113Gbps rainbow visible light laser communication system based on 10λ laser WDM emitting module in fiber-free space-fiber link.

With the advent of the sixth-generation mobile communication standard (6 G), the visible light communication (VLC) technology based on wavelength division multiplexing (WDM) technology can effectively solve the problem of shortage of spectrum resources and insufficient channel capacity. This paper introduces one of our technical achievements, namely the construction of a near-real-time visible light laser communication (VLLC) system based on WDM, which includes a self-designed 10-λ fully-packaged visible light laser emission module, 1 m multimode fiber - 0.175 m free space - 1 m multimode fiber optical transmission link, and receiver array. In the transmitter system, we adopt adaptive discrete multitone (DMT) modulation technique combined with Quadrature Amplitude Modulation (QAM) modulation scheme to obtain maximum spectral efficiency (SE). In the receiving system, we utilize the sparse-structured reservoir computing post-equalization algorithm to achieve superior equalization performance on the basis of the traditional post-equalization algorithm. The experimental results indicate that this quasi-real-time communication system has achieved a signal transmission rate of 113.175Gbps. To the best of our knowledge, this work has set a record in the field of high-speed visible light laser communication. Therefore, the laser communication system constructed by this work, with its flexibility in deployment and high-speed performance, demonstrates the significant potential application of visible light laser communication in data center interconnection and high-speed indoor access networks.

15.26Gb/s Si-substrate GaN high-speed visible light photodetector with super-lattice structure.

In this paper, we studied a series of high-speed photodetectors (PD) with different super-lattice interlayer periods and the scale of the effective area to examine their communication performance. The mini-PDs are designed with a single 1 mm × 1 mm effective area. The mini-PDs have three different super-lattice (SL) periods in the interlayer: 8, 15, and 32. The micro-PD sample has multiple 50um by 50um photosensitive areas that form a 4 × 4 receiver array, which shares a common N electrode. Its SL period is 26. The experiment shows that mini-PDs have the advantages such as better tolerance to beam spot deviation, larger field of view (FoV), higher responsibility, and wider peak width in spectral response. But micro-LED samples outperform the others in communication capacity and wavelength selectivity. The 8, 15, and 32 SL mini-PD samples achieve 6.6, 7.3, and 8.8 Gb/s data rates, respectively. The micro-PD gains the maximum data rate of 14.38Gb/s without applying waveform level post-equalization, and 15.26Gb/s after using an NN-based post-equalizer. This experiment shows that with proper DSP, GaN-based PD would be suitable for high-speed VLC systems, especially for the short wavelength spectrum in visible light.

Construction and Validation of the Postgraduate Research Innovation Ability Scale (PRIAS): A Three-Dimensional Structural Model Based on Componential Theory of Creativity.

Purpose: To explore the structure of postgraduate research innovation ability and verify the Postgraduate Research Innovation Ability Scale. Patients and Methods: This study was based on the componential theory of creativity. First, we drafted an item pool from the literature review, semi-structured interviews, and group discussions. A total of 125 postgraduates were selected for the pre-test. After item selection and exploratory factor analysis, an 11-item, 3-factor postgraduate research innovation ability scale was formed. The scale was applied to a sample of 330 postgraduates from various domestic universities. Exploratory factor analysis and confirmatory factor analysis were used to examine the factor structure of the scales. Results: The results support a three-factor model including creativity-relevant processes, domain-relevant skills, and intrinsic motivation for the Postgraduate Research Innovation Ability Scale. The scale showed good internal consistency (α =0.89) and test-retest reliability (r=0.86). Exploratory factor analysis showed that the KMO value was 0.87, and the Bartlett's sphericity test results were significant. Confirmatory factor analysis confirmed that the three-factor construct demonstrated a good model fit (χ2/df=1.945, GFI=0.916, CFI=0.950, RMSEA=0.076). Conclusion: The Postgraduate Research Innovation Ability Scale has good reliability and validity, and it can be used for future research in related fields.

Modulation format recognition in a UVLC system based on reservoir computing with coordinate transformation and folding algorithm.

Modulation format recognition (MFR) is one of the key technologies in adaptive optical systems and widely used in both commercial and civil applications. With the rapid development of deep learning, MFR algorithm based on neural networks (NN) has achieved impressive success. Due to the high complexity of underwater channels, to gain better performance of MFR tasks in underwater visible light communication (UVLC), the NN tend to be designed with a complex structure, which is costly in computation and hinders fast allocation and real-time processing. In this paper, we propose a lightweight and efficient method based on reservoir computing (RC), whose trainable parameters are only 0.3% of common NN-based methods. To improve the performance of RC in MFR tasks, we propose powerful feature extraction algorithms including coordinate transformation and folding algorithm. The proposed RC-based methods are implemented for six modulation formats, including OOK, 4QAM, 8QAM-DIA, 8QAM-CIR, 16APSK, and 16QAM. The experimental results show that our RC-based methods take only a few seconds for training process and under different pin voltages of LED, the accuracy for almost all exceeds 90%, and the highest is close to 100%. Analysis on how to design a well-performed RC to strike a balance between accuracy and time cost is also investigated, providing a useful guide for RC implementations in MFR.

Effect of Green Plants on Individuals' Mental Stress during the COVID-19 Pandemic: A Preliminary Study.

The COVID-19 pandemic has not only jeopardized people's physical health, but also put additional strain on their mental health. This study explored the role of indoor natural elements (i.e., green plants) in relieving individuals' mental stress during a prolonged stressful period. A pilot and three formal studies examined the effect of indoor green plants placed in living and working environments on people's perceived stress during the pandemic and further uncovered its underlying mechanism emphasizing a mediating role of emotion. The pilot study confirmed that the severity of the pandemic positively correlated with individuals' level of stress. Study 1 then demonstrated that indoor green plants in people's living environments might reduce their perceived stress during the pandemic, which is referred to as the "plant effect". Study 2 repeated the plant effect in a field experiment conducted in a working environment and Study 3 revealed a mediating role of positive emotion. This study provides preliminary evidence for the mitigating effect of indoor green plants on individuals' mental stress during the COVID-19 pandemic period. The indoor green plants placed in living and working environments may elicit positive emotion, which in turn reduce people's mental stress. In addition, our results reveal that growth status of the indoor green plants affected the plant effect as well.

Irrational Consumption during the COVID-19 Period.

The outbreak of the COVID-19 pandemic has severely impacted the world economy and has, most presumably, exerted a great deal of stress on citizens, in turn leading to the call for timely assessments of how this period might actually impact individuals at the level of everyday well-being and in their behaviors such as consumer decisions. Through one pilot study and two online survey studies, we tentatively investigated this latter question, and demonstrated that the COVID-19 pandemic may increase perceived stress and impair individuals' sleep quality, which in turn impels their irrational consumption. This research provides preliminary evidence for the impact of the present pandemic on irrational consumption and contributes to the literature on stress and consumer behavior.

Self-Handicapping in Chinese Medical Students During the COVID-19 Pandemic: The Role of Academic Anxiety, Procrastination and Hardiness.

Background: In the face of the 2019 Coronavirus Disease (COVID-19) outbreak, Chinese medical students worried about their future studies which might make them more susceptible to academic anxiety. Previous studies have shown that academic anxiety is an important risk factor for self-handicapping, but there are few studies to explore the relationship between the two which may be mediated or moderated by other variables. Therefore, this study investigated how Chinese medical students' academic anxiety is correlated to their self-handicapping in time of COVID-19 epidemic, and explored the moderating and mediating effects of hardiness and procrastination. Methods: In this study, 320 Chinese medical students' psychological traits were measured with Academic Anxiety Questionnaire, Self-Handicapping Scale, General Procrastination Scale and Hardiness Scale to explore the potential associations between these variables. Results: The most obvious finding to emerge from this study was that self- handicapping had a positive correlation with academic anxiety and procrastination, but had a negative correlation with hardiness; hardiness had a negative association with academic anxiety and procrastination; and academic anxiety and procrastination were positively correlated. In addition, the relationship between academic anxiety and self-handicapping of Chinese medical students was not only partially mediated by procrastination, but also moderated by hardiness. Furthermore, medical students who had lower hardiness had stronger direct effect, while the indirect effect was strong at high and low conditions of hardiness. Conclusion: In time of the COVID-19 epidemic, the academic anxiety and self-handicapping of medical students are influenced by procrastination and hardiness to a great extent. Thus, in addition to suggesting that more attention should be paid to the academic anxiety and procrastination of medical students, in the future, more attention should be paid to cultivating the hardiness of medical students and exerting its interventional role in self-handicapping.

Influence of Sand-Cement Ratio and Polycarboxylate Superplasticizer on the Basic Properties of Mortar Based on Water Film Thickness.

Previous studies demonstrated that water film thickness (WFT) is a key factor that affects the fluidity of mortar. Changes in the sand-cement (S/C) ratio and polycarboxylate superplasticizer (PCE) dosage will affect the WFT. In this study, several mortar samples with different S/C ratios and different PCE dosages were prepared, and the basic properties of the mortar were measured. The results show that as the S/C ratio increases, the packing density of the mortar will decrease, the WFT will decrease, and the cohesiveness will increase, resulting in a decrease in the flow spread and strength of the mortar. When the PCE dosage is increased, the packing density of the mortar will increase, the WFT will increase, and the cohesiveness will decrease, which increases the flow spread of the mortar. When the water-cement (W/C) ratio is low, the S/C ratio has a significant effect on the strength, and the strength will increase with the increasing of the PCE dosage. When the W/C ratio is high, the strength of the mortar will be reduced once the PCE dosage exceeds the saturation value. In the case of different S/C ratios or different PCE dosages, the WFT can be used as a measure of mortar cohesiveness and flow spread.

Effects of PCE on the Dispersion of Cement Particles and Initial Hydration.

The effects of polycarboxylate superplasticizers (PCEs) on the dispersing properties and initial hydration of cement particles with various water-to-cement (w/c) ratios was investigated, including the water film thickness (WFT), rheology, fluidity, adsorption of PCEs, zeta potential, degree of hydration, hydration products. The experimental results demonstrate that the initial rheological and fluidity parameters were more sensitive to the PCE dosage at a lower w/c because the WFT and the zeta potential on cement particles change more significantly. Moreover, the higher adsorption amounts of the PCEs at a lower w/c lead to a stronger inhibition of the initial hydration, whilst, at the same PCE dosage, the cement pastes have a more rapid fluidity loss and quicker hydration reactions at a higher w/c due to a lower adsorption amount of the PCE on cement particles.

Impact of the Perceived Mental Stress During the COVID-19 Pandemic on Medical Students' Loneliness Feelings and Future Career Choice: A Preliminary Survey Study.

The outbreak of the COVID-19 epidemic continues to unfold globally, and its negative impact on the public's mental health is starting to reveal. Serving as reserve talents for the healthcare system, medical students are not yet professionally matured enough to face one of the worst global public health crises. This may exert increased mental stress and loneliness feelings, which in turn negatively influence medical students' future career choice. To address the issue, we conducted three online survey studies investigating how the epidemic affects the mental health as well as career attitude of medical students in China during the COVID-19 pandemic outbreak. The results revealed preliminary evidence showing that the perceived stress induced by the COVID-19 epidemic might negatively affect medical students' future career choice, and the feeling of loneliness may play a mediating role. This study invites more attention to medical students' mental health during severe public health crisis such as the COVID-19 pandemic.

Genome-wide association study of antipsychotic-induced sinus bradycardia in Chinese schizophrenia patients.

Second-generation antipsychotics (SGAs) play a critical role in current treatment of schizophrenia (SCZ). It has been observed that sinus bradycardia, rare but in certain situations life threatening adverse drug reaction, can be induced by SGAs across different schizophrenia populations. However, the roles of genetic factors in this phenomenon have not been studied yet. In the present study, a genome-wide association study of single nucleotide polymorphisms (SNPs) was performed on Chinese Han SCZ patients to identify susceptibility loci that were associated with sinus bradycardia induced by SGAs. This study applied microarray to obtain genotype profiles of 88 Han Chinese SCZ patients. Our results found that there were no SNPs had genome-wide significant association with sinus bradycardia induced by SGAs. The top GWAS hit located in gene KIAA0247, which mainly regulated by the tumor suppressor P53 and thus plays a role in carcinogenesis based on resent research and it should not be a susceptibility locus to sinus bradycardia induced by SGAs. Using gene-set functional analysis, we tested that if top 500 SNPs mapped genes were relevant to sinus bradycardia. The result of gene prioritization analysis showed CTNNA3 was strongly correlated with sinus bradycardia, hinting it was a susceptibility gene of this ADR. Our study provides a preliminary study of genetic variants associated with sinus bradycardia induced by SGAs in Han Chinese SCZ patients. The discovery of a possible susceptibility gene shed light on further study of this adverse drug reaction in Han Chinese SCZ patients.

Synapse-associated protein 90/postsynaptic density-95-associated protein (SAPAP) is expressed differentially in phencyclidine-treated rats and is increased in the nucleus accumbens of patients with schizophrenia.

Phencyclidine (PCP) induces a psychotomimetic state that closely resembles schizophrenia. Therefore, PCP-treated animals can provide a model for schizophrenia. Using differential display, we identified a gene regulated by the delayed action of PCP in rat nucleus accumbens (NAcs). Sequence analysis showed that the cDNA clone obtained was identical to rat synapse-associated protein 90/postsynaptic density-95-associated protein 1 (SAPAP1). Quantitative reverse transcriptase (RT)-PCR analysis showed that SAPAP1 mRNA had increased significantly in rat NAc (P<0.0001) and hippocampus (P<0.01) 24 h after a PCP (10 mg/kg) injection as compared to the controls. Immunoquantification using an anti-SAPAP1 antibody indicated that immunoreactivity for SAPAP1 increased significantly (P&<0.05) in the NAcs of unmedicated patients with schizophrenia, as compared to the control subjects and medicated patients with schizophrenia. Our findings support the hypothesis that there is abnormal glutamatergic neurotransmission in schizophrenia and show evidence of abnormalities in the intracellular signal transduction via N-methyl-D-aspartate (NMDA) receptors.

Decreased calcineurin and increased phosphothreonine-DARPP-32 in the striatum of rats behaviorally sensitized to methamphetamine.

We investigated changes in signal transduction via calcineurin (CaN) in the striatum of rats behaviorally sensitized to methamphetamine (Meth). The rats were injected with Meth (4 mg/kg, s.c.) five times a week for 3 weeks and then were given a challenge dose of Meth (2 mg/kg, s.c.). Seven days after the challenge test, we determined the levels of CaN Aalpha and Abeta by Western blotting. We further immunoquantified DARPP-32 (dopamine- and cAMP-regulated phosphoprotein, mw 32,000) and phosphothreonine-DARPP-32, which can be dephosphorylated at threonine sites by CaN. We found that both CaN Aalpha and Abeta were significantly decreased in the particulate fractions but were not changed in the soluble fractions from the striatum of Meth-sensitized rats as compared with control rats. The same findings were observed in the striatum of rats 6 h after the injection of PCP (10 mg/kg, s.c.). In the striatum of Meth-sensitized rats, phosphothreonine-DARPP-32 immunoreactivities significantly increased, but DARPP-32 immunoreactivities were not significantly different from those of the control rats. These results indicate that the activity of signal transduction via CaN is functionally decreased in the striatum of Meth-sensitized rats.

Differential changes in glutamatergic transmission via N-methyl-D-aspartate receptors in the hippocampus and striatum of rats behaviourally sensitized to methamphetamine.

We searched for changes in glutamatergic transmission via N-methyl-D-aspartate (NMDA) receptors in the hippocampus and striatum of rats behaviourally sensitized to methamphetamine (Meth). Prior to being given a challenge dose of Meth (2 mg/kg, s.c.), the rats were given Meth (4 mg/kg, s.c.) five times a week for 3 wk. Seven days after the challenge test, we examined glutamate (Glu) release from hippocampal and striatal slices evoked by 30 mm KCl, and NMDA-evoked dopamine (DA) release from striatal slices. We further immunoquantified NMDAR1, R2A and R2B receptors as well as the fodrin alpha-subunit, a 240 kDa cytoskeletal protein that is cleaved to form 150 kDa limited proteolytic fragments by NMDA receptor stimulation. In the study of KCl-evoked Glu release, Glu release from the hippocampus was 31% lower in the Meth-sensitized rats than in the control rats, while Glu release from the striatum was 34% higher in the Meth-sensitized rats. NMDAR1, R2A and R2B immunoreactivities in the striatum were significantly lower in the Meth-sensitized rats (by 12, 13 and 12%, respectively) than those in the control rats. However, no differences in the immunoreactivities were found for the hippocampus. Immunoquantification of the fodrin alpha-subunit in the hippocampus revealed that 150 kDa fragments were significantly lower (by 10%) in the Meth-sensitized rats than in the control rats. In contrast to the control rats, NMDA-evoked DA release from the striatum was diminished in the Meth-sensitized rats. These results indicate that the activity of the Glu system is functionally decreased in the hippocampus of Meth-sensitized rats, whereas the Glu system in the striatum of Meth- sensitized rats shows adaptive and functional changes in the receptors in response to the increased Glu release.