Nanoparticular surface-bound PCBs, PCDDs, and PCDFs-a novel class of potentially higher toxic POPs

In a previous study, Env Sci Poll Res:1-7, 2015 showed that polychlorinated biphenyls (PCBs), polychlorinated dibenzo dioxins (PCDDs), and polychlorinated dibenzo furanes (PCDFs) are found in commercially available (nano) particular titanium dioxide as a result of the fabrication. Here, we give a brief perspective and reason the toxicity of these new classes of persistent organic pollutants (POPs) by reviewing also their nanoparticular properties, such as surface-to-volume ratio, photocatalytic activity, polarity shifts, and stealth effect. These insights point towards a new class of POPs and toxicologic effects, which are related to the size but not a result of nanotechnology itself. We pave the way to the understanding of until now unresolved very complex phenomena, such as the indoor exposure, formation, and transformation of POP and sick-building syndrome. This is a fundamental message for nanotoxicology and kinetics and should be taken into account when determining the toxicity of nanomaterials and POPs separately and as a combination

Capital C, geometric optimization of a free-form steel gridshell towards planar quadrilateral glass units

The former Diamond-exchange building in Amsterdam, now called Capital C, is restored to its former glory and currently undergoing a major renovation. This listed building has been returned to its original design and topped with a spatial gridshell roof structure of glass and steel, designed by renowned architect office ZJA Zwarts & Jansma Architects. This paper focuses on the geometric optimization of the free-form gridshell towards planar quad glass units.   The final shape of the gridshell is determined by a parametric computer model. With a by ZJA in-house written program, the boundary conditions were defined, where after the software searches the ideal shape. In the case of Capital C, the ideal shape was a geometrical free-form shape but with planar or minimal curved quadrilateral glass. This to represent the faceted aesthetics of the diamond, representing the building’s heritage. In addition to the look, optimizing to planar glass panes also increased the feasibility and cost-efficiency of the design. During this process Octatube, as a specialist Design and Build contractor, was approached and challenged to realize this innovative and complex design.   In principle the gridshell has one repetitive structural steel connection. However due to its shape every connection is unique and itself composed of many unique parts. In the final design, approximately 1000 different steel elements and 200 different glass units are applied. With a traditional design method, where all elements are modelled one by one, a minor change to the geometric shape of the shell would lead to a large amount of labour. A time-consuming and error-prone job. Therefore the design is automated, by means of an in-house developed parametric tool by Octatube, which converts the complex basic geometry into a FEM-model and detailed production model.   The applied methods of parametric design and engineering allowed the team to not only optimize the glass-design until late in the engineering phase, incorporating a file-to-factory workflow, it also allowed for fast and very precise pre-fabrication. Not unimportant when installing a free-form glass and steel gridshell on top of a listed building in the heart of Amsterdam

Актуальность и основные аспекты антикризисного менеджмента предприятием

Целью данной статьи является выявление значимости и основных аспектов антикризисного менеджмента

Cognitive outcomes in meningioma patients undergoing surgery: individual changes over time and predictors of late cognitive functioning

Background Meningioma patients are known to face cognitive deficits before and after surgery. We examined individual changes in cognitive performance over time and identified preoperative predictors of cognitive functioning 12 months after surgery in a large sample of meningioma patients. Methods Patients underwent neuropsychological assessment (NPA) using CNS Vital Signs 1 day before (T0), and 3 (T3) and 12 (T12) months after surgery. Patients’ sociodemographically-corrected scores on 7 cognitive domains were compared to performance of a normative sample using one-sample z tests and Chi-square tests of independence. Reliable change indices with correction for practice effects were calculated for individual patients. Linear mixed effects models were used to identify preoperative predictors of performance at T12. Results At T0, 261 patients were assessed, and 229 and 82 patients were retested at T3 and T12, respectively. Patients showed impaired cognitive performance before and after surgery, and although performance improved on the group-level, cognitive scores remained significantly lower than in the normative sample up to T12. On the individual level, performance remained stable in the majority of patients. Better preoperative performance, younger age, male sex, and higher educational level predicted better late cognitive performance. Conclusions Meningioma patients face serious and persistent pre- and postsurgical cognitive deficits. A preoperative NPA together with sociodemographic characteristics may provide valuable information on the late cognitive outcome of individual meningioma patients. These results can help to inform patients and clinicians on late cognitive outcomes at an early stage, and emphasizes the importance of presurgical NPA and timely cognitive rehabilitation

Iodine-131 labelled octreotide: Not an option for somatostatin receptor therapy

Gamma-emitting radiopeptides are useful for scintigraphy of tumours on the basis of receptor binding. Likewise, β-emitting radiopeptides may be used in radionuclide therapy of such tumours. As iodine-131 suggested to be suitable for this purpose, experiments were performed using three somatostatin analogues, in which the effects of coupling of a therapeutic dose of 131I to such peptides were investigated. This study deals with the radioiodination of very small amounts of peptide on a therapeutic scale, the required purification procedures after radioiodination, and the influence of high beta fluxes from 131I. On a peptide during radioiodination and purification. Based on the regularly used therapeutic doses of 131I in cancer treatment and our previous experience with [111In-DTPA-D-Phe1]-octreotide, it was assumed that a minimal effective therapeutic dose of 3.7 GBq 131I has to be coupled to a maximum of ≃ 100 μg peptide, representing only a slight excess of peptide over 131I. This contrasts with non-peptide radiopharmaceuticals in which high compound to radionuclide ratios are usually used. Labelling at low peptide to radionuclide ratios (low labelling yields) results in the formation of di-iodinated compounds, whereas at high peptide to radionuclide ratios (high labelling yields) mono-iodinated products of low specific activity are formed. Thus, after radioiodination the desired mono-iodinated peptide has to be separated from unreacted iodide, and from di-iodinated and unreacted peptide, as both compounds compete for the receptors. Possible radiolysis of the peptide during labelling and separation steps were investigated by irradiating 30 μg unlabelled peptide with 370 MBq 131I in a small volume. The peptide composition of the incubation mixtures was investigated by high-performance liquid chromatography after irradiation for 30 min to 24 h. The results showed that the peptide was degraded with a half-life of less than 1 h. During the preparation of a real therapeutic dose (at much higher β-flux) the peptide will be degraded even faster during the various steps required. In conclusion, intact mono-iodinated 131I-labelled somatostatin analogues for peptide receptor therapy will be difficult to obtain

Evaluation in vitro and in rats of161Tb-DTPA-octreotide, a somatostatin analogue with potential for intraoperative scanning and radiotherapy

The characteristics of terbium-161 diethylene triamine penta-acetic acid (DTPA) labelled octreotide with respect to specific binding to somatostatin (octreotide) receptors on rat brain cortex membranes, biological activity, uptake and excretion by isolated perfused rat livers and metabolism in vivo in normal and tumour-bearing rats were determined and compared to those of indium-111 DTPA-octreotide. The results of the binding studies demonstrate that161Tb-DTPA-octreotide is a high-affinity radioligand for somatostatin receptors, with an affinity comparable to that of111In-DTPA-octreotide. Rat growth hormone secretion inhibition experiments showed that161Tb-DTPA-octreotide has a similar potency to111In-DTPA-octreotide.161Tb-DTPA-octreotide appeared to be taken up even less by the isolated perfused rat liver than111In-DTPA-octreotide, as almost no tracer disappeared from the perfusion medium. Furthermore, hardly any radioactivity was found in the liver, and excretion into the bile was negligible. The biodistribution studies showed that for octreotide receptor-positive organs, such as pancreas and adrenals, uptake of161Tb-DTPA-octreotide is lower then that of111In-DTPA-octreotide. However, as the clearance from the blood of the former compound is faster than that of the latter, the tissue/blood ratio is higher in the case of161Tb-DTPA-octreotide than with111In-DTPA-octreotide. Furthermore, these studies demonstrated that the uptake of161Tb-DTPA-octreotide by the renal tubular cells after glomerular filtration can be reduced by administration of lysine or sodium maleate. Increase in urine production before and during the experiment had no effect on the kidney uptake of161Tb-DTPA-octreotide. Finally, it appeared that a maximal labelling efficiency of161Tb-DTPA-octreotide is essential, as with decreasing efficiency the uptake in the octreotide receptor-positive organs decreased, whereas non-specific uptake in the other organs was increased. It is concluded that, on the basis of the favourable physical characteristics of161Tb combined with the in vitro and in vivo studies performed with161Tb-DTPA-octreotide, the latter is a promising radiopharmaceutical for both intraoperative scanning and radiotherapy. Studies in patients need to be performed now to see whether161Tb-DTPA-octreotide can indeed open new therapeutic applications for patients bearing octreotide receptor-positive tumours

Diagnosis and treatment of vascular graft and endograft infections:a structured clinical approach

A vascular graft or endograft infection (VGEI) is a severe complication that can occur after vascular graft or endograft surgery and is associated with high morbidity and mortality rates. A multidisciplinary approach, consisting of a team of vascular surgeons, infectious diseases specialists, medical microbiologists, radiologists, nuclear medicine specialists, and hospital pharmacists, is needed to adequately diagnose and treat VGEI. A structured diagnostic, antibiotic, and surgical treatment algorithm helps clinical decision making and ultimately aims to improve the clinical outcome of patients with a VGEI