Correction of manufacturing deviations in waveguide filters and manifold multiplexers using metal insertions

Microwave filters and multiplexers commonly employ tuning screws to compensate for small errors occurring during the fabrication process. Nevertheless, the use of tuning screws has some disadvantages, because the small gaps between the screws and the holes are prone to create unwanted effects when dealing with high-power signals, especially for space applications, and are also the source of potential radiation losses. In this paper, an alternative technique to correct manufacturing deviations is presented, in which tuning screws are replaced by fixed metal insertions. In this case, the correction is made by means of designing new insertion pieces that will be able to correct those small deviations. In order to find the dimensions of the new pieces, a space-mapping technique is applied. For verification purposes, the method has been applied over a circular-waveguide dual-mode filter and later over a manifold multiplexer containing the same type of filters. However, the technique can be directly extended to other types of waveguide filters and multiplexers where tuning screws are also employed.Cogollos Borras, S.; Carceller Candau, C.; Taroncher Calduch, M.; Boria Esbert, VE.; Guglielmi, M.; Vicente Quiles, CP.; Brumos Vicente, M. (2015). Correction of manufacturing deviations in waveguide filters and manifold multiplexers using metal insertions. International Journal of Microwave and Wireless Technologies. 7(3):219-227. doi:10.1017/S1759078715000513S21922773Guglielmi, M., Molina, R. C., & Melcon, A. A. (1992). Dual-mode circular waveguide filters without tuning screws. IEEE Microwave and Guided Wave Letters, 2(11), 457-458. doi:10.1109/75.165643Steer, M. B., Bandler, J. W., & Snowden, C. M. (2002). Computer-aided design of RF and microwave circuits and systems. IEEE Transactions on Microwave Theory and Techniques, 50(3), 996-1005. doi:10.1109/22.989983Kudsia, C., Cameron, R., & Tang, W.-C. (1992). Innovations in microwave filters and multiplexing networks for communications satellite systems. IEEE Transactions on Microwave Theory and Techniques, 40(6), 1133-1149. doi:10.1109/22.141345Bandler, J. W., Biernacki, R. M., Shao Hua Chen, Hemmers, R. H., & Madsen, K. (1995). Electromagnetic optimization exploiting aggressive space mapping. IEEE Transactions on Microwave Theory and Techniques, 43(12), 2874-2882. doi:10.1109/22.475649Cogollos S. ; Boria V.E. ; Soto P. ; Gimeno B. ; Guglielmi M. : Efficient CAD tool for inductively coupled rectangular waveguide filters with rounded corners, in 31st European Microwave Conf., 24–26 September 2001, 1–4Ke-Li Wu. (1999). An optimal circular-waveguide dual-mode filter without tuning screws. IEEE Transactions on Microwave Theory and Techniques, 47(3), 271-276. doi:10.1109/22.750222Bandler, J. W., Cheng, Q. S., Dakroury, S. A., Mohamed, A. S., Bakr, M. H., Madsen, K., & Sondergaard, J. (2004). Space Mapping: The State of the Art. IEEE Transactions on Microwave Theory and Techniques, 52(1), 337-361. doi:10.1109/tmtt.2003.820904Williams, A. E. (1970). A Four-Cavity Elliptic Waveguide Filter. IEEE Transactions on Microwave Theory and Techniques, 18(12), 1109-1114. doi:10.1109/tmtt.1970.1127419Amari, S., LeDrew, C., & Menzel, W. (2006). Space-mapping optimization of planar coupled-resonator microwave filters. IEEE Transactions on Microwave Theory and Techniques, 54(5), 2153-2159. doi:10.1109/tmtt.2006.872811Brumos M. ; Boria V.E. ; Guglielmi M. ; Cogollos S. : Correction of manufacturing deviations in circular-waveguide dual-mode filters using aggressive space mapping, in European Microwave Conf., Rome, 2014, 624–627.Accatino, L., Bertin, G., & Mongiardo, M. (1996). A four-pole dual mode elliptic filter realized in circular cavity without screws. IEEE Transactions on Microwave Theory and Techniques, 44(12), 2680-2687. doi:10.1109/22.554629Cogollos, S., Brumos, M., Boria, V. E., Vicente, C., Gil, J., Gimeno, B., & Guglielmi, M. (2012). A Systematic Design Procedure of Classical Dual-Mode Circular Waveguide Filters Using an Equivalent Distributed Model. IEEE Transactions on Microwave Theory and Techniques, 60(4), 1006-1017. doi:10.1109/tmtt.2012.2183381Atia, A. E., & Williams, A. E. (1972). Narrow-Bandpass Waveguide Filters. IEEE Transactions on Microwave Theory and Techniques, 20(4), 258-265. doi:10.1109/tmtt.1972.1127732Wu, K.-L., Zhao, Y.-J., Wang, J., & Cheng, M. K. K. (2004). An Effective Dynamic Coarse Model for Optimization Design of LTCC RF Circuits With Aggressive Space Mapping. IEEE Transactions on Microwave Theory and Techniques, 52(1), 393-402. doi:10.1109/tmtt.2003.820901FEST3D 6.8.4 Aurora Software and Testing, S.L. (on behalf of ESA/ESTEC), Valencia, Spain, 2013. Available: http://www.fest3d.com.Bandler, J. W., Biernacki, R. M., Shao Hua Chen, Grobelny, P. A., & Hemmers, R. H. (1994). Space mapping technique for electromagnetic optimization. IEEE Transactions on Microwave Theory and Techniques, 42(12), 2536-2544. doi:10.1109/22.33979

Case report: A third variant in the 5′ UTR of TWIST1 creates a novel upstream translation initiation site in a child with Saethre-Chotzen syndrome

Introduction: Saethre-Chotzen syndrome, a craniosynostosis syndrome characterized by the premature closure of the coronal sutures, dysmorphic facial features and limb anomalies, is caused by haploinsufficiency of TWIST1. Although the majority of variants localize in the coding region of the gene, two variants in the 5′ UTR have been recently reported to generate novel upstream initiation codons. Methods: Skeletal dysplasia Next-generation sequencing (NGS) panel was used for genetic analysis in a patient with bicoronal synostosis, facial dysmorphisms and limb anomalies. The variant pathogenicity was assessed by a luciferase reporter promoter assay. Results: Here, we describe the identification of a third ATG-creating de novo variant, c.-18C>T, in the 5′ UTR of TWIST1 in the patient with a clinical diagnosis of Saethre-Chotzen syndrome. It was predicted to create an out-of-frame new upstream translation initiation codon resulting in a 40 amino acid larger functionally inactive protein. We performed luciferase reporter promoter assays to demonstrate that the variant does indeed reduce translation from the main open reading frame. Conclusion: This is the third variant identified in this region and confirms the introduction of upstream ATGs in the 5′ UTR of TWIST1 as a pathogenic mechanism in Saethre-Chotzen syndrome. This case report shows the necessity for performing functional characterization of variants of unknown significance within national health services

Treatment of subclinical hyperthyroidism: Effect on body composition

Background: subclinical hyperthyroidism (SHT) is associated with harmful effects on cardiovascular system, bone metabolism and progression to clinical hyperthyroidism. Loss of weight is a common fact in patients with clinical hyperthyroidism and of particular relevance in elderly patients. Objective: to assess changes in body composition after radioiodine therapy for SHT due to toxic nodular goiter. Subjects and methods: prospective controlled cohort study. Patients with persistent SHT due to toxic nodular goiter were purposed to receive treatment with radioiodine (treatment group) or to delay treatment until the study was over (control group). All treated patients received 555 MBq of 131I. Body composition (lean mass, fat mass and bone mineral content) was determined by dual-energy X-ray absorptiometry (DEXA) at baseline and 12 months after. Results: twenty-nine patients were studied (age 69.5 ± 11.5; 75.9% women; BMI 27.1 ± 5.7 kg/m²; serum thyrotropin (TSH) 0.20 ± 0.21 µUI/mL; serum free thyroxine (T4) 1.01 ± 0.19 ng/dL), 17 belonging to the treatment group and 12 to the control group. Study groups were comparable, although there was a trend for the treatment group to have more fat mass. No longitudinal changes in body composition were noted in either group, except for a trend to gain fat mass. However, when individuals with age > 65 years were selected, only patients who received radioiodine therapy showed a significant increase in body weight (from 64.1 ± 10.0 to 66.9 ± 9.2 kg), BMI (from 27.3 ± 4.8 to 28.7 ± 4.5 kg/m²), fat mass (from 26.1 ± 8.5 to 27.8 ± 7.9 kg), lean mass (from 36.3 ± 0.4 to 37.4 ± 0.4 kg) and skeletal muscle mass index (SMI) (from 6.0 ± 0.6 to 6.3 ± 0.6 kg/m²). Conclusions: treatment of SHT has impact on body composition in subjects older than 65 years. Weight gain reflects increases in fat and, more interestingly, in lean mass

Constitutional mismatch repair deficiency (CMMRD) presenting with high-grade glioma, multiple developmental venous anomalies and malformations of cortical development-a multidisciplinary/multicentre approach and neuroimaging clues to clinching the diagnosis

Constitutional mismatch repair deficiency syndrome (CMMRD) is a rare cancer-predisposition syndrome associated with a high risk of developing a spectrum of malignancies in childhood and adolescence, including brain tumours. In this report, we present the case of an 8-year-old boy with acute headache, vomiting and an episode of unconsciousness in whom brain imaging revealed a high-grade glioma (HGG). The possibility of an underlying diagnosis of CMMRD was suspected radiologically on the basis of additional neuroimaging findings, specifically the presence of multiple supratentorial and infratentorial developmental venous anomalies (DVAs) and malformations of cortical development (MCD), namely, heterotopic grey matter. The tumour was debulked and confirmed to be a HGG on histopathology. The suspected diagnosis of CMMRD was confirmed on immunohistochemistry and genetic testing which revealed mutations in PMS2 and MSH6. The combination of a HGG, multiple DVAs and MCD in a paediatric or young adult patient should prompt the neuroradiologist to suggest an underlying diagnosis of CMMRD. A diagnosis of CMMRD has an important treatment and surveillance implications not only for the child but also the family in terms of genetic counselling

Efficient boundary integral-resonant mode expansion method implementation for full-wave analysis of passive devices based on circular waveguides with arbitrary perturbations

This paper is a preprint of a paper submitted to IET Microwaves Antennas and Propagation and is subject to Institution of Engineering and Technology Copyright. If accepted, the copy of record will be available at IET Digital LibraryIn this study, the efficient full-wave analysis of passive devices composed of circular and arbitrarily-shaped waveguides is considered. For this purpose, the well-known boundary integral-resonant mode expansion (BI RME) method has been properly extended. Circular waveguides are used for resonant mode expansion, whereas the arbitrary contour is defined by any combination of straight, circular and elliptical segments, thus allowing the exact representation of the most widely used geometries. The proposed algorithm extends previous implementations of the BI RME method based on circular waveguides by considering circular and elliptical arcs for defining arbitrary geometries. Similarly, it allows the efficient analysis of passive devices based on circular waveguides with arbitrary perturbations, thus providing more accurate results with less computational efforts than a rectangular waveguide-based BI RME approach. The extended method has been successfully tested with several practical application examples, having compared its performance with the BI RME method based on rectangular waveguides.This work was supported by Ministerio de Ciencia e Innovacion, Spanish Government, under Research Project TEC2010-21520-C04-01.Carceller Candau, C.; Cogollos Borras, S.; Soto Pacheco, P.; Gil Raga, J.; Boria Esbert, VE.; Vicente Quiles, CP.; Gimeno Martinez, B. (2013). Efficient boundary integral-resonant mode expansion method implementation for full-wave analysis of passive devices based on circular waveguides with arbitrary perturbations. IET Microwaves Antennas and Propagation. 7(1):44-53. https://doi.org/10.1049/iet-map.2012.0603S44537

Conductance and application of organic molecule pairs as nanofuses

We propose that a pair of organic molecules can mimic the behavior of a macroscopic fuse at nanoscale, one component of the pair being the on state and the other the off state. For this task wemake use of density-functional theory to calculate the physical properties of selected molecules, which have also been synthesized by our team. By this means we obtain the transmission spectra and the current of the proposed devices, which allows us to compare the behavior of the on and off states.Of particular interest is the on/off switch ratios, defined as the current ratios of the on and off structures at the corresponding bias voltage. In a first stage, we examine the best linker between the device and the electrode for high on/off switch ratios. Once this is determined, we test the influence of the electron richness of the system to provide a high on/off switch ratio. The entire analysis is also supported by the molecular projected self-consistent Hamiltonian, which provides a good way of understanding the molecular behavior. All the calculations support that interesting on/off switch ratios of two orders of magnitude could be obtained with these prototypical nanofusesWe thank the Regional Government of Andalucía for financial support (Projects No. P06-FQM-01726 and No. P09-FQM-04571), the “Centro de Supercomputación de la Universidad de Granada,” and the “Centro de Computación Científica-UAM” for computation time. The authors are also grateful to the Spanish Secretaría de Estado de Universidades e Investigación, Ministerio de Educación y Ciencia, for financial support within research projects TEC2007-66812 and TEC2010-16211. N.F. thanks the Regional Government of Andalucía for her research contract, and LAC thanks the University of Granada for his research contrac

How good are rodent models of carcinogenesis in predicting efficacy in humans? A systematic review and meta-analysis of colon chemoprevention in rats, mice and men

Tumours in rodent and human colon share many histological and genetic features. To know if rodent models of colon carcinogenesis are good predictors of chemopreventive efficacy in humans, we made a meta-analysis of aspirin, beta-carotene, calcium, and wheat bran studies. Controlled intervention studies of adenoma recurrence in human volunteers were compared with chemoprevention studies of carcinogen-induced tumours in rats, and of polyps in Min (Apc(+/-)) mice: 6714 volunteers, 3911 rats and 458 mice were included in the meta-analyses. Difference between models was small since most global relative risks were between 0.76 and 1.00. A closer look showed that carcinogen-induced rat studies matched human trials for aspirin, calcium, carotene, and were compatible for wheat bran. Min mice results were compatible with human results for aspirin, but discordant for calcium and wheat bran (no carotene study). These few results suggest that rodent models roughly predict effect in humans, but the prediction is not accurate for all agents. Based on three cases only, the carcinogen-induced rat model seems better than the Min mouse model. However, rodent studies are useful to screen potential chemopreventive agents, and to study mechanisms of carcinogenesis and chemoprevention

Differences in the signaling pathways of α1A- and α1B-adrenoceptors are related to different endosomal targeting

Aims: To compare the constitutive and agonist-dependent endosomal trafficking of α1A- and α1B-adrenoceptors (ARs) and to establish if the internalization pattern determines the signaling pathways of each subtype. Methods: Using CypHer5 technology and VSV-G epitope tagged α1A- and α1B-ARs stably and transiently expressed in HEK 293 cells, we analyzed by confocal microscopy the constitutive and agonist-induced internalization of each subtype, and the temporal relationship between agonist induced internalization and the increase in intracellular calcium (determined by FLUO-3 flouorescence), or the phosphorylation of ERK1/2 and p38 MAP kinases (determined by Western blot). Results and Conclusions: Constitutive as well as agonist-induced trafficking of α1A and α1B ARs maintain two different endosomal pools of receptors: one located close to the plasma membrane and the other deeper into the cytosol. Each subtype exhibited specific characteristics of internalization and distribution between these pools that determines their signaling pathways: α1A-ARs, when located in the plasma membrane, signal through calcium and ERK1/2 pathways but, when translocated to deeper endosomes, through a mechanism sensitive to β-arrestin and concanavalin A, continue signaling through ERK1/2 and also activate the p38 pathway. α1B-ARs signal through calcium and ERK1/2 only when located in the membrane and the signals disappear after endocytosis and by disruption of the membrane lipid rafts by methyl-β-cyclodextrin

A case series of Diffuse Glioneuronal Tumours with Oligodendroglioma-like features and Nuclear Clusters (DGONC).

In this study, we report three paediatric cases of Diffuse Glioneuronal Tumours with Oligodendroglioma-like features and Nuclear Clusters (DGONC)

Guía docente común de las titulaciones de Ingeniero en Electrónica en las universidades andaluzas

El presente documento constituye el resultado del trabajo elaborado de acuerdo con la Convocatoria de Elaboración de Guías Docentes de Titulaciones Andaluzas conforme al Sistema de Créditos Europeos (años 2005/2006) de la Dirección General de Universidades, dependiente de la Secretaría General de Universidades, Investigación y Tecnología de la Consejería de Innovación, Ciencia y Empresa de la Junta de Andalucía