Global optimization of freeform support structures

Postojeći su arhitektonski projekti usmjereni konstrukcijama slobodnih i neodređenih oblika. Veza između onoga što se želi postići projektom i izrade predstavlja izazov kod izvedbe potporne konstrukcije koja je geometrijski održiva, a trebala bi zadovoljiti određene estetske, izvedbene, toplinske zahtjeve i one koji se odnose na čvrstoću. Kako bi se osigurao kontakt rubova dodirnih izolacijskih panela cijelom njihovom debljinom, rubovi moraju biti odrezani pod različitim kutovima što dovodi do razlika u visini vrhova kuta te razlika u položaju unutarnjih metalnih ploča izolacijskih panela. Osnovni cilj predstavljenog istraživanja je razvoj postupka optimizacije pomoću kojega će se postići minimalna razlika u visini spoja kod svih spojišta, uzimajući u obzir sve površine slobodnog oblika pojedinog arhitektonskog projekta. Da bi se nadoknadile zaostale razlike u visini spojeva predlaže se korištenje držača razmaka različitih debljina. Mreže uglavnom četverokutne strukture konusnih svojstava zahtijevaju optimizaciju visine vrhova kutova kako bi se kod svih greda postigle približno minimalne razlike u visini spojeva. U članku se razmatra globalna minimizacija razlika u visini spojeva na uzorku arhitektonskog projekta slobodnog oblika, s mrežom uglavnom četverokutne strukture s konusnim svojstvima. Usporedba razlika u visini spojeva prije i poslije optimizacije pokazuje znatno poboljšanje.The trends in current architectural design are leading towards structures with free and irregular forms. The connection between the design intent and the fabrication presents a challenge when creating a support structure that is geometrically viable and should possess certain aesthetics, fabricational, thermal and strength requirements. To ensure the contact of edges of neighborhood insulation panels along their thickness, their edges must be cut under different angles which cause the differences in vertex heights and further the differences of the positions of the inner metal sheets of the insulation panels. The main goal of the presented research is the development of the optimization procedure by which the minimal joint height differences will be achieved in all the joints, taking into account all free form surfaces of the individual architectural design. To compensate for the residual joint height differences the usage of spacers of different thicknesses is proposed. Quad-dominant meshes with conical properties require optimization of the vertex heights to align all beams at approximately minimal joint height differences. The paper considers global minimization of joint height differences for a sample of free form architectural design, meshed with quad-dominant mesh with conical properties. The comparison of the joint height differences before and after the optimization shows the substantial improvement

Cathepsins B, L and cystatin C in cyst fluid of ovarian tumors

Contains fulltext : 88032.pdf (publisher's version ) (Closed access)INTRODUCTION: In cancer, an extracellular and membrane bound localization of cathepsins contribute to the invasion of tumor cells at the basement membrane. METHODS: This is the first study that explored levels of cathepsins B (CatB), L (CatL) and their inhibitor cystatin C (CysC) in the cystic fluid (CF) of ovarian tumors (n = 110). RESULTS: CF contained considerable amounts of CatB, CatL and CysC. Remarkable differences in CatB and CatL and CysC CF levels were found between different histopathological tumor subtypes. Levels of CatB and CysC were significantly higher in CF of malignant serous tumors compared to those found in benign serous tumors (p = 0.010 and p = 0.001 respectively), whereas levels of CatL were significantly higher in CF of malignant mucinous tumors compared to those found in benign mucinous tumors (p = 0.035). CatB and CysC showed a strong correlation in the group of patients with malignant serous tumors (p < 0.001; R = 0.921) suggesting that the increase in CatB might be balanced by a corresponding increase in CysC. CONCLUSION: Further studies are warranted to investigate cathepsins as possible prognostic biomarkers for the aggressiveness of ovarian cancer.1 mei 201

Holistic spectroscopy: complete reconstruction of a wide-field, multiobject spectroscopic image using a photonic comb

The primary goal of Galactic archaeology is to learn about the origin of the Milky Way from the detailed chemistry and kinematics of millions of stars. Wide-field multifibre spectrographs are increasingly used to obtain spectral information for huge samples of stars. Some surveys (e.g. GALAH) are attempting to measure up to 30 separate elements per star. Stellar abundance spectroscopy is a subtle art that requires a very high degree of spectral uniformity across each of the fibres. However, wide-field spectrographs are notoriously non-uniform due to the fast output optics necessary to image many fibre outputs on to the detector. We show that precise spectroscopy is possible with such instruments across all fibres by employing a photonic comb – a device that produces uniformly spaced spots of light on the CCD to precisely map complex aberrations. Aberrations are parametrized by a set of orthogonal moments with ∼100 independent parameters. We then reproduce the observed image by convolving high-resolution spectral templates with measured aberrations as opposed to extracting the spectra from the observed image. Such a forward modelling approach also trivializes some spectroscopic reduction problems like fibre cross-talk, and reliably extracts spectra with a resolution ∼2.3 times above the nominal resolution of the instrument. Our rigorous treatment of optical aberrations also encourages a less conservative spectrograph design in the future

Towards real-time cardiovascular magnetic resonance guided transarterial CoreValve implantation: in vivo evaluation in swine

<p>Abstract</p> <p>Background</p> <p>Real-time cardiovascular magnetic resonance (rtCMR) is considered attractive for guiding TAVI. Owing to an unlimited scan plane orientation and an unsurpassed soft-tissue contrast with simultaneous device visualization, rtCMR is presumed to allow safe device navigation and to offer optimal orientation for precise axial positioning. We sought to evaluate the preclinical feasibility of rtCMR-guided transarterial aortic valve implatation (TAVI) using the nitinol-based Medtronic CoreValve bioprosthesis.</p> <p>Methods</p> <p>rtCMR-guided transfemoral (n = 2) and transsubclavian (n = 6) TAVI was performed in 8 swine using the original CoreValve prosthesis and a modified, CMR-compatible delivery catheter without ferromagnetic components.</p> <p>Results</p> <p>rtCMR using TrueFISP sequences provided reliable imaging guidance during TAVI, which was successful in 6 swine. One transfemoral attempt failed due to unsuccessful aortic arch passage and one pericardial tamponade with subsequent death occurred as a result of ventricular perforation by the device tip due to an operating error, this complication being detected without delay by rtCMR. rtCMR allowed for a detailed, simultaneous visualization of the delivery system with the mounted stent-valve and the surrounding anatomy, resulting in improved visualization during navigation through the vasculature, passage of the aortic valve, and during placement and deployment of the stent-valve. Post-interventional success could be confirmed using ECG-triggered time-resolved cine-TrueFISP and flow-sensitive phase-contrast sequences. Intended valve position was confirmed by ex-vivo histology.</p> <p>Conclusions</p> <p>Our study shows that rtCMR-guided TAVI using the commercial CoreValve prosthesis in conjunction with a modified delivery system is feasible in swine, allowing improved procedural guidance including immediate detection of complications and direct functional assessment with reduction of radiation and omission of contrast media.</p