K alpha yields from Ti foils irradiated with ultrashort laser pulses

We have studied the emission of Kalpha radiation from Ti foils irradiated with ultrashort (45 fs) laser pulses. We utilized the fundamental (800 nm) light from a Ti:sapphire laser on bare foils and foils coated with a thin layer of parylene E (CH). The focusing was varied widely to give a range of intensities from approximately 10(15)-10(19) W cm(-2). Our results show a conversion efficiency of laser to Kalpha energy of similar to 10(-4) at tight focus for both types of targets. In addition, the coated targets exhibited strong secondary peaks of conversion at large defocus, which we believe are due to modification of the extent of preformed plasma due to the dielectric nature of the plastic layer. This in turn affects the level of resonance absorption. A simple model of Kalpha production predicts a much higher conversion than seen experimentally and possible reasons for this are discussed.

Screening of electrophilic compounds yields an aziridinyl peptide as new active-site directed SARS-CoV main protease inhibitor.

The coronavirus main protease, Mpro, is considered a major target for drugs suitable to combat coronavirus infections including the severe acute respiratory syndrome (SARS). In this study, comprehensive HPLC- and FRET-substrate-based screenings of various electrophilic compounds were performed to identify potential Mpro inhibitors. The data revealed that the coronaviral main protease is inhibited by aziridine- and oxirane-2-carboxylates. Among the trans-configured aziridine-2,3-dicarboxylates the Gly-Gly-containing peptide 2c was found to be the most potent inhibitor.

Thin film capacitor cut from single crystals using focused ion beam milling

The focused ion beam microscope (FIB) has been used to fabricate thin parallel-sided ferroelectric capacitors from single crystals of BaTiO3 and SrTiO3. A series of nano-sized capacitors ranging in thickness from similar to660 nm to similar to300 nm were made. Cross-sectional high resolution transmission electron microscopy (HRTEM) revealed that during capacitor fabrication, the FIB rendered around 20 nm of dielectric at the electrode-dielectric interface amorphous, associated with local gallium impregnation. Such a region would act electrically in series with the single crystal and would presumably have a considerable negative influence on the dielectric properties. However, thermal annealing prior to gold electrodes deposition was found to fully recover the single crystal capacitors and homogenise the gallium profile. The dielectric testing of the STO ultra-thin single crystal capacitors was performed yielding a room temperature dielectric constant of similar to300, as is the case in bulk. Therefore, there was no evidence of a collapse in dielectric constant associated with thin film dimensions.

Selection with melphalan or paclitaxel (Taxol) yields variants with different patterns of multidrug resistance, integrin expression and in vitro invasiveness

A melphalan-resistant variant (Roswell Park Memorial Institute (RPMI)-2650M1) and a paclitaxel-resistant variant (RPMI-1650Tx) of the drug-sensitive human nasal carcinoma cell line, RPMI-2650. were established. The multidrug resistance (MDR) phenotype in the RPMI-2650Tx appeared to be P-glycoprotein (PgP)-mediated. Overexpression of multidrug resistant protein (MRP) family members was observed in the RPMI-2650M1 cells, which were also much more invasive in vitro than the parental cell line or the paclitaxel-resistant variant. Increased expression of alpha (2), alpha (5), alpha (6), beta (1) and beta (4) integrin subunits, decreased expression of alpha (4) integrin subunit, stronger adhesion to collagen type IV, laminin, fibronectin and matrigel, increased expression of MMP-2 and MMP-9 and significant motility compared with the parental cells were observed, along with a high invasiveness in the RPMI-7650M1 cells. Decreased expression of the alpha (2) integrin subunit, decreased attachment to collagen type IV, absence of cytokeratin 18 expression, no detectable expression of gelatin-degrading proteases and poor motility may be associated with the non-invasiveness of the RPMI-2650Tx variant. These results suggest that melphalan exposure can result in not only a MDR phenotype. but could also make cancer cells more invasive, whereas paclitaxel exposure resulted in MDR without increasing the in vitro invasiveness in the RPMI-2650 cells. (C) 2001 Elsevier Science Ltd. All rights reserved.

Cut down by some cowardly miscreants’: Plant maiming, or the Malicious Cutting of Plants as an Act of Protest in Eighteenth and Nineteenth Century Rural England

Since the publication of Hobsbawm and Rudé's Captain Swing our understanding of the role(s) of covert protests in Hanoverian rural England has advanced considerably. Whilst we now know much about the dramatic practices of incendiarism and animal maiming and the voices of resistance in seemingly straightforward acquisitive acts, one major gap remains. Despite the fact that almost thirty years have passed since E. P. Thompson brought to our attention that under the notorious ‘Black Act’ the malicious cutting of trees was a capital offence, no subsequent research has been published. This paper seeks to address this major lacuna by systematically analysing the practices and patterns of malicious attacks on plants (‘plant maiming’) in the context of late eighteenth- and early nineteenth-century southern England. It is shown that not only did plant maiming take many different forms, attacking every conceivable type of flora, but also that it was universally understood and practised. In some communities plant maiming was the protestors' weapon of choice. As a social practice it therefore embodied wider community beliefs regarding the defence of plebeian livelihoods and identities.

An Unkind Cut: Circumcision, Death and the Impact of Irish Health Policy on Asylum Seekers

Healthcare and the wider social determinants of health are the keystone of a number of complex progressive social justice issues that evoke complex emotions. As the demography of Ireland rapidly changes, the practices and expectations of some asylum seekers presents new opportunities for the providers of health service provision and reform. This paper looks at some of the emotions evoked in health care issues and draws on observations and interviews from empirical fieldwork carried out for the Health Research Board. The research was conducted both in the Adelaide and Meath Hospital, incorporating the National Children’s Hospital, Tallaght and in a number of refugee reception centres in Ireland. At one level honouring faith choices within a healthcare setting is a societal acknowledgement made to people at their most vulnerable, that the potent and cathartic transformative rituals they value are significant in mediating and managing their emotions - at another level, it is a practical and a symbolic communication of a statutory commitment to inter-culturalism and community cohesion..