PET, a TPA concentration of 0.1 g/mL, mass ratio PET:H2O of 1:8, 220 °C of temperature, and 180 min of reaction time, a PET conversion of up to 100.0% and a TPA yield of 95.5% were achieved. Furthermore, the produced TPA exhibited a high purity of 99%, similar to that of fresh TPA, and was easily recoverable for PET hydrolysis without tedious workup and purification processes. More importantly, the hydrolysis efficiency was maintained over eight consecutive reaction cycles. Overall, this study provides a green, easy, and low-cost technology to recover and reuse TPA for waste PET hydrolysis.
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Ácidos Ftálicos , Polietilenotereftalatos , Catálise , HidróliseRESUMO
Most phenolic resins are synthesized with non-renewable petroleum-based phenol and formaldehyde, which have adverse effects on the environment and human health. To achieve green and sustainable production of phenolic resins, it is important to replace non-renewable toxic phenol and formaldehyde. Herein, a new strategy was proposed to completely replace phenol and formaldehyde, using lignin-derived monomers to synthesize renewable phenolic resins. Lithium aluminum hydride was utilized to reduce lignin-derived monomers, including vanillin, methyl vanillate, and syringaldehyde, to generate the corresponding vanillyl and syringic alcohol. With oxalic acid as the catalyst, vanillyl and syringic alcohol could be polymerized to phenolic resins without using formaldehyde. The structure of the phenolic resins based on lignin-derived monomers was analyzed by Fourier transform infrared spectroscopy and 13C and 31P nuclear magnetic resonance spectroscopy. Differential scanning calorimetry and thermogravimetric analysis were performed to characterize the thermal properties of the phenolic resins. The phenolic resins based on lignin-derived monomers exhibited excellent adhesion strength (6.14 MPa), glass transition temperature (Tg) (107-115 °C), and thermal stability, and its performance was similar to that of the commercial Novolak phenolic resin. This study presents a promising green and sustainable approach to synthesize renewable phenolic resins based on lignin-derived monomers without using formaldehyde.
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Química Verde/métodos , Lignina/química , Fenóis/química , Resinas Sintéticas/síntese química , Adesivos/química , Benzaldeídos/química , Formaldeído/química , Ácido Oxálico/química , PolimerizaçãoRESUMO
Developing low-cost and sustainable fractionation technology is the key to achieve the maximal utilization of lignocellulosic biomass. This study reported benzenesulfonic acid (BA) as a green hydrotrope for efficient lignocellulose conversion into two fractions at atmospheric pressure: (1) a primarily cellulosic solid residue that can be utilized to produce high-value building blocks (lignocellulosic nanomaterials or sugars), and (2) the collected spent acid liquor that can be diluted with anti-solvent to easily obtain lignin nanoparticles. BA hydrotropic method exhibited greater reaction selectivity to solubilize lignin, where approximately 80% lignin were removed at only 80 °C in 20 min. The lower lignin content substrates resulted in relatively higher enzymatic hydrolysis efficiency of 80% and less entangled lignocellulosic nanofibrils (LCNF). Furthermore, the separated lignin particles size can be easily adjusted by the initial acid concentration. Overall, this work presented a promising and simple technology in achieving lignocellulose separation and utilization under mild conditions.