Safety of different concentrations of glycerine enema for meconium evacuation in preterm infants: study protocol for a randomised controlled trial.

INTRODUCTION: Various approaches are employed to expedite the passage of meconium in preterm infants within the neonatal intensive care unit (NICU), with glycerine enemas being the most frequently used. Due to the potential risk of high osmolality-induced harm to the intestinal mucosa, diluted glycerine enema solutions are commonly used in clinical practice. The challenge lies in the current lack of knowledge regarding the safest and most effective concentration of glycerine enema. This research aims to ascertain the safety of different concentrations of glycerine enema solution in preterm infants. METHODS AND ANALYSIS: This study protocol is for a single-centre, two-arm, parallel-group, double-blind and non-inferiority randomised controlled trial. Participants will be recruited from a NICU in a teriary class A hospital in China, and eligible infants will be randomly allocated to either the glycerine (mL): saline (mL) group in a 3:7 ratio or the 1:9 ratio group. The enema procedure will adhere to the standardised operational protocols. Primary outcomes encompass necrotising enterocolitis and rectal bleeding, while secondary outcomes encompass feeding parameters, meconium passage outcomes and splanchnic regional oxygen saturation. Analyses will compare the two trial arms based on an intention-to-treat allocation. ETHICS AND DISSEMINATION: This trial is approved by the ethics committee of the Medical Ethics Committee of West China Second University Hospital of Sichuan University. The results will be published in a peer-reviewed journal. TRIAL REGISTRATION NUMBER: ChiCTR2300079199.

Allogeneic hematopoietic stem cell transplantation for juvenile myelomonocytic leukemia with intestinal Behçet's disease: A case report.

Behçet's disease (BD) is a rare condition that is seldom associated with hematological malignancies. In this case report, we present the unique case of a 7-year-old girl diagnosed with juvenile myelomonocytic leukemia (JMML) and intestinal BD. The patient received allogeneic hematopoietic stem cell transplantation (allo-HSCT), which resulted in complete remission of both JMML and BD. Our findings suggest that allo-HSCT may be a feasible treatment option for JMML patients with coexisting BD, and holds promise for achieving remission of both illnesses. However, further clinical investigations are needed to validate these findings.

Analysis of the prevalence and influencing factors of hyperuricemia in children and adolescents aged 6-17 years in northeastern Sichuan Province.

OBJECTIVE: To investigate the factors influencing hyperuricemia in children and adolescents and to provide a scientific basis for early prevention and treatment. METHODS: A retrospective study (2017-2021) of the prevalence of hyperuricemia in children and adolescents was conducted, and the factors influencing hyperuricemia were analyzed by multi-factor logistic regression. RESULTS: The overall prevalence of hyperuricemia in children and adolescents aged 6-17 years in northeast Sichuan Province was 55.12% (8676/15,739), of which 60.68% (5699/9392) in boys and 46.90% (2977/6347) in girls; the prevalence of hyperuricemia from 2017 to 2021 was 52.40% ( 1540/2939), 52.56% (1642/3124), 52.11% (1825/3502), 58.33% (1691/2899), and 60.40% (1978/3275), respectively; the prevalence rates of 6-12 years old were 48.92% (864/1766), 50.46% (769/1524), and 52.73% (685/1299), 56.99% (693/1216), 35.46% (444/1252), 46.33% (524/1131), 60.50% (720/1190), and 66.82% (739/1106), 58.95% (652/1106), and 62.17% (761/1106) for 13-17 years old, respectively, 62.17% (761/1224), 63.19% (855/1353), and 61.70% (970/1572), respectively. Logistic regression showed that the prevalence of male (OR = 1.451, 95% CI 1.034 to 2.035, p = 0.031), age (OR = 1.074, 95% CI 1.024 to 1.126, p = 0.003), overweight/obesity (OR = 1.733, 95% CI 1.204∼2.494, p = 0.003), blood creatinine (OR = 1.018, 95% CI 1.005∼1.031, p = 0.007), triglycerides (OR = 1.450, 95% CI 1.065∼1.972, p = 0.018), blood calcium (OR = 6.792, 95% CI 1.373∼33.594, p = 0.019), and systolic blood pressure (OR = 1.037, 95% CI 1.018∼1.057, p < 0.001) were influential factors for the development of hyperuricemia. CONCLUSION: The prevalence of hyperuricemia was higher in children and adolescents aged 6-17 years in northeastern Sichuan Province, with a higher prevalence in boys than in girls, and the prevalence increased with age.

Association of low-density lipoprotein-cholesterol with all-cause and cause-specific mortality.

AIMS: To explore the association between low-density lipoprotein-cholesterol (LDL-C) and all-cause and cause-specific mortality based on a prospective cohort study. METHODS: Among 10850 individuals enrolled from National Health and Nutrition Examination Survey (NHANES) 1999-2014, 1355 (12.5%) died after an average follow-up of 5.7 years. Cox proportional regression models were used to determine the association between LDL-C with the risk of mortality. RESULTS: The level of LDL-C was L-shaped associated with the risk of all-cause mortality, namely a low level was related to an increased mortality risk. The level of LDL-C associated with the lowest risk of all-cause mortality was 124 mg/dL (3.2 mmol/L) in the overall population, and 134 mg/dL (3.4 mmol/L) in individuals not receiving lipid lowering treatment. Compared with participants with LDL-C of 110-134 mg/dL (2.8-3.5 mmol/L), the multivariable adjusted hazard ratio was 1.18 (95% confidence interval 1.01 to 1.38) for individuals with the lowest quartile for all-cause mortality. In participants with coronary heart diseases, the conclusion was similar but the critical point was lower. CONCLUSIONS: We found that low levels of LDL-C increased the risk of all-cause mortality, and the lowest risk of all-cause mortality for LDL-C concentration was 124 mg/dL (3.2 mmol/L). Our results provide a reasonable range of LDL-C when to initiate a statin therapy in clinical practice.

Analysis of the prevalence and influencing factors of hyperuricemia in children and adolescents aged 6-17 years in northeastern Sichuan Province

Abstract Objective: To investigate the factors influencing hyperuricemia in children and adolescents and to provide a scientific basis for early prevention and treatment. Methods: A retrospective study (2017-2021) of the prevalence of hyperuricemia in children and adolescents was conducted, and the factors influencing hyperuricemia were analyzed by multifactor logistic regression. Results: The overall prevalence of hyperuricemia in children and adolescents aged 6-17 years in northeast Sichuan Province was 55.12% (8676/15,739), of which 60.68% (5699/9392) in boys and 46.90% (2977/6347) in girls; the prevalence of hyperuricemia from 2017 to 2021 was 52.40% ( 1540/2939), 52.56% (1642/3124), 52.11% (1825/3502), 58.33% (1691/2899), and 60.40% (1978/ 3275), respectively; the prevalence rates of 6-12 years old were 48.92% (864/1766), 50.46% (769/1524), and 52.73% (685/1299), 56.99% (693/1216), 35.46% (444/1252), 46.33% (524/1131), 60.50% (720/1190), and 66.82% (739/1106), 58.95% (652/1106), and 62.17% (761/1106) for 13-17 years old, respectively, 62.17% (761/1224), 63.19% (855/1353), and 61.70% (970/1572), respectively. Logistic regression showed that the prevalence of male (OR = 1.451, 95% CI 1.034 to 2.035, p = 0.031), age (OR = 1.074, 95% CI 1.024 to 1.126, p = 0.003), overweight/obesity (OR = 1.733, 95% CI 1.204~2.494, p = 0.003), blood creatinine (OR = 1.018, 95% CI 1.005~1.031, p = 0.007), triglycerides (OR = 1.450, 95% CI1.065~1.972, p = 0.018), blood calcium (OR = 6.792, 95% CI 1.373~33.594, p = 0.019), and systolic blood pressure (OR = 1.037, 95% CI 1.018~1.057, p < 0.001) were influential factors for the development of hyperuricemia. Conclusion: The prevalence of hyperuricemia was higher in children and adolescents aged 6-17 years in northeastern Sichuan Province, with a higher prevalence in boys than in girls, and the prevalence increased with age.

Online Activity Recognition Combining Dynamic Segmentation and Emergent Modeling.

Activity recognition is fundamental to many applications envisaged in pervasive computing, especially in smart environments where the resident's data collected from sensors will be mapped to human activities. Previous research usually focuses on scripted or pre-segmented sequences related to activities, whereas many real-world deployments require information about the ongoing activities in real time. In this paper, we propose an online activity recognition model on streaming sensor data that incorporates the spatio-temporal correlation-based dynamic segmentation method and the stigmergy-based emergent modeling method to recognize activities when new sensor events are recorded. The dynamic segmentation approach integrating sensor correlation and time correlation judges whether two consecutive sensor events belong to the same window or not, avoiding events from very different functional areas or with a long time interval in the same window, thus obtaining the segmented window for every single event. Then, the emergent paradigm with marker-based stigmergy is adopted to build activity features that are explicitly represented as a directed weighted network to define the context for the last sensor event in this window, which does not need sophisticated domain knowledge. We validate the proposed method utilizing the real-world dataset Aruba from the CASAS project and the results show the effectiveness.

[Responses of radial growth of Pinus sylvestris var. mongolica and Larix gmelinii to climate change]. / 樟子松和落叶松径向生长对气候变化的响应.

In the context of global warming, the increases of temperature may affect tree growth and thus disturb ecosystem balance. In this study, we explored the main limiting factors for radial growth of Pinus sylvestris var. mongolica and Larix gmelinii in the Mohe area of Greater Khingan Mountains by using growth-climate response function analysis and moving correlation analysis, as well as the interspecific difference of the responses of radial growth to rapid warming. The results showed that the radial growth of P. sylvestris var. mongolica and L. gmelinii was affected by both temperature and precipitation. P. sylvestris var. mongolica was more sensitive to climate change than L. gmelinii, and its sensitivity to climate factors was more stable than L. gmelinii. The radial growth of P. sylvestris var. mongolica was significantly positively correlated with the monthly mean temperature and the monthly mean minimum temperature of the growing season, while that of L. gmelinii was significantly positively correlated with the monthly mean temperature and the monthly mean maximum temperature of winter. Precipitation in winter promoted the growth of P. sylvestris var. mongolica, whereas precipitation in the late growing season of the previous year inhibited the radial growth of L. gmelinii. After the rapid warming in 1990, the limiting effect of precipitation on P. sylvestris var. mongolica changed from negative to significantly positive, with the inhibition effect of high temperature being greater than the promotion effect. The inhibitory effect of high temperature on L. gmelinii was enhanced, and the limiting effect of precipitation on L. gmelinii was also enhanced after heating up. The growth rate decreased significantly, with obvious difference being observed in the correlations between the growth rate of two species with temperature and precipitation. Our results could provide scientific basis for forest ecosystem management and protection in Greater Khingan Mountains.

Traffic-related metrics and adverse birth outcomes: A systematic review and meta-analysis.

Given the inconsistency of epidemiologic evidence for associations between maternal exposures to traffic-related metrics and adverse birth outcomes, this manuscript aims to provide clarity on this topic. Pooled meta-estimates were calculated using random-effects analyses. Subgroup analyses were conducted by study area, study design, and Newcastle-Ottawa quality score (NOS). Funnel plots and Egger's test were conducted to evaluate the publication bias, and Fail-safe Numbers (Fail-safe N) were measured to evaluate the robustness of models. From the initial 740 studies (last search, July 11, 2019), 26 studies were included in our analysis. The pooled odds ratio for the change in small for gestational age associated with per 500 m decrease in the distance to roads was 1.016 (95% CI: 1.004, 1.029). Subgroup analyses revealed significant positive associations between term low birth weight and traffic density in higher-quality literatures with higher NOS [1.060 (95% CI: 1.002, 1.121)], cohort studies [1.020 (95% CI: 1.006, 1.033)], and studies in North America [1.018 (95% CI: 1.005, 1.131)]. The buffer of traffic density made no difference in the effect size. Traffic density seemed to be a better indicator of traffic pollution than the distance to roads.

Temporal trends of bladder cancer incidence and mortality from 1990 to 2016 and projections to 2030.

BACKGROUND: Bladder cancer is a leading cause of cancer-related deaths all over the world. Epidemiological studies of bladder cancer are therefore crucial for policy making. This study was carried out to describe the characteristics of changes in the incidence and mortality of bladder cancer from 1990 to 2016 by age group, gender, geographical region, and sociodemographic index (SDI) and to simultaneously project future trends up to 2030. METHODS: Incidence and mortality trends in bladder cancer from 1990 to 2016 were described based on data and methodologies from the Global Burden of Disease (GBD) Study. The data also allowed the future trends of bladder cancer incidence and mortality to be predicted by ARIMA model. Trends were analyzed by age group, gender, and SDI. Projections to 2030 were sub-analyzed by SDI countries. R software (x64 version 3.5.1), SAS (version 9.3), and SPSS (version 22.0) were used throughout the process. RESULTS: Globally, in 2016, there were 437,442 [95% uncertainty interval (UI), 426,709-447,912] new bladder cancer cases and 186,199 (95% UI, 180,453-191,686) bladder cancer-associated deaths. Between 1990 and 2016, changes in the age-standardized incidence rate (ASIR) of bladder cancer decreased by 5.91% from 7.11 (95% UI, 6.93-7.27) in 1990 to 6.69 (95% UI, 6.52-6.85) in 2016. The age-standardized death rate (ASDR) decreased from 3.58 (95% UI, 3.49-3.68) to 2.94 (95% UI, 2.85-3.03) over the same period of time. In future, the greatest occurrence of bladder cancer will be in high SDI countries, followed by high-middle SDI countries. Moreover, bladder cancer incidence rates may increase substantially in middle SDI countries, while the incidence rates will remain relatively stable for men and women in other SDI countries. From 2017 to 2030, bladder cancer deaths will continue to increase in low SDI countries, while deaths in other SDI countries will continue to decrease. CONCLUSIONS: There was a regional difference in the incidence and mortality trends of bladder cancer between 1990 and 2016. Overall, the situation is not optimistic. From 2017 to 2030, the incidence of bladder cancer will continue to rise, especially in high and high-middle SDI countries, where decision-makers should propose appropriate policies on the screening and prevention of bladder cancer.

Temporal trends of kidney cancer incidence and mortality from 1990 to 2016 and projections to 2030.

BACKGROUND: This study aims to present the trends of incidence and mortality of kidney cancer from 1990 to 2016 by age, gender, geographical region, regional, and sociodemographic index (SDI), and then forecast the future trends to 2030. METHODS: Data of this study were gathered from the Global Burden of Disease Study (GBD), including 195 countries and territories, accounting for 21 regions. Over-time trends from 1990 to 2016 were analyzed by gender, geographical region, age range and SDI. Based on the big data, we forecasted the future trends to 2030 by ARIMA model. All the data were analyzed by R software (x64 version 3.5.1), SAS (version 9.3) and SPSS (version 22.0). RESULTS: Globally, in 2016, there were 342,100 [95% uncertainty interval (UI), 330,759-349,934] incident cases of kidney cancer and the number of deaths were 131,800 (127,335-136,185). The age-standardized incidence rate (ASIR) and death rate (ASDR) were 4.97 (4.81-5.09) per 100,000 and 2.00 (1.93-2.06) per 100,000, respectively. Globally, the estimated risk of kidney cancer for male within the age of 30 and 70 is around 0.79% compared to 0.41% for female. In other words, the probability of developing kidney cancer was generally higher in male than in female. By 2030, incidence of kidney cancer in both sexes are projected to increase substantially in high SDI, followed by middle SDI, low-middle SDI, and low SDI countries. High SDI and low SDI countries will also have increased mortality rates of kidney cancers. Globally, the trends in deaths due to kidney cancer will remain stable. CONCLUSIONS: The incidence and death rate of kidney cancer are highly variable among SDI countries and regions but have increased uniformly from 1990 to 2016. By 2030, the future incidence of kidney cancer will grow continuously especially in high SDI countries, middle SDI, low-middle SDI, and low SDI countries.

Estimates of over-time trends in incidence and mortality of testicular cancer from 1990 to 2030.

BACKGROUND: This study aims to explore and project the temporal trends in incidence and mortality of testicular cancer. Moreover, it can provide theoretical guidance for the rational allocation of health resources. METHODS: This study analyzed existing data on testicular cancer morbidity and mortality from 1990 to 2016 and predicted time-varying trends of age-standardized incidence rate (ASIR) and age-standardized death rate (ASDR) from 2017 to 2030 in different ages, regions and sociodemographic index (SDI) quintile sub-groups. RESULT: Globally, numbers of testicular cancer cases in 2016 [66,833; 95% uncertainty interval (UI), 64,487-69,736] are 1.8 times larger than in 1990 (37,231; 95% UI, 36,116-38,515). The testicular cancer-related death cases increased slightly from 8,394 (95% UI, 7,980-8,904) in 1990 to 8,651 (95% UI, 8,292-9,027) in 2016. In aspect of ASIR, the data showed an up-trend from 0.74 (95% UI, 0.72-0.77) in 1990 to 0.88 (95% UI, 0.85-0.92) in 2016. The ASDR of testicular cancer declined from 0.18 (95% UI, 0.17-0.19) in 1990 to 0.12 (95% UI, 0.11-0.12) in 2016. From 2017 to 2030, predictions of trends in testicular cancer indicate that the ASIRs of most SDI countries are rising, but the ASDRs trends in testicular cancer will decrease. CONCLUSIONS: By analyzing the available and reliable data in different ages, regions and SDI, this study shows a significant upward trend in incidence and a slow upward trend in mortality of testicular cancer from 1990 to 2016, and simultaneously, predicts the increase of ASIR and the downward trend of ASDR in 2017-2030.

Estimates of over-time trends in incidence and mortality of prostate cancer from 1990 to 2030.

BACKGROUND: This research aims to identify the current and future trends in the incidence and death rate of prostate cancer and to provide the necessary data support for making relevant health decisions. METHODS: This study used the collected data and methodologies to describe the incidence and mortality trends of prostate cancer from 1990 to 2016. Based on the data, this paper projected the future trends in prostate cancer incidence and death rate. RESULTS: In 2016, prostate cancer cases [1,435,742; 95% uncertainty interval (UI), 1,293,395-1,618,655] were nearly 2.5-fold the number in 1990 (579,457; 95% UI, 521,564-616,107). Deaths increased by 2.0-fold from 191,687 (95% UI, 168,885-209,254) in 1990 to 380,916 (95% UI, 320,808-412,868) in 2016. The global age-standardized incidence rate (ASIR) increased from 17.75 (95% UI, 18.91-15.95) in 1990 to 22.12 (95% UI, 19.92-24.91) in 2016, changing 24.62%. The global change of age-standardized death rate (ASDR) has declined slightly, but in some regions it shows a trend of growth. By sociodemographic index (SDI) sub-types, prostate cancer will frequently occur in high SDI countries from 1990 to 2030. Simultaneously, the highest mortality will present in low SDI countries. CONCLUSIONS: Through projecting and analyzing incidence and mortality rate of prostate cancer, from 1990 to 2030, by different ages, regions and SDI sub-types, this result may reveal the relationship between prostate cancer and financial development. At the same time, the result also showed a sufficiently heavy burden of prostate cancer, but the burden varies greatly in each region. The burden is a challenge and will require attention for all levels of society. The current study is beneficial to formulate more specific and efficient policies.

Exploring the Laplace Prior in Radio Tomographic Imaging with Sparse Bayesian Learning towards the Robustness to Multipath Fading.

Radio tomographic imaging (RTI) is a technology for target localization by using radiofrequency (RF) sensors in a wireless network. The change of the attenuation field caused by thetarget is represented by a shadowing image, which is then used to estimate the target's position.The shadowing image can be reconstructed from the variation of the received signal strength (RSS)in the wireless network. However, due to the interference from multi-path fading, not all the RSSvariations are reliable. If the unreliable RSS variations are used for image reconstruction, someartifacts will appear in the shadowing image, which may cause the target's position being wronglyestimated. Due to the sparse property of the shadowing image, sparse Bayesian learning (SBL) canbe employed for signal reconstruction. Aiming at enhancing the robustness to multipath fading,this paper explores the Laplace prior to characterize the shadowing image under the frameworkof SBL. Bayesian modeling, Bayesian inference and the fast algorithm are presented to achieve themaximum-a-posterior (MAP) solution. Finally, imaging, localization and tracking experiments fromthree different scenarios are conducted to validate the robustness to multipath fading. Meanwhile,the improved computational efficiency of using Laplace prior is validated in the localization-timeexperiment as well.

QRStree: A prefix tree-based model to fetal QRS complexes detection.

Non-invasive fetal electrocardiography (NI-FECG) plays an important role in fetal heart rate (FHR) measurement during the pregnancy. However, despite the large number of methods that have been proposed for adult ECG signal processing, the analysis of NI-FECG remains challenging and largely unexplored. In this study, we propose a prefix tree-based framework, called QRStree, for FHR measurement directly from the abdominal ECG (AECG). The procedure is composed of three stages: Firstly, a preprocessing stage is employed for noise elimination. Secondly, the proposed prefix tree-based method is used for fetal QRS complexes (FQRS) detection. Finally, a correction stage is applied for false positive and false negative correction. The novelty of the framework relies on using the range of FHR to establish the connections between the FQRS. The consecutive FQRS can be considered as strings composed of alphabet items, thus we can use the prefix tree to store them. A vertex of the tree contains an alphabet, thus a path of the tree gives a string. Such that, by storing the connections of the FQRS into the prefix tree structure, the problem of FQRS detection converts to a problem of optimal path selection. Specifically, after selecting the optimal path of the tree, the nodes in the optimal path are collected as detected FQRS. Since the prefix tree can cover every possible combination of the FQRS candidates, it has the potential to reduce the occurrence of miss detections. Results on two different databases show that the proposed method is effective in FHR measurement from single-channel AECG. The focus on single-channel FHR measurement facilitates the long-term monitoring for healthcare at home.

Fetal electrocardiography extraction with residual convolutional encoder-decoder networks.

In the context of fetal monitoring, non-invasive fetal electrocardiography is an alternative approach to the traditional Doppler ultrasound technique. However, separating the fetal electrocardiography (FECG) component from the abdominal electrocardiography (AECG) remains a challenging task. This is mainly due to the interference from maternal electrocardiography, which has larger amplitude and overlaps with the FECG in both temporal and frequency domains. The main objective is to present a novel approach to FECG extraction by using a deep learning strategy from single-channel AECG recording. A residual convolutional encoder-decoder network (RCED-Net) is developed for this task of FECG extraction. The single-channel AECG recording is the input to the RCED-Net. And the RCED-Net extracts the feature of AECG and directly outputs the estimate of FECG component in the AECG recording. The AECG recordings from two different databases are collected to illustrate the efficiency of the proposed method. And the achieved results show that the proposed technique exhibits the best performance when compared to the existing methods in the literature. This work is a proof of concept that the proposed method could effectively extract the FECG component from AECG recordings. The focus on single-channel FECG extraction technique contributes to the commercial applications for long-term fetal monitoring.

In-Line Monitoring the Degradation of Polypropylene under Multiple Extrusions Based on Raman Spectroscopy.

Polymer degradation is a common problem in the extrusion process. In this work, Raman spectroscopy, a robust, rapid, and non-destructive tool for in-line monitoring, was utilized to in-line monitor the degradation of polypropylene (PP) under multiple extrusions. Raw spectra were pretreated by chemometrics methods to extract variations of spectra and eliminate noise. The variation of Raman intensity with the increasing number of extrusions was caused by the scission of PP chains and oxidative degradation, and the variation trend of Raman intensity indicated that long chains were more likely to be damaged by the extrusion. For the quantitative analysis of degradation, the partial least square was used to build a model to predict the degree of PP degradation measured by gel permeation chromatography (GPC). For the calibration set, the coefficient of determination (R2) and the root mean square error of cross-validation (RMSECV) were 0.9859 and 1.2676%, and for the prediction set, R2 and the root mean square error of prediction (RMSEP) were 0.9752 and 1.7228%, which demonstrated the accuracy of the proposed model. The in-line Raman spectroscopy combined with the chemometrics methods was proved to be an accurate and highly effective tool, which can monitor the degradation of polymer in real time.

Efficient Recognition of Informative Measurement in the RF-Based Device-Free Localization.

Device-Free Localization (DFL) based on the Radio Frequency (RF) is an emerging wireless sensing technology to perceive the position information of the target. To realize the real-time DFL with lower power, Back-projection Radio Tomographic Imaging (BRTI) has been used as a lightweight method to achieve the goal. However, the multipath noise in the RF sensing network may interfere with the measurement and the BRTI reconstruction performance. To resist the multipath interference in the observed data, it is necessary to recognize the informative RF link measurements that are truly affected by the target appearance. However, the existing methods based on the RF link state analysis are limited by the complex distribution of the RF link state and the high time complexity. In this paper, to enhance the performance of RF link state analysis, the RF link state analysis is transformed into a decomposition problem of the RF link state matrix, and an efficient RF link recognition method based on the low-rank and sparse decomposition is proposed to sense the spatiotemporal variation of the RF link state and accurately figure out the target-affected RF links. From the experimental results, the RF links recognized by the proposed method effectively reflect the target-induced RSS measurement variation with less time. Besides, the proposed method by recognizing the informative measurement is helpful to improve the accuracy of BRTI and enhance the efficiency in actual DFL applications.

Application of Raman Spectroscopy for In-Line Measurement of Dispersion Uniformity of Polypropylene-Polystyrene Blends During Melt Extrusion.

At present, there is a widespread phenomenon that product quality is difficult to monitor during the process of polymer melt modification such as blending, filling, and reinforcement. In consideration of this problem, this paper proposes an in-line Raman spectroscopy technique for measuring dispersion uniformity of polystyrene (PS) in polypropylene (PP)/PS blends during melt extrusion. On the basis of the optimal partial least squares (PLS) calibration model for quantitative determination of PS content in PP/PS, the fluctuations of PS content in extruding PP/PS with a mass percentage of 70 : 30 at different screw rotation speeds were predicted. The coefficient of variation (CV) of PS content at each screw rotation speed was obtained to accurately compare the dispersion uniformity, which was in agreement with the PS dispersion result characterized by the scanning electron microscope (SEM). In addition, the sensitivity of the measurement was validated by calculating the CV of PP/PS with mass percentages of 69 : 31 and 71 : 29. All of the above demonstrated that the in-line measurement system of Raman spectroscopy was able to accurately measure the dispersion uniformity of PS during the blending extrusion of PP/PS and demonstrated good sensitivity to minor changes in the blends composition.