The reactivity of cyclopropyl cyanide in titan's atmosphere: a possible pre-biotic mechanism

Cyclopropyl cyanide and other simple nitriles detected in Titan's atmosphere could be precursors leading to the formation of organic macromolecules in the atmosphere of Saturn's largest satellite. Proposing a thermodynamically possible mechanism that explains their formation and supports experimental results represents a difficult challenge. Experiments done in the Atomic and Molecular Physics Laboratory at the University of Trento (AMPL) have studied the ion-molecule reaction between cyclopropyl cyanide and its protonated form, with reaction products being characterized by mass spectrometry. In addition to the expected ion-molecule adduct stabilized by non-covalent long-range interactions, in this work we prove that another distinct species having the same mass to charge ratio (m/z) of 135 is also produced. Moreover, from a previous study of the neutral cyclopropyl cyanide potential energy surface (PES) which shows a partial biradical character it has been possible to characterize the formation through the bimolecular reaction of a new covalent cyclic organic molecule. Calculations have been carried out at the ab initio Møller-Plesset (MP2) level of theory, ensuring the connectivity of the stationary points by using the intrinsic reaction coordinate (IRC) procedure. In order to characterize the reaction transition state, multireference calculations were done using a complete active space involving six electrons and six molecular orbitals [CAS (6 e, 6 m.o.)]. This study opens the possibility of exploring the formation of new organic molecules by gaseous phase ion-molecule interaction schemes, with such molecules having relevance in interstellar space and in astrobiology (and may be involved in prebiotic molecular evolution)

Dehydrohalogenation and dehydration reactions of i‑C3H7Br and i‑C3H7OH by sodium ions studied by guided ion beam techniques and quantum chemical methods

Dehydrohalogenation and dehydration reactions of gas-phase i-C3H7Br and i-C3H7OH molecules induced by collision with Na+, all participants being in their electronic ground state, were studied experimentally in our laboratory using a radiofrequency-guided ion beam apparatus and covering the 0.10-10.00 eV center of mass (CM) energy range. In Na+ + i-C3H7Br collisions the formation of [C3H6-Na]+ and [HBr-Na]+ by dehydrohalogenation was observed and quantified, as well as that of the ion-molecule adduct [Na-i-C3H7Br]+ together with its decomposition products C3H7+ and NaBr. In Na+ + i-C3H7OH collisions the dehydration product [H2O-Na]+ was also found, while [C3H6-Na]+ was hardly detected. Moreover, the [Na-i-C3H7OH]+ adduct formation as well as its decomposition into C3H7+ and NaOH were also quantified. For all these processes, absolute reaction cross sections were measured as a function of the CM collision energy. From measured excitation functions, rate constants for the formation of [C3H6-Na]+, [HBr-Na]+, and [H2O-Na]+ at 303 K were obtained. Complementing the experiments, exhaustive ab initio structure calculations at the MP2 level of theory were performed, giving information on the most relevant features of the potential energy surfaces (PESs) where the dehydrohalogenation, dehydration, and decomposition reactions take place adiabatically for both collision systems. On these PESs different stationary points associated with potential energy minima and transition state barriers were characterized, and their connectivity was ensured using the intrinsic-reaction-coordinate method. The main topology features of the ab initio calculated PESs allowed a qualitative interpretation of the experimental data also exposing the role of the sodium ion as a catalyst in elimination reaction

Experimental and ab initio studies of the reactive processes in gas phase i-C3H7Br and i-C3H7OH collisions with potassium ions

Collisions between potassium ions and neutral i-C3H7Br and i-C3H7OH, all in their electronic ground state, have been studied in the 0.10 10.00 eV center of mass (CM) collision energy range, using the radiofrequency-guided ion beam technique. In K+ + i-C3H7Br collisions KHBr+ formation was observed and quantified, while the analogous KH2O+ formation in K+ + i-C3H7OH was hardly detected. Moreover, formation of the ion-molecule adducts and their decomposition leading to C3H7 + and either KBr or KOH, respectively, have been observed. For all these processes, absolute crosssections were measured as a function of the CM collision energy. Ab initio structure calculations at the MP2 level have given information about the potential energy surfaces (PESs) involved. In these, different stationary points have been characterized using the reaction coordinate method, their connectivity being ensured by using the intrinsic-reaction-coordinate method. From the measured excitation function for KHBr+ formation the corresponding thermal rate constant at 303 K has been calculated. The topology of the calculated PESs allows an interpretation of the main features of the reaction dynamics of both systems, and in particular evidence the important role played by the potential energy wells in controlling the reactivity for the different reaction channels

Surgical Infection Reduction Program of the Observatory of Surgical Infection (PRIQ-O): Delphi prioritization and consensus document on recommendations for the prevention of surgical site infection

La infección de localización quirúrgica es la complicación más frecuente y más evitable de la cirugía, pero las guías clínicas para su prevención tienen un seguimiento insuficiente. Presentamos los resultados de un consenso Delphi realizado por un panel de expertos de 17 sociedades científicas con revisión crítica de la evidencia científica y guías internacionales, para seleccionar las medidas con mayor grado de evidencia y facilitar su implementación. Se revisaron 40 medidas y se emitieron 53 recomendaciones. Se priorizan 10 medidas principales para su inclusión en bundles de prevención: ducha preoperatoria; correcta higiene quirúrgica de manos; no eliminación del vello del campo quirúrgico o eliminación con maquinilla eléctrica; profilaxis antibiótica sistémica adecuada; uso de abordajes mínimamente invasivos; descontaminación de la piel con soluciones alcohólicas; mantenimiento de la normotermia; protectores-retractores plásticos de herida; cambio de guantes intraoperatorio, y cambio de material quirúrgico y auxiliar antes del cierre de las heridasSurgical site infection is the most frequent and avoidable complication of surgery, but clinical guidelines for its prevention are insufficiently followed. We present the results of a Delphi consensus carried out by a panel of experts from 17 Scientific Societies with a critical review of the scientific evidence and international guidelines, to select the measures with the highest degree of evidence and facilitate their implementation. Forty measures were reviewed and 53 recommendations were issued. Ten main measures were prioritized for inclusion in prevention bundles: preoperative shower; correct surgical hand hygiene; no hair removal from the surgical field or removal with electric razors; adequate systemic antibiotic prophylaxis; use of minimally invasive approaches; skin decontamination with alcoholic solutions; maintenance of normothermia; plastic wound protectors-retractors; intraoperative glove change; and change of surgical and auxiliary material before wound closur

Mortality and cardiovascular disease burden of uncontrolled diabetes in a registry-based cohort: the ESCARVAL-risk study

BACKGROUND: Despite the epidemiological evidence about the relationship between diabetes, mortality and cardiovascular disease, information about the population impact of uncontrolled diabetes is scarce. We aimed to estimate the attributable risk associated with HbA1c levels for all-cause mortality and cardiovascular hospitalization. METHODS: Prospective study of subjects with diabetes mellitus using electronic health records from the universal public health system in the Valencian Community, Spain 2008-2012. We included 19,140 men and women aged 30 years or older with diabetes who underwent routine health examinations in primary care. RESULTS: A total of 11,003 (57%) patients had uncontrolled diabetes defined as HbA1c ≥6.5%, and, among those, 5325 participants had HbA1c ≥7.5%. During an average follow-up time of 3.3 years, 499 deaths, 912 hospitalizations for coronary heart disease (CHD) and 786 hospitalizations for stroke were recorded. We observed a linear and increasingly positive dose-response of HbA1c levels and CHD hospitalization. The relative risk for all-cause mortality and CHD and stroke hospitalization comparing patients with and without uncontrolled diabetes was 1.29 (95 CI 1.08,1.55), 1.38 (95 CI 1.20,1.59) and 1.05 (95 CI 0.91, 1.21), respectively. The population attributable risk (PAR) associated with uncontrolled diabetes was 13.6% (95% CI; 4.0-23.9) for all-cause mortality, 17.9% (95% CI; 10.5-25.2) for CHD and 2.7% (95% CI; - 5.5-10.8) for stroke hospitalization. CONCLUSIONS: In a large general-practice cohort of patients with diabetes, uncontrolled glucose levels were associated with a substantial mortality and cardiovascular disease burden

Differential scanning calorimetry and elasticity of textured, heat set and mechanical strained polylactide multifilaments

Industrially textured PLA multifilaments were heat set under different conditions at 110 ºC for 1 min and subjected to one cycle of deformation up to 20%. Thermal transitions of the original textured, heat set and cyclic strained filaments were measured using differential scanning calorimetry from 25 to 250 ºC. Cyclic deformation induces an endo-exo transition at peak temperatures between 55 - 60 ºC that is not observed in the original textured and heat set multifilaments. There is another endo-exo transition with peak temperatures between 67 and 72 ºC in all filaments, the intensity of which varies according to texturing conditions, heat setting and cycle strain. Texturing conditions, heat setting and cyclic strain play a role in thermal transitions, the strain at breaking and elastic properties of the filaments. The crystallinity and magnitude of the endo-exo thermal events detected by DSC are related to the strain at breaking and elasticity of polylactide textured multifilamentsPostprint (published version

The role of Li+ ions in the gas phase dehydrohalogenation and dehydration reactions of i-C3H7Br and i-C3H7OH molecules studied by radiofrequency-guided ion beams techniques and ab initio methods

Gas phase reactive collisions between lithium ions and i-C3H7X (X = Br, OH) molecules have been studied under single collision conditions in the center of mass (CM) 0.01-10.00 eV energy range using a radiofrequency-guided ion beam apparatus. Mass spectrometry analysis of the products did show the presence of [C3H6-Li]+, [HX-Li]+, C3H7+, and C2H3+ as well as of the [Li-i-C3H7Br]+ adduct while [Li-i-C3H7OH]+ was hardly detected. For all these reactive processes, the corresponding cross sections have been measured in absolute units as a function of the CM collision energy. Quantum chemistry ab initio calculations done at the second orderM¨oller Plesset level have provided relevant information on the topology of the potential energy surfaces (PESs) where a reaction takes place allowing the characterization of the stationary points on the respective PESs along their reaction pathways. The connectivity of the different stationary points localized on the PESs was ensured by using the intrinsic reaction coordinate (IRC) method, confirming the adiabatic character of the reactions. The main topology features of the reactive PESs, in the absence of dynamical calculations, were used to interpret at the qualitative level the behavior of the experimental excitations functions, evidencing the role played by the potential energy barriers on the experimental dynamics of the reactions. Reaction rate constants at 303.2 K for different reactions have been calculated from measured excitation functions

Genome-wide association and HLA fine-mapping studies identify risk loci and genetic pathways underlying allergic rhinitis

Allergic rhinitis is the most common clinical presentation of allergy, affecting 400 million people worldwide, with increasing incidence in westernized countries1,2. To elucidate the genetic architecture and understand the underlying disease mechanisms, we carried out a meta-analysis of allergic rhinitis in 59,762 cases and 152,358 controls of European ancestry and identified a total of 41 risk loci for allergic rhinitis, including 20 loci not previously associated with allergic rhinitis, which were confirmed in a replication phase of 60,720 cases and 618,527 controls. Functional annotation implicated genes involved in various immune pathways, and fine mapping of the HLA region suggested amino acid variants important for antigen binding. We further performed genome-wide association study (GWAS) analyses of allergic sensitization against inhalant allergens and nonallergic rhinitis, which suggested shared genetic mechanisms across rhinitis-related traits. Future studies of the identified loci and genes might identify novel targets for treatment and prevention of allergic rhinitis