ViewR: Architectural-Scale Multi-User Mixed Reality with Mobile Head-Mounted Displays.

The emergence of mobile head-mounted displays with robust "inside-out" markerless tracking and video-passthrough permits the creation of novel mixed reality (MR) experiences in which architectural spaces of arbitrary size can be transformed into immersive multi-user visualisation arenas. Here we outline ViewR, an open-source framework for rapidly constructing and deploying architectural-scale multi-user MR experiences. ViewR includes tools for rapid alignment of real and virtual worlds, tracking loss detection and recovery, user trajectory visualisation and world state synchronisation between users with persistence across sessions. ViewR also provides control over the blending of the real and the virtual, specification of site-specific blending zones, and video-passthrough avatars, allowing users to see and interact with one another directly. Using ViewR, we explore the transformation of large architectural structures into immersive arenas by creating a range of experiences in various locations, with a particular focus on architectural affordances such as mezzanines, stairs, gangways and elevators. Our tests reveal that ViewR allows for experiences that would not be possible with pure virtual reality, and indicate that, with certain strategies for recovering from tracking errors, it is possible to construct large scale multi-user MR experiences using contemporary consumer virtual reality head-mounted displays.

Improving Blood Monocyte Energy Metabolism Enhances Its Ability to Phagocytose Amyloid-ß and Prevents Alzheimer's Disease-Type Pathology and Cognitive Deficits.

Deficiencies in the clearance of peripheral amyloid ß (Aß) play a crucial role in the progression of Alzheimer's disease (AD). Previous studies have shown that the ability of blood monocytes to phagocytose Aß is decreased in AD. However, the exact mechanism of Aß clearance dysfunction in AD monocytes remains unclear. In the present study, we found that blood monocytes in AD mice exhibited decreases in energy metabolism, which was accompanied by cellular senescence, a senescence-associated secretory phenotype, and dysfunctional phagocytosis of Aß. Improving energy metabolism rejuvenated monocytes and enhanced their ability to phagocytose Aß in vivo and in vitro. Moreover, enhancing blood monocyte Aß phagocytosis by improving energy metabolism alleviated brain Aß deposition and neuroinflammation and eventually improved cognitive function in AD mice. This study reveals a new mechanism of impaired Aß phagocytosis in monocytes and provides evidence that restoring their energy metabolism may be a novel therapeutic strategy for AD.

Effects of Chemotherapy on Neuroinflammation, Neuronal Damage, Neurogenesis, and Behavioral Performance in Bone Marrow Transplantation Recipient Mice.

As bone marrow transplant (BMT) is gradually applied to the study of central nervous system (CNS) disease, it is needed to investigate the proper dose of chemotherapy to eradicate bone marrow cells while bringing little damage to brain. In the present study, we established a BMT model with varied busulfan and cyclophosphamide (Bu-Cy) dosages. The recipient mice's chimera rate, neuronal death, neuroinflammation, and behavioral functions were all investigated. Chimerism of peripheral blood cells was shown to rise with Bu-Cy treatment doses, with 60.7% in the Bu(20 mg/kg)/Cy(100 mg/kg) group and 93.0% in the Bu(35 mg/kg)/Cy(100 mg/kg) group. Recipients with Bu(35 mg/kg)/Cy(100 mg/kg) therapy had brain injury, increased neuroinflammation, diminished neurogenesis and cognitive abnormalities, whereas animals given a lesser dosage had no such brain damages. Conclusively, considering the chimerism and the possibility to damage brain, we recommend Bu(20 mg/kg)/Cy(100 mg/kg) is the ideal dose in BMT for studying CNS diseases in the C57/BL6 mouse strain.

Inhibiting α1-adrenergic receptor signaling pathway ameliorates AD-type pathologies and behavioral deficits in APPswe/PS1 mouse model.

The role of α1 adrenergic receptors (α1-ARs) signaling pathway in the pathogenesis of Alzheimer's disease (AD) has rarely been investigated. Clarifying the pathophysiological functions of α1-ARs in the AD brain is helpful for better understanding the pathogenesis and screening novel therapeutic targets of AD. This study included 2 arms of in vivo investigations: 1) 6-month-old female APPswe/PS1 mice were intravenously treated with AAV-PHP.eB-shRNA (α1-ARs)-GFP or AAV-PHP.eB-GFP for 3 months. 2) 3-month-old female APPswe/PS1 mice were daily treated with 0.5 mg/kg terazosin or an equal volume of saline for 6 months. SH-SY5Y cell lines bearing human amyloid precursor protein were treated with terazosin or saline for investigating possible mechanisms. α1-ARs knockdown mice exhibited improved behavioral performances in comparison with control mice. α1-ARs knockdown mice had significantly lower brain amyloid burden, as reflected by soluble Aß species, compact and total Aß plaques, than control mice. α1-ARs inhibitor terazosin substantially reduced Aß deposition, attenuated downstream pathologies including tau hyperphosphorylation, glial activation, neuronal loss, synaptic dysfunction et al., and rescued behavioral deficits in APPswe/PS1 mice. In vitro investigation demonstrated that α1-ARs inhibition down-regulated BACE1 expression, and promoted ser9 phosphorylation of GSK-3ß, thus reducing Aß production. This study indicates that inhibition of α1-ARs signaling pathway might represent a promising therapeutic strategy for AD.

Visible-light metalens far-field nanofocusing effects with active tuning of focus based on MIM subwavelength structures used in an integrated imaging array.

We propose a structure of a far-field nanofocusing metalens with focal shifting that is actively tuned at visible wavelengths. Surface plasmon polaritons (SPPs) can be excited by the metal-insulator-metal (MIM) subwavelength structure at visible wavelengths. The coherent interference of SPPs emitted by subwavelength nanostructures can form a nanoscale focus. When the SPPs are excited and pass through several concentric ring gratings with specific aspect ratios, the extraordinary optical transmission phenomenon occurs. Two metal concentric ring gratings achieve double diffraction, scattering light to the far field. An anisotropic or isotropic electrically adjustable refractive index material, such as liquid-crystal or optical phase change material, is filled in a dielectric layer between two metal layers, and the effective refractive index is modulated by electronically controlled active tuning. The focal shift is achieved by changing the effective refractive index of the intermediate dielectric. In addition, different incident wavelengths correspond to different effective refractive indices to achieve time-division-multiplexing multi-wavelength achromatic focusing. The finite-difference time-domain method was used to simulate the effect of substrate effective refractive index variation on achromatic superfocusing. The results show that the super-resolution focal spot (FWHM=0.158λ0) with long focal length (FL=5.177λ0) and large depth of field (DOF=3.412λ0) can be achieved by optimizing the design parameters. The visible plasma metalens has potential applications in high-density optical storage and optical microscopic imaging, especially in three-dimensional display for light field and integral imaging.

Physiological clearance of Aß by spleen and splenectomy aggravates Alzheimer-type pathogenesis.

BACKGROUND: A previous study demonstrated that nearly 40%-60% of brain Aß flows out into the peripheral system for clearance. However, where and how circulating Aß is cleared in the periphery remains unclear. The spleen acts as a blood filter and an immune organ. The aim of the present study was to investigate the role of the spleen in the clearance of Aß in the periphery. METHODS: We investigated the physiological clearance of Aß by the spleen and established a mouse model of AD and spleen excision by removing the spleens of APP/PS1 mice to investigate the effect of splenectomy on AD mice. RESULTS: We found that Aß levels in the splenic artery were higher than those in the splenic vein, suggesting that circulating Aß is cleared when blood flows through the spleen. Next, we found that splenic monocytes/macrophages could take up Aß directly in vivo and in vitro. Splenectomy aggravated behaviour deficits, brain Aß burden and AD-related pathologies in AD mice. CONCLUSION: Our study reveals for the first time that the spleen exerts a physiological function of clearing circulating Aß in the periphery. Our study also suggests that splenectomy, which is a routine treatment for splenic rupture and hypersplenism, might accelerate the development of AD.

Motion parallax and lossless resolution autostereoscopic 3D display based on a binocular viewpoint tracking liquid crystal dynamic grating adaptive screen.

The autostereoscopic 3D display has two important indicators, both the number of viewpoints and display resolution. However, it's a challenge to improve both the viewpoint and the resolution. Here, we develop a fixed-position multiview and lossless resolution autostereoscopic 3D display system that includes the dynamic liquid crystal (LC) grating screen. This display system consists of an LC display panel and an LC grating screen. The synchronization of the frame switching of the LC display panel and the LC grating screen shutter enables the preserved resolution. The "eye space" design makes the viewpoint dense enough and determines the LC grating screen's parameters. We use binocular viewpoint tracking technology to realize the LC grating screen's adaptive control based on the above work. Different binocular views are rendered in real-time according to the different positions of a single pair of stereoscopic viewpoints in the eye space, making the motion parallax possible. We present the working principle and mathematical analysis. We implement a prototype for verifying the principle. According to the experiment results analysis, this prototype can achieve viewpoint tracking and motion parallax based on resolution lossless and viewpoint dense enough.

Physiological clearance of amyloid-beta by the kidney and its therapeutic potential for Alzheimer's disease.

Amyloid-ß (Aß) accumulation in the brain is a pivotal event in the pathogenesis of Alzheimer's disease (AD), and its clearance from the brain is impaired in sporadic AD. Previous studies suggest that approximately half of the Aß produced in the brain is cleared by transport into the periphery. However, the mechanism and pathophysiological significance of peripheral Aß clearance remain largely unknown. The kidney is thought to be responsible for Aß clearance, but direct evidence is lacking. In this study, we investigated the impact of unilateral nephrectomy on the dynamic changes in Aß in the blood and brain in both humans and animals and on behavioural deficits and AD pathologies in animals. Furthermore, the therapeutic effects of the diuretic furosemide on Aß clearance via the kidney were assessed. We detected Aß in the kidneys and urine of both humans and animals and found that the Aß level in the blood of the renal artery was higher than that in the blood of the renal vein. Unilateral nephrectomy increased brain Aß deposition; aggravated AD pathologies, including Tau hyperphosphorylation, glial activation, neuroinflammation, and neuronal loss; and aggravated cognitive deficits in APP/PS1 mice. In addition, chronic furosemide treatment reduced blood and brain Aß levels and attenuated AD pathologies and cognitive deficits in APP/PS1 mice. Our findings demonstrate that the kidney physiologically clears Aß from the blood, suggesting that facilitation of Aß clearance via the kidney represents a novel potential therapeutic approach for AD.

Structural design of cobalt phosphate on nickel foam for electrocatalytic oxygen evolution.

The elaborate design and synthesis of low-cost, efficient and stable electrocatalysts for the oxygen evolution reaction (OER), which may alleviate the current energy shortage and environment pollution, is still a great challenge. Herein, metal phosphonate precursors with controllable morphologies were synthesizedin situon the surface of nickel foam with different solvents, and could be easily converted into carbon- and nitrogen-doped cobalt phosphate through a calcination method. The OER catalytic performance of the final products was studied in detail. The results showed that the nanowire shaped samples of CoPiNF-800 synthesized with deionized water under hydrothermal conditions had the strongest electrochemical performance. They exhibited extraordinary catalytic activity with a very low overpotential of 222 mV at 100 mA cm-2, the smallest impedance and excellent electrochemical stability. These results not only demonstrate the possibility of preparing low-cost OER catalysts based on transition metal phosphate, but also aid our understanding of the controllable synthesis process of different morphologies.

How clinician-patient communication affects trust in health information sources: Temporal trends from a national cross-sectional survey.

BACKGROUND: Understanding patients' trust in health information sources is critical to designing work systems in healthcare. Patient-centered communication during the visit might be a major factor in shaping patients' trust in information sources. OBJECTIVE: The purpose of this paper is to explore relationships between patient ratings of clinician communication during the visit and patient trust in health information sources. METHODOLOGY: We conducted a secondary analysis of the nationally-representative Health Information National Trends Surveys; HINTS4 Cycle1 (2011), HINTS4 Cycle4 (2014), and HINTS5 Cycle1 (2017), and HINTS5 Cycle2 (2018). We created a composite score of patient-centered communication from five questions and dichotomized at the median. We created multivariable logistic regression models to see how patient-centered communication influenced trust in different information sources across cycles. Consecutively, we used hierarchical analysis for aggregated data. RESULTS: We analyzed data from 14,425 individuals. In the adjusted logistic models for each cycle and the hierarchical model, clinicians' perceived patient-centered communication skills were significantly associated with increased trust in the clinicians as an information source. CONCLUSION: Clinicians still represent an essential source of trustworthy information reinforced by patient-centered communication skills. Given that trust helps build healing relationships that lead to better healthcare outcomes, communication sets an essential foundation to establish necessary trust. Interpreting information from the internet sources for patients is likely to remain a vital clinician function.

Online Medical Record Nonuse Among Patients: Data Analysis Study of the 2019 Health Information National Trends Survey.

BACKGROUND: Online medical records are being used to organize processes in clinical and outpatient settings and to forge doctor-patient communication techniques that build mutual understanding and trust. OBJECTIVE: We aimed to understand the reasons why patients tend to avoid using online medical records and to compare the perceptions that patients have of online medical records based on demographics and cancer diagnosis. METHODS: We used data from the Health Information National Trends Survey Cycle 3, a nationally representative survey, and assessed outcomes using descriptive statistics and chi-square tests. The patients (N=4328) included in the analysis had experienced an outpatient visit within the previous 12 months and had answered the online behavior question regarding their use of online medical records. RESULTS: Patients who were nonusers of online medical records consisted of 58.36% of the sample (2526/4328). The highest nonuser rates were for patients who were Hispanic (460/683, 67.35%), patients who were non-Hispanic Black (434/653, 66.46%), and patients who were older than 65 years (968/1520, 63.6%). Patients older than 65 years were less likely to use online medical records (odds ratio [OR] 1.51, 95% CI 1.24-1.84, P<.001). Patients who were White were more likely to use online medical records than patients who were Black (OR 1.71, 95% CI 1.43-2.05, P<.001) or Hispanic (OR 1.65, 95% CI 1.37-1.98, P<.001). Patients who were diagnosed with cancer were more likely to use online medical records compared to patients with no cancer (OR 1.31, 95% CI 1.11-1.55, 95% CI 1.11-1.55, P=.001). Among nonusers, older patients (≥65 years old) preferred speaking directly to their health care providers (OR 1.76, 95% CI 1.35-2.31, P<.001), were more concerned about privacy issues caused by online medical records (OR 1.79, 95% CI 1.22-2.66, P<.001), and felt uncomfortable using the online medical record systems (OR 10.55, 95% CI 6.06-19.89, P<.001) compared to those aged 18-34 years. Patients who were Black or Hispanic were more concerned about privacy issues (OR 1.42, 1.09-1.84, P=.007). CONCLUSIONS: Studies should consider social factors such as gender, race/ethnicity, and age when monitoring trends in eHealth use to ensure that eHealth use does not induce greater health status and health care disparities between people with different backgrounds and demographic characteristics.

Blood cell-produced amyloid-ß induces cerebral Alzheimer-type pathologies and behavioral deficits.

It is traditionally believed that cerebral amyloid-beta (Aß) deposits are derived from the brain itself in Alzheimer's disease (AD). Peripheral cells such as blood cells also produce Aß. The role of peripherally produced Aß in the pathogenesis of AD remains unknown. In this study, we established a bone marrow transplantation model to investigate the contribution of blood cell-produced Aß to AD pathogenesis. We found that bone marrow cells (BMCs) transplanted from APPswe/PS1dE9 transgenic mice into wild-type (Wt) mice at 3 months of age continuously expressed human Aß in the blood, and caused AD phenotypes including Aß plaques, cerebral amyloid angiopathy (CAA), tau hyperphosphorylation, neuronal degeneration, neuroinflammation, and behavioral deficits in the Wt recipient mice at 12 months after transplantation. Bone marrow reconstitution in APPswe/PS1dE9 mice with Wt-BMCs at 3 months of age reduced blood Aß levels, and alleviated brain Aß burden, neuronal degeneration, neuroinflammation, and behavioral deficits in the AD model mice at 12 months after transplantation. Our study demonstrated that blood cell-produced Aß plays a significant role in AD pathogenesis, and the elimination of peripheral production of Aß can decrease brain Aß deposition and represents a novel therapeutic approach for AD.

Ultra-broadband large-angle beam splitter based on a homogeneous metasurface at visible wavelengths.

Metasurface-based beam splitters with high efficiency, large split angle, wide bandwidth and easy fabrication are highly desirable and still in pursuit. In this paper, we propose a heuristic scheme for designing an ultra-broadband high-efficiency power beam splitter based on a homogeneous metasurface. The conversion efficiency and total transmission intensity of the power splitter stays higher than 95% and 0.66 within the wavelength region from 604 nm to 738 nm, respectively. Particularly, the conversion efficiency can maintain greater than 99% in 58 nm bandwidth. The angle between two split beams can reach a maximum of 157.82° at the wavelength of 738 nm. In addition to simplified design and easy fabrication, the proposed power beam splitter possesses high robustness as well. We expect that our design can pave a new way for realizing high-performance metasurface-based beam splitters.

Beyond dipole excitation: the performance of quadrupole-based Huygens' metasurface.

Due to the utilization of overlapped dipole resonances, traditional Huygens' metasurfaces suffer from dipole interactions. In this Letter, we propose a design of phase-gradient Huygens' metasurface based on the quadrupole resonances excited in the cross-shaped structures. The quadrupole resonances are theoretically shown insensitive to the quadrupole interactions. Benefiting from this intrinsic property, the proposed metasurface can well suppress element interaction influence and exhibits some impressive properties, including the ability to suppress high diffraction orders, tunable anomalous refractive angles, and high transmission efficiency. The numerical results show promising potential for quadrupole resonances to be applied in advanced Huygens' metasurface designs.

Naturally Occurring Antibodies to Tau Exists in Human Blood and Are Not Changed in Alzheimer's Disease.

Hyperphosphorylated tau is an important pathological agent in Alzheimer's disease (AD). Tau effluxes from the brain to the blood could potentially stimulate the production of naturally occurring antibodies (NAbs). We aimed to investigate whether NAbs to tau (NAbs-tau) was generated in human blood and to figure out the alteration of plasma NAbs-tau level in AD patients. About 192 AD patients and 192 age-matched and non-demented controls (NC) were enrolled in the present study. Immunofluorescence staining and western blot assays were used to confirm the existence of NAbs-tau in human blood. The plasma level of NAbs-tau in NC and AD group was analyzed by ELISA. Immunofluorescence staining and western blot assays confirmed the existence of NAbs-tau in human blood. However, no significant difference in the plasma level of NAbs-tau was observed between NC and AD group. Furthermore, the plasma level of NAbs-tau had no significant correlation with MMSE scores. The present study confirmed that NAbs-tau exists in human blood but does not differ in level between the NC and AD group. Plasma NAbs-tau is not a reliable biomarker for AD.

Broadband Ultrathin Transmission Quarter Waveplate with Rectangular Hole Array Based on Plasmonic Resonances.

The control of the polarization states of light plays an important role in modern optical systems. However, traditional polarization manipulating devices often have narrow bandwidth and their large size makes it difficult for them to achieve miniaturization and integration of optical systems. This work presents an ultrathin quarter waveplate with a periodic silver film 2 × 2 rectangular hole array with a thickness less than λ/50. Numerical simulation shows that the waveplate can efficiently transform a circular polarized wave into a linearly polarized one at the center of 1550 nm, and its bandwidth is 525 nm. Furthermore, the quarter waveplate can efficiently invert linear polarization into circular polarization at 1550 nm, which ellipticity is near unit. With an array of small holes on a metal film to enhance transmission, this structure can increase the transmission to 0.44. The broadband quarter waveplate can be used in communication system and near infrared band system, and be integrated with other optical devices at nanoscale to achieve polarization operation, detection, and sensing.

Design of spontaneous parametric down-conversion in integrated hybrid SixNy-PPLN waveguides.

High-efficient and high-purity photon sources are highly desired for quantum information processing. We report the design of a chip-scale hybrid SixNy and thin film periodically-poled lithium niobate waveguide for generating high-purity type-II spontaneous parametric down-conversion (SPDC) photons in the telecommunication band. The modeled second harmonic generation efficiency of 225% W-1 • cm-2 is obtained at 1560nm. Joint spectral analysis is performed to estimate the frequency correlation of SPDC photons, yielding intrinsic purity with up to 95.17%. The generation rate of these high-purity photon pairs is estimated to be 2.87 × 107 pairs/s/mW within the bandwidth of SPDC. Our chip-scale hybrid waveguide design has the potential for large-scale on-chip quantum information processing and integrated photon-efficient quantum key distribution through high-dimensional time-energy encoding.

Mechanisms of 2π phase control in dielectric metasurface and transmission enhancement effect.

Metasurfaces, two-dimensional structures composed of nanoantennas in an array configuration, can be used to fully control electromagnetic waves, which requires a 2π phase shift. Herein, we apply the silicon metasurface as an example to interpret the mechanisms of full 2π phase coverage. It is found that the mechanism varies from Fabry-Pérot resonance to Mie resonance as the period increases for a metasurface with certain height. Particularly, there is a transition region between these two types of resonance. We present the corresponding periods and wavelength regions of the different mechanisms when considering the phase-gradient metasurface with at most three diffraction orders. Moreover, the transmission enhancement of metasurface is investigated. The transmission efficiency can be effectively improved when the nanoantenna is changed from a uniform structure to a gradient-index one. We expect that the results can simplify the design process and provide a reference for the future design of all-dielectric metasurface with 2π phase control.

All-dielectric colored truncated cone metasurfaces with silicon Mie magnetic resonators.

We propose high-index truncated cone silicon metasurfaces based mainly on magnetic Mie resonances. From numerical simulation, the intensity of the reflection peak reaches almost 90%, and the full width at half-maximum (FWHM) of the reflectance spectrum is 43 nm. Specific colors covering the entire visible spectrum with saturation close to 1 are available by selecting appropriate geometric dimensions and period of the structure. In summary, the structural colors achieved by the proposed metasurfaces are superior to previous research in comprehensive aspects of reflection peak, the FWHM of the reflectance spectrum, and the saturation of the color. Furthermore, the proposed structure works with a low aspect ratio of 0.46, which largely relieves the difficulty of process manufacturing.