Research on duplex underwater wireless laser communication system

To improve the bit error rate (BER) of underwater wireless laser communication and increase communication speed, a duplex underwater wireless laser communication system is designed. The system uses both blue and green lasers to transmit signals simultaneously, and adopts an improved modulation and demodulation algorithm to achieve separate modulation of the two sets of signals. A duplex underwater wireless laser communication system builds based on 440 and 550 nm lasers. On the basis of analyzing the absorption and scattering characteristics of seawater in laser communication, the influence of turbulence on communication efficiency is discussed. Improved the traditional duplex modulation algorithm and conducted communication testing at a depth of 2.0 m underwater. The experimental results show that when the communication distance increases from 5 to 50 m, the BER of the unoptimized duplex mode increases from 2.34 × 10−7 to 3.5 × 10−5. After adopting the optimization algorithm, the BER increases from 2.81 × 10−7 to 1.18 × 10−6, and the signal attenuation has been significantly suppressed. The duplex communication structure and algorithm can effectively reduce the impact of communication distance on bit BER

Understanding public transport satisfaction in post COVID-19 pandemic

The influence of the COVID-19 pandemic will linger for an extended period, although it is under control and public transport is gradually resuming its operations. However, there is limited understanding of passengers\u27 construal regarding this public health crisis and their perceptions of safety and feelings of satisfaction toward public transport after suffering through the spread of such an infectious disease. Therefore, the aim of this research is to understand passengers\u27 psychological responses to the pandemic over time in terms of their emotional arousal and mental construal, as public transport begins to resume its operations with the pandemic almost entirely contained. A cross-sectional survey was conducted in eight cities of China where the public transport system had been temporally closed because of the pandemic. The results indicated that (1) passengers\u27 feelings of safety enhanced their overall satisfaction with regard to public transport, (2) state anxiety has a negative effect on perceived safety, (3) state anxiety increases as passengers are psychologically closer to the pandemic, and (4) passengers pay more attention to information that is psychologically closer to the pandemic and perceive lesser safety on public transport. These findings not only reveal the internal mechanisms behind how passengers perceive safety but may also provide significant information for future disaster emergency management. Based on the results, some feasible suggestions are proposed to avoid the loss of ridership and help public transport systems recover from the crisis

Battery capacity design for electric vehicles considering the diversity of daily vehicles miles traveled

In this paper, we study battery capacity design for battery electric vehicles (BEVs). The core of such design problems is to find a good tradeoff between minimizing the capacity to reduce financial costs of drivers and increasing the capacity to satisfy daily travel demands. The major difficulty of such design problems lies in modeling the diversity of daily travel demands. Based on massive trip records of taxi drivers in Beijing, we find that the daily vehicle miles traveled (DVMT) of a driver (e.g., a taxi driver) may change significantly in different days. This investigation triggers us to propose a mixture distribution model to describe the diversity in DVMT for various driver in different days, rather than the widely employed single distribution model. To demonstrate the merit of this new model, we consider value-at-risk and mean-variance battery capacity design problems for BEV, with respect to conventional single and new mixture distribution models of DVMT. Testing results indicate that the mixture distribution model better leads to better solutions to satisfy various drivers.This is a manuscript of an article published as Li, Zhiheng, Shan Jiang, Jing Dong, Shoufeng Wang, Zhennan Ming, and Li Li. "Battery capacity design for electric vehicles considering the diversity of daily vehicles miles traveled." Transportation Research Part C: Emerging Technologies 72 (2016): 272-282. DOI: 10.1016/j.trc.2016.10.001. Posted with permission.</p

Vinpocetine Inhibits NF-κB-Dependent Inflammation in Acute Ischemic Stroke Patients

Immunity and inflammation play critical roles in the pathogenesis of acute ischemic stroke. Therefore, immune intervention, as a new therapeutic strategy, is worthy of exploration. Here, we tested the inflammation modulator, vinpocetine, for its effect on the outcomes of stroke. For this multi-center study, we recruited 60 patients with anterior cerebral circulation occlusion and onset of stroke that had exceeded 4.5 h but lasted less than 48 h. These patients, after random division into two groups, received either standard management alone (controls) or standard management plus vinpocetine (30 mg per day intravenously for 14 consecutive days, Gedeon Richter Plc., Hungary). Vinpocetine treatment did not change the lymphocyte count; however, nuclear factor kappa-light-chain-enhancer of activated B cell activation was inhibited as seen not only by the increased transcription of IκBα mRNA but also by the impeded phosphorylation and degradation of IκBα and subsequent induction of pro-inflammatory mediators. These effects led to significantly reduced secondary lesion enlargement and an attenuated inflammation reaction. Compared to controls, patients treated with vinpocetine had a better recovery of neurological function and improved clinical outcomes during the acute phase and at 3-month follow-up. These findings identify vinpocetine as an inflammation modulator that could improve clinical outcomes after acute ischemic stroke. This study also indicated the important role of immunity and inflammation in the pathogenesis of acute ischemic stroke and the significance of immunomodulatory treatment. CLINICAL TRIAL REGISTRATION INFORMATION: www.clinicaltrials.gov . Identifier: NCT02878772

Laparoendoscopic single-site surgery for deep infiltrating endometriosis based on retroperitoneal pelvic spaces anatomy: a retrospective study

Abstract Transumbilical single-port laparoscopy is widely used in gynecological surgery. However, it is rarely used in the treatment of deep infiltrating endometriosis due to its own shortcomings and the complex condition of deep infiltrating endometriosis. The study aims to introduce a transumbilical single-port laparoscopic surgery based on retroperitoneal pelvic spaces anatomy, which can complete the operation of deep infiltrating endometriosis more easily. A retrospective analysis of 63 patients with deep infiltrating endometriosis treated by transumbilical single-port laparoscopy using this method was conducted. The operation duration was 120.00 (85.00 ± 170.00) (35–405) min, the estimated blood loss was 68.41 ± 39.35 ml, the postoperative hospital stay was 5.00 (4.00–6.00) days, and the incidence of postoperative complications was 4.76% (3/63). 1 patient was found to have intestinal injury during operation, 1 patient had ureteral injury after operation, and 1 patient had postoperative pelvic infection, with a recurrence rate of 9.52%. The postoperative scar score was 3.00 (3.00–4.00) and the postoperative satisfaction score was 9.00 (8.00–10.00). In summary, this study demonstrates the feasibility of transumbilical single-port laparoscopic surgery for deep infiltrating endometriosis based on retroperitoneal pelvic spaces anatomy. Hysterectomy, adenomyosis resection, etc. are also feasible with this method, boasting more obvious advantages. This method can make transumbilical single-port laparoscopy more widely used in deep infiltrating endometriosis

Development of chitosan/gelatin hydrogels incorporation of biphasic calcium phosphate nanoparticles for bone tissue engineering

The chitosan/gelatin hydrogel incorporated with biphasic calcium phosphate nanoparticles (BCP-NPs) as scaffold (CGB) for bone tissue engineering was reported in this article. Such nanocomposite hydrogels were fabricated by using cycled freeze-thawing method, of which physicochemical and biological properties were regulated by adjusting the weight ratio of chitosan/gelatin/BCP-NPs. The needle-like BCP-NPs were dispersed into composites uniformly, and physically cross-linked with chitosan and gelatin, which were identified via Scanning Electron Microscope (SEM) images and Fourier Transform Infrared Spectroscopy (FT-IR) analysis. The porosity, equilibrium swelling ratio, and compressive strength of CGB scaffolds were mainly influenced by the BCP-NPs concentration. In vitro degradation analysis in simulated body fluids (SBF) displayed that CGB scaffolds were degraded up to at least 30 wt% in one month. Also, CCK-8 analysis confirmed that the prepared scaffolds had a good cytocompatibility through in culturing with bone marrow mesenchymal stem cells (BMSCs). Finally, In vivo animal experiments revealed that new bone tissue was observed inside the scaffolds, and gradually increased with increasing months, when implanted CGB scaffolds into large necrotic lesions of rabbit femoral head. The above results suggested that prepared CGB nanocomposites had the potential to be applied in bone tissue engineering