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1.
Sci Total Environ ; 803: 149805, 2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-34492494

RESUMO

Accurate, high spatial and temporal resolution water quality monitoring in inland waters is vital for environmental management. However, water quality monitoring in inland waters by satellite remote sensing remains challenging due to low signal-to-noise ratios (SNRs) and instrumental resolution limitations. We propose the concept of proximal remote sensing for monitoring water quality. The proximal hyperspectral imager, developed by Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences (CAS) and Hikvision Digital Technology, Ltd., is a high spatial, temporal and spectral resolution (1 nm) sensor for continuous observation, allowing for effective and practical long-term monitoring of inland water quality. In this study, machine learning and empirical algorithms were developed and validated using in situ total nitrogen (TN), total phosphorus (TP), chemical oxygen demand (COD) concentrations and spectral reflectance from Lake Taihu (N = 171), the Liangxi River (N = 94) and the Fuchunjiang Reservoir (N = 109) covering different water quality. Our dataset includes a large range for three key water quality parameters of TN from 0.93 to 6.46 mg/L, TP from 0.04 to 0.62 mg/L, and COD from 1.32 to 15.41 mg/L. Overall, the back-propagation (BP) neural network model had an accuracy of over 80% for TN (R2 = 0.84, RMSE = 0.33 mg/L, and MRE = 11.4%) and over 90% for TP (R2 = 0.93, RMSE = 0.02 mg/L, and MRE = 12.4%) and COD (R2 = 0.91, RMSE = 0.66 mg/L, and MRE = 9.3%). Our results show that proximal remote sensing combined with machine learning algorithms has great potential for monitoring water quality in inland waters.


Assuntos
Tecnologia de Sensoriamento Remoto , Qualidade da Água , Monitoramento Ambiental , Lagos , Rios
2.
Environ Res ; 203: 111848, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34390714

RESUMO

Cyanobacterial blooms are increasing in magnitude, frequency, and duration worldwide. However, our knowledge of cyanobacterial blooms dynamics and driving mechanisms is still limited due to their high spatiotemporal variability. To determine the potential driving mechanisms of cyanobacterial blooms in oligotrophic lakes, we collected a high-frequency depth profile of chlorophyll fluorescence (ChlF) and synchronous water quality, hydrometeorological data in early spring 2016 in oligotrophic Lake Qiandaohu. The vertical distribution of ChlF exhibited two patterns, "aggregated" and "discrete", using Morisita's index, and the aggregated ChlF presented subsurface chlorophyll maxima during the thermal stratification period. The ChlF concentration was positively correlated with water temperature and negatively correlated with turbidity. Significantly linear relationships were observed between ChlF vertical structure parameters (e.g., Morisita's index, subsurface chlorophyll maxima depth and thickness) and thermal stratification parameters (e.g., mixing layer depth and relative water column stability). After rainstorm floods, the ChlF pattern suddenly change from "aggregated" to "discrete" and a ChlF concentration <1 µg/L was observed for 7-11 days with a significant increase in the mixing depth layer and turbidity. The results suggest that cyanobacterial blooms are robustly associated with thermal stratification and rainstorm floods in the deep and oligotrophic lake. Thermal stratification boosts surface phytoplankton accumulation by increasing water temperature, enhancing light availability and restricting phytoplankton vertical distribution. Rainstorm floods interrupt the accumulation by disrupting thermal stratification and decreasing the available light. Furthermore, wind speed and air temperature both regulate the phytoplankton dynamics by affecting thermal stratification. Our research quantifies the cyanobacterial bloom dynamics and their relationship between environmental factors, improving our knowledge of the driving mechanisms of cyanobacterial bloom for the protection of drinking water safety and aquatic organism health in lakes.

3.
Environ Chem Lett ; : 1-11, 2021 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-34744548

RESUMO

Despite large decreases of emissions of air pollution during the coronavirus disease 2019 (COVID-19) lockdown in 2020, an unexpected regional severe haze has still occurred over the North China Plain. To clarify the origin of this pollution, we studied air concentrations of fine particulate matter (PM2.5), NO2, O3, PM10, SO2, and CO in Beijing, Hengshui and Baoding during the lockdown period from January 24 to 29, 2020. Variations of PM2.5 composition in inorganic ions, elemental carbon and organic matter were also investigated. The HYSPLIT model was used to calculate backward trajectories and concentration weighted trajectories. Results of the cluster trajectory analysis and model simulations show that the severe haze was caused mainly by the emissions of northeastern non-stopping industries located in Inner Mongolia, Liaoning, Hebei, and Tianjin. In Beijing, Hengshui and Baoding, the mixing layer heights were about 30% lower and the maximum relative humidity was 83% higher than the annual averages, and the average wind speeds were lower than 1.5 m s-1. The concentrations of NO3 -, SO4 2-, NH4 +, organics and K+ were the main components of PM2.5 in Beijing and Hengshui, while organics, K+, NO3 -, SO4 2-, and NH4 + were the main components of PM2.5 in Baoding. Contrary to previous reports suggesting a southerly transport of air pollution, we found that northeast transport caused the haze formation. Supplementary Information: The online version contains supplementary material available at 10.1007/s10311-021-01314-8.

4.
Front Med (Lausanne) ; 8: 732413, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34746175

RESUMO

Introduction: Glomerular hyperfiltration (GHF) is an early kidney injury. We investigated whether GHF is associated with arterial stiffness expressed by increase of brachial-ankle pulse wave velocity (baPWV) and pulse pressure (PP), and whether the coexistence of GHF and abnormal metabolism increases the risk of arterial stiffness. Methods: In this prospective cohort study, 2,133 non-chronic kidney disease (CKD) participants aged ≥40 years were followed for a mean period of 3.3 years. The extent of arterial stiffness was expressed by measures of baPWV and PP. GHF was defined as eGFR exceeding the age- and sex-specific 90th percentile. Multivariate logistic regression models were used to assess the association between GHF/abnormal metabolism and increased baPWV/PP. The interaction indexes of GHF and abnormal metabolism on arterial stiffness were calculated based on the OR in a multivariate logistic regression model. Results: GHF alone was not associated with increased baPWV or PP in all participants in this study. However, when GHF coexisted with abnormal metabolism, the risk of increased PP increased 3.23-fold [OR = 3.23(1.47-7.13)] compared with participants with normal filtration and normal metabolism, in which the interaction accounted for 55.1% of the total effect and 79.8% of the effect from GHF and abnormal metabolism. After subtracting the independent effects of GHF and abnormal metabolism, their combined effect still resulted in a 1.78-fold increase in PP. Conclusion: GHF could interact with abnormal metabolism to significantly enhance arterial stiffness. Since abnormal metabolism commonly exists in the general population, even slight changes in renal function should be distinguished to prevent arterial stiffness risk.

5.
Animals (Basel) ; 11(11)2021 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-34827754

RESUMO

The large yellow croaker (Larimichthys crocea) is an important marine economic fish in China; however, its intolerance to hypoxia causes widespread mortality. To understand the molecular mechanisms underlying hypoxia tolerance in L. crocea, the transcriptome gene expression profiling of three different tissues (blood, gills, and liver) of L. crocea exposed to hypoxia and reoxygenation stress were performed. In parallel, the gene relationships were investigated based on weighted gene co-expression network analysis (WGCNA). Accordingly, the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis showed that several pathways (e.g., energy metabolism, signal transduction, oxygen transport, and osmotic regulation) may be involved in the response of L. crocea to hypoxia and reoxygenation stress. In addition, also, four key modules (darkorange, magenta, saddlebrown, and darkolivegreen) that were highly relevant to the samples were identified by WGCNA. Furthermore, some hub genes within the association module, including RPS16, EDRF1, KCNK5, SNAT2, PFKL, GSK-3ß, and PIK3CD, were found. This is the first study to report the co-expression patterns of a gene network after hypoxia stress in marine fish. The results provide new clues for further research on the molecular mechanisms underlying hypoxia tolerance in L. crocea.

6.
Zool Res ; 42(6): 746-760, 2021 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-34636194

RESUMO

Oxygen is an essential molecule for animal respiration, growth, and survival. Unlike in terrestrial environments, contamination and climate change have led to the frequent occurrence of hypoxia in aquatic environments, thus impacting aquatic animal survival. However, the adaptative mechanisms underlying fish responses to environmental hypoxia remain largely unknown. Here, we used large yellow croaker ( Larimichthys crocea) and large yellow croaker fry (LYCF) cells to investigate the roles of the Hif-1α/Hsf1/Hsp70 signaling pathway in the regulation of cellular redox homeostasis, and apoptosis. We confirmed that hypoxia induced the expression of Hif-1α, Hsf1, and Hsp70 in vivo and in vitro. Genetic Hsp70 knockdown/overexpression indicated that Hsp70 was required for maintaining redox homeostasis and resisting oxidative stress in LYCF cells under hypoxic stress. Hsp70 inhibited caspase-dependent intrinsic apoptosis by maintaining normal mitochondrial membrane potential, enhancing Bcl-2 mRNA and protein expression, inhibiting Bax and caspase3 mRNA expression, and suppressing caspase-3 and caspase-9 activation. Hsp70 suppressed caspase-independent intrinsic apoptosis by inhibiting nuclear translocation of apoptosis-inducing factor (AIF) and disturbed extrinsic apoptosis by inactivating caspase-8. Genetic knockdown/overexpression of Hif-1α and dual-luciferase reporter assay indicated that Hif-1α activated the Hsf1 DNA promoter and enhanced Hsf1 mRNA transcription. Hsf1 enhanced Hsp70 mRNA transcription in a similar manner. In summary, the Hif-1α/Hsf1/Hsp70 signaling pathway plays an important role in regulating redox homeostasis and anti-apoptosis in L. crocea under hypoxic stress.


Assuntos
Fatores de Transcrição de Choque Térmico/metabolismo , Homeostase/fisiologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Oxigênio/farmacologia , Perciformes/metabolismo , Transdução de Sinais/fisiologia , Animais , Apoptose , Linhagem Celular , Clonagem Molecular , Biologia Computacional , Regulação da Expressão Gênica/efeitos dos fármacos , Fatores de Transcrição de Choque Térmico/genética , Homeostase/efeitos dos fármacos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Oxirredução , Oxigênio/química , Perciformes/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Água/química
7.
Brain Sci ; 11(10)2021 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-34679331

RESUMO

Functional connectivity, representing a statistical coupling relationship between different brain regions or electrodes, is an influential concept in clinical medicine and cognitive neuroscience. Electroencephalography-derived functional connectivity (EEG-FC) provides relevant characteristic information about individual differences in cognitive tasks and personality traits. However, it remains unclear whether these individual-dependent EEG-FCs remain relatively permanent across long-term sessions. This manuscript utilizes machine learning algorithms to explore the individual specificity and permanence of resting-state EEG connectivity patterns. We performed six recordings at different intervals during a six-month period to examine the variation and permanence of resting-state EEG-FC over a long period. The results indicated that the EEG-FC networks are quite subject-specific with a high-precision identification accuracy of greater than 90%. Meanwhile, the individual specificity remained stable and only varied slightly after six months. Furthermore, the specificity is mainly derived from the internal connectivity of the frontal lobe. Our work demonstrates the existence of specific and permanent EEG-FC patterns in the brain, providing potential information for biometric applications.

8.
Laryngoscope ; 2021 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-34709658

RESUMO

OBJECTIVES: To develop a novel grading system and appropriate surgical approaches for patients with diffuse type tensosynovial giant cell tumor (D-TGCT) of the temporal bone. STUDY DESIGN: Retrospective cohort study. METHODS: We retrospectively reviewed 31 patients with temporal bone D-TGCT between June 2012 and July 2021. All patients underwent comprehensive clinical evaluations, including clinical presentations, hearing threshold, imaging studies, surgical approaches, and prognosis. A grading system was developed based on the tumor location and adjacent neurovascular structures involvement according to imaging and intraoperative findings. RESULTS: In this study, grade II tumors were the most common (13/31), followed by grades I (7/31), III (7/31), and IV (4/31) tumors. Seven grade I patients received the subtemporal middle cranial fossa approach (SMCF) combined with the canal wall up mastoidectomy and tympanoplasty (CWUT). Nine grade II patients underwent SMCF combined with subtotal petrosectomy (SPTR), and four grade II patients underwent SMCF combined with CWUT. Seven grade III patients received SMCF combined with SPTR and dura mater reconstruction, and four grade IV patients underwent infratemporal fossa approach type B. Gross total resection was achieved in all patients, and the median follow-up time was 30.1 months (range, 4-96 months). Three patients (one grade II, one grade III, and one grade IV) had recurrence during follow-up, and the patient with grade III tumor had two recurrences. CONCLUSIONS: Gross total resection is the first-line treatment for patients with D-TGCT of the temporal bone. This novel grading system enables surgeons to select optimal surgical strategy. Long-term follow-up is mandatory postoperatively. LEVEL OF EVIDENCE: 4 Laryngoscope, 2021.

9.
Int J Biol Sci ; 17(14): 3689-3701, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34671193

RESUMO

Esophageal squamous cell carcinoma (ESCC) is one of the most common gastrointestinal tumors, accounting for almost half a million deaths per year. Cancer-associated fibroblasts (CAFs) are the major constituent of the tumor microenvironment (TME) and dramatically impact ESCC progression. Recent evidence suggests that exosomes derived from CAFs are able to transmit regulating signals and promote ESCC development. In this study, we compared different the component ratios of miRNAs in exosomes secreted by CAFs in tumors and with those from normal fibroblasts (NFs) in precancerous tissues. The mRNA level of hsa-miR-3656 was significantly upregulated in the former exosomes. Subsequently, by comparing tumor cell development in vitro and in vivo, we found that the proliferation, migration and invasion capabilities of ESCC cells were significantly improved when miR-3656 was present. Further target gene analysis confirmed ACAP2 was a target gene regulated by miR-3656 and exhibited a negative regulatory effect on tumor proliferation. Additionally, the downregulation of ACAP2 triggered by exosomal-derived miR-3656 further promotes the activation of the PI3K/AKT and ß-catenin signaling pathways and ultimately improves the growth of ESCC cells both in vitro and in xenograft models. These results may represent a potential therapeutic target for ESCC and provide a new basis for clinical treatment plans.

10.
Front Cardiovasc Med ; 8: 735679, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34621801

RESUMO

Background: Both baseline blood pressure (BP) and cumulative BP have been used to estimate cardiovascular event (CVE) risk of higher BP, but which one is more reliable for recommendation to routine clinical practice is unclear. Methods: In this prospective study, conducted in the Kailuan community of Tanshan City, China, a total of 95,702 participants free of CVEs at baseline (2006-2007) were included and followed up until 2017. Time-weighted cumulative BP that expresses the extent of cumulative BP exposure is defined as the sum of the mean of two consecutive systolic or diastolic BP times the interval between the two determinations, then normalized by the total follow-up duration. Incident CVEs during 2006-2017 were confirmed by review of medical records. We performed a competing risk regression analysis to assess CVE risk of the different durations of higher BP exposure. ROC analysis was performed to assess the predictive value of higher BP on CVE occurrence. Results: We found that when the risk of higher BP on CVE occurrence was estimated based on time-weighted cumulative BP, the hazard ratios (HRs) increased with the increase in duration of higher BP exposure in each of the four BP groups: <120/<80, 120-129/<80, 130-139/80-89, and ≥140/≥90 mmHg; this time trend also occurred across the four different BP groups, with the higher BP group exhibiting CVE risk earlier during the follow-up. These results were confirmed by the same analysis performed on participants without baseline hypertension. However, such reasonable time trends did not occur when a single baseline BP was used as the primary estimation. We also demonstrated that the predictive values of baseline systolic and diastolic BP that predict CVE occurrence were only 0.6-3.2 and 0.2-3.1% lower, respectively, than those of cumulative BP combined with baseline BP during follow-up. Conclusions: Baseline BP remains a useful indicator for predicting future occurrence of CVEs. Nevertheless, time-weighted cumulative BP could more reliably estimate the CVE risk of higher BP exposure than baseline BP.

11.
J Hazard Mater ; 416: 126194, 2021 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-34492958

RESUMO

The improvement of stability is a crucial and challenging issue for industrial catalyst, which affects not only the service time but also the cost of catalyst. This is especially prominent for that applied in harsh environment atmospheres, such as the exhaust of diesel vehicles. Herein, we reported a new strategy to improve the high-temperature hydrothermal stability of Cu-SSZ-13, which is a promising catalyst for the treatment of exhaust emitted from diesel vehicles through the NH3-SCR NOx route. Different from that reported in literature, we managed to improve the high-temperature hydrothermal stability of Cu-SSZ-13 by coating the surface with a nanolayer of stable SiO2 material using the atomic layer deposition (ALD) method. The coating of SiO2 layers effectively suppressed the leaching of alumina from the SSZ-13 molecular sieve even after the hydrothermal aging at 800 °C for 16 h with 12.5% water in air. Meanwhile, the ultra-thin SiO2 nanolayer does not block the pores of zeolites and affect the catalytic activity of Cu-SSZ-13 contribute to the superiority of the ALD technology.

12.
Mol Plant ; 2021 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-34562666

RESUMO

Phosphorous (P) and iron (Fe), two essential nutrients for plant growth and development, are highly abundant elements in the earth's crust but often display low availability to plants. Due to the ability to form insoluble complexes, the antagonistic interaction between P and Fe nutrition in plants has been noticed for decades. However, the underlying molecular mechanism modulating the signaling and homeostasis between them remains obscure. Here, we show that the possible iron sensors HRZs, the iron deficiency-induced E3 ligases, could interact with the central regulator of phosphate (Pi) signaling, PHR2, and prompt its ubiquitination at lysine residues K319 and K328, leading to its degradation in rice. Consistent with this, the hrzs mutants displayed a high Pi accumulation phenotype. Furthermore, we found that iron deficiency could attenuate Pi starvation signaling by inducing the expression of HRZs, which in turn trigger PHR2 protein degradation. Interestingly, on the other hand, rice PHRs could negatively regulate the expression of HRZs to modulate iron deficiency responses. Therefore, PHR2 and HRZs form a reciprocal inhibitory module to coordinate Pi and iron signaling and homeostasis in rice. Taken together, our results uncover a molecular link between Pi and iron master regulators, which fine-tunes plant adaptation to Pi and iron availability in rice.

13.
Front Microbiol ; 12: 541451, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34349730

RESUMO

Occurrence of sulfonamide antibiotics has been reported in surface waters with the exposures ranging from < 1 ng L-1 to approximately 11 µg L-1, which may exert adverse effects on non-target algal species, inhibiting algal growth and further hindering the delivery of several ecosystem services. Yet the molecular mechanisms of sulfonamide in algae remain undetermined. The aims of the present work are: (1) to test the hypothesis whether sulfamethoxazole (SMX) inhibits the folate biosynthesis in a model green alga Raphidocelis subcapitata; and (2) to explore the effects of SMX at an environmentally relevant concentration on algal health. Here, transcriptomic analysis was applied to investigate the changes at the molecular levels in R. subcapitata treated with SMX at the concentrations of 5 and 300 µg L-1. After 7-day exposure, the algal density in the 5 µg L-1 group was not different from that in the controls, whereas a marked reduction of 63% in the high SMX group was identified. Using the adj p < 0.05 and absolute log2 fold change > 1 as a cutoff, we identified 1 (0 up- and 1 downregulated) and 1,103 (696 up- and 407 downregulated) differentially expressed genes (DEGs) in the 5 and 300 µg L-1 treatment groups, respectively. This result suggested that SMX at an environmentally relevant exposure may not damage algal health. In the 300 µg L-1 group, DEGs were primarily enriched in the DNA replication and repair, photosynthesis, and translation pathways. Particularly, the downregulation of base and nucleotide excision repair pathways suggested that SMX may be genotoxic and cause DNA damage in alga. However, the folate biosynthesis pathway was not enriched, suggesting that SMX does not necessarily inhibit the algal growth via its mode of action in bacteria. Taken together, this study revealed the molecular mechanism of action of SMX in algal growth inhibition.

14.
J Oncol ; 2021: 5177140, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34422049

RESUMO

Objective: To study the safety of apatinib combined with chemotherapy in the treatment of advanced gastric carcinoma (GCA). Methods: 74 patients with advanced GCA treated in the oncology department of Weifang People's Hospital (January 2019-January 2020) were enrolled in this study and equally split into study group (SG) and reference group (RG) according to the odd and even admission numbers. RG underwent chemotherapy alone, while SG received apatinib combined with chemotherapy. The clinical indicators of serum matrix metalloproteinase 9 (MMP-9), serum interleukin-2 receptor (SIL-2R), and immune cell level were detected in the two groups before and after treatment to analyze the therapeutic effect of different treatment methods on patients with advanced gastric carcinoma. Results: No obvious differences in gender ratio, average age, average BMI, pathological staging, pathological types, organ metastasis types, and residence were observed between the two groups (P > 0.05). The short-term follow-up results showed that the disease control rate (DCR) in SG was markedly higher compared with RG (P < 0.05). The MMP-9 and SIL-2R levels in both groups after treatment decreased (P < 0.05), and the levels in SG after treatment were notably lower compared with RG (P < 0.001). Compared with RG, CD3+, CD4+, and CD4+/CD8+ levels in SG after treatment were notably higher (P < 0.001), while the CD8+ level was notably lower (P < 0.001). The median progression-free survival (MPFS) and overall survival (OS) in SG were markedly higher compared with RG (P < 0.001). The GQOLI-74 scores in both groups after treatment increased (P < 0.001), and the GQOLI-74 score in SG after treatment was markedly higher compared with RG (P < 0.001). The total incidence of adverse reactions was lower in SG than in RG (P < 0.05). Conclusion: Apatinib combined with chemotherapy is superior to chemotherapy alone in effectively improving treatment outcomes in patients with advanced GCA.

15.
Biomedicines ; 9(8)2021 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-34440055

RESUMO

A maytansin derivative, DM1, is a promising therapeutic compound for treating tumors, but is also a highly poisonous substance with various side effects. For clinical expansion, we tried to develop novel peptide-drug conjugates (PDCs) with DM1. In the study, a one-bead one-compound (OBOC) platform was used to screen and identify a novel, highly stable, non-natural amino acid peptide targeting the tyrosine receptor FGFR2. Then, the identified peptide, named LLC2B, was conjugated with the cytotoxin DM1. Our results show that LLC2B has high affinity for the FGFR2 protein according to an isothermal titration calorimetry (ITC) test. LLC2B-Cy5.5 binding to FGFR2-positive cancer cells was confirmed by fluorescent microscopic imaging and flow cytometry in vitro. Using xenografted nude mouse models established with breast cancer MCF-7 cells and esophageal squamous cell carcinoma KYSE180 cells, respectively, LLC2B-Cy5.5 was observed to specifically target tumor tissues 24 h after tail vein injection. Incubation assays, both in aqueous solution at room temperature and in human plasma at 37 °C, suggested that LLC2B has high stability and strong anti-proteolytic ability. Then, we used two different linkers, one of molecular disulfide bonds and another of a maleimide group, to couple LLC2B to the toxin DM1. The novel peptide-drug conjugates (PDCs) inhibited tumor growth and significantly increased the maximum tolerated dose of DM1 in xenografted mice. In brief, our results suggest that LLC2B-DM1 can be developed into a potential PDC for tumor treatment in the future.

16.
Zool Res ; 42(5): 592-605, 2021 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-34387415

RESUMO

The large yellow croaker (Larimichthys crocea), which is an economically important mariculture fish in China, is often exposed to environmental hypoxia. Reactive oxygen species (ROS) homeostasis is essential for the maintenance of normal physiological conditions in an organism. Direct evidence that environmental hypoxia leads to ROS overproduction is scarce in marine fish. Furthermore, the sources of ROS overproduction in marine fish under hypoxic stress are poorly known. In this study, we investigated the effects of hypoxia on redox homeostasis in L. crocea and the impact of impaired redox homeostasis on fish. We first confirmed that hypoxia drove ROS production mainly via the mitochondrial electron transport chain and NADPH oxidase complex pathways in L. crocea and its cell line (large yellow croaker fry (LYCF) cells). We subsequently detected a marked increase in the antioxidant systems of the fish. However, imbalance between the pro-oxidation and antioxidation systems ultimately led to excessive ROS and oxidative stress. Cell viability showed a remarkable decrease while oxidative indicators, such as malondialdehyde, protein carbonylation, and 8-hydroxy-2 deoxyguanosine, showed a significant increase after hypoxia, accompanied by tissue damage. N-acetylcysteine (NAC) reduced ROS levels, alleviated oxidative damage, and improved cell viability in vitro. Appropriate uptake of ROS scavengers (e.g., NAC and elamipretide Szeto-Schiller-31) and inhibitors (e.g., apocynin, diphenylene iodonium, and 5-hydroxydecanoate) may be effective at overcoming hypoxic toxicity. Our findings highlight previously unstudied strategies of hypoxic toxicity resistance in marine fish.


Assuntos
Antioxidantes/metabolismo , Peixes/metabolismo , Estresse Oxidativo/fisiologia , Oxigênio/química , Oxigênio/metabolismo , Espécies Reativas de Oxigênio , Animais , Linhagem Celular , Sobrevivência Celular , Meio Ambiente , Homeostase , NADP
17.
Small ; 17(37): e2103702, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34390185

RESUMO

Micromanipulation techniques that are capable of assembling nano/micromaterials into usable structures such as topographical micropatterns (TMPs) have proliferated rapidly in recent years, holding great promise in building artificial electronic and photonic microstructures. Here, a method is reported for forming TMPs based on optoelectronic tweezers in either "bottom-up" or "top-down" modes, combined with in situ photopolymerization to form permanent structures. This work demonstrates that the assembled/cured TMPs can be harvested and transferred to alternate substrates, and illustrates that how permanent conductive traces and capacitive circuits can be formed, paving the way toward applications in microelectronics. The integrated, optical assembly/preservation method described here is accessible, versatile, and applicable for a wide range of materials and structures, suggesting utility for myriad microassembly and microfabrication applications in the future.


Assuntos
Micromanipulação , Óptica e Fotônica , Eletrônica , Fótons
18.
Bioresour Technol ; 341: 125781, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34454235

RESUMO

Bacterial cellulose (BC) has a huge global market due to its excellent properties and wide range of applications. However, due to high production costs, low productivity, and unsatisfactory scale-up production, industrialisation has been slow. Herein, stabilization of strain, optimisation of culture conditions, and a cheap carbon source were combined to achieve highly efficient, low-cost, large-scale BC production in 20 L containers. Optimisation of culture conditions increased both BC productivity and sugar conversion ratio significantly, from 2.08 g/L/day and 9.78% to 17.13 g/L/day and 70.31%, respectively. Furthermore, BC productivity and sugar conversion ratio reached 13.96 g/L/day and 85.50% using corn stover total hydrolysate as carbon source. The low-cost, facile, and highly efficient process can generate large quantities of BC, and could promote industrialisation of BC production.


Assuntos
Celulose , Enterobacter , Zea mays
19.
Pest Manag Sci ; 77(12): 5475-5488, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34351686

RESUMO

BACKGROUND: In 2017 Tuta absoluta was identified as an invasive species in China. Due to its rapid geographic expansion and the severe crop damage it causes, T. absoluta poses a serious threat to China's tomato production industry. To determine its geographic distribution and host range, intensive surveys and routine monitoring were conducted across the Chinese mainland between 2018 and 2019. The population colonization coefficient (PCC; ratio of colonized sites and prefectures) and population occurrence index (POI; ratio of infested host species and PCCs) were calculated. RESULTS: In northwestern China, T. absoluta populations established in Xinjiang exhibited a medium PCC value (~0.03). In southwestern China, populations in Yunnan and its five neighboring provinces exhibited high (~0.50 in Yunnan and Guizhou), or low (<0.02 in Guangxi, Sichuan, Hunan, and Chongqing) PCC values. In the Chinese mainland, infestations of four crop plant species (tomato, eggplant, potato, and Chinese lantern) and two wild plant species (black nightshade and Dutch eggplant) were identified; tomatoes were infested in every colonized province. Chinese lantern and Dutch eggplant are potentially novel hosts. Yunnan, Guizhou, and Xinjiang experienced the most serious damage (POI). In southwestern China, observed damage significantly decreased with increased distance from the first discovery site of T. absoluta to the farthest county of an infested province increased. CONCLUSION: T. absoluta populations are well-established and could potentially spread to other regions of China. The present study helps to inform the establishment of better pest management guidelines and strategies in China and tomato-producing regions worldwide. © 2021 Society of Chemical Industry.


Assuntos
Lycopersicon esculentum , Mariposas , Animais , China/epidemiologia , Surtos de Doenças , Especificidade de Hospedeiro , Larva , América do Sul
20.
Insects ; 12(7)2021 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-34209609

RESUMO

The tomato leaf miner, Tuta absoluta is a destructive pest of tomato. The leaf-mining activities of its larvae can cause significant yield losses. Real-time quantitative polymerase chain reaction (RT-qPCR) is commonly used to measure gene expression, and the selection of stable reference genes for calibration and standardization is critical for accurate use of RT-qPCR. We studied the stable expression of nine common housekeeping genes in T. absoluta. These were examined at different developmental stages, in larval tissues, as well as those induced by exposure to 20E and insecticides. Four dedicated algorithms (geNorm, BestKeeper, NormFinder, and ΔCt method) and online tool (RefFinder) were used to analyze and rank the tested reference genes. Based on the standardized gene expression data of target gene ecdysone receptor (EcR), the applicability of specific reference genes was verified. The results clarify that the optimal internal reference genes vary greatly under different experimental conditions. GAPDH and RPS11 were the best reference genes for developmental stages; RPL28 and RPL10 for different tissues; EF1α and RPL28 for 20E treatment; EF1α and RPL7A for insecticide treatments. The most suitable reference genes in all experimental conditions are EF1α and RPL28.

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