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1.
Small ; 20(17): e2307728, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38263806

ABSTRACT

Herein, the structure of integrated M3D inverters are successfully demonstrated where a chemical vapor deposition (CVD) synthesized monolayer WSe2 p-type nanosheet FET is vertically integrated on top of CVD synthesized monolayer MoS2 n-type film FET arrays (2.5 × 2.5 cm) by semiconductor industry techniques, such as transfer, e-beam evaporation (EBV), and plasma etching processes. A low temperature (below 250 °C) is employed to protect the WSe2 and MoS2 channel materials from thermal decomposition during the whole fabrication process. The MoS2 NMOS and WSe2 PMOS device fabricated show an on/off current ratio exceeding 106 and the integrated M3D inverters indicate an average voltage gain of ≈9 at VDD = 2 V. In addition, the integrated M3D inverter demonstrates an ultra-low power consumption of 0.112 nW at a VDD of 1 V. Statistical analysis of the fabricated inverters devices shows their high reliability, rendering them suitable for large-area applications. The successful demonstration of M3D inverters based on large-scale 2D monolayer TMDs indicate their high potential for advancing the application of 2D TMDs in future integrated circuits.

2.
Nanoscale ; 15(45): 18233-18240, 2023 Nov 23.
Article in English | MEDLINE | ID: mdl-37943087

ABSTRACT

Achieving self-powered photodetection without biasing is a notable challenge for photodetectors. In this work, we demonstrate the successful fabrication of large-scale van der Waals epitaxial molybdenum disulfide (MoS2) on a p-GaN/sapphire substrate using a straightforward chemical vapor deposition (CVD) technique. Our research primarily centers on the characterization of these photodetectors produced through this method. The MoS2/GaN heterojunction photodetector showcases a broad and extensive photoresponse spanning from ultraviolet A (UVA) to near-infrared (NIR). When illuminated by a 532 nm laser, its self-powered photoresponse is characterized by a rise time (τr) of ∼18.5 ms and a decay time (τd) of ∼123.2 ms. The photodetector achieves a responsivity (R) of ∼0.13 A W-1 and a specific detectivity (D*) of ∼3.8 × 1010 Jones at zero bias. Additionally, while utilizing a 404 nm laser, the photodetector reaches a maximum R and D* of ∼1.7 × 104 A/W and ∼1.6 × 1013 Jones, respectively, at Vb = 5 V. The operational mechanism of the device can be explained by the diode characteristics involving a tunneling current in the presence of reverse bias. The exceptional performance of these photodetectors can be attributed to the pristine interface between the CVD-grown MoS2 and GaN, providing an impeccably clean tunneling surface. Additionally, our investigation has unveiled that MoS2/GaN heterostructure photodetectors, featuring MoS2 coverage percentages spanning from 20% to 50%, exhibit improved responsivity capabilities at an external bias voltage. As a result, this facile CVD growth technique for MoS2 photodetectors holds significant potential for large-scale production in the manufacturing industry.

3.
Appl Psychol Meas ; 47(7-8): 460-477, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37997579

ABSTRACT

Computerized adaptive testing (CAT) can improve test efficiency, but it also causes the problem of unbalanced item usage within a pool. The effect of uneven item exposure rates can not only induce a test security problem due to overexposed items but also raise economic concerns about item pool development due to underexposed items. Therefore, this study proposes a two-stage Sympson-Hetter (TSH) method to enhance balanced item pool utilization by simultaneously controlling the minimum and maximum item exposure rates. The TSH method divides CAT into two stages. While the item exposure rates are controlled above a prespecified level (e.g., rmin) in the first stage to increase the exposure rates of the underexposed items, they are controlled below another prespecified level (e.g., rmax) in the second stage to prevent items from overexposure. To reduce the effect on trait estimation, TSH only administers a minimum sufficient number of underexposed items that are generally less discriminating in the first stage of CAT. The simulation study results indicate that the TSH method can effectively improve item pool usage without clearly compromising trait estimation precision in most conditions while maintaining the required level of test security.

4.
Nanoscale ; 15(6): 2586-2594, 2023 Feb 09.
Article in English | MEDLINE | ID: mdl-36691938

ABSTRACT

Since quantum computers have been gradually introduced in countries around the world, the development of the many related quantum components that can operate independently of temperature has become more important for enabling mature products with low power dissipation and high efficiency. As an alternative to studying cryo-CMOSs (complementary metal-oxide-semiconductors) to achieve this goal, quantum tunneling devices based on 2D materials can be examined instead. In this work, a vertical graphene-based quantum tunneling transistor has been used as a frequency modulator. The transistor can operate via different quantum tunneling mechanisms and generates, by applying the appropriate bias, voltage-resistance curves characteristic of variable nonlinear resistance for both base and emitter voltages. We experimentally demonstrate frequency modulation from input signals over the range of 100 kHz to 10 MHz, enabling a tunable frequency doubler or tripler in just a single transistor. This frequency multiplication with a tunneling mechanism makes the graphene-based tunneling device a promising option for frequency electronics in the emerging field of quantum technologies.

5.
Nanoscale Horiz ; 7(12): 1533-1539, 2022 Nov 21.
Article in English | MEDLINE | ID: mdl-36285561

ABSTRACT

The negative differential resistance (NDR) effect has been widely investigated for the development of various electronic devices. Apart from traditional semiconductor-based devices, two-dimensional (2D) transition metal dichalcogenide (TMD)-based field-effect transistors (FETs) have also recently exhibited NDR behavior in several of their heterostructures. However, to observe NDR in the form of monolayer MoS2, theoretical prediction has revealed that the material should be more profoundly affected by sulfur (S) vacancy defects. In this work, monolayer MoS2 FETs with a specific amount of S-vacancy defects are fabricated using three approaches, namely chemical treatment (KOH solution), physical treatment (electron beam bombardment), and as-grown MoS2. Based on systematic studies on the correlation of the S-vacancies with both the device's electron transport characteristics and spectroscopic analysis, the NDR has been clearly observed in the defect-engineered monolayer MoS2 FETs with an S-vacancy (VS) amount of ∼5 ± 0.5%. Consequently, stable NDR behavior can be observed at room temperature, and its peak-to-valley ratio can also be effectively modulated via the gate electric field and light intensity. Through these results, it is envisioned that more electronic applications based on defect-engineered layered TMDs will emerge in the near future.

6.
ACS Nano ; 15(8): 13085-13093, 2021 Aug 24.
Article in English | MEDLINE | ID: mdl-34313105

ABSTRACT

Strong coupling between light and matter is the foundation of promising quantum photonic devices such as deterministic single photon sources, single atom lasers, and photonic quantum gates, which consist of an atom and a photonic cavity. Unlike atom-based systems, a strong coupling unit based on an emitter-plasmonic nanocavity system has the potential to bring these devices to the microchip scale at ambient conditions. However, efficiently and precisely positioning a single or a few emitters into a plasmonic nanocavity is challenging. In addition, placing a strong coupling unit on a designated substrate location is a demanding task. Here, fluorophore-modified DNA strands are utilized to drive the formation of particle-on-film plasmonic nanocavities and simultaneously integrate the fluorophores into the high field region of the nanocavities. High cavity yield and fluorophore coupling yield are demonstrated. This method is then combined with e-beam lithography to position the strong coupling units on designated locations of a substrate. Furthermore, polariton energy under the detuning of fluorophore embedded nanocavities can fit into a model consisting of three sets of two-level systems, implying vibronic modes may be involved in the strong coupling. Our system makes strong coupling units more practical on the microchip scale and at ambient conditions and provides a stable platform for investigating fluorophore-plasmonic nanocavity interaction.

7.
ACS Nano ; 15(4): 6756-6764, 2021 Apr 27.
Article in English | MEDLINE | ID: mdl-33734665

ABSTRACT

The integration of graphene and other two-dimensional (2D) materials with existing silicon semiconductor technology is highly desirable. This is due to the diverse advantages and potential applications brought about by the consequent miniaturization of the resulting electronic devices. Nevertheless, such devices that can operate at very high frequencies for high-speed applications are eminently preferred. In this work, we demonstrate a vertical graphene base hot-electron transistor that performs in the radio frequency regime. Our device exhibits a relatively high current density (∼200 A/cm2), high common base current gain (α* ∼ 99.2%), and moderate common emitter current gain (ß* ∼ 2.7) at room temperature with an intrinsic current gain cutoff frequency of around 65 GHz. Furthermore, cutoff frequency can be tuned from 54 to 65 GHz by varying the collector-base bias. We anticipate that this proposed transistor design, built by the integrated 2D material and silicon semiconductor technology, can be a potential candidate to realize extra fast radio frequency tunneling hot-carrier electronics.

8.
ACS Nano ; 14(7): 8539-8550, 2020 Jul 28.
Article in English | MEDLINE | ID: mdl-32520534

ABSTRACT

The rechargeable aluminum-ion battery (AIB) is a promising candidate for next-generation high-performance batteries, but its cathode materials require more development to improve their capacity and cycling life. We have demonstrated the growth of MoSe2 three-dimensional helical nanorod arrays on a polyimide substrate by the deposition of Mo helical nanorod arrays followed by a low-temperature plasma-assisted selenization process to form novel cathodes for AIBs. The binder-free 3D MoSe2-based AIB shows a high specific capacity of 753 mAh g-1 at a current density of 0.3 A g-1 and can maintain a high specific capacity of 138 mAh g-1 at a current density of 5 A g-1 with 10 000 cycles. Ex situ Raman, XPS, and TEM characterization results of the electrodes under different states confirm the reversible alloying conversion and intercalation hybrid mechanism during the discharge and charge cycles. All possible chemical reactions were proposed by the electrochemical curves and characterization. Further exploratory works on interdigital flexible AIBs and stretchable AIBs were demonstrated, exhibiting a steady output capacity under different bending and stretching states. This method provides a controllable strategy for selenide nanostructure-based AIBs for use in future applications of energy-storage devices in flexible and wearable electronics.

9.
ACS Appl Mater Interfaces ; 12(28): 32041-32053, 2020 Jul 15.
Article in English | MEDLINE | ID: mdl-32400158

ABSTRACT

In this work, we demonstrated nano-scaled Laue diffractions by a focused polychromatic synchrotron radiation beam to discover what happens in MoS2 when van der Waals epitaxy is locally invalid. A stronger exciton recombination with a local charge depletion in the density of 1 × 1013 cm-2, extrapolated by Raman scattering and photoluminescence, occurs in grains, which exhibits a preferred orientation of 30° rotation with respect to the c-plane of a sapphire substrate. Else, the charge doping and trion recombination dominate instead. In addition to the breakthrough in extrapolating mesoscopic crystallographic characteristics, this work opens the feasibility to manipulate charge density by the selection of the substrate-induced disturbances without external treatment and doping. Practically, the 30° rotated orientation in bilayer MoS2 films is promoted on inclined facets in the patterned sapphire substrate, which exhibits a periodic array of charge depletion of about 1.65 × 1013 cm-2. The built-in manipulation of carrier concentrations could be a potential candidate to lateral and large-area electronics based on 2D materials.

10.
Appl Psychol Meas ; 44(3): 182-196, 2020 May.
Article in English | MEDLINE | ID: mdl-32341606

ABSTRACT

When computerized adaptive testing (CAT) is under stringent item exposure control, the precision of trait estimation will substantially decrease. A new item selection method, the dynamic Stratification method based on Dominance Curves (SDC), which is aimed at improving trait estimation, is proposed to mitigate this problem. The objective function of the SDC in item selection is to maximize the sum of test information for all examinees rather than maximizing item information for individual examinees at a single-item administration, as in conventional CAT. To achieve this objective, the SDC uses dominance curves to stratify an item pool into strata with the number being equal to the test length to precisely and accurately increase the quality of the administered items as the test progresses, reducing the likelihood that a high-discrimination item will be administered to an examinee whose ability is not close to the item difficulty. Furthermore, the SDC incorporates a dynamic process for on-the-fly item-stratum adjustment to optimize the use of quality items. Simulation studies were conducted to investigate the performance of the SDC in CAT under item exposure control at different levels of severity. According to the results, the SDC can efficiently improve trait estimation in CAT through greater precision and more accurate trait estimation than those generated by other methods (e.g., the maximum Fisher information method) in most conditions.

11.
Nanoscale Res Lett ; 14(1): 213, 2019 Jun 25.
Article in English | MEDLINE | ID: mdl-31240467

ABSTRACT

In this work, three-dimensional (3D) CoMoSe4 nanosheet arrays on network fibers of a carbon cloth denoted as CoMoSe4@C converted directly from CoMoO4 nanosheet arrays prepared by a hydrothermal process followed by the plasma-assisted selenization at a low temperature of 450 °C as an anode for sodium-ion battery (SIB) were demonstrated for the first time. With the plasma-assisted treatment on the selenization process, oxygen (O) atoms can be replaced by selenium (Se) atoms without the degradation on morphology at a low selenization temperature of 450 °C. Owing to the high specific surface area from the well-defined 3D structure, high electron conductivity, and bi-metal electrochemical activity, the superior performance with a large sodium-ion storage of 475 mA h g-1 under 0.5-3 V potential range at 0.1 A g-1 was accomplished by using this CoMoSe4@C as the electrode. Additionally, the capacity retention was well maintained over 80 % from the second cycle, exhibiting a satisfied capacity of 301 mA h g-1 even after 50 cycles. The work delivered a new approach to prepare a binary transition metallic selenide and definitely enriches the possibilities for promising anode materials in SIBs with high performances.

12.
Appl Radiat Isot ; 148: 152-159, 2019 Jun.
Article in English | MEDLINE | ID: mdl-30959352

ABSTRACT

One of the hallmarks of cancer is increased cell proliferation. Measurements of cell proliferation by estimation of DNA synthesis with several radiolabeled nucleosides have been tested to assess tumor growth. Deoxycytidine can be phosphorylated by deoxycytidine kinase (dCK) and is incorporated into DNA. This study evaluated a radiofluorinated deoxycytidine analog, 5-[18F]fluoro-2'-deoxycytidine ([18F]FdCyd), as a proliferation probe and compared it with 5-[18F]fluoro-2'-deoxyuridine ([18F]FdUrd), 3'-deoxy-3'-[18F]fluorothymidine ([18F]FLT), and [18F]fluorodeoxyglucose ([18F]FDG) in a tumor-bearing mouse model. [18F]FdCyd was synthesized from two precursors by direct electrophilic substitution. The serum stability and partition coefficient of [18F]FdCyd were evaluated in vitro. Positron emission topography (PET) imaging of Lewis lung carcinoma (LLC)-bearing mice with [18F]FdCyd, [18F]FdUrd, [18F]FLT, and [18F]FDG were evaluated. [18F]FdCyd was stable in mouse serum and normal saline for up to 4 h. With all radiotracers except [18F]FLT, PET can clearly delineate the tumor lesion. [18F]FdCyd and [18F]FdUrd showed high accumulation in the liver and kidney. The SUV and tumor-to-muscle (T/M) ratios derived from PET imaging of the radiotracers were [18F]FDG > [18F]FdCyd > [18F]FdUrd > [18F]FLT. Selective retention in tumors with a favorable tumor/muscle ratio makes [18F]FdCyd a protential candidate for further investigation as a proliferation imaging agent.


Subject(s)
Deoxycytidine/analogs & derivatives , Floxuridine/administration & dosage , Fluorodeoxyglucose F18/administration & dosage , Radiopharmaceuticals/administration & dosage , Animals , Cell Line, Tumor , Deoxycytidine/administration & dosage , Deoxycytidine/blood , Deoxycytidine/pharmacokinetics , Floxuridine/pharmacokinetics , Fluorodeoxyglucose F18/pharmacokinetics , Heterografts , Male , Mice , Mice, Inbred C57BL , Positron-Emission Tomography/methods , Radiopharmaceuticals/pharmacokinetics , Tissue Distribution
13.
Nucl Med Biol ; 68-69: 22-30, 2019.
Article in English | MEDLINE | ID: mdl-30578136

ABSTRACT

INTRODUCTION: Multiple peptide receptors are co-expressed in many types of cancers. Arg-Gly-Asp (RGD) and GE11 peptides specifically target integrin αVß3 and EGFR, respectively. Recently, we designed and synthesized a heterodimer peptide NOTA-c(RGDyK)-GE11 (NOTA-RGD-GE11). The aim of this study was to investigate the characteristics of NOTA-RGD-GE11 for dual receptor imaging. METHODS: NOTA-RGD-GE11 heterodimer was labelled with 68Ga. The dual receptor binding affinity was investigated by antibody competition binding assay. The in vitro and in vivo characteristics of [68Ga]Ga-NOTA-RGD-GE11 were investigated and compared with that of monomeric peptides [68Ga]Ga-NOTA-RGD and [68Ga]Ga-NOTA-GE11. RESULTS: NOTA-RGD-GE11 had binding affinities with both integrin αVß3 and EGFR. The dual receptor targeting property of [68Ga]Ga-NOTA-RGD-GE11 was validated by blocking studies in a NCI-H292 tumour model. [68Ga]Ga-NOTA-RGD-GE11 showed higher tumour uptake than [68Ga]Ga-NOTA-RGD and [68Ga]Ga-NOTA-GE11 in biodistribution and PET/CT imaging studies. CONCLUSION: The dual receptor targeting and enhanced tumour uptake of [68Ga]Ga-NOTA-RGD-GE11 warrant its further investigation for dual integrin αVß3 and EGFR-targeted tumour imaging.


Subject(s)
ErbB Receptors/metabolism , Gallium Radioisotopes , Heterocyclic Compounds, 1-Ring/chemistry , Integrin alphaVbeta3/metabolism , Oligopeptides/chemistry , Peptides/chemistry , Positron Emission Tomography Computed Tomography/methods , Animals , Biological Transport , Cell Line, Tumor , Humans , Isotope Labeling , Mice , Mice, Nude , Peptides/metabolism , Peptides/pharmacokinetics , Tissue Distribution
14.
J Labelled Comp Radiopharm ; 61(12): 885-894, 2018 10.
Article in English | MEDLINE | ID: mdl-30089196

ABSTRACT

The aim of this study was to formulate and evaluate the freeze-dried kit of NOTA-hexavalent lactoside (NOTA-HL) for the preparation of 68 Ga-labeled glycoligand for PET imaging of the asialoglycoprotein receptor (ASGPR). 68 GaCl3 was obtained from a commercial 68 Ge/68 Ga generator. Single-vial kits of HL were formulated. Optimization of radiolabeling with 68 Ga, various evaluations of NOTA-HL kits, and in vitro stability study of 68 Ga-HL were carried out. PET/CT imaging of normal mice injected with 68 Ga-NOTA-HL was performed. NOTA-HL kit was successfully formulated. High radiochemical yields (>95%) were obtained by 68 Ga radiolabeling. The NOTA-HL kits were stable for at least 12 months, and 68 Ga-NOTA-HL exhibited good in vitro stability. PET studies in normal mice revealed high specific accumulation of activity in the liver. The NOTA-HL kit was developed for fast 68 Ga labeling. 68 Ga-NOTA-HL showed high specific uptake in liver. The availability of ready-to-use NOTA-HL kits combined with 68 Ge/68 Ga generators would provide an efficient approach for PET imaging of ASGPR.


Subject(s)
Asialoglycoprotein Receptor/metabolism , Gallium Radioisotopes/chemistry , Glycosides/chemistry , Glycosides/chemical synthesis , Isotope Labeling/methods , Positron Emission Tomography Computed Tomography , Animals , Heterocyclic Compounds, 1-Ring/chemistry , Mice , Radiochemistry
15.
Nanotechnology ; 29(22): 225707, 2018 Jun 01.
Article in English | MEDLINE | ID: mdl-29528843

ABSTRACT

Two-dimensional electron gas (2DEG) is crucial in condensed matter physics and is present on the surface of liquid helium and at the interface of semiconductors. Monolayer MoS2 of 2D materials also contains 2DEG in an atomic layer as a field effect transistor (FET) ultrathin channel. In this study, we synthesized double triangular MoS2 through a chemical vapor deposition method to obtain grain boundaries for forming a ripple structure in the FET channel. When the temperature was higher than approximately 175 K, the temperature dependence of the electron mobility µ was consistent with those in previous experiments and theoretical predictions. When the temperature was lower than approximately 175 K, the mobility behavior decreased with the temperature; this finding was also consistent with that of the previous experiments. We are the first research group to explain the decreasing mobility behavior by using the Wigner crystal phase and to discover the temperature independence of ripplon-limited mobility behavior at lower temperatures. Although these mobility behaviors have been studied on the surface of liquid helium through theories and experiments, they have not been previously analyzed in 2D materials and semiconductors. We are the first research group to report the similar temperature-dependent mobility behavior of the surface of liquid helium and the monolayer MoS2.

16.
ACS Appl Mater Interfaces ; 10(11): 9645-9652, 2018 Mar 21.
Article in English | MEDLINE | ID: mdl-29309121

ABSTRACT

Direct reduction of metal oxides into a few transition metal dichalcogenide (TMDCs) monolayers has been recently explored as an alternative method for large area and uniform deposition. However, not many studies have addressed the characteristics and requirement of the metal oxides into TMDCs by the selenization/sulfurization processes, yielding a wide range of outstanding properties to poor electrical characteristics with nonuniform films. The large difference implies that the process is yet not fully understood. In particular, the selenization/sulfurization at low temperature leads to poor crystallinity films with poor electrical performance, hindering its practical development. A common approach to improve the quality of the selenized/sulfurized films is by further increasing the process temperature, thus requiring additional transfer in order to explore the electrical properties. Here, we show that by finely tuning the quality of the predeposited oxide the selenization/sulfurization temperature can be largely decreased, avoiding major substrate damage and allowing direct device fabrication. The direct relationship between the role of selecting different metal oxides prepared by e-beam evaporation and reactive sputtering and their oxygen deficiency/vacancy leading to quality influence of TMDCs was investigated in detail. Because of its outstanding physical properties, the formation of tungsten diselenide (WSe2) from the reduction of tungsten oxide (WO x) was chosen as a model for proof of concept. By optimizing the process parameters and the selection of metal oxides, layered WSe2 films with controlled atomic thickness can be demonstrated. Interestingly, the domain size and electrical properties of the layered WSe2 films are highly affected by the quality of the metal oxides, for which the layered WSe2 film with small domains exhibits a metallic behavior and the layered WSe2 films with larger domains provides clear semiconducting behavior. Finally, an 8'' wafer scale-layered WSe2 film was demonstrated, giving a step forward in the development of 2D TMDC electronics in the industry.

17.
Int J Clin Pharm ; 38(1): 88-95, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26499503

ABSTRACT

BACKGROUND: Care of the elderly with diabetes is more complicated than that for other age groups. The elderly and/or those with multiple comorbidities are often excluded from randomized controlled trials of treatments for diabetes. The heterogeneity of health status of the elderly also increases the difficulty in diabetes care; therefore, diabetes care for the elderly should be individualized. Motivated patients educated about diabetes benefit the most from collaborating with a multidisciplinary patient-care team. A pharmacist is an important team member by serving as an educator, coach, healthcare manager, and pharmaceutical care provider. OBJECTIVE: To evaluate the effects of pharmaceutical care on glycemic control of ambulatory elderly patients with type 2 diabetes. SETTING: A 421-bed district hospital in Nantou City, Taiwan. METHOD: We conducted a randomized controlled clinical trial involving 100 patients with type 2 diabetes with poor glycemic control (HbA1c levels of ≥9.0 %) aged ≥65 years over 6 months. Participants were randomly assigned to a standard-care (control, n = 50) or pharmaceutical-care (intervention, n = 50) group. Pharmaceutical care was provided by a certified diabetes-educator pharmacist who identified and resolved drug-related problems and established a procedure for consultations pertaining to medication. The Mann­Whitney test was used to evaluate nonparametric quantitative data. Statistical significance was defined as P < 0.05. MAIN OUTCOME MEASURE: The change in the mean HbA1c level from the baseline to the next level within 6 months after recruiting. RESULTS: Nonparametric data (Mann­Whitney test) showed that the mean HbA1c level significantly decreased (0.83 %) after 6 months for the intervention group compared with an increase of 0.43 % for the control group (P ≤ 0.001). Medical expenses between groups did not significantly differ (−624.06 vs. −418.7, P = 0.767). There was no significant difference in hospitalization rates between groups. CONCLUSION: The pharmacist intervention program provided pharmaceutical services that improved long-term, safe control of blood sugar levels for ambulatory elderly patients with diabetes and did not increase medical expenses.


Subject(s)
Diabetes Mellitus, Type 2/drug therapy , Hypoglycemic Agents/therapeutic use , Medication Therapy Management , Patient Education as Topic , Pharmacists , Pharmacy Service, Hospital , Age Factors , Aged , Biomarkers/blood , Blood Glucose/drug effects , Blood Glucose/metabolism , Cost-Benefit Analysis , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/diagnosis , Diabetes Mellitus, Type 2/economics , Drug Costs , Female , Glycated Hemoglobin/metabolism , Health Knowledge, Attitudes, Practice , Hospital Costs , Hospitalization , Hospitals, District , Humans , Hypoglycemic Agents/adverse effects , Hypoglycemic Agents/economics , Male , Medication Adherence , Medication Therapy Management/economics , Patient Care Team , Patient Education as Topic/economics , Pharmacists/economics , Pharmacy Service, Hospital/economics , Taiwan , Time Factors , Treatment Outcome
18.
Nano Lett ; 15(12): 7905-12, 2015 Dec 09.
Article in English | MEDLINE | ID: mdl-26524388

ABSTRACT

The vertical transport of nonequilibrium charge carriers through semiconductor heterostructures has led to milestones in electronics with the development of the hot-electron transistor. Recently, significant advances have been made with atomically sharp heterostructures implementing various two-dimensional materials. Although graphene-base hot-electron transistors show great promise for electronic switching at high frequencies, they are limited by their low current gain. Here we show that, by choosing MoS2 and HfO2 for the filter barrier interface and using a noncrystalline semiconductor such as ITO for the collector, we can achieve an unprecedentedly high-current gain (α ∼ 0.95) in our hot-electron transistors operating at room temperature. Furthermore, the current gain can be tuned over 2 orders of magnitude with the collector-base voltage albeit this feature currently presents a drawback in the transistor performance metrics such as poor output resistance and poor intrinsic voltage gain. We anticipate our transistors will pave the way toward the realization of novel flexible 2D material-based high-density, low-energy, and high-frequency hot-carrier electronic applications.

19.
Nat Commun ; 6: 7430, 2015 Jun 25.
Article in English | MEDLINE | ID: mdl-26109177

ABSTRACT

High-performance piezoelectricity in monolayer semiconducting transition metal dichalcogenides is highly desirable for the development of nanosensors, piezotronics and photo-piezotransistors. Here we report the experimental study of the theoretically predicted piezoelectric effect in triangle monolayer MoS2 devices under isotropic mechanical deformation. The experimental observation indicates that the conductivity of MoS2 devices can be actively modulated by the piezoelectric charge polarization-induced built-in electric field under strain variation. These polarization charges alter the Schottky barrier height on both contacts, resulting in a barrier height increase with increasing compressive strain and decrease with increasing tensile strain. The underlying mechanism of strain-induced in-plane charge polarization is proposed and discussed using energy band diagrams. In addition, a new type of MoS2 strain/force sensor built using a monolayer MoS2 triangle is also demonstrated. Our results provide evidence for strain-gating monolayer MoS2 piezotronics, a promising avenue for achieving augmented functionalities in next-generation electronic and mechanical-electronic nanodevices.

20.
J Labelled Comp Radiopharm ; 58(7): 299-303, 2015 Jun 15.
Article in English | MEDLINE | ID: mdl-25997858

ABSTRACT

Radiolabeled Arg-Gly-Asp (RGD) peptide analogs have been extensively studied for αvß3 integrin-targeted angiogenesis imaging. According to recently presented evidence, the dodecapeptide GE11 has high affinity to the epidermal growth factor receptor (EGFR), which is overexpressed in many types of cancer. Dual-receptor molecular imaging probes with two different heterodimeric peptides exhibit improved cancer targeting efficacy. In the present study, the design and synthesis of a new RGD-GE11 peptide heterodimer for dual αvß3 integrin/EGFR-targeted cancer imaging are described. The RGD-GE11 heterodimer was linked with 6-aminohexanoic acid (6-Ahx) and cysteine and conjugated with 1,4,7-triazacyclononane-N,N',N″-triacetic acid (NOTA) to form NOTA-RGD-cys-6-Ahx-GE11. The monomeric peptides, NOTA-cys-6-Ahx-GE11 and c(RGDyK), were formed by a peptide synthesizer. The peptide heterodimer NOTA-RGD-GE11 was obtained by NOTA-cys-6-Ahx-GE11 and maleimidopropyl-c(RGDyK) conjugation with a thioether linkage. The NOTA peptide conjugate was labeled with freshly eluted (68)Ga and purified using reversed-phase high-performance liquid chromatography. The (68)Ga-NOTA-RGD-cys-6-Ahx-GE11 was successfully prepared, in this study, with a radiochemical yield of 85% and a radiochemical purity of >98%. These results warrant further investigation of this heterodimeric peptide's binding affinity to the receptors.


Subject(s)
Coordination Complexes/chemistry , Coordination Complexes/chemical synthesis , Oligopeptides/chemistry , Peptides, Cyclic/chemical synthesis , Peptides/chemistry , Radiopharmaceuticals/chemical synthesis , Coordination Complexes/pharmacology , Epidermal Growth Factor/metabolism , Integrin alphaVbeta3/metabolism , Peptides, Cyclic/pharmacology , Positron-Emission Tomography
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