Qudit-based high-dimensional controlled-not gate.

High-dimensional quantum systems expand quantum channel capacity and information storage space. By implementing high-dimensional quantum logic gates, the speed of quantum computing can be practically enhanced. We propose a deterministic 4 × 4-dimensional controlled-not (CNOT) gate for a hybrid system without ancillary qudits required, where the spatial and polarization states of a single photon serve as a control qudit of four dimensions, whereas two electron-spin states in nitrogen-vacancy (NV) centers act as a four-dimensional target qudit. As the control qudits are easily operated employing simple optical elements and the target qudits are available for storage, the CNOT gate works in a deterministic way, and it can be flexibly extended to n × n-dimensional (n > 4) quantum gates for other hybrid systems or different photonic degrees of freedoms. The efficiency and fidelity of the CNOT gate are analyzed aligning with current technological capabilities, finding that they have satisfactory performances.

Decoherence-free-subspace-based deterministic conversions for entangled states with heralded robust-fidelity quantum gates.

The decoherence-free subspace (DFS) serves as a protective shield against certain types of environmental noise, allowing the system to remain coherent for extended periods of time. In this paper, we propose two protocols, i.e., one converts two-logic-qubit Knill-Laflamme-Milburn (KLM) state to two-logic-qubit Bell states, and the other converts three-logic-qubit KLM state to three-logic-qubit Greenberger-Horne-Zeilinger states, through cavity-assisted interaction in DFS. Especially, our innovative protocols achieve their objectives in a heralded way, thus enhancing experimental accessibility. Moreover, single photon detectors are incorporated into the setup, which can predict potential failures and ensure seamless interaction between the nitrogen-vacancy center and photons. Rigorous analyses and evaluations of two schemes demonstrate their abilities to achieve near-unit fidelities in principle and exceptional efficiencies. Further, our protocols offer progressive solutions to the challenges posed by decoherence, providing a pathway towards practical quantum technologies.

Recent advances and challenges of the use of the CRISPR/Cas system as a non-nucleic acid molecular diagnostic.

The clustered regularly interspaced short palindromic DNA sequence repeats (CRISPR) and CRISPR-associated (Cas) (CRISPR/Cas) systems are currently applied not only as a gene editing tool but also as a novel molecular diagnostic technique. The CRISPR/Cas systems have emerged as an efficient molecular diagnostic system that can detect nucleic acids, proteins and small molecule compounds, by converting a non-nucleic acid into a nucleic acid signal of Cas-identifiable and keeping inherent properties of high sensitivity and specificity. While its multiple advantages for nucleic acid detection have been widely published in excellent reviews, there have been no systematic analyses and reviews on the principles and characteristics of CRISPR/Cas-based diagnostic systems for non-nucleic acids. The present work reviewed the basic process, principles, characteristics, strategies, recent advances, and challenges of CRISPR/Cas-based molecular diagnostic methods for detecting non-nucleic acids, which may provide a basis or some references for future development and application as molecular diagnostic tools.

[Inhibition of osthole for resorption of rats femur tissue in vitro].

OBJECTIVE: To investigate osthole effect on femoral tissue resorption activity of rat in vitro. METHODS: Six SD rats weighted (80 ± 5) g were used to isolate and culture femoral tissue (diaphyses and metaphysis) in vitro. The cultured tissue were devided into control group, estradiol group and osthole group. The femoral tissue was treated with final concentration of 1 x 10(-5) mol/L osthole and 1 x 10(-8) mol/L estradiol culture in vitro at 48 hours after cultured. Tartrate-resistant acid phosphatase (StrACP) activity, glucose and Lactic acid content, StrACP, MCSF (Macrophage colony stimulating factor) and CTSK (Cathepsin K) mRNA was detected by Real-Time RT-PCR were detected. RESULTS: Concetration of Alkaline phosphatase activity were 2226 and 2498 in 1 x 10(-5) mol/L osthole and 1 x 10(-8) mol/L estradiol respectively. As compared with control group, the activity of StrACP of 1 x 10(-5) mol/L osthole and 1 x 10(-8) mol/L estradiol were inhibited at 6, 9, 12 days (P < 0.05); under treatment of in l x 10(-5) mol/L osthole, the content of Lactic acid were increased and the content of glucose were decreased at 3, 6, 9 days (P < 0.05); StrACP, MCSF and CTSK mRNA expression level were inhibited at 6, 9 days (P < 0.05). CONCLUSION: Osthole can inhibit bone resorption and raise the level of nutrition metabolism of femurs tissue.

Coagulation kinetics of humic aggregates in mono- and di-valent electrolyte solutions.

Coagulation behaviors of humic acids (HAs) aggregates in electrolyte solutions at different pHs, valences and concentrations of electrolyte cations were investigated using dynamic light scattering technique in combination of other analytical tools. For monovalent electrolyte sodium chloride (NaCl) solution, at its low concentrations the average hydrodynamic radius () of aggregates kept nearly constant. However, at high NaCl concentrations, could be scaled to the time t as ∝ t(a), suggesting a diffusion-limited colloid aggregation (DLCA). The coagulation value of NaCl in a buffer at pH 7.1 was calculated to be in a range of 61.3-84.4 mM. Divalent cation Mg(2+) was far more effective in enhancing the HA coagulation, as evidenced by a lower coagulation value (between 1.0 and 1.7 mM) and a more rapid coagulation rate. Such an enhancement could be explained by the combined effects of electrostatic repulsion, complexation and bridging. The highest coagulation rate (d/dt) and coagulation value at different pHs followed the order of: acidic > neutral > alkaline, and alkaline > neutral > acidic, respectively. Such a difference was associated with the extent of hydrogen bond and electrostatic repulsion at different protonation/deprotonation states of carboxyl and phenolic -OH groups. Transmission electron microscopic imaging reveals that HA was predominantly globular aggregates with a rough periphery at pH 5.26, and was changed to smooth spherical particles at pH 10.00. These results are useful for better understanding the coagulation behaviors of HAs in both natural and engineered aqueous systems.

pH dependence of structure and surface properties of microbial EPS.

The flocculation of microorganisms plays a crucial role in bioreactors, and is substantially affected by pH. However, the mechanism for such an effect remains unclear. In this work, with an integrated approach, the pH dependence of structure and surface property of microbial extracellular polymeric substances (EPS), excreted from Bacillus megaterium TF10, and accordingly its flocculation is elucidated. From the Fourier transform infrared spectra and acid-base titration test results, the main functional groups and buffering zones in the EPS responsible for the microbial flocculation are indentified. The laser light scattering analysis reveals that the deprotonated or protonated states of these functional groups in EPS result in more dense and compact structure at a lower pH because of hydrophobicity and intermolecular hydrogen bonds. The zeta potential measurements identify the isoelectric point and indicate that the electrostatic repulsion action of EPS is controlled by pH. The highest flocculation efficiency is achieved near the isoelectric point (pH 4.8). These results clearly demonstrate that the EPS structure, surface properties, and accordingly the microbial flocculation are dependent heavily on pH in solution.