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Showing papers by "Hai phong University Of Medicine and Pharmacy published in 2016"


Journal ArticleDOI
TL;DR: The low cytotoxicity allele LNK was significantly associated with increased cancer susceptibility and the LNK allele was more efficiently targeted by miR-1245 and thus determined lower NKG2D expression in NK cells with the L NK genotype.
Abstract: Human papillomavirus (HPV) is the most common sexually transmitted agent worldwide and is etiologically linked to several cancers, including cervical and genital cancers. NKG2D, an activating receptor expressed by NK cells, plays an important role in cancer immune-surveillance. We analyzed the impact of a NKG2D gene variant, rs1049174, on the incidence of HPV-related cancers in Vietnamese patients and utilized various molecular approaches to elucidate the mechanisms of NKG2D receptor regulation by rs1049174. In a group of 123 patients with HPV+ anogenital cancers, the low cytotoxicity allele LNK was significantly associated with increased cancer susceptibility (p = 0.016). Similar results were also observed in a group of 153 women with cervical cancer (p = 0.05). In functional studies, NK cells from individuals with LNK genotype showed a lower NKG2D expression and displayed less efficient NKG2D-mediated functions than NK cells with HNK genotype. Notably, the rs1049174 variant occurs within a targeting site for miR-1245, a negative regulator of NKG2D expression. Compared with the higher cytotoxicity allele HNK, the LNK allele was more efficiently targeted by miR-1245 and thus determined lower NKG2D expression in NK cells with the LNK genotype. The NKG2D variants may influence cancer immunosurveillance and thus determine susceptibility to various malignancies, including HPV-induced cancers.

42 citations


Book ChapterDOI
01 Jan 2016
TL;DR: The Finite Element Method (FEM) is used to obtain the diagrams and the maximum values of von Mises stress and displacements for healthy knee, for the three studied cases of OA knee, orthotic devices-assemblies and for orthotic device—OA knee assemblies.
Abstract: The first aim of this paper is the development of a virtual model of a new orthotic device, starting from an existent orthotic device, currently used in knee rehabilitation and from the virtual models developed for healthy knee joint and for the knee joint affected by osteoarthritis (OA) disease with varus inclination of 5°, 10°, 15°. The second aim consists in the obtaining of stress and displacements using numerical simulations for healthy knee joint, for knee joint affected by osteoarthritis (OA) and for orthotic device—OA knee assemblies. The Finite Element Method (FEM) is used to obtain the diagrams and the maximum values of von Mises stress and displacements for healthy knee, for the three studied cases of OA knee, orthotic devices-assemblies. These values are extracted and compared. Finally, an experimental study is provided in order to compare the range of motion and the amplitude of the flexion-extension knees of a five patients group with OA knees with and without orthosis, and to mark out the advantages of the proposed orthotic device.

32 citations


Journal ArticleDOI
TL;DR: It is suggested that integrating large-scale RDS and strong peer support may provide a method for rapidly linking high-risk PWID to combined prevention and care, and greatly reducing HIV transmission among PWID in resource-limited settings.
Abstract: Combined prevention for HIV among persons who inject drugs (PWID) has led to greatly reduced HIV transmission among PWID in many high-income settings, but these successes have not yet been replicated in resource-limited settings. Haiphong, Vietnam experienced a large HIV epidemic among PWID, with 68% prevalence in 2006. Haiphong has implemented needle/syringe programs, methadone maintenance treatment (MMT), and anti-retroviral treatment (ART), but there is an urgent need to identify high-risk PWID and link them to services. We examined integration of respondent-driven sampling (RDS) and strong peer support groups as a mechanism for identifying high-risk PWID and linking them to services. The peer support staff performed the key tasks that required building and maintaining trust with the participants, including recruiting the RDS seeds, greeting and registering participants at the research site, taking electronic copies of participant fingerprints (to prevent multiple participation in the study), and conducting urinalyses. A 6-month cohort study with 250 participants followed the RDS cross-sectional study. The peer support staff maintained contact with these participants, tracking them if they missed appointments, and providing assistance in accessing methadone and ART. The RDS recruitment was quite rapid, with 603 participants recruited in three weeks. HIV prevalence was 25%, Hepatitis C (HCV) prevalence 67%, and participants reported an average of 2.7 heroin injections per day. Retention in the cohort study was high, with 86% of participants re-interviewed at 6-month follow-up. Assistance in accessing services led to half of the participants in need of methadone enrolled in methadone clinics, and half of HIV-positive participants in need of ART enrolled in HIV clinics by the 6-month follow-up. This study suggests that integrating large-scale RDS and strong peer support may provide a method for rapidly linking high-risk PWID to combined prevention and care, and greatly reducing HIV transmission among PWID in resource-limited settings.

29 citations


Journal ArticleDOI
TL;DR: Compared to CCT, MMT is both less expensive and more effective in achieving drug-free days and could be a cost-saving strategy for reducing illicit drug use among heroin dependent individuals in Vietnam.

26 citations


Journal ArticleDOI
TL;DR: The current HIV epidemic among PWID in Haiphong is in a declining phase, but estimated incidence among non-MSM new injectors is approximately 1/100 person-years and there is a substantial gap in provision of ART for HIV seropositives.

24 citations


Journal ArticleDOI
TL;DR: A simple and uncomplicated in-house protocol for removal of human DNA from blood sepsis samples as a pre-analytical tool to prepare DNA for subsequent PCR assays is reported.
Abstract: Blood cultures are commonly employed to identify bacterial pathogens causing sepsis. PCR assays to diagnose septicemia require extraction of bacterial DNA from blood samples and thus, delay the initiation of appropriate antimicrobial treatment. The presence of abundant human DNA may hamper the sensitivity of PCR in the detection of bacteria. We used serial dilutions of E. Coli spiked pseudo-blood-sepsis samples to develop a simple method that combines the use of a polar detergent solvent and adjustment of the basic pH to remove human DNA. A 16S rRNA gene-based screening algorithm was established to differentiate Gram-positive and Gram-negative groups of bacteria and the family of Enterobacteriaceae. A stringent validation with appropriate controls was implemented. The method of human DNA removal was then applied on 194 sepsis blood samples and 44 cerebrospinal fluid (CSF) samples by real-time PCR. This uncomplicated and straightforward approach allows to remove up to 98 % of human DNA from peripheral blood of septic patients. The inhibitory effect of human DNA is efficiently prevented and the detection limit of real-time PCR is increased to 10 E. Coli CFUs/ml. This sensitivity is 10 times higher compared to conventional real-time PCR assays. The classical blood culture detected 58/194 (30 %) of sepsis and 9/44 (21 %) of CSF samples. Out of the 194 blood samples tested, the conventional real-time PCR targeting 13 common sepsis causing pathogens correctly detected the bacterial DNA in 16/194 (8 %) only and 14/44 (32 %) in cerebrospinal fluid samples. Our newly established approach was able to provide correct diagnoses in 78 (40 %) of the 194 blood samples and in 14 (32 %) of the CSF samples. The combination of both blood cultures and our technique raised the rate of sepsis diagnoses to 112/194 (58 %). Of the total group tested positive, 46 (24 %) cases showed overlap with the classical methodology. We report a simple optimized in-house protocol for removal of human DNA from blood sepsis samples as a pre-analytical tool to prepare DNA for subsequent PCR assays. With the detection increase of our in-house DNA removal approach, subsequent PCR assays can reach detection limits of 10 E. coli CFUs/ml and significantly improve the diagnostic rate in blood sepsis cases.

22 citations


Book ChapterDOI
04 Jul 2016
TL;DR: A comparison between an experimental study of flexion-extension movement in human legs joints and numerical simulations on a virtual mannequin computed in ADAMS virtual environment is presented.
Abstract: The paper presents a comparison between an experimental study of flexion-extension movement in human legs joints and numerical simulations on a virtual mannequin computed in ADAMS virtual environment. Using Biometrics system which is a data acquisition system based on electrogoniometers, data were collected for the right and left ankle, knee and hip during experimental gait overground on force platforms. The mean flexion-extension cycles for legs joints were obtained. The obtained experimental data series were be introduced as input data in the joints of the virtual mannequin and a walking simulation was performed in ADAMS environment software. The variation of ground forces during walking are obtained by experimental data and by virtual simulation.

21 citations


Book ChapterDOI
30 Jun 2016
TL;DR: The variation of joints forces and torques during walking obtained by virtual simulation could be used in future work in order to obtain stress and displacements maps in bones and joints by applying the finite element method.
Abstract: The paper presents a comparison between an experimental study of flexion-extension movement in human leg joints and numerical simulations on a virtual mannequin computed in ADAMS virtual environment. Using Biometrics data acquisition system based on electrogoniometers, data were collected for each of three joints of right and left legs during experimental climbing and descending on stairs. The mean flexion-extension cycles for legs joints were obtained. This obtained experimental data series were introduced as input in the joints of the virtual mannequin and a walking simulation was performed in ADAMS environment software. The variation of joints forces and torques during walking obtained by virtual simulation could be used in future work in order to obtain stress and displacements maps in bones and joints by applying the finite element method.

20 citations


Book ChapterDOI
01 Jan 2016
TL;DR: Larger values of LLEs obtained for patients group suffering by osteoarthritis are associated with more divergence and increase of knee variability, while smaller values obtained for healthy subjects reflect increase of local stability, less divergence and variability, less sensitivity to perturbations and higher resistance to stride-to-stride variability.
Abstract: The objective of this study is to quantify and investigate nonlinear motion of the human knee joint for a sample of 7 healthy subjects on plane treadmill and inclined treadmill with an angle of 10° and for both knees of a sample of 3 patients who suffer of osteoarthritis, only on the plane treadmill, using nonlinear dynamics stability analysis. The largest Lyapunov exponent (LLE) and correlation dimensions are calculated as chaotic measures from the experimental time series of the flexion-extension angle of human knee joint. Larger values of LLEs obtained for patients group suffering by osteoarthritis are associated with more divergence and increase of knee variability, while smaller values obtained for healthy subjects reflect increase of local stability, less divergence and variability, less sensitivity to perturbations and higher resistance to stride-to-stride variability. The use of nonlinear tools may provide additional insight on the nature of the step-to-step fluctuations present in human and robotic locomotion.

17 citations


Journal ArticleDOI
TL;DR: Current smoking and a higher cumulative smoking exposure are associated with a higher risk of death in patients with metastatic renal cell carcinoma treated with cytoreductive nephrectomy and even at this stage, smoking negatively affects kidney cancer outcomes.
Abstract: To assess the association of smoking status with standard clinicopathological features and overall survival (OS) in a large multi-institutional cohort of patients with metastatic renal cell carcinoma (mRCC) treated with cytoreductive nephrectomy (CNT). A total of 613 patients with mRCC treated with CNT in US and Europe institutions between 1990 and 2013 were included. Smoking history comprised smoking status, smoking duration in years, number of cigarettes per day and years since smoking cessation. Cumulative smoking exposure was categorized as light short term, heavy long term and moderate. Association between smoking history and OS was assessed by Cox regression logistic analysis. One hundred and seventy-one patients (27.9 %) never smoked, 193 (31.5 %) were former smokers and 249 (40.6 %) were current smokers. Smoking status was associated with a higher number of metastases (p < 0.001) and an abnormal preoperative corrected calcium level (p = 0.01). Median follow-up was 16 (IQR 7–24) months. Current smokers had a shorter OS than never and former smokers (log rank, p = 0.004). Smoking status was significantly associated with OS in univariable analysis (HR 1.45; 95 % CI 1.16–1.82; p < 0.001), and in multivariable analysis that adjusted for established prognostic factors (HR 1.46; 95 % CI 1.16–1.84; p = 0.002). Daily consumption of more than 20 cigarettes, more than 20 years of smoking exposure and heavy long exposure were all independent prognosticators of worse OS. Current smoking and a higher cumulative smoking exposure are associated with a higher risk of death in patients with mRCC treated with CNT. Even at this stage, smoking negatively affects kidney cancer outcomes.

12 citations


Journal Article
TL;DR: Management of this disease remains difficult due to the lack of validated biomarkers and the limitations of current predictive and prognostic tools, so further efforts and collaborations are necessary to allow their integration in daily practice.
Abstract: Introduction The aim of this review was to provide an overview of current biomarkers and risk stratification models in urothelial cancer of the upper urinary tract (UTUC). Evidence acquisition A non-systematic Medline/PubMed literature search was performed using the terms "biomarkers", "preoperative models", "postoperative models", "risk stratification", together with "upper tract urothelial carcinoma". Original articles published between January 2003 and August 2015 were included based on their clinical relevance. Additional references were collected by cross referencing the bibliography of the selected articles. Evidence synthesis Various promising predictive and prognostic biomarkers have been identified in UTUC thanks to the increasing knowledge of the different biological pathways involved in UTUC tumorigenesis. These biomarkers may help identify tumors with aggressive biology and worse outcomes. Current tools aim at predicting muscle invasive or non-organ confined disease, renal failure after radical nephroureterectomy and survival outcomes. These models are still mainly based on imaging and clinicopathological feature and none has integrated biomarkers. Risk stratification in UTUC is still suboptimal, especially in the preoperative setting due to current limitations in staging and grading. Identification of novel biomarkers and external validation of current prognostic models may help improve risk stratification to allow evidence-based counselling for kidney-sparing approaches, perioperative chemotherapy and/or risk-based surveillance. Conclusions Despite growing understanding of the biology underlying UTUC, management of this disease remains difficult due to the lack of validated biomarkers and the limitations of current predictive and prognostic tools. Further efforts and collaborations are necessaryry to allow their integration in daily practice.

Journal ArticleDOI
TL;DR: Results highlight for the first time the extreme vulnerability of human adipose-derived stem cells to valve-specific mechanical forces and suggest that careful, progressive mechanical adaptation to valves-specific forces might encourage stem cell differentiation towards the VIC phenotype.
Abstract: The goal of this study was to test the hypothesis that stem cells, as a response to valve-specific extracellular matrix “niches” and mechanical stimuli, would differentiate into valvular interstitial cells (VICs). Porcine aortic root scaffolds were prepared by decellularization. After verifying that roots exhibited adequate hemodynamics in vitro, we seeded human adipose-derived stem cells (hADSCs) within the interstitium of the cusps and subjected the valves to in vitro pulsatile bioreactor testing in pulmonary pressures and flow conditions. As controls we incubated cell-seeded valves in a rotator device which allowed fluid to flow through the valves ensuring gas and nutrient exchange without subjecting the cusps to significant stress. After 24 days of conditioning, valves were analyzed for cell phenotype using immunohistochemistry for vimentin, alpha-smooth muscle cell actin (SMA) and prolyl-hydroxylase (PHA). Fresh native valves were used as immunohistochemistry controls. Analysis of bioreactor-conditioned valves showed that almost all seeded cells had died and large islands of cell debris were found within each cusp. Remnants of cells were positive for vimentin. Cell seeded controls, which were only rotated slowly to ensure gas and nutrient exchange, maintained about 50% of cells alive; these cells were positive for vimentin and negative for alpha-SMA and PHA, similar to native VICs. These results highlight for the first time the extreme vulnerability of hADSCs to valve-specific mechanical forces and also suggest that careful, progressive mechanical adaptation to valve-specific forces might encourage stem cell differentiation towards the VIC phenotype.

Journal ArticleDOI
TL;DR: In this paper, a new N-sulfonamide ligand (HL1 = N-(5-(4-methoxyphenyl)-[1,3,4]-thiadiazole-2-yl)-toluenesulfonamides) and two Cu(II) complexes, [Cu(L1)2(py)2] (C1) and [cu(L2)2 (py) 2(H2O)] (C2) were synthesized.
Abstract: A new N-sulfonamide ligand (HL1 = N-(5-(4-methoxyphenyl)-[1,3,4]–thiadiazole–2-yl)-toluenesulfonamide) and two Cu(II) complexes, [Cu(L1)2(py)2] (C1) and [Cu(L2)2(py)2(H2O)] (C2) (HL2 = N-(5-(4-methylphenyl)-[1,3,4]–thiadiazole–2-yl)-benzenesulfonamide) were synthesized. The X-ray crystal structures of the complexes were determined. In the complex C1, the Cu(II) ion is four-coordinated, forming a CuN4 chromophore and in the complex C2, the Cu(II) ion is five-coordinated, forming a CuN4O chromophore. The ligand acts as monodentate, coordinating the Cu(II) ion through a single Nthiadiazole atom. The molecules from the reaction medium (pyridine and water) are also involved in the coordination of the Cu(II) ion. The complexes C1 and C2 are square-planar and a slightly distorted square pyramidal, respectively. The compounds were characterized by FT-IR, electronic, EPR spectroscopic and magnetic methods. The nuclease binding activity studies of the synthesized complexes confirm their capacity to cleave the DNA molecule. The cytotoxicity studies were carried out on melanoma cell line WM35 which confirm that both compounds inhibit the growth of these cells. They have a higher activity compared to a platinum drug, carboplatin.

Journal ArticleDOI
TL;DR: The bone marrow narrows the T2-distributions, increasing resolution, but will not influence significantly the peaks positions; therefore, the NMR relaxometry is a valuable tool to characterize the pore distributions and effects of induced osteoporosis in diverse bones sections.
Abstract: The aim of this work is to show that the bones with marrow, treated as a quasi-porous media, can be successfully used to study the effects of ovariectomy-induced osteoporosis. Proton one-dimensional (1D) nuclear magnetic resonance (NMR) T 2-distribution and two-dimensional (2D) T 2–T 2 exchange maps combined with histological images were used to measure the proximal part of the femoris, diaphysis and distal epiphysis of ovariectomized and non-ovariectomized Wistar albino rats. The 1D normalized T 2 distributions showed four peaks which were associated with protons in four major pools: (1) the protons from bounded water to collagenous matrix; (2) fluids in osteocyte lacunae and canaliculi channels; (3) fluids in secondary pores like Haversian and transverse Volkmann canals and (4) soft matter like bone marrow and fluids in primary pores like trabecular bone cavities. The peak’s association and hierarchical structure of pores in femoral bone were supported by a 2D T 2–T 2 exchange map and by a series of dehydration experiments monitored by NMR measurements. The bone marrow narrows the T 2-distributions, increasing resolution, but will not influence significantly the peaks positions; therefore, the NMR relaxometry is a valuable tool to characterize the pore distributions and effects of induced osteoporosis in diverse bones sections.

Journal ArticleDOI
TL;DR: The paper presents the functional analysis of a parallel robotic system used for transperineal prostate biopsy using the integrated MATLAB software, which offers a correlation between the structure of the robot and the surrounding medical environment.
Abstract: The paper presents the functional analysis of a parallel robotic system used for transperineal prostate biopsy. A simulation system to study the robot functional analysis was developed using the integrated MATLAB software. Given the fact that the robotic system is used in a medical environment, it has to meet certain safety requirements indicated by the medical doctors. In order to fulfill these needs an appeal to complex simulation software has to be made to help choosing the best kinematic solution for the robotic system. The designed simulation software offers a correlation between the structure of the robot and the surrounding medical environment, pointing out its workspace and possible configurations that might harm the human patient during the biopsy.

Book ChapterDOI
04 Jul 2016
TL;DR: The paper presents the design of a needle insertion module for robotic assisted transperineal prostate biopsy, using a commercially available biopsy gun, to be used as an end-effector for different robotic systems suitable for this medical task.
Abstract: The paper presents the design of a needle insertion module for robotic assisted transperineal prostate biopsy, using a commercially available biopsy gun. The module is designed to be used as an end-effector for different robotic systems suitable for this medical task. The geometric and kinematic parameters of the insertion module are presented in correlation with a set of experimental data that supplied critical inputs for the solution development.

Journal ArticleDOI
07 Mar 2016
TL;DR: A pre-program survey was designed by the authors in order to gauge medical students’ expectations, specific interests, preferences, anxieties, and abilities to fruitfully participate in such a program, along with the implications of moving the program towards a more professional and academic focus.
Abstract: Online cultural exchanges between students of different nationalities may be quite common in this digital age but expanding and adjusting them to include new and more specialized participants can be a challenging task. The Online Cultural Exchange Program (OCEP), currently hosted by the University of Miyazaki (Japan) has been functioning successfully since 2007 (see Araki, Shirasaka, and Larson, 2008), gradually expanding its scope from nursing students alone to include engineering and agriculture majors, consisting largely of online written personal introductions and light-hearted cultural exchanges. However, recent planned expansions of the program into the Faculty of Medicine between the host university in Japan and a new participant in Vietnam has demanded a re-evaluation of what is expected from the program with regard to its utility for medical students. In order to develop a focus suited to the academic and professional needs of medical students in both the hosting university (Miyazaki, Japan) and the new Vietnamese participant (Haiphong University of Medicine and Pharmacy) a pre-program survey was designed by the authors in order to gauge medical students’ expectations, specific interests, preferences, anxieties, and abilities to fruitfully participate in such a program. In this paper, some salient results of these surveys are presented, along with the implications of moving the program towards a more professional and academic focus, and cultural factors that may affect participant expectations and potential outcomes. We expect that the data generated from these surveys may inform and influence similar international online exchange and learning programs being established elsewhere. Keywords: online cultural exchange programs; medical students; CALL programs; Japan; Vietnam DOI: http://doi.org/10.17576/3L-2016-2201-06

Journal ArticleDOI
TL;DR: In this paper, the effects of varus tilt on contact stresses in the three components of total knee prostheses using 3D finite element analysis were investigated using Ansys simulation environment, six complex virtual models of human knee joint-prosthesis assembly obtained for six different varus tilts which increase from 176o to 191o, with an increment of 3o.
Abstract: In this paper the effects of varus tilt on contact stresses in the three components of total knee prostheses using 3D finite element analysis were investigated. Using Ansys simulation environment, six complex virtual models of human knee joint–prosthesis assembly obtained for six different varus tilts which increase from 176o to 191o, with an increment of 3o have been subjected to finite element analysis in order to obtain the stress maps and total displacements maps.

Journal ArticleDOI
TL;DR: In this paper, the authors present the 3D geometric modeling of the knee prosthesis components using the latest generation of CAD-CAE applications as DesignModeler and SpaceClaim under Ansys Workbench software package.
Abstract: This paper presents the three-dimensional geometric modeling of the knee prosthesis components using the latest generation of CAD-CAE applications as DesignModeler and SpaceClaim under Ansys Workbench software package. The mesh generation and the contact conditions are presented. The parameterized virtual models of the knee prosthesis allow different changes in shape or dimensions which can lead to the optimization of the implant and of the biomechanics of the prosthetic knee.

Journal ArticleDOI
14 Mar 2016
TL;DR: Results indicate an increase in free radicals and NOx production and a decrease of the antioxidant defense system in all the three regions of the brain after IHH exposure, while Que provides substantial neuroprotection against IHH-induced oxidative/nitrosative damage.
Abstract: High altitude exposure is an extreme physiological oxidative/nitrosative stress and the brain is more sensitive tissue of the body. Quercetin (Que) is a natural flavonoid abundant in fruits and vegetables. The present study investigated the brain region specific changes in striatum, hippocampus and cortex on oxidative/nitrosative stress markers and the effects of Que administration in rats exposed to intermittent hypobaric hypoxia (IHH). Wistar male rats were exposed to short-term (2 days) or long-term (4 weeks, 5 days/week) IHH in a hypobaric chamber. Half of the rats received Que (30 mg/kg body weight) daily, before each IHH exposure. Control rats were kept under normobaric normoxia (Nx) and treated in a corresponding manner. After the last exposure to IHH, the brain was removed and the oxidative/nitrosative stress markers were determined in the three parts of the brain (striatum, hippocampus and cortex) tissue homogenate: the free radicals (malondialdehyde, MDA and carbonylated proteins, CP), nitrite plus nitrate (NOx) production and activity of antioxidant enzymes (superoxide dismutase, SOD and catalase, CAT). Results indicate an increase in free radicals and NOx production and a decrease of the antioxidant defense system in all the three regions of the brain after IHH exposure. The Que treatment significantly lower the free radicals and NOx production and significantly higher the SOD and CAT levels in all the three brain regions after IHH exposure. The observation suggests that the hypoxia differentially affects the brain regions and Que provides substantial neuroprotection against IHH-induced oxidative/nitrosative damage. DOI: 10.5935/1984-6835.20160027


Journal ArticleDOI
TL;DR: In this paper, it was shown that the quantum chromodynamics model of light is a universal model in the description of matter, regardless of the connection between forces and colors, and that the color is an interaction property: of the interaction of light with matter.
Abstract: The color is an interaction property: of the interaction of light with matter. Classically speaking it is therefore akin to the forces. But while forces engendered the mechanical view of the world, the colors generated the optical view. One of the modern concepts of interaction between the fundamental particles of matter – the quantum chromodynamics – aims to fill the gap between mechanics and optics, in a specific description of strong interactions. We show here that this modern description of the particle interactions has ties with both the classical and quantum theories of light, regardless of the connection between forces and colors. In a word, the light is a universal model in the description of matter. The description involves classical Yang-Mills fields related to color.

Book ChapterDOI
15 Jun 2016
TL;DR: The research work done for development of a lightweight and low-cost robotic glove that post-stroke patients can use to recover hand functionality and on two types of recuperative actions (tele-operation and program based actions).
Abstract: The paper presents the research work done for development of a lightweight and low-cost robotic glove that post-stroke patients can use to recover hand functionality. The work focused on two directions for the robotic glove structure (exoskeleton and wearable soft robotic glove) and on two types of recuperative actions (tele-operation and program based actions). Given the performance tests ran for the robotic gloves, better results were shown with the wearable soft robotic glove that could also be combined with Functional Electrical Stimulation in order to improve the post-stroke hand rehabilitation.


Journal ArticleDOI
TL;DR: The effects of antero-posterior tibial slope on contact stresses in the three components of total knee prosthesis is investigated using 3D finite element method and starting from the virtual model of the human knee joint-prosthesis assembly.
Abstract: In this paper, using 3D finite element method and starting from the virtual model of the human knee joint-prosthesis assembly, we investigate the effects of antero-posterior tibial slope on contact stresses in the three components of total knee prosthesis. Using AnsysWorkbench15.07 software, the stress and displacements maps are obtained for knee-prosthesis assemblies and for their components, considering two loading force: 800N and 2400N and two cases of prosthetic knee varus slope: 176o and b) 191o. For each prosthesis-knee assembly and for each considered force, two variants of antero-posterior tibial slope were considered: 00 and 50.



Journal ArticleDOI
TL;DR: The present study aimed to evaluate the methods that the authors can today use to assess the degree of osseointegration of the synthetic bone augmentation materials to design and produce an efficient bone graft.
Abstract: Bone graft substitute materials play an important role in oral rehabilitation and understanding the biological effects of these materials is important for an optimum use. Many bone graft substitutes have been approved for clinical use but this large variability make it hard to select a graft materials. The present study aimed to evaluate the methods that we can today use to assess the degree of osseointegration of the synthetic bone augmentation materials.For this study we made three study groups, each of them consisting of six laboratory rats. On the maxilla of this animals 3-mm diameter experimental cavities were carried out. For the first study group the cavities were augmented with the collagen fleece Alveoprotect, for the second group with the synthetic bone graft Ossceram nano, and in the third group the experimental cavities were left unaugmented. The obtained samples were subjected to three examination methods: clinical and radiological examination, Optical Coherence Tomography (OCT), and a histological study.The evaluation methods of bone graft materials may be divided in two categories: in vivo and in vitro methods. In vivo methods include clinical evaluation and imagistic such as radiological or computer tomography (CT) evaluation. Even a minimal but careful direct clinical observation allows observing the appearance of the bone defect healing at its different stages. CBCT scan is the imaging method of choice in the graft materials repairment of the osseous defects because provides 3D volumetric measurements of newly formed hard tissues.Optical Coherence Tomography (OCT) is a constantly growing imaging method characterized by high spatial resolution and noninvasive subsurface detection. The OCT allowed us to evaluate the surface and subsurface of the ongoing healing bone defects in a non-destructive manner.For the in vitro methods histological methods represents the classical evaluation of the bone graft materials biological integration. On the histological samples we generally noticed the experimental defects filling with connective tissue with various bone ingrowths from the surrounding bone tissue.However new emerging methods give new opportunities to a more accurate research of this materials. The microcomputed tomography analysis may determine the relationships and differences in three-dimensional bone mineral density and microtrabecular structures between bone grafts and their adjacent native boneTo design and produce an efficient bone graft, the researchers and clinicians should have sufficient knowledge of the characteristics of grafts such as osteogenesis, osteoinductivity, and osteoconductivity, and their other advantages and disadvantages.

Journal ArticleDOI
TL;DR: The aim of the study was to evaluate the influence of each layer of porcelain fused to the metal coping on the final aspect of a metal ceramic restoration using the Ivoclar dSign system.
Abstract: A fixed restoration has many important properties. Not only it has to resist in the harsh oral environment but it also has to resist bite forces and to remain intact for an extended period of time and porcelain has all these qualities and it also gives excellent esthetic results. The aim of the study was to evaluate the influence of each layer of porcelain fused to the metal coping on the final aspect of a metal ceramic restoration using the Ivoclar dSign system. Therefore we have chosen three methods to apply the porcelain by varying the thickness of the dentin and enamel layers fused on the metal substructure. The layer thickness of the opaque porcelain, the body porcelain (dentin), and the incisal porcelain greatly influence the final aspect of the metal ceramic restoration and this variation must be taken into consideration in order for the dental technician to obtain the desired shade

Journal ArticleDOI
TL;DR: In this paper, a computational partition coefficient study of water and octanol for a series of monomeric compounds analyzed showed the contribution of chemical structures dependent descriptors of substances on this parameter.
Abstract: Monomers used in dentistry allow tackling shrinkage problem during polymerization of dental composites.These monomers may cross biomembranes, a phenomenon that can lead to various toxic responses. An important factor that express the lipophilicity of these compounds is the partition coefficient. This parameter allows assessment of the solubility of a monomer to another and, generally, of a material to another.Computational partition coefficients study of water / octanol for a series of monomeric compounds analyzed showed the contribution of chemical structures dependent descriptors of substances on this parameter. The purpose of the assessment of these molecular descriptors is to show their importance in the partition of the substances studied in two phases aqueous and lipid (n-octanol).This allows optimization of the action of compounds activity very useful in finding new monomers used in dental reconstruction.