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1.
Small ; 20(7): e2303506, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37806770

RESUMO

Aseptic loosening of prostheses is a highly researched topic, and wear particle-induced macrophage polarization is a significant cause of peri-prosthetic osteolysis. Exosomes derived from bone marrow mesenchymal stem cells (BMSCs-Exos) promote M2 polarization and inhibit M1 polarization of macrophages. However, clinical application problems such as easy clearance and lack of targeting exist. Exosomes derived from M2 macrophages (M2-Exos) have good biocompatibility, immune escape ability, and natural inflammatory targeting ability. M2-Exos and BMSCs-Exos fused exosomes (M2-BMSCs-Exos) are constructed, which targeted the osteolysis site and exerted the therapeutic effect of both exosomes. M2-BMSCs-Exos achieved targeted osteolysis after intravenous administration inhibiting M1 polarization and promoting M2 polarization to a greater extent at the targeted site, ultimately playing a key role in the prevention and treatment of aseptic loosening of prostheses. In conclusion, M2-BMSCs-Exos can be used as a precise and reliable molecular drug for peri-prosthetic osteolysis. Fused exosomes M2-BMSCs-Exos  were originally proposed and successfully prepared, and exosome fusion technology provides a new theoretical basis and solution for the clinical application of therapeutic exosomes.


Assuntos
Exossomos , Células-Tronco Mesenquimais , Osteólise , Humanos , Administração Intravenosa , Macrófagos
2.
Opt Express ; 31(2): 2359-2372, 2023 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-36785251

RESUMO

Due to the bulky interrogation devices, traditional fiber optic sensing system is mainly connected by wire or equipped only for large facilities. However, the advancement in neural network algorithms and flexible materials has broadened its application scenarios to bionics. In this paper, a multi-joint waveguide bending sensor based on color dyed filters is designed to detect bending angles, directions and positions. The sensors are fabricated by casting method using soft silicone rubber. Besides, required optical properties of sensor materials are characterized to better understand principles of the sensor design. Time series neural networks are utilized to predict bending position and angle quantitatively. The results confirm that the waveguide sensor demodulated by the data-driven neural network algorithm performs well and can be used for engineering applications.

3.
Sensors (Basel) ; 23(17)2023 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-37687790

RESUMO

Bionic robotics, driven by advancements in artificial intelligence, new materials, and manufacturing technologies, is attracting significant attention from research and industry communities seeking breakthroughs. One of the key technologies for achieving a breakthrough in robotics is flexible sensors. This paper presents a novel approach based on wavelength and time division multiplexing (WTDM) for distributed optical waveguide shape sensing. Structurally designed optical waveguides based on color filter blocks validate the proposed approach through a cost-effective experimental setup. During data collection, it combines optical waveguide transmission loss and the way of controlling the color and intensity of the light source and detecting color and intensity variations for modeling. An artificial neural network is employed to model and demodulate a data-driven optical waveguide shape sensor. As a result, the correlation coefficient between the predicted and real bending angles reaches 0.9134 within 100 s. To show the parsing performance of the model more intuitively, a confidence accuracy curve is introduced to describe the accuracy of the data-driven model at last.

4.
J Org Chem ; 87(21): 14840-14845, 2022 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-36269623

RESUMO

Herein, we disclose a strategy to realize α,ß-difunctionalization and C-N bond cleavage of saturated amines with benzo[c]isoxazoles via a B(C6F5)3-catalyzed consecutive hydrogen-borrowing and [4 + 2] cycloaddition followed by a C-N bond cleavage process. In general, the reactions proceed efficiently in the absence of any oxidant and metal catalyst to afford a broad range of quinoline derivatives starting from easily accessible substrates in an atom-economical manner.

5.
J Environ Manage ; 301: 113806, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34731958

RESUMO

Understanding the sources, natural background levels (NBLs), and threshold values (TVs) of the major ions in groundwater is essential for the effective protection of water resources. In this study, a total of 70 shallow groundwater samples were collected in Suzhou, Huaibei Plain, China. A variety of statistical methods and cumulative probability distribution techniques were performed to identify the sources, NBLs, and TVs of the major ions. The major ion concentrations found in decreasing order as follows: HCO3- > SO42- > NO3- > Cl- and Na+ > Ca2+ > Mg2+. Piper diagram for hydrochemical types shows that groundwater types were Mg-HCO3 (36%), Ca-HCO3 (34%), and Na-HCO3 (30%). According to the factor and the Unmix model analysis, anthropogenic (agriculture-related) and geogenic source (water-rock interactions-related) were identified to be responsible for the chemical composition of the groundwater in the study area, and their mean contributions for the major ion concentrations are 47.9% and 52.1%, respectively. The NBLs for Na+, Ca2+, Mg2+, Cl-, SO42-, and NO3- were determined to be 29.5-44.2, 26.2-38.9, 18.9-39.5, 1.0-9.9, 12.9-19.4, and 2.1-16.5 mg/L, respectively, and the TVs were calculated as 122.1, 169.5, 39.5, 129.6, 134.7, and 18.3 mg/L, respectively. Moreover, this study shows the feasibility and reliability of using these multivariate statistical methods and natural background levels to evaluate the status of groundwater quality.


Assuntos
Água Subterrânea , Poluentes Químicos da Água , China , Monitoramento Ambiental , Íons , Reprodutibilidade dos Testes , Poluentes Químicos da Água/análise , Qualidade da Água
6.
Angew Chem Int Ed Engl ; 60(19): 10756-10765, 2021 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-33624914

RESUMO

The tracking of cellular senescence usually depends on the detection of senescence-associated ß-galactosidase (SA-ß-gal). Previous probes for SA-ß-gal with this purpose only cover a single dimension: the accumulation of this enzyme in lysosomes. However, this is insufficient to determine the destiny of senescence because endogenous ß-gal enriched in lysosomes is not only related to senescence, but also to some other physiological processes. To address this issue, we introduce our fluorescent probes including a second dimension: lysosomal pH, since de-acidification is a unique feature of the lysosomes in senescent cells. With this novel design, our probes achieved excellent discrimination of SA-ß-gal from cancer-associated ß-gal, which enables them to track cellular senescence as well as tissue aging more precisely. Our crystal structures of a model enzyme E. coli ß-gal mutant (E537Q) complexed with each probe further revealed the structural basis for probe recognition.


Assuntos
Corantes Fluorescentes/química , beta-Galactosidase/química , Senescência Celular , Escherichia coli/enzimologia , Corantes Fluorescentes/síntese química , Mutação , beta-Galactosidase/genética , beta-Galactosidase/metabolismo
7.
J Org Chem ; 85(23): 15600-15609, 2020 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-33180489

RESUMO

An efficient synthesis of ß-methylsulfonylated N-heterocycles via FeCl3-catalyzed C(sp3)-H dehydrogenation and C(sp2)-H methylsulfonylation of inactivated cyclic amines with the promotion and participation of inorganic sodium metabisulfite and dicumyl peroxide (DCP) has been developed. Notably, bifunctional DCP acted not only as an oxidant to promote the dehydrogenation but also as a methyl radical to participate in the sulfone formation. With this protocol, a number of ß-methylsulfonylated tetrahydropyridines, tetrahydroazepines, and pyrroles were obtained in a facile one-pot manner.

8.
J Org Chem ; 83(20): 12514-12526, 2018 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-30239199

RESUMO

An efficient and regioselective synthesis of 2-ene-1,4-diones, 4-hydroxycyclopent-2-en-1-ones, or 2-(furan-3-yl)acetamides is successfully realized through palladium-catalyzed one-pot multicomponent reactions of allenols with aryl iodides and carbon monoxide in the presence of tertiary amines. Interestingly, the selectivity depends on the substitution patterns of the allenol substrates. To be specific, from the reaction of allenols with no substituent attached on the internal position of the allenic moiety, 2-ene-1,4-diones or 4-hydroxycyclopent-2-en-1-ones were formed selectively through carbonylation of aryl iodide followed by acylation of allenol with the in situ formed acyl palladium species, ß-hydride elimination of the in situ formed allyl palladium complex, and further tautomerization or intramolecular aldol reaction. From the reaction of allenols bearing a substituent at the internal position of the allenic unit, on the other hand, diversely substituted 2-(furan-3-yl)acetamides were formed through a cascade process combining carbonylation of aryl iodide, acylation, and carbonylation of allenol followed by intramolecular condensation and amination by tertiary amine featuring an oxidant-free C-N bond cleavage.

9.
Bioorg Med Chem Lett ; 28(4): 547-551, 2018 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-29422390

RESUMO

α1-Adrenoceptor (α1-AR) antagonists are considered to be the most effective monotherapy agents for lower urinary tract symptoms associated with benign prostatic hyperplasia (LUTS/BPH). In this study, we synthesized compounds 2-17, which are novel piperazine derivatives that contain methyl phenylacetate. We then evaluated the vasodilatory activities of these compounds. Among them, we found that compounds 2, 7, 12, which contain 2-OCH3, 2-CH3 or 2, 5-CH3, respectively, exhibited potent α1-blocking activity similar to protype drug naftopidil (1). The antagonistic effects of 2, 7, and 12 on the (-)-noradrenaline-induced contractile response of isolated rat prostatic vas deferens (α1A), spleen (α1B) and thoracic aorta (α1D) were further characterized to assess the sub receptor selectivity. Compared with naftopidil (1) and terazosin, compound 12 showed the most desirable α1D/1A subtype selectivity, especially improved α1A subtype selectivity, and the ratios pA2 (α1D)/pA2 (α1B) and pA2 (α1A)/pA2 (α1B) were 17.0- and 19.5-fold, respectively, indicating less cardiovascular side effects when used to treat LUTS/BPH. Finally, we investigated the chiral pharmacology of 12. We found, however, that the activity of enantiomers (R)-12 and (S)-12 are not significantly different from that of rac-12.


Assuntos
Antagonistas de Receptores Adrenérgicos alfa 1/farmacologia , Naftalenos/farmacologia , Fenilacetatos/farmacologia , Piperazinas/farmacologia , Vasodilatadores/farmacologia , Antagonistas de Receptores Adrenérgicos alfa 1/síntese química , Antagonistas de Receptores Adrenérgicos alfa 1/química , Animais , Aorta/efeitos dos fármacos , Masculino , Contração Muscular/efeitos dos fármacos , Naftalenos/síntese química , Naftalenos/química , Fenilacetatos/síntese química , Fenilacetatos/química , Piperazinas/síntese química , Piperazinas/química , Prazosina/análogos & derivados , Prazosina/farmacologia , Coelhos , Ratos Sprague-Dawley , Baço/efeitos dos fármacos , Estereoisomerismo , Ducto Deferente/efeitos dos fármacos , Vasodilatadores/síntese química , Vasodilatadores/química
10.
Guang Pu Xue Yu Guang Pu Fen Xi ; 36(9): 2858-62, 2016 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-30084615

RESUMO

Rapid source identification of mine water inrush has great significance for early warning and rescuing after the mine water inrush. Conventional method taking the concentration of ions as the discriminant factor takes such a long time that a method of rapid source identification of mine water inrush is in urgent need. This method is combined with Laser induced fluorescence (LIF) technology and Partial Least Squares-Discriminant Analysis (PLS-DA) algorithm. In the experiment, 405 nm laser was used to excite the water and 100 groups of fluorescence spectrum from 5 different aquifer of the mine were obtained. According to the spectra curve features, the data was compressed to obtain proper spectral data. 15 groups of spectrum of each water inrush samples were applied, with a total of 75 groups of spectrum as the prediction set while the rest of 25 groups of spectrum as the test set. To verify the experimental result, an experimental model was built with soft independent modeling of class analogy (SIMCA) to compare with PLS-DA. The result shows that the fluorescence spectra of different aquifer water samples is of great difference, without any pre-treatment, the PLS-DA algorithm based on the PLS model has higher modeling accuracy compared with SIMCA algorithm, which reaches to 100%, the validation results and the correlation of separation of variables are both more than 0.951, the RMSECV and RMSEP are both less than 0.123, using the model to identify the 5 water samples of test set, the accuracy are up to 100%.

11.
Guang Pu Xue Yu Guang Pu Fen Xi ; 36(1): 243-7, 2016 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-27228775

RESUMO

Rapid source identification of mine water inrush is of great significance for early warning and prevention in mine water hazard. According to the problem that traditional chemical methods to identify source takes a long time, put forward a method for rapid source identification of mine water inrush with laser induced fluorescence (LIF) technology and soft independent modeling of class analogy (SIMCA) algorithm. Laser induced fluorescence technology has the characteristics of fast analysis, high sensitivity and so on. With the laser assisted, fluorescence spectrums can be collected real-time by the fluorescence spectrometer. According to the fluorescence spectrums, the type of water samples can be identified. If the database is completed, it takes a few seconds for coal mine water source identification, so it is of great significance for early warning and post-disaster relief in coal mine water disaster. The experiment uses 405 nm laser emission laser into the 5 kinds of water inrush samples and get 100 groups of fluorescence spectrum, and then put all fluorescence spectrums into preprocessing. Use 15 group spectrums of each water inrush samples, a total of 75 group spectrums, as the prediction set, the rest of 25 groups spectrums as the test set. Using principal component analysis (PCA) to modeling the 5 kinds of water samples respectively, and then classify the water samples with SIMCA on the basis of the PCA model. It was found that the fluorescence spectrum are obvious different of different water inrush samples. The fluorescence spectrums after preprocessing of Gaussian-Filter, under the condition of the principal component number is 2 and the significant level α = 5%, the accuracy of prediction set and testing set are all 100% with the SIMCA to classify the water inrush samples.

12.
Br J Educ Psychol ; 94(2): 601-621, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38545830

RESUMO

AIM: This study adopted a three-wave random intercept cross-lagged panel model to explore the longitudinal reciprocal relationships between (a) the teacher-student relationship (TSR) quality and (b) the parent-child relationship (PCR) quality and positive affect among Chinese primary school students. SAMPLES: Two primary school student samples, including 3505 and 2505 students, were tracked with their perceived relationship quality with math teachers and parents and their positive affect levels in mathematics learning over three academic years. RESULTS: The results demonstrated that more closeness with parents could significantly predict students' subsequent higher level of positive affect in mathematics learning. However, more closeness with their math teachers did not show significant prediction. Meanwhile, more conflict with math teachers and parents could significantly predict their subsequent lower degree of perceived positive affect in mathematics learning. That is, a reciprocal association lines in the PCR quality and positive affect, whereas only a unidirectional association exists between the TSR and positive affect. The predictions of the experienced positive affect on their perceived interpersonal relationships with math teachers and parents were stronger than those in the reverse association. CONCLUSIONS: This study identifies that while the effects of closeness with math teachers and parents on positive affect in students' math learning differ, conflict with math teachers and parents indeed harms students' experienced positive affect in math learning. More attention should also be paid to fostering positive affect in math learning.

13.
J Contam Hydrol ; 261: 104300, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38242063

RESUMO

Long-term agricultural activities have affected the sustainable development of groundwater in the Northern Anhui Plain, East China. It is, therefore, important to identify areas at high groundwater pollution risk in the Northern Anhui Plain to ensure effective protection of regional water resources. In this study, 60 groundwater samples were collected from the shallow aquifer of the plain and analyzed for nitrate (NO3-) concentrations. In addition, 10 environmental and geological factors including the elevations, distances-to-rivers, slope angles, orientations of slopes, land cover types, topographic wetness index (TWI), geomorphology, lithology, soil types, and precipitation amounts in the study area were selected as input layers. The light gradient boosting machine (LightGBM) and random forest (RF) algorithms, combined with the geographic information system (GIS), were performed to generate the groundwater pollution occurrence probability maps. The descriptive statistics showed that the NO3- concentrations in the shallow groundwater ranged from 4.3 to 73.6 mg/L. Most sampling wells exhibited NO3- concentrations above the threshold of 18.3 mg/L. The prediction results of the LightGBM and RF algorithms indicated a high groundwater NO3- pollution risk in the southern part of the plain. However, the LightGBM algorithm had a better prediction performance than RF, with a higher Kappa value of 0.84. Moreover, the frequency ratio method revealed that the precipitation amounts contributed to the groundwater NO3- pollution risk in the study area by 38.14%, followed by the elevations, slope angles, TWI, land cover types, and slope aspects, with contributions of 21.4, 13.02, 8.37, 7.44, and 6.51%, respectively. In the future, sampling of additional wells and further anthropogenic factors shall be considered for the development of more effective groundwater nitrate pollution prevention strategies provided to decision makers.


Assuntos
Água Subterrânea , Poluentes Químicos da Água , Nitratos/análise , Sistemas de Informação Geográfica , Monitoramento Ambiental/métodos , Poluentes Químicos da Água/análise , China , Medição de Risco , Aprendizado de Máquina
14.
Int J Surg ; 110(4): 2115-2121, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38241323

RESUMO

BACKGROUND: The association between postoperative outcomes of robotic-assisted total knee arthroplasty (RA-TKA) and nutrition status among elderly adults remained unclear. The authors aimed to evaluate these associations and provide a nutrition status reference for the surgical technique selection of TKA. METHODS: In the present study, the authors used data from a multicenter, prospective, randomized controlled project, which recruited patients underwent TKA therapy. A total of 88 elderly adults (age ≥65 years old) were included in this study. Their preoperative and postoperative demographic data and radiographic parameters were collected. Clinical outcomes, including postoperative hip-knee-ankle (HKA) angle deviation, knee society score (KSS), 10 cm visual analog scale, and so on, were observed and compared between the RA-TKA group and the conventional TKA group. Logistic regression was performed to adjust several covariates. In addition, according to the results of restricted cubic splines analyses, all participants were categorized into two groups with GNRI≤100 and GNRI >100 for further subgroup analyses. RESULTS: Our results showed despite having a lower postoperative HKA angle deviation, the RA-TKA group had a similar postoperative KSS score compared with the conventional TKA group in elderly adults. Among elderly patients with GNRI>100, RA-TKA group achieved significantly more accurate alignment (HKA deviation, P =0.039), but did not obtain more advanced postoperative KSS scores because of the compensatory effect of good nutrition status. However, among elderly patients with GNRI≤100, RA-TKA group had significantly higher postoperative KSS scores compared to the conventional TKA group ( P =0.025) and this association were not altered after adjustment for other covariates. CONCLUSION: Considering the clinical outcomes of conventional TKA may be more susceptible to the impact of nutrition status, elderly patients with GNRI≤100 seem to be an applicable population for RA-TKA, which is more stable and would gain significantly more clinical benefits compared with conventional TKA.


Assuntos
Artroplastia do Joelho , Estado Nutricional , Procedimentos Cirúrgicos Robóticos , Humanos , Artroplastia do Joelho/métodos , Artroplastia do Joelho/efeitos adversos , Feminino , Masculino , Idoso , Procedimentos Cirúrgicos Robóticos/métodos , Procedimentos Cirúrgicos Robóticos/efeitos adversos , Estudos Prospectivos , Resultado do Tratamento , Idoso de 80 Anos ou mais , Avaliação Geriátrica , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia
15.
Sci Total Environ ; 946: 174231, 2024 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-38917909

RESUMO

Nitrous oxide (N2O) is increasingly regarded as a significant greenhouse gas implicated in global warming and the depletion of the ozone layer, yet it is also recognized as a valuable resource. This paper comprehensively reviews innovative microbial denitrification techniques for recovering N2O from nitrogenous wastewater and flue gas. Critical analysis is carried out on cutting-edge processes such as the coupled aerobic-anoxic nitrous decomposition operation (CANDO) process, semi-artificial photosynthesis, and the selective utilization of microbial strains, as well as flue gas absorption coupled with heterotrophic/autotrophic denitrification. These processes are highlighted for their potential to facilitate denitrification and enhance the recovery rate of N2O. The review integrates feasible methods for process control and optimization, and presents the underlying mechanisms for N2O recovery through denitrification, primarily achieved by suppressing nitrous oxide reductase (Nos) activity and intensifying competition for electron donors. The paper concludes by recognizing the shortcomings in existing technologies and proposing future research directions, with an emphasis on prioritizing the collection and utilization of N2O while considering environmental sustainability and economic feasibility. Through this review, we aim to inspire interest in the recovery and utilization of N2O, as well as the development and application of related technologies.

16.
Heliyon ; 10(5): e26925, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38486773

RESUMO

This study aims to accurately identify mine water sources and reduce the hazards caused by water inrush accidents in coal mines. Taking the Gubei coal mine as an example, the water quality results of the water samples from the Cenozoic unconsolidated aquifer, Permian sandstone fracture aquifer, and Carboniferous Taiyuan Formation limestone karst fracture aquifer in the mine area were tested, and K++Na+, Ca2+, Mg2+, Cl-, SO42-, HCO3-, TDS (Total Dissolved Solids), and pH were selected as the main indicators to study the water chemistry characteristics of the aquifer through water chemistry component analysis, major ion content analysis, Piper trilinear analysis, and correlation analysis. Thirty-five groups of water samples were randomly selected and imported into SPSS software for factor analysis (FA) and downsized to three main factors as the input variables of the artificial neural network model. The particle swarm optimization (PSO) code was written based on the MATLAB platform to improve the self-adjustment weights and acceleration factors for optimizing the initial weights and thresholds of the Back-Propagation (BP) neural network. The training and prediction samples were learned in the ratio of 8:2, and the recognition results were compared with the traditional BP neural network model. Results showed that the groundwater of the Gubei coal mine demonstrated a water quality vertical zoning pattern, and the chemical composition was dominated by cation K++Na+ and anion Cl-. The FA-PSO-BP neural network model has a higher accuracy of water source discrimination compared with the cluster analysis and the FA-BP neural network model. The FA-PSO-BP neural network model is worthy of further application in the problem of water source identification in mine water inrush.

17.
Sci Total Environ ; 912: 169706, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38159762

RESUMO

Mining cities are ecotone areas where human and natural components interact. Indeed, the negative effects of mining activities on drinking water quality have become a serious public concern worldwide. To elucidate groundwater genesis and reactive transport path controlling the water pollution, a multi-bodies system in the Sunan Mine area in China was considered in this study. The results of the mineral phase characterizations, hydrochemical analysis, and multiple stable isotopes (δ2H/δ18O, δ34S and 87Sr/86Sr) indicated that calcite, dolomite, gypsum, quartz, halite, organic carbon, and gases (O2, CO2 and H2O) were the primary reactants in the aquifer system, accompanied by dissolution and precipitation of minerals, cation exchange, desulfation, and evaporation. An inverse hydrogeochemical model was employed to identify three paths, Path 1 demonstrated that mine water mainly originated from the Quaternary loose aquifer water (QLA), Permian fractured sandstone aquifer water (PFA), and Carbonifer fractured limestone aquifer water (CFA), accompanied by high K++Na+ and HCO3- concentrations due to the carbonate dissolution, halite dissolution, and cation exchange processes. Path 2 showed that the recharge of the CFA and Ordovician fractured limestone aquifer (OFA) occurred from the shallow recharge zone to the deeper OFA water through faults and fractures, mainly involving halite dissolution, carbonate dissolution, and gypsum dissolution. Path 3 demonstrated the interaction between the Hui River, collapsed pond water, and QLA, accompanied by gypsum dissolution, calcite dissolution, and cation exchange. Although the shallow QLA quality met the WHO drinking water standards, the pollution risk from the surface collapse pit water cannot be ignored. Therefore, effective approaches need to be considered in the study area to reduce the connection between the collapse pit water and QLA. The study results can help decision makers to predict water quality of complex water systems in ecotone areas and other similar regions worldwide.

18.
Chem Commun (Camb) ; 59(26): 3874-3877, 2023 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-36916451

RESUMO

Oxoammonium salt-promoted diverse functionalization of saturated cyclic amines with different dinucleophiles under mild conditions is presented. Specifically, when thiocyanate is used as a 1,3-dinucleophile, hexahydrothiazolo[4,5-b]pyridin-2(3H)-one derivatives are formed via the formation of the ß-TEMPO-tethered cyclic iminium ion as a key intermediate. By contrast, when benzene-1,2-diamine is used as a 1,4-dinucleophile, 2-alkylquinoxaline derivatives are afforded via generation of the ß-oxo cyclic iminium ion as a key intermediate. In addition, the usefulness of 2-alkylquinoxalines is showcased through their facile conversion into N-(2-oxo-2-(quinoxalin-2-yl)ethyl)nitrous amides featuring the synthetically useful N-NO moiety and the carbonyl group.

19.
Sci Total Environ ; 895: 165186, 2023 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-37385500

RESUMO

Groundwater contaminants from natural and anthropogenic sources pose a serious threat to the ecological environment and public health. In this study, 30 groundwater samples were collected from shallow wells at a large central water source in the North Anhui Plain, eastern China. Hydrogeochemical methods, positive matrix factorization (PMF) model, and Monte Carlo simulation were used to determine the characteristics, sources, and human health risks of inorganic and organic analytes in groundwater. The groundwater was weakly alkaline with high total hardness and was dominated by HCO3-Mg·Ca, HCO3-Ca·Mg, and HCO3-Ca·Mg·Na hydrochemical facies. The concentration of naphthalene was at a safe level, while the concentrations of F-, NO3- and Mn in 16.7 %, 26.7 % and 40 % of the samples, respectively, exceeded threshold risk-based values based on Chinese groundwater quality standards. Hydrogeochemical methods revealed that water-rock interactions (including weathering of silicate minerals, dissolution of carbonates, and cation exchange), acidity, and runoff conditions control the migration and enrichment of these analytes in groundwater. The PMF model indicated that local geogenic processes, hydrogeochemical evolution, agricultural activities, and petroleum-related industrial sources were the main factors affecting groundwater quality, with contributions of 38.2 %, 33.7 %, 17.8 %, and 10.3 %, respectively. A health risk evaluation model based on Monte Carlo simulation indicated that 77.9 % of children were exposed to a total noncarcinogenic risk above safe thresholds, about 3.4 times higher than the risk to adults. The main contributor to human health risk was F- originating from geogenic processes; thus, F- was identified as a priority for control. This study demonstrates the feasibility and reliability of combining source apportionment techniques and health risk assessment to evaluate groundwater quality.


Assuntos
Água Subterrânea , Poluentes Químicos da Água , Criança , Adulto , Humanos , Qualidade da Água , Monitoramento Ambiental/métodos , Método de Monte Carlo , Reprodutibilidade dos Testes , Poluentes Químicos da Água/análise , Água , China , Medição de Risco
20.
Environ Sci Pollut Res Int ; 30(13): 39184-39198, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36598722

RESUMO

Anthropogenic and geological factors play an essential role in the variability of groundwater quality, resulting in a weak spatial dependence of groundwater trace elements. Thus, it is an essential study to investigate the factors affecting groundwater quality and its spatial abundance of trace elements (including As, B, and other metalloids). In this study, samples are obtained from a Permian sandstone fracture aquifer in a coal mining area. A multivariate statistical analysis, hydrogeochemistry modeling, and spatial autocorrelation analysis were used to analyze the data. The results showed that Moran index was positive for all trace elements, which had good spatial autocorrelation. The Local indicators of spatial association (LISA) indicated that trace elements were clustered. The hydrogeochemical modeling results indicated that the precipitation and stability of iron-phase minerals, such as rhodochrosite and arsenic (As) absorption on the surface of iron-phase minerals in the aquifer, may limit concentrations in the southern region. The spatial autocorrelations of both As and Boron (B) were positive (high-high) in the western areas, indicating that As contamination occurred from both natural geological causes and human coal mining activities. In contrast, B contamination was mainly linked to the influence of human agricultural or industrial activities. Over 96% of the groundwater concentrations of As (10 µg/L) and B (300 µg/L) in the study area exceeded World Health Organization (WHO) limits. Overall, the results of this work could help decision-makers involved in regional water quality management visualize disperse zones where specific anthropogenic and geological processes may threaten groundwater quality.


Assuntos
Arsênio , Minas de Carvão , Água Subterrânea , Oligoelementos , Poluentes Químicos da Água , Humanos , Arsênio/análise , Oligoelementos/análise , Boro/análise , Monitoramento Ambiental/métodos , Água Subterrânea/química , Ferro/análise , Minerais/análise , Análise Espacial , Poluentes Químicos da Água/análise
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