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1.
Heliyon ; 9(11): e21024, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37928017

RESUMO

Helping behavior positively influences organizational effectiveness, which is why the importance of this behavior is highlighted in Chinese enterprises, and employees are encouraged to engage in it. However, from an actor-centric perspective, helping behavior is not always beneficial. In this paper, cognitive-affective personality system theory is applied to link helping behavior to task performance, thus enhancing the understanding of the effects of helping behavior. By adopting a two-wave questionnaire survey, data from 202 leader-subordinate dyads were gathered. Then, the BruceR (V0.7.2) package of Rstudio (V4.1.1) was used to generate a multi-mediated moderation model and test the hypotheses. The following results were obtained: 1) Helping behavior was negatively associated with task performance. 2) Cognitive irritation and emotional exhaustion serially mediated the influences of helping behavior on task performance. 3) Team-level communal goal striving moderated the indirect influence of helping behavior on task performance; the indirect influence was only significant when the levels of team communal goal striving were low. From an actor-centric perspective, this paper presents evidence for the connection between helping behavior and task performance. Numerous implications for management approaches are presented to maximize the management of helping behavior.

2.
Fitoterapia ; 163: 105343, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36328169

RESUMO

In this study, it was confirmed at first time that the crude extracts of Psoralea corylifolia seeds (PCE34) can reduce serum lipids (AST, ALT, TG, TC, LDL, ALP, ACP and LDH), body weight and serum sugar, increase HDL and serum insulin in hyperlipidemic wistar rat induced by high-fat diet in vivo. Furthermore, eight new chalcones 1-8, one new flavanone 12, one new coumarin 14, three new meroterpenes 15-17 and one new bakuchiol 20 together with seven known compounds (9-11, 13, 18-19 and 21) were isolated from the PCE34. Their structures were elucidated based on analyses of their spectroscopic (UV, CD, NMR and HREIMS) data. All the isolates were evaluated for in vitro inhibitory activity against DGAT1/2, PTP1B and α-Glucosidase. Among them, compounds 1-3, 8-11, 14-17, 19 and 20 were found to exhibit selective inhibitory activity on DGAT1 with IC50 values ranging from 66.7 ± 1.2 to 87.2 ± 1.3 µM; 1, 8-12, 14 and 20 has the best inhibit active on PTP1B with IC50 values ranging from 13.8 ± 1.1 to 19.1 ± 1.6 µM; 1-12 and 14 displayed the significant inhibitory activities on α-Glucosidase with IC50 values ranging from 29.1 ± 1.2 to 79.4 ± 1.2 µM.


Assuntos
Psoralea , Ratos , Animais , Psoralea/química , alfa-Glucosidases , Estrutura Molecular , Sementes/química , Ratos Wistar
3.
Sci Total Environ ; 739: 139860, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32544677

RESUMO

River deltas contain complex self-organizing channel networks that continuously exchange fluxes of water, matter, energy, and information with their surroundings. The connectivity of these exchange processes plays a crucial role in controlling the evolution and dynamic stability of river deltas. However, connectivity patterns related to tidal channel networks have rarely been studied, especially in the Yellow River Delta (YRD), which is impacted by severe reclamation. Here, we evaluated the potential hydrological connectivity dynamics between the tidal channel network and its surroundings using an index of connectivity (IC) in the whole YRD and its three sub-regions: erosion zone, oil field zone and deposition zone. The results suggested that different areas had different spatial connectivity potential. The mean value of the IC related to the channel networks showed little difference for any zones. However, the total connectivity response area (CRA; set of connectivity response units) varied with the study scale. A decreasing trend was found on the delta scale and a relatively stable trend was found in the deposition zone. In terms of dynamic connectivity, the tidal flat system did not show a continuous trend over time. Our results indicated that the YRD is such a dynamic complex that a relatively stable connectivity pattern is unlikely to be achieved over time. Therefore, future ecological restoration based on hydrological connectivity needs to consider more related influencing factors and their temporal and spatial dynamics.

4.
Sci Total Environ ; 723: 138051, 2020 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-32217392

RESUMO

In recent decades, rivers have been among the most gravely disturbed ecosystems due to intense anthropogenic impacts. Accurate spatial evaluation of river network connectivity is necessary for providing an improved empirical basis for management, conservation, and restoration initiatives. In this study, we focused on the stream continuity-oriented hydrological connectivity of the river network ecosystem. An evaluation model was established using spatiotemporal hydrological data, temporal data on dam development, and a new stream continuity-oriented connectivity index (SCI). The Pearl River basin was selected as the study area to demonstrate the model application using data since 1960. The model showed that the SCI values had significantly and steadily decreasing characteristics in the entire basin from 1960 to 2018, with a total decrease during this period of 26% throughout the river network. The connectivity of the river network declined as the number of dams increased, and dams built on main trunks had a larger impact on the connectivity than those on tributaries. These model results can help government regulators identify the worst connected areas of the river network and take effective measures to reduce the impact of human interferences. Thus, the model can provide practical guidance and support to the conservation, management, and restoration of the river ecosystem.

5.
Sci Total Environ ; 689: 21-30, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31260896

RESUMO

Frequent and severe disruptions of natural river flows associated with human activities significantly alter hydrological connectivity in large river networks, with deleterious effects on fish diversity. Understanding the relationship between fish diversity and river network connectivity is fundamental to ensuring species persistence, ecosystem integrity, and human well-being. Here, we provide a review of the mechanisms by which river network connectivity (RNC) affects fish diversity. We review the relationships between forms, systems and types of RNC and fish diversity, based on more than 100 previous studies. In summary, sustaining RNC promotes fish diversity in longitudinal and lateral axes, and species sorting, dispersal dynamics, and habitat availability are the main factors driving the distribution of fish diversity, followed by nutrition and trophic dynamics. Our work highlights the effects of RNC on fish diversity, and provides a mechanistic understanding of how RNC affects fish diversity across river basins, thus providing scientific guidance for protecting fish biodiversity and improving the health of river network ecosystems.


Assuntos
Biodiversidade , Ecossistema , Peixes , Rios , Animais , Hidrologia
6.
Luminescence ; 24(4): 266-70, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19294663

RESUMO

A novel inhibitory kinetic fluorimetric method for the determination of trace methomyl was proposed. It was shown that the Fenton reagent oxidized rhodamine B in acid medium which enabled the fluorescence quenching of the latter. The presence of trace methomyl clearly inhibited the reaction. Upon addition of EDTA, a good linear relationship between the inhibitory effect and the concentration of methomyl was observed, together with improved stabilization and sensitivity. Factors affecting the determination of trace methomyl were investigated systematically. Under the optimum conditions, the linear range for the determination of methomyl was 0.04-2.2 microg/mL; the detection limit and the quantification limit for methomyl were 0.011 and 0.037 microg/mL, respectively. The proposed method was applied to the determination of methomyl in four environmental soil samples, six environmental water samples and one synthetic sample; the results were compared with those determined by the HPLC method. The recoveries and the relative errors were 83.5-101.2 and 0.47-2.02%, respectively. The possible reaction mechanism has also been discussed.


Assuntos
Fluorometria/métodos , Água Doce/análise , Metomil/análise , Resíduos de Praguicidas/análise , Solo/análise , Corantes Fluorescentes/química , Peróxido de Hidrogênio/química , Ferro/química , Cinética , Metomil/química , Oxirredução , Rodaminas/química , Fatores de Tempo
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