A case-control study to identify risk factors associated with avian influenza subtype H9N2 on commercial poultry farms in Pakistan

A 1:1 matched case-control study was conducted to identify risk factors for avian influenza subtype H9N2 infection on commercial poultry farms in 16 districts of Punjab, and 1 administrative unit of Pakistan. One hundred and thirty-three laboratory confirmed positive case farms were matched on the date of sample submission with 133 negative control farms. The association between a series of farm-level characteristics and the presence or absence of H9N2 was assessed by univariable analysis. Characteristics associated with H9N2 risk that passed the initial screening were included in a multivariable conditional logistic regression model. Manual and automated approaches were used, which produced similar models. Key risk factors from all approaches included selling of eggs/birds directly to live bird retail stalls, being near case/infected farms, a previous history of infectious bursal disease (IBD) on the farm and having cover on the water storage tanks. The findings of current study are in line with results of many other studies conducted in various countries to identify similar risk factors for AI subtype H9N2 infection. Enhancing protective measures and controlling risks identified in this study could reduce spread of AI subtype H9N2 and other AI viruses between poultry farms in Pakistan

Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

Effect of Heterogeneity in Additively Manufactured Dielectric Structures on RF Response of Microstrip Patch Antennas

Microstrip patch antennas with a tunable radiofrequency (RF) response are a great candidate for additive manufacturing (AM) process. First, three separate sets of ABS samples were created at three different machine preset fill densities using an extrusion based 3D printer. Once fabricated, actual solid volume fraction of each set of samples was measured using a 3D X‐ray computed tomography microscope. It is observed that the factory preset fill‐density values are only applied to the core region and actual solid volume fractions for each sample set are different from printer‐preset values. Also, the printed materials appeared to exhibit anisotropy such that the thickness direction dielectric properties are different from the in‐plane properties (planar isotropy). Microstrip patch antennas created on the AM fabricated ABS were tested for resonant frequencies using a vector network analyzer (VNA). The measured resonant frequencies combined with ANSYS‐HFSS simulation were used to estimate bulk dielectric constant of ABS and equivalent dielectric properties in planar and thickness directions. It is observed that the antenna resonant frequency decreases with an increase in core solid volume fraction. Also, in‐plane permittivity appeared to have minimal effect on antenna resonant frequency, while the thickness direction properties have substantial effects

Effect of Heterogeneity in Additively Manufactured Dielectric Structures on RF Response of Microstrip Patch Antennas

Microstrip patch antennas with a tunable radiofrequency (RF) response are a great candidate for additive manufacturing (AM) process. First, three separate sets of ABS samples were created at three different machine preset fill densities using an extrusion based 3D printer. Once fabricated, actual solid volume fraction of each set of samples was measured using a 3D X‐ray computed tomography microscope. It is observed that the factory preset fill‐density values are only applied to the core region and actual solid volume fractions for each sample set are different from printer‐preset values. Also, the printed materials appeared to exhibit anisotropy such that the thickness direction dielectric properties are different from the in‐plane properties (planar isotropy). Microstrip patch antennas created on the AM fabricated ABS were tested for resonant frequencies using a vector network analyzer (VNA). The measured resonant frequencies combined with ANSYS‐HFSS simulation were used to estimate bulk dielectric constant of ABS and equivalent dielectric properties in planar and thickness directions. It is observed that the antenna resonant frequency decreases with an increase in core solid volume fraction. Also, in‐plane permittivity appeared to have minimal effect on antenna resonant frequency, while the thickness direction properties have substantial effects

The Effects of Printed Lattice Cell Structure Superstrates on Printed Patch Antennas

This work demonstrates a fully printed patch antenna consisting of a three‐dimensional (3D) printed Ultem 9085 substrate and a 3D printed body‐centered cubic lattice cell structure (LCS) superstrate made of Verowhite Plus. The radiating patch was fabricated by manual screen‐printing method using commercially available silver pastes. The superstrate was affixed to the top of the patch to mitigate shock‐induced damage to the patch. The antenna, which operates close to 5 GHz (an alternative frequency band to 2.4 GHz for data link applications) was designed as a test platform to quantify the effects of a printed superstrate on the resonant frequency and bandwidth. The addition of the superstrate shifted the resonant frequency by 0.1 GHz; and while this is not insignificant it still provides a promising strategy for adding vibration mitigation to radio frequency (RF) structures. Further, it was used to assess a less computationally expensive scheme for modeling of RF antennas involving cellular structures. In this scheme, the LCS superstrate is treated as a solid with dielectric properties that resemble that of a porous medium. Comparisons of measured and simulated S11 before and after adding the LCS superstrate revealed that the scheme yields results that are in good agreement with the experiment. Results from this work can provide guidance in the fabrication of low‐cost fully printed patch antennas with LCS superstrate for specific frequency application

The Effects of Printed Lattice Cell Structure Superstrates on Printed Patch Antennas

This work demonstrates a fully printed patch antenna consisting of a three‐dimensional (3D) printed Ultem 9085 substrate and a 3D printed body‐centered cubic lattice cell structure (LCS) superstrate made of Verowhite Plus. The radiating patch was fabricated by manual screen‐printing method using commercially available silver pastes. The superstrate was affixed to the top of the patch to mitigate shock‐induced damage to the patch. The antenna, which operates close to 5 GHz (an alternative frequency band to 2.4 GHz for data link applications) was designed as a test platform to quantify the effects of a printed superstrate on the resonant frequency and bandwidth. The addition of the superstrate shifted the resonant frequency by 0.1 GHz; and while this is not insignificant it still provides a promising strategy for adding vibration mitigation to radio frequency (RF) structures. Further, it was used to assess a less computationally expensive scheme for modeling of RF antennas involving cellular structures. In this scheme, the LCS superstrate is treated as a solid with dielectric properties that resemble that of a porous medium. Comparisons of measured and simulated S11 before and after adding the LCS superstrate revealed that the scheme yields results that are in good agreement with the experiment. Results from this work can provide guidance in the fabrication of low‐cost fully printed patch antennas with LCS superstrate for specific frequency application