Biomedical subjects

Dacheng Li

Publications and source records attributed to Dacheng Li.

7 recordsLinked to original sources

PubMed2025

Chromosome-level genome assembly of bivalve mollusk, Xishishe Coelomactra antiquata.

Coelomactra antiquata, a significant marine economic shellfish in China, is experiencing a natural population decline due to habitat destruction and overfishing, making the restoration and conservation of its natural resources an urgent priority. This study provides a high - quality chromosome - level genome assembly for C. antiquata, created by PacBio and Hi - C sequencing and resulting in a 19 - chromosome map. The assembly encompasses a genome size of 807.31 Mb, with a contig N50 of 17.35 Mb and a scaffold N50 of 42.90 Mb. A total of 28,070 protein - coding genes were identified, 25,959 of which were functionally annotated. Overall, this study offers a chromosome - level genome for C. antiquata that is highly continuous and complete, providing an indispensable resource for subsequent molecular and genetic studies of this species.

Animals↗

PubMed2005

Code counting of optical fringes: methodology and realization.

A new optical fringe-counting method that entails coding interference fringes is proposed. This method features not only the implementation of reliable bidirectional optical fringe counting but also the accurate counting of oscillating optical fringes. Its main merit is the achievement of a higher phase resolution, lambda/16 (lambda, wavelength), as opposed to lambda/8 of earlier fringe-counting methods. The robustness of fringe-code counting with regard to relative phase variations in the sine and cosine interference signals constitutes another merit of this method. The principle and realization circuit of the fringe-code-counting method are described in detail, and the experimental results with a resolution of lambda/16 are presented to show the feasibility of this method.

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PubMed2004

One- or two-dimensional 2,3-naphtho crown ether complexes [Na(N15C5)]2[M(SCN)4] and [K(N18C6)]2[M(SCN)4] (M = Pd, Pt) constructed by pi-pi stacking interactions.

Four novel 2,3-naphtho-15-crown-5 (N15C5) and 2,3-naphtho-18-crown-6 (N18C6) complexes [Na(N15C5)]2[Pd(SCN)4] (1), [Na(N15C5)]2[Pt(SCN)4] (2), [K(N18C6)]2[Pd(SCN)4] (3) and [K(N18C6)]2[Pt(SCN)4] (4) were synthesized and characterized by elemental analysis, FT-IR spectra and single-crystal X-ray diffraction. The structure analyses reveal that both 1 and 2 are assembled into zigzag chains by the strong intermolecular pi-pi stacking interactions between adjacent 2,3-naphthylene groups of N15C5. The molecules of complexes 3 and 4 are linked into 1D chains by the bridging K-O(ether) interactions between the adjacent [K(N18C6)]+ units and the resulting chains are constructed into a novel 2D network by inter-chain pi-pi stacking interactions between the neighboring 2,3-naphthylene moieties of N18C6. According to the supramolecular self-assemblies of complexes 1-4, two types of stacking model of naphthylene groups are given and discussed.

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PubMed2003

Crystal structure of [p-C6H4(CH2ImMe)2][PtCl6].

The structure of the title complex consists of a [p-C6H4(CH2ImMe)2]2+ and [PtCl6](2-) pair. The platinum atom is hexacoordinated by six chloride ions in octahedral coordination geometry. The average Pt-Cl bond distance is 2.3199 A. The imidazolium cation and hexachloroplatinate anion are linked via hydrogen bonds, and the crystal packing is governed by the CH...Cl interactions.

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PubMed2003

Crystal structure of [Pt2I4(TEPOP)2] (TEPOP = tetraethyldiphosphite).

The structure of the dinuclear complex [Pt2I4(TEPOP)2] (TEPOP = tetraethyldiphosphite) was determined by X-ray diffraction. The two platinum atoms are doubly bridged by two (EtO)2POP(OEt)2 ligands and constitute an eight-membered ring. The platinum atoms have a square-planar geometry, which are completed by two phosphorous and two iodine atoms in a mutually cis arrangement.

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PubMed2002

Dual-wavelength interferometric technique with subnanometric resolution.

A new fringe subdivision method that employs a large synthetic wavelength to subdivide fringes formed by a small single wavelength is proposed. Based on this subdivision method, we demonstrate a novel dual-wavelength interferometric technique with subnanometric resolution, whose potential fringe subdivision factor derived from an evaluation of the interferometer can reach up to 1/440,000. Theoretical analysis and experimental results with a resolution of 0.05 nm are presented to show the feasibility of the interferometric technique.

Journal Article↗

PubMedDate not supplied

Numerical and experimental research on the near-field optical virtual probe.

A near-field optical virtual probe (NFOVP) is a type of immaterial tip based on the principle of near-field evanescent wave interference. Evanescent wave interference and the aperture type play very significant roles in generating near-field optical virtual probes. Two evanescent waves, propagating in opposite directions, will interfere to generate the confinement field. The central peak of the wave distribution carries the preponderance of energy. An aperture can be used to suppress the sidelobe in the energy distribution while forming the NFOVP. In this paper, the NFOVP is investigated numerically by means of the three-dimensional (3-D) finite-difference time-domain (FDTD) method. Some significant factors in the creation of the NFOVP, such as the shape and size of the aperture, the incident light, and the specimen (nanoparticle), are studied and discussed. The optical field of the evanescent wave interference has been measured by near-field scanning optical microscopy (NSOM), and the preliminary experimental results are shown.

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