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1.
Plant Physiol ; 194(2): 787-804, 2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-37815230

RESUMO

Root development influences plant responses to environmental conditions, and well-developed rooting enhances plant survival under abiotic stress. However, the molecular and genetic mechanisms underlying root development and abiotic stress tolerance in plants remain unclear. In this study, we identified the MYB transcription factor-encoding gene IbMYB73 by cDNA-amplified fragment length polymorphism and RNA-seq analyses. IbMYB73 expression was greatly suppressed under abiotic stress in the roots of the salt-tolerant sweet potato (Ipomoea batatas) line ND98, and its promoter activity in roots was significantly reduced by abscisic acid (ABA), NaCl, and mannitol treatments. Overexpression of IbMYB73 significantly inhibited adventitious root growth and abiotic stress tolerance, whereas IbMYB73-RNAi plants displayed the opposite pattern. IbMYB73 influenced the transcription of genes involved in the ABA pathway. Furthermore, IbMYB73 formed homodimers and activated the transcription of ABA-responsive protein IbGER5 by binding to an MYB binding sites I motif in its promoter. IbGER5 overexpression significantly inhibited adventitious root growth and abiotic stress tolerance concomitantly with a reduction in ABA content, while IbGER5-RNAi plants showed the opposite effect. Collectively, our results demonstrated that the IbMYB73-IbGER5 module regulates ABA-dependent adventitious root growth and abiotic stress tolerance in sweet potato, which provides candidate genes for the development of elite crop varieties with well-developed root-mediated abiotic stress tolerance.


Assuntos
Ácido Abscísico , Ipomoea batatas , Ácido Abscísico/farmacologia , Ácido Abscísico/metabolismo , Ipomoea batatas/genética , Ipomoea batatas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , Estresse Fisiológico/fisiologia , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
2.
Small ; 20(7): e2305873, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37803396

RESUMO

N-doped carbon (NC)-encapsulated transition metal (TM) nanocomposites are considered as alternatives to Pt-based hydrogen evolution reaction (HER) electrocatalysts; however, their poor electron transfer and mass diffusion capability at high current densities hinder their practical application. Herein, an oriented coupling strategy for the in situ grafting of ultrafine Co nanoparticle-embedded hollow porous C polyhedra onto Si nanowires (Co/NC-HP@Si-NWs) is proposed to address this concern. Experimental investigations reveal that the intimate coupling between the Si-NW and Co/NC nanocage forms a multithreaded conductive network, lowering the energy barrier for internal electron transfer. When functionalized as an HER electrocatalyst in 0.5 m H2 SO4 , Co/NC-HP@Si-NWs deliver overpotentials as low as 57 and 440 mV at 10 and 500 mA cm-2 , respectively, which are much better than those of the pristine Co/NC-HP. Moreover, Co/NC-HP@Si-NWs show an outstanding cycle durability of 24 h at 10 and 500 mA cm-2 . The findings of this study are expected to inspire revolutionary work on the development of Si-mediated TM-based electrocatalysts for the HER.

3.
Nat Commun ; 14(1): 1248, 2023 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-36871002

RESUMO

Metastable metal oxides with ribbon morphologies have promising applications for energy conversion catalysis, however they are largely restricted by their limited synthesis methods. In this study, a monoclinic phase iridium oxide nanoribbon with a space group of C2/m is successfully obtained, which is distinct from rutile iridium oxide with a stable tetragonal phase (P42/mnm). A molten-alkali mechanochemical method provides a unique strategy for achieving this layered nanoribbon structure via a conversion from a monoclinic phase K0.25IrO2 (I2/m (12)) precursor. The formation mechanism of IrO2 nanoribbon is clearly revealed, with its further conversion to IrO2 nanosheet with a trigonal phase. When applied as an electrocatalyst for the oxygen evolution reaction in acidic condition, the intrinsic catalytic activity of IrO2 nanoribbon is higher than that of tetragonal phase IrO2 due to the low d band centre of Ir in this special monoclinic phase structure, as confirmed by density functional theory calculations.

4.
Nanoscale ; 15(48): 19703-19708, 2023 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-38039054

RESUMO

Electrochemical seawater splitting is an intriguing strategy for green hydrogen production. Constructing advanced electrocatalysts for the hydrogen evolution reaction (HER) in seawater is extremely demanded for accelerating the sluggish kinetic process. Herein, a Ru nanocluster anchored on boron- and nitrogen-doped carbon (Ru/NBC) catalyst was successfully synthesized for the HER in alkaline/seawater electrolytes. Remarkably, Ru/NBC exhibits outstanding activity and durability, delivering low overpotentials@10 mA cm-2 in 1.0 M KOH (30 mV) and 1.0 M KOH + seawater electrolyte (35 mV), outperforming Pt/C, Ru/NC, Ru/BC and Ru/C. Additionally, Ru/NBC also provides a high specific activity of 0.093 mA cm-2ECSA at an overpotential of 150 mV, which is higher than those of Ru/NC, Ru/BC and Ru/C, respectively. Density functional theory calculation results demonstrate that the Ru-B formed interfacial chemical bond can regulate the electronic structure of Ru active sites of Ru/NBC, which can facilitate the adsorption of water and hydrogen in alkaline media. This work provides a feasible strategy to fabricate outstanding electrocatalysts for the HER in alkaline/alkaline seawater electrolytes.

5.
PLoS One ; 17(12): e0278769, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36490285

RESUMO

Extraversion is the best and most consistent predictor of important leadership outcomes. However, there has been little exploration and examination of the mechanisms underlying the effects of extraverted leadership on performance. Drawing on distal-proximal motivational theory and situational strength theory, the present study proposes and examines a moderated mediation model that explains how leader extraversion affects team performance and how situational characteristics strengthen or constrain this relationship. Respondents were recruited through management team training courses run by the eight Chinese companies. We conducted two rounds of electronic questionnaire collection. The first round of data was collected during the training session. Four weeks later, we collected the data through the training courses' WeChat groups. Data collected from 226 Chinese team leaders was analyzed using SPSS 26 and Mplus 7. We find that leader extraversion predicts team performance through a motivational mechanism operationalized as leader work engagement. We further find that goal clarity and process clarity play an important role in strengthening the positive effect of leader extraversion on leader work engagement as well as the motivational mechanism, providing an empirical explanation of how leader extraversion affects team performance through a motivational mechanism operationalized as leader work engagement. We also explore how two potential situational characteristics, operationalized as goal clarity and process clarity of leaders, affect the relationship between leader extraversion and leader work engagement as well as the motivational mechanism. Addionally, the findings suggest important practical implications for the organizations seeking to identify effective team leaders.


Assuntos
Liderança , Personalidade , Extroversão Psicológica , Motivação
6.
Nat Commun ; 13(1): 5828, 2022 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-36192414

RESUMO

Designing well-ordered nanocrystal arrays with subnanometre distances can provide promising materials for future nanoscale applications. However, the fabrication of aligned arrays with controllable accuracy in the subnanometre range with conventional lithography, template or self-assembly strategies faces many challenges. Here, we report a two-dimensional layered metastable oxide, trigonal phase rhodium oxide (space group, P-3m1 (164)), which provides a platform from which to construct well-ordered face-centred cubic rhodium nanocrystal arrays in a hexagonal pattern with an intersurface distance of only 0.5 nm. The coupling of the well-ordered rhodium array and metastable substrate in this catalyst triggers and improves hydrogen spillover, enhancing the acidic hydrogen evolution for H2 production, which is essential for various clean energy-related devices. The catalyst achieves a low overpotential of only 9.8 mV at a current density of -10 mA cm-2, a low Tafel slope of 24.0 mV dec-1, and high stability under a high potential (vs. RHE) of -0.4 V (current density of ~750 mA cm-2). This work highlights the important role of metastable materials in the design of advanced materials to achieve high-performance catalysis.

7.
Front Oncol ; 12: 956706, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36620591

RESUMO

Introduction: To investigate the influences of time interval between multimodality therapies on survival for locally advanced gastric cancer (LAGC) patients, 627 patients were included in a retrospective study, and 350 who received neoadjuvant chemotherapy (NACT) based on SOX (S-1 plus Oxaliplatin)/XELOX (Capecitabine plus Oxaliplatin) treatment, radical surgery, and adjuvant chemotherapy (AC) from 2005.01 to 2018.06 were eligible for analyses. Methods: Three factors were used to assess influences, including time interval from NACT accomplishment to AC initiation (PECTI), time to surgery after NACT accomplishment (TTS), and time to adjuvant chemotherapy after surgery (TAC). Results: Concerning PECTIs, 99 (28.29%) experienced it within 9 weeks, 188 (53.71%) within 9-13 weeks, 63 (18.00%) over 13 weeks. Patients' 5-year overall survival (OS) significantly decreased as trichotomous PECTI increased (78.6% vs 66.7% vs 55.7%, P = .02). Analogously, there was a significant decrease for dichotomous TTS (within vs over 5 weeks) in OS (P = .03) and progression free survival (PFS) (P = .01) but not for dichotomous TAC (within vs over 6 weeks) in OS and PFS (P = .40). Through multivariate Cox analyses, patients with PECTI over 13 weeks had significantly worse OS (P = .03) and PFS (P = .02). Furthermore, extended TTS had significantly worse OS and PFS but insignificantly worse OS and PFS than extended TAC. Therefore, gastric patients receiving perioperative SOX/XELOX chemotherapy and surgery with extended PECTI over 9 weeks or TTS over 5 weeks would have a negative correlation with PFS and OS, and worse when PECTI over 13 weeks. Nomograms (including PECTI, ypT, ypN, Area Under Curve (AUC) = 0.81) could predict patient survival probability and guide intervention with net benefit. Discussion: In control of PECTI, TTS could be extended appropriately, and shortened TAC might make a remedy, and delayed TAC might be allowed when TTS was shortened.

8.
Ann Hematol ; 90(3): 331-41, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20872002

RESUMO

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains the only curative therapy for chronic myelogenous leukemia (CML). In this study, the long-term outcomes of HLA-matched sibling donor (MSD) with mismatched related donor (MRD) and unrelated donor (URD) transplantation for CML in the first chronic phase (CML-CP1) using different graft vs. host disease (GVHD) prophylaxis regimens according to donor source and the degree of HLA matching were compared. The data of 91 patients with CML-CP1 were analyzed with respect to GVHD, overall survival (OS), and transplant-related mortality (TRM). The incidence of grade II-IV acute GVHD was 25.5% in the MSD and 40.5% in the MRD/URD group (P = 0.133). The 1-year cumulative incidence of chronic GVHD was not different between the MSD and the MRD/URD groups, while extensive chronic GVHD was different between the two groups (31.9% vs. 10.8%, P = 0.023). The 5-year cumulative relapse rate was not different between the MSD and the MRD/URD groups, while TRM was different between the two groups (6.6% vs. 26.3%, P = 0.010). The 5-year cumulative OS was 90.9%, 71.5%, and 85.4% in the MSD, the MRD/URD, and the HLA allele-matched URD transplantation, respectively (MSD vs. MRD/URD, P = 0.013; MSD vs. HLA allele-matched URD, P = 0.437). In conclusion, survival in HLA allele-matched URD is equivalent to MSD, but in MRD and mismatched URD is inferior to MSD in patients with CML-CP1 undergoing allo-HSCT using different GVHD prophylaxis regimens according to donor source and degree of HLA matching. Patients undergoing MRD/URD transplantation have an equal quality of life as patients undergoing MSD transplantation.


Assuntos
Antígenos HLA/imunologia , Transplante de Células-Tronco Hematopoéticas , Leucemia Mieloide de Fase Crônica/terapia , Doadores de Tecidos , Adolescente , Adulto , China , Feminino , Doença Enxerto-Hospedeiro/imunologia , Doença Enxerto-Hospedeiro/prevenção & controle , Teste de Histocompatibilidade , Humanos , Leucemia Mieloide de Fase Crônica/imunologia , Leucemia Mieloide de Fase Crônica/mortalidade , Leucemia Mieloide de Fase Crônica/patologia , Masculino , Pessoa de Meia-Idade , Recidiva , Irmãos , Análise de Sobrevida , Fatores de Tempo , Transplante Homólogo , Resultado do Tratamento , Adulto Jovem
9.
Zhonghua Yi Xue Za Zhi ; 91(20): 1379-83, 2011 May 31.
Artigo em Zh | MEDLINE | ID: mdl-21756807

RESUMO

OBJECTIVE: To evaluate the efficacy of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in the conditioning of different intensities for acute leukemias of ambiguous lineage (ALAL). METHODS: A total of 38 ALAL patients were treated with two conditioning of different intensities in our hospital from March 2002 to August 2010. The standard conditioning included TBI + Cy or Bu + Cy, intensified conditioning included Fludarabine + Ara-C + TBI + Cy. Cyclosporine A (CsA) and methotrexate (MTX) were administered in patients with human leukocyte antigen-matched sibling donor. And CsA, MTX plus antihuman thymocyte globulin and/or mycophenolate were used in all patients with HLA-mismatched related donor and unrelated donors transplants for graft-versus-host disease (GVHD) prophylaxis. COX regression was used to evaluate the prognostic factors of ALAL. RESULTS: Among 38 ALAL patients, 19 received the standard conditioning while another 19 the intensified conditioning. All patients achieved hematopoietic reconstitution. The 5-year overall survival (OS) and the disease-free survival (DFS) were 35.5% and 25.7% respectively. The 5-year OS rates were 20.2% and 48.1% (P = 0.233) and DFS 6.5% and 43.1% (P = 0.031) in the standard and intensified conditioning groups respectively. The 5-year cumulative relapsing incidence was 58.9% in all patients and 87.6% vs 30.4% in the standard and intensified conditioning groups respectively (P = 0.003). Through a COX regression model for univariate analysis, the intensified conditioning and chronic GVHD were protective factors for DFS (P = 0.001, 0.031). CONCLUSION: The intensified conditioning in ALAL patients undergoing allo-HSCT may improve the long-term patient survival and decrease the relapse of leukemia. The graft versus leukemic effect has some efficacy in ALAL patients undergoing allo-HSCT.


Assuntos
Transplante de Células-Tronco Hematopoéticas/métodos , Leucemia/cirurgia , Condicionamento Pré-Transplante , Adolescente , Adulto , Criança , Feminino , Humanos , Leucemia/terapia , Masculino , Pessoa de Meia-Idade , Transplante Homólogo , Resultado do Tratamento , Adulto Jovem
10.
Theranostics ; 11(19): 9234-9242, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34646368

RESUMO

Sonodynamic therapy (SDT) triggered by ultrasound (US) can overcome pivotal limitations of photo-therapy owing to its high depth-penetration and low phototoxicity. However, there is still a need to develop more efficient sonosensitizes to enhance the therapy efficiency. Methods: In this study, Pt nanoparticles (Pt NPs) are reduced on silicon nanowires (SiNWs) by in situ reduction to prepare Si-Pt nanocomposites (Si-Pt NCs). Results: Si-Pt NCs can produce reactive oxygen radicals (ROS) under ultrasound (US) irradiation, which have sonodynamic therapy (SDT) effect. Meanwhile, Si-Pt NCs can convert excess hydrogen peroxide (H2O2) into ROS in the tumor microenvironment, which endow strong chemodynamic therapy (CDT) effect. Taking the advantages of the mesoporous structure of SiNWs, the SDT and CDT effects of Si-Pt NCs are stronger than those of the pure Pt NPs and SiNWs. Besides, the mild photothermal effect of Si-Pt NCs further improves the SDT&CDT activity and realizes the combined cancer therapy. Conclusion: The developed Si-Pt NCs with the ability of photothermal enhanced SDT/CDT combined therapy play a momentous role in the novel cancer treatment.


Assuntos
Platina/química , Silício/química , Terapia por Ultrassom/métodos , Linhagem Celular Tumoral , China , Terapia Combinada , Humanos , Nanopartículas Metálicas , Nanocompostos , Nanopartículas , Nanofios/química , Espécies Reativas de Oxigênio , Microambiente Tumoral
11.
World J Clin Cases ; 9(11): 2542-2554, 2021 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-33889619

RESUMO

BACKGROUND: The laparoscopic technique has been widely applied for early gastric cancer, with the advantages of minimal invasion and quick recovery. However, there is no report about the safety and oncological outcome of laparoscopic gastrectomy with D2 lymph node dissection for patients after neoadjuvant chemoradiotherapy. CASE SUMMARY: A 60-year-old man was diagnosed with advanced distal gastric cancer, cT4aN1M0 stage III. The neoadjuvant chemoradiotherapy was performed based on the regimen of gross tumor volume 50G y/25 f and clinical target volume 45 Gy/25 f, as well as concurrent S-1 60 mg Bid. Then laparoscopic distal gastrectomy with D2 lymph node dissection was undertaken successfully for him after achieving partial response evaluated by radiological examination. The patient recovered smoothly without moderate or severe postoperative complications. The postoperative pathological stage was ypT3N0M0 with American Joint Committee on Cancer tumor regression grade 1. He was still in good condition after 5 years of follow-up. CONCLUSION: Neoadjuvant chemoradiotherapy followed by laparoscopic technique could be applicable and may achieve satisfactory oncological outcomes. Our finding requires further validation by cohort studies.

12.
World J Gastrointest Oncol ; 13(12): 2161-2179, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-35070049

RESUMO

BACKGROUND: Current tumor regression grade (TRG) evaluations are based on various systems which brings confusion for oncologists and pathologists when interpreting results. The recent six-tier system (JGCA2017-TRG) recommended by the Japanese Gastric Cancer Association (JGCA) is worth investigating, as four-tier TRG systems are favored in various parts of the world. AIM: To compare the predictive accuracies of five published TRG systems. METHODS: Data were retrospectively collected from patients with locally advanced gastric cancer (LAGC) who underwent neoadjuvant chemotherapy followed by D2 Lymphadenectomy between January 2005 and January 2014 at our institution. Outcomes were overall survival (OS) and disease-free survival (DFS), which were evaluated separately using the following TRG systems: JGCA2017, JGCA, Becker, AJCC/CAP, and Mandard. RESULTS: All five published TRG systems were independent predictors for OS and DFS. Concordance indices of the JGCA2017, JGCA, Becker, AJCC/CAP-TRG, and Mandard systems were 0.651/0.648 0.652/0.649, 0.693/0.695, 0.688/0.685, and 0.674/0.675 for OS and DFS, respectively. The four-tier Becker system showed the highest c-index, which was significantly greater than that of the six-tier JGCA2017 and five-tier JGCA systems (P < 0.05 in OS and DFS). When residual tumor percentages were reset as: "no residual tumor", < 10%, < 100%, and "no response", the rearranged cutoff values achieved a maximum c-index with 0.728 for OS and 0.737 for DFS, which was superior to the other five systems. CONCLUSION: The newly introduced six-tier JGCA-TRG system cannot increase prognostic stratification. The four-tier Becker system is more suitable for LAGC patients. A population-based study is warranted to define the optimal criterion for TRG in LAGC patients.

13.
J Laparoendosc Adv Surg Tech A ; 30(7): 713-722, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32471317

RESUMO

Background: With the rapid aging of global population, the number of elderly patients with gastric cancer is increasing. This study aimed to evaluate short- and long-term outcomes after laparoscopic gastrectomy (LG) versus open gastrectomy (OG) in elderly gastric cancer patients. Materials and Methods: We searched PubMed, EMBASE, and the Cochrane library databases from January 1994 to May 2019. Surgical safety, postoperative complications, number of harvested lymph nodes, and overall survival rate were included and analyzed. The qualities of the included studies were evaluated by Newcastle-Ottawa Quality Assessment Scale. The evidence of outcomes was evaluated using the GRADE approach. The Review Manager® 5.3 (Cochrane, London, UK) and Stata® 14.0 (StataCorp., College Station, Texas) were used to analyze the outcomes. Results: Thirteen studies containing 4768 elderly patients with gastric cancer were included in this meta-analysis. LG was more favorable than OG in terms of overall postoperative morbidity (odds ratio [OR]: 0.56; 95% confidence interval [CI]: 0.44 to 0.70; P < .00001), the postoperative stay (standardized mean difference [SMD]: -0.56; 95% CI: -0.76 to (-0.37); P < .00001), and the number of harvested lymph nodes (SMD: 0.19; 95% CI: 0.09 to 0.29; P = .0003). No significant difference was found in anastomotic leakage rate (OR: 0.82; 95% CI: 0.59 to 1.12; P = .21), mental disease (OR: 0.79; 95% CI: 0.44 to 1.44; P = .44), or overall survival rate (P = .62) between two groups. However, in the subgroup with a cutoff age of 80 years, the anastomotic leakage rate was higher in LG (OR: 10.27; 95% CI: 1.31 to 80.35; P = .03). Conclusions: LG was more favorable than OG in the elderly patients <80 years old with gastric cancer.


Assuntos
Gastrectomia/métodos , Laparoscopia , Neoplasias Gástricas/cirurgia , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Humanos , Estadiamento de Neoplasias , Neoplasias Gástricas/patologia , Resultado do Tratamento
14.
J Colloid Interface Sci ; 539: 257-262, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30590233

RESUMO

Hydrogen is considered as a promising energy source because of its high combustion heat and clean products. Among the various hydrogen evolution methods, electrocatalysis is the most convenient and effective way. However it is still problematic to find low-cost and high-efficiency electrocatalysts. In this work, Os-Ag-Si and Os-Au-Si ternary electrocatalysts were investigated. It is interesting that Os-Ag-Si exhibits higher hydrogen evolution performance than that of Os-Au-Si, even though Ag is a worse HER catalyst than Au. The optimal ternary catalyst Os-Ag-Si with mass ratio of 15:15:70 (Os:Ag:Si) was synthesized by a facile SiH bond reduction method, which shows superior hydrogen evolution reaction performance with a low Tafel slope of 40 mV·dec-1. In addition, the current density of Os-Ag-Si-15 catalyst surpasses that of 20% Pt/C when the overpotential is larger than 160 mV. The introduction of Ag in the Os-Ag-Si ternary catalyst could enhance the electrocatalytic activity, reduce the cost of catalysts, and even be better than Os-Au-Si.

15.
Front Psychol ; 10: 2137, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31632313

RESUMO

Feedback seeking relates positively to organizational identification and task performance. However, an individual generally views seeking feedback as risky. It remains unclear whether, why, and when ethical leadership impacts on feedback-seeking behavior. This research aimed to explore the mediating role of psychological safety in the relationship between ethical leadership and nurses' feedback seeking and to further explore the moderating effect of power distance in this mechanism. After eliminating invalid surveys, the sample included 458 pairs. The SPSS PROCESS macro was used for the data analysis. The results indicate that ethical leadership positively affected nurses' feedback-seeking. Ethical leadership influences feedback seeking through psychological safety. With high power distance, ethical leadership significantly positively influenced psychological safety and then positively affected feedback-seeking behavior. In sum, in the context of high-power distance, ethical leadership is especially important for psychological safety and feedback-seeking behavior.

16.
J Colloid Interface Sci ; 522: 242-248, 2018 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-29604442

RESUMO

Pd nanoparticles grown in-situ on the surface of silicon nanowires (Pd-SiNW nanocomposites) were employed as electrocatalysts in hydrogen evolution reaction and exhibited satisfactory catalytic performance. Here, SiNWs served as the carrier with vast surface area. It is interesting to note that Pd-SiNW nanocomposites were more stable for hydrogen evolution reaction than the commercial Pt/C catalysts, which might be attributed to the three-dimensional crisscrossing structure of the composites and the strong interaction between Pd and Si. The strong interaction is due to the low lattice mismatch in the epitaxial growth of Pd particles on the surface of Si. Such special structure and interaction help to tightly hold Pd nanoparticles, which could avoid the loss of catalysts and keep the catalyst from being agglomerated and growing large.

17.
Bioresour Technol ; 249: 783-790, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29136933

RESUMO

The alkaline solubilization of excess mixed sludge was investigated and subsequently the released phosphorus was recovered as magnesium ammonium phosphate (MAP). Considerable and rapid release of glycogen and protein was encountered after alkaline addition into the sludge. Only 45.0% of sludge cells were destructed after 240 min treatment in R1 while the corresponding ratio was 96.1% in R3 according to the release of DNA. Non-apatite inorganic phosphorus (NAIP) in the alkaline treated sludge decreased due to the dissolution of Al(OH)3 and AlPO4, which was the dominant reason for phosphorus release. Soluble orthophosphate (SOP) in the supernatant of alkaline treated sludge could be recovered quickly with the recovery efficiency of 84.6% within 5 min and about 53-55% of P participated in MAP reaction, producing large amounts of acicular crystals.


Assuntos
Esgotos , Estruvita , Fosfatos , Fósforo
18.
Front Psychol ; 8: 1802, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29163249

RESUMO

Finding ways to enhance employee proactive behavior is a focal concern for academics and practitioners. Previous studies have found a positive association between empowering leadership and proactive behavior (Martin et al., 2013; Li et al., 2017). However, these studies lack elaboration on mechanisms and do not rule out the effect of employees' proactive personality during empirical testing. We investigate empowering leadership from individual perspective due to the variation of empowerment levels even in the same team. Our research proposes a more elaborated theoretical model that explains why, and when, empowering leadership might promote employee proactive behavior. Specifically, we examine mediating mechanisms based on social cognitive theory and propose trust in leader competency as boundary condition. Using a sample of 280 leader-follower dyads from a large state-owned Chinese company, our results revealed that (1) empowering leadership was positively related to proactive behavior, with role breadth self-efficacy acting as a mediator for this relationship; (2) employees' trust in leader competency moderated both the empowering leadership-subordinate proactive behavior relationship and the mediating effect of role breadth self-efficacy, such that the empowering leadership-subordinate proactive behavior relationship was weaker, and the mediating effect of role breadth self-efficacy was stronger, for employees with high levels of trust in leader competency.

19.
Huan Jing Ke Xue ; 36(6): 2054-60, 2015 Jun.
Artigo em Zh | MEDLINE | ID: mdl-26387307

RESUMO

Taking a pumped storage reservoir located in southern China as the research object, the paper established a three-dimensional hydrodynamic and eutrophication model of the reservoir employing EFDC (environmental fluid dynamics code) model, calibrated and verified the model using long-term hydraulic and water quality data. Based on the model results, the effects of nitrogen and phosphorus concentrations on the algae growth were analyzed, and the response of algae to nitrogen and phosphorus concentration and quantity of pumping water was also calculated. The results showed that the nitrogen and phosphorus concentrations had little limit on algae growth rate in the reservoir. In the nutrients reduction scenarios, reducing phosphorus would gain greater algae biomass reduction than reducing nitrogen. When reducing 60 percent of nitrogen, the algae biomass did not decrease, while 12.4 percent of algae biomass reduction could be gained with the same reduction ratio of phosphorus. When the reduction ratio went to 90 percent, the algae biomass decreased by 17.9 percent and 35.1 percent for nitrogen and phosphorus reduction, respectively. In the pumping water quantity regulation scenarios, the algae biomass decreased with the increasing pumping water quantity when the pumping water quantity was greater than 20 percent of the current value; when it was less than 20 percent, the algae biomass increased with the increasing pumping water quantity. The algae biomass decreased by 25.7 percent when the pumping water quantity was doubled, and increased by 38.8 percent when it decreased to 20 percent. The study could play an important role in supporting eutrophication controlling in water source area.


Assuntos
Eutrofização , Nitrogênio/química , Fósforo/química , Água/química , Biomassa , China , Meio Ambiente , Modelos Teóricos , Qualidade da Água , Abastecimento de Água
20.
Nanoscale ; 5(24): 12330-4, 2013 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-24162334

RESUMO

Silicon nanowires are important semiconductor with core/shell structure. In this work, the piezoelectric material alpha-quartz was grown in the interface of silicon nanowires by thermal treatment at 600 °C for 0.5 h. These nanowires were employed as starting materials to fabricate piezoelectric nanogenerators, which could convert kinetic energy into electrical one, exhibiting an output voltage of 36.5 V and a response current of 1.4 µA under a free-falling object of 300 g at a height of 30 cm.

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