Machine Learning Enhanced Optical Microscopy for the Rapid Morphology Characterization of Silver Nanoparticles.

The rapid characterization of nanoparticles for morphological information such as size and shape is essential for material synthesis as they are the determining factors for the optical, mechanical, and chemical properties and related applications. In this paper, we report a computational imaging platform to characterize nanoparticle size and morphology under conventional optical microscopy. We established a machine learning model based on a series of images acquired by through-focus scanning optical microscopy (TSOM) on a conventional optical microscope. This model predicts the size of silver nanocubes with an estimation error below 5% on individual particles. At the ensemble level, the estimation error is 1.6% for the averaged size and 0.4 nm for the standard deviation. The method can also identify the tip morphology of silver nanowires from the mix of sharp-tip and blunt-tip samples at an accuracy of 82%. Furthermore, we demonstrated online monitoring for the evolution of the size distribution of nanoparticles during synthesis. This method can be potentially extended to more complicated nanomaterials such as anisotropic and dielectric nanoparticles.

A Snakeskin-Inspired, Soft-Hinge Kirigami Metamaterial for Self-Adaptive Conformal Electronic Armor.

A majority of soft-body creatures evolve armor or shells to protect themselves. Similar protection demand is for flexible electronics working in complex environments. Existing works mainly focus on improving the sensing capabilities such as electronic skin (E-skin). Inspired by snakeskin, a novel electronic armor (E-armor) is proposed, which not only possesses mechanical flexibility and electronic functions similar to E-skin, but is also able to protect itself and the underlying soft body from external physical damage. The geometry of the kirigami mechanical metamaterial (Kiri-MM) ensures auxetic stretchability and meanwhile large areal coverage for sufficient protection. Moreover, to suppress the inherent but undesired out-of-plane buckling of conventional Kiri-MMs for conformal applications, soft hinges are used to form a distinct soft (hinges)-rigid (tiles) configuration. Analytical, computational, and experimental studies of the mechanical behaviors of the soft-hinge Kiri-MM E-armor demonstrate the merits of this design, i.e., stretchability, conformability, and protectability, as applied to flexible electronics. Deploying a conductive soft material at the hinges enables facile wiring strategies for large-scale circuit arrays. Functional E-armor systems for controllable display and sensing purposes provide simple examples of a wide spectrum of applications of this concept.

Differences in School Performance Between Only Children and Non-only Children: Evidence From China.

This study aimed to investigate the features of only child status related to physical health, mathematics achievement, and school feelings and expectations from a different perspective. A representative sample of 91,619 Grade 4 students with an average age of 10.4 ± 0.7, among which 28,631 were only children, were assessed. We used propensity score matching (PSM) and the average treatment effects on the treatment to analyze data. The treatment was the only child of a family. The results indicated that only children have better academic achievement and school feelings (only for urban only child girls), while non-only children have better physical status and anaerobic fitness (AF). In addition, gender and rural vs. urban areas differences were also explored. The adverse situation for rural only boys is emphasized for families, researchers, and governments to focus on. Some suggestions are given under the Two- and Three-Child Policy.

Decreased Plasma Levels of Growth Differentiation Factor 11 in Patients With Schizophrenia: Correlation With Psychopathology and Cognition.

Schizophrenia is linked with abnormal neurodevelopment, on which growth differentiation factor 11 (GDF-11) has a great impact. However, a direct evidence linking GDF-11 to the pathophysiology of schizophrenia is still lacking. The current study aimed to investigate the relationship between plasma GDF-11 levels and both psychopathological symptoms and cognitive function in schizophrenia. Eighty-seven schizophrenia patients and 76 healthy controls were enrolled in the present study. The symptomatology of schizophrenia was evaluated using the Positive and Negative Syndrome Scale (PANSS). Cognitive function was assessed by Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) including twelve neurocognitive tests in five aspects of cognitive function. Plasma GDF-11 levels were determined by enzyme-linked immunosorbent assay (ELISA). We found that plasma levels of GDF-11 were significantly lower in schizophrenia patients relative to healthy controls. Correlation analysis showed significant negative correlations between the GDF-11 levels and the PANSS total score, the positive symptoms score, the negative symptoms score or the general score. Additionally, positive associations were observed between plasma GDF-11 levels and the visuospatial/constructional, attention, immediate memory, or delayed memory in patients. Partial correlation analysis showed that these correlations were still significant after adjusting for age, gender, education years, body mass index, duration of illness, and age of onset except for the visuospatial/constructional and attention index. Multiple regression analysis revealed that GDF-11 was an independent contributor to the immediate memory, delayed memory and RBANS total score in patients. Collectively, the correlations between plasma GDF-11 and psychopathological and cognitive symptoms suggest that abnormal GDF-11 signaling might contribute to schizophrenic psychopathology and cognitive impairments and GDF-11 could be a potential and promising biomarker for schizophrenia.

Electrodeposition of Ni3Se2/MoSex as a bifunctional electrocatalyst towards highly-efficient overall water splitting.

Electrochemically splitting water into hydrogen and oxygen plays a significant role in the commercialization of hydrogen energy as well as fuel cells, but it remains a challenge to design and fabricate low-cost and high-efficiency electrocatalysts. Herein, we successfully prepared Ni3Se2/MoSex on nickel foam via a facile electrodeposition method. To understand the electrochemical mechanism occurring in the electrodeposition process, a new model was proposed, providing insight into the nucleation and growth of deposited materials. The as-prepared Ni3Se2/MoSex exhibits splendid electrochemical performance with 82 mV and 270 mV overpotentials to drive a current density of 10 mA cm-2 in 1 M KOH aqueous solution for HER and OER, respectively. Moreover, a driving potential of 1.57 V is required to reach a current density of 10 mA cm-2 for a configured full cell with Ni3Se2/MoSex working as both the anode and cathode towards overall water splitting, outperforming the state-of-the-art commercial full cells assembled with noble-based metals. The advanced catalytic performance should be attributed to the numerous in situ formed interfaces, allowing π-electron transfer from Ni to Mo via O2- bridging, subsequently optimizing the adsorption features of oxygenated species (OER) and favorable Volmer/Heyrovsky reaction (HER). This work offers an effective and scalable fabrication prototype for the preparation of bifunctional electrocatalysts with electrodeposition.

The Effect of Social-Emotional Competency on Child Development in Western China.

This study investigated the effects of social-emotional competency on pupils' academic achievement, academic emotions and attitudes, and interpersonal relationships. Participants were 7106 fourth-grade and fifth-grade students in western China. The results were: (1) social-emotional competency positively predicted pupils' academic achievement (including reading, mathematics, and science); (2) social-emotional competency predicted pupils' academic emotions and attitudes, including learning anxiety and interest, and academic emotions and attitudes played a mediating role in the relation between social-emotional competency and academic achievement; and (3) social-emotional competency positively predicted pupils' interpersonal relationships, including peer relationships and teacher-student relationships, and interpersonal relationships played a mediating role in the relation between social-emotional competency and academic achievement. These findings highlighted the importance of social-emotional competency to child development in western China, where many children might lack their parents' company.

Relationship of Physical Education Curriculum Implementation and Mathematics Achievement in Chinese Youth.

PURPOSE: Previous studies indicated a positive association between physical education (PE) and mathematics achievement (MA). This study explored how PE curriculum implementation relates to MA using data from the China National Assessment of Education Quality (CNAEQ) in 2015, including Mathematics (CNAEQ-MA 2015) as well as Physical Education & Health (CNAEQ-PEH 2015). METHOD: This study included 22,619 students (48.7% girls) age 13.96 ± 0.64 yr. from the national sample of Grade 8 students from CNAEQ. During 2015, MA and cardiorespiratory fitness (CF) were assessed. PE curriculum implementation, personal hygiene, eating habits, PE interest, mathematics interest, and self-confidence were collected via a self-report student survey. Personal hygiene and eating habits were combined to create the latent variable, healthy lifestyle (HL). Structural equation modeling was applied to examine the associations. Socioeconomic status, school location, Body Mass Index (BMI), and sex were all controlled. RESULTS: PE curriculum implementation had an indirect, positive association with MA through CF, HL-mathematics interest, and HL-mathematics self-confidence. Together, the model explained 27.8% of the variance in MA. CONCLUSION: PE curriculum implementation may benefit mathematics education, and this link is mainly through HL, CF, mathematics interest, and self-confidence.

"Cuju"-Structured Iron Diselenide-Derived Oxide: A Highly Efficient Electrocatalyst for Water Oxidation.

Electrocatalysts with outstanding performance have been highly desired toward exploration of new energy storage and conversion devices/systems as well as making an efficient and eco-friendly utilization of green energy. In this study, we composed an iron-based binary diselenide-derived oxide (Fe-SDO) with a facile one-step hydrothermal method to utilize the earth-abundant iron and the probably prosperous catalytic performance of metal-selenides compounds. The catalyst exhibits an overpotential of 226 mV at a current density of 10 mA/cm2, a Tafel slope of 41 mV dec-1, and robust durability after catalyzing vigorous OER for 36 h constantly. Through several analytical methods conducted before and after the oxygen evolution reaction activation on FeSe2 it was discovered that such catalyst possessed a morphology as "Cuju"-like balls with porosity inside in which we explored the vacancy defects and lattice distortion that play significant roles in generating the high electrocatalytic performance of our proposed catalyst by inducing remarkable electron conductivity in the porous Cuju balls (a Chinese traditional football). Throughout our work the superb electrocatalyst performance of the iron-based compounds was demonstrated, and subsequently the underlying reason for such electrocatalyst performance was addressed, which may push boundaries for the exploration of iron-based compounds as OER catalyst and large-scale commercial application of such compounds in the future.