Hindered proton collectivity in 16(28)S12: possible magic number at Z=16

The reduced transition probability B(E2;0(gs)(+)→2(1)(+)) for (28)S was obtained experimentally using Coulomb excitation at 53 MeV/nucleon. The resultant B(E2) value 181(31) e(2)fm(4) is smaller than the expectation based on empirical B(E2) systematics. The double ratio |M(n)/M(p)|/(N/Z) of the 0(gs)(+)→2(1)(+) transition in (28)S was determined to be 1.9(2) by evaluating the M(n) value from the known B(E2) value of the mirror nucleus (28)Mg, showing the hindrance of proton collectivity relative to that of neutrons. These results indicate the emergence of the magic number Z=16 in the |T(z)|=2 nucleus (28)S.

Surface-Sensitive XAFS in the Hard X-ray Region with Sub-Monolayer Sensitivity

Surface-sensitive X-ray absorption fine structure (XAFS) with sub-monolayer sensitivity based on grazing-incidence fluorescence detection is reported. The efficiency of fluorescence detection increased by more than two orders of magnitude by combining a multipole wiggler with a multi-element Si(Li) solid-state detector. The capability of the present technique for structural studies of surfaces and buried interfaces in the hard X-ray region was demonstrated by As K-edge XAFS studies of the InP(001) surface exposed to AsH(3) flow. The results indicated that ~0.1 monolayer As atoms are incorporated into the surface replacing the P atoms.

Surgical therapy in two patients with pedunculated hepatocellular carcinoma

Hepatocellular carcinoma (HCC) occurring as an appendage from the main hepatic parenchyma is a rare entity, of which two cases are herein described. Because proper surgical management of this tumor (pedunculated HCC) is unclear, the world's literature was reviewed to determine optimal therapy. Thirty-four cases were documented, including the two cases reported herein. Diagnosis was usually obscure, despite modern invasive and noninvasive methods, and laparotomy or autopsy were required for specific identification of tumor type. Sixteen resections were reported among 18 explorations. One patient had transarterial embolization. Fifteen received medical therapy only. Surgically treated patients usually died of metastatic disease, whereas most medically treated patients died of gastrointestinal or tumor hemorrhage. Pedunculated HCC may be more amenable to curative resection than ordinary HCC due to its unique localization and growth pattern.

Determination of individual conjugated bile acids in human bile

A method has been developed and validated for the determination of the six major conjugated bile acids, cholesterol, and total phospholipids in bile of human subjects previously injected with 4-(14)C-cholesterol. The procedure is designed for use with 5-10 ml of duodenal or T-tube bile and eliminates difficulties associated with existing methods for bile acid determination, in particular the requirement for preliminary saponification under pressure or the use of paper chromatography. Saponification under pressure is employed only in steps where partial destruction of the steroid moiety of conjugated bile acids is not a crucial matter. A preliminary Folch extraction and washing step separated free cholesterol and phospholipids (bottom layer) from the six major conjugated bile acids (top layer). The conjugated bile acids were then fractionated cleanly by thin-layer chromatography to give four groups, the (14)C content of each of which was determined. A second aliquot of the top layer was used to determine (after deconjugation) the radioactivity ratio of deoxycholic acid to chenodeoxycholic acid for the two unresolved groups (dihydroxycholanoic acid conjugates with glycine and taurine, respectively). A third aliquot was used for determination of specific activities of the methyl esters of cholic, chenodeoxycholic, and deoxycholic acids derived from the total bile salts. Appropriate calculations yielded the concentration in bile of all six major bile acid conjugates.

1,2-3-H cholesterol as a tracer in studies of human cholesterol metabolism

1,2-(3)H-Cholesterol was fed to a subject together with 4-(14)C-cholesterol at a known (3)H/(14)C ratio. The ratio was satisfactorily preserved in cholesterol recovered from plasma, red cells, and bile, and in bile acids of bile. Isotopic fractionation was seen during thin-layer chromatographic isolation of cholesterol. In work with 1,2-(3)H-cholesterol or its metabolites care should be taken to recover chromatographic bands in their entirety.