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The friction type tensioner is an energy absorbing component in belt drive system which has hysteretic torque and nonlinear damping. In this paper, a hysteretic model is used for describing the tensioner’s operating torque versus the imposed angle, and considered into the dynamic analysis of a belt drive system. The modeling process for calculating the vibration responses of a belt drive system is presented, and two iterative methods are proposed for estimating the tensioner’s nonlinear damping in a varying excitation frequency. One timing belt drive system is taken as a case study. The system’s vibration responses, such as the oscillation angle of tensioner arm, the transmission error between pulleys and the hub load on pulley are calculated and compared with the measured values, which validate the presented methods. The influence of iterative method on the computational efficiency and iterative accuracy are both discussed. At last a modified method is presented to improve iterative efficiency. The presented technique can improve the computational efficiency with a good computational accuracy.

This study aimed to better understand the prognostic effect of multiple genetic markers and identify more subpopulations at ultra high risk of poor outcome in bone marrow (BM) metastatic neuroblastoma (NB).We screened the MYCN, 1p36 and 11q23 loss of heterozygosity (LOH) statuses of 154 patients by interphase fluorescence in situ hybridization of BM cells. The clinical characteristics of patients with the three markers and their associations with prognosis were analysed.MYCN amplification and LOH at 1p36 and 11q23 were identified in 16.2%, 33.1% and 30.5% of patients, respectively. There were strong associations between MYCN amplification and 1p36 LOH as well as 11q23 LOH. Both MYCN amplification and 1p36 LOH were strongly associated with high levels of lactate dehydrogenase (LDH) and neuron-specific enolase, more than 3 metastatic organs, and more events. 11q23 LOH occurred mainly in patients older than 18 months, and those who had high LDH levels. In univariate analysis, patients with MYCN amplification had poorer prognosis than those without. Patients with 1p36 LOH had a 3-year event-free survival (EFS) and overall survival lower than those without. 11q23 LOH was associated with poorer EFS only for patients without MYCN amplification. In a multivariate model, MYCN amplification was independently associated with decreased EFS in all cohorts. 11q23 LOH was an independent prognostic factor for patients without MYCN amplification, whereas 1p36 LOH was not an independent marker regardless of MYCN amplification. Compared with all cohorts, patients with both MYCN amplification and 1p36 LOH had the worst outcome and clinical features.Patients with both MYCN amplification and 1p36LOH had the worst survival rate, indicating an ultra high-risk group. Our results may be applied in clinical practice for accurate risk stratification in future studies.

In the existing studies, the hysteretic model of tensioner is applied in analysis of a belt drive system which can improve the computational accuracy. But the computational efficiency is low and not suitable for system optimization. In this paper, an approach is presented to simplify the tensioner’s hysteretic model into an equivalent stiffness and damping which is used for improving the computational efficiency of vibration responses of the belt drive system. A simplified model and computation method of a belt drive system is established. The hysteretic model of a belt tensioner consists of a linear stiffness and viscous damping based on the averaging energy method to simplify the hysteretic parameters and improve the computational efficiency. The equivalent linear stiffness and damping of the tensioner are estimated using an iterative technique. A timing belt drive system is considered as a case study. The belt system's vibration responses are obtained and compared with the measured results to evaluate the performance of the presented approach. The computational results are compared with a previously published method, and the difference between the proposed method (Method I) and the previously published method (Method II) is discussed. The presented method has the following merits: (1) The linearization of tensioner’s hysteretic model can improve the computational efficiency greatly with an acceptable computational accuracy. (2) The semi-analytic method which is used to derive the system equations can further reduce the amount of computation. It is suitable for parameter optimization of system.

The rapid development of science and technology promotes the intensive development of robotics and the application of ADAMS in the field of robotics is constantly expanding. Research on robot kinematics and dynamics is the core issue of biped robot animation simulation. It is of great significance to propose an efficient and improved inverse kinematics algorithm for the development of robotic bionics in China. In this paper, the BIOLOID robot assembly kit is used as the research platform. Based on this, the biped robot kinematics equations and dynamic equations are deduced, and a three-step programming method is used to carry out reasonable gait planning for the biped robot. A simplified virtual prototype model of the lower limb of a biped robot, and the motion trajectories of the joints are input to perform motion simulation of the robot’s static walking. The feasibility of gait planning is verified by analyzing the dynamic images obtained from the simulation experiments and the experimental data of each joint vector. This paper uses the Denavit-Hartenberg rule to construct a biped robot animation simulation kinematics model, deduces a matrix expression describing joint vectors between adjacent links, and solves the biped robot’s positive kinematics equation by chain multiplication rule; An efficient and improved inverse kinematics algorithm is proposed. This solution has the characteristics of high accuracy, high efficiency and few redundant solutions. The experimental study found that the three-step planning method for biped robotic static walking planning is feasible and can reach 98%, and can meet the pre-planning requirements.

Age estimation based on the mineralized morphology of teeth is one of the important elements of forensic anthropology. To explore the most suitable age assessment protocol for adolescents in the South China population, 1477 panoramic radiographs images of people aged 2–18 years in the South were collected and staged by the Demirjian mineralization staging method. The dental age were estimated using the parameters of the Demirjian and Willems. Mathematical optimization and machine learning optimization were also performed in the data processing process in an attempt to obtain a more accurate model. The results show that Willems' method is more accurate in estimating the dental age of the South China population, while the model can be further optimized by re-assigning the model through a non-intercept regression method. The machine learning model presented excellent results in terms of the efficacy comparison results with the traditional mathematical model, and the machine learning model under the Boosting framework such as Gradient Boosting Decision Tree (GBDT) significantly reduced the error in dental age estimation compared to the traditional mathematical method. This machine learning processing method based on traditional assessment data can effectively reduce the error of assessment while saving arithmetic power. This study demonstrates the effectiveness of the GBDT algorithm in optimizing forensic age estimation models and provides a reference for other regions to use this scheme for age assessment model architecture, also the lightweight nature of machine learning offers the possibility of widespread forensic anthropological age estimation.

To find a method to distinguish exogenous gamma-hydroxybutyrate (GHB) from endogenous GHB by establishing ultra-high performance liquid chromatography-mass spectrometry (UPLC-MS) based on exosome for quantitative detection of GHB in the rat blood.Adult male SD rats were divided into 1 h, 5 h, 10 h administration group and control group. After 1 h, 5 h and 10 h of single precursor of GHB gamma-butyrolactone (GBL) intraperitoneal injection in administration groups, 5 mL blood was collected from the abdominal aorta. Meanwhile, the control group was given a same dose of normal saline, and 5 mL blood was collected at 1 h. Among the 5 mL blood, 0.5 mL was directly detected by HPLC-MS after pretreatment, and exosomes were extracted from the remaining blood by differential centrifugation and detected.The concentration of GHB in the control group was (87.36±33.48) ng/mL, and the concentration with administration at 1 h, 5 h and 10 h was (110 400.00±1 766.35) ng/mL, (1 479.00±687.01) ng/mL and (133.60±12.17) ng/mL, respectively. The results of exosome detection showed that no peak GHB signal was detected in the control group and the 10 h administration group, and the concentrations of GHB at 1 h and 5 h administration groups were (91.47±33.44) ng/mL and (49.43±7.05) ng/mL, respectively.GHB was detected in blood exosome by UPLC-MS, which indicated that exogenous GHB could be detected in plasma exosomes, while endogenous GHB could not be detected, suggesting that this method may be used as a basis to determine whether there is exogenous drug intake.

Background: In the clinic, death from nontraumatic pulmonary fat embolism associated with minor soft tissue contusion, surgery, cancer chemotherapy, hematologic disorders and so on has been reported. Patients often present with atypical manifestations and rapid deterioration, making diagnosis and treatment difficult. However, there are no reported cases of death from pulmonary fat embolism after acupuncture therapy. This case aims to emphasize that awareness of nontraumatic pulmonary fat embolism as a complication of acupuncture therapy needs to be improved. In addition, it suggests that in such cases, autopsy should be used to identify the source of fat emboli. Case presentation: The patient, a 72-year-old woman, experienced symptoms of dizziness and fatigue after silver-needle acupuncture therapy. She experienced a significant drop in blood pressure and died 2 hours later despite treatment and resuscitation. A systematic autopsy and histopathology examination (H&E and Sudan Ⅲ staining) were performed. More than 30 pinholes were observed on the surface of the lower back. Focal hemorrhages were seen surrounding the pinholes in the subcutaneous fatty tissue. Microscopically, numerous fat emboli were observed in the interstitial pulmonary artery and a large number of alveolar wall capillaries, in addition to the vessels of the heart, liver, spleen and thyroid gland. The lungs showed congestion and edema. However, the cause of death was identified as pulmonary fat embolism. Conclusion: This article suggests that high vigilance for risk factors and the complication of pulmonary fat embolism following silver-needle acupuncture therapy should be exercised. In postmortem examinations, examining the peripheral arterial system and the venous system draining from noninjured sites for the formation of fat emboli is helpful to differentiate posttraumatic and nontraumatic pulmonary fat embolism.

Water dropwort (Oenanthe javanica (Blume) DC.) is an important vegetable crop. Nutrient liquid culture has become an important cultivation method in the production of water dropwort. However, the effects of different nutrient solution cultivation methods on the growth and quality of water dropwort remains unclear. In this study, to screen the most suitable nutrient solution formula for the cultivation of water dropwort, the effects of different nutrient solution formulas (Hoagland, Cooper, Dutch greenhouse, Garden-style, Yamasaki and SCAU) on plant physiological and quality characteristics are investigated. The plant height, root length, water content (%), distribution rate of dry matter (%), chlorophyll, VC, flavonoid, total phenolic, DPPH and dietary fiber of water dropwort under different nutrient solutions were determined. According to the analytic hierarchy process (AHP) of the growth index and quality index of water dropwort under different nutrient solutions, the Yamazaki nutrient solution was considered to be the most suitable nutrient solution formula for water dropwort. To further confirm the differences of water dropwort under nutrient solution culture and soil culture, the broadly targeted metabolomics were performed. A total of 485 metabolites were detected in water dropwort under optimal nutrient solution and soil cultivation. Metabolomics analysis showed that flavonoids were the most abundant differential accumulated metabolites, and most flavonoids were up-regulated. A qRT-PCR assay indicated that the structural genes of the flavonoid biosynthesis pathway (PAL, C4H, CHS, CHI, F3H, DFR, UFGT) were significantly higher under the Yamasaki nutrient solution treatment. The current study provided a theoretical basis and technical guidance for the nutrient solution cultivation of water dropwort. Meanwhile, this study provides new insights into the study of flavonoids in water dropwort.

SrRuO3 is an orthogonally distorted perovskite (Pbnm) structure whose ferromagnetism is often viewed as an itinerant ferromagnet. Although SrRuO3 has been studied for more than half a century, its structure, magnetism and transport properties are still poorly understood. In this paper, the structure and magnetic evolution of SrRuO3 are discussed in depth through the substitution of Ca2+ for Sr2+ at A sites. The results show that as the Ca substitution increases, the lattice constant decreases, the orthogonal distortion becomes larger, and the saturation magnetization MS, Curie temperature TC and Weiss temperature θp decrease accordingly. Eventually, the ferromagnetic SrRuO3 changes to paramagnetic CaRuO3. The critical exponent β of samples with different substitution contents was obtained by fitting the experimental results, and the value for SrRuO3 (β = 0.55) was similar to that obtained by mean field theory. However, the value increases with the substitution x of Ca, which can't be explained by any scaling theory. The results show that the increase in the value of β is related to the magnetic disorder caused by different magnetic interactions. Analysis using the Rhodes-Wohlfarth criterion indicates that Sr1-xCaxRuO3 has both itinerant-electron and localized-electron magnetism, which is consistent with the theoretical predictions.

Methamphetamine (METH) abuse is a significant public health concern globally. Cardiac toxicity is one of the important characteristics of METH, in addition to its effects on the nervous system. However, to date, research on the cardiotoxic injury induced by METH consumption has been insufficient. To systematically analyze the potential molecular mechanism of cardiac toxicity in METH-associated heart failure (HF), a rat model was constructed with a dose of 10 mg/kg of METH consumption. Cardiac function was evaluated by echocardiography, and HE staining was used to clarify the myocardial histopathological changes. Integrated analyses, including mRNA, miRNA and lncRNA, was performed to analyze the RNA expression profile and the potential molecular mechanisms involved in METH-associated HF. The results showed that METH caused decreased myocardial contractility, with a decreased percent ejection fraction (%EF). Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analyses of the RNAs with expression changes revealed abnormal circadian rhythm regulation in the METH groups, with circadian rhythm-related genes and their downstream effectors expressed differentially, especially the aryl hydrocarbon receptor nuclear translocator-like (Arntl). Competing endogenous RNA (ceRNA) networks associated with circadian rhythm, including Arntl, was also observed. Therefore, this study revealed that long-term METH consumption was associated with the HF in a rat model by decreasing the %EF, and that the abnormal circadian rhythm could provide new directions for investigating the METH-associated HF, and that the differentially expressed genes in this model could provide candidate genes for the identification and assessment of cardiac toxicity in METH-associated HF, which is fundamental for further understanding of the disease.

Water dropwort (Oenanthe javanica) is a popular vegetable with high nutritional value and distinctive flavor. The flavor is mainly correlate with the biosynthesis of terpenoids. Shading cultivation was used to improve the flavor in the production of water dropwort. However, the changes of terpenoids and the genes involved in terpenoids biosynthesis under shading treatment remains unclear. In this study, the long- and short-reads transcriptomes of water dropwort were constructed. In total, 57,743 non-redundant high-quality transcripts were obtained from the transcriptome. 28,514 SSRs were identified from non-redundant transcripts and the mono-nucleotide repeats were the most abundant SSRs. The lncRNAs of water dropwort were recognized and their target genes were predicted. The volatile compound contents in petioles and leaf blades of water dropwort were decreased after the shading treatment. The DEGs analysis was performed to identify the terpenoids biosynthesis genes. The results indicated that 5,288 DEGs were differentially expressed in petiole, of which 22 DEGs were enriched in the terpenoids backbone biosynthesis pathway. A total of 12 DEGs in terpenoids biosynthesis pathway were selected and further verified by qRT-PCR assay, demonstrating that the terpenoids biosynthesis genes were down-regulated under shading treatment. Here, the full-length transcriptome was constructed and the regulatory genes related to terpenoids biosynthesis in water dropwort were also investigated. These results will provide useful information for future researches on functional genomics and terpenoids biosynthesis mechanism in water dropwort.

To study the transcriptomic changes of astrocytes in the brain of rats exposed to methamphetamine (METH) and its possible mechanism in neurotoxicity.The rats were intraperitoneally injected with METH (15 mg/kg) every 12 h for 8 times in total to establish the subacute rat model of METH. After the model was successfully established, the striatum was extracted, and astrocytes were separated by the magnetic bead method. Transcriptome sequencing was performed on selected astrocytes, and the differentially expressed genes were analyzed by gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis.A total of 876 differentially expressed genes were obtained by transcriptome sequencing, including 321 up-regulated genes and 555 down-regulated genes. GO analysis revealed that differentially expressed genes were mainly concentrated in cell structure, biological process regulation, extracellular matrix and organelle functions. KEGG pathway enrichment analysis showed that steroids biosynthesis, fatty acid biosynthesis, peroxisome proliferators-activated receptor (PPAR), adenosine 5'-monophosphate-activated protein kinase (AMPK) and other signaling pathways were significantly changed.METH can cause structural changes of astrocytes through multiple targets, among which cellular structure, steroids biosynthesis and fatty acid biosynthesis may play an important role in nerve injury, providing a new idea for forensic identification of METH related death.

The mechanism of methamphetamine toxicity and addiction is the key research direction of forensic toxicology, and the development of omics technology provides a new platform for further study of this direction. METH toxic damage and addiction are reflected differently in genes, ribonucleic acid (RNA) transcription, protein and metabolism. This article summarizes the achievements and shortcomings of multi-omics technologies such as genome, transcriptome, metabolome and proteome in the study of METH damage and addiction, and discusses the strategies and advantages of multi-omics combined analysis in the study of METH toxic damage and addiction mechanism, in order to provide more useful reference information for forensic toxicology of METH.甲基苯丙胺（methamphetamine，METH）的毒性损伤和成瘾机制是法医毒理学关注的重点，而组学技术的发展为此类研究提供了新的平台。METH毒性损伤和成瘾在基因、核糖核酸（ribonucleic acid，RNA）转录、蛋白和代谢水平均有不同的体现。本文拟从基因组、转录组、代谢组、蛋白质组等多组学技术出发，总结其在METH损伤和成瘾相关研究中的成果与不足，并对多组学联合分析在METH毒性损伤和成瘾机制研究中的策略和优势进行论述，从而为METH的法医毒理学鉴定提供更多参考信息。.