Near-infrared aggregation-induced enhanced electrochemiluminescence from tetraphenylethylene nanocrystals: a new generation of ECL emitters.

Herein, we observed near-infrared electrochemiluminescence (NIR ECL) emission from tetraphenylethylene nanocrystals (TPE NCs), which exhibit high ECL efficiency and excellent biocompatibility compared with the current NIR ECL emitters (such as semiconductor quantum dots and metal nanoclusters). The strong ECL signal of TPE NCs originates from the aggregation-induced enhanced ECL emission via improvement of the efficiency of electron hole recombination and suppression of the nonradiative transition. Impressively, the TPE NCs exhibit an enormous red-shifted ECL emission (678 nm) relative to the blue-light photoluminescence (PL) emission (440 nm). Compared to fluorescence imaging which is limited by photobleaching and autofluorescence, the NIR ECL emission of TPE NCs is highly favorable to diminish background interference over visible light and realize deeper tissue penetration, which expands the ECL emission of organic nanomaterials to the NIR region for broader biological applications.

Morphology-Controlled 9,10-Diphenylanthracene Nanoblocks as Electrochemiluminescence Emitters for MicroRNA Detection with One-Step DNA Walker Amplification.

The electrochemiluminescence (ECL) properties of polycyclic aromatic hydrocarbons (PAHs) are excellent on account of the high photoluminescence quantum yield. However, the poor solubility and radical instability of PAHs in the aqueous solution severely restricted further biological application. Here 9,10-diphenylanthracene (DPA) nanoblocks (NBs) with good dispersibility and stability in aqueous solution were prepared according to morphology-controlled technology employing water-soluble polymers as a protectant. Furthermore, an ECL "off-on" switch biosensor was developed based on a novel ECL ternary system with DPA NBs as luminophore, dissolved O2 as coreactant, and Pt-Ag alloy nanoflowers as the coreaction accelerator, which achieved a high-intense initial ECL signal. Subsequently, the Fc-DNA as ECL signal quencher was assembled on the electrode surface to quench the initial ECL signal for a "signal-off" state. Meanwhile, DNA swing arm was modified on the electrode surface for one-step DNA walker amplification. Interestingly, in the presence of miRNA-141 and T7 Exo, the one-step DNA walker amplification was executed to recover a strong ECL signal as a "signal-on" state by the digestion of Fc-DNA. Thus the developed ECL "off-on" switch biosensor possesses a detection limit down to 29.5 aM for ultrasensitive detection of miRNA-141, which is expected to be applicable to the detection of miRNA in clinic tumor cells.

Ternary Electrochemiluminescence System Based on Rubrene Microrods as Luminophore and Pt Nanomaterials as Coreaction Accelerator for Ultrasensitive Detection of MicroRNA from Cancer Cells.

As the only endogenous coreactant in the electrochemiluminescence (ECL) system, the dissolved O2 was the ideal candidate due to the mild reaction and easy operation, but compared to S2O82-, the dissolved O2 with weaker redox activity suffers from the poor enhancement effect of the luminophore, which restricted the further application in bioanalysis. Here, a high-intense ECL signal was gained by the employing of Pt nanomaterials as a coreaction accelerator to generate more of the intermediate of dissolved O2 to promote the coreaction efficiency. On the basis of a new ternary ECL system of Pt nanomaterials as the coreaction accelerator, dissolved O2 as the coreactant, and a neotype rubrene microrods as the luminophore, an efficient "on-off-on" solid-state ECL switch platfrom was designed for ultrasensitive microRNA (miRNA) detection with a background reduction strategy of ferrocene-labeled single-stranded DNA (Fc-DNA) as a quencher. In the presence of miRNA 141, the Pt nanoparticles labeled hairpin (HP1/PtNPs) was opened to produce plenty of Pt nanoparticles labeled output DNA (S1/PtNPs) and release the miRNA-141 to participate in the next cycle. Then, the S1/PtNPs were captured on the surface of the electrode by the complementary strand to obtain the super "signal on" state with extremely high ECL signal. This novel solid-state ECL platform exhibited excellent sensitivity from 10 aM to 100 pM with a detection limit of 2.1 aM, which provided a new approach for ultrasensitive ECL bioanalysis.

RF Spectrum Sensing Based on an Overdamped Nonlinear Oscillator Ring for Cognitive Radios.

Existing spectrum-sensing techniques for cognitive radios require an analog-to-digital converter (ADC) to work at high dynamic range and a high sampling rate, resulting in high cost. Therefore, in this paper, a spectrum-sensing method based on a unidirectionally coupled, overdamped nonlinear oscillator ring is proposed. First, the numerical model of such a system is established based on the circuit of the nonlinear oscillator. Through numerical analysis of the model, the critical condition of the system's starting oscillation is determined, and the simulation results of the system's response to Gaussian white noise and periodic signal are presented. The results show that once the radio signal is input into the system, it starts oscillating when in the critical region, and the oscillating frequency of each element is fo/N, where fo is the frequency of the radio signal and N is the number of elements in the ring. The oscillation indicates that the spectrum resources at fo are occupied. At the same time, the sampling rate required for an ADC is reduced to the original value, 1/N. A prototypical circuit to verify the functionality of the system is designed, and the sensing bandwidth of the system is measured.

[Study on the regulation role of semen persicae to cAMP-PKA signal pathway in the rats with cold and heat blood stasis syndrome].

OBJECTIVE: To study the regulation role of with neutral property to cAMP-PKA pathway in the rats with cold and heat blood stasis syndromes and it's mechanism. METHODS: 60 rats were randomly divided into normal control group, model control group, Semen Persicae group, radix salvia miltiorrhiza group, rhizoma chuanxiong group, 12 rats per group. The three herb groups were orally given relative herbs decoction, whose dosages were equal to 10 times the human clinical dose, normal and model control groups were orally given water, 2 times/day, 20 mL/kg, for 7 days. Experiments in rats with cold and heat blood stasis syndromes were carried on respectiverly. In heat blood stasis syndromes, except normal control group, the other groups were intraperitoneally injected 10% carrageenan, 5 mL/kg, 1 times/day, for 3 days;24 hours after the last injection, subcutaneously injected 20% dry yeast suspension, 10 mL/kg. In cold blood stasis syndromes, except normal control group, the other groups were put into fridge, temperature--(18 +/- 2) degrees C, 2 hours/ times, 2 times/day, for 7 days. Separately draw 5 ml abdominal aortic blood and taken abdominal aorta, 6 hours and 12 hours after finishing the model in the two syndromes. Tested the cAMP content by elisa, tested the PKA protein expression by Western blot. RESULTS: Semen Persicae with neutral property, could decrease the content of cAMP in plasma (P < 0.01), inhibit the expression of protein PKA (P < 0.05) in rats with heat stagnation and blood stasis syndrome, increase the plasma content of cAMP (P < 0.01) and increase the expression of protein PKA (P < 0.01) in rats with cold stagnation and blood stasis syndrome. Semen Persicae had two-way adjustment action on CAMP-PKA signal pathway. CONCLUSION: In different internal environment of heat stagnation and blood stasis syndrome, cold stagnation and blood stasis syndrome, Semen Persicae with neutral property has two-way adjustment to cAMP-PKA signaling channel, which may be one of the mechanism of it's two-way application.

[Experimental study on two-way application of drugs with neutral property for promoting blood circulation and removing blood stasis on cold and heat blood stasis syndromes II].

OBJECTIVE: To further study the characteristics of drugs with neutral property in two-way application and conditioned dominance by observing the action characteristic of 10 traditional Chinese medicines with neutral property in hemorheological indicators of heat stagnation and blood stasis syndrome and cold stagnation and blood stasis syndrome rats. METHOD: The model of heat stagnation and blood stasis syndrome rats was established by injecting carrageenan and dry yeast, while the model of cold stagnation and blood stasis syndrome rats was established by body freezing. Subsequently, 10 traditional Chinese medicines with neutral property, 5 traditional Chinese medicines with heat property and 5 traditional Chinese medicines with cold property were selected for intervention to observe the changes in such indicators as whole blood viscosity, plasma viscosity and hematocrit and analyze the action characteristics of drugs with neutral property. RESULT: ANOVA showed that among six of the 10 traditional Chinese medicines with neutral property, including Typhae Pollen, Sarcandrae Herba and Sappan lignum, could obviously increase the hemorheological indicators of both heat stagnation and blood stasis syndrome and cold stagnation and blood stasis syndrome rats; five traditional Chinese medicines with cold property, such as Salviae Miltiorrhizae Radix et Rhizoma, Leonuri Herba, Rhei Radix et Rhizoma, could significantly ameliorate the hemorheological indicators of heat stagnation and blood stasis syndrome rats (P < 0.01 or P < 0.05), and Salvia Miltiorrhiza Radix et Rhizoma alone could ameliorate the hemorheological indicators of cold stagnation and blood stasis syndrome rats (P < 0.05); all of the five traditional Chinese medicines with heat property could significantly ameliorate the hemorheological indicators of cold stagnation and blood stasis syndrome rats (P < 0.01), among which Carthami Flos and Notoginseng Radix et Rhizoma could significantly ameliorate the hemorheological indicators of cold stagnation and blood stasis syndrome rats. According to the average high-shear blood viscosity analysis, drugs with neutral property showed similar action characteristics to those with cold property in ameliorating hemorheology indicators of heat stagnation and blood stasis syndrome rat and better effect than those with heat property in reducing whole blood viscosity; and traditional Chinese medicines with neutral property have the similar action characteristics to those with heat property in improving the hemorheology indicators of cold stagnation and blood stasis syndrome rat and better effect than those with heat property in reducing whole blood viscosity. CONCLUSION: Under the condition of heat stagnation and blood stasis syndrome, traditional Chinese medicines with neutral property show the similar action characteristics to those with cold property; but under the condition of cold stagnation and blood stasis syndrome, traditional Chinese medicines with neutral property show the similar action characteristics to those with heat property. This indicates that traditional Chinese medicines with neutral property show both heat and cold properties under he conditions of heat stagnation and blood stasis syndrome and cold stagnation and blood stasis syndrome.

[Experimental study on two-way application of traditional Chinese medicines capable of promoting blood circulation and removing blood stasis with neutral property in cold and hot blood stasis syndrome I].

OBJECTIVE: To study the action characteristics of "two-way application and conditioned dominance" of traditional Chinese medicines with neutral property by observing the action characteristic of 10 traditional Chinese medicines capable of promoting blood circulation and removing blood stasis with neutral property in the microcirculation in rats with heat stagnation and blood stasis syndrome. METHOD: The rat model with heat stagnation and blood stasis syndrome was established by injecting carrageenan and dry yeast, and the rat model with cold stagnation and blood stasis syndrome was built by the body freezing method. Ten traditional Chinese medicines with neutral property, including 5 with hot property and 5 with cold property, were selected for intervention to observe blood flow rate and flow state indicators in rat auricles and make a comparative analysis on action characteristics of traditional Chinese medicines with neutral property. RESULT: ANOVA showed that among the 10 traditional Chinese medicines with neutral property, 6 such as Typhae Pollen, Sappan Lignum and Vaccariae Semen can obviously increase the blood flow rate (P < 0.01 or P < 0.05) in the above two models; all of the 5 traditional Chinese medicines with cold property can increase the blood flow rate (P < 0.01 or P < 0.05) in the rat model with heat stagnation and blood stasis syndrome, but only Salvia miltiorrhiza can increase the blood flow rate (P < 0.01 or P < 0.05) in the rat models with cold stagnation and blood stasis syndrome, while other medicines showed no notable effect; among the 5 traditional Chinese medicines with hot property, Carthamus tinctorius and Ligusticum chuanxiong can increase the blood flow rate (P < 0.01 or P < 0.05) in the rat models with cold stagnation and blood stasis syndrome, but had no obvious effect to the blood flow rate in the rat models with heat stagnation and blood stasis syndrome. According to the analysis on average blood flow rate, traditional Chinese medicines with natural and cold properties showed similar effect on heat stagnation and blood stasis syndrome and better effect in increasing blood flow rate than those with hot property; those with natural and hot properties showed similar effect and better effect in increasing blood flow rate than those with cold property. CONCLUSION: Under the condition of heat stagnation and blood stasis syndrome, traditional Chinese medicines with neutral property have the similar action characteristics with those with cold property; wile under the condition of cold stagnation and blood stasis syndrome, traditional Chinese medicines with neutral property have the similar action characteristics with the Chinese medicinal herbs with hot property. This indicates the action characteristics of "two-way application and conditioned dominance" of traditional Chinese medicines with neutral property to some extent.

[Effects of nuclear factor-kappa B p65 ASODN on transforming growth beta-1 and intercellular adhesion molecule-1 of rat hepatic stellate cells].

OBJECTIVE: To study the effects of nuclear factor (NF)-kappa B p65 ASODN on transforming growth factor beta-1 (TGF beta 1) and intercellular adhesion molecule-1 (ICAM-1) of rat hepatic stellate cells (HSC) and the mechanisms of NF-kappa B p65 ASODN in treating liver fibrosis. METHODS: Type IV collagen enzyme digestion and density centrifugation methods were used to separate rat hepatic stellate cells. NF-kappa B p65 ASODN was manually synthesized and completely phosphorothioate-modified. The changes of TGF beta 1 and ICAM-1 mRNA were detected by RT-PCR and albumen of TGF beta 1 and ICAM-1 were detected by ELISA. The changes of NF-kappa B activity were determined by ELISA. RESULTS: NF-kappa B activity and the expressions of ICAM-1 and TGF beta 1 increased after the HSC were treated by TNF alpha. NF-kappa B activity weakened after being treated with NF-kappa B p65 ASODN (0.001-1.000 micromol/L), P less than 0.05 in a dose dependent manner. Transferring NF-kappa B p65 ASODN (0.001-1.000 micromol/L) also weakened the expression of ICAM-1 and TGF beta 1 mRNA and the protein induced by TNF alpha in HSC. It was also in a dose dependent manner, P less than 0.05. CONCLUSIONS: After transferring NF-kappa B p65 ASODN into HSC, their NF-kappa B activity decreased, and their mRNA and protein expressions of ICAM-1 and TGF beta 1 also decreased. This may serve as a new way in treating hepatic fibrosis.