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DNA is commonly employed as a substrate for the building of artificial logic networks due to its excellent biocompatibility and programmability. Till now, DNA logic circuits are rapidly evolving to accomplish advanced operations. Nonetheless, nowadays, most DNA circuits remain to be disposable and lack of field programmability and thereby limits their practicability. Herein, inspired by the Configurable Logic Block (CLB), the CLB‐based erasable field‐programmable DNA circuit that uses clip strands as its operation‐controlling signals is presented. It enables users to realize diverse functions with limited hardware. CLB‐based basic logic gates (OR and AND) are first constructed and demonstrated their erasability and field programmability. Furthermore, by adding the appropriate operation‐controlling strands, multiple rounds of programming are achieved among five different logic operations on a two‐layer circuit. Subsequently, a circuit is successfully built to implement two fundamental binary calculators: half‐adder and half‐subtractor, proving that the design can imitate silicon‐based binary circuits. Finally, a comprehensive CLB‐based circuit is built that enables multiple rounds of switch among seven different logic operations including half‐adding and half‐subtracting. Overall, the CLB‐based erasable field‐programmable circuit immensely enhances their practicability. It is believed that design can be widely used in DNA logic networks due to its efficiency and convenience. [ABSTRACT FROM AUTHOR]

In this study, a novel high‐temperature and high‐pressure foam evaluator with variable diameters inner cell and cylinder flip function was designed on our own, which can solve the problems such as difficulties in foam generation and inaccurate determination of various foam parameters by the same type of instruments, through which the foaming performance of more than 10 betaine surfactants was evaluated. The results show that: (1) the higher the pressure, the higher the foaming rate of the foaming agent and the more stable the foam, but the foam stability of the foamers at low and high pressures, and low and high temperatures do not correspond exactly, and the foaming agent used needs to be screened under simulated reservoir conditions. (2) The comprehensive foaming performance of different types of foamers with different molecular structures found that hydroxy sulfobetaine with longer carbon chains has a relatively better foaming performance. Therefore, for the reservoir conditions of temperature 130°C, pressure 30 MPa, and salinity 22 × 104 mg/L, hydroxy sulfobetaine, which does not contain an amide group in the molecule, can be considered preferentially as a foaming agent. The results can guide the selection of foaming agents for high‐temperature and high‐salinity reservoirs. [ABSTRACT FROM AUTHOR]

Dendrimers are a family of nano‐sized three‐dimensional polymers with unique dendritic branching structures and compact spherical geometries. In recent years, dendrimers have made a series of breakthroughs in the biomedical field. In this review, we introduce the synthesis principles, modification methods, and new materials designed based on dendrimers; discuss the importance of cytotoxicity of dendrimers for applications; and elaborate on their applications in the field of molecular assembly and cancer diagnosis and treatment. We speculate that in the near future, more new materials based on dendrimers will be applied in the biomedical field. [ABSTRACT FROM AUTHOR]

Life‐like hierarchical architecture shows great potential for advancing intelligent biosensing, but modular expansion of its sensitivity and functionality remains a challenge. Drawing inspiration from intracellular liquid‐liquid phase separation, we discovered that a DNA‐encoded artificial cell with a liquid core (LAC) can enhance peroxidase‐like activity of Hemin and its DNA G‐quadruplex aptamer complex (DGAH) without substrate‐selectivity, unlike its gelled core (GAC) counterpart. The LAC is easily engineered as an ultrasensitive biosensing system, benefiting from DNA′s high programmability and unique signal amplification capability mediated by liquid‐liquid phase separation. As proof of concept, its versatility was successfully demonstrated by coupling with two molecular recognition elements to monitor tumor‐related microRNA and profile cancer cell phenotypes. This scalable design philosophy offers new insights into the design of next generation of artificial cells‐based biosensors. [ABSTRACT FROM AUTHOR]

A modified instrument was designed to evaluate foam properties under high temperature and pressure. The type and molar ratio of betaine surfactants were screened to develop the heat‐resistant and salt‐tolerant foam for Tahe oilfield (130°C, 220 g/L), and the effects of temperature and pressure on foam properties were also investigated. The synergism between surfactants and the enhanced oil recovery (EOR) mechanism of foam flooding in fractured‐vuggy reservoirs were studied. Experimental results showed the developed foam had excellent foaming ability and foam stability when the lauramidopropyl hydroxyl sulfobetaine (LHSB): erucic amide propyl betaine (EAB) molar ratio ranged from 1:1 to 1:2 (initial foam volume was 392 ml when the molar ratio was 1:1, drainage half‐time was 5.75 min and foam half‐time was 72 min when the molar ratio was 1:2 at 130°C and 2 MPa). The synergistic effect was found to reach its maximum when the LHSB:EAB molar ratio ranged from 1:1 to 1:2 according to interaction parameters, which agreed with the results of foam properties. Foam stability was found to considerably increase with increasing pressure, but decrease with increasing temperature. However, temperature and pressure were found to have consistent effects on foaming ability, that is, the foaming ability increased with increasing temperature and pressure. The flooding test showed foam flooding exhibited better sweep efficiency and higher recovery ratio in the fractured‐vuggy model than gas flooding and water flooding. This could be because injected foam did not channel through the top (or bottom) path due to its high viscosity and moderate density. [ABSTRACT FROM AUTHOR]

Structural colorations with artificially engineered nanostructures provide a dye‐free mechanism for subdiffraction color generation with enhanced stability and environment friendliness. However, it remains elusive to create universally deep subwavelength pixels for arbitrary coloration at the single pixel level. The main obstacles are the unavoidable near‐field coupling between neighboring pixels and the angular dependent hues associated with the scattering process. Here, a generic principle is proposed and developed to create deep subwavelength bright‐field structural colors at the single pixel level by using alumina disk‐on‐film nanocavities. As a result of the gap‐plasmon‐induced perfect absorption, wide‐angle complementary colors are achieved across the full visible spectrum where both the near‐field coupling and angular dispersion are strongly suppressed. Deep subwavelength pixels down to 160 nm × 160 nm and green colors produced by composite pixels are experimentally demonstrated. The strategy represents a significant step toward practical application of structural colors at the single pixel level for nanoscale optical and optoelectronic devices. [ABSTRACT FROM AUTHOR]

Development of ratiometric fluorescent hypochlorite probes with strong long wavelength fluorescence in aqueous medium, high resistance to photobleaching, high sensitivity and selectivity, and low biological toxicity remains a challenge. In this work, a molecular design strategy is proposed that can transform the traditional squaraine dyes (SQs) with aggregation‐caused quenching character into aggregation‐induced emission (AIE)‐active luminogens by functionalizing the end‐groups with tetraphenylethylene units and further introducing hydrophilic sulfonate group as the side chains. The resulting TPE‐SQ5 not only emits strong deep‐red fluorescence with a high quantum yield of 11.0% and high photostability, but more encouragingly can serve as a ratiometric fluorescent hypochlorite probe with high selectivity and sensitivity (detection limit: 5.6 nm), which indeed is the first report for SQs. The detailed sensing mechanism study demonstrates that the oxindole product with sulfonate substitution is responsible for the ratiometric fluorescent response. Furthermore, TPE‐SQ5 nanoparticles with high biocompatibility and low cytotoxicity are successfully used for ratiometrically imaging exogenous and endogenous hypochlorite in living cells. [ABSTRACT FROM AUTHOR]

Using DNA nanostructures as templates to synthesize shape‐controlled polydopamine (PDA) is a promising strategy to realize the fabrication of exquisite PDA nanomaterials. However, previous studies using small DNA tiles as templates could only afford very simple structures such as lines and crosses due to the limited space on the template and the relatively low resolution of the PDA nanopatterns. Therefore, the best resolution of the PDA nanostructures that can be achieved by this technique is carefully investigated. And by connecting several DNA tiles together, larger DNA templates are built up and achieve the synthesis of complicated digital nanopatterned PDA structures. [ABSTRACT FROM AUTHOR]

Main observation and conclusion: Endonuclease IV (Endo IV) has the side activity to cleave the apurinic/apyrimidinic site in the single‐stranded DNA probe (AP‐ssDNA), which adversely affects its performance in single‐nucleotide variation (SNV) detection. In this work, we developed a simple strategy to inhibit Endo IV's side activity by introducing an assistant strand into the detection system. The assistant strand effectively inhibited the side‐activity of Endo IV by confining the freedom of AP‐ssDNA through rigid double‐stranded DNA formation, and the inhibition efficiency could reach 98%. About 20 times enhancement of the discrimination factor (DF) was obtained compared to the detection system without the assistant strand. After optimization, a mean DF value was calculated to be 738 for different mutation types, and the sample with 0.005% allele frequency was discriminated from the wild‐type target. Another advantage of using an assistant strand was that the SNV detection could be executed at physiological temperature without precise temperature optimization as in other Endo IV‐based SNV detection system. Besides, EGFR T790M mutant in the synthesized and clinical samples was detected by our strategy. The results showed satisfactory sensitivity and accuracy by comparison with Sanger sequencing. Thus, this strategy has the potential to be applied in the field of precision medicine. [ABSTRACT FROM AUTHOR]

Petroleum resins have excellent thermal tolerance and selective plugging capability. As the environment temperature exceeds their softening point, petroleum resins transform from a solid into a viscous Newton fluid, accompanied by the transformation of the system from particle dispersoid to emulsion. The presence of phase transition decides that the seepage regularity and plugging characteristics of petroleum resins are different from either particle dispersoid or emulsion. Herein, rheological measurements and physical model flooding experiments were performed to investigate the injection and plugging performance of petroleum resins. A correlation chart of the injection pressure, formation permeability, and the ratio of resin particle size to pore diameter is established. The dispersoid is demonstrated to present good injectivity when the ratio of the resin particle size to the pore‐throat diameter of the porous media is lower than 0.35. Moreover, when the environment temperature is lower than or around the petroleum resin softening point, the injection performance of the dispersoid is not affected by temperature. Comparably, while the environment temperature is 30 °C higher than the resin softening point, the injection pressure increases due to phase transition. As indicated by the plugging experiment, the presented petroleum resin dispersoid plugging agent manifests excellent performance even in the case that the permeability of water‐channeling paths is up to 20 μm2, reaching a water plugging efficiency of over 85%. For water‐channeling fractures with widths of 0.05–0.5 mm, the plugging pressure gradient can exceed 5 MPa m−1. As suggested by combined analysis of injection and plugging performance, the disperse system should be optimized in accordance with the formation condition during field practice. Specifically, the ratio of the resin particle size to the formation pore diameter should be kept lower than 0.35, while the softening point of the petroleum resin should be 10–20 °C lower than the formation temperature. [ABSTRACT FROM AUTHOR]

Amphiphilic surface groups play an important role in many biological processes. The synthesis of amphiphilic polyphenylene dendrimer branches (dendrons), providing alternating hydrophilic and lipophilic surface groups and one reactive ethynyl group at the core is reported. The amphiphilic surface groups serve as biorecognition units that bind to the surface of adenovirus 5 (Ad5), which is a common vector in gene therapy. The Ad5/dendron complexes showed high gene transduction efficiencies in coxsackie‐adenovirus receptor (CAR)‐negative cells. Moreover, the dendrons offer incorporation of new functions at the dendron core by in situ post‐modifications, even when bound to the Ad5 surface. Surfaces coated with these dendrons were analyzed for their blood‐protein binding capacity, which is essential to predict their performance in the blood stream. A new platform for introducing bioactive groups to the Ad5 surface without chemically modifying the virus particles is provided. [ABSTRACT FROM AUTHOR]

Monosodium iodoacetate (MIA) is an inhibitor of glyceraldehyde-3-phosphate dehydrogenase activity, and causes dose-dependent cartilage degradation resembling the pathological changes of human osteoarthritis (OA). In this study, we assessed the apoptosis induced by MIA and clarified the underlying mechanisms using the primary rat chondrocytes. The apoptosis of primary rat chondrocytes was analyzed by flow cytometry. The levels of mitochondrial membrane potential (ΔΨm) were evaluated using fluorescence spectrophotometer. The production of reactive oxygen species (ROS) was determined by fluorescence spectrophotometer. Apoptosis-related protein cytochrome c and procaspase-3 expressions were examined by Western blotting. We found that MIA treatment induces apoptosis in chondrocytes, as confirmed by increases in the percent of apoptotic cells, up-regulation of cytochrome c and caspase-3 protein levels. Treatment with MIA increases ROS production and decreases the levels of ΔΨm. The antioxidant, N-acetylcysteine (NAC), significantly prevented the production of ROS, the reduction of ΔΨm, the release of cytochrome c and the activation of caspase-3. Further, NAC completely protected the cells from MIA-induced apoptosis. Together these observations suggest that the mechanisms of MIA-induced apoptosis are primarily via ROS production and mitochondria-mediated caspase-3 activation in primary rat chondrocytes. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31: 364-369, 2013 [ABSTRACT FROM AUTHOR]