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1.
J Colloid Interface Sci ; 678(Pt B): 40-49, 2024 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-39236353

RESUMO

Redox-active lignin rich in phenolic hydroxyl groups is an ingenious charge storage material. However, its insulating nature limits the storage/release of electrons and requires the construction of electron transfer channels within it. Herein, nanoparticles (PANI/DKL-NPs) are prepared by co-assembly via π-π interactions between conducting polyaniline (PANI) and demethylated Kraft lignin (DKL) molecules for the first time, and rapid electron transfer inside DKL is achieved. The co-assembled PANI/DKL-NPs consist of interpenetrating structures of PANI and DKL at the molecular scale, and the content of PANI molecules interspersed within them is controllable. Meanwhile, the extensive and abundant mesoporous structure in nanoscale PANI/DKL-NPs facilitates ion transport and electron storage. Based on this favorable microstructure, the specific capacitance of PANI/DKL-NPs at 1 A·g-1 is as high as 532 F·g-1, which is 780 % and 90.68 % higher compared to DKL-NPs and PANI-NPs, respectively. Meanwhile, the rate performance of PANI/DKL-NPs is significantly enhanced than that of DKL-NPs (33.11 %) and comparable to that of PANI-NPs (more than 69 %). Furthermore, the symmetric supercapacitor (PANI/DKL-NPs//PANI/DKL-NPs) assembled from it achieves a high energy density of 27.49 Wh·kg-1 at 400 W·kg-1 power density, and superb flexibility and mechanical stability. Therefore, the co-assembly of DKL and PANI will effectively stimulate the energy storage potential of lignin, providing a practical pathway to promote the development of biopolymers in energy storage.

2.
Huan Jing Ke Xue ; 45(8): 4837-4846, 2024 Aug 08.
Artigo em Chinês | MEDLINE | ID: mdl-39168700

RESUMO

To understand the pollution status, distribution characteristics, and pollution sources of soil heavy metals in tourist cities in northwest China, the soil content of heavy metals As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn in the main areas of Dunhuang City was collected and analyzed. The soil heavy metal pollution level was quantitatively evaluated by the methods of the geo-accumulation index and improved Nemerow pollution index, and the sources of heavy metal pollution were quantitatively analyzed using cluster analysis and the positive matrix factorization (PMF) model. The contribution rate of each pollution source to ecological risk was determined by combining the PMF model and comprehensive ecological risk index. The results showed that except for the mean contents of As and Ni, the mean contents of Cd, Cr, Cu, Hg, Pb, and Zn were all higher than the background values in Gansu Province. However, the average content of the eight elements was lower than the screening value of construction land in the Standard for Soil Pollution Risk Control of Soil Environmental Quality Construction Land (trial) (GB 36600-2018). Among them, the enrichment of Cd, Pb, and Hg was more serious, and the exceedance rate was higher than 90%. The results of the geo-accumulation index indicated that urban soils were mainly polluted by Hg in the study area, and Cd, Cr, Cu, Pb, and Zn pollution also existed in different degrees. The improved Nemerow pollution index illustrated that the comprehensive pollution degree of the soil was clean to moderate pollution, and the overall pollution was light pollution. Based on the PMF model, we could conclude that soil heavy metals in the study area were affected by natural sources, industrial deposition sources, industrial sources, traffic sources, and comprehensive sources, and the contribution rates were 29.28%, 25.86%, 20.13%, 16.5%, and 8.23%, respectively. The specific source-integrated ecological risk assessment model found that the industrial deposition source contributed the most to the ecological risk in the study area and could be regarded as the priority control pollution source, and Hg was considered to be the priority control pollution element for ecological risk.

3.
Int J Biometeorol ; 68(6): 1155-1167, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38499792

RESUMO

It can provide a basis for decision making for the conservation and sustainable use of forest ecosystems in mountains to understand the stoichiometric properties and nutrient allocation strategies of major tree species. However, the plant nutrient allocation strategies under different environmental gradients in forest systems of arid and semi-arid mountains are not fully understand. Therefore, three typical regions in the Qilian Mountains on the eastern edge of the Qinghai-Tibet Plateau were selected based on precipitation and temperature gradients, and the stoichiometric characteristics and nutrient allocation strategies of Qinghai spruce (Picea crassifolia) of the dominant tree species under different environmental gradients were investigated. The results showed that (1) the stoichiometric characteristics of plant tissues were different in the three regions. (2) The importance of each tissue in the plant nutrient allocation varied in different regions, showing that the plant roots are more important in the warm-wet region, while the plant leaves, branches and trunks are more important in the transition and hot-dry regions. (3) The influencing factors affecting plant nutrient allocation strategies were inconsistent across regions, which showed that plant nutrient allocation strategies in the warm-wet and transition region were mainly influenced by soil factors, while they were more influenced by climatic factors in the hot-dry region. The patterns of plant nutrient allocation strategies and drivers under different environmental gradients could help us better understand the ecological adaptation mechanism and physiological adjustment mechanism of forest ecosystem in mountains.


Assuntos
Picea , Picea/metabolismo , Tibet , Folhas de Planta/metabolismo , Folhas de Planta/química , Temperatura , Raízes de Plantas/metabolismo , Solo/química , China , Nitrogênio/análise , Nitrogênio/metabolismo , Nutrientes/análise , Nutrientes/metabolismo , Chuva , Clima , Caules de Planta/metabolismo , Caules de Planta/química
4.
Huan Jing Ke Xue ; 45(3): 1724-1738, 2024 Mar 08.
Artigo em Chinês | MEDLINE | ID: mdl-38471884

RESUMO

Assessments of the soil environmental quality of farmland and pollution source apportionment are the foundation for ensuring national food security and agricultural sustainable development, as well as an important prerequisite for the pursuit to keep our lands clean. This study evaluated the characteristics of heavy metal pollution in farmland soils in the Yellow River Basin from 2000 to 2023, based on the data of heavy metal contents including As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn, using the geo-accumulation index method. Source apportionment was conducted by employing a positive matrix factorization (PMF) model. The probabilistic health risks were evaluated by coupling Monte Carlo simulation with a human health risk assessment model, and priority pollution sources and elements were identified. The results showed that:① the average content of all heavy metals in farmland soils within the study area was lower than the screening values specified in the soil environment quality risk control standard for soil contamination of agriculture land (GB 15618-2018) (pH>7.5). However, the contents of Cd, As, and Zn in the samples exceeded their screening values, with percentages of 21.69%, 5.56%, and 1.23%, respectively, with Cd having the highest rate of exceedance. ② Hg and Cd were moderately polluted, Cu and Pb were slightly polluted, and the other elements were not polluted. ③ The main sources of heavy metals in farmland soil were traffic-industrial sources, natural-agricultural sources, industrial-natural sources, and agricultural-industrial sources, with contribution rates of 37.04%, 26.69%, 21.72%, and 14.55%, respectively. ④ Heavy metals in farmland soil posed carcinogenic health risks to adults and children but did not have non-carcinogenic risks; As and Cd were priority control elements for human health risks, and industrial-natural sources and agricultural-industrial sources were priority control sources in the study area.


Assuntos
Mercúrio , Metais Pesados , Poluentes do Solo , Adulto , Criança , Humanos , Solo , Fazendas , Rios , Cádmio , Chumbo , Monitoramento Ambiental/métodos , Poluentes do Solo/análise , Metais Pesados/análise , Medição de Risco , China
5.
Sci Total Environ ; 924: 171595, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38492585

RESUMO

Understanding the dynamics of tree recovery after drought is critical for predicting the state of tree growth in the context of future climate change. While there has been a great deal of researches showing that drought events can cause numerous significant negative effects on tree growth, the positive effects of post-drought wetting events on tree growth remain unclear. Therefore, we analyzed the effect of wet and dry events on the radial growth of trees in Central Asia using data on the width of tree rings. The results showed that 1) Drought is the main limiting factor for radial growth of trees in Central Asia, and that as the intensity and sensitivity of drought increases, tree resistance decreases and recovery rises, and more frequent droughts reduce tree resistance. 2) Tree radial growth varied significantly with wet and dry conditions, with wet events before and after drought events significantly enhancing tree radial growth. 3) When drought is followed by a wetting event, the relationship between tree resistance and recovery is closer to the "line of full resilience", with a significant increase in recovery, and compensatory growth is more likely to occur. Thus, wetting events have a significant positive effect on tree radial growth and are a key factor in rapid tree growth recovery after drought.


Assuntos
Mudança Climática , Secas , Florestas
6.
Environ Geochem Health ; 46(2): 55, 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38263529

RESUMO

Source-specific risk apportionment for soil potentially toxic metals (PTMs) is of great significance for contamination prevention and risk management in urban environments. Eighty-five urban soil samples were obtained from an oasis-tourist city, China and examined for eight PTMs (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn). The pollution levels, sources, and ecological risk of soil PTMs were quantified, and their source-specific ecological and human health effects were also estimated using the multi-proxy approaches. The results demonstrated that accumulation of Cd, Hg, Pb, Cr, Cu, and Zn in soils was observed compared to their background levels, and the soils experienced varying degrees of PTMs pollution, especially at sites with high-intensity anthropogenic activities. Natural sources, atmospheric deposition, industrial sources, vehicular emissions, and comprehensive inputs were the principal sources, with contributions of 29.28%, 25.86%, 20.13%, 16.50%, and 8.23%, respectively. The integrated ecological risks of PTMs in soils were moderate at most sites, with atmospheric deposition being the dominant contributor to ecological risks. Children exhibited pronounced non-cancer risks, but adults had no notable non-cancer risks. Moreover, there were potential carcinogenic risks for both children and adults within the study region. Non-cancer and carcinogenic risks were more significant for children than adults, and traffic emissions were the primary contributor to non-cancer risks (adults: 20.53%, children: 20.49%) and carcinogenic risks (adults: 22.95%, children: 22.08%). The industrial and traffic activities were considered as priority control sources for soil pollution control and risk management, with Hg, Cd, Zn, and Pb corresponding to the priority elements. This study highlights the source-specific ecological and human health effects of PTMs pollution in urban soils, thereby providing valuable information for targeted pollution control and priority source management.


Assuntos
Cádmio , Mercúrio , Adulto , Criança , Humanos , Chumbo , Carcinogênese , Carcinógenos , China , Poluição Ambiental , Solo , Medição de Risco
7.
Int J Biol Macromol ; 255: 128254, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37992922

RESUMO

Deacidification and strengthening play pivotal roles in the enduring conservation of aged paper. In this study, we innovatively propose the use of reduced cellulose nanofibrils (rCNFs) and aminopropyltriethoxysilane modified CaCO3 (APTES-CaCO3) for preserving aged paper. The sodium borohydride-mediated reduction of cellulose nanofibrils diminished the carboxylate content and O/C mass ratio in rCNFs, which in turn amplified the swelling of rCNFs and their crosslinking potential with paper fibers. By introducing amino groups to the CaCO3 surface, the dispersion property of APTES-CaCO3 in organic solvent was enhanced, as well as the deacidification ability and the retention on the paper. The distinct structures and attributes of rCNFs and APTES-CaCO3 were characterized by various techniques. Following the conservation application to aged paper using this system, a desired internal pH value of 8.31 and an alkaline reserve of 0.8056 mol/kg were achieved, alongside a 33.6 % elevation in the tensile index. The aging resistance of the treated paper was evaluated by dry heat and hygrothermal aging tests. The findings revealed that the treatment bestowed the treated paper with outstanding anti-aging properties, notably in terms of internal pH, alkaline reserve and mechanical robustness. Additionally, the paper's brightness was amplified, while its color alteration remained negligible.


Assuntos
Celulose , Nanofibras , Celulose/química , Nanofibras/química , Resistência à Tração , Propilaminas
8.
World Neurosurg ; 183: 206-213, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38143026

RESUMO

BACKGROUND: Since tethered cord syndrome (TCS) may lead to neurologic and motor dysfunction, surgeries often are applied to relieve the symptoms. The aim of the research was to explore the current global research trends of TCS surgery. METHODS: In this article, articles on TCS surgery in the Web of Science Core Collection from 1980 to 2023 were searched. Research trends, countries, institutions, journals, authors, highly cited articles, and key words were analyzed using bibliometric methods. The literature co-citation network was mapped using VOSviewer, and research hotspots and trends were analyzed using CiteSpace. RESULTS: A total of 432 publications were included. The number of publications and related research interest in the field of TCS surgery has increased globally year by year. The United States is the largest contributor (154 publications). The journal Childs Nervous System has the greatest number of publications (48 publications) and the most frequently cited journal is Neurosurgery (973 citations). In network visualization, the institution with the greatest contribution is University of California System (16 publications). Lee JY and Wang KC are the authors with the greatest number of publications (8 publications), and the most frequently cited author is Klekamp J (268 citations). Neurogenic bladder and spina bifida may be the next hot spot in this field. CONCLUSIONS: This study will help researchers to identify the mainstream research directions and the latest hotspots in the field of TCS surgery and provide a reference for further research.


Assuntos
Dermatite , Defeitos do Tubo Neural , Neurocirurgia , Criança , Humanos , Bibliometria , Instalações de Saúde , Defeitos do Tubo Neural/cirurgia
9.
Huan Jing Ke Xue ; 44(10): 5689-5703, 2023 Oct 08.
Artigo em Chinês | MEDLINE | ID: mdl-37827785

RESUMO

To investigate the characteristics and sources of potentially toxic elemental contamination in soils around the coal-fired power plant, we selected the soil around the Jingyuan power plant as the object of investigation. Thirty-six and 27 soil samples collected from the urban and farmland areas were analyzed for PTEs (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn), respectively. We employed the geoaccumulation index, single-factor pollution index, and improved Nemerow integrated pollution index to evaluate the contamination characteristics of PTEs, and combined correlation analysis with absolute principal component scores-multiple linear regression (APCS-MLR) and positive matrix factorization (PMF) receptor models were used to quantitatively analyze the pollution sources of PTEs. The results revealed that all the average concentrations of other soil metals around Jingyuan power plant exceeded their corresponding background values of Gansu Province, except for As, in agricultural soil, and Hg exhibited significant spatial non-homogeneity, and thus it was visibly affected by anthropogenic activities. The values of the single-factor pollution and geoaccumulation indices indicated that the soils of both sites were mainly contaminated with Cd, Cr, Ni, and Pb, and Hg contamination was reflected in wide areas for both sites. Additionally, the results of the improved Nemerow index demonstrated that the investigated soil was between moderately contaminated and heavily contaminated. Further, the comprehensive pollution degree of urban soil was higher than that of agricultural soil. Moreover, source apportionment revealed that PTEs in urban soil were derived from mixed sources of traffic activities and coal combustion, mixed sources of traffic activities and industrial and mining activities, and atmospheric deposition from industrial activities, with contribution rates of APCS-MLR of 35.2%, 25.1%, and 23.4%, respectively. The PMF contribution rates were 40.2%, 12.4%, and 47.7%, respectively. PTEs in agricultural soil were from one mixture source of industrial, mining, agricultural, and traffic sources, and the other mixed source was of traffic activities and coal combustion, with a APCS-MLR contribution rate of 40.3% and 35.9% and a contribution rate of PMF of 36.2% and 18.0%, respectively. In addition, another mixed source of agricultural activities and coal combustion was obtained using the PMF model, with a contribution rate of 48.5%.

10.
Sci Total Environ ; 903: 166864, 2023 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-37683873

RESUMO

Global climate change is exacerbating drought pressure on forests. However, the response patterns and physiological mechanisms of conifer species to drought, specifically in terms of radial growth, ecological resilience and soil water utilization, are not clearly understood. This study aims to quantify the effects of resilience on radial growth and identify the role of soil moisture utilization strategies in the resilience of species under drought intensities. We focus on two conifer species, Picea crassifolia (spruce) and Pinus tabuliformis (pine), located on the southern edge of the Tengger Desert in northwestern China. The dynamics of radial growth and ecological resilience were identified, and the seasonal growth rates of species based on soil water were simulated using the VS-oscilloscope model under varying drought stress. The results showed that spruce growth and recovery contributed by soil water were suppressed with frequent severe droughts, leading to a decline in growth (-0.5 cm2 year-1/10a, p < 0.05), despite its greater resistance to mild and moderate drought (-4.63 %). However, pine exhibited a stronger recovery (+40.25 %, p < 0.05) and higher variation in growth (-0.3 cm2 year-1/10a, p < 0.05) under soil moisture stress, despite its weaker resistance to drought (-23.53 %, p < 0.05). These findings provide insights into the growth, resilience, and water adaptation mechanisms of species under drought events, and theoretical support for the conservation and management of conifer diversity and forest ecosystem stability in climate-sensitive regions.

11.
Environ Geochem Health ; 45(11): 8169-8186, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37548849

RESUMO

Identifying the contamination and sources of potentially toxic elements (PTEs) in road-dust sediment (RDS) and the surrounding greenspace soil of urban environments and understanding their ecological-health risks are important for pollution management and public health. The contamination characteristics, ecological and probabilistic health risks, and source apportionment of eight PTEs (Cd, Pb, Cr, Cu, Ni, As, Zn, and Hg) in the Yellow River Custom Tourist Line of Lanzhou, which is the largest open urban riverfront scenic park in China, were investigated. The results showed that all the RDS PTE mean concentrations exceeded their soil background values, whereas for the surrounding greenspace soils, the concentrations of the PTEs, except for Cr and Ni, were also higher than their local background levels. Moreover, the RDS-soil system was mainly contaminated by Cd, Zn, Pb, Cu, and Hg to varying degrees, and the integrated ecological risks of PTEs in the RDS and soil were high and considerable at most sites, respectively. The probabilistic health risk assessment results demonstrated that the non-carcinogenic hazard risk for humans was negligible, but the total carcinogenic risks should be considered. Source apportionment using a positive matrix factorization model combined with multivariate statistical analyses revealed that Cr, Ni, and As in the RDS-soil system were from natural and industrial sources, Cd, Pb, Zn, Cu came from vehicle emissions and pesticide and fertilizer applications, and Hg was from natural and industrial sources and utilization of pesticides with fertilizers. This work provides scientific evidence for urban planning and human health protection in urban environments.


Assuntos
Mercúrio , Metais Pesados , Praguicidas , Poluentes do Solo , Humanos , Solo , Cádmio/análise , Chumbo/análise , Parques Recreativos , Monitoramento Ambiental/métodos , Poluentes do Solo/toxicidade , Poluentes do Solo/análise , Metais Pesados/toxicidade , Metais Pesados/análise , Mercúrio/análise , China , Medição de Risco , Praguicidas/análise , Poeira/análise
12.
Chem Commun (Camb) ; 59(72): 10745-10748, 2023 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-37581907

RESUMO

We propose a practical strategy to design a series of heavy-atom-free synergistic phototherapy agents (CSQs) with both photodynamic therapy (PDT) and photothermal therapy (PTT) under NIR wavelength excitation by simply replacing the indole salt of xanthene Changsha (CS) with quinoline salt.


Assuntos
Nanopartículas , Neoplasias , Fotoquimioterapia , Quinolinas , Humanos , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico , Fototerapia , Cloreto de Sódio , Neoplasias/tratamento farmacológico , Quinolinas/farmacologia
13.
J Stomatol Oral Maxillofac Surg ; 124(6S): 101589, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37543208

RESUMO

OBJECTIVE: Superior laryngeal nerve block (SLNB) is a regional anesthesia technique for addressing airway response. However, SLNB on the efficacy of sedation in patients with delayed extubation is unknown, particularly for maxillofacial surgery (MS). The aim of the study was to assess whether ultrasound guided (UG) SLNB reduces the incidence of moderate to severe cough for delayed extubation in MS with free flap reconstruction. METHODS: 60 patients were randomly assigned to the GEA group (control group) and the SLNB group (UG-SLNB postoperatively, study group). During the initial two postoperative hours, the incidence of moderate and severe cough, agitation, and the number of patients requiring rescue propofol and flurbiprofen were recorded. Additionally, the time spent under the target level of sedation, postoperative hemodynamics, and the total does of propofol during the postoperative 24 h were recorded. RESULTS: The data showed the SLNB group had a significantly lower incidence of moderate to severe cough and agitation (p < 0.05), and a longer sedation time (p < 0.05). The number of patients required rescue propofol and flurbiprofen, as well as the hemodynamic changes, were significantly different between the two groups (p < 0.05). CONCLUSION: The use of UG-SLNB is associated with reduced incidence of postoperative cough. Moreover, SLNB can enhance the efficacy of postoperative sedation with need of fewer agents postoperatively. CLINICAL TRIAL REGISTRATION: ChiCTR2000039982.


Assuntos
Anestesia por Condução , Flurbiprofeno , Retalhos de Tecido Biológico , Propofol , Cirurgia Bucal , Humanos , Extubação , Tosse , Ultrassonografia de Intervenção , Nervos Laríngeos
14.
Huan Jing Ke Xue ; 44(6): 3475-3487, 2023 Jun 08.
Artigo em Chinês | MEDLINE | ID: mdl-37309964

RESUMO

In order to investigate the contamination levels of dust and its surrounding green land soil heavy metal pollution and potential ecological and health risks in the scenic areas of urban waterfront parks, the gardens, squares, and theme parks of the Yellow River Custom Tourist Line in Lanzhou were selected as the research area, using 27 dust samples and 26 soil samples from its surrounding green lands. The contamination characteristics and potential ecological risks of eight heavy metals (Cr, Ni, Cu, Zn, As, Cd, Hg, and Pb) were evaluated using the geo-accumulation index (Igeo), single-factor pollution index (Pi), Nemerow integrated pollution index (PN), and improved potential ecological risk index (RI). The human health risk assessment was also evaluated using the exposure risk model. The results showed that the average concentrations of the other heavy metals in the surface dusts were higher than the background values of Gansu Province and Lanzhou City, except that the As mean concentrations in the surface dusts and the surrounding green land soils were slightly lower than the Gansu Province background values. For its surrounding green land soils, the mean concentrations of the other heavy metals (Cu, Zn, Cd, Hg, and Pb) exceeded the soil background values of Gansu Province and Lanzhou City, whereas the Cr and Ni mean concentrations were lower than their corresponding soil background values of Gansu Province and Lanzhou City. The geo-accumulation and single-factor pollution indices demonstrated that a slight to moderate pollution of Cr, Cu, Zn, Cd, Hg, and Pb occurred in surface dusts, and Cu, Zn, Cd, Hg, and Pb appeared in varying degrees of contamination levels in its surrounding green land soils. The Nemerow integrated pollution index analysis manifested that the overall contamination status of the study areas was between slightly and heavily polluted. The potential ecological risk index suggested that Cd and Hg were recognized as significant pollutant elements and that the RI of the other heavy metals were all below 40, presenting slight ecological risk. The health risk assessment indicated that ingestion was the dominant exposure pathway for heavy metals from the surface dusts and the surrounding green land soils, and no carcinogenic and noncarcinogenic risks posed threats to adults and children.


Assuntos
Mercúrio , Metais Pesados , Adulto , Criança , Humanos , Cádmio , Chumbo , Rios , Poeira
15.
Int J Mol Sci ; 24(11)2023 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-37298432

RESUMO

The development of high-performance fluorescence probes has been an active area of research. In the present work, two new pH sensors Zn-3,5-Cl-saldmpn and Zn-3,5-Br-saldmpn based on a halogenated Schiff ligand (3,5-Cl-saldmpn = N, N'-(3,3'-dipropyhnethylamine) bis (3,5-chlorosalicylidene)) with linearity and a high signal-to-noise ratio were developed. Analyses revealed an exponential intensification in their fluorescence emission and a discernible chromatic shift upon pH increase from 5.0 to 7.0. The sensors could retain over 95% of their initial signal amplitude after 20 operational cycles, demonstrating excellent stability and reversibility. To elucidate their unique fluorescence response, a non-halogenated analog was introduced for comparison. The structural and optical characterization suggested that the introduction of halogen atoms can create additional interaction pathways between adjacent molecules and enhance the strength of the interaction, which not only improves the signal-to-noise ratio but also forms a long-range interaction process in the formation of the aggregation state, thus enhancing the response range. Meanwhile, the above proposed mechanism was also verified by theoretical calculations.


Assuntos
Corantes Fluorescentes , Bases de Schiff , Ligantes , Fluorescência , Bases de Schiff/química , Corantes Fluorescentes/química , Concentração de Íons de Hidrogênio
16.
Huan Jing Ke Xue ; 44(5): 2562-2573, 2023 May 08.
Artigo em Chinês | MEDLINE | ID: mdl-37177930

RESUMO

In order to investigate the contamination characteristics and potential sources of heavy metals from the urban river surface sediments in the Yellow River Basin, we selected the Lanzhou reach of the Yellow River as the object of investigation. A total of 46 surface sediment samples were collected along the Lanzhou reach of the Yellow River, and the contents of eight heavy metals, Cr, Ni, Cu, Zn, As, Cd, Hg, and Pb, were determined by using inductively coupled plasma mass spectrometry and an atomic fluorescence spectrometer. Contamination indexes including single factor pollution index (Pi) and geo-accumulation index (Igeo), together with the sediment pollution index (SPI), were used to assess heavy metal pollution characteristics and ecological risk levels in the urban river surface sediments of the Lanzhou reach of the Yellow River. Pearson's correlation analysis (CA), positive matrix factorization (PMF), and principal component analysis/absolute principal component score (PCA/APCS) were jointly employed to quantitatively analyze pollution sources of heavy metals. The results showed that the mean concentrations of the majority of heavy metals exceeded their corresponding background values of Gansu Province and Lanzhou City with the exception of As, and the spatial distribution of high concentrations of heavy metals was mainly concentrated in the corner of the river. Based on the single factor pollution and geo-accumulation indexes of the eight heavy metals, in the Lanzhou reach of the Yellow River, Cr was the dominant pollution element in the urban river surface sediments, followed by Cd and Ni. Additionally, the SPI values for the eight heavy metals in the surface sediments ranged from 0.48 to 8.56, presenting natural to low ecological risk level. Furthermore, source apportionment revealed that a mixture source of industrial and agricultural activities (77.6%) was the largest contributor of Cr, Ni, Zn, As, Cd, and Pb in the urban river surface sediments, followed by natural sources (11.4%) and a mixed source of industrial and traffic activities (11%).

17.
Medicine (Baltimore) ; 102(17): e33600, 2023 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-37115079

RESUMO

RATIONALE: Tethered cord syndrome (TCS) represents a spectrum of neurological symptoms that are caused by constant or intermittent axial traction of the terminal cone of the spinal cord due to abnormal positioning. It is uncommon for abnormal structures of TCS to be accompanied by split cord malformation, thoracic spinal stenosis, and other spinal cord diseases. PATIENT CONCERNS: A 45-year-old male patient visited our hospital due to severe lower back pain, extensive left lower limb muscle weakness, and intermittent claudication. DIAGNOSES: TCS combined with stenosis of the thoracic canal, split cord malformation, and kyphosis deformity. INTERVENTIONS: The patient underwent Dekyphosis operation combined with limited osteotomy symptoms. OUTCOMES: The patient felt the right lower limb improved after surgery. At 4-month follow-up, a radiological examination showed adequate decompression of the spinal cord and a good internal fixation position. Overall, the patient's clinical symptoms significantly improved. CONCLUSION: This is a rare case of TCS combined with thoracic disc herniation and bony mediastinum. A more conservative invasive surgical approach was elected and markedly improved the patient's symptoms. Additional clinical cases are needed to confirm the stability and feasibility of this surgical approach.


Assuntos
Cifose , Defeitos do Tubo Neural , Masculino , Humanos , Adulto , Pessoa de Meia-Idade , Vértebras Torácicas/cirurgia , Defeitos do Tubo Neural/complicações , Defeitos do Tubo Neural/cirurgia , Medula Espinal/cirurgia , Osteotomia/efeitos adversos , Cifose/complicações , Cifose/cirurgia , Dor nas Costas , Resultado do Tratamento
18.
BMC Plant Biol ; 23(1): 199, 2023 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-37062838

RESUMO

BACKGROUND: Understanding the stoichiometric characteristics and nutrient allocation strategies of dominant tree species in montane forest systems can provide a basis for decision-making in relation to montane system management. Therefore, according to precipitation and temperature gradients, we selected three typical areas in the Qilian Mountains on the eastern margin of the Qinghai-Tibet Plateau to analyse the spatial relations of plant-soil stoichiometric characteristics and nutrient allocation strategies of plant tissues for Qinghai spruce (Picea crassifolia) along different environmental gradients. RESULTS: 1) The plant and soil stoichiometric characteristics had similar spatial patterns. The C content of plants and soils tended to decrease with increasing latitude, and the N and P contents and the N:P ratio tended to increase with increasing latitude. 2) The stoichiometric characteristics of the plant tissues also interacted with each other and showed synergistic trade-offs. Nutrient allocation in the eastern section of the Qilian Mountains was similar to that in the western section, while more N and P in the plant stems were allocated to maintain plant growth in the relatively arid western Sect. 3) The nutrient allocation strategies in the plant tissues were mainly regulated by soil and climate. CONCLUSIONS: Information on plant-soil stoichiometric characteristics along different gradients can help us better understand the nutrient patterns and dynamics of forest ecosystems under arid and semiarid conditions at a wide geographic scale from the perspective of plant nutrient partitioning.


Assuntos
Ecossistema , Picea , Tibet , Solo , Plantas , Nutrientes , China
20.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-1030452

RESUMO

Objective To observe the effects of tetrandrine on the proliferation,migration,and invasion of melanoma cell B16,and to explore its effects on epithelial mesenchymal transition(EMT)and potential regulatory mechanisms.Methods(1)The proliferation of B16 cells was detected by CCK-8 assay after 0,2,4,6,8 and 10 μmol·L-1 of tetrandrine intervention for 24 and 48 hours.The colony formation ability of B16 cells was detected by plate clone formation assay after 1,2 and 4 μmol·L-1 of tetrandrine intervention;the migration and invasion ability of B16 cells was detected by cell scratch assay and Transwell invasion assay;the expressions of N-cadherin,Vimentin and E-cadherin related to EMT in B16 cells were detected by Western Blot assay.The mouse melanoma lung metastasis model was replicated by tail vein injection of B16 cells to observe the effects of tetrandrine(50 and 100 mg·kg-1)administered by gavage on the number of metastatic tumor nodules in the lungs of mice.(2)The CTD,SwissTargetPrediction and Similarity Ensemble Approach databases were used to predict the targets of tetrandrine;the GeneCards database was used to search for targets related to melanoma disease;the intersection of these two databases was taken as the potential target of tetrandrine for melanoma treatment.The intersected targets were imported into STRING database to construct protein-protein interaction(PPI)network and screen the core targets;the intersected targets were imported into DAVID database for GO function and KEGG pathway enrichment analysis;and molecular docking between tetrandrine and the core targets was verified by Autodock software.(3)In vivo experimental validation:after intervention of 1,2 and 4 μmol·L-1 tetrandrine,Western Blot method was used to detect the expression of the key pathway AKT/NF-κB/CREB pathway-related proteins;and AKT agonist SC79 was used to validate the replication experiments.Results(1)The IC50 of B16 cells intervened by tetrandrine was 4.273 and 4.085 μmol·L-1 at 24 and 48 hours.Compared with the control group,the colony forming ability,scratch healing rate and invasion rate of cells in the 1,2 and 4 μmol·L-1 tetrandrine group were all significantly reduced(P<0.05,P<0.01,P<0.001);the expressions of cellular Vimentin and N-cadherin protein expressions were significantly down-regulated(P<0.01,P<0.001),and E-cadherin protein expression was significantly up-regulated(P<0.01,P<0.001).Compared with the model control group,the number of melanoma lung metastatic nodules was significantly reduced in the mice in the high-dose group of tetrandrine(P<0.05).(2)A total of 60 potential targets were obtained for the treatment of melanoma with tetrandrine;core targets such as AKT1,TNF,CCND1,RELA,CASP9,CHUK,and CREBBP were further screened,among which AKT1 was the most strongly interacting target;the signaling pathways such as apoptosis,FoxO,TNF,PI3K-AKT,and NF-κB were mainly involved.The molecular docking showed that tetrandrine had strong binding activity with AKT1,TNF,RELA and other core targets.Compared with the control group,protein expressions of p-AKT/AKT,p-NF-κB p65/NF-κ B p65,and p-CREB/CREB were significantly down-regulated in the cells of the tetrandrine 1,2,and 4 μmol·L-1 groups(P<0.05,P<0.01);protein expressions of p-AKT and p-NF-κB p65 were significantly up-regulated in the cells of the SC79 group(P<0.001).Compared with the SC79 group,protein expressions of p-AKT,p-NF-κB p65,and p-CREB were significantly down-regulated in the cells of the 2 μmol·L-1 tetrandrine+ SC79 group(P<0.001).Conclusion Tetrandrine may inhibit the proliferation,migration,invasion and EMT of mouse melanoma by regulating the AKT/NF-κB/CREB pathway,and thus inhibit the lung metastasis of mouse melanoma.

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