1,214 research outputs found

    Are Controversial Issues in Cervical Total Disc Replacement Resolved or Unresolved?: A Review of Literature and Recent Updates

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    Since the launch of cervical total disc replacement (CTDR) in the early 2000s, many clinical studies have reported better outcomes of CTDR compared to those of anterior cervical discectomy and fusion. However, CTDR is still a new and innovative procedure with limited indications for clinical application in spinal surgery, particularly, for young patients presenting with soft disc herniation with radiculopathy and/or myelopathy. In addition, some controversial issues related to the assessment of clinical outcomes of CTDR remain unresolved. These issues, including surgical outcomes, adjacent segment degeneration (ASD), heterotopic ossification (HO), wear debris and tissue reaction, and multilevel total disc replacement (TDR) and hybrid surgeries are a common concern of spine surgeons and need to be resolved. Among them, the effect of CTDR on patient outcomes and ASD is theoretically and clinically important; however, this issue remains disputable. Additionally, HO, wear debris, multilevel TDR, and hybrid surgery tend to favor CTDR in terms of their effects on outcomes, but the potential of these factors for jeopardizing patients' safety postoperatively and/or to exert harmful effects on surgical outcomes in longer-term follow-up cannot be ignored. Consequently, it is too early to determine the therapeutic efficacy and cost-effectiveness of CTDR and will require considerable time and studies to provide appropriate answers regarding the same. For these reasons, CTDR requires longer-term follow-up data

    Generation of Functional Insulin-Producing Cells from Neonatal Porcine Liver-Derived Cells by PDX1/VP16, BETA2/NeuroD and MafA

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    Abstract Surrogate b-cells derived from stem cells are needed to cure type 1 diabetes, and neonatal liver cells may be an attractive alternative to stem cells for the generation of b-cells. In this study, we attempted to generate insulin-producing cells from neonatal porcine liver-derived cells using adenoviruses carrying three genes: pancreatic and duodenal homeobox factor1 (PDX1)/VP16, BETA2/NeuroD and v-maf musculo aponeurotic fibrosarcoma oncogene homolog A (MafA), which are all known to play critical roles in pancreatic development. Isolated neonatal porcine liver-derived cells were sequentially transduced with triple adenoviruses and grown in induction medium containing a high concentration of glucose, epidermal growth factors, nicotinamide and a low concentration of serum following the induction of aggregation for further maturation. We noted that the cells displayed a number of molecular characteristics of pancreatic b-cells, including expressing several transcription factors necessary for b-cell development and function. In addition, these cells synthesized and physiologically secreted insulin. Transplanting these differentiated cells into streptozotocin-induced immunodeficient diabetic mice led to the reversal of hyperglycemia, and more than 18% of the cells in the grafts expressed insulin at 6 weeks after transplantation. These data suggested that neonatal porcine liver-derived cells can be differentiated into functional insulin-producing cells under the culture conditions presented in this report and indicated that neonatal porcine liverderived cells (NPLCs) might be useful as a potential source of cells for b-cell replacement therapy in efforts to cure type I diabetes

    Food loss and waste: a carbon footprint too big to be ignored

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    Eight to ten percent of total global greenhouse gas emissions are associated with food loss and waste. Tackling the challenges of food loss and sustainable food waste management is key to fulfilling the Paris Agreement. However, among the Nationally Determined Contributions to the Paris Agreement, very few countries make references to food loss and waste. In this work, we reviewed the problem of food loss and waste from a global viewpoint and highlighted the opportunities of managing food loss and waste towards carbon mitigation and beyond. The importance of developing a coherent collaboration among all associated stakeholders was implied. Some recent policy developments and the impacts of COVID-19 pandemic are discussed followed by the summarization of potential solutions to tackling the fool loss and waste challenge

    Power Limiter with PIN Diode Embedded in Cavity to Minimize Parasitic Inductance

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    This letter introduces a power limiter that limits the input power to protect the receiver when a large power enters the radio frequency receiver. When the power limiter receives a large power signal, a positive-intrinsic-negative (PIN) diode is turned on to limit the input power by lowering the impedance. We analyzed the characteristics of the power limiter according to the method of connecting the PIN diode in parallel with the input and output transmission lines of the power limiter. By embedding a PIN diode into the cavity and minimizing the length of the wire, a power limiter was designed and implemented to minimize parasitic inductance. In the S-band, the proposed power limiter’s insertion loss was below 0.5 dB, and the reflection loss characteristics were below 15 dB. Furthermore, it achieved an output P1dB of 21.8 dBm at 3.5 GHz

    LTCC-Based DC-DC Converter for Reduction of Switching Noise and Radiated Emissions

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    In this study, a low-temperature co-fired ceramic (LTCC)-based direct current (DC)-DC converter is proposed for reducing stray inductance and mitigating electromagnetic interference. The dominant radiating loop of the proposed LTCC-based DC-DC converter features a multilayer design, which helps suppress noise sources and reduce radiated emissions. The peak voltage of switching noise for the proposed DC-DC converter at the frequency of 500 kHz is approximately 8.98% lower than that of a conventional DC-DC converter. In addition, the radiated emission level of the proposed DC-DC converter is lower than that of the conventional DC-DC converter. In sum, the proposed LTCC-technology-based multilayer design reduces the peak voltage of switching noise and the radiated emission of the DC-DC converter

    Measurement of 129 I Radioactivity in Groundwater of Radioactive Waste Disposal Site

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    The investigation of the environmental radioactivity around the radioactive waste disposal site in Gyeongju is being carried out. The radioactivity of 129 I in groundwater and seaweed are to be measured. The analytical method to measure the radioactivity of 129 I in aqueous media was established. This method contains oxidation-reduction reaction, anion-exchange separation and palladium precipitation. The 129 I radioactivity in the PdI 2 precipitates was measured by using low-energy gamma spectrometer. The counts of peak at 39.6 keV of gamma energy were used for determination of 129 I radioactivity. The chemical recovery was determined by the weights of PdI 2 precipitates. The deionized water and groundwater spiked with 129 I tracer were tested. In the case of deionized water, the relative deviations of measured concentration from spiked one are from 1.1 to 10.7%. The relative deviations of measured radioactivity from spiked one in the groundwater experiments are 2.9 and 3.7%. The measured concentration is in good agreement with spiked one. The groundwater sampled from radioactive waste disposal site was tested. The concentrations of 129 I in the groundwater are below minimum detectable activities of 36.7 and 36.6 mBq/L

    Breath analyzer for personalized monitoring of exercise-induced metabolic fat burning

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    Dionisio V. Del Orbe recibió su Licenciatura en Ingeniería Aeronáutica de la Universidad de Western Michigan (2012), EE. UU., y una Maestría en Ingeniería de Manufactura Microelectrónica del Instituto de Tecnología de Rochester (2015), EE. UU. Recibió su doctorado en Ingeniería Mecánica KAIST (2022), Corea del Sur, y trabajó como investigador de posgrado en el Departamento de Investigación de TIC Médicas y de Bienestar en ETRI, Corea del Sur. Su investigación se centra en sensores de gases químicos para diversas aplicaciones, especialmente, análisis de aliento y detección de gases tóxicos/inflamables; también tiene intereses en dispositivos portátiles y flexibles. Actualmente, es docente e investigador en UNAPEC, República Dominicana.Obesity increases the risk of chronic diseases, such as type 2 diabetes mellitus, dyslipidemia, and cardiovascular diseases. Simple anthropometric measurements have time limitations in reflecting short-term weight and body fat changes. Thus, for detecting, losing or maintaining weight in short term, it is desirable to develop portable/ compact devices to monitor exercise-induced fat burn in real time. Exhaled breath acetone and blood-borne β-hydroxybutyric acid (BOHB) are both correlated biomarkers of the metabolic fat burning process that takes place in the liver, predominantly post-exercise. Here, we have fabricated a compact breath analyzer for convenient, noninvasive and personalized estimation of fat burning in real time in a highly automated manner. The analyzer collects end-tidal breath in a standardized, user-friendly manner and it is equipped with an array of four low-power MEMS sensors for enhanced accuracy; this device presents a combination of required and desirable design features in modern portable/compact breath analyzers. We analyzed the exhaled breath (with our analyzer) and the blood samples (for BOHB) in 20 participants after exercise; we estimated the values of BOHB, as indication of the fat burn, resulting in Pearson coefficient r between the actual and predicted BOHB of 0.8. The estimation uses the responses from the sensor array in our analyzer and demographic and anthropo- metric information from the participants as inputs to a machine learning algorithm. The system and approach herein may help guide regular exercise for weight loss and its maintenance based on individuals’ own metabolic changes
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