Purifacation of Wild Type EcoRI Endonuclease and EcoRI Endonuclease RS187Crystal Growth of WT EcoRI Endonuclease-DNA comlex and EcoRI Endonuclease

EcoRI endonuclease is a very useful tool to study the structural mechanism of protein-DNA recognition. In this work, wild type EcoRI Endonuclease and EcoRI Endonuclease mutant RS187 were purified to high purity. Crystals of wild type EcoRI Endonuclease-DNA 13mer complex have been obtained with good size and shape. Some small crystals of EcoRI Endonuclease RS187-DNA 13mer complex were also grown

Combining Battery‐Type and Pseudocapacitive Charge Storage in Ag/Ti3C2Tx MXene Electrode for Capturing Chloride Ions with High Capacitance and Fast Ion Transport

The recent advances in chloride‐ion capturing electrodes for capacitive deionization (CDI) are limited by the capacity, rate, and stability of desalination. This work introduces Ti3C2Tx/Ag synthesized via a facile oxidation‐reduction method and then uses it as an anode for chloride‐ion capture in CDI. Silver nanoparticles are formed successfully and uniformly distributed with the layered‐structure of Ti3C2Tx. All Ti3C2Tx/Ag samples are hydrophilic, which is beneficial for water desalination. Ti3C2Tx/Ag samples with a low charge transfer resistance exhibit both pseudocapacitive and battery behaviors. Herein, the Ti3C2Tx/Ag electrode with a reaction time of 3 h exhibits excellent desalination performance with a capacity of 135 mg Cl− g−1 at 20 mA g−1 in a 10 × 10−3 m NaCl solution. Furthermore, low energy consumption of 0.42 kWh kg−1 Cl− and a desalination rate of 1.5 mg Cl− g−1 min−1 at 50 mA g−1 is achieved. The Ti3C2Tx/Ag system exhibits fast rate capability, high desalination capacity, low energy consumption, and excellent cyclability, which can be ascribed to the synergistic effect between the battery and pseudocapacitive behaviors of the Ti3C2Tx/Ag hybrid material. This work provides fundamental insight into the coupling of battery and pseudocapacitive behaviors during Cl− capture for electrochemical desalination

Outer Channel of DNA-Based Data Storage: Capacity and Efficient Coding Schemes

In this paper, we consider the outer channel for DNA-based data storage, where each DNA string is either correctly transmitted, or being erased, or being corrupted by uniformly distributed random substitution errors, and all strings are randomly shuffled with each other. We first derive the capacity of the outer channel, which surprisingly implies that the uniformly distributed random substitution errors are only as harmful as the erasure errors. Next, we propose efficient coding schemes which encode the bits at the same position of different strings into a codeword. We compute the soft/hard information of each bit, which allows us to independently decode the bits within a codeword, leading to an independent decoding scheme. To improve the decoding performance, we measure the reliability of each string based on the independent decoding result, and perform a further step of decoding over the most reliable strings, leading to a joint decoding scheme. Simulations with low-density parity-check codes confirm that the joint decoding scheme can reduce the frame error rate by more than 3 orders of magnitude compared to the independent decoding scheme, and it can outperform the state-of-the-art decoding scheme in the literature in a wide parameter regions.Comment: This paper has been submitted to IEEE Trans. Inf. Theor

Assessment of heterotrophic growth supported by soluble microbial products in anammox biofilm using multidimensional modeling

Anaerobic ammonium oxidation (anammox) is known to autotrophically convert ammonium to dinitrogen gas with nitrite as the electron acceptor, but little is known about their released microbial products and how these are relative to heterotrophic growth in anammox system. In this work, we applied a mathematical model to assess the heterotrophic growth supported by three key microbial products produced by bacteria in anammox biofilm (utilization associated products (UAP), biomass associated products (BAP), and decay released substrate). Both One-dimensional and two-dimensional numerical biofilm models were developed to describe the development of anammox biofilm as a function of the multiple bacteria-substrate interactions. Model simulations show that UAP of anammox is the main organic carbon source for heterotrophs. Heterotrophs are mainly dominant at the surface of the anammox biofilm with small fraction inside the biofilm. 1-D model is sufficient to describe the main substrate concentrations/fluxes within the anammox biofilm, while the 2-D model can give a more detailed biomass distribution. The heterotrophic growth on UAP is mainly present at the outside of anammox biofilm, their growth on BAP (HetB) are present throughout the biofilm, while the growth on decay released substrate (HetD) is mainly located in the inner layers of the biofilm

DEM-based analysis of water inrush process of underground engineering face with intermittent joints in karst region

Water inrush disaster of karst tunnel often lead to significant economic losses and serious casualties, which is an urgent engineering roadblock to be solved in the construction of tunnel in karst area. In this paper, three-dimensional discrete element method considering fluid-solid coupling effect and structural characteristics of water-mud resistant rock mass is adopted to systematically study the evolution law of displacement field and seepage field of intermittent joint type water-mud resistant rock mass of tunnel face and its water inrush critical characteristics during the process of sequential excavation of karst tunnel close to the frontal high-pressure water-rich karst cavity. The results show that: With the tunnel face gradually approaching the front-concealed high-pressure water-rich karst cavity, the stability of water-mud resistant rock mass is increasingly affected by high-pressure karst water, and karst water pressure gradually becomes the main control factor. The closer the tunnel face is to the front-concealed high-pressure water-rich karst cavity, the greater the extrusion displacement of karst tunnel face and its increase amplitude, the higher damage degree of water-mud resistant rock mass of face. With the advance of tunnel excavation, the intermittent cracks in the water-mud resistant rock mass of face gradually connect and form a stable hydraulic connection. The flow velocity and seepage pressure of karst water rise significantly at the moment of overall instability of face and the formation of water inrush channel, showing obvious precursor characteristics. The research achievements provide a reference for early warning and prevention and control of water inrush disaster of karst tunnel face