technical note
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2022 ◽  
Vol 17 (1) ◽  
Author(s):  
Akihiko Hiyama ◽  
Taku Ukai ◽  
Satoshi Nomura ◽  
Masahiko Watanabe

Abstract Background The subcutaneous screw rod system, commonly known as the internal pelvic fixator (INFIX), is useful in managing unstable pelvic ring fractures. Conventional INFIX and transiliac–transsacral (TITS) screw techniques are performed using C-arm fluoroscopy. There have been problems with medical exposure and screw insertion accuracy with these techniques. This work describes new INFIX and TITS techniques using intraoperative computed tomography (CT) navigation and C-arm fluoroscopy for pelvic ring fracture. Methods A typical case is presented in this study. An 86-year-old woman suffered from an unstable pelvic ring fracture due to a fall from a height. INFIX and TITS screw fixation with intraoperative CT navigation were selected to optimize surgical invasiveness and proper implant placement. Results The patient was placed in a supine position on a Jackson table. An intraoperative CT navigation was imaged, and screws were inserted under the navigation. Postoperative X-rays and CT confirmed that the screw was inserted correctly. This technique was less invasive to the patient and had little radiation exposure to the surgeon. Rehabilitation of walking practice was started early after the surgery, and she was able to walk with the assistance of a walker by the time of transfer. Conclusions The technique employed in our case study has the cumulative advantages of safety, accuracy, and reduced radiation exposure, together with the inherent advantages of functional outcomes of previously reported INFIX and TITS screw techniques. Further experience with this approach will refine this technique to overcome its limitations and facilitate its wider use.


2022 ◽  
Author(s):  
Marius Møller Rokstad ◽  
Karel Antonie van Laarhoven

Abstract. Drinking water distribution networks form an essential part of modern-day critical infrastructure. Sectorizing a network into district metered areas is a key technique for pressure management and water loss reduction. Sectorizing an existing network from scratch is, however, an exceedingly complex design task that designs in a well-studied general mathematical problem. Numerical optimization techniques such as evolutionary algorithms can be used to search for near-optimal solutions to such problems, but doing so within a reasonable timeframe remains an ongoing challenge. In this work, we introduce two heuristic tricks that use information of the network structure and information of the operational requirements of the drinking water distribution network to modify the basic evolutionary algorithm used to solve the general problem. These techniques not only reduce the time required to find good solutions, but also ensure that these solutions better match the requirements of drinking water practice. Both techniques were demonstrated by applying them in the sectorization of the actual distribution network of a large city.


2022 ◽  
Vol 26 (1) ◽  
pp. 91-116
Author(s):  
Andreas Riedl ◽  
Yafei Li ◽  
Jon Eugster ◽  
Nina Buchmann ◽  
Werner Eugster

Abstract. Non-rainfall water (NRW), defined here as dew, hoar frost, fog, rime, and water vapour adsorption, might be a relevant water source for ecosystems, especially during summer drought periods. These water inputs are often not considered in ecohydrological studies, because water amounts of NRW events are rather small and therefore difficult to measure. Here we present a novel micro-lysimeter (ML) system and its application which allows us to quantify very small water inputs from NRW during rain-free periods with an unprecedented high accuracy of ±0.25 g, which corresponds to ±0.005 mm water input. This is possible with an improved ML design paired with individual ML calibrations in combination with high-frequency measurements at 3.3 Hz and an efficient low-pass filtering to reduce noise level. With a set of ancillary sensors, the ML system furthermore allows differentiation between different types of NRW inputs, i.e. dew, hoar frost, fog, rime, and the combinations among these, but also additional events when condensation on leaves is less probable, such as water vapour adsorption events. In addition, our ML system design allows one to minimize deviations from natural conditions in terms of canopy and soil temperatures, plant growth, and soil moisture. This is found to be a crucial aspect for obtaining realistic NRW measurements in short-statured grasslands. Soil temperatures were higher in the ML compared to the control, and thus further studies should focus on improving the thermal soil regime of ML. Our ML system has proven to be useful for high-accuracy, long-term measurements of NRW on short-statured vegetation-like grasslands. Measurements with the ML system at a field site in Switzerland showed that NRW input occurred frequently, with 127 events over 12 months with a total NRW input of 15.9 mm. Drainage-water flow of the ML was not measured, and therefore the NRW inputs might be conservative estimates. High average monthly NRW inputs were measured during summer months, suggesting a high ecohydrological relevance of NRW inputs for temperate grasslands.


2022 ◽  
Vol 17 (1) ◽  
Author(s):  
Sohil S. Desai ◽  
Ryan A. Nelson ◽  
Kayla C. Korbel ◽  
William N. Levine ◽  
Steven S. Goldberg

Abstract Background Anatomic total shoulder arthroplasty is typically performed through the deltopectoral approach followed by either a subscapularis tenotomy, tendon peel, or lesser tuberosity osteotomy to provide adequate exposure. These subscapularis-takedown methods have been associated with incomplete subscapularis healing, however, and as a result often lead to functional deficits and complications. Subscapularis-sparing approaches have been introduced to mitigate these complications, but thus far have either been limited to hemiarthroplasty or resulted in residual inferior humeral head osteophytes and humeral component size mismatch. The present technique demonstrates the possibility for surgeons to capitalize on the improved patient outcomes that are afforded by subscapularis-sparing approaches, while still utilizing the deltopectoral interval to perform a total glenohumeral joint arthroplasty. Methods This article describes in detail the placement of a stemless anatomic TSA with the use of angled glenoid instruments through a subscapularis-sparing deltopectoral approach. Postoperatively, patients are placed in a sling but are instructed to remove as tolerated, as early as the 1st postoperative week. Physical therapy is started at week 1 with a 4-phase progression. Conclusions This technique using a TSA system with a polyaxial glenoid reamer and angled pegs on the backside of the glenoid allows the potential for maintenance of the strong postoperative radiographic and patient-reported outcomes that are achieved using traditional TSA approaches, with the advantage of accelerated rehabilitation protocols and decreased risk of subscapularis insufficiency that result from the use of subscapularis-sparing approaches.


2022 ◽  
Author(s):  
Hanyue Zhou ◽  
Minsong Cao ◽  
Martin Ma ◽  
Stephanie Yoon ◽  
Amar Kishan ◽  
...  

Author(s):  
Daniel De-Liang Loh ◽  
Min Wei Chen ◽  
Jia Xu Lim ◽  
Nicole Chwee Har Keong ◽  
Ramez Wadie Kirollos

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