Search results for "alkane"
showing 10 items of 162 documents
Identification and H(D)-bond energies of C-H(D)Cl interactions in chloride-haloalkane clusters: a combined X-ray crystallographic, spectroscopic, and…
2016
The cationic (1,3,5-triazapentadiene)Pt(II) complex [Pt{NH[double bond, length as m-dash]C(N(CH2)5)N(Ph)C(NH2)[double bond, length as m-dash]NPh}2]Cl2 ([]Cl2) was crystallized from four haloalkane solvents giving [][Cl2(CDCl3)4], [][Cl2(CHBr3)4], [][Cl2(CH2Cl2)2], and [][Cl2(C2H4Cl2)2] solvates that were studied by X-ray diffraction. In the crystal structures of [][Cl2(CDCl3)4] and [][Cl2(CHBr3)4], the Cl(-) ion interacts with two haloform molecules via C-DCl(-) and C-HCl(-) contacts, thus forming the negatively charged isostructural clusters [Cl(CDCl3)2](-) and [Cl(CHBr3)2](-). In the structures of [][Cl2(CH2Cl2)2] and [][Cl2(C2H4Cl2)2], cations [](2+) are linked to a 3D-network by a syste…
Reactions in the presence of irradiated semiconductors: Are they simply photocatalytic?
2018
A generally accepted classification distinguishes semiconductor photocatalysis in type A and type B. The first class comprehends reactions where the primary redox products (radical anions and cations) further evolve giving rise to the final reduced and oxidized species. Type B reactions occur when the primary redox products undergo intermolecular bond formation to addition products. Recently, some photocatalytic reactions have been reported wherein the photocatalytically produced compounds are not the final products. In fact, they react in the solution bulk or catalytically on the surface of the semiconductor with other species thus producing the target compounds. These reactions, hereby re…
How do cuticular hydrocarbons evolve? Physiological constraints and climatic and biotic selection pressures act on a complex functional trait
2017
Cuticular hydrocarbons (CHCs) cover the cuticles of virtually all insects, serving as a waterproofing agent and as a communication signal. The causes for the high CHC variation between species, and the factors influencing CHC profiles, are scarcely understood. Here, we compare CHC profiles of ant species from seven biogeographic regions, searching for physiological constraints and for climatic and biotic selection pressures. Molecule length constrained CHC composition: long-chain profiles contained fewer linear alkanes, but more hydrocarbons with disruptive features in the molecule. This is probably owing to selection on the physiology to build a semi-fluid cuticular layer, which is necessa…
TRPM8 Channel Activation Reduces the Spontaneous Contractions in Human Distal Colon
2020
The transient receptor potential-melastatin 8 (TRPM8) is a non-selective Ca2+-permeable channel, activated by cold, membrane depolarization, and different cooling compounds. TRPM8 expression has been found in gut mucosal, submucosal, and muscular nerve endings. Although TRPM8 plays a role in pathological conditions, being involved in visceral pain and inflammation, the physiological functions in the digestive system remain unclear as yet. The aims of the present study were: (i) to verify the TRPM8 expression in human distal colon
Exposure to perfluoroalkyl substances and thyroid function in pregnant women and children: A systematic review of epidemiologic studies
2017
Introduction: Thyroid hormones (THs) are especially important for brain maturation and development during the fetal period and childhood. Several epidemiological studies have assessed the possible association between exposure to perfluoroalkyl substances (PFAS) and thyroid outcomes during the early stages of life. We aimed to review this evidence. Methods: We conducted a systematic review in compliance with the PRISMA Statement (search conducted in PubMed and Embase, as well as in the citations of the selected articles). We chose studies if they dealt with thyroid-stimulating hormone (TSH), triiodothyronine (T3), thyroxin (T4), or thyroid dysfunctions, and perfluorohexane sulfonate (PFHxS),…
Exposure to Perfluoroalkyl Substances and Metabolic Outcomes in Pregnant Women: Evidence from the Spanish INMA Birth Cohorts
2017
BACKGROUND: Exposure to perfluoroalkyl substances (PFASs) may increase risk for metabolic diseases; however, epidemiologic evidence is lacking at the present time. Pregnancy is a period of enhanced tissue plasticity for the fetus and the mother and may be a critical window of PFAS exposure susceptibility. OBJECTIVE: We evaluated the associations between PFAS exposures and metabolic outcomes in pregnant women. METHODS: We analyzed 1,240 pregnant women from the Spanish INMA [Environment and Childhood Project (INfancia y Medio Ambiente)] birth cohort study (recruitment period: 2003-2008) with measured first pregnancy trimester plasma concentrations of four PFASs (in nanograms/milliliter). We u…
Perfluoroalkyl substances and immune cell counts in adults from the Mid-Ohio Valley (USA)
2021
Highlights • The literature on PFASs and circulating levels of immune cells is scarce. • Study of the association between PFASs and white blood cells at two different time points. • Cross-sectional study on the association between PFASs and lymphocyte subsets. • Positive association between PFHxS and total lymphocytes, especially for cell count. • Positive, but less consistent, association between PFOA and PFOS and total lymphocytes.
Beclomethasone dipropionate hydrofluoroalkane for the treatment of allergic rhinitis
2016
Allergic rhinitis (AR) is a common respiratory disease, and its prevalence is increasing all over the world, both in adults and in children. Patients experience symptoms that may negatively impact on physical, social and psychological well-being. Hence, if left untreated, allergic rhinitis may significantly affect quality of life. Under current guidelines, intranasal corticosteroids are considered the most effective drugs and they are recommended as first-line therapy. Among the several corticosteroid intranasal sprays available, beclomethasone dipropionate is one of the most prescribed. Recently, new intranasal hydrofluoroalkane-propelled formulations with little or no impact on the ozone …
Calorimetric investigation of water/lecithin/cyclohexane microemulsions
1997
The enthalpies of dilution of water/lecithin/cyclohexane microemulsion-gels at variousR values (R=[water]/[lecithin]) and molar enthalpies of solution of water in lecithin/cyclohexane at a fixed lecithin concentration were determined calorimetrically at 25°C. Through a description of the process of dilution of water/lecithin/cyclohexane microemulsion-gels as one involving mainly the scission of lecithin reversed micelles in to smaller ones, the concentration dependence of the enthalpy was rationalized. Surprisingly, in order to account for the dilution enthalpies, it was not necessary to hypothesize a thermal effect arising from the breakage of the micellar network present in the micremulsi…