Pressure-induced superconductivity in topological parent compound Bi2Te3.

We report a successful observation of pressure-induced superconductivity in a topological compound Bi(2)Te(3) with T(c) of ∼3 K between 3 to 6 GPa. The combined high-pressure structure investigations with synchrotron radiation indicated that the superconductivity occurred at the ambient phase without crystal structure phase transition. The Hall effects measurements indicated the hole-type carrier in the pressure-induced superconducting Bi(2)Te(3) single crystal. Consequently, the first-principles calculations based on the structural data obtained by the Rietveld refinement of X-ray diffraction patterns at high pressure showed that the electronic structure under pressure remained topologically nontrivial. The results suggested that topological superconductivity can be realized in Bi(2)Te(3) due to the proximity effect between superconducting bulk states and Dirac-type surface states. We also discuss the possibility that the bulk state could be a topological superconductor.

[Peutz-Jeghers syndrome: report of 4 cases].

OBJECTIVE: Four patients with Peutz-Jeghers syndrome were consecutively observed according to their clinical manifestation, pathologic characteristic, family history. METHODS: Four cases were analyzed according to their clinical observation, X-ray detection, pathological diagnosis and family history. RESULTS: Peutz-Jeghers syndrome had characteristic of family inhereditary. Intestinal lesion was correlative to canceration of polypus. CONCLUSION: Family inhereditary detection should be performed in Peutz-Jeghers syndrome patients. The patients whose intestinal lesion was located in colon were considered high risk patients. They should be intensively cared regularly in long-term.

[Protective effects of baicalin, mannitol and dexamethasone on infective brain edema in rats].

OBJECTIVE: To compare the therapeutic effects of baicalin, mannitol and dexamethasone on infective brain edema(IBE) in rats. METHODS: Forty normal Sprague-Dawley(SD) rats (200 +/- 30) g by weight were divided into 5 groups randomly: (1) normal saline control group(NS, n = 8); (2) infective brain edema group (BE, n = 8); (3) mannitol treatment group(MAN, n = 8); (4) dexamethasone treatment group(DXM, n = 8); and (5) baicalin treatment group(BC, n = 8). Pertussis bacilli(PB, contained bacilli in 10.8 x 10(9), 0.2 ml-1.kg-1) were injected into the left carotid arteries through the left common carotid arteries by puncture to obtain BE models. The contents of brain water, sodium ion, potassium ion and Evans blue in brain tissues were observed too. RESULTS: The contents of brain water, sodium ion, and EB in BE group were higher than those in BE group(P < 0.01), they decreased in MAN, DXM, BC groups and were lower than those in BE group(P < 0.01). In MAN, DXM, BC groups, there were no significant difference in the contents of brain water and sodium ion(P > 0.05). The EB content in BC group was higher than that in MAN and DXM groups(P < 0.01). The content of potassium ion in BE group was higher than that in MAN and DXM groups, the content of potassium ion was similar to that in NS group, but lower than that in BC group. Light microscope inspection in MAN, DXM and BC groups showed lessened brain edema, slight increase of perivascular space, and occasional nerve cell pyknotic nucleus. We found on nerve cell vacuolar degeneration in DXM group. CONCLUSION: Baicalin, mannitol and dexamethasone all have similar protective effects on infective brain edema in rats.

[Effects of isoprenaline on apoptosis related gene expression in rat myocardium cells].

AIM: To study the relationship between acute myocardial ischemia rat induced by isoprenaline (Iso) and expression of some apoptosis related genes in myocardium. METHODS: Acute myocardial ischemic rat model was induced by subcutaneous injection of large doses of Iso. The myocardial expression of apoptosis related genes, Fas, CPP32, Bcl-2 and Bax, were detected with RT-PCR method. The influences of aloperine (Alo, 20 mg.kg-1) and propranolol (Prop, 2 mg.kg-1) on apoptosis related genes were also investigated by the same method. RESULTS: Myocardial expression of Fas, CPP32 and Bcl-2 were increased in acute myocardial ischemic rats, but no significance was detected in Bax expression. Both Alo and Prop were shown to decrease the expression of Fas and CPP32, and increase expression of Bcl-2. Prop also showed down regulated effect on expression of Bax. CONCLUSION: Subcutaneous injection of large doses of Iso was shown to induce expressions of apoptosis related genes in rat myocardium, which were also influences by Alo and Prop.

Skeletal maturity of the hand and wrist in Chinese children in Changsha assessed by TW2 method.

Skeletal maturity of 2122 normal children aged 2-20 years in the southern Chinese city of Changsha have been assessed by the TW2 score method. These mean bone ages are lower than the British standards up to puberty and thereafter higher than the British standards.