Effect of adding 0.3 wt% Ni into the Sn–0.7 wt%Cu solder: part I: wetting behavior on Cu and Ni substrates

Comparative wetting behavior of Sn-0.7Cu and Sn-0.7Cu-0.3Ni solders on Cu and Ni substrates were assessed through the wetting balance test. No-clean (NC), non-activated (R) and water soluble organic acid (WS) fluxes were used to assess the wetting behavior for three different solder bath temperatures of 255, 275 and 295 °C. Experimental results unveiled that adding of 0.3 wt% Ni into Sn-0.7Cu solder can improve the wetting on Cu substrate when NC and WS fluxes are used. However, such addition of Ni did not improve the wetting of Sn-0.7Cu solder for R-type flux. In the case of Ni substrate, addition of Ni helped to improve the wetting for all three types of fluxes as higher wetting forces were documented for Sn-0.7Cu-0.3Ni solder compared to the Sn-0.7Cu solder. Among the fluxes, worst performance was observed for R-type flux. Very large contact angles were recorded for both solders with this kind of flux. Experimental results also revealed that higher solder bath temperature played an important role to lower the contact angle, to increase the wetting force and to enhance the wetting. Computer modeling of wetting balance test also revealed that both the wetting force and meniscus height are inversely proportional to the contact angles. Besides, solder bath depth and radius do not affect significantly on the wetting behavior.

Synthesis and enzymatic evaluation of the guanosine analogue 2-amino-6-mercapto-7-methylpurine ribonucleoside (MESG): insights into the phosphorolysis reaction mechanism based on the blueprint transition state: SN1 or SN2?

A modified experimental procedure for the synthesis of MESG (2-amino-6-mercapto-7-methylpurine ribonucleoside) 1 has been successfully performed and its full characterization is presented. High resolution ESI(+)-MSMS indicates both the nucleoside bond cleavage as the main fragmentation in the gas phase and a possible SN1 mechanism. Ab initio transition state calculations based on the blue print transition state support this mechanistic rationale and discard an alternative SN2 mechanism. Assays using purine nucleoside phosphorylase (PNP) enzyme (human and M. tuberculosis sources) indicate its efficiency in the phosphorolysis of MESG and allow the quantitative determination of inorganic phosphate in real time assay.

The reporting behaviours of student nurses who have experienced verbal abuse

Background: There is evidence that student nurses are vulnerable to experiencing verbal abuse from a variety of sources and under-reporting of verbal abuse is prevalent throughout the nursing profession. The objective of the study is to explore the reporting behaviours of student nurses who have experienced verbal abuse. Method: For this study a definition of verbal abuse was adopted from current Department of Health (England) guidelines. Questionnaires were distributed in 2005 to a convenience sample of 156 third year nursing students from one pre-registration nursing programme in England. A total of 114 questionnaires were returned, giving an overall response rate of 73.0%. Results: Fifty one students (44.7% of responses) reported verbal abuse; all of these completed the section exploring reporting behaviours. The incidents involved patients in thirty three cases (64.7%); eight cases (15.7%) involved visitors or relatives and ten cases (19.6%) involved other healthcare workers. Thirty two students (62.7%) stated that they did report the incident of verbal abuse they experienced and nineteen (37.3%) of respondents reported that they did not. Only four incidents developed from an oral report to being formally documented. There was a statistically significant association (P = 0.003) between the focus of verbal abuse (patient/visitor or colleague) and the respondents reporting practices with respondents experiencing verbal abuse from colleagues less likely to report incidents. Most frequent feelings following experiences of verbal abuse from colleagues were feelings of embarrassment and hurt/shock. Most frequent consequences of experiencing verbal abuse from patients or relatives were feeling embarrassed and feeling sorry for the abuser. When comparing non reporters with reporters, the most frequent feelings of non reporters were embarrassment and hurt and reporters, embarrassment and feeling sorry for the abuser. When considering levels of support after the incident the mean rating score of respondents who reported the incident was 5.40 (standard deviation 2.89) and of those that did not, 4.36 (standard deviation 2.87) which was not statistically significant (p = 0.220). Conclusions: 1. Not documenting experiences of verbal abuse formally in writing is a prevalent phenomenon within the sample studied and reporting practices are inconsistent. 2. Both Higher Education Institutions and health care providers should consider emphasising formal reporting and documenting of incidents of verbal abuse during student nurse training and access to formal supportive services should be promoted. 3. Effective incident reporting processes and analysis of these reports can lead to an increased awareness of how to avoid negative interactions in the workplace and how to deal with incidents effectively.

Organometallic pincer-type complexes: recent applications in synthesis and catalysis

YCY pincer palladacycles, where YCY is typically an SCS, NCN, PCP, SeCSe anionic six-electron donor ligand (e.g. see 1-6, Scheme 1.1), are a well-established family of organometallic complexes with manifold applications in catalysis, synthesis and materials science [1-24]. Their synthesis can be achieved by many routes including C-H activation, oxidative addition, transmetalation and trans-cyclopalladation [25].