Programmable High-Speed and Hyper-Efficiency DNA Signal Magnifier.

Herein, a programmable dual-catalyst hairpin assembly (DCHA) for realizing the synchronous recycle of two catalysts is developed, displaying high reaction rate and outstanding conversion efficiency beyond traditional nucleic acid signal amplifications (NASA). Once catalyst I interacts with the catalyst II, the DCHA can be triggered to realize the simultaneous recycle of catalysts I and II to keep the highly concentrated intermediate product duplex I-II instead of the steadily decreased one in typical NASA, which can accomplish in about only 16 min and achieves the outstanding conversion efficiency up to 4.54 × 108 , easily conquering the main predicaments of NASA: time-consuming and low-efficiency. As a proof of the concept, the proposed DCHA as a high-speed and hyper-efficiency DNA signal magnifier is successfully applied in the rapid and ultrasensitive detection of miRNA-21 in cancer cell lysates, which exploits the new generation of universal strategy for the applications in biosensing assay, clinic diagnose, and DNA nanobiotechnology.

Engineering a Rolling-Circle Strand Displacement Amplification Mediated Label-Free Ultrasensitive Electrochemical Biosensing Platform.

In this work, an original rolling-circle strand displacement amplification (RC-SDA) was developed by introducing a circle DNA with two recognition domains as a template instead of the limited liner DNA template in traditional strand displacement amplification (SDA), which displayed much shorter reaction time down to 30 min and quite higher conversion efficiency of more than 1.77 × 108 compared with those of traditional strand displacement amplification (SDA) and could be applied to construct a label-free biosensor for ultrasensitive detection of an HIV DNA fragment. Once the target HIV DNA fragment interacts with the template circle DNA, the RC-SDA could be activated to dramatically output amounts of mimic target DNA with the assistance of the Phi29 DNA polymerase and Nb.BbvCI enzyme. In application, while the output products were captured by the DNA tetrahedral nanoprobe (DTNP) modified electrode, the electrochemical tag silver nanoclusters (AgNCs) on DTNP would be released from the electrode surface, accompanied with an obviously decreased electrochemical signal. This way, the developed signal-off biosensor was successfully applied to realize the rapid and ultrasensitive detection of target HIV DNA fragment with a detection limit down to 0.21 fM, which exploits the new generation of a universal strategy beyond the traditional ones for applications in biosensing assay, clinic diagnosis, and DNA nanobiotechnology.

Programmable mismatch-fueled high-efficiency DNA signal converter.

Herein, by directly introducing mismatched reactant DNA, high-reactivity and high-threshold enzyme-free target recycling amplification (EFTRA) is explored. The developed high-efficiency EFTRA (HEEFTRA) was applied as a programmable DNA signal converter, possessing higher conversion efficiency than the traditional one with perfect complement owing to the more negative reaction standard free energy (ΔG). Once traces of input target miRNA interact with the mismatched reactant DNA, amounts of ferrocene (Fc)-labeled output DNA could be converted via the EFTRA. Impressively, the Fc-labeled output DNA could be easily captured by the DNA tetrahedron nanoprobes (DTNPs) on the electrode surface to form triplex-forming oligonucleotide (TFO) at pH = 7.0 for sensitive electrochemical signal generation and the DTNPs could be regenerated at pH = 10.0, from which the conversion efficiency (N) will be accurately obtained, benefiting the selection of suitable mismatched bases to obtain high-efficiency EFTRA (HEEFTRA). As a proof of concept, the HEEFTRA as an evolved DNA signal converter is successfully applied for the ultrasensitive detection of miRNA-21, which gives impetus to the design of other signal converters with excellent efficiency for ultimate applications in sensing analysis, clinical diagnosis, and other areas.

Aromatic-Turmerone Attenuates LPS-Induced Neuroinflammation and Consequent Memory Impairment by Targeting TLR4-Dependent Signaling Pathway.

SCOPE: Curcuma longa (turmeric) is a folk medicine in South and Southeast Asia, which has been widely used to alleviate chronic inflammation. Aromatic-turmerone is one of the main components abundant in turmeric essential oil. However, little information is available from controlled studies regarding its biological activities and underlying molecular mechanisms against chronic inflammation in the brain. In the current study, we employed a classical LPS model to study the effect and mechanism of aromatic-turmerone on neuroinflammation. METHODS AND RESULTS: The effects of aromatic-turmerone were studied in LPS-treated mice and BV2 cells. The cognitive function assays, protein analyses, and histological examination were performed. Oral administration of aromatic-turmerone could reverse LPS-induced memory disturbance and normalize glucose intake and metabolism in the brains of mice. Moreover, aromatic-turmerone significantly limited brain damage, through inhibiting the activation of microglia and generation of inflammatory cytokines. Further study in vitro revealed that aromatic-turmerone targeted Toll-like receptor 4 mediated downstream signaling, and lowered the release of inflammatory mediators. CONCLUSION: These observations indicate that aromatic-turmerone is effective in preventing brain damage caused by neuroinflammation and may be useful in the treatment of neuronal inflammatory diseases.

Gold-Catalyzed Intramolecular Tandem Cyclization of Indole-Ynamides: Diastereoselective Synthesis of Spirocyclic Pyrrolidinoindolines.

A gold-catalyzed intramolecular tandem cyclization of indole-ynamide affords tetracyclic spirocyclic pyrrolidinoindoline bearing an all-carbon quaternary stereocentre in a single step; however, when the reaction was carried out in the presence of BF3 ⋅Et2 O, the corresponding tricyclic spirocyclic pyrrolidinoindoline-based enones are produced through a key 1,5-hydride shift. The developed chemistry provides a diastereoselective and straightforward entry to structurally diverse polycylic pyrrolidinoindolines from indole-ynamides in one-pot reactions under mild conditions.

Effect of gums on the rheological characteristics and microstructure of acid-induced SPI-gum mixed gels.

The effect of addition of xanthan gum (XG) and guar gum (GG) on the rheological properties and microstructure of glucono-δ-lactone induced soy protein isolate (SPI)-XG gels and SPI-GG gels was investigated using steady and dynamic rheological tests, creep-recovery and confocal laser scanning microscopy (CLSM). Results showed that the apparent viscosity of SPI-gum (XG, GG) mixed solutions increased with the increase in the gum (XG, GG) concentration. The storage (G') and loss (G″) moduli of SPI-gum (XG, GG) mixed gels increased in the presence and increase in the gum (XG, GG) concentration. The Burger's model fitted the creep recovery data well (R(2)>0.919) and showed that both the instantaneous and equilibrium (retarded) elastic components of this model increased with the increase in SPI and gum concentrations. The proportion occupied by gum in mixed gels was found to increase with the increase in the concentration of gums which increased the density of protein aggregates in the mixed gels.

[Vibrational temperature of plasma plume in atmospheric pressure air].

A tri-electrode discharge device was designed in a dielectric barrier discharge configurations to generate a fairly large volume plasma plume in atmospheric pressure air. The discharge characteristics of the plasma plume were investigated by an optical method. The discharge emission from the plasma plume was collected by a photomultiplier tube. It was found that the number of discharge pulse per cycle of the applied voltage increased with increasing the peak value of the applied voltage. The emission spectra of the plasma plume were collected by a spectrometer. The vibrational temperature was calculated by fitting the experimental data to the theoretical one. Results showed that the vibrational temperature of the plasma plume decreases with increasing the U(p). Spatially resolved measurement of the vibrational temperature was also conducted on the plasma plume with the same method. Results showed that the vibrational temperature increases firstly and then decreases with increasing distance from the nozzle. The vibrational temperature reachs its maximum when the distance is 5.4 mm from the nozzle. These experimental phenomena were analyzed qualitatively based on the discharge theory. These results have important significance for the industrial applications of the plasma plume in atmospheric pressure air.

[Measurement of active particles generated in a coaxial barrier discharge by spectral method].

Coaxial dielectric barrier discharge has extensive application prospects. A dielectric barrier discharge device with water electrode was used to investigate the discharge properties and spectral intensity emitted from active particles in the air by optical method. Results indicate that the optical emission spectra consist of spectral lines from oxygen atoms (777.5 and 844.6 nm), which implies that oxygen atoms with high chemical activity were generated in the discharge plasma. Through spatially resolved measurements, spectral intensities from oxygen atoms were given as functions of the experimental parameters such as the value of the applied voltage, the gas flow rate and argon content. Results show that the spectral line intensity from oxygen atom increases with increasing the peak value of the applied voltage, increases with increasing the gas flow rate, reaches its maximum with a gas flow rate of 30 L x min(-1) and then decreases with further increasing the gas flow rate. Similarly, the spectral line intensity increases firstly and then decreases with increasing argon content (in a mixture of argon and air) and a maximum is reached when argon content is 16.7%.

[Comparative investigation of the discharge characteristics of a single needle jet and needle-plate jet].

In the present paper, discharge characteristics were studied in atmospheric pressure argon by a single needle jet and needle-plate jet through combination of optical measurement and electrical one. Results show that the length and cross-sectional area of the plasmas generated in the two jets increase with increasing the peak value of the applied voltage. The cross-sectional area generated by needle-plate jet is bigger than that of the single needle jet at the same voltage. A lower inception voltage is needed for the needle-plate jet compared with the single needle jet at the same U(p). Through the spectra emitted from the two jets, electron temperature and vibration temperature wee compared for the plasmas generated by the single needle jet and needle-plate jet, respectively. It can be found that the electron temperature and the vibrational temperature of the two jets increase with increasing U(p). The needle-plate jet has higher values of electron temperature and vibrational temperature than the single needle jet at the same U(p). These results have significant values for the industrial application of the atmospheric pressure plasma jet.

Asymmetric total synthesis of caribenol A via an intramolecular Diels-Alder reaction.

A total synthesis of the caribenol A (1), a novel natural product with an intriguing tetracyclic framework, has been achieved. The synthesis features an intramolecular Diels-Alder (IMDA) reaction for the facile construction of the tricyclic [5-7-6] skeleton of caribenol A (1) and a biomimetic oxidation reaction for the formation of the 2-hydroxyfuran-2(5H)-one motif of caribenol A (1) as key steps. This synthetic approach also reveals that the sp(2) carbon at C(2) in substrate 8 is a critical factor for the formation of the tricyclic [5-7-6] skeleton in 7.

[Experimental investigation of electrical characteristics and vibrational temperature of barrier discharge in flowing argon].

The electrical characteristics and vibrational temperature were investigated as functions of gas gap width, driving frequency and gas flow rate in flowing argon by using a dielectric barrier discharge device with transparent water electrodes. Electrical measurement results show that the discharge with a smaller gas gap width has a higher value of peak current and consumes more power than that with a larger gap width. Both the peak value of discharge current and consumed power increase monotonically with increasing the driving frequency, and decrease with increasing the gas flow rate. Through analyzing the vibrational systems of nitrogen molecule by optical emission spectroscopy, it was found that the vibrational temperature has a similar trend with the peak value of discharge current and consumed power by changing the driving frequency, gas gap width and gas flow rate. These results are important to the industrial applications of atmospheric pressure barrier discharge in flowing gas.

[Spectral investigation of atmospheric pressure plasma column].

Atmospheric pressure plasma column has many important applications in plasma stealth for aircraft. In the present paper, a plasma column with a length of 65 cm was generated in argon at atmospheric pressure by using dielectric barrier discharge device with water electrodes in coaxial configurations. The discharge mechanism of the plasma column was studied by optical method and the result indicates that a moving layer of light emission propagates in the upstream region. The propagation velocity of the plasma bullet is about 0.6 x 10(5) m x s(-1) through optical measurement. Spectral intensity ratios as functions of the applied voltage and driving frequency were also investigated by spectroscopic method. The variation in spectral intensity ratio implies a change in the averaged electron energy. Results show that the averaged electron energy increases with the increase in the applied voltage and the driving frequency. These results have significant values for industrial applications of the atmospheric pressure discharge and have extensive application potentials in stealth for military aircraft.

Intention to obtain human papillomavirus vaccination among taiwanese undergraduate women.

BACKGROUND: The human papillomavirus (HPV) vaccine provides an effective strategy against HPV infection, genital warts, and cervical cancer. While the HPV vaccine is available worldwide, acceptance outside of Western countries is unknown. The purpose of the study was to examine health beliefs and intention to obtain the HPV vaccination among undergraduate women in Taiwan. A predictive model of HPV vaccination intention was investigated. METHODS: A convenience sample of 845 female undergraduate students (mean age = 20 years, aged: 17-36 years) recruited from 5 universities located in South Taiwan, provided data. A self-administered questionnaire requested demographic information, gynecologic history, awareness of HPV and the vaccine, health beliefs, and intention to obtain the HPV vaccine. RESULTS: Over 50% of the undergraduate women were aware of HPV and the HPV vaccine. Sixty-three percent of the students reported a high intention to obtain the HPV vaccine. Demographic factors predicting HPV vaccination included: age, family history of gynecologic cancer, personal history of gynecological visit, sexual experience, and awareness of HPV and the HPV vaccine. Health belief factors predicting HPV vaccination included: personal susceptibility of disease, perception of disease severity, attributes of HPV, cost and availability of vaccine, attributes of HPV, and recommendations from others. CONCLUSIONS: Improving undergraduate women's HPV vaccination rate will require educational campaigns, specifically focused on the efficacy, safety, and benefits of the HPV vaccine and the attributes of HPV infection. Targeting incoming students who are not yet sexually active could achieve successful outcomes.