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Silk-based nerve guidance conduits with macroscopic holes modulate the vascularization of regenerating rat sciatic nerve

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Neural Regeneration Research 2025年第6期20卷 1789-1800页

作者： Carina hromada Patrick heimel Markus Kerbl LászlóGál Sylvia Nürnberger Barbara Schaedl James Ferguson Nicole Swiadek Xavier Monforte Johannes C.heinzel Antal Nógrádi andreas h.Teuschl-Woller David hercher Department Life Science Engineering University of Applied Sciences Technikum WienViennaAustria Austrian Cluster for Tissue Regeneration ViennaAustria Ludwig Boltzmann Institute for Traumatology The Research Center in Cooperation with AUVAViennaAustria University Clinic of Dentistry Medical University of ViennaViennaAustria Department of Plastic Reconstructive and Aesthetic SurgeryLandesklinikum Wiener Neustadt2700 Wiener NeustadtAustria Department of Anatomy Histology and EmbryologyAlbert Szent-Györgyi Medical SchoolUniversity of SzegedSzegedHungary Medical University of Vienna Department of Orthopedics and Trauma SurgeryDevision of Trauma SurgeryViennaAustria Department of hand- PlasticReconstructive and Burn SurgeryBG Unfallklinik TuebingenUniversity of TuebingenTuebingenGermany

Peripheral nerve injuries induce a severe motor and sensory deficit. Since the availability of autologous nerve transplants for nerve repair is very limited, alternative treatment strategies are sought, including the use of tubular nerve guidance conduits(tNGCs). however, the use of tNGCs results in poor functional recovery and central necrosis of the regenerating tissue, which limits their application to short nerve lesion defects(typically shorter than 3 cm). Given the importance of vascularization in nerve regeneration, we hypothesized that enabling the growth of blood vessels from the surrounding tissue into the regenerating nerve within the tNGC would help eliminate necrotic processes and lead to improved regeneration. In this study, we reported the application of macroscopic holes into the tubular walls of silk-based tNGCs and compared the various features of these improved silk^(+) tNGCs with the tubes without holes(silk^(–) tNGCs) and autologous nerve transplants in an 8-mm sciatic nerve defect in rats. Using a combination of micro-computed tomography and histological analyses, we were able to prove that the use of silk^(+) tNGCs induced the growth of blood vessels from the adjacent tissue to the intraluminal neovascular formation. A significantly higher number of blood vessels in the silk^(+) group was found compared with autologous nerve transplants and silk^(–), accompanied by improved axon regeneration at the distal coaptation point compared with the silk^(–) tNGCs at 7 weeks postoperatively. In the 15-mm(critical size) sciatic nerve defect model, we again observed a distinct ingrowth of blood vessels through the tubular walls of silk^(+) tNGCs, but without improved functional recovery at 12 weeks postoperatively. Our data proves that macroporous tNGCs increase the vascular supply of regenerating nerves and facilitate improved axonal regeneration in a short-defect model but not in a critical-size defect model. This study suggests that further optimizatio

关键词： axon regeneration blood vessel functional recovery macroporous nerve lesion peripheral nerve repair sciatic nerve silk-based nerve guidance conduit vascularization

A DIFFUSION–TRANSPORT hYBRID METhOD FOR ACCELERATING OPTICAL TOMOGRAPhY

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Journal of Innovative Optical health Sciences 2010年第4期3卷 293-305页

作者： hYUN KEOL KIM andreas h.hIELSChER Department of Biomedical Engineering Columbia University New YorkNY 10027USA Department of Radiology Columbia University New YorkNY 10032USA Department of Electrical Engineering Columbia University New YorkNY 10027USA

It is well acknowledged that the equation of radiative transfer(ERT)provides an accurate prediction of light propagation in biological tissues,while the diffusion approximation(DA)is of limited accuracy for the transport ***,ERT-based reconstruction codes require much longer computation times as compared to DA-based reconstruction *** introduce here a computationally efficient algorithm,called a diffusion–transport hybrid solver,that makes use of the DA-or low-order ERT-based inverse solution as an initial guess for the full ERT-based reconstruction *** evaluate the performance of this hybrid method,we present extensive studies involving numerical tissue phantoms and experimental *** a result,we show that the hybrid method reduces the reconstruction time by a factor of up to 23,depending on the physical character of the problem.

关键词： Optical tomography reconstruction time radiative transfer equation

Update on the management of sigmoid diverticulitis

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World Journal of Gastroenterology 2021年第9期27卷 760-781页

作者： Mark h hanna andreas M Kaiser Division of Colorectal Surgery Department of SurgeryCity of Hope National Medical CenterDuarteCA 91010-3000United States

Diverticular disease and diverticulitis are the most common non-cancerous pathology of the *** has traditionally been considered a disease of the elderly and associated with cultural and dietary *** has been a growing evolution in our understanding and the treatment guidelines for this *** provide an updated review of the epidemiology,pathogenesis,classification and highlight changes in the medical and surgical management of *** is increasingly being seen in young patients(han previously *** similarities and overlap with inflammatory bowel disease and irritable bowel syndrome *** tomography imaging represents the standard to classify the severity of *** to the traditional hinchey classification might serve to better delineate mild and intermediate forms as well as better classify chronic presentations of ***-operative management is primarily based on antibiotics and supportive measures,but antibiotics may be omitted in mild *** colonoscopy remains advisable after an acute attack,particularly after a complicated *** surgery is needed for the most severe as well as refractory cases,whereas elective resections are individualized and should be considered for chronic,smoldering,or recurrent forms and respective complications(stricture,fistula,etc.)and for patients with factors highly predictive of recurrent *** is no longer a disease of the *** evolving understanding of diverticulitis as a clinical entity has led into a more nuanced approach in both the medical and surgical management of this common ***-surgical management remains the appropriate treatment for greater than 70%of *** individuals with non-relenting,persistent,or recurrent symptoms and those with complicated disease and sequelae,a segmental colectomy remains the most effec

关键词： Diverticulitis Epidemiology Antibiotics Surgical resection Laparoscopic lavage Classification

Structural Finite Element Software Coupling Using Adapter Elements

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Computer Modeling in Engineering & Sciences 2019年第9期120卷 719-737页

作者： andreas h.Schellenberg Yuli huang Stephen A.Mahin Senior Engineer Maffei Structural EngineeringSan FranciscoCA 94111USA Senior Structural Analyst ArupSan FranciscoCA 94111USA

This paper describes a versatile and computationally efficient method for coupling several finite element analysis(FEA)programs together so that the unique modeling and analysis capabilities of each code can be utilized simultaneously to simulate the static or dynamic response of a complete numerical *** arbitrary number of finite element analysis software packages can be coupled by adding two special types of elements,namely generic and adapter elements,to each of the finite element applications using their programming *** elements are inserted at the interfaces between the different sub-domains of the complete system modeled by each finite element analysis software *** of data between the coupled FEA codes is accomplished in a modular and synchronized manner using OpenFresco(Opensource Framework for Experimental Setup and Control).OpenFresco is an objectoriented,environment independent software framework initially developed for hybrid simulation in which certain aspects of a complete structure are simulated numerically and other aspects are simultaneously tested *** important practical advantage of this coupled analysis approach is that all of the connected FEA codes run concurrently and continuously,decreasing analysis time consumption by an order of magnitude or more compared to more traditional approaches that shut down and restart the coupled analysis codes at each integration time *** implementation and accuracy of this approach to FE software coupling are demonstrated using dynamic analyses of three simple structural models from the field of earthquake engineering.

关键词： Software coupling co-simulation adapter element OpenFresco

Simulation of microswimmer hydrodynamics with multiparticle collision dynamics

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Chinese Physics B 2020年第7期29卷 55-61页

作者： andreas Zottl Institute for Theoretical Physics TU WienWiedner Hauptstraße 8-101040 WienAustria

In this review we discuss the recent progress in the simulation of soft active matter systems and in particular the hydrodynamics of microswimmers using the method of multiparticle collision dynamics,which solves the hydrodynamic flows around active objects on a coarse-grained *** first present a brief overview of the basic simulation method and the coupling between microswimmers and *** then review the current achievements in simulating flexible and rigid microswimmers using multiparticle collision dynamics,and briefly conclude and discuss possible future directions.

关键词： active matter multiparticle collision dynamics microswimmers coarse-grained hydrodynamic simulations

Source-specific risk assessment for cadmium in wheat and maize:Towards an enrichment model for China

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Journal of Environmental Sciences 2023年第3期125卷 723-734页

作者： Zhong Zhuang Qiqi Wang Siyu huang Andrea Giovanna NinoSavala Yanan Wan huafen Li andreas h.Schweiger andreas Fangmeier Jürgen Franzaring Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation Key Laboratory of Plant-Soil Interactions of the Ministry of EducationCollege of Resources and Environmental SciencesChina Agricultural UniversityBeijing 100193China State Key Laboratory of North China Crop Improvement and Regulation Hebei Agricultural UniversityBaoding 071001China Institute of Landscape and Plant Ecology University of Hohenheim70599 StuttgartGermany

Cadmium (Cd) pollution of agricultural soil is of public concern due to its high potential toxicity and *** study aimed to reveal the risk of Cd accumulation in soil and wheat/maize systems,with a specific focus on the source-specific ecological risk,human health risk and Cd enrichment *** this we investigated more than 6100 paired soil and grain samples with 216 datasets including soil Cd contents,soil ph and grain Cd contents of 85 sites from *** results showed that mining activities,sewage irrigation,industrial activities and agricultural practices were the critical factors causing Cd accumulation in wheat and maize cultivated ***,mining activities contributed to a higher Cd accumulation risk in the southwest China and Middle Yellow River regions;sewage irrigation influenced the Cd accumulation in the North China *** addition,the investigated sites were classified into different categories by comparing their soil and grain Cd contents with the Chinese soil screening values and food safety values,*** enrichment models were developed to predict the Cd levels in wheat and maize *** results showed that the models exhibited a good performance for predicting the grain Cd contents among safe and warning sites of wheat (R2=0.61 and 0.72,respectively);while the well-fitted model for maize was prone to the overestimated sites (R2=0.77).This study will provide national viewpoints for the risk assessments and prediction of Cd accumulation in soil and wheat/maize systems.

关键词： Ecological risk Enrichment models Cadmium health risk assessment Pollution sources

Tunable structural colors on display

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Light(Science & Applications) 2022年第6期11卷 1036-1037页

作者： andreas Tittl Chair in hybrid Nanosystems Nanoinstitute MunichFaculty of PhysicsLudwig-Maximilians-Universitat MünchenKoniginstraβe 1080539 MünchenGermany

Structural coloration takes inspiration from the bright hues found in nature to control the reflection and transmission of light from artificially structured *** them with active electrical tuning heralds breakthrough... 详细信息

关键词： materials tuning breakthrough

Geoscience material structures prediction via CALYPSO methodology

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Chinese Physics B 2019年第10期28卷 38-49页

作者： andreas hermann Centre for Science at Extreme Conditions and SUPA School of Physics and Astronomy The University of Edinburgh

Many properties of planets such as their interior structure and thermal evolution depend on the high-pressure properties of their constituent materials. This paper reviews how crystal structure prediction methodology can help shed light on the transformations materials undergo at the extreme conditions inside planets. The discussion focuses on three areas:(i) the propensity of iron to form compounds with volatile elements at planetary core conditions(important to understand the chemical makeup of Earth's inner core),(ii) the chemistry of mixtures of planetary ices(relevant for the mantle regions of giant icy planets), and(iii) examples of mantle minerals. In all cases the abilities and current limitations of crystal structure prediction are discussed across a range of example studies.

关键词： crystal structure prediction core materials planetary ices hydrous minerals

Pressure induced stability: from pneumatic structures to Tensairity~

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Journal of Bionic Engineering 2004年第3期1卷 141-148页

作者： Rolf h. Luchsinger Mauro Pedretti andreas Reinhard Prospective Concepts ag Flughofstrasse 41 8152 Glattbrugg SwitzerlandAirlight Ltd. Via Croce 1 6710 Biasca Switzerland Prospective Concepts ag Flughofstrasse 41 8152 Glattbrugg Switzerland

Structural stabilization by a pressurized fluid is very common in nature, however hardly found in technology. Car tires, hot air balloons, airships and airhouses are among the few technical exceptions, which are stabilized by a compressed medium, typically air. Restricted by simple geometries and a very limited load bearing capacity these pneumatic structures could succeed only in very specialized applications. Nevertheless, prospective concepts ag has systematically investigated pneumatic structures during the last few years. As a major result, it was demonstrated that almost any shape can be made with pneumatic structures and that astonishing structures such as the pneumatic airplane Stingray can be realized even with low air pressure. On top of that, Airlight Ltd. in close collaboration with prospective concepts ag has recently developed the fundamental new structural concept Tensairity. The synergetic combination of an inflated structure with conventional structural elements such as cables and struts yields pneumatic light-weight structures with the load bearing capacity of steel girders. Thus, complex forms and high strength open up many new opportunities for pressure induced stability in technology. An overview of these recent developments is presented and the close relationship of pneumatic structures with biology is outlined.

关键词： pneumatic structures tensairity web technology aviation self-repairing membrane