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1.
Small ; : e2312254, 2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38874100

RESUMO

Nanoimprinting large-area structures, especially high-density features like meta lenses, poses challenges in achieving defect-free nanopatterns. Conventional high-resolution molds for nanoimprinting are often expensive, typically constructed from inorganic materials such as silicon, nickel (Ni), or quartz. Unfortunately, replicated nanostructures frequently suffer from breakage or a lack of definition during demolding due to the high adhesion and friction at the polymer-mold interface. Moreover, mold degradation after a limited number of imprinting cycles, attributed to contamination and damaged features, is a common issue. In this study, a disruptive approach is presented to address these challenges by successfully developing an anti-sticking nanocomposite mold. This nanocomposite mold is created through the co-deposition of nickel atoms and low surface tension polytetrafluoroethylene (PTFE) nanoparticles via electroforming. The incorporation of PTFE enhances the ease of polymer release from the mold. The resulting Ni-PTFE nanocomposite mold exhibits exceptional lubrication properties and a significantly reduced surface energy. This robust nanocomposite mold proves effective in imprinting fine, densely packed nanostructures down to 100 nm using thermal nanoimprinting for at least 20 cycles. Additionally, UV nanoimprint lithography (UV-NIL) is successfully performed with this nanocomposite mold. This work introduces a novel and cost-effective approach to reusable high-resolution molds, ensuring defect-reduction production in nanoimprinting.

2.
Environ Pollut ; 352: 124125, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38740244

RESUMO

Nanoplastics pollution has emerged as a global issue due to its widespread potential toxicity. This study delved in to toxic effects of nanoplastics on juvenile P. clarkii and molecular mechanisms from perspectives of growth, biochemical, histopathological analysis and transcriptome level for the first time. The findings of this study indicated that nanoplastics of different concentrations have varying influence mechanisms on juvenile P. clarkii. Nanoplastics have inhibitory effects on growth of juvenile P. clarkii, can induce oxidative stress. The biochemical analysis and transcriptome results indicated that 10 mg/L nanoplastics can activate the antioxidant defense system and non-specific immune system in juvenile P. clarkii, and affect energy metabolism and oxidative phosphorylation. While 20 mg/L and 40 mg/L have a destructive influence on the immune function in juvenile P. clarkii, leading to lipid peroxidation and oxidative damage, and induce apoptosis, can affect ion transport and osmotic pressure regulation. The findings of this study can offer foundational data for delving further into impacts of nanoplastics on crustaceans and toxicity mechanism.


Assuntos
Astacoidea , Estresse Oxidativo , Poluentes Químicos da Água , Animais , Poluentes Químicos da Água/toxicidade , Astacoidea/efeitos dos fármacos , Astacoidea/crescimento & desenvolvimento , Astacoidea/fisiologia , Estresse Oxidativo/efeitos dos fármacos , Microplásticos/toxicidade , Peroxidação de Lipídeos/efeitos dos fármacos , Transcriptoma/efeitos dos fármacos
3.
Kaohsiung J Med Sci ; 40(7): 660-670, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38801488

RESUMO

Bladder cancer (BC) poses high morbidity and mortality, with urinary exosomal microRNA (miR)-21 showing potential value in its diagnosis and prognosis, and we probed its specific role. We prospectively selected 116 BC patients and 116 healthy volunteers as the BC and control groups, respectively. BC urinary exosomal miR-146a-5p, miR-93-5p, miR-663b, miR-21, and miR-4454 relative expression levels were assessed. The correlations between clinical indexes and urinary exosomal miR-21, prognostic value of miR-21, and diagnostic value of the five candidate miRNAs, urine cytology, and miRNA joint diagnostic panel for BC and urinary exosomal miR-21, miR-4454, and urine cytology for Ta-T1 and T2-T4 stage BC were analyzed. Urinary exosomal miR-146a-5p, miR-93-5p, miR-663b, miR-21, and miR-4454 were highly expressed in BC patients. miR-146a-5p, miR-93-5p, miR-663b, miR-21, miR-4454, miRNA combined diagnostic panel, and urine cytology had certain diagnostic value for BC, with miR-21, miR-4454, and miRNA co-diagnostic panel showing the highest diagnostic value. Collectively, urinary exosomal miR-21 was closely related to Tumor-Node-Metastasis staging and grading in BC patients. Urinary exosomal miR-21 had high diagnostic value for BC and Ta-T1 and T2-T4 stage BC, and had high predictive value for BC poor prognosis, providing an effective indicator for the occurrence, development, and prognostic assessment of BC.


Assuntos
Exossomos , MicroRNAs , Neoplasias da Bexiga Urinária , Humanos , MicroRNAs/urina , MicroRNAs/genética , Neoplasias da Bexiga Urinária/diagnóstico , Neoplasias da Bexiga Urinária/urina , Neoplasias da Bexiga Urinária/genética , Neoplasias da Bexiga Urinária/patologia , Feminino , Exossomos/genética , Exossomos/metabolismo , Masculino , Pessoa de Meia-Idade , Prognóstico , Idoso , Biomarcadores Tumorais/urina , Biomarcadores Tumorais/genética , Detecção Precoce de Câncer , Regulação Neoplásica da Expressão Gênica , Estudos de Casos e Controles , Estadiamento de Neoplasias
4.
Aquat Toxicol ; 268: 106861, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38340542

RESUMO

Abamectin is a globally used pesticide, which is one of 16-member macrocyclic lactones compound. As an environmental contaminant, pesticide residues pose a great threat to the health and survival of aquatic animals. Procambarus clarkii is one of the most important economic aquatic animals in China. It is necessary to explore the toxic mechanism of abamectin to P. clarkii. In this study, the toxic mechanism of abamectin to P. clarkii was investigated by 0, 3 and 6 µg/L abamectin stress for 28 days. The digestive-, antioxidant- and immune- related enzymes activities, genes expression levels, and histological observations were analytical indicators of growth performance, digestive capacity, and defense systems. The results in this study showed that with abamectin concentration increasing, the growth of P. clarkii was stunted significantly, and the mortality rate increased significantly. With exposure time and abamectin concentration increasing, the expression levels of related genes, the activities of digestive-, antioxidant-, and immune- related enzymes decreased ultimately. Moreover, through histological observation, it was found that with abamectin concentration increasing, the hepatopancreas, muscle, and intestine were damaged. As elucidated by the results, once abamectin exists in the environment for a long time, even low doses will threaten to healthy growth and survival of P. clarkii. This study explored the potential toxicity and the toxic mechanism of abamectin to P. clarkii, and provides a theoretical basis for further study on the toxicity of pesticides to aquatic animals.


Assuntos
Ivermectina/análogos & derivados , Praguicidas , Poluentes Químicos da Água , Animais , Antioxidantes/metabolismo , Astacoidea/metabolismo , Poluentes Químicos da Água/toxicidade , Ivermectina/toxicidade , Praguicidas/metabolismo
5.
Toxics ; 11(10)2023 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-37888662

RESUMO

The effects of herbicides on non-target organisms in paddy fields have become a popular research topic. As a widely used herbicide, it is necessary to explore the potential toxicity of metamifop in non-target organisms, especially aquatic animals, in co-culture mode. In the present study, we evaluated the effects of metamifop (0, 0.2, 0.4, 0.6, and 0.8 mg/L) on the defense system (antioxidation, immunity, and apoptosis) in Monopterus albus. Reactive oxygen species (ROS) production, malondialdehyde (MDA) content, and protein carbonylation (PCO) increased significantly (p < 0.05) with the increasing metamifop concentration, resulting in oxidative damage. In the antioxidant system, superoxide dismutase (SOD) and catalase (CAT) activities increased significantly (p < 0.05) in the 0.2 mg/L treatment group compared with the control group, and decreased in 0.4, 0.6, and 0.8 mg/L treatment groups. Glutathione peroxidase (GPX) activity decreased significantly (p < 0.05) with the increasing metamifop concentration. In the immune system, white cell number (WCN) increased significantly (p < 0.05) in 0.2 mg/L treatment group, and then decreased with the increase in metamifop concentration. Compared with control group, acid phosphatase (ACP) activity not only increased significantly (p < 0.05) in 0.2 mg/L treatment group, but also decreased significantly (p < 0.05) compared with the increase in metamifop concentration. However, in all treatment groups, alkaline phosphatase (AKP) activity was significantly lower than that in the control group (p < 0.05). In the inflammatory response, TNF-α and IL-1ß expression levels in the NF-κB signaling pathway decreased significantly (p < 0.05) with the increase in metamifop concentration, while IL-8 expression level in the same signaling pathway increased significantly (p < 0.05) in treatment groups. The expression levels of genes related to apoptosis showed that apoptosis was promoted after exposure to metamifop. The results of the present study show that metamifop induced oxidative damage via a high level of ROS production, and then inhibited or damaged the defense systems of M. albus.

6.
Fish Shellfish Immunol ; 142: 109137, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37827246

RESUMO

Abamectin, a pesticide of 16-member macrocyclic lactones, is widely applied in agriculture. As an important environmental factor, pesticides pose a great threat to defense system in aquatic animals. Procambarus clarkii is one of the most important economic aquatic animals in China. It is necessary to explore the defense mechanism of P. clarkii to abamectin. In this study, P. clarkii were exposed to 0, 0.2, 0.4, 0.6 mg/L abamectin, immune- and antioxidant-related enzymes activities, genes expression levels, and histological observations were used to analyze the defense capacity of P. clarkii to abamectin. With increasing abamectin concentration, reactive oxygen species (ROS) level and malondiadehyde (MDA) content increased significantly. Meanwhiile, acid phosphate (ACP), alkaline phosphatase (AKP) activities, total haemocyte counts (THC), and Crustin expression level decreased significantly, superoxide dismutase (SOD), catalase (CAT) activities, total antioxidant capacity (T-AOC), and GPX expression level also decreased significantly. Hematoxylin & eosin (H&E) observation showed that with increasing abamectin concentration, hepatopancreas were damaged, especially membrane structure. Through TUNEL observation and apoptosis-related genes (PcCTSL, Bcl-2, Bax, BI-1, PcCytc, caspase-3) expression levels, with increasing abamectin concentration, apoptosis rate increased significantly. Results of this study indicated that abamectin caused oxidative damage to P. clarkii, resulting in damage to defense system, suppression of nonspecific immunity and antioxidation, and promotion of apoptosis. It provided theoretical basis for healthy P. clarkii culture, and for further study on defense mechanism of aquatic animals to pesticides.


Assuntos
Antioxidantes , Praguicidas , Animais , Antioxidantes/metabolismo , Astacoidea , Praguicidas/metabolismo , Praguicidas/farmacologia , Apoptose
7.
Aquat Toxicol ; 261: 106631, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37422926

RESUMO

As an important trace element and the accessory factor of many enzymatic processes, heavy metal copper is essential to aquatic animals. The toxic mechanism of copper on gill function of M. nipponense was clarified for the first time in terms of histopathological analysis, physiology, biochemistry and the expression of important genes. The results obtained by present in present research showed that heavy metal copper could affect normal respiratory and metabolic activities in M. nipponense. Copper stress could cause damage to the mitochondrial membrane of gill cells in M. nipponense, and the activity of mitochondrial respiratory chain complex could be inhibited by copper. Copper could affect normal electron transport and mitochondrial oxidative phosphorylation, resulting in the inhibition of energy production. High concentrations of copper could disrupt intracellular ion balance and induce cytotoxicity. The oxidative stress could be induced by copper, leading to excessive ROS. Copper could reduce the mitochondrial membrane potential, lead to the leakage of apoptotic factors, and induce apoptosis. Copper could damage structure of gill, affect normal respiration of gill. This study provided fundamental data for exploring impacts of copper on gill function in aquatic organisms and potential mechanisms of copper toxicity.


Assuntos
Palaemonidae , Poluentes Químicos da Água , Animais , Cobre/toxicidade , Cobre/metabolismo , Palaemonidae/genética , Brânquias/metabolismo , Poluentes Químicos da Água/toxicidade , Estresse Oxidativo
8.
Artigo em Inglês | MEDLINE | ID: mdl-37354751

RESUMO

As an important aquaculture fish in the Heilongjiang River Basin, Pseudobagrus ussuriensis has high economic value, and all-male culture is beneficial to the economic development of this fish. In this study, the transcriptomes of gonads in males and females were analyzed, and some genes related to gonad development were found. A total of 82,931 unigenes were found (average length 1504 bp, N50 1829 bp). In addition, 4689 differentially expressed genes (DEGs; including 1424 genes upregulated and 3265 genes downregulated in males) were identified. Some genes associated with testis development (such as Dmrt1 and Ropn1l) were significantly upregulated in males, while genes related to ovary development (such as Wnt2, PLC, Cyp19a, ZP3) were significantly downregulated in males, demonstrating that these genes have a crucial influence on gonad development in P. ussuriensis. Some signaling pathways related to gonad development were found, such as the Wnt pathway and oocyte meiosis. The results of RNA-seq obtained in this study provide theoretical data for elucidating the potential mechanism of gonad development of P. ussuriensis and reliable genomic data for the establishment of mono-sex breeding of P. ussuriensis.


Assuntos
Peixes-Gato , Transcriptoma , Feminino , Masculino , Animais , Peixes-Gato/genética , Gônadas/metabolismo , Perfilação da Expressão Gênica , RNA-Seq
9.
Pestic Biochem Physiol ; 193: 105446, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37248015

RESUMO

The use of herbicides is believed to have an impact on the metabolism, physiology and biochemistry of fish. In this study, we studied the effects of metamifop on the production and metabolism of Monopterus. albus living in the water. According to the semi-lethal concentration of metamifop for 96 h, four MET concentration groups (0.2-, 0.4-, 0.6- and 0.8 mg L-1) were set up for 96 h exposure test. The ammonia discharge rate decreased, hemolymph ammonia content increased significantly, and hemolymph urea nitrogen content decreased at all time periods of metamifop exposure. In liver, the protein content decreased, the neutral protease content increased significantly (p < 0.01), amino acid content increased, and ATP content increased significantly (p < 0.01). In brain, the protein content increased, the activity of acid protease, neutral protease and alkaline protease all decreased, amino acid content decreased significantly (p < 0.01), and the content of ATP decreased. Glutamic-pyruvic transaminase (GPT) activity did not change in liver but decreased in brain. Glutamine synthetase (GS) activity decreased in liver and increased in brain. Glutaminase (GLS) activity decreased in liver and increased in brain. In conclusion, the liver and brain tissues of M. albus react differently to MET exposure. The liver mainly synthesizes energy through hydrolyzed protein, while the brain mainly synthesizes protein. Amino acids produced by protein hydrolysis cannot be converted to alanine for storage, and the degraded amino acids lead to the elevation of endogenous ammonia. MET inhibits the removal of ammonia from M. albus. Only liver tissue can detoxify the eel by converting ammonia into glutamine. Brain should have to tolerate high levels of endogenous ammonia.


Assuntos
Amônia , Smegmamorpha , Animais , Amônia/metabolismo , Aminoácidos/metabolismo , Glutamina/metabolismo , Fígado/metabolismo , Smegmamorpha/metabolismo , Trifosfato de Adenosina/metabolismo , Glutamato-Amônia Ligase/metabolismo , Ureia/metabolismo
10.
J Colloid Interface Sci ; 644: 230-237, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37119640

RESUMO

In-situ preparation of polymer electrolytes (PEs) can enhance electrolyte/electrode interface contact and accommodate the current large-scale production line of lithium-ion batteries (LIBs). However, reactive initiators of in-situ PEs may lead to low capacity, increased impedance and poor cycling performance. Flammable and volatile monomers and plasticizers of in-situ PEs are potential safety risks for the batteries. Herein, we adopt lithium difluoro(oxalate)borate (LiDFOB)-initiated in-situ polymerization of solid-state non-volatile monomer 1,3,5-trioxane (TXE) to fabricate PEs (In-situ PTXE). Fluoroethylene carbonate (FEC) and methyl 2,2,2-trifluoroethyl carbonate (FEMC) with good fire retardance, high flash point, wide electrochemical window and high dielectric constant were introduced as plasticizers to improve ionic conductivity and flame retardant property of In-situ PTXE. Compared with previously reported in-situ PEs, In-situ PTXE exhibits distinct merits, including free of initiators, non-volatile precursors, high ionic conductivity of 3.76 × 10-3 S cm-1, high lithium-ion transference number of 0.76, wide electrochemical stability window (ESW) of 6.06 V, excellent electrolyte/electrode interface stability and effectively inhibition of Li dendrite growth on the lithium metal anode. The fabricated LiFePO4 (LFP)/Li batteries with In-situ PTXE achieve significantly boosted cycle stability (capacity retention rate of 90.4% after 560 cycles) and outstanding rate capability (discharge capacity of 111.7 mAh g-1 at 3C rate).

11.
Ultrason Sonochem ; 95: 106359, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36907100

RESUMO

In the scale-up fabrication process for electroformed Ni-MoS2/WS2 composite moulds, the formulation of nanosheets is critical, since the size, charge, and their distribution can largely affect the hardness, surface morphology and tribological properties of the moulds. Additionally, the long-term dispersion of hydrophobic MoS2/WS2 nanosheets in a nickel sulphamate solution is problematic. In this work, we studied the effect of ultrasonic power, processing time, surfactant types and concentrations on the properties of nanosheets to elaborate their dispersion mechanism and control their size and surface charge in divalent nickel electrolyte. The formulation of MoS2/WS2 nanosheets was optimized for effective electrodeposition along with nickel ions. A novel strategy of intermittent ultrasonication in the dual bath was proposed to resolve the problem of long-term dispersion, overheating, and deterioration of 2D material deposition under direct ultrasonication. Such strategy was then validated by electroforming 4-inch wafer-scale Ni-MoS2/WS2 nanocomposite moulds. The results indicated that the 2D materials were successfully co-deposited into composite moulds without any defects, along with the mould microhardness increasing by ∼2.8 times, the coefficient of friction reducing by two times against polymer materials, and the tool life increasing up to 8 times. This novel strategy will contribute to the industrial manufacturing of 2D material nanocomposites under ultrasonication process.

12.
Front Physiol ; 14: 1088880, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36744025

RESUMO

Metamifop (MET) is a widely used herbicide. It is likely for it to enter water environment when utilized, thus potential impacts may be produced on aquatic animals. Little information is available about its effects on the endocrine system of fish to date. In the current study, female rice field eels (Monopterus albus) were exposed to different MET concentrations (0, 0.2, 0.4, 0.6, 0.8 mg L -1) for 96 h to examine the effect of MET on the hypothalamic-pituitary-gonadal (HPG) axis and sexual reversal. The results showed that high concentrations of MET exposure increased vitellogenin (VTG) levels in liver and plasma, but plasma sex hormone levels were not affected by MET exposure. MET exposure increased the expression of CYP19A1b and CYP17 that regulate sex hormone production in the brain, but the expression of genes (CYP19A1a, CYP17, FSHR, LHCGR, hsd11b2, 3ß-HSD) associated with sex hormone secretion in the ovary and the estrogen receptor genes (esr1, esr2a, esr2b) in the liver were all suppressed. In addition, the expression of sex-related gene (Dmrt1) was suppressed. This study revealed for the first time that MET has estrogen-like effects and has a strong interference with the expression of HPG axis genes. MET did not show the ability to promote the sexual reversal in M. albus, on the contrary, the genes expression showed that the occurrence of male pathway was inhibited.

13.
ACS Omega ; 7(23): 20104-20117, 2022 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-35721891

RESUMO

A hydrophobic surface modification followed by solvent vapor-assisted thermal bonding was developed for the fabrication of cyclic olefin copolymer (COC) microfluidic chips. The modifier species 1H,1H,2H,2H-perfluorooctyl trichlorosilane (FOTS) was used to achieve the entrapment functionalization on the COC surface, and a hydrophobic surface was developed through the formation of a Si-O-Si crosslink network. The COC surface coated with 40 vol % cyclohexane, 59 vol % acetone, and 1 vol % FOTS by ultrasonic spray 10 and 20 times maintained its hydrophobicity with the water contact angle increasing from ∼86 to ∼115° after storage for 3 weeks. The solvent vapor-assisted thermal bonding was optimized to achieve high bond strength and good channel integrity. The results revealed that the COC chips exposed to 60 vol % cyclohexane and 40 vol % acetone for 120 s have the highest bond strength, with a burst pressure of ∼17 bar, which is sufficient for microfluidics applications such as droplet generation. After bonding, the channel maintained its integrity without any channel collapse. The hydrophobicity was also maintained, proved by the water contact angle of ∼115° on the bonded film, as well as the curved shape of water flow in the chip channel by capillary test. The combined hydrophobic treatment and solvent bonding process show significant benefits for scale-up production compared to conventional hydrophilic treatment for bonding and hydrophobic treatment using surface grafting or chemical vapor deposition since it does not require nasty chemistry, long-term treatment, vacuum chamber, and can be integrated into production line easily. Such a process can also be extended to permanent hydrophilic treatment combined with the bonding process and will lay a foundation for low-cost mass production of plastic microfluidic cartridges.

14.
Ecotoxicol Environ Saf ; 236: 113465, 2022 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-35364505

RESUMO

The copper, as heavy metal has important impacts on the antioxidant and immune defense systems in aquatic organisms, and the toxic effects of copper can be accumulated and magnified with the food chain, thus posing a threat to food safety as well as ecosystems. This study explored the response of the antioxidant system and non-specific immunity in M. nipponense to copper stress. Low concentration of copper (0.05, 0.1 mg L-1) had positive effects on the non-specific immunity in M. nipponense, while the non-specific immunity in M. nipponense could be affect negatively or even be inhibited by high copper concentration (0.15 mg L-1). Even low concentrations of copper could cause oxidative stress, and high copper concentration (0.15 mg L-1) could induce oxidative damage and even apoptosis, and thus causing damage to the antioxidant defense system in M. nipponense. Low concentration of copper could affect the gill and hepatopancreas structure in M. nipponense, but high level oxidative stress caused by high copper concentration could cause oxidative damage to these tissue, resulting in the destruction of gill and hepatopancreas. This study provides the safety concentration for using copper-containing fish drugs in the actual culture of M. nipponense and provides basic data for the toxicity mechanism of copper to M. nipponense.


Assuntos
Palaemonidae , Animais , Antioxidantes/farmacologia , Proteínas de Artrópodes/farmacologia , Cobre/toxicidade , Ecossistema , Imunidade Inata
15.
Ecotoxicol Environ Saf ; 224: 112651, 2021 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-34419645

RESUMO

As a non-essential and toxic element, cadmium poses an important threat to aquatic organisms and human food safety. In this study, the effects of cadmium on antioxidant and non-specific immunity of Macrobrachium nipponense were studied from the physiological and biochemical indexes, histology and expression of related genes. These results showed that low concentrations (0.01, 0.02 mg/L) of cadmium have a positive effect on the non-specific immunity of M. nipponense, but high concentration (0.04 mg/L) of cadmium could inhibit or even damage the non-specific immunity of M. nipponense. The cadmium could induce oxidative stress in M. nipponense, and M. nipponense actived the antioxidant defense system to deal with oxidative stress, but high concentration (0.04 mg/L) of cadmium could inhibit the antioxidant defense system of M. nipponense, leading to oxidative damage, and may induce apoptosis in severe case. At the same time, the results of histology showed that cadmium can damage the structure of gill and hepatopancreas tissues of M. nipponense. This study provides theoretical data for evaluating the influences of heavy metal cadmium on M. nipponense and the toxic mechanism of heavy metal cadmium.

16.
Ecol Evol ; 9(3): 1523-1531, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30805179

RESUMO

Understanding how patterns of leaf nutrient traits respond to groundwater depth is crucial for modeling the nutrient cycling of desert riparian ecosystems and forecasting the responses of ecosystems to global changes. In this study, we measured leaf nutrients along a transect across a groundwater depth gradient in the downstream Heihe River to explore the response of leaf nutrient traits to groundwater depth and soil properties. We found that leaf nutrient traits of dominant species showed different responses to groundwater depth gradient. Leaf C, leaf N, leaf P, and leaf K decreased significantly with groundwater depth, whereas patterns of leaf C/N and leaf N/P followed quadratic relationships with groundwater depth. Meanwhile, leaf C/P did not vary significantly along the groundwater depth gradient. Variations in leaf nutrient traits were associated with soil properties (e.g., soil bulk density, soil pH). Groundwater depth and soil pH jointly regulated the variation of leaf nutrient traits; however, groundwater depth explained the variation of leaf nutrient traits better than did soil pH. At the local scale in the typical desert riparian ecosystem, the dominant species was characterized by low leaf C, leaf N, and leaf P, but high leaf N/P and leaf C/P, indicating that desert riparian plants might be more limited by P than N in the growing season. Our observations will help to reveal specific adaptation patterns in relation to the groundwater depth gradient for dominant desert riparian species, provide insights into adaptive trends of leaf nutrient traits, and add information relevant to understanding the adaptive strategies of desert riparian forest vegetation to moisture gradients.

17.
Artigo em Inglês | MEDLINE | ID: mdl-29320458

RESUMO

Precipitation is a key environmental factor determining plant community structure and function. Knowledge of how community characteristics and leaf stoichiometric traits respond to variation in precipitation is crucial for assessing the effects of global changes on terrestrial ecosystems. In this study, we measured community characteristics, leaf stoichiometric traits, and soil properties along a precipitation gradient (35-209 mm) in a desert ecosystem of Northwest China to explore the drivers of these factors. With increasing precipitation, species richness, aboveground biomass, community coverage, foliage projective cover (FPC), and leaf area index (LAI) all significantly increased, while community height decreased. The hyperarid desert plants were characterized by lower leaf carbon (C) and nitrogen/phosphorus (N/P) levels, and stable N and P, and these parameters did not change significantly with precipitation. The growth of desert plants was limited more by N than P. Soil properties, rather than precipitation, were the main drivers of desert plant leaf stoichiometric traits, whereas precipitation made the biggest contribution to vegetation structure and function. These results test the importance of precipitation in regulating plant community structure and composition together with soil properties, and provide further insights into the adaptive strategy of communities at regional scale in response to global climate change.


Assuntos
Clima Desértico , Ecossistema , Folhas de Planta/química , Chuva , Solo/química , Biomassa , Carbono/análise , China , Mudança Climática , Nitrogênio/análise , Fósforo/análise , Plantas
18.
Ecol Evol ; 7(14): 5482-5492, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28770084

RESUMO

Vegetation patterns and spatial organization are influenced by the changing environmental conditions and human activities. However, the effect of environment on vegetation at different vegetation classification levels has been unclear. We conducted an analysis to explore the relationship between environment and vegetation in the land use/land cover (LULC), vegetation group, vegetation type, and formation and subformation levels using redundancy analysis with seven landscape metrics and 33 environmental factors in the upper reaches of the Heihe River basin in an arid area of China to clarify this uncertainty. Atmospheric counter radiation was the most important factor at the four levels. The effect of soil was the second determinant factor at three levels (except in vegetation formation and subformation level). The number of variables whose relationship to vegetation reached significant levels varied from 26 to 28, and 20 variables were the same at all four levels. The factors affecting vegetation were basically the same at vegetation group level and vegetation-type level. It was sufficient to analyze the relationship between environmental and vegetation patterns only in LULC, vegetation group and vegetation formation and subformation level in mountainous regions; different factors should be considered at different vegetation levels.

19.
Chin J Integr Med ; 23(10): 733-739, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27796823

RESUMO

OBJECTIVE: To determine whether additional Chinese medicine (CM) could prolong survival and improve the quality of life (QOL) in patients with advanced non-small cell lung cancer (NSCLC) compared with Western medicine (WM) alone. METHODS: This was a multicenter, prospective cohort study. A total of 474 hospitalized patients with stage III-IV NSCLC were recruited and divided into 2 groups. Patients in the WM group received radiotherapy, chemotherapy, and optimal supportive therapy according to the National Comprehensive Cancer Network (NCCN) guidelines. In the integrative medicine (IM) group, individualized CM (Chinese patent medicines and injections) and WM were administered. The primary end point was overall survival, and the secondary end points were time to disease progression, adverse events, and QOL. Follow-up clinical examinations and chest radiography were performed every 2 months. RESULTS: The median survival was 16.60 months in the IM group and 13.13 months in the WM group (P<0.01). The incidences of loss of appetite, nausea, and vomiting in the IM group were significantly lower than those in the WM group (P<0.05). The QOL based on Functional Assessment of Cancer Therapy-Lung in the IM group was markedly higher than that in the WM group at the fourth course (P<0.05). CONCLUSIONS: Additional CM may prolong survival and improve the QOL patients with NSCLC. The adverse effects of radio- and chemotherapy may be attenuated as CM is used in combination with conventional treatments.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/patologia , Medicamentos de Ervas Chinesas/uso terapêutico , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Medicamentos de Ervas Chinesas/efeitos adversos , Humanos , Medicina Integrativa , Pessoa de Meia-Idade , Análise Multivariada , Estadiamento de Neoplasias , Modelos de Riscos Proporcionais , Estudos Prospectivos , Qualidade de Vida , Análise de Sobrevida , Resultado do Tratamento
20.
Sci Total Environ ; 572: 119-128, 2016 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-27494658

RESUMO

Vegetation phenology is a sensitive indicator of ecosystem response to climate change, and plays an important role in the terrestrial biosphere. Improving our understanding of alpine vegetation phenology dynamics and the correlation with climate and grazing is crucial for high mountains in arid areas subject to climatic warming. Using a time series of SPOT Normalized Difference Vegetation Index (NDVI) data from 1998 to 2013, the start of the growing season (SOS), end of the growing season (EOS), growing season length (GSL), and maximum NDVI (MNDVI) were extracted using a threshold-based method for six vegetation groups in the Heihe River headwaters. Spatial and temporal patterns of SOS, EOS, GSL, MNDVI, and correlations with climatic factors and livestock production were analyzed. The MNDVI increased significantly in 58% of the study region, whereas SOS, EOS, and GSL changed significantly in <5% of the region. The MNDVI in five vegetation groups increased significantly by a range from 0.045 to 0.075. No significant correlation between SOS and EOS was observed in any vegetation group. The SOS and GSL were highly correlated with temperature in May and April-May, whereas MNDVI was correlated with temperature in August and July-August. The EOS of different vegetation groups was correlated with different climatic variables. Maximum and minimum temperature, accumulated temperature, and effective accumulated temperature showed stronger correlations with phenological metrics compared with those of mean temperature, and should receive greater attention in phenology modeling in the future. Meat and milk production were significantly correlated with the MNDVI of scrub, steppe, and meadow. Although the MNDVI increased in recent years, ongoing monitoring for rangeland degradation is recommended.

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