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1.
Faraday Discuss ; 201: 71-86, 2017 09 08.
Article in English | MEDLINE | ID: mdl-28678276

ABSTRACT

The highly porous titanium based metal-organic framework NH2-MIL-125(Ti) has recently attracted significant attention in the field of photocatalysis as a promising material for H+ reduction. This work reveals charge transfer upon visible light illumination from this MOF to two different charge acceptors, as an alternative to sacrificial electron donors. Charge transfer is demonstrated through a combined spectroscopic study between this MOF and: (1) 2-(1H-pyrazol-3-yl)phenol, a molecule that functionally mimics the tyrosine-histidine pair, responsible for shuttling the holes to the oxygen evolving centre in natural photosynthesis, and (2) TEMPO, a well known and stable radical. Charge transfer of the holes from the MOF to these occluded molecules takes place on the picosecond time scale. This work suggests that, by coupling a stable and recyclable charge acceptor to the photogenerated holes, the charges can be utilised for oxidation reactions and, thus, link the reduction to the oxidation reactions in water splitting.

2.
Phys Chem Chem Phys ; 19(15): 9724-9728, 2017 Apr 12.
Article in English | MEDLINE | ID: mdl-28361132

ABSTRACT

To understand specific ion effects on a molecular level we explore the effect of salts on the rotational mobility of a model amide using dielectric spectroscopy. Based on our previous studies on the effect of strong denaturing anions or cations, here we study the additivity of the anionic and cationic effect. Using salts consisting of denaturing spherical anions and spherical cations we find such salts to affect the amide according to what one expects based on the additive activity of the individual ions. The guanidinium (Gdm+) cation appears to be a notable exception, as our results suggest that GdmI (and accordingly GdmSCN) is less efficient in hindering the rotation of the amide than KI or GdmCl.

5.
Int J Obes (Lond) ; 40(5): 883-6, 2016 05.
Article in English | MEDLINE | ID: mdl-26841729

ABSTRACT

The United States Equal Employment Opportunity Commission has proposed rules allowing employers to penalize employees up to 30% of health insurance costs if they fail to meet 'health' criteria, such as reaching a specified body mass index (BMI). Our objective was to examine cardiometabolic health misclassifications given standard BMI categories. Participants (N=40 420) were individuals aged 18+ in the nationally representative 2005-2012 National Health and Nutrition Examination Survey. Using the blood pressure, triglyceride, cholesterol, glucose, insulin resistance and C-reactive protein data, population frequencies/percentages of metabolically healthy versus unhealthy individuals were stratified by BMI. Nearly half of overweight individuals, 29% of obese individuals and even 16% of obesity type 2/3 individuals were metabolically healthy. Moreover, over 30% of normal weight individuals were cardiometabolically unhealthy. There was no significant race-by-BMI interaction, but there was a significant gender-by-BMI interaction, F(4,64)=3.812, P=0.008. Using BMI categories as the main indicator of health, an estimated 74 936 678 US adults are misclassified as cardiometabolically unhealthy or cardiometabolically healthy. Policymakers should consider the unintended consequences of relying solely on BMI, and researchers should seek to improve diagnostic tools related to weight and cardiometabolic health.


Subject(s)
Body Mass Index , Cardiovascular Diseases/diagnosis , Electronic Health Records/statistics & numerical data , Metabolic Syndrome/diagnosis , Nutrition Surveys , Obesity/diagnosis , Adult , Bias , Cardiovascular Diseases/epidemiology , Female , Humans , Insurance Coverage/statistics & numerical data , Insurance, Health/statistics & numerical data , Male , Metabolic Syndrome/epidemiology , Obesity/complications , Obesity/epidemiology , United States/epidemiology
6.
Phys Chem Chem Phys ; 18(2): 1346-7, 2016 Jan 14.
Article in English | MEDLINE | ID: mdl-26661946

ABSTRACT

Correction for 'Quantifying transient interactions between amide groups and the guanidinium cation' by V. Balos et al., Phys. Chem. Chem. Phys., 2015, 17, 28539-28543.

7.
Phys Chem Chem Phys ; 17(43): 28539-43, 2015 Nov 21.
Article in English | MEDLINE | ID: mdl-26461077

ABSTRACT

We study the interaction of the guanidinium cation, a widely used protein denaturant, with amide groups, the common structural motif of proteins. Our results provide evidence for direct contact between guanidinium and ∼2 amide groups, but the interaction is transient and weaker than for other cations with high charge-density.


Subject(s)
Amides/chemistry , Guanidine/chemistry , Acetamides/chemistry , Cations , Entropy , Protein Denaturation , Proteins/chemistry , Proteins/metabolism , Water/chemistry
8.
Int J Obes (Lond) ; 39(12): 1721-6, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26248659

ABSTRACT

BACKGROUND: Correctly identifying oneself as being overweight is presumed to be a prerequisite to successful weight management. The present research examined the effect that perceiving oneself as being 'overweight' has on risk of future weight gain in US and UK adults. METHODS: Data from three longitudinal studies; US National Longitudinal Study of Adolescent Health (Add Health) 2001/2002-2008/2009, UK National Child Development Study (NCDS) 1981-2002/2004, and Midlife in the United States (MIDUS) 1995/1996-2004/2005, were used to examine the impact of perceiving oneself as being overweight on weight gain across adulthood in over 14 000 US and UK adults. RESULTS: Participants who perceived their weight status as being overweight were at an increased risk of subsequent weight gain. This effect was observed irrespective of weight status at baseline and whether weight status perceptions were accurate or inaccurate. In the MIDUS sample, perceiving oneself as being overweight was associated with overeating in response to stress and this mediated the relationship between perceived overweight and weight gain. CONCLUSIONS: Perceiving oneself as being 'overweight' is counter-intuitively associated with an increased risk of future weight gain among US and UK adults.


Subject(s)
Body Image/psychology , Population Surveillance , Weight Gain , Adolescent , Adult , Attitude to Health , Female , Humans , Life Style , Longitudinal Studies , Male , Middle Aged , Reproducibility of Results , Self Concept , United Kingdom/epidemiology , United States/epidemiology
9.
Rev Sci Instrum ; 82(10): 104703, 2011 Oct.
Article in English | MEDLINE | ID: mdl-22047313

ABSTRACT

We describe a variable path length waveguide setup developed to accurately measure the complex dielectric permittivity of liquids. This is achieved by measuring the complex scattering parameter of the liquid in a waveguide section with a vector network analyzer in combination with an E-band frequency converter. The automated measurement procedure allows fast acquisition at closely spaced intervals over the entire measurement bandwidth: 60-90 GHz. The presented technique is an absolute method and as such is not prone to calibration errors. The technique is suited to investigate low-loss as well as high-loss liquids in contrast to similar setups described previously. We present measurements for a high-loss liquid (water), an intermediate-loss sample (ethanol), and for nearly loss-less n-octane. Due to the available phase information, the present data have an improved accuracy in comparison with literature data.

10.
J Phys Chem B ; 115(43): 12638-47, 2011 Nov 03.
Article in English | MEDLINE | ID: mdl-21902254

ABSTRACT

We study the reorientation dynamics of water molecules around ions using terahertz dielectric relaxation spectroscopy and polarization-resolved femtosecond infrared pump-probe spectroscopy. The results are discussed in relation to the ion-specific Hofmeister series and the concomitant "structure-making" and "structure-breaking" effects of ions on water. We show that when a dissolved salt consists of a strongly hydrated ion with a weakly hydrated counterion the reorientation of water molecules around the strongly hydrated ion is anisotropic, in the sense that differently charged ions affect reorientation along different molecular axes: cations mainly slow the reorientation dynamics of the water dipole vectors, and anions mainly slow down the reorientation dynamics of the hydroxyl group that points toward the anion. In both cases, motion along only one molecular axis is impeded, so that the hydration shell is best described as semirigid. In this semirigid hydration picture, water molecules in the first hydration shell show anisotropic reorientation, whereas water molecules outside the first hydration shell remain unaffected. The inferred anisotropy in molecular motion explains why terahertz dielectric relaxation spectroscopy, which probes dipolar relaxation, is more sensitive to cation hydration effects while femtosecond infrared pump-probe spectroscopy, which is sensitive to reorientation of hydroxyl groups, is more sensitive to anion hydration effects. We also show that dissolution of CsI-a salt for which both cation and anion are weakly hydrated-has little effect on water reorientation dynamics, with hydration water displaying dynamics that are similar to those in bulk water.


Subject(s)
Ions/chemistry , Water/chemistry , Cesium/chemistry , Dielectric Spectroscopy , Iodides/chemistry , Lithium Chloride/chemistry , Spectrophotometry, Infrared , Time Factors
11.
J Chem Phys ; 129(10): 104505, 2008 Sep 14.
Article in English | MEDLINE | ID: mdl-19044922

ABSTRACT

In this study we present the results of a first principles molecular dynamics simulation of a single 1-ethyl-3-methyl-imidazolium chloride [C(2)C(1)im][Cl] ion pair dissolved in 60 water molecules. We observe a preference of the in plane chloride coordination with respect to the cation ring plane as compared to the energetic slightly more demanding on top coordination. Evaluation of the different radial distribution functions demonstrates that the structure of the hydration shell around the ion pair differs significantly from bulk water and that no true ion pair dissociation in terms of completely autonomous solvation shells takes place on the timescale of the simulation. In addition, dipole moment distributions of the solvent in distinct solvation shells around different functional parts of the [C(2)C(1)im][Cl] ion pair are calculated from maximally localized Wannier functions. The analysis of these distributions gives evidence for a depolarization of water molecules close to the hydrophobic parts of the cation as well as close to the anion. Examination of the angular distribution of different OH(H(2)O)-X angles in turn shows a linear coordination of chloride accompanied by a tangential orientation of water molecules around the hydrophobic groups, being a typical feature of hydrophobic hydration. Based on these orientational aspects, a structural model for the obvious preference of ion pair association is developed, which justifies the associating behavior of solvated [C(2)C(1)im][Cl] ions in terms of an energetically favorable interface between the solvation shells of the anion and the hydrophobic parts of the cation.

12.
J Chem Phys ; 129(18): 184501, 2008 Nov 14.
Article in English | MEDLINE | ID: mdl-19045408

ABSTRACT

This study deals with the dielectric spectra of mixtures of the ionic liquid 1-butyl-3-methyl-imidazolium (BMIM(+)) tetrafluoroborate with water at three selected mole fractions 0.767

Subject(s)
Ionic Liquids/chemistry , Water/chemistry , Electric Impedance , Models, Chemical
13.
J Chem Phys ; 128(21): 214509, 2008 Jun 07.
Article in English | MEDLINE | ID: mdl-18537435

ABSTRACT

Broadband dielectric and terahertz spectroscopy (10(-2)-10(+12) Hz) are combined with pulsed field gradient nuclear magnetic resonance (PFG-NMR) to explore charge transport and translational diffusion in the 1-butyl-3-methylimidazolium tetrafluoroborate ionic liquid. The dielectric spectra are interpreted as superposition of high-frequency relaxation processes associated with dipolar librations and a conductivity contribution. The latter originates from hopping of charge carriers on a random spatially varying potential landscape and quantitatively fits the observed frequency and temperature dependence of the spectra. A further analysis delivers the hopping rate and enables one to deduce--using the Einstein-Smoluchowski equation--the translational diffusion coefficient of the charge carriers in quantitative agreement with PFG-NMR measurements. By that, the mobility is determined and separated from the charge carrier density; for the former, a Vogel-Fulcher-Tammann and for the latter, an Arrhenius temperature dependence is obtained. There is no indication of a mode arising from the reorientation of stable ion pairs.

14.
Complement Ther Med ; 14(4): 237-46, 2006 Dec.
Article in English | MEDLINE | ID: mdl-17105693

ABSTRACT

OBJECTIVES: We investigated the effectiveness of homeopathic Arnica montana on postoperative swelling and pain after arthroscopy (ART), artificial knee joint implantation (AKJ), and cruciate ligament reconstruction (CLR). DESIGN: Three randomised, placebo-controlled, double-blind, sequential clinical trials. SETTING: Single primary care unit specialised in arthroscopic knee surgery. PARTICIPANTS: Patients suffering from a knee disease that necessitated arthroscopic surgery. INTERVENTIONS: Prior to surgery, patients were given 1 x 5 globules of the homeopathic dilution 30x (a homeopathic dilution of 1:10(30)) of arnica or placebo. Following surgery, 3 x 5 globules were administered daily. PRIMARY OUTCOME MEASURES: The primary outcome parameter was difference in knee circumference, defined as the ratio of circumference on day 1 (ART) or day 2 (CLR and AKJ) after surgery to baseline circumference. RESULTS: A total of 227 patients were enrolled in the ART (33% female, mean age 43.2 years;), 35 in the AKJ (71% female, 67.0 years), and 57 in the CLR trial (26% female; 33.4 years). The percentage of change in knee circumference was similar between the treatment groups for ART (group difference Delta=-0.25%, 95% CI: -0.85 to 0.41, p=0.204) and AKJ (Delta=-1.68%, -4.24 to 0.77, p=0.184) and showed homeopathic arnica to have a beneficial effect compared to placebo in CLR (Delta=-1.80%, -3.30 to -0.30, p=0.019). CONCLUSIONS: In all three trials, patients receiving homeopathic arnica showed a trend towards less postoperative swelling compared to patients receiving placebo. However, a significant difference in favour of homeopathic arnica was only found in the CLR trial.


Subject(s)
Arnica , Homeopathy/methods , Knee Joint/surgery , Orthopedic Procedures/adverse effects , Adult , Aged , Double-Blind Method , Edema/drug therapy , Female , Humans , Male , Middle Aged , Pain, Postoperative/drug therapy
15.
Tumour Biol ; 27(6): 329-33, 2006.
Article in English | MEDLINE | ID: mdl-17033203

ABSTRACT

OBJECTIVE: Impairment in cell-mediated immunity has long been recognized in classical Hodgkin's lymphoma (cHL). The immunosuppressive environment at the tumor site and/or a primary T-cell defect may contribute to an ineffective immune clearance of Hodgkin/Reed-Sternberg (H/R-S) cells. Here, we analyzed whether circulating T lymphocytes of cHL patients show specific alterations in gene expression with possible impact on anti-tumor immunity. MATERIAL AND METHODS: Gene expression profiles were performed from CD3+ T cells isolated from peripheral blood samples of untreated patients with cHL versus two control groups consisting of healthy donors and patients with sarcoidosis. The regulation of gene expression was confirmed in additional patients for selected genes by real-time RT-PCR. RESULTS AND CONCLUSION: Circulating T cells of cHL show a Th1 immune response likely supporting anti-tumor immunity. However, the molecular profile reveals an association between cell cycle transition/proliferation and induction of immune regulatory genes which may limit an effective anti-tumor immune response of differentiated Th1 cells.


Subject(s)
Hodgkin Disease/immunology , T-Lymphocytes/immunology , Adult , CD3 Complex/genetics , CD4-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes , Female , Gene Expression Profiling , Hodgkin Disease/genetics , Humans , Immunity, Cellular , Lymphocyte Count , Male , Middle Aged , Neoplasm Staging , RNA, Neoplasm/genetics , RNA, Neoplasm/isolation & purification
16.
BMC Genomics ; 7: 263, 2006 Oct 19.
Article in English | MEDLINE | ID: mdl-17052335

ABSTRACT

BACKGROUND: Aplastic anemia (AA) is a bone marrow failure syndrome mostly characterized by an immune-mediated destruction of marrow hematopoietic progenitor/stem cells. The resulting hypocellularity limits a detailed analysis of the cellular immune response. To overcome this technical problem we performed a microarray analysis of CD3+ T-cells derived from bone marrow aspirates and peripheral blood samples of newly diagnosed AA patients and healthy volunteers. Two AA patients were additionally analyzed after achieving a partial remission following immunosuppression. The regulation of selected candidate genes was confirmed by real-time RT-PCR. RESULTS: Among more than 22,200 transcripts, 583 genes were differentially expressed in the bone marrow of AA patients compared to healthy controls. Dysregulated genes are involved in T-cell mediated cytotoxicity, immune response of Th1 differentiated T-cells, and major regulators of immune function. In hematological remission the expression levels of several candidate genes tend to normalize, such as immune regulators and genes involved in proinflammatory immune response. CONCLUSION: Our study suggests a pivotal role of Th1/Tc1 differentiated T-cells in immune-mediated marrow destruction of AA patients. Most importantly, immune regulatory genes could be identified, which are likely involved in the recovery of hematopoiesis and may help to design new therapeutic strategies in bone marrow failure syndromes.


Subject(s)
Anemia, Aplastic/genetics , Cell Differentiation/genetics , Cyclosporine/therapeutic use , T-Lymphocytes/metabolism , Adult , Aged , Anemia, Aplastic/blood , Anemia, Aplastic/therapy , Antilymphocyte Serum/blood , Antilymphocyte Serum/therapeutic use , Bone Marrow Cells/drug effects , Bone Marrow Cells/immunology , Bone Marrow Cells/metabolism , CD3 Complex/blood , Cell Differentiation/drug effects , Cell Differentiation/immunology , Cluster Analysis , Female , Humans , Immunosuppressive Agents/therapeutic use , Immunotherapy , Male , Middle Aged , Oligonucleotide Array Sequence Analysis/methods , Reproducibility of Results , Reverse Transcriptase Polymerase Chain Reaction , T-Lymphocytes/drug effects , T-Lymphocytes/immunology
17.
Ann Hematol ; 85(11): 747-58, 2006 Nov.
Article in English | MEDLINE | ID: mdl-16871392

ABSTRACT

The immune system is challenged by randomly generated immune receptors that by chance can recognize self-antigens. Immunological tolerance functions as a fundamental concept in the control of a broad spectrum of immune responses not only to autoantigens but also to foreign antigens. During the past decade, CD4+ CD25+ regulatory T-cells (Tregs) have emerged as key players in the development of immunological tolerance. This review will present an update on the current knowledge about the phenotype, function, and clinical relevance of this regulatory T-cell population. The therapeutical potential of Tregs to specifically suppress immune responses in autoimmunity and transplantation and their inhibitory effects in anti-tumor immune responses will be discussed.


Subject(s)
Immune System Diseases/therapy , T-Lymphocytes, Regulatory/physiology , Animals , Antigens, Surface , Humans , Immunotherapy , Mice , Neoplasms/immunology , T-Lymphocytes, Regulatory/classification , T-Lymphocytes, Regulatory/immunology , Transplantation Immunology
18.
FEMS Immunol Med Microbiol ; 43(3): 373-84, 2005 Mar 01.
Article in English | MEDLINE | ID: mdl-15708311

ABSTRACT

The development of novel approaches that allow accurate targeting of therapeutics to the intestinal mucosa is a major task in the research on intestinal inflammation. For the first time, a live genetically modified bacterial strain has been approved by Dutch authorities as a therapeutic agent for experimental therapy of intestinal bowel disease (IBD) in humans. Genetically modified probiotics can very well be used as carriers for localized antigen delivery into the intestine. Therapeutic safety, however, of such a carrier organism, is crucial, especially when a specific probiotic strain has to be used under diseased conditions. In this study, we tested the potential of Escherichia coli NISSLE 1917 to serve as a safe carrier for targeted delivery of recombinant proteins to the intestinal mucosa. In a well-defined and very sensitive immunological system, we demonstrate that intestinal recombinant E. coli NISSLE 1917 has no effect on migration, clonal expansion and activation status of specific CD4+ T cells, neither in healthy mice nor in animals with acute colitis. Furthermore, recombinant E. coli NISSLE 1917 has no effect on the induction or breakdown of peripheral T-cell tolerance in an autoimmune environment. The excellent colonization properties of E. coli NISSLE 1917 render this strain an ideal candidate as carrier organism for gut-focused in situ synthesis of therapeutic molecules.


Subject(s)
Escherichia coli/genetics , Escherichia coli/immunology , Immunity, Mucosal , Intestinal Mucosa/immunology , Probiotics , Animals , Autoimmunity , Base Sequence , CD4-Positive T-Lymphocytes/immunology , Colitis/immunology , Colitis/pathology , Colitis/therapy , DNA, Bacterial/genetics , Drug Carriers , Hemagglutinins/administration & dosage , Hemagglutinins/genetics , Hemagglutinins/immunology , Humans , Immunization , Mice , Mice, Inbred BALB C , Mice, Knockout , Mice, Transgenic , Recombinant Proteins/administration & dosage , Recombinant Proteins/genetics , Safety , Self Tolerance
19.
Vet Rec ; 140(15): 399-400, 1997 Apr 12.
Article in English | MEDLINE | ID: mdl-9141223

ABSTRACT

A dermatitis characterised by discrete, raised, plaque-like and cracked skin lesions of variable sizes on the udder, the hind quarters, the lips and muzzle of all the cows in a herd was suspected of being caused by the oat straw used in bedding, after initial feed analysis and skin culture were negative for toxins and dermatophytes. Mycological analysis indicated an extensive infestation of the oat straw by Fusarium sporotrichioides, a toxic mould, and an immunochemical assay indicated dermatotoxic trichothecenes in the straw (0.22 microgram/g dried straw). An ethyl acetate extract of the straw induced a necrotic response on shaved rat skin. Ingestion of the toxic bedding straw and inhalation of toxic straw dust probably also caused the internal haemorrhage and lung emphysema observed in the two cows that died. The regression of the dermatitis and the recovery of general herd health after the withdrawal of the oat straw further supported the diagnosis.


Subject(s)
Avena/microbiology , Cattle Diseases/etiology , Dermatomycoses/veterinary , Fusarium/isolation & purification , Animals , Avena/chemistry , Cattle , Cattle Diseases/pathology , Dermatomycoses/etiology , Dermatomycoses/pathology , Female , Gastrointestinal Hemorrhage/etiology , Gastrointestinal Hemorrhage/mortality , Gastrointestinal Hemorrhage/veterinary , Mycoses/complications , Mycoses/pathology , Mycoses/veterinary , Mycotoxins/adverse effects , Mycotoxins/analysis , Mycotoxins/pharmacology , Pulmonary Emphysema/etiology , Pulmonary Emphysema/mortality , Pulmonary Emphysema/veterinary , Rats , Rats, Sprague-Dawley , Skin/drug effects , Skin/pathology
20.
Forensic Sci Int ; 84(1-3): 53-60, 1997 Jan 17.
Article in English | MEDLINE | ID: mdl-9042710

ABSTRACT

The hair samples of 15 grizzled patients with a permanent medical treatment by amitriptyline, carbamazepine, chlorprothixene, diclofenac, doxepine, indomethacine, maprotiline or metoclopramide, or with a chronic heroin and cocaine abuse were separated into white and pigmented fibers and both fractions were independently investigated by GC-MS. The drugs were found in pigmented fibers as well as in white fibers, but the concentrations in the white fibers were smaller than in the pigmented ones for the most of the samples investigated. The concentration ratio of the drugs or their metabolites in both hair fractions (white/pigmented) was found to be between 0.09 and 1.57 (mean 0.70, 30 concentration pairs). There are large differences in this ratio between different subjects with the same drug, whereas for different drugs in the same subject in many cases similar ratios were measured. As a reason a different grade of pigmentation of the hair and the influence of the drug structure are discussed. From these results it follows that the natural hair colour is an important parameter in the evaluation of drug concentration in hair.


Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/pharmacokinetics , Antidepressive Agents, Tricyclic/pharmacokinetics , Antipsychotic Agents/pharmacokinetics , Hair Color/drug effects , Hair/metabolism , Narcotics/pharmacokinetics , Binding Sites , Gas Chromatography-Mass Spectrometry , Hair/drug effects , Humans , Melanins/metabolism , Substance Abuse Detection/methods
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