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1.
Environ Sci Technol ; 58(18): 8020-8031, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38629457

RESUMO

Cyanobacterial blooms introduce autochthonous dissolved organic matter (DOM) into aquatic environments, but their impact on surface water photoreactivity has not been investigated through collaborative field sampling with comparative laboratory assessments. In this work, we quantified the apparent quantum yields (Φapp,RI) of reactive intermediates (RIs), including excited triplet states of dissolved organic matter (3DOM*), singlet oxygen (1O2), and hydroxyl radicals (•OH), for whole water samples collected by citizen volunteers from more than 100 New York lakes. Multiple comparisons tests and orthogonal partial least-squares analysis identified the level of cyanobacterial chlorophyll a as a key factor in explaining the enhanced photoreactivity of whole water samples sourced from bloom-impacted lakes. Laboratory recultivation of bloom samples in bloom-free lake water demonstrated that apparent increases in Φapp,RI during cyanobacterial growth were likely driven by the production of photoreactive moieties through the heterotrophic transformation of freshly produced labile bloom exudates. Cyanobacterial proliferation also altered the energy distribution of 3DOM* and contributed to the accelerated transformation of protriptyline, a model organic micropollutant susceptible to photosensitized reactions, under simulated sunlight conditions. Overall, our study provides insights into the relationship between the photoreactivity of surface waters and the limnological characteristics and trophic state of lakes and highlights the relevance of cyanobacterial abundance in predicting the photoreactivity of bloom-impacted surface waters.


Assuntos
Cianobactérias , Lagos , Lagos/microbiologia , New York , Eutrofização , Monitoramento Ambiental
2.
Environ Sci Technol ; 58(19): 8518-8530, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38693060

RESUMO

Wastewater-based epidemiology (WBE) has been widely implemented around the world as a complementary tool to conventional surveillance techniques to inform and improve public health responses. Currently, wastewater surveillance programs in the U.S. are evaluating integrated approaches to address public health challenges across multiple domains, including substance abuse. In this work, we demonstrated the potential of online solid-phase extraction coupled with liquid chromatography-high-resolution mass spectrometry to support targeted quantification and nontargeted analysis of psychoactive and lifestyle substances as a step toward understanding the operational feasibility of a statewide wastewater surveillance program for substance use assessment in New York. Target screening confirmed 39 substances in influent samples collected from 10 wastewater treatment plants with varying sewershed characteristics and is anticipated to meet the throughput demands as the statewide program scales up to full capacity. Nontarget screening prioritized additional compounds for identification at three confidence levels, including psychoactive substances, such as opioid analgesics, phenethylamines, and cathinone derivatives. Consumption rates of 12 target substances detected in over 80% of wastewater samples were similar to those reported by previous U.S.-based WBE studies despite the uncertainty associated with back-calculations. For selected substances, the relative bias in consumption estimates was sensitive to variations in monitoring frequency, and factors beyond human excretion (e.g., as indicated by the parent-to-metabolite ratios) might also contribute to their prevalence at the sewershed scale. Overall, our study marks the initial phase of refining analytical workflows and data interpretation in preparation for the incorporation of substance use assessment into the statewide wastewater surveillance program in New York.


Assuntos
Águas Residuárias , Águas Residuárias/química , New York , Humanos , Poluentes Químicos da Água/análise , Monitoramento Ambiental/métodos , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , Extração em Fase Sólida
3.
BMC Musculoskelet Disord ; 25(1): 455, 2024 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-38851675

RESUMO

BACKGROUND: Masquelet membrane induction technology is one of the treatment strategies for large bone defect (LBD). However, the angiogenesis ability of induced membrane decreases with time and autologous bone grafting is associated with donor site morbidity. This study investigates if the PRP-FG-nHA/PA66 scaffold can be used as a spacer instead of PMMA to improve the angiogenesis ability of induced membrane and reduce the amount of autologous bone graft. METHODS: Platelet rich plasma (PRP) was prepared and PRP-FG-nHA/PA66 scaffold was synthesized and observed. The sustained release of VEGFA and porosity of the scaffold were analyzed. We established a femur LBD model in male SD rats. 55 rats were randomly divided into four groups depending on the spacer filled in the defect area. "Defect only" group (n = 10), "PMMA" group (n = 15), "PRP-nHA/PA66" group (n = 15) and "PRP-FG-nHA/PA66" group (n = 15 ). At 6 weeks, the spacers were removed and the defects were grafted. The induced membrane and bone were collected and stained. The bone formation was detected by micro-CT and the callus union was scored on a three point system. RESULTS: The PRP-FG-nHA/PA66 scaffold was porosity and could maintain a high concentration of VEGFA after 30 days of preparation. The induced membrane in PRP-FG-nHA/PA66 group was thinner than PMMA, but the vessel density was higher.The weight of autogenous bone grafted in PRP-FG-nHA/PA66 group was significantly smaller than that of PMMA group. In PRP-FG-nHA/PA66 group, the bone defect was morphologically repaired. CONCLUSION: The study showed that PRP-FG-nHA/PA66 scaffold can significantly reduce the amount of autologous bone graft, and can achieve similar bone defect repair effect as PMMA. Our findings provide some reference and theoretical support for the treatment of large segmental bone defects in humans.


Assuntos
Fêmur , Plasma Rico em Plaquetas , Ratos Sprague-Dawley , Alicerces Teciduais , Animais , Masculino , Ratos , Fêmur/cirurgia , Fêmur/patologia , Fator A de Crescimento do Endotélio Vascular , Regeneração Óssea/fisiologia , Neovascularização Fisiológica , Transplante Ósseo/métodos , Durapatita/química , Modelos Animais de Doenças , Osteogênese/fisiologia
4.
Int Wound J ; 21(1): e14361, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37641210

RESUMO

More and more meta-analyses have been conducted to compare the effects of intramedullary fixation (IF) and plate fixation (PF) on the outcome of midshaft clavicle fractures. It can affect the doctors' treatment decisions. A number of studies have been conducted in order to assist surgeons in selecting optimal operative procedures and to recommend operative treatment of clavicle fractures in accordance with the best available research. Our analysis of the IF and PF of clavicle fractures was done through a search for PubMed, Emabase, Web of Science, and Cochrane Library. Two different researchers analysed the research literature for quality of analysis and data extraction. The analysis of the data was done with RevMan 5.3. The 95% CI and OR models have been computed by means of either fixed-dose or randomize. In addition, RCT in 114 references have been reviewed and added for further analysis. It is concluded that the application of plate and intramedullary fixation in the middle clavicle operation has remarkable influence on the outcome of post-operation. There was a lower risk of postoperative wound infection in IF (OR, 5.92; 95% CI, 2.46, 14.27 p < 0.0001), smaller surgical incisions (MD, 6.57; 95% CI, 4.90, 8.25 p < 0.0001), and shorter operative time (MD, 17.09; 95% CI 10.42, 23.77 p < 0.0001), less blood loss (MD, 63.62; 95% CI, 55.84, 71.39 p < 0.0001) and shorter hospital stay (MD, 1.05; 95% CI, 0.84, 1.25 p < 0.0001). However, there is no statistical significance in the incidence of wound dehiscence. Thus, the effect of IF on the incidence of injury is better than that of the inner plate in the middle of the clavicle.


Assuntos
Fixação Intramedular de Fraturas , Fraturas Ósseas , Humanos , Clavícula/cirurgia , Clavícula/lesões , Fixação Intramedular de Fraturas/métodos , Fraturas Ósseas/cirurgia , Infecção da Ferida Cirúrgica/epidemiologia , Infecção da Ferida Cirúrgica/etiologia , Infecção da Ferida Cirúrgica/prevenção & controle , Reoperação , Resultado do Tratamento , Fixação Interna de Fraturas/efeitos adversos , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/cirurgia
5.
Environ Sci Technol ; 57(19): 7526-7536, 2023 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-37140470

RESUMO

N-Nitrosamines form as byproducts during oxidative water treatment and occur as impurities in consumer and industrial products. To date, two methods based on chemiluminescence (CL) detection of nitric oxide liberated from N-nitrosamines via denitrosation with acidic triiodide (HI3) treatment or ultraviolet (UV) photolysis have been developed to enable the quantification of total N-nitrosamines (TONO) in environmental water samples. In this work, we configured an integrated experimental setup to compare the performance of HI3-CL and UV-CL methods with a focus on their applicability for TONO measurements in wastewater samples. With the use of a large-volume purge vessel for chemical denitrosation, the HI3-CL method achieved signal stability and detection limits comparable to those achieved by the UV-CL method which utilized a microphotochemical reactor for photolytic denitrosation. Sixty-six structurally diverse N-nitroso compounds (NOCs) yielded a range of conversion efficiencies relative to N-nitrosodimethylamine (NDMA) regardless of the conditions applied for denitrosation. On average, TONO measured in preconcentrated raw and chloraminated wastewater samples by the HI3-CL method were 2.1 ± 1.1 times those measured by the UV-CL method, pointing to potential matrix interferences as further confirmed by spike recovery tests. Overall, our comparative assessment of the HI3-CL and UV-CL methods serves as a basis for addressing methodological gaps in TONO analysis.


Assuntos
Nitrosaminas , Nitrosaminas/química , Águas Residuárias , Fotólise , Luminescência , Dimetilnitrosamina/análise , Dimetilnitrosamina/química
6.
Environ Sci Technol ; 57(30): 11231-11240, 2023 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-37467161

RESUMO

Current methods for evaluating catalytic degradation reactions of environmental pollutants primarily rely on chromatography that often suffers from intermittent analysis, a long turnaround period, and complex sample pretreatment. Herein, we propose a quantitative time-resolved visualization method to evaluate the progress of catalytic degradation reactions by integrating sample pretreatment [single-drop microextraction, (SDME)], fluorescence sensing, and a smartphone detection platform. The dechlorination reaction of chlorobenzene derivatives was first investigated to validate the feasibility of this approach, in which SDME plays a critical role in direct sample pretreatment, and inorganic CsPbBr3 perovskite encapsulated in a metal-organic framework (MOF-5) was utilized as the fluorescent chromogenic agent (FLCA) in SDME to realize fast in situ colorimetric detection via the color switching from green (CsPbBr3) to blue (chlorine lead bromide, inorganic CsPbCl3 perovskite). The smartphone, which can calculate the B/G value of FLCA, serves as a data output window for quantitative time-resolved visualization. Further, a [Eu(PMA)]n (PMA= pyromellitic acid) fluorescent probe was constructed to use as an FLCA for the in situ evaluation of cinnamaldehyde and p-nitrophenol catalytic reduction. This approach not only minimizes the utilization of organic solvents and achieves quantitively efficient time-resolved visualization but also provides a feasible method for in situ monitoring of the progress of catalytic degradation reactions.


Assuntos
Poluentes Ambientais , Fluorescência , Óxidos , Solventes
7.
BMC Musculoskelet Disord ; 24(1): 962, 2023 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-38082305

RESUMO

BACKGROUND: Open distal tibial fractures pose significant challenges regarding treatment options and patient outcomes. This retrospective single-centre study aimed to compare the stability, clinical outcomes, complications, and financial implications of two surgical interventions, namely the external locking plate and the combined frame external fixator, to manage open distal tibial fractures. METHODS: Forty-four patients with distal open tibial (metaphyseal extraarticular) fractures treated between 2020 and 2022 were selected and formed into two main groups, Group A and Group B. Group A (19 patients) are patients that underwent treatment using the external locking plate technique, while Group B (25 patients) received the combined frame external fixator approach. Age, gender, inpatient stay, re-operation rates, complications, functional recovery (measured by the Johner-Wrush score), pain ratings (measured by the Visual Analogue Scale [VAS]), and cost analyses were evaluated for each group. Statistical analyses using SPSS were conducted to compare the outcomes between the two groups. RESULTS: The research found significant variations in clinical outcomes, complications, and cost consequences between Group A and Group B. Group A had fewer hospitalisation periods (23.687.74) than Group B (33.5619.47). Re-operation rates were also considerably lower in Group A (26.3%) than in Group B (48%), owing to a greater prevalence of pin-tract infections and subsequent pin loosening in the combination frame external fixator group. The estimated cost of both techniques was recorded and analysed with the locking average of 26,619.69 ± 9,602.352 and the combined frame average of 39,095.64 ± 20,070.077. CONCLUSION: This study suggests that although the two approaches effectively manage open distal tibia fractures, the locking compression plate approach (Group A) has an advantage in treating open distal tibia fractures. Shorter hospitalisation times, reduced re-operation rates, and fewer complications will benefit patients, healthcare systems, and budget allocation. Group A's functional recovery results demonstrate the locking plate technique's ability to improve recovery and patient quality of life. According to the cost analysis, the locking plate technique's economic viability and cost-effectiveness may optimise healthcare resources for open distal tibia fractures. These findings might improve patient outcomes and inform evidence-based orthopaedic surgery.


Assuntos
Fraturas Expostas , Fraturas da Tíbia , Humanos , Tíbia/cirurgia , Estudos Retrospectivos , Qualidade de Vida , Fixadores Externos , Fraturas da Tíbia/diagnóstico por imagem , Fraturas da Tíbia/cirurgia , Fixação de Fratura/efeitos adversos , Fixação de Fratura/métodos , Fraturas Expostas/cirurgia , Placas Ósseas , Resultado do Tratamento
8.
J Am Chem Soc ; 144(29): 13021-13025, 2022 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-35748600

RESUMO

Metal-organic framework (MOF) glasses are a fascinating new class of materials, yet their prosperity has been impeded by the scarcity of known examples and limited vitrification methods. In the work described in this report, we applied synergistic stimuli of vapor hydration and thermal dehydration to introduce structural disorders in interpenetrated dia-net MOF, which facilitate the formation of stable super-cooled liquid and quenched glass. The material after stimulus has a glass transition temperature (Tg) of 560 K, far below the decomposition temperature of 695 K. When heated, the perturbed MOF enters a super-cooled liquid phase that is stable for a long period of time (>104 s), across a broad temperature range (26 K), and has a large fragility index of 83. Quenching the super-cooled liquid gives rise to porous MOF glass with maintained framework connectivity, confirmed by EXAFS and PDF analysis. This method provides a fundamentally new route to obtain glassy materials from MOFs that cannot be melted without causing decomposition.

9.
Environ Sci Technol ; 56(3): 1688-1701, 2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-35041388

RESUMO

Photochemical and microbial processing are the prevailing mechanisms that shape the composition and reactivity of dissolved organic matter (DOM); however, prior research has not comparatively evaluated the impacts of these processes on the photoproduction of reactive intermediates (RIs) from freshly sourced terrestrial DOM. We performed controlled irradiation and incubation experiments with leaf and soil samples collected from an acid-impacted lake watershed in the Adirondack Mountain region of New York to examine the effects of DOM processing on the apparent quantum yields of RIs (Φapp,RI), including excited triplet states of DOM (3DOM*), singlet oxygen (1O2), and hydroxyl radicals (•OH). Photodegradation led to net reductions in Φapp,1O2, Φapp,3DOM*, and Φapp,•OH, whereas (photo-)biodegradation resulted in increases in Φapp,1O2 and Φapp,3DOM*. Photodegradation and (photo-)biodegradation also shifted the energy distribution of 3DOM* in different directions. Multivariate statistical analyses revealed the potential relevance of photo-biodegradation in driving changes in Φapp,1O2 and Φapp,3DOM* and prioritized five bulk DOM optical and redox properties that best explained the variations in Φapp,1O2 and Φapp,3DOM* along the watershed terrestrial-aquatic continuum. Our findings highlight the contrasting impacts of photochemical and microbial processes on the photoreactivity of freshly sourced terrestrial DOM and invite further studies to develop a more holistic understanding of their implications for aquatic photochemistry.


Assuntos
Matéria Orgânica Dissolvida , Lagos , Radical Hidroxila , Fotólise
10.
Environ Sci Technol ; 56(23): 16726-16736, 2022 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-36331382

RESUMO

Organic micropollutants (OMPs) represent an anthropogenic stressor on stream ecosystems. In this work, we combined passive sampling with suspect and nontarget screening enabled by liquid chromatography-high-resolution mass spectrometry to characterize complex mixtures of OMPs in streams draining mixed-use watersheds. Suspect screening identified 122 unique OMPs for target quantification in polar organic chemical integrative samplers (POCIS) and grab samples collected from 20 stream sites in upstate New York over two sampling seasons. Hierarchical clustering established the co-occurrence profiles of OMPs in connection with watershed attributes indicative of anthropogenic influences. Nontarget screening leveraging the time-integrative nature of POCIS and the cross-site variability in watershed attributes prioritized and confirmed 11 additional compounds that were ubiquitously present in monitored streams. Field sampling rates for 37 OMPs that simultaneously occurred in POCIS and grab samples spanned the range of 0.02 to 0.22 L/d with a median value of 0.07 L/d. Comparative analyses of the daily average loads, cumulative exposure-activity ratios, and multi-substance potentially affected fractions supported the feasibility of complementing grab sampling with POCIS for OMP load estimation and screening-level risk assessments. Overall, this work demonstrated a multi-watershed sampling and screening approach that can be adapted to assess OMP contamination in streams across landscapes.


Assuntos
Rios , Poluentes Químicos da Água , Rios/química , Monitoramento Ambiental/métodos , Poluentes Químicos da Água/análise , Ecossistema , Compostos Orgânicos/química
11.
Environ Sci Technol ; 56(3): 1713-1723, 2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-35015525

RESUMO

Current colorimetric probes for fluoride (F-) primarily rely on organic chromophores that often suffer from unsatisfactory selectivity, complex organic synthesis, and low aqueous compatibility. Herein, we proposed a highly specific colorimetric method for F- with 100% aqueous compatibility by triggering the intrinsic peroxidase-like activity of a AgPt-Fe3O4 nanozyme encapsulated in SiO2 shells. The excellent catalytic performance of the AgPt-Fe3O4 nanozyme serves as an ideal platform for sensitive colorimetric sensing. After being encapsulated in SiO2, the enzyme-like activity of AgPt-Fe3O4 is inhibited and only F- can exclusively etch the SiO2 shell to expose the active site of the nanozyme, thereby inducing color changes via oxidation of the chromogenic substrate. The limit of detection of the proposed method can reach as low as 13.73 µM in aqueous solution, which is lower than the maximum allowable concentration (79 µM) stipulated in the World Health Organization drinking water regulation. More importantly, this method is highly specific toward F- over other types of anions commonly found in environmental water, making it capable of analyzing sewage samples with very complex matrices. Finally, the nanoprobe is embedded into a test strip by electrostatic spinning to enable the rapid, visual, and on-site detection of F-.


Assuntos
Colorimetria , Dióxido de Silício , Ânions , Catálise , Colorimetria/métodos , Fluoretos , Dióxido de Silício/química
12.
Angew Chem Int Ed Engl ; 61(2): e202110082, 2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-34653302

RESUMO

Switching materials in channels of nonlinear optics (NLOs) are of particular interest in NLO material science. Numerous crystalline NLO switches based on structural phase transition have emerged, but most of them reveal a single-step switch between two different second-harmonic-generation (SHG) states, and only very rare cases involve three or more SHG states. Herein, we report a new organic-inorganic hybrid salt, (Me3 NNH2 )2 [CdI4 ], which is an unprecedented case of a reversible three-step NLO switch between SHG-silent, -medium, -low, and -high states, with high contrasts of 25.5/4.3/9.2 in a temperature range of 213-303 K. By using the combined techniques of variable-temperature X-ray single-crystal structural analyses, dielectric constants, solid-state 13 C nuclear magnetic resonance spectroscopy, and Hirshfeld surface analyses, we disclose that this four-state switchable SHG behavior is highly associated with the stepwise-changed molecular dynamics of the polar organic cations. This finding demonstrates well the complexity of molecular dynamics in simple hybrid salts and their potential in designing new advanced multistep switching materials.

13.
Cancer Cell Int ; 21(1): 414, 2021 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-34362387

RESUMO

BACKGROUND: Ferroptosis, a novel form of regulated cell death, has been implicated in the pathogenesis of cancers. Nevertheless, the potential function and prognostic values of ferroptosis in bladder urothelial carcinoma (BLCA) are complex and remain to be clarified. Therefore, we proposed to systematically examine the roles of ferroptosis-associated genes (FAGs) in BLCA. METHODS: According to The Cancer Genome Atlas (TCGA) database, differently expressed FAGs (DEFAGs) and differently expressed transcription factors (DETFs) were identified in BLCA. Next, the network between DEFAGs and DETFs, GO annotations and KEGG pathway analyses were performed. Then, through univariate, LASSO and multivariate regression analyses, a novel signature based on FAGs was constructed. Moreover, survival analysis, PCA analysis, t-SNE analysis, ROC analysis, independent prognostic analysis, clinicopathological and immune correlation analysis, and experimental validation were utilized to evaluate the signature. RESULTS: Twenty-eight DEFAGs were identified, and four FAGs (CRYAB, TFRC, SQLE and G6PD) were finally utilized to establish the FAGs based signature in the TCGA cohort, which was subsequently validated in the GEO database. Moreover, we found that immune cell infiltration, immunotherapy-related biomarkers and immune-related pathways were significantly different between two risk groups. Besides, nine molecule drugs with the potential to treat bladder cancer were identified by the connectivity map database analysis. Finally, the expression levels of crucial FAGs were verified by the experiment, which were consistent with our bioinformatics analysis, and knockdown of TFRC could inhibit cell proliferation and colony formation in BLCA cell lines in vitro. CONCLUSIONS: Our study identified prognostic ferroptosis-associated genes and established a novel FAGs signature, which could accurately predict prognosis in BLCA patients.

14.
Environ Sci Technol ; 55(22): 15215-15226, 2021 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-34730951

RESUMO

Characterizing the occurrence, sources, and fate of organic micropollutants (OMPs) in lake-river systems serves as an important foundation for constraining the potential impacts of OMPs on the ecosystem functions of these critical landscape features. In this work, we combined suspect and nontarget screening with mass balance modeling to investigate OMP contamination in the Onondaga Lake-Three Rivers system of New York. Suspect and nontarget screening enabled by liquid chromatography-high-resolution mass spectrometry led to the confirmation and quantification of 105 OMPs in water samples collected throughout the lake-river system, which were grouped by their concentration patterns into wastewater-derived and mixed-source clusters via hierarchical cluster analysis. Four of these OMPs (i.e., galaxolidone, diphenylphosphinic acid, N-butylbenzenesulfonamide, and triisopropanolamine) were prioritized and identified by nontarget screening based on their characteristic vertical distribution patterns during thermal stratification in Onondaga Lake. Mass balance modeling performed using the concentration and discharge data highlighted the export of OMPs from Onondaga Lake to the Three Rivers as a major contributor to the OMP budget in this lake-river system. Overall, this work demonstrated the utility of an integrated screening and modeling framework that can be adapted for OMP characterization, fate assessment, and load apportionment in similar surface water systems.


Assuntos
Lagos , Poluentes Químicos da Água , Ecossistema , Monitoramento Ambiental , Lagos/análise , Rios , Águas Residuárias/análise , Poluentes Químicos da Água/análise
15.
Anal Chem ; 92(14): 9989-9996, 2020 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-32551556

RESUMO

In situ monitoring of products generated by important heterogeneous catalytic reactions is of great significance for chemical industry, particularly when the products or intermediates are not sufficiently stable or occur at trace-level concentrations. It is therefore highly desirable to develop an integrated in situ catalysis and extraction method, which can simultaneously catalyze the reaction and enrich products while maintaining compatibility with analytical instrumentation. Herein, we propose an approach by depositing different types of metal nanocrystals, including gold, platinum, and palladium nanoparticles, onto fibrous silica microspheres coated fibers for integrated in situ catalysis and extraction. As a proof-of-concept, several typical chemical reactions, including the reduction of p-nitrophenol, epoxidation of styrene, oxidation of benzyl alcohol, and dechlorination of p-chlorophenol, were investigated to validate the feasibility of this method. Our results show that these coatings not only function as catalysts to accelerate the selected reactions but also serve as adsorbents to extract the reactants, intermediates, and products for direct gas chromatographic analysis, suggesting the viability of this approach for the in situ evaluation of catalytic processes. By this approach, the yield, selectivity, and kinetics of a reaction can be readily assessed. This approach can also be extended to investigate the catalytic performance of the same metal nanocrystals with different morphology, surface facet, structure, or surface functionalization. This approach will find broad generality for assessing the catalytic efficiency and selectivity of new catalysts or new chemical reactions and dynamic processes in these reactions.

16.
Environ Sci Technol ; 54(17): 10654-10667, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32786602

RESUMO

The Adirondack Mountain region of New York, a historical hotspot for atmospheric sulfur and nitrogen deposition, features abundant lakes that are experiencing browning associated with recovery from acidification. Yet, much remains unknown about the photoreactivity of Adirondack lake waters. We quantified the apparent quantum yields (Φapp,RI) of photochemically produced reactive intermediates (RIs), such as excited triplet states of dissolved organic matter (3DOM*), singlet oxygen (1O2), and hydroxyl radicals (•OH), for surface waters collected from 16 representative Adirondack lakes. Φapp,3DOM* and Φapp,1O2 for native Adirondack lake waters fell within ranges reported for whole waters and DOM isolates from various sources, while Φapp,•OH were substantially lower than those measured for other aquatic samples. Orthogonal partial least squares and multiple linear regression analyses identified the spectral slope coefficient from 290 to 400 nm (S290-400) as the most effective predictor of Φapp,RI among measured water chemistry parameters and bulk DOM properties. Φapp,RI also exhibited divergent responses to controlled pH adjustment and aluminum or iron addition simulating hypothetical scenarios relevant to past and future water chemistry conditions of Adirondack lakes. This study highlights the need for continued research on changes in photoreactivity of acid-impacted aquatic ecosystems in response to browning and subsequent impacts on photochemical processes.


Assuntos
Ecossistema , Lagos , Radical Hidroxila , New York , Nitrogênio
17.
Environ Sci Technol ; 54(21): 13759-13770, 2020 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-33064942

RESUMO

The widespread occurrence of organic micropollutants (OMPs) is a challenge for aquatic ecosystem management, and closing the gaps in risk assessment of OMPs requires a data-driven approach. One promising tool for increasing the spatiotemporal coverage of OMP data sets is through the active involvement of citizen volunteers to expand the scale of OMP monitoring. Working collaboratively with volunteers from the Citizens Statewide Lake Assessment Program (CSLAP), we conducted the first statewide study on OMP occurrence in surface waters of New York lakes. Samples collected by CSLAP volunteers were analyzed for OMPs by a suspect screening method based on mixed-mode solid-phase extraction and liquid chromatography-high resolution mass spectrometry. Sixty-five OMPs were confirmed and quantified in samples from 111 lakes across New York. Hierarchical clustering of OMP occurrence data revealed the relevance of 11 most frequently detected OMPs for classifying the contamination status of lakes. Partial least squares regression and multiple linear regression analyses prioritized three water quality parameters linked to agricultural and developed land uses (i.e., total dissolved nitrogen, specific conductance, and a wastewater-derived fluorescent organic matter component) as the best combination of predictors that partly explained the interlake variability in OMP occurrence. Lastly, the exposure-activity ratio approach identified the potential for biological effects associated with detected OMPs that warrant further biomonitoring studies. Overall, this work demonstrated the feasibility of incorporating citizen science approaches into the regional impact assessment of OMPs.


Assuntos
Lagos , Poluentes Químicos da Água , Ciência do Cidadão , Ecossistema , Humanos , New York , Poluentes Químicos da Água/análise
18.
Anal Chem ; 91(8): 5091-5097, 2019 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-30919615

RESUMO

While a growing number of solid-phase microextraction (SPME) coatings have been developed, a generalized protocol is still needed to tailor-make SPME coatings with desirable properties for efficient extraction of diverse analytes from sample matrixes. In this work, we developed a versatile approach to prepare SPME coatings with tunable properties by controllable in situ transformation of well-aligned ZNRs into zeolitic imidazolate frameworks-8 (ZIF-8) via reaction with 2-methylimidazole (2-MI). During this process, ZNRs supplied Zn2+ and served as a "hard template" for the in situ growth of well-aligned ZIF-8 with enhanced surface area for adsorption. Because ZNRs and ZIF-8 exhibit markedly different properties, we obtained a series of ZNRs/ZIF-8 hybrid composites, whose morphology, porosity, polarity, and charge transfer resistance can be fine-tuned by simply controlling the concentration of 2-MI. Preparing ZNRs/ZIF-8 SPME coatings with desired properties enabled effective extraction of a wide range of polar and nonpolar compounds including aliphatic hydrocarbons, polycyclic aromatic hydrocarbons, alcohols, phenols, anilines, and ionic drugs.

19.
Environ Sci Technol ; 53(2): 928-937, 2019 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-30547581

RESUMO

This study focused on synthesis and characterization of Ti4O7 reactive electrochemical membranes (REMs) amended with powder-activated carbon (PAC) or multiwalled carbon nanotubes (MWCNTs). These composite REMs were evaluated for simultaneous adsorption and electrochemical reduction of N-nitrosodimethylamine (NDMA). The carbon-Ti4O7 composite REMs had high electrical conductivities (1832 to 2991 S m-1), where carbon and Ti4O7 were in direct electrical contact. Addition of carbonaceous materials increased the residence times of NDMA in the REMs by a factor of 3.8 to 5.4 and therefore allowed for significant electrochemical NDMA reduction. The treatment of synthetic solutions containing 10 µM NDMA achieved >4-log NDMA removal in a single pass (liquid residence time of 11 to 22 s) through the PAC-REM and MWCNT-REM with the application of a -1.1 V/SHE cathodic potential, with permeate concentrations between 18 and 80 ng L-1. The treatment of a 6.7 nM NDMA-spiked surface water sample, under similar operating conditions (liquid residence time of 22 s), achieved 92 to 97% removal with permeate concentrations between 16 and 40 ng L-1. Density functional theory calculations determined a probable reaction mechanism for NDMA reduction, where the rate-limiting step was a direct electron transfer reaction.


Assuntos
Nanotubos de Carbono , Poluentes Químicos da Água , Adsorção , Carvão Vegetal , Dimetilnitrosamina , Titânio
20.
J Biochem Mol Toxicol ; : e22158, 2018 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-29719090

RESUMO

Here, we aimed to investigate the carcinogenic effects of apolipoprotein C1 (APOC1) in prostate cancer (PCa). APOC1 expression was evaluated in PCa and normal prostate specimens, and lentivirus-mediated RNA interference was used to knockdown APOC1 in DU145 cells. The effects of APOC1 silencing on cell proliferation, cell cycle arrest, and apoptosis were assessed. APOC1 expression was much higher in PCa tissues than in normal tissues. Moreover, APOC1 silencing inhibited cell proliferation and colony formation, arrested cell cycle progression, and enhanced apoptosis in DU145 cells. Additionally, APOC1 silencing decreased survivin, phospho-Rb, and p21 levels and increased cleaved caspase-3 expression. These data supported the procarcinogenic effects of APOC1 in the pathogenesis of PCa and suggested that targeting APOC1 may have applications in the treatment of PCa.

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