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1.
Nanoscale Adv ; 6(14): 3624-3631, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38989517

RESUMO

Two-dimensional (2D) van der Waals (vdW) heterostructures are considered as promising candidates for realizing multifunctional applications, including photodetectors, field effect transistors and solar cells. In this work, we performed first-principles calculations to design a 2D vdW MoTe2/MoS2 heterostructure and investigate its electronic properties, contact types and the impact of an electric field and in-plane biaxial strain. We find that the MoTe2/MoS2 heterostructure is predicted to be structurally, thermally and mechanically stable. It is obvious that the weak vdW interactions are mainly dominated at the interface of the MoTe2/MoS2 heterostructure and thus it can be synthesized in recent experiments by the transfer method or chemical vapor deposition. The construction of the vdW MoTe2/MoS2 heterostructure forms a staggered type II band alignment, effectively separating the electrons and holes at the interface and thereby extending the carrier lifetime. Interestingly, the electronic properties and contact types of the type II vdW MoTe2/MoS2 heterostructure can be tailored under the application of external conditions, including an electric field and in-plane biaxial strain. The semiconductor-semimetal-metal transition and type II-type I conversion can be achieved in the vdW MoTe2/MoS2 heterostructure. Our findings underscore the potential of the vdW MoTe2/MoS2 heterostructure for the design and fabrication of multifunctional applications, including electronics and optoelectronics.

2.
Nanoscale Adv ; 6(4): 1193-1201, 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38356616

RESUMO

The emergence of van der Waals (vdW) heterostructures, which consist of vertically stacked two-dimensional (2D) materials held together by weak vdW interactions, has introduced an innovative avenue for tailoring nanoelectronic devices. In this study, we have theoretically designed a metal/semiconductor heterostructure composed of NbS2 and Janus MoSSe, and conducted a thorough investigation of its electronic properties and the formation of contact barriers through first-principles calculations. The effects of stacking configurations and the influence of external electric fields in enhancing the tunability of the NbS2/Janus MoSSe heterostructure are also explored. Our findings demonstrate that the NbS2/MoSSe heterostructure is not only structurally and thermally stable but also exfoliable, making it a promising candidate for experimental realization. In its ground state, this heterostructure exhibits p-type Schottky contacts characterized by small Schottky barriers and low tunneling barrier resistance, showing its considerable potential for utilization in electronic devices. Additionally, our findings reveal that the electronic properties, contact barriers and contact types of the NbS2/MoSSe heterostructure can be tuned by applying electric fields. A negative electric field leads to a conversion from a p-type Schottky contact to an n-type Schottky contact, whereas a positive electric field gives rise to a transformation from a Schottky into an ohmic contact. These insights offer valuable theoretical guidance for the practical utilization of the NbS2/MoSSe heterostructure in the development of next-generation electronic and optoelectronic devices.

3.
Healthcare (Basel) ; 12(4)2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-38391808

RESUMO

Background: The grassroots healthcare system is the closest and most community-oriented force, working as an extended arm of the primary healthcare network to implement healthcare programs at the household level. Its comprehensive development is a crucial task set by the Vietnamese government. Job satisfaction significantly influences the performance of healthcare staff within this system. Objective: to assess job satisfaction among healthcare staff using the short-form of the Minnesota Satisfaction Questionnaire while also evaluating the Vietnamese translation of this scale. Methods: A descriptive cross-sectional study with analysis based on the responses of 587 healthcare staff using the Vietnamese-translated version of the MSQ short-form scale. The response data from the participants were subjected to CFA, and if the proposed CFA model did not fit the data, EFA was conducted. Results: The results indicate that the new model, which evaluates job-related factors in three distinct groups, is more suitable than the original model. The 14 questions of the MSQ scale were analyzed and categorized into Autonomy, Obligation, and Specificity based on the participants' responses. The confirmatory factor analysis (CFA) conducted on the new model demonstrated favorable fit indices: CFI = 0.934, TLI = 0.917, GFI = 0.919, and RMSEA = 0.093 (90% CI: 0.085-0.102). Conclusions: The Vietnamese version of the MSQ short form demonstrates reliability and validity. It also provides additional data on the effectiveness of the MSQ short form in measuring job satisfaction.

4.
PLoS One ; 18(12): e0279691, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38085730

RESUMO

INTRODUCTION: Breastfeeding has many benefits for mothers, children, and the environment over both the short and longr-term. Prenatal intention to breastfeed is a powerful predictor of short-term breastfeeding outcomes. OBJECTIVE: This study aims to analyze breastfeeding intentions, including the intention to feed infants with breastmilk only and to continue exclusive breastfeeding to 6 months among pregnant mothers in Hanoi, Vietnam. METHODS: The analysis included 1230 singleton mothers, between 24- and 36-weeks' gestation, who attended antenatal clinics in two hospitals in Hanoi in 2020. RESULTS: The proportion of mothers with an "breastfeeding intention" (i.e., intention to feed an infant with breastmilk only) and "exclusive breastfeeding intention" to 6 months was 59.9% and 41.7%, respectively. Mothers who were 25 years or older (aOR = 1.35, 95%CI:1.00-1.81), had an undergraduate educational degree or higher (aOR = 1.38, 95%CI: 1.08-1.76), had observed another woman breastfeeding (aOR = 1.43, 95%CI: 1.03-2.00), were not living with parents-in-law (aOR = 1.34, CI: 1.05-1.70), and were multiparous (aOR = 1.60, 95%CI: 1.16-2.19) had higher odds of "exclusive breastfeeding intention" to 6 months. Among primiparous women, those who thought their husbands support breastfeeding were more likely to intend to feed an infant with breastmilk only. Among multiparous women, feeding the previous child with breastmilk exclusively before the introduction of complementary foods and not giving solid foods together with water until 6 months, were significant predictors for both breastfeeding intentions. CONCLUSION: Mothers without exclusive breastfeeding experience should be provided with greater support to promote exclusive breastfeeding intention and outcomes.


Assuntos
Aleitamento Materno , Intenção , Lactente , Criança , Feminino , Gravidez , Humanos , Estudos Transversais , Vietnã , Mães , Vitaminas
5.
Langmuir ; 39(48): 17251-17260, 2023 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-37972320

RESUMO

Conducting heterostructures have emerged as a promising strategy to enhance physical properties and unlock the potential application of such materials. Herein, we conduct and investigate the electronic and transport properties of the BSe/Sc2CF2 heterostructure using first-principles calculations. The BSe/Sc2CF2 heterostructure is structurally and thermodynamically stable, indicating that it can be feasible for further experiments. The BSe/Sc2CF2 heterostructure exhibits a semiconducting behavior with an indirect band gap and possesses type-II band alignment. This unique alignment promotes efficient charge separation, making it highly promising for device applications, including solar cells and photodetectors. Furthermore, type-II band alignment in the BSe/Sc2CF2 heterostructure leads to a reduced band gap compared to the individual BSe and Sc2CF2 monolayers, leading to enhanced charge carrier mobility and light absorption. Additionally, the generation of the BSe/Sc2CF2 heterostructure enhances the transport properties of the BSe and Sc2CF2 monolayers. The electric fields and strains can modify the electronic properties, thus expanding the potential application possibilities. Both the electric fields and strains can tune the band gap and lead to the type-II to type-I conversion in the BSe/Sc2CF2 heterostructure. These findings shed light on the versatile nature of the BSe/Sc2CF2 heterostructure and its potential for advanced nanoelectronic and optoelectronic devices.

6.
Dig Dis Sci ; 68(12): 4407-4417, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37861877

RESUMO

BACKGROUND: The accurate evaluation of liver fibrosis is crucial for the treatment and follow up of chronic hepatitis B (CHB) patients. AIM: We examined the efficiency of serum Mac-2 Binding Protein Glycosylation isomer (M2BPGi) in diagnosing liver fibrosis stages in CHB patients. METHODS: A cross-sectional study was conducted on 177 adult CHB patients visiting the University Medical Center Ho Chi Minh City, Vietnam between October 2019 and December 2021. M2BPGi, ARFI, APRI, and FIB-4 were tested against FibroScan® for sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). The optimal M2BPGi cut-off values were identified based on the area under the receiver operating characteristic (AUROC) curve. RESULTS: There was a strong agreement between M2BPGi and FibroScan® (r = 0.77, P < 0.001). The optimal M2BPGi cut-off index (C.O.I) for detecting significant fibrosis (F ≥ 2) was 0.79 with an AUROC of 0.77, 67.3% sensitivity, 70% specificity, 60.6% NPV, and 75.3% PPV. Compared with APRI (61%) and FIB-4 (47%), M2BPGi had the greatest sensitivity for diagnosing F ≥ 2. M2BPGi combined with APRI yielded highest diagnosis performance for F ≥ 2 with an AUROC of 0.87. The optimal cut-off index of M2BPGi for diagnosing cirrhosis (F4) was 1.3 with an AUROC of 0.91, 88% sensitivity, 87.4% specificity, 97% NPV, and 61% PPV. The AUROC of M2BPGi for diagnosing F4 was comparable to that of ARFI (0.93). CONCLUSIONS: With cut-off values of 0.79 C.O.I and 1.3 C.O.I, M2BPGi could be an effective method for diagnosing significant fibrosis and cirrhosis in CHB patients, respectively.


Assuntos
Hepatite B Crônica , Adulto , Humanos , Hepatite B Crônica/complicações , Hepatite B Crônica/diagnóstico , Glicosilação , Estudos Transversais , Biomarcadores , Cirrose Hepática/diagnóstico por imagem , Curva ROC
7.
Arch Craniofac Surg ; 24(4): 174-178, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37654237

RESUMO

BACKGROUND: This study aimed to identify the location of the optic foramen in relation to the anterior sphenoid sinus wall, which is essential information for surgeons in planning and performing endoscopic transnasal surgery. METHODS: Computed tomography scans of 200 orbits from 100 adult patients with no abnormalities were examined. The results included the location of the optic foramen in relation to the anterior sphenoid sinus wall and the distance between them, as well as the distance from the optic foramen and the anterior sphenoid sinus wall to the carotid prominence in the posterior sphenoid sinus. RESULTS: The optic foramen was anterior to the anterior sphenoid sinus wall in 48.5% of orbits, and posterior in the remaining 51.5%. The mean distance from the optic foramen to the anterior sphenoid sinus wall was 3.82 ± 1.25 mm. The mean distances from the optic foramen and the anterior sphenoid sinus wall to the carotid prominence were 7.67 ± 1.73 and 7.95 ± 2.53 mm, respectively. CONCLUSION: The optic foramen was anterior to the anterior wall of the sphenoid sinus in approximately half of the orbits examined in this study, and posterior in the remaining half. The mean distance from the optic foramen to the anterior sphenoid sinus wall of the sphenoid sinus was 3.82 ± 1.25 mm.

8.
Nanoscale Adv ; 5(18): 4979-4985, 2023 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-37705766

RESUMO

Two-dimensional (2D) metal-semiconductor heterostructures play a critical role in the development of modern electronics technology, offering a platform for tailored electronic behavior and enhanced device performance. Herein, we construct a novel 2D metal-semiconductor MoSH@MoS2 heterostructure and investigate its structures, electronic properties and contact characteristics using first-principles investigations. We find that the MoSH@MoS2 heterostructure exhibits a p-type Schottky contact, where the specific Schottky barrier height varies depending on the stacking configurations employed. Furthermore, the MoSH@MoS2 heterostructures possess low tunneling probabilities, indicating a relatively low electron transparency across all the patterns of the MoSH@MoS2 heterostructures. Interestingly, by modulating the electric field, it is possible to modify the Schottky barriers and achieve a transformation from a p-type Schottky contact into an n-type Schottky contact. Our findings pave the way for the development of advanced electronics technology based on metal-semiconductor MoSH@MoS2 heterostructures with enhanced tunability and versatility.

9.
Phys Chem Chem Phys ; 25(35): 23829-23835, 2023 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-37641558

RESUMO

We theoretically study the role of adsorbed gas molecules on the electronic and optical properties of monolayer ß12-borophene with {a,b,c,d,e} atoms in its unit cell. We focus our attention on molecules NH3, NO, NO2, and CO, which provide additional states permitted by the host electrons. Utilizing the six-band tight-binding model based on an inversion symmetry (between {a,e} and {b,d} atoms) and the Kubo formalism, we survey the anisotropic electronic dispersion and the optical multi-interband spectrum produced by molecule-boron coupling. We consider the highest possibilities for the position of molecules on the boron atoms. For molecules on {a,e} atoms, the inherent metallic phase of ß12-borophene becomes electron-doped semiconducting, while for molecules on {b,d} and c atoms, the metallic phase remains unchanged. For molecules on {a,e} and {b,d} atoms, we observe a redshift (blueshift) optical spectrum for longitudinal/transverse (Hall) component, while for molecules on c atoms, we find a redshift (blueshift) optical spectrum for longitudinal (transverse/Hall) component. We expect that this study provides useful information for engineering field-effect transistor-based gas sensors.

10.
J Phys Condens Matter ; 35(43)2023 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-37467755

RESUMO

We study the transport properties of monolayers MoSi2N4, WSi2N4, and MoSi2As4in a perpendicular magnetic field. The Landau level (LL) band structures including spin and exchange field effects are derived and discussed using a low-energy effective model. We show that the LLs band structures of these materials are similar to those of phosphorene and transition-metal dichalcogenides rather than graphene or silicene. The combination of strong spin-orbit coupling and exchange fields reduces the degradation of the LLs, leading to new plateaus in the Hall conductivity and Hall resistivity and new peaks in the longitudinal conductivity and longitudinal resistivity. The effect of the exchange field, carrier density, and LLs band structure on the conductivities and resistivities have been investigated. At high temperatures, the steps in Hall conductivity and resistivity plateaus disappear and reduce to their corresponding classical forms.

11.
Nanoscale Adv ; 5(9): 2583-2589, 2023 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-37143808

RESUMO

Constructing heterostructures has proven to be an effective strategy to manipulate the electronic properties and enlarge the application possibilities of two-dimensional (2D) materials. In this work, we perform first-principles calculations to generate the heterostructure between boron phosphide (BP) and Sc2CF2 materials. The electronic characteristics and band alignment of the combined BP/Sc2CF2 heterostructure, as well as the effects of an applied electric field and interlayer coupling, are examined. Our results predict that the BP/Sc2CF2 heterostructure is energetically, thermally and dynamically stable. All considered stacking patterns of the BP/Sc2CF2 heterostructure possess semiconducting behavior. Furthermore, the formation of the BP/Sc2CF2 heterostructure gives rise to the generation of type-II band alignment, which causes photogenerated electrons and holes to move in opposite ways. Therefore, the type-II BP/Sc2CF2 heterostructure could be a promising candidate for photovoltaic solar cells. More interestingly, the electronic properties and band alignment in the BP/Sc2CF2 heterostructure can be tuned by applying an electric field and modifying the interlayer coupling. Applying an electric field not only causes modulation of the band gap, but also leads to the transition from a semiconductor to a gapless semiconductor and from type-II to type-I band alignment of the BP/Sc2CF2 heterostructure. In addition, changing the interlayer coupling gives rise to modulation of the band gap of the BP/Sc2CF2 heterostructure. Our findings suggest that the BP/Sc2CF2 heterostructure is a promising candidate for photovoltaic solar cells.

12.
Langmuir ; 39(18): 6637-6645, 2023 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-37116116

RESUMO

van der Waals heterostructures provide a powerful platform for engineering the electronic properties and for exploring exotic physical phenomena of two-dimensional materials. Here, we construct a graphene/BSe heterostructure and examine its electronic characteristics and the tunability of contact types under electric fields. Our results reveal that the graphene/BSe heterostructure is energetically, mechanically, and thermodynamically stable at room temperature. It forms a p-type Schottky contact and exhibits a high carrier mobility, making it a promising candidate for future Schottky field-effect transistors. Furthermore, applying an electric field not only reduces contact barriers but also induces a transition from a p-type to an n-type Schottky contact and from a Schottky to an ohmic contact, offering further potential for the control and manipulation of the heterostructure's electronic properties. Our findings offer a rational basis for the design of energy-efficient and tunable heterostructure devices based on the graphene/BSe heterostructure.

14.
RSC Adv ; 13(11): 7436-7442, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36895771

RESUMO

Nowadays, it would be ideal to develop high-performance photovoltaic devices as well as highly efficient photocatalysts for the production of hydrogen via photocatalytic water splitting, which is a feasible and sustainable energy source for addressing the challenges related to environmental pollution and a shortage of energy. In this work, we employ first-principles calculations to investigate the electronic structure, optical properties and photocatalytic performance of novel SiS/GeC and SiS/ZnO heterostructures. Our results indicate that both the SiS/GeC and SiS/ZnO heterostructures are structurally and thermodynamically stable at room temperature, suggesting that they are promising materials for experimental implementation. The formation of SiS/GeC and SiS/ZnO heterostructures gives rise to reduction of the band gaps as compared to the constituent monolayers, enhancing the optical absorption. Furthermore, the SiS/GeC heterostructure possesses a type-I straddling gap with a direct band gap, while the SiS/ZnO heterostructure forms a type-II band alignment with indirect band gap. Moreover, a red-shift (blue-shift) has been observed in SiS/GeC (SiS/ZnO) heterostructures as compared with the constituent monolayers, enhancing the efficient separation of photogenerated electron-hole pairs, thereby making them promising candidates for optoelectronic applications and solar energy conversion. More interestingly, significant charge transfers at the interfaces of SiS-ZnO heterostructures, have improved the adsorption of H, and the Gibbs free energy ΔH* becomes close to zero, which is optimal for the hydrogen evolution reaction to produce hydrogen. The findings pave the path for the practical realization of these heterostructures for potential applications in photovoltaics and photocatalysis of water splitting.

15.
Comput Methods Programs Biomed ; 232: 107451, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36893580

RESUMO

BACKGROUND AND OBJECTIVES: Advanced artificial intelligence and machine learning have great potential to redefine how skin lesions are detected, mapped, tracked and documented. Here, we propose a 3D whole-body imaging system known as 3DSkin-mapper to enable automated detection, evaluation and mapping of skin lesions. METHODS: A modular camera rig arranged in a cylindrical configuration was designed to automatically capture images of the entire skin surface of a subject synchronously from multiple angles. Based on the images, we developed algorithms for 3D model reconstruction, data processing and skin lesion detection and tracking based on deep convolutional neural networks. We also introduced a customised, user-friendly, and adaptable interface that enables individuals to interactively visualise, manipulate, and annotate the images. The interface includes built-in features such as mapping 2D skin lesions onto the corresponding 3D model. RESULTS: The proposed system is developed for skin lesion screening, the focus of this paper is to introduce the system instead of clinical study. Using synthetic and real images we demonstrate the effectiveness of the proposed system by providing multiple views of a target skin lesion, enabling further 3D geometry analysis and longitudinal tracking. Skin lesions are identified as outliers which deserve more attention from a skin cancer physician. Our detector leverages expert annotated labels to learn representations of skin lesions, while capturing the effects of anatomical variability. It takes only a few seconds to capture the entire skin surface, and about half an hour to process and analyse the images. CONCLUSIONS: Our experiments show that the proposed system allows fast and easy whole body 3D imaging. It can be used by dermatological clinics to conduct skin screening, detect and track skin lesions over time, identify suspicious lesions, and document pigmented lesions. The system can potentially save clinicians time and effort significantly. The 3D imaging and analysis has the potential to change the paradigm of whole body photography with many applications in skin diseases, including inflammatory and pigmentary disorders. With reduced time requirements for recording and documenting high-quality skin information, doctors could spend more time providing better-quality treatment based on more detailed and accurate information.


Assuntos
Neoplasias Cutâneas , Imagem Corporal Total , Humanos , Inteligência Artificial , Redes Neurais de Computação , Neoplasias Cutâneas/diagnóstico por imagem , Algoritmos
16.
Case Rep Gastroenterol ; 17(1): 82-88, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36760465

RESUMO

Lately, emerging data suggest an association between the development of inflammatory bowel disease and anti-interleukin-17 therapy. Megacolon is a life-threatening complication of acute severe ulcerative colitis (ASUC), but its treatment has not yet been established in current practice guidelines. We report a rare case of known psoriasis treated by secukinumab in a patient who presented with ASUC and colonic dilatation. Neither steroids nor standard infliximab regimen was effective. Finally, rescue therapy with accelerated infliximab strategy resulted in excellent recovery. In certain cases of steroid-refractory ASUC complicated by megacolon, accelerated infliximab regimen can be an alternative to surgery.

17.
Dalton Trans ; 52(7): 2080-2086, 2023 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-36692487

RESUMO

The generation of layered heterostructures from a combination of two or more different two-dimensional (2D) materials is considered as a powerful strategy to modify the electronic properties of 2D materials and enhance their performance in devices. Herein, using first-principles calculations, we systematically study the electronic properties and the band alignment in a heterostructure formed from 2D boron phosphide (BP) and silicane (SiH) monolayers. The BP/SiH heterostructure is structurally and mechanically stable in the ground state. The generation of the BP/SiH heterostructure leads to a reduction in the band gap, thus enhancing the optical absorption coefficient compared to the constituent BP and SiH monolayers. In addition, the BP/SiH heterostructure has a high carrier mobility of 3.2 × 104 cm2 V-1 s-1. Furthermore, the combined BP/SiH heterostructure gives rise to the formation of a type-II band alignment, inhibiting the recombination of the photogenerated carriers. The electronic properties and band alignment of the BP/SiH heterostructure can be tuned by an applied external electric field, which causes a reduction in the band gap and leads to the transition of the band alignment from type-II to type-I. Our findings could act as theoretical guidance for the use of the BP/SiH heterostructure in the design of high-efficiency nanodevices.

18.
Nat Prod Res ; 37(21): 3563-3571, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35749654

RESUMO

Tecoma stans is a tropical plant that is widely used in folk medicine. Little is known about the chemical constituents of flowers of this plant. From flowers of the native plant in Vietnam, 12 compounds were isolated and elucidated, including one new compound tecomastane (1) and eleven known compounds, (3S,5R,6S,7E)-5,6-epoxy-3-hydroxy-7-megastigmane-9-one (2), bosciallin (3), chakyunglupulin B (4), (2S,6R)-2,6-dimethyloctane-1,8-diol (5), cleroindicin F (6), rengyoxide (7), 3,4-dihydroxybenzoic acid (8), methyl 3,4-dihydrobenzoate (9), 3,5-dihydroxybenzoic acid (10), luteolin (11), and indole-3-carboxylic acid (12). Compound 5 was a new natural product. The chemical structures of isolated compounds were identified by interpretation of their spectroscopic data (1D, 2D NMR, and HRESIMS) and by comparison with the literature. Compounds 1-7 and 10-12 were evaluated for alpha-glucosidase inhibition and antimicrobial activity against antibiotic-resistant, pathogenic bacteria Enterococcus faecium, Staphylococcus aureus, and Acinetobacter baumannii.

19.
Phys Chem Chem Phys ; 24(41): 25144-25150, 2022 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-36239182

RESUMO

Stacking different two-dimensional materials to generate a vertical heterostructure has been considered a promising way to obtain the desired properties and improve device performance. Here, in this work, using first principles calculations, we design a vertical heterostructure by stacking graphene (GR) and silicane (SiH) and investigate the electronic properties and electrical contact in the GR/SiH heterostructure as well as the possibility of tuning these properties under an external electric field and vertical strain. The GR/SiH heterostructure is structurally and mechanically stable at the equilibrium interlayer separation. The GR/SiH heterostructure exhibits a p-type Schottky contact with a small Schottky barrier of 0.43 eV, presenting great tunability of the electrical contact from Schottky to Ohmic contact under different conditions. The external electric field not only leads to a transition from the p-type to n-type Schottky contact but also induces a transformation from a Schottky contact to Ohmic one. Furthermore, changing the interlayer separation can be considered a useful tool to regulate the Schottky barriers and electric contact in the GR/SiH heterostructure, which is prominent for constructing electronic devices. Our findings could provide an effective tool for the design of high-performance nanoelectronic devices based on the GR/SiH heterostructure.

20.
Indian J Radiol Imaging ; 32(3): 287-293, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36177272

RESUMO

Background Acoustic radiation force impulse point shear wave elastography (ARFI-pSWE), measuring shear-wave velocity (SWV), has been utilized to examine the liver stiffness caused by different etiologies. However, information on its reliability in staging liver fibrosis in chronic hepatitis B (CHB) patients is scarce. Purpose The aim of the study is to examine the diagnostic performance of ARFI-pSWE and determine the optimal SWV cut-off values to predict significant fibrosis ( F ≥2) and cirrhosis (F4) in CHB patients. Material and Methods All 114 adult CHB patients visiting the University Medical Center, Ho Chi Minh City, Vietnam between February 2019 and March 2021 underwent liver stiffness measurement using ARFI-pSWE and FibroScan. SWV results were tested against FibroScan for sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). The area under the receiver operating characteristic (AUROC) curve was used to identify the optimal SWV cut-off values. Results There was a strong agreement between ARFI-pSWE and FibroScan ( r = 0.92, p <0.001). The optimal SWV cut-off value for detecting significant fibrosis was 1.37 m/s with an AUROC of 0.975, sensitivity of 83.3%, specificity of 100%, PPV of 100%, and NPV of 81%. The optimal cut-off value for predicting cirrhosis was 1.70 m/s with an AUROC of 0.986, sensitivity of 97%, specificity of 93%, PPV of 95%, and NPV of 96%. Conclusion ARFI-pSWE could be an effective technique for evaluating liver fibrosis in CHB patients. SWV cut-off values of 1.37 and 1.70 m/s could be used to diagnose significant fibrosis and cirrhosis, respectively.

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