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Abstract Transparent roofs and walls offer a compelling solution for harnessing natural light. However, traditional glass roofs and walls face challenges such as glare, privacy concerns, and overheating issues. In this study, we present a polymer-based micro-photonic multi-functional metamaterial. The metamaterial diffuses 73% of incident sunlight, creating a more comfortable and private indoor environment. The visible spectral transmittance of the metamaterial (95%) surpasses that of traditional glass (91%). Furthermore, the metamaterial is estimated to enhance photosynthesis efficiency by ~9% compared to glass roofs. With a high emissivity (~0.98) close to that of a mid-infrared black body, the metamaterial is estimated to have a cooling capacity of ~97 W/m2 at ambient temperature. The metamaterial was about 6 °C cooler than the ambient temperature in humid Karlsruhe. The metamaterial exhibits superhydrophobic performance with a contact angle of 152°, significantly higher than that of glass (26°), thus potentially having excellent self-cleaning properties.

The current paper investigated underlying mechanisms that produce culture and gender differences in social anxiety. European-Canadian (n = 99; 47% female) and Asian-Canadian (n = 94; 54% female) undergraduate students completed questionnaires measuring levels of independence, interdependence, masculinity, femininity, and social anxiety. Asian Canadians reported a similar level of social anxiety to European Canadians, and females reported higher social anxiety than males. Mediational analyses revealed that levels of independence, interdependence, and masculinity mediated the association between culture and social anxiety, whereas levels of masculinity mediated the association between gender and social anxiety. Cultural differences in social anxiety are explained by the extent to which individuals define themselves as independent and interdependent, while gender differences in social anxiety are explained by the extent to which individuals identify themselves with a masculine gender role. Our findings suggest the orthogonal impact of culture and gender on individuals' social anxiety. Implications and limitations of the findings are discussed., Author(s): Kristen E. Zentner [sup.1] , Hajin Lee [sup.2] , Bryce S. Dueck [sup.3] , Takahiko Masuda [sup.4] Author Affiliations: (1) grid.254645.4, 0000 0001 0702 7079, Faculty of Graduate Studies, [...]

Background: Although substantial motion at the acromioclavicular joint (ACJ) occurs during overhead shoulder motion, the influence of ACJ arthritis on postoperative outcomes of patients undergoing reverse total shoulder arthroplasty (rTSA) is unclear. We assessed the influence of ACJ arthritis, defined by degenerative radiographic changes, and its severity on clinical outcomes after primary rTSA. Methods: We conducted a retrospective review of a prospectively collected shoulder arthroplasty database of patients that underwent primary rTSA with a minimum 2-year clinical follow-up. Imaging studies of included patients were evaluated to assess ACJ arthritis classified by radiographic degenerative changes of the ACJ; severity was based upon size and location of osteophytes. Both the Petersson classification and the King classification (a modified Petersson classification addressing superior osteophytes and size of the largest osteophyte) were used to evaluate the severity of degenerative ACJ radiographic changes. Severe ACJ arthritis was characterized by large osteophytes (≥2 mm). Active range of motion (ROM) in abduction, forward elevation, and external and internal rotation as well as clinical outcome scores (American Shoulder and Elbow Surgeons Shoulder, Constant, Shoulder Pain and Disability Index, simple shoulder test, University of California, Los Angeles scores) were assessed both preoperatively and at the latest follow-up; outcomes were compared based on severity of ACJ arthritis. Multivariable linear regression models were used to determine whether increasing severity of ACJ arthritis was associated with poorer outcomes. Results: A total of 341 patients were included with a mean age of 71 ± 8 years and 55% were female. The mean follow-up was 5.1 ± 2.4 years. Preoperatively, there were no differences in outcomes based on the severity of ACJ pathology. Postoperatively, there were no differences in outcomes based upon the severity of ACJ arthritis except for greater preoperative to postoperative improvement in active internal rotation in patients with normal or grade 1 ACJ arthritis vs. grade 2 and 3 (3 ± 2 vs. 1 ± 2 and 1 ± 3, P = .029). Patients with ACJ arthritis and osteophytes ≥2 mm had less favorable Shoulder Pain and Disability Index scores, corresponding to greater pain (−49.3 ± 21.5 vs. −41.3 ± 26.8, P = .015). On multivariable linear regression, increased severity of ACJ arthritis was not independently associated with poorer postoperative ROM or outcome scores. Conclusion: Overall, our results demonstrate that greater ACJ arthritis severity score is not associated with poorer outcome scores and has minimal effect on ROM. However, patients with the largest osteophytes (≥2 mm) did have slightly worse pain postoperatively. Radiographic presence of high-stage ACJ arthritis should not alter the decision to undergo rTSA.

Teachers assume personal responsibility in four domains: student motivation, student achievement, relationships with students, and the quality of their own teaching. In all existing research, pre-service and practicing teachers score lowest in the motivation domain. This may be because some teachers view motivation as a shared responsibility or one that is contingent on external factors. Thus, the purpose of this research was to examine pre-service teachers' reflections on two different perspectives on personal responsibility for student motivation - one that reflected high internal unmitigated responsibility and one that reflected shared and contextualized responsibility. Pre-service teachers watched two video vignettes, and then reflected on the perspectives in an open-ended written format. The descriptive statistics confirmed that responsibility for motivation was the lowest of the four domains. Moreover, the percentage pre-service teacher felt responsible for student motivation predicted which video vignette they selected. Thematic analysis of pre-service teachers' reflection revealed four themes that give insight to how pre-service teachers make sense of responsibility for student motivation: people responsible, external factors, strategies to support motivation, and emotions. The results are discussed in light of methodological, theoretical, and practical implications.

Abstract Short-wave infrared (SWIR) fluorescence could become the new gold standard in optical imaging for biomedical applications due to important advantages such as lack of autofluorescence, weak photon absorption by blood and tissues, and reduced photon scattering coefficient. Therefore, contrary to the visible and NIR regions, tissues become translucent in the SWIR region. Nevertheless, the lack of bright and biocompatible probes is a key challenge that must be overcome to unlock the full potential of SWIR fluorescence. Although rare-earth-based core-shell nanocrystals appeared as promising SWIR probes, they suffer from limited photoluminescence quantum yield (PLQY). The lack of control over the atomic scale organization of such complex materials is one of the main barriers limiting their optical performance. Here, the growth of either homogeneous (α-NaYF4) or heterogeneous (CaF2) shell domains on optically-active α-NaYF4:Yb:Er (with and without Ce3+ co-doping) core nanocrystals is reported. The atomic scale organization can be controlled by preventing cation intermixing only in heterogeneous core-shell nanocrystals with a dramatic impact on the PLQY. The latter reached 50% at 60 mW/cm2; one of the highest reported PLQY values for sub-15 nm nanocrystals. The most efficient nanocrystals were utilized for in vivo imaging above 1450 nm.

Expectancy Value Theory (EVT) is a prominent theory on student motivation. To add to the growing research in this area, we investigated students within a large, mandatory course outside of the STEM areas, to examine perceptions of success utilizing an EVT lens. The aim of our study was twofold. First, to examine students' open-ended responses about what makes them feel successful. Second, to determine if students' indorsement of expectancy, value, and control could predict their feelings of success. The study consisted of 210 students who completed an online questionnaire with items related to demographics, EVT components, and questions about their success in the course. Deductive coding was utilized to examine their feelings of success based on the EVT components. Regression analysis was utilized to predict perceptions of success. Students identified several components of their course that were associated with expectancy, value, and cost. Students' perceptions of success were positively predicted by expectancy and negatively predicted by cost while value was not a significant predictor. Our results speak to the importance of expectancy, value, and cost when designing large, mandatory courses. We provided several recommendations for instructors when designing courses, and also highlight limitations and future research directions.

Background: Previous research has shown that pre-service teachers have low responsibility for student motivation and feel underprepared to deal with motivational issues. As an extension, researchers have designed interventions to shift teachers' beliefs about motivation or equip them with approaches to instruction, but never both. Aims: Following best practices for motivation interventions, we created a one-session online intervention and tested its efficacy to shift pre-service teachers' self-reported beliefs and approaches to instruction to be more supportive of student motivation. The intervention included priming, materials designed for mindsets and/or for approaches to instruction, a consolidation activity, and take-home materials. Sample: A convenience sample of 384 pre-service teachers from one Canadian university participated. Methods: We embedded an experimental design into multiple sections of a required assessment course. After completing a pre-test, participants were randomly assigned to one of four conditions: beliefs-only, approaches-only, combined beliefs and approaches, or control. After completing the online module, students received a lecture on assessment practices and motivation. Results: The results from our MANCOVA showed that pre-service teachers who participated in the beliefs-only condition reported increased levels of responsibility for student motivation, more growth mindset beliefs, and less fixed mindset beliefs than participants in the other conditions. The approaches-only condition did not influence self-reported mastery or performance approaches to instruction and the combined condition had no effect on beliefs or approaches. Conclusions: We discuss the implications for educating pre-service teachers about student motivation and suggest that beliefs and approaches to instruction need to be addressed separately.

Abstract For optoelectronic applications of metal–organic framework (MOF) thin films, it is important to be able to fabricate films and heterostructures that are highly oriented relative to the substrate's surface normal. However, process optimization to achieve this is difficult without sufficiently detailed structural characterization of the deposited films. It is demonstrated that 2D grazing‐incidence wide‐angle X‐ray scattering (GIWAXS) data from a laboratory system go a long way to providing such characterization and can 1) better test structural models than 1D scans, 2) provide a quantitative estimate—useful for process optimization—of the fraction of the deposited film that has the desired surface‐oriented texture (2D powder), and 3) deliver such information as a function of depth into the film—useful for heterostructure characterization. Herein, GIWAXS data collection and analysis are introduced in the context of understanding MOF thin films, then it is shown how the desired oriented fraction (2D powder fraction) of UiO‐66 fabricated by vapor‐assisted conversion can be increased from 4% to over 95% by minimizing nucleation in solution. Finally, it is demonstrated that heterostructures of UiO‐66 and UiO‐67 can be grown wherein both layers are highly ordered (UiO‐66 83%, UiO‐67 >94%) once synthetic protocols are optimized.

Photoluminescence quantum yield (ϕ) is a key parameter of any luminescent material. There are two main ways to determine this value: 1) absolute, which requires calculation of the number of emitted and absorbed photons; and 2) relative, which utilizes the emission of a reference sample with known ϕ. Both methods become more complicated in case of upconversion (UC) photoluminescence, due to its nonlinear nature. The main obstacle to employing the relative method is the lack of a suitable reference with known UC quantum yield (UCQY, ϕ UC). Herein, a new UCQY reference material is presented, based on SrF2:1%Yb3+,1%Er3+ single crystal, for the relative measurement of ϕ UC for near‐infrared (976 nm)‐to‐visible UC. When utilizing this reference material, the ϕ UC is determined to be 2.5% (at 100 W cm−2) for α‐NaYF4:18%Yb3+,2%Er3+@CaF2 nanocrystals (NCs). This result coincides very well with the value for the same NCs determined using the absolute method of ϕ UC = 2.4% (at 100 W cm−2). The intensity dependence of UCQY yield for the NCs determined using the SrF2:1%Yb3+,1%Er3+ reference exhibits good agreement with the results acquired with the absolute method. In addition, various effects that can have an impact on the measured UCQY using absolute and relative methods are discussed.

Abstract A significant impediment to the deployment of anti-counterfeiting technologies is the reliance on specialized hardware. Here, anti-counterfeiting labels are developed that are both excited and detected using a smartphone. The persistent luminescence pattern and color changes on the timescale of hundreds of milliseconds to seconds. The labels can be authenticated by comparing still images from the red and green channels of video acquired at known times after flashlight excitation against expected reference patterns. The labels are based on a green-emitting SrAl2O4: Eu2+,Dy3+ (SAED), and red-emitting CaS:Eu2+ phosphors whose lifetimes are varied: (i) for SAED from 0.5 to 11.7 s by annealing the commercial material in air; and (ii) CaS:Eu2+ from 0.1 to 0.6 s by varying the dopant concentration. Examples of anti-counterfeiting labels exhibiting changing emission patterns and colors on a seven-segment display, barcode, and emoji are demonstrated. These results demonstrate that phosphors with visible absorption and tunable persistent luminescence lifetimes on the order of hundreds of milliseconds to seconds are attractive for anti-counterfeiting applications as they allow authentication to be performed using only a smartphone. Further development should allow richer color shifts and enhancement of security by embedding further covert anti-counterfeiting features.

The effect of triplet-triplet annihilation (TTA) on the room-temperature phosphorescence (RTP) in metal-organic frameworks (MOFs) is studied in benchmark RTP MOFs based on Zn metal centers and isophthalic or terephthalic acid linkers (ZnIPA and ZnTPA). The ratio of RTP to singlet fluorescence is observed to decrease with increasing excitation power density. Explicitly, in ZnIPA the ratio of the RTP to fluorescence is 0.58 at 1.04 mW cm−2, but only 0.42 at (the still modest) 52.6 mW cm−2. The decrease in ratio is due to the reduction of RTP efficiency at higher excitation due to TTA. The density of triplet states increases at higher excitation power densities, allowing triplets to diffuse far enough during their long lifetime to meet another triplet and annihilate. On the other hand, the shorter-lived singlet species can never meet an annihilate. Therefore, the singlet fluorescence scales linearly with excitation power density whereas the RTP scales sub-linearly. Equivalently, the efficiency of fluorescence is unaffected by excitation power density but the efficiency of RTP is significantly reduced at higher excitation power density due to TTA. Interestingly, in time-resolved measurements, the fraction of fast decay increases but the lifetime of long tail of the RTP remains unaffected by excitation power density. This may be due to the confinement of triplets to individual grains, leading decay to be faster until there is only one triplet per grain left. Subsequently, the remaining “lone triplets” decay with the unchanging rate expressed by the long tail. These results increase the understanding of RTP in MOFs by explicitly showing the importance of TTA in determining the (excitation power density dependent) efficiency of RTP. Also, for applications in optical sensing, these results suggest that a method based on long tail lifetime of the RTP is preferable to a ratiometric approach as the former will not be affected by variation in excitation power density whereas the latter will be.

Unclonable anticounterfeiting labels can be based on micrometer‐scale randomness created by stochastic processes like the distribution of luminescent microparticles in a transparent layer. Adding a microlens array to the layer can simplify the hardware needed for authentication in that magnification is no longer required. The bright point‐pattern generated under light‐emitting diode illumination can be captured by a standard digital camera. Shifting the angle of incidence (AOI) relocates the microlens foci changing the bright point‐pattern. This provides unclonability, as several distinct bright point patterns at different AOI can be required for authentication. However, it also imposes technical requirements for the authentication setup in terms of the tolerance with which the AOI must be controlled. Herein, the AOI tolerance, the deviation of angle between reference and test image for which sufficiently similar bright point patterns are recorded that they are considered matching by the authentication algorithm, is investigated. Using microlens arrays with a focal length of 550 μm, the average size of the phosphor particle was varied from 9 ± 1 to 32.5 ± 2 μm, resulting in a relaxation of tolerance from 0.8° to 3.6°. Methods to further increase the AOI tolerance and facilitate the practical implementation of these labels are discussed.

Thin films of crystalline solids with substantial free volume built from organic chromophores and metal secondary building units (SBUs) are promising for engineering new optoelectronic properties through control of interchromophore coupling. Zn‐based SBUs are especially relevant in this case because they avoid quenching the chromophore's luminescence. We find that layer‐by‐layer spin‐coating using Zn acetate dihydrate and benzene‐1,4‐dicarboxylic acid (H2BDC) and biphenyl‐4,4'‐dicarboxylic acid (H2BPDC) linkers readily produces crystalline thin films. However, analysis of the grazing‐incidence wide‐angle X‐ray scattering (GIWAXS) data reveals the structures of these films vary significantly with the linker, and with the metal‐to‐linker molar ratio used for fabrication. Under equimolar conditions, H2BPDC creates a type of structure like that proposed for SURMOF‐2, whereas H2BDC generates a different metal‐hydroxide‐organic framework. Large excess of Zn2+ ions causes the growth of layered zinc hydroxides, irrespective of the linker used. Density functional theory (DFT) calculations provide structural models with minimum total energy that are consistent with the experimentally observed diffractograms. In the broader sense, this work illustrates the importance in this field of careful structure determination, e. g., by utilizing GIWAXS and DFT simulations to determine the structure of the obtained crystalline metal‐organic thin films, such that properties can be rationally engineered and explained. [ABSTRACT FROM AUTHOR]

Down‐conversion (DC) is a phenomenon that can enable the observation of photoluminescent quantum yield (PLQY) values exceeding 100%. A comprehensive study of the DC properties of BaF2–based single crystals with different Er3+ doping levels (1–25 mol.%) is presented. The samples exhibit a PLQY of 110% in the 1550–1650 nm under 405 nm excitation. This remarkable PLQY is attributed to a cross‐relaxation process within the energy levels of Er3+. Furthermore, when considering all emitted photons in the 1000–1650 nm range, the PLQY reaches 153% for a sample doped with 5 mol.% of Er3+. By integrating the emission of this single crystal with a Ge diode, serving as an example of a photovoltaic device sensitive to short‐wave infrared light, a significant enhancement in short‐circuit current is demonstrated. In a broader context, the presented material holds promise for improving the spectral response of low‐bandgap photovoltaic devices. [ABSTRACT FROM AUTHOR]

A theoretical framework to optimize photonic structure designs for upconversion enhancement is lacking. Here, the authors present a comprehensive theoretical model and confirm the model’s predictions by experimental realisation of 1D-photonic upconverter devices with large statistics and parameter scans.

Optical gain of 8.3 km−1 is obtained in a neodymium‐doped silica fiber under simulated sunlight (intensity = 2.1 kW m−2). The fiber gain medium (length = 50 m) is coiled and attached to a solid‐state luminescent solar concentrator (LSC) disk (diameter = 180 mm). The disk/fiber unit is placed in a cavity comprising highly reflective (HRM) and dichroic (DM) mirrors to increase the photon confinement by a factor of 2.2 compared with a liquid LSC (also employing HRM/DM). The enhancement is mainly due to the air gap between HRM/DM and LSC, which affords total internal reflection (TIR) in the solid‐state LSC and an ideal boundary condition for the multilayer mirrors. The numerical calculations indicate that an additional 2.2‐times enhancement is achievable with a side wall exhibiting 90% diffuse reflection. This has been experimentally confirmed (1.9‐times optical‐gain enhancement is realized by adding a polytetrafluoroethylene side‐wall reflector). Overall, the solid‐state LSC‐based solar‐pumped laser (SPL) comprising reflective side walls exhibits a gain factor of 4.2, which is superior to its liquid‐state predecessor. Further improvements employing a solid‐state LSC design and fiber optimization will facilitate the market penetration of SPLs.

Abstract Detection of micropollutants such as steroid hormones occurring in the aquatic environment at concentrations between ng/L and µg/L remains a major challenge, in particular when treatment efficiency is to be evaluated. Steroid hormones are typically analysed using mass-spectrometry methods, requiring pre-concentration and/or derivatisation procedures to achieve required detection limits. Free of sample preparation steps, the use of radiolabelled contaminants with liquid scintillation counting is limited to single-compound systems and require a separation of hormone mixtures before detection. In this work, a method was developed coupling ultra-high-pressure liquid chromatography (UHPLC) with flow scintillation analysis (FSA) for separation and detection of radiolabelled estrone, 17ß-estradiol, testosterone and progesterone. Adjustment of the flow rate of scintillation liquid and UHPLC mobile phase, gradient time, column temperature, and injection volume allowed the separation of steroid hormones and degradation products. The limit-of-detection (LOD = 1.5–2.4 ng/L) and limit-of-quantification (LOQ = 3.4–4.3 ng/L) for steroid hormones were comparable with the current state-of-the-art technique (LC-MS/MS) for non-derivatised compounds. Although the method cannot be applied to real water samples (unless spiked with radiotracers), it serves as a useful tool for the development of water treatment technologies at laboratory scale as demonstrated via: i) adsorption on polymer-based spherical activated carbon, ii) retention in nanofiltration, iii) photodegradation using a photocatalytic membrane.