The Effects of Lesson Study Concept on the Online Engineering Course Delivery

Short Abstract: Introducing the “Learning Progress Tracking System (LPTS)” that allows the instructor to effectively monitor students’ Lesson Study outcomes for the online delivered engineering courses. Full Abstract: One of the biggest challenges of use Lesson Study pedagogy for online delivery course lies in the “live observation”. “Live observation” is critical for the Lesson Study because it allows the instructor to track the student learning during the class period. It is hard to “observe and track” learning process for the online students. In order to overcome this challenge, the research team developed a “Learning Progress Tracking System (LPTS)”. The function of LPTS is to reflect students’ learning outcomes at different stages. This LPTS system includes learning progress, learning outcome, time intervals between each learning stage, and other parameters

A review of development of micro-channel heat exchanger applied in air-conditioning system

AbstractMicro-channel heat exchanger(MCHX) has been increasingly applied in HVAC&R(Heating, Ventilation, and Air Conditioning & Refrigeration) field due to its higher efficiently heat transfer rate, more compact structure, lower cost. The characteristics of micro-channel heat transfer and fluid dynamics are summarized in this paper. The methods about optimizations (ie, geometry and thermodynamic performance) and the advantages and disadvantages of the MCHX are analyzed

Deletion of sphingosine kinase 2 attenuates cigarette smoke-mediated chronic obstructive pulmonary disease-like symptoms by reducing lung inflammation

Cigarette smoke (CS) is the leading cause of chronic obstructive pulmonary disease (COPD), which is characterized by chronic bronchial inflammation and emphysema. Growing evidence supports the hypothesis that dysfunctional cystic fibrosis transmembrane conductance regulator (CFTR) is critically involved in the pathogenesis of CS-mediated COPD. However, the underlying mechanism remains unclear. Here, we report that supressed CFTR expression is strongly associated with abnormal phospholipid metabolism and increased pulmonary inflammation. In a CS-exposed mouse model with COPD-like symptoms, we found that pulmonary expression of sphingosine kinase 2 (SphK2) and sphingosine-1-phosphate (S1P) secretion were significantly upregulated. Therefore, we constructed a SphK2 gene knockout (SphK2-/-) mouse. After CS exposure for six months, histological lung section staining showed disorganized alveolar structure, increased pulmonary fibrosis, and emphysema-like symptoms in wild-type (WT) mice, which were less pronounced in SphK2-/- mice. Further, SphK2 deficiency also decreased CS-induced pulmonary inflammation, which was reflected by a remarkable reduction in pulmonary infiltration of CD45+CD11b+ neutrophils subpopulation and low levels of IL-6 and IL-33 in bronchial alveolar lavage fluid. However, treatment with S1P receptor agonist suppressed CFTR expression and increased Nf-κB-p65 expression and its nuclear translocation in CS-exposed SphK2-/-mice, which also aggravated small airways fibrosis and pulmonary inflammation. In contrast, inhibition of S1P signaling with the S1P receptor analogue FTY720 rescued CFTR expression, suppressed Nf-κB-p65 expression and nuclear translocation, and alleviated pulmonary fibrosis and inflammation after CS exposure. Our results demonstrate that SphK2-mediated S1P production plays a crucial role in the pathogenesis of CS-induced COPD-like disease by impairing CFTR activity and promoting pulmonary inflammation and fibrosis

Pharmacological changes in cellular Ca2+ homeostasis parallel initiation of atrial arrhythmogenesis in murine langendorff-perfused hearts

Intracellular Ca2+ overload has been associated with established atrial arrhythmogenesis. The present experiments went on to correlate acute initiation of atrial arrhythmogenesis in Langendorff-perfused mouse hearts with changes in Ca2+ homeostasis in isolated atrial myocytes following pharmacological procedures that modified the storage or release of sarcoplasmic reticular (SR) Ca2+ or inhibited entry of extracellular Ca2+.Caffeine (1mmol/L) elicited diastolic Ca2+ waves in regularly stimulated atrial myocytes immediately following addition. This was followed by a decline in the amplitude of the evoked transients and the disappearance of such diastolic events, suggesting partial SR Ca2+ depletion.Cyclopiazonic acid (CPA; 0.15µmol/L) produced more gradual reductions in evoked Ca2+ transients and abolished diastolic Ca2+ events produced by the further addition of caffeine.Nifedipine (0.5µmol/L) produced immediate reductions in evoked Ca2+ transients. Further addition of caffeine produced an immediate increase followed by a decline in the amplitude of the evoked Ca2+ transients, without eliciting diastolic Ca2+ events.These findings correlated with changes in spontaneous and provoked atrial arrhythmogenecity in mouse isolated Langendorf-perfused hearts. Thus, caffeine was pro-arrhythmogenic immediately following but not >5min after application and both CPA and nifedipine pretreatment inhibited such arrhythmogenesis.Together, these findings relate acute atrial arrhythmogenesis in intact hearts to diastolic Ca2+ events in atrial myocytes that, in turn, depend upon a finite SR Ca2+ store and diastolic Ca2+ release following Ca2+-induced Ca2+ release initiated by the entry of extracellular Ca2+

Application of finite element modeling and viscoelasticity theory in characterization and prediction of dielectric relaxation process in polymer nanodielectrics

Nanodielectrics, typically defined as polymer composites with nanosized ceramic fillers, have demonstrated significant improvements in electrical endurance, breakdown strength and dielectric constant relative to their constituent materials, which leads to enhanced energy storage capabilities. The key role played by the large interfacial area surrounding nanofillers proves to be essential to the enhancement, yet quantitative models to predict the altered dielectric properties in the interfacial area are rarely seen. In this presentation, we apply a finite element modeling approach, originally developed for viscoelasticity analysis, to predict the frequency and temperature dependence of dielectric permittivity spectra in polymer nanodielectrics containing functionalized silica fillers. The dispersion state of nanofillers in the finite element model is determined from descriptor-based analysis of scanning electron micrographs, and the interfacial area surrounding the fillers is explicitly configured into the geometry. The dielectric permittivity spectra of the polymer matrix are imported into the model using a series of Debye relaxation functions. The analogy between dielectric permittivity and viscoelastic modulus allows for a simple mathematical conversion between the two physically distinct quantities, which enables the usage of Prony Series when fitting the dielectric spectrum. With the assistance of a earlier developed algorithm to fit the viscoelastic modulus, the parameters of Debye relaxation series function are obtained. Using the above morphology and physical property inputs, dielectric spectroscopy experiments over a range of frequencies and temperatures can be simulated. Properties of the interfacial region are obtained through an iterative comparison between model output and experimental results. It is observed that the distribution of dielectric relaxation times of the interface could be expressed using those of the polymer matrix multiplied by frequency shift factors that vary with different functionalization of the silica filler surfaces. Our results indicate that surface energy parameters of the filler and the polymer matrix can vary the dielectric response of the composites, which is consistent with earlier observations of the viscoelastic properties of polymer nanocomposites. Further discussion on the results also provides insight into the underlying dielectric relaxation mechanism in the interfacial area

The influence of different metal atoms on the performance of metalloporphyrin-based sensor reaction with propanol

Density functional theory (DFT) method was carried out to investigate the molecular interaction between metalloporphyrin-based sensor and propanol. The relative energies were used to determine the most stable state of metalloporphyrin and its complexes at three different spin states for further theoretical studies. The low-spin states were found to be the most stable states for cobalt porphyrin (CoP), tin porphyrin (Sn), and zinc porphyrin (ZnP) before exposure to propanol and CoP, SnP, ZnP, iron porphyrin (FeP), ruthenium porphyrin (RuP) after exposure to propanol. The intermediate-spin state was found to be the most stable states for the other metalloporphyrins and their complexes, except for manganese porphyrin (MnP) after exposure to propanol. The calculated binding energies were shown the following order for metalloporphyrin-based sensor-binding propanol: MnP>ZnP>CoP>RuP>SnP>FeP>AgP>CuP. This calculated result may be useful for the theoretical design of metalloporphyrin-based sensor for propanol determination and perhaps other analyte

ANALYSIS ON 113 CASES OF ADVERSE REACTIONS CAUSED BY Β-LACTAM ANTIBIOTICS

The objectives of this study were to learn about the characteristics and rules of the occurrence of adverse reactions caused by lactam antibiotics and provide a reference for clinical drug use. Methods: A retrospective study was made to analyse the 113 case reports of adverse reactions caused by β-lactam antibiotics collected in our hospital between 2007 and 2009. Results: 113 cases of ADR involved 17 kinds of β-lactam antibiotics, headed by ceftriaxone sodium. The most common manifestation was skin and accessory damage; nervous system and gastrointestinal system damage were also easier to find, and the administration route was mainly intravenous infusion. Conclusion: The clinical application of β-lactam antibiotics should pay attention to adverse reaction monitoring and rational drug use to reduce the incidence of adverse reactions

Biomechanical evaluation of ortho-bridge system and proximal femoral nail antirotation in intertrochanteric fractures with lateral wall fracture based on finite element analysis

BackgroundThe integrity of the lateral wall in femoral intertrochanteric fractures significantly impacts fracture stability and internal fixation. In this study, we compared the outcomes of treating intertrochanteric fractures with lateral wall involvement using the ortho-bridge system (OBS) combined with proximal femoral nail antirotation (PFNA) versus simple PFNA from a biomechanical perspective.MethodsFinite-element models of femoral intertrochanteric fractures with lateral wall involvement were subjected to fixation with OBS combined with PFNA and simple PFNA. Von Mises stress measurements and corresponding displacement assessments for each component of the model, including the proximal femur and lateral wall, were used to evaluate the biomechanical effects of OBS fixation on bone and intramedullary nail stability.ResultsUsing PFNA alone to fix intertrochanteric fractures with lateral wall involvement resulted in von Mises stress levels on the lateral wall exceeding safe stress tolerances for bone growth. OBS fixation significantly reduced stress on the lateral wall of the femur and minimized the stress on each part of the intramedullary nail, reducing the overall displacement.ConclusionIn cases of intertrochanteric fractures with lateral wall involvement, PFNA fixation alone may compromise the biomechanical integrity of the lateral femoral wall, increasing the risk of postoperative complications. The addition of OBS to PFNA significantly reduces stress on the lateral femoral wall. Consequently, OBS should be considered for lateral wall fixation when managing intertrochanteric fractures combined with lateral wall fractures

The Protective Effects of Ciji-Hua’ai-Baosheng II Formula on Chemotherapy-Treated H22 Hepatocellular Carcinoma Mouse Model by Promoting Tumor Apoptosis

Ciji-Hua’ai-Baosheng II Formula (CHB-II-F) is a traditional Chinese medical formula that has been shown in clinical practice to relieve side effects of chemotherapy and improve quality of life for cancer patients. In order to understand the mechanism of its protective effects on chemotherapy, mice with transplanted H22 hepatocellular carcinoma were employed in this study. Ninety-two mice were injected subcutaneously with H22 HCC cell suspension into the right anterior armpit. After mice were treated with 5-fluorine pyrimidine (5-FU), they were divided into six groups as untreated group, 5-FU group, 5-FU plus Yangzheng Xiaoji Capsule group and three groups of 5-FU plus different concentrations of CHB-II-F. Twenty mice were euthanized after 7 days of treatment in untreated and medium concentration of CHB-II-F groups and all other mice were euthanized after 14 days of treatment. Herbal components/metabolites were analyzed by UPLC-MS. Tumors were evaluated by weight and volume, morphology of light and electron microscope, and cell cycle. Apoptosis were examined by apoptotic proteins expression by western blot. Four major components/metabolites were identified from serum of mice treated with CHB-II-F and they are β-Sitosterol, Salvianolic acid, isobavachalcone, and bakuchiol. Treatment of CHB-II-F significantly increased body weights of mice and decreased tumor volume compared to untreated group. Moreover, CHB-II-F treatment increased tumor cells in G0-G1 transition instead of in S phase. Furthermore, CHB-II-F treatment increased the expression of pro-apoptotic proteins and decreased the expression anti-apoptotic protein. Therefore, CHB-II-F could improve mice general condition and reduce tumor cell malignancy. Moreover, CHB-II-F regulates apoptosis of tumor cells, which could contribute its protective effect on chemotherapy