Compensation schemes for uneven illumination and LED light-emitting instability in optical camera communication system.

In order to increase the data rate of the optical camera communication (OCC) system, the 8-composite-amplitude-shift-keying modulation (8CASK) OCC system is used in this work. However, if the static decision thresholds are employed to demodulate multi-level ASK signal, uneven illumination of LED lamps and LED light-emitting instability lead to the fluctuation of the gray range in the picture and degrade the bit-error-rate (BER) performance. In this work, we propose and demonstrate a demodulation scheme, using the uneven illumination compensation algorithm, the pixel matrix threshold overall update algorithm and the secondary decision algorithm, to mitigate the impact of illumination unevenness and LED light-emitting instability. The BER performance is evaluated and compared with other demodulation schemes. The experimental results demonstrate that the communication rate of our proposed scheme can reach 9kbit/s at a distance of 250 cm where the illumination is 135lux, and the BER is 8.01 × 10-5.

Low-complexity frequency domain frame synchronization for short-reach IM/DD optical fiber transmission systems.

We propose a low-complexity frequency domain frame synchronization method for short-reach intensity modulation and direct detection (IM/DD) systems. A four-level pulse amplitude modulation-training sequence (PAM4-TS) is specially designed for the proposed method, which has an obvious peak in the amplitude spectrum that is higher than the normal signal. The proposed method comprises a coarse synchronization stage and a fine synchronization stage. Firstly, the coarse synchronization stage takes advantage of the feature of PAM4-TS to obtain the approximate position of the frame head by identifying the peak value in amplitude spectrum of the segmented received signal. Then, the fine synchronization stage calculates the correlation between the coarse synchronization result and PAM4-TS by multiplying the two in the frequency domain. Compared with the traditional sliding window correlation method realized in the time domain, both simulation and experimental results of C-band 50 Gbit/s PAM4 transmission demonstrate that the proposed method reduces the multiplication complexity by up to about 96.01% without any additional performance penalty.

Impact of a clinical care pathway developed through the action research method on the psychological well-being and quality of life in male patients with urethral stricture.

BACKGROUND: The objective of this study is to examine the development of a clinical care pathway utilizing an action research methodology for male patients with urethral stricture, and to assess the psychological and quality of life outcomes following the implementation of this pathway. METHODS: Ninety patients diagnosed with urethral stricture, admitted to our hospital between May 2021 and May 2022, were selected as the study cohort. Employing a random number method, these patients were allocated into an observation group and a control group, each comprising 45 individuals. The control cohort employs standard care protocols for individuals with urethral stenosis, while the experimental group employs an action research methodology to develop a clinical care pathway specific to the management of patients with urethral stenosis, with an intervention cycle of 3 months. The investigation evaluated the impact of the intervention by scrutinizing pre- and post-intervention data through the utilization of the WHO Quality of Life Scale (WHOQOL-BREF), in addition to the Anxiety Rating Scale and the Depression Rating Scale. RESULTS: Prior to the intervention, no significant differences were observed in WHOQOL-BREF scores across dimensions, as well as anxiety and depression scores between the 2 groups (P > .05). Subsequent to the intervention, the patients in the observation group exhibited significantly higher scores across all WHOQOL-BREF dimensions and total scores compared to the control group, with statistical significance (P < .05). Moreover, anxiety and depression scores in the observation group were markedly lower than those in the control group, demonstrating statistical significance (P < .05). CONCLUSION: The implementation of a clinical nursing pathway rooted in action research methodology proves to be an effective strategy for enhancing clinical nursing practices, elevating patient quality of life, and diminishing the prevalence of anxiety and depression.

Molecular basis of inherited protein C deficiency results from genetic variations in the signal peptide and propeptide regions.

BACKGROUND: Inherited protein C deficiency (PCD) caused by mutations in protein C (PC) gene (PROC) increases the risk of thrombosis. Missense mutations in PC's signal peptide and propeptide have been reported in patients with PCD, but their pathogenic mechanisms, except mutations in R42 residue, remain unclear. OBJECTIVES: To investigate the pathogenic mechanisms of inherited PCD caused by 11 naturally occurring missense mutations in PC's signal peptide and propeptide. METHODS: Using cell-based assays, we evaluated the impact of these mutations on various aspects such as activities and antigens of secreted PC, intracellular PC expression, subcellular localization of a reporter protein, and propeptide cleavage. Additionally, we investigated their effect on pre-messenger RNA (pre-mRNA) splicing using a minigene splicing assay. RESULTS: Our data revealed that certain missense mutations (L9P, R32C, R40C, R38W, and R42C) disrupted PC secretion by impeding cotranslational translocation to the endoplasmic reticulum or causing endoplasmic reticulum retention. Additionally, some mutations (R38W and R42L/H/S) resulted in abnormal propeptide cleavage. However, a few missense mutations (Q3P, W14G, and V26M) did not account for PCD. Using a minigene splicing assay, we observed that several variations (c.8A>C, c.76G>A, c.94C>T, and c.112C>T) increased the incidence of aberrant pre-mRNA splicing. CONCLUSION: Our findings suggest that variations in PC's signal peptide and propeptide have varying effects on the biological process of PC, including posttranscriptional pre-mRNA splicing, translation, and posttranslational processing. Additionally, a variation could affect the biological process of PC at multiple levels. Except for W14G, our results provide a clear understanding of the relationship between PROC genotype and inherited PCD.

[Expression and Clinical Significance of MMSA-8 and MMSA-1 in Bone Marrow of Patients with M2 Acute Myeloid Leukemia].

OBJECTIVE: To detect the expression of multiple myeloma-associated antigen (MMSA)-8 and MMSA-1 in bone marrow mononuclear cells of patients with acute myeloid leukemia, and explore their roles in acute myeloid leukemia. METHODS: A total of 83 patients with M2 acute myeloid leukemia in our hospital from January 2019 to January 2020 were selected as research group, during the same period, 15 patients diagnosed iron deficiency anemia were selected as control group. Real-time fluorescence quantitative PCR was used to detect the levels of MMSA-8 and MMSA-1 in bone marrow mononuclear cells. Patients in the research group were divided into remission and non remission according to the clinical curative effect, and were divided into good prognosis, medium prognosis, and poor prognosis according to the prognosis. The relationship between MMSA-8, MMSA-1 and clinical efficacy, prognosis was analyzed. In addition, the general data of patients in the research group were collected, including white blood cell count (WBC), hemoglobin (Hb), platelet count (PLT), and percentage of bone marrow progenitor cells at admission. Pearson method was used to analyze the correlation between MMSA-8, MMSA-1 and clinical data, and MMSA-8 and MMSA-1. RESULTS: The analysis results about mRNA levels of MMSA-8 and MMSA-1 in bone marrow mononuclear cells of patients showed that patients in the research group were significantly higher than those in the control group (P<0.05); In the research group, patients without remission were also significantly higher than those with remission, as well as those with medium and poor prognosis than with good prognosis, while only mRNA level of MMSA-1 in patients with poor prognosis was significantly higher than those with medium prognosis (P<0.05). Pearson analysis showed that MMSA-8, MMSA-1 were positively correlated with WBC (r=0.468, r=0.516), and MMSA-8 was positively correlated with MMSA-1 (r=0.318). CONCLUSION: The levels of MMSA-8 and MMSA-1 in bone marrow mononuclear cells of patients with M2 acute myeloid leukemia are increased, which are closely related to the occurrence and development of the disease, and have certain value for the prognosis.

[Effect of Carvacrol on the Biological Behavior of Leukemia Cells and Its Mechanism].

OBJECTIVE: To explore the effect of carvacrol on the biological behavior of leukemia cells and its regulation to circ-0008717/miR-217 molecular axis. METHODS: Human acute lymphoblastic leukemia cells Molt-4 were cultured in vitro, and different concentrations of carvacrol were added to the cells. si-NC and si-circ-0008717 were transfected into Molt-4 cells (si-NC group, si-circ-0008717 group). pcDNA, pcDNA-circ-0008717, anti-miR-NC, anti-miR-217 were transfected into Molt-4 cells and then added to carvacrol-treated cells (carvacrol+pcDNA group, carvacrol+pcDNA-circ-0008717 group, carvacrol+anti-miR-NC group, carvacrol+anti-miR-217 group). MTT, plate clone formation experiment, and flow cytometry were used to detect the viability of the cell, colony formation number, and apoptosis rate of cells, respectively. The RT-qPCR method was used to detect the expression levels of circ-0008717 and miR-217. The dual luciferase reporter gene experiment was used to detect the targeting relationship between circ-0008717 and miR-217. RESULTS: After carvacrol treatment, the cell viability decreased significantly (r=-0.9405), expression level of circ-0008717 decreased (r=-0.9117), colonies formed number decreased (r=-0.9256), while the cell apoptosis rate increased (r= 0.8464), and the expression level of miR-217 increased (r=0.9468). Compared with the si-NC group, the expression level of miR-217 in si-circ-0008717 group increased (P＜0.001), the cell apoptosis rate increased (P＜0.001), while cell viability decreased (P＜0001), the number of colonies formed decreased (P＜0.001). Compared with the carvacrol+pcDNA group, the cell viability of the carvacrol+pcDNA-circ-0008717 group increased (P＜0.001), the number of colonies formed increased (P＜0.001), while the cell apoptosis rate decreased (P＜0.001). circ-0008717 could target miR-217. The cell viability of the carvacrol+anti-miR-217 group increased (P＜0.001), and the number of colonies formed increased (P＜0.001), while the cell apoptosis rate decreased (P＜0001) as compared with the carvacrol+anti-miR-NC group. CONCLUSION: Carvacrol can promote the expression of miR-217 by down-regulating the expression of circ-0008717, thereby reducing the proliferation and cloning ability of leukemia cells and promoting cell apoptosis.

Clinical characteristics of patients with 2019 coronavirus disease in a non-Wuhan area of Hubei Province, China: a retrospective study.

BACKGROUND: Since December 2019, the 2019 coronavirus disease (COVID-19) has expanded to cause a worldwide outbreak that more than 600,000 people infected and tens of thousands died. To date, the clinical characteristics of COVID-19 patients in the non-Wuhan areas of Hubei Province in China have not been described. METHODS: We retrospectively analyzed the clinical characteristics and treatment progress of 91 patients diagnosed with COVID-19 in Jingzhou Central Hospital. RESULTS: Of the 91 patients diagnosed with COVID-19, 30 cases (33.0%) were severe and two patients (2.2%) died. The severe disease group tended to be older (50.5 vs. 42.0 years; p = 0.049) and have more chronic disease (40% vs. 14.8%; p = 0.009) relative to mild disease group. Only 73.6% of the patients were quantitative polymerase chain reaction (qPCR)-positive on their first tests, while typical chest computed tomography images were obtained for each patient. The most common complaints were cough (n = 75; 82.4%), fever (n = 59; 64.8%), fatigue (n = 35; 38.5%), and diarrhea (n = 14; 15.4%). Non-respiratory injury was identified by elevated levels of aspartate aminotransferase (n = 18; 19.8%), creatinine (n = 5; 5.5%), and creatine kinase (n = 14; 15.4%) in laboratory tests. Twenty-eight cases (30.8%) suffered non-respiratory injury, including 50% of the critically ill patients and 21.3% of the mild patients. CONCLUSIONS: Overall, the mortality rate of patients in Jingzhou was lower than that of Wuhan. Importantly, we found liver, kidney, digestive tract, and heart injuries in COVID-19 cases besides respiratory problems. Combining chest computed tomography images with the qPCR analysis of throat swab samples can improve the accuracy of COVID-19 diagnosis.

Accurate and Robust Monocular SLAM with Omnidirectional Cameras.

Simultaneous localization and mapping (SLAM) are fundamental elements for many emerging technologies, such as autonomous driving and augmented reality. For this paper, to get more information, we developed an improved monocular visual SLAM system by using omnidirectional cameras. Our method extends the ORB-SLAM framework with the enhanced unified camera model as a projection function, which can be applied to catadioptric systems and wide-angle fisheye cameras with 195 degrees field-of-view. The proposed system can use the full area of the images even with strong distortion. For omnidirectional cameras, a map initialization method is proposed. We analytically derive the Jacobian matrices of the reprojection errors with respect to the camera pose and 3D position of points. The proposed SLAM has been extensively tested in real-world datasets. The results show positioning error is less than 0.1% in a small indoor environment and is less than 1.5% in a large environment. The results demonstrate that our method is real-time, and increases its accuracy and robustness over the normal systems based on the pinhole model. We open source in https://github.com/lsyads/fisheye-ORB-SLAM.

High-Precision Indoor Visible Light Positioning Using Modified Momentum Back Propagation Neural Network with Sparse Training Point.

In this letter, we propose an indoor visible light positioning technique using a Modified Momentum Back-Propagation (MMBP) algorithm based on received signal strength (RSS) with sparse training data set. Unlike other neural network algorithms that require a large number of training data points to locate accurately, we have realized high-precision positioning for 100 test points with only 20 training points in a 1.8 m × 1.8 m × 2.1 m localization area. In order to verify the adaptability of the MMBP algorithm, we experimentally demonstrate two different training data acquisition methods adopting either even or arbitrary training sets. In addition, we also demonstrate the positioning accuracy of the traditional RSS algorithm. Experimental results show that the average localization accuracy optimized by our proposed algorithm is only 1.88 cm for the arbitrary set and 1.99 cm for the even set, while the average positioning error of the traditional RSS algorithm reaches 14.34 cm. Comparison indicates that the positioning accuracy of our proposed algorithm is 7.6 times higher. Results also show that the performance of our system is higher than some previous reports based on RSS and RSS fingerprint databases using complex machine learning algorithms trained by a large amount of training points.

OSNR and nonlinear noise power estimation for optical fiber communication systems using LSTM based deep learning technique.

The optical signal-to-noise ratio (OSNR) and fiber nonlinearity are critical factors in evaluating the performance of high-speed optical fiber communication systems. Recently, several deep learning based methods have been put forward to monitor OSNR of a fiber communication system. In this work, we propose a long short-term memory (LSTM) network based method to simultaneously estimate OSNR and nonlinear noise power caused by fiber nonlinearity. In the training step, LSTM network extracts the essential features in frequency domain of the input signal. Then, with the built model in the training step, the LSTM output the OSNR and nonlinear noise power of the signal under test. The simulation by VPI software is carried on a 5-channel long haul optical transmission system with the launched optical power of -3.0~ + 3.0dBm per channel. The results show that the test error of OSNR is less than 1.0dB with the reference OSNR from 15 to 30dB for QPSK, 16QAM and 64QAM signal. The test error of nonlinear noise power is less than 1.0dB for QPSK and 16QAM signal when the Laser linewidth is 6 KHz and 100 KHz respectively. The proposed method is a promising candidate for nonlinearity-insensitive OSNR and accurate nonlinear noise power estimation in multi-channel long haul optical fiber communication systems.

Fusion Based on Visible Light Positioning and Inertial Navigation Using Extended Kalman Filters.

With the rapid development of smart technology, the need for location-based services (LBS) increases every day. Since classical positioning technology such as GPS cannot satisfy the needs of indoor positioning, new indoor positioning technologies, such as Bluetooth, Wi-Fi, and Visible light communication (VLC), have already cut a figure. VLC positioning has been proposed because it has higher accuracy, costs less, and is easier to accomplish in comparison to the other indoor positioning technologies. However, the practicality of VLC positioning is limited since it is easily affected by multipath effects and the layout of LEDs. Thus, we propose a fusion positioning system based on extended Kalman filters, which can fuse the VLC position and the inertial navigation data. The accuracy of the fusion positioning system is in centimeters, which is better compared to the VLC-based positioning or inertial navigation alone. Furthermore, the fusion positioning system has high accuracy, saves energy, costs little, and is easy to install, making it a promising candidate for future indoor positioning applications.

Gender effect on pre-attentive change detection in major depressive disorder patients revealed by auditory MMN.

Gender differences in rates of major depressive disorder (MDD) are well established, but gender differences in cognitive function have been little studied. Auditory mismatch negativity (MMN) was used to investigate gender differences in pre-attentive information processing in first episode MDD. In the deviant-standard reverse oddball paradigm, duration auditory MMN was obtained in 30 patients (15 males) and 30 age-/education-matched controls. Over frontal-central areas, mean amplitude of increment MMN (to a 150-ms deviant tone) was smaller in female than male patients; there was no sex difference in decrement MMN (to a 50-ms deviant tone). Neither increment nor decrement MMN differed between female and male patients over temporal areas. Frontal-central MMN and temporal MMN did not differ between male and female controls in any condition. Over frontal-central areas, mean amplitude of increment MMN was smaller in female patients than female controls; there was no difference in decrement MMN. Neither increment nor decrement MMN differed between female patients and female controls over temporal areas. Frontal-central MMN and temporal MMN did not differ between male patients and male controls. Mean amplitude of increment MMN in female patients did not correlate with symptoms, suggesting this sex-specific deficit is a trait- not a state-dependent phenomenon.

A multi-fork z-axis quartz micromachined gyroscope.

A novel multi-fork z-axis gyroscope is presented in this paper. Different from traditional quartz gyroscopes, the lateral electrodes of the sense beam can be arranged in simple patterns; as a result, the fabrication is simplified. High sensitivity is achieved by the multi-fork design. The working principles are introduced, while the finite element method (FEM) is used to simulate the modal and sensitivity. A quartz fork is fabricated, and a prototype is assembled. Impedance testing shows that the drive frequency and sense frequency are similar to the simulations, and the quality factor is approximately 10,000 in air. The scale factor is measured to be 18.134 mV/(°/s) and the nonlinearity is 0.40% in a full-scale input range of ±250 °/s.

Modulation based cells distribution for visible light communication.

Cells distribution for visible light communication can enhance the capacity of the data transmission by the reuse of optical spectrum. In this paper, we adopt three modulation formats as OOK, PPM and PWM for neighboring cells A, B and C respectively. The prototype experiment results demonstrate the error free transmission of 1.0 Mbit/s and 6.25 Mbit/s visible light communication system with our scheme. With the available LED, we can expect that the data rate of a visible light communication system with seamless connectivity can be up to 71.4 Mbit/s.

Enhancement of LED indoor communications using OPPM-PWM modulation and grouped bit-flipping decoding.

Combination of overlapping pulse position modulation and pulse width modulation at the transmitter and grouped bit-flipping algorithm for low-density parity-check decoding at the receiver are proposed for visible Light Emitting Diode (LED) indoor communication system in this paper. The results demonstrate that, with the same Photodetector, the bit rate can be increased and the performance of the communication system can be improved by the scheme we proposed. Compared with the standard bit-flipping algorithm, the grouped bit-flipping algorithm can achieve more than 2.0 dB coding gain at bit error rate of 10-5. By optimizing the encoding of overlapping pulse position modulation and pulse width modulation symbol, the performance can be further improved. It is reasonably expected that the bit rate can be upgraded to 400 Mbit/s with a single available LED, thus transmission rate beyond 1 Gbit/s is foreseen by RGB LEDs.

Ca(2+) channel currents of cortical neurons from pure and mixed cultures.

Voltage-gated Ca(2+) channels (VGCCs) are key regulators of many neuronal functions, and involved in multiple central nervous system diseases. In the last 30 years, a large number of injury and disease models have been established based on cultured neurons. Culture with serum develops a mixture of neurons and glial cells, while culture without serum develops pure neurons. Both of these neuronal-culture methods are widely used. However, the properties of Ca(2+) currents in neurons from these two cultures have not been compared. In this study, we cultured rat cortical neurons in serum-containing or -free medium and then recorded the Ca(2+) channel currents using patch-clamp technique. Our results showed that there were significant differences in the amplitude and activation properties of whole-cell Ca(2+) channel currents, and of non-L-type Ca(2+) channel currents between the neurons from these two culture systems. Our data suggested that the difference of whole-cell Ca(2+) currents may result from the differences in non-L-type currents. Understanding of these properties will considerably advance studies of VGCCs in neurons from pure or mixed culture.

[Detection of Borna disease virus-p24 specific antibody in the sera of schizophrenic patients of China by means of Western-blot].

BACKGROUND: To investigate whether Borna disease virus (BDV) infection is related to the schizophrenic patients from China. METHODS: A reliable Western-blot method for detection of BDV-p24 antibody was established by adjusting the reaction conditions of BDV-p24 recombinant protein and specific antibodies. The sera of schizophrenic patients and normal controls from Heilongjiang Province were screened for specific BDV-p24 antibody by this method, and the BDV-p24 antibody positive sera were confirmed by the Western-blot method with sera-GST protein absorption. RESULTS: Ten of 116 (8.6%) schizophrenic patients were found to be positive for BDV-p24 specific antibody, while no BDV-p24 specific antibody was found in sera of normal controls. CONCLUSIONS: The results demonstrate that the Borna disease virus infection also exists in China, and the infection is possibly associated with schizophrenia in some way.

[Detection of antibody against Borna disease virus-p24 in the plasma of Chinese patients with chronic fatigue syndrome by Western-blot analysis].

OBJECTIVE: To evaluate the prevalence of infection with Borna disease virus (BDV) in Chinese patients with chronic fatigue syndrome (CFS) and control subjects, and to discuss the etiological association between CFS and infection with BDV. METHODS: The CDC (1994) diagnostic criteria for CFS were used for case definition. Sixty-one patients suffered from CFS were from 11 Provinces in China. To detect the antibody against BDV-p24 on the plasma samples from all cases and 73 healthy control subjects by Western-blotting analysis. RESULTS: 7 of the sixty-one cases and 0 of the controls were sero-positive for BDV-p24 antibody, there was a statistical significant difference between the two groups (11.48% vs 0%; P less than 0.010). CONCLUSION: Chinese patients with CFS showed sero-positive identifying BDV infection, by comparison, anti.BDV-p24 antibody prevalence in patients was significantly higher than in controls. An etiological association may exist between CFS and BDV infection.