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1.
Microb Pathog ; 161(Pt A): 105273, 2021 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-34740811

RESUMO

The Streptomyces virginiae strain W18 was screened from soil, which exhibited broad-spectrum antibacterial activity against fish pathogens. Safety assays showed that strain W18 had no toxicity to fish. Additionally, strain W18 promoted the growth performance of Carassius auratus after feeding in feed mixed with bacteria for one month. Moreover, the activities of AKP, ACP, and SOD in the serum of C. auratus were significantly increased, while the activity of LZM did not greatly change. To detect the expression levels of the genes related to immune factors in the livers, kidneys, and spleens of C. auratus, qRT-PCR was performed. The expression levels of KEAP1, IL-8, TNF-α, IL-ß, and C3 were upregulated in all three organs compared to the control, but LZM expression was downregulated in the kidney. The challenge experiment illustrated that the probability of infection with Aeromonas veronii was reduced by 60% and 40% when C. auratus was fed with two different doses of strain W18 in advance. The whole genome of strain W18 was sequenced, and the gene clusters of secondary metabolites in strain W18 were analyzed by AntiSMASH. The results showed that strain W18 contained a total of 26 gene clusters, and functional annotation analysis was conducted by using the non-coding databases COG and KEGG. All of the above results indicated that the use of strain W18 as a feed additive could enhance the resistance of C. auratus toward pathogenic bacteria and disease. In conclusion, an antagonistic strain (W18) against fish pathogenic bacteria was obtained in this study, which is of great significance for finding new treatment methods for bacterial diseases in the aquaculture industry.

2.
Phys Chem Chem Phys ; 23(41): 23748-23757, 2021 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-34643191

RESUMO

CuZrO3 has been hypothesized to be a catalytic material with potential applications for CO2 reduction. Unfortunately, this material has received limited attention in the literature, and to the best of our knowledge the exact crystal structure is still unknown. To address this challenge, we utilize several different structural prediction techniques in concert, including the Universal Structure Predictor: Evolutionary Xtallography (USPEX), the Materials Project Structure Predictor, and the Open Quantum Materials Database (OQMD). Leveraging these structural prediction techniques in conjunction with Density-Functional Theory (DFT) calculations, we determine a possible structure for CuZrO3, which resembles a "sandwich" morphology. Our calculations reveal that this new structure is significantly lower in energy than a previously hypothesized perovskite structure, albeit it still has a thermodynamic preference to decompose into CuO and ZrO2. In addition, we experimentally tried to synthesize CuZrO3 based on literature reports and compared computational to experimental X-ray Diffraction (XRD) patterns confirming that the final product is a mixture of CuO and ZrO2. Finally, we conducted a computational surface energetics and CO2 adsorption study on our discovered sandwich morphology, demonstrating that CO2 can adsorb and activate on the material. However, these CO2 adsorption results deviate from previously reported results further confirming that the CuZrO3 is a metastable form and may not be experimentally accessible as a well-mixed oxide, since phase segregation to CuO and ZrO2 is preferred. Taken together, our combined computational and experimental study provides evidence that the synthesis of CuZrO3 is extremely difficult and if this oxide exists, it should have a sandwich-like morphology.

3.
Front Public Health ; 9: 691554, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34631641

RESUMO

Objective: This paper aimed to systematically review the application methods and components of step counter-based physical activity (PA) promotion programs in patients with chronic obstructive pulmonary disease (COPD). The effects of longer-duration (≥12 weeks) programs on PA, exercise capacity, quality of life, and dyspnea were discussed. Methods: This review was performed in accordance with the preferred reporting items for systematic reviews and meta-analysis. Online data resources PubMed, Web of Science, Embase, and EBSCO were searched. The publication year was limited between January 2000 to August 2020. All randomized controlled trials with ≥12-week duration of step counter-based PA promotion programs of COPD were included. Two researchers independently assessed the quality of the included studies and extracted their characteristics. Results: Nine studies involving 1,450 participants were included. Step counters, counseling, exercise goals, diaries, and tele-communicational approaches were common components of these programs. The PA feedback tools were mostly pedometers (n = 8), whereas accelerometers were often used as assessment tools of PA (n = 5). All studies implemented counseling: five applied behavioral change theories, and three reported motivational interview techniques simultaneously. Six studies reported detailed exercise goals. The usual exercise goal was to reach a total of 8,000-10,000 steps/day. Three research studies used diaries, and five applied tele-communication approaches to deliver interventions. The programs could be implemented alone (n = 4), in combination with exercise training (n = 2), or with pulmonary rehabilitation (n = 2). All studies showed a significant increase in the PA (≥793 steps/day). Three studies observed a significant improvement in exercise capacity (≥13.4 m), and two reported a significant increase in the quality of life (p < 0.05). No study showed significant between-group differences in dyspnea. Conclusion: There are a few studies assessing the impact of long-duration (≥12 weeks) step counter-based interventions in COPD, with different methodologies, although all studies included counseling and exercise goal setting. These interventions seem to have a positive effect on PA. A few studies also showed benefit on exercise capacity and quality of life.


Assuntos
Doença Pulmonar Obstrutiva Crônica , Qualidade de Vida , Dispneia , Exercício Físico , Tolerância ao Exercício , Humanos , Doença Pulmonar Obstrutiva Crônica/terapia
4.
Nurse Educ Pract ; 57: 103244, 2021 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-34715643

RESUMO

AIM: The Reporting of Clinical Adverse Events Scale is a tool for evaluating the attitudes of medical staff toward reporting adverse events in clinical practice. This study aimed to assess the reliability and validity of the Reporting of Clinical Adverse Events Scale translated into Chinese used with trainee nurses in mainland China. DESIGN: The Chinese version of the Reporting of Clinical Adverse Events Scale was developed following guidelines for the cross-cultural adaptation of self-reporting measures. METHODS: The reliability and validity of the Chinese version of the Reporting of Clinical Adverse Events Scale was tested on 773 nursing interns by online investigation. Confirmatory factor analysis was performed on 350 questionnaires completed by the participants while exploratory factor analysis was performed on 423 questionnaires to test the structural validity of the scale. RESULTS: There were 23 items included in the Chinese version of the Reporting of Clinical Adverse Events Scale. The Cronbach's α-coefficient for the internal consistency of the total score was found to be 0.84 with a test-retest reliability value of 0.82, indicating a high level of reliability. Five common factors were extracted. The structural validity on the Kaiser-Meyer-Olkin test was 0.87 and the contribution rate of cumulative variance was 58.51%. The content validity values ranged between 0.86 and 1.00. CONCLUSION: The Chinese version of the Reporting of Clinical Adverse Events Scale is a valid and reliable tool for evaluating nursing interns' attitudes toward reporting clinical adverse events in China. This validation of the Chinese version of the scale also extends the use of the scale to a different population. TWEETABLE ABSTRACT: Nursing interns are responsible for a relatively high incidence of adverse events and their attitude to reporting these is crucial to patient safety. The Chinese version of the Reporting of Clinical Adverse Events Scale will be helpful for evaluating the reporting attitude of nursing interns.

5.
J Gastric Cancer ; 21(3): 268-278, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34691811

RESUMO

Purpose: While several prognostic models for the stratification of death risk have been developed for patients with advanced gastric cancer receiving first-line chemotherapy, they have seldom been tested in the Chinese population. This study investigated the performance of these models and identified the optimal tools for Chinese patients. Materials and Methods: Patients diagnosed with metastatic or recurrent gastric adenocarcinoma who received first-line chemotherapy were eligible for inclusion in the validation cohort. Their clinical data and survival outcomes were retrieved and documented. Time-dependent receiver operating characteristic (ROC) and calibration curves were used to evaluate the predictive ability of the models. Kaplan-Meier curves were plotted for patients in different risk groups divided by 7 published stratification tools. Log-rank tests with pairwise comparisons were used to compare survival differences. Results: The analysis included a total of 346 patients with metastatic or recurrent disease. The median overall survival time was 11.9 months. The patients were different into different risk groups according to the prognostic stratification models, which showed variability in distinguishing mortality risk in these patients. The model proposed by Kim et al. showed relative higher predicting abilities compared to the other models, with the highest χ2 (25.8) value in log-rank tests across subgroups, and areas under the curve values at 6, 12, and 24 months of 0.65 (95% confidence interval [CI]: 0.59-0.72), 0.60 (0.54-0.65), and 0.63 (0.56-0.69), respectively. Conclusions: Among existing prognostic tools, the models constructed by Kim et al., which incorporated performance status score, neutrophil-to-lymphocyte ratio, alkaline phosphatase, albumin, and tumor differentiation, were more effective in stratifying Chinese patients with gastric cancer receiving first-line chemotherapy.

6.
Ann Palliat Med ; 2021 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-34498472

RESUMO

Doubling of the optic disc is rare in clinic, which appears as true doubling or pseudo-doubling. Bilateral doubling of the optic discs is even more less seen in clinic. Here, we report the case of a 35-year-old woman who presented to the clinic for a physical examination. The patient's best-corrected visual acuity was 0.6 OD with +2.25 DS/3.50 DC×175°, and 0.9 OS with -3.00 DS/0.50 DC×145°. The intraocular pressure of each eye was normal. Fundoscopy examination revealed an enlarged suspected optic disc in both eyes. Visual field examination revealed an additional blind spot in each eye. Optical coherence tomography (OCT) analysis showed a normal macular thickness and profile. B-scan ultrasound revealed a single optic nerve shadow in each eye. Cranial computed tomography (CT) showed only 1 optic foramen and 1 optic nerve in each eye. Although double-blind spots were demonstrated by visual field examination, and pits in both optic disc regions for both eyes were shown by OCT, it was not enough to support the diagnosis of true doubling of the optic disc. Consequently, the diagnosis of bilateral pseudo-doubling of optic discs was made based on the clinical evidence, leading to the consideration of possible causality of other ophthalmic diseases.

7.
Elife ; 102021 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-34351275

RESUMO

Methadone maintenance treatment (MMT) can alleviate opioid dependence. However, MMT possibly increases the risk of motor vehicle collisions. The current study investigated preliminary estimation of motor vehicle collision incidence rates. Furthermore, in this population-based retrospective cohort study with frequency-matched controls, opiate adults receiving MMT (cases) and those not receiving MMT (controls) were identified at a 1:2 ratio by linking data from several nationwide administrative registry databases. From 2009 to 2016, the crude incidence rate of motor vehicle collisions was the lowest in the general adult population, followed by that in opiate adults, and it was the highest in adults receiving MMT. The incidence rates of motor vehicle collisions were significantly higher in opiate users receiving MMT than in those not receiving MMT. Kaplan-Meier curves of the incidence of motor vehicle collisions differed significantly between groups, with a significant increased risk during the first 90 days of follow-up. In conclusion, drivers receiving MMT have higher motor vehicle collision risk than those not receiving MMT in opiate users, and it is worthy of noticing road safety in such drivers, particularly during the first 90 days of MMT.


Assuntos
Acidentes de Trânsito/estatística & dados numéricos , Analgésicos Opioides/efeitos adversos , Metadona/administração & dosagem , Adulto , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Veículos Automotores , Tratamento de Substituição de Opiáceos/efeitos adversos , Estudos Retrospectivos , Risco , Taiwan , Adulto Jovem
8.
Int J Mol Sci ; 22(15)2021 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-34360893

RESUMO

Flowering is a morphogenetic process in which angiosperms shift from vegetative growth to reproductive growth. Flowering time has a strong influence on fruit growth, which is closely related to productivity. Therefore, research on crop flowering time is particularly important. To better understand the flowering period of the tomato, we performed transcriptome sequencing of early flower buds and flowers during the extension period in the later-flowering "Moneymaker" material and the earlier-flowering "20965" homozygous inbred line, and we analyzed the obtained data. At least 43.92 million clean reads were obtained from 12 datasets, and the similarity with the tomato internal reference genome was 92.86-94.57%. Based on gene expression and background annotations, 49 candidate genes related to flowering time and flower development were initially screened, among which the greatest number belong to the photoperiod pathway. According to the expression pattern of candidate genes, the cause of early flowering of "20965" is predicted. The modes of action of the differentially expressed genes were classified, and the results show that they are closely related to hormone regulation and participated in a variety of life activities in crops. The candidate genes we screened and the analysis of their expression patterns provide a basis for future functional verification, helping to explore the molecular mechanism of tomato flowering time more comprehensively.


Assuntos
Produtos Agrícolas/crescimento & desenvolvimento , Produtos Agrícolas/genética , Flores/crescimento & desenvolvimento , Flores/genética , Genes de Plantas , Lycopersicon esculentum/crescimento & desenvolvimento , Lycopersicon esculentum/genética , Transcriptoma , Produtos Agrícolas/metabolismo , Flores/metabolismo , Regulação da Expressão Gênica de Plantas , Redes Reguladoras de Genes , Estudos de Associação Genética/métodos , Lycopersicon esculentum/metabolismo , Fotoperíodo , Proteínas de Plantas/genética , RNA-Seq/métodos , Transdução de Sinais/genética
9.
J Healthc Eng ; 2021: 3831453, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34462648

RESUMO

Bladder cancer, the ninth most common cancer worldwide, requires fast diagnosis and treatment to prevent disease progression and improve patient survival. However, patients with bladder cancer often experience considerable delays in diagnosis. One reason for such delays is that hematuria, a major symptom of bladder cancer, has a high probability of also being a warning sign for urinary tract diseases. Another reason is that the sensitivity of the body parts affected by bladder cancer deters patients from undergoing cystoscopy and influences patients' "physician shopping" behavior. In this study, the analytic hierarchy process was used to determine critical variables influencing delayed diagnosis; moreover, the variables were used to construct models for predicting delayed diagnosis in patients with hematuria by using several machine learning techniques. Furthermore, the critical variables associated with delayed diagnosis of bladder cancer in patients with hematuria were evaluated using GainRatio technology. The study sample was selected from a population-based database. The model evaluation results indicated that the prediction model established using decision tree algorithms outperformed the other models. The critical risk factors for delayed diagnosis of bladder cancer were as follows: (1) cystoscopy performed 6 months after hematuria diagnosis and (2) physician shopping.

10.
Front Chem ; 9: 638216, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34307294

RESUMO

Inorganic nitride nanomaterials have attracted widespread attention for applications in renewable energy due to novel electrochemical activities and high chemical stabilities. For different renewable energy applications, there are many possibilities and uncertainties about the optimal nitride phases and nanostructures, which further promotes the exploration of controllable preparation of nitride nanomaterials. Moreover, unlike conventional nitrides with bulk or ceramic structures, the synthesis of nitride nanomaterials needs more accurate control to guarantee the target nanostructure along with the phase purity, which make the whole synthesis still a challenge to achieve. In this mini review, we mainly summarize the synthesis methods for inorganic nitride nanomaterials, including chemistry vapor deposition, self-propagation high-temperature synthesis, solid state metathesis reactions, solvothermal synthesis, etc. From the perspective of nanostructure, several novel nitrides, with nanostructures like nanoporous, two-dimensional, defects, ternary structures, and quantum dots, are showing unique properties and getting extensive attentions, recently. Prospects of future research in design and synthesis of functional inorganic nitrides are also discussed.

12.
mSphere ; 6(3): e0045421, 2021 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-34106770

RESUMO

Bacteriophages play critical roles in impacting microbial community succession both ecologically and evolutionarily. Although the majority of phage genetic diversity has been increasingly unveiled, phages infecting members of the ecologically important genus Alteromonas remain poorly understood. Here, we present a comprehensive analysis of a newly isolated alterophage, vB_AcoS-R7M (R7M), to characterize its life cycle traits, genomic features, and putative evolutionary origin. R7M harbors abundant genes identified as host-like auxiliary metabolic genes facilitating viral propagation. Genomic analysis suggested that R7M is distinct from currently known alterophages. Interestingly, R7M was found to share a set of similar characteristics with a number of siphophages infecting diverse aquatic opportunistic copiotrophs. We therefore proposed the creation of one new subfamily (Queuovirinae) to group with these evolutionarily related phages. Notably, tail genes were less likely to be shared among them, and baseplate-related genes varied the most. In-depth analyses indicated that R7M has replaced its distal tail with a Rhodobacter capsulatus gene transfer agent (RcGTA)-like baseplate and further acquired a putative receptor interaction site targeting Alteromonas. These findings suggest that horizontal exchanges of viral tail adsorption apparatuses are widespread and vital for phages to hunt new hosts and to adapt to new niches. IMPORTANCE The evolution and ecology of phages infecting members of Alteromonas, a marine opportunistic genus that is widely distributed and of great ecological significance, remain poorly understood. The present study integrates physiological and genomic evidence to characterize the properties and putative phage-host interactions of a newly isolated Alteromonas phage, vB_AcoS-R7M (R7M). A taxonomic study reveals close evolutionary relationships among R7M and a number of siphophages infecting various aquatic copiotrophs. Their similar head morphology and overall genetic framework suggest their putative common ancestry and the grouping of a new viral subfamily. However, their major difference lies in the viral tail adsorption apparatuses and the horizontal exchanges of which possibly account for variations in host specificity. These findings outline an evolutionary scenario for the emergence of diverse viral lineages of a shared genetic pool and give insights into the genetics and ecology of viral host jumps.

14.
Asian Pac Isl Nurs J ; 5(4): 251-258, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33791414

RESUMO

Background: Tobacco control activities have mostly influenced those smokers who found it easier to quit and, thus, remaining smokers are those who are less likely to stop smoking. This phenomenon is called "hardening hypothesis," which individuals unwilling or unable to quit smoking and likely to remain so. The aim of this study was to identify the factors correlated with smoking cessation among hardcore smokers. Methods: A cross-sectional descriptive correlational research design was employed. Hardcore smokers from communities in Taiwan were recruited to participate in the study (N = 187). Self-report questionnaires were used to collect demographic data as well as data on nicotine dependence, quitting self-efficacy, social smoking motives, attitudes towards the Tobacco Hazards Prevention Act (THPA), and smoking cessation. Logistic regression analysis was used to examine the factors that were related to quit smoking. Results: About 30.3% (n = 54) reported having experienced quitting smoking over 7 days in the past year. Logistic regression analysis indicated that attitudes towards the THPA was identified as a particularly important factor contributing to the increase in smoking cessation among hardcore smokers. Conclusions: Nurses should cooperate with smoking cessation coaches to facilitate the improvement of attitudes towards the THPA as a key means through which to increase the smoking cessation rate among hardcore smokers.

16.
Sci Total Environ ; 747: 141533, 2020 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-32795806

RESUMO

Oxygen vacancies and Ti3+ defects in anatase TiO2 have attracted great attention to address the insufficient optical absorption and photoinduced charge-carrier separation in photocatalysis. In this study, we demonstrate a superficial and innovative approach for synthesizing anatase TiO2 nanoparticles with abundant oxygen vacancies via γ-ray irradiation reduction at room temperature. X-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance (EPR) confirm that oxygen vacancies and Ti3+ defects can be quantitatively and extensively obtained by merely regulating the irradiation dosage. Photoelectrochemical measurements suggest that oxygen vacancies and Ti3+ defects promoted the separation of electron-hole pairs and then enhanced the photocatalytic degradation performance for organic pollutant. In comparison with TiO2 (no irradiation), the sample (49.5 kGy irradiation) exhibited a 20.0-fold enhancement in visible-light decomposition of phenol. In addition, the results of scavenge experiments and mechanism analysis revealed that O2- are the dominant active species. The excited electrons generated at the conduction band and oxygen vacancy level of TiO2-x-49.5 conspicuously contributes to generate much more ·O2- species. This novel study shows at room temperature, the γ-ray approach of irradiation leads to faster formation and quantification of oxygen vacancies in the semiconductor materials.

17.
Phytomedicine ; 76: 153260, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32535483

RESUMO

BACKGROUND: Aderivative of Shiitake mushrooms, Lentinan is used to control malignant pleural effusion (MPE) through intrathoracic infusion. PURPOSE: To determine the clinical response, survival and safety of Lentinan plus chemical irritants, and the optimal combinations with chemical irritants, indication, threshold and optimal regimen for achieving the desired responses. STUDY DESIGN: We performed a new systematic review and meta-analysis following the PRISMA guidelines. METHODS: We collected all randomized controlled trials (RCTs) regarding Lentinan plus chemical irritants from Chinese and English electronic databases (from inception until March 2019). We evaluated their bias risk, synthesized data using meta-analysis, and summarized evidence quality following the Grades of Recommendation Assessment, Development and Evaluation approach. RESULTS: We included 65 RCTs involving 4,080 patients and nine chemical irritants. Most trials had unclear bias risk. Lentinan with cisplatin significantly improved complete response [Risk ratio (RR) = 1.68, 95% confidence intervals (CI) (1.51 to 1.87), p < 0.00001, Fig.3a] and quality of life [RR = 1.51 95% CI (1.41 to 1.62), p < 0.00001, Fig.4], and decreased the risk of treatment failure, myelosuppression, gastrointestinal reaction, and chest pain. For patients with moderate to large volume of the pleural effusion, primary treatment, KPS score ≥ 50-60, or anticipated survival time ≥ 3months, Lentinan (3-4 mg/time, once a week for three to four times) withcisplatin (30-40 mg/m2 or 50-60 mg/m2) significantly improved complete response and decreased failure. Most results were robust and moderate quality. CONCLUSION: The results suggest that Lentinan with chemical irritants, especially cisplatin is beneficial to the patient with MPE, and provide evidence for the indication, threshold, and optimal regimen that may achieve success and decrease failure.

18.
Biomed Res Int ; 2020: 4808072, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32309433

RESUMO

Preeclampsia (PE) is termed as a systemic disease that involves multiple organs; however, the exact etiology is still quite unclear. It is believed that the poor remodeling of uterine spiral arteries triggers PE, thereby causing failed placentation and producing inflammatory factors. The decline of blood flow results in lowering the nutrients and oxygen received by the fetus and augmenting the placental pressure in PE. Decidual immune cells, especially uterine natural killer (uNK) cells, are involved in the process of placentation. Decidual NK (dNK) cells significantly contribute to the vascular remodeling through the secretion of cytokines and angiogenic mediators in normal placental development. The abnormal activation of NK cells in both the peripheral blood and the decidua was counted among the causes leading to PE. The correlation existing between maternal killer cell immunoglobulin-like receptor (KIR) and HLA-C in trophoblast cells constitutes a robust evidence for the genetic etiology of PE. The combinations of the two kinds of gene systems, together with the KIR genotype in the mother and the HLA-C group in her fetus, are likely to exactly decide the pregnancy outcome. The women, who have the inappropriate match of KIR/HLA-C, are likely to be prone to the augmented risk of PE. However, the combinations of KIR/HLA-C in PE undergo ethnic changes. The extensive prospective research works in Europe, Asia, and Africa are required for providing more findings in PE patients.


Assuntos
Antígenos HLA-C/imunologia , Células Matadoras Naturais/imunologia , Pré-Eclâmpsia/imunologia , Pré-Eclâmpsia/fisiopatologia , Receptores KIR/imunologia , Útero/fisiologia , Animais , Feminino , Feto , Genótipo , Antígenos HLA-C/genética , Humanos , Gravidez/imunologia , Receptores KIR/genética , Trofoblastos , Artéria Uterina/fisiopatologia
19.
J Nanosci Nanotechnol ; 20(9): 5906-5915, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32331196

RESUMO

An amino-functionalized water-retaining agent (PPM40-NH2) and a water-retaining agent lacking functionalization (PPM40) were prepared to investigate their selective Cd(II) removal properties. The affinity for Cd(II) was increased after introducing the amino functional group. The SFCd/Ca of PPM40-NH2 was 3-7 fold higher than that of PPM40 although the CCa was 100-1000 times higher than that of CCd. The chelating effect of -COOH and -NH2 in PPM40-NH2 corresponded well with the selective adsorption of Cd(II), as confirmed by simulations. A seed germination experiment demonstrated that PPM40-NH2 could act as a filter of heavy metals to supply "clean" water for the roots of the pakchoi plant. The leaching experiment indicated that PPM40-NH2 is an efficient in situ fixation agent for the remediation of agricultural soil contaminated with Cd(II) in the presence of high concentrations of Ca(II) salts.

20.
ACS Appl Mater Interfaces ; 12(14): 16512-16520, 2020 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-32175722

RESUMO

Efficient and stable electrocatalysts for oxygen reduction reaction and freestanding electrode structure were developed to reduce the use of polymer binders in the cathode of metal-air batteries. Considering the unique geometrical configurations of helical carbon nanotubes (CNTs) and improved properties compared with straight CNTs, we prepared high-purity Co@CoOx/helical nitrogen-doped carbon nanotubes (Co@CoOx/HNCNTs) on a carbon fiber paper by hydrothermal and single-step in situ chemical vapor deposition strategies. Under an optimized growth time (1 h), the synthesized Co@CoOx/HNCNTs provide richer edge defects and active sites and show prominent electrocatalytic performance toward oxygen reduction reaction (ORR) under alkaline media compared with Co@CoOx/HNCNTs-0.5 h and Co@CoOx/HNCNTs-2 h. The soft X-ray absorption spectroscopy technique is used to investigate the influences of different growth times on the electronic structure and local chemical configuration of Co@CoOx/HNCNTs. Furthermore, the Al-air coin cell employing Co@CoOx/HNCNTs-1 h as the binder-free cathode exhibits an open-circuit voltage of 1.48 V, a specific capacity of 367.31 mA h g-1 at the discharge current density of 1.0 mA cm-2, and a maximum power density (Pmax) of 3.86 mW cm-2, which are superior to those of Co@CoOx/HNCNTs-0.5 h and Co@CoOx/HNCNTs-2 h electrodes. This work provides valuable insights into the development of scalable binder-free cathodes, exploiting HNCNT composite materials with an outstanding electrocatalytic performance for ORR in Al-air systems.

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