The role of neutral Rh(PONOP)H, free NMe2H, boronium and ammonium salts in the dehydrocoupling of dimethylamine-borane using the cationic pincer [Rh(PONOP)(η2-H2)]+ catalyst

The σ-amine-borane pincer complex [Rh(PONOP)(η1-H3B·NMe3)][BArF4] [2, PONOP = κ3-NC5H3-2,6-(OPtBu2)2] is prepared by addition of H3B·NMe3 to the dihydrogen precursor [Rh(PONOP)(η2-H2)][BArF4], 1. In a similar way the related H3B·NMe2H complex [Rh(PONOP)(η1-H3B·NMe2H)][BArF4], 3, can be made in situ, but this undergoes dehydrocoupling to reform 1 and give the aminoborane dimer [H2BNMe2]2. NMR studies on this system reveal an intermediate neutral hydride forms, Rh(PONOP)H, 4, that has been prepared independently. 1 is a competent catalyst (2 mol%, ∼30 min) for the dehydrocoupling of H3B·Me2H. Kinetic, mechanistic and computational studies point to the role of NMe2H in both forming the neutral hydride, via deprotonation of a σ-amine-borane complex and formation of aminoborane, and closing the catalytic cycle by reprotonation of the hydride by the thus-formed dimethyl ammonium [NMe2H2]+. Competitive processes involving the generation of boronium [H2B(NMe2H)2]+ are also discussed, but shown to be higher in energy. Off-cycle adducts between [NMe2H2]+ or [H2B(NMe2H)2]+ and amine-boranes are also discussed that act to modify the kinetics of dehydrocoupling

Clinical features and outcomes of elderly hospitalised patients with chronic obstructive pulmonary disease, heart failure or both

Background and objective: Chronic obstructive pulmonary disease (COPD) and heart failure (HF) mutually increase the risk of being present in the same patient, especially if older. Whether or not this coexistence may be associated with a worse prognosis is debated. Therefore, employing data derived from the REPOSI register, we evaluated the clinical features and outcomes in a population of elderly patients admitted to internal medicine wards and having COPD, HF or COPD + HF. Methods: We measured socio-demographic and anthropometric characteristics, severity and prevalence of comorbidities, clinical and laboratory features during hospitalization, mood disorders, functional independence, drug prescriptions and discharge destination. The primary study outcome was the risk of death. Results: We considered 2,343 elderly hospitalized patients (median age 81 years), of whom 1,154 (49%) had COPD, 813 (35%) HF, and 376 (16%) COPD + HF. Patients with COPD + HF had different characteristics than those with COPD or HF, such as a higher prevalence of previous hospitalizations, comorbidities (especially chronic kidney disease), higher respiratory rate at admission and number of prescribed drugs. Patients with COPD + HF (hazard ratio HR 1.74, 95% confidence intervals CI 1.16-2.61) and patients with dementia (HR 1.75, 95% CI 1.06-2.90) had a higher risk of death at one year. The Kaplan-Meier curves showed a higher mortality risk in the group of patients with COPD + HF for all causes (p = 0.010), respiratory causes (p = 0.006), cardiovascular causes (p = 0.046) and respiratory plus cardiovascular causes (p = 0.009). Conclusion: In this real-life cohort of hospitalized elderly patients, the coexistence of COPD and HF significantly worsened prognosis at one year. This finding may help to better define the care needs of this population

A study on the microbial quality of sealed products for feminine hygiene

Introduction. Sanitary tampons have been in existence for over 60 years. Their use may present certain health risks, potentially associated with an abnormal change of microbial flora in the vagina (e.g., toxic shock syndrome). Tampon production and marketing are regulated differently in different countries. In Australia, Canada and the USA, tampons are classified as Class-II medical devices and their marketing requires pre-clinical and clinical studies, including microbiological trials. In Europe, tampons are considered consumer products and safety-related data are provided only if the manufacturer deems them to be useful. Sterility of these products is not requested by law; thus they may represent a potential vehicle for microorganisms. Due to the lack of data on microbial characteristics of tampons, an analytical investigation was carried out to characterize and quantify the microbial flora present on sealed tampons of various brands present on the market in Italy. Methods. Traditional cultural methods were used to characterize and quantify bacteria and fungi. Identification of colonies was performed with biochemical techniques. Results. Results showed low microbial concentrations in 93% of the positive samples. A rare presence of opportunistic pathogens was detected and a few samples (6%) were characterized by bacterial species of human origin. Conclusions. In the light of these data, the examined tampons were found to have good hygienic quality. Nevertheless, to minimize the microbial risks linked to the use of these products, strict hygienic rules during their production and manipulation have to be adopted

Behavior of pseudomonas aeruginosa and enterobacter aerogenes in water from filter jugs

Careless use conditions of filter jugs were applied to simulate and evaluate the behavior of two ubiquitous aquatic bacterial species, Pseudomonas aeruginosa and Enterobacter aerogenes. According to a reference protocol, nine different jugs of popular brands sold in the Italian market were used for the test. Separately, a suspension of the two bacteria was spiked in water used for filling the jugs. The concentration of the test organisms and total aerobic microbial count (TAMC) was measured daily in the filtered water along a period corresponding to the cartridge lifetime. Results showed a different trend of bacterial behavior. E. aerogenes was detectable exclusively on the first day after jug filling, while P. aeruginosa confirmed its persistence over time in all the jugs and its ability to potentially colonize surfaces and cartridges. The TAMC was detected at a concentration range from 102 to 107 CFU/100 mL in all the tests, high values that were not far from those raised in bottled flat natural mineral water weeks after bottling

AN INNOVATIVE SYSTEM BASED ON BIOIMPEDANCE MEASUREMENTS TO DEFINE THE BLADDER VOLUME

Objectives: Alteration of the bladder sense of fullness due to spinal cord injury or radical cystectomy leads to the inability to plan micturition timing. The development of a system for the fullness detection would be highly desirable and would enable autonomous and spontaneous management of micturition by the patient. Here the design of an innovative system of bladder volume monitoring based on bioimpedance measurements is presented. Methods: Bioimpedance measurements are performed on ex-vivo bladder tissue using traditional ECG sensors. Two couples of electrodes in different arrangements were applied on the bladder walls to detect degree of filling by 50ml step, from 0ml to 300ml. The bioimpedance values are obtained for frequencies ranging from 1 kHz to 2 MHz. Moreover, different compositions of artificial urine were tested, by varying relevant ions concentration. Results: The impedance variations were recorded around 20ohm in average from empty to full status. However, the impedance variation was dependent to ion concentration in urine. Discussion: The experiment shows the feasibility of this approach and the need to find the sensors arrangement able to normalize measurements with respect to urine composition. Conclusions: A novel system to detect the bladder filling based on bioimpedence measures is reported. This approach could be feasible both in presence of natural or artificial/reconstructed bladder. Future work will target accurate volume estimation independently on urine composition, as well as combination with other sensing strategies. Acknowledgements: The authors acknowledge INAIL (Istituto Nazionale Assicurazioni Infortuni sul Lavoro) for providing their collaboration within the BioSUP project

Valutazione comparativa di procedure analitiche per il rilevamento di Enterobacteriaceae in acque marine costiere

Biblioteca Centrale CNR / CNR - Consiglio Nazionale delle RichercheSIGLEITItal

Synthesis and Electronic Structure of Bis(imino)pyridine Iron Metallacyclic Intermediates in Iron-Catalyzed Cyclization Reactions

The bis­(imino)­pyridine iron dinitrogen compound, (^iPr(TB)PDI)­Fe­(N₂)₂ (^iPr(TB)PDI = 2,6-(2,6-ⁱPr₂-C₆H₃-NC-(CH₂)₃)₂(C₅H₁N)) is an effective precatalyst for the [2π + 2π] cycloaddition of diallyl amines as well as the hydrogenative cyclization of N-tosylated enynes and diynes. Addition of stoichiometric quantities of amino-substituted enyne and diyne substrates to (^iPr(TB)PDI)­Fe­(N₂)₂ resulted in isolation of catalytically competent bis­(imino)­pyridine iron metallacycle intermediates. A combination of magnetochemistry, X-ray diffraction, and Mössbauer spectroscopic and computational studies established <i>S</i> = 1 iron compounds that are best described as intermediate-spin iron­(III) (<i>S</i>_Fe = 3/2) antiferromagnetically coupled to a chelate radical anion (<i>S</i>_PDI = 1/2). Catalytically competent bis­(imino)­pyridine iron diene and metallacycles relevant to the [2π + 2π] cycloaddition were also isolated and structurally characterized. The combined magnetic, structural, spectroscopic, and computational data support an Fe­(I)–Fe­(III) catalytic cycle where the bis­(imino)­pyridine chelate remains in its one-electron reduced radical anion form. These studies revise a previous mechanistic proposal involving exclusively ferrous intermediates and highlight the importance of the redox-active bis­(imino)­pyridine chelate for enabling catalytic cyclization chemistry with iron