Restoration Of Shape Research Articles

Robotic harvesting of the occluded fruits with a precise shape and position reconstruction approach

AbstractOcclusion is one of the key factors affecting the success rate of vision‐based fruit‐picking robots. It is important to accurately locate and grasp the occluded fruit in field applications, However, there is yet no universal and effective solution. In this paper, a high‐precision estimation method of spatial geometric features of occluded targets based on deep learning and multisource images is presented, enabling the selective harvest robot to envision the whole target fruit as if its occlusions do not exist. First, RGB, depth and infrared images are acquired. And pixel‐level matched RGB‐D‐I fusion images are obtained by image registration. Second, aiming at the problem of detecting the occluded tomatoes in the greenhouse, an extended Mask‐RCNN network is designed to extract the target tomato. The target segmentation accuracy is improved by 7.6%. Then, for partially occluded tomatoes, a shape and position restoration method is used to recover the obscured tomato. This algorithm can extract tomato radius and centroid coordinates directly from the restored depth image. The mean Intersection over Union is 0.895, and the centroid position error is 0.62 mm for the occluded rate under 25% and the illuminance between 1 and 12 KLux. And hereby a dual‐arm robotic harvesting system is improved to achieve a picking time of 11 s per fruit, an average gripping accuracy of 8.21 mm, and an average picking success rate of 73.04%. The proposed approach realizes a high‐fidelity geometrics reconstruction instead of mere image style restoration, which endows the robot with the ability to see through obstacles in the field scenes and improves its operational success rate in its result.

Математический расчет и значение коэффициента восстановления формы грудной клетки при планировании торакопластики врожденной воронкообразной деформации грудной клетки

Актуальность. Врожденная воронкообразная деформация грудной клетки характеризуется разным по глубине и ширине западением грудины и передних отделов ребер. Формообразование, его прогнозирование, расчет деформированного состояния грудной клетки и их изучение при планировании торакопластики по D. Nuss по поводу этой патологии является важной проблемой ортопедии и торакальной хирургии. Цель работы — расчет коэффициента восстановления формы грудной клетки путем соотношения глубины воронкообразной деформации и размера грудной клетки во фронтальной плоскости до и после математического моделирования торакопластики по D. Nuss. Материалы и методы. Для оценки перемещений ребер в зависимости от глубины деформации грудной клетки h были построены две модели. Первая модель представляет собой плоскую раму на опорах, элементы которой состоят из хрящевых частей ребер и грудины. Для данной модели определялась зависимость усилия F, которое необходимо для исправления глубины деформации грудной клетки. Вторая модель представляет собой изогнутый стержень, моделирующий ребро, к одному из концов которого приложена опорная нагрузка, вычисленная при анализе первой модели. Для данной модели определялось перемещение точки фиксации пластины под действием заданного усилия. Для получения более точных результатов были проведены исследования методом конечных элементов на модели грудной клетки. Результаты. Моделировалась коррекция глубины воронкообразной деформации без фиксации пластины к ребрам. Была проведена оценка перемещений участков ребер в месте фиксации пластины при разной глубине воронкообразной деформации грудной клетки: h = 2–5 см. Анализ результатов расчета показал, что после коррекции глубины деформации грудной клетки происходит уменьшение ее размера во фронтальной плоскости. Так, при максимальной глубине деформации h = 5 см отклонение участков ребер в месте фиксации пластины произошло на 2,4 см. Выводы. Установлена зависимость между глубиной воронкообразной деформации и размером грудной клетки во фронтальной плоскости при моделировании новообразованной формы грудной клетки при торакопластике по D. Nuss. Математически рассчитан коэффициент восстановления формы грудной клетки, который составляет 2 (2∆=h), где h — глубина воронкообразной деформации. Практическое значение коэффициента заключается в том, что при планировании торакопластики и придании формы пластине расстояние между ее латеральными концами, которые соответствуют форме грудной клетки и прилегают к ребрам, перед коррекцией воронкообразной деформации необходимо уменьшить на 1/2 h, где h — глубина воронкообразной деформации, для полноценного прилегания к ребрам в послеоперационном периоде.

SOME ASPECTS OF RETRACTION THE GINGIVAL SULCUS

In order to achieve an optimal fit between the crown and the margin formed below the gingival margin, a good mapping of the space behind the margin is required. This can be accomplished in a variety of ways. At various stages, general dentists and prosthodontists apply gum retraction across the board on a daily basis. Gum retraction was first described in 1941 by Thompson. Today, a large assortment of retraction cords is presented on the material market. One of the main requirements forhigh-precision impressions is a clear display of the gingival sulcus around the abutment teeth. To obtain high-quality impressions, it is necessary to ensure the unimpeded position of the impression material in this area, which is ensured by retraction. With the generalized form of increased abrasion of the hard tissues of the teeth, all teeth or most of them are subject to restoration of the anatomical shape, therefore it is important to choose a retraction method that would not only allow obtaining ahigh-quality impression, but also minimize its negative effect. Since 1975, PubMed and Google Scholar have searched for studies on gingival tissue management prior to impression creation on fixed dentures. The conclusions were extracted and summarized by us. Gingival retraction methods are divided intomechanical, chemical or surgical types. This article discusses the various methods of gingival retraction for subsequent double-layer impressions.

Visualizing how inclusion of higher reciprocal space in SWAXS data analysis improves shape restoration of biomolecules: case of lysozyme

Query remains whether use of increased resolution data from X-ray scattering aids in better understanding of the dynamic shape of the biomolecule in solution? To address this, we acquired Small/Wide angle X-ray scattering (SWAXS) data in the q range of 0.008 − 1.72 Å−1 from dilute solutions of lysozyme (0.9 to 5 mg/ml). Samples lacked any interparticulate effect and datasets showed Bragg peaks at q∼0.325, 0.65 and 1.4 Å−1, as reported before by other authors. Considering an averaged profile, we estimated shape parameters and distance distribution profiles of interatomic vectors by gradually increasing input qmax value. Interestingly, use of higher resolution led to emergence of new peaks amongst smaller vectors. Deconvolution of these peaks provided positions of smaller peaks which correlated well with an earlier theoretical work. These peaks arise from secondary structures or due to non-uniform internal motions within the larger shape of this protein. Dummy residue modeling considering uniform density yielded model(s) with holes or cavities when considering higher q values implying limitations of this method. Employing normal mode calculations, we searched for better fitting model of lysozyme using differentially ranged SWAXS data and a crystal structure of lysozyme as starting structure. Comparison of refined models with structures from crystallography and NMR data showed that use of data till mid q region resulted in adjustments near the center of mass of starting structure, and inclusion of higher resolution induced pan-structure adjustments. We conclude that high resolution SWAXS data analysis provides additional dimension towards understanding biomolecular structural dynamics. Communicated by Ramaswamy H. Sarma

Less Invasive Treatment of 265 Intraarticular Calcaneal Fractures with An Interlocking Nail (C-nail)

Objectives: Less invasive restoration of joint congruity and calcaneal shape in displaced intra-articular calcaneal fractures via a sinus tarsi approach followed by minimally invasive internal fixation with an interlocking nail (C-nail) results in a low rate of soft-tissue complications and good outcomes. Design: Prospective case-control study. Setting: Regional Hospital Trauma Department Patients: A total of 265 calcaneal fractures were treated by using the C-nail between 2011 and 2018 at the Department of Traumatology at the Regional Hospital Pardubice. Intervention: The reduced joint surface was fixed with one or two screws with short thread. All other fragments were fixed after reduction with the C-Nail introduced through the tuberosity. The fragments were fixed with 7 interlocking screws passing through the nail. Main Outcome Measures: Patients were assessed for complications, restoration of Böhler angle, posterior facet reduction with postoperative computed tomography, and weight-bearing radiographs after 6 and 12 months. Results: Wound edge necrosis was seen in three cases (1.1%) and soft tissue infection was observed in one case (0.4%). Böhler’s angle was improved from 5.9° preoperatively to 32.1° postoperatively, measuring 27.6° after 12 months. Conclusions: Two hundred forty-nine patients (222 males and 27 females; mean age 47.3 years) with 265 calcaneal fractures were treated between 2011 and 2018 less-invasively. The sinus tarsi-approach with use of the C-nail shows low risk of infection due to high stability of the fixed fracture.

Large-scale open-source three-dimensional growth curves for clinical facial assessment and objective description of facial dysmorphism

Craniofacial dysmorphism is associated with thousands of genetic and environmental disorders. Delineation of salient facial characteristics can guide clinicians towards a correct clinical diagnosis and understanding the pathogenesis of the disorder. Abnormal facial shape might require craniofacial surgical intervention, with the restoration of normal shape an important surgical outcome. Facial anthropometric growth curves or standards of single inter-landmark measurements have traditionally supported assessments of normal and abnormal facial shape, for both clinical and research applications. However, these fail to capture the full complexity of facial shape. With the increasing availability of 3D photographs, methods of assessment that take advantage of the rich information contained in such images are needed. In this article we derive and present open-source three-dimensional (3D) growth curves of the human face. These are sequences of age and sex-specific expected 3D facial shapes and statistical models of the variation around the expected shape, derived from 5443 3D images. We demonstrate the use of these growth curves for assessing patients and show that they identify normal and abnormal facial morphology independent from age-specific facial features. 3D growth curves can facilitate use of state-of-the-art 3D facial shape assessment by the broader clinical and biomedical research community. This advance in phenotype description will support clinical diagnosis and the understanding of disease pathogenesis including genotype–phenotype relations.

Experimental agents to improve fracture healing: utilizing the WNT signaling pathway.

The process of bone healing largely recapitulates bone development in the embryo and ideally achieves complete restoration of bone shape and structure. However, because successful fracture healing requires tight interactions of numerous cell types and signaling molecules, any disruption of this highly coordinated processes can result in delayed healing or even non-union formation. The rate of fracture healing complications in orthopedic patients is reported to be 5-20%. Therefore, there is a need for new therapeutic strategies to improve fracture healing in patients with healing complications. One treatment strategy would include the easy and safe application of a pharmacological agent inducing osteoanabolic effects during fracture healing. One potential promising molecular target is the osteoanabolic WNT signaling pathway. This pathway plays an important role during embryonic bone development, homeostasis, mechanotransduction, development of osteoporosis and bone regeneration. This review focuses on preclinical studies targeting WNT signaling molecules to accelerate fracture healing. The three main investigated antagonists of the WNT signaling pathway, which can be blocked experimentally by antibodies, are Sclerostin, Dickkopf-1 and Midkine. Treating animals with antibodies against these proteins enhanced bone formation in the fracture callus. This indicates a therapeutic potential for these antibodies to accelerate fracture healing in patients with orthopedic complications.

Mechanical Bending and Modulation of Photoactuation Properties in a One-Dimensional Pb(II) Coordination Polymer

With emergent research on stimuli responsive materials, dynamic crystals are at the forefront of investigation. However, research on the mechanical properties of coordination polymers (CPs) is still in its infancy. Elastic deformation induced by pressure and photoactuation are rare occurrences in CPs, let alone their combination in a single CP. Here, we report a one-dimensional (1D) CP comprising PbBr2 chains with 3-fluoro-4’-styrylpyridine arms showing excellent elasticity and photomechanical properties. A slender crystal can be bent to make a circle and write different shapes with restoration of original shape upon removal of the applied force. In addition, photomechanical properties triggered by [2+2] cycloaddition of the olefinic ligand can be modulated easily by variation of the crystal sizes. Crystals with bigger width show destructive photosalient effects while the smaller ones show plastic deformation like bending, twisting, curling etc. upon UV irradiation. This example provides avenue for designing CPs for multi-stimuli responsive actuating properties.

Objective evaluation of orbito-zygomatic reconstruction with scapular tip free flaps to restore facial projection and orbital volume

BackgroundRestoring anatomical contour and position of the malar eminence and orbital rim following ablative mid-face procedures is critical in maintaining facial contour and orbit position. ObjectiveTo report our reconstructive approach using the scapular tip free-flap (STFF) for orbito-zygomatic defects, evaluating contour and overall shape restoration. MethodsThe study included 2 series: a clinical cohort of 15 consecutive patients who underwent an orbito-zygomatic reconstruction with a STFF and a cohort of 10 patients who had CT scan imaging but did not have orbito-zygomatic surgical resection or reconstruction. Using a 3D software, overall conformance (OC) and contour conformance (CC) with respect to the mirrored contralateral (clinical cohort) or native zygoma (preclinical cohort) were analyzed. Postoperative orbital volumes were also measured in the clinical cohort. Mean, median, root-mean-square (RMS), minimum and maximum measurements were obtained both for OC and CC. Conformance values of clinical and preclinical cohort were compared to objectively evaluate the quality of reconstruction in terms of orbito-zygomatic framework restoration (Mann-Whitney test). ResultsAll measurements for OC and CC between scapular tip and the zygoma showed no differences, both on the clinical (RMS: OC 3.29 mm vs CC 3.32 mm -p = NS-) and preclinical (RMS: OC 2.03 mm and CC 2.31 mm -p = NS-) cohorts. Moreover, there were no differences in post-operative orbital volumes in the clinical cohort. Clinical outcomes of the case-series are also reported. ConclusionThe STFF is highly effective in restoring facial projection and orbital volume in orbito-zygomatic reconstruction.

Restoration of the rotor grooves shape of an asynchronous motor according to the test results

Restoration of the rotor grooves shape of an asynchronous motor according to the test results

Designer Cranioplasty at Budget Prices: A Novel Use of 3D Printing Technology

Abstract Background Cranioplasty using synthetic materials for restoration of the exact shape of the skull has always remained a challenge until the development of 3D printing technology. However, the high-cost of available 3D printed implants limits their extensive use. Objectives To study the effectiveness of a low-cost, 3D-printed template for molding the polymethyl methacrylate (PMMA) (bone cement) in order to achieve exact contours of the skull specific to each patient. Materials and Methods 10 cranioplasties have been performed between July 2018 to December 2019 in a variety of craniotomy defects using bone cement flaps shaped using custom-made molds. The mold was 3D-printed and based on each patient’s CT images in digital imaging and communications in medicine (DICOM). Miniplates and screws were used to fix the flap. Postoperatively, clinical and radiological evaluation were done to assess patient satisfaction and accuracy of contour achieved. Results Patient satisfaction as well as accuracy of contouring, as seen on postoperative CT scans, were excellent. There were no notable complications on follow-up. Conclusion PMMA cranioplasty flap, contoured using a 3D-printed mold, is a very cost-effective alternative for restoration of skull contour for various craniotomy defects.Polymethyl methacrylate (PMMA) molded to form the exact shape of lost calvarium using 3D printed plastic templates is a smart and economical solution.

The Mechanical Fingerprint of Circulating Tumor Cells (CTCs) in Breast Cancer Patients.

Simple SummaryDetection of circulating tumor cells (CTCs) in the blood of cancer patients is a challenging issue, since they adapt to the biochemical and physical landscape of the bloodstream. We approached the issue of CTC identification on a biophysical level. For the first time, we recorded the mechanical deformation profiles of potential CTCs, which were isolated from the blood of breast cancer patients, at the force regime of the deforming blood flow. Mechanical fingerprints of CTCs were significantly different from healthy white blood cells. We used machine learning to further evaluate the differences and identify discrimination criteria. Our results suggest that mechanical characterization of CTCs at low forces is a promising path towards CTC detection.Circulating tumor cells (CTCs) are a potential predictive surrogate marker for disease monitoring. Due to the sparse knowledge about their phenotype and its changes during cancer progression and treatment response, CTC isolation remains challenging. Here we focused on the mechanical characterization of circulating non-hematopoietic cells from breast cancer patients to evaluate its utility for CTC detection. For proof of premise, we used healthy peripheral blood mononuclear cells (PBMCs), human MDA-MB 231 breast cancer cells and human HL-60 leukemia cells to create a CTC model system. For translational experiments CD45 negative cells—possible CTCs—were isolated from blood samples of patients with mamma carcinoma. Cells were mechanically characterized in the optical stretcher (OS). Active and passive cell mechanical data were related with physiological descriptors by a random forest (RF) classifier to identify cell type specific properties. Cancer cells were well distinguishable from PBMC in cell line tests. Analysis of clinical samples revealed that in PBMC the elliptic deformation was significantly increased compared to non-hematopoietic cells. Interestingly, non-hematopoietic cells showed significantly higher shape restoration. Based on Kelvin–Voigt modeling, the RF algorithm revealed that elliptic deformation and shape restoration were crucial parameters and that the OS discriminated non-hematopoietic cells from PBMC with an accuracy of 0.69, a sensitivity of 0.74, and specificity of 0.63. The CD45 negative cell population in the blood of breast cancer patients is mechanically distinguishable from healthy PBMC. Together with cell morphology, the mechanical fingerprint might be an appropriate tool for marker-free CTC detection.

Top-down and sideways: Herbivory and cross-ecosystem connectivity shape restoration success at the salt marsh-upland ecotone.

Wetland restoration provides remarkable opportunities to understand vegetation dynamics and to inform success of future projects through rigorous restoration experiments. Salt marsh restoration typically focuses on physical factors such as sediment dynamics and elevation. Despite many demonstrations of strong top-down effects on salt marshes, the potential for consumers to affect salt marsh restoration projects has rarely been quantified. Recently, major restoration projects at the Elkhorn Slough National Estuarine Research Reserve in central California, USA provided an opportunity to examine how herbivory influences restoration success. We quantified the strength of consumer effects by comparing caged to uncaged plantings, and compared effects among plant species and sites. We used camera traps to detect which herbivores were most common and how their abundance varied spatially. Beyond characterizing consumer effects, we also tested management strategies for reducing negative effects of herbivory at the restoration sites, including caging, mowing, and acoustic playbacks of predator sounds. We found extremely strong consumer effects at sites with extensive stands of exotic forbs upland of the high marsh; uncaged restoration plants suffered heavy herbivory and high mortality, while most caged plants survived. Brush rabbits (Sylvilagus bachmani) were by far the most frequent consumers of these high marsh plants. Our work thus provides the first evidence of mammal consumers affecting salt marsh restoration success. Mowing of tall exotic forb cover adjacent to the marsh at one restoration site greatly reduced consumption, and nearly all monitored plantings survived at a second restoration site where construction had temporarily eliminated upland cover. Playbacks of predator sounds did not significantly affect restoration plantings, but restoration efforts in marsh communities vulnerable to terrestrial herbivory may benefit from concurrent restoration of predator communities in the upland habitats surrounding the marsh. A landscape approach is thus critical for recognizing linkages between terrestrial and marine vegetation.

Custom-Made Zirconium Dioxide Implants for Craniofacial Bone Reconstruction.

Reconstruction of the facial skeleton is challenging for surgeons because of difficulties in proper shape restoration and maintenance of the proper long-term effect. ZrO2 implant application can be a solution with many advantages (e.g., osseointegration, stability, and radio-opaqueness) and lacks the disadvantages of other biomaterials (e.g., metalosis, radiotransparency, and no osseointegration) or autologous bone (e.g., morbidity, resorption, and low accuracy). We aimed to evaluate the possibility of using ZrO2 implants as a new application of this material for craniofacial bone defect reconstruction. First, osteoblast (skeleton-related cell) cytotoxicity and genotoxicity were determined in vitro by comparing ZrO2 implants and alumina particle air-abraded ZrO2 implants to the following: 1. a titanium alloy (standard material); 2. ultrahigh-molecular-weight polyethylene (a modern material used in orbital surgery); 3. a negative control (minimally cytotoxic or genotoxic agent action); 4. a positive control (maximally cytotoxic or genotoxic agent action). Next, 14 custom in vivo clinical ZrO2 implants were manufactured for post-traumatologic periorbital region reconstruction. The soft tissue position improvement in photogrammetry was recorded, and clinical follow-up was conducted at least 6 years postoperatively. All the investigated materials revealed no cytotoxicity. Alumina particle air-abraded ZrO2 implants showed genotoxicity compared to those without subjection to air abrasion ZrO2, which were not genotoxic. The 6-month and 6- to 8-year clinical results were aesthetic and stable. Skeleton reconstructions using osseointegrated, radio-opaque, personalized implants comprising ZrO2 material are the next option for craniofacial surgery.

APPLIANCE OF CAD / CAM MODELING IN PROSTHETICS OF BONE DEFECTS OF FACIAL BONES

The aim: Improving the ability to restore the shape and function of the bones of the maxillofacial area through the use of their own techniques. Materials and methods: Materials and methods: This research was carry out on the basis of the Department of Surgical Dentistry and Maxillofacial Surgery of Kharkov National Medical University in the Department of Head and Neck Surgery, Kharkov "Regional Clinical Hospital" (2018-2020 years). Examination and treatment of 26 patients, aged from 19 to 55 years, who needed reconstructive surgery to restore the anatomical shape, integrity and function of the maxilla or mandibular jaw. Results: All patients were treated according to the developed method (utility model patent № 145754 "Method of treating traumatic fractures of the maxillofacial area in adults using bone osteosynthesis 3D modeled titanium mini plates"), which consists in 3D modeling, based on previously performed computed tomography, and exploitation individually modeled titanium mini grids and titanium endoprostheses. The experience of this technique shown the advantage of the proposed method not only in the correction of traumatic defects, but also defects of the jaw bones that occur due to the removal of bulky neoplasms. Conclusions: Individual 3D simulated mini grids / plates and endoprostheses, according to the study provide maximum adaptation and restoration of anatomical shape, relief of jaws, their integrity and contour, provide prevention of pathological fractures by stabilizing residual bone tissue (titanium mini grids) serves as a carcass , provide prevention of prolapse (germination) of soft tissues in the area of postoperative bone defect (mini grid does not allow soft tissues to germinate in the area of postoperative bone defect on the outside), which improves functional and cosmetic results. Thus, our proposed method of osteosynthesis using 3D simulated titanium miniplates can be recommended for use in clinical practice.

Comparative Analysis of the Properties of Temporary Cement – An In Vitro Study

Introduction: Microbial eradication from the pulpal spaces plays a pivotal role in the success of endodontic treatment. The intricate internal tooth anatomy challenges the clinician at every instance - be it the cleaning, shaping, or complete restoration of the root canal system. Aim: To assess and compare sealing ability, water sorption and solubility of temporary restorative materials. Material and Method: Thirty extracted premolars were endodontically treated and restored with temporary restorations, 10 teeth in each group. The groups were - Cavit G, Zinconol, Coltosol F. Teeth were thermocycled and sectioned. Microleakage was tested with Methylene blue dye under stereomicroscope. For solubility and sorption analysis, disc-shaped specimens (10 each) were prepared and restored with temporary cements and divided into three groups, depending on the cement used. Specimens were stored in desiccator; dry mass (m1) was obtained. After storing in distilled water, mass after saturation (m2) and thereafter constant dry mass was obtained (m3). Water sorption and solubility was determined by prescribed formulas. Kruskal Wallis and Dunn’s Post-hoc test were used for microleakage. For water sorption and solubility Kolmogorov-Smirnov normality test, ANOVA and Tukey’s post hoc test were used. Result: Coltosol exhibited least microleakage followed by Cavit and Zinconol. Cavit exhibited maximum sorption and solubility, followed by Coltosol and Zinconol. Conclusion: Coltosol exhibited the least amount of microleakage compared to Cavit and Zinconol. It also demonstrated intermediate level of sorption and solubility. Hence it can be recommended for use as a temporary restorative material during endodontic treatment.

3D shape restoration of binocular structure light in small field of view based on image bundles

提出基于传像束传像和双目结构光相结合的三维测量系统，实现对无法直接成像场景，如爆轰、冲击等环境下的小视场物体三维面形测量。测量时，结构光直接投影到待测物体表面，变形条纹图像首先被成像到传像束前端面，再被传递到传像束后端面，并最终被成像到相机像平面，再由三频相位展开技术计算出对应相位分布后，即可根据双目匹配计算出待测物体高度。实验表明，传像束系统能完成高精度的微小物体三维形貌重建，且由于传像束的引入，增加了测量系统的灵活性。

Influence of Anisotropy on the Deformation of a Polymer Composite with Shape Memory

The influence of the orientation of the reinforcing fibers on the deformation and damage of the shape memory composite during bending and torsion, as well as the restoration of the initial shape of the sample upon activation of the shape memory effect (SME), has been studied. The composite is a three-layer carbon fiber impregnated with a shape memory polymer, the activating factor of which is temperature. The influence of fiber orientation on the formation of systems of irreversible structural defects in the process of shape fixation was revealed. The distribution of these defects determines the degree of shape recovery upon SME activation and the reproducibility of the original shape upon repeating the “shape fixation–recovery” cycles.

Mathematical and physical modeling shape memory polymer composites

In the article the influence of fiber orientation on the deformation character of specimens from composites with shape memory (EMC) under transverse and longitudinal bending is studied. Also, restoration of the initial configuration of the sample upon activation of the shape memory effect (SME) is considered. The effect of fiber orientation on the formation of systems of irreversible structural defects during molding is revealed. The degree of shape restoration upon SME implementation and the reproducibility of the original form upon repetition of the shape fixing-recovering cycles depend on these defects. Variants of a material model with linear hardening and a Voigt model for describing the shape memory effect in modeling the stages of molding and restoration are considered.

Effect of Nicotine on the Rat’s Tongue and the Possible Protective Role of Royal Jelly Light and Scanning Electron Microscopic Study

Background: nicotine (NIC) is an active substance in tobacco, the excessive use of tobacco products has been associated with various lesions in the oral cavity. Royal jelly (RJ) believed by many authors to be an anti-oxidant that protects different organs. Aim of the work: this study aimed to detect the effect of nicotine on the structure of the tongue and the possible protective effect of royal jelly. Materials and methods: 30 adult male rats were equally categorized into 3 groups. Group I: 10 rats used as the control group; Group II: 10 rats received nicotine sulphate 2 mg/kg subcutaneously daily for 4 weeks; Group III: 10 rats received nicotine as the previous group and royal jelly (100 mg/kg by intra-gastric tube daily) for 4 weeks. After 24 hrs of the last dose, the animals were dissected. Tongues were processed for the histological and scanning electron microscopic study.Results: group II revealed that the lingual dorsal surface was formedof irregularly and destructed papillae. Most of these papillae were thin with blunted or absent tips. Fungiform papillae showed destruction of their epithelium and ill-defined pores. Lamina propria showed depletion of the collagen fibers, skeletal muscle fibers revealed separations and destruction. Group III revealed restoration of the normal appearance at some regions and presence of nicotine effects at the others within light microscope and apparent restoration of the normal shape as seen within the electron microscope. Conclusion nicotine has harmful effects on the tongue and the addition of RJ can decrease these harmful effects, but not prevent it.