Probabilistic response of a fractional-order hybrid vibration energy harvester driven by random excitation.

The stochastic response of a fractional-order hybrid vibration energy harvester is investigated in this paper. Equivalent system can be derived by the variable transformation. Then, the probability density functions of mechanical states are obtained by the stochastic averaging technique. The good agreement between numerical simulation and analytical results demonstrates the effectiveness of the proposed method. Mean square voltage, mean square current, and mean output power are presented to illustrate the device output performance. Results imply that the hybrid vibration energy harvesting system can generate higher mean output power than that from a separate piezoelectric system and an electromagnetic system.

Repeated transcutaneous electrical nerve stimulation of nonspecific acupoints of the upper body attenuates stress-induced visceral hypersensitivity in rats.

Irritable bowel syndrome (IBS) is a common stress-related gastrointestinal disorder and visceral hypersensitivity (VH) is characteristically found in IBS patients. Transcutaneous electrical nerve stimulation (TENS) applied to certain acupoints has been shown to benefit IBS patients. Here, we investigated whether nonspecific acupoint is involved in the efficacy of TENS treatment for IBS. Twenty-five male rats were randomly assigned to four experimental groups and one sham-control group. The four experimental groups were defined as TENS-RR, TENS-RL, TENS-LR, and TENS-LL based on the location of the two TENS patches [right (R) or left (L)]. The former and latter letter pairs indicate that the patch locations were the upper chest and upper back, respectively. The heterotypic intermittent stress (HIS) protocol was performed for 16 days. VH was assessed by electromyography to evaluate response to rectal distention (RD). Modulated medium-frequency TENS, sweep range 1-10 Hz, amplitude slightly above the supra motor threshold, was applied 30 min per day followed by RD every second day for the final 7 days of the 16-day HIS period. VH was induced after the rats had been subjected to HIS for 10 days. A significant reduction of VH was observed only in the TENS-LL group compared with that in the sham-control group. These data suggest that repeated TENS treatment can alleviate stress-induced VH in rats. Further, whether TENS patches are attached to the left or right side of the body, which are nonspecific acupoints for gastrointestinal functions, may be an important factor in the treatment of stress-associated gastrointestinal symptoms.

MicroRNA­132 mediates proliferation and migration of pulmonary smooth muscle cells via targeting PTEN.

Pulmonary arterial hypertension (PAH) is a severe and progressive disease characterized by the remodeling of small pulmonary arteries. The aberrant proliferation of pulmonary arterial smooth muscle cells (PASMCs) is the primary feature of PAH. MicroRNA (miR)­132 has been demonstrated to inhibit the proliferation of vascular smooth muscle cells and repress neointimal formation. Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is a direct target of miR­132 that has been revealed to be involved in the development of PAH. However, the role of miR­132 in PAH remains unclear. The present study demonstrated that miR­132 expression was upregulated in monocrotaline­induced PAH rats and platelet­derived growth factor­induced PASMCs. In addition, treatment of PASMCs with miR­132 mimics inhibited their proliferation, whereas miR­132 inhibition exhibited the opposite effects. Furthermore, miR­132 mimics promoted cell migration and maintained the PASMC contractile phenotype. Finally, the expression levels of PTEN were significantly decreased in PAH and PASMCs treated with miR­132 mimics. Taken collectively, the data suggested that miR­132 regulated PASMC function via PTEN and that it may be used as a potential target for the treatment of PAH.

Asymmetrical responses of skin blood flow in ischemic hindlimbs to electrical stimulation of the unilateral forelimb.

The regulation of skin blood flow (SBF) is primarily mediated by the sympathetic nervous system, but the effects of electrical stimulation (ES) of one limb on SBF in the other limbs remain unknown. The present study investigated the effects of unilateral forelimb ES on SBF in the bilateral hindlimbs in anesthetized rats. Bilateral hindlimb ischemia was induced by tourniquet application for 60min. After reperfusion for 24h, ES (3 or 125Hz) was applied to the upper one-fourth of the triceps brachii muscle of the left or right forelimb for 30min. Rats that did not receive ES were used as the controls. Bilateral hindlimb SBF was measured by a laser Doppler line scanner for 20min before ES, 30min during ES, and 9min after ES. The results showed significant differences in SBF in the right but not left hindlimb between the control group and experimental group that received 125-Hz ES of the right forelimb. Right hindlimb SBF significantly increased within 3min following the application of 125-Hz ES to the right forelimb. No significant changes in SBF were observed in the left or right hindlimb when 125-Hz ES was applied to the left forelimb. Moreover, 3-Hz ES of the left or right forelimb did not significantly change SBF in either hindlimb compared with the control group. These results indicate that unilateral forelimb ES causes a differential SBF response in the hindlimb via a specific somatosympathetic reflex, and ES-induced SBF improvements in the ischemic hindlimb are frequency-dependent.

A novel self-adaptive microalgae photobioreactor using anion exchange membranes for continuous supply of nutrients.

A novel self-adaptive microalgae photobioreactor using anion exchange membranes (AEM-PBR) for continuous supply of nutrients was proposed to improve microalgae biomass production. The introduction of anion exchange membranes to the PBR can realize continuous supply of nutrients at desired rates, which is beneficial to the growth of microalgae. The results showed that the maximum biomass concentration obtained in the AEM-PBR under continuous supply of nitrogen at an average rate of 19.0mgN/L/d was 2.98g/L, which was 129.2% higher than that (1.30g/L) in a PBR with all the nitrogen supplied in batch at initial. In addition, the feeding rates of nitrogen and phosphorus were optimized in the AEM-PBR to maximize biomass production. The maximum biomass concentration of 4.38g/L was obtained under synergistic regulation of nitrogen and phosphorus feeding rates at 19.0mgN/L/d and 4.2mgP/L/d. The AEM-PBR demonstrates a promising approach for high-density cultivation of microalgae.

[Spatial distribution of human activities and their influences on landscape patterns in Daqingshan Nature Reserve].

Based on forest inventory data and field survey information, and by using GIS spatial analysis technique and landscape indices, this paper studied the spatial distribution of three categories of human activities (settlement, roads, and other sources of disturbances) and their impacts on landscape patterns in three sub-divided regions, i. e., the west, central and east regions of the Daqingshan Nature Reserve in Inner Mongolia. Results showed that the impacts of human activities were stronger in the east and west regions and weaker in the central region. Among the three subdivided regions, the landscape pattern in the west region was predominantly affected by other sources of disturbances, making the landscape patterns of coniferous forests, broadleaf forests and shrubs tended to be of aggregated distribution; the central region was mainly affected by roads, resulting in reduced landscape patch aggregation of broadleaf forests and shrubs; the east region was mostly affected by settlement, resulting in increased fragmentation of coniferous forests and broadleaf forests and apparent increases in landscape patch aggregation of shrubs and grasslands.

[Impact of baseline pulse pressure on new-onset cardio-and cerebrovascular events in diabetic population].

OBJECTIVE: To observe the association between baseline pulse pressure (PP) level and new-onset cardio-cerebrovascular events in diabetic population. METHODS: Physical examination data between July 2006 to October 2007 from a total of 101 510 employees of Kailuan Group were reviewed, 8306 subjects with a fasting plasma glucose level of ≥ 7.0 mmol/L or with confirmed diabetes diagnosis and were enrolled in this prospective cohort study. Subjects were followed up for 38-53 (48.1 ± 3.1) months and the cardio-cerebrovascular events were obtained every six months, association between baseline PP and new-onset cardio-cerebrovascular events in the diabetic population were analyzed. RESULTS: (1) Incidences of total cardio-cerebrovascular events in the PP groups were 3.4%, 2.8%, 4.5%, 6.4%, respectively. Incidences of cerebral infarction events and myocardial infarction were 2.1%, 1.6%, 2.9%, 3.9% and 1.1%, 0.7%, 1.0%, 1.7%, respectively. (2) Multivariate Cox's proportional hazards regression analysis indicated that baseline PP group was the risk factor for total cardio-cerebrovascular events, cerebral infarction events and myocardial infarction, and the risk for all the events of the PP ≥ 60 mm Hg (1 mm Hg = 0.133 kPa) group was increasing. The values of RR(95%CI) were 1.88 (95%CI 1.34-2.65, P < 0.01), 1.92 (95%CI 1.23-2.99, P < 0.01) and 1.52 (95%CI 0.82-2.81, P > 0.05) after adjust the other factors.(3) In line with increasing level of baseline PP, age, BMI, SBP, DBP, HDL-C, and hs-CRP levels significantly increased in this diabetic population (P < 0.01 or P < 0.05). CONCLUSION: The level of high baseline PP is a risk factor for new-onset cardio-cerebrovascular events in diabetic population.

Prevalence of clinical and subclinical thyroid disease in a peritoneal dialysis population.

AIMS: We investigated dialysis duration, dose of erythropoietin (EPO), and clinical manifestations in peritoneal dialysis (PD) patients with subclinical hypothyroidism. METHODS: This cross-sectional study, performed in 3 centers, assessed 122 adult patients on PD for more than 6 months with regard to demographic data, dialysis duration, thyroid function, biochemical data, EPO dose, and clinical manifestations. Thyroid dysfunction was determined by serum thyroid-stimulating hormone, free thyroxine, total thyroxine, total triiodothyronine, antithyroid peroxidase antibodies, and auto-antibodies against thyroglobulin. RESULTS: Of the 122 study patients, 98 (80.3%) were assessed as having euthyroidism; 19 (15.6%), subclinical hypothyroidism; and 5 (4.1%), subclinical hyperthyroidism. The proportion of women (74.2% vs. 57.1%, p = 0.038), the mean duration of PD (58.1 months vs. 37.9 months, p = 0.032), and the weighted mean monthly EPO dose (1.22 µg/kg vs. 1.64 µg/kg, p = 0.009) were significantly higher in the subclinical hypothyroidism group than in the euthyroidism group, but the prevalences of coronary artery disease and cerebrovascular disease were not. From the multivariate model, PD duration was more significant than sex as a risk factor for subclinical hypothyroidism (p = 0.0132). CONCLUSIONS: Subclinical hypothyroidism is frequent in PD patients, especially female patients and patients with a longer PD duration. Compared with euthyroid patients, patients with subclinical hyperthyroidism need a higher dose of EPO to maintain a stable hemoglobin level.

Falcarindiol impairs the expression of inducible nitric oxide synthase by abrogating the activation of IKK and JAK in rat primary astrocytes.

The effects of falcarindiol on the expression of inducible nitric oxide synthase (iNOS) induced by lipopolysaccharide/interferon-gamma (LPS/IFN-gamma) in rat primary astrocytes were investigated. The molecular mechanisms underlying falcarindiol that confers its effect on iNOS expression were also elucidated. Falcarindiol abrogated the LPS/IFN-gamma-mediated induction of iNOS by about 80%. Falcarindiol attenuated the induction of iNOS in a concentration-dependent manner. The inhibitory effect of falcarindiol on iNOS induction was attributable to decrease in the protein content and the mRNA level of iNOS. Treatment with 50 microM of falcarindiol for 30 min decreased LPS/IFN-gamma-induced nuclear factor-kappaB (NF-kappaB) activation by 32%. Treatment with 50 microM of falcarindiol for 60 min diminished the LPS/IFN-gamma-mediated activation of IkappaB kinase-alpha (IKK-alpha) and IKK-beta by 28.2 and 29.7%, respectively. Falcarindiol modulated the nuclear translocation of signal transducer and activator of transcription 1 (Stat1) in a time-dependent manner. Falcarindiol (50 microM) decreased the tyrosine phosphorylation of janus kinase 1 (JAK1) by 84.8% at 5 min. Falcarindiol also abrogated the tyrosine phoshorylation of JAK2 by 82.3% at 10 min.The present study demonstrates that falcarindiol attenuated the activation of IKK and JAK contributing to the blockade of activation of NF-kappaB and Stat1, thereby leading to the suppression of iNOS expression.