Non-invasive continuous blood pressure measurement based on mean impact value method, BP neural network, and genetic algorithm

BACKGROUND

Non-invasive continuous blood pressure monitoring can provide an important reference and guidance for doctors wishing to analyze the physiological and pathological status of patients and to prevent and diagnose cardiovascular diseases in the clinical setting. Therefore, it is very important to explore a more accurate method of non-invasive continuous blood pressure measurement.

OBJECTIVE

To address the shortcomings of existing blood pressure measurement models based on pulse wave transit time or pulse wave parameters, a new method of non-invasive continuous blood pressure measurement - the GA-MIV-BP neural network model - is presented.

METHOD

The mean impact value (MIV) method is used to select the factors that greatly influence blood pressure from the extracted pulse wave transit time and pulse wave parameters. These factors are used as inputs, and the actual blood pressure values as outputs, to train the BP neural network model. The individual parameters are then optimized using a genetic algorithm (GA) to establish the GA-MIV-BP neural network model.

RESULTS

Bland-Altman consistency analysis indicated that the measured and predicted blood pressure values were consistent and interchangeable.

CONCLUSIONS

Therefore, this algorithm is of great significance to promote the clinical application of a non-invasive continuous blood pressure monitoring method.

Transductive Zero-Shot Learning With Adaptive Structural Embedding

Zero-shot learning (ZSL) endows the computer vision system with the inferential capability to recognize new categories that have never seen before. Two fundamental challenges in it are visual-semantic embedding and domain adaptation in cross-modality learning and unseen class prediction steps, respectively. This paper presents two corresponding methods named Adaptive STructural Embedding (ASTE) and Self-PAced Selective Strategy (SPASS) for both challenges. Specifically, ASTE formulates the visual-semantic interactions in a latent structural support vector machine framework by adaptively adjusting the slack variables to embody different reliablenesses among training instances. To alleviate the domain shift problem in ZSL, SPASS borrows the idea from self-paced learning by iteratively selecting the unseen instances from reliable to less reliable to gradually adapt the knowledge from the seen domain to the unseen domain. Consequently, by combining SPASS and ASTE, we present a self-paced Transductive ASTE (TASTE) method to progressively reinforce the classification capacity. Extensive experiments on three benchmark data sets (i.e., AwA, CUB, and aPY) demonstrate the superiorities of ASTE and TASTE. Furthermore, we also propose a fast training (FT) strategy to improve the efficiency of most existing ZSL methods. The FT strategy is surprisingly simple and general enough, which speeds up the training time of most existing ZSL methods by 4~300 times while holding the previous performance.

Glibenclamide Enhances the Therapeutic Benefits of Early Hypothermia after Severe Stroke in Rats

Glibenclamide (GBC) is an antidiabetic drug that is in a class of medications known as sulfonylureas, which play critical roles in attenuating brain edema and reducing mortality in ischemic stroke patients. Therapeutic hypothermia (TH) is another robust neuroprotectant that prevents brain swelling and improves the neurological outcomes of stroke patients. However, whether the combination of GBC and TH can be used as a reliable neuroprotectant in ischemic stroke remains largely unknown. We used the middle cerebral artery occlusion (MCAO) rat model as well as oxygen and glucose deprivation-reoxygenation (OGD/R) endothelial cells as ischemic stroke models to investigate the efficacy and mechanisms of treating ischemic stroke with the combination of GBC and TH. The serum glucose, mortality rate, neurobehavioral functions, tight junctions, endothelial cells and inflammatory cytokines were evaluated in the stroke models after treatment with GBC, TH or the combination of them. After 5-hour occlusion and subsequent reperfusion, rats exhibited a large volume of hemispheric swelling and a high mortality rate. Stroke rats treated with the combined therapy did not exhibit hypoglycemia. The combination of GBC and TH exhibited synergistic neuroprotective effects in stroke rats that were associated with greater reductions in edema volume, better improvement in neurobehavioral functions, prevention of tight junction loss, and reduction of expression of the inflammatory cytokines COX-2 and iNOS. In OGD/R endothelia cells, the combination reduced endothelial cell death. This study demonstrated that both GBC and TH are neuroprotective after the severe stroke; however, combined therapy with GBC and TH enhanced the efficiency and efficacy of the effects of TH and GBC in the treatment of ischemia. This combined therapy may facilitate the clinical translation of TH management for severe stroke. The combination of GBC and TH seems to be a feasible and promising clinical strategy to alleviate cerebral injury following severe stroke.

Glibenclamide Prevents Water Diffusion Abnormality in the Brain After Cardiac Arrest in Rats

BACKGROUND

Glibenclamide (GBC) improves neurological outcome after cardiac arrest (CA) in rats. In this study, we sought to elucidate the mechanism responsible for the neuroprotective effects of GBC by using a high-field MRI system.

METHODS

Male Sprague-Dawley rats were subjected to 10-min asphyxial CA followed by cardiopulmonary resuscitation (CPR). Diffusion-weighted imaging (DWI) as well as conventional T2-weighted imaging was conducted prior to CA and at 24, 48, and 72 h after resuscitation. Afterward, histological examination was performed.

RESULTS

Twelve rats were randomized to receive GBC (n = 6) or vehicle (n = 6) at 15 min after return of spontaneous circulation, while four rats were set as sham control. Rats that underwent CA/CPR and received vehicle exhibited distinct neurological deficit, which was alleviated by GBC treatment. Marked water diffusion abnormality as demonstrated by hyperintense DWI in vulnerable regions of the brain was detected after CA/CPR, with the most prominent hyperintense DWI observed in the hippocampal CA1 region at 72 h. Consistently, histological examination revealed neuronal swelling, dendritic injury, and activation of astrocytes and microglia in the hippocampal CA1 region in vehicle-treated rats. Correlation analysis revealed that the ADC values in the hippocampus were significantly correlated with the histological findings (all p < 0.05).

CONCLUSION

These results suggest that the neuroprotective effects of GBC after CA was exerted, as least in part, through prevention of water diffusion abnormality, namely brain edema.

Hyperchloremia Is Associated With Poorer Outcome in Critically Ill Stroke Patients

Background and Purpose: This study aims to explore the cause and predictive value of hyperchloremia in critically ill stroke patients.

Materials and Methods: We conducted a retrospective study of a prospectively collected database of adult patients with first-ever acute ischemic stroke (AIS) or intracerebral hemorrhage (ICH) admitted to the neurointensive care unit (NICU) of a university-affiliated hospital, between January 2013 and December 2016. Patients were excluded if admitted beyond 72 h from onset, if they required neurocritical care for less than 72 h, and were treated with hypertonic saline within 72 h or had creatinine clearance less than 15 mL/min.

Results: Of 405 eligible patients, the prevalence of hyperchloremia ([Cl⁻] ≥ 110 mmol/L) was 8.6% at NICU admission ([Cl⁻]₀) and 17.0% within 72 h ([Cl⁻]_max). Thirty-eight (9.4%) patients had new-onset hyperchloremia and 110 (27.1%) had moderate increase in chloride (Δ[Cl⁻] ≥ 5 mmol/L; Δ[Cl⁻] = [Cl⁻]_max − [Cl⁻]₀) in the first 72 h after admission, which were found to be determined by the sequential organ failure assessment score in multivariate logistic regression analysis. Neither total fluid input nor cumulative fluid balance had significant association with such chloride disturbance. New-onset hyperchloremia and every 5 mmol/L increment in Δ[Cl⁻] were both associated with increased odds of 30-day mortality and 6-month poor outcome, although no independent significance was found in multivariate models.

Conclusion: Hyperchloremia tends to occur in patients more severely affected by AIS and ICH. Although no independent association was found, new-onset hyperchloremia and every 5 mmol/L increment in Δ[Cl⁻] were related to poorer outcome in critically ill AIS and ICH patients.

Subject terms: clinical studies, intracranial hemorrhage, ischemic stroke, mortality/survival, quality and outcomes.

Metformin Improves Neurologic Outcome Via AMP-Activated Protein Kinase-Mediated Autophagy Activation in a Rat Model of Cardiac Arrest and Resuscitation

Background

Sudden cardiac arrest (CA) often results in severe injury to the brain, and neuroprotection after CA has proved to be difficult to achieve. Herein, we sought to investigate the effects of metformin pretreatment on brain injury secondary to CA and cardiopulmonary resuscitation.

Methods and Results

Rats were subjected to 9‐minute asphyxial CA after receiving daily metformin treatment for 2 weeks. Survival rate, neurologic deficit scores, neuronal loss, AMP‐activated protein kinase (AMPK), and autophagy activation were assessed at indicated time points within the first 7 days after return of spontaneous circulation. Our results showed that metformin pretreatment elevated the 7‐day survival rate from 55% to 85% and significantly reduced neurologic deficit scores. Moreover, metformin ameliorated CA‐induced neuronal degeneration and glial activation in the hippocampal CA1 region, which was accompanied by augmented AMPK phosphorylation and autophagy activation in affected neuronal tissue. Inhibition of AMPK or autophagy with pharmacological inhibitors abolished metformin‐afforded neuroprotection, and augmented autophagy induction by metformin treatment appeared downstream of AMPK activation.

Conclusions

Taken together, our data demonstrate, for the first time, that metformin confers neuroprotection against ischemic brain injury after CA/cardiopulmonary resuscitation by augmenting AMPK‐dependent autophagy activation.

[The significance of clinical indicators of different Gram-stained bacteria resulted in secondary intracranial infection after craniocerebral operation]

Objective: To compare and analyze the clinical characteristics and laboratory parameters of central nervous system (CNS) infection caused by different Gram-stained bacteria after craniocerebral surgery, and to provide a preliminary basis for early anti-infection treatment to reduce the use of extended-spectrum antibiotics and the generation of resistant strains. Methods: A single center retrospective study was conducted to investigate the clinical data of patients with intracranial infection after craniocerebral surgery from January 2012 to December 2016 in PLA general hospital. The general conditions, clinical features, laboratory parameters, antibiotic treatments and prognosis were analyzed. Results: A toal of 813 cases of CNS infection after craniocerebral surgery were found during the 5-year period, with an incidence rate of 5.43% (813/14 986). The positive rate of cerebrospinal fluid (CSF)culture was 9.72% (79/813). According to the criteria, 71 cases were included in the study. Among all the cases, 64.8% (46/71) of which were Gram-positive bacteria (G(+) ) and 35.2% (25/71) were identified as Gram-negative bacteria (G(-)). The duration between surgery and meningitis events, as well as the period of antibiotic treatment for G(+) bacteria group were 5.0 (4.0, 6.0) days and (18.3±6.8) days, which were shorter than those of the G(-) bacteria group 9.0(7.0, 11.0) days and (29.2±9.9) days (Z=-6.184, t=-5.245, both P<0.01) , and the differences were statistically significant. The serum procalcitonin concentration in the G(+) group was lower than that in G(-) group [1.02(0.83, 1.27)μg/L vs 2.68(1.97, 5.07)μg/L, Z=-5.719, P<0.01]. The cerebrospinal fluid glucose content was higher than that of G(-) bacteria group[(2.13±1.30) mmol/L vs (1.09±0.95) mmol/L, t=3.512, P<0.01]. The protein level was lower than that of G(-) bacteria group [(1 615.93±848.83) mg/L vs (2 480.60±1 105.28) mg/L, t=-3.679, P<0.01]. Serum C-reactive protein concentrations in the two groups did not show any statistical significance [(96.2±46.1) mg/L vs (117.8±46.3) mg/L, t=-1.884, P>0.05]. In addition, the mortality rate of the G(-) bacteria group was 16.0% (4/25), and 0 in G(+) bacteria group. Conclusion: The time of onset of intracranial infection, serum PCT concentration, and cerebrospinal fluid glucose and protein content caused by Gram-positive bacteria and Gram-negative bacteria are found to be significantly different, and these findings could serve as a preliminary guide for the selection of antibiotics in early experiential anti-infective treatments without the etiology report.

Sirolimus-coated, poly(L-lactic acid)-modified polypropylene mesh with minimal intra-peritoneal adhesion formation in a rat model

PURPOSE

This study evaluated the manufacturing method and anti-adhesion properties of a new composite mesh in the rat model, which was made from sirolimus (SRL) grafts on a poly(L-lactic acid) (PLLA)-modified polypropylene (PP) hernia mesh.

METHODS

PLLA was first grafted onto argon-plasma-treated native PP mesh through catalysis of stannous chloride. SRL was grafted onto the surface of PP-PLLA meshes using catalysis of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) and 4-dimethylaminopyridine (DMAP) in a CH₂Cl₂ solvent. Sprague-Dawley female rats received either SRL-coated meshes, PP-PLLA meshes, or native PP meshes to repair abdominal wall defects. At different intervals, rats were euthanized by a lethal dose of chloral hydrate and adhesion area and tenacity were evaluated. Sections of the mesh with adjacent tissues were assessed histologically.

RESULTS

Attenuated total reflection Fourier transformed infrared (ATR-FTIR) spectroscopy indicated the existence of a C=O group absorption peak (1724.1 cm^-1), and scanning electron microscope morphological analysis indicated that the surface of the PP mesh was covered with SRL. Compared to the native PP meshes and PP-PLLA meshes, SRL-coated meshes demonstrated the greatest ability to decrease the formation of adhesions (P < 0.05) and inflammation.

CONCLUSIONS

The SRL-coated composite mesh showed minimal formation of intra-abdominal adhesions in a rat model of abdominal wall defect repair.

Prevalence and natural course of occult hepatitis B virus infection in residents of 2 communities of Wuwei City, Gansu Province, China

Occult hepatitis B infection (OBI) is characterized by serum hepatitis B surface antigen (HBsAg) negative and hepatitis B virus (HBV) DNA positive (HBsAg-/HBV DNA+). Occult hepatitis B infection in community-based populations has been scarcely investigated, and OBI outcomes remain unclear, especially in Wuwei, a region located in Northwest China. This region is one of the areas in China that has the highest prevalence of chronic HBV infection. A prospective study was performed in the general population of 2 towns of Wuwei from June 2011 to May 2014. A questionnaire was used to collect demographic and medical data, and serum samples were collected from the participants and stored until analysis. DNA was detected using quantitative PCR (qPCR) or nested PCR, the HBV DNA from HBV DNA-positive or possible positive (below the detection limit) subjects was extracted and amplified by nested PCR, and the PCR products were sequenced. Sequence analysis was performed using the Mega 6.0 program and CLC sequence viewer software. Hepatitis B virus DNA was detected in 90 of 3,080 HBsAg-negative subjects, and the prevalence of OBI in the study population was 2.92% (90/3,080, 95% CI: 2.33%-3.51%). Hepatitis B virus genomes in 51 of 80 objects (63.75%) contained mutations in the "a" determinant of HBsAg. After 2 years follow-up, 42 of 90 HBV DNA of OBI subjects remained positive, and the natural clearance rate of OBI subjects was 53.3%. Occult hepatitis B infection prevalence in this cohort was much lower than chronic HBV infection in the same region. HBV DNA was cleared in most OBI subjects during the 2 year period. Our data suggest that some OBI may represent a late stage of resolving the HBV infection process.

Measurements of Multiparticle Correlations in d+Au Collisions at 200, 62.4, 39, and 19.6 GeV and p+Au Collisions at 200 GeV and Implications for Collective Behavior

Recently, multiparticle-correlation measurements of relativistic p/d/^{3}He+Au, p+Pb, and even p+p collisions show surprising collective signatures. Here, we present beam-energy-scan measurements of two-, four-, and six-particle angular correlations in d+Au collisions at sqrt[s_{NN}]=200, 62.4, 39, and 19.6 GeV. We also present measurements of two- and four-particle angular correlations in p+Au collisions at sqrt[s_{NN}]=200  GeV. We find the four-particle cumulant to be real valued for d+Au collisions at all four energies. We also find that the four-particle cumulant in p+Au has the opposite sign as that in d+Au. Further, we find that the six-particle cumulant agrees with the four-particle cumulant in d+Au collisions at 200 GeV, indicating that nonflow effects are subdominant. These observations provide strong evidence that the correlations originate from the initial geometric configuration, which is then translated into the momentum distribution for all particles, commonly referred to as collectivity.

Transductive Zero-Shot Learning With a Self-Training Dictionary Approach

As an important and challenging problem in computer vision, zero-shot learning (ZSL) aims at automatically recognizing the instances from unseen object classes without training data. To address this problem, ZSL is usually carried out in the following two aspects: 1) capturing the domain distribution connections between seen classes data and unseen classes data and 2) modeling the semantic interactions between the image feature space and the label embedding space. Motivated by these observations, we propose a bidirectional mapping-based semantic relationship modeling scheme that seeks for cross-modal knowledge transfer by simultaneously projecting the image features and label embeddings into a common latent space. Namely, we have a bidirectional connection relationship that takes place from the image feature space to the latent space as well as from the label embedding space to the latent space. To deal with the domain shift problem, we further present a transductive learning approach that formulates the class prediction problem in an iterative refining process, where the object classification capacity is progressively reinforced through bootstrapping-based model updating over highly reliable instances. Experimental results on four benchmark datasets (animal with attribute, Caltech-UCSD Bird2011, aPascal-aYahoo, and SUN) demonstrate the effectiveness of the proposed approach against the state-of-the-art approaches.

Nuclear Dependence of the Transverse-Single-Spin Asymmetry for Forward Neutron Production in Polarized p+A Collisions at sqrt[s_{NN}]=200 GeV

During 2015, the Relativistic Heavy Ion Collider (RHIC) provided collisions of transversely polarized protons with Au and Al nuclei for the first time, enabling the exploration of transverse-single-spin asymmetries with heavy nuclei. Large single-spin asymmetries in very forward neutron production have been previously observed in transversely polarized p+p collisions at RHIC, and the existing theoretical framework that was successful in describing the single-spin asymmetry in p+p collisions predicts only a moderate atomic-mass-number (A) dependence. In contrast, the asymmetries observed at RHIC in p+A collisions showed a surprisingly strong A dependence in inclusive forward neutron production. The observed asymmetry in p+Al collisions is much smaller, while the asymmetry in p+Au collisions is a factor of 3 larger in absolute value and of opposite sign. The interplay of different neutron production mechanisms is discussed as a possible explanation of the observed A dependence.

Morphological-adaptive photoacoustic tomography with flexible transducer and flexible orientation light

Although conventional photoacoustic tomography (PAT) provides high optical contrast and high ultrasound resolution in depth, its fixed-energy-distribution laser and unchangeable-shaped detector hinder its implementations on clinical routine breast screening. In this Letter, for the first time, to the best of our knowledge, we present a fully flexible photoacoustic coupling system (FPACS) that integrates optical fiber bundles and a flexible ultrasonic transducer for morphological-adaptive breast detection. The experimental results show that the system has better resolution and higher energy utilization than traditional PAT systems, even at the edge of the imaging region. Moreover, the system can achieve morphological adaption, suggesting that the FPACS provides the potential for clinical routine breast screening.

Overt and occult hepatitis B virus infection among community children in Northwest China

Although a universal newborn hepatitis B (HB) immunization programme has been implemented in China, hepatitis B virus (HBV) breakthrough infection, including HB surface antigen (HBsAg)-positive infection and occult HBV infection (OBI), still occurs during infancy or childhood. Obtaining the actual prevalence of HBV infection in general children is important for preventing and controlling the spread of HB. Accordingly, we investigated the prevalence of overt infection and OBI in community children and compared the serological and virological characteristics of OBI and HBsAg carrier children to clarify the mechanisms related to OBI. In total, 6 706 community children <12 years of age were included from a population-based HBV seroepidemiological investigation in Northwest China. The HBsAg carrier rate in community children was 1.60% (107/6706), and the anti-HBs positive rate was 57.35% (3846/6706). Additionally, 1192 HBsAg-negative children were examined for OBI using nested PCR. The prevalence of OBI in local children was 1.26% (15/1192), and the predominant OBI genotypes were C and D. The 15 OBI children and 29 HBsAg-positive children from the same population did not have a statistical significant difference in age, gender, alanine aminotransferase (ALT), proportion of anti-HBs or anti-HBc, viral genotypes or mutations. Children with chronic overt infection had higher viral loads than OBI children (P=.004). These results suggested that HBV overt and occult infection of children was more serious in underdeveloped north-west regions. HBV neonatal immunization and catch-up programmes should be strengthened and supplemented. None of specific viral mutations or genotypes related to OBI were found. OBI may be a specific stage of HBV infection.

[The research of near-infrared blood glucose measurement using particle swarm optimization and artificial neural network]

Existing near-infrared non-invasive blood glucose detection modelings mostly detect multi-spectral signals with different wavelength, which is not conducive to the popularization of non-invasive glucose meter at home and does not consider the physiological glucose dynamics of individuals. In order to solve these problems, this study presented a non-invasive blood glucose detection model combining particle swarm optimization (PSO) and artificial neural network (ANN) by using the 1 550 nm near-infrared absorbance as the independent variable and the concentration of blood glucose as the dependent variable, named as PSO-2ANN. The PSO-2ANN model was based on two sub-modules of neural networks with certain structures and arguments, and was built up after optimizing the weight coefficients of the two networks by particle swarm optimization. The results of 10 volunteers were predicted by PSO-2ANN. It was indicated that the relative error of 9 volunteers was less than 20%; 98.28% of the predictions of blood glucose by PSO-2ANN were distributed in the regions A and B of Clarke error grid, which confirmed that PSO-2ANN could offer higher prediction accuracy and better robustness by comparison with ANN. Additionally, even the physiological glucose dynamics of individuals may be different due to the influence of environment, temper, mental state and so on, PSO-2ANN can correct this difference only by adjusting one argument. The PSO-2ANN model provided us a new prospect to overcome individual differences in blood glucose prediction.

[Effect of image fusion technology of radioactive particles implantation before and after the planning target and dosimetry]

Objective: To compare the post-implant target volumes and dosimetric evaluation with pre-plan, the gross tumor volume(GTV) by CT image fusion-based and the manual delineation of target volume in CT guided radioactive seeds implantation. Methods: A total of 10 patients treated under CT-guidance (125)I seed implantation during March 2016 to April 2016 were analyzed in Peking University Third Hospital.All patients underwent pre-operative CT simulation, pre-operative planning, implantation seeds, CT scanning after seed implantation and dosimetric evaluation of GTV.In every patient, post-implant target volumes were delineated by both two methods, and were divided into two groups. Group 1: image fusion pre-implantation simulation and post-operative CT image, then the contours of GTV were automatically performed by brachytherapy treatment planning system; Group 2: the contouring of the GTV on post-operative CT image were performed manually by three senior radiation oncologists independently. The average of three data was sets. Statistical analyses were performed using SPSS software, version 3.2.0. The paired t-test was used to compare the target volumes and D(90) parameters in two modality. Results: In Group 1, average volume of GTV in post-operation group was 12-167(73±56) cm(3). D(90) was 101-153 (142±19)Gy. In Group 2, they were 14-186(80±58)cm(3) and 96-146(122±16) Gy respectively. In both target volumes and D(90), there was no statistical difference between pre-operation and post-operation in Group 1.The D(90) was slightly lower than that of pre-plan group, but there was no statistical difference (P=0.142); in Group 2, between pre-operation and post-operation group, there was a significant statistical difference in the GTV (P=0.002). The difference of D(90) was similarly (P<0.01). Conclusion: The method of delineation of post-implant GTV through fusion pre-implantation simulation and post-operative CT scan images, the contours of GTV are automatically performed by brachytherapy treatment planning system appears to have improved more accuracy, reproducibility and convenience than manual delineation of target volume by maximum reduce the interference from artificial factor and metal artifacts. Further work and more cases are required in the future.

A novel mutation R190H in the AT-hook 1 domain of MeCP2 identified in an atypical Rett syndrome

Background

Mutations in Methyl-CpG binding protein 2 (MECP2) have been identified as the disease-causing mutations in Rett Syndrome (RTT). However, no mutation in the AT-hook 1 domain of MECP2 has been reported in RTT yet. The function of AT-hook 1 domain of MECP2 has not been described either.

Methods

The clinical and radiological features of a girl with progressive hyperactivity and loss of acquired linguistic and motor functions were presented. Next generation sequencing was used to screen the causative gene. Effect of the mutant protein on histone 3 methylation was assessed in vitro experiment.

Results

The patient was diagnosed with an atypical RTT at the age of nine. Magnetic resonance imaging revealed a loss of whole-brain volume and abnormal myelination. Genetic analysis identified a de novo novel missense mutation of MECP2 (NM_004992, c.570G->A, p.Arg190His). This mutation is located in the AT-hook 1 domain of MeCP2 protein. Overexpression of the mutant MeCP2 in cultured neuroblastoma cells SH-SY5Y revealed increased level of dimethylated histone 3 lysine 9, a transcriptional repressor marker.

Conclusion

A novel missense mutation in AT-hook 1 domain of MeCP2 was identified in a patient with atypical RTT. Clinical data and in vitro experiment result imply that R190H mutation in AT-hook1 may cause dysfunction of MeCP2 and be a pathogenic variant.

Polymer Flow Behavior Analysis Based on Physical Visualization Technology for Ultrasonic Vibration-Assisted Injection Molding

To understand the flow behavior of a melted polymer during injection molding with ultrasonic vibration, a new visualization device was developed and a method was proposed to analyze the filling velocity field during the injection molding process. Using the device and method, both the influence of ultrasonic vibration on the velocity of the filling front and the velocity distribution of a polypropylene melt within a cavity are discussed. The results showed that the filling front velocity of the melt was improved by ultrasonic vibration (the filling front velocity was improved by up to 27% when 200 W of ultrasonic power was applied). In addition, it was shown that the velocity gradient of the melt within the cavity decreased, and that the velocity distribution became more uniform during ultrasonic vibration.