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1.
Circ Res ; 134(5): 505-525, 2024 03.
Artículo en Inglés | MEDLINE | ID: mdl-38422177

RESUMEN

BACKGROUND: Chronic overconsumption of lipids followed by their excessive accumulation in the heart leads to cardiomyopathy. The cause of lipid-induced cardiomyopathy involves a pivotal role for the proton-pump vacuolar-type H+-ATPase (v-ATPase), which acidifies endosomes, and for lipid-transporter CD36, which is stored in acidified endosomes. During lipid overexposure, an increased influx of lipids into cardiomyocytes is sensed by v-ATPase, which then disassembles, causing endosomal de-acidification and expulsion of stored CD36 from the endosomes toward the sarcolemma. Once at the sarcolemma, CD36 not only increases lipid uptake but also interacts with inflammatory receptor TLR4 (Toll-like receptor 4), together resulting in lipid-induced insulin resistance, inflammation, fibrosis, and cardiac dysfunction. Strategies inducing v-ATPase reassembly, that is, to achieve CD36 reinternalization, may correct these maladaptive alterations. For this, we used NAD+ (nicotinamide adenine dinucleotide)-precursor nicotinamide mononucleotide (NMN), inducing v-ATPase reassembly by stimulating glycolytic enzymes to bind to v-ATPase. METHODS: Rats/mice on cardiomyopathy-inducing high-fat diets were supplemented with NMN and for comparison with a cocktail of lysine/leucine/arginine (mTORC1 [mechanistic target of rapamycin complex 1]-mediated v-ATPase reassembly). We used the following methods: RNA sequencing, mRNA/protein expression analysis, immunofluorescence microscopy, (co)immunoprecipitation/proximity ligation assay (v-ATPase assembly), myocellular uptake of [3H]chloroquine (endosomal pH), and [14C]palmitate, targeted lipidomics, and echocardiography. To confirm the involvement of v-ATPase in the beneficial effects of both supplementations, mTORC1/v-ATPase inhibitors (rapamycin/bafilomycin A1) were administered. Additionally, 2 heart-specific v-ATPase-knockout mouse models (subunits V1G1/V0d2) were subjected to these measurements. Mechanisms were confirmed in pharmacologically/genetically manipulated cardiomyocyte models of lipid overload. RESULTS: NMN successfully preserved endosomal acidification during myocardial lipid overload by maintaining v-ATPase activity and subsequently prevented CD36-mediated lipid accumulation, CD36-TLR4 interaction toward inflammation, fibrosis, cardiac dysfunction, and whole-body insulin resistance. Lipidomics revealed C18:1-enriched diacylglycerols as lipid class prominently increased by high-fat diet and subsequently reversed/preserved by lysine/leucine/arginine/NMN treatment. Studies with mTORC1/v-ATPase inhibitors and heart-specific v-ATPase-knockout mice further confirmed the pivotal roles of v-ATPase in these beneficial actions. CONCLUSION: NMN preserves heart function during lipid overload by preventing v-ATPase disassembly.


Asunto(s)
Cardiomiopatías , Resistencia a la Insulina , Animales , Ratones , Ratas , Adenosina Trifosfatasas , Arginina , Cardiomiopatías/inducido químicamente , Cardiomiopatías/prevención & control , Antígenos CD36/genética , Fibrosis , Inflamación , Leucina , Lípidos , Lisina , Diana Mecanicista del Complejo 1 de la Rapamicina , Miocitos Cardíacos , Mononucleótido de Nicotinamida , Receptor Toll-Like 4/genética
2.
J Nanobiotechnology ; 22(1): 299, 2024 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-38812031

RESUMEN

BACKGROUND: Discrepancies in the utilization of reactive oxygen species (ROS) between cancer cells and their normal counterparts constitute a pivotal juncture for the precise treatment of cancer, delineating a noteworthy trajectory in the field of targeted therapies. This phenomenon is particularly conspicuous in the domain of nano-drug precision treatment. Despite substantial strides in employing nanoparticles to disrupt ROS for cancer therapy, current strategies continue to grapple with challenges pertaining to efficacy and specificity. One of the primary hurdles lies in the elevated levels of intracellular glutathione (GSH). Presently, predominant methods to mitigate intracellular GSH involve inhibiting its synthesis or promoting GSH efflux. However, a conspicuous gap remains in the absence of a strategy capable of directly and efficiently clearing GSH. METHODS: We initially elucidated the chemical mechanism underpinning oridonin, a diminutive pharmacological agent demonstrated to perturb reactive oxygen species, through its covalent interaction with glutathione. Subsequently, we employed the incorporation of maleimide-liposomes, renowned for their capacity to disrupt the ROS delivery system, to ameliorate the drug's water solubility and pharmacokinetics, thereby enhancing its ROS-disruptive efficacy. In a pursuit to further refine the targeting for acute myeloid leukemia (AML), we harnessed the maleic imide and thiol reaction mechanism, facilitating the coupling of Toll-like receptor 2 (TLR2) peptides to the liposomes' surface via maleic imide. This strategic approach offers a novel method for the precise removal of GSH, and its enhancement endeavors are directed towards fortifying the precision and efficacy of the drug's impact on AML targets. RESULTS: We demonstrated that this peptide-liposome-small molecule machinery targets AML and consequently induces cell apoptosis both in vitro and in vivo through three disparate mechanisms: (I) Oridonin, as a Michael acceptor molecule, inhibits GSH function through covalent bonding, triggering an initial imbalance of oxidative stress. (II) Maleimide further induces GSH exhaustion, aggravating redox imbalance as a complementary augment with oridonin. (III) Peptide targets TLR2, enhances the directivity and enrichment of oridonin within AML cells. CONCLUSION: The rationally designed nanocomplex provides a ROS drug enhancement and targeted delivery platform, representing a potential solution by disrupting redox balance for AML therapy.


Asunto(s)
Diterpenos de Tipo Kaurano , Glutatión , Leucemia Mieloide Aguda , Liposomas , Especies Reactivas de Oxígeno , Diterpenos de Tipo Kaurano/química , Diterpenos de Tipo Kaurano/farmacología , Glutatión/metabolismo , Glutatión/química , Liposomas/química , Leucemia Mieloide Aguda/tratamiento farmacológico , Leucemia Mieloide Aguda/metabolismo , Humanos , Especies Reactivas de Oxígeno/metabolismo , Animales , Ratones , Línea Celular Tumoral , Receptor Toll-Like 2/metabolismo , Antineoplásicos/farmacología , Antineoplásicos/química , Apoptosis/efectos de los fármacos
3.
Biochem Biophys Res Commun ; 684: 149125, 2023 12 03.
Artículo en Inglés | MEDLINE | ID: mdl-37897912

RESUMEN

Ferroptosis, an emerging form of programmed cell death, has garnered substantial attention as a potential target for cancer therapy. However, despite the potential promise, no ferroptosis-related therapies have progressed to clinical trials. Identifying disease types sensitive to ferroptosis and developing specific ferroptosis-targeting drugs are critical focal points in the field of ferroptosis-based treatment. In this study, we conducted a comprehensive database analysis and presented compelling evidence indicating a high expression of GPX4 in patients with acute lymphoblastic leukemia (ALL), significantly correlating with poor prognosis. Notably, elevated GPX4 expression is closely associated with ALL relapse, a major challenge in the treatment of this disease. Building upon these findings, we devised a novel peptide-based Proteolysis Targeting Chimeras (PROTAC) drug targeting GPX4 through computer-aided design. In contrast to existing drugs that target the conjugative enzyme active site, our design focused on a peptide drug targeting the non-active site of GPX4. Furthermore, we strategically selected MDM2, an E3 ligase highly expressed in ALL, for the PROTAC drug design. This deliberate choice amplifies the drug's effect on cancer cells while minimizing its impact on normal cells, achieving desirable selectivity for cancer cells. Leveraging nanogold delivery, we successfully facilitated intracellular action of the GPX4-targeting peptide PROTAC drug, denoted as Au-PGPD (peptide GPX4 PROTAC drug). Au-PGPD effectively induced GPX4 degradation and inhibited ALL cell proliferation. Remarkably, Au-PGPD exhibited significantly less efficacy on normal cells, underscoring the selectivity and safety of our design.


Asunto(s)
Ferroptosis , Leucemia-Linfoma Linfoblástico de Células Precursoras , Humanos , Proteolisis , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Péptidos , Apoptosis , Quimera Dirigida a la Proteólisis , Proteínas Proto-Oncogénicas c-mdm2
4.
Oral Dis ; 29(4): 1668-1679, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-35255186

RESUMEN

Long non-coding RNAs (lncRNAs) are thought to play important roles in non-syndromic orofacial clefts (NSOFC). Clinical diagnosis was categorized as either non-syndromic cleft lip with or without cleft palate (NSCL/P), or non-syndromic cleft palate only (NSCPO). Tissues excised from the trimmed wound edge were reserved as experimental samples; adjacent normal control was used as a positive control, and tissue from healthy individuals was used as a blank control. Target lncRNAs in the collected tissues were identified using microarrays and quantitative reverse transcription PCR (RT-qPCR). Immunohistochemical (IHC) staining and RT-qPCR were used to verify the target mRNAs. Pathway, gene ontology (GO) enrichment, and TargetScan predictions were employed to construct competing endogenous RNA networks (ceRNA networks) and explore their potential functions. RNA-Seq revealed 24 upregulated and 43 downregulated lncRNAs; MALAT1 and NEAT1 were screened and validated using RT-qPCR. Common NSOFC risk factors were positively correlated with MALAT1 and NEAT1 expression. Bioinformatics predicted four ceRNA networks; GO enrichment focused on their potential functions. RT-qPCR and IHC data were consistent with respect to expression levels of proteins and the mRNAs that encode them. As MALAT1 and NEAT1 are associated with the severity of NSOFC, they represent potential therapeutic targets and prognostic biomarkers.


Asunto(s)
Labio Leporino , Fisura del Paladar , MicroARNs , ARN Largo no Codificante , Humanos , Labio Leporino/genética , Fisura del Paladar/genética , ARN Largo no Codificante/genética , Factores de Riesgo , MicroARNs/genética
5.
Skin Res Technol ; 29(1): e13269, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36704881

RESUMEN

BACKGROUND: Acne is the eighth-most prevalent inflammatory skin disease with no optimal treatment. Photodynamic therapy (PDT) is an effective treatment for severe acne. AIMS: The effect of PDT on the composition and diversity of skin microflora in severe acne patients was studied. MATERIALS AND METHODS: A total of 18 patients with severe acne and 8 healthy individuals were selected for this study. Patients were treated with 5-aminolevulinic acid-mediated PDT once a week three times in total; the skin microbiome was measured by 16S ribosomal RNA gene sequencing before and after treatment (1 week after each PDT). RESULTS: The microflora composition was different between healthy controls and patients, and between patients before and after treatment. Alpha diversity indices were lower in patients than those in control. There were 15 bacterial genera with high relative abundance that had noticeable changes during treatment. At the genus level,particularly Cutibacterium acnes (C. acnes formerly Propionibacterium acnes), there was no statistically significant difference among different group. The abundances of Staphylococcus epidermidis and Staphylococcus aureus were low. DISCUSSION: The microbial composition is different between severe acne patients acne patients and healthy individuals. The therapeutic efficacy of severe acne treated with PDT is associated with the composition and diversity of skin microbiota. CONCLUSION: The skin microbial composition changes after PDT treatment. PDT is an effective method for the treatment of severe acne.


Asunto(s)
Acné Vulgar , Microbiota , Fotoquimioterapia , Humanos , Acné Vulgar/tratamiento farmacológico , Piel/microbiología , Ácido Aminolevulínico/uso terapéutico , Ácido Aminolevulínico/farmacología , Propionibacterium acnes/genética , Fotoquimioterapia/efectos adversos
6.
Sensors (Basel) ; 23(17)2023 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-37687879

RESUMEN

A fuzzy PI controller was utilized to realize the modal matching between a driving and detecting model. A simulation model was built to study electrostatic decoupling controlling technology. The simulation results show that the modal matching can be gained by the fuzzy PI controller. The frequency difference between the driving mode and the detection mode is less than 1 Hz, and the offset of the input DC is smaller than 0.6 V. The optimal proportionality factor and integral coefficient are 1.5 and 20, respectively. The fuzzy PI controlling technology provides a good way for the parameter optimization to gain modal matching of micro gyro, via which the detecting accuracy and stability can be improved greatly.

7.
Int J Mol Sci ; 25(1)2023 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-38203302

RESUMEN

Delta-like non-canonical Notch ligand 1 (DLK1), which inhibits the differentiation of precursor adipocytes, is a recognized marker gene for precursor adipocytes. Lipids play a crucial role in energy storage and metabolism as a vital determinant of beef quality. In this study, we investigated the mechanism of the DLK1 gene in lipid metabolism by constructing adipose tissue-specific knockout mice. We examined some phenotypic traits, including body weight, liver coefficient, fat index, the content of triglyceride (TG) and cholesterol (CHOL) in abdominal white adipose tissue (WAT) and blood. Subsequently, the fatty acid content and genes related to lipid metabolism expression were detected in DLK1-/- and wild-type mice via GC-MS/MS analysis and quantitative real-time PCR (qRT-PCR), respectively. The results illustrated that DLK1-/- mice exhibited significant abdominal fat deposition compared to wild-type mice. HE staining and immunohistochemistry (IHC) results showed that the white adipocytes of DLK1-/- mice were larger, and the protein expression level of DLK1-/- was significantly lower. Regarding the blood biochemical parameters of female mice, DLK1-/- mice had a strikingly higher triglyceride content (p < 0.001). The fatty acid content in DLK1-/- mice was generally reduced. There was a significant reduction in the expression levels of the majority of genes that play a crucial role in lipid metabolism. This study reveals the molecular regulatory mechanism of fat metabolism in mice and provides a molecular basis and reference for the future application of the DLK1 gene in the breeding of beef cattle with an excellent meat quality traits. It also provides a molecular basis for unravelling the complex and subtle relationship between adipose tissue and health.


Asunto(s)
Metabolismo de los Lípidos , Espectrometría de Masas en Tándem , Femenino , Bovinos , Animales , Ratones , Ratones Noqueados , Metabolismo de los Lípidos/genética , Ligandos , Tejido Adiposo , Adipocitos Blancos , Ácidos Grasos , Triglicéridos
8.
Environ Monit Assess ; 195(4): 455, 2023 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-36892619

RESUMEN

Inter-basin water transfer (IBWT) projects have been widely constructed to alleviate the pressure on water resources in water shortage basins. However, the ecological effects of IBWT projects have often been ignored. Based on the Soil and Water Assessment Tool (SWAT) model and a constructed total ecosystem services (TES) index, the impacts of IBWT projects on recipient basin ecosystem services were analyzed in this study. The results showed that the TES index was relatively stable from 2010 to 2020, but in the wet season it was 1.36 times that of the other months with high water yield and nutrient loads. Spatially, areas with high index values were mainly distributed in the sub-basins around the reservoirs. The IBWT projects had positive impacts on ecosystem services, and the TES index with IBWT projects was 5.98% higher than that without projects. Water yield and total nitrogen were the two most affected indexes, with increased of 5.65% and 5.41%, respectively, under the impacts of IBWT projects. Seasonally, the change rates of the TES index were less than 3% while the change rates of water yield and nitrogen load peaked at 8.23% and 53.42%, respectively, in March, owing to the large amount of water released from the reservoirs. Areas affected by the three evaluated IBWT projects accounted for 61%, 18%, and 11% of the watershed, respectively. Under the impact of each project, the TES index generally increased, whereas the impact decreased as the distance from the inflow location increased. Intense changes in ecosystem services occurred in sub-basin 23, the sub-basin closest to an IBWT project, with water yield, water flow, and local climate regulation increasing the largest.


Asunto(s)
Ecosistema , Ríos , Suelo , Agua , Monitoreo del Ambiente , Nitrógeno/análisis
9.
Biochem Biophys Res Commun ; 629: 152-158, 2022 11 12.
Artículo en Inglés | MEDLINE | ID: mdl-36122452

RESUMEN

Acute myeloid leukemia (AML) is the most common blood cancer in adults. Patients' 5-year overall survival is less than 30% thus having a poor prognosis. To date, the development of novel target therapies is still necessary to ameliorate patients' survival. Antibody-drug conjugates (ADCs) represent a promising class of drugs for the treatment of AML. CD33 is highly expressed on AML cells, and the FDA-approved CD33-targeted ADC drug-gemtuzumab ozogamicin (GO) has proved the feasibility of CD33-targeted ADC drug design. In this study, we constructed a novel CD33-targeted ADC drug composed of a humanized anti-CD33 antibody and oridonin as a payload with a cleaved chemical linker. Oridonin is a natural product that has great cancer therapy potential while its poor bioavailability and targeting ability limited its clinical use. Herein, we demonstrated that antiCD33-oridonin specifically delivered oridonin in AML cells improved AML cells killing ability of oridonin. Meanwhile, it did not show any non-specific toxicity on CD33 negative cells. In summary, we developed a novel AML targeting ADC with clinical application potential, and therefore provided a new solution for the druggability improvement of oridonin.


Asunto(s)
Productos Biológicos , Inmunoconjugados , Leucemia Mieloide Aguda , Adulto , Aminoglicósidos , Anticuerpos Monoclonales Humanizados/uso terapéutico , Productos Biológicos/uso terapéutico , Diterpenos de Tipo Kaurano , Gemtuzumab , Humanos , Inmunoconjugados/uso terapéutico , Leucemia Mieloide Aguda/tratamiento farmacológico
10.
Neoplasma ; 69(5): 1029-1040, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35652621

RESUMEN

The study was performed to ascertain the mechanism of sodium butyrate (NaB) mediating the proliferative and invasive properties of oral squamous cell carcinoma (OSCC) cells. The cell proliferative, migrating, and invasive potentials were detected by CCK-8, colony formation, EdU, and Transwell assays. The expression of proliferation- and invasion-related proteins, HDAC1, and HSPB7 in OSCC cells were evaluated by western blot. Immunofluorescence was also performed to evaluate the HDAC1 expression. The enrichment of histone deacetylase HDAC1 in the promoter region of HSPB7 was assessed by the ChIP assay. In vivo growth of OSCC cells was measured by tumorigenesis in nude mice (n=18). The t-test was employed for comparisons of data between the two groups. One-way ANOVA was utilized for comparisons of data among multiple groups, and repeated-measures ANOVA for comparisons of data at different time points among groups, followed by Bonferroni post-hoc test. The data showed that HDAC1 expression was highly upregulated in OSCC cells compared to human normal oral keratinocytes (HNOKs) (p<0.0001), and NaB diminished the HDAC1 expression in OSCC cells. NaB restricted OSCC cell proliferative, migrating, and invasive capabilities by downregulating HDAC1. HSPB7 expression was downregulated in OSCC cells versus HNOKs (p<0.0001). HDAC1 inversely orchestrated the HSPB7 expression in OSCC cells through histone deacetylation modification, and NaB augmented the HSPB7 expression by inhibiting HDAC1. Moreover, NaB inhibited OSCC cell growth in vivo by elevating HSPB7 levels through the HDAC1 repression. In conclusion, NaB restrained cell proliferation and invasion in OSCC cells via HSPB7 upregulation by decreasing the HDAC1 expression.


Asunto(s)
Carcinoma de Células Escamosas , Neoplasias de Cabeza y Cuello , MicroARNs , Neoplasias de la Boca , Animales , Ácido Butírico/farmacología , Carcinoma de Células Escamosas/genética , Línea Celular Tumoral , Movimiento Celular , Proliferación Celular , Regulación Neoplásica de la Expresión Génica , Proteínas de Choque Térmico HSP27/metabolismo , Histona Desacetilasa 1 , Histona Desacetilasas/metabolismo , Histonas , Humanos , Ratones , Ratones Desnudos , Neoplasias de la Boca/tratamiento farmacológico , Neoplasias de la Boca/genética , Sincalida/metabolismo , Carcinoma de Células Escamosas de Cabeza y Cuello
11.
J Environ Manage ; 305: 114382, 2022 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-34973559

RESUMEN

The spatial distributions, sources, and source-specific risk apportionments of 26 antibiotics (5 categories) in the Fenhe River basin were determined based on sample data. The results showed that antibiotics were widely distributed in the surface water. There were significant differences between the different types of antibiotics, and the highest mean concentration was that of the sulfonamide category (33.74 ng/L), accounting for 36% of the total antibiotic concentration. Spatially, all antibiotics were mainly detected in the middle and downstream areas. The ecological risk assessment results showed that the significant risk rate of antibiotics accounted for 70% and was mainly distributed in the downstream area; however, the risks differed between the 5 categories. Quinolone antibiotics exhibited the highest significant risk rate, reaching 100%. The ecological risk associated with sulfamethoxazole was the highest among all detected antibiotics. The following five main factors influenced the antibiotic concentrations: aquaculture, pharmaceutical wastewater, livestock discharges, domestic sewage, and sewage treatment plants. Among these, pharmaceutical wastewater sources contributed the most (35%) to the total antibiotic concentration, and were distributed throughout the river. Although livestock discharges were not the main reason for the high level of ecological risk, these discharges were highest at certain sites in the midstream region. Different pollution sources posed different levels of ecological risk to the Fenhe River basin, the highest of which was pharmaceutical wastewater with a significant risk rate of 58%.


Asunto(s)
Monitoreo del Ambiente , Contaminantes Químicos del Agua , Antibacterianos/análisis , China , Medición de Riesgo , Ríos , Contaminantes Químicos del Agua/análisis
12.
BMC Oral Health ; 22(1): 62, 2022 03 08.
Artículo en Inglés | MEDLINE | ID: mdl-35260122

RESUMEN

BACKGROUND: The application of calcium phosphate (CaP)-based bone substitutes plays an important role in periodontal regeneration, implant dentistry and alveolar bone reconstruction. The incorporation of strontium (Sr) into CaP-based bone substitutes appears to improve their biological properties, but the reported in vivo bone repair performance is inconsistent among studies. Herein, we conducted a systematic review and meta-analysis to investigate the in vivo performance of Sr-doped materials. METHODS: We searched PubMed, EMBASE (via OVIDSP), and reference lists to identify relevant animal studies. The search, study selection, and data extraction were performed independently by two investigators. Meta-analyses and sub-group analyses were conducted using Revman version 5.4.1. The heterogeneity between studies were assessed by I2. Publication bias was investigated through a funnel plot. RESULTS: Thirty-five studies were finally enrolled, of which 16 articles that reported on new bone formation (NBF) were included in the meta-analysis, covering 31 comparisons and 445 defects. The overall effect for NBF was 2.25 (95% CI 1.61-2.90, p < 0.00001, I2 = 80%). Eight comparisons from 6 studies reported the outcomes of bone volume/tissue volume (BV/TV), with an overall effect of 1.42 (95% CI 0.65-2.18, p = 0.0003, I2 = 75%). Fourteen comparisons reported on the material remaining (RM), with the overall effect being -2.26 (95% CI - 4.02 to - 0.50, p = 0.0009, I2 = 86%). CONCLUSIONS: Our study revealed that Sr-doped calcium phosphate bone substitutes improved in vivo performance of bone repair. However, more studies are also recommended to further verify this conclusion.


Asunto(s)
Sustitutos de Huesos , Fosfatos de Calcio , Animales , Sustitutos de Huesos/uso terapéutico , Huesos , Fosfatos de Calcio/uso terapéutico , Humanos , Estroncio/uso terapéutico
13.
Environ Monit Assess ; 194(2): 108, 2022 Jan 19.
Artículo en Inglés | MEDLINE | ID: mdl-35048218

RESUMEN

Land-use changes have a significant impact on the hydrological cycle and non-point source (NPS) pollution discharge and transport. Thus, using dynamic land-use inputs in the simulation models is important. However, there is currently no clear standard for which situation the land-use data should be updated in the models. In this study, we quantified the impacts of land-use change on hydrological and NPS pollution simulation outputs, and analyzed the thresholds for land-use change level and time nodes. The results indicated that the error caused by land-use change had a linear relationship with the land-use change level. The total nitrogen (TN) output error was the most sensitive to land-use change, with a gradient of 0.73. The impact of land-use change on the model outputs was different at different temporal scales. Flow and TN had the highest output errors at a daily scale, while sediment had the highest output error at an annual scale. The threshold analysis results revealed that the land-use change thresholds for the flow, sediment, and TN simulations were 40%, 30%, and 10%, respectively. When the land-use change level exceeded the threshold, the model simulation error increased dramatically. The land-use change time node would also affect the simulation performance, especially for TN. This study initially explored the quantified standard for land-use data updates in the SWAT model. The results could be useful for improving the simulation accuracy of the SWAT model and may provide ideas for follow-up studies.


Asunto(s)
Hidrología , Contaminación Difusa , China , Monitoreo del Ambiente , Modelos Teóricos , Nitrógeno/análisis , Ríos , Calidad del Agua
14.
Environ Monit Assess ; 194(6): 434, 2022 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-35575942

RESUMEN

In this study, a framework for ecological risk assessment based on ecosystem service values and risk probability was established. Remote sensing was used to estimate the value of ecosystem services at the regional scale. Considering the natural and anthropogenic factors and using the entropy weight method to assign weights, probability index was constructed. In addition, multiple scenarios based on the ordered weighted averaging (OWA) method were simulated to reduce subjective uncertainty in the assessment. The results showed that the ecosystem service values generated by the gas regulation value accounted for the largest proportion, with a ratio of 46% in the Beijing-Tianjin-Hebei region. From 2005 to 2015, the value of ecosystem services decreased, falling by 2.5 × 107 Yuan. The level of ecological risk was relatively high, with a corresponding area ratio of 32.89%. Spatially, the areas with high risk were concentrated in the southeastern areas, and areas with relatively low risk were distributed in the western and northern areas. This high risk was probably caused by urbanization which was characterized by reduction of farmland and increase in impervious surface. Multi-scenario simulation showed that the areas of unstable ecological risk zones covered 30% and were mainly concentrated in the surroundings of developing cities. In areas of unstable risk distribution, the relationship between development and protection should be considered. This framework increases the reliability and practicability of ecological risk assessment results and has potential application value for regional risk control in the context of urbanization.


Asunto(s)
Simulación por Computador , Conservación de los Recursos Naturales , Ecosistema , Monitoreo del Ambiente , Beijing , China , Ciudades , Monitoreo del Ambiente/métodos , Reproducibilidad de los Resultados , Medición de Riesgo , Urbanización
15.
Environ Sci Technol ; 55(21): 14546-14555, 2021 11 02.
Artículo en Inglés | MEDLINE | ID: mdl-34677952

RESUMEN

Croplands are the largest anthropogenic source of nitrous oxide (N2O), a powerful greenhouse gas that contributes to the growing atmospheric N2O burden. However, few studies provide a comprehensive depiction of future cropland-N2O emissions on a national scale due to a lack of accurate cropland prediction data. Herein, we present a newly developed distributed land-use change prediction model for the high-precision prediction of national-scale land-use change. The high-precision land-use data provide an opportunity to elucidate how the changes in cropland area will affect the magnitude and spatial distribution of N2O emissions from China's croplands during 2020-2070. The results showed a declining trend in China's total cropland-N2O emissions from 0.44 ± 0.03 Tg N/year in 2020 to 0.39 ± 0.07 Tg N/year in 2070, consistent with a cropland area reduction from (1.78 ± 0.02) × 108 ha to (1.40 ± 0.15) × 108 ha. However, approximately 31% of all calculated cities in China would emit more than the present level. Furthermore, different land use and climate change scenarios would have important impacts on cropland-N2O emissions. The Grain for Green Plan implemented in China would effectively control emissions by approximately 12%.


Asunto(s)
Agricultura , Gases de Efecto Invernadero , China , Productos Agrícolas , Gases de Efecto Invernadero/análisis , Óxido Nitroso/análisis , Suelo
16.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 37(1): 75-79, 2020 Jan 10.
Artículo en Zh | MEDLINE | ID: mdl-31922603

RESUMEN

OBJECTIVE: To assess the association of JAG2 gene single nucleotide polymorphisms with the occurrence of nonsyndromic cleft lip with or without cleft palate (NSCLP) among northwest Chinese population. METHODS: A case-control study was carried out on 301 NSCLP patients and 304 healthy controls. An iMLDR(TM) genotyping technique was used to detect three single nucleotide polymorphisms (SNPs) [rs741859 (T/C), rs11621316 (A/G) and rs1057744(C/T)] of the JAG2 gene. Allelic and genotypic frequencies and haplotypic distribution among the two groups were compared. RESULTS: A significant difference was found in the frequency of C and T alleles for rs741859 between the two groups. The CT genotype of rs741859 could significantly reduce the risk for NSCLP to 65% (P< 0.05) and the risk for cleft lip with or without cleft palate (CL/P) to 62% (P< 0.05). rs11621316 and rs1057744 are in the same linkage disequilibrium (LD) region with a high degree of linkage (γ 2> 0.8), whose distribution difference between the two groups was not statistically significant (P> 0.05). CONCLUSION: The CT genotype of the JAG2 gene rs741859 may confer a protective effect for NSCLP among northwest Chinese population.


Asunto(s)
Labio Leporino , Fisura del Paladar , Proteína Jagged-2 , Polimorfismo de Nucleótido Simple , Estudios de Casos y Controles , China , Labio Leporino/genética , Fisura del Paladar/genética , Frecuencia de los Genes , Genotipo , Humanos , Proteína Jagged-2/genética
18.
Macromol Rapid Commun ; 38(5)2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28105792

RESUMEN

Two soluble poly(phenyltriazolylcarboxylate)s (PPTCs) with high molecular weights (M w up to 26 800) are synthesized by the metal-free 1,3-dipolar polycycloadditions of 4,4'-isopropylidenediphenyl diphenylpropiolate (1) and tetraphenylethene-containing diazides (2) in dimethylformamide at 150 °C for 12 h in high yields (up to 93%). The resultant polymers are soluble in common organic solvents and are thermally stable with 5% weight loss temperatures higher than 375 °C. The PPTCs are nonemissive in solutions, but become highly luminescent upon aggregation, showing a phenomenon of aggregation-induced emission. Their aggregates can be used as fluorescent chemosensors for high-sensitivity detection of explosives.


Asunto(s)
Azidas/química , Reacción de Cicloadición , Fenilpropionatos/química , Polímeros/síntesis química , Triazoles/síntesis química , Estructura Molecular , Polímeros/química , Triazoles/química
19.
Water Sci Technol ; 73(4): 924-34, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26901737

RESUMEN

Based on water sample data collected from the Yangtze River Estuary (YRE) during four sampling periods in 2010 and 2011, the total nitrogen (TN) and total phosphorus (TP) content were evaluated using the traditional single-factor evaluation (TSE) and the fuzzy comprehensive evaluation (FCE). Statistical analyses showed that the average TN and TP for the four periods were 2.60 mg/L and 0.11 mg/L, respectively. August 2010 showed the lowest TN (1.57 mg/L), and February 2011 showed the highest TP (0.15 mg/L). The annual spatial distribution results indicated that an area of high TN concentration (TN ≥ 3.0 mg/L) occurred in the adjacent sea and increased on an eastward gradient. An area of high TP concentration (TP ≥0.10 mg/L) occurred in the inner YRE and decreased on an eastward gradient. There were significant differences in the results of TSE and FCE. The TSE results only reflected the TN evaluation results for certain locations of the YRE. The FCE method combined the effects of the TN and TP factors, and the results indicate that the Chinese water quality classification of Class 5 was dominant in the YRE.


Asunto(s)
Nitrógeno/análisis , Fósforo/análisis , Ríos/química , Contaminantes Químicos del Agua/análisis , China , Monitoreo del Ambiente , Estuarios , Calidad del Agua
20.
Water Sci Technol ; 74(5): 1051-9, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27642824

RESUMEN

Soil and water conservation in the Three Gorges Reservoir Area of China is important, and soil erosion is a significant issue. In the present study, spatial Markov chains were applied to explore the impacts of the regional context on soil erosion in the Xiangxi River watershed, and Thematic Mapper remote sensing data from 1999 and 2007 were employed. The results indicated that the observed changes in soil erosion were closely related to the soil erosion levels of the surrounding areas. When neighboring regions were not considered, the probability that moderate erosion transformed into slight and severe erosion was 0.8330 and 0.0049, respectively. However, when neighboring regions that displayed intensive erosion were considered, the probabilities were 0.2454 and 0.7513, respectively. Moreover, the different levels of soil erosion in neighboring regions played different roles in soil erosion. If the erosion levels in the neighboring region were lower, the probability of a high erosion class transferring to a lower level was relatively high. In contrast, if erosion levels in the neighboring region were higher, the probability was lower. The results of the present study provide important information for the planning and implementation of soil conservation measures in the study area.


Asunto(s)
Monitoreo del Ambiente/métodos , Fenómenos Geológicos , Suelo , China , Conservación de los Recursos Naturales/métodos , Cadenas de Markov , Ríos , Abastecimiento de Agua
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