Live-cell tracking using SIFT features in DIC microscopic videos.

In this paper, a novel motion-tracking scheme using scale-invariant features is proposed for automatic cell motility analysis in gray-scale microscopic videos, particularly for the live-cell tracking in low-contrast differential interference contrast (DIC) microscopy. In the proposed approach, scale-invariant feature transform (SIFT) points around live cells in the microscopic image are detected, and a structure locality preservation (SLP) scheme using Laplacian Eigenmap is proposed to track the SIFT feature points along successive frames of low-contrast DIC videos. Experiments on low-contrast DIC microscopic videos of various live-cell lines shows that in comparison with principal component analysis (PCA) based SIFT tracking, the proposed Laplacian-SIFT can significantly reduce the error rate of SIFT feature tracking. With this enhancement, further experimental results demonstrate that the proposed scheme is a robust and accurate approach to tackling the challenge of live-cell tracking in DIC microscopy.

Establishment and application of an analytical method for PINK1 gene exon copy number / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To establish a method for analyzing the PTEN-induced kinase 1 gene (PINK1) exon copy number and apply it to the analysis of PINK1 gene exon copy number variation (CNV) in patients with autosomal recessive early-onset Parkinsonism (AREP).</p><p><b>METHODS</b>Real-time PCR was used to analyze the exon copy number in 22 probands with AREP from unrelated Chinese Han families and 30 healthy controls.</p><p><b>RESULTS</b>Copy numbers of exons 1-8 of the PINK1 gene were analyzed, and satisfactory reaction conditions and primers for exons of the PINK1 gene were obtained. No exon CNV in the PINK1 gene was detected in this group.</p><p><b>CONCLUSION</b>An analytical method for PINK1 gene exon copy number was established. The exon CNV in the PINK1 gene was rare in Chinese patients with AREP.</p>

An alternative theory on relaxation rates in cuprate superconductors.

Transport properties of high transition temperature (high-T(c)) superconductors apparently demonstrate two distinct relaxation rates in the normal state. We propose that this superficial inconsistence can be resolved with an effective carrier (quasiparticle) density n almost linear in temperature T. Experimental evidence both for and against this explanation is analyzed and we conclude that this offers a clear yet promising scenario. Band structure calculation was utilized to determine the Fermi surface topology of the cuprate superconductor versus doping. The results demonstrate that an electron-like portion of the Fermi surface exists in a wide range of doping levels even for a p-type superconductor, exemplified by La(2-x)Sr(x)CuO(4-δ) (LSCO). Such electron-like segments have also been confirmed in recent photoemission electron spectroscopy. The Coulomb interaction between electron-like and hole-like quasiparticles then forms a bound state, similar to that of an exciton. As a result the number of charge carriers upon cooling temperature is decreased. A quantum mechanical calculation of scattering cross section demonstrates that a T(2) relaxation rate is born out of an electron-hole collision process. Above the pseudogap temperature T(*) the normal state of high-T(c) cuprates is close to a two-component Fermi liquid. It, however, assumes non-Fermi-liquid behavior below T(*).

Mutation analysis of ATP13A2 gene in Chinese patients with familial autosomal recessive early-onset parkinsonism / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the mutation characteristics of ATP13A2 gene in Chinese patients with familial autosomal recessive early-onset parkinsonism (AREP).</p><p><b>METHODS</b>Mutations of ATP13A2 gene were screened by polymerase chain reaction combined with DNA direct sequencing in patients with familial AREP.</p><p><b>RESULTS</b>No pathogenic mutations in ATP13A2 gene were detected in this group. Six reported polymorphisms were identified. They were IVS6+70A>G, IVS12+66A>G, m.1849C>T, IVS20-56 G>A, m2671C>T and m2824G>A.</p><p><b>CONCLUSION</b>ATP13A2 gene mutations may be rare in Chinese patients with familial autosomal recessive early-onset parkinsonism.</p>