Comparative Study of the Dissociative Ionization of 1,1,1-Trichloroethane Using Nanosecond and Femtosecond Laser Pulses

Changes in the laser induced molecular dissociation of 1,1,1-trichloroethane (TCE) were studied using a range of intensities and standard laser wavelengths with nanosecond and femtosecond pulse durations. TCE contains C-H, C-C and C-Cl bonds and selective bond breakage of one or more of these bonds is of scientific interest. Using laser ionization time of flight mass spectrometry, it was found that considerable variation of fragment ion peak heights as well as changes in relative peak ratios is possible by varying the laser intensity (by attenuation), wavelength and pulse duration using standard laser sources. The nanosecond laser dissociation seems to occur via C-Cl bond breakage, with significant fragmentation and only a few large mass ion peaks observed. In contrast, femtosecond laser dissociative ionization results in many large mass ion peaks. Evidence is found for various competing dissociation and ionization pathways. Variation of the nanosecond laser intensity does not change the fragmentation pattern, while at high femtosecond intensities large changes are observed in relative ion peak sizes. The total ionization yield and fragmentation ratios are presented for a range of wavelengths and intensities, and compared to the changes observed due to a linear chirp variation

Patients with rheumatoid arthritis have an altered circulatory aggrecan profile

<p>Abstract</p> <p>Background</p> <p>Rheumatoid arthritis (RA) is a chronic auto-immune disease with extensive articular cartilage destruction. Aggrecan depletion, mediated by aggrecanases is one of the first signs of early cartilage erosion. We investigated, whether measurement of aggrecan and fragments thereof in serum, could be used as biomarkers for joint-disease in RA patients and furthermore characterized the fragments found in the circulation.</p> <p>Methods</p> <p>The study consisted of 38 patients, 12 males (62.2 ± 16.0 years) and 26 females (59.8 ± 20.7 years) diagnosed with RA: 41.5 ± 27.5 mm/h erythrocyte sedimentation rate (ESR), 38.4 ± 34.7 mg/ml C-reactive protein (CRP) and 4.8 ± 1.7 disease activity score (DAS) and 108 healthy age-matched controls. Aggrecan levels were measured using two immunoassays, i.e. the ³⁷⁴ARGSVI-G2 sandwich ELISA measuring aggrecanase-mediated aggrecan degradation and the G1/G2 sandwich assay, detecting aggrecan molecules containing G1 and/or G2 (total aggrecan) We further characterized serum samples by western blots, by using monoclonal antibodies F-78, binding to G1 and G2, or by BC-3, detecting the aggrecanase-generated N-terminal ³⁷⁴ARGSVI neo-epitope.</p> <p>Results</p> <p>Total aggrecan levels in RA patients were significantly decreased from 824.8 ± 31 ng/ml in healthy controls to 570.5 ± 30 ng/ml (31% decrease, P < 0.0001), as measured by the G1/G2 ELISA. Western blot analysis with F-78 showed one strong band at 10 kDa, and weaker bands at 25 and 45 kDa in both healthy controls and RA patients. In contrast, staining for aggrecanase-activity revealed only one strong band in RA patients of 45 kDa.</p> <p>Conclusion</p> <p>This is the first study, which characterizes different aggrecan fragments in human serum. The data strongly suggests that total aggrecan levels, i.e. aggrecan molecules containing G1 and/or G2 are lower in RA patients, and that RA patients have at least one specific subpopulation of aggrecan fragments, namely aggrecanse generated ³⁷⁴ARGSVI fragments. Further clinical studies are needed to investigate the potential of G1/G2 as a structure-related biochemical marker in destructive joint-diseases.</p

Sustained Effects of Incredible Years as a Preventive Intervention in Preschool Children with Conduct Problems

The present study evaluated preventive effects of the Incredible Years program for parents of preschool children who were at risk for a chronic pattern of conduct problems, in the Netherlands. In a matched control design, 72 parents of children with conduct problems received the Incredible Years program. These families (intervention group) were compared with 72 families who received care as usual (control group). Two years after termination of the intervention, it appeared that observed and selfrated parenting skills were significantly improved in the intervention group. Likewise, in this group, observed child conduct problems showed sustained intervention effects. The decrease in observed critical parenting mediated the decrease in observed child conduct problems over time. In addition, it appeared that parental influence increased over time

Bridging between professionals in perinatal care: Towards shared care in The Netherlands

Relatively high perinatal mortality rates in the Netherlands have required a critical assessment of the national obstetric system. Policy evaluations emphasized the need for organizational improvement, in particular closer collaboration between community midwives and obstetric caregivers in hospitals. The leveled care system that is currently in place, in which professionals in midwifery and obstetrics work autonomously, does not fully meet the needs of pregnant women, especially women with an accumulation of non-medical risk factors. This article provides an overview of the advantages of greater interdisciplinary collaboration and the current policy developments in obstetric care in the Netherlands. In line with these developments we present a model for shared care embedded in local 'obstetric collaborations'. These collaborations are formed by obstetric caregivers of a single hospital and all surrounding community midwives. Through a broad literature search, practical elements from shared care approaches in other fields of medicine that would suit the Dutch obstetric system were selected. These elements, focusing on continuity of care, patient centeredness and interprofessional teamwork form a comprehensive model for a shared care approach. By means of this overview paper and the presented model, we add direction to the current policy debate on the development of obstetrics in the Netherlands. This model will be used as a starting point for the pilot-implementation of a shared care approach in the 'obstetric collaborations', using feedback from the field to further improve it. © Springer Science+Business Media New York 2012

Serum matrix metalloproteinase 3 levels during treatment with sulfasalazine or combination of methotrexate and sulfasalazine in patients with early rheumatoid arthritis

Objective. To determine the effects of treatment with sulfasalazine (SSZ) or the combination of methotrexate (MTX) and SSZ on serum matrix metalloproteinase 3 (MMP-3) levels in patients with early rheumatoid arthritis (RA). Methods. Eighty-two patients with early RA (symptoms <1 year and DMARD-naive at presentation) were selected who had been treated with SSZ (2000 mg/day) or with the combination of MTX (7.5-15 mg/week) and SSZ. Serum MMP-3 levels, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), swollen joint count (SJC), tender joint count (TJC), Ritchie articular index (RAI), and the Disease Activity Score (DAS) were determined at 4 week intervals during a followup of 28 weeks for each treatment group. Response was based on clinical grounds and CRP at 12, 20, and 28 weeks. Results. SSZ responders (n = 52) had lower baseline values of serum MMP-3, CRP, and ESR, compared to partial/nonresponders (n = 30). but did not differ in joint scores and DAS. In the SSZ responder group all variables decreased. In the SSZ partial/nonresponders, CRP, ESR, and SJC decreased in contrast to serum MMP-3, TJC, RAI, and DAS-3. After addition of MTX all variables decreased in 24 of the 30 patients who had shown a partial or no response taking SSZ. In the SSZ responders there was a delayed decrease in serum MMP-3 compared to CRP. Conclusion. Serum MMP-3 levels decrease in patients with early RA who respond to SSZ or to the combination of MTX and SSZ. In patients who respond to SSZ the changes in serum MMP-3 levels indicate a delayed response compared to CRP