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1.
Environ Pollut ; 267: 115492, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33254672

RESUMO

Dichlorodiphenyltrichloroethane (DDT) is well known for its harmful effects and has been banned around the world. However, DDT is still frequently detected in natural environments, particularly in aquaculture and harbor sediments. In this study, 15 surface sediment samples were collected from a typical tropical bay (Zhanjiang Bay) in the South China Sea, and the levels of DDT and its metabolites in sediment and porewater samples were investigated. The results showed that concentrations of DDXs (i.e., DDT and its metabolites) in bulk sediments were 1.58-51.0 ng g-1 (mean, 11.5 ng g-1). DDTs (DDT and its primary metabolites, dichlorodiphenyldichloroethane (DDD) and dichlorodiphenyldichloroethylene (DDE)) were the most prominent, accounting for 73.2%-98.3% (86.1% ± 12.8%) of the DDXs. Additionally, high-order metabolites (i.e., 1-chloro-2,2-bis(4'-chlorophenyl)ethylene (p,p'-DDMU), 2,2-bis(p-chlorophenyl)ethylene (p,p'-DDNU), 2,2-bis(p-chlorophenyl)ethanol (p,p'-DDOH), 2,2-bis(p-chlorophenyl)methane (p,p'-DDM), and 4,4'-dichlorobenzophenone (p,p'-DBP)) were also detected in most of the sediment and porewater samples, with DDMU and DBP being predominant. The DDTs concentration differed among the sampling sites, with relatively high DDTs concentrations in the samples from the aquaculture zone and an area near the shipping channel and the Haibin shipyard. The DDD/DDE ratios indicated a reductive dichlorination of DDT to DDD under anaerobic conditions at most of the sampling sites of Zhanjiang Bay. The possible DDT degradation pathway in the surface sediments of Zhanjiang Bay was p,p'-DDT/p,p'-DDD(p,p'-DDE)/p,p'-DDMU/p,p'-DDNU/ … /p,p'-DBP. The DDXs in the sediments of Zhanjiang Bay were mainly introduced via mixed sources of industrial DDT and dicofol, including fresh input and historical residue. The concentrations of DDXs in porewater samples varied from 66.3 to 250 ng L-1, exhibiting a distribution similar to that in the accompanying sediments. However, the content of high-order metabolites was relatively lower in porewater than in sediment, indicating that high-order degradation mainly occurs in particles. Overall, this study helps in understanding the distribution, source, and degradation of DDT in a typical tropical bay.

2.
Environ Pollut ; 268(Pt A): 115906, 2020 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-33120333

RESUMO

Fluorescence spectroscopy is a commonly used technique to analyze dissolved organic matter in aquatic environments. Given the high sensitivity and non-destructive analysis, fluorescence has recently been used to study water-soluble organic carbon (WSOC) in atmospheric aerosols, which have substantial abundance, various sources and play an important role in climate change. Yet, current research on WSOC characterization is rather sparse and limited to a few isolated sites, making it challenging to draw fundamental and mechanistic conclusions. Here we presented a review of the fluorescence properties of atmospheric WSOC reported in various field and laboratory studies, to discuss the current advances and limitations of fluorescence applications. We highlighted that photochemical reactions and relevant aging processes have profound impacts on fluorescence properties of atmospheric WSOC, which were previously unnoticed for organic matter in aquatic environments. Furthermore, we discussed the differences in sources and chemical compositions of fluorescent components between the atmosphere and hydrosphere. We concluded that the commonly used fluorescence characteristics derived from aquatic environments may not be applicable as references for atmospheric WSOC. We emphasized that there is a need for more systematic studies on the fluorescence properties of atmospheric WSOC and to establish a more robust reference and dataset for fluorescence studies in atmosphere based on extensive source-specific experiments.

3.
Environ Pollut ; 262: 114266, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32155548

RESUMO

Humic-like substances (HULIS) are complex mixtures that are highly associated with brown carbon (BrC) and are important components of biomass burning (BB) emissions. In this study, we investigated the light absorption, emission factors (EFs), and amounts of HULIS emitted from the simulated burning of 27 types of regionally important rainforest biomass in Southeast Asia. We observed that HULIS had a high mass absorption efficiency at 365 nm (MAE365), with an average value of 2.6 ± 0.83 m2 g-1 C. HULIS emitted from BB accounted for 65% ± 13% of the amount of water-soluble organic carbon (WSOC) and 85% ± 10% of the light absorption of WSOC at 365 nm. The EFs of HULIS from BB averaged 2.3 ± 2.1 g kg-1 fuel, and the burning of the four vegetation subtypes (herbaceous plants, shrubs, evergreen trees, and deciduous trees) exhibited different characteristics. The differences in EFs among the subtypes were likely due to differences in lignin content in the vegetation, the burning conditions, or other factors. The light absorption characteristics of HULIS were strongly associated with the EFs. The annual emissions (minimum-maximum) of HULIS from BB in this region in 2016 were 200-371 Gg. Furthermore, the emissions from January to April accounted for 99% of the total annual emissions of HULIS, which is likely the result of the burning activities during this season. The most significant emission regions were Cambodia, Burma, Thailand, and Laos. This study, which evaluated emissions of HULIS by simulating open BB, contributes to a better understanding of the light-absorbing properties and regional budgets of BrC in this region.


Assuntos
Poluentes Atmosféricos/análise , Material Particulado/análise , Aerossóis , Ásia Sudeste , Biomassa , Camboja , Carbono/análise , Monitoramento Ambiental , Floresta Úmida , Tailândia
4.
Sci Total Environ ; 718: 137322, 2020 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-32092515

RESUMO

It is essential to fully understand the physicochemical properties and sources of atmospheric chromophores to evaluate their impacts on environmental quality and global climate. Three-dimensional excitation-emission matrix (EEM) fluorescence spectroscopy is an important method for directly characterizing the occurrences, origins, and chemical behaviors of atmospheric chromophores. However, there is still a lack of adequate information on the sources and chemical structures of EEM-defined chromophores. This situation limits the extensive application of the EEM method in the study of atmospheric chromophores. Under these adverse conditions, this work uses the analysis of EEM data by the parallel factor (PARAFAC) analysis model and a comprehensive comparison of the types and abundances of different chromophores in different aerosol samples (combustion source samples, secondary organic aerosols, and ambient aerosols) to demonstrate that the EEM method can distinguish among different chromophore types and aerosol sources. Indeed, approximately half of all fluorescent substances can be attributed to specific chemicals and sources. These findings provide an important basis for the study of the sources and chemical processes of atmospheric chromophores by the EEM approach.

5.
Environ Pollut ; 256: 113408, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31662267

RESUMO

The m-aminophenol (m-AP) is a widely used industrial chemical, which enters water, soils, and sediments with waste emissions. A common soil metal oxide, birnessite (δ-MnO2), was found to mediate the transformation of m-AP with fast rates under acidic conditions. Because of the highly complexity of the m-AP transformation, mechanism-based models were taken to fit the transformation kinetic process of m-AP. The results indicated that the transformation of m-AP with δ-MnO2 could be described by precursor complex formation rate-limiting model. The oxidative transformation of m-AP on the surface of δ-MnO2 was highly dependent on reactant concentrations, pH, temperature, and other co-solutes. The UV-VIS absorbance and mass spectra analysis indicated that the pathway leading to m-AP transformation may be the polymerization through the coupling reaction. The m-AP radicals were likely to be coupled by the covalent bonding between unsubstituted C2, C4 or C6 atoms in the m-AP aromatic rings to form oligomers as revealed by the results of activation energy and mass spectra. Furthermore, the toxicity assessment of the transformation productions indicated that the toxicity of m-AP to the E. coli K-12 could be reduced by MnO2 mediated transformation. The results are helpful for understanding the environmental behavior and potential risk of m-AP in natural environment.


Assuntos
Aminofenóis/química , Óxidos/química , Poluentes Químicos da Água/química , Aminofenóis/toxicidade , Escherichia coli , Cinética , Compostos de Manganês , Oxirredução , Estresse Oxidativo , Água , Poluentes Químicos da Água/toxicidade
6.
Environ Sci Technol ; 53(23): 13607-13617, 2019 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-31682114

RESUMO

Water-soluble organic compounds (WSOC) and methanol-soluble organic compounds (MSOC) in smoke particles emitted from residential coal combustion were characterized by ultrahigh-resolution mass spectrometry. The results showed that the molecular compositions of WSOC and MSOC are different. S-containing compounds (CHOS and CHONS) are found to be the dominant components (65-87%) of the WSOC, whereas CHO and CHON compounds make a great contribution (79-96%) to the MSOC samples. It is worth noting that greater abundance of S-containing compounds was found in smoke produced from coal combustion compared to biomass burning and atmospheric samples. The molecular compositions of WSOC and MSOC also varied significantly depending on the maturity of the coal. The WSOC and MSOC derived from the combustion of low-maturity coal contained a higher proportion of oxidized functional groups but with a lower degree of aromaticity than the compounds derived from the combustion of high-maturity coal. Our findings suggest that organic molecules with a high modified aromaticity index, low O/C ratio, and low polarity showed stronger light absorption. This study also suggests that CHO and CHON compounds significantly contributed to the light absorption of WSOC and MSOC and that the contribution of CHON may be stronger.


Assuntos
Carvão Mineral , Metanol , Ciclotrons , Análise de Fourier , Espectrometria de Massas , Espectrometria de Massas por Ionização por Electrospray , Água
7.
Sci Rep ; 9(1): 17757, 2019 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-31780678

RESUMO

Adenylate kinase 2 (AK2), an isoenzyme of the AK family, may have momentous extra-mitochondrial functions, especially in tumourigenesis in addition to the well-known control of energy metabolism. In this study, we provided the first evidence that AK2 is overexpressed in lung adenocarcinoma. The positive expression of AK2 is associated with tumor progression, and poor survival in patients with pulmonary adenocarcinoma. Knockdown of AK2 could suppress proliferation, migration, and invasion as well as induce apoptosis and autophagy in human lung adenocarcinoma cells. Remarkably, silencing AK2 exerted the greater tumor suppression roles when combined with hydroxychloroquine, an effective autophagy inhibitor, in vitro and in xenografts mouse models. Our data have probably provided preclinical proof that systematic inhibition of AK2 and autophagy could be therapeutically effective on lung cancer.


Assuntos
Adenocarcinoma de Pulmão/diagnóstico , Adenilato Quinase/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias Pulmonares/diagnóstico , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/patologia , Adenilato Quinase/análise , Animais , Linhagem Celular Tumoral , Proliferação de Células , Progressão da Doença , Feminino , Técnicas de Silenciamento de Genes , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus , Pessoa de Meia-Idade , Prognóstico
8.
Biomed Pharmacother ; 118: 109382, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31545257

RESUMO

Renal cell carcinoma (RCC) is one of the most lethal urological malignancies, yet its pathogenesis remains unclear. Here, we reported a long non-coding RNA (lncRNA), NONHSAT 113026 (NOAT113026), which may play an important role in the pathogenesis of RCC. The expression level of NOAT113026 was estimated by qPCR from 76 pairs of RCC and non-tumor (NT) samples. The correlation between NOAT113026 and clinical data of RCC patients was analyzed. NOAT113026 was overexpressed in 786-O and ACHN cell lines by lentivirus-mediated technology and the oncological behavioral changes of RCC cells were observed along with tumorigenicity in experimental nude mice. Compared to the adjacent tissues, NOAT113026 was noticeably downregulated in RCC. Survival analysis showed that the lower the expression level of NOAT113026 was, the shorter the disease-free survival and overall survival in RCC would be. Overexpression of NOAT113026 can decrease the ability of cell migration, invasion, proliferation, and colony formation by regulating NF-κB/p50 and SLUG through a mechanism that involves lncRNA-mRNA interactions. In conclusion, our data suggest that NOAT113026 could be a carcinostatic RNA in RCC, which may serve as a potential prognostic factor and a promising therapeutic target for malignant RCC.


Assuntos
Carcinogênese/genética , Carcinoma de Células Renais/genética , Carcinoma de Células Renais/patologia , Neoplasias Renais/genética , Neoplasias Renais/patologia , Subunidade p50 de NF-kappa B/metabolismo , RNA Longo não Codificante/metabolismo , Fatores de Transcrição da Família Snail/metabolismo , Regiões 3' não Traduzidas/genética , Animais , Sequência de Bases , Biomarcadores Tumorais/metabolismo , Carcinogênese/patologia , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Transição Epitelial-Mesenquimal/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Inflamação/patologia , Masculino , Camundongos Nus , Invasividade Neoplásica , Prognóstico , RNA Longo não Codificante/genética , Regulação para Cima/genética
9.
Huan Jing Ke Xue ; 40(4): 1734-1741, 2019 Apr 08.
Artigo em Chinês | MEDLINE | ID: mdl-31087914

RESUMO

Sixteen surface sediment samples were collected from the estuary of the Suixi river to the mouth of Zhanjiang Bay and then analyzed for organochlorine pesticides (OCPs) by GC-MS to investigate their distribution and ecological risk. The results showed that the concentrations of OCPs in the sediments ranged from nd to 189.52 ng·g-1 (mean 32.17 ng·g-1), including HCHs (mean 5.81 ng·g-1) and DDTs (mean 26.90 ng·g-1). The distribution characteristics showed that the highest OCPs concentrations were found in the estuary and the main shipping lane areas, and the concentration in the nearshore area was higher than that offshore. Source analysis indicated that the HCHs mainly originated from agricultural applications, while no industrial input was observed. Some "hot-spots" areas occurred in harbors and shipping channels, likely as a result of the presence of paint flakes. Additionally, the concentrations of DDTs were found to be higher than the limits of Chinese Marine sediment quality criteria, and p,p'-DDT was the main type of DDT, presenting inevitable adverse biological effects and high ecological risk. Compared with other bays in China, the concentrations of OCPs in this study were in the upper-median pollution level, especially in harbors and boat maintenance facility areas. High OCPs inputs may occur, and thereby represent a certain ecological risk in Zhanjiang Bay.

10.
Huan Jing Ke Xue ; 40(2): 532-539, 2019 Feb 08.
Artigo em Chinês | MEDLINE | ID: mdl-30628314

RESUMO

The light absorption and fluorescence characteristics of atmospheric water-soluble organic compounds (WSOC) and humic-like substances (HULIS) during the winter season in Guangzhou were examined using UV-vis spectroscopy and excitation-emission matrix spectroscopy combined with parallel factor analysis (EEM-PARAFAC). The results showed that the SUVA254, HIX, and MAE365 values of HULIS were higher than those of WSOC, suggesting that the former had higher aromaticity, humification, and light-absorption capacity in winter atmospheric PM2.5 in Guangzhou. EEM-PARAFAC analysis identified three fluorescence components, including fulvic-like acid (C1), humic-like acid (C2), and protein-like (C3) components. The total humic-like components (C1+C2) accounted for 78% and 85% for WSOC and HULIS, respectively, which indicated that humic-like fluorescence components were the major components for both WSOC and HULIS and that HULIS were enriched with the dominant humic-like fluorophores. In addition, the aromaticity, humification, light-absorbing capacity, and C2 levels of WSOC and HULIS during the haze episode were significantly higher than those in the non-haze episode. This suggested that the water-soluble organics with higher molecular weights and stronger light-absorption capacities tended to form during the haze episode. The correlations analysis revealed strong negative correlations between C1 levels of WSOC and HULIS and HIX, MAE365, OCsec, K+, SO42-, and NH4+. Additionally, strong positive correlations were observed between C2 levels and the same factors. These results implied that the decrease in C1 and increase in C2 might lead to increased humification and light-absorption in WSOC and HULIS, and biomass burning and secondary organic aerosols might contribute to the C2 component.

11.
Environ Sci Technol ; 53(2): 595-603, 2019 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-30584761

RESUMO

Brown carbon (BrC) fractions, including water-soluble organic carbon (WSOC), water-soluble humic-like substances (HULISw), alkaline soluble organic carbon (ASOC), and methanol soluble organic carbon (MSOC) were extracted from particles emitted from the residential combustion of coal with different geological maturities. The abundances and light absorption properties of these BrC fractions were comprehensively studied. The results showed that the abundances of the different constituents of the BrC fraction varied greatly with the extraction solvent, accounting for 4.3%-46%, 2.3%-23%, 3.2%-14%, and 76%-98% of the total carbon content in particles. The specific UV-vis absorbance (SUVA254) of BrC fractions followed the order of MSOC > ASOC > HULISw > WSOC. The WSOC and MSOC fractions from the combustion of low maturity coal had relatively low SUVA254 and high SR values. The mass absorption efficiencies (MAE365) for ASOC and MSOC were higher than for WSOC, and WSOC and MSOC from low maturity coal combustion had relatively low levels of light absorption. These findings indicated that coal combustion is a potential source of atmospheric BrC and the abundance and light absorption of the coal combustion-derived BrC fractions were strongly dependent on the extraction methods used and the coal maturity rather than the coal shapes.


Assuntos
Poluentes Atmosféricos , Carvão Mineral , Carbono , China , Monitoramento Ambiental , Material Particulado
12.
Anticancer Agents Med Chem ; 19(2): 248-255, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30378503

RESUMO

BACKGROUND: The Oral Squamous Cell Carcinoma (OSCC) is one of the most frequent cancer types. Failure of treatment of OSCC is potentially lethal because of local recurrence, regional lymph node metastasis, and distant metastasis. Chemotherapy plays a vital role through suppression of tumorigenesis. Cyclosporine A (CsA), an immunosuppressant drug, has been efficiently used in allograft organ transplant recipients to prevent rejection, and also has been used in a subset of patients with autoimmunity related disorders. The present study aims to investigate novel and effective chemotherapeutic drugs to overcome drug-resistance in the treatment of OSCC. METHODS: Cells were incubated in the standard way. Cell viability was assayed using the MTT assay. Cell proliferation was determined using colony formation assay. The cell cycle assay was performed using flow cytometry. Apoptosis was assessed using fluorescence-activated cell sorting after stained by the Annexin V-fluorescein isothiocyanate (FITC). Cell migration and invasion were analyzed using wound healing assay and tranwell. The effect of COX-2, c-Myc, MMP-9, MMP-2, and NFATc1 protein expression was determined using Western blot analysis while NFATc1 mRNA expression was determined by RT-PCR. RESULTS: In vitro studies indicated that CsA inhibited partial OSCC growth by inducing cell cycle arrest, apoptosis, and the migration and invasion of OSCC cells. We also demonstrated that CsA could inhibit the expression of NFATc1 and its downstream genes COX-2, c-Myc, MMP-9, and MMP-2 in OSCC cells. Furthermore, we analyzed the expression of NFATc1 in head and neck cancer through the Oncomine database. The data was consistent with the experimental findings. CONCLUSION: The present study initially demonstrated that CsA could inhibit the progression of OSCC cells and can mediate the signal molecules of NFATc1 signaling pathway, which has strong relationship with cancer development. That explains us CsA has potential to explore the possibilities as a novel chemotherapeutic drug for the treatment of OSCC.


Assuntos
Antineoplásicos/farmacologia , Carcinoma de Células Escamosas/tratamento farmacológico , Ciclosporina/farmacologia , Neoplasias Bucais/tratamento farmacológico , Antineoplásicos/síntese química , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Ciclo Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ciclosporina/síntese química , Ciclosporina/química , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Estrutura Molecular , Neoplasias Bucais/metabolismo , Neoplasias Bucais/patologia , Relação Estrutura-Atividade , Células Tumorais Cultivadas , Cicatrização/efeitos dos fármacos
13.
Chemosphere ; 218: 624-631, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30502701

RESUMO

In this study, the influences of feedstock and pyrolysis temperature on carbon fractions of biochar were investigated. Four types of organic wastes (rice straw (RS), pine wood (PW), pig manure (PM) and sewage sludge (SS)) were pyrolyzed at different temperatures (300 °C, 400 °C, 500 °C, 600 °C and 700 °C). Biochar produced at low temperature exhibited high yields, high dissolved organic carbon (DOC) content and unstable organic carbon content. In contrast, biochar formed at high temperature showed high C content and C stability with a low O/C and H/C ratios. In addition, the biochar pyrolyzed from PW contained the lowest DOC of the four biochar types. The properties of DOC fractions (F1, F2 and F3) released from biochar differed depending on feedstock, pyrolysis temperatures, and extraction procedures. The highest specific ultraviolet absorbance at 254 nm of the F1 and F2 fractions were observed for RS biochar, suggesting that more aromatic organic matter was present in sequentially extracted fractions of RS biochar than in extracts from the other biochars. In addition, the hot water extracts (F2) mostly showed higher aromaticity than cold water extracts (F1). The stability of biochars was greatly enhanced at pyrolysis temperatures >500 °C. If the biochars produced in this study were to be used for carbon sequestration in soil, the first priority should be PW, followed in order by RS and PM.


Assuntos
Carbono/química , Carvão Vegetal/química , Esterco , Madeira/química , Animais , Carbono/análise , Sequestro de Carbono , Temperatura Alta , Oryza/química , Pinus/química , Caules de Planta/química , Pirólise , Esgotos , Solo/química , Suínos , Água/química
14.
Oral Radiol ; 34(3): 251-256, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30484038

RESUMO

OBJECTIVES: Bone quality comprises bone mineral density and trabecular microstructure. The aim of this study was to explore the effectiveness of cone-beam computed tomography (CBCT) in evaluating bone quality of large odontogenic cystic lesions after decompression using CBCT and BoneJ software, and to determine whether secondary definitive surgery can be guided using CBCT data. METHODS: Twenty-seven patients with large odontogenic cystic lesions treated by decompression were evaluated by CBCT. Medical history and perioperative details were analyzed. RESULTS: The [Formula: see text]CT values for all patients with cystic lesions decreased after decompression, with no differences for age, sex, and histology (p > 0.05). Bone volume fraction and trabecular number of new cancellous bone (0.012%, 0.17/mm3) were lower than those of normal cancellous bone (0.189%, 0.47/mm3) (p < 0.05), while new cancellous bone trabecular separation (11.344 ± 2.556 mm) was stronger than normal cancellous bone trabecular separation (4.833 ± 2.232 mm) (p < 0.05). There were no differences in trabecular thickness between new cancellous bone (3.812 ± 1.593 mm) and normal cancellous bone (4.598 ± 3.573 mm) (p = 0.746). The [Formula: see text]CT values of five patients with favorable osteogenesis were - 72, -86, - 86, -47, and - 55, those of three patients with moderate osteogenesis were - 107, -120, and - 71, and those of two patients with poor osteogenesis were - 165 and - 127 during secondary definitive surgery. CONCLUSIONS: CBCT is considered beneficial for evaluating bone quality of large odontogenic cystic lesions after decompression, while providing potentially useful information for referral to secondary definitive surgery.


Assuntos
Tomografia Computadorizada de Feixe Cônico , Adulto , Descompressão , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Cistos Odontogênicos
15.
Med. oral patol. oral cir. bucal (Internet) ; 23(3): e359-e366, mayo 2018. tab, ilus
Artigo em Inglês | IBECS | ID: ibc-175889

RESUMO

Background: This study was to evaluate the use of virtual planning and 3D printing modeling in mandibular reconstruction and compare the operation time and surgical outcome of this technique with conventional method. Material and Methods: Between 2014 and 2017, 15 patients underwent vascularized fibula flap mandibular reconstruction using virtual planning and 3D printing modeling. Titanium plates were pre-bent using the models and cutting guides were used for osteotomies. 15 patients who underwent mandibular reconstruction using fibula flap without aid of virtual planning and 3D printing models were selected as control group. The operation time was recorded and compared in two groups. Accuracy of reconstruction was measured by superimposing the preoperative image onto the postoperative image of mandible. The selected bony landmark, distance and angle were measured. Results: The mean total operation time and reconstruction time were 1.60±0.37 and 5.54±0.50 hours in computer-assisted group, respectively; These were 2.58±0.45 and 6.54±0.70 hours in conventional group, respectively. Both operation time and reconstruction time were shorter in computer-assisted group. The difference between the preoperative and postoperative intercondylar distances, intergonial angle distances, anteroposterior distances and gonial angles were 2.92±1.15 and 4.48±1.41mm, 2.93±1.19 and 4.79±1.48mm, 4.31±1.24 and 5.61±1.41mm, 3.85±1.68° and 5.88±2.12° in the computer-assisted and conventional group, respectively. The differences between the preoperative and postoperative mandible is smaller in the computer-assisted group. Conclusions: Virtual planning and 3D printing modeling have the potential to increase mandibular reconstruction accuracy and reduce operation time. we believe that this technology for mandibular reconstruction in selected patients will become a used method and improve the quality of reconstruction


No disponible


Assuntos
Humanos , Masculino , Feminino , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Retalhos de Tecido Biológico , Reconstrução Mandibular/métodos , Impressão Tridimensional , Planejamento de Assistência ao Paciente , Estudos Retrospectivos , Fíbula/transplante
16.
Environ Sci Technol ; 52(5): 2575-2585, 2018 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-29385328

RESUMO

Water-soluble humic like substances (HULIS) in smoke particles emitted from combustion of biomass materials and coal were characterized by ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry. The formulas identified were classified into four main groups: CHO, CHON, CHOS, and CHONS. The average H/C and O/C ratios are 1.13-1.33, 1.01-1.13, 1.26-1.48, 1.09-1.24 and 0.21-0.41, 0.27-0.45, 0.41-0.46, 0.44-0.61 for the CHO, CHON, CHOS, and CHONS groups, respectively. The CHO compound was the predominant component (43%-72%) of the smoke HULIS from biomass burning (BB) and coal combustion, followed by the CHON group for BB-smoke HULIS and the S-containing groups (i.e., CHOS and CHONS) for coal-smoke HULIS. These results indicate that the primary HULIS emitted from biomass burning contain a high abundance of CHON species, which appear to be made up mainly of oxidized nitrogen functional groups such as nitro compounds and/or organonitrates. The coal-smoke HULIS contained more compounds with relatively low molecular weight and high aromaticity index (AImod). They were significantly enriched in S-containing compounds with high double bond equivalent (≥4), and O/S ratios suggest that they are most likely made up of aromatic organosulfates and nitrooxy organosulfates that are usually found in polluted atmospheres. These findings imply that the primary emissions from combustion of biomass and coal fuels are potential sources of water-soluble HULIS in an atmospheric matrix and that coal combustion is an especially important source of sulfate compounds.


Assuntos
Carvão Mineral , Água , Biomassa , Ciclotrons , Análise de Fourier , Substâncias Húmicas , Espectrometria de Massas , Fumaça , Espectrometria de Massas por Ionização por Electrospray
17.
Environ Monit Assess ; 186(1): 247-56, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23943243

RESUMO

Organochlorine pesticides (OCPs) have variously been phased out in agricultural activities, but they are still widely detected in air, water, and soil systems due to their recalcitrant nature in the environment. The purposes of this study were to assess potential OCP pollution via dry and wet deposition over the fast developing Pearl River Delta area with 41,700 km(2), where the main effort has been focused on emerging pollutants such as petroleum hydrocarbons and PM2.5. We quantified both the dry and wet deposition fluxes of 19 OCPs including dichlorodiphenyltrichloroethanes (DDTs), endosulfans (Endos), and hexachlorocyclohexanes (HCHs). The results showed that each year about 67.4, 42.0, 15.0, and 8.07 kg of total OCPs, DDTs, Endos, and HCHs were returned to the ground, among which 11.7, 10.4, 0.84, and 0.16 kg were in the dry deposition forms. The large spatial variations in OCP deposition fluxes indicated that OCP pollution in the air is mainly influenced on local scales because evaporation from local soil is likely the major source of the phased out OCPs. Source analysis indicated that DDTs may be still in use as antifouling agent and/or dicofol, but Endos and HCHs were mainly derived from the residual of historical usage. The study suggests that the historical OCP pollutants are persistent at high levels in this area and should not be overlooked, while we tackle emerging pollutants.


Assuntos
Monitoramento Ambiental , Poluentes Ambientais/análise , Hidrocarbonetos Clorados/análise , Praguicidas/análise , Atmosfera/química , China , Poluição Ambiental/estatística & dados numéricos
18.
Chemosphere ; 93(9): 1710-9, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23773442

RESUMO

Humic-like substances (HULIS) are significant constituents of aerosols, and the isolation and characterization of HULIS by solid-phase extraction methods are dependent on the sorbents used. In this study, we used the following five methods: ENVI-18, HLB-M, HLB-N, XAD-8 and DEAE, to isolate atmospheric HULIS at an urban site. Then we conducted a comparative investigation of the HULIS chemical characteristics by means of elemental analysis, Fourier transform infrared spectroscopy, (1)H nuclear magnetic resonance spectroscopy and off-line thermochemolysis with tetramethylammonium hydroxide. The results indicate that HULIS isolated using different methods show many similarities in chemical composition and structure. Some differences were however also observed between the five isolated HULIS: HULISHLB-M contains a relatively high content of OCH group, compared to HULISENVI-18 and HULISXAD-8; HULISXAD-8 contains a relatively high content of hydrophobic and aromatic components, compared to HULISENVI-18 and HULISHLB-M; HULISDEAE contains the highest content of aromatic functional groups, as inferred by (1)H NMR spectra, but a great amount of salts generally present in the HULISDEAE and thereby limited the choices for characterizing the materials (i.e., elemental analysis and TMAH thermochemolysis); HULISHLB-N has relatively high levels of H and N, a high N/C atomic ratio, and includes N-containing functional groups, which suggests that it has been altered by 2% ammonia introduced in the eluents. In summary, we found that ENVI-18, HLB-M, and XAD-8 are preferable methods for isolation and characterization of HULIS in atmospheric aerosols. These results also suggest that caution is required when applying DEAE and HLB-N isolating methods for characterizing atmospheric HULIS.


Assuntos
Aerossóis/análise , Poluentes Atmosféricos/análise , Atmosfera/química , Monitoramento Ambiental/métodos , Substâncias Húmicas/análise , Compostos de Amônio Quaternário/química , Adsorção , Aerossóis/química , Poluentes Atmosféricos/química , Etanolaminas , Resinas de Troca Iônica/química , Espectroscopia de Ressonância Magnética , Espectroscopia de Infravermelho com Transformada de Fourier
19.
Air Qual Atmos Health ; 3(3): 139-147, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20700381

RESUMO

Guangzhou is the central city in the Pearl River Delta (PRD), China, and is one of the most polluted cities in the world. To characterize the ambient falling dust pollution, two typical sampling sites: urban (Wushan) and suburban (University Town) areas in Guangzhou city were chosen for falling dust collection over 1 year at time intervals of 1 or 2 months. The flux of dry deposition was calculated. In addition, mineral composition and morphology of atmospheric falling dust were studied by X-ray diffraction, scanning electron microscopy, and microscopic observation. The results revealed that the dust flux in Guangzhou city was 3.34-3.78 g/(m(2) month) during the study period. The main minerals in the dust were quartz, illite, calcite, kaolinite, gypsum, plagioclase, dolomite, and amorphous matter. The morphological types included grained and flaky individual minerals, chain-like aggregates, spherical flying beads, and irregular aggregates, with the chain-like and spherical aggregates indicators of industrial ash. The major dusts were derived from industrial and construction activities. The gypsum present in the dust collected in winter season was not only derived from cement dust but may also have originated from the reaction of calcic material with sulfuric acids resulting from photooxidation of SO(x) and NO(x), which confirmed serious air pollution due to SO(x) and NO(x) in Guangzhou. The abatement of fossil fuel combustion emissions and construction dust will have a significant beneficial effect on dust reduction.

20.
J Environ Sci (China) ; 21(12): 1658-66, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-20131595

RESUMO

The organic matter in tropospheric aerosol plays an important role in atmospheric physical and chemical processes. The bulk of organic matter, representing a significant proportion of the total suspended particulate (TSP) mass, is bound to polymeric material whose structure and properties are largely unknown. Here we used thermodesorption gas chromatography/mass spectrometry (Td-GC/MS) to study organic compounds of low molecular mass and pyrolysis gas chromatography/mass spectrometry (Py-GC/MS) to characterize the chemical structure of macromolecules in TSP samples collected in different seasons from different sites in Guangzhou. n-Alkanes, fatty acids and nitriles were the predominant compounds in the thermodesorption products, whereas aromatics, fatty acids, nitriles and n-alkanes/alkenes were the major compounds in the pyrolysates. The results indicated that aromatics were main units in macromolecules. The fatty acids and nitriles formed from carboxylic ammonium salts were detected in both thermodesorption products and pyrolysates at a certain concentration, indicating the importance of these compounds in TSP formation. The TSP source mainly determined the occurrence of compounds in samples from urban, suburban and forest sites, whereas the TSP source and formation process maybe controlled the seasonal variation in compounds detected. High levels of nitriles in summer samples from suburban and forest sites coincide with the release of ammonium from the land and of fatty acids from vegetation at these sites.


Assuntos
Compostos Orgânicos/química , Material Particulado/química , Ácidos Graxos/análise , Cromatografia Gasosa-Espectrometria de Massas , Temperatura Alta , Compostos de Nitrogênio/análise , Compostos de Oxigênio/análise , Estações do Ano
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