602 research outputs found

    Comparison of diffusivities data of streptocyanine dyes by electrochemical and NMR-DOSY methods

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    Diffusivity data of streptocyanine dyes in acetonitrile were investigated using both transient voltammetric techniques and NMR-DOSY. Results of voltammetric measurements allow determination of the diffusion coefficient D values in the range of 1.2-1.6 x 10-9 m² s-1 for the target dyes. Deuterated acetonitrile solvent was used for NMR-DOSY experiments and diffusivities of streptocyanines are given after calibration of acetonitrile on its tracer diffusion value of D∗ACN of 4.37 x 10-⁹. The results for the two methods appear to be in good agreement allowing use of the convenient NMR-DOSY method to measure diffusivity of streptocyanine dyes at low concentrations and so giving a direct access to the number of exchanged electrons using limiting current electrochemical techniques. This last method affords a great advantage of obtaining diffusion coefficients by non-electrochemical method

    Association of a Frailty Screening Initiative With Postoperative Survival at 30, 180, and 365 Days

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    IMPORTANCE As the US population ages, the number of operations performed on elderly patients will likely increase. Frailty predicts postoperative mortality and morbidity more than age alone, thus presenting opportunities to identify the highest-risk surgical patients and improve their outcomes. OBJECTIVE To examine the effect of the Frailty Screening Initiative (FSI) on mortality and complications by comparing the surgical outcomes of a cohort of surgical patients treated before and after implementation of the FSI. DESIGN, SETTING, AND PARTICIPANTS This single-site, facility-wide, prospective cohort quality improvement project studied all 9153 patients from a level 1b Veterans Affairs medical center who presented for major, elective, noncardiac surgery from October 1, 2007, to July 1, 2014. INTERVENTIONS Assessment of preoperative frailty in all patients scheduled for elective surgery began in July 2011. Frailty was assessed with the Risk Analysis Index (RAI), and the records of all frail patients (RAI score,≥ 21) were flagged for administrative review by the chief of surgery (or designee) before the scheduled operation. On the basis of this review, clinicians from surgery, anesthesia, critical care, and palliative care were notified of the patient’s frailty and associated surgical risks; if indicated, perioperative plans were modified based on team input. MAIN OUTCOMES AND MEASURES Postoperative mortality at 30, 180, and 365 days. RESULTS From October 1, 2007, to July 1, 2014, a total of 9153 patients underwent surgery (mean [SD] age, 60.3 [13.5] years; female, 653 [7.1%]; and white, 7096 [79.8%]). Overall 30-day mortality decreased from 1.6%(84 of 5275 patients) to 0.7%(26 of 3878 patients, P \u3c .001) after FSI implementation. Improvement was greatest among frail patients (12.2% [24 of 197 patients] to 3.8% [16 of 424 patients], P \u3c .001), although mortality rates also decreased among the robust patients (1.2% [60 of 5078 patients] to 0.3% [10 of 3454 patients], P \u3c .001). The magnitude of improvement among frail patients increased at 180 (23.9% [47 of 197 patients] to 7.7% [30 of 389 patients], P \u3c .001) and 365 days (34.5% [68 of 197 patients] to 11.7% [36 of 309 patients], P \u3c .001). Multivariable models revealed improved survival after FSI implementation, controlling for age, frailty, and predicted mortality (adjusted odds ratio for 180-day survival, 2.87; 95% CI, 1.98-4.16). CONCLUSIONS AND RELEVANCE Implementation of the FSI was associated with reduced mortality, suggesting the feasibility of widespread screening of patients preoperatively to identify frailty and the efficacy of system-level initiatives aimed at improving their surgical outcomes. Additional investigation is required to establish a causal connection

    Study of the Histamine Electrochemical Oxidation Catalyzed by Nickel Sulfate

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    Thin layer technique was applied to the indirect anodic oxidation of histamine, catalyzed by NiSO4. Coulometric determination of the electron number demonstrates that histamine complexes Ni(II) and resulting adducts can be electrochemically oxidized in a single‐electron reaction, to lead Ni(III)‐histamine. The system Ni(III)/Ni(II) acts as ‘redox mediator’ for histamine oxidation. The equilibrium constant of the Ni(II)‐histamine complex formation was 106 , value showing the strong affinity between species. High content of histamine (>0.1 M), detected in fresh fish (previously exposed to the sun) extracts, showing potentialities for future design of a sensor for direct measurement in fish

    Exposure to widespread drinking water chemicals, blood inflammation markers, and colorectal cancer

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    Background: Trihalomethanes (THMs) and nitrate are widespread chemicals in drinking water associated with colorectal cancer risk but mechanisms are not well understood. Objectives: We explored the association between exposure to THMs and nitrate in drinking water and inflammation markers, and the link with colorectal cancer risk. Methods: A subset of 198 colorectal cancer cases and 205 controls from the multicase-control study MCC-Spain were included. Average concentration of THMs (chloroform, bromodichloromethane, dibromochloromethane, bromoform) and nitrate in tap water at the residence was estimated from age 18 until 2 years before the interview ("long term") and for a recent period (3 years before diagnosis). Serum levels of EGF, eotaxin, G-CSF, IL-17E, IL-1rA, IL-8, IP-10, MDC, MPO, periostin, VEGF, and C-reactive protein (CRP) were measured. We estimated the linear association between inflammation markers and exposure among controls, and the odds ratio of colorectal cancer associated with THM and nitrate exposure, and inflammation markers. A mediation analysis was conducted to identify inflammation markers in the pathway between THM/nitrate exposure and colorectal cancer. Results: Serum concentrations of EGF, IL-8, IL-17E and eotaxin increased with recent residential levels of brominated THMs, chloroforom and/or total THM. No associations were observed for nitrate and for long-term residential THM levels. All residential exposures except chloroform were positively associated with colorectal cancer. Serum concentrations of VEGF and periostin were positively associated with colorectal cancer, while EGF was inversely associated. One protein-exposure combination (periostin-recent ingested brominated THMs) slightly mediated the association with colorectal cancer risk. Discussion: Results suggest that estimated THM exposure is involved in inflammation processes. However, the study design was limited to stablish etiologically relevant associations between the protein levels and colorectal cancer risk. The lack of association between nitrate exposure and inflammation markers suggests other biological mechanisms are involved in the link with colorectal cancer.Acknowledgements: We acknowledge support from the Spanish Ministry of Science and Innovation through the “Centro de Excelencia Severo Ochoa 2019-2023” Program (CEX2018-000806-S), and support from the Generalitat de Catalunya through the CERCA Program. This work was funded by the 7th Framework Programme EXPOSOMICS Project (grant agreement 308610), the Acci´on Transversal del C´ancer del Consejo de Ministros del 11/10/2007, and the Instituto de Salud Carlos III-FEDER (PI08/1770, PI08/0533, PI11/00226) FIS grants

    P-Stereogenic Phosphines for the Stabilisation of Metal Nanoparticles. A Surface State Study

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    Palladium and ruthenium nanoparticles have been prepared following the organometallic precursor decomposition methodology, under dihydrogen pressure and in the presence of borane protected P-stereogenic phosphines. NMR (Nuclear Magnetic Resonance) monitoring of the corresponding syntheses has permitted to determine the optimal metal/ligand ratio for leading to small and well-dispersed nanoparticles. Exchange ligand reactions of the as-prepared materials have proven the strong interaction of the phosphines with the metal surface; only oxidative treatment using hydrogen peroxide could release the phosphine-based stabiliser from the metal surface. Pd and Ru nanoparticles have been evaluated in hydrogenation reactions, confirming the robustness of the stabilisers, which selectively permitted the hydrogenation of exocyclic C=C bonds, preventing the coordination of the aromatic rings and as a result, their hydrogenation

    Association of ionizing radiation dose from common medical diagnostic procedures and lymphoma risk in the Epilymph case-control study

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    Medical diagnostic X-rays are an important source of ionizing radiation (IR) exposure in the general population; however, it is unclear if the resulting low patient doses increase lymphoma risk. We examined the association between lifetime medical diagnostic X-ray dose and lymphoma risk, taking into account potential confounding factors, including medical history. The international Epilymph study (conducted in the Czech-Republic, France, Germany, Ireland, Italy, and Spain) collected self-reported information on common diagnostic X-ray procedures from 2,362 lymphoma cases and 2,465 frequency-matched (age, sex, country) controls. Individual lifetime cumulative bone marrow (BM) dose was estimated using time period-based dose estimates for different procedures and body parts. The association between categories of BM dose and lymphoma risk was examined using unconditional logistic regression models adjusting for matching factors, socioeconomic variables, and the presence of underlying medical conditions (atopic, autoimmune, infectious diseases, osteoarthritis, having had a sick childhood, and family history of lymphoma) as potential confounders of the association. Cumulative BM dose was low (median 2.25 mGy) and was not positively associated with lymphoma risk. Odds ratios (ORs) were consistently less than 1.0 in all dose categories compared to the reference category (less than 1 mGy). Results were similar after adjustment for potential confounding factors, when using different exposure scenarios, and in analyses by lymphoma subtype and by type of control (hospital-, population-based). Overall no increased risk of lymphoma was observed. The reduced ORs may be related to unmeasured confounding or other sources of systematic bias.We found little evidence that chronic medical conditions confound lymphoma risk and medical radiation associations
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