Detection and estimation of various biomolecular samples are often required in research and clinical laboratory applications. Present work demonstrates the functioning of a surface‐enhanced Raman ...scattering (SERS) substrate that has been obtained by drop‐casting of citrate‐reduced gold nanoparticles (AuNPs) of average dimension of 23 nm on a bare blu‐ray digital versatile disc (BR‐DVD) substrate. The performance of the proposed SERS substrate has been initially evaluated with standard Raman active samples, namely malachite green (MG) and 1,2‐bis(4‐pyridyl)ethylene (BPE). The designed SERS substrate yields an average enhancement factor of 3.2 × 106 while maintaining reproducibility characteristics as good as 94% over the sensing region of the substrate. The usability of the designed SERS substrate has been demonstrated through the detection and analysis of purified rotavirus double‐stranded RNA (dsRNA) samples in the laboratory environment condition. Rotavirus RNA concentrations as low as 10 ng/μL could be detected with the proposed sensing scheme.
A highly sensitive, low‐cost surface‐enhanced Raman scattering (SERS) substrate has been developed for detection and analysis of the Raman spectrum of rotavirus RNA by exploiting the patterned nanochannels of a commercially available blu‐ray digital versatile disc (BR‐DVD) as substrate. Gold nanoparticles of dimension comparable to the depth of the nanochannels generate enhanced hot‐spot regions in combination with guided‐mode resonance field. The proposed SERS substrate yields a high enhancement factor along with a good degree of reproducibility of the scattered Raman signal.
As Barbie's popularity began to decline across the first decade of the twenty-first century, the iconic doll underwent a makeover and became a maven of the straight-to-DVD sector. Across the movies ...produced since 2001, the narratives reflect an awareness of feminist criticism and seek to remediate Barbie's particular femininity and the associated gender performance that has fallen into disfavor. Interestingly, these efforts are often facilitated by a movement in time and place that relocates Barbie from the here and now, as she plays the protagonist role in adaptations of classic works of fiction set in the past. Working with methods of textual analysis and informed by the history of literature for children, media studies, and feminist theory, we explore the complex composition of Mattel's straight-to-DVD Barbie movies and consider how the adaptations intersect with feminist discourses. Looking closely at Barbie and the Three Musketeers (2009) in the wider context of the DVD series, we argue that the Barbie DVDs perform a post-feminist pedagogy and inculcate the post-feminist sensibility among young viewers and consumers worldwide.
This letter first identifies a new mode of lowfrequency harmonic instability when combining grid-forming control with the typical DC voltage droop control necessitated in multi-terminal high voltage ...direct-current transmissions. This mode does not exist when grid-following control is applied and its mechanism is explicitly revealed by the DC-side input admittance modeling of the converter. Then, a phase compensator plus a virtual power system stabilizer are introduced to pacify the input admittance within the critical frequency range and de-risk the related instability. Last, it is also demonstrated that the proposed control strategy achieves excellent performance in contingent active power imbalance ride-through in the DC system. All the analyses are verified by electro-magnetic-transient simulations with a modular multi-level converter model comprising 278 submodules per arm.
Purpose
To analyse the postoperative foveal avascular zone (FAZ) area, superficial vessel density (SVD) and deep vessel density (DVD) and their correlation with functional (best‐corrected visual ...acuity, BCVA) and anatomical outcomes (foveal macular thickness, FMT) after surgery for rhegmatogenous retinal detachment (RRD) repair.
Method
Patients with RRD eyes, successfully treated with a single pars plana vitrectomy (PPV) with gas tamponade and a minimum 12 months follow‐up, were re‐examined. Foveal avascular zone (FAZ) area, SVD, DVD and FMT were evaluated by using optical coherence tomography angiography (OCTA) and compared to fellow eye.
Results
Fifty‐six patients with macula‐on and 37 with macula‐off RRD were included in the study. In both groups, no difference in FMT and FAZ area was found compared to fellow eyes. In macula‐on RRD eyes, a lower parafoveal DVD (p = 0.001) was detected; FAZ area was related to FMT (p = 0.025), and the postoperative BCVA was correlated with parafoveal DVD (p = 0.010) and FAZ area (p = 0.003). In macula‐off RRD eyes, lower parafoveal SDV (p = 0.012), and foveal and parafoveal DVD (p = 0.012 and p < 0.001, respectively) were observed. BCVA was related to FAZ area (p = 0.012), foveal SVD (p = 0.005) and parafoveal DVD (p = 0.010).
Conclusion
Rhegmatogenous retinal detachment eyes successfully treated with PPV had lower vessel density in the superficial and deep retinal plexus compared to fellow healthy eyes; BCVA was related to FAZ area and vessel density.
The creative industries have frequently expressed concern that they can't compete with freely available copies of their content. Competing with free is particularly concerning for movie studios, ...whose content may be more prone to single-use consumption than other industries such as music. This issue has gained renewed importance recently with the advent of new digital video recording and distribution technologies, and the widespread availability of Internet piracy. We examine competition between "free" and paid video content in two important contexts: the impact of legitimate free distribution in one channel on sales through paid channels, and the impact of illegitimate free distribution in pirated channels on sales through paid channels. We do this by studying the impact of movie broadcasts on DVD demand and the impact of piracy availability at the time of broadcast on DVD demand. Our data include all movies shown on over-the-air and cable television during an eight-month period in 2005-2006. With respect to the impact of movie broadcasts on piracy and sales, we find that movie broadcasts on over-the-air networks result in a significant increase in both DVD sales at Amazon. com and illegal downloads for those movies that are available on BitTorrent at the time of broadcast. With respect to the impact of piracy on sales, we use the television broadcast as an exogenous demand shock and find that the availability of pirated content at the time of broadcast has no effect on post-broadcast DVD sales gains. Together our results suggest that creative artists can use product differentiation and market segmentation strategies to compete with freely available copies of their content. Specifically, the post-broadcast increase in DVD sales suggests that giving away content in one channel can stimulate sales in a paid channel if the free content is sufficiently differentiated from its paid counterpart. Likewise, our finding that the presence of pirated content does not cannibalize sales for the movies in our sample suggests that if free and paid products appeal to separate customer segments, the presence of free products need not harm paid sales.
Distance-based readout is one of the most user-friendly and simple colorimetric signaling methods widely applied for paper-based analytical devices (PADs). This work presents the integration of ...distance readout PADs into a centrifugal platform enabling affordable, rapid, and sample volume-independent colorimetric assays. Centrifugally assisted distance-based PADs (CD-PADs) eliminate the requirement to use micropipets for sample introduction and reduce the overall time for distance-based assays. All device fabrication steps were performed through computer-controlled print, cut, and laminate (PCL) techniques oriented toward mass production. The inexpensive centrifugal platform was built on a recycled DVD player combined with an open source microcomputer (Arduino). Assay protocols, including rotational velocity and rotation time, were optimized to obtain a maximum dynamic range and reproducible results for sample volume metering (coefficient of variation 3.62%). A colorimetric Ni2+ assay chosen to demonstrate measurements on CD-PADs allowed the detection of nickel ions (Ni2+) with naked-eye interpretation within 1.5 min and a limit of detection (LOD) of 44.1 ng of Ni2+, which to the best of our knowledge is the lowest value reported for a distance-based Ni2+ assay.
Purpose
This study tested the hypothesis that a novel, audio-visual-directed, home-based exercise training intervention would be effective at improving cardiometabolic health and mental well-being in ...inactive premenopausal women.
Methods
Twenty-four inactive premenopausal women (39 ± 10 years) were randomly assigned to an audio-visual-directed exercise training group (DVD;
n
= 12) or control group (CON;
n
= 12). During the 12-week intervention period, the DVD group performed thrice-weekly training sessions of 15 min. Training sessions comprised varying-intensity movements involving multiplanar whole-body accelerations and decelerations (average heart rate (HR) = 76 ± 3% HR
max
). CON continued their habitual lifestyle with no physical exercise. A series of health markers were assessed prior to and following the intervention.
Results
Following the DVD intervention, HDL cholesterol (pre: 1.83 ± 0.45, post: 1.94 ± 0.46 mmol/L) and mental well-being, assessed via the Warwick Edinburgh Mental Well-Being Scale, improved (
P
< 0.05). Conversely, LDL cholesterol, triglycerides, fasting glucose, body composition and resting blood pressure and HR were unchanged following the DVD intervention (
P
> 0.05). There were no pre-post intervention changes in any of the outcome variables in the CON group (
P
> 0.05).
Conclusion
The present study suggests that a novel, audio-visual-directed exercise training intervention, consisting of varied-intensity movements interspersed with spinal and lower limb mobility and balance tasks, can improve HDL cholesterol and mental well-being in premenopausal women. Therefore, home-based, audio-visual-directed exercise training (45 min/week) appears to be a useful tool to initiate physical activity and improve aspects of health in previously inactive premenopausal women.
Achieving light harvesting is crucial for the efficiency of the solar cell. Constructing optical structures often can benefit from micro‐nanophotonic imprinting. Here, a simple and facile strategy is ...developed to introduce a large area grating structure into the perovskite‐active layer of a solar cell by utilizing commercial optical discs (CD‐R and DVD‐R) and achieve high photovoltaic performance. The constructed diffraction grating on the perovskite active layer realizes nanophotonic light trapping by diffraction and effectively suppresses carrier recombination. Compared to the pristine perovskite solar cells (PSCs), the diffraction‐grating perovskite devices with DVD obtain higher power conversion efficiency and photocurrent density, which are improved from 16.71% and 21.67 mA cm−2 to 19.71% and 23.11 mA cm−2. Moreover, the stability of the PSCs with diffraction‐grating‐structured perovskite active layer is greatly enhanced. The method can boost photonics merge into the remarkable perovskite materials for various applications.
Diffraction grating is introduced into a perovskite active layer via optical discs. The constructed architecture enhances light harvesting and photon‐to‐electron conversion efficiency by diffracting the incident light. Besides, it also improves the charge extraction process and suppresses electron–hole recombination. The diffraction‐grating perovskite devices achieve a high power conversion efficiency of 19.71%.
Light harvesting is crucial for thin‐film solar cells. To substantially reduce optical loss in perovskite solar cells (PSCs), hierarchical light‐trapping nano‐architectures enable absorption ...enhancement to exceed the conventional upper limit and have great potential for achieving state‐of‐the art optoelectronic performances. However, it remains a great challenge to design and fabricate a superior hierarchical light‐trapping nano‐architecture, which exhibits extraordinary light‐harvesting ability and simultaneously avoids deteriorating the electrical performance of PSCs. Herein, colorful efficient moiré‐PSCs are designed and fabricated incorporating moiré interference structures by the imprinting method with the aid of a commercial DVD disc. It is experimentally and theoretically demonstrated that the light harvesting ability of the moiré interference structure can be well manipulated through changing the rotation angle (0°–90°). The boosted short‐circuit current is credited to augment light diffraction channels, leading to elongated optical paths, and fold sunlight into the perovskite layer. Moreover, the imprinting process suppresses the trap sites and voids at the active‐layer interfaces with eliminated hysteresis. The moiré‐PSC with an optimized 30° rotation angle achieves the best enhancement of light harvesting (28.5% higher than the pristine), resulting in efficiencies over 20.17% (MAPbI3) and 21.76% ((FAPbI3)1‐x (MAPbBr3)x).
A moiré interference structure augments light‐diffraction channels, leading to elongated optical paths, and “folds” sunlight into the perovskite layer. Besides, the sets of moiré diffracted light achieve “1 + 1 = 3” comparing to the single diffraction grating. Therefore, moiré perovskite solar cells are constructed by way of a commercial DVD disc, resulting in a champion efficiency up to 20.17% (MAPbI3) and 21.76% ((FAPbI3)1‐x(MAPbBr3)x).
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