Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 66
Filtrar
1.
J Obstet Gynaecol Res ; 50(4): 751-757, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38263573

RESUMO

We report a case of fetal nasal chondromesenchymal hamartoma (NCMH) first noted on prenatal ultrasound at 34 weeks. A solid-cystic mass which predominantly hyperechoicgenic and relatively clear margin, was located on the left nasal cavity and pharynx, with anterior extension and moderate blood flow. Further follow-up ultrasound examination depicted an enlargement of the tumor. Fetal magnetic resonance imaging (MRI) showed an inhomogeneous signal lesion involving the ethmoid sinuses, nasal cavity, and pharynx. The infant, delivered via cesarean section at 37 + 5 weeks, required urgent neonatology intervention due to respiratory difficulties. Neonatal MRI and computer tomography were subsequently performed at 1 day after birth. Surgical excision occurred at 7 days, confirming NCMH via histological examination. Awareness of this entity, is essential to avoid potentially harmful therapies, especially in prenatal period. Considered NCMH in diagnosis when fetal nasal masses presenting with predominantly high-level echo, well-defined margins and moderate vascularity.


Assuntos
Cesárea , Hamartoma , Gravidez , Lactente , Recém-Nascido , Humanos , Feminino , Diagnóstico Diferencial , Hamartoma/diagnóstico por imagem , Hamartoma/patologia , Feto/patologia , Diagnóstico Pré-Natal , Imageamento por Ressonância Magnética
2.
Dentomaxillofac Radiol ; 53(4): 222-232, 2024 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-38426379

RESUMO

OBJECTIVES: Preoperative identification of different stromal subtypes of pleomorphic adenoma (PA) of the salivary gland is crucial for making treatment decisions. We aimed to develop and validate a model based on histogram analysis (HA) of ultrasound (US) images for predicting tumour stroma ratio (TSR) in salivary gland PA. METHODS: A total of 219 PA patients were divided into low-TSR (stroma-low) and high-TSR (stroma-high) groups and enrolled in a training cohort (n = 151) and a validation cohort (n = 68). The least absolute shrinkage and selection operator regression algorithm was used to screen the most optimal clinical, US, and HA features. The selected features were entered into multivariable logistic regression analyses for further selection of independent predictors. Different models, including the nomogram model, the clinic-US (Clin + US) model, and the HA model, were built based on independent predictors using logistic regression. The performance levels of the models were evaluated and validated on the training and validation cohorts. RESULTS: Lesion size, shape, cystic areas, vascularity, HA_mean, and HA_skewness were identified as independent predictors for constructing the nomogram model. The nomogram model incorporating the clinical, US, and HA features achieved areas under the curve of 0.839 and 0.852 in the training and validation cohorts, respectively, demonstrating good predictive performance and calibration. Decision curve analysis and clinical impact curves further confirmed its clinical usefulness. CONCLUSIONS: The nomogram model we developed offers a practical tool for preoperative TSR prediction in PA, potentially enhancing clinical decision-making.


Assuntos
Adenoma Pleomorfo , Nomogramas , Neoplasias das Glândulas Salivares , Ultrassonografia , Humanos , Adenoma Pleomorfo/diagnóstico por imagem , Adenoma Pleomorfo/patologia , Feminino , Neoplasias das Glândulas Salivares/diagnóstico por imagem , Neoplasias das Glândulas Salivares/patologia , Masculino , Pessoa de Meia-Idade , Ultrassonografia/métodos , Adulto , Idoso , Estudos Retrospectivos , Adolescente , Valor Preditivo dos Testes
3.
Mol Reprod Dev ; 2023 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-38018308

RESUMO

We have investigated whether inflammasomes and pyroptosis are activated in maternal nicotine exposure (MNE) offspring mice and whether they are involved in MNE-promoted metabolic associated fatty liver disease (MAFLD) in adult offspring. We injected pregnant mice subcutaneously with saline vehicle or nicotine twice a day on gestational days 11-21. Offspring mice from both groups were fed with a normal diet (ND) or a high-fat diet (HFD) for 6 months at postnatal day 21 to develop the MAFLD model. Serum biochemical indices were analyzed, and liver histology was performed. The expression levels of inflammasome and pyroptosis proteins were detected by western blot. We found MNE significantly aggravated the injury of MAFLD in adult offspring mice. MNE activated inflammasomes and pyroptosis in both infant and adult offspring mice. HFD treatment activated inflammasomes but not pyroptosis at 3 months, while it showed no effect at 6 months. However, pyroptosis was more severe in MNE-HFD mice than in MNE-ND mice at 6 months. Taken together, our data suggest MNE promotes MAFLD progression in adult offspring mice. MNE also induces NLRP3 and NLRP6 inflammasome activation and pyroptosis in both infant and adult offspring mice, which may be involved in MNE-promoted progression of MAFLD.

4.
J Org Chem ; 88(14): 9835-9842, 2023 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-37433741

RESUMO

Efficient synthesis of phenylalanine-derived oxazoles and imidazolidones can be achieved by copper-catalyzed reactions that are controlled by directing groups and proceed by selective C-O or C-N coupling. This strategy employs inexpensive commercial copper catalysts and readily available starting materials. It uses a convenient reaction procedure and provides a reliable approach to the versatile and flexible assembly of heterocyclic building blocks.

5.
J Ultrasound Med ; 42(3): 603-611, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35722660

RESUMO

OBJECTIVES: To investigate the characteristic ultrasonographic findings of adenoid cystic carcinoma (ACC) in major salivary glands and identify the value of polar vessel in color Doppler flow imaging (CDFI) for the diagnosis of ACC. METHODS: From January 2017 to December 2021, 76 patients with parotid and submandibular gland tumors, including 14 patients with ACC, as confirmed by surgery and histopathology, were enrolled. Their clinicopathologic information and ultrasound (US) features were recorded and analyzed. The performance of polar vessel in CDFI for differentiating ACC from non-ACC (benign tumors and mucoepidermoid carcinoma [MEC]) was analyzed. RESULTS: ACC in the major salivary gland was more likely to be associated with pain symptoms (P = .027) and unclear borders and rough edges in grayscale US (P = .002, .015, respectively) than benign tumors. Compared to MEC, ACC tended to feature a homogeneous internal echo (P = .008). ACC of the major salivary gland had a significantly higher incidence of polar vessel sign than that of non-ACC (benign tumors and MEC) (P < .0001, .0001, respectively). The polar vessel sign showed good performance in distinguishing between ACC and non-ACC, with an area under the receiver operating characteristic curve of 0.857, a sensitivity of 71.4%, a specificity of 100%, and an accuracy of 94.7%. Positive predictive value and negative predictive value were calculated at 100% and 93.9%, respectively. CONCLUSIONS: The US sign of polar vessel has high diagnostic efficiency, and it may have important potential for use as a new complementary sign for the diagnosis of ACC in major salivary glands.


Assuntos
Carcinoma Adenoide Cístico , Carcinoma Mucoepidermoide , Neoplasias das Glândulas Salivares , Humanos , Carcinoma Adenoide Cístico/diagnóstico por imagem , Carcinoma Adenoide Cístico/patologia , Carcinoma Adenoide Cístico/cirurgia , Neoplasias das Glândulas Salivares/diagnóstico por imagem , Glândulas Salivares/diagnóstico por imagem , Carcinoma Mucoepidermoide/patologia , Glândula Parótida/patologia
6.
Sensors (Basel) ; 23(24)2023 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-38139739

RESUMO

Head pose estimation serves various applications, such as gaze estimation, fatigue-driven detection, and virtual reality. Nonetheless, achieving precise and efficient predictions remains challenging owing to the reliance on singular data sources. Therefore, this study introduces a technique involving multimodal feature fusion to elevate head pose estimation accuracy. The proposed method amalgamates data derived from diverse sources, including RGB and depth images, to construct a comprehensive three-dimensional representation of the head, commonly referred to as a point cloud. The noteworthy innovations of this method encompass a residual multilayer perceptron structure within PointNet, designed to tackle gradient-related challenges, along with spatial self-attention mechanisms aimed at noise reduction. The enhanced PointNet and ResNet networks are utilized to extract features from both point clouds and images. These extracted features undergo fusion. Furthermore, the incorporation of a scoring module strengthens robustness, particularly in scenarios involving facial occlusion. This is achieved by preserving features from the highest-scoring point cloud. Additionally, a prediction module is employed, combining classification and regression methodologies to accurately estimate head poses. The proposed method improves the accuracy and robustness of head pose estimation, especially in cases involving facial obstructions. These advancements are substantiated by experiments conducted using the BIWI dataset, demonstrating the superiority of this method over existing techniques.

7.
Liver Int ; 41(8): 1867-1878, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33894105

RESUMO

AIM: The aim of this study is to investigate the effect of maternal nicotine exposure (MNE) on the development of metabolic associated fatty liver disease (MAFLD) in adulthood offspring and the underlying mechanism. METHODS: Pregnant mice (n = 22) were subcutaneously injected with either saline vehicle (n = 11) or nicotine (n = 11) twice a day on gestational days 11-21. Offspring mice (n = 176) from both groups were weaned at postnatal day 21, and for 6 months after postnatal day 21, 96 mice were fed either a standard chow diet (n = 48) or a high-fat diet (n = 48). Serum lipid indicators, liver function indicators, insulin, and liver mitochondrial respiration were analyzed. The expression levels of fibrosis-related proteins, phosphorylated PI3K, phosphorylated Akt, sterol regulatory element-binding transcription factor 1 (SREBP1c), and peroxisome proliferator-activated receptor alpha (PPAR-α) were detected in the liver by immunohistochemistry and Western blotting. RESULTS: MNE significantly decreased the weight of both maternal and offspring mice (~30%) and inhibited organ growth in offspring mice (P < .05). MNE also significantly increased serum levels of total bile acid, triglycerides, total cholesterol, glucose, alanine aminotransferase, aspartate aminotransferase, low-density lipoprotein, and insulin while decreasing serum high-density lipoprotein levels and mitochondrial respiration activity in mice fed either the normal diet or high-fat diet (all P < .05). These effects of MNE on lipid metabolism and insulin resistance were mediated via PI3K and Akt phosphorylation and down-regulation of SREBP1c and PPAR-α. CONCLUSION: Our data indicate MNE induces lipid metabolism disorder and insulin resistance to promote MAFLD progression in adult offspring through activation of PI3K/Akt signaling and suppression of SREBP1c and PPARα protein expression.


Assuntos
Fígado Gorduroso , Resistência à Insulina , Efeitos Tardios da Exposição Pré-Natal , Animais , Dieta Hiperlipídica , Fígado Gorduroso/induzido quimicamente , Fígado Gorduroso/metabolismo , Feminino , Metabolismo dos Lipídeos , Fígado/metabolismo , Camundongos , Nicotina/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Gravidez , Proteínas Proto-Oncogênicas c-akt/metabolismo
8.
Environ Sci Technol ; 55(24): 16597-16606, 2021 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-34874719

RESUMO

Nitrate removal from groundwater remains a challenge. Here, we report on the development of a flow-through, electrically charged, granular-activated carbon (GAC)-filled column, which effectively removes nitrate. In this system, the GAC functioned as an anode, while a titanium sheet acted as a cathode. The high removal rate of nitrate was achieved through a combination of electrosorption and electrochemical transformation to N2. The column could be readily regenerated in situ by reversing the polarity of the applied potential. We demonstrate that in the presence of chloride, the mechanism responsible for the observed nitrate removal involves a combination of electroadsorption of nitrate to the anodically charged GAC, electroreduction of nitrate to ammonium, and the oxidation of ammonium to N2 gas by reactive chlorine and other oxidative radicals (with nearly 100% N2 selectivity). Given the ubiquitous presence of chloride in groundwater, this method represents a ready, green, and sustainable treatment process with significant potential for the remediation of contaminated groundwater.


Assuntos
Água Subterrânea , Poluentes Químicos da Água , Purificação da Água , Adsorção , Carvão Vegetal , Nitratos , Poluentes Químicos da Água/análise
9.
Med Sci Monit ; 27: e931327, 2021 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-34172694

RESUMO

BACKGROUND The aim of this study was to evaluate the effectiveness of grayscale ultrasound (GSUS), power Doppler imaging (PDI), and contrast-enhanced ultrasonography (CEUS) in early rheumatoid arthritis (RA) diagnosis through animal experiments. MATERIAL AND METHODS A rabbit RA model was constructed. The animals were randomly divided into 2 groups, namely, the RA model group and the control group. GSUS, PDI, and CEUS were performed in the model group during early RA and were compared with pathology of synovial biopsies. The consistency of 3 types of ultrasonography was evaluated in tandem with pathological grading. RESULTS 23 rabbits in the RA model group completed the experiment. GSUS showed that the synovial thickening of grades 1, 2 and 3 occurred in 12, 19, and 15 joints, respectively. The sensitivity, specificity, and accuracy of PDI in the diagnosis of knee joint synovitis in RA grades 1, 2, and 3 were 80.56% (29/36), 60.00% (6/10), and 76.09% (35/46), respectively, while those with CEUS were 94.44% (34/36), 90.00% (9/10), and 93.47% (43/46), respectively. The differences in diagnostic sensitivity, specificity, and accuracy of the 2 methods were statistically significant. Additionally, the thickness of the synovium measured with GSUS precontrast was greater than that of postcontrast. CONCLUSIONS RA evaluated with GSUS is often more hypertrophied than when evaluated with CEUS, while evaluation by PDI is less hypertrophied than that by CEUS. However, from a practical view point, GSUS and PDI are of sufficient practical value, except for in a few special cases.


Assuntos
Artrite Reumatoide/diagnóstico por imagem , Meios de Contraste , Aumento da Imagem/métodos , Ultrassonografia/métodos , Animais , Artrite Reumatoide/patologia , Biópsia , Modelos Animais de Doenças , Masculino , Coelhos , Reprodutibilidade dos Testes , Membrana Sinovial/diagnóstico por imagem , Membrana Sinovial/patologia
10.
Med Sci Monit ; 27: e929408, 2021 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-33819211

RESUMO

BACKGROUND The aim of this study was to assess the interaction between thyroid malignancies and thyroid anterior capsule by ultrasound quantification to determine extra-capsular invasion. MATERIAL AND METHODS A total of 145 patients preoperatively diagnosed with malignant nodules under the thyroid anterior capsule were selected and routinely examined by ultrasound. The length of the nodules (from the junction of the nodule capsule to the deepest point of the nodule, vertical diameter, V) and the distance between the nodule protruding from thyroid capsule and the highest protruding (ledge length, L) nodule were used to obtain the L/V ratio. These parameters where then used to compare the efficacy of predicting extra-thyroid extension (ETE) between L/V, the aspect ratio of the tumor, and manual judgment. RESULTS Out of 145 nodules, there were 63 ETEs and 82 non-ETEs determined by ultrasound. Extra-capsular invasion was associated with L//V ratio, but there was no significant correlation between capsular invasion and AR (aspect ratio), age, location, or presence of clustered calcification. The ability of the ratio of L/V to predict extra-capsular invasion was superior to the predictive ability of the AR ratio. With a Youden index of 0.593, the L/V ratio was 0.2325. The use of the L/V ratio to determine the presence of ETE was superior to subjective visual judgment. CONCLUSIONS The calculation of L/V ratio by ultrasound could more precisely predict the ETE compared with manual judgment, which indirectly reflects the interaction between thyroid capsule and malignant nodules. The above conclusions need to be confirmed by a range of cases.


Assuntos
Carcinoma Papilar/diagnóstico , Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/diagnóstico , Ultrassonografia/métodos , Adulto , Carcinoma Papilar/patologia , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Estudos Retrospectivos , Neoplasias da Glândula Tireoide/patologia
11.
J Cell Mol Med ; 24(11): 6149-6161, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32347017

RESUMO

Bone loss (osteopenia) is a common complication in human solid tumour. In addition, after surgical treatment of gynaecological tumour, osteoporosis often occurs due to the withdrawal of oestrogen. The major characteristic of osteoporosis is the low bone mass with micro-architectural deteriorated bone tissue. And the main cause is the overactivation of osteoclastogenesis, which is one of the most important therapeutic targets. Inflammation could induce the interaction of RANKL/RANK, which is the promoter of osteoclastogenesis. Triptolide is derived from the traditional Chinese herb lei gong teng, presented multiple biological effects, including anti-cancer, anti-inflammation and immunosuppression. We hypothesized that triptolide could inhibits osteoclastogenesis by suppressing inflammation activation. In this study, we confirmed that triptolide could suppress RANKL-induced osteoclastogenesis in bone marrow mononuclear cells (BMMCs) and RAW264.7 cells and inhibited the osteoclast bone resorption functions. PI3K-AKT-NFATc1 pathway is one of the most important downstream pathways of RANKL-induced osteogenesis. The experiments in vitro indicated that triptolide suppresses the activation of PI3K-AKT-NFATc1 pathway and the target point located at the upstream of AKT because both NFATc1 overexpression and AKT phosphorylation could ameliorate the triptolide suppression effects. The expression of MDM2 was elevated, which demonstrated the MDM-p53-induced cell death might contribute to the osteoclastogenesis suppression. Ovariectomy-induced bone loss and inflammation activation were also found to be ameliorated in the experiments in vivo. In summary, the new effect of anti-cancer drug triptolide was demonstrated to be anti-osteoclastogenesis, and we demonstrated triptolide might be a promising therapy for bone loss caused by tumour.


Assuntos
Reabsorção Óssea/tratamento farmacológico , Reabsorção Óssea/prevenção & controle , Diterpenos/uso terapêutico , Fatores de Transcrição NFATC/metabolismo , Osteogênese , Fenantrenos/uso terapêutico , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Acetatos/farmacologia , Animais , Benzopiranos/farmacologia , Biomarcadores/metabolismo , Diterpenos/química , Diterpenos/farmacologia , Compostos de Epóxi/química , Compostos de Epóxi/farmacologia , Compostos de Epóxi/uso terapêutico , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Osteoclastos/efeitos dos fármacos , Osteoclastos/metabolismo , Osteoclastos/patologia , Osteogênese/efeitos dos fármacos , Ovariectomia , Fenantrenos/química , Fenantrenos/farmacologia , Proteínas Proto-Oncogênicas c-akt/agonistas , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Ligante RANK/metabolismo , Células RAW 264.7
12.
Environ Sci Technol ; 54(17): 10668-10677, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32786552

RESUMO

Per and polyfluoroalkyl substances (PFAS), legacy chemicals used in firefighting and the manufacturing of many industrial and consumer goods, are widely found in groundwater resources, along with other regulated compounds, such as chlorinated solvents. Due to their strong C-F bonds, these molecules are extremely recalcitrant, requiring advanced treatment methods for effective remediation, with hydrated electrons shown to be able to defluorinated these compounds. A combined photo/electrochemical method has been demonstrated to dramatically increase defluorination rates, where PFAS molecules sorbed onto appropriately functionalized cathodes charged to low cell potentials (-0.58 V vs Ag/AgCl) undergo a transient electron transfer event from the electrode, which "primes" the molecule by reducing the C-F bond strength and enables the bond's dissociation upon the absorption of a hydrated electron. In this work, we explore the impact of headgroup and chain length on the performance of this two-electron process and extend this technique to chlorinated solvents. We use isotopically labeled PFAS molecules to take advantage of the kinetic isotope effect and demonstrate that indeed PFAS defluorination is likely driven by a two-electron process. We also present density functional theory calculations to illustrate that the externally applied potential resulted in an increased rate of electron transfer, which ultimately increased the measured defluorination rate.


Assuntos
Fluorocarbonos , Água Subterrânea , Eletrodos , Elétrons , Cinética
13.
Environ Sci Technol ; 53(9): 5256-5265, 2019 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-30990998

RESUMO

Yellow mealworms (larvae of Tenebrio molitor, Coleoptera: Tenebrionidae) have been proven to be capable of biodegrading polystyrene (PS) products. Using four geographic sources, we found that dark mealworms (larvae of Tenebrio obscurus) ate PS as well. We subsequently tested T. obscurus from Shandong, China for PS degradation capability. Our results demonstrated the ability for PS degradation within the gut of T. obscurus at greater rates than T. molitor. With expanded PS foam as the sole diet, the specific PS consumption rates for T. obscurus and T. molitor at similar sizes (2.0 cm, 62-64 mg per larva) were 32.44 ± 0.51 and 24.30 ± 1.34 mg 100 larvae-1 d-1, respectively. After 31 days, the molecular weight ( Mn) of residual PS in frass (excrement) of T. obscurus decreased by 26.03%, remarkably higher than that of T. molitor (11.67%). Fourier transform infrared spectroscopy (FTIR) indicated formation of functional groups of intermediates and chemical modification. Thermo gravimetric analysis (TGA) suggested that T. obscurus larvae degraded PS effectively based on the proportion of PS residue. Co-fed corn flour to T. obscurus and wheat bran to T. molitor increased total PS consumption by 11.6% and 15.2%, respectively. Antibiotic gentamicin almost completely inhibited PS depolymerization. High-throughput sequencing revealed significant shifts in the gut microbial community in both Tenebrio species that were associated with the PS diet and PS biodegradation, with changes in three predominant families (Enterobacteriaceae, Spiroplasmataceae, and Enterococcaceae). The results indicate that PS biodegradability may be ubiquitous within the Tenebrio genus which could provide a bioresource for plastic waste biodegradation.


Assuntos
Besouros , Tenebrio , Animais , Biodegradação Ambiental , China , Larva , Poliestirenos
14.
J Ultrasound Med ; 38(6): 1501-1509, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30280402

RESUMO

OBJECTIVES: To investigate the applicability and value of ultrasound (US) in the diagnosis of anorectal atresia. METHODS: Between January 2008 and January 2016, we prospectively evaluated 63,101 fetuses (gestational age, 20-38 weeks), including low- and high-risk populations using 2-dimensional US scans. An abnormal imaging finding was defined as an anal canal diameter of less than the 95% confidence interval (small anal canal) of the normal range or the absence of an anal canal and rectum. Imaging findings were considered normal on detection of an anal canal with a normal width and the absence of abnormalities. Prenatal imaging findings were confirmed by a postnatal or postmortem examination. RESULTS: Among the investigated fetuses, 28 showed evidence of anorectal atresia on US scans, and 22 of those with anorectal atresia had additional anomalies. Six cases of isolated anorectal atresia were successfully detected during the preclusive prenatal US scans. Four cases of a low imperforate anus (including 2 covered anuses) yielded false-negative results, indicating a diagnostic rate of 87.5% (28 of 32). The normal appearance of the fetal rectum and anal canal ruled out anorectal atresia in 30 fetuses with a dilated colon. Additionally, there were 3 false-positive cases, in which a narrow anal canal was observed. CONCLUSIONS: Identifying the abnormal appearance or absence of the fetal anal canal and rectum on preclusive US anomaly scans is useful for prenatal diagnosis or exclusion of anorectal atresia, which may help improve the detection of isolated anorectal atresia. Furthermore, a combined evaluation of the longitudinal and axial appearances of the fetal anal canal and rectum can improve diagnostic accuracy.


Assuntos
Malformações Anorretais/diagnóstico por imagem , Malformações Anorretais/embriologia , Ultrassonografia Pré-Natal/métodos , Canal Anal/diagnóstico por imagem , Canal Anal/embriologia , Feminino , Humanos , Gravidez , Estudos Prospectivos , Reto/diagnóstico por imagem , Reto/embriologia , Reprodutibilidade dos Testes
15.
Ecotoxicol Environ Saf ; 176: 270-278, 2019 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-30947030

RESUMO

This study examines the adsorption and desorption characteristics of heavy metals in road dust (RD) for the aspect of integrated stormwater management. The chemical fractionations of Cu, Zn, Ni, and Cd were determined by a three-step sequential extraction protocol. Pseudo-first-order and Pseudo-second-order kinetic models, along with Langmuir, Freundlich, and Temkin isotherms were adopted to simulate the batch experimental data. The proportional shift of metals' chemical fractionations in original RD, adsorption equilibrium, and desorption equilibrium were determined. Results show that RD has a remarkable affinity to adsorb heavy metal within a short time. The adsorption processes were well described by the Pseudo-second-order kinetic model (R2 = 0.98-0.99) and Freundlich isotherm (R2 = 0.89-0.98) for most of the given metals indicating that the chemical adsorption was probably the rate-controlling step and the binding energy for each site was not identical. The maximum adsorption capacities for Cu, Cd, Zn, and Ni were 6300 mg kg-1, 5800 mg kg-1, 4000 mg kg-1, and 3200 mg kg-1, respectively. A linear fit to the equilibrium pH and the total amounts of the adsorbed metals indicates a strong pH-dependent adsorption. According to the proportional shift of metals' chemical fractionations during the adsorption and desorption processes, the exchangeable fractions of heavy metals in RD were irreversible. It suggests that a portion of the surface sites of RD would be not exchangeable once it was occupied.


Assuntos
Poeira/análise , Metais Pesados/análise , Poluentes Químicos da Água/análise , Adsorção , Cinética
16.
Environ Sci Technol ; 52(11): 6466-6475, 2018 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-29767520

RESUMO

Sulfidation of nanoscale zerovalent iron (nZVI) has shown some fundamental improvements on reactivity and selectivity toward pollutants in dissolved-oxygen (DO)-stimulated Fenton-like reaction systems (DO/S-nZVI system). However, the pristine microstructure of sulfide-modified nanoscale zerovalent iron (S-nZVI) remains uncovered. In addition, the relationship between pollutant removal and the oxidation of the S-nZVI is largely unknown. The present study confirms that sulfidation not only imparts sulfide and sulfate groups onto the surface of the nanoparticle (both on the oxide shell and on flake-like structures) but also introduces sulfur into the Fe(0) core region. Sulfidation greatly inhibits the four-electron transfer pathway between Fe(0) and oxygen but facilitates the electron transfer from Fe(0) to surface-bound Fe(III) and consecutive single-electron transfer for the generation of H2O2 and hydroxyl radical. In the DO/S-nZVI system, slight sulfidation (S/Fe molar ratio = 0.1) is able to nearly double the oxidative removal efficacy of diclofenac (DCF) (from 17.8 to 34.2%), whereas moderate degree of sulfidation (S/Fe molar ratio = 0.3) significantly enhances both oxidation and adsorption of DCF. Furthermore, on the basis of the oxidation model of S-nZVI, the DCF removal process can be divided into two steps, which are well modeled by parabolic and logarithmic law separately. This study bridges the knowledge gap between pollutant removal and the oxidation process of chemically modified iron-based nanomaterials.


Assuntos
Ferro , Poluentes Químicos da Água , Adsorção , Diclofenaco , Peróxido de Hidrogênio , Estresse Oxidativo , Sulfetos
17.
Environ Sci Technol ; 50(11): 5597-605, 2016 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-27183309

RESUMO

Nanoscale zerovalent iron (nZVI) and its derivatives hold promise for remediation of several pollutants but their environmental implications are not completely clear. In this study, the physicochemical properties and aggregation kinetics of sulfide/silica-modified nZVI (FeSSi) were compared in algal media in which Chlamydomonas reinhardtii had been cultured for 1, 2, or 11 days in order to elicit the effects of organic matter produced by the freshwater algae. Furthermore, transformation of FeSSi particles were investigated in C. reinhardtii cultures in exponential (1-d) and slowing growth (11-d) phases while monitoring the response of algae. We found evidence for steric stabilization of FeSSi by algal organic matter, which led to a decrease in the particles' attachment efficiency. Transformation of FeSSi was slower in 11-d cultures as determined via inductively coupled plasma and X-ray analyses. High concentrations of FeSSi caused a lag in algal growth, and reduction in steady state population size, especially in cultures in exponential phase. The different outcomes are well described by a dynamic model describing algal growth, organic carbon production, and FeSSi transformations. This study shows that feedback from algae may play important roles in the environmental implications of engineered nanomaterials.


Assuntos
Ferro/química , Fitoplâncton , Nanopartículas Metálicas/química , Nanopartículas/química , Sulfetos/química , Poluentes Químicos da Água/química
18.
J Ultrasound Med ; 35(10): 2223-30, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27573797

RESUMO

OBJECTIVES: Progress in developing novel rational treatments for rheumatoid arthritis (RA) critically depends on preclinical work in experimental animals. However, there is lack of insight into the most appropriate mode of noninvasive measurement of disease status in experimental RA. This study compared sonography with serum biomarkers in a rabbit model of RA. METHODS: Six-month-old male New Zealand White rabbits were randomized into 2 groups: antigen-induced arthritis group (n = 25), which was subjected to ovalbumin immunization and intra-articular injection; and control group (n = 5). Pathologic changes in the knee joints were evaluated by sonography, and serum C-reactive protein, tumor necrosis factor TNF-α, and interleukin 1 were measured by enzyme-linked immunosorbent assay. Synovial pathologic scores were obtained by ultrasound-guided biopsy. RESULTS: A total of 23 rabbits (2 rabbits died before the end of the study) in the antigen-induced arthritis group and 5 rabbits in the control group completed the study. Sonographic scores for all rabbits were graded from 0 to 3, according to grayscale sonography, synovitis, and blood flow. Synovial lesions were evident on sonography before week 4; however, serum biomarkers slowly increased until weeks 5 and 6 (P < .05). Although both sonography and serum biomarkers correlated significantly with synovitis scoring, the correlations for the sonographically derived parameters were better. The correlation indices between pathologic scores and synovial membranes thickness, blood flow, and resistive index were 0.798, 0.557, and -0.320, respectively, whereas the correlation indices between pathologic scores and tumor necrosis factor α, interleukin 1, and C-reactive protein levels were 0.451, 0.503, and 0.529. CONCLUSIONS: Sonographic findings had better correlations with histologic scoring than serologic biomarkers of disease activity in the RA rabbit model, especially at early stages. Local pathologic assessment of disease status by sonography is possible.


Assuntos
Artrite Reumatoide/sangue , Artrite Reumatoide/diagnóstico por imagem , Ultrassonografia , Animais , Artrite Reumatoide/patologia , Biomarcadores/sangue , Biópsia , Proteína C-Reativa , Modelos Animais de Doenças , Ensaio de Imunoadsorção Enzimática , Interleucina-1/sangue , Articulação do Joelho/diagnóstico por imagem , Articulação do Joelho/patologia , Masculino , Coelhos , Reprodutibilidade dos Testes , Índice de Gravidade de Doença , Fator de Necrose Tumoral alfa/sangue
19.
Angew Chem Int Ed Engl ; 55(10): 3491-5, 2016 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-26837053

RESUMO

The first example of nickel-catalyzed decarboxylative fluoroalkylation of α,ß-unsaturated carboxylic acids has been developed with commonly available fluoroalkyl halides. This novel transformation has demonstrated broad substrate scope, excellent functional-group tolerance, mild reaction conditions, and excellent stereoselectivity. Mechanistic investigations indicate that a fluoroalkyl radical is involved in the catalytic cycle.

20.
J Environ Sci (China) ; 36: 1-8, 2015 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-26456600

RESUMO

Low-cost but high-efficiency composites of iron-containing porous carbons were prepared using sewage sludge and ferric salts as raw materials. Unlike previous time- and energy-consuming manufacturing procedures, this study shows that pyrolyzing a mixture of sludge and ferric salt can produce suitable composites for lead adsorption. The specific surface area, the total pore volume and the average pore width of the optimal composite were 321m(2)/g, 0.25cm(3)/g, and 3.17nm, respectively. X-ray diffraction analysis indicated that ferric salt favored the formation of metallic iron, while Fourier transform infrared spectroscopy revealed the formation of hydroxyl and carboxylic groups. The result of batch tests indicated that the adsorption capacity of carbons activated with ferric salt could be as high as 128.9mg/g, while that of carbons without activation was 79.1mg/g. The new manufacturing procedure used in this study could save at least 19.5kJ of energy per gram of activated carbon.


Assuntos
Carbono/química , Ferro/química , Chumbo/química , Poluentes Químicos da Água/química , Adsorção , Carvão Vegetal/química , Compostos Férricos/química , Sais/química , Esgotos/química , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa