Structural Design and DLP 3D Printing Preparation of High Strain Stable Flexible Pressure Sensors.

Flexible pressure sensors are crucial force-sensitive devices in wearable electronics, robotics, and other fields due to their stretchability, high sensitivity, and easy integration. However, a limitation of existing pressure sensors is their reduced sensing accuracy when subjected to stretching. This study addresses this issue by adopting finite element simulation optimization, using digital light processing (DLP) 3D printing technology to design and fabricate the force-sensitive structure of flexible pressure sensors. This is the first systematic study of how force-sensitive structures enhance tensile strain stability of flexible resistive pressure sensors. 18 types of force-sensitive structures have been investigated by finite element design, simultaneously, the modulus of the force-sensitive structure is also a critical consideration as it exerts a significant influence on the overall tensile stability of the sensor. Based on simulation results, a well-designed and highly stretch-stable flexible resistive pressure sensor has been fabricated which exhibits a resistance change rate of 0.76% and pressure sensitivity change rate of 0.22% when subjected to strains ranging from no tensile strain to 20% tensile strain, demonstrating extremely low stretching response characteristics. This study presents innovative solutions for designing and fabricating flexible resistive pressure sensors that maintain stable sensing performance even under stretch conditions.

Oligonucleotide drugs and their progress in stomatology / 中华口腔医学杂志

Oligonucleotide drugs have the characteristics of targeting, modifiability and high biosafety. Recent studies have shown that oligonucleotide can be used to make biosensors, vaccine adjuvants, and has the functions of inhibiting alveolar bone resorption, promoting jaw and alveolar bone regeneration, anti-tumor, destroying plaque biofilm, and precise control of drug release. Therefore, it has a broad application prospect in the field of stomatology. This article reviews the classification, action mechanism and research status of oligonucleotide in stomatology. The aim is to provide ideas for further research and application of oligonucleotide.

Oligonucleotide drugs and their progress in stomatology / 中华口腔医学杂志

Oligonucleotide drugs have the characteristics of targeting, modifiability and high biosafety. Recent studies have shown that oligonucleotide can be used to make biosensors, vaccine adjuvants, and has the functions of inhibiting alveolar bone resorption, promoting jaw and alveolar bone regeneration, anti-tumor, destroying plaque biofilm, and precise control of drug release. Therefore, it has a broad application prospect in the field of stomatology. This article reviews the classification, action mechanism and research status of oligonucleotide in stomatology. The aim is to provide ideas for further research and application of oligonucleotide.

Autopsy results from a COVID-19 patient treated in a tropical area, and a review of the epidemiological history.

Since the start of the COVID-19 pandemic, there has been an urgent need to produce accurate and sensitive tests. However, there have been instances where a positive nucleic acid test turns negative after treatment, and then positive again. This case report describes such an instance from the tropical region of Hainan, China. The patient was a 61-year-old female who went to Hainan on vacation from Wuhan during the COVID-19 pandemic in 2020. Symptoms appeared 9 d after arriving in Hainan, and it was confirmed that the nucleic acid test was positive after 4 repeats. Her condition declined rapidly, her heart stopped beating, and she was admitted in a coma to the ICU. After treatment, the SARS-CoV-2 virus nucleic acid test of several nasopharyngeal swabs were negative, and tests on whole blood, anal swabs, and urine were also negative. Later, however, nucleic acid tests on a lower respiratory tract sputum swab and lower respiratory tract lavage fluid were positive. An autopsy examination was carried out 12 h after her death, and multi-organ secretions were extracted for nucleic acid testing. The SARS-CoV-2 virus nucleic acid was only detected in the swabs from the end of the bronchus, which was confirmed by the visualization of the coronavirus by electron microscopy. Autopsy confirmed that the damage was mainly concentrated in the lungs and immune organs and tissues throughout the body. Epidemiology indicated that none of the people she came into contact with after arriving in Hainan, including close contacts, were infected. This is in sharp contrast to the highly contagious virus in Wuhan in the temperate zone during the same period. This case report indicates: (1) The high temperatures in tropical areas may have an impact on the spread and harm of COVID-19, and (2) The reason why nucleic acid testing for COVID-19 was initially negative and then positive after treatment may be related to the survival of the SARS-CoV-2 virus in deep lung tissues.

High Mechanical Properties of Stretching Oriented Poly(butylene succinate) with Two-Step Chain Extension.

The structure, morphology, fracture toughness and flaw sensitivity length scale of chain-extended poly(butylene succinate) with various pre-stretch ratios were studied. PBS modification adopted from a multifunctional, commercially available chain-extension containing nine epoxy groups (ADR9) as the first step chain extension and hydroxyl addition modified dioxazoline (BOZ) as the second step. Time-temperature superposition (TTS) studies show that the viscosity increased sharply and the degree of molecular branching increased. Fourier transform infrared spectroscopy (FT-IR) confirm successful chain extension reactions. The orientation of the polymer in the pre-stretch state is such that spherulites deformation along the stretching direction was observed by polarized light optical microscopy (PLOM). The fracture toughness of sample (λfix = 5) is Γ ≈ 106 J m-2 and its critical flaw sensitivity length scale is Γ/Wc ≈ 0.01 m, approximately 5 times higher than PBS without chain-extension (Γ ≈ 2 × 105 J m-2 and Γ/Wc ≈ 0.002 m, respectively). The notch sensitivity of chain-extended PBS is significantly reduced, which is due to the orientation of spherulites more effectively preventing crack propagation. The principle can be generalized to other high toughness material systems.

Early changes to the extracellular space in the hippocampus under simulated microgravity conditions.

The smooth transportation of substances through the brain extracellular space (ECS) is crucial to maintaining brain function; however, the way this occurs under simulated microgravity remains unclear. In this study, tracer-based magnetic resonance imaging (MRI) and DECS-mapping techniques were used to image the drainage of brain interstitial fluid (ISF) from the ECS of the hippocampus in a tail-suspended hindlimb-unloading rat model at day 3 (HU-3) and 7 (HU-7). The results indicated that drainage of the ISF was accelerated in the HU-3 group but slowed markedly in the HU-7 group. The tortuosity of the ECS decreased in the HU-3 group but increased in the HU-7 group, while the volume fraction of the ECS increased in both groups. The diffusion rate within the ECS increased in the HU-3 group and decreased in the HU-7 group. The alterations to ISF drainage and diffusion in the ECS were recoverable in the HU-3 group, but neither parameter was restored in the HU-7 group. Our findings suggest that early changes to the hippocampal ECS and ISF drainage under simulated microgravity can be detected by tracer-based MRI, providing a new perspective for studying microgravity-induced nano-scale structure abnormities and developing neuroprotective approaches involving the brain ECS.

Managing Vibration Training Safety by Using Knee Flexion Angle and Rating Perceived Exertion.

Whole-body vibration (WBV) is commonly applied in exercise and rehabilitation and its safety issues have been a major concern. Vibration measured using accelerometers can be used to further analyze the vibration transmissibility. Optimal bending angles and rating of perceived exertion (RPE) evaluations have not been sufficiently explored to mitigate the adverse effect. Therefore, the aims of this study were to investigate the effect of various knee flexion angles on the transmissibility to the head and knee, the RPE during WBV exposure, and the link between the transmissibility to the head and the RPE. Sixteen participants randomly performed static squats with knee flexion angles of 90, 110, 130, and 150 degrees on a WBV platform. Three accelerometers were fixed on the head, knee, and center of the vibration platform to provide data of platform-to-head and platform-to-knee transmissibilities. The results showed that the flexion angle of 110 degrees induced the lowest platform-to-head transmissibility and the lowest RPE (p < 0.01). A positive correlation between RPE and the platform-to-head transmissibility was observed. This study concluded that a knee flexion of about 110 degrees is most appropriate for reducing vibration transmissibility. The reported RPE could be used to reflect the vibration impact to the head.

Research progress on chemical constituents and biological activities of Arisaematis Rhizoma / 中国中药杂志

Arisaematis Rhizoma included in the Chinese Pharmacopoeia is the dried tuber of Arisaema erubescens, A. heterophyllum or A. amurense in the family Araceae. This paper mainly focuses on the classification and summary of the chemical components and structures reported in recent years in the above three varieties of this medicinal material included in the pharmacopoeia, including alkaloids, flavonoids, phenylpropanoids, lignans and benzene ring derivatives, steroids and terpenes, glycosides and esters, etc. Then we reviewed the reported biological activities of these chemical components, including cytotoxicity, antitumor activity, antibacterial activity, nematicidal activity, etc. Although there have been reports on the review of the chemical composition of the medicinal material, the structure and classification of the chemical composition in these reviews are not clear enough. This review provides a basis for the later study of the chemical composition of this medicinal material, especially the identification of the chemical structures. And most of the current reviews on the biological activity of this medicinal material are mainly for the crude extract. This paper mainly summarized the biological activity of related monomer compounds and expected to lay a foundation for the development of novel high-efficiency and low-toxicity active leading compounds from Arisaematis Rhizoma.

A numerical simulation method of natural fragment formation and injury to human thorax.

OBJECTIVE: Fragment injury is a type of blast injury that is becoming more and more common in military campaigns and terrorist attacks. Numerical simulation methods investigating the formation of natural fragments and injuries to biological targets are expected to be developed. METHODS: A cylindrical warhead model was established and the formation process of natural fragments was simulated using the approach of tied nodes with failure through the explicit finite element (FE) software of LS-DYNA. The interaction between the detonation product and the warhead shell was simulated using the fluid-structure interaction algorithm. A method to simulate the injury of natural fragments to a biological target was presented by transforming Lagrange elements into smooth particle hydrodynamics (SPH) particles after the natural fragments were successfully formed. A computational model of the human thorax was established to simulate the injury induced by natural fragments by the node-to-surface contact algorithm with erosion. RESULTS: The discontinuous velocities of the warhead shell at different locations resulted in the formation of natural fragments with different sizes. The velocities of natural fragments increased rapidly at the initial stage and slowly after the warhead shell fractured. The initial velocities of natural fragments at the central part of the warhead shell were the largest, whereas those at both ends of the warhead shell were the smallest. The natural fragments resulted in bullet holes that were of the same shape as that of the fragments but slightly larger in size than the fragments in the human thorax after they penetrated through. Stress waves propagated in the ribs and enhanced the injury to soft tissues; additionally, ballistic pressure waves ahead of the natural fragments were also an injury factor to the soft tissues. CONCLUSION: The proposed method is effective in simulating the formation of natural fragments and their injury to biological targets. Moreover, this method will be beneficial for simulating the combined injuries of natural fragments and shock waves to biological targets.

Augmented reality-assisted training with selected Tai-Chi movements improves balance control and increases lower limb muscle strength in older adults: A prospective randomized trial.

BACKGROUND: Tai-Chi benefits older adults by enhancing balance control and increasing the muscle strength of the lower limbs. However, a complete set of traditional Tai-Chi exercises is sometimes too difficult for beginners. We investigated whether practicing augmented reality-assisted training with selected Tai-Chi movements tailored to the practitioner's ability (selected Tai-Chi, or sTC) is as effective as performing a complete set of Tai-Chi sequences (complete traditional Tai-Chi, or tTC). METHODS: In this prospective randomized trial carried out in the Beitou District of Taipei City, Taiwan, community-dwelling adults aged ≥65 and without any debilitating diseases (n = 28) were included. Participants were randomly assigned to the sTC group (n = 14) or the tTC group (n = 14). Participants in the sTC group practiced selected Tai-Chi movements using the augmented reality Tai-Chi training system. Participants of the tTC group were asked to complete the 24-form Yang-style Tai-Chi following the instructions of Tai-Chi masters. Each training session lasted 30 min, with 3 sessions per week for 8 weeks. Pre- and post-intervention evaluations included functional balance tests, comprising the Berg Balance Scale (BBS), Timed Up and Go test (TUG), and Functional Reach Test (FRT), as well as muscle strength measurements of the lower extremities. RESULTS: Pre-intervention evaluations showed significant differences in FRT (p = 0.034) and left hip abductor muscle strength (p = 0.046) between the sTC and tTC groups. After 8 weeks of training, the BBS, TUG, and FRT scores in the sTC group showed significant improvement overall. Although all three functional balance test scores improved in the tTC group, only the improvement in BBS was statistically significant (p = 0.001). After 8 weeks, all muscle strength measurements increased by an average of 3.1 ± 1.0 kgw in the sTC group and 1.6 ± 0.8 kgw in the tTC group. CONCLUSIONS: The augmented reality-assisted training with selected Tai-Chi movements, designed based on objective measurements of the practitioner's capability, improved balance control and muscle strength of lower limbs at least as effectively as the complete sequence of traditional Tai-Chi exercises. TRIAL REGISTRATION: This study was approved by the Institutional Review Board of National Yang-Ming University (IRB number: 1000087). Written informed consent was obtained from all participants.

UPLC-Q-TOF/MS Based Metabolomics Approach to Study the Hepatotoxicity of Cantharidin on Mice.

Cantharidin is the major bioactive compound extracted from the blister beetle, a traditional Chinese medicine, and has been proved to be a natural component with widely antitumor activity. However, clinical application of cantharidin is relatively restricted due to its potential toxic effects, especially hepatotoxicity. Although cantharidin-induced liver injury has been reported, the underlying molecular mechanisms remain unclear. In the present study, an UPLC-Q-TOF/MS based metabolomics approach combined with blood biochemical analysis, histopathological examination, and cell apoptosis assay were used to investigate the mechanisms of cantharidin-induced hepatotoxicity. A total of 54 significantly changed metabolites and 14 disturbed metabolic pathways were identified in the cantharidin exposed groups. Among them, four metabolites (oxidized glutathione, glutathione, 3-sulfinoalanine, and deoxycholic acid 3-glucuronide) were selected based on their high impact value and potential biological function in the process of liver injury post cantharidin treatment. Our study provides a deeper understanding of the mechanisms of cantharidin-induced hepatotoxicity and may contribute to reduce the liver injury and gain more effective and safe clinical use of cantharidin. In addition, our results also demonstrated that cantharidin could impair multiple biological processes in liver, and future studies will be necessary to reveal the detailed molecular mechanisms of cantharidin-induced hepatotoxicity.

Population data of 19 autosomal STR loci in the Li population from Hainan Province in southernmost China.

In the present study, population data of 19 autosomal STR loci included in the Goldeneye™ DNA ID System 20A in 653 Li individuals was obtained and population genetic relationships among 13 populations were investigated. MDS and phylogenetic analysis suggested that the Hainan Li population kept a close genetic relationship with the Chinese Han populations, especially for Southern Han populations (Guangdong Han, Sichuan Han, and Hunan Han). Our results indicated that the 19 autosomal STRs are highly discriminative and polymorphic in the Hainan Li population suitable for personal forensic identification and paternity testing.

Feasibility and outcome of an individualized Tai Chi program for improving balance and strength in the elderly: A pilot study.

BACKGROUND: Traditional Tai Chi is too complex for most elderly individuals. There have been few reports regarding the development of simplified Tai Chi programs to suit the physical needs of elderly adults. However, these programs were not individualized according to the participants' balance control abilities. OBJECTIVE: Purpose of this study is to develop an individualized Tai Chi program and report the feasibility of the program. METHODS: Phase 1: Five Tai Chi masters performed the Tai Chi movements on a force platform. Based on the results of center of pressure displacement and the individual's balance abilities, an individualized program was developed.Phase 2: Ten community-dwelling older adults received 24 half-hour-sessions, using the individualized Tai Chi exercise program. The Berg Balance Scale (BBS) score, Timed Up & Go (TUG) test, forward reach, and strength of the knee extensor were determined before and after intervention. RESULTS: Participants achieved improved performance on balance control as measured with BBS (p≤0.001), TUG (p = 0.004) and forward reach (p = 0.035) as well as knee extensor strength (p = 0.002) after the program. CONCLUSIONS: This preliminary result suggests that the individualized Tai Chi program is potentially effective to improve balance function and knee extensor strength of the elderly.

The evaluation of forensic characteristics and the phylogenetic analysis of the Ong Be language-speaking population based on Y-STR.

The Ong Be language, an important branch of the Tai-Kadai language family, is one of the most distinctive languages on Hainan Island. Ong Be language speakers, who have lived in the Lingao district of Hainan Island for generations, were classified as Han Chinese in the early days of the establishment of the People's Republic of China but have distinct differences from the Han Chinese in language, lifestyle, customs and values and particularly in appearances and features. Currently, Y-chromosomal short tandem repeat (STR) haplotypes have been widely used in genetic applications, such as human forensics, historical investigations and genealogical research. In this study, 487 unrelated male individuals residing in the Lingao district volunteered, and their Y-STR haplotypes were investigated using the Yfiler and Yfiler Plus with 17 and 27 Y-STR loci, respectively. Furthermore, we combined our population data on the Lingao people with existing datasets from Asian nations (East, South and Southeast Asia) to explore the genetic variance and relationships with Han Chinese from different administrative regions in Northern and Southern China and Chinese ethnic minorities officially recognized by the PRC. Population comparisons demonstrated that the Lingao people had distant relationships with Asian nations at the national level and had relatively close genetic and linguistic relationships with Hainan Li and Guizhou Gelao, both of whom belong to the Tai-Kadai language family. The present results increase our understanding of the genetic relationships between the Lingao people and other groups, and further research in genetics and other areas is still needed to trace the origin of the Lingao people.

Application of enhanced recovery after surgery in perioperative period of hepatectomy:a Meta - analysis / 临床肝胆病杂志

Objective To systematically review the value of enhanced recovery after surgery(ERAS)in the perioperative period of hepatec-tomy. Methods A literature search was conducted in PubMed,Embase,Cochrane Library,Sinomed,Wanfang Data,VIP,and CNKI to iden-tify the articles on the application of ERAS in the perioperative period of hepatectomy published up to July 2017. Quality evaluation and data extraction were performed for the included articles. A Meta - analysis was performed using Revman 5.3 software. Results A total of 17 articles were included,with 14 randomized controlled trials and 3 controlled clinical trials. A total of 2220 patients were involved and divided into ERAS group(n=1002)and control group(n=1218). Compared with the control group,the ERAS group had significantly shortened length of postoperative hospital stay(weighted mean difference[WMD]= -2.58,95% confidence interval[CI]:-3.47 to-1.70,P<0.05),functional rehabilitation time(WMD= -3.39,95%CI:-4.32 to -2.45,P<0.05),and time to first flatus(standardized mean difference[SMD]= -1.56,95%CI:-2.15 to -0.97,P<0.05),as well as reduced complication rate(odds ratio[OR]=0.64,95%CI:0.52-0.78,P<0.05)and hospital costs(SMD= -0.85,95%CI:-1.23 to -0.47,P<0.05).There were no significant differences between the two groups in readmission rate(OR =1.28,95%CI:0.69 -2.69,P > 0.05),operation time(WMD = -11.36,95%CI:-23.25 to 0.53,P>0.05),and intraoperative blood loss(WMD= -22.62,95%CI:-38.89 to -6.34,P>0.05).Conclusion ERAS is safe and effective in the perioperative period of hepatectomy and holds promise for clinical application.

iRSpot-EL: identify recombination spots with an ensemble learning approach.

MOTIVATION: Coexisting in a DNA system, meiosis and recombination are two indispensible aspects for cell reproduction and growth. With the avalanche of genome sequences emerging in the post-genomic age, it is an urgent challenge to acquire the information of DNA recombination spots because it can timely provide very useful insights into the mechanism of meiotic recombination and the process of genome evolution. RESULTS: To address such a challenge, we have developed a predictor, called IRSPOT-EL: , by fusing different modes of pseudo K-tuple nucleotide composition and mode of dinucleotide-based auto-cross covariance into an ensemble classifier of clustering approach. Five-fold cross tests on a widely used benchmark dataset have indicated that the new predictor remarkably outperforms its existing counterparts. Particularly, far beyond their reach, the new predictor can be easily used to conduct the genome-wide analysis and the results obtained are quite consistent with the experimental map. AVAILABILITY AND IMPLEMENTATION: For the convenience of most experimental scientists, a user-friendly web-server for iRSpot-EL has been established at http://bioinformatics.hitsz.edu.cn/iRSpot-EL/, by which users can easily obtain their desired results without the need to go through the complicated mathematical equations involved. CONTACT: bliu@gordonlifescience.org or bliu@insun.hit.edu.cnSupplementary information: Supplementary data are available at Bioinformatics online.

Study on therapeutic effects of arthroscopic repair on medial patellar retinaculum acute injury / 中国骨伤

<p><b>OBJECTIVE</b>To accurately define the injury position of medial patellar retinaculum with acute injury under the guiding of high frequency ultrasonography, and to study therapeutic effects of suture operation on medial patellar retinaculum in the injuried position.</p><p><b>METHODS</b>From June 2009 to March 2014, there were 17 patients with acute patellar dislocation, 6 males and 11 females with average age of (16.2±6.2) years old. The duration time of patellar dislocation was 2 weeks. Before operation, the medial patellar retinaculum of all patients were examined with the high frequency ultrasonography, and the skin with the non-continuous fiber was iudicated as the surface mark under the high frequency ultrasonography. The injury position of medial retinaculum was in the middle of 5 patients who were treated with suture operation of arthroscopic medial retinaculum. The injury position was in the patellar edge in 12 patients who were treated with fixing bone anchor on patella and arthroscopic suture operation of medial retinaculum. The CT examination and Kujala scores, patellar tilt angle on CT film, measured maximal angles of passive or active knee flexion and apprehension test were observed before treatment and postoperative 18 months.</p><p><b>RESULTS</b>Eighteen months after treatment, Kujala scores were 92.2±11.1 and patellar tilt angle were(11.5±4.2) °, and there was no statistical difference between post-operation and pre-operation. The difference between maximal angles of passive knee flexion(133.5±4.2) ° and normal had no statistically significance. Maximal angles of active knee flexion were(153.5±4.6) °. Ultrasonography showed the continuous fiber of medial retinaculum. A patient showed positive apprehension test and no patient had the recurrence patella instability after operation.</p><p><b>CONCLUSIONS</b>The injury position of medial patellar retinaculum was accurately shown by high frequency ultrasonography and treated with arthroscopic suture operation. Knee immobilization time after operation was shorten. Eighteen months after operation, knee joint function was good, and no patient had the recurrence patella instability.</p>

Transcription factor Sp1 in regulation of transcription of VEGF in hypoxia-induced hepatocellular cells / 军事医学

Objective To investigate the role of Sp1 in the regulation of transcription of vascular endothelial growth factor ( VEGF ) in hypoxia-induced HepG2 cells.Methods Quantitative real-time polymerase chain reaction and immunoblot assay were used to examine the effect of hypoxia on Sp1 protein and VEGF mRNA expression .Mithramycin A, the selective inhibitor of Sp1 and knock-out Sp1 gene with siRNA were used to examine the effect on VEGF mRNA expression induced by hypoxia in HepG2 cells.Results Hypoxia induced Sp1 protein and VEGF mRNA expression in HepG2 cells.Mithramycin A produced a concentration-dependent decrease of hypoxia-induced VEGF mRNA expression . After inhibition of Sp1 RNAi, VEGF mRNA expression was significantly repressed in HepG 2 cells.Conclusion Hypoxia can increase the expression of Sp1 protein and VEGF mRNA in HepG2 cells induced by hypoxia.The transcription of VEGF is regulated by Sp1 in hypoxia-induced HepG2 cells.