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1.
ACS Nano ; 2021 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-33400494

RESUMO

Micelles of Pluronic F108 (EO132PO50EO132)/P104 (EO27PO61EO27) surfactant mixtures swollen with toluene were found to template silica nanotubes that formed double-helical structures under appropriately selected aqueous acidic solution conditions. In particular, the double-helical nanotube structure (DHNTS) formed as a main product at 15 °C for 30-37.5 wt % of Pluronic P104 in a surfactant mixture, with 35 wt % being particularly suitable. The formation of DHNTSs appears to involve a spontaneous wrapping of micelle-templated nanotubes around one another, while a similar structure was known to form only under confinement of anodic alumina pores of appropriate diameter. In addition to DHNTSs, other helical or circular structures, such as a helical nanotube tightly wrapped around a straight nanotube, or nanotube(s) wrapped around a sphere, were observed in many cases as minor components. DHNTSs formed as a major component at a well-defined proportion of silica precursor to surfactant at 15 °C, while the relative amount of the swelling agent and the hydrochloric acid concentration could be varied considerably. The hydrothermal treatment temperature was used to adjust the pore diameter of the DHNTS. However, structures formed without the hydrothermal treatment or with the treatment at a moderate temperature appeared very soft, while the treatment at excessively high temperature resulted in a development of significant gaps in the nanotube walls. Our results establish DHNTS as a well-defined ordered mesoporous silica with ultralarge (∼35 nm) helical mesopores of some degree of diameter adjustability, accessible under aqueous conditions using common nonionic surfactants as templating agents.

2.
Artigo em Inglês | MEDLINE | ID: mdl-33412526

RESUMO

Edge and bulk energy levels can coexist in a quantum dot (QD) made of a topological insulator. Interference effect will occur between bulk and edge levels and also between degenerate edge levels. It can be observed in the transport behavior. For the former, it acts as Fano interference with edge and bulk levels contributing continuous and resonant transport channels, respectively. Generally speaking, Fano interference can be realized in a two-armed junction with a single QD or a one-armed junction with at least two QDs. But here it is realized in a one-armed junction with a single QD. As for the interference between degenerate edge levels, it leads to a spin and space dependent scattering process. Spin of an incident electron will either be conserved or rotate about an axis for transmitting into different leads. It is determined by the local spin polarization of edge levels and the accumulated phase in transport paths in the QD. It may be used in the design of a spin field-effect transistor.

3.
J Fluoresc ; 2021 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-33410088

RESUMO

A highly selective turn-on fluorescent and naked-eye colourimetric dual-channel probe for cyanide anions (CN-) has been designed and characterized. In the mixed solution (DMSO / H2O, 9:1, v / v), only CN- could cause an increase in the UV absorption intensity and the corresponding fluorescence intensity increased, and other anions had no significant effect on the probe. After treatment with cyanide in the probe solution, the solution showed a noticeable colour change, from light yellow to purple. Moreover, a fluorescence spectrophotometer can be used to observe that the fluorescence intensity of the solution is significantly enhanced. The response of the colourimetric and fluorescent dual-channel probe to CN- was attributed to nucleophilic addition, and the mechanism was determined by 1H NMR spectroscopy. In addition, this probe was used to detect CN- in actual water samples, including river water, drinking water, and tap water. The spiked CN- recovery rate is very high (97.2%-100.06%), and analytical precision is also very high (RSD < 2%), which shows its feasibility and reliability for detecting cyanide ions in actual water samples.

4.
Clin Exp Rheumatol ; 2021 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-33427622

RESUMO

OBJECTIVES: Predicting response to anti-tumour necrosis factor alpha (anti-TNFα) drugs at baseline remains an elusive goal in rheumatoid arthritis (RA) management. The purpose of this study was to determine if baseline genetic variants of PTPRC, AFF3, myD228, CHUK, MTHFR1, MTHFR2, CD226 and a number of KIR and HLA alleles could predict response to anti-TNF-α in rheumatoid arthritis patients. METHODS: Peripheral blood samples were collected from 238 RA patients treated with anti-TNFα drugs. Genotyping was performed using biochip array technology by Randox Laboratories Ltd. and sequence specific polymerase chain reaction. Linear regression analysis was performed to investigate the role of these genotypes in predicting response to treatment, as defined by European League Against Rheumatism (EULAR) response classification and absolute change in disease activity score (DAS28). RESULTS: Of 238 RA patients analysed, 50.4% received adalimumab, 29.7% received etanercept, 14.8% received infliximab, 3.4% certoluzimab and 1.7% golimumab. The MTHFR1 variant rs1801133 was significantly associated with the EULAR response, p=0.044. Patients with the HLA-DRB1*0404 allele displayed a significantly larger reduction in DAS28 compared to non-carriers (mean -2.22, -1.67 respectively, p=0.033). CD226 rs763361 was the only SNP variant significantly associated with ΔDAS28 (p=0.029). CONCLUSIONS: This study has investigated individual allele associations with reductions in DAS28 across a range of anti-TNFα treatments. A combined predictive model indicates that patients with the HLA-DRB1*0404 allele and without the CD226 rs763361 polymorphism exhibit the largest reduction in DAS28 after anti-TNF-α treatment.

6.
Molecules ; 26(2)2021 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-33445777

RESUMO

A series of fluorinated 7-hydroxycoumarin derivatives containing an oxime ether moiety have been designed, synthesized and evaluated for their antifungal activity. All the target compounds were determined by 1H-NMR, 13C-NMR, FTIR and HR-MS spectra. The single-crystal structures of compounds 4e, 4h, 5h and 6c were further confirmed using X-ray diffraction. The antifungal activities against Botrytis cinerea (B. cinerea), Alternariasolani (A. solani), Gibberella zeae (G. zeae), Rhizoctorzia solani (R. solani), Colletotrichum orbiculare (C. orbiculare) and Alternaria alternata (A. alternata) were evaluated in vitro. The preliminary bioassays showed that some of the designed compounds displayed the promising antifungal activities against the above tested fungi. Strikingly, the target compounds 5f and 6h exhibited outstanding antifungal activity against B. cinerea at 100 µg/mL, with the corresponding inhibition rates reached 90.1 and 85.0%, which were better than the positive control Osthole (83.6%) and Azoxystrobin (46.5%). The compound 5f was identified as the promising fungicide candidate against B. cinerea with the EC50 values of 5.75 µg/mL, which was obviously better than Osthole (33.20 µg/mL) and Azoxystrobin (64.95 µg/mL). Meanwhile, the compound 5f showed remarkable antifungal activities against R. solani with the EC50 values of 28.96 µg/mL, which was better than Osthole (67.18 µg/mL) and equivalent to Azoxystrobin (21.34 µg/mL). The results provide a significant foundation for the search of novel fluorinated 7-hydroxycoumarin derivatives with good antifungal activity.

7.
Adv Healthc Mater ; : e2001369, 2021 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-33448103

RESUMO

Owing to the insufficient guidance of new bone formation in orthopedic and craniomaxillofacial surgery, construction of a guided bone regeneration membrane to support vascularized bone regeneration remains a challenge. Herein, an electrospun asymmetric double-layer polycaprolactone/collagen (PCL/Col) membrane modified by metal-organic framework (MOF) crystals is developed. The optimization of the PCL/Col weight ratio (1:1 and 1:1.5) enables the composite membrane with a balanced tensile strength (only fell by 49.9% in wet conditions) and a controlled degradation rate (completely degraded at 12 weeks). The MOF crystals can provide a pH-responsive release of Zn2+ ions. In vitro experiments indicate that the barrier layer functions to prevent the infiltration of fibrous connective tissue. The MOF crystal layer functions to enhance osteogenesis and angiogenesis in vitro. Using a rat calvarial defect model, the MOF crystals exhibit a sign of osteoinductivity along with blood vessel formation after 8 weeks post-surgery. Strikingly, when assessed in a chick chorioallantoic membrane model, the MOF modified membrane demonstrates a significant angiogenic response, which can be envisaged as its outstanding merits over the commercially Col membrane. Therefore, the MOF crystals represent an exciting biomaterial option, with neovascularization capacity for bone tissue engineering and regenerative medicine.

8.
Mol Med ; 27(1): 4, 2021 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-33413076

RESUMO

BACKGROUND: Vascular cognitive impairment (VCI) is a common cognitive disorder caused by cerebrovascular disease, ranging from mild cognitive impairment to dementia. Studies have shown that aerobic exercise might alleviate the pathological development of VCI, and our previous study observed that aerobic exercise could alleviate VCI through NF-κB/miR-503/BDNF pathway. However, there are few studies on the mechanism. Therefore, it is of great significance to fill the gaps in the mechanism for the early diagnosis of VCI and the clinical prevention and treatment of vascular dementia. METHODS: CircRNA microarray analysis and quantitative real-time PCR were used to detect the expression of circRNA regulating synaptic be exocytosis 2 (RIMS2) (circRIMS2). Cell apoptosis was determined by TdT-mediated dUTP nick-end labeling (TUNEL) assay. The dual-luciferase reporter assay was performed to verify the interaction between circRIMS2 and miR-186, as well as miR-186 and BDNF. RNA pull-down assay detected the binding between circRIMS2 and miR-186. A VCI mouse model was established by repeated ligation of bilateral common carotid arteries (2VO). The lentiviral interfering vector was injected into the VCI mice through the lateral ventricle. The mice in the aerobic exercise group performed 30 min (12 m/min) running for 5 days a week. A Morris water maze test was performed after 4 weeks. RESULTS: The expression of circRIMS2 and BDNF in the serum of VCI patients was significantly reduced, miR-186 expression was increased, and the expression of circRIMS2 was increased in the 2VO group of mice undergoing aerobic exercise. The expression levels of circRIMS2 and BDNF in the oxygen and glucose deprivation-treated (OGD-treated) cells were decreased, the miR-186 expression and cell apoptosis were increased, while the effect was weakened after transfection with the lentiviral vector pLO-ciR-RIMS2. CircRIMS2 could bind to miR-186, and after interference with circRIMS2 in HT22 cells, the expression of miR-186 was increased. Besides, miR-186 could bind to BDNF, and BDNF expression was decreased because of the overexpression of miR-186 in HT22 cells. The expression level of BDNF in the pLO-ciR-RIMS2 group was increased, and apoptosis was decreased, but the miR-186 mimic weakened the effect of pLO-ciR-RIMS2. Aerobic exercise could shorten the average time that mice reached the platform in the Morris water maze, increase the expression level of circRIMS2 and BDNF, reduce miR-186 expression, and inhibit neuronal apoptosis. However, the interference with circRIMS2 weakened this effect. CONCLUSION: The expression of circRIMS2 was down-regulated in VCI and aerobic exercise reduced neuronal apoptosis, and circRIMS2 improved VCI through the circRIMS2/miR-186/BDNF axis.

9.
Sci China Life Sci ; 2021 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-33439457

RESUMO

We aimed to assess the associations of large artery stenosis (LAS) and cerebral small vessel disease (CSVD) with the risk of ischemic stroke and to investigate their respective and combined contributions. In the prospective population-based Shunyi Study, 1,082 stroke-free participants aged 55.9±9.1 years were included. Participants were followed for incident stroke throughout the study period (2013-2019). Total small vessel disease score was used to measure CSVD burden. Cervico-cerebral large artery stenosis was evaluated via brain magnetic resonance angiography and carotid ultrasound. We estimated the risk of ischemic stroke in relation to LAS and CSVD with Cox regression models. During a mean follow-up of 4.2 years, 34 participants (3.1%) experienced at least one ischemic stroke. Severe LAS (≥50% stenosis versus no stenosis: HR=3.27 (95% CI: 1.31-8.18)) and high CSVD burden (total small vessel disease score 2-4 versus 0 point: HR=12.73 (4.83-33.53)) were associated with increased stroke risk independently. In multivariate models, CSVD burden (7.72%) explained a larger portion of the variation in stroke risk than severity of LAS (3.49%). Our findings identified that both LAS and CSVD were associated with future ischemic stroke in asymptomatic subjects, while those with high CSVD burden deserve more attention in primary prevention of stroke.

10.
Aging Cell ; : e13298, 2021 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-33440070

RESUMO

Impaired osteoblast function is involved in osteoporosis, and microRNA (miRNA) dysregulation may cause abnormal osteoblast osteogenic activity. However, the influence of miRNA on osteoblast activity and the underlying mechanisms remain elusive. In this study, miR-103-3p was found to be negatively correlated with bone formation in bone specimens from elderly women with fractures and ovariectomized (OVX) mice. Additionally, miR-103-3p directly targeted Mettl14 to inhibit osteoblast activity, and METTL14-dependent N6 -methyladenosine (m6 A) methylation inhibited miR-103-3p processing by the microprocessor protein DGCR8 and promoted osteoblast activity. Moreover, miR-103-3p inhibited bone formation in vivo, and therapeutic inhibition of miR-103-3p counteracted the decreased bone formation in OVX mice. Further, METTL14 was negatively correlated with miR-103-3p but positively correlated with bone formation in bone specimens from elderly women with fractures and OVX mice. Collectively, our results highlight the critical roles of the miR-103-3p/METTL14/m6 A signaling axis in osteoblast activity, identifying this axis as a potential target for ameliorating osteoporosis.

11.
Heart Fail Rev ; 2021 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-33443725

RESUMO

Noninvasive positive-pressure ventilation (NPPV) is recognized as an effective adjuvant therapy for sleep-disordered breathing (SDB) in heart failure patients with reduced ejection fraction (HFrEF + SDB). In recent years, some studies have found that adaptive servo-ventilation (ASV) has a negative impact on survival, especially among patients with central sleep apnea (CSA), the use of which is controversial. This study aims to explore the effects of NPPV on cardiac function and survival in patients with sleep-disordered breathing and chronic congestive heart failure. This meta-analysis was based on literature searches of publications published before August 31, 2019, in the PubMed, EMBASE, Cochrane Library, and Web of Science databases. A total of 88 independent studies were summarized and compared, comprising a sampling of 19,259 subjects. Compared with the nontreatment group, treatment with ASV had no effect on all-cause mortality in patients with HFrEF + CSA (hazard ratio (HR) = 1.13 [0.84, 1.51]). Short-term treatment with ASV, e.g., 3-6 months, was significantly beneficial regarding event-free survival in patients with HFrEF + CSA (HR = 0.13 [0.04, 0.45]). Periodic short-term (e.g., 3-6 months) positive-pressure ventilation can significantly improve cardiac function, which is beneficial for the survival of patients with HFrEF + CSA. Attention should be paid to the length and period of treatment, as prolonged treatment may have negative effects.

12.
Immunology ; 162(1): 3-10, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32876334

RESUMO

Hydrogen sulphide (H2 S) is the latest identified small gaseous mediator enabled by its lipophilic nature to freely permeate the biological membranes. Initially, H2 S was recognized by its roles in neuronal activity and vascular relaxation, which makes it an important molecule involved in paracrine signalling pathways. Recently, the immune regulatory function of gasotransmitters, H2 S in particular, is increasingly being appreciated. Endogenous H2 S level has been linked to macrophage activation, polarization and inflammasome formation. Mechanistically, H2 S-induced protein S-sulphydration suppresses several inflammatory pathways including NF-κB and JNK signalling. Moreover, H2 S serves as a potent cellular redox regulator to modulate epigenetic alterations and to promote mitochondrial biogenesis in macrophages. Here in this review, we intend to summarize the recent advancements of H2 S studies in macrophages, and to discuss with focus on the therapeutic potential of H2 S donors by targeting macrophages. The feasibility of H2 S signalling component as a macrophage biomarker under disease conditions would be also discussed.

13.
Biol Trace Elem Res ; 199(2): 604-610, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32436066

RESUMO

Selenium is an essential micronutrient that plays an important role in immunity. However, the mechanism that Selenium modulates mastitis is not fully clear. In this experiment, we investigated whether selenium can inhibit the activation of the NLRP3 inflammasome in a mouse model of Staphylococcus aureus-induced mastitis. Eighty BALB/c female mice were fed with experimental Selenium deficiency basal diet for 2 weeks to achieve the purpose of selenium consumption until pregnancy. Pregnant mice were randomly divided into four groups (control group; selenium supplement group; Staphylococcus aureus infection group and Staphylococcus aureus infection after selenium supplement group). Twenty-four hours after challenging, all mice were euthanized and mammary tissue samples were aseptically collected. Through pathological staining, western blot analysis, real-time fluorescence quantitative polymerase chain reaction analysis, and enzyme-linked immunosorbent assay, the regulation effect of Selenium on NLRP3 inflammasome was detected. The result showed that compared with the control group, selenium significantly inhibited the expression of NLRP3, ASC, Caspase-1, Caspase-1 p20, and Pro-IL-1ß (p < 0.01). Meanwhile the mRNA expression and release of IL-1ß was suppressed in the treatment group compared with Staphylococcus aureus infection group (p < 0.01). Therefore, these results suggest that dietary selenium can attenuate Staphylococcus aureus mastitis by inhibition of the NLRP3 inflammasome.

14.
Waste Manag ; 120: 635-641, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33172738

RESUMO

In this study, an attempt is made to obtain porous activated carbon microspheres (ACMs) as supercapacitor electrodes by recycling waste novolak phenol formaldehyde (NPF) resins. These NPF-ACMs were prepared by a three-step procedure of hydrothermal synthesis, carbonization, and activation in turn. The effects of temperature, time, and sodium dodecyl sulfonate (SDS) addition on NPF-based microspheres were studied by the orthogonal method. The optimal preparation process of NPF-based microspheres was the following: 230 °C, 4 h, and a mass ratio of SDS: NPF of 24:1 by hydrothermal synthesis. Based on the above optimal conditions, NPF-ACMs were made, the yield of the microspheres after carbonization and chemical activation are 54% and 38%, and their electrochemical properties were analyzed. The NPF-ACMs had uniform size, a high surface area of 2528 m2 g-1, good dispersion, a low impedance of 0.46 Ω, highest specific capacitance of 118.6 F g-1 at 0.5 A g-1, good rate capability with 79% retention from 0.1 to 10 A g-1. Moreover, it showed high capacitance retention of 99.5% after 1000 cycles at a scan rate of 5 mV s-1. The results showed that waste NPF can be used as promising ACMs of the electrode material to increase its utilization value.


Assuntos
Carvão Vegetal , Fenol , Formaldeído , Microesferas , Fenóis
15.
Chemosphere ; 263: 128319, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33297252

RESUMO

Green rust functionalized geopolymer of composite cementitious materials (GR-CCM) was synthesized to improve the adsorption and subsequent stabilization/solidification of chromate in a holistic operating system. The initial pH in solution exhibited the most significant effect on the chromate removal by GR-CCM among three adsorption factors. The maximum monolayer adsorption capacity and theoretical saturation capacity of GR-CCM for Cr(VI) in the acidic condition were 55.01 mg/g and 41.70 mg/g, respectively. Amorphousness brought by loading GR weakened the crystallinity of composite cementitious materials (CCM), which enhanced the adsorption capacity of CCM and boosted the solidification process. The mixed-valent iron species in the GR-CCM not only directly engaged in the adsorption and reduction of chromate also positively strengthened the solidification of Cr species during the whole treatment. This study facilitates the application of GRs on the geopolymer materials and demonstrates the combination of adsorption and immobilization for the treatment of other potential heavy metal contamination.


Assuntos
Cromatos , Metais Pesados , Adsorção , Cinza de Carvão , Ferro
16.
Org Lett ; 23(1): 25-30, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33352052

RESUMO

A cobalt-catalyzed regio- and enantioselective γ-amination of ß,γ-unsaturated N-acylpyrazoles that delivers the corresponding γ-amination products in good regio- and enantioselectivity has been established. Moreover, the nitrogen-containing compounds could be easily synthesized. DFT calculations have been provided to explain regio- and enantioselectivity for this γ-amination. The chiral γ-amination products were readily converted into the chiral γ-amino acid derivatives.

17.
Magn Reson Med ; 85(4): 2136-2144, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33107146

RESUMO

PURPOSE: The recently introduced inhomogeneous magnetization transfer (ihMT) method has predominantly been applied for imaging the central nervous system. Future applications of ihMT, such as in peripheral nerves and muscles, will involve imaging in the vicinity of adipose tissues. This work aims to systematically investigate the partial volume effect of fat on the ihMT signal and to propose an efficient fat-separation method that does not interfere with ihMT measurements. METHODS: First, the influence of fat on ihMT signal was studied using simulations. Next, the ihMT sequence was combined with a multi-echo Dixon acquisition for fat separation. The sequence was tested in 9 healthy volunteers using a 3T human scanner. The ihMT ratio (ihMTR) values were calculated in regions of interest in the brain and the spinal cord using standard acquisition (no fat saturation), water-only, in-phase, and out-of-phase reconstructions. The values obtained were compared with a standard fat suppression method, spectral presaturation with inversion recovery. RESULTS: Simulations showed variations in the ihMTR values in the presence of fat, depending on the TEs used. The IhMTR values in the brain and spinal cord derived from the water-only ihMT multi-echo Dixon images were in good agreement with values from the unsuppressed sequence. The ihMT-spectral presaturation with inversion recovery combination resulted in 24%-35% lower ihMTR values compared with the standard non-fat-suppressed acquisition. CONCLUSION: The presence of fat within a voxel affects the ihMTR calculations. The IhMT multi-echo Dixon method does not compromise the observable ihMT effect and can potentially be used to remove fat influence in ihMT.

18.
Mol Med Rep ; 23(1)2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33179079

RESUMO

SH3 domain­containing kinase­binding protein 1 (CIN85), an 85 kDa protein known to be a member of the signal adaptor family, is abnormally expressed in several human malignancies and has been found to be involved in the growth, migration and invasion of these tumors. The objective of the present study was to clarify the clinical significance of CIN85 in human esophageal squamous cell carcinoma (ESCC), as well as its in vitro functions. CIN85 expression was evaluated in 129 cases of ESCC and its adjacent normal tissues using immunohistochemistry to explore its clinical relevance and prognostic value. The functions of CIN85 in the ESCC TE1 cell line were analyzed in vitro using the interfering short hairpin RNA silencing technique. MTS, wound healing, clone formation and Transwell assays were used to detect the proliferation, migration and invasion of ESCC cells. CIN85 expression was identified mainly in ESCCs and their adjacent normal tissues, and the high expression of CIN85 was significantly associated with advanced Tumor Node Metastasis stage and lymph node metastasis. CIN85 gene silencing significantly inhibited TE1 cell proliferation, migration and invasion. These results demonstrated that CIN85 was highly expressed in advanced stage ESCC and lymph node metastasis, and played a critical role in tumor proliferation and progression. Therefore, CIN85 may be a promising therapeutic target for human ESCC.

19.
Sci Total Environ ; 754: 142076, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32920391

RESUMO

Individual cell heterogeneity within a population can be critical to its peculiar function and fate. Conventional algal cell-based assays mainly analyze the average responses from a population of algal cells. Therefore, the mechanisms through which changes in population characteristics are driven by the behavior of single algal cells are still not well understood. Algal cells may modulate their physiology and metabolism by changing their morphology in response to environmental stress. In this study, an algal single-cell culture and analysis system was developed to investigate the potential role of morphological changes by algal cells during adaptation to nutrient stress based on a microwell array chip. The surface-to-volume ratio of Microcystis aeruginosa (M. aeruginosa) and the volume of Scenedesmus obliquus (S. obliquus) significantly increased with increasing culture time under nutrient stress. The eccentricity of M. aeruginosa and S. obliquus gradually increased and decreased, respectively, with increasing culture time, indicating that the morphology of M. aeruginosa and S. obliquus became increasingly irregular and regular, respectively, under nutrient stress. There were significant correlations between the morphological characteristics and physiological characteristics of M. aeruginosa and S. obliquus under nutrient stress. In M. aeruginosa, an increased surface-to-volume ratio facilitated a high specific fluorescence intensity, specific Raman intensity, and maximum electron transport rate. In S. obliquus, increased cell volume enhanced nutrient absorption, which facilitated a higher specific growth rate. M. aeruginosa and S. obliquus adopted different adaptation strategies in response to nutrient stress based on morphological changes. These findings facilitate the development of management strategies for controlling harmful cyanobacterial blooms.


Assuntos
Microcystis , Scenedesmus , Aclimatação , Nutrientes
20.
J Environ Manage ; 280: 111697, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33246753

RESUMO

Biohazard performance of Sr radionuclide can be significantly magnified by its release from the contaminated sedimentation. In this study, hydroxyapatite nanoparticle-functionalized activated carbon electrode (AC-HAP) was synthesized and stacked to the cathode compartment of the electrokinetic (EK) system to develop a unipolar three-dimensional (3D) electrochemical process for Sr2+ removal from spiked soils. Sr2+ adsorption by AC-HAP can be fitted by the pseudo-first-order and pseudo-second-order kinetic models and the Langmuir, Freundlich, and Temkin isotherm models. The largest monolayer adsorption capacity of AC-HAP of 69.49 mg g-1 was evaluated in the pH range of 10-12 and at 40 °C. 3D EK further intensified the adsorption process of AC-HAP and the corresponding Sr2+ removal from aqueous environments. Voltage gradients and proposing time had a significant effect on the migration and transmission of Sr2+ in the electrolyzer. The influence of competitive ions on Sr2+ removal in the stock solutions followed Al3+ < Mg2+ < K+ < Na+ < Ca2+ while followed Al3+ < Na+ < K+ < Mg2+ < Ca2+ in 3D EK. The first three cycles for AC-HAP had taken roughly 50% of the reusability percentage. Sr2+ removal from spiked samples in 3D EK was achieved by acid dissolution, electromigration, and selective uptake on particle electrode.


Assuntos
Carvão Vegetal , Nanopartículas , Adsorção , Durapatita , Eletrodos , Solo , Estrôncio
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