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The well-defined 2D or 3D structure of covalent organic frameworks (COFs) makes it have great potential in photoelectric conversion and ions conduction fields. Herein, a new donor-accepter (D-A) COF material, named PyPz-COF, constructed from electron donor 4,4',4â³,4'â³-(pyrene-1,3,6,8-tetrayl)tetraaniline and electron accepter 4,4'-(pyrazine-2,5-diyl)dibenzaldehyde with an ordered and stable π-conjugated structure is reported. Interestingly, the introduction of pyrazine ring endows the PyPz-COF a distinct optical, electrochemical, charge-transfer properties, and also brings plentiful CN groups that enrich the proton by hydrogen bonds to enhance the photocatalysis performance. Thus, PyPz-COF exhibits a significantly improved photocatalytic hydrogen generation performance up to 7542 µmol g-1 h-1 with Pt as cocatalyst, also in clear contrast to that of PyTp-COF without pyrazine introduction (1714 µmol g-1 h-1 ). Moreover, the abundant nitrogen sites of the pyrazine ring and the well-defined 1D nanochannels enable the as-prepared COFs to immobilize H3 PO4 proton carriers in COFs through hydrogen bond confinement. The resulting material has an impressive proton conduction up to 8.10 × 10-2 S cm-1 at 353 K, 98% RH. This work will inspire the design and synthesis of COF-based materials with both efficient photocatalysis and proton conduction performance in the future.
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Atmospheric nitrogen deposition has a crucial impact on the structure and function of soil microorganisms of wetland ecosystems. Therefore, carrying out a study on the effects of soil carbon metabolism capacity has a great significance for the protection and utilization of wetland ecosystems. In this study, the effects of simulated nitrogen deposition on the carbon metabolic capacity of soil microorganisms in Calamagrostis angustifolia wetland for five consecutive years was investigated using Biolog-Eco technology. The results showed:â soil water content (SMC), pH, nitrate nitrogen (NO3-), ammonium nitrogen (NH4+), dissolved organic carbon (DOC), and total nitrogen (TN) contents were significantly different (P<0.05) under different nitrogen deposition conditions. â¡ The average well color development (AWCD) values of soil microorganisms within different N depositions were in the order of CK (control)>HN (high nitrogen treatment)>LN (low nitrogen treatment). LN significantly reduced the Shannon diversity index of soil microorganisms, and HN significantly reduced the Pielou index of soil microorganisms (P<0.05). ⢠LN significantly inhibited the intensity of the utilization of carbohydrates, alcohols, amines, and acids by soil microorganisms (P<0.05); HN significantly promoted the utilization of esters by microorganisms, but HN caused soil microorganisms to inhibit the carbon sources of carbohydrates, amines, and acids (P<0.05). ⣠Redundancy analysis showed that NH4+, DOC, and pH were the main environmental factors affecting the functional diversity of soil microbial communities in Calamagrostis angustifolia wetland in the Sanjiang Plain. Long-term nitrogen deposition will lead to the reduction in soil microbial functional diversity; the microbial activity related to the utilization of carbon source substrates is also significantly reduced, and the ability of microorganisms to utilize a single carbon source substrate also changes.
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Nitrogênio , Solo , Aminas/metabolismo , Carboidratos , Carbono/química , Ecossistema , Nitrogênio/análise , Poaceae , Solo/química , Microbiologia do Solo , Áreas AlagadasRESUMO
Anaerobic digestates were potential mediums for cultivating oleaginous microalgae, but their various components brought uncertainties for aglal growth and lipids production. In this study, three microalgae strains were tested to grow on four typical anaerobic digestates. The results showed that anaerobic food wastewater was an optimal medium for C. pyrenoidosa and S. obliquus culture (N. oleoabundanst cannot survive), achieving the highest biomass (2.15-2.32 g L-1) and lipids production (20.6-32.5 mg L-1·d-1). In contrast, three microalgae strains could grow suboptimally in anaerobic municipal (0.79-0.95 g L-1) and toilet (0.92-1.40 g L-1) wastewater, but showed poor performances in anaerobic swine wastewater. The growth of microalgae removed 40.9-63.4% of TOC, 83.7-96.3% of NH4+-N and 70.3-89.4% of TP in the three ADs. In addition, it was unfortunately found that the lipids content and saturation degree in fatty acids significantly decreased in ADs with sufficient nutrients. It suggests that some measures should be taken to balance biomass, lipids production and quality for cultivating microalgae in anaerobic digestates.
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Poluentes Ambientais , Microalgas , Anaerobiose , Animais , Biomassa , Ácidos Graxos , Suínos , Águas ResiduáriasRESUMO
Background: Boosting the individual learning passion of medical students is a novel approach to improve their academic performance. It facilitates the medical education reform, motivating both policymakers and educators to focus on the function of positive psychology in the career development of medical students. Therefore, this study aimed (1) to assess the status of two types of learning passion; (2) to clarify the relationship between self-esteem and two types of learning passion among Chinese medical students; (3) to examine the mediating role of psychological capital (PsyCap) in the relationship between self-esteem and two types of learning passion, respectively; and (4) to identify the moderating role of professional identity in the relationship between PsyCap and two types of learning passion, respectively. Methods: A cross-sectional online survey was conducted from April to June 2016 in China. A total of 1,218 valid questionnaires (effective completion rate: 67.93%) were collected from four medical schools. Results: Self-esteem significantly and positively influenced medical students' PsyCap (ß = 0.637, P < 0.01) and two types of learning passion, including harmonious learning passion (ß = 0.589, P < 0.01) and obsessive learning passion (ß = 0.436, P < 0.01). PsyCap fully mediated the relationship (ß = 0.578, P < 0.01) between self-esteem and harmonious learning passion positively, whereas it suppressed the relationship (ß = 0.490, P < 0.01) between self-esteem and obsessive learning passion. Further, professional identity significantly moderated the correlation between PsyCap and harmonious learning passion (ß = -0.554, P < 0.05), rather than obsessive learning passion (P > 0.05). Conclusion: Two types of learning passion of medical students are positively influenced by self-esteem and PsyCap. Medical students with high-level self-esteem should possess strong PsyCap, which augments their harmonious as well as obsessive learning passion. Moreover, the positive effect of medical students' PsyCap on harmonious learning passion is more notable among those with a lower professional identity. Finally, this study argues that strengths-based interventions of self-esteem and PsyCap are a beneficial approach for future enhancing learning passion in the domain of medical education.
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Taking Deyeuxia angustifolia as the research object, a representative plant of wetland in Sanjiang Plain, we analyzed the variations of individual size and biomass among the habitats of swamp wetlands, swampy meadows, typical meadows and miscellaneous grass meadows, and the relationship between reproductive components and plant biomass. We explored the effects of water level on individual biomass and reproductive allocation of D. angustifolia in different types of wetlands. The results showed that plant biomass, height and the characteristics of sexual reproduction significantly decreased with the increases of water level. The reproductive thresholds of D. angustifolia in miscellaneous grass meadow, typical meadow, swampy meadow, and swamp wetland were 0.245, 0.149, 0.148 and 0.157 g, respectively. There was a significantly negative correlation between plant size and reproductive allocation in three habitats except swampy meadow. Compared with individual size, soil water content had a stronger effect on reproductive allocation of D. angustifolia. The different investment between individual size and reproductive allocation in different habitats was the basic condition that contributes to the good ecological adaptability of D. angustifolia.
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Água , Áreas Alagadas , China , Ecossistema , Poaceae , ReproduçãoRESUMO
Emerging evidence shows that chronic inflammation mediated by toll-like receptors (TLRs) contributes to diabetic nephropathy. Myeloid differentiation primary-response protein-88 (MyD88) is an essential adapter protein of all TLRs except TLR3 in innate immunity. It is unclear whether MyD88 could be a therapeutic target for diabetic nephropathy. Here, we used a new small-molecule MyD88 inhibitor, LM8, to examine the pharmacological inhibition of MyD88 in protecting kidneys from inflammatory injury in diabetes. We showed that MyD88 was significantly activated in the kidney of STZ-induced type 1 diabetic mice in tubular epithelial cells as well as in high glucose-treated rat tubular epithelial cells NRK-52E. In cultured tubular epithelial cells, we show that LM8 (2.5-10 µM) or MyD88 siRNA attenuated high-concentration glucose-induced inflammatory and fibrogenic responses through inhibition of MyD88-TLR4 interaction and downstream NF-κB activation. Treatment with LM8 (5, 10 mg/kg, i.g.) significantly reduced renal inflammation and fibrosis and preserved renal function in both type 1 and type 2 diabetic mice. These renoprotective effects were associated with reduced MyD88-TLR4 complex formation, suppressed NF-κB signaling, and prevention of inflammatory factor expression. Collectively, our results show that hyperglycemia activates MyD88 signaling cascade to induce renal inflammation, fibrosis, and dysfunction. Pharmacological inhibition of MyD88 may be a therapeutic approach to mitigate diabetic nephropathy and the inhibitor LM8 could be a potential candidate for such therapy.
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Nefropatias Diabéticas/prevenção & controle , Hipoglicemiantes/uso terapêutico , Túbulos Renais/efeitos dos fármacos , Fator 88 de Diferenciação Mieloide/antagonistas & inibidores , Animais , Western Blotting , Diabetes Mellitus Experimental/complicações , Nefropatias Diabéticas/metabolismo , Imunoprecipitação , Rim/efeitos dos fármacos , Rim/patologia , Túbulos Renais/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Reação em Cadeia da Polimerase em Tempo Real , Ressonância de Plasmônio de SuperfícieRESUMO
Acute lung injury (ALI) is a sudden onset systemic inflammatory response. ALI causes severe morbidity and death and currently no effective pharmacological therapies exist. Natural products represent an excellent resource for discovering new drugs. Screening anti-inflammatory compounds from the natural product bank may offer viable candidates for molecular-based therapies for ALI. In this study, 165 natural compounds were screened for anti-inflammatory activity in lipopolysaccharide (LPS)-challenged macrophages. Among the screened compounds, flavokawain B (FKB) significantly reduced LPS-induced pro-inflammatory IL-6 secretion in macrophages. FKB also reduced the formation of LPS/TLR4/MD2 complex by competitively binding to MD2, suppressing downstream MAPK and NF-κB signaling activation. Finally, FKB treatment of mice reduced LPS-induced lung injury, systemic and local inflammatory cytokine production, and macrophage infiltration in lungs. These protective activities manifested as increased survival in the ALI model, and reduced mortality upon bacterial infection. In summary, we demonstrate that the natural product FKB protects against LPS-induced lung injury and sepsis by interacting with MD2 and inhibiting inflammatory responses. FKB may potentially serve as a therapeutic option for the treatment of ALI.
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Lesão Pulmonar Aguda , Produtos Biológicos , Antígeno 96 de Linfócito/metabolismo , Lesão Pulmonar Aguda/induzido quimicamente , Lesão Pulmonar Aguda/tratamento farmacológico , Lesão Pulmonar Aguda/metabolismo , Animais , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Citocinas/metabolismo , Flavonoides , Lipopolissacarídeos , Pulmão/metabolismo , Camundongos , NF-kappa B/metabolismoRESUMO
The problem of mobile phone addiction and academic procrastination among medical students has been widely acknowledged. This study aimed to explore the influence of demographic factors on mobile phone addiction, academic procrastination, and academic achievement among medical students. Further, it investigated the association between mobile phone addiction, academic procrastination, and academic achievement. This cross-sectional study was conducted between May and June 2019. A total of 3 511 medical students participated in an online questionnaire survey (effective response rate = 81.7%). Demographic factors, the Scale of Academic Achievement, the short scale of the Mobile Phone Problem Use (MPPUS-10), and the Academic Procrastination Scale-Short (APS-S) were used. Hierarchical multiple regression analysis revealed that the average scores for academic procrastination, mobile phone addiction, and academic achievement were 2.66 ± 0.91, 5.13 ± 1.53, and 4.51 ± 0.71, respectively. Moreover, there were significant differences in gender, grade, leadership experience, and family monthly income across mobile phone addiction, academic procrastination, and academic achievement. Mobile phone addiction was negatively associated with learning dedication, learning performance, and relationship facilitation. Academic procrastination was negatively associated with learning dedication, learning performance, relationship facilitation, and objective achievement. Mobile phone addiction and academic procrastination was revealed as prevalent among Chinese medical students, and negatively influences their academic achievement. It is critical to establish a more efficient learning environment for Chinese medical students to minimize the negative impact of mobile phone addiction and academic procrastination.
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Objectives: The main objectives of this study were to describe the current state of character strengths (CSs) of nurses; explain how they affect stress, sleep quality, and subjective health status; and reveal the mediating role of stress for the subject matter on the association between CSs, sleep quality, and subjective health status. Methods: A cross-sectional online survey was conducted from September to October 2020 in China. A multistage stratified sampling method was used, and 1,221 valid questionnaires across 100 cities in 31 provinces were collected. Results: For the participants in this survey, the three dimensions of CSs ranging from high to low were caring (4.20 ± 0.640), self-control (3.53 ± 0.763), and inquisitiveness (3.37 ± 0.787). There was difference in CSs scores across age (F = 8.171, P < 0.01), professional categories (F = 5.545, P < 0.01), and job tenure (F = 9.470, P < 0.01). The results showed that CSs significantly affected the psychological stress (ß = -0.365, P< 0.01), sleep quality (ß = 0.312, P< 0.01), and subjective health (ß = 0.398, P< 0.01) of nurses. Moreover, psychological stress partially mediated the association between CSs and both types of health outcomes. Conclusion: In China, the CSs of nurses are at high levels. We find that nurses with high-level CSs are likely to experience less psychological stress and exhibit healthy psycho-physiological responses, which contribute to positive health outcomes. Finally, our study argues that strength-based interventions of positive psychology in hospitals should be provided to minimize threats to the physical and psychological health of health professionals, which is a beneficial choice for future hospital reforms in the domain of occupational health management.
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Learning motivation is a significant factor that ensures quality in medical education, and might affect the academic performance and well-being of medical students. This study aimed to explore the status of achievement goal orientations among medical students in China and to further identify the association among academic performance, academic well-being, and achievement goal orientations. Data were collected through a cross-sectional, anonymous survey conducted with 3,511 respondents (effective response rate = 81.7%), from four medical universities in China, and demographic factors, achievement goal orientations, academic performance, and academic well-being were assessed. The average score of achievement goal orientations of Chinese medical students suggested a difference in demographic factors, including sex, year of study, experience of leadership cadre, and family income. Both mastery and performance-avoidance goals were associated with academic performance, subjective academic stress, subjective learning adaptability, subjective sleep quality, and subjective well-being. Performance-approach goals were related to academic performance, subjective academic stress, and subjective learning adaptability. The achievement goal orientations of the medical students in this study were at a middle level. The findings emphasize the importance of mastery goals for promoting the academic performance and well-being of medical students. More care and attention toward achievement goal orientations can be beneficial for the improvement of the academic performance and well-being among medical students.
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Septic tank effluent from rural areas was an ideal medium for cultivating oleaginous microalgae. However, the characteristics of septic tank effluents varied greatly due to the different incoming wastewater, and bring uncertain risks for algal growth. In this study, an oleaginous microalgae was cultivated in septic effluents from different mixed wastewater. The results showed that the effluent from pure toilet wastewater was the best medium to achieve the highest biomass yield (1.68 g·L-1) and productivity (154.6 mg·L-1·d-1). In contrast, the discharge of kitchen or laundry wastewater reduced the biomass production by 50.5-79.1%. That caused much lower lipids production in effluents from mixed wastewater regardless of its high lipids content and saturation degree. The results suggest that the discharge of kitchen or laundry wastewater bring risks for biomass and lipids production, and should be separated from the toilet wastewater before entering into septic tank.
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Chlorella , Poluentes Ambientais , Microalgas , Lipídeos , Águas ResiduáriasRESUMO
Microalgae cultivation in anaerobic food wastewater was a feasible way for high biomass production and nutrients recycling. In this study, Chlorella pyrenoidosa culture on anaerobic food wastewater was processed outdoors using a pilot-scale tubular photobioreactor. The microalgae showed rapid growth in different seasons, achieving high biomass production of 1.83-2.10 g L-1 and specific growth rate of 0.73-1.59 d-1. The biological contamination and dissolved oxygen were controlled at suitable levels for algal growth in the tubular photobioreactor. Lipids content in harvested biomass was 8.1-15.3% of dried weight, and the analysis in fatty acids revealed high quality with long carbon chain length and high saturation. Additionally, algal growth achieved effective pollutants purification from wastewater, removing 42.3-53.8% of CODCr, 82.6-88.7% of TN and 59.7-67.6% of TP. This study gave a successful application for scaled-up microalgae culture in anaerobic food processing wastewater for biodiesel production and wastewater purification.
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Chlorella , Microalgas , Anaerobiose , Biomassa , Manipulação de Alimentos , Nutrientes , Fotobiorreatores , Águas ResiduáriasRESUMO
Anaerobically digested waste sludge contains very high concentrations of ammonium and phosphate that are difficult to be purified using traditional processes. Mixotrophic culture of microalgae is a potential way to achieve ammonium and phosphate removal, while harvesting considerable biomass for biodiesel production. In this study, four typical volatile organic acids that could be potentially produced from sludge fermentation were tested for algal mixotrophic culture in anaerobically digested waste sludge. The results showed that the addition of propionate and isovaleric acid had no significant improvement on biomass production, and even inhibited algal growth at low concentration. Fortunately, the addition of acetic and n-butyric acid (initial C/N = 10) increased biomass production by1.9-2.4 times compared to the blank culture. Higher biomass production increased ammonium and orthophosphate removal to 88.3-97.1% and 80.4-93.0%, respectively. Moreover, the optimal addition of volatile organic acids enhanced lipids production by 3.9-6.3 times, while achieving higher saturation degree in biodiesels. The results suggest that adding these optimal volatile organic acids is suitable to enhance nutrients recycling and algal biodiesel production from anaerobically digested waste sludge.
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Eliminação de Resíduos Líquidos , Compostos de Amônio , Biocombustíveis , Biomassa , Chlorella/crescimento & desenvolvimento , Fermentação , Lipídeos/biossíntese , Microalgas/fisiologia , Nutrientes , Compostos Orgânicos , Reciclagem , EsgotosRESUMO
Insufficient organics in anaerobic digestate of sludge limited algal mixotrophic culture and caused low lipids production. In this study, enhancing lipids production and pollutants removal by adding acidified starch wastewater was tested for Chlorella pyrenoidosa mixotrophic culture. The results showed that an optimal addition of acidified starch wastewater into anaerobic digestate of sludge (1:1, v/v) improved biomass and lipids production by 0.5-fold (to 2.59â¯g·L-1) and 3.2-fold (87.3â¯mg·L-1·d-1), respectively. The acidified starch wastewater addition also improved the quality of algal biodiesel with higher saturation (typically in C16:0 and C18:0). In addition, 62% of total organic carbon, 99% of ammonium and 95% of orthophosphate in mixed wastewater were effectively removed by microalgae. This study provides a promising way to improve biodiesel production and nutrients recovery from anaerobic digestate of sludge using waste carbon source.
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Chlorella , Microalgas , Anaerobiose , Biomassa , Carbono , Lipídeos , Nutrientes , Esgotos , Águas ResiduáriasRESUMO
To explore the distribution of fungal community in soil of brown coniferous forest in Daxing'anling and its relationship with soil characteristics, soil fungal community structure and diversity in three forest types, light brown coniferous forest, grass brown coniferous forest, and typical brown coniferous forest, were analyzed by high-throughput sequencing technology. The relationship between soil fungal community and soil characteristics was analyzed by R and SPSS 17.0 software. The results showed that soil physical and chemical characteristics differed significantly across the three brown coniferous forests. A total of 111 species belonged to six phyla, 23 class, 46 orders, 74 families and 88 genera were recorded in this study. Ascomycetes and basidiomycetes were dominant phyla. There were significant differences in relative abundance of phyla among three forest types. There was no significant difference in the Ace and Chao1 diversity indices among three brown coniferous forests, whereas there were significant differences in the Shannon and Simpson indices. Results from canonical correlation analysis and correlation analysis showed that both α and ß diversity were significantly correlated with soil moisture, soil pH, soil organic matter, soil total nitrogen, and soil total potassium. The results indicated that soil characteristics were important factors affecting soil fungal diversity of brown coniferous forest in Xing'an larch forest in Daxing'anling.
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Solo , Traqueófitas , China , Florestas , FungosRESUMO
BACKGROUND: Medical students struggle with a heavy workload during their comparatively long course of study in China. The future of medical science depends largely on whether or not medical students become qualified. This study aims to explore whether medical students' academic adaptability affects learning outcomes. This paper will not only provide scientific evidence for educators and administrators of medical schools but will also benefit students by improving their aptitude and adaptability through a thorough discussion on their educational environment. METHODS: We conducted a cross-sectional survey from September to December 2016. A total of 1977 respondents completed the questionnaire with a response rate of 79.08%. A cross-sectional survey was used in this study. Descriptive statistics, factor analysis, General Linear Model (GLM) analysis, standard multiple regression, and hierarchical multiple regression were performed for data analysis using the Statistical Package for Social Sciences software (SPSS Version 19.0, SPSS Inc., Chicago, IL, USA). RESULTS: Out of the 1977 students, 1586 (80.2%) had mean academic adaptability levels over 3. Findings suggested that academic adaptability (Mean = 3.32), immersion in learning (Mean = 3.20), and academic performance (Mean = 3.39), were at the middle level while academic burnout (Mean = 2.17) was at a low level. Academic adaptability of medical students showed a significant negative relation to academic burnout (Beta = - 0.705, P<0.01), there was a significant positive relation between academic adaptability and immersion in learning (Beta = 0.655, P<0.01) and academic performance (Beta = 0.407, P<0.01). CONCLUSIONS: Higher levels of academic adaptability are associated with lower levels of burnout and higher levels of immersion in learning and academic performance. It might be helpful for medical schools to consider academic adaptability and ways of enhancing such skills in order to enhance student performance and engagement while in school.
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Desempenho Acadêmico/psicologia , Esgotamento Psicológico , Aprendizagem , Estudantes de Medicina/psicologia , Adolescente , China , Estudos Transversais , Análise Fatorial , Feminino , Humanos , Masculino , Inquéritos e Questionários , Adulto JovemRESUMO
Anaerobic wastewater potentially was an ideal medium for cultivating microalgae. The coupled effect of ammonium, temperature and pH on lipids accumulation was a core issue during algal culture using anaerobic wastewater. Therefore, their combined effects on Chlorella pyrenoidosa culture and lipids accumulation in anaerobic effluent were investigated. Free ammonia induced from the rising pH and temperature inhibited algal growth, but significantly promoted lipid accumulation. The highest lipids content reached 30.2% when pH rose to 8.3-8.5 (25⯰C, ammonium 280â¯mg/L), which was 1.6-fold higher than that under neutral condition. Moreover, the percentage of unsaturated fatty acids (un-SFAs) increased to 74.8-77.9% at pH 8.3-8.5, whereas it was only 56.1-58.9% under neutral condition. The C18:2 and C18:3 dominated the un-SFAs increase at high pH, typically the percentage of C18:3 increased by 74.5-153.1%. This study provides a potential way for lipid accumulation in algal culture using anaerobic wastewater.
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Amônia/metabolismo , Compostos de Amônio/análise , Chlorella/metabolismo , Metabolismo dos Lipídeos , Águas Residuárias/microbiologia , Compostos de Amônio/metabolismo , Anaerobiose , Biomassa , Concentração de Íons de Hidrogênio , Lipídeos/análise , Temperatura , Águas Residuárias/químicaRESUMO
Alcohol wastewater (AW) as carbon source for enhancing Chlorella pyrenoidosa growth and lipid accumulation in anaerobically digested starch wastewater (ADSW) was performed in outdoor cultivation. The biomass and lipid production significantly increased while adding optimal amount of AW (AW/ADSW=1:15) during exponential phase. In comparison with blank ADSW culture, the optimal AW addition increased the biomass production, lipid content and productivity by 35.29%, 102.68% and 227.91%, respectively. However, AW addition caused severe bacterial contamination and the total bacterial increased by 4.62-fold. Simultaneously, the optimal consortia of microalgae/bacteria effectively removed nutrients from the wastewater, including 405.18±36.47mgCODCr/L/day, 49.15±5.54mgN/L/day and 6.72±1.24mgP/L/day.
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Chlorella , Lipídeos , Águas Residuárias , Biomassa , Carbono , Microalgas , AmidoRESUMO
For hydrogel patches, the laboratory tests could not fully reveal the existing problems of full scale of industrial production, and there are few studies about the preparation technique for the industrial manufacturing process of hydrogel patches. So, the purpose of this work was to elucidate the effects of mainly technological operation and its parameters on the performance of hydrogel patches at the industrial-scale production. The results revealed the following: (1) the aqueous phase was obtained by polyvinylpyrrolidone (PVP) along with tartaric acid dissolved in purified water, then feeding this into a vacuum mixer as a whole in one batch, thus extended the crosslinking reaction time of hydrogel paste (matrix) and allowed the operation of coating/cutting-off to be carried out easily, and there was no permeation of backing layer; (2) the gel strength of the hydrogel patches increased with the increase of working temperature, however, once the temperature exceeded 35 ± 2 °C, the hydrogel paste would lose water severely and the resultant physical crosslinking structure which has lower gel/cohesive strength would easily bring gelatinization/residues during application; (3) the relative humidity (RH) of the standing-workshop was dynamically controlled (namely at 35 ± 2 °C, keeping the RH at 55 ± 5% for 4 days, then 65 ± 5% for 2 days), which would make patches with satisfactory characteristics such as better flexibility, higher adhesive force, smooth flat matrix surface, and without gelatinization/residues and warped edge during the using process; (4) the aging of the packaged hydrogel patches was very sensitive to storage temperature, higher temperature, higher gel strength and lower adhesiveness. The storage temperature of 10 ± 2 °C could effectively prevent matrix aging and adhesion losing, which would also facilitate the expiration date of patches extended obviously. In conclusion, this work provides an optimized and feasible preparation technique for the industrial production of the hydrogel patches and establishes the hydrogel patches as a novel carrier for transdermal drug delivery.
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Hidrogéis/química , Adesividade , Administração Cutânea , Povidona/química , Tartaratos , Tecnologia Farmacêutica/métodos , Temperatura , ÁguaRESUMO
Nuclear factor of activated T cells (NFAT) is a multifunctional cytokine family. NFAT5 was recently reported to be involved in many neuronal functions, but its specific function remains unclear. In this study, our aim is to investigate whether NFAT5 overexpression can protect astrocytes against oxygen-glucose-serum deprivation/restoration (OGSD/R) damage. In vivo, rats were subjected to ischemia-reperfusion injury, resulting in increased water content, infarct volume, and expression of NFAT5 protein in rat spinal cord. After primary culture for spinal cord astrocytes, the in vitro OGSD/R model was established. The results of the CCK8 assay and flow cytometry showed that, in the OGSD/R group, astrocyte cell viability was downregulated, but astrocyte apoptosis increased. Caspase 3 activity increased as well. Levels of NFAT5, as detected by real-time quantitative PCR and western blot, decreased under OGSD/R, as did SIRT1. Commercial kits for activity assays were used to show that OGSD/R inhibited SIRT1 activation but accelerated SOD activation after OGSD/R. Next, pcDNA-NFAT5 or NFAT5 siRNA was transfected into astrocytes. Overexpression of NFAT5 not only promoted the survival of the astrocytes and SIRT1 activation under OGSD/R but also inhibited cell apoptosis and SOD activation. Moreover, overexpression of NFAT5 apparently diminished histone acetylation and promoted the nuclear transport of Nrf2. Our results show that NFAT5 protects spinal astrocytes in a manner that depends on activation of the SIRT1/Nrf2 pathway. These findings present a novel potential molecular mechanism for NFAT5 therapy in the context of spinal cord injury.