Effects of free carriers on piezoelectric nanogenerators and piezotronic devices made of GaN nanowire arrays.

This study investigates the role of carrier concentration in semiconducting piezoelectric single-nanowire nanogenerators (SNWNGs) and piezotronic devices. Unintentionally doped and Si-doped GaN nanowire arrays with various carrier concentrations, ranging from 10(17) (unintentionally doped) to 10(19) cm(-3) (heavily doped), are synthesized. For SNWNGs, the output current of individual nanowires starts from a negligible level and rises to the maximum of ≈50 nA at a doping concentration of 5.63 × 10(18) cm(-3) and then falls off with further increase in carrier concentration, due to the competition between the reduction of inner resistance and the screening effect on piezoelectric potential. For piezotronic applications, the force sensitivity based on the change of the Schottky barrier height works best for unintentionally doped nanowires, reaching 26.20 ± 1.82 meV nN(-1) and then decreasing with carrier concentration. Although both types of devices share the same Schottky diode, they involve different characteristics in that the slope of the current-voltage characteristics governs SNWNG devices, while the turn-on voltage determines piezotronic devices. It is demonstrated that free carriers in piezotronic materials can influence the slope and turn-on voltage of the diode characteristics concurrently when subjected to strain. This work offers a design guideline for the optimum doping concentration in semiconductors for obtaining the best performance in piezotronic devices and SNWNGs.

Efficacy and safety of weekly versus triweekly cisplatin concurrent with radiotherapy in nasopharyngeal carcinoma: A meta-analysis.

BACKGROUND: Cisplatin-based concurrent chemoradiotherapy is a standard of care for locally advanced nasopharyngeal carcinoma (NPC), and weekly and triweekly cisplatin are both alternative regimens based on the results of squamous cell carcinoma of the head and neck. However, there is a lack of direct evidence on the efficacy and safety of weekly versus triweekly cisplatin concurrent with radiotherapy in NPC alone. This meta-analysis aimed to identify which regimen is more superior between weekly and triweekly cisplatin in patients with NPC treated with concurrent chemoradiotherapy. METHODS: The PubMed, Embase, and Cochrane Library were searched for eligible literatures. Clinical outcome measures including 1-year overall survival (OS), 3-year OS, 5-year OS, 5-year loco-regional failure-free survival, 5-year distant metastasis-free survial and the most common 3 grade or higher acute toxicities (hematological toxicity, mucositis and nausea and vomiting) were analyzed by RevMan 5.4 software; significance level was 0.05. RESULTS: Seven clinical controlled studies with 1795 patients were included in the meta-analysis. There were no significant differences between weekly and triweekly cisplatin in 1-year OS, 3-year OS, 5-year OS, 5-year loco-regional failure-free survival, and 5-year distant metastasis-free survial) (all P > .05). Grade 3 or higher mucositis and nausea and vomiting showed similar between the 2 arms. However, grade 3 or higher hematological toxicity of weekly cisplatin was significantly higher than that of triweekly cisplatin (1.55; 95% CI, 1.22-1.98, P = .0004). CONCLUSIONS: Weekly cisplatin resulted in similar survival benifit as triweekly cisplatin, but with higher hematological toxicity.

Freestanding Three-Dimensional CuO/NiO Core-Shell Nanowire Arrays as High-Performance Lithium-Ion Battery Anode.

We demonstrate significant improvement of CuO nanowire arrays as anode materials for lithium ion batteries by coating with thin NiO nanosheets conformally. The NiO nanosheets were designed two kinds of morphologies, which are porous and non-porous. By the NiO nanosheets coating, the major active CuO nanowires were protected from direct contact with the electrolyte to improve the surface chemical stability. Simultaneously, through the observation and comparison of TEM results of crystalline non-porous NiO nanosheets, before and after lithiation process, we clearly prove the effect of expected protection of CuO, and clarify the differences of phase transition, crystallinity change, ionic conduction and the mechanisms of the capacity decay further. Subsequently, the electrochemical performances exhibit lithiation and delithiation differences of the porous and non-porous NiO nanosheets, and confirm that the presence of the non-porous NiO coating can still effectively assist the diffusion of Li+ ions into the CuO nanowires, maintaining the advantage of high surface area, and improves the cycle performance of CuO nanowires, leading to enhanced battery capacity. Optimally, the best structure is validated to be non-porous NiO nanosheets, in contrary to the anticipated porous NiO nanosheets. In addition, considering the low cost and facile fabrication process can be realized further for practical applications.

Ultrathin (Bi1-xSbx)2Se3 Field Effect Transistor with Large ON/OFF Ratio.

Ultrathin three-dimensional topological insulator films are promising for use in field effect devices. (Bi1-xSbx)2Se3 ultrathin films were fabricated on SrTiO3 substrate, where large resistance changes of ∼25 000% could be achieved using the back gate voltage. We suggest that the large ON/OFF ratio was caused by the combined effect of Sb-doping and the reduction of film thickness down to the ultrathin regime. The crossover of different quantum transport under an electric field may form the basis for topological insulators (TI)-based spin transistors with large ON/OFF ratios in the future.

An empirical study on the impact of quality antecedents on tax payers' acceptance of Internet tax-filing systems.

This study used the Technology Acceptance Model (TAM) to examine taxpayers' acceptance of the Internet tax-filing system. Based on data collected from 141 experienced taxpayers in Taiwan, the acceptance and the impact of quality antecedents on taxpayers' perceived usefulness (PU) and perceived ease of use (PEOU) of the system were assessed and evaluated. The results indicated that the model of Internet tax-filing system was accepted with a reasonable goodness-of-fit. Three important findings include the following items. First, TAM proves to be a valid model to explain the taxpayers' acceptance of the Internet tax-filers' system. Meanwhile, PU has created more impact than PEOU on taxpayers' intention to use the system. Second, PU is positively influenced by such factors as information system quality (ISQ), information quality (IQ), as well as perceived credibility (PC). Third, IQ has a positive impact on PEOU. Based on the research findings, implications and limitations are then discussed for future possible research.

Ultrasensitive Thin-Film-Based Alx Ga1-x N Piezotronic Strain Sensors via Alloying-Enhanced Piezoelectric Potential.

Alx Ga1-x N thin-film-based piezotronic strain sensors with ultrahigh strain sensitivity are fabricated through alloying of AlN with GaN. The strain sensitivity of the ternary compound Alx Ga1-x N is higher than those of the individual binary compounds GaN and AlN. Such a high performance can be attributed to the piezoelectric constant enhancement via intercalation of Al atoms into the GaN matrix, the effect of residual strain, and a suppressed screening effect.

An assessment of patient safety in acupuncture process under EMR support.

With the facilitating roles of IT, this study is to investigate the safety issues of the acupuncture process in the current practices under EMR support. A self-administered questionnaire survey was conducted in 80 Chinese medicine practice hospitals and clinics in Taiwan. Concerns over patient safety during the acupuncture process were raised, such as an inconsistency between the practice and prescription and a lack of monitoring patient's condition during the treatment. Confirming the physicians' prescription and documenting patients' reaction for patient record management are needed to add to the EMR system for patient safety while performing acupuncture. The results of this study can be used by the government or medical institutes to assess the work flow and set up standards of EMRs design for their acupuncture treatment to ensure patient safety and to enhance healthcare quality.

Critical factors for the adoption of mobile nursing information systems in Taiwan: the nursing department administrators' perspective.

The trend towards point-of-care and the advance in mobile technologies bring the potential to employ Mobile Nursing Information Systems (MNIS) in nursing care routines. However, adopting the MNIS is not simply a case of purchasing the required hardware and software, but rather a social interaction process between users, organizations, and the environment. Therefore, this study developed a framework of twelve factors affecting the decision to adopt/not to adopt the MNIS in the nursing department, and tested it from the perspective of the nursing administrators. A mail survey was conducted to collect the opinions of 84 nursing administrators, and a discriminant analysis was used to identify the critical factors for the adoption/non-adoption of the MNIS. Business competition, external suppliers' support, and internal needs were identified as being significantly associated with the adoption of MNIS. Potential adopters can apply the results of this study as a reference when making the adoption decision regarding MNIS, while non-adopters and vendors can examine the resistance to MNIS.