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1.
J Magn Reson Imaging ; 2024 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-38440902

RESUMEN

BACKGROUND: Extracorporeal membrane oxygenation (ECMO), has partly improved congenital diaphragmatic hernia (CDH) outcomes, yet the overall morbidity and mortality remain high. Existing prenatal indicators for CDH fetuses are operator-dependent, time-consuming, or less accurate, a new simple and accurate indicator to indicate adverse events in CDH patients is needed. PURPOSE: To propose and assess the association of a new MRI parameter, the relative mediastinal displacement index (RMDI), with adverse events including in-hospital deaths or the need for ECMO in fetuses with isolated left CDH (iLCDH). STUDY TYPE: Retrospective analysis. SUBJECTS: One hundred thirty-nine fetuses were included in the iLCDH group (24 with adverse events and 115 without) and 257 fetuses were included in the control group from two centers in Guangzhou. FIELD STRENGTH/SEQUENCE: 3.0 T, T2WI-TRUFI; 1.5 T, T2WI-FIESTA. ASSESSMENT: Three operators independently measured the → DL $$ \underset{\mathrm{DL}}{\to } $$ , → DR $$ \underset{\mathrm{DR}}{\to } $$ , and DH on the axial images. The calculation formula of the RMDI was ( → DL $$ \underset{\mathrm{DL}}{\to } $$ + → DR $$ \underset{\mathrm{DR}}{\to } $$ )/DH . STATISTICAL TESTS: The independent sample t test, Mann-Whitney U test, Chi-square test, Chi-square test continuity correction, Fisher's test, linear regression analysis, logistic regression analysis, intraclass correlation coefficient, receiver operating characteristic curve analysis, and Delong test. A P value <0.05 was considered statistically significant. RESULTS: The RMDI did not change with gestational age in the iLCDH group (with [P = 0.189] and without [P = 0.567] adverse events) and the control group (P = 0.876). There were significant differences in RMDI between the iLCDH group (0.89 [0.65, 1.00]) and the control group (-0.23 [-0.34, -0.16]). In the iLCDH group, RMDI was the only indicator left for indicating adverse events, and the best cutoff value was 1.105. Moreover, there was a significant difference in diagnostic accuracy between the RMDI (AUC = 0.900) and MSA (AUC = 0.820), LHR (AUC = 0.753), o/e LHR (AUC = 0.709), and o/e TFLV (AUC = 0.728), respectively. DATA CONCLUSION: The RMDI is expected to be a simple and accurate tool for indicating adverse events in fetuses with iLCDH. EVIDENCE LEVEL: 4 TECHNICAL EFFICACY: Stage 1.

2.
Eur Radiol ; 2024 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-38753194

RESUMEN

OBJECTIVES: To analyze the ability of magnetic resonance (MR) to identify cystic biliary atresia (CBA) and choledochal cyst (CC). METHODS: Infants (≤ 1 year old) who were diagnosed with CBA or CC type I/IV from January 2010 to July 2023 were retrospectively reviewed. Imaging characteristics on MR were compared between the CBA and CC groups. Binary logistic regression and the area under the receiver operating characteristic curve (AUC) were analyzed for the identification of CBA. RESULTS: Sixty-three patients with CBA (median age, 30 days) and 172 patients with CC (median age, 60 days) were included. Gallbladder (GB) wall thickness (cutoff, 1.2 mm) showed 98.4% sensitivity and 100% specificity (AUC, 0.998). MR-triangular cord thickness (MR-TCT) (cutoff, 4.1 mm) showed 100% sensitivity and 95.9% specificity (AUC, 0.986). The bile duct loop visualization showed 96.8% sensitivity and 100% specificity (AUC, 0.984). Proximal bile duct (PBD) diameter (cutoff, 1.3 mm) showed 92.1% sensitivity and 95.3% specificity (AUC, 0.977). Cyst wall thickness (cutoff, 1 mm) showed 77.8% sensitivity and 95.3% specificity (AUC, 0.942). The combination of GB wall thickness > 1.2 mm and MR-TCT > 4.1 mm, GB wall thickness > 1.2 mm and loop visualization, GB wall thickness > 1.2 mm, and cyst wall thickness > 1 mm showed 100% sensitivity and 100% specificity (AUC, 1.000). CONCLUSIONS: Imaging characteristics on MR might be used to identify CBA and CC, and the combination of GB wall thickness and MR-TCT, or loop visualization, or cyst wall thickness, has a perfect diagnostic value. CLINICAL RELEVANCE STATEMENT: Early and accurate differentiation of CBA and CC is essential, but current methods rely on inherently subjective ultrasound. Biliary features on MRI allow for an objective, accurate diagnosis.

3.
Eur J Pediatr ; 183(4): 1901-1910, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38337095

RESUMEN

The aim of the study was to determine the relationship between flatfoot morphology and body mass and height in children aged 6-12 years. A total of 6471 Chinese children (mean age 9.0 ± 1.9 years, 41% female) were assessed for foot morphometry, body height, and body mass index. Foot morphology, including foot length, width, girth, arch height, hallux valgus angle, and rearfoot valgus angle, was measured using a 3D laser scanner. Flatfoot evaluations were conducted using the Sztriter-Godunov index (KY) from footprints. All measurements were analyzed by age and sex using the mean values of the left and right sides. Comparisons were performed between flatfoot groups, between body mass index (BMI) groups, and between body height groups. The study revealed a significant decrease in the incidence of bipedal flatfoot with age (p < 0.001), whereas the prevalence of obesity remained consistent (p > 0.05). Bipedal flatfoot was associated with distinct morphological changes, including lower arches, reduced instep height, diminished ankle heights and a greater rearfoot valgus angle (p < 0.05). When comparing the BMI groups, overweight children had larger and thicker feet (p < 0.05), but no differences were found in arch height and ankle height (p > 0.05). When comparing the body height groups, short-statured children had a shorter feet girth, shorter arches, and shorter ankle height (p < 0.05), but no differences were found in the rearfoot valgus angle (p > 0.05). CONCLUSION: The main characteristics of flat feet include lower arches and instep heights and ankle heights but higher rearfoot valgus angles. In general, overweight children's feet do not have the common features of flat feet. In contrast, short children had similar features of flatfoot except for rearfoot valgus. Assessment of posture, such as rearfoot valgus, can be critical in identifying children with flat feet. WHAT IS KNOWN: • The morphology of children's feet is associated with body growth, but the relationship between flatfeet and body mass and height remains controversial. WHAT IS NEW: • Three-dimensional foot measurement shows that body mass is generally not associated with flatfeet, while short children have lower arches but no rearfoot valgus.


Asunto(s)
Pie Plano , Niño , Humanos , Femenino , Masculino , Pie Plano/epidemiología , Pie Plano/complicaciones , Sobrepeso , Estatura , Pie/anatomía & histología , Obesidad/complicaciones
4.
World J Surg Oncol ; 22(1): 26, 2024 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-38263144

RESUMEN

OBJECTIVE: To explore the risk factors for disease progression after initial treatment of type B thymomas using a predictive nomogram model. METHODS: A single-center retrospective study of patients with type B thymoma was performed. The Cox proportional hazard model was used for univariate and multivariate analyses. Variables with statistical and clinical significance in the multivariate Cox regression were integrated into a nomogram to establish a predictive model for disease progression. RESULTS: A total of 353 cases with type B thymoma were retrieved between January 2012 and December 2021. The median follow-up was 58 months (range: 1-128 months). The 10-year progression-free survival (PFS) was 91.8%. The final nomogram model included R0 resection status and Masaoka stage, with a concordance index of 0.880. Non-R0 resection and advanced Masaoka stage were negative prognostic factors for disease progression (p < 0.001). No benefits of postoperative radiotherapy (PORT) were observed in patients with advanced stage and non-R0 resection (p = 0.114 and 0.284, respectively). CONCLUSION: The best treatment strategy for type B thymoma is the detection and achievement of R0 resection as early as possible. Long-term follow-up is necessary, especially for patients with advanced Masaoka stage and who have not achieved R0 resection. No prognostic benefits were observed for PORT.


Asunto(s)
Timoma , Neoplasias del Timo , Humanos , Nomogramas , Estudios Retrospectivos , Pronóstico , Progresión de la Enfermedad
5.
Sci Technol Adv Mater ; 25(1): 2351354, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38800054

RESUMEN

The synergistic disruption of intracellular redox homeostasis through the combination of ferroptosis/gas therapy shows promise in enhancing the antitumor efficacy. However, the development of an optimal delivery system encounters significant challenges, including effective storage, precise delivery, and controlled release of therapeutic gas. In this study, we propose the utilization of a redox homeostasis disruptor that is selectively activated by the tumor microenvironment (TME), in conjunction with our newly developed nanoplatforms (MC@HMOS@Au@RGD), for highly efficient ferroptosis therapy of tumors. The TME-triggered degradation of HMOS initiates the release of MC and AuNPs from the MC@HMOS@Au@RGD nanoplatform. The released MC subsequently reacts with endogenous hydrogen peroxide (H2O2) and H+ to enable the on-demand release of CO gas, leading to mitochondrial damage. Simultaneously, the released AuNPs exhibit GOx-like activity, catalyzing glucose to generate gluconic acid and H2O2. This process not only promotes the decomposition of MnCO to enhance CO production but also enhances the Fenton-like reaction between Mn2+ and H2O2, generating ROS through the modulation of the H+ and H2O2-enriched TME. Moreover, the generation of CO bubbles enables the monitoring of the ferroptosis treatment process through ultrasound (US) imaging. The efficacy of our prepared MC@HMOS@Au@RGD disruptors in ferroptosis therapy is validated through both in vitro and in vivo experiments.


A strategy of disrupted redox homeostasis specifically initiated by the tumor microenvironment and our constructed MC@HMOS@Au@RGD nanoplatforms is proposed for ultrasound (US) imaging-guided potent ferroptosis therapy of tumors.

6.
J Environ Manage ; 356: 120642, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38503227

RESUMEN

The polysilicate aluminum ferric (PSAF) was synthesized via copolymerization of polysilicic acid (PSi), AlCl3 and FeCl3 for treating oily wastewater from Daqing gas field. This study investigated the effects of key preparation factors such as the degree of PSi's preactivation and the ratio of (Fe + Al)/Si and Al/Fe on both polymerization and coagulation performance exhibited by PSAF. To determine the optimal timing for introducing Al3+ and Fe3+, zeta potential, viscosity and particle size were investigated. Additionally, infrared spectroscopy, X-ray powder diffraction, polarizing microscopy and scanning electron microscope analysis were employed to investigate the structure and morphology of PSAF. The results indicate that under conditions characterized by a SiO2 mass fraction of 2.5% and pH = 4.5, an optimal timing for introducing Al3+ and Fe3+ is at 100 min when PSi exhibits moderate polymerization along with sufficient stability. When considering molar ratios such as (Al + Fe)/Si being 6:4 and Al/Fe being 5:5, respectively, PSAF falls within a "stable zone" enabling storage period up to 32 days. Moreover, Jar test results demonstrate that at a dosage of 200 mg/L PSAF for oily wastewater treatment in gas fields could reach the maximum turbidity removal efficiency up to 99.5% while oil removal efficiency reach 88.6% without pH adjustment. The copolymerization facilitates the formation of larger PSAF aggregates with positive potential, thereby augmenting the coagulants' adsorption bridging and charge neutralization capabilities. As a result, PSAF has great potential as a practical coagulant for treating oil-containing wastewater in industrial settings.


Asunto(s)
Aguas Residuales , Purificación del Agua , Aluminio/química , Dióxido de Silicio , Polímeros , Hierro/química , Purificación del Agua/métodos , Compuestos Férricos/química
7.
Small ; 19(7): e2206606, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36461684

RESUMEN

For complex cascade biocatalysis, multienzyme compartmentalization helps to optimize substrate transport channels and promote the orderly and tunable progress of step reactions. Herein, a simple and general synthesis strategy is proposed for the construction of a multienzyme biocatalyst by compartmentalizing glucose oxidase and horseradish peroxidase (GOx and HRP) within core-shell zeolite imidazole frameworks (ZIF)-8@ZIF-8 nanostructures. Owing to the combined effects of biomimetic mineralization and the fine regulation of the ZIF-8 growth process, the uniform shell encloses the seed (core) surface by epitaxial growth, and the bienzyme system is accurately localized in a controlled manner. The versatility of this strategy is also reflected in ZIF-67. Meanwhile, with the ability to covalently bind divalent metal ions, lithocholic acid (LCA) is used as a competitive ligand to improve the pore structure of the ZIF from a single micropore to a hierarchical micro/mesopore network, which greatly increases mass transfer efficiency. Furthermore, the multienzyme cascade reaction is exemplified by the oxidation of o-phenylenediamine (OPD). The findings show that the bienzyme assembly strategy significantly affects the biocatalytic efficiency mainly by influencing the utilization efficiency of the intermediate (Hydrogen peroxide, H2 O2 ) between the step reactions. This study sheds new light on facile synthetic routes to constructing in vitro multienzyme biocatalysts.


Asunto(s)
Nanoestructuras , Zeolitas , Zeolitas/química , Nanoestructuras/química , Peroxidasa de Rábano Silvestre/metabolismo , Biocatálisis , Imidazoles/química
8.
Cancer Invest ; 41(6): 601-616, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37401814

RESUMEN

With the SARS-CoV-2 mutations evolving and prompt of SARS-CoV-2 vaccines, no information is available on SARS-CoV-2 vaccination status in Chinese patients with lung cancer. An electronic questionnaire including sociodemographic characteristics, vaccine status, side effect post-vaccination, and attitude towards a fourth dose of vaccine was conducted within 1018 Chinese patients with lung cancer from October 18th, 2022, to November 25th, 2022. Among 1018 patients, a total of 75 (13.7%) patients reported acceptable systemic adverse events in those had received the SARS-CoV-2 vaccine (549, 54%), the most common of which was fever (39, 7%). Factors including females (OR, 1.512; 95% CI, 1.076-2.124), residents in the municipality (OR, 2.048; 95% CI, 1.238-3.389), undergoing therapy (OR, 2.897; 95% CI, 1.348-6.226), disagree to vaccines is safe for patients with lung cancer (OR, 3.816; 95% CI, 2.198-6.626) contributed to hesitancy. Among 373 patients had received three doses, half respondents (206, 55.2%) were hesitant to receive a fourth dose due to the safety concern and efficacy towards the variants. In conclusion, low vaccine uptake rates in patients with lung cancer could be improved by increasing confidence in vaccine safety, particularly for those with negative beliefs. Appropriate guidance and individualized vaccination plans that meet the healthcare needs of patients with lung cancer were needed during the constantly evolving pandemic.


Asunto(s)
COVID-19 , Neoplasias Pulmonares , Femenino , Humanos , Vacunas contra la COVID-19/efectos adversos , Estudios Transversales , Pueblos del Este de Asia , COVID-19/prevención & control , SARS-CoV-2
9.
Respir Res ; 24(1): 161, 2023 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-37330514

RESUMEN

BACKGROUND: Pre-operative and post-operative hypoxemia are frequent complications of Stanford type A aortic dissection (AAD). This study explored the effect of pre-operative hypoxemia on the occurrence and outcome of post-operative acute respiratory distress syndrome (ARDS) in AAD. METHOD: A total of 238 patients who underwent surgical treatment for AAD between 2016 and 2021 were enrolled. Logistic regression analysis was conducted to investigate the effect of pre-operative hypoxemia on post-operative simple hypoxemia and ARDS. Post-operative ARDS patients were divided into pre-operative normal oxygenation group and pre-operative hypoxemia group that were compared for clinical outcomes. Post-operative ARDS patients with pre-operative normal oxygenation were classified as the real ARDS group. Post-operative ARDS patients with pre-operative hypoxemia, post-operative simple hypoxemia, and post-operative normal oxygenation were classified as the non-ARDS group. Outcomes of real ARDS and non-ARDS groups were compared. RESULT: Logistic regression analysis showed that pre-operative hypoxemia was positively associated with the risk of post-operative simple hypoxemia (odds ratios (OR) = 4.81, 95% confidence interval (CI): 1.67-13.81) and post-operative ARDS (OR = 8.514, 95% CI: 2.64-27.47) after adjusting for the confounders. The post-operative ARDS with pre-operative normal oxygenation group had significantly higher lactate, APACHEII score and longer mechanical ventilation time than the post-operative ARDS with pre-operative hypoxemia group (P < 0.05). Pre-operative the risk of death within 30 days after discharge was slightly higher in ARDS patients with pre-operative normal oxygenation than in ARDS patients with pre-operative hypoxemia, but there was no statistical difference(log-rank test, P = 0.051). The incidence of AKI and cerebral infarction, lactate, APACHEII score, mechanical ventilation time, intensive care unit and post-operative hospital stay, and mortality with 30 days after discharge were significantly higher in the real ARDS group than in the non-ARDS group (P < 0.05). After adjusting for confounding factors in the Cox survival analysis, the risk of death within 30 days after discharge was significantly higher in the real ARDS group than in the non-ARDS group (hazard ratio(HR): 4.633, 95% CI: 1.012-21.202, P < 0.05). CONCLUSION: Preoperative hypoxemia is an independent risk factor for post-operative simple hypoxemia and ARDS. Post-operative ARDS with pre-operative normal oxygenation was the real ARDS, which was more severe and associated with a higher risk of death after surgery.


Asunto(s)
Disección Aórtica , Síndrome de Dificultad Respiratoria , Humanos , Síndrome de Dificultad Respiratoria/diagnóstico , Síndrome de Dificultad Respiratoria/epidemiología , Síndrome de Dificultad Respiratoria/etiología , Disección Aórtica/cirugía , Respiración Artificial , Pulmón , Hipoxia/diagnóstico , Hipoxia/epidemiología , Hipoxia/etiología , Estudios Retrospectivos
10.
Phys Chem Chem Phys ; 25(12): 8853-8860, 2023 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-36916352

RESUMEN

The stability of two-dimensional (2D) materials upon exposure to ambient conditions is significant for their applications. In this paper, the air stability of the BeO monolayer with and without vacancy defects is carefully studied via DFT calculations. Our results suggest high structural and electronic stability of BeO monolayers upon exposure to O2, N2, CO2 and H2O even with Be vacancies. O vacancies are not favorable in free-standing BeO monolayers and can be easily healed by H2O or CO2 adsorption. Due to the high stability, large band gap and atomic flat surface, BeO monolayers are expected to be an ideal encapsulation material for 2D electronic devices.

11.
Phys Chem Chem Phys ; 25(2): 1214-1219, 2023 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-36524708

RESUMEN

Recently, a new edge structure named ZZ(U) has been evidenced as the lowest-energy structure for bilayer phosphorene nanoribbons (PNRs). Owing to strong quantum confinement effects and edge states, width and edge are the two most important factors that influence the properties of PNRs in nanosized microelectronics. In this study, we systematically investigated the evolution of the electronic properties of bilayer PNRs with different edge configurations as the widths vary. The four types of edges explored include ZZ(Pristine), ZZ(Klein), ZZ(Tube), and newly found ZZ(U). As the widths change from 14 to 40 Å, the ZZ(Pristine) are always metallic with edge states penetrating the Fermi level, while the others are semiconductors. The edge states in ZZ(Klein) are located in the two lowest conduction bands. However, in ZZ(U), the edge states are nearly hidden in the bulk band structure, and its carrier transportation exhibits almost perfect 2D layers, nearly eliminating the U-edge influence. Our results pave the way for phosphorene's utilization in electronics and optoelectronics.

12.
Phys Chem Chem Phys ; 25(48): 33152-33158, 2023 Dec 13.
Artículo en Inglés | MEDLINE | ID: mdl-38047897

RESUMEN

Magnetic Fe3O4 nanoparticles show promising applications in nanomedicine. However, the saturation magnetization (MS) of Fe3O4 nanoparticles synthesized in laboratory is usually not high enough, which greatly limits their application in drug delivery and magnetic hyperthermia. Here, by accurate hybrid density functional computation, the doping behavior of group III elements (including Al, Ga, and In) and the effects on magnetic and electronic properties are well studied. The results show that the doping behavior depends on the concentration of dopants. Interestingly, appropriate Ga and In doping concentrations can significantly increase the MS of Fe3O4. In addition, the doping of group III elements (Al, Ga and In) into Fe3O4 would not induce any defect states in the band gap but slightly increases the band gap. Our results provide a simple and feasible scheme for increasing the MS of magnetite, which is significant for the applications of Fe3O4 nanoparticles in drug delivery and magnetic hyperthermia.

13.
Xenobiotica ; 53(12): 670-680, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37971898

RESUMEN

Maintaining proper blood flow is critical to promoting good health. Nattokinase is a serine protease from Bacillus subtilis that has significant in vitro thrombolytic activity, but its mechanism as a dietary supplement to prevent thrombosis through intestinal absorption and transport is still unclear.The purpose of this study is to study the transport and internalisation mechanism of NK in the small intestine using animal models and Caco-2 cell monolayer models.This study first evaluated the preventive effect of supplementing low dose (4000 FU (Fibrin Unit)/kg, n = 6), medium dose (8000 FU/kg, n = 6), and high dose (12000 FU/kg, n = 6) of nattokinase on carrageenan induced thrombosis in mice. Subsequently, we used the rat gut sac model, ligated intestinal loop model, and Caco-2 cell uptake model to study the intestinal transport mechanism of NK.Results indicate that NK is a moderately absorbed biomolecule whose transport through enterocytes is energy- and time-dependent. Chlorpromazine, nystatin and EIPA all inhibited the endocytosis of NK to varying degrees, indicating that the endocytosis of NK in Caco-2 cells involves macropinocytosis, clathrin-mediated and caveolae-mediated pathway. These findings offer a theoretical basis for investigating the mechanism of oral NK supplementation in greater depth.


Asunto(s)
Intestino Delgado , Trombosis , Humanos , Ratas , Ratones , Animales , Células CACO-2 , Suplementos Dietéticos
14.
Int Wound J ; 20(10): 3999-4005, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37386845

RESUMEN

To find potential biomarkers based on miRNA and their potential targets in splenic monocytes in burn-injured mice. Male Balb/c mice were subjected to sham or scalding injury of 15% total body surface area. Spenic CD11b+ monocytes were purified with magnetic beads. The monocytes were cultured in the presence of lipopolysaccharide. The proliferation of monocytes was detected by MTT assay, and the cytokines in the supernatant were examined by enzyme linked immunosorbent assay. The purified monocytes were also under total RNA extraction. The differential monocytic miRNAs expression between the sham and burn-injured mice was analysed by miRNA microarray. The activity of monocytes was comparable between the two groups (p > 0.05). However, monocytes from burn-injured mice secreted higher levels of tumour necrosis factor (TNF)-α and transforming growth factor-ß, but lower level of monocyte chemoattratctant protein-1. A total of 54 miRNAs were differentially expressed in monocytes from burn relative to sham-injured mice (fold >3). Further quantitative reverse transcription polymerase chain reaction confirmed that the expression of miR-146a was significantly down-regulated, while miR-3091-6p was up-regulated after burn injury. Using the combination of Miranda and TargetScan softwares, we found that mir-146a may regulate 180 potential target genes including TNF receptor related factor 6 (TRAF6), interleukin-1 receptor related kinase 1 (IRAK1) and CD28. Mir-3091-6p may regulate 39 potential targets, including SOCS7 (cytokine signal transduction inhibitor 7) and ARRB2 (arrestin, ß 2). The miRNAs expressed by monocytes after burn injury may be involved in the regulation of innate immune response in burn injury.


Asunto(s)
Quemaduras , MicroARNs , Ratones , Masculino , Animales , Monocitos/metabolismo , MicroARNs/genética , Citocinas/metabolismo , Inmunidad Innata , Quemaduras/genética , Proteínas Supresoras de la Señalización de Citocinas/metabolismo
15.
Waste Manag Res ; 41(2): 431-441, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36250214

RESUMEN

Various products made from biodegradable polymers have been increasing rapidly in the market since the use of non-biodegradable materials has been banned, particularly for the disabled packaging materials. Burning remains the most popular method that is increasingly used in treating city wastes. The impact of these polymers on environmental during thermal degradation and combustion is an important issue for city waste management. In this work, the thermal degradation and combustion behaviours of the most popular synthetic biodegradable polymers in the market, poly(lactide acid) (PLA), poly(e-caprolactone) (PCL), poly(butylene succinate) (PBS), poly(butylene adipate-co-terephthalate) (PBAT) and polyhydroxyalkenoates (PHA), are investigated. Both isothermal and non-isothermal thermal decomposition in oxygen and nitrogen environment were studied using thermogravimetric analysis combining with differential scanning calorimeter and coupled with Fourier transform infrared spectroscopy and gas chromatograph/mass spectroscopy. The combustion behaviour was investigated by a combustion colorimeter. The study results show that thermal degradation temperatures are PCL > PBS > PLA > PBAT > PHA. The thermal decomposition of all the polyesters started from scission reaction (cis-elimination), and then a stereoselective cis-elimination, which resulted in the formation of trans-crotonic acid and its oligomers. They all decomposed into CO2 and water in excess oxygen environment above 800°C. Various chemical products with smaller molecules were detected under oxygen-free conditions, including oligomers and unsaturated carboxylic acid. The order of the total heat release of the materials from high to low is as follows: PHA > PCL > PBAT > PBS > PLA. The combustion values of these polyesters are lower than those of polyolefins; thus, they will not damage furnace used currently. The results provide some important and useful data for managing these new city waste.


Asunto(s)
Poliésteres , Polímeros , Polímeros/química , Poliésteres/química , Poliésteres/metabolismo , Temperatura
16.
Small ; 18(2): e2105130, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34862720

RESUMEN

Edge termination plays a vital role in determining the properties of 2D materials. By performing compelling ab initio simulations, a lowest-energy U-edge [ZZ(U)] reconstruction is revealed in the bilayer phosphorene. Such reconstruction reduces 60% edge energy compared with the pristine one and occurs almost without an energy barrier, implying it should be the dominating edge in reality. The electronic band structure of phosphorene nanoribbon with such reconstruction resembles that of an intrinsic 2D layer, exhibiting nearly edgeless band characteristics. Although ZZ(U) changes the topology of phosphorene nanoribbons, simulated transmission electron microscope, scanning transmission electron microscope and scanning tunneling microscope images indicate it is very hard to be identified. One possible identified method is infrared/Raman analyses because the ZZ(U) edge alters vibrational modes dramatically. In addition, it also increases the thermal conductivity of PNR 1.4 and 2.3 times than the pristine and Klein edges.

17.
Small ; 18(40): e2203274, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36050882

RESUMEN

The design and synthesis of novel two-dimensional (2D) materials that possess robust structural stability and unusual physical properties may open up enormous opportunities for device and engineering applications. Herein, a 2D sumanene lattice that can be regarded as a derivative of the conventional Kagome lattice is proposed. The tight-binding analysis demonstrates sumanene lattice contains two sets of Dirac cones and two sets of flat bands near the Fermi surface, distinctively different from the Kagome lattice. Using first-principles calculations, two possible routines for the realization of stable 2D sumanene monolayers (named α phase and ß phase) are theoretically suggested, and an α-sumanene monolayer can be experimentally synthesized with chemical vapor deposition using C21 H12 as a precursor. Small binding energies on Au(111) surface (e.g., -37.86 eV Å-2 for α phase) signify the possibility of their peel-off after growing on the noble metal substrate. Importantly, the GW plus Bethe-Salpeter equation calculations demonstrate both monolayers have moderate band gaps (1.94 eV for α) and ultrahigh carrier mobilities (3.4 × 104 cm2  V-1  s-1 for α). In particular, the α-sumanene monolayer possesses a strong exciton binding energy of 0.73 eV, suggesting potential applications in optics.

18.
Langmuir ; 38(10): 3189-3201, 2022 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-35245061

RESUMEN

This work reports on the formation of closely packed conductive droplets demonstrating polygon-like patterns at the interface in partially wetted ternary polymer systems prepared by melt blending and annealing treatment. The low-density polyethylene/poly(ether-block-amide)/poly(butylene-adipate-co-terephthalate) (LDPE/PEBA/PBAT) blend showed an intermediate partial wetting tendency where the interfacially localized conductive PEBA phase developed connected structure after blending but transformed into dispersed droplets upon annealing. The coalescence of the PEBA droplets appeared to be initiated by the Rayleigh-type instability in the thin PBAT film separating PEBA. However, the intrinsic coalescence rate of the PEBA droplets was very low due to the low interfacial tension of PEBA/PBAT. This slow coalescence of PEBA combined with the fast reduction in the interfacial area during annealing and the intermediate partial wetting state of the LDPE/PEBA/PBAT system resulted in a unique morphology of closely packed PEBA droplets with polygon-like patterns at a volume fraction of 50/10/40. Two other representative ternary polymer blends, LDPE/PEBA/polypropylene (PP) and compatibilized LDPE/PEBA/polystyrene (PS), with strong and weak partial wetting morphologies were also examined to highlight the mechanism for the morphology development in the LDPE/PEBA/PBAT blend.

19.
Gynecol Oncol ; 167(1): 37-41, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35931469

RESUMEN

PURPOSE: The lungs are the most common site of metastasis in patients with gestational trophoblastic neoplasia. We investigated surgical management and prognostic factors of patients with refractory gestational trophoblastic neoplasia to assess the value of lung metastasis resection. PATIENTS AND METHODS: The clinical data of patients with refractory gestational trophoblastic neoplasia and lung metastasis treated at Peking Union Medical College Hospital from January 2005 to December 2020 were retrospectively analyzed. Surgical characteristics and survival outcomes were analyzed. RESULTS: In total, 213 patients with refractory gestational trophoblastic neoplasia and lung metastasis were screened, and 148 patients who underwent unilateral lung resection were analyzed. Patients' median age was 32 years. Lobectomy was performed in 65.5% of patients, while wedge resection was performed in 34.5%. The rate of postoperative complications was 12.2%. The pathological rate was 66.2%. Video-assisted thoracoscopic surgery showed better surgical characteristics than thoracotomy did. Compared with lobectomy, wedge resection had a shorter operative time, shorter duration of chest tube placement, shorter postoperative hospital stay, and fewer postoperative complications. The median follow-up period was 36 months. During follow-up, 90.5% of patients achieved complete remission. The 5-year disease-free and overall survival rates were 80.4% and 92.6%, respectively. More previous chemotherapy courses and failure to achieve normal ß-human chorionic gonadotropin levels postoperatively were predictors of poor prognosis. CONCLUSIONS: Surgical treatment of lung metastasis is valuable and safe for patients with refractory gestational trophoblastic neoplasia. The minimally invasive video-assisted thoracoscopic approach and wedge resection are recommended.


Asunto(s)
Enfermedad Trofoblástica Gestacional , Neoplasias Pulmonares , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Gonadotropina Coriónica Humana de Subunidad beta , Femenino , Enfermedad Trofoblástica Gestacional/tratamiento farmacológico , Humanos , Neoplasias Pulmonares/secundario , Recurrencia Local de Neoplasia/patología , Complicaciones Posoperatorias/tratamiento farmacológico , Embarazo , Pronóstico , Estudios Retrospectivos
20.
J Surg Res ; 280: 333-347, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36030610

RESUMEN

INTRODUCTION: To determine if Exendin-4 could be a therapeutic agent for burn-induced hyperglycemia. MATERIALS AND METHODS: Male Balb/c mice received a bolus of Exendin-4 intraperitoneally immediately after 15% total body surface area scald injury. Tail glucose levels were recorded and T-cell functions were analyzed at 4 h and 24 h postburn (pb). Pancreatic pathology was observed consecutively. The secretions of cytokines were detected in serum, spleen, and lung. Apoptosis of splenic CD3+ T-cells was examined by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling and flow cytometry. RESULTS: Although Exendin-4 could attenuate burn-induced hyperglycemia in mice at 4 h pb, it accelerated their survival dose dependently with progressive depletion of splenocyte number. T-cell function underwent two-phasic changes following Exendin-4 treatment. Compared to placebo mice, T-cell from Exendin-4-treated mice was manifested with increased proliferation, while decreased IL-2 secretion and lower ratio of IL-4/IFN-γ at 4 h pb. However, at 24 h pb, it showed decreased proliferation, while increased IL-2 secretion and higher ratio of IL-4/IFN-γ. Exendin-4 could elicit higher circulating IL-6 and IL-10 levels at 4 h pb, which were pronounced in the lung at 24 h pb. In the meanwhile, severe inflammation could be found in the pancreas. At 24 h pb, the numbers of terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling or caspase-3 positive cells and the apoptosis of CD3+ T-cells were significantly increased in the spleens of Exendin-4 mice relative to placebo mice. CONCLUSIONS: These data support a pathogenic role of Exendin-4 signaling during thermal injury, warning against its clinical application in acute insults.


Asunto(s)
Quemaduras , Hiperglucemia , Ratones , Masculino , Animales , Exenatida/uso terapéutico , Interleucina-10 , Caspasa 3 , Interleucina-4 , Interleucina-2 , ADN Nucleotidilexotransferasa , Interleucina-6 , Quemaduras/complicaciones , Quemaduras/tratamiento farmacológico , Quemaduras/patología , Ratones Endogámicos BALB C , Citocinas , Glucosa
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