Wire Loop Research Articles

Femoral Artery–Systemic-Pulmonary Shunt–Femoral Vein Wire Loop to Assist Balloon Pulmonary Valvuloplasty in Infants with Discordant Atrioventricular and Ventriculoarterial Connection, Ventricular Septal Defect, and Extremely Severe Pulmonary Stenosis

Femoral Artery–Systemic-Pulmonary Shunt–Femoral Vein Wire Loop to Assist Balloon Pulmonary Valvuloplasty in Infants with Discordant Atrioventricular and Ventriculoarterial Connection, Ventricular Septal Defect, and Extremely Severe Pulmonary Stenosis

Antibiotic Treatment and Antibiogram Profiles of E.coli Isolated from Selected Poultry Farms in Ido-Ekiti

Aims: Antibiotic therapy in poultry is alleged to spread multiple antibiotic resistant bacteria. This study seeks to correlate antibiotic treatment in poultry with the occurrence of multiple bacterial resistances to critically important antibiotics and also determine the potential sources of acquisition of these bacteria.
 Study Design: Experimental design.
 Place and Duration of Study: Department of Microbiology, Ekiti State University, Ado-Ekiti between February 2017 and December 2019.
 Methodology: Data on antibiotic treatment, poultry management practices and use of natural water bodies in the area of study were collected from farm managers and residents using a questionnaire. The locations of the source area and their relative distances were determined using the Geographical System Information Software, Mapit. Fresh fecal droppings from poultry birds were randomly sampled with a sterile swab stick and transferred into a freshly-procured, sealed, factory-packed polythene bag. Farm feed, water, and soil from disposal sites were also collected in sterile universal containers. The suspension of the fecal droppings was streaked on Eosin Methylene Blue agar plates with sterile wire loop and incubated at 37 °C for 18-24 hours. Soil and water samples from the waste disposal sites were serially diluted and streaked as previously. The isolates were characterized using relevant biochemical tests. Modified Kirby Bauer method was used to determine the isolates’ susceptibility to nine tested antibiotics, and the results were interpreted based on CLSI guidelines.
 Results: Most of the examined birds, (92%) were exposed to antibiotics, of which 64% of the antibiotics were administered for therapeutic purposes, prophylaxis (27%) and enhancement of egg production in layers (9%). All the antibiotics were administered by mixing them in a specified quantity of water. The majority (46%) of the birds were first exposed to antibiotics at the age of 2 weeks. Routine charts were used by 25% of the farmers for the administration of antibiotics. Data from farm records show that eleven antibiotics were selectively used on the farms. Sulfonamide and diaveridine, an anti-coccidiostat, were administered in most of the farms (50%), while tylosine, metronidazole and chloramphenicol recorded the least (8.3%). Carbapenem, penicillin, and cephalosporin were not administered. From the data obtained on antibiotics-presence in two retail markets, tetracycline, neomycin, gentamycin and erythromycin were available in both retail markets, cephalosporins, meropenem, and metronidazole were not sold for poultry consumption. Both the percentage occurrences of E. coli from fresh poultry droppings (44.1%) and waste disposal sites (33.3%) were relatively low. Higher antibiotic percentage resistance to ciprofloxacin (87%), ofloxacin (83%), sulfonamide, and tetracycline (78%) were found in the isolates. Multiple antibiotic-resistant profiles occurred in patterns and different patterns were replicated across various farms. Also, 46 multiple antibiotic-resistant patterns were recorded, and two of these patterns (AMC, CIP, OFX, CN, SXT, TET and CRO, CAZ, AMC, CIP, OFX, CN, MEM, SXT) were spread across 50% of the farms. There was history of diarrhea in some respondents (12%), linked to human exposure to contaminated natural water bodies. From correlation studies, both data on antibiotic treatment and that from market survey were directly related to the antibiotic-resistant profiles of isolates. The Spearman correlation coefficient are (rs (3) = 0.866, p = .333) and (rs (3) = 0 .667, p = .500) respectively.
 Conclusion: The development and spread of multiple antibiotic-resistant bacteria of poultry origin are primarily attributed to poor antibiotic formulation policy, crude antibiotic treatment on poultry farms, and indiscriminate supply of antibiotics to untrained poultry personnel. The effectiveness of the super drugs used for the treatment of superbugs in poultry birds may be undermined if policies on the antibiotic formulation, dispensing, and therapy are not reviewed.

Characterization and applications of Thermomonas hydrothermalis isolated from Jordan's hot springs for biotechnological and medical purposes

We identified and investigated the biological activities of Thermomonas hydrothermalis, isolated bacteria strains present in Jordan's hot springs, based on their morphological, biochemical, and physiological characteristics. The colonies exhibited light brown with a diameter ranging from 0.5 to 2.0 mm. For screening their metabolic activities, API 50CHB strips and esculin were used. We phylogenetically typified the isolated bacteria by applying 16S ribosomal DNA gene amplification and sequencing followed by the Basic Local Alignment Search Tool (BLAST) tests. About 100 μL of the enriched sample was streaked on nutrient agar using a calibrated wire loop, while 20 μg crude powder was mixed with dimethyl sulfoxide (DMSO) to test their activities against standard pathogenic bacterial strains (ATCC). The water samples collected from the hot springs had temperatures ranging between 44–56 °C, pH between 7.11–8.51, and electrical conductivity between 1.06–1.41 ms/cm. To utilize their isolate for characterization and applications, pH, temperature, and generation time were optimized. It was found that the Gram-negative isolated bacteria strain exhibited an optimum growth at 55 °C, pH 8.5, and 30 min of generation time (GT). The BLAST results showed a 99 % of similar identity of the sample to Thermomonas hydrothermalis. Due to their antibacterial effects against Gram-positive and Gram-negative bacteria, bioactive compounds identified using gas chromatography–mass spectroscopy (GC–MS) had novel features such as 4(3 H)-pyrimidinone, dihydroxy-1,5- naphthyridine, actinomycine-D, and pyrrolo [1,2-a]pyrazine-1,4-dione hygrazides. Screening of cytotoxic activity tests using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay was conducted toward their water extract, which exerted cytostimulatory effects on human lung fibroblasts (MRC-5) with an IC50 of 5.109 μg/mL and accelerated wound closure. Overall, the implications of this study provided new insights into the bioproducts of Thermomonas hydrothermalis and offered opportunities to utilize their isolate for biotechnological and medicinal applications.

Improving the bonding stability between resin cements and zirconia-based ceramic using different surface treatments.

To evaluate the effects of airborne-particle abrasion with alumina particles or silicamodified alumina particles on the bond strength between zirconia and conventional MDP-based (Ph; Panavia F 2.0, Kuraray) or self-adhesive (SA; RelyX U200, 3M ESPE) resin cements. Five surface treatments were evaluated: C = no surface treatment; AB = airborne-particle abrasion with alumina particles (BIO-ART Dental Supplies and Equipment); ABP = AB combined with MDP-based primer (Alloy Primer, Kuraray); SS = airborne-particle abrasion with silica-modified alumina particles (CoJet, 3M ESPE) combined with silane (RelyX Ceramic Primer, 3M ESPE); and SSP = SS combined with MDP-based primer. The surface roughness (Ra) of the airborne particle-abraded samples (n = 5) was measured by a contact profilometer (Mitutoyo Surftest SJ-401, Mitutoyo). Cylinders of the resin cements tested were bonded to the surface-treated zirconia. The microshear test was performed by the application of a load with a wire loop parallel to the adhesive interface until debonding of the resin cement cylinders. The microshear bond strength (μSBS) of the samples was measured before and after being subjected to thermocycling (TC; 5°C to 55°C, 60 seconds dwell time for 3,000 cycles; MSCT, Marcelo Nucci). One-way (Ra) and two-way (μSBS) analysis of variance followed by Tukey post hoc test (α = .05) were used. The SS (Ph: 12.6 MPa; Ph-TC: 6.37 MPa; SA: 11.8 MPa; SA-TC: 9.37) and SSP (Ph: 10.4 MPa; Ph-TC: 5.82 MPa; SA: 10.4 MPa; SA-TC: 10.0) surface treatments produced the highest surface roughness values (P < .001). The SS samples achieved the highest immediate bond strength for both resin cements. However, after TC, SA resin cement associated with any surface treatment produced the highest bond strength values. The self-adhesive resin cement promoted higher and more stable bond strength values when associated with a surface roughening method.

Line scan-based rapid magnetic resonance imaging of repetitive motion

Two-dimensional (2D) line scan-based dynamic magnetic resonance imaging (MRI) is examined as a means to capture the interior of objects under repetitive motion with high spatiotemporal resolutions. The method was demonstrated in a 9.4-T animal MRI scanner where line-by-line segmented k-space acquisition enabled recording movements of an agarose phantom and quail eggs in different conditions—raw and cooked. A custom MR-compatible actuator which utilized the Lorentz force on its wire loops in the scanner’s main magnetic field effectively induced the required periodic movements of the objects inside the magnet. The line-by-line k-space segmentation was achieved by acquiring a single k-space line for every frame in a motion period before acquisition of another line with a different phase-encode gradient in the succeeding motion period. The reconstructed time-course images accurately represented the objects’ displacements with temporal resolutions up to 5.5 ms. The proposed method can drastically increase the temporal resolution of MRI for imaging rapid periodic motion of objects while preserving adequate spatial resolution for internal details when their movements are driven by a reliable motion-inducing mechanism.

Endobronchial Blocker Placement for Lung Isolation in Children: A Simple Head Turn Technique.

Endobronchial blockers are frequently used for lung isolation in children <8 years of age. The aim of our report is to highlight the problem that we have encountered with the wire-guided endobronchial blocker (WEB), where the wire loop used to couple the blocker and the fiberoptic scope (FOS) may straddle the carina. We describe the "uncoupled head turn technique" that we have adopted to avoid this problem. If the coupled technique is deemed necessary, a method to keep the wire loop snug around the FOS is described to avoid the straddling problem.

Three-dimensional finite-difference modeling of time-domain electromagnetic responses for a large-loop source

The time-domain/transient electromagnetic (TEM) method employs an alternating magnetic field that is established by passing a bidirectional pulsed current through a transmitter loop. A large wire loop on or above the earth is one of the most widely used sources in TEM survey systems. To simulate TEM responses of the large loop system, the effect of the loop size must be considered in a numerical modeling scheme. We have developed an efficient three-dimensional (3D) TEM modeling algorithm using a staggered-grid finite-difference time-domain (FDTD) method. In this paper, we first derive FDTD TEM equations using fictitious displacement currents based on an explicit mid-point method. Then, we employed a conversion method to efficiently obtain stepoff TEM responses from step-on responses. Further, following the concept of the conversion method, the charging and discharging processes of current waveform in loop does not need to be identical, implying we can apply the simulation scheme for more general source waveforms. The developed algorithm has been verified through comparison of numerical results for a homogeneous halfspace medium. Finally, we analyze TEM responses generated from a large loop source for a 3D conductive body buried in a homogeneous half space.

Bandwidth enhancement and cross-polarization suppression of slot antenna

ABSTRACT In this paper, a novel method is presented for bandwidth enhancement and cross-pol suppression of microstrip-fed slot antenna with circular and vertical wire loops. Two antenna topologies have exhibited 528 and 438 MHz −10 dB bandwidth in comparison with 73 MHz −10 dB bandwidth of reference slot antenna with poor cross-pol. To improve those cross-pol characteristics, we have designed another two antenna topologies, which produced 471 and 615 MHz −10 dB bandwidth in comparison with reference antenna. Cross-pol suppression is achieved by using vertical wire loops. The simulated results were verified with measured results and found excellent agreement.

Flexible Multi-Turn Multi-Gap Coaxial RF Coils: Design Concept and Implementation for Magnetic Resonance Imaging at 3 and 7 Tesla.

Magnetic resonance has become a backbone of medical imaging but suffers from inherently low sensitivity. This can be alleviated by improved radio frequency (RF) coils. Multi-turn multi-gap coaxial coils (MTMG-CCs) introduced in this work are flexible, form-fitting RF coils extending the concept of the single-turn single-gap CC by introducing multiple cable turns and/or gaps. It is demonstrated that this enables free choice of the coil diameter, and thus, optimizing it for the application to a certain anatomical site, while operating at the self-resonance frequency. An equivalent circuit for MTMG-CCs is modeled to predict their resonance frequency. Possible configurations regarding size, number of turns and gaps, and cable types for different B 0 field strengths are calculated. Standard copper wire loop coils (SCs) and flexible CCs made from commercial coaxial cable were fabricated as receive-only coils for 3 T and transmit/receive coils at 7 T with diameters between 4 and 15 cm. Electromagnetic simulations are used to investigate the currents on MTMG-CCs, and demonstrate comparable specific absorption rate of 7 T CCs and SCs. Signal-to-noise ratio (SNR), transmit efficiency, and active detuning performance of CCs were compared in bench tests and MR experiments. For the form-fitted receive-only CCs at 3 T no significant SNR degradation was found as compared to flat SCs on a balloon phantom. Form-fitted transmit/receive CCs at 7 T showed higher transmit efficiency and SNR. MTMG-CCs can be sized to optimize sensitivity, are flexible and lightweight, and could therefore enable the fabrication of wearable coils with improved patient comfort.

Clinico-histomorphologic Characteristics of Lupus Nephritis, Experience at a Center at Dhaka.

Lupus nephritis (LN) is one of the most serious systemic lupus erythematosus complications since it is the major predictor of poor prognosis. We present the clinico-histomorphologic characteristics of LN at a center in Dhaka. The study group comprised diagnosed cases of LN on core-needle renal biopsy specimens received in the Department of Histopathology, Armed Forces Institute of Pathology, Dhaka, from January 2018 to June 2019. Histological evaluation and direct immunofluorescence (DIF) study was carried out on each specimen. Each case was classified according to the International Society for Nephrology/Renal Pathology Society (ISN/RPS) Classification 2003 of LN. A total of 104 (9.20%) LN cases were included of total 1130 nonneoplastic renal biopsy specimens. The mean age was 28.29 ± 12.24 years, with a male:female ratio of 1:4.47. According to the ISN/RPS 2003 classification, most of the LN belong to class IV (42, 40.38%), followed by class III (27, 25.96%), class II (22, 21.15%), and so on. The mean age of class IV LN was 25.95 ± 10.15 years, with M:F = 1:4.25. The mean urinary total protein (UTP) was 4.62 ± 4.47 g/24 h and the mean serum creatinine was 1.87 ± 1.12 mg/dL. On histopathology, 22 (52.38%) had crescent formation, 27 (64.28%) had wire loop formation with subendothelial thrombi, and 30 (71.42%) had necrotizing lesion. Interstitial fibrosis and tubular atrophy (IFTA) was ≥25% in eight (19.04%) class IV LN. Among the subclasses, most common was IV-G (A/C) - 16 (38.09%), followed by IV-S (A/C) - nine (21.42%) and IV-S (A) and IV-G (A) each eight (19.04%). In four (9.52%) cases, class IV + V lesion was found. The mean age of class III LN was 26 ± 11.02 years, with a male:female of 1:26. The mean UTP was 3.45 ± 2.4 and serum creatinine was 1.71 ± 1.51. Among these, crescent was found in eight (29.63%) cases, wire loop and subendothelial thrombi in 11 (37.04%) cases, and necrotizing lesions in eight (29.63%) cases. IFTA was >25% in 14.81% of cases of class III LN. Among 27 class III LN, 17 (62.96%) were classified as III (A) and 10 (37.04%) as III (A/C). Two class III LN had an association with class V and two have presented with TMA. The mean age of class II LN was 29.95+ 12.26 years, with M:F = 1:2.66. UTP was 3.53 ± 2.43 g/24 h and serum creatinine was 1.52 ± 1.5 mg/dL for class II LN. Histologically, these cases had focal/diffuse mesangial proliferation with 25% IFTA in 9.09% of cases. One of the class II LN had associated amyloidosis. Among class V LN, the mean age was 45.12 + 13.64 years, with M:F = 1:3. The mean UTP was 4.06 ± 1.71 g/24 h and serum creatinine was 1.64 ± 0.94 mg/dL. Histologically, 37.5% had >25% IFTA. The mean age of class I lesion was 27.25 ± 17.42 years with equal number of males and females. The mean serum creatinine level was 0.65 ± 0.18 mg/dL and UTP was 2.71 ± 2.3 g/24 h for class I lesion. Only one class VI LN case was found which had IFTA 40% and presented with generalized edema. On DIF, among 100 cases, 86 were found with full-house immune deposits of different intensity; IgM was lacking in 10 cases and IgA was lacking in seven cases, while three cases lacked C3 deposits. The mean activity index was 7.10 and the mean chronicity index was 3.23 among 69 cases of proliferative LN. Among different histological classes of LN, the prevalence of class IV was more in this study which had the most severe form of clinical presentation, biochemical parameters (raised serum creatinine level), and histological findings (crescent formation and IFTA).

Dizajn i kompjuterska simulacija automatski kontrolisanog hidromehaničkog sistema za proizvodnju elemenata sita sa klinastim žicom

The article presents a design of mechatronic system used for the production of wire elements used in looped wedge wire screen manufacturing. Details related to the design of the hydromechanical subsystem, the control subsystem, as well as the simulation of the operation process of the entire system are presented

Silicone finger prosthesis with customized ring wire loop substructure as a retentive aid

Finger prosthesis is an artificial replacement of missing fingers. Defects of fingers or hands due to congenital reasons or trauma may affect the individual physically, emotionally, and psychologically. Major problem that we can anticipate during prosthetic replacement of missing or lost fingers is retention. The anatomy of the residual stump of the defect is the most important factor that will determine the mode of retention. Retention of the prosthesis can be enhanced by the numerous methods. This case report describes a cost-effective and simple approach of rehabilitation of a partially amputated finger using a custom-made ring-wire loop substructure which helped to enhance the fit and retention of the prosthesis along with fulfilling the functional demands of the patient.

The Finite Element Method (FEM) Approach to Determine Wire Loop Tooth and the Shaft of the Areca Nut Thresher Machine

The Finite Element Method (FEM) Approach to Determine Wire Loop Tooth and the Shaft of the Areca Nut Thresher Machine

Improved accuracy in high-frequency AC transport measurements in pulsed high magnetic fields.

We show theoretically and experimentally that accurate transport measurements are possible even within the short time provided by pulsed magnetic fields. For this purpose, a new method has been devised, which removes the noise component of a specific frequency from the signal by taking a linear combination of the results of numerical phase detection using multiple integer periods. We also established a method to unambiguously determine the phase rotation angle in AC transport measurements using a frequency range of tens of kilohertz. We revealed that the dominant noise in low-frequency transport measurements in pulsed magnetic fields is the electromagnetic induction caused by mechanical vibrations of wire loops in inhomogeneous magnetic fields. These results strongly suggest that accurate transport measurements in short-pulsed magnets are possible when mechanical vibrations are well suppressed.

Arthroscopic Reduction and Fixation by Cerclage Wire Loop for Tibial Spine Avulsion in Adults: Short-term Results.

Background:Several arthroscopic techniques for the treatment of avulsion tibial spine fractures have been described in the literature.Purpose:To evaluate the outcomes of the arthroscopically assisted stainless steel wiring technique in the treatment of avulsed tibial spine in adults.Study Design:Case series; Level of evidence, 4.Methods:This retrospective study involved 28 patients (28 knees), 16 to 42 years of age, with tibial spine avulsion fracture that was treated using arthroscopic reduction and cerclage wire fixation by a single surgeon between March 2015 and August 2018. The degrees of avulsion in these patients were type II (n = 12), type III (n = 10), and type IV fractures (n = 6). Clinical assessment included International Knee Documentation Committee (IKDC) objective score (which noted swelling), range of knee movement, Tegner activity scale, Lachman test, and pivot-shift test compared with the normal opposite knee.Results:The mean follow-up period was 24.1 months (range, 18-30 months). The mean IKDC score was 93.7 (range, 88.5-98.9); the IKDC score was normal in 22 patients and nearly normal in 6 patients. The Lachman test was grade 1 in 25 patients and grade 2 in 3 patients, whereas the pivot-shift test was grade 0 in 26 patients and grade 1 in 2 patients. All patients achieved their preinjury Tegner activity levels. Radiological assessment showed healing in all patients within a mean of 12 weeks after surgery.Conclusion:The outcomes of all patients were satisfactory; fixation by cerclage wiring permitted reduction of tibial spine fragment anatomically to its fracture bed, provided stable fixation in displaced tibial spine avulsion, and allowed for early rehabilitation and weightbearing because of stable fixation.

Double Trapezoidal Wave Transmitting System with Controllable Turn-Off Edge

For time domain transient electromagnetic measurement, the negative sign often appears in the polarization region, which contains the induced polarization information. It is considered that the polarization effect is caused by the capacitance charge of the earth. Extending the turn-off time of the emission current means increasing the charging time, and reducing the charging voltage, which makes the polarization effect easier to observe. Therefore, a double trapezoidal wave transmitting system with a controllable turn-off edge is designed in this paper. In the process of current transmitting, the turn-off time can be controlled by changing the clamping voltage depending on the passive clamping technology. By cutting into the absorption resistance, the current oscillation can be eliminated under the condition of ensuring linearity. To verify the effectiveness of the system, we designed a polarized wire loop based on the filament model simulating the polarized earth. Comparing the response of the wire loop, the emission current with short and long turn-off times contributes to inducing the induction and polarization fields respectively. The double trapezoidal wave transmitting system with a controllable turn-off edge is suitable for measuring the induced polarization effect.

The “AIIMS hairpin loop” technique for ‘extreme’ volar rim fractures of distal radius

Background: Treatment of distal radius fractures has seen a paradigm shift since the use of volar locking plates became popular. However, there is a subset of fractures, which includes extreme distal volar rim fractures, that is often not amenable to fixation by volar locking plates as there is insufficient bone mass to put screws. These fractures as such are quite rare but carry a huge morbidity due to frequent lack of anatomical reduction and fixation. A number of different techniques like hook plates, specially designed distal volar locking plates and loop wire techniques have been described for these fractures, but they have been found to be less helpful when the fracture fragments are very small.Methods: Herein, we describe our experience on 6 patients, using a novel surgical technique for fixation of distal radius volar rim fractures which works equally well even when the fragments are quite small (2–3 mm). The technique uses low cost and readily available implants (K wire and conventional volar locking plate) without the need of any special implants.Results: The total of 6 cases of distal radius volar rim fractures (AO/OTA Type B3 = 4, Type C1 = 2) were operated. The mean age was 50.83 years (range: 31–72). The mean follow-up duration was 43.3 months (range: 26–66). The mean size of the volar fragment was 3.66 mm (range: 2–5). The mean pronation and supination were 72.5° (60–80) and 74.2° (60–85). The main flexion and extension were 52.5° (40–75) and 58.3° (50–80) respectively. The mean grip strength was 19.8 kg (4–38) and it was mean 79.3% (40–130%) compared to uninjured side. The mean PRWE score was 12.3 (2–31). One patient developed symptoms of Complex Regional Pain syndrome 1 (CRPS 1) which resolved with conservative management and no other complications were noted.Conclusion: Our technique offers an indigenous, cost-effective way for fixation of extreme volar rim fracture fragments which can be easily adopted and used by surgeons in developing countries.

An Improved External Penile Prosthesis

Current external penile supports and prostheses are almost perfect in design and technology. However, their applications are still very limited because they make most women uncomfortable during intercourse. In order to improve women’s overall satisfaction, this article proposes an improved external penile prosthesis, namely the External Penile Prosthesis Band (EPPB), which consists of a double-layer cloth and a set of embedded metal wire loops.

Penetration of Bone by Inferior Vena Cava Filters: Safety and Technical Success of Percutaneous Retrieval

The technical success and safety of percutaneous inferior vena cava filters (IVCF) retrieval when filter elements are penetrating into adjacent bony structures is unknown. Therefore, our purpose was to evaluate the technical success and safety of IVCF retrieval when filter elements are penetrating into adjacent bone. Using percutaneous IVCF retrievals from 2008 to 2018 in adult patients, we conducted a multi-institutional, retrospective review of filters found to penetrate lumbar vertebrae by computed tomography scans. Technical success following the retrieval procedure was recorded. Patient records were assessed for complications from retrieval. 13 patients (2 males; 11 females; mean age: 53.2 years (range: 22-71) were included. Hundred percent of the filters were optional (retrievable) filters. Venous thromboembolism (VTE) with a contraindication to anticoagulation (n = 7; 53.8%) and prophylaxis without venous thromboembolism (n = 3; 23.1%) were the 2 most common indications for IVCF placement. Two filters (15.4%) had >15° of tilt relative to the IVC prior to retrieval while no IVCFs had migrated or caused caval thrombosis. One filter (7.7%) was found to have a fractured strut prior to retrieval. Ten patients (76.9%) were either on anticoagulants or antiplatelet medications at the time of retrieval. No patients were on antibiotics and no patients received periprocedural antibiotics. Median dwell time was 116.5 days (range: 49-5395). All 13 IVCFs were successfully retrieved in a single session (technical success: 100%). Standard snare technique was used in 8 cases (61.5%), endobronchial forces were used in 3 cases (23.1%), and wire loop snare technique was used in 2 cases (15.4%). There were no complications in any patient. Percutaneous retrieval of IVCFs with elements that have penetrated into adjacent vertebrae is both safe and technically feasible.

The Traveling Wave Loop Antenna: A Terminated Wire Loop Aerial for Directional High-Frequency Ocean RADAR Transmission

In this paper we document the design, development, results, performance and field applications of a compact directive transmit antenna for the long-range High Frequency ocean RADAR (HFR) systems operating in the International Telecommunication Union (ITU) designated 4MHz and 5MHz radiodetermination bands. The antenna design is based on the combination of the concepts of an electrically small loop with that of travelling wave antenna. This has the effect of inducing a radiated wave predominantly in a direction opposed to that of energy flow on the antenna structures. We demonstrate here that travelling wave design allows for a more compact antenna than other directive options, it has straightforward feed-point matching arrangements, and a flat frequency and phase response over an entire radiodetermination band. In situ measurements of the antenna radiation pattern, obtained with the aid of a drone, correlate well with those obtained from simulations, and show between 8dB and 30dB front-to-back suppression, with a 3dB beam width in the forward lobe of 100∘ or more. The broad-beam radiation pattern ensures proper illumination over the ocean and the significant front-to-back suppression guarantees reduced interference to terrestrial services. The proposed antenna design is compact and straight forward and can be easily deployed by minimal modifications of an existing transmission antenna. The design may be readily adapted to different environments due to the relative insensitivity of its radiation pattern and frequency response to geometric detail. The only downside to these antennas is their relatively low radiation efficiency which, however, may easily be compensated for by the available power output of a typical HFR transmitter. Antennas based on this design are currently deployed at the SeaSonde HFR sites in New South Wales, Australia, with operational ranges up to 200 km offshore despite their low radiating efficiency and the extremely low output power in use at these installations. Due to their directional pattern, it is also planned to test these antennas in phased-array Wellen RADAR (WERA) systems in both the standard receive arrays: where in-band radio frequency noise of terrestrial origin is impacting on data quality, and in the transmit array: to possibly simplify splitting, phasing and tuning requirements.