Space-charge Effect on Electroresistance in Metal-Ferroelectric-Metal capacitors.

Resistive switching through electroresistance (ER) effect in metal-ferroelectric-metal (MFM) capacitors has attracted increasing interest due to its potential applications as memories and logic devices. However, the detailed electronic mechanisms resulting in large ER when polarisation switching occurs in the ferroelectric barrier are still not well understood. Here, ER effect up to 1000% at room temperature is demonstrated in C-MOS compatible MFM nanocapacitors with a 8.8 nm-thick poly(vinylidene fluoride) (PVDF) homopolymer ferroelectric, which is very promising for silicon industry integration. Most remarkably, using theory developed for metal-semiconductor rectifying contacts, we derive an analytical expression for the variation of interfacial barrier heights due to space-charge effect that can interpret the observed ER response. We extend this space-charge model, related to the release of trapped charges by defects, to MFM structures made of ferroelectric oxides. This space-charge model provides a simple and straightforward tool to understand recent unusual reports. Finally, this work suggests that defect-engineering could be an original and efficient route for tuning the space-charge effect and thus the ER performances in future electronic devices.

Yindanxinnaotong, a Chinese compound medicine, synergistically attenuates atherosclerosis progress.

Yindanxinnaotong (YD), a traditional Chinese medicine, has been introduced to clinical medicine for more than a decade, while its pharmacological properties are still not to be well addressed. This report aimed to explore the anti-atherosclerosis properties and underlying mechanisms of YD. We initially performed a computational prediction based on a network pharmacology simulation, which clued YD exerted synergistically anti-atherosclerosis properties by vascular endothelium protection, lipid-lowering, anti-inflammation, and anti-oxidation. These outcomes were then validated in atherosclerosis rats. The experiments provided evidences indicating YD's contribution in this study included, (1) significantly reduced the severity of atherosclerosis, inhibited reconstruction of the artery wall and regulated the lipid profile; (2) enhanced antioxidant power, strengthened the activity of antioxidant enzymes, and decreased malondialdhyde levels; (3) significantly increased the viability of umbilical vein endothelial cells exposed to oxidative stress due to pretreatment with YD; (4) significantly reduced the level of pro-inflammatory cytokines; (5) significantly down-regulated NF-kB/p65 and up-regulated IkB in the YD-treated groups. Overall, these results demonstrated that YD intervention relieves atherosclerosis through regulating lipids, reducing lipid particle deposition in the endothelial layer of artery, enhancing antioxidant power, and repressing inflammation activity by inhibiting the nuclear factor-kappa B signal pathway.

[Study on preventive and therapeutic effects of combined application of yindanxinnaotong soft capsule and exercise on atherosclerotic rats].

To explore the prevention effect of the joint combination of Yindanxinnaotong soft capsule (YDXNT) and exercise (swimming) on atherosclerotic rats. The method of 3 x 3 factorial design, including two factors (YDXNT and swimming) and three levels (0, 1, 2 g x kg(-1) YDXNT; 0, 0.5, 1 h swimming), was mainly adopted. The atherosclerotic rat model was established by ligating their left common carotid arteries and feeding high-fat diet. After 8 weeks, blood samples were collected from their thoracic aorta to determine blood viscosity, plasma viscosity, fibrinogen (FIB), nitric oxide (NO), 6-keto-PGF(1alpha) endothelin (ET) and thromboxane B2 (TXB2). The tissues of left common carotid arteries of the rats were collected to detect the positive expression of SM22alpha and determine the semi-quantitation through the immunohistochemical staining. The result showed that the combination of YDXNT and swimming can significantly decrease the plasma viscosity (F = 3.241, P = 0.017), the high and low shear blood viscosity (F = 6.444, P = 0.001; F = 3.002, P = 0.024) and FIB (F = 4.046, P = 0.005). The increased NO and 6-keto-PGF(1alpha) and the decreased ET and TXB2 indicated a significant interaction (P < 0.05). The swimming showed an obvious main effect in the expression of up-regulated protein SM22alpha (F = 8.088, P = 0.001). The study suggested that the combined administration of YDXNT and swimming could improve the hemorheological parameters of atherosclerotic rats, protect the vascular endothelium, inhibit the vascular remodeling in atherosclerosis and positively prevent the atherosclerosis.

[Protection effect of Yindan Xinnaotong capsule and main compositions compatibility on myocardial ischemia/reperfusion injury].

OBJECTIVE: To study the protected effect of Yindan Xinnaotong capsule (YDXNTC) and main components compatibility on myocardium ischemia/reperfusion injury. METHOD: Global ischemia/reperfusion was adopted to induce myocardial ischemia/reperfusion injury (MIRI) in isolated rat heart. Sprague-Dawley (SD) rats were divided into control, model, YDXNTC, Ginkgo biloba extract (GBE) group, ethanol extract of Salvia miltiorrhiza (SM-E) group, aqueous extract of Salvia miltiorrhiza (SM-H) group, mixed compatibility of other components in YDXNTC (MC), GBE and SM-E compatibility (GSEC), GBE and SM-H compatibility (GSHC), and SM-E and SM-H compatibility (SEHC). During the experiment, electrocardiogram was recorded to observe cardiac arrest time, heart resuscitation time, regaining normal rhythm time, the incidence and duration of arrhythmias (VT/VF). At the end of reperfusion, hearts were arrested and homogenated to assay the activity of superoxide dismutase (SOD), and the content of malondialdehyde (MDA), lactate dehydrogenase (LDH), creatine kinase-MB (CK-MB), cardiac troponin I. RESULT: (1) YDXNTC, SM-E, SM-H and MC elevated cardiac arrest time, also reduced rebeating time, restoring normal rhythm time as well as the duration of arrhythmia, but no remarkable impact on VT/VF occurrence. GBE was effective for incidence of VT/VF, also achieved good effect on shortening rebeating time, restoring normal rhythm time and arrhythmia duration. Likewise, obviously reduced rebeating time, restoring normal rhythm time and arrhythmia duration, and evaluated cardiac arrest time were also exhibited in compatibility groups except that no lengthened cardiac arrest time was detected in GSHC. And the incidence of VT/VF was decreased by GSEC. (2) YDXNT, ginkgo biloba extract (GBE), ethanol extract of salvia miltiorrhiza (SM-E), GBE and SM-E compatibility (GSEC), and SM-E and aqueous extract of salvia miltiorrhiza (SM-H) compatibility (SEHC) could improved SOD and decreased MDA level SM-H, mixed compatibility of other elements in YDXNTC (MC) and GBE and SM-H compatibility (GSHC) showed a role on MDA reduction. (3) LDH was declined by YDXNT and SM-H. CK-MB was reduced by GBE, SM-E, SM-H, and GSEC. (4) The release of cTnI was only inhibited by GSEC. CONCLUSION: YDXNTC, primary materials and main components compatibility has a certain protection effect on MIRI, its mechanism may be related to antioxidant and calcium overload reduction.

[Experimental study on anti-atherosclerotic effect of compatibility of active components of danshen and shanzha].

OBJECTIVE: To investigate the effect of active components of Danshen and Shanzha of different matching proportions on atherosclerosis (AS), in the expectation of obtaining the optimum combination method. METHOD: Atherosclerotic rats were fed with high fat diet, and injected with vitamin D3 and ovalbumin. Aqueous extracts of Danshen (DSA) and Shanzha (SZA) and lipophilic extracts of danshen (DSL) were adopted for a low, medium and high-dose orthogonal experiment, to observe the effect of their different matching proportions on lipid level, oxidative stress, endothelial function and inflammatory reaction. The principal component analysis and cluster analysis were adopted for the multi-objective optimization of experimental results. RESULT: Compared with the model group, all of samples with different proportions of DSA, DSL and SZA showed effect in lowering lipid level, scavenging free radicals, reducing endothelial dysfunction and inhibiting inflammation. According to the variance analysis, DSA2-SZA2-DSL1, DSA3-SZA2-DSL1, DSA3-SZA3 -DSL3 and DSA3-SZA1-DSL1 were the optimal proportions for lowering lipid level, scavenging free radicals, reducing endothelial dysfunction and inhibiting inflammation, respectively. According to the results of the multi-objective optimization, DSA2-SZA1-DSL2 was the optimal proportions of anti-AS. CONCLUSION: All of active components of Danshen and Shanzha of different matching proportions show the anti-AS effect in rats to varying degrees, but with different focus in different matching proportions.

[Study on compound compatibility of Jinglingzi powder based on absorption-metabolism model].

OBJECTIVE: To establish an absorption-metabolic model suitable for studying the complex traditional Chinese medicine (TCM) system, with the classic Jinlingzi Powder formula as the example, in order to explore the correlation among absorption behavior and absorption-metabolism behavior of different Jinlingzi Powder formulas and their compound compatibility. METHOD: An absorption-metabolic model suitable for TCM study was established according to in vivo characteristics of drugs, to combine the intestinal absorption model with the liver microsomal metabolism model. A quantitative analysis was conduced for absorbable components of Jinlingzi Powder and its absorption-metabolism components by HPLC. RESULT: The model could be used for studies on the absorption-metabolism process of TCM. Among the 15 main components which were derived from Jinlingzi Powder extracts, 10 could be absorbed by intestinal tract. A new component peak was shown after metabolism with the A-M model. The absorbable components of Jinlingzi Powder were related to its compatibility. Toosendan was found to be the major factor impacting the main component-absorption ratio (Ar) and absorption-metabolism ratio (Mr), followed by Rhizoma Corydalis. CONCLUSION: The absorption-metabolism model suitable for studying the complex traditional Chinese medicine system was established and used for the study on compound compatibility of Jinglingzi Powder. The compatibility of the formula has an impact on absorbable component ratio of Jinlingzi Powder, which helps interpret the theory of formula compatibility from the angle of in vitro compound pharmacokinetics (the difference between absorption and metabolism). Toosendan is the main factor impacting overall absorption and absorption-metabolism, while Rhizoma Corydalis is the minor factor.