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1.
J Med Virol ; 96(1): e29376, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38235850

RESUMO

Semliki Forest virus (SFV) viral replicon particles (VRPs) have been frequently used in various animal models and clinical trials. Chimeric replicon particles offer different advantages because of their unique biological properties. We here constructed a novel three-plasmid packaging system for chimeric SFV/SIN VRPs. The capsid and envelope of SIN structural proteins were generated using two-helper plasmids separately, and the SFV replicon contained the SFV replicase gene, packaging signal of SIN, subgenomic promoter followed by the exogenous gene, and 3' UTR of SIN. The chimeric VRPs carried luciferase or eGFP as reporter genes. The fluorescence and electron microscopy results revealed that chimeric VRPs were successfully packaged. The yield of the purified chimeric VRPs was approximately 2.5 times that of the SFV VRPs (1.38 × 107 TU/ml vs. 5.41 × 106 TU/ml) (p < 0.01). Furthermore, chimeric VRPs could be stored stably at 4°C for at least 60 days. Animal experiments revealed that mice immunized with chimeric VRPs (luciferase) had stronger luciferase expression than those immunized with equivalent amount of SFV VRPs (luciferase) (p < 0.01), and successfully expressed luciferase for approximately 12 days. Additionally, the chimeric VRPs expressed the RBD of SARS-CoV-2 efficiently and induced robust RBD-specific antibody responses in mice. In conclusion, the chimeric VRPs constructed here met the requirements of a gene delivery tool for vaccine development and cancer therapy.


Assuntos
Vírus da Floresta de Semliki , Sindbis virus , Camundongos , Animais , Vírus da Floresta de Semliki/genética , Sindbis virus/genética , Plasmídeos/genética , Replicon , Luciferases/genética , Vetores Genéticos
2.
BMC Pediatr ; 23(1): 7, 2023 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-36597051

RESUMO

BACKGROUND: Left-to-right shunt congenital heart disease is more likely to induce recurrent respiratory infections in the patients which exacerbate pulmonary hypertension and thereby impairs cardiac function. It is urgent to explore a non-invasive and accurate diagnostic method that can show the cardiac anatomy and associated malformations in clinical research. OBJECTIVE: To determine the diagnostic value of peripheral mucin domain protein-3 (Tim-3), N-terminal pro-brain natriuretic peptide (NT proBNP), sestrin2 testing in patients with the left-to-right shunt congenital heart disease and heart failure. METHODS: Fifty-two neonates with with left to right shunt congenital heart disease and 30 healthy neonates were enrolled. Blood samples were collected within 24 h of admission from newborns for determining the content of TiM-3, NT proBNP, and Sestrin2. Analyzing the ROC curve provided insight into the diagnostic accuracy. Both a Spearman's rank correlation test and a logistic regression analysis were carried out. RESULTS: TiM-3, NT proBNP, and Sestrin2 levels in peripheral blood were statistically different in the three groups (P < 0.05). There were significant differences in LVEF and LVFS among the three groups (P < 0.05). When used to diagnose heart failure in conjunction with left-to-right shunt congenital heart disease, TiM-3, NT proBNP, and Sestrin2 exhibited sensitivity of 58.3, 58.3, and 83.3%, respectively, and specificity of 85.0, 72.5, and 70.0%. ROC curve analysis showed that the AUCs of Tim-3, NT proBNP, and sestrin2 in predicting the outcome of left-to-right shunted congenital heart disease combined with heart failure were 0.744 (95% CI, 0.580 to 0.908), 0.608 (95% CI, 0.359 to 0.857), respectively 0.744 (95% CI 0.592 to 0.896). CONCLUSION: Tim-3, NT proBNP, and sestrin2 can accurately differentiate heart failure from non-combined heart failure from left-to-right shunt congenital heart disease.


Assuntos
Cardiopatias Congênitas , Insuficiência Cardíaca , Humanos , Recém-Nascido , Receptor Celular 2 do Vírus da Hepatite A , Cardiopatias Congênitas/complicações , Cardiopatias Congênitas/diagnóstico , Insuficiência Cardíaca/complicações , Insuficiência Cardíaca/diagnóstico , Peptídeo Natriurético Encefálico , Biomarcadores
3.
Molecules ; 27(15)2022 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-35897914

RESUMO

Allobetulin is structurally similar tobetulinic acid, inducing the apoptosis of cancer cells with low toxicity. However, both of them exhibited weak antiproliferation against several tumor cell lines. Therefore, the new series of allobetulon/allobetulin-nucleoside conjugates 9a-10i were designed and synthesized for potency improvement. Compounds 9b, 9e, 10a, and 10d showed promising antiproliferative activity toward six tested cell lines, compared to zidovudine, cisplatin, and oxaliplatin based on their antitumor activity results. Among them, compound 10d exhibited much more potent antiproliferative activity against SMMC-7721, HepG2, MNK-45, SW620, and A549 human cancer cell lines than cisplatin and oxaliplatin. In the preliminary study for the mechanism of action, compound 10d induced cell apoptosis and autophagy in SMMC cells, resulting in antiproliferation and G0/G1 cell cycle arrest by regulating protein expression levels of Bax, Bcl-2, and LC3. Consequently, the nucleoside-conjugated allobetulin (10d) evidenced that nucleoside substitution was a viable strategy to improve allobetulin/allobetulon's antitumor activity based on our present study.


Assuntos
Antineoplásicos , Cisplatino , Antineoplásicos/farmacologia , Apoptose , Linhagem Celular Tumoral , Proliferação de Células , Cisplatino/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Estrutura Molecular , Nucleosídeos/farmacologia , Oxaliplatina/farmacologia , Relação Estrutura-Atividade
4.
Neurol Sci ; 42(6): 2337-2345, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33043395

RESUMO

AIMS: To detect abnormal eye movements in Parkinson's disease and explore its correlation with clinical characteristics and their value for diagnosis. METHODS: We recruited forty-nine Parkinson's disease patients, including 35 early Parkinson's disease patients (Hoehn-Yahr: 1 to 2 stage) and 14 advanced Parkinson's disease patients (Hoehn-Yahr: 3 to 5 stage) and 23 healthy controls. Clinical manifestations in Parkinson's disease patients were recorded. Oculomotor performances including fixation, gaze, saccade in horizontal and vertical direction, and smooth pursuit in horizontal and vertical direction were measured by video-oculography. RESULTS: We found that five oculomotor parameters, namely square wave jerk frequency, latency of downward saccade, latency of upward saccade, accuracy of upward saccade, and gain of horizontal smooth pursuit were significantly different in Parkinson's disease patients and controls. When combining all these five parameters, we got the diagnostic sensitivity of 78.3% and specificity of 95.2%. More deficits in upward saccade than in other directions were associated with disease duration and progression of Parkinson's disease. CONCLUSION: Our primary study suggests that oculomotor examination might serve as an aid in the clinical assessment of Parkinson's disease patients and differentiating between early Parkinson's disease and normal controls.


Assuntos
Transtornos da Motilidade Ocular , Doença de Parkinson , Movimentos Oculares , Humanos , Transtornos da Motilidade Ocular/diagnóstico , Transtornos da Motilidade Ocular/etiologia , Doença de Parkinson/complicações , Doença de Parkinson/diagnóstico , Acompanhamento Ocular Uniforme , Movimentos Sacádicos
5.
Int J Clin Pract ; 75(6): e13939, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33336480

RESUMO

OBJECTIVE: Serum sodium overcorrection and hypernatremia are significant health risks. We conducted a systematic review and meta-analysis to evaluate the risks of vaptans in hypernatremia and serum sodium overcorrection. METHODS: We searched PubMed, Embase, and CENTRAL for randomised controlled trials. We included studies comparing vaptans and placebo with data on hypernatremia and serum sodium overcorrection. The study quality was assessed using the Cochrane Collaboration's risk-of-bias assessment tool. Fixed-effect model meta-analysis was used to pool the data. Different analyses were performed to ensure the accuracy of the results. RESULTS: Twenty-eight studies were included in the meta-analysis of hypernatremia incidence. Treatment with vaptans resulted in a higher risk of hypernatremia than placebo (3.8% vs 1.0%, odds ratio [OR] 2.69; 95% confidence interval [CI] 1.97-3.68). The subgroup with baseline hyponatremia had a lower risk of hypernatremia incidence; however, the use of loop diuretics increased the risk. Fourteen studies were included in the analysis of the incidence of serum sodium overcorrection. A higher risk of serum sodium overcorrection was found in using vaptans vs placebo (4.4% vs 1.4%; OR 2.26; 95% CI 1.32-3.86). CONCLUSION: Vaptans showed higher risks in the incidence of hypernatremia and serum sodium overcorrection than placebo. In addition, combination with loop diuretics increased the risk of hypernatremia. The risk of serum sodium overcorrection should be concerned in patients with hyponatremia and normal serum sodium equally. Using a low dose of vaptans can reduce both risks.


Assuntos
Hipernatremia , Hiponatremia , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto , Sódio
6.
Cytokine ; 133: 155173, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32585582

RESUMO

Diabetic foot ulcers (DFU) remain a serious public health problem. However, the current evaluation and confirmation of the efficacy of DFU is unclear. The present study aimed to measure the alterations of circulating proteins in patients after DFU healing for the exploration of the prognostic biomarkers. The serum cytokine profiles of DFU patients before and after treatment were analyzed by a human antibody microarray technology using diabetic patients and healthy population as control groups. The results showed that ten differential cytokines were associated with DFU healing. Among these ten cytokines, comparing to DFU group, nine ones (Jagged-1, CD14, Cathepsin S, Syndecan 4, MDC, TARC, Angiopoietin-4, Clusterin and HGFR) were significantly up-regulated in DFU-treated group and Follistatin-like 1 was significantly down-regulated, while their levels in DFU-treated group showed no significant differences from those in control groups. Furthermore, ELISA validation also showed that compares to DFU group four of ten (MDC, TARC, Clusterin, and Syndecan 4) were increased in DFU-treated group equal to the levels in control groups, consistent with the array results. Our finding shows that these four cytokines may have great potential for prognostic evaluation of DFU healing.


Assuntos
Anticorpos/uso terapêutico , Biomarcadores/sangue , Citocinas/sangue , Pé Diabético/sangue , Pé Diabético/tratamento farmacológico , Cicatrização/efeitos dos fármacos , Estudos de Casos e Controles , Diabetes Mellitus/sangue , Regulação para Baixo/efeitos dos fármacos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Regulação para Cima/efeitos dos fármacos
7.
Chemistry ; 24(15): 3671-3676, 2018 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-29359832

RESUMO

A difluorobenzothiadiazole-based fluorescent material with a D-π-A-π-D structure exhibits a reversible mechanofluorochromic characteristic in the solid state. Its red fluorescent emission switches to near-infrared fluorescence upon mechanical stimulation, but recover after fuming the ground solid powder with dichloromethane.

8.
Org Biomol Chem ; 16(30): 5517-5523, 2018 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-30027183

RESUMO

Two naphthalimide-based fluorescent probes containing a thiomorpholine (Np-NS) or a sulfoxide-morpholine (Np-NSO) component are reported. The morpholine unit of non-fluorescent Np-NS and Np-NSO can transform into sulphone-morpholine and be accompanied by blue fluorescence upon oxidative stress, ascribed to the formation of sulphone-morpholine on probes. This sensing behavior displays that they can selectively respond to glutathione to generate a green emission by a sulfonamide-based detection moiety both in vitro and in living cells. Interestingly, the different oxidation states of a sulphur atom on a thiomorpholine ring can be utilized to regulate responsiveness of these probes towards glutathione. Such an oxidation strategy would provide a possibility for enhancing the response rate.

9.
Org Biomol Chem ; 14(44): 10331-10351, 2016 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-27714207

RESUMO

Supramolecular chemistry and self-assembly provide a valuable chance to understand the complicated topological structures on a molecular level. Two types of classical mechanically interlocked molecules, rotaxanes and catenanes, possess non-covalent mechanical bonds and have attracted more attention not only in supramolecular chemistry but also in the fields of materials science, nanotechnology and bioscience. In the past decades, the template-directed clipping reaction based on imine chemistry has become one of the most efficient methods for the construction of functionalized rotaxanes and catenanes. In this review, we outlined the main progress of rotaxanes and catenanes using the template-directed clipping approach of imine chemistry. The review contains the novel topological structures of rotaxanes and catenanes, functions and applications.

11.
Environ Pollut ; 357: 124460, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38945193

RESUMO

It has been well-investigating that individual phthalates (PAEs) or polycyclic aromatic hydrocarbons (PAHs) affect public health. However, there is still a gap that the mixture of PAEs and PAHs impacts birth outcomes. Through innovative methods for mixtures in epidemiology, we used a metabolome Exposome-Wide Association Study (mExWAS) to evaluate and explain the association between exposure to PAEs and PAHs mixtures and birth outcomes. Exposure to a higher level of PAEs and PAHs mixture was associated with lower birth weight (maximum cumulative effect: 143.5 g) rather than gestational age. Mono(2-ethlyhexyl) phthalate (MEHP) (posterior inclusion probability, PIP = 0.51), 9-hydroxyphenanthrene (9-OHPHE) (PIP = 0.53), and 1-hydroxypyrene (1-OHPYR) (PIP = 0.28) were identified as the most important compounds in the mixture. In mExWAS, we successfully annotated four overlapping metabolites associated with both MEHP/9-OHPHE/1-OHPYR and birth weight, including arginine, stearamide, Arg-Gln, and valine. Moreover, several lipid-related metabolism pathways, including fatty acid biosynthesis and degradation, alpha-linolenic acid, and linoleic acid metabolism, were disturbed. In summary, these findings may provide new insights into the underlying mechanisms by which PAE and PAHs affect fetal growth.

12.
Asian J Androl ; 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38727211

RESUMO

ABSTRACT: Infections and inflammatory reactions in the male genital tract are the leading causes of male infertility with a prevalence of 6%-10%, primarily affecting testicular and epididymal function and ultimately compromising sperm quality. However, most infertile patients with genital infection/inflammation are asymptomatic and easily overlooked. Traditional indicators, including white blood cells, elastase, and other components in semen, can reflect inflammation of the genital tract, but there is still a lack of a uniform standard method of detection. Therefore, it is necessary to explore reliable markers in semen that reflect the inflammatory status of the genital tract. Using the experimental autoimmune orchitis (EAO) model to simulate noninfectious chronic orchitis, we successfully collected ejaculated seminal fluid from EAO rats using optimized electrical stimulation devices. Proteomic analysis was performed using isobaric tags for relative and absolute quantification (iTRAQ). Compared to the control group, 55 upregulated and 105 downregulated proteins were identified in seminal plasma samples from the EAO group. In a preliminary screening, the inflammation-related protein S100A8/A9 was upregulated. We further verified that S100A8/A9 was increased in seminal plasma and highly expressed in testicular macrophages of the EAO model. In patients with oligoasthenospermia and genital tract infections, we also found that S100A8/A9 levels were remarkably increased in seminal plasma and testicular macrophages. S100A8/A9 in semen may be a potential biomarker for chronic genital inflammation. Our study provides a new potential biomarker for early diagnosis and further understanding of male infertility caused by genital inflammation.

13.
Radiother Oncol ; 197: 110334, 2024 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-38801945

RESUMO

BACKGROUND: All known randomized trials of stereotactic radiotherapy (SRT) versus whole brain radiotherapy (WBRT) for brain metastases (BMs) comprise mixed histologies. The phase III HYBRID trial (NCT02882984) attempted to evaluate the non-inferiority of SRT vs. WBRT specifically for EGFR-mutated non-small cell lung cancer (EGFRm NSCLC) BMs. METHODS: Inclusion criteria were ≤ 5 BMs (any size) from treatment-naïve EGFRm NSCLC. All patients started a first-generation tyrosine kinase inhibitor on the first day of WBRT (37.5 Gy/15 fractions) or SRT (25-40 Gy/5 fractions per tumor volume). The primary endpoint was 18-month intracranial progression-free survival (iPFS; intention-to-treat). RESULTS: The trial commenced in June 2015 and was closed in April 2021 after screening 208 patients but enrolling 85 (n = 41 WBRT, n = 44 SRT; median follow-up 31 and 36 months, respectively). Respectively, 9.5 % vs. 10.2 % of patients experienced intracranial progression at 18 months, and the median iPFS was 21.4 vs. 22.3 months (p > 0.05 for all). The SRT arm experienced higher overall survival and cognitive preservation (p < 0.05 for all). The most notable reason for low enrollment was patients not wishing to risk neurocognitive decline from WBRT. CONCLUSIONS: Although this phase III trial was underpowered, there was no evidence that SRT yielded outcome detriments compared to WBRT for EGFRm NSCLC BMs. Lessons from prematurely closed trials are valuable, as they often provide important experiential perspectives for investigators designing/executing future trials. In the current era, randomized trials involving WBRT without cognitive sparing measures may be at high risk of underaccrual; trial investigators are encouraged to carefully consider our experience when attempting to design such trials. However, trials of molecular-/biologically-stratified patients are highly recommended as the notion of "individualized medicine/oncology" continues to expand.

14.
Front Endocrinol (Lausanne) ; 14: 1176019, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37334312

RESUMO

Background: The purpose of this study is to establish a novel nomogram model for accurate detection of non-alcoholic fatty liver disease (NAFLD) in the Chinese population based on sex hormone binding globulin (SHBG) and other routine laboratory tests. Methods: A total of 1417 participants (1003 testing and 414 validations) were enrolled into the study. Risk factors independently associated with NAFLD were identified and incorporated in the new nomogram, SFI. The performance of nomogram was assessed by analysis of receiver operating characteristic (ROC) curve, calibration curve, and decision curve. Results: We formulated a new nomogram incorporating four independent factors: SHBG, body mass index (BMI), ALT/AST, and triglycerides (TG). The nomogram achieved good indexes of area under ROC 0.898 (95% confidence interval 0.865-0.926) in predicting NAFLD, which was significantly superior to previously reported models of FLI, HSI, LFS, and LAP. The calibration curve and decision curve demonstrated high performance and clinical utility of the nomogram in predicting NAFLD. Conclusion: The nomogram SFI has high performance in predicting NAFLD in Chinese population and may be used as a cost-effective screening model to assess NAFLD in the general population.


Assuntos
Hepatopatia Gordurosa não Alcoólica , Humanos , Hepatopatia Gordurosa não Alcoólica/diagnóstico , Hepatopatia Gordurosa não Alcoólica/epidemiologia , Hepatopatia Gordurosa não Alcoólica/complicações , Nomogramas , Globulina de Ligação a Hormônio Sexual , População do Leste Asiático , Fatores de Risco
15.
Curr Med Imaging ; 19(9): 1031-1040, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36606588

RESUMO

BACKGROUND: Delphian lymph node (DLN) has been considered to be a gate that predicts widespread lymph node involvement, higher recurrence and mortality rates of head and neck cancer. OBJECTIVE: This study aimed to establish a preoperative ultrasonography integrated machine learning prediction model to predict Delphian lymph node metastasis (DLNM) in patients with diagnosed papillary thyroid carcinoma (PTC). METHODS: Ultrasonographic and clinicopathologic variables of PTC patients from 2014 to 2021 were retrospectively analyzed. The risk factors associated with DLNM were identified and validated through a developed random forest (RF) algorithm model based on machine learning and a logistic regression (LR) model. RESULTS: A total of 316 patients with 402 thyroid lesions were enrolled for the training dataset and 280 patients with 341 lesions for the validation dataset, with 170 (28.52%) patients developed DLNM. The elastography score of ultrasonography, central lymph node metastasis, lateral lymph node metastasis, and serum calcitonin were predictive factors for DLNM in both models. The RF model has better predictive performance in the training dataset and validation dataset (AUC: 0.957 vs. 0.890) than that in the LR model (AUC: 0.908 vs. 0.833). CONCLUSION: The preoperative ultrasonography integrated RF model constructed in this study could accurately predict DLNM in PTC patients, which may provide clinicians with more personalized clinical decision-making recommendations preoperatively. Machine learning technology has the potential to improve the development of DLNM prediction models in PTC patients.


Assuntos
Carcinoma Papilar , Neoplasias da Glândula Tireoide , Humanos , Câncer Papilífero da Tireoide/diagnóstico por imagem , Câncer Papilífero da Tireoide/patologia , Neoplasias da Glândula Tireoide/diagnóstico por imagem , Neoplasias da Glândula Tireoide/cirurgia , Metástase Linfática/diagnóstico por imagem , Estudos Retrospectivos , Algoritmo Florestas Aleatórias , Carcinoma Papilar/diagnóstico por imagem , Carcinoma Papilar/cirurgia , Carcinoma Papilar/complicações
16.
Front Surg ; 9: 917559, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35959115

RESUMO

Background: Colorectal surgery is associated with a high risk of surgical site infection (SSI). In March 2017, we developed an intervention, called "PRESS", with the aim of reducing colorectal superficial SSI. This study assessed the effect of the new intervention in reducing the rates of superficial SSI in colorectal surgery. Methods: This study was a retrospective review of 312 PRESS+ patients compared to 171 historical control PRESS- patients who were 18 years of age or older and underwent elective colorectal surgery with clean-contaminated wounds from January 2015 to June 2020. In the PRESS+ groups, we pressed the incision downward hard with clean gauze after the interrupted suturing of the skin. Propensity score matching with 15 variables was performed in a 1:1 ratio to reduce selection bias. Univariate analysis and multivariate analysis were performed to identify risk factors associated with SSI. Results: The characteristics of the PRESS+ (n = 160) and PRESS- (n = 160) groups were well balanced after propensity score matching. The PRESS+ group had a lower superficial SSI rate (1.9% vs. 6.9%, P = 0.029) and a lower overall SSI rate (2.5% vs. 10.0%, P = 0.006) than the PRESS- group. Furthermore, multivariate analysis showed that the incisional press was an effective protective factor for superficial SSI (adjusted odds ratio = 0.215, 95% confidence interval = 0.057-0.818, P = 0.024). In addition, female sex (P = 0.048) and blood transfusion (P = 0.011) were demonstrated to be independent risk factors for superficial SSI. Conclusion: The incisional press after suturing is a simple, costless, and effective intervention in reducing superficial incisional SSI.

17.
Bioresour Technol ; 362: 127855, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36037838

RESUMO

A hybrid activated sludge membrane-aerated biofilm reactor based on a two-stage simultaneous nitrification-denitrification (SND) process was built, and its utility for treating interflow with low chemical oxygen demand (COD)/total nitrogen (TN) (COD/N) was explored. The operating performance, functional microbial communities, and functional genes for nitrogen metabolism were evaluated at low COD/N (4-1.3). The reactor could achieve stable operation at COD/N = 4-1.5, and the removal efficiency of COD, TN, and ammonia nitrogen was stable at 90.30 ± 2.36 %, 85.69 ± 2.22 %, and 89.52 ± 6.06 %, respectively. The SND rates were 70.89 % and 50.75 % when influent COD/N was 2.0 and 1.7, respectively, indicating that SND makes an important contribution to nitrogen removal under these two COD/N conditions. Microbial analysis revealed that the sampling sites with a high abundance of denitrification genes in the outer ring experienced aerobic conditions, inferring that aerobic denitrification also plays an important role in denitrification.


Assuntos
Nitrogênio , Esgotos , Biofilmes , Análise da Demanda Biológica de Oxigênio , Reatores Biológicos , Desnitrificação , Nitrificação , Nitrogênio/metabolismo , Eliminação de Resíduos Líquidos , Águas Residuárias
18.
Polymers (Basel) ; 14(18)2022 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-36146033

RESUMO

Medulla tetrapanacis is composed of a lignocellulosic biopolymer and has a regular porous structure, which makes it a potential biomass material for preparing porous N-doped biochar. Herewith, N-doped Medulla tetrapanacis biochar (UBC) was successfully prepared by modification with urea and NaHCO3 under pyrolysis at 700 °C. The nitrogen-containing groups were efficiently introduced into biochar, and the micro-pore structures of the UBC were developed with sizeable specific surface area, which was loaded with massive adsorption sites. The adsorption kinetics and isotherms of the UBC conformed to pseudo-second-order and Langmuir model. The superior adsorption capacities of the UBC for methylene blue (MB) and congo red (CR) were 923.0 mg/g and 728.0 mg/g, and the capacities for Cu2+ and Pb2+ were 468.5 mg/g and 1466.5 mg/g, respectively. Moreover, the UBC had a stronger affinity for Cr3+ and Fe3+ in multiple metal ions and retained at a preferable adsorption performance for dyes and heavy metals after five cycles. Precipitation, complexation, and physical adsorption were the main mechanisms of the UBC-adsorbing metal ions and dyes. Thus, lignocellulosic biochar has great potential for removing dyes and heavy metals in aqueous solutions.

19.
Materials (Basel) ; 15(6)2022 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-35329694

RESUMO

The influence of different replacement ratios of steel-slag powder as cement-replacement material on the fracture performance of concrete is studied in this paper. A three-point bending fracture test is carried out on slag powder-cement-based concrete (SPC)-notched beams with steel-slag powder as cementitious materials, partially replacing cement (0%, 5%, 10%, 15%, and 20%). Load-deflection curves and load-crack-opening displacement curves of SPC-notched beams with five different replacement ratios of steel-slag powder were obtained. The effects of different steel-slag-powder replacement ratios on the fracture properties (fracture energy, fracture toughness, and double-K fracture parameters) of the SPC were analyzed and discussed. The results showed that the incorporation of appropriate steel-slag powder can affect the fracture performance of SPC. Compared with concrete without steel-slag powder, adding appropriate steel-slag powder can effectively improve the bond performance between aggregate and matrix because the steel-slag powder contains hydration activity substances such as calcium oxide and aluminium trioxide. The fracture energy and fracture toughness of SPC increased and then decreased with the increase in steel-slag-powder replacement ratios, and the SPC concrete showed best fracture performance with a 5% steel slag powder replacement ratio. Its fracture energy increases by 13.63% and fracture toughness increases by 53.22% compared with NC.

20.
Artigo em Inglês | MEDLINE | ID: mdl-36194321

RESUMO

Beijing-Tianjin-Hebei region is a capital economic circle for the future. Promoting the coordinated development of its population, economy, resources and environment is a major national strategy. And as towns and cities continue to expand, the volume of construction waste is gradually expanding, posing a major challenge to the sustainable development of the construction industry. In order to solve this problem, this paper used portable X-ray fluorescence spectrometry to realize the on-site rapid monitoring of heavy metals in construction waste, and the correlation analysis result was R2 = 0.9908. The visualization of enrichment factor evaluation results was realized through ArcGIS. The Beijing-Tianjin-Hebei region is mainly polluted by heavy metal elements Cr, Zn, Pb and Hg, showing regional pollution characteristics, and the results of mercury morphology analysis show that all are inorganic mercury pollution, and methylmercury is not detected, and the cause can be traced to heavy industrial production in Tangshan City, which is consistent with industrial ecology. The results of leaching toxicity and cation anion analysis showed that the construction waste in Beijing-Tianjin-Hebei region had environmental risks to the surrounding surface water and groundwater. The resource treatment and disposal path were determined by means of XRD, ternary phase diagram and oxide composition analysis to avoid secondary pollution. This study explores the environmental properties and resource utilization pathways of construction waste in the Beijing-Tianjin-Hebei region, laying the foundation for research work on construction waste in the development of national urban agglomerations, effectively solving regional environmental pollution problems and promoting the sustainable development of the construction industry.

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