Experimental observation of autosoliton propagation in a dispersion-managed system guided by nonlinear optical loop mirrors

Observation of autosoliton propagation in a dispersion-managed optical transmission system controlled by in-line nonlinear fiber loop switches is reported for what is believed to be the first time. The system is based on a strong dispersion map with large amplifier spacing. Operation at transmission rates of 10 and 40 Gbits/s is demonstrated. ©2004 Optical Society of America

Graphene-black phosphorus printed photodetectors

Layered materials (LMs) produced by liquid phase exfoliation (LPE) can be used as building blocks for optoelectronic applications. However, when compared with mechanically exfoliated flakes, or films prepared by chemical vapor deposition (CVD), LPE-based printed optoelectronic devices are limited by mobility, defects and trap states. Here, we present a scalable fabrication technique combining CVD with LPE LMs to overcome such limitations. We use black phosphorus inks, inkjet-printed on graphene on Si/SiO2, patterned by inkjet printing based lithography, and source and drain electrodes printed with an Ag ink, to prepare photodetectors (PDs). These have an external responsivity (R ext)∼337 A W−1 at 488 nm, and operate from visible (∼488 nm) to short-wave infrared (∼2.7 µm, R ext ∼ 48 mA W−1). We also use this approach to fabricate flexible PDs on polyester fabric, one of the most common used in textiles, achieving R ext ∼ 6 mA W−1 at 488 nm for an operating voltage of 1 V. Thus, our combination of scalable CVD and LPE techniques via inkjet printing is promising for wearable and flexible applications

Comparison of Tissue Injury from Focused Ultrasonic Propulsion of Kidney Stones Versus Extracorporeal Shock Wave Lithotripsy

Purpose Focused ultrasonic propulsion is a new non-invasive technique designed to move kidney stones and stone fragments out of the urinary collecting system. However, the extent of tissue injury associated with this technique is not known. As such, we quantitated the amount of tissue injury produced by focused ultrasonic propulsion under simulated clinical treatment conditions, and under conditions of higher power or continuous duty cycles, and compared those results to SWL injury. Materials and Methods A human calcium oxalate monohydrate stone and/or nickel beads were implanted (with ureteroscopy) into 3 kidneys of live pigs (45–55 kg) and repositioned using focused ultrasonic propulsion. Additional pig kidneys were exposed to SWL level pulse intensities or continuous ultrasound exposure of 10 minutes duration (ultrasound probe either transcutaneous or on the kidney). These kidneys were compared to 6 kidneys treated with an unmodified Dornier HM3 Lithotripter (2400 shocks, 120 SWs/min and 24 kV). Histological analysis was performed to assess the volume of hemorrhagic tissue injury created by each technique (% functional renal volume, FRV). Results SWL produced a lesion of 1.56±0.45% FRV. Ultrasonic propulsion produced no detectable lesion with the simulated clinical treatment. A lesion of 0.46±0.37% FRV or 1.15±0.49% FRV could be produced if excessive treatment parameters were used while the ultrasound probe was placed on the kidney. Conclusions Focused ultrasonic propulsion produced no detectable morphological injury to the renal parenchyma when using clinical treatment parameters and produced injury comparable in size to SWL when using excessive treatment parameters

Stillbirth outcome capture and classification in population-based surveys: EN-INDEPTH study.

BACKGROUND: Household surveys remain important sources of stillbirth data, but omission and misclassification are common. Classifying adverse pregnancy outcomes as stillbirths requires accurate reporting of vital status at birth and gestational age or birthweight for every pregnancy. Further categorisation, e.g. by sex, or timing (intrapartum/antepartum) improves data to understand and prevent stillbirth. METHODS: We undertook a cross-sectional population-based survey of women of reproductive age in five health and demographic surveillance system sites in Bangladesh, Ethiopia, Ghana, Guinea-Bissau and Uganda (2017-2018). All women answered a full birth history with pregnancy loss questions (FBH+) or a full pregnancy history (FPH). A sub-sample across both groups were asked additional stillbirth questions. Questions were evaluated using descriptive measures. Using an interpretative paradigm and phenomenology methodology, focus group discussions with women exploring barriers to reporting birthweight for stillbirths were conducted. Thematic analysis was guided by an a priori codebook. RESULTS: Overall 69,176 women reported 98,483 livebirths (FBH+) and 102,873 pregnancies (FPH). Additional questions were asked for 1453 stillbirths, 1528 neonatal deaths and 12,620 surviving children born in the 5 years prior to the survey. Completeness was high (> 99%) for existing FBH+/FPH questions on signs of life at birth and gestational age (months). Discordant responses in signs of life at birth between different questions were common; nearly one-quarter classified as stillbirths on FBH+/FPH were reported born alive on additional questions. Availability of information on gestational age (weeks) (58.1%) and birthweight (13.2%) was low amongst stillbirths, and heaping was common. Most women (93.9%) were able to report the sex of their stillborn baby. Response completeness for stillbirth timing (18.3-95.1%) and estimated proportion intrapartum (15.6-90.0%) varied by question and site. Congenital malformations were reported in 3.1% stillbirths. Perceived value in weighing a stillborn baby varied and barriers to weighing at birth a nd knowing birthweight were common. CONCLUSIONS: Improving stillbirth data in surveys will require investment in improving the measurement of vital status, gestational age and birthweight by healthcare providers, communication of these with women, and overcoming reporting barriers. Given the large burden and effect on families, improved data must be made available to end preventable stillbirths

Tropical Data: Approach and Methodology as Applied to Trachoma Prevalence Surveys

PURPOSE: Population-based prevalence surveys are essential for decision-making on interventions to achieve trachoma elimination as a public health problem. This paper outlines the methodologies of Tropical Data, which supports work to undertake those surveys. METHODS: Tropical Data is a consortium of partners that supports health ministries worldwide to conduct globally standardised prevalence surveys that conform to World Health Organization recommendations. Founding principles are health ministry ownership, partnership and collaboration, and quality assurance and quality control at every step of the survey process. Support covers survey planning, survey design, training, electronic data collection and fieldwork, and data management, analysis and dissemination. Methods are adapted to meet local context and needs. Customisations, operational research and integration of other diseases into routine trachoma surveys have also been supported. RESULTS: Between 29th February 2016 and 24th April 2023, 3373 trachoma surveys across 50 countries have been supported, resulting in 10,818,502 people being examined for trachoma. CONCLUSION: This health ministry-led, standardised approach, with support from the start to the end of the survey process, has helped all trachoma elimination stakeholders to know where interventions are needed, where interventions can be stopped, and when elimination as a public health problem has been achieved. Flexibility to meet specific country contexts, adaptation to changes in global guidance and adjustments in response to user feedback have facilitated innovation in evidence-based methodologies, and supported health ministries to strive for global disease control targets

Feasibility study of adding a common-mode choke in PLC modem for EMI suppression

The feasibility of adding a common-mode (CM) choke in the analog front end (AFE) circuit of a power line communication (PLC) modem to reduce theCMnoise coupling onto the power line is investigated. Based on a two-current-probe measurement approach, theCMand the differential-mode (DM) equivalent electrical models of a PLC modem are first developed. Both the CM and the DM attenuations due to the addition of a CM choke when the PLC modem is connected onto the power line network are then determined. Besides the CM noise attenuation, the impact of the CM choke on the PLC signal, which isDMin nature, is also studied.Published versio

Reduction of CM noise emissions from PLC modem using optically coupled signaling

This paper investigates the feasibility of implementing an optical coupler in the analog front-end (AFE) circuit of a power line communication (PLC) modem to reduce the common mode (CM) noise coupling onto the power lines. Based on a two-currentprobe measurement approach, an equivalent CM circuit model is developed to predict the expected CM current generated by the PLC modem when it is plugged onto the power line network. The model provides insight into the CM noise coupling mechanism from any PLC modem onto the power line network, so that the effectiveness of using an optical coupling technique in reducing the CM current from the power line network can be properly quantified.Accepted versio

Radio-frequency common-mode noise propagation model for power-line cable

Electromagnetic-interference (EMI) radiation from a power-line communications (PLC) network has been a major concern for the widespread use of broadband PLC technology. It is also well known that the dominant radiation mode of the PLC network is common mode (CM) by nature. Therefore, for electromagnetic- compatibility planning purposes, knowledge of the CM noise propagation path of the power line in the frequency range of 1 to 30 MHz is essential to provide insight of EMI radiation emitted by the power line. Based on a two-current-probe measurement approach, the CM noise propagation model for a three-wire power-line cable can be derived and represented by an equivalent two-wire CMtransmission line. The equivalentCMnoise propagation model allows us to predict the CM noise current on the power line with reasonable accuracy. The model will serve as a valuable tool in the future to identify effective ways to suppress EMI radiation from the PLC network.Published versio

Modeling and analysis of common-mode current propagation in broadband power-line communication networks

This paper proposes a new approach to modeling the common-mode (CM) current propagation path of electrical power-line cables for broadband power-line communications (PLC). In this approach, a CM current propagation model for a three-wire power-line cable is developed using the multiconductor transmission-line theory. The model is used to study the electromagnetic-interference radiation mechanism from the PLC network in the frequency range of 1 to 30 MHz. The accuracy of the model is verified through numerical simulations and practical measurements conducted on the actual power-line network. The developed model allows us to predict the CM current in the power-line cable with reasonable accuracy.Published versio

Laparoscopic Cholecystectomy In The Academy Medicalcentre, Khartoum, Sudan

Objective: To highlight the results of minimum access surgery in Sudanese patients. Design: Prospective audit of laparoscopic cholecystectomies. Setting: The Academy Medical center (Yastabshiroon), Teaching University Hospital. Subjects: All the patients who had this type of surgery were included in the study. Clinical and operative data were evacuated from March 2002 to March 2004. Main outcome measures: One hundred and twenty patients had laparoscopic cholecystectomy at the center. There were 97 females and 23 males; age range was 22-90 years with a mean of 52 years. Indications for surgery were repeated attacks of biliary colic in 38, chronic cholecystitis in 60, acute cholecystis in 10 and mucocele in 12 patients. Results: Three patients with chronic cholecystitis had peri-portal fibrosis due to bilharzial infestations, in spite of which laparoscopic surgery was successful. Operating time was 25-120 minutes with a mean of 47 minutes. Conversion was performed in six (2%) patients because of bleeding and four for extensive dense adhesions. There was one mortality case of a 75-year-old female who had pulmonary embolus. Hospital stay was 16-24 hours with a mean of 22 hours. Two patients had port site discharge. Conclusion: In general, patients were satisfied with the results of surgery and this encourages us to popularise this procedure to take off in the Sudan. East African Medical Journal Vol.82(1) 2005: 10-1