Technetium-99m-HMPAO brain SPECT in Beh?et's disease

Beh?et's disease (BD) is an idiopathic multisystem disorder. Involvement of the central nervous system (CNS) occurs in 4%-48% of cases. The aim of this study was to evaluate 99mTc-hexamethyl propyleneamine oxime (HMPAO) SPECT findings in BD patients and eventually to detect CNS involvement by depicting cerebral blood flow disturbances. METHODS: Technetium-99m-HMPAO brain SPECT was performed on 33 consecutive BD patients. Qualitative and quantitative evaluation of the cortical uptake was done using an automatic program that generated 32 regions of interest (ROIs). An uptake index for each ROI was obtained. Reference values were obtained from a healthy control group (n = 20). Twenty-five patients also had an MRI study. RESULTS: Twelve of 32 patients (36%) presented with a clinical neurological disorder. SPECT and visual evaluation revealed that 17 patients (51.5%) had abnormalities; 9 of 25 MRI studies (36%) were abnormal. Using the quantitative approach for SPECT, 23 patients (69.7%) had abnormally low values. Six of 12 patients with neurological symptoms had a visually abnormal SPECT scan, whereas quantitative analysis showed abnormalities in 11 patients. Of the 21 patients with no neurological findings, 9 had abnormal SPECT results, and 12 had low uptake indexes. CONCLUSION: HMPAO brain SPECT shows high rates of cerebral blood flow abnormalities in BD patients presenting with neuropsychiatric symptoms, and it also is frequently abnormal in asymptomatic BD patients who have no abnormalities on MR scans. Compared with visual analysis, quantitative analysis detects an even higher rate of SPECT changes in BD patients.     

Regulated production of mature insulin by non-beta-cells

Rat hepatoma cells were engineered to express, in a regulated manner, mature human insulin as an approach to the development of artificial beta-cells for insulin-dependent diabetes mellitus (IDDM) gene therapy. A chimeric gene obtained by linking a 2.4-kb fragment of the P-enolpyruvate carboxykinase (PEPCK) gene promoter to a human proinsulin gene (PEPCK/Insm), containing genetically engineered furin endoprotease cleavage sites, was stably transfected into FTO-2B rat hepatoma cells. The FTOInsm cells expressed high levels of insulin mRNA and protein after Northern blot or immunocytochemical analysis. High-performance liquid chromatography (HPLC) fractionation of culture medium and cell extracts revealed that about 90% of the proinsulin was processed to mature insulin. Insulin secretion was very fast, and 15 min after induction with dibutyryl cyclic AMP (Bt2cAMP) plus dexamethasone significant amounts of the hormone were released. Moreover, during the first hour, the rise in insulin concentration in the medium was 10-fold that detected in nontreated FTOInsm cells. Insulin produced by FTOInsm cells was biologically active because it blocked endogenous PEPCK gene expression and induced glucose uptake and lactate production. Thus, our results showed that genetically engineered FTOInsm hepatoma cells synthesized, processed, and secreted active insulin. The implantation of encapsulated engineered FTOInsm cells might provide a safe and practical therapeutic approach for IDDM treatment.     

Edge contribution to forward scattering by spheres

Edge functions T1 and T2, which describe the polarization-dependent edge contribution to forward scattering by spheres, are derived from the exact Mie solution. All the relative refractive indices and the 64 < x < 2048 size parameter range are considered. The edge functions significantly improve the approximation methods that can be used to calculate forward-scattering patterns. For m close to 1, an asymptotic approximation is used. Otherwise, the familiar geometrical optics approximation and the similar physical optics approximation for glory rays are used. Both geometrical and physical optics equations can be deduced from the above-mentioned asymptotic approximation.     

Experimental evaluation of dynamic resource orchestration in multi-layer (packet over flexi-grid optical) networks

Network services in 5G will be rolled out as pools of virtual network functions (VNFs) exploiting the advantages of both software-defined networking and network function virtualization. In this context, 5G network services are envisaged as ordered sequences of VNFs resulting in the so-called VNF Forwarding Graphs (VNFFGs). Such VNFs can be allocated over a number of distributed but interconnected data centers (DCs). In this work, a cloud/network orchestrator is discussed to dynamically process and accommodate VNFFG requests over a pool of DCs interconnected by a multi-layer (packet/flexi-grid optical) transport network infrastructure. Two different cloud and network resource allocation algorithms are proposed aiming at: (1) minimizing the distance between the selected DCs and (2) minimizing the load (i.e., consumed cloud resources) of the chosen DCs. In the performance evaluation, the proposed algorithms are experimentally validated and compared on the CTTC ADRENALINE testbed.

     

Näherung für elastisch‐plastische Kerbbeanspruchungen einschließend thermisch induzierte Beanspruchungen

Strukturmechanische Belastungen unterscheiden sich maßgeblich von thermischen und somit verformungskontrollierten Belastungen, was sich insbesondere bei der Anwendung von herkömmlichen Kerbnäherungsverfahren zeigt. Im Rahmen dieser Ausarbeitung wird eine Methodik präsentiert, die es erlaubt, elastisch‐plastische Kerbbeanspruchungen infolge thermischer Belastung auf Grundlage fiktiv‐elastischer Berechnungen im Bauteil approximativ zu berechnen. Weiterhin wird gezeigt, wie die erzielten lokalen elastisch‐plastischen Teillösungen für die mechanische und die thermische Belastung miteinander kombiniert werden können und welchen Einfluss das auf die Güte der Ergebnisse hat.     

Visualization of Dopant Oxygen Atoms in a Bi2Sr2CaCu2O8+δ Superconductor

A proper amount of excess oxygen plays a significant role in hole‐doped cuprate high‐T_c superconductivity. Here, the dopant oxygen in Bi₂Sr₂CaCu₂O_8+δ is directly imaged via integrated differential phase contrast combined with state‐of‐the‐art scanning transmission electron microscopy. The location of dopant oxygen is observed to be consistent with the position inferred from local strain analysis of the incommensurate structure. The influence of dopant oxygen on the local atomic lattice and electronic structure is further explored using first‐principle calculations. The dopant oxygen atoms not only aggravate the distortions of the local atomic arrangement but also alter the electronic states by transferring charge from the BiO planes to the CuO₂ planes. The underlying mechanism of charge transfer is resolved. The results may also be applicable to other oxygen‐doped cuprates with high‐T_c superconductivity.     

Scattering and absorption of turbid materials determined from reflection measurements. 2: measuring method and calibration

A new experimental method has been developed to determine the scattering and absorption characteristics of a turbid material. Existing methods usually require transmission and reflection measurements carried out on a thin slab of the material under study; this method is based on reflection measurements carried out on bulk material. This will be of great advantage in many applications. This paper describes the measuring system and indicates the area of application of the method. Calibration measurements have been carried out to substantiate the approach.     

Effect of calcium addition on zinc aluminate spinel

The addition of calcium to zinc aluminate, prepared by coprecipitation methods, causes an increase in the specific surface area and a modification of the crystal morphology. However, the catalytic isobutane dehydrogenation properties remain unchanged. Careful characterization studies (XRD, TGA and SEM) indicate that calcium may be deposited on the zinc aluminate surface.     

Modified ferrous oxidation‐xylenol orange method to determine lipid hydroperoxides in fried snacks

A modified ferrous oxidation‐xylenol orange (FOX) method was adapted to measure lipid hydroperoxides (LHP) in lipid extracts from snack foods fried in vegetable oils. First, a methanol‐based FOX reaction medium was assayed, but this became turbid upon addition of the lipid extracts dissolved in ethanol. To avoid the precipitation of lipids, the polarity of the reaction medium was reduced by lowering its water content and by replacing the methanol as the basis of the medium for less polar solvents. Some of the solvents used instead of methanol yielded a lower FOX reaction response. Of the reaction media assayed, the one based on dichloromethane/ethanol (3:2, vol/vol) was not turbid at high lipid extract concentrations (assayed at up to 25 mg of lipid extract/mL reaction medium) and provided the same response level as the methanol‐based medium. Thus, this FOX method shows high sensitivity and is particularly useful for lipid extracts with low LHP content. This method was also successfully applied to edible oils. Solvents such as 2‐propanol, ethyl acetate and butanol were discarded, because they easily produce hydroperoxides, which interfere in the FOX reaction. Xylenol orange preparations from a number of suppliers were tested, and some differences affecting the sensitivity of the reaction were observed.     

Mesomorphic transitions in a mixture of a flexible and a semi-rigid polymer

Phase studies on a mixture of two polymers are presented, one of which is mesomorphic. We have systematically examined the influence of the molecular weight of the flexible polymer (including the oligomers) and of the semi-flexible polymer. In addition to the effect of the molecular weight, specific interactions are important for compatibility and formation of a homogeneous mesomorphic phase. The nature of this phase is demonstrated to be cholesteric and the pitch is determined.