Ultra-wideband Single Jurkat Human T-lymphocyte Cell Characterization, Dielectrophoresis, and Electroporation Using One Vector Network Analyzer

For the first time, single-cell trapping, characterization, electroporation, and de-trapping were demonstrated by conveniently programming the frequency and power of the same ultra-wideband vector network analyzer (VNA) to perform the different functions across its bandwidth of 9 kHz‒9 GHz. On one hand, trapping of a live biological cell was accomplished by applying to a coplanar waveguide (CPW) through the VNA a continuous wave (CW) signal of 3 dBm and 5 MHz, corresponding to attractive dielectrophoresis. On the other hand, detrapping of a live biological cell was also accomplished to complete a better control of the cell in microfluidics using electromagnetic method, after both the lower and the higher crossover frequencies of Clausius-Mossotti function were carefully studied. A detrapping experiment was designed to validate the CM function, which demonstrated that the lower and the higher crossover frequencies were around 60 kHz and 300 MHz, respectively, from positive force to negative force in single-cell dielectrophoresis predicted by the Clausius-Mossotti function theoretical calculation, despite the highly nonuniform electric field distribution between small and narrowly spaced electrodes, which was greatly disturbed by the cell. The validation was based on live Jurkat human T-lymphocyte cells that were resuspended in isotonic sucrose solution, and should be further tested on different cells in their culture media. With further validation, the Clausius-Mossotti function can be used to help optimize the dielectrophoresis configuration and algorithm for more complicated cell manipulation. After a cell is trapped on the CPW, the VNA was switched to 9 dBm and 100 kHz for electroporation. Before and after electroporation, the cell could be characterized from 9 kHz to 9 GHz by setting the VNA at −18 dBm to assess the effect of electroporation. This breakthrough not only greatly improves the accuracy and efficiency of electrical cell characterization, but also can enable its throughput to approach that of optical cytometers in the future

Is first pregnancy age associated with hypertension in the Chinese rural women population?

IntroductionThe purpose of this study was to investigate the relationship between first pregnancy age and hypertension later in the life of women from Chinese rural areas.MethodsIn total, 13,493 women were enrolled in the Henan Rural Cohort study. Logistic regression and linear regression were used to evaluate the association between first pregnancy age and hypertension and blood pressure indicators [including systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP)]. The restricted cubic spline was used to examine the dose–response relationship between the first pregnancy age and hypertension or blood pressure indicators.ResultsAfter adjusting for potential confounders, each 1-year increase in first pregnancy age was associated with a 0.221 mmHg increase in SBP values, a 0.153 mmHg increase in DBP values, and a 0.176 mmHg decrease in MAP values (all P < 0.05). The β of SBP, DBP, and MAP showed a trend of first increasing and then decreasing with increasing first pregnancy age and there was no statistical significance after first pregnancy age beyond 33 years on SBP, DBP, and MAP, respectively. A 1-year increment in first pregnancy age was associated with a 2.9% [OR (95% CI): 1.029 (1.010, 1.048)] higher odds of prevalent hypertension. The odds of hypertension increased sharply and then eventually leveled off with an increment of first pregnancy age after adjusting for potential confounders.ConclusionFirst pregnancy age might increase the risk of hypertension later in life and might be an independent risk factor for hypertension in women

Association of gestational age at birth with subsequent suspected Developmental Coordination Disorder in early childhood

Importance. It remains unknown whether children born at different degrees of prematurity, early-term and post-term might have a higher risk of developing Developmental Coordination Disorder (DCD) compared to completely full-term children (39-40 gestational weeks). Objective. To differentiate between suspected DCD in children with different gestational ages based on a national representative sample in China. DESIGN, SETTING, AND PARTICIPANTS We conducted a retrospective cohort study in China from 2018 to 2019. A total of 152,433 children from 2,403 public kindergartens in 551 cities of China aged 3-5 years old were included in the final analysis. The association between gestational age and motor performance was investigated. A multi-level regression model was developed to determine the strength of association for different gestational ages associated with suspected DCD when considering kindergartens as clusters. Main outcomes and measures. Children’s motor performance was assessed using the Little Developmental Coordination Disorder Questionnaire (LDCDQ), completed by parents. Gestational age was determined according to the mother’s medical records. Results. Of the 152,433 children aged 3-5 years old, 80,370 (52.7%) were male, and 72,063 (47.3%) were female. There were 45,052 children aged 3 years old (29.6%), 59,796 aged 4 years old(39.2%), and 47,585 children aged 5 years old (31.2%). The LDCDQ total scores for very-preterm (β=-1.74, 95%CI: -1.98, 1.50; p<0.001), moderately-preterm (β=-1.24, 95%CI: -1.60, -0.89; p<0.001), late-preterm (β=-0.92, 95%CI: -1.08, -0.76; p<0.001), early-term (β=-0.36, 95%CI: -0.46, -0.25; p<0.001) and post-term children (β=-0.47, 95%CI: -0.67, -0.26; p<0.001) were significantly lower than full-term children when adjusting for child, family and maternal health characteristics. The very-preterm (OR=1.35, 95%CI: 1.23,1.48; p<0.001), moderately-preterm (OR=1.18, 95%CI: 1.02, 1.36; p<0.001), late-preterm (OR =1.24, 95%CI: 1.16,1.32; p<0.001), early-term (OR =1.11, 95%CI: 1.06,1.16; p<0.001) and post-term children (OR =1.167, 95%CI: 1.07, 1.27; p<0.001) were more likely to fall in the suspected Developmental Coordination Disorder (DCD) category on the LDCDQ compared with completely full-term children after adjusting for the same characteristics. The associations between different gestational ages and suspected DCD were stronger in boys and older (5 year old) children (each p<0.05). Conclusions and relevance. We found significant associations between every degree of prematurity at birth, early-term and post-term birth with suspected DCD when compared with full-term birth. Our findings have important implications for understanding motor development in children born at different gestational ages. Long-term follow-up and rehabilitation interventions should be considered for early- and post-term born children

Global variations in diabetes mellitus based on fasting glucose and haemogloblin A1c

Fasting plasma glucose (FPG) and haemoglobin A1c (HbA1c) are both used to diagnose diabetes, but may identify different people as having diabetes. We used data from 117 population-based studies and quantified, in different world regions, the prevalence of diagnosed diabetes, and whether those who were previously undiagnosed and detected as having diabetes in survey screening had elevated FPG, HbA1c, or both. We developed prediction equations for estimating the probability that a person without previously diagnosed diabetes, and at a specific level of FPG, had elevated HbA1c, and vice versa. The age-standardised proportion of diabetes that was previously undiagnosed, and detected in survey screening, ranged from 30% in the high-income western region to 66% in south Asia. Among those with screen-detected diabetes with either test, the agestandardised proportion who had elevated levels of both FPG and HbA1c was 29-39% across regions; the remainder had discordant elevation of FPG or HbA1c. In most low- and middle-income regions, isolated elevated HbA1c more common than isolated elevated FPG. In these regions, the use of FPG alone may delay diabetes diagnosis and underestimate diabetes prevalence. Our prediction equations help allocate finite resources for measuring HbA1c to reduce the global gap in diabetes diagnosis and surveillance.peer-reviewe

Damping torque coefficient analysis of PMSG‐based WT with VSG control considering wind turbine dynamics

Abstract This paper expands the damping torque coefficient analysis (DTCA) for studying the small‐signal stability of permanent magnet synchronous generator (PMSG)‐based wind turbine (WT) under virtual synchronous generator (VSG) control with consideration of WT dynamics. Firstly, the typical VSG is implemented in the grid‐side voltage source converter (GSVSC), which enables selfsynchronization without phase‐locked loop (PLL). The maximum power point track (MPPT) algorithms are utilized to give the power reference for VSG. Then, the corresponding inertia and damping support can be provided by the kinetic energy of PMSG. Based on the established model, the DTCA is analytically conducted to not only reveal the key factors that influence the WT stability but also provide guidance for parameter tuning. As a result, it is important to find that the WT dynamics impair the damping and even lead to system instability. Moreover, the minimum value of VSG damping control parameter is analytically given to ensure the system stability under any load below the rated wind speed. Finally, the case studies considering one single PMSG connected to a large grid with and without inclusion of WT dynamics are performed and compared to demonstrate the accuracy of the proposed model and evaluate the applications of DTCA

Signaling Mechanisms of Stem Cell Therapy for Intervertebral Disc Degeneration

Low back pain is the leading cause of disability worldwide. Intervertebral disc degeneration (IDD) is the primary clinical risk factor for low back pain and the pathological cause of disc herniation, spinal stenosis, and spinal deformity. A possible approach to improve the clinical practice of IDD-related diseases is to incorporate biomarkers in diagnosis, therapeutic intervention, and prognosis prediction. IDD pathology is still unclear. Regarding molecular mechanisms, cellular signaling pathways constitute a complex network of signaling pathways that coordinate cell survival, proliferation, differentiation, and metabolism. Recently, stem cells have shown great potential in clinical applications for IDD. In this review, the roles of multiple signaling pathways and related stem cell treatment in IDD are summarized and described. This review seeks to investigate the mechanisms and potential therapeutic effects of stem cells in IDD and identify new therapeutic treatments for IDD-related disorders

The Difficulty to Break a Relational Complexity Network Can Predict Air Traffic Controllers' Mental Workload and Performance in Conflict Resolution

Objective: To test the network disentangling model for explaining air traffic controllers' (ATCos) conflict resolution performance. The network rigidity index (NRI), and the steps to break the relational complexity network following a central-available-node-first rule, was hypothesized to explain the overall task demand, whereas marginal-effort-decrease rule was expected to explain the actual operational outcome. Background: Understanding the conflict resolution process of ATCos is important for aviation safety and efficiency. However, linear models are insufficient. We proposed a new model that ATCos behavior can be largely considered as a process to break the relational complexity network, in which nodes represent the aircraft while links represent the cognitive complexity to understand the aircraft dyad relationship. Method: Twenty-one professional ATCos completed 27 conflict resolution scenarios that varied in the NRI and other control variables. Multilevel regression analyses were performed to understand the influence of the NRI on the number of interventions, mental workload, and unresolved rate. A cross-validation was performed to evaluate the predictive power of the model. Results: NRI influenced ATCos intervention number in a curvilinear manner, which further leads to ATCo's mental workload. The deviance between the number of interventions and the NRI was strongly linked with unresolved rate. Cross-validation suggests that the models predictions are robust. Conclusion: The network disentangling model provides a useful theory-driven way to explain controllers' conflict resolution workload and other important performance outcomes such as intervention probability. Application: The proposed model can potentially be used for workload management, sector design, and intelligent decision support tool development