900 research outputs found

    Validation of a patient-specific system for mandible-first bimaxillary surgery: ramus and implant positioning precision assessment and guide design comparison

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    In orthognathic surgery, the use of patient-specific osteosynthesis devices is a novel approach used to transfer the virtual surgical plan to the patient. The aim of this study is to analyse the quality of mandibular anatomy reproduction using a mandible-first mandibular-PSI guided procedure on 22 patients. Three different positioning guide designs were compared in terms of osteosynthesis plate positioning and mandibular anatomical outcome. PSIs and positioning guides were designed according to virtual surgical plan and 3D printed using biocompatible materials. A CBCT scan was performed 1 month after surgery and postoperative mandibular models were segmented for comparison against the surgical plan. A precision comparison was carried out among the three groups. Correlations between obtained rami and plates discrepancies and between planned rami displacements and obtained rami discrepancies were calculated. Intraoperatively, all PSIs were successfully applied. The procedure was found to be accurate in planned mandibular anatomy reproduction. Different guide designs did not differ in mandibular outcome precision. Plate positional discrepancies influenced the corresponding ramus position, mainly in roll angle and vertical translation. Ramus planned displacement was found to be a further potential source of inaccuracy, possibly due to osteosynthesis surface interference

    Collection, Storage and Protein Extraction Method of Gingival Crevicular Fluid for Proteomic Analysis

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    قد يعكس السائل اللثوي (GCF)  الأحداث المرتبطة بحركة الأسنان التقويمية. تم إجراء محاولات لتحديد المؤشرات الحيوية التي تعكس قوة تقويم الأسنان المثلى ، والعواقب غير المرغوب فيها (مثل ارتشاف الجذر) وطرق واساليب تسريع حركة الأسنان . ان الهدف من هذه الدراسة هوانشاء طريقة مثلى لتجميع وتخزين واستخلاص البروتين الكلي القياسي من السائل اللثوي من مواقع اللثة الصحية ظاهريا من مرضى تقويم الأسنان تتماشى مع الطرق المتطورة لتحديد وتشخيص البروتينات كمؤشرات حيوية. تضمنت الدراسة ثمانية عشر مريضًا اللذين يحتاجون إلى قلع كل من الضواحك الأولى للفك العلوي والتي تم تعيينها عشوائيًا لتسليط القوة إما للقوة الثقيلة (225 جم) أو القوة الخفيفة (25 جم) ، وتم جمع السائل اللثوي لفترات زمنية متعددة بعد ساعة واحدة ويوم واحد و 7 أيام و 14 يومًا و 21 يومًا و 28 يومًا من بدء التجربة. تم استخدام اشرطة لثوية لجمع السائل، اما محلول الفوسفات الملحي (PBS) لاستخلاص وانتزاع البروتينات من هذه الشرائط  بسرعة طرد مركزي تبلغ 10000 دورة في الدقيقة لمدة 5 دقائق وتخزينها عند -80 درجة مئوية. أجري اختبار برادفورد لتقدير تركيز البروتين ، ثم تم إجراء التحليل الكهربائي لهلام دوديسيل كبريتات الصوديوم (SDS-PAGE) لمعرفة درجة نقاء البروتينات في العينات التي تم جمعها وتم التحقق من صحة طريقة الجمع عن طريق النشاف المناعي الغربي لإنزيم اللعاب ألفا أميليز. أظهر بروتوكول الجمع والتخزين واستخلاص البروتين الحالي أفضل النتائج لاستخلاص البروتين ونقاوته مع مجموعة مثبتة خالية من التلوث باللعاب. وتوصلت الدراسة الى إن حجم السائل الصغير من المواقع الصحية ومشاكل التبخر لمثل هذا السائل الواعد يحفزنا على التحقيق في بروتوكول جديد يتيح الحفظ الأمثل لعينة السائل اللثوي وقد يعمل البروتوكول المتبع حاليًا كمرجع للدراسات البروتينية المستقبلية التي تبحث عن المؤشرات الحيوية لـسائل اللثوي في تشخيص ومراقبة حركة الأسنان التقويمية.Gingival crevicular fluid (GCF) may reflect the events associated with orthodontic tooth movement. Attempts have been conducted to identify biomarkers reflecting optimum orthodontic force, unwanted sequallea (i.e. root resorption) and accelerated tooth movement. The aim of the present study is to find out a standardized GCF collection, storage and total protein extraction method from apparently healthy gingival sites with orthodontics that is compatible with further high-throughput proteomics. Eighteen patients who required extractions of both maxillary first premolars were recruited in this study. These teeth were randomly assigned to either heavy (225g) or light force (25g), and their site specific GCF was collected at baseline and after 1hr, 1day, 7days, 14days, 21days and 28days post force application. Periostrips were used for GCF collection and subsequent phosphate buffered saline (PBS) was used for immediate protein elution with centrifugal speed of 10000rpm for 5min and stored at -80°C. Protein concentration was estimated using Bradford colorimetric assay. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) was carried out to resolve the purity of proteins in the collected samples and the method of collection was validated by western immuno-blotting of alpha amylase salivary enzyme. The current collection, storage and protein extraction protocol showed the best protein recovery and purity with validated collection free of salivary contamination. In conclusion, tiny GCF volume from healthy sites and evaporation issues of such promising non-invasive fluid motivate us to investigate a standardized protocol enabling optimal preservation of GCF sample and the currently followed protocol may serve as a reference for future proteomic studies searching for GCF biomarkers in diagnosing and monitoring orthodontic tooth movement

    A putative ATPase mediates RNA transcription and capping in a dsRNA virus.

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    mRNA transcription in dsRNA viruses is a highly regulated process but the mechanism of this regulation is not known. Here, by nucleoside triphosphatase (NTPase) assay and comparisons of six high-resolution (2.9-3.1 Å) cryo-electron microscopy structures of cytoplasmic polyhedrosis virus with bound ligands, we show that the large sub-domain of the guanylyltransferase (GTase) domain of the turret protein (TP) also has an ATP-binding site and is likely an ATPase. S-adenosyl-L-methionine (SAM) acts as a signal and binds the methylase-2 domain of TP to induce conformational change of the viral capsid, which in turn activates the putative ATPase. ATP binding/hydrolysis leads to an enlarged capsid for efficient mRNA synthesis, an open GTase domain for His217-mediated guanylyl transfer, and an open methylase-1 domain for SAM binding and methyl transfer. Taken together, our data support a role of the putative ATPase in mediating the activation of mRNA transcription and capping within the confines of the virus

    KNOWLEDGE AND DOCUMENTATION OF RENAISSANCE WORKS OF ART: THE REPLICA OF THE “ANNUNCIATION” BY BEATO ANGELICO

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    The Annunciation by Guido di Pietro from Mugello, known as Beato Angelico, is a wide tempera painting with some fine gold foil placed on a wooden support, today hosted at the Museum of the Basilica of Santa Maria delle Grazie, in San Giovanni Valdarno. On the occasion of the exhibition “Masaccio e Angelico. Dialogo sulla verità nella pittura”, the museum asked to the Department of Architecture at the University of Bologna to develop a digital high-resolution surrogate to favour deep investigations, to plan restoration and to simply tell the stories behind the artwork. Two tasks were accomplished: to let visitors discover the secrets in the painting and to let scholars study the artwork, to better understand the masterpiece. This paper introduces the outcomes of the research developed to digitize the Annunciation, following a dedicated pipeline developed to improve the fruition of its digital replica, originated from different input sources, and surrogating the user experience on the real object. This work presents a method for the 3D reconstruction of the surfaces based on different techniques for elements with different depth resolutions (i.e., the painting and the wooden frame) which combine photogrammetry and photometric stereo exploiting both procedures and pushing forward the boundaries of Gigapixel Imaging and photogrammetric-based 3D model representation

    Recognition of feature curves on 3D shapes using an algebraic approach to Hough transforms

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    Feature curves are largely adopted to highlight shape features, such as sharp lines, or to divide surfaces into meaningful segments, like convex or concave regions. Extracting these curves is not sufficient to convey prominent and meaningful information about a shape. We have first to separate the curves belonging to features from those caused by noise and then to select the lines, which describe non-trivial portions of a surface. The automatic detection of such features is crucial for the identification and/or annotation of relevant parts of a given shape. To do this, the Hough transform (HT) is a feature extraction technique widely used in image analysis, computer vision and digital image processing, while, for 3D shapes, the extraction of salient feature curves is still an open problem. Thanks to algebraic geometry concepts, the HT technique has been recently extended to include a vast class of algebraic curves, thus proving to be a competitive tool for yielding an explicit representation of the diverse feature lines equations. In the paper, for the first time we apply this novel extension of the HT technique to the realm of 3D shapes in order to identify and localize semantic features like patterns, decorations or anatomical details on 3D objects (both complete and fragments), even in the case of features partially damaged or incomplete. The method recognizes various features, possibly compound, and it selects the most suitable feature profiles among families of algebraic curves

    NEW VALIDATED METHOD DEVELOPMENT FOR THE ESTIMATION OF SULFAMETHOXAZOLE AND TRIMETHOPRIM IN BULK FORM BY VISIBLE SPECTROSCOPY

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    Objective: To develop three novel, sensitive, simple validated visible spectrophotometric methods for the quantitative estimation of sulfamethoxazole (SMZ) and trimethoprim (TMP) in bulk form. Methods: Methods were based on coupling the diazotized aromatic primary amino group of the studied drugs with o-phenylenediamine (OPD) in an acidic medium. The first two methods have been proposed for estimation of SMZ and rest for TMP. The resulting products were measured by spectrophotometric (method I, II and III) tools. The methods were validated as per ICH guidelines. Results: In method I, the absorbance was measured at 482 and 457 nm with linearity ranges of 4.0-40.0 and 5.0-45.0 µg/ml for SMZ. On the other hand, method III was devoted to estimate TMP spectrophotometrically at 457 nm with linearity range of 5-30 μg/ml. The r2 value for all methods were found to be 0.99. The percentage recoveries of SMZ and TMP were found to be 97.98%, 97.56% and 97.55% respectively. The developed methods were subjected to detailed validation procedure in their pure forms. Conclusion: The study concludes that visible spectrophotometric validation methods can be very efficient and economically promising technique for the quantitative analysis of SMZ and TMP in bulk form. The statistical analysis of data indicates that the developed methods were reproducible and specific. It was found that there is a good agreement between the obtained results and those obtained by the reported methods; moreover they can be used for the routine estimations of SMZ and TMP in bulk form

    The Houses of the Salt Workers in Cervia

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    The "houses of the salt workers" in Cervia, Italy, are an 18th-century town planning marvel commissioned by the Apostolic Chamber. These buildings, shaped like a bastioned quadrilateral, house salt workers and their families. Despite some deterioration, they maintain their unique charm. They consist of a basement, two above-ground floors, and a spacious attic, with and without courtyards The conservation project, based on drawings produced following a photogrammetric survey, focuses on preserving the original typology, structure, and materials. This includes reconstructing load-bearing walls, reorganizing façade openings, restoring old brick skirting, and enhancing characteristic arches. This complex holds significant architectural and urbanistic importance as one of Italy's few foundation city examples

    The Appearance of Platelet-Polymer Composite Coatings: Microstructural Characterization, Hybrid Modeling, and Predictive Design.

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    The appearance of a platelet-containing polymer composite coating is governed by the microstructure and optical properties included scattering particles and platelets. Many models attempt to predict the coating's appearance, but do not utilize the complete 3D-microstructure, reducing their predictive utility. In this thesis, laser scanning confocal microscopy was used to measure the effect of platelet orientation on angle-dependent lightness, and quantify the spacing between platelets, from which a new microstructural property, the gap factor, was determined. The gap factor is a measure of the average gap size between platelets per unit material surface length. It ranged from 0 to 2 for the systems studied in this thesis. An increase in gap factor of about 0.1, keeping the orientation similar, reduced the near-specular lightness of the physical samples by more than 20%. A 3D hybrid-simulation was created using wave-optics to simulate the bidirectional-reflection-distribution-function (BRDF) for individual platelets. This was combined with ray-tracing to quantify the scattering behavior of a platelet array. This model more accurately predicted the lightness of a silver paint sample than an orientation-based microfacet-model, and was used to study how the surface roughness of the platelets influences lightness. The lightness at 15 degrees off-specular was about 130 when the root-mean square of the amplitude of the roughness, sigma(RMS), was much less than the wavelength of light. Lightness reduced to about 80 when sigma(RMS) was about equal to the wavelength of light. This effect of sigma(RMS) on lightness was found to be more significant with decreases in the roughness correlation length. The hybrid model was also used to study how width, thickness, and volume concentration of the platelets change the near-specular and backscattered lightness. The observed reduction in near-specular lightness with gap factor was verified. However, the resultant 2nd-order exponential decay was weaker than observed. This was attributed wave-scattering by faces and edges, behavior not included in the current model, but may be added in the future. This hybrid model can be used in the future to design unique microstructures to produce new and novel visual or functional effects using manufacturing techniques such as 3D-printing.PhDMaterials Science and EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/133404/1/cseubert_1.pd

    Durability tests on lime-based mortars from the historic built heritage of Catania (Eastern Sicily, Italy): An experimental study

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    Supplementary data to this article can be found online at https://doi.org/10.1016/j.jobe.2023.108137Mortars, like any other natural and artificial stone materials, are subject to atmospheric weathering agents which affect their durability according to the intrinsic characteristics of the material, such as mineralogical composition, texture and pore structure. This paper aims to investigate the physical-chemical durability of lime-based mortars made with two different volcanic aggregates, locally known as azolo and ghiara, peculiar of the historic built heritage of Catania (Eastern Sicily, Italy). An experimental approach has been used, based on the reproduction in laboratory of historic mortars by using ancient recipes. The experimental samples have been characterized from a physical point of view and then subject to accelerated aging tests. Specifically, the samples have undergone: i) mineralogical investigations through X-ray diffraction (XRD); ii) thin section analysis by polarized optical microscopy; iii) pore structure analysis through mercury intrusion porosimetry (MIP); iii) water absorption by capillarity; iii) water vapor permeability test; iv) accelerated aging test by salt crystallization; v) decay by sulfur dioxide. Results obtained highlight that the higher microporosity which characterizes the ghiara mortars is certainly responsible for their greater water absorption by capillarity as well as for their lower resistance to salt crystallization and exposure to sulfur dioxide, with respect to azolo-based ones.PNRR project PE5 “CHANGES - Cultural Heritage Active Innovation for Sustainable Society” – Spoke 5 (CUP E63C22001960006)EU-funded PON REACT project (CUP E65F21002200005)RNM 179 of the Junta de Andalucía (Spain

    Illuminant metamerism on artistic paintings = Metamerija uvjetovana promjenom osvjetljenja u slikarstvu

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    Metamerija uvjetovana promjenom osvjetljenja sve se više koristi u različitim područjima kao što su znanosti o boji, tisku, pakiranju, vizualnoj percepciji, slikarstvu, muzejima itd. Kada se promatraju umjetničke slike metamerija se odnosi na pojavu u kojoj se čini da se različiti pigmenti ili kombinacije pigmenata podudaraju pod istim izvorom svjetlosti ali pokazuju primjetnu razliku u boji kada se gledaju pod drugim izvorom svjetla. U kontekstu umjetničkih slika, pigmenti se sastoje od različitih kemijskih spojeva koji apsorbiraju i reflektiraju specifične valne duljine svjetlosti i mogu imati različita spektralna svojstva i interakcije s uvjetima osvjetljenja, utječući na vidni sustav i percepciju boje. Karakteriziranje spektralnih karakteristika različitih boja i otisaka putem kolorimetrijskih mjerenja igra ključnu ulogu u kvantificiranju i analizi metamerije uvjetovane promjenom osvjetljenja usporedbom razlika u boji između različitih izvora svjetlosti. Ovaj doktorski rad fokusirao se na fenomen metamerije uvjetovane promjenom osvjetljenja u kontekstu umjetničkih slika izloženih različitim izvorima osvjetljenja. Sveobuhvatni cilj bio je pronaći optimalan izvor svjetlosti koji ublažava perceptivne nepravilnosti i poboljšava prosječnu vizualnu percepciju. Središnja hipoteza ove teze je da prisutnost metamerije uvjetovane promjenom osvjetljenja na slikama ovisi o specifičnim tehnikama slikanja koje se koriste. Istraživanje metamerije uvjetovane promjenom osvjetljenja dalo je uvjerljive rezultate, nedvosmisleno utvrđujući da različite tehnike slikanja daju različit izgled pod različitim uvjetima osvjetljenja, potvrđujući ideju da metamerija uvjetovana promjenom osvjetljenja igra ključnu ulogu u doživljaju umjetničkih slika. Nadalje, važno otkriće leži u učinkovitosti standardizirane LED rasvjete u ublažavanju manifestacije metamerije uvjetovane promjenom osvjetljenja, posebno kada je karakterizirana dobro definiranom spektralnom distribucijom. Glavni cilj ovoga rada usmjeren je na optimizaciju uvjeta osvjetljenja kako bi se smanjile varijacije na slikama. Postalo je očito da se kvantifikacija razlike doživljaja boja temelji na temelju razlike u boji ∆E, što dovodi do upotrebe indeksa metamerije (MI) za definiranje perceptivnih nijansi metamerije uvjetovane promjenom osvjetljenja unutar domene promatranja umjetničkih djela rađenih različitim tehnikama. U okviru ove disertacije provedeno je istraživanje kako bi se pronašle mogućnosti smanjenja metamerije uvjetovane promjenom osvjetljenja u različitim slikarskim tehnikama, standardizirala i smanjila metamerija uvjetovana promjenom osvjetljenja u percepciji slika. Korištenjem visokokvalitetnog procesa ispisa koji može točno reproducirati boje, primijenjenaje kalibracija pisača kako bi se osigurala vjernost i dosljednost boja. Ispis probnih uzoraka rađen je na mat papiru koji pomoći smanjuje refleksiji i pruža bolju percepciju sa smanjenim udjelom sjajnosti materijala. Ovo istraživanje definira usporedbu slika sa sličnim motivom i uzorkom višebojne reprodukcije, pružajući uvid u to kako ljudi percipiraju boju i doživljavaju veličinu metamerije uvjetovane promjenom osvjetljenja pod standardiziranim uvjetima različitih izvora svjetlosti: LED svjetlo 3000K, 4000K, 6500K, Wolfram svjetlo i halogeno svjetlo, odnosno pod njihovom spektralnom distribucijom snage (SPD). Zadatak ove disertacije bio je pronaći znanstvenu povezanost između metamerije uvjetovane promjenom osvjetljenja na slikama rađenim različitim slikarskim tehnikama, kao što su tempera, ulje, akril, pastel i akvarel. Proučavanje metamerije uvjetovane promjenom osvjetljenja na umjetničkim slikama provedeno je objektivnim i subjektivnim istraživanjem, pri čemu standardizirani promatrači procjenjuju podudarnosti ili razlike boja pod različitim izvorima svjetlosti. Koristeći takve modele, može se predvidjeti kako će slika izgledati pod različitim uvjetima osvjetljenja i bolje razumjeti čimbenike koji doprinose smanjenju metamerije uvjetovane promjenom osvjetljenja. Umjetničke slike, koje su primjeri sinteze različitih kemijskih spojeva, karakteriziraju pigmenti koji selektivno apsorbiraju i reflektiraju određene valne duljine svjetlosti. Odabir suptraktivnih boja s izvorne slike, predisponiranih metameriji uvjetovanoj promjenom osvjetljenja, stvara različite spektralne vrijednosti koji su u interakciji s različitim osvjetljenjima. Time se izrazito utječe na vizualni sustav, na razumijevanje doživljaja boja i manifestaciju metamerije uvjetovane promjenom osvjetljenja. Jedinstvene karakteristike pigmenta, povezane s različitim tehnikama slikanja, daju male razlike u refleksiji svjetlosti u usporedbi s ljudskim vizualnim sustavom boja. U biti, zagonetka metamerije uvjetovane promjenom osvjetljenja nalazi se unutar domene percepcije boja, zamršenog aspekta koji uvijek može stovoriti problem u doživljaju boja kod promatrača. Iako je procjena metamerije uvjetovane promjenom osvjetljenja unutar jednotonskih boja relativno jednostavna, procjena višetonskih slika pod različitim svjetlosnim uvjetima zahtjeva uspostavljanje objektivnog mjerenja koja može kvantificirati razlike u bojama.Ovo je istraživanje potkrijepilo je izvedivost mjerenja metamerije uvjetovane promjenom osvjetljenja kod višebojnih slika analizom polja balansa sive boje, precizno reproduciranog putem empirijski testiranih uzoraka. Razlike koje se mogu uočiti unutar polja sivog balansa podložne su kvantificiranju, čime se sažima bit metamerije uvjetovane promjenom osvjetljenja putem indeksa metamerije. Kako su se u radu istraživale različite slikarske tehnike u kombinaciji s raznim izvorima osvjetljenja, u radu je ustanovljeno da ljudi različite tehnike drugačije percipiraju kod različitihizvora osvjetljenja. Tako je ustanovljeno da se kod slika koje su rađene temperom metamerija uvjetovana promjenom osvjetljenja najmanji kada se koriste izvori osvjeteljanje s temperaturom boje u korelaciji (CCT) u rasponu od 3000K do 4000K. Kod ulja na platnu, najmanja metamerija uvjetovana promjenom osvjetljenja dogodio se kod temperature boje u korelaciji između 2700K i 4000K. Međutim ono što je ustanovljeno je također da kod ulja na platnu ljudi vide boje različitije, odnosno veća je dispergiranost promatrača i to prvenstveno u dijelu doživljaja razlike u svjetlini. Kod slika rađenih tehnikom akrila pokazalo se se da je metamerija uvjetovana promjenom osvjetljenja najmanji kada se koriste hladnije boje i to prvenstveno kod halogenog svjetla koje ima takvu spektralnu refleksiju. Kod ove tehnike je također ustanovljeno da ljudi radi navedene temperature boje u korelaciji bolje percipiraju boje koje su toplije, odnosno kod hladnijih boja došlo je do smanjene metamerije upravo radi interakcije s temperaturom boje svjetlosti. Kod akvarela je ustanovljeno da da se boje relativno jednako percipiraju u rasponu temperature boje u korelaciji od 2700K - 4000K, međutim, primjećeno je da se plave nijanse na takvim slikama manje percipiraju u navedenoj temperaturi boje u korelaciji, pa se ustanovilo da je za navedenu tehniku bolje osvjeteljenje hladnijeg izvora osvjetljenja s temperaturom boje u korelaciji od 6500 K. U kontekstu pastelnih umjetničkih djela, iako je najbolji raspon za najmanju metameriju uvjetovaua promjenom osvjetljenja, ustanovljeno je da se kod žutih tonaliteta ipak ustanovila manja metamerija uvjetovana promjenom osvjeteljnja, s tim da treba uzeti u obzir i različite izvore svjetlosti koji pokazuju drugačiji indeks metamerije u navedenom rasponu, što je detaljno objašnjeno u zaključcima disertacije
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