171 research outputs found
Low Correlation Interference OFDM-NLFM Waveform Design for MIMO Radar Based on Alternating Optimization.
The OFDM chirp signal is suitable for MIMO radar applications due to its large time-bandwidth product, constant time-domain, and almost constant frequency-domain modulus. Particularly, by introducing the time-frequency structure of the non-linear frequency modulation (NLFM) signal into the design of an OFDM chirp waveform, a new OFDM-NLFM waveform with low peak auto-correlation sidelobe ratio (PASR) and peak cross-correlation ratio (PCCR) is obtained. IN-OFDM is the OFDM-NLFM waveform set currently with the lowest PASR and PCCR. Here we construct the optimization model of the OFDM-NLFM waveform set with the objective function being the maximum of the PASR and PCCR. Further, this paper proposes an OFDM-NLFM waveform set design algorithm inspired by alternating optimization. We implement the proposed algorithm by the alternate execution of two sub-algorithms. First, we keep both the sub-chirp sequence code matrix and sub-chirp rate plus and minus (PM) code matrix unchanged and use the particle swarm optimization (PSO) algorithm to obtain the optimal parameters of the NLFM signal's time-frequency structure (NLFM parameters). Next, we keep current optimal NLFM parameters unchanged, and optimize the sub-chirp sequence code matrix and sub-chirp rate PM code matrix using the block coordinate descent (BCD) algorithm. The above two sub-algorithms are alternately executed until the objective function converges to the optimal solution. The results show that the PASR and PCCR of the obtained OFDM-NLFM waveform set are about 5 dB lower than that of the IN-OFDM
Relationship between occupational stress and job burnout among rural-to-urban migrant workers in Dongguan, China: a cross-sectional study
Objectives: In China, there have been an increasing number of migrant workers from rural to urban areas, and migrant workers have the highest incidence of occupational diseases. However, few studies have examined the impact of occupational stress on job burnout in these migrant workers. This study aimed to investigate the relationship between occupational stress and job burnout among migrant workers. Design: This study used a cross-sectional survey. Setting: This investigation was conducted in Dongguan city, Guangdong Province, China. Participants: 3806 migrant workers, aged 18–60 years, were randomly selected using multistage sampling procedures. Primary and secondary outcome measures: Multistage sampling procedures were used to examine demographic characteristics, behaviour customs and jobrelated data. Hierarchical linear regression and logistic regression models were constructed to explore the relationship between occupational stress and burnout. Results: Demographics, behaviour customs and jobrelated characteristics significantly affected on burnout. After adjusting for the control variable, a high level of emotional exhaustion was associated with high role overload, high role insufficiency, high role boundary, high physical environment, high psychological strain, high physical strain, low role ambiguity, low responsibility and low vocational strain. A high level of depersonalisation was associated with high role overload, high role ambiguity, high role boundary, high interpersonal strain, high recreation, low physical environment and low social support. A low level of personal accomplishment was associated with high role boundary, high role insufficiency, low responsibility, low social support, low physical environment, low self-care and low interpersonal strain. Compared to the personal resources, the job strain and personal strain were more likely to explain the burnout of rural-to-urban migrant workers in our study. Conclusions: The migrant workers have increased job burnouts in relation to occupational stress. Relieving occupational stress and maintaining an appropriate quantity and quality of work could be important measures for preventing job burnout among these workers
Endovascular Recanalization of Non-acute Symptomatic Middle Cerebral Artery Total Occlusion and Its Short-Term Outcomes
Background and Purpose: The optimal treatment for patients with non-acute symptomatic middle cerebral artery (MCA) total occlusion and a high risk of recurrent ischemic stroke despite medical management is not well-established. We aimed to assess the feasibility, safety, and short-term outcomes of angioplasty and stenting for these patients.Methods: Data of 22 patients with non-acute symptomatic MCA total occlusion who have failed medical management and undergone endovascular recanalization were retrospectively collected in our prospective database. All occlusive lesions were predilated with conventional balloons, followed by paclitaxel-coated coronary balloon inflation or not, and then a remedial stenting was performed or not, depending on the discretion of the operator. The rate of successful recanalization, perioperative outcomes, and short-term outcomes, such as restenosis and stroke recurrence, was analyzed.Results: Successful recanalization was achieved in 95.5% of patients, with 14 patients undergoing balloon angioplasty and 7 patients undergoing remedial stenting. Seven patients developed perioperative complications, including one patient with persistent neurological deficit. Over a median clinical follow-up duration of 5.0 months, only one patient had recurrent ischemic symptoms attributed to the cessation of antiplatelet treatment owing to postoperative intracranial hemorrhage. The proportion of patients who achieved favorable clinical outcome (modified ranking scale score of 0–2) was 85.7%. Post-procedural repeat vascular imaging was performed at 4.5 ± 1.84 months, with nine and one patient undergoing cerebral angiography and magnetic resonance angiography, respectively. One (10%) artery presented with asymptomatic reocclusion.Conclusions: Angioplasty and stenting may be feasible for the patients with non-acute symptomatic atherosclerotic MCA total occlusive disease who have failed medical management
Differential Analysis of Gut Microbiota Correlated With Oxidative Stress in Sows With High or Low Litter Performance During Lactation
It has been suggested that gut microbiota play a critical role in maternal metabolic oxidative stress responses and offspring growth. However, whether the gut microbiota and oxidative stress status of the sows affect the litter performance during lactation is unclear. A total of 66 Yorkshire sows were identified as high (H) or low (L) litter performance sows based on litter weight at day 21 of lactation. Ten sows per group with similar parity, backfat thickness, and litter weight after cross-foster from the H or L group were collected randomly to analyze the oxidative stress and gut microbiota during lactation. The result showed that the serum total antioxidant capacity was higher in the H group, while 8-hydroxy-deoxyguanosine and thiobarbituric acid reactive substances were lower in the H group at farrowing. Four distinct clusters of bacteria were related to litter performance and reproductive periods of sows. Twelve differentially abundant taxa during gestation and 13 taxa during lactation were identified as potential biomarkers between the H group and the L group. Moreover, the litter performance and the antioxidant capacity of sows were positively correlated with Bacteroides_f__Bacteroidaceae but negatively with Phascolarctobacterium and Streptococcus. In conclusion, this study found that gut microbiota and oxidative stress were significantly correlated with the litter performance of sows during lactation
Paper-based microfluidic aptasensors
For in-situ disease markers detection, point-of-care (POC) diagnosis has great advantages in speed and cost compared with traditional techniques. The rapid diagnosis, prognosis, and surveillance of diseases can significantly reduce disease-related mortality and trauma. Therefore, increasing attention has been paid to the POC diagnosis devices due to their excellent diagnosis speed and portability. Over the past ten years, paper-based microfluidic aptasensors have emerged as a class of critical POC diagnosis devices and various aptasensors have been proposed to detect various disease markers. However, most aptasensors need further improvement before they can actually enter the market and be widely used. There is thus an urgent need to sort out the key points of preparing the aptasensors and the direction that needs to be invested in. This review summarizes the representative articles in the development of paper-based microfluidic aptasensors. These works can be divided into paper-based optical aptasensors and paper-based electrochemical aptasensors according to their output signals. Significant focus is applied to these works according to the following three parts: (1) The ingenious design of device structure; (2) Application and synthesis of nanomaterial; (3) The detection principle of the proposed aptasensor. This is a detailed and comprehensive review of paper-based microfluidic aptasensors. The accomplishments and shortcomings of the current aptasensors are outlined, the development direction and the future prospective are given. It is hoped that the research in this review can provide a reference for further development of more advanced, more effective paper-based microfluidic aptasensors for POC disease markers diagnosi
Prediction of wheat SPAD using integrated multispectral and support vector machines
Rapidly obtaining the chlorophyll content of crop leaves is of great significance for timely diagnosis of crop health and effective field management. Multispectral imagery obtained from unmanned aerial vehicles (UAV) is being used to remotely sense the SPAD (Soil and Plant Analyzer Development) values of wheat crops. However, existing research has not yet fully considered the impact of different growth stages and crop populations on the accuracy of SPAD estimation. In this study, 300 materials from winter wheat natural populations in Xinjiang, collected between 2020 to 2022, were analyzed. UAV multispectral images were obtained in the experimental area, and vegetation indices were extracted to analyze the correlation between the selected vegetation indices and SPAD values. The input variables for the model were screened, and a support vector machine (SVM) model was constructed to estimate SPAD values during the heading, flowering, and filling stages under different water stresses. The aim was to provide a method for the rapid acquisition of winter wheat SPAD values. The results showed that the SPAD values under normal irrigation were higher than those under water restriction. Multiple vegetation indices were significantly correlated with SPAD values. In the prediction model construction of SPAD, the different models had high estimation accuracy under both normal irrigation and water limitation treatments, with correlation coefficients of predicted and measured values under normal irrigation in different environments the value of r from 0.59 to 0.81 and RMSE from 2.15 to 11.64, compared to RE from 0.10% to 1.00%; and under drought stress in different environments, correlation coefficients of predicted and measured values of r was 0.69–0.79, RMSE was 2.30–12.94, and RE was 0.10%–1.30%. This study demonstrated that the optimal combination of feature selection methods and machine learning algorithms can lead to a more accurate estimation of winter wheat SPAD values. In summary, the SVM model based on UAV multispectral images can rapidly and accurately estimate winter wheat SPAD value
Using Lymphocyte and Plasma Hsp70 as Biomarkers for Assessing Coke Oven Exposure among Steel Workers
Identification of prognostic risk model based on plasma cell markers in hepatocellular carcinoma through single-cell sequencing analysis
Hepatocellular carcinoma (HCC) represents a substantial global health burden. Tumorinfiltrating B lymphocytes (TIL-Bs) contribute to tumor progression and significantly impact the efficacy of tumor therapy. However, the characteristics of TIL-Bs in HCC and their effect on HCC therapy remain elusive. Single-cell RNA sequencing (scRNAseq) was applied to investigate the heterogeneity, cellular differentiation and cell-cell communication of TIL-Bs in HCC. Further, the Cancer Genome Atlas-liver hepatocellular carcinoma (TCGA-LIHC) and liver cancer institutes (LCI) cohorts were applied to construct and validate the plasma cell marker-based prognostic risk model. The relationship between the prognostic risk model and the responsiveness of immunotherapy and chemotherapy in patients with HCC were estimated by OncoPredict and tumor immune dysfunction and exclusion (TIDE) algorithm. Finally, we established nomogram and calibration curves to evaluate the precision of the risk score in predicating survival probability. Our data identified five subtypes of TIL-Bs in HCC, each exhibiting varying levels of infiltration in tumor tissues. The interactions between TIL-Bs and other cell types contributed to shaping distinct tumor microenvironments (TME). Moreover, we found that TIL-Bs subtypes had disparate prognostic values in HCC patients. The prognostic risk model demonstrated exceptional predictive accuracy for overall survival and exhibited varying sensitivities to immunotherapy and chemotherapy among patients with HCC. Our data demonstrated that the risk score stood as an independent prognostic predictor and the nomogram results further affirmed its strong prognostic capability. This study reveals the heterogeneity of TIL-Bs and provides a prognostic risk model based on plasma cell markers in HCC, which could prove valuable in predicting prognosis and guiding the choice of suitable therapies for patients with HCC
A nanobody-based molecular toolkit for ubiquitin–proteasome system explores the main role of survivin subcellular localization
Targeted protein degradation is a powerful tool for determining the function of specific proteins nowadays. Survivin is the smallest member of the inhibitor of the apoptosis protein (IAP) family. It exists in the cytoplasm and nucleus of cells, but the exact function of survivin in different subcellular locations retained unclear updates due to the lack of effective and simple technical means. In this study, we created a novel nanoantibody-based molecular toolkit, namely, the ubiquitin–proteasome system (Nb4A-Fc-T2A-TRIM21), that can target to degrade survivin localized in cytoplasmic and cell nuclear by ubiquitinating, and by which to verify the potential roles of survivin subcellular localization. Also, the results showed that the cytoplasmic survivin mainly plays an anti-apoptotic function by directly or indirectly inhibiting the caspase pathway, and the nuclear survivin mainly promotes cell proliferation and participates in the regulation of the cell cycle. In addition, the Nb4A-Fc-T2A-TRIM21 system can degrade the endogenous survivin protein in a large amount by the ubiquitin–proteasome pathway, and the system can provide theoretical support for ubiquitination degradation targeting other endogenous proteins
Validation of American Joint Committee on Cancer 8th edition of TNM staging in resected distal pancreatic cancer
BACKGROUND
In order to improve risk stratification and clinical management of the pancreatic ductal adenocarcinoma (PDAC), the American Joint Committee on Cancer (AJCC) has published its eighth edition staging manual. Some major changes have been introduced in the new staging system for both T and N categories. Given the rarity of resectable disease, distal pancreatic cancer is likely underrepresented in the published clinical studies, and how the impact of the staging system actually reflects on to clinical outcomes remain unclear.
AIM
To validate the AJCC 8th edition of TNM staging in distal PDAC.
METHODS
A retrospective cohort study was performed in seven academic medical centers in the United States. Clinicopathological prognostic factors associated with progression-free survival (PFS) and overall survival (OS) were evaluated through univariate and multivariate analyses.
RESULTS
Overall, 454 patients were enrolled in the study, and were divided into 2 subgroups: Invasive intraductal papillary mucinous neoplasms (IPMN) (115 cases) and non-IPMN associated adenocarcinoma (339 cases). Compared to invasive IPMN, non-IPMN associated adenocarcinomas are more common in relatively younger patients, have larger tumor size, are more likely to have positive lymph nodes, and are associated with a higher tumor (T) stage and nodal (N) stage, lymphovascular invasion, perineural invasion, tumor recurrence, and a worse PFS and OS. The cohort was predominantly categorized as stage 3 per AJCC 7th edition staging manual, and it’s more evenly distributed based on 8th edition staging manual. T and N staging of both 7th and 8th edition sufficiently stratify PFS and OS in the entire cohort, although dividing into N1 and N2 according to the 8th edition does not show additional stratification. For PDAC arising in IPMN, T staging of the 7th edition and N1/N2 staging of the 8th edition appear to further stratify PFS and OS. For PDAC without an IPMN component, T staging from both versions fails to stratify PFS and OS.
CONCLUSION
The AJCC 8th edition TNM staging system provides even distribution for the T staging, however, it does not provide better risk stratification than previous staging system for distal pancreatic cancer
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