Here we report that attempted preparation of low-valent Ca
complexes in the form of LCa-CaL (where L is a bulky β-diketiminate ligand) under dinitrogen (N
) atmosphere led to isolation of LCa(N
)CaL, ...which was characterized crystallographically. The N
- anion in this complex reacted in most cases as a very potent two-electron donor. Therefore, LCa(N
)CaL acts as a synthon for the low-valent Ca
complex LCa-CaL, which was the target of our studies. The N
- anion could also be protonated to diazene (N
H
) that disproportionated to hydrazine and N
The role of Ca d orbitals for N
activation is discussed.
A complex of a metal in its zero oxidation state can be considered a stabilized, but highly reactive, form of a single metal atom. Such complexes are common for the more noble transition metals. ...Although rare examples are known for electronegative late-main-group p-block metals or semimetals
, it is a challenge to isolate early-main-group s-block metals in their zero oxidation state
. This is directly related to their very low electronegativity and strong tendency to oxidize. Here we present examples of zero-oxidation-state magnesium (that is, magnesium(0)) complexes that are stabilized by superbulky, monoanionic, β-diketiminate ligands. Whereas the reactivity of an organomagnesium compound is typically defined by the nucleophilicity of its organic groups and the electrophilicity of Mg
cations, the Mg
complexes reported here feature electron-rich Mg centres that are nucleophilic and strongly reducing. The latter property is exemplified by the ability to reduce Na
to Na
. We also present a complex with a linear Mg
core that formally could be described as a Mg
-Mg
-Mg
unit. Such multinuclear mixed-valence Mg
clusters are discussed as fleeting intermediates during the early stages of Grignard reagent formation. Their remarkably strong reducing power implies a rich reactivity and application as specialized reducing agents.
Child maltreatment is underreported in the United States and in North Carolina. In North Carolina and other states, mandatory reporting laws require various professionals to make reports, thereby ...helping to reduce underreporting of child maltreatment. This study aims to understand why emergency medical services (EMS) professionals may fail to report suspicions of maltreatment despite mandatory reporting policies.
A web-based, anonymous, voluntary survey of EMS professionals in North Carolina was used to assess knowledge of their agency's written protocols and potential reasons for underreporting suspicion of maltreatment (n=444). Results were based on descriptive statistics. Responses of line staff and leadership personnel were compared using chi-square analysis.
Thirty-eight percent of respondents were unaware of their agency's written protocols regarding reporting of child maltreatment. Additionally, 25% of EMS professionals who knew of their agency's protocol incorrectly believed that the report should be filed by someone other than the person with firsthand knowledge of the suspected maltreatment. Leadership personnel generally understood reporting requirements better than did line staff. Respondents indicated that peers may fail to report maltreatment for several reasons: they believe another authority would file the report, including the hospital (52.3%) or law enforcement (27.7%); they are uncertain whether they had witnessed abuse (47.7%); and they are uncertain about what should be reported (41.4%).
This survey may not generalize to all EMS professionals in North Carolina.
Training opportunities for EMS professionals that address proper identification and reporting of child maltreatment, as well as cross-agency information sharing, are warranted.
While there are quite a number of reports on vascular injuries complicating hip arthropasty by acetabular component screw fixation, retractor tip pressure or extruding bone cement, the incidence of ...deep femoral vessel injuries in operative fixation of proximal femoral fractures is comparatively seldom described. We report on two patients with per- and subtrochanteric femoral fractures who sustained injuries of deep femoral artery branches during the implantation of a dynamic hip screw (DHS) and a dynamic condylar screw (DCS), which resulted in a massive thigh hematoma and a fist-size pseudoaneurysm respectively and necessitated surgical intervention in either case. We blame these vascular injuries on the pressure of Hohmann retractors exposing the femoral bone or on the drilling of boreholes for plate attachment. After discussing various operative procedures, we conclude that intramedullar implants are safer than plates with regard to potential vascular complications.
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