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1.
Se Pu ; 42(5): 474-480, 2024 Apr 08.
Artigo em Chinês | MEDLINE | ID: mdl-38736391

RESUMO

A method was established for the simultaneous detection of 12 prohibited veterinary drugs, including ß2-receptor agonists, nitrofuran metabolites, nitroimidazoles, chlorpromazine, and chloramphenicol, in pig urine. The sample was pretreated by enzymolysis, acid hydrolysis/derivatization, and liquid-liquid extraction combined with solid-phase extraction. Detection was performed using ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Ammonium acetate solution (0.2 mol/L, 4.5 mL) and ß-glucuronidase/aryl sulfatase (40 µL) were added to the sample, which was subsequently enzymolized at 37 ℃ for 2 h. Then, 1.5 mL of 1.0 mol/L hydrochloric acid solution and 100 µL of 0.1 mol/L o-nitrobenzaldehyde solution were added to the sample. The mixture was incubated at 37 ℃ for 16 h, and the analytes were extracted with 8 mL of ethyl acetate by liquid-liquid extraction. The lower aqueous phase obtained after extraction was extracted and purified using a mixed cation-exchange solid-phase extraction column. The extracts were combined, the extraction solution was blow-dried with nitrogen, and the residue was redissolved for determination. The samples were analyzed under multiple-reaction monitoring mode with both positive and negative electrospray ionization, and quantified using an isotope internal standard method. The correlation coefficients (r) of the 12 compounds were >0.99. The limits of detection (LODs) and quantification (LOQs) of chloramphenicol were 0.05 and 0.1 µg/L, respectively, and the LODs and LOQs of the other compounds were 0.25 and 0.5 µg/L, respectively. The mean recoveries and RSDs at 1, 2, and 10 times the LOQ were 83.6%-115.3% and 2.20%-12.34%, respectively. The proposed method has the advantages of high sensitivity, good stability, and accurate quantification; thus, it is suitable for the simultaneous determination of the 12 prohibited veterinary drug residues in pig urine.


Assuntos
Resíduos de Drogas , Espectrometria de Massas em Tandem , Drogas Veterinárias , Animais , Espectrometria de Massas em Tandem/métodos , Suínos , Cromatografia Líquida de Alta Pressão/métodos , Drogas Veterinárias/urina , Drogas Veterinárias/análise , Resíduos de Drogas/análise , Cloranfenicol/urina , Cloranfenicol/análise
2.
Sci Total Environ ; 912: 169284, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38103618

RESUMO

The global emphasis on informatization and low-carbon development is growing. Using staggered Difference-In-Differences (DID) methodology, this research examines the impact of digital infrastructure development on urban carbon dioxide emissions and explores its underlying causal mechanisms. Drawing from a comprehensive 2009-2019 panel dataset of 240 Chinese cities, the study employs the "Broadband China" policy as a reliable proxy for digital infrastructure construction (DIC). The findings indicate that DIC effectively reduces urban carbon dioxide emissions, fostering sustainable low-carbon regional economic development. The results withstand robustness tests, revealing heterogeneous effects, with coastal cities and those with stronger environmental regulations experiencing more significant reductions. The study suggests that upgrading industrial structure and enhancing green innovation capacity are effective methods for DIC to mitigate urban carbon emissions. The paper concludes with policy recommendations, emphasizing leveraging policy dividends, addressing regional disparities, and adopting a multi-path development approach. Providing new insights and empirical data, this research contributes to understanding the relationship between DIC and urban carbon emissions, offering policy guidance for China's carbon reduction efforts and strategic objectives of carbon peaking and neutrality.

3.
Sci Total Environ ; 892: 164592, 2023 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-37302591

RESUMO

To limit the effects of carbon emissions and realize the Sustainable Development Goals (SDGs), countries worldwide seek efficient energy usage, economic sustainability, and natural resource blessing. Studies at the continental level mostly neglected the differences between the continents, while this study explores the long-run effect of natural resource rents, economic development, and energy consumption on carbon emissions and their interactions across the global panel of 159 countries divided into six continents from 2000 to 2019. Recently proposed panel estimators, causality tests, variance decomposition, and impulse response techniques were adopted. Findings from the panel estimator revealed that economic development contributed to environmental sustainability. At the same time, energy consumption increases ecological pollution globally and on most continents. The interaction between economic development and energy consumption positively impacted ecological pollution. Natural resources' rent was found to promote environmental pollution in Asia. The causality test results were mixed across continents and globally. However, findings from the impulse response and variance decomposition confirmed that economic development and energy consumption counted higher variations of carbon emissions than natural resource rents within the 10-year forecast. This study provides a valuable baseline for formulating policies related to the economy-energy-resources­carbon nexus.


Assuntos
Dióxido de Carbono , Desenvolvimento Econômico , Dióxido de Carbono/análise , Poluição Ambiental , Recursos Naturais , Ásia , Energia Renovável , Carbono
4.
Crit Rev Food Sci Nutr ; 63(20): 4351-4370, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-34793262

RESUMO

Whole grains (WGs) may have various health benefits, including lowering blood glucose and improving insulin sensitivity. To conduct a meta-analysis of the effects of WGs compared with non-WGs on changes in fasting glucose, fasting insulin, glycated hemoglobin (HbA1c), and homeostasis model assessment of insulin resistance (HOMA-IR). A systematic literature search was performed for all published randomized controlled trials on the effects of WG intake on fasting glucose, fasting insulin, HbA1c and HOMA-IR response up to February 2021. Weighted mean differences (WMD) were calculated. Pre-specified subgroup and univariate meta-regression analyses were explored to identify the sources of heterogeneity. Sensitivity analysis and bias analysis were conducted to appraise study quality. Among 12,435 articles screened for eligibility, data were extracted from 48 articles. Meta-analysis of 4,118 participants showed that WG consumption resulted in a significant reduction in fasting glucose by -0.15 mmol/L, fasting insulin by -2.71 pmol/L, HbA1c by -0.44%, and HOMA-IR by -0.28, respectively. Compared with mixed grains, brown rice, and wheat, oats were significantly lower on marker of glycemic. Besides, multiple interventions per day consolidated effectiveness of WGs. WG consumption decreased the levels of fasting glucose, fasting insulin, HbA1c, and HOMA-IR compared with non-WG consumption.Supplemental data for this article is available online at https://doi.org/10.1080/10408398.2021.2001429 .


Assuntos
Diabetes Mellitus Tipo 2 , Resistência à Insulina , Humanos , Hemoglobinas Glicadas , Grãos Integrais , Ensaios Clínicos Controlados Aleatórios como Assunto , Glicemia , Insulina
5.
Medicine (Baltimore) ; 102(52): e36308, 2023 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-38206709

RESUMO

BACKGROUND: Once-weekly insulin is expected to improve treatment compliance and durability and lead to better glycemic control. Several clinical trials on once-weekly insulin have recently been published. We conducted a systematic review and meta-analysis to investigate the efficacy and safety of once-weekly insulin versus once-daily insulin in type 2 diabetes (T2D). METHODS: The following databases were searched for studies: PubMed, EMBASE, and Cochrane library (From January 1, 1946 to May 9, 2023). All randomized trials comparing weekly versus daily insulin in T2D were eligible for inclusion. Data analysis was performed using STATA 17.0 software (Stata Corporation, College Station, TX). The main outcomes and indexes included reduction in Hemoglobin A1c (HbA1c), fasting plasma glucose and bodyweight, proportion of patients achieving HbA1c < 7%, time-in-range 70 to 180 mg/dL and adverse events. RESULTS: This systematic review and meta-analysis included 7 randomized controlled studies involving 2391 patients (1347 receiving 1-week insulin and 1044 receiving 1-day insulin). Once-weekly insulin was not inferior to once-daily insulin in HbA1c change [estimated treatment difference (ETD) = -0.05; 95% confidence intervals (CI): -0.14 to 0.04), HbA1c  < 7% (odds ratio = 1.14; 95% CI: 0.87-1.50), fasting plasma glucose (ETD = 0.09; 95% CI: -0.19 to 0.36) and body weight loss (ETD = 0.27; 95% CI: -0.36 to 0.91). In terms of time-in-range 70 to 180 mg/dL, weekly insulin was superior to daily insulin (MTD = 3.84; 95% CI: 1.55-6.08). Icodec was associated with higher incidence of all adverse events (odds ratio = 1.20; 95% CI: 1.03-1.48; P = .024), but did not result in high risk of serious and severe adverse events. Moreover, icodec and Basal Insulin Fc did not result in higher incidence of hypoglycemia compared with insulin daily. CONCLUSION: Our meta-analysis found that insulin weekly was well tolerated and effective for glycemic control. Once-weekly insulin was not inferior to once-daily insulin in both efficacy and safety in T2D.


Assuntos
Diabetes Mellitus Tipo 2 , Humanos , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/efeitos adversos , Insulina Glargina/efeitos adversos , Hemoglobinas Glicadas , Glicemia , Insulina/efeitos adversos
6.
BMC Pregnancy Childbirth ; 22(1): 983, 2022 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-36587196

RESUMO

BACKGROUND: IL-6 induces the upregulation of indoleamine 2,3-dioxygenase (IDO1) at the maternal-foetal interface, but the regulation mechanisms of IDO1 by IL-6 at this interface have not been fully understood. METHODS: Western blotting, qRT-PCR and/or immunohistochemistry were employed to measure the expression of IDO1, IL-6, SHP-1/2, SOCS3 and STAT3/p (STAT3 and pSTAT3) in tissues of chorionic villi and decidua (TCVD) in vivo and in cultured TCVD that were treated with IL-6 in the presence or absence of an IL-6 inhibitor. RESULTS: Mutually positive relationships among the protein levels of IL-6, IDO1, SHP-1/2 and STAT3/p was observed, and the expression of IDO1, SHP-1/2 and STAT3/p was increased in a dose-dependent manner in TCVD in vivo and in cultured TCVD treated with IL-6 at increasing concentrations (0-100 ng/ml). The level of IL-6 was negatively related to SOCS3 level in TCVD. The expression of SOCS3 was increased in a dose-dependent manner, and SOCS3 level was positively correlated with SHP-1, SHP-2 and STAT3/p level in cultured TCVD treated with 0-2 ng/ml IL-6; however, opposite results were observed after treatment with 2-100 ng/ml IL-6. The IL-6-induced upregulation of IDO1, SHP-1, SHP-2 and STAT3/p expression could be reversed, while the IL-6-induced upregulation of SOCS3 expression was exacerbated by Corylifol A. CONCLUSIONS: In normal pregnancy, IL-6 upregulates the expression of IDO1 by promoting SHP-1/2 expression via STAT3/p and simultaneously negatively regulates the expression of SOCS3. High expression of IL-6 causes the upregulation of IDO1 expression and the downregulation of SOCS-3 expression, which may be beneficial for maintaining immunological tolerance.


Assuntos
Vilosidades Coriônicas , Interleucina-6 , Gravidez , Humanos , Feminino , Proteína 3 Supressora da Sinalização de Citocinas/metabolismo , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Regulação para Cima , Proteínas Supressoras da Sinalização de Citocina/genética , Proteínas Supressoras da Sinalização de Citocina/metabolismo , Decídua
7.
Environ Sci Pollut Res Int ; 29(31): 47810-47817, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35190980

RESUMO

Green innovation undoubtedly plays a significant role in generating employment opportunities, improving green economic activity, and increasing environmental sustainability. This study scrutinizes the effect of energy efficiency and green innovation on CO2 emissions for China using nonlinear autoregressive distributed lag (NARDL) from 1991 to 2019. Findings show that energy efficiency and green innovation contribute to reducing CO2 emissions in China. Energy efficiency and green innovation are also important nonlinear determinants of CO2 emissions. An increase in energy efficiency and green innovation lowers CO2 emissions, while a fall in energy efficiency and green innovation increases CO2 emissions in China in the long run. Some policy measures are suggested to attain carbon neutrality.


Assuntos
Dióxido de Carbono , Desenvolvimento Econômico , Carbono , Dióxido de Carbono/análise , China , Conservação de Recursos Energéticos
8.
Environ Sci Pollut Res Int ; 29(13): 19019-19032, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34705211

RESUMO

The purpose of this paper is to determine the spatial spillover effects of renewable energy on carbon emissions in China's less-developed areas. However, few studies have considered this issue from the perspective of less-developed areas. Based on panel data of 21 provinces in China from 2000 to 2017, this paper analyzes the spatial spillover effects of renewable energy on carbon emissions using Moran's I and Spatial Durbin Model (SDM). The results suggest that, first, Moran's I ranges from 0.378 to 0.519, Moran scatter plot presents that provinces are located in the high-high (HH) and low-low (LL) quadrants, indicating provincial carbon emissions in the study area have a significant spatial correlation and agglomeration. Second, under the three matrices, the direct effect coefficients of renewable energy are -0.2522, -0.2639 and -0.2601, this shows that renewable energy is beneficial to local carbon emissions reduction. In contrast, the indirect effect coefficients of renewable energy are 0.0605, 0.1012 and 0.1125, which means higher renewable energy consumption in a single area is conducive to the improvement of carbon emissions to neighbouring areas. Third, urbanization, industrialization, physical capital and other variables have different impacts on local and nearby carbon emissions. This study provides empirical evidence to achieve carbon emission reduction targets by government policymakers.


Assuntos
Carbono , Energia Renovável , Dióxido de Carbono , China , Desenvolvimento Econômico , Desenvolvimento Industrial , Urbanização
9.
Environ Sci Pollut Res Int ; 28(43): 61201-61212, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34173143

RESUMO

Carbon emission has been documented as a significant component of greenhouse gas that has been a significant source of environmental distortion globally. Based on panel data of 15 nations from 1980 to 2017, this study empirically investigates the impact of energy consumption, economic growth, urbanization, and energy consumption on carbon emission using panel co-integration tests and pooled mean group ARDL (PMG-ARDL) techniques. We augment the model with urbanization to establish the role urbanization plays in energy consumption, economic growth, and carbon emission nexus. Findings confirm that in the long run and short run, urbanization has no significant effect on the environment quality. On the other hand, energy consumption was found to enhance environmental destruction significantly in the short run and long run. Additional findings confirmed that economic growth causes environmental distortion in the long run for the sampled nations. Government officials and policymakers need to pay special attention to enhance adequate energy, urban planning, and emission reduction without affecting the economic development to achieve urban-economic-energy sustainability, which is key to attaining a green and clean environment.


Assuntos
Desenvolvimento Econômico , Urbanização , Carbono , Dióxido de Carbono
10.
Artigo em Inglês | MEDLINE | ID: mdl-33802489

RESUMO

Chinese government policy officially identify the Yangtze River Economic Belt (YREB) as one of regional green development strategies firstly in 2014. This strategy can be regarded as quasi-natural experiment, this paper aims to test its impact on regional environmental total factor productivity (TFP). First, slack-based measure model is used to calculate the environmental TFP from 2005 to 2017 at provincial level. Second, based on Chinese official statistics, differences-in-differences (DID) method is applied to construct an evaluation model of policy effect, combining with the kernel matching in propensity score matching (PSM) method. The results show that environmental TFP of YREB has significant spatial differences, with characteristic of high-east and low-west, its average level is 11.69 percentage points higher than the national average. YREB strategy promotes regional economic growth, but it does no effect on the regional environmental TFP yet. Modelling suggests that YREB strategy may play a role in the short term. From the significance of the control variables, infrastructure construction level is positively correlated with environmental TFP, while per capita GDP, financial development and energy consumption intensity have negative effect on environmental TFP. Based on this, policymakers should focus on green development, promoting industrial transformation, and enhancing environmental protection.


Assuntos
Rios , Desenvolvimento Sustentável , China , Conservação dos Recursos Naturais , Desenvolvimento Econômico
11.
Autoimmunity ; 54(3): 156-162, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33792452

RESUMO

Indoleamine 2,3-dioxygenase1(IDO1) is one of the most important proteins in protect the embryos from the mother's immune system during pregnancy. However, the regulation of the protein expression at the maternal-foetal interface is not fully known. We aimed to study the regulation of IDO1 expression by progesterone in villi and decidua of in early pregnancy. Fifty cases of early pregnancy women's villi and decidua were collected. Tissue explants of chorionic villi and the decidua were cultured in media containing in different concentrations of progesterone, in the presence or absence of mifepristone. Western blot analysis and immunofluorescence were used to detect the expression of IDO1 in chorionic villi and decidua in cultured tissues. IDO1 protein was identified in chorionic villi and decidua tissues of normal pregnant women, and the expression of IDO1in the decidua was significantly higher than those in chorionic villi. Progesterone decreased IDO1 expression in early pregnancy chorionic villi and decidua, and mifepristone, as the progesterone inhibitor, reverted this effect. In normal physiological state of pregnancy, progesterone may be involved in the regulation of immune tolerance by negative regulation of IDO1 expression at maternal foetal interface. Progesterone may down-regulate IDO1 expression during early pregnancy.


Assuntos
Vilosidades Coriônicas/metabolismo , Decídua/metabolismo , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Progesterona/metabolismo , Adulto , Feminino , Humanos , Gravidez
12.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi ; 37(2): 158-163, 2021 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-33504422

RESUMO

Objective To investigate the regulatory effect of interleukin-6 (IL-6) on the expression of indoleamine 2, 3-dioxygenase (IDO) in the early pregnant chorionic villi and decidua tissues. Methods The chorionic villi and decidua tissues of women who received induced abortion at early pregnancy were collected. The expression of IL-6 and IDO in the chorionic villi and decidua tissues was detected by Western blotting. Subsequently, 10, 50 and 100 ng/mL IL-6 was added into the chorionic villi and decidua tissues to culture for 48 hours. In addition, changes in the IDO mRNA and protein expression levels in chorionic villi and decidua tissues were detected by real-time quantitative reverse PCR (qRT-PCR) and Western blotting. Results Both IDO and IL-6 were expressed in human early pregnant chorionic villi and decidua tissues. Besides, the expression of these two proteins were positively correlated (r=0.72, 0.91). After being cultured with 10, 50 and 100 ng/mL IL-6 for 48 hours, IDO protein expression significantly increased in the cultured early pregnant chorionic villi and decidua tissues in an IL-6 concentration-dependent manner. Conclusion The expression of IL-6 and IDO proteins at the maternal-fetal interface show a positive correlation in normal physiological pregnancy, and IL-6 may up-regulate the expression of IDO.


Assuntos
Vilosidades Coriônicas , Interleucina-6 , Decídua , Feminino , Humanos , Indolamina-Pirrol 2,3,-Dioxigenase/genética , Interleucina-6/genética , Gravidez , RNA Mensageiro
13.
Artigo em Inglês | MEDLINE | ID: mdl-32977687

RESUMO

This paper examines the environmental Kuznets curve (EKC) relationship between energy consumption and economic growth in upper-middle-income regions of China with the panel data of 21 provinces from 2000 to 2017. The influence mechanism of socio-economic factors on the EKC of these regions is also detected. The results show that the energy consumption EKC fitting map in these regions conforms to the classical environmental Kuznets curve, which is an inverted "N" type, and the inflection point is ahead and more accurate after adding spatial effects. The direct effect of energy consumption has delayed the inflection point, indicating that the level of industrialization, urbanization, and population density have a significant impact on EKC. At the same time, it is found that the level of industrialization and population density have a positive relationship with energy consumption, while the level of urbanization has a negative correlation with energy consumption. The spatial spillover effect of the indirect effects of total energy consumption, coal consumption, and crude oil consumption shows that the level of industrialization has a significant and negative link with EKC. The increase in the level of industrialization will affect the total energy consumption of neighboring areas and the consumption of coal and crude oil.


Assuntos
Dióxido de Carbono , Desenvolvimento Econômico , Energia Renovável , Urbanização , Poluentes Atmosféricos , Dióxido de Carbono/análise , China , Conservação dos Recursos Naturais , Humanos , Renda
14.
Water Res ; 183: 116055, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32622235

RESUMO

N-nitrosodimethylamine (NDMA) as one emerging disinfection by-product has been investigated globally since 1990s. However, its main precursors are still unclear. We found that NDMA formation potential (NDMAFP) of various water samples increased firstly and then decreased gradually during incubation with microorganism. We hypothesized that NDMA precursors could be produced through metabolism of nitrogenous components and then gradually be biodegraded. To verify this hypothesis, six amino acids (AAs), peptone and ammonium were separately incubated with microorganism and NDMAFP was measured regularly. The average molar yield of the substrates to NDMAFP were 60-200 × 10-6 for the AAs, 350 × 10-6 for peptone under aerobic condition. The extracellular fraction with molecular weight (MW) less than 1 k Dalton contributed the majority to NDMAFP in the peptone experiment, followed by that with MW between 10 k and 0.22 µm and the intracellular materials. Dimethylamine and methylamine were detected during the experiments but their contribution to NDMAFP is quite limited. The results indicate that the nitrosamine precursors may not be the direct metabolite of AAs or peptones but the excretion of living bacteria or the components in dead bacteria body. Our results inferred that AA metabolism may give an NDMAFP of 0.12 nmol/L (maximum) or 0.09 nmol/L (average) in water under aerobic condition. This estimation of NDMAFP from AA metabolism can account for 38% (maximum) or 27% (average) of the median NDMAFP in waters of China (0.32 nmol/L) reported before.


Assuntos
Nitrosaminas , Poluentes Químicos da Água/análise , Purificação da Água , China , Dimetilnitrosamina , Nitrogênio
15.
Am J Reprod Immunol ; 83(1): e13197, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31599074

RESUMO

PROBLEM: Indoleamine 2,3-dioxygenase (IDO) is a key protein that participates in the protection of embryos against the mother's immune system during pregnancy. How the expression of this protein is regulated at the maternal-fetal interface remains largely unknown. METHOD OF STUDY: The chorionic villi and decidua of women in early pregnancy were collected. Tissue explants of the chorionic villi and decidua were cultured in media containing varying concentrations of 17ß-estradiol and estriol with or without fulvestrant. Western blot analysis and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) were used to detect the expression of IDO and the suppressors of cytokine signaling 3 (SOCS3) in the cultured tissues from chorionic villi and decidua. RESULTS: Both IDO and SOCS3 were expressed in chorionic villi and decidua. The expression of IDO was increased in tissue explants from chorionic villi and decidua cultured in medium containing different concentrations of 17ß-estradiol or estriol, and this increase was reversed when fulvestrant was added to the medium. The expression of IDO was upregulated, and SOCS3 expression was downregulated the most in tissue explants from chorionic villi and decidua that were cultured in medium containing 17ß-estradiol at a concentration of 10 ng/mL or estriol at a concentration of 1 µg/mL. This increase in IDO and decrease in SOCS3 were reversed when fulvestrant was added to the medium at a concentration of 10 µg/mL. CONCLUSION: At a concentration similar to that present during pregnancy, estrogen may upregulate the expression of IDO via downregulating SOCS3, which implies that estrogen may contribute to the prevention of allogeneic fetal rejection, and further studies may strengthen the possibility of using estrogen as an immune modulator.


Assuntos
Vilosidades Coriônicas/efeitos dos fármacos , Decídua/efeitos dos fármacos , Estradiol/farmacologia , Estriol/farmacologia , Estrogênios/farmacologia , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Proteína 3 Supressora da Sinalização de Citocinas/metabolismo , Adulto , Vilosidades Coriônicas/metabolismo , Decídua/metabolismo , Feminino , Humanos , Indolamina-Pirrol 2,3,-Dioxigenase/genética , Gravidez , Proteína 3 Supressora da Sinalização de Citocinas/genética , Adulto Jovem
16.
Sci Total Environ ; 697: 133993, 2019 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-32380594

RESUMO

N­nitrosodimethylamine (NDMA) was detected in the source water of some Chinese drinking water treatment plants (DWTPs), which decreased in concentration along the treatment train. Volatilization, photolysis, and/or biodegradation were suspected of being capable of attenuating NDMA. In this study, the contribution of these mechanisms to NDMA removal was investigated by a field study in a conventional DWTP with aerated bio-pretreatment, as well as in laboratory-based experiments. The effluent of each unit process (i.e., aerated bio-pretreatment tank, horizontal sedimentation tank, sand filter) of this DWTP was sampled in the winter and summer, and the concentration of NDMA, its formation potential, and other water quality parameters were measured. NDMA removal by volatilization and biodegradation was simulated in batch experiments, and that by photolysis was calculated with parameters reported in the literature. The sampling results indicated that the aerated biofilm reactor of this DWTP removed 48% of the NDMA in August and 22% in December. According to modeling results, it could be well explained by photolysis (NDMA removal of 51% in summer and 25% in winter) and biotreatment (NDMA removal of 0.2-12% in summer and 0.1-6.1% in winter), with little contribution from aeration (NDMA removal of 0.8%). The sampling results indicated that the sedimentation tank removed 19% of NDMA in August and 9.2% in December. According to modeling results, it could be well explained by photolysis (NDMA removal of 16% in August and 9.4% in December), but little by volatilization. Thus, photolysis was shown to be the most important process for NDMA removal in this DWTP. Further investigation is needed to better understand NDMA removal during biotreatment.


Assuntos
Dimetilnitrosamina/isolamento & purificação , Água Potável/química , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos , Biodegradação Ambiental , Fotólise , Volatilização
17.
J Insect Sci ; 18(4)2018 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-29982810

RESUMO

The ratio of protein and carbohydrate in an insect's nutritional regime can significantly influence its survival, growth, and fecundity. The effects of 11 different artificial diets containing protein (p): carbohydrate (c) ratios were determined in larvae of the phytophagus ladybug, Henosepilachna vigintioctopunctata (F.) (Coleoptera: Coccinellidae). We recorded the developmental times and survival rates of the larvae and weighed their pupae. When the concentration of carbohydrates was kept constant while the concentration of proteins was increased (p29:c20, p31:c20, p33:c20, and p35:c20), H. vigintioctopunctata could successfully complete the larval and pupal stages. The highest survival rate and greatest pupal mass of H. vigintioctopunctata were 72% and 19.5 mg, respectively, when reared on the p33:c20 diet. H. vigintioctopunctata larvae, however, were unable to develop into adults when the concentration of protein remained constant while the level of carbohydrates was increased (p20:c23, p20:c25, p20:c27, and p20:c29), or when the total amount (p + c) was kept at 48% (p22:c26, p 24:c24, p26:c22). Evidently, changing the availability of quality diet, especially the total protein levels, can significantly affect the performance to H. vigintioctopunctata. Our results indicated that the maximum development and survival of H. vigintioctopunctata larvae occurred within a narrow range-when the p:c ratio was (33:20).


Assuntos
Besouros/fisiologia , Carboidratos da Dieta/metabolismo , Proteínas Alimentares/metabolismo , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Besouros/efeitos dos fármacos , Besouros/crescimento & desenvolvimento , Dieta , Carboidratos da Dieta/administração & dosagem , Proteínas Alimentares/administração & dosagem , Relação Dose-Resposta a Droga , Feminino , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Larva/fisiologia , Longevidade/efeitos dos fármacos , Masculino , Pupa/efeitos dos fármacos , Pupa/crescimento & desenvolvimento , Pupa/fisiologia
18.
Sci Rep ; 7(1): 14447, 2017 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-29089555

RESUMO

The multi-device open-circuit fault is a common fault of ANPC (Active Neutral-Point Clamped) three-level inverter and effect the operation stability of the whole system. To improve the operation stability, this paper summarized the main solutions currently firstly and analyzed all the possible states of multi-device open-circuit fault. Secondly, an order-reduction optimal control strategy was proposed under multi-device open-circuit fault to realize fault-tolerant control based on the topology and control requirement of ANPC three-level inverter and operation stability. This control strategy can solve the faults with different operation states, and can works in order-reduction state under specific open-circuit faults with specific combined devices, which sacrifices the control quality to obtain the stability priority control. Finally, the simulation and experiment proved the effectiveness of the proposed strategy.

19.
J Econ Entomol ; 110(5): 2084-2091, 2017 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-28961786

RESUMO

Henosepilachna vigintioctopunctata (F.) is a widespread pest found on many solanaceous vegetables. The development and fecundity of H. vigintioctopunctata were studied on three cultivars ('Zihong', 'Eyou', and 'Baijiao') of eggplant, Solanum melongena L., using the two-sex life table theory. These results were then compared with similar parameters from a wild alternate host, Solanum nigrum. Our results showed that there were no significant differences between the developmental times of the larval stages, pupae, oviposition period, adult longevity, and the fecundity of H. vigintioctopunctata reared on the three eggplant cultivars. The survival rates of H. vigintioctopunctata larvae reared on the three eggplant cultivars were higher than that on S. nigrum. The fecundity of H. vigintioctopunctata adults reared on S. nigrum (724.12 eggs), however, was significantly higher than on each of the three eggplant cultivars. The values for the intrinsic rate of increase (r), finite rate of increase (λ), and net reproductive rate (R0) for H. vigintioctopunctata when reared on S. nigrum were 0.1225 d-1,1.1303 d-1, and 299.6 offspring, respectively. Each of these was significantly higher than comparable values when reared on the cultivar Eyou and Baijiao but were not different from those reared on the Zihong. Our results indicated that H. vigintioctopunctata is well adapted to all tested host plant cultivars and that S. nigrum is an important alternate wild hostplant that may potentially contribute to future outbreaks of H. vigintioctopunctata if not taken into consideration when planning an integrated control strategy against the pest.


Assuntos
Besouros/crescimento & desenvolvimento , Solanum melongena , Animais , Feminino , Fertilidade , Larva/crescimento & desenvolvimento , Longevidade , Oviposição , Pupa/crescimento & desenvolvimento , Solanum nigrum , Especificidade da Espécie
20.
J Environ Sci (China) ; 58: 331-339, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28774624

RESUMO

N-nitrosodimethylamine (NDMA) precursors consist of a positively charged dimethylamine group and a non-polar moiety, which inspired us to develop a targeted cation exchange technology to remove NDMA precursors. In this study, we tested the removal of two representative NDMA precursors, dimethylamine (DMA) and ranitidine (RNTD), by strong acidic cation exchange resin. The results showed that pH greatly affected the exchange efficiency, with high removal (DMA>78% and RNTD>94%) observed at pHMg2+>RNTD+>K+>DMA+>NH4+>Na+. The partition coefficient of DMA+ to Na+ was 1.41±0.26, while that of RNTD+ to Na+ was 12.1±1.9. The pseudo second-order equation fitted the cation exchange kinetics well. Bivalent inorganic cations such as Ca2+ were found to have a notable effect on NA precursor removal in softening column test. Besides DMA and RNTD, cation exchange process also worked well for removing other 7 model NDMA precursors. Overall, NDMA precursor removal can be an added benefit of making use of cation exchange water softening processes.


Assuntos
Dimetilnitrosamina/análise , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Cátions/química , Dimetilnitrosamina/química , Poluentes Químicos da Água/química
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