Search

Neovascular age-related macular degeneration (nAMD) is a prevalent cause of permanent vision loss and blindness in the elderly worldwide, with a significant impact on patients' daily lives. However, burdens related to nAMD from the patients' perspective have not been well documented. Here we developed a new questionnaire after eliciting nAMD patients' daily challenges followed by a pilot survey. Seven daily life burden domains were identified, and a quantitative survey was conducted using the questionnaire in the real-world clinic. Of the total 153 participants (mean age, 76.3 ± 8.3 years), 67 (43.8%) had bilateral nAMD, and 79 (52.7%) were classified into severe nAMD according to the best-corrected visual acuity with cut-off value of 0.52 in logMAR. Patients with bilateral and severe nAMD had significantly higher burden scores across all domains. Network models for the bilateral and severe disease subgroups identified the interactions between "activity of daily living" and "hand–eye coordination" and between "use of electronic devices" and "face recognition" domains, which were considered to be important burdens for the patients. These results can advance ophthalmologists' understanding of the impact of nAMD on patients' daily lives and the importance of active and continuing treatment for patients with nAMD. [ABSTRACT FROM AUTHOR]

Background: The Dysphagia Symptom Questionnaire (DSQ) is a patient-reported outcome measure that assesses the frequency and severity of dysphagia in patients with eosinophilic esophagitis (EoE); however, it has only been validated for use in patients with EoE aged 11–40 years. This study examined the content validity of the DSQ and its usability on an electronic handheld device in children aged 7–10 years with EoE. Methods: In this qualitative, observational cohort study, participants were recruited to partake in two rounds of interviews. During visit 1, a cognitive interview examined EoE-associated concepts and the appropriateness of the DSQ for assessing dysphagia. Participants completed the DSQ daily for 2 weeks, and DSQ scores were calculated. After 2 weeks, a second interview assessed the usability of the DSQ on the electronic device and the burden associated with completing it daily. Results: Overall, 16 participants were included (aged 7–8 years: n = 8; aged 9–10 years: n = 8); most were male (75%) and white (81%), and the mean (standard deviation [SD]) age was 8.4 (1.3) years. The most commonly reported EoE-associated concept was 'trouble with swallowing' (63% [10/16]). Most participants reported that the questions were 'easy to complete' and 'relevant to someone with EoE and dysphagia'. Overall, participants reported understanding the questions and associated responses; however, further probing demonstrated inconsistent comprehension. Key challenging concepts included 'solid food', 'trouble swallowing', 'vomit', and 'relief'; some participants also reported difficulty differentiating between pain levels (31% [4/13]). Most caregivers reported that their child had experienced dysphagia (94% [15/16]); however, mean (SD) DSQ scores over the study period were low (7.3 [7.4]), suggesting infrequent and mild dysphagia, or a lack of comprehension of the questions. Most participants reported that completing the DSQ on the electronic device was easy (93% [14/15]) and they would be willing to complete it for longer than 2 weeks (73% [11/15]). Conclusions: Difficulties with comprehension and comprehensiveness suggest that the DSQ may not be sufficiently comprehensive for use in all patients in this population, and wording/phrasing changes are required before use in a clinical trial setting. [ABSTRACT FROM AUTHOR]

The Green's function method is recognized to be a very powerful tool for modelling quantum transport in nanoscale electronic devices. As atomistic calculations are generally expensive, numerical methods and related algorithms have been developed accordingly to optimize their computation cost. In particular, recursive techniques have been efficiently applied within the Green's function calculation approach. Recently, with the discovery of Moiré materials, several attractive superlattices have been explored using these recursive Green's function techniques. However, numerical difficulty issues were reported as most of these superlattices have relatively large supercells, and consequently a huge number of atoms to be considered. In this article, improvements to solve these issues are proposed in order to keep optimizing the recursive Green's function calculations. These improvements make the electronic structure calculations feasible and efficient in modelling large superlattice-based devices. As an illustrative example, twisted bilayer graphene superlattices are computed and presented to demonstrate the efficiency of the method. [ABSTRACT FROM AUTHOR]

With the continuous development of science and technology, electronic devices have begun to enter all aspects of human life, becoming increasingly closely related to human life. Users have higher quality requirements for electronic devices. Electronic device testing has gradually become an irreplaceable engineering process in modern manufacturing enterprises to guarantee the quality of products while preventing inferior products from entering the market. Considering the large output of electronic devices, improving the testing efficiency while reducing the testing cost has become an urgent problem to be solved. This study investigates the electronic device testing machine allocation problem (EDTMAP), aiming to improve the production of electronic devices and reduce the scheduling distance among testing machines through reasonable machine allocation. First, a mathematical model was formulated for the EDTMAP to maximize both production and the scheduling distance among testing machines. Second, we developed a discrete multi-objective artificial bee colony (DMOABC) algorithm to solve EDTMAP. A crossover operator and local search operator were designed to improve the exploration and exploitation of the algorithm, respectively. Numerical experiments were conducted to evaluate the performance of the proposed algorithm. The experimental results demonstrate the superiority of the proposed algorithm compared with the non-dominated sorting genetic algorithm II (NSGA-II) and strength Pareto evolutionary algorithm 2 (SPEA2). Finally, the mathematical model and DMOABC algorithm were applied to a real-world factory that tests radio-frequency modules. The results verify that our method can significantly improve production and reduce the scheduling distance among testing machines. [ABSTRACT FROM AUTHOR]

High-conductivity yarns with remarkable flexibility and sensitivity have great potential for application in manufacturing wearable electronics. However, the development of electronic textiles (E-textiles) is still limited by the insufficient extents of size manipulation and weight reduction. In this study, a novel nanofiber yarn with a high flexibility, durability, and sensitivity was prepared by a facile electrospinning technique. The composite yarn with silver nanowires used as a reinforcement for polyurethane nanofibers exhibits a high elongation at break (500 %), conductivity (0.4 kΩ/cm), and durability (recovery after 200 tensile cycles). Furthermore, the yarn was used to monitor body language. The results showed distinct fluctuations in resistance in response to subtle changes in expression and small movements of the body. In addition, the composite yarn was examined as a potential electric heater material. The yarn's surface temperature rised to 62.6 °C in 5 s, which proved its excellent electrothermal properties, and it could be realized even at 1 V. The combination of highly conductive structural components, i.e., silver nanowires and the flexible polyurethane nanofibers is a promising design strategy for producing new multifunctional composites for wearable devices. [ABSTRACT FROM AUTHOR]

Strain engineering has become one of the effective methods to tune the electronic structures of materials, which can be introduced into the molecular junction to induce some unique physical effects. The various γ-graphyne nanoribbons (γ-GYNRs) embedded between gold (Au) electrodes with strain controlling have been designed, involving the calculation of the spin-dependent transport properties by employing the density functional theory. Our calculated results exhibit that the presence of strain has a great effect on transport properties of molecular junctions, which can obviously enhance the coupling between the γ-GYNR and Au electrodes. We find that the current flowing through the strained nanojunction is larger than that of the unstrained one. What is more, the length and strained shape of the γ-GYNR serves as the important factors which affect the transport properties of molecular junctions. Simultaneously, the phenomenon of spin-splitting occurs after introducing strain into nanojunction, implying that strain engineering may be a new means to regulate the electron spin. Our work can provide theoretical basis for designing of high performance graphyne-based devices in the future. [ABSTRACT FROM AUTHOR]

The purpose of this study was to explore the impact that portable electronic device use in bed after lights out has on sleep/wake behaviour within an adult population. Specifically, this study aimed to (1) identify patterns of use of electronic devices in bed; (2) examine the relationship between electronic device use in bed and sleep/wake behaviour; and (3) examine the impact of demographic variables on electronic device use in bed. Using a cross-sectional design, telephone interviews were conducted with 1,225 participants (52% female). Survey questions asked about participant demographic variables, their sleep/wake history, and their pre-sleep behaviours, which included electronic device usage. Forty-two percent of participants reported using electronic devices in bed after lights out, and 27% of adults who reported 'always' using electronic devices in bed were spending over an hour per night using them. Sleep characteristics were significantly different in device users compared to non-device users (p < 0.001). Frequency of device use was associated with later sleep times, and duration of device use was associated with shorter sleep duration and decreased sleep quality. Older adults were less likely to use devices in bed after lights out, and had less duration of usage. Electronic device use in bed was found to reduce sleep duration and sleep quality in adults. To further our understanding of the impact device use in bed has on adult sleep behaviour, future studies should consider employing objective measurements of both sleep behaviour and device usage. [ABSTRACT FROM AUTHOR]

Graphene with atomically smooth and configuration-specific edges plays the key role in the performance of graphene-based electronic devices. Remote hydrogen plasma etching of graphene has been proven to be an effective way to create smooth edges with a specific zigzag configuration. However, the etching process is still poorly understood. In this study, with the aid of a custom-made plasma-enhanced hydrogen etching (PEHE) system, a detailed graphene etching process by remote hydrogen plasma is presented. Specifically, we find that hydrogen plasma etching of graphene shows strong thickness and temperature dependence. The etching process of single-layer graphene is isotropic. This is opposite to the anisotropic etching effect observed for bilayer and thicker graphene with an obvious dependence on temperature. On the basis of these observations, a geometrical model was built to illustrate the configuration evolution of graphene edges during etching, which reveals the origin of the anisotropic etching effect. By further utilizing this model, armchair graphene edges were also prepared in a controlled manner for the first time. These investigations offer a better understanding of the etching process for graphene, which should facilitate the fabrication of graphene-based electronic devices with controlled edges and the exploration of more interesting properties of graphene. [ABSTRACT FROM AUTHOR]

This paper inquires the effectiveness of a PCM-based heat sink as a reliable solution to portable electronic devices. This sink is composed of a PCM with low thermal conductivity and fins to boost its conductivity. The optimization is subjected to fixed heat sink volume filled with PCM between vertical equidistant fins. New fins are installed in the unheated space existing in each enclosure which is not involved in thermal distribution from vertical fins to the PCM. Based on the same principle, new fins generations are augmented stepwise to the multi-scale structure. The steps of adding fins will continue up to the point that the objective function reaches its maximal value, i.e., maximizing the longest safe operation time without allowing the electronics to reach the critical temperature. The results indicate that in each length of the enclosure, the optimum volume fraction and the best fins distance values exist in which the heat sink performance becomes maximum, and adding more fins lowers the performance of the heat sink. Increasing the enclosure's length by $$2^{n}$$ does not change them. For an enclosure with constant length, the optimal number of steps for adding fins within the enclosure is a function of the fin thickness. The results indicate that increasing the thickness changes the optimal number of adding fins inside the enclosure (normally a decrease). As the fin thickness is lowered, there will be a higher effect by adding vertical fins in the enclosure. Numerical simulations cover the Rayleigh number range $$2\times 10^{5}\le \hbox {Ra}_{\mathrm{H}} \le 2.7\times 10^{8}$$ , where H is the heat sink height. [ABSTRACT FROM AUTHOR]

The currently available 3D printing still cannot simultaneously deal with the metal and nonmetal inks together due to their huge difference in the melting points and poor compatible printability between each other. Here through introducing the low melting point alloy BiInSnZn and silicone rubber as functional inks, we proposed a compatible hybrid 3D printing method for manufacturing the desired device, the supporting substrate and the allied package structure together. The principle of pneumatic-typed 3D printing of multiple inks was described and typical physical properties of the ink BiInSnZn were measured. Several key factors dominating the printing quality such as the temperature of the printing head, the air pressure exerted upon the liquid metal ink in the syringe, the moving velocity and the height of the printing head etc. were clarified. A general way of directly printing out 3D structured electronic devices consisting of both metal and nonmetal materials was demonstrated. Such hybrid objects were patterned and formed up layer by layer with BiInSnZn alloy and silicone rubber which would become solidified after standing for a period of time under room temperature. To illustrate the compatible printability of these printing inks, a three-layer tricolor LED stereo circuit with controlled lighting capability was further manufactured and evaluated. The present study opens an important hybrid 3D printing way for directly manufacturing functional and structural end devices in an easy and low cost way. [ABSTRACT FROM AUTHOR]

We investigated a new low-temperature bonding process utilizing Cu nanoparticle paste without addition of sintering promoter. Joint bonding strengths above 30 MPa were achieved even at a low bonding temperature of 250ºC. We attribute the higher bonding strengths of joints fabricated using the vacuum preheating process to the rapid progression of Cu nanoparticle sintering due to the activated nanoparticle surface at lower temperatures. The increase in bonding strength depended on the applied pressure, in addition to the bonding temperature. The formation of a dimple-like morphology was confirmed in the ductile fracture area. This indicated that the joint bonded strongly with the bonding layer, in agreement with the results of bonding tests carried out on strongly bonded joints. The bonding ability of the joints obtained using Cu nanoparticle paste could be improved by controlling the joint fabrication conditions. [ABSTRACT FROM AUTHOR]

The optimal placement of electronic components on a printed circuit board (PCB) requires satisfying multiple conflicting design objectives as most of the components have different power dissipation, operating temperature, types of material and dimension. In addition, most electronic companies are currently emphasizing on designing a smaller package electronic system in order to increase the system performance. This paper presents a new self organizing genetic algorithm (SOGA) method for solving this multi-objective optimization problem. The SOGA can be viewed as a cascade of two GAs which consists of two steps fitness evaluation process to ensure that the fitness of selected chromosomes for each iteration process is optimally selected. The algorithm is developed based on weighted sum approach genetic algorithm (WSGA) where an inner loop GA is used to optimize the selection of weights of the WSGA. Experiments are conducted to evaluate the performance of SOGA. Four objective functions are formulated in the experiments which are temperature of components, area of PCB, high power component placement and high potential critical components distance. Comparisons of the performance of SOGA are made with two well known methods namely fixed weight GA (FWGA) and random weighted GA (RWGA). The results show that the SOGA gives a better optimal solution as compared to the other methods. [ABSTRACT FROM AUTHOR]

Purpose: Minimally Invasive Surgery procedures are commonly used in many surgical practices, but surgeons need specific training models and devices due to its difficulty and complexity. In this paper, an innovative electronic device for endosurgical skills training (EDEST) is presented. A study on reliability for this device was performed. Method: Different electronic components were used to compose this new training device. The EDEST was focused on two basic laparoscopic tasks: triangulation and coordination manoeuvres. A configuration and statistical software was developed to complement the functionality of the device. A calibration method was used to assure the proper work of the device. A total of 35 subjects (8 experts and 27 novices) were used to check the reliability of the system using the MTBF analysis. Results: Configuration values for triangulation and coordination exercises were calculated as 0.5 s limit threshold and 800-11,000 lux range of light intensity, respectively. Zero errors in 1,050 executions (0%) for triangulation and 21 errors in 5,670 executions (0.37%) for coordination were obtained. A MTBF of 2.97 h was obtained. Conclusions: The results show that the reliability of the EDEST device is acceptable when used under previously defined light conditions. These results along with previous work could demonstrate that the EDEST device can help surgeons during first training stages. [ABSTRACT FROM AUTHOR]

Background, aim and scope: Nanostructured polymer particles are produced to be used in ball grid array (BGA) and chip scale packaging (CSP). The technology could replace conventional BGA and CSP metal balls, and the hypothesis is that the shift could be eco-efficient as polymer core particles increase the reliability. For the first time, these particles are environmentally evaluated. Materials and methods: The change in GWP100 and Eco-Indicator'99 (H) scores when replacing traditional component packaging, here quad flat pack to BGA/CSP, was explored both on component and printed circuit board assembly (PCBA) level. This was followed by comparisons between BGA packages using different types of metal-plated monodispersed polymer particle (MPP) balls and conventional balls, respectively. Results and discussion: For BGAs, the silicon (Si) die dominates COe emissions, but for Eco-Indicator'99(H), solder balls are not negligible. Excluding the Si die and component assembly, the LFBGA-84 to WCSP-64 would reduce COe by about 98% and Eco-Indicator'99 (H) by about 90%. Overall, for BGA-256 using same size balls, gold-plated MPP technology decreases the Eco-Indicator'99(H) score by about 25% compared to Pb-based or Pb-free balls. Gold production dominated GWP100 and Eco-Indicator'99 (H) for the gold-plated MPP. Each microsystem is unique, and new environmental impact estimations must be done for the sub-structures of each electronic device. Screening process-sum life cycle assessment (LCA) gives similar understanding of impacts as resource productivity methods. Even though the metal mass per ball is greatly reduced, it is a weak indicator of environmental impacts which are driven by each material's specific environmental characteristics. Conclusions: The ball share of the BGA-256 GWP100 and Eco-Indicator'99 (H) score is small, and the BGA/CSP producers can marginally improve the environmental performance by focusing on the balls. On a comparable IC packaging basis, the introduction of WCSP packaging technology implies a significant environmental footprint reduction. On PCBA level, the contribution of BGA balls is negligible. Results for metal-plated MPP BGA balls suggest that gold usage is the key environmental performance indicator of interest. Recommendations and perspectives: Even though WCSP clearly reduces the component level impacts, the PCBA (board) level impact could increase as the CSP miniaturisation is paralleled with more PWB layers. This effect should be included in further system expansions. For LCA, in general, update of all LCIA methods, which include ozone depletion, with the latest results for dinitrogen monoxide is needed. [ABSTRACT FROM AUTHOR]

This paper describes an electronic device for the measurement of the diameter of the tip opening of micropipettes. The device measures the threshold pressure required to produce bubbles from the micropipette submerged in a liquid and displays the tip inner diameter in micrometres. We demonstrate that this technique can be used effectively in a range of liquids of different density, surface tension and viscosity and that the thickness of the glass from which the micropipettes are made does not influence the measurements. [ABSTRACT FROM AUTHOR]

A versatile device for a patch-clamp amplifier is described. This device contains: (i) an acoustic indicator to monitor the input resistance of the patch pipette, which is used in search-mode to indicate the formation of seals; (ii) two pulse generators; and (iii) a staircase generator to produce various pulse and voltage step programs; (iv) a lowpass filter which is used to filter the output of the patch clamp amplifier; and (v) a remote control which is used to control the entire patch clamp experiment. This remote control is used to switch between search-, current clamp-, and voltage clamp-mode, to activate the respective stimulus potential programs, and to control the tape recorder. This electronic device can be easily connected to patch clamp amplifiers. [ABSTRACT FROM AUTHOR]