RESUMEN
AIM: To examine the main effects and interaction effects of outcome expectations (e.g., anticipated satisfactory salary and benefits), nurse identity (a sense of membership in the nursing profession), and information-access efficiency of the electronic medical record system (how the system enables nurses to quickly retrieve the needed information) on nurses' retention. DESIGN: This study uses a cross-sectional survey and adopts proportionate random sampling to recruit a representative sample of nurses of a medical centre in Taiwan. METHODS: This study successfully obtained completed questionnaires from 430 nurses during December 2021 to January 2022. Data are analysed by using hierarchical regressions. RESULTS: Positive outcome expectations and identification as a member in the nursing profession are associated with retention. Information-access efficiency strengthens the link between outcome expectations and retention, while nurse identity weakens this link. CONCLUSION: Outcome expectations can help retain nurses, particularly those who perceive high levels of information-access efficiency and possess weak nurse identity. That is, outcome expectations have a complementary role with nurse identity in retaining nurses. IMPLICATIONS FOR THE PROFESSION: Nurse managers should devise means to build positive outcome expectations for nurses. In addition, either strengthening nurses' identification with the nursing profession or improving the information-access efficiency of the electronic medical system may also help retain nurses. IMPACT: This study examined how to transform outcome expectation to nurse retention, offering nurse managers to devise new means to retain nurses. REPORTING METHOD: STROBE statement was chosen as EQUATOR checklist. PATIENT OR PUBLIC CONTRIBUTION: No patient or public contribution.
RESUMEN
AIM: To investigate whether education, tenure, being an advanced practice nurse, skill level, and time pressure impact perceptions of "having a place" and, further, turnover intentions. BACKGROUND: Nursing shortages persist worldwide. Nurses' turnover intentions are negatively related to their perceptions of "having a place" (i.e., the feeling that the nursing workplace is their territory). However, the sources of nurses' perceptions of the perception of "having a place" remain unknown. METHODS: Our research employed a cross-sectional and correlational design. This research was conducted at a large-scale hospital in northern Taiwan from December 2021 to January 2022. We used personnel data pertaining to 430 nurses as well as scales for time pressure, "having a place" and turnover intentions to assess nurses' intention to leave their place of employment. The inclusion criteria focused on full-time nurses who worked for the hospital under investigation. Most of our participants were women. The STROBE statement was used as the EQUATOR checklist (supplemental file). RESULTS: "Having a place" was positively related to educational level, tenure, and skill level, while being an advanced practice nurse was negatively associated with perceptions of "having a place," which in turn were negatively related to turnover intention among nurses. CONCLUSION: Our study is the first to examine the antecedents of nurses' perceptions of "having a place," which include education, tenure, and skill level. IMPLICATIONS FOR NURSING POLICY: Nursing policymakers could encourage nurses to pursue higher degrees and update their nursing skills while instilling perceptions of "having a place" in nurses with a brief tenure and advanced practice nurses.
RESUMEN
BACKGROUND: Robots are introduced into health care contexts to assist health care professionals. However, we do not know how the benefits and maintenance of robots influence nurse-robot engagement. OBJECTIVE: This study aimed to examine how the benefits and maintenance of robots and nurses' personal innovativeness impact nurses' attitudes to robots and nurse-robot engagement. METHODS: Our study adopted a 2-wave follow-up design. We surveyed 358 registered nurses in operating rooms in a large-scale medical center in Taiwan. The first-wave data were collected from October to November 2019. The second-wave data were collected from December 2019 to February 2020. In total, 344 nurses participated in the first wave. We used telephone to follow up with them and successfully followed-up with 331 nurses in the second wave. RESULTS: Robot benefits are positively related to nurse-robot engagement (ß=.13, P<.05), while robot maintenance requirements are negatively related to nurse-robot engagement (ß=-.15, P<.05). Our structural model fit the data acceptably (comparative fit index=0.96, incremental fit index=0.96, nonnormed fit index=0.95, root mean square error of approximation=0.075). CONCLUSIONS: Our study is the first to examine how the benefits and maintenance requirements of assistive robots influence nurses' engagement with them. We found that the impact of robot benefits on nurse-robot engagement outweighs that of robot maintenance requirements. Hence, robot makers should consider emphasizing design and communication of robot benefits in the health care context.
Asunto(s)
Robótica , Humanos , Estudios Transversales , Hospitales , Encuestas y Cuestionarios , Personal de SaludRESUMEN
AIMS: To examine how nurses' self-efficacy impacts professional engagement (professional opportunities exploration and workplace improvement participation), nurses' turnover intention and further on actual turnover. BACKGROUND: The problem of nursing shortage has become a common global issue. Nurses' self-efficacy could reduce nurses' turnover intention. However, whether professional engagement could connect nurses' self-efficacy and their actual turnover remains unknown. DESIGN: This study adopts a three-wave follow-up design. METHODS: This study uses proportionate random sampling to survey nurses in a large medical centre in Taiwan. Totally, 417 participants were enrolled from December 2021 to January 2022 (first wave) and followed up from February 2022 to March 2022 (second wave). The data of nurses' actual turnover (or not) were traced in May 2022 (third wave). STROBE statement was chosen as the EQUATOR checklist. RESULTS: Self-efficacy was positively linked to outcome expectation, which is positively linked to professional opportunities exploration. Self-efficacy was positively linked to career interest and workplace improvement participation. Professional engagement was negatively linked to nurses' intention to leave the target hospital, which was positively linked to actual turnover. CONCLUSION: This study uniquely finds that professional engagement is the key to the mechanism underlying the influence of nurse' self-efficacy on their actual turnover. IMPACT: Our findings impact nursing management that professional engagement is as well important as nurses' self-efficacy, with an aim to maintain the professional nursing workforce. PATIENT OR PUBLIC CONTRIBUTION: Nurses complete the questionnaires, return them to the investigators and permit investigators to check their personnel data.
Asunto(s)
Enfermeras y Enfermeros , Personal de Enfermería en Hospital , Humanos , Autoeficacia , Estudios Transversales , Intención , Lugar de Trabajo , Reorganización del Personal , Encuestas y Cuestionarios , Satisfacción en el TrabajoRESUMEN
The COVID-19 epidemic has had a great adverse impact on the world, having taken a heavy toll, killing hundreds of thousands of people. In order to help the world better combat COVID-19 and reduce its death toll, this study focuses on the COVID-19 mortality. First, using the multiple stepwise regression analysis method, the factors from eight aspects (economy, society, climate etc.) that may affect the mortality rates of COVID-19 in various countries is examined. In addition, a two-layer nested heterogeneous ensemble learning-based prediction method that combines linear regression (LR), support vector machine (SVM), and extreme learning machine (ELM) is developed to predict the development trends of COVID-19 mortality in various countries. Based on data from 79 countries, the experiment proves that age structure (proportion of the population over 70 years old) and medical resources (number of beds) are the main factors affecting the mortality of COVID-19 in each country. In addition, it is found that the number of nucleic acid tests and climatic factors are correlated with COVID-19 mortality. At the same time, when predicting COVID-19 mortality, the proposed heterogeneous ensemble learning-based prediction method shows better prediction ability than state-of-the-art machine learning methods such as LR, SVM, ELM, random forest (RF), long short-term memory (LSTM) etc.
RESUMEN
INTRODUCTION: Under the current opt-in system, the deceased organ donation rate remains low in Hong Kong. An opt-out system and an opt-in system combined with organ allocation priority (ie, priority to donors as transplant recipients) have been proposed to encourage willingness among the general population towards deceased organ donation. This study aimed to compare willingness, and its determinants, across these three legislative systems. METHODS: A random telephone survey of Hong Kong permanent residents aged ≥18 years was conducted between August and October 2016 using an anonymous questionnaire. Willingness towards deceased organ donation was compared between the legislative systems with McNemar's test. Determinants of willingness were tested by logistic regression. RESULTS: The proportion of those willing to consider deceased organ donation under the current opt-in system would significantly increase after combining it with allocation priority (64.5% vs 73.4%; P=0.018). "Fairness or reciprocity" was the major reported reason underlying the increase. In contrast, willingness would decrease after introducing the opt-out system (60.1%), although not significantly (P=0.336). The reduction might be attributable to a "belief of being forced to donate". Under the allocation priority system, reduced willingness to donate was associated with advanced age, lower educational attainment, and lower monthly household income. Under the opt-out system, reduced willingness was associated with being married, having a lower household income, and distrust of local government. CONCLUSIONS: An opt-in system with allocation priority could induce willingness to donate, whereas an opt-out system may reduce willingness. The findings have implications for policy-making and promotion of organ donation.
Asunto(s)
Obtención de Tejidos y Órganos/legislación & jurisprudencia , Adolescente , Adulto , Estudios Transversales , Femenino , Hong Kong , Humanos , Masculino , Formulación de Políticas , Adulto JovenRESUMEN
Phalaenopsis orchids have been regenerated by inducing protocorm-like bodies (PLBs) from etiolated leaf sections. However, the physiological and molecular mechanisms of secondary PLB development and subsequent proliferation have not been explored. Bisectionally cutting primary PLBs resulted in more secondary PLBs at 5 weeks, suggesting an embryogenic stem cell property imposed by wounding of primary PLB tissues. The ethylene precursors ethephon and 1-aminocyclopropanecarboxylic acid and the ethylene perception inhibitor silver nitrate increased PLB formation, while aminoethoxyvinylglycine decreased PLB formation. Ethylene content in wounded PLB explants increased over culture time in media containing ethylene precursors or inhibitors. mRNA levels of PhACS2, PhACS3, and PhACO were increased by ethephon and decreased by ethylene inhibitors. Expression of genes in the ethylene signaling pathway was enhanced following ethylene-precursor treatment and was mitigated by ethylene inhibitors during PLB proliferation. Transcription of PhETR and PhEIN3, as well as PhERS, PhCTR, and PhGTP, was significantly increased 12 h after ethylene treatment. Ethylene and physical wounding stimulated secondary PLB formation in Phalaenopsis, probably through ethylene biosynthesis and signal transduction.
Asunto(s)
Etilenos/farmacología , Orchidaceae/citología , Orchidaceae/embriología , Regeneración/efectos de los fármacos , Semillas/citología , Proliferación Celular/efectos de los fármacos , Etilenos/biosíntesis , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Orchidaceae/efectos de los fármacos , Orchidaceae/genética , Regeneración/genética , Semillas/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Transducción de Señal/genética , Células Madre/citología , Células Madre/efectos de los fármacosRESUMEN
Cluster ions of H7(+)/D7(+) and H9(+)/D9(+) produced in a supersonic molecular beam with a pulsed discharge source are mass selected and studied with infrared laser photodissociation spectroscopy. Photodissociation occurs by the loss of H2 (D2) from each cluster, producing resonances in the 2000-4500 cm(-1) region. Vibrational patterns indicate that these ions consist of an H3(+) (D3(+)) core ion solvated by H2 (D2) molecules. There is no evidence for the shared proton structure seen previously for H5(+). The H3(+) ion core vibrational bands are weakened and broadened significantly, presumably by enhanced rates of intramolecular vibrational relaxation. Computational studies at the DFT/B3LYP or MP2 levels of theory (including scaling) are adequate to reproduce qualitative details of the vibrational spectra, but neither provides quantitative agreement with vibrational frequencies.
RESUMEN
Objective: The purpose of this paper is to investigate whether playing exergames can enhance quality of life among young adults and it examines the potential moderators. Methods: A 12-week randomized controlled trial was conducted. Quality of life was measured using the short-form 36-item version (SF-36) scale. All the participants were between 20 and 24 years old in Taiwan. Participants in the intervention group (n = 55) were asked to play exergames for 12 weeks, three times a week and 30 minutes at a time, while participants in the control group (n = 62) did not play exergames. The changes in the scores on quality of life between the beginning and the end of the 12-week trial were calculated. Independent t-tests were used to analyze the differences. Results: The intervention group participants experienced an enhanced quality of life in terms of physical functioning, role-physical (role limitations due to physical health), general health, and social functioning. Moreover, the intervention group participants who were not enthusiastic about exercisers experienced an enhanced quality of life in physical functioning, role-physical, and general health. The intervention group participants who attempted to control their weight experienced enhanced general health, vitality, and mental health. Conclusion: Playing exergaming could contribute to users' quality of life in terms of both physical and mental health.
Asunto(s)
Videojuego de Ejercicio , Juegos de Video , Humanos , Adulto Joven , Adulto , Calidad de Vida , Juegos de Video/psicología , Examen Físico , TaiwánRESUMEN
Protonated benzene cluster ions, H(C(6)H(6))(2)(+) and H(C(6)H(6))(3)(+), are produced in a pulsed electrical discharge source coupled to a supersonic expansion. Mass-selected complexes are investigated with infrared photodissociation spectroscopy in the 1000-3200 cm(-1) region using the method of argon tagging. The IR spectra of H(C(6)H(6))(2)(+)-Ar and H(C(6)H(6))(3)(+)-Ar contain broad bands in the high frequency region resulting from CH-π hydrogen bonds. Sharp peaks are observed in the fingerprint region arising from the ring modes of both the C(6)H(7)(+) and C(6)H(6) moieties. M06-2X calculations have been performed to investigate the structures and vibrational spectra of energetically low-lying configurations of these complexes. H(C(6)H(6))(2)(+) is predicted to have three nearly isoenergetic conformers: the parallel displaced (PD), T-shaped (TS), and canted (C) structures [Jaeger, H. M.; Schaefer, H. F.; Hohenstein, E. G.; Sherrill, C. D. Comput. Theor. Chem. 2011, 973, 47-52]. A comparison of the experimental dimer spectrum with those predicted for the three isomers suggests an average structure between the TS and PD conformers, which is consistent with the low energy barrier predicted to separate these two structures. No evidence is found for the C dimer even though it lies only 1.2 kcal/mol above the PD dimer. Although the trimer is also computed to have many low lying isomers, the IR spectrum limits the possible species present.
Asunto(s)
Benceno/química , Dimerización , Protones , Vibración , Modelos Moleculares , Conformación Molecular , Espectrofotometría InfrarrojaRESUMEN
Pulsed discharges containing methanol or ethanol produce ions having the nominal formula [C,H(3),O](+), i.e. m/z = 31. Similar ions resulting from electron impact ionization in mass spectrometers are long recognized to have either the CH(2)OH(+) protonated formaldehyde or CH(3)O(+) methoxy cation structures. The H(2)OCH(+) oxonio-methylene structure has also been suggested by computational chemistry. To investigate these structures, ions are expanded in a supersonic beam, mass-selected in a time-of-flight spectrometer, and studied with infrared laser photodissociation spectroscopy. Sharp bands in the O-H and C-H stretching and fingerprint regions are compared to computational predictions for the three isomeric structures and their vibrational spectra. Protonated formaldehyde is the most abundant isomer, but methoxy is also formed with significant abundance. The branching ratio of these two ion species varies with precursors and formation conditions.
RESUMEN
To achieve the goals of carbon peak and carbon neutrality, the low-carbon transformation (LCT) of high-carbon firms is inevitable. We construct game models of a supply chain with different dominant types under a mixed carbon policy that embraces carbon cap-and-trade and carbon tax. Solving each dominant model, we derive the effective area and optimal threshold of the mixed carbon policy to guide LCT. We find that the selling price, market demand, and profit of the supply chain system are equal in different dominant models due to the mixed carbon policy, but when a company dominates the supply chain, its profit is higher than when it is a subordinate. In addition, the high-carbon manufacturers (HCM) will pursue LCT only when the sum of the carbon tax rates and carbon trading prices is within a certain threshold, and the subordinate HCM are more likely to be driven to pursue LCT. Therefore, the government should adopt a differentiated hybrid carbon policy, setting a high (low) carbon tax rate for the HCM in a dominant (subordinate) position.
Asunto(s)
Carbono , Impuestos , Comercio , Gobierno , PolíticasRESUMEN
Vaccination is a well-known method to protect the public against an epidemic outbreak, e.g., COVID-19. To this end, the government of a country or region would strive to achieve its target of vaccination coverage. Limited by the total vaccine capacity of public hospitals, the government may need to cooperate with private hospitals or clinics for more vaccination. Exploring in this paper government coordination of public and private resources for vaccination, we model a vaccine system consisting of a public hospital, a profit-maximizing private clinic, and self-interested individuals, under three scenarios: (1) without information sharing (concerning vaccine inventory and vaccine price), (2) with information sharing and subsidy, and (3) with information sharing and allocation. We find that, under scenario (1), the vaccine demand is fully satisfied by the public hospital and the private clinic cannot make any profit. Under scenario (2), the private clinic is willing to enter the vaccine market with a positive profit-maximizing vaccination coverage. Under scenario (3), the socially optimal vaccination coverage may be lower than that under scenario (1). Moreover, we conduct a sensitivity analysis to generate practical implications of the research findings for vaccination policy-making. Our results provide both theoretical and managerial insights on vaccine supply decision, government intervention, and vaccination coverage.
RESUMEN
The CoNe(+) diatomic cation is produced by laser vaporization in a pulsed-nozzle source and studied with photodissociation spectroscopy at visible wavelengths. Vibronic structure is assigned to the (3)Π(2) â (3)Δ(3) band system correlating to the Co(+)((3)P(2) â (3)F(4)) + Ne asymptote. The origin band (13,529 cm(-1)) and a progression of 14 other vibrational bands are detected ending in the dissociation limit at 14,191 cm(-1). The excited state dissociation energy is therefore D(0)(') = 662 cm(-1), and an energetic cycle using this, the origin band energy, and the atomic transition produces a ground state dissociation energy of D(0)(") = 930 cm(-1). The excited state vibrational frequency is 116.1 cm(-1). A rotationally resolved study of the origin band confirms the electronic transition assignment and provides the bond distance of r(0)(") = 2.36 Å. The properties of CoNe(+) are compared to those of other CoRG(+) and MNe(+) complexes studied previously.
RESUMEN
In this paper, we present a selective and differential medium, termed Vibrio alginolyticus (VAL) agar, developed for the isolation and identification of V. alginolyticus. The presence of bile salts, high salinity and high incubation temperature allows the selective growth of moderately halophilic Vibrio species. Differentiation of bacteria is achieved by identifying species capable of sucrose fermentation, made visible by the pH indicator bromocresol purple. In this study, all of the 26 strains of V. alginolyticus and only three of the 99 strains representing 30 species (including 19 Vibrio species) other than V. alginolyticus were able to grow in the VAL medium. The remaining three strains could be further differentiated from V. alginolyticus according to colour or the diameter of colonies produced on VAL agar plates. Colonies isolated from shellfish rearing water and infected shrimp through the use of VAL agar plates were all positively identified as V. alginolyticus by conventional tests and 16S rDNA sequencing. The testing of specificity and differentiation capability of VAL shows the potential of the agar as a medium for the primary isolation of V. alginolyticus from pathological and environmental samples.
Asunto(s)
Técnicas de Tipificación Bacteriana/métodos , Medios de Cultivo , Vibrio alginolyticus/fisiología , ARN Ribosómico 16S/genética , Reproducibilidad de los Resultados , Salinidad , Sensibilidad y Especificidad , Mariscos/microbiología , Vibrio alginolyticus/crecimiento & desarrollo , Vibrio alginolyticus/aislamiento & purificaciónRESUMEN
This paper is to produce different scenarios in forecasts for international tourism demand, in light of the COVID-19 pandemic. By implementing two distinct methodologies (the Long Short Term Memory neural network and the Generalized Additive Model), based on recent crises, we are able to calculate the expected drop in the international tourist arrivals for the next 12 months. We use a rolling-window testing strategy to calculate accuracy metrics and show that even though all models have comparable accuracy, the forecasts produced vary significantly according to the training data set, a finding that should be alarming to researchers. Our results indicate that the drop in tourist arrivals can range between 30.8% and 76.3% and will persist at least until June 2021.
RESUMEN
Establishment and characterization of two cobia, Rachycentron canadum, cell lines derived from cobia brain (CB) and cobia fin (CF) are described. Caudal fin and brain from juvenile cobia were dissociated for 30 and 10 min, respectively, in phosphate-buffered saline containing 0.25% trypsin at 25 degrees C. The optimal culture condition for both dissociated cells (primary cell culture) was at 28 degrees C in Leibovitz-15 medium containing 10% foetal bovine serum. The cells have been sub-cultured at a ratio of 1:2 for more than 160 passages over a period of 3 years. Origin of the cultured cells was verified by comparison of their sequences of mitochondrial cytochrome oxidase subunit I genes (cox I) with the cox 1 sequence from cobia muscle tissue. The cell lines showed polyploidy. No mycoplasma contamination was detected. Susceptibility to grouper iridovirus was observed for the CB cell line but not the CF cell line. Both cell lines expressed green fluorescent protein after being transfected with green fluorescent reporter gene driven by the cytomegalovirus promoter.
Asunto(s)
Encéfalo/citología , Enfermedades de los Peces/virología , Iridovirus/fisiología , Nodaviridae/fisiología , Perciformes/virología , Animales , Bovinos , Línea Celular , Cromosomas , Medios de Cultivo/química , Infecciones por Virus ADN/veterinaria , Susceptibilidad a Enfermedades/veterinaria , Susceptibilidad a Enfermedades/virología , Infecciones por Virus ARN/veterinaria , Temperatura , TransfecciónRESUMEN
During vertebrate embryogenesis, the muscle-specific helix-loop-helix protein myogenin is expressed in muscle cell precursors in the developing somite myotome and limb bud before muscle fiber formation and is further upregulated during myogenesis. We show that cis-acting DNA sequences within the 5' flanking region of the mouse myogenin gene are sufficient to direct appropriate temporal, spatial, and tissue-specific transcription of myogenin during mouse embryogenesis. Myogenin-lacZ transgenes trace the fate of embryonic cells that activate myogenin transcription and suggest that myogenic precursor cells that migrate from the somite myotome to the limb bud are committed to a myogenic fate in the absence of myogenin transcription. Activation of a myogenin-lacZ transgene can occur in limb bud explants in culture, indicating that signals required for activation of myogenin transcription are intrinsic to the limb bud and independent of other parts of the embryo. These results reveal multiple populations of myogenic precursor cells during development and suggest the existence of regulators other than myogenic helix-loop-helix proteins that maintain cells in the early limb bud in the myogenic lineage.
Asunto(s)
Proteínas Musculares/genética , Músculos/embriología , ARN Mensajero/análisis , Secuencias Reguladoras de Ácidos Nucleicos/genética , Transcripción Genética/genética , Animales , Diferenciación Celular , Movimiento Celular , Cloranfenicol O-Acetiltransferasa/genética , Hibridación Genética , Operón Lac/genética , Ratones/anatomía & histología , Ratones/embriología , Ratones Endogámicos C57BL , Ratones Endogámicos CBA , Ratones Transgénicos , Músculos/anatomía & histología , Músculos/citología , Miogenina , Técnicas de Cultivo de Órganos , Proteínas Recombinantes , Células Madre , Distribución TisularRESUMEN
Expression of the myogenic helix-loop-helix (HLH) protein myogenin in muscle cell precursors within somites and limb buds is among the earliest events associated with myogenic lineage determination in vertebrates. Mutations in the myogenin promoter that abolish binding sites for myogenic HLH proteins or myocyte enhancer factor-2 (MEF-2) suppressed transcription of a linked lacZ transgene in subsets of myogenic precursors in mouse embryos. These results suggest that myogenic HLH proteins and MEF-2 participate in separable regulatory circuits leading to myogenin transcription and provide evidence for positional regulation of myogenic regulators in the embryo.
Asunto(s)
Embrión de Mamíferos/metabolismo , Proteínas Musculares/genética , Músculos/embriología , Transactivadores/genética , Transcripción Genética , Animales , Sitios de Unión , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Extremidades/embriología , Femenino , Factores de Transcripción MEF2 , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos CBA , Ratones Transgénicos , Músculos/metabolismo , Mutación , Factores Reguladores Miogénicos , Miogenina , Regiones Promotoras Genéticas , Factores de Transcripción/genética , Factores de Transcripción/metabolismoRESUMEN
Electron field emission from a single nanoemitter is a barrier tunneling, quantum mechanical process that can, therefore, be described by the well-known Fowler-Nordheim (FN) equation. At high emission current densities, however, the space charge caused by the cathode may affect the current density-voltage (J-V) characteristics predicted by the FN theory. In this study, we theoretically investigated the effect of space charge on FE nanodevices, including diode and triode structures. The J-V characteristics of FE nanodevices were obtained by analytically (diode structures) or numerically (triode structures) solving the coupled FN equation and Poisson's equation. We discuss the behavior of FE nanodiodes and nanotriodes displaying different geometries, dimensions and work functions of their emitter materials. In the high current density region, space charge plays an important role in FE nanodevices; the threshold current density of space-charge limitation is related to the electric field distributions. Besides, our theoretical results are in good agreement with the experimental results reported previously.