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We aimed to evaluate the usefulness of C-reactive protein (CRP) and procalcitonin (PCT) as markers of infection, sepsis and as predictors of antibiotic response after non-emergency major abdominal surgery. We enrolled, from June 2015 to June 2019, all patients who underwent surgery due to abdominal infection (peritoneal abscess, peritonitis) or having sepsis episode after surgical procedures (i.e. hepatectomy, bowel perforation, pancreaticoduodenectomy (PD), segmental resection of the duodenum (SRD) or biliary reconstruction in a Tertiary Care Hospital. Serum CRP (cut-off value < 5 mg/L) and PCT (cut-off value < 0.1mcg/L) were measured in the day when fever was present or within 24 h after abdominal surgery. Both markers were assessed every 48 h to follow-up antibiotic response and disease evolution up to disease resolution. We enrolled a total of 260 patients underwent non-emergency major abdominal surgery and being infected or developing infection after surgical procedure with one or more microbes (55% mixed Gram-negative infection including Klebsiella KPC, 35% Gram-positive infection, 10% with Candida infection), 58% of patients had ICU admission for at least 96 h, 42% of patients had fast track ICU (48 h). In our group of patients, we found that PCT had a trend to increase after surgical procedure; particularly, those undergoing liver surgery had higher PCT than those underwent different abdominal surgery (U Mann–Whitney p < 0.05). CRP rapidly increase after surgery in those developing infection and showed a statistical significant decrease within 48 h in those subject being responsive to antibiotic treatment and having a clinical response within 10 days independently form the pathogens (bacterial or fungal). Further we found that those having CRP higher than 250 mg/L had a reduced percentage of success treatment at 10 days compared to those < 250 mg/mL (U Mann–Whitney p < 0.05). PCT did not show any variation according to treatment response. CRP in our cohort seems to be a useful marker to predict antibiotic response in those undergoing non-emergency abdominal surgery, while PCT seem to be increased in those having major liver surgery, probably due to hepatic production of cytokines. [ABSTRACT FROM AUTHOR]

ABSTRACT This article describes the design of a passive Bi-band Fresnel reflectarray (20-30 GHz). It is focused on the design of the reflecting panel of the reflectarray. Two different primary feeds will be used at 20 and 30 GHz, respectively for demonstrating the proposed concept. Nevertheless, in the final design a switched primary feed will have to be used. The dual operation band is obtained with multiple resonant elementary cells. Although the paper deals with linearly polarized primary feed, an interesting property of these cells is that they also work with circular polarization. Moreover, a phase correction based on Fresnel zones is used in order to ensure the best tradeoff between simplicity and radiating performance. Finally, the reflecting panel is made and radiation pattern and gain measurements are shown. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:1025-1028, 2016 [ABSTRACT FROM AUTHOR]

Antifungal prophylaxis may be required in high-risk patients undergoing liver transplantation and for that reason we aimed to verify its role and its related impact on the graft. From January 2006 throughout 2012, 250 liver transplants were evaluated and 54 patients identified as being at higher risk were randomly selected to undergo the following schedule: 28 patients received liposomal amphotericin B and 26 received caspofungin. We evaluated, throughout 12 months, renal and liver function tests, bacterial and fungal infection episodes, and intensive care unit (ICU) stay, as well as the Th1 and Th2 cytokine network. Differences were analyzed according to non-parametric tests (two-tailedpvalues). Neither of the groups showed episodes of invasive fungal infection during the 12 months follow-up; however, patients receiving prophylaxis with liposomal amphotericin B had reduced episodes of bacterial infections coupled with an improved immune system response compared with those receiving caspofungin. Finally, a reduced stay in the ICU was also observed. In conclusion, even if the results of liposomal amphotericin B and caspofungin prophylaxis strategies did not differ in terms of invasive fungal infection rate, patients receiving prophylaxis with liposomal amphotericin B had a reduced ICU stay and an improved Th2 status, as well as a reduced number of post-transplant bacterial infections. Further studies are required to better address and evaluate these findings. [ABSTRACT FROM AUTHOR]

On board systems are of growing interest for aerospace applications due to the increase of air traffic as well for civil as for military applications. Moreover, the spread out of drones leads to new security issues. On board systems requires not only detection capabilities but also a 'sense and avoid' operation mode. This article describes the study of a X-band antenna that could be suitable for this application. First, a 2 × 2 circularly polarized antenna array is designed, fabricated and measured. Then an optimization process using a micro Genetic Algorithm (mGA) coupled to a 'home made' 3D-TLM electromagnetic software is applied to improve its performances. A metamaterial type Partially Reflective Surface (PRS) is inserted above the whole structure for this purpose. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26150 [ABSTRACT FROM AUTHOR]

We describe the design, fabrication and measurements of an axisynunetric dielectric lens, featuring a sectorial radiation pattern at 77 GHz. It will be used as the primary feed of a tens-based compact antenna test range (CATR). Due to symmetry of revolution, the sectorial lens proffle can be designed in one dimension by using phase only control. The phase variation is echoed on the lens depth. The resulting stepped lens is simulated using France Telecom Orange Labs SRSRD software ("in-house" software developed for dielectric axisynunetric radiating structures) and measured in an anechoic chamber at 77 Gus. Two lenses were fabricated with different materials: PVC and polyurethane, respectively. Good agreements were obtained between simulations and measurements. Less than 0.2 dB ripple in the central beam are obtained for the polyurethane lens although relatively high secondary lobes occur at 110. Comparisons between the near field of a CATR illuminated by a small horn providing a uniform amplitude taper and the sectorial lens are conducted using numerical simulations. Results show that on-axis oscillations are reduced from 6 to I dB with the sectorial lens. [ABSTRACT FROM AUTHOR]

A high gain Fresnel zone plate reflector is presented for helicopter collision avoidance radar at 94 GHz The antenna system consists of a compact, airtightness and low return loss primary source illuminating a printed reflector with Fresnel plate zone phase correction. In order to increase the overall efficiency, the reflector combines 8 correcting zones in its center and 4 on the border. Reflected phase of over 3600 is achieved by means of circular ring or combined circular and ring patches. The reflector is fabricated using standard photolithographic techniques. The primary source consists of a small FSS made by a double slot array antenna pasted on the aperture of a standard WR-10 waveguide. Antenna measurements were conducted using a compact base arrangement. The antenna performs 37.8 dBi at the center frequency of 94 GHz with a maximum value of the return loss value not exceeding -25 dB. The frequency bandwidth at -3 dB in gain and return loss is of 9%. [ABSTRACT FROM AUTHOR]

A hyperbolic W-band lens antenna has been designed to study the measurement limitations of a far-field range at short far-field conditions in LEAT, University of Nice, France. A reference measurement is performed at 94 GHz in a planar near-field range at TKK, Helsinki University of Technology, Finland. Near-field measurement accuracy is calculated and the measurement results of the different ranges are analysed. It turns out that unrealistically good results can be obtained if a defocused antenna is measured in short far-field conditions. [ABSTRACT FROM AUTHOR]

Most reflectarrays use a half-wavelength cell size. In this paper, we present a new reflector-antenna configuration that provides beam scanning and gain improvements by reducing the size of the cells. Small reflectarrays with cell sizes λ/2 and λ/4, respectively, have been designed at 94 GHz. The measured λ/4 reflectarray at 94 GHz achieves a beam scanning angle of ±60° with a loss of gain of 1 dB, whereas the λ/2 one exhibits a loss of 3 dB. Numerical simulations show that the improvement does not appear significant below the limit of λ/6. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 966–968, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21534 [ABSTRACT FROM AUTHOR]

This paper presents a millimeter waveguide-to-microstrip line transition based on E-mode coupling. It uses a standard W-band waveguide and a microstrip line made on alumina substrate. It has been designed for the center frequency of 94 GHz. A back-to-back transition has been done and measured between 90 and 100 GHz. A bandwidth of more than 12% with insertion loss of -5 dB is demonstrated for a microstrip length of about 21 mm. Complementary measurements show that the transition itself achieves 0.6-dB losses. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 47: 518–520, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21216 [ABSTRACT FROM AUTHOR]

A W-band high gain lens antenna has been realised and measured. A hyperbolic lens made in ECCOSTOCK 0005 is associated to an optimised modified circular horn related to a circular-to-rectangular waveguide transition in order to fit the WR-10 standard waveguide. The antenna provides more than 30 dBi gain between 75 and 110 GHz. It is competitive in several fields of applications: first, obstacle detection radar application (at 77 or 94 GHz), secondly metrology, for example, in order to measure radar cross-sections over the whole W-band with a single antenna. [ABSTRACT FROM AUTHOR]

This letter describes the design of a uniplanar parallel-series-fed linear array of Vivaldi antennas. Matching conditions have been optimized with an equivalent-circuit model. The array exhibits 12dBi gain in the substrate plane, 80% radiation efficiency, and low cross polarization over 5% bandwidth centered at 4.2GHz. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 60–62, 2001. [ABSTRACT FROM AUTHOR]

The response of a twin Vivaldi antenna to even and odd excitations is used to achieve pattern diversity at a single frequency (4.4 GHz). In the even mode, the antenna radiates at boresight with a 6.5 dBi gain. The odd mode radiates symmetrically with a 6 dBi gain. © 2000 John Wiley & Sons, Inc. Microwave Opt Technol Lett 27: 207–209, 2000. [ABSTRACT FROM AUTHOR]

A double slot array antenna pasted on the aperture of a standard WR-10 waveguide is presented. Its compactness and airtightness make it suitable for serving as a primary source for reflector antennas. Compared to a standard WR-10 open-ended waveguide, it acts as a small FSS to provide up to 12 dB return loss enhancement within 9% bandwidth centred on 94 GHz, whereas radiation pattern and gain are similar. Good agreement is found between measured and predicted characteristics between 90 and 100 GHz. A return loss improvement is of particular interest while considering an antenna system with short focal length. [ABSTRACT FROM AUTHOR]

A single-layer reflector antenna combining eight and four correcting Fresnel zones is presented. The progressive phase shift is achieved by circular and annular patches. The choice of a quarter-wavelength thickness substrate provides naturally 0 and 180° correcting zones that simplify the reflector design. A prototype of reflector antenna working at 94 GHz has been designed, built and measured. Measurement results show 70% improvement of antenna aperture efficiency compared to the half-wave Fresnel zone plate reflector [1]. [ABSTRACT FROM AUTHOR]

Presents a simple computer aided design formula and network interpretation for loss evaluation in microstrip superconductor-conductor bilayer structure. Influence of the thickness ratio of the two layers on bilayer losses; Requirements for the design of superconducting structures; Steps in the extraction of equivalent circuit.