ON THE DIFFERENCES OF THE NATURES OF AUPOINTS AND CHINESE HERBAL MEDICINES

The acupoints and Chinese herbal medicines are quite different in their natures. In the present paper, the authors expound the differences of the natures between the acupoints and Chinese herbal medicines from a） substance carriers, b） the underlying mechanism in actions, and c） individual characteristics, etc..

Purification of full-length human Pregnane and Xenobiotic Receptor:polyclonal antibody preparation for immunological characterization

Pregnane and Xenobiotic Receptor (PXR; or Steroid and Xenobiotic Receptor, SXR), a new member of the nuclear receptor superfamily, is thought to modulate a network of genes that are involved in xenobiotic metabolism and elimination. To further explore the role of PXR in body’s homeostatic mechanisms, we for the first time, report successful prokary- otic expression and purification of full-length PXR and preparation of polyclonal antibody against the whole protein. The full-length cDNA encoding a 434 amino acids protein was sub-cloned into prokaryotic expression vector, pET-30b and transformed into E. coli BL21(DE3) cells for efficient over expression. The inclusion body fraction, containing the expressed recombinant protein, was purified first by solubilizing in sarcosine extraction buffer and then by affinity column chromatography using Ni-NTA His-Bind matrix. The efficacy of anti-PXR antibody was confirmed by immunocytology, Western blot analysis, EMSA and immunohistochemistry. The antibody obtained was capable of detecting human and mouse PXR with high specificity and sensitivity. Immunofluorescence staining of COS-1 cells transfected with human or mouse PXR showed a clear nuclear localization. Results from immunohistochemistry showed that level of PXR in liver sections is immunologically detectable in the nuclei. Similar to exogenously transfected PXR, Western blot analysis of cell extract from HepG2 and COLO320DM cells revealed a major protein band for endogenous PXR having the expected molecular weight of 50 kDa. Relevance of other immunodetectable bands with reference to PXR isoforms and current testimony are evaluated. Advantages of antibody raised against full-length PXR protein for functional characterization of receptor is discussed and its application for clinical purposes is envisaged.

Electronic and Shallow Impurity States in Semiconductor Heterostructures Under an Applied Electric Field

With the use of variational method to solve the effective mass equation, we have studied the electronic and shallow impurity states in semiconductor heterostructures under an applied electric field. The electron energy levels are calculated exactly and the impurity binding energies are calculated with the variational approach. It is found that the behaviors of electronic and shallow impurity states in heterostructures under an applied electric field are analogous to that of quantum wells. Our results show that with the increasing strength of electric field, the electron confinement energies increase, and the impurity binding energy increases also when the impurity is on the surface, while the impurity binding energy increases at first, to a peak value, then decreases to a value which is related to the impurity position when the impurity is away from the surface. In the absence of electric field, the result tends to the Levine's ground state energy (-1/4 effective Rydberg) when the impurity is on the surface, and the ground impurity binding energy tends to that in the bulk when the impurity is far away from the surface. The dependence of the impurity binding energy on the impurity position for different electric field is also discussed.

A novel type of functional epirubicin liposomes modified with DSPE-PEG_(2000)-cyclopamine conjugate for eliminating heterogeneous breast cancer cells

Common chemotherapy is unable to eliminate the heterogeneous side population of cancer cells （such as cancer stem-like cells）, resulting in poor prognosis. The heterogeneity of cancer cells causes an extensive multidrug resistance through the aberrantly active Hedgehog （Hh） signaling pathway. Cyclopamine is a chemical compound that can block Hh signaling pathway, and a combination use of cyclopamine with anticancer drug would be beneficial for killing heterogeneous cancer cells. In the present study, we aimed to develop a kind type of fimctional drug liposomes for eliminating heterogeneous cancer, The study was performed on human breast cancer cells. A distearoylphosphoethanolamine polyethylene glycol （DSPE-PEG2000）-cyclopamine conjugate was newly synthesized by a nucleophilic substitution reaction, and confirmed by MALDI-TOF mass. An HPLC method was established and validated for qualification of epirubicin. Functional epimbicin liposomes were successful constructed by modifying with DSPE-PEG2o00-cyclopamine, displaying a particle size in nano-scale （approximately 98 nm） and a high epirubicin encapsulation （〉97%）. The CD44＋/CD24-side population was characterized in defining heterogeneous breast cancer cells. As compared with regular epirubicin liposomes, fimctional epirubicin liposomes exhibited an evidently enhanced cellular drug uptake and a significant killing effect in overall breast cancer cells. In conclusion, the functional epirubicin liposomes could be a useful drug delivery carrier for eliminating heterogeneous breast cancer cells.

Majorana zero mode in the vortex of an artificial topological superconductor

Majorana fermion （MF）, an exotic particle that is identical to its own antiparticle, was recently found in solid matter as a quasiparticle excitation, the Majorana zero mode （MZM）, in the vortex of an artificial topological superconductor （TSC）. This artificial TSC, first proposed by Fu and Kane in 2008, is a heterostructure made of a topological insulator BiETe3 and an s-wave superconductor NbSe2. This paper will briefly review the experimental progresses based on the Bi2Te3/NbSe2 heterostructure. All evidences are self-consistent and reveal that the MZM exists in the center of vortex. Those experimental results are also supported by theory. This finding is a milestone in the research ofMajorana fermions in solid state physics and a starting point of MZM＇s application in topological quantum computation.