Surface lattice dynamics and electron-phonon interaction in cesium ultra-thin films.

The phonon dispersion curves of ultrathin films of Cs(110) on Pt(111) measured with inelastic helium atom scattering (HAS) are reported and compared with density-functional perturbation theory (DFPT) calculations. The combined HAS and DFPT analysis also sheds light on the bulk phonon dynamics of bcc-Cs, on which very little is known from neutron scattering due to its large neutron capture cross-section. Moreover the temperature dependence of the elastic HAS Debye-Waller exponent of Cs(110)/Cu(111) ultrathin films allows for an estimation of the electron-phonon coupling strength λ as a function of the film thickness.

Characterisation of CTX-M and AmpC genes in human isolates of Escherichia coli identified between 1995 and 2003 in England and Wales.

CTX-M and AmpC genes in human isolates of Escherichia coli, their genetic environment and their host plasmids were examined. Isolates (n=103) were selected based on resistance (minimum inhibitory concentration (MIC)> or =1 microg/mL) to ceftriaxone and cefotaxime. Polymerase chain reaction (PCR) and sequencing identified 29 isolates containing bla(CTX-M-15), 1 each of bla(CTX-M-2) (a strain originating from Israel) and bla(CTX-M-40), 20 isolates containing bla(CMY-7), 4 bla(CMY-2) and 1 bla(CMY-21). This is the first study of plasmid-mediated AmpC genes in E. coli in the UK. Eleven cefoxitin-resistant, AmpC PCR-negative isolates had ampC promoter region mutations. All bla(CTX-M-15) and 24 of 25 bla(CMY) genes were associated with an ISEcp1-like element. The bla(CTX-M-2) was located in an orf513-bearing class 1 integron. Plasmid restriction digests suggest transfer of genes between different plasmid backbones.

Co-ordinator of the health team.

We at the Diabetes Foundation see the general practitioner as the co-ordinator of the community health team. As a branch of this team we rely on the communications and referrals of the general practitioner.

The use of heparin in patients with ruptured abdominal aortic aneurysms.

The use of systemic heparin in patients with ruptured abdominal aortic aneurysms (rAAAs) remains a contentious issue with no clear guidelines. This review reports the current understanding, at a molecular and clinical level, of the possible benefits and risks of heparin in emergency aneurysm repair (both open and endovascular). MEDLINE, EMBASE, AMED, SCOPUS, CINAHL and Cochrane Library were searched for all articles containing the keywords 'rupture', 'abdominal', 'aneurysm' and 'heparin'. Current experience, indications and outcomes were analyzed. Articles were searched for both endovascular and open repair of AAAs. A total of eight studies were included for analysis in the systematic review. Of these, only one paper focused specifically on heparin use in open repair of ruptures and suggested a benefit. Of the remaining seven, two were self-reporting retrospective studies assessing individual surgeons' practice, one was a case report and the remaining four included mention of heparin use but with no outcome data. The evidence available suggests that a pro-coagulable state exists in rAAAs. This may be responsible for the morbidity and mortality postprocedure, which arises predominantly from multiple organ failure and cardiac compromise rather than outright hemorrhage. This diathesis may respond well to heparin administration, suggesting that heparin administration in ruptured aneurysms is appropriate.

Sub-20 nm short channel carbon nanotube transistors.

Carbon nanotube field-effect transistors with sub-20 nm long channels and on/off current ratios of >10(6) are demonstrated. Individual single-walled carbon nanotubes with diameters ranging from 0.7 to 1.1 nm grown from structured catalytic islands using chemical vapor deposition at 700 degrees C form the channels. Electron beam lithography and a combination of HSQ, calix[6]arene, and PMMA e-beam resists were used to structure the short channels and source and drain regions. The nanotube transistors display on-currents in excess of 15 microA for drain-source biases of only 0.4 V.

Spectroscopy of the conformational disorder in molecular films: tetracosane and squalane on Pt(111).

The spectroscopic investigation of the molecular vibrations of adsorbed branched and unbranched alkane molecules using helium atom scattering (HAS) provides evidence for the thermal formation of gauche defects in tetracosane (C24H50) monolayers above 200 K. HAS results for the vibration of tetracosane molecules perpendicular to the Pt(111) surface reveal a strong frequency decrease and peak broadening above the transition temperature which can be related to a reduction of the force holding the molecules to the surface. This reduction of the force is interpreted as being due to the thermal formation of gauche defects within the tetracosane molecules.

Transcriptional profiling of human microvascular endothelial cells in the proliferative and quiescent state using cDNA arrays.

Endothelial cells are known to be a rich source of transcriptional gene expression. Recent technological advances now permit the detailed profiling of mRNA expression using arrays of known cDNAs on blots. We have used such arrays to examine expression of mRNA by primary isolates of human foreskin microvascular endothelial cells in the proliferative and quiescent state. Cells were stimulated by a combination of known growth factors for these cells including epidermal growth factor (EGF), vascular endothelial growth factor (VEGF), and 'endothelial cell growth supplement (ECGS)' either alone or in combination. Analysis showed the expression of many mRNAs but of the 588 examined, only one, namely monocyte chemotactic protein-1 (MCP-1), showed a decrease on treatment with EGF. A combination of image grabbing followed by subtractive densitometry enabled identification of the mRNAs upregulated in proliferating endothelium. In consideration of the possibility of selective vascular targeting, of particular interest was the increase in expression of the mRNA for the cell surface proteins vascular endothelial (VE-) and neural (N-) cadherin and alpha5, alphav, beta1 and beta3 integrins. The alpha5 integrin offers a previously unrecognized opportunity for vascular targeting.