242 research outputs found

    A pseudospectral method for the simulation of 3-D ultrasonic and seismic waves in heterogeneous poroelastic borehole environments

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    We present a novel approach for the comprehensive, flexible and accurate simulation of poroelastic wave propagation in 3-D cylindrical coordinates. An important application of this method is the realistic modelling of complex seismic wave phenomena in fluid-filled boreholes, which represents a major, as of yet largely unresolved, problem in exploration geophysics. To this end, we consider a numerical mesh consisting of three concentric domains representing the borehole fluid in the centre followed by the mudcake and/or casing, and the surrounding porous formation. The spatial discretization is based on a Chebyshev expansion in the radial direction and Fourier expansions in the vertical and azimuthal directions as well as a Runge–Kutta integration scheme for the time evolution. Trigonometric interpolation and a domain decomposition method based on the method of characteristics are used to match the boundary conditions at the fluid/porous-solid and porous-solid/porous-solid interfaces as well as to reduce the number of gridpoints in the innermost domain for computational efficiency. We apply this novel modelling approach to the particularly challenging scenario of near-surface borehole environments. To this end, we compare 3-D heterogeneous and corresponding rotationally invariant simulations, assess the sensitivity of Stoneley waves to formation permeability in the presence of a casing and evaluate the effects of an excavation damage zone behind a casing on sonic log recordings. Our results indicate that only first arrival times of fast modes are reasonably well described by rotationally invariant approximations of 3-D heterogenous media. We also find that Stoneley waves are indeed remarkably sensitive to the average permeability behind a perforated PVC casing, and that the presence of an excavation damage zone behind a casing tends to dominate the overall signature of recorded seismograms

    PHP64 Reorganisation of Hospital Emergency Services: A Business Case for Quality Improvement

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    In Switzerland, emergency care has no gatekeeping system and emergency wards are increasingly overcrowded by walk-in patients. This leads to inefficient use of spezialised resources. Treatment costs are paid by public sources and, beyond some co-payment, reimbursed by health care insurances via tariffs. Given the problems above, a public hospital (Stadtspital Waid; Zurich; catchment population 180'000 people) reorganised its emergency service in 2008. A nurse led triage system and a General Practitioner-led emergency service was implemented beside the conventional emergency ward

    Living Rhythms: Movements Toward Health and Holiness

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    Human beings can honestly profess to believe what they do not believe. (Dallas Willard) Christians seek relational health apart from spiritual health and vice versa. The problem is one of belief that it is possible to live in intimate fellowship with the Lord while in broken or unhealthy other primary relationships. Jesus addressed the problem of compartmentalized thinking when one of the Pharisees asked him to identify the most important commandment (singular) in the Law. Jesus\u27 answer inextricably linked loving God with loving others in his response of not one but two commandments: You shall love the LORD your God with all your heart, and with all your soul, and with all your mind. This is the greatest and first commandment. And a second is like it: \u27You shall love your neighbor as yourself.\u27 On these two commandments hang all the law and the prophets. (Matthew 22: 36-40 [NRSV]) Compartmentalized spirituality and unhealthy relationships directly and negatively influence one another, preventing the goal of living in the fullness of abundant life in Christ. (John 10:10) Advocating core competencies of honesty, humility, and teachability provides a foundation for health and the starting point for spiritual growth

    Kann die 18F-FDG-PET/CT-Untersuchung die Panendoskopie zur Detektion von synchronen Zweitkarzinomen ersetzen?

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    Ziel der Arbeit war es, die Wertigkeit der 18F-FDG-PET/ CT-Untersuchung bezĂŒglich synchroner Zweitkarzinome im Vergleich mit der Panendoskopie beim initialen Staging zu untersuchen. 311 Patienten wurden mit beiden Untersuchungsmethoden abgeklĂ€rt. Als Referenz galt die zytologische, histologische und/oder klinische oder radiologische Untersuchung. Die PrĂ€valenz fĂŒr synchrone Zweitkarzinome betrug mit der Panendoskopie 4,5%, wĂ€hrend die PrĂ€valenz mittels PET/ CT-Untersuchung 6,1% betrug. Die SensitivitĂ€t fĂŒr die Panendoskopie betrug 74%, die SpezifitĂ€t 99,7%, der positiv prĂ€diktive Wert 93% und der negativ prĂ€diktive Wert 98%. Die SensitivitĂ€t fĂŒr die PET/CT-Untersuchung betrug 100%, die SpezifitĂ€t 95,7% der positiv prĂ€diktive Wert 59% und der negativ prĂ€diktive Wert 100%. Die PET/CT-Untersuchung scheint der Panendoskopie ĂŒberlegen zu sein. Bei bezĂŒglich synchroner Zweitkarzinome unauffĂ€lligem PET/CT kann die Panendoskopie auf die Endoskopie und Beurteilung des PrimĂ€rtumors beschrĂ€nkt werden kann. Aufgrund der hohen Kosten und der grossen Anzahl falsch positiver Resultate, welche durch das PET/CT generiert werden, empfehlen wir die DurchfĂŒhrung dieser Untersuchung nur bei fortgeschrittenen Tumoren mit der Frage nach Fernmetastasen. Die Panendoskopie bleibt weiterhin der Goldstandar

    Investigation of Different Library Preparation and Tissue of Origin Deconvolution Methods for Urine and Plasma cfDNA Methylome Analysis.

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    Methylation sequencing is a promising approach to infer the tissue of origin of cell-free DNA (cfDNA). In this study, a single- and a double-stranded library preparation approach were evaluated with respect to their technical biases when applied on cfDNA from plasma and urine. Additionally, tissue of origin (TOO) proportions were evaluated using two deconvolution methods. Sequencing cfDNA from urine using the double-stranded method resulted in a substantial within-read methylation bias and a lower global methylation (56.0% vs. 75.8%, p ≀ 0.0001) compared to plasma cfDNA, both of which were not observed with the single-stranded approach. Individual CpG site-based TOO deconvolution resulted in a significantly increased proportion of undetermined TOO with the double-stranded method (urine: 32.3% vs. 1.9%; plasma: 5.9% vs. 0.04%; p ≀ 0.0001), but no major differences in proportions of individual cell types. In contrast, fragment-level deconvolution led to multiple cell types, with significantly different TOO proportions between the two methods. This study thus outlines potential limitations of double-stranded library preparation for methylation analysis of cfDNA especially for urinary cfDNA. While the double-stranded method allows jagged end analysis in addition to TOO analysis, it leads to significant methylation bias in urinary cfDNA, which single-stranded methods can overcome

    Potential benefits of laparoscopic repair of duodenal atresia: Insights from a retrospective comparative study

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    Introduction: Congenital duodenal obstruction (CDO) repair can be performed open or laparoscopically. We aimed to determine the potential benefit of laparoscopic repair regarding tolerance of enteral feeding, postoperative pain, hospital stay, and complication rate. Materials and Methods: In a single-center retrospective cohort study, we compared neonates with isolated CDO operated open versus laparoscopically from 2010 to 2019. No transanastomotic tubes were used, and anastomoses were created in a side-to-side fashion in all cases. An early feeding policy is applied for all cases operated at our institution. Statistical comparison was performed using the Mann–Whitney's test or Fisher's exact test where appropriate. Results Forty-one patients analyzed were similar regarding body weight, gestational age, and proportion of patients with trisomy 21. Median follow-up was 21 months. Four (20%) out of 20 laparoscopic procedures started laparoscopically were converted to open. Comparing the 21 open with the 16 laparoscopically completed patients, median anesthetic duration was shorter by 18% in the open versus laparoscopic completed group (218 vs. 179 minutes, respectively; p = 0.025). Median postoperative time to full enteral feeds was shorter by 4 days in the first group (7 vs. 11 days, respectively; p = 0.028). In accordance, the median duration of parenteral nutrition (PN) was less than half in the laparoscopic completed compared with the open group (5 vs. 11.5 days, respectively; p = 0.031). Postoperative opioids were required for only half the duration in the laparoscopically completed group compared with open (2 vs. 4 days, respectively; p = 0.026). Outcomes such as length of stay, the occurrence of strictures or adhesions requiring reintervention, or line sepsis were similar in both groups. Conclusion: Patients undergoing laparoscopic CDO repair at our institution benefited from shorter time to full enteral feeds, and reduced the need for PN as well as postoperative pain medication

    Delivery of non-viral naked DNA vectors to liver in small weaned pigs by hydrodynamic retrograde intrabiliary injection

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    Hepatic gene therapy by delivering non-integrating therapeutic vectors in newborns remains challenging due to the risk of dilution and loss of efficacy in the growing liver. Previously we reported on hepatocyte transfection in piglets by intraportal injection of naked DNA vectors. Here, we established delivery of naked DNA vectors to target periportal hepatocytes in weaned pigs by hydrodynamic retrograde intrabiliary injection (HRII). The surgical procedure involved laparotomy and transient isolation of the liver. For vector delivery, a catheter was placed within the common bile duct by enterotomy. Under optimal conditions, no histological abnormalities were observed in liver tissue upon pressurized injections. The transfection of hepatocytes in all tested liver samples was observed with vectors expressing luciferase from a liver-specific promoter. However, vector copy number and luciferase expression were low compared to hydrodynamic intraportal injection. A 10-fold higher number of vector genomes and luciferase expression was observed in pigs using a non-integrating naked DNA vector with the potential for replication. In summary, the HRII application was less efficient (i.e., lower luciferase activity and vector copy numbers) than the intraportal delivery method but was significantly less distressful for the piglets and has the potential for injection (or re-injection) of vector DNA by endoscopic retrograde cholangiopancreatography

    Sub-100 nm-scale Aluminum Nanowires by Stencil Lithography: Fabrication and Characterization

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    We present the fabrication process and electrical characterization of sub-100 nm scale Al nanowires (NWs) fabricated by stencil lithography (SL). We use a stencil with sub- 100 nm wide nanoslits patterned by focused ion beam (FIB) milling. The stencil is aligned and clamped onto a substrate containing predefined electrical contacts. Then a 60 nm-thick layer of Aluminum (Al) is deposited through the stencil producing NWs with lengths of ~1, 2 and 5 Όm and widths down to 65 nm. The NWs show an ohmic behavior with values varying from 30 Ω up to 300 Ω, depending on the dimensions of the structures. We have extracted a resistivity for the Al NWs of ~10 x 10-8 Ωm. We also show that stencils can be cleaned and reused, proving that SL is a cost-efficient and scalable manufacturing method for the direct fabrication of metallic NWs on a full wafer scale
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