Discrete dynamics analysis for nonlinear collocated multivariable mass-damper-spring intelligent mechanical vibration systems

A new time-discretization method for the development of nonlinear collocated multivariable mass-damper-spring (MDS) intelligent mechanical vibration systems is proposed. It is based on the Runge-Kutta series expansion method and zero-order hold assumption. In this paper, we show that the mathematical structure of the new discretization scheme is explored and characterized in order to represent the discrete dynamics properties for nonlinear collocated multivariable MDS intelligent mechanical vibration systems. In particular, the decent effects of the time-discretization method on key properties of nonlinear multivariable MDS mechanical vibration systems, such as discrete zero dynamics and asymptotic stability, are examined. The resulting time-discretization provides discrete dynamics behavior for nonlinear MDS mechanical vibration systems, which enabling the application of existing controller design techniques. The ideas presented here generalize well-known results from the linear case to nonlinear plants

Ecological Balance of Oral Microbiota is Required to Maintain Oral Mesenchymal Stem Cell Homeostasis

Oral microbiome is essential for maintenance of oral cavity health. Imbalanced oral microbiome causes periodontal and other diseases. It is unknown whether oral microbiome affect oral stem cells function. In this study, we used a common clinical anti-biotic treatment approach to alter oral microbiome ecology and examine whether oral mesenchymal stem cells (MSCs) are affected. We found that altered oral microbiome resulted gingival MSCs deficiency, leading to a delayed wound healing in male mice. Mechanistically, oral microbiome release LPS that stimulates the expression of microRNA-21 (miR-21) and then impair the normal function of gingival MSCs and wound healing process through miR-21/Sp1/TERT pathway. This is the first study indicate that interplay between oral microbiome and MSCs homeostasis in male mice

The Fas/Fap-1/Cav-1 Complex Regulates IL-1RA Secretion in Mesenchymal Stem Cells to Accelerate Wound Healing

Mesenchymal stem cells (MSCs) are capable of secreting exosomes, extracellular vesicles, and cytokines to regulate cell and tissue homeostasis. However, it is unknown whether MSCs use a specific exocytotic fusion mechanism to secrete exosomes and cytokines. We show that Fas binds with Fas-associated phosphatase–1 (Fap-1) and caveolin-1 (Cav-1) to activate a common soluble N-ethylmaleimide–sensitive factor (NSF) attachment protein receptor (SNARE)–mediated membrane fusion mechanism to release small extracellular vesicles (sEVs) in MSCs. Moreover, we reveal that MSCs produce and secrete interleukin-1 receptor antagonist (IL-1RA) associated with sEVs to maintain rapid wound healing in the gingiva via the Fas/Fap-1/Cav-1 cascade. Tumor necrosis factor–α (TNF-α) serves as an activator to up-regulate Fas and Fap-1 expression via the nuclear factor κB pathway to promote IL-1RA release. This study identifies a previously unknown Fas/Fap-1/Cav-1 axis that regulates SNARE-mediated sEV and IL-1RA secretion in stem cells, which contributes to accelerated wound healing

Discrete dynamics analysis for nonlinear collocated multivariable mass-damper-spring intelligent mechanical vibration systems

A new time-discretization method for the development of nonlinear collocated multivariable mass-damper-spring (MDS) intelligent mechanical vibration systems is proposed. It is based on the Runge-Kutta series expansion method and zero-order hold assumption. In this paper, we show that the mathematical structure of the new discretization scheme is explored and characterized in order to represent the discrete dynamics properties for nonlinear collocated multivariable MDS intelligent mechanical vibration systems. In particular, the decent effects of the time-discretization method on key properties of nonlinear multivariable MDS mechanical vibration systems, such as discrete zero dynamics and asymptotic stability, are examined. The resulting time-discretization provides discrete dynamics behavior for nonlinear MDS mechanical vibration systems, which enabling the application of existing controller design techniques. The ideas presented here generalize well-known results from the linear case to nonlinear plants

Improvement of the Asymptotic Properties of Zero Dynamics for Sampled-Data Systems in the Case of a Time Delay

It is well known that the existence of unstable zero dynamics is recognized as a major barrier in many control systems, and deeply limits the achievable control performance. When a continuous-time system with relative degree greater than or equal to three is discretized using a zero-order hold (ZOH), at least one of the zero dynamics of the resulting sampled-data model is obviously unstable for sufficiently small sampling periods, irrespective of whether they involve time delay or not. Thus, attention is here focused on continuous-time systems with time delay and relative degree two. This paper analyzes the asymptotic behavior of zero dynamics for the sampled-data models corresponding to the continuous-time systems mentioned above, and further gives an approximate expression of the zero dynamics in the form of a power series expansion up to the third order term of sampling period. Meanwhile, the stability of the zero dynamics is discussed for sufficiently small sampling periods and a new stability condition is also derived. The ideas presented here generalize well-known results from the delay-free control system to time-delay case

Case Report: Acute cerebral infarction as the initial manifestation of malignant tumors with trousseau syndrome in the elderly

Both acute cerebral infarction and malignant tumors are prevalent in the elderly. However, acute cerebral infarction is rarely present as the first clinical manifestation of malignant tumors. By searching the Picture Archiving and Communication System from 2010 to 2022 and the medical record database from 2003 to 2022, we found three cases of Trousseau syndrome, one male and two females with an average age of 69.3 ± 3.2 years, presenting with acute cerebral infarction. Two patients denied having hypertension, diabetes, and coronary heart disease. The average value of the D-dimer was 17.83 ± 12.39 mg/L (normal range, 0 to 0.55 mg/L). Magnetic resonance imaging (MRI) of the brain showed scattered and multiple small infarcts in the watershed area. The sites of infarction were not those that are typically caused by vascular atherosclerosis. One of the females was diagnosed with pancreatic cancer (T2N2M1, stage IV), the male was diagnosed with gastric cancer (T4N3M1, stage IV), and the other female was diagnosed with lung adenocarcinoma (rTxN3M1b, stage IV). The patient with pancreatic cancer underwent a comprehensive geriatric assessment, which revealed that she had a disability, dementia, malnutrition, short life expectancy, and high chemotherapy risk. Ultimately, the patient opted for conservative care, and 3 months after being discharged, she passed away from an acute upper gastrointestinal hemorrhage. Elderly patients with unexplained D-dimer elevation, multiple cerebral vascular lesions detected on MRI, and an absence of typical stroke risk factors need to be monitored for Trousseau syndrome. To screen for cancer, tumor markers and related imaging should be performed first. Trousseau syndrome is primarily treated with chemotherapy, radiotherapy and anticoagulant therapy. The risk of bleeding should be assessed carefully when using anticoagulant therapy in the elderly. Comprehensive geriatric assessment can assist in weighing the benefits and side effects of cancer treatment, making correct medical choices, and improving patients’ quality of life

Healing Rate and Post-obturation Pain of Single-versus Multiple-visit Endodontic Treatment for Infected Root Canals: A Systematic Review

Abstract Introduction: The choice of single-versus multiple-visit root canal treatment for infected teeth is in dispute. The purpose of this systematic review was to compare the healing rate and post-obturation pain of single-versus multiple-visit root canal treatment for teeth with infected root canals. Methods: An exhaustive literature search combined with specified inclusion criteria was performed to identify randomized or quasi-randomized controlled trials (RCTs or quasi-RCTs), comparing root canal treatment in single and multiple appointments (2 or more visits) in patients with infected root canals. Results: Ten RCTs were identified and included in this review. Of these, 6 compared the healing rate and 5 compared the prevalence of post-obturation pain in single-and multiple-visit root canal treatment on teeth with infected root canals. No significant difference was observed in the healing rate between single-versus multiple-visit root canal treatment, as well as the incidence of medium-term post-obturation pain. As to the short-term follow up, the prevalence of postobturation pain was significantly lower in single-visit than in multiple-visit group. Conclusions: On the basis of current studies, the healing rate of single-and multiple-visit root canal treatment is similar for infected teeth. Patients experience less frequency of short-term post-obturation pain after single-visit than those having multiple-visit root canal treatment. (J Endod 2010;-:1-8

Association between isolated hypothyroxinaemia in early pregnancy and perinatal outcomes

Background: The effect of isolated maternal hypothyroxinaemia (IMH) on pregnancy complications and neonatal outcomes in human beings is still controversial. Methods: This was a retrospective cohort study based on the electronic medical register system. The records of women with a singleton pregnancy who sought antenatal examination between January 2014 and December 2015 at Shanghai First Maternity and Infant Hospital were extracted from the electronic medical records system. Thyroid-stimulating hormone (TSH), free thyroxine (fT4) and anti-thyroperoxidase autoantibody (TPO-Ab) was measured before 20 gestational weeks, and a multiple logistic regression model was used to estimate the odds ratios of pregnancy complications and neonatal outcomes between euthyroid women and those with isolated hypothyroxinaemia. Results: A total of 8173 women were included in this study, of whom 34 2 (4.18%) were diagnosed with IMH. Regression analysis showed that IMH diagnosed in the second trimester (13–20 weeks) was associated with an increased risk of hypertensive disorders of pregnancy (OR = 2.66, 95% CI: 1.38–5.10) and placenta abruption (OR = 3.64, 95% CI: 1.07–12.41), but not with preterm delivery (OR = 1.09, 95% CI: 0.50–2.40), small or large gestational age of infant (OR = 0.91, 95% CI: 0.39–2.12; OR = 1.16, 95% CI: 0.72–1.86), macrosomia (OR = 1.71, 95% CI: 0.95–3.07), gestational diabetes mellitus (OR = 1.36, 95% CI: 0.86–2.15) and placenta previa (OR = 1.62, 95% CI: 0.39–7.37). Conclusion: IMH could be a risk factor for hypertensive disorders of pregnancy

Electrospun ZnO/Bi 2

ZnO/Bi2O3 nanofibers were synthesized by a simple electrospinning method and both the UV and visible light responsive photocatalytic properties were studied by the decolorization of RhB dye. Thermogravimetric analysis/differential thermal analysis (TGA-DTA), X-ray diffraction (XRD), scanning electron microscope (SEM), and UV-vis diffuse reflectance spectra (DRS) were employed to study the structure, morphology, and optical properties of the ZnO/Bi2O3 nanofibers, respectively. The relationship between the ZnO/Bi2O3 ratio and photocatalytic activity was also studied, and the composite with a molar ratio of 23 : 1 demonstrated the best activity under both excitations. The photocatalytic mechanisms for the composite fibers can be described as the direct photocatalysis under UV excitation and photosensitation for visible light irradiation. The enhanced photocatalytic activities can be ascribed to the effective electron-hole pairs separation that leads to the promoted photocatalytic efficiency