Structural study in Highly Compressed BiFeO3 Epitaxial Thin Films on YAlO3

We report a study on the thermodynamic stability and structure analysis of the epitaxial BiFeO3 (BFO) thin films grown on YAlO3 (YAO) substrate. First we observe a phase transition of MC-MA-T occurs in thin sample (<60 nm) with an utter tetragonal-like phase (denoted as MII here) with a large c/a ratio (~1.23). Specifically, MII phase transition process refers to the structural evolution from a monoclinic MC structure at room temperature to a monoclinic MA at higher temperature (150oC) and eventually to a presence of nearly tetragonal structure above 275oC. This phase transition is further confirmed by the piezoforce microscopy measurement, which shows the rotation of polarization axis during the phase transition. A systematic study on structural evolution with thickness to elucidate the impact of strain state is performed. We note that the YAO substrate can serve as a felicitous base for growing T-like BFO because this phase stably exists in very thick film. Thick BFO films grown on YAO substrate exhibit a typical "morphotropic-phase-boundary"-like feature with coexisting multiple phases (MII, MI, and R) and a periodic stripe-like topography. A discrepancy of arrayed stripe morphology in different direction on YAO substrate due to the anisotropic strain suggests a possibility to tune the MPB-like region. Our study provides more insights to understand the strain mediated phase co-existence in multiferroic BFO system.Comment: 18 pages, 6 figures, submitted to Journal of Applied Physic

Iloprost improves running performance at 5,000 m in Han but not in Tibetans

Background: Tibetans experience lose less aerobic exercise capacity in hypoxia compared to lowland Han. We tested if inhalation of iloprost (to counter hypoxic pulmonary vasoconstriction) and furosemide (to decrease afferent vagal traffic from pulmonary receptors) improve performance in hypoxia in Han compared to Tibetans. Methods: 8 Tibetans and 8 Han, living at 2,260 m, did incremental uphill treadmill running to exhaustion at ambient pressure on day 1, followed by three runs at 5,000 m (hypobaric chamber) after inhalation of iloprost (ILO), furosemide (FUR) or placebo (PLA), on different days in a counter-balanced order. Results: In Han the performance decrement from 2,260 m to 5,000 m was greater than in Tibetans (p<0.05). In Han iloprost improved performance at 5,000 m compared to placebo (p<0.05 vs. PLA); furosemide had no effects. In Tibetans there were no treatment effects. Peripheral O2saturations at peak exercise at 5,000 m, were higher by ～8 % in the Tibetans (p<0.05 vs. Han). Maximum heart rate was lowered by 13±6 bpm in Han at 5,000 m regardless of treatment compared to 2,260 m (p<0.05). Tibetans reached similar maximum heart rates ∼200 bpmat 5,000 m and 2,260 m, independent of treatment. Conclusions: The blunting of the exercise impairment in severe hypoxia in Han during maximal exercise after inhalation of iloprost suggests that hypoxic pulmonary vasoconstriction and right ventricular function are potential performance limiting factors in Han in hypoxia

A low-voltage band-gap reference circuit with second-order analyses

SUMMARY A new band-gap reference (BGR) circuit employing sub-threshold current is proposed for low-voltage operations. By employing the fraction of V BE and the sub-threshold current source, the proposed BGR circuit with chip area of 0.029 mm 2 was fabricated in the standard 0.18 m CMOS triple-well technology. It generates reference voltage of 170 mV with power consumption of 2.4 W at supply voltage of 1 V. The agreement between simulation and measurement shows that the variations of reference voltage are 1.3 mV for temperatures from −20 to 100 • C, and 1.1 mV per volt for supply voltage from 0.95 to 2.5 V, respectively

Traditional Chinese Medicine ZHENG Identification Provides a Novel Stratification Approach in Patients with Allergic Rhinitis

Background. We aimed to apply the ZHENG identification to provide an easy and useful tool to stratify the patients with allergic rhinitis (AR) through exploring the correlation between the quantified scores of AR symptoms and the TCM ZHENGs. Methods. A total of 114 AR patients were enrolled in this observational study. All participants received the examinations of anterior rhinoscopy and acoustic rhinometry. Their blood samples were collected for measurement of total serum immunoglobulin E (IgE), blood eosinophil count (Eos), and serum eosinophil cationic protein (ECP). They also received two questionnaire to assess the severity scores of AR symptoms and quantified TCM ZHENG scores. Multiple linear regression analysis was used to determine explanatory factors for the score of AR manifestations. Results. IgE and ECP level, duration of AR, the 2 derived TCMZHENG scores of “Yin-Xu − Yang-Xu”, and “Qi-Xu + Blood-Xu” were 5 explanatory variables to predict the severity scores of AR symptoms. The patients who had higher scores of “Yin-Xu − Yang-Xu” or “Qi-Xu + Blood-Xu” tended to manifest as “sneezer and runner” or “blockers,” respectively. Conclusions. The TCM ZHENG scores correlated with the severity scores of AR symptoms and provided an easy and useful tool to stratify the AR patients

Differential Brain and Muscle Tissue Oxygenation Responses to Exercise in Tibetans Compared to Han Chinese

The Tibetans’ better aerobic exercise capacity at altitude remains ill-understood. We tested the hypothesis that Tibetans display better muscle and brain tissue oxygenation during exercise in hypoxia. Using near-infrared spectrometry (NIRS) to provide indices of tissue oxygenation, we measured oxy- and deoxy-hemoglobin ([O2Hb] and [HHb], respectively) responses of the vastus lateralis muscle and the right prefrontal cortex in ten Han Chinese and ten Tibetans during incremental cycling to exhaustion in a pressure-regulated chamber at simulated sea-level (air at 1 atm: normobaric normoxia) and 5,000 m (air at 0.5 atm: hypobaric hypoxia). Hypoxia reduced aerobic capacity by ∼22% in both groups (d = 0.8, p &lt; 0.001 vs. normoxia), while Tibetans consistently outperformed their Han Chinese counterpart by ∼32% in normoxia and hypoxia (d = 1.0, p = 0.008). We found cerebral [O2Hb] was higher in Tibetans at normoxic maximal effort compared Han (p = 0.001), while muscle [O2Hb] was not different (p = 0.240). Hypoxic exercise lowered muscle [O2Hb] in Tibetans by a greater extent than in Han (interaction effect: p &lt; 0.001 vs. normoxic exercise). Muscle [O2Hb] was lower in Tibetans when compared to Han during hypoxic exercise (d = 0.9, p = 0.003), but not during normoxic exercise (d = 0.4, p = 0.240). Muscle [HHb] was not different between the two groups during normoxic and hypoxic exercise (p = 0.778). Compared to Han, our findings revealed a higher brain tissue oxygenation in Tibetans during maximal exercise in normoxia, but lower muscle tissue oxygenation during exercise in hypoxia. This would suggest that the Tibetans privileged oxygenation of the brain at the expense of that of the muscle

Study on the continuous phase evolution and physical properties of gas-atomized high-entropy alloy powders

In this study, AlCoCrFeNi high entropy alloy (HEA) powders were fabricated by gas atomization process, and the effects of annealing heat treatment on phase evolution and mechanical properties were investigated. The as-atomized powders have pure BCC phase with a spherical shape and equal composition distribution, and then the FCC and sigma phase sequentially generated after annealing. The mechanical property such as hardness was evidently enhanced, which was caused by precipitation hardening effect. After the raw powders were annealed at 600 °C, the FCC (Al-Ni) phase began to precipitate, the its phase intensity raised with the annealing temperature. Then, the sigma phase (Fe-Cr) formed as the annealing temperature reached 800 °C. Both mechanical properties and lattice constant were influenced by heating effect. According to the results, the lattice became loose with the increasing temperature. In summary, the mechanical properties and phase constitutions of gas-atomized AlCoCrFeNi HEA powders can be adjusted via annealing process, resulting in precipitation hardening effect

Abnormal glucose tolerance and insulin resistance in polycystic ovary syndrome amongst the Taiwanese population- not correlated with insulin receptor substrate-1 Gly972Arg/Ala513Pro polymorphism

BACKGROUND: Insulin resistance and glucose dysmetabolism in polycystic ovary syndrome (PCOS) are related with the polymorphisms in the genes encoding the insulin receptor substrate (IRS) proteins, especially Gly972Arg/Ala513Pro polymorphism being reported to be associated with type-2 diabetes and PCOS. We intended to assess the prevalence of abnormal glucose tolerance (AGT) and insulin resistance in Taiwanese PCOS women. We also tried to assess whether the particular identity of Gly972Arg/Ala513Pro polymorphic alleles of the IRS-1 gene mutation can be used as an appropriate diagnostic indicator for PCOS. METHODS: We designed a prospective clinical study. Forty-seven Taiwanese Hoklo and Hakka women, diagnosed with PCOS were enrolled in this study as were forty-five healthy Hoklo and Hakka women as the control group. Insulin resistance was evaluated with fasting insulin, fasting glucose/insulin ratio, and homeostasis model assessment index for insulin resistance (HOMA(IR)). The genomic DNA of the subjects was amplified by PCR and digested by restriction fragmented length polymorphism (RFLP) with Bst N1 used for codon 972 and Dra III for codon 513. RESULTS: AGT was found in 46.8% of these PCOS patients and was significantly related to high insulin resistance rather than the low insulin resistance. Those patients with either insulin resistance or AGT comprised the majority of PCOS affected patients (AGT + fasting insulin ≥17: 83%, AGT + glucose/insulin ratio ≥6.5: 85.1%, AGT + HOMA(IR )≥ 2: 87.2%, and AGT + HOMA(IR )≥ 3.8: 72.3%). None of the tested samples revealed any polymorphism due to the absence of any Dra III recognition site or any Bst N1 recognition site in the amplified PCR fragment digested by restriction fragmented length polymorphism. CONCLUSION: There is significantly high prevalence of AGT and insulin resistance in PCOS women, but Gly972Arg and Ala513Pro polymorphic alleles of IRS-1 are rare and are not associated with the elevated risk of PCOS amongst Taiwanese subjects. This is quite different from the similar study in phylogenetically diverged Caucasian subjects

Switch activation of PI-PLC downstream signals in activated macrophages with wortmannin

AbstractPhosphatidylinositol (4,5)-bisphosphate (PtdIns(4,5)P2) has been known to serve as a substrate for phosphatidylinositol 3-kinase (PI3K) and phosphoinositide-specific phospholipase C (PI-PLC), which can produce PtdIns(3,4,5)P3 and inositol 1,4,5-trisphosphate (Ins(1,4,5)P3) and diacylglycerol (DAG), respectively. In this study, we elucidated the role of PI-PLC during the LPS-activated mouse macrophages RAW264.7 treated with PI3K inhibitor wortmannin. First, wortmannin treatment enhanced Ins(1,4,5)P3 production and iNOS expression in LPS-activated macrophages. Inhibition of PI3K by p85 siRNA also showed an enhancement of iNOS expression. On the other hand, overexpression of PI3K by ras-p110 expression plasmid significantly decreased iNOS expression in LPS-activated macrophages. In addition, overexpression of wild-type or dominant-negative Akt expression plasmid did not affect the iNOS expression in LPS-activated macrophages. Second, treatment of PI-PLC inhibitor U73122 reversed the enhancement of iNOS expression, the increase of phosphorylation level of ERK, JNK and p38, and the increase of AP-1-dependent gene expression in wortmannin-treated and LPS-activated macrophages. However, NF-κB activity determined by EMSA assay and reporter plasmid assay did not change during LPS-activated macrophages with or without wortmannin. We propose that the inhibition of PI3K by wortmannin in mouse macrophages enhances the PI-PLC downstream signals, and subsequently increases the LPS induction of iNOS expression independently of Akt pathway