Stability analysis of the five-dimensional energy demand-supply system

summary:In this paper, a five-dimensional energy demand-supply system has been considered. On the one hand, we analyze the stability for all of the equilibrium points of the system. For each of equilibrium point, by analyzing the characteristic equation, we show the conditions for the stability or instability using Routh-Hurwitz criterion. Then numerical simulations have been given to illustrate all of cases for the theoretical results. On the other hand, by introducing the phenomenon of time delay, we establish the five-dimensional energy demand-supply model with time delay. Then we analyze the stability of the equilibrium points for the delayed system by the stability switching theory. Especially, Hopf bifurcation has been considered by showing the explicit formulae using the central manifold theorem and Poincare normalization method. For each cases of the theorems including the Hopf bifurcation, numerical simulations have been given to illustrate the effectiveness of the main results

Increased apoptosis in human knee osteoarthritis cartilage related to the expression of protein kinase B and protein kinase Cα in chondrocytes

Protein kinase B (Akt) and protein kinase Cα (PKCα) play important roles in the regulation of cell apoptosis. The aim of this study was to investigate the expression of Akt and PKCa in chondrocytes of human knee osteoarthritic (OA) cartilage, further evaluating their role in chondrocyte apoptosis during OA progression. Human knee OA cartilages were obtained from 38 patients undergoing knee arthroplasty, which is the medium-late stage of OA. Healthy knee cartilages were obtained from 11 amputees. The samples taken from the condyle of femur were collected routinely for morphological, immunohistochemical and Western blot detection, respectively. Light microscopy and laser-scanning confocal microscopy were used for morphological observation. The optical density with computer image analysis evaluated the intensity of immunohistochemical reaction of Akt and PKCα in OA cartilage. Western blot detected the protein expression levels. The results indicated that Akt and PKCa were involved in OA progression, along with the increase of cell apoptosis. In OA cartilage, Akt decreased (p < 0.05) and PKCα increased (p < 0.05). There was a negative correlation and interaction between Akt and PKCα (r = –0.8). These results demonstrated that both Akt and PKCα are related to increased chondrocyte apoptosis in human OA cartilage. The correlation between human OA progression, the role of Akt and PKCα, and chondrocyte apoptosis allows for new therapeutic strategies to be considered

Dual-band circularly-polarized shared-aperture array for C/X-Band satellite communications

A novel method of achieving a single-feed circularly-polarized (CP) microstrip antenna with both broad impedance bandwidth and axial ratio (AR) bandwidth is presented. The CP characteristics are generated by employing a resonator to excite the two orthogonal modes of the patch via two coupling paths and the required 90 o phase difference is achieved by using the different orders of the two paths. The presented method, instead of conventional methods that power dividers and phase delay lines are usually required, not only significantly enhances the bandwidths of the antenna, but also results in a compact feed, reduced loss and high gain. Based on this method, a dual-band shared-aperture CP array antenna is implemented for C/X-band satellite communications. The antenna aperture includes a 2 × 2 array at C-band and a 4 ×4 array at X-band. To accommodate the C/X-band elements into the same aperture while achieving a good isolation between them, the C-band circular patches are etched at the four corners. The measured results agree well with the simulations, showing a wide impedance bandwidth of 21% and 21.2% at C-and X-band, respectively. The C-and X-band 3-dB AR bandwidths are 13.2% and 12.8%. The array also exhibits a high aperture efficiency of over 55%, low side-lobe (C-band: −12.5 dB; X-band: −15 dB) and high gain (C-band: 14.5 dBic; X-band: 17.5 dBic)

Spindle oscillations are generated in the dorsal thalamus and modulated by the thalamic reticular nucleus

Spindle waves occur during the early stage of slow wave sleep and are thought to arise in the thalamic reticular nucleus (TRN), causing inhibitory postsynaptic potential spindle-like oscillations in the dorsal thalamus that are propagated to the cortex. We have found that thalamocortical neurons exhibit membrane oscillations that have spindle frequencies, consist of excitatory postsynaptic potentials, and co-occur with electroencephalographic spindles. TRN lesioning prolonged oscillations in the medial geniculate body (MGB) and auditory cortex (AC). Injection of GABA~A~ antagonist into the MGB decreased oscillation frequency, while injection of GABA~B~ antagonist increased spindle oscillations in the MGB and cortex. Thus, spindles originate in the dorsal thalamus and TRN inhibitory inputs modulate this process, with fast inhibition facilitating the internal frequency and slow inhibition limiting spindle occurrence

Nonlinear Analysis of Auscultation Signals in TCM Using the Combination of Wavelet Packet Transform and Sample Entropy

Auscultation signals are nonstationary in nature. Wavelet packet transform (WPT) has currently become a very useful tool in analyzing nonstationary signals. Sample entropy (SampEn) has recently been proposed to act as a measurement for quantifying regularity and complexity of time series data. WPT and SampEn were combined in this paper to analyze auscultation signals in traditional Chinese medicine (TCM). SampEns for WPT coefficients were computed to quantify the signals from qi- and yin-deficient, as well as healthy, subjects. The complexity of the signal can be evaluated with this scheme in different time-frequency resolutions. First, the voice signals were decomposed into approximated and detailed WPT coefficients. Then, SampEn values for approximated and detailed coefficients were calculated. Finally, SampEn values with significant differences in the three kinds of samples were chosen as the feature parameters for the support vector machine to identify the three types of auscultation signals. The recognition accuracy rates were higher than 90%

Chronic stress induces steatohepatitis while decreases visceral fat mass in mice

BACKGROUND: Prolonged stress leads over time to allostatic load on the body and is likely to exacerbate a disease process. Long-term of stress exposure is one of a risk factor for metabolism-related diseases such as obesity and type 2 diabetes. However, the relationship between chronic stress and non-alcoholic fatty liver disease (NAFLD) remain unknown. METHODS: To address the hypothesis that chronic stress associate to NAFLD development, we subjected C57bl/6 mice to electric foot shock and restraint stress for 12 weeks to set up chronic stress model. Then the serum and hepatic triglyceride (TG), total cholesterol (TC) were measured. Hepatic HE and Oil red O staining were used to specify the state of the NAFLD. To investigate whether inflammation takes part in the stress-induced NAFLD process, related visceral fat, serum and hepatic inflammatory factors were measured. RESULTS: We observed that chronic stress led to an overall increase of hepatic triglyceride and cholesterol while decreasing body weight and visceral fat mass. Microvesicular steatosis, lobular inflammation and ballooning degeneration were seen in stress liver section. This effect was correlated with elevated hepatic and serum inflammatory factors. Although the amount of visceral fat was decreased in stress group, various adipocytokines were elevated. CONCLUSIONS: We showed that chronic stress is associated to NAFLD and chronic inflammation in visceral fat, though food intake and visceral fat mass were decreased. These results may contribute to better understanding of the mechanism from steatosis to steatohepatitis, and propose a novel insight into the prevention and treatment of NAFLD

Molecular Analysis of Spring Viraemia of Carp Virus in China: A Fatal Aquatic Viral Disease that Might Spread in East Asian

Spring viraemia of carp (SVC) is a fatal viral disease for cyprinid fish, which is caused by spring viraemia of carp virus (SVCV). To date, no SVC outbreak has been reported in China. Between 1998 and 2002, outbreaks of SVC were reported in ornamental and wild fish in Europe and America, imported from multiple sources including China. Based on phylogenetic analysis, the viral strain isolated from America was shown to be originated from Asia. These outbreaks not only resulted in huge economic losses, but also raise an interesting question as to whether SVCV really exists in China and if so, is it responsible for SVC outbreaks? From 2002 to 2006, we screened 6700 samples from ornamental fish farms using the cell culture method of the Office International des Epizooties (OIE), and further verified the presence of SVCV by ELISA and real-time quantitative RT-PCR. Two infected samples were found and the complete genome of SVCV was sequenced from one of the isolates, termed SVCV-C1. Several unique hallmarks of SVCV-C1 were identified, including six amino acid (KSLANA) insertion in the viral RNA-dependent RNA polymerase (L) protein and ten nucleotide insertion in the region between glycoprotein (G) and L genes in European SVCV strains. Phylogenetic tree analysis of the full-length G protein of selected SVCV isolates from the United Kingdom and United States revealed that G proteins could be classified into Ia and Id sub genogroups. The Ia sub genogroup can be further divided into newly defined sub genogroups Ia-A and Ia-B. The isolates derived from the United States and China including the SVCV-C1 belongs to in the Ia-A sub genogroup. The SVCV-C1 G protein shares more than 99% homology with the G proteins of the SVCV strains from England and the United States, making it difficult to compare their pathogenicity. Comparison of the predicted three-dimensional structure based on the published G protein sequences from five SVCV strains revealed that the main differences were in the loops of the pleckstrin homology domains. Since SVCV is highly pathogenic, we speculate that SVC may therefore pose a serious threat to farmed cyprinid fish in China

Downregulation of KLF8 expression by shRNA induces inhibition of cell proliferation in CAL27 human oral cancer cells

Objectives: KLF8 is a member of KLF transcription factors which play an important tolr in oncogenesis. It is barely expressed in normal human epithelial cells but highly overexpressed in several types of human cancer cell lines. In the present study, we investigate the role of KLF8 in oral cancer and the effects of KLF8 knockdown via lentivirus mediated siRNA infection in human adenosquamos carcinoma CAL 27 cells. Study Design: We developed a vector-based siRNA expression system that can induce RNAi in CAL 27 oral cancer cells. Downregulation of KLF8 was confirmed by evaluating GFP expressions, RT-PCR and western blot analysis. Finally, the effects of KLF8 downregulation were analyzed by MTT assay and colony formation assays. Results: The expression levels of KLF8 mRNA and proteins are reduced in CAL 27 cells that transfected with 21- nt siRNA against KLF8. Lentivirus-mediated silencing of KLF8 reduces cell proliferation and colonies number, thereby indicating the role of KLF8 in cell proliferation and tumorigenesis. Conclusions: These results strongly suggest that KLF8 is essential for growth of CAL 27 cancer cells. A better understanding of KLF8 function and processing may provide novel insights into the clinical therapy of oral cancer

Expression of soluble vascular endothelial growth factor receptor-1 and placental growth factor in fetal growth restriction cases and intervention effect of tetramethylpyrazine

AbstractObjectiveTo investigate the expression of soluble vascular endothelial growth factor receptor-1 (sFlt-1) and placental growth factor (PLGF) in the fetal growth restriction (FGR) cases and the intervention mechanism of tetramethylpyrazine.MethodsA total of 60 fetal growth restriction cases that admitted to our hospital were randomly divided into ligustrazine intervention group (group A) and nutritional support group (group B). A total of 50 healthy pregnant women were also enrolled as control group (group C). Expression level of maternal serum sFlt1, PLGF and fetal growth parameters including HC, AC, FL, BPD, EFW as well as placenta PLGF, sFlt-1 mRNA expression were recorded and compared among the three groups. A total of 15 SD rats were selected and were divided into three groups, TMP group, alcohol and tobacco group and blank control group. Three groups of rats were dissected on the twentieth day of gestation.ResultsExpression level of sFlt-1 and PLGF in group A was not significantly different from that of group C (P>0.05); but significant difference in SFlt1 and PLGF expression level was observed between group C and group B (P<0.05). Before treatment, HC, AC, FL, BPD and EFW of group A and group B were significant lower than those of group C, but after treatment, those parameters in group A were significantly improved (P<0.05). In the animal experiment there was no significant difference in sFlt-1 between treatment group and FGR group without treatment or control group (P>0.05). There was significant difference in PLGF between FGR group with treatment and FGR group without treatment or control group (P<0.01).ConclusionsPLGF level is decreased and sFlt-1 increased in patients suffered from fetal growth restriction, and FGR rats show increased sFlt-1 and decreased PLGF, thus they can be indicator of the fetal growth restriction. Ligustrazine can effectively improve sFlt-1, PLGF expression level in fetal growth restriction cases, which can be used as treatment for FGR