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We performed density functional theory and tight-binding molecular dynamics calculations to investigate the formation of suspended linear atom chains when stretching gold nanowires along the [110] crystal orientation. We determined that chain formation can occur only when the crystal symmetry is broken in the early stages of the elongation process. Such crystallographic asymmetry can be induced by stretching the wire along a slightly off-axis tensile direction or by introducing thermal fluctuations. Our observation of the off-axis formation of these chains agrees with experimental findings., Comment: 4 pages, 3 figures

Prostaglandin E 9-ketoreductase, NAD+-dependent 15-hydroxyprostaglandin dehydrogenase (type I), and NADP+-dependent 15-hydroxyprostaglandin dehydrogenase (type II) have been partially purified from swine renal medulla and cortex. Eleven times more NAD+-dependent 15-hydroxyprostaglandin dehydrogenase activity was found in the cortex than in the medulla. On the other hand, about twice as much NADP+-dependent dehydrogenase activity was found in the medulla than in the cortex. The prostaglandin 9-ketoreductase activities were equally distributed in the swine kidney cortex and medulla.

In 38 adriamycin experiments and 4 daunorubicin experiments, radioimmunoassay readily and reproducibly detects and estimates these drugs and immunologically similar metabolites in patients' plasma and urine to at least 120 hr after dosing without interference by concurrent medication. The plasma drug decay follows first-order kinetics in a triphasic pattern. Radioimmunoassay and fluorescence assay show similar decay up to 4 hr but diverge at that point with the fluorescence assay yielding higher values. Pharmocokinetic differences are amplified in patients with liver dysfunction and may be caused by fluorescent drug metabolites not sensitive to radioimmunoassay or nonspecific fluorescent materials. The radioimmunoassay offers the capability to measure adriamycin and daunorubicin in clinical settings in which fluorescence assay is not available.

Conditioned medium (CM) from two squamous cell carcinoma cell lines, SCC-9 and SCC-13, stimulated bone resorption in neonatal mouse calvariae in organ culture. Enhanced bone resorption induced by CM was associated with an increased production of prostaglandin-E2 (PGE2) by the calvariae. Complete inhibition of stimulated PGE2 synthesis by indomethacin only partially inhibited bone resorption-stimulating activity (BRSA) in the CM. Neither SCC-9 nor SCC-13 CM stimulated cAMP production in rat osteosarcoma cells (ROS 17/2.8). The BRSA in CM was completely inhibited by an antibody to interleukin-1 alpha (IL-1 alpha). Fractionation of SCC-9 CM by gel filtration and HPLC ion exchange chromatography revealed a single peak of BRSA and PGE2 synthesis-stimulating activity at 17-20K (termed SCMII). In mouse calvariae, SCMII increased medium Ca2+ and PGE2 in a dose-dependent manner at concentrations from 20 ng protein/ml to a maximum of 500 ng protein/ml. Preincubation of SCMII with antibody to IL-1 alpha completely inhibited SCMII-induced bone resorption. SCMII also enhanced thymocyte proliferation with activity that was equivalent to 353 U/ml IL-1. Antibodies to IL-1 beta and tumor necrosis factor had no effect on SCMII-induced bone resorption. Using specific enzyme-linked immunosorbent assays for IL-1 alpha and IL-1 beta, IL-1 alpha was measured in high concentrations in both crude and partially purified fractions of SCC-9 and SCC-13 CM. In contrast, IL-1 beta was either undetectable or present in amounts below those that stimulate bone resorption. In addition, SCMII did not enhance cAMP production in bone cells. We conclude that the BRSA produced by the two squamous cell carcinoma cell lines SCC-9 and SCC-13 is IL-1 alpha.

Prostaglandins E and F2α and metabolites 13,14-dihydro-15-keto-PGE2 and 13,14-dihydro-15-keto-PGF2α were measured by specific radioimmunassay in outflows from isolated, perfused guinea-pig lungs. Samples were collected from non-sensitized and sensitized guinea-pigs during baseline period and during challenge with ovalbumen or NaCl. Anaphylactic reaction greatly increased the release of both metabolites. Catecholamines, particularly epinephrine markedly reduced the content of metabolites in the outflow. Inhibition of prostaglandin release is parallel to that of histamine and points to the important role catecholamines may play in allergic reactions, specifically in modulating the release of mediators.

Publication of the "Atlas of Cancer Mortality for U.S. Counties, 1950-1969" caused a great deal of concern in counties shown in the Atlas to have had high cancer mortality rates in relation to the United States as a whole. An analysis was made of temporal trends of cancer mortality in Bergen County, a "high-rate county" in northeastern New Jersey, by calculating age-adjusted cancer mortality rates by sex and site for Bergen County residents for the period 1962-75. Mortality rates and time rates of change in mortality rates were compared to those in the United States as a whole. Male and female rates for respiratory cancer and male rates for all sites combined increased significantly more quickly in the United States than in Bergen County during the study period. The authors discuss these trends and recommended that recent time-specific mortality rates be furnished to county health commissions on a regular basis.

This study investigated the relations among appraisals, emotions and coping strategies when adolescents were confronted with a stressful event: the High School Diploma examination. Italian students (N = 610) completed a questionnaire three weeks before the beginning of the exam. Data were reduced by means of principal component analyses and then multiple regression analyses were conducted to assess the relations among appraisals, emotions and coping strategies. The results suggest that students who perceived their coping potential as high, and had an internal locus of control, felt more intense positive emotions such as happiness and challenge, and adopted coping strategies such as focusing on positive aspects of the experience and seeking social support. In contrast, students who perceived their coping potential as low, and had an external locus of control, experienced more intense emotions of helplessness and frustration and adopted avoidance and isolation strategies.