Autonomous Internet of Things (IoT) Data Reduction Based on Adaptive Threshold.

With the development of intelligent IoT applications, vast amounts of data are generated by various volume sensors. These sensor data need to be reduced at the sensor and then reconstructed later to save bandwidth and energy. As the reduced data increase, the reconstructed data become less accurate. Usually, the trade-off between reduction rate and reconstruction accuracy is controlled by the reduction threshold, which is calculated by experiments based on historical data. Considering the dynamic nature of IoT, a fixed threshold cannot balance the reduction rate with the reconstruction accuracy adaptively. Aiming to dynamically balance the reduction rate with the reconstruction accuracy, an autonomous IoT data reduction method based on an adaptive threshold is proposed. During data reduction, concept drift detection is performed to capture IoT dynamic changes and trigger threshold adjustment. During data reconstruction, a data trend is added to improve reconstruction accuracy. The effectiveness of the proposed method is demonstrated by comparing the proposed method with the basic Kalman filtering algorithm, LMS algorithm, and PIP algorithm on stationary and nonstationary datasets. Compared with not applying the adaptive threshold, on average, there is an 11.7% improvement in accuracy for the same reduction rate or a 17.3% improvement in reduction rate for the same accuracy.

Genetic Algorithm-Based Online-Partitioning BranchyNet for Accelerating Edge Inference.

In order to effectively apply BranchyNet, a DNN with multiple early-exit branches, in edge intelligent applications, one way is to divide and distribute the inference task of a BranchyNet into a group of robots, drones, vehicles, and other intelligent edge devices. Unlike most existing works trying to select a particular branch to partition and deploy, this paper proposes a genetic algorithm (GA)-based online partitioning approach that splits the whole BranchyNet with all its branches. For this purpose, it establishes a new calculation approach based on the weighted average for estimating total execution time of a given BranchyNet and a two-layer chromosome GA by distinguishing partitioning and deployment during the evolution in GA. The experiment results show that the proposed algorithm can not only result in shorter execution time and lower device-average energy cost but also needs less time to obtain an optimal deployment plan. Such short running time enables the proposed algorithm to generate an optimal deployment plan online, which dynamically meets the actual requirements in deploying an intelligent application in the edge.

A Dew-Condensation Sensor Exploiting Local Variations in the Relative Refractive Index on the Dew-Friendly Surface of a Waveguide.

We propose a sensor technology for detecting dew condensation, which exploits a variation in the relative refractive index on the dew-friendly surface of an optical waveguide. The dew-condensation sensor is composed of a laser, waveguide, medium (i.e., filling material for the waveguide), and photodiode. The formation of dewdrops on the waveguide surface causes local increases in the relative refractive index accompanied by the transmission of the incident light rays, hence reducing the light intensity inside the waveguide. In particular, the dew-friendly surface of the waveguide is obtained by filling the interior of the waveguide with liquid H2O, i.e., water. A geometric design for the sensor was first carried out considering the curvature of the waveguide and the incident angles of the light rays. Moreover, the optical suitability of waveguide media with various absolute refractive indices, i.e., water, air, oil, and glass, were evaluated through simulation tests. In actual experiments, the sensor with the water-filled waveguide displayed a wider gap between the measured photocurrent levels under conditions with and without dew, than those with the air- and glass-filled waveguides, as a result of the relatively high specific heat of the water. The sensor with the water-filled waveguide exhibited excellent accuracy and repeatability as well.

Current status of premature mortality from four non-communicable diseases and progress towards the Sustainable Development Goal target 3.4: a population-based study in northeast China, 2004-2017.

BACKGROUND AND AIM: According to the United Nations' Sustainable Development Goal (SDG) target 3.4, premature mortality from four non-communicable diseases (cardiovascular diseases, cancer, chronic respiratory diseases, and diabetes mellitus, collectively referred to as NCD4) should achieve a minimum decline of 33% in 2030 relative to 2015. This remains a challenge for China. This study aimed to evaluate the current status and progress towards this target in Liaoning Province, one of the three provinces in northeast China. METHODS: We calculated the premature mortality rates (PMRs) per year and average annual percentage changes (AAPCs) from NCD4 using mortality data between 2004 and 2017. The trend was analyzed in the whole population, as well as in subpopulations of gender (male/female) and inhabiting area (urban/rural). PMRs from NCD4 for 2030 were projected by fitting a linear regression based on the current trend, which was identified by a Joinpoint model. FINDINGS: In the whole population, only chronic respiratory diseases showed a significant decline (AAPC: - 6.5%, p < 0.05), while only cancer showed a significant increase (AAPC: + 1.3%, p < 0.05); taken together, NCD4 showed a significant increase (AAPC: + 0.6%, p < 0.05). In the subpopulations, while males showed a significant increase in NCD4 (AAPC: + 1.5%, p < 0.05), cardiovascular diseases (AAPC: + 1.7%, p < 0.05), cancer (AAPC: + 1.8%, p < 0.05), and diabetes mellitus (AAPC: + 4.2%, p < 0.05), females showed a significant decline in NCD4 (AAPC: - 1.2%, p < 0.05), cardiovascular diseases (AAPC: - 1.8%, p < 0.05), diabetes mellitus (AAPC: - 2.1%, p < 0.05), but showed a mild increase in cancer (AAPC: + 0.5%, p > 0.05). A comparative analysis of the projected PMRs for 2030 with the 2015 levels revealed that only chronic respiratory diseases are expected to achieve the SDG target 3.4, apart from in the urban male subpopulation. CONCLUSION: Except for chronic respiratory diseases, NCD4 cannot be expected to achieve the SDG target 3.4 in the whole population of Liaoning Province. Under these circumstances, special attention should be paid to reducing the risks of cancer and providing preventative interventions for men.

Surface wrinkle formation by liquid crystalline polymers for significant light extraction enhancement on quantum dot light-emitting diodes.

We propose an optimal outcoupling structure of a quantum-dot light-emitting diode (QLED) and present material properties based on numerical calculations via the ray-tracing method, in which light extraction properties are obtained according to the surface wrinkles on a substrate. After analyzing the designed microstructure elements, the optimal model was derived and applied to the QLEDs; consequently, the outcoupling efficiency enhanced by 31%. The liquid crystalline polymer forming the random surface wrinkles not only achieves an excellent light extraction through plasma crosslinking but also facilitates large-area processes. We propose an optical design rule for high-efficiency QLED design by analyzing the electro-optical efficiency, emission spectrum, and angular radiation pattern of the optical device.

A cross-sectional study on associations of physical symptoms, health self-efficacy, and suicidal ideation among Chinese hospitalized cancer patients.

BACKGROUND: Epidemiological studies have shown increased risk of suicide in cancer patients compared with the general population. The present study aimed to examine the association between physical symptoms and suicidal ideation in Chinese hospitalized cancer patients and test the modifying effect of health self-efficacy on the association. METHODS: A cross-sectional study was conducted with 544 hospitalized cancer patients in two general hospitals in northeast China via face-to-face interviews. Suicidal ideation was measured by using the first four items on the Yale Evaluation of Suicidality scale and then dichotomized into a positive and negative score. Multivariate logistic regression analyses were conducted to examine the impacts of physical symptoms, health self-efficacy, and their interactions on suicidal ideation. RESULTS: The suicidal ideation rate was 26.3% in the enrolled cancer patients. Logistic regression showed that insomnia (aOR = 1.84, 95% CI 1.13 to 3.00, p = 0.015) and lack of appetite (aOR = 2.14, 95% CI 1.26 to 3.64, p = 0.005) were significantly associated with suicidal ideation. Low health self-efficacy had a marginally significant exaggerating effect on the association between pain and suicidal ideation (aOR = 2.77, 95% CI 0.99 to 7.74, p = 0.053), after adjusting for significant socio-demographics, clinical characteristics, and depression. CONCLUSIONS: These findings demonstrate significant associations between physical symptoms (insomnia and/or lack of appetite) and suicidal ideation and highlight the potential modifying role of health self-efficacy in the identification and prevention of suicide among cancer patients.

Current heterosexual marriage is associated with significantly decreased levels of anxiety symptoms among Chinese men who have sex with men.

BACKGROUND: The high heterosexual marriage rate could be a 'double-edge' sword for the emotional health of Chinese men who have sex with men (MSM). The aim of this study was to determine if current marriage and breakdown of marriage (divorce) have different effects on the mental health of Chinese MSM. METHODS: Eight hundred seven MSM were recruited using respondent-driven sampling from four cities in northeastern China. Gay-related stressful events (GRSE) were measured using the Gay Related Stressful Life Events Scale; social support was measured by the Social Support Rating Scale (SSRS); and depressive and anxiety symptoms were assessed using the Self-Rating Depression Scale (SDS) and Self-Rating Anxiety Scale (SAS), respectively. RESULTS: Of the study participants, 13.4% were married to women and 4.5% were divorced. The rates of marriage or divorce were 35.3 and 75.8% for participants 30-39 and > 40 years of age, respectively. The current married MSM had the highest SDS (50.0 ± 10.9) and SSRS (35.8 ± 8.6) levels, but the lowest SAS (38.7 ± 12.1) levels. Divorced MSM had the highest SAS (44.4 ± 9.6) and lowest SSRS (30.8 ± 8.1) levels. Age, GESE number, and HIV infection were predictors for SDS and SAS, and current marriage was associated with significantly decreased level of SAS (ß = - 0.136, P = 0.001) based on multiple linear analysis. CONCLUSIONS: Current marriage is associated with significantly decreased levels of anxiety symptoms among Chinese MSM. More studies are needed to understand the mechanisms underlying the effects of different marriage status on the emotional distress of Chinese MSM.

A single-tube sample preparation method based on a dual-electrostatic interaction strategy for molecular diagnosis of gram-negative bacteria.

A single-tube method based on a dual-electrostatic interaction (EI) strategy for bacteria capture and DNA extraction was designed to enable the highly sensitive detection of nucleic acids. Specially designed magnetic nanoparticles were developed to meet the opposing requirements of a single-tube method, which exist between the strong EI required for efficient bacteria capture and the weak EI required for DNA extraction with minimal DNA adsorption. A dual-EI strategy for the single-tube (DESIGN) method was thus developed to integrate bacteria enrichment, bacteria cell lysis, and DNA recovery in a single tube, thereby minimizing precious sample loss and reducing handling time. Subsequently, we evaluated the performance with a variety of concentrations from 5 to 100 colony-forming units (CFU)/10 mL human urine and milk samples. The DESIGN method achieved the simple and sensitive detection of Salmonella enterica serovar Typhimurium in 10 mL of human urine and milk samples up to 5 CFU by quantitative PCR. Furthermore, the DESIGN method detected Brucella ovis and Escherichia coli from 10 mL of human urine with a detection limit up to 5 CFU/10 mL. Graphical abstract.

Environmentally Robust Memristor Enabled by Lead-Free Double Perovskite for High-Performance Information Storage.

Memristors are emerging as a rising star of new computing and information storage techniques. However, the practical applications are severely challenged by their instability toward harsh conditions, including high moisture, high temperatures, fire, ionizing irradiation, and mechanical bending. In this work, for the first time, lead-free double perovskite Cs2 AgBiBr6 is utilized for environmentally robust memristors, enabling highly efficient information storage. The memory performance of the typical indium-tin-oxide/Cs2 AgBiBr6 /Au sandwich-like memristors is retained after 1000 switching cycles, 105 s of reading, and 104 times of mechanical bending, comparable to other halide perovskite memristors. Most importantly, the memristive behavior remains robust in harsh environments, including humidity up to 80%, temperatures as high as 453 K, an alcohol burner flame for 10 s, and 60 Co γ-ray irradiation for a dosage of 5 × 105 rad (SI), which is not achieved by any other memristors and commercial flash memory techniques. The realization of an environmentally robust memristor from Cs2 AgBiBr6 with a high memory performance will inspire further development of robust electronics using lead-free double perovskites.

Detection of NO2 Down to One ppb Using Ion-in-Conjugation-Inspired Polymer.

Nitrogen dioxide (NO2 ) emission has severe impact on human health and the ecological environment and effective monitoring of NO2 requires the detection limit (limit of detection) of several parts-per-billion (ppb). All organic semiconductor-based NO2 sensors fail to reach such a level. In this work, using an ion-in-conjugation inspired-polymer (poly(3,3'-diaminobenzidine-squarine, noted as PDBS) as the sensory material, NO2 can be detected as low as 1 ppb, which is the lowest among all reported organic NO2 sensors. In addition, the sensor has high sensitivity, good reversibility, and long-time stability with a period longer than 120 d. Theoretical calculations reveal that PDBS offers unreacted amine and zwitterionic groups, which can offer both the H-bonding and ion-dipole interaction to NO2 . The moderate binding energies (≈0.6 eV) offer high sensitivity, selectivity as well as good reversibility. The results demonstrate that the ion-in-conjugation can be employed to greatly improve sensitivity and selectivity in organic gas sensors by inducing both H-bonding and ion-dipole attraction.

Pseudohalide-Induced 2D (CH3 NH3 )2 PbI2 (SCN)2 Perovskite for Ternary Resistive Memory with High Performance.

Recently, organic-inorganic hybrid perovskites (OIHP) are studied in memory devices, but ternary resistive memory with three states based on OIHP is not achieved yet. In this work, ternary resistive memory based on hybrid perovskite is achieved with a high device yield (75%), much higher than most organic ternary resistive memories. The pseudohalide-induced 2D (CH3 NH3 )2 PbI2 (SCN)2 perovskite thin film is prepared by using a one-step solution method and fabricated into Al/perovskite film/indium-tin oxide (glass substrate as well as flexible polyethylene terephthalate substrate) random resistive access memory (RRAM) devices. The three states have a conductivity ratio of 1:103 :107 , long retention over 10 000 s, and good endurance properties. The electrode area variation, impedance test, and current-voltage plotting show that the two resistance switches are attributable to the charge trap filling due to the effect of unscreened defect in 2D nanosheets and the formation of conductive filaments, respectively. This work paves way for stable perovskite multilevel RRAMs in ambient atmosphere.

Generation of intensity-tunable structural color from helical photonic crystals for full color reflective-type display.

A new concept of intensity-tunable structural coloration is proposed on the basis of a helical photonic crystal (HPC). The HPCs are constructed from a mixture of chiral reactive mesogens by spin-coating, followed by the photo-polymerization. A liquid crystal (LC) layer, being homogeneously aligned, is prepared on the HPCs to serve as a tunable waveplate. The electrical modulation of the phase retardation through the LC layer directly leads to the intensity-tunable Bragg reflection from the HPCs upon the incidence of the polarized light. The bandwidths of the structural colors are found to be well preserved regardless of the applied voltage. A prototype of a full color reflective-type display, incorporated with three primary color units, is demonstrated. Our concept of decoupling two mutually independent functions, the intensity modulation by the tunable waveplate and the color reflection by the HPCs provides a simple and powerful way of producing a full color reflective-type display which possesses high color purity, high optical efficiency, the cycling durability, and the design flexibility.

Assembly of P3HT/CdSe nanowire networks in an insulating polymer host.

Nanoparticles may act as compatibilizing agents for blending of immiscible polymers, leading to changes in blend morphology through a variety of mechanisms including interfacial adsorption, aggregation, and nucleation of polymer crystals. Herein, we report an approach to define highly structured donor/acceptor networks based on poly(3-hexylthiophene) (P3HT) and CdSe quantum dots (QDs) by demixing from an insulating polystyrene (PS) matrix. The incorporation of QDs led to laterally phase-separated co-continuous structures with sub-micrometer dimensions, and promoted crystallization of P3HT, yielding highly interconnected P3HT/QD hybrid nanowires embedded in the polymer matrix. These nanohybrid materials formed by controlling phase separation, interfacial activity, and crystallization within ternary donor/acceptor/insulator blends, offer attractive morphologies for potential use in optoelectronics.

Ion-in-Conjugation: Squaraine as an Ultrasensitive Ammonia Sensor Material.

An organic thin-film gas sensor based on squaraine detects ammonia as low as 40 ppb with impressive reversibility and stability. The resonance-stabilized zwitterionic characteristics offer squaraines high affinity and sensitivity toward electron-rich analytes without irreversible chemical binding, while the embedded squaric ring makes SA-CH3 highly sensitive. The symmetric molecular geometry and good crystallinity also contribute to the high performance.

Better Organic Ternary Memory Performance through Self-Assembled Alkyltrichlorosilane Monolayers on Indium Tin Oxide (ITO) Surfaces.

Recently, surface engineering of the indium tin oxide (ITO) electrode of sandwich-like organic electric memory devices was found to effectively improve their memory performances. However, there are few methods to modify the ITO substrates. In this paper, we have successfully prepared alkyltrichlorosilane self-assembled monolayers (SAMs) on ITO substrates, and resistive random access memory devices are fabricated on these surfaces. Compared to the unmodified ITO substrates, organic molecules (i.e., 2-((4-butylphenyl)amino)-4-((4-butylphenyl)iminio)-3-oxocyclobut-1-en-1-olate, SA-Bu) grown on these SAM-modified ITO substrates have rougher surface morphologies but a smaller mosaicity. The organic layer on the SAM-modified ITO further aged to eliminate the crystalline phase diversity. In consequence, the ternary memory yields are effectively improved to approximately 40-47 %. Our results suggest that the insertion of alkyltrichlorosilane self-assembled monolayers could be an efficient method to improve the performance of organic memory devices.

Origami structures with a critical transition to bistability arising from hidden degrees of freedom.

Origami is used beyond purely aesthetic pursuits to design responsive and customizable mechanical metamaterials. However, a generalized physical understanding of origami remains elusive, owing to the challenge of determining whether local kinematic constraints are globally compatible and to an incomplete understanding of how the folded sheet's material properties contribute to the overall mechanical response. Here, we show that the traditional square twist, whose crease pattern has zero degrees of freedom (DOF) and therefore should not be foldable, can nevertheless be folded by accessing bending deformations that are not explicit in the crease pattern. These hidden bending DOF are separated from the crease DOF by an energy gap that gives rise to a geometrically driven critical bifurcation between mono- and bistability. Noting its potential utility for fabricating mechanical switches, we use a temperature-responsive polymer-gel version of the square twist to demonstrate hysteretic folding dynamics at the sub-millimetre scale.

Concept of active parallax barrier on polarizing interlayer for near-viewing autostereoscopic displays.

We proposed a concept of an active parallax barrier using a liquid crystal-on-polarizing interlayer (LPI) for near-viewing autostereoscopic displays. In contrast to a conventional two-panel configuration where two independent panels are stacked together for displaying and parallaxing purposes, a monolithic one-panel architecture was demonstrated with the help of the LPI. The LPI was constructed using a polarizer sheet, one side of which provided the support for the active parallax barrier and the other served as the substrate for the image panel. For the active parallax barrier, an array of periodically patterned indium-tin-oxide electrodes was first prepared on the LPI and bi-level structures were subsequently fabricated for the cell gap and the liquid crystal alignment. Our monolithic one-panel architecture allows the near-viewing distance property which is essential for mobile applications.

Grayscale gel lithography for programmed buckling of non-Euclidean hydrogel plates.

Shape programmable materials capable of morphing from a flat sheet into controlled three dimensional (3D) shapes offer promise in diverse areas including soft robotics, tunable optics, and bio-engineering. We describe a simple method of 'grayscale gel lithography' that relies on a digital micromirror array device (DMD) to control the dose of ultraviolet (UV) light, and therefore the extent of swelling of a photocrosslinkable poly(N-isopropyl acrylamide) (PNIPAm) copolymer film, with micrometer-scale spatial resolution. This approach allows for effectively smooth profiles of swelling to be prescribed, enabling the preparation of buckled 3D shapes with programmed Gaussian curvature.

Prevalence and risk factors for lifetime suicide ideation, plan and attempt in Chinese men who have sex with men.

BACKGROUND: To describe the level and risk factors for suicidal behaviors in Chinese men who have sex with men (MSM). METHODS: A total of 807 MSM were recruited using a respondent-driven sampling method from Anshan, Benxi, Dandong, and Shenyang cities in northeastern China. RESULTS: Chinese MSM had lifetime prevalences of suicide ideation (18.3%), plan (8.7%) and attempt (4.6%) that were about 2.8, 5.8 and 5.8 times greater than that of male adults in the general population of China. The MSM with any psychiatric disorders were 4-7 times more likely to think about, plan or attempt suicide than those MSM with no disorder, and there was a clear relationship between the number of comorbid disorders and suicidal behaviors. Multiple regression analysis showed that major depression, bipolar disorder, dysthymia and alcohol use disorder significantly increased the risk for suicide ideation, but not for suicide attempt. Drug dependence disorder, panic disorder and generalized anxiety disorder significantly increased the risk for suicide attempt, but not for suicide ideation. More advanced education reduced the risk of suicidal behaviors, sexual orientations revealed to or discovered by family members or friends significantly increased risk of these suicidal behaviors. CONCLUSIONS: Chinese MSM have significantly increased risk for suicidal behaviors, mental disorders and their comorbidities could be the largest risk factors for the elevated suicidal behaviors in Chinese MSM. Reducing the family and social stigma and rejection of homosexual behavior and early detection and effective treatment of psychiatric disorders and their comorbidities in MSM may help to decrease suicidal behaviors of Chinese MSM.

Self-organized wrinkling patterns of a liquid crystalline polymer in surface wetting confinement.

Self-organized wrinkling patterns of a liquid crystalline polymer, dictated by the chemico-physically anisotropic nature of surface wettability, are demonstrated in confined geometries. The symmetry of the geometrical constraints of the confinement primarily governs the periodic wrinkling patterns of such a polymer in the wetting region. In a circular geometry, the number of the radial domains with multi-fold symmetries is linearly proportional to the radius of the confinement. The physical origin of the wrinkling process comes from the periodic bend-splay distortions through the relaxation of the curvature elasticity.