Addressing the Nature of Phosphinidene Sulfides via the Synthesis of P-S Heterocycles.

The phosphorus-sulfur heterocycles 1,2-thiaphosphetenes and phosphirene sulfides have been prepared, and represent the first structurally characterized derivatives for either class of compound. These strained P-S ring systems are formed by the reaction of a phosphinidene sulfide and alkyne. Using an internal alkyne, only the 3-membered PV , phosphirene sulfide was produced, whereas a terminal alkyne yielded a mixture of phosphirene sulfide and 1,2-thiaphosphetene (PIII ). Detailed computational analysis revealed that for numerous derivatives of alkynes, the corresponding 4-membered rings are always more stable than the 3-membered isomers. The electronic nature of "free" phosphinidene sulfides (R-P=S) is discussed based on computational results.

Preparation and Characterization of P2 BCh Ring Systems (Ch=S, Se) and Their Reactivity with N-Heterocyclic Carbenes.

Four-membered rings with a P2 BCh core (Ch=S, Se) have been synthesized by the reaction of phosphinidene chalcogenide (Ar*P=Ch) and phosphaborene (Mes*P=BNR2 ). The mechanistic pathways towards these rings are explained by detailed computational work that confirmed the preference for the formation of P-P, not P-B, bonded systems, which seems counterintuitive given that both phosphorus atoms contain bulky ligands. The reactivity of the newly synthesized heterocycles, as well as that of the known (RPCh)n rings (n=2, 3), was probed by the addition of N-heterocyclic carbenes, which revealed that all investigated compounds can act as sources of low-coordinate phosphorus species.

Phosphorus-Chalcogen Ring Expansion and Metal Coordination.

The reactivity of 4-membered (RPCh)2 rings (Ch = S, Se) that contain phosphorus in the +3 oxidation state is reported. These compounds undergo ring expansion to (RPCh)3 with the addition of a Lewis base. The 6-membered rings were found to be more stable than the 4-membered precursors, and the mechanism of their formation was investigated experimentally and by density functional theory calculations. The computational work identified two plausible mechanisms involving a phosphinidene chalcogenide intermediate, either as a free species or stabilized by a suitable base. Both the 4- and 6-membered rings were found to react with coinage metals, giving the same products: (RPCh)3 rings bound to the metal center from the phosphorus atom in tripodal fashion.

Transition Metal Functionalization of P4 Using a Diarylgermylene Anchor.

The manipulation of white phosphorus (P4) has been a long-standing challenge for chemists. While the holy grail remains at finding a method to catalytically activate and functionalize P4 to yield new organophosphorus compounds, fundamental research lies in developing procedures to control the reactivity of elemental phosphorus. In this work, Lewis acidic transition metal moieties M(CO)5 (M = Cr, Mo, W) and AuCl react with P4 derivatized with a low valent germanium compound. For both M(CO)5 and AuCl, bis-functionalized products can be formed; however the monosubstituted derivatives are found to be more stable, and the decomposition can be monitored by 31P{1H} NMR spectroscopy. The selective reactivity of white phosphorus, once a P-P bond has been activated, is a key step in yielding new organophosphorus compounds.

Trapping Rare and Elusive Phosphinidene Chalcogenides.

Four-membered rings with a P2 Ch2 core (Ch=S, Se) and phosphorus in the +3 oxidation state have been synthesized. The utility of these rings as a source of monomeric phosphinidene chalcogenides was probed by the addition of an N-heterocyclic carbene, resulting in a base-stabilized phosphinidene sulfide. Similarly, persistence of the phosphinidene selenide in solution was shown through cycloaddition chemistry with 2,3-dimethylbutadiene at elevated temperatures. The observed reactivity was explained by detailed computational work that established the conditions upon which the P2 Ch2 rings can liberate phosphinidene chalcogenides.

Reversible, photoinduced activation of P4 by low-coordinate main group compounds.

Two unique systems based on low-coordinate main group elements that activate P4 are shown to quantitatively release the phosphorus cage upon short exposure to UV light. This reactivity marks the first reversible reactivity of P4, and the germanium system can be cycled 5 times without appreciable loss in activity. Theoretical calculations reveal that the LUMO is antibonding with respect to the main group element-phosphorus bonds and bonding with respect to reforming the P4 tetrahedron, providing a rationale for this unprecedented activity, and suggesting that the process is tunable based on the substituents.

A pilot study using synthetic feline facial pheromone for the management of feline idiopathic cystitis.

Synthetic feline facial pheromone (FFP) (Feliway; Ceva Animal Health) was assessed for the management of cats with recurrent feline idiopathic cystitis (FIC). Nine of 12 cats completed the randomised, double-blinded, placebo-controlled, crossover pilot study. They had their environment treated daily with either FFP or placebo for 2 months, after which time the treatment groups were reversed. Owners used visual analogue scales to define the severity of their cat's clinical signs and behavioural changes. Five (56%) of the owners stated that their cat's overall health was better when they were using FFP. Four (44%) of the owners noticed no difference between when using the FFP and when using the placebo. While there were no statistical differences between the two treatment groups there was a trend for the cats exposed to FFP to show fewer days with clinical signs of cystitis (FFP total, mean per cat+/-standard deviation, 30, 4.3+/-6.7; placebo 69, 9.9+/-19.1), a lower overall clinical score (1667, 238+/-476; 2009, 287+/-425), a reduced number of episodes of cystitis (9, 1.3+/-2.0; 10, 1.4+/-2.1) and reduced negative behavioural traits (e.g., less aggression and fear) (-128, -18.3+/-65.8; -73, -10.4+/-35.1).

A study of environmental and behavioural factors that may be associated with feline idiopathic cystitis.

The cause of cystitis in many cats remains unknown. The aim of this study was to determine whether or not any environmental or behavioural factors, particularly those that could be considered potentially stressful, were associated with feline idiopathic cystitis (FIC). The questionnaire-based study involved comparing 31 cats with FIC to 24 cats in the same households that did not have cystitis. They were also compared with a control population of 125 clinically healthy cats. Compared with the live-in controls and the control population, the cats with FIC were significantly more likely to be male, overweight and pedigree. Several stress factors were found to be associated with FIC. The factor that stood out most prominently was living with another cat with which there was conflict. The findings support the hypothesis that stress may be implicated in some cases of FIC.

Nursing students' experience of ethical problems and use of ethical decision-making models.

Using a conceptual framework and method combining ethical enquiry and phenomenology, we asked 73 senior baccalaureate nursing students to answer two questions: (1) What is nursing students' experience of an ethical problem involving nursing practice? and (2) What is nursing students' experience of using an ethical decision-making model? Each student described one ethical problem, from which emerged five content categories, the largest being that involving health professionals (44%). The basic nature of the ethical problems consisted of the nursing students' experience of conflict, resolution and rationale; 85% of the students stated that using an ethical decision-making model was helpful. Although additional research is needed, these findings have important implications for nursing ethics education and practice.

The value, be, do ethical decision-making model: balancing students' needs in school nursing.

How should school nurses balance the needs of students with complex health problems and the needs of all the other students under their care? School nurses experience this and many other stressful ethical problems. The ethical decision-making model, "Value, Be, Do: Guidelines for Resolving Ethical Conflict," provides a philosophical tool for effective resolutions and ethical nursing practice.

The effect of weight loss intervention on antihypertensive medication requirements in the hypertension Optimal Treatment (HOT) study.

Obesity is a significant risk factor for hypertension and the cardiovascular sequelae of hypertension. Weight loss has been shown to be effective in lowering blood pressure in overweight individuals. The purpose of this study was to show the impact of a weight loss intervention on overall medication requirements for obese, hypertensive patients. This was a substudy of the Hypertension Optimal Treatment (HOT) study. HOT study patients who had a body mass index > or =27 kg/m2 were randomized to receive either the weight loss intervention, which included dietary counseling and group support, or to serve as the control group. Patients' weights and number of medication steps (per HOT protocol) required to achieve target diastolic blood pressure were measured at 3, 6, 12, 18, 24, and 30 months. Patients in the weight loss group lost significantly more weight than the control group only at 6 months (-3.2+/-4.3 v. -1.8+/-2.7 kg [mean +/- SD] for weight loss group versus control, respectively, P = .05). The weight loss group tended to regain weight after the first 6 months of the study. However, patients in the weight loss group used a significantly fewer number of medication steps than the control group at all time intervals except 3 months. Weight loss appears to be a useful tool in blood pressure management in patients who require medication to control their blood pressure.

Mothers with multiple sclerosis and their children: effects of fatigue and exacerbations on maternal support.

BACKGROUND: Mothers with multiple sclerosis (MS) often face fatigue and episodic exacerbations during their child-rearing years. These problems affect their support of their children, including physical affection. Children, depending on their age and gender, may or may not understand the changes. OBJECTIVES: To increase knowledge about mothers with MS concerning the relationship of fatigue and functional status to the perception of physical affection with their children, their perceptions of physical affection with their children in relation to exacerbation of their symptoms and the age and gender of their children, and the children's perceptions of their mothers' physical affection in relation to the children's age and gender and exacerbations in their mothers' symptoms. METHOD: Thirty-five mothers with relapsing-remitting MS and a child of each mother were studied, using interviews and questionnaires. RESULTS: Functional status and fatigue were not significant predictors of physical affection during an exacerbation. When the mothers' symptoms were stable, perceptions of mothers and children with respect to maternal physical affection were similar. Significant changes were reported in both the mothers' perceptions of their physical affection and the children's perceptions of their mothers' physical affection during exacerbations. There was a significant difference between the perceptions of the mothers and children regarding the magnitude of that change. Mothers significantly underestimated changes in their physical affection. CONCLUSIONS: Physical affection was selected as an important aspect of family functioning that could be affected by characteristics of illness, including exacerbations, fatigue, and functional status. However, fatigue and functional status did not explain the perception of physical affection during an exacerbation.