Search results for: soft tissue sarcoma
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 2404

Search results for: soft tissue sarcoma

1684 Effects of Family Order and Informal Social Control on Protecting against Child Maltreatment: A Comparative Study of Seoul and Kathmandu

Authors: Thapa Sirjana, Clifton R. Emery

Abstract:

This paper examines the family order and Informal Social Control (ISC) by the extended families as a protective factor against Child Maltreatment. The findings are discussed using the main effects and the interaction effects of family order and informal social control by the extended families. The findings suggest that IPV mothers are associated with child abuse and child neglect. The children are neglected in the home more and physical abuse occurs in the case, if mothers are abused by their husbands. The mother’s difficulties of being abused may lead them to neglect their children. The findings suggest that ‘family order’ is a significant protective factor against child maltreatment. The results suggest that if the family order is neither too high nor too low than that can play a role as a protective factor. Soft type of ISC is significantly associated with child maltreatment. This study suggests that the soft type of ISC by the extended families is a helpful approach to develop child protection in both the countries. This study is analyzed the data collected from Seoul and Kathmandu families and neighborhood study (SKFNS). Random probability cluster sample of married or partnered women in 20 Kathmandu wards and in Seoul 34 dongs were selected using probability proportional to size (PPS) sampling. Overall, the study is to make a comparative study of Korea and Nepal and examine how the cultural differences and similarities associate with the child maltreatment.

Keywords: child maltreatment, intimate partner violence, informal social control and family order Seoul, Kathmandu

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1683 Preparation of Fe3Si/Ferrite Micro-and Nano-Powder Composite

Authors: Radovan Bures, Madgalena Streckova, Maria Faberova, Pavel Kurek

Abstract:

Composite material based on Fe3Si micro-particles and Mn-Zn nano-ferrite was prepared using powder metallurgy technology. The sol-gel followed by autocombustion process was used for synthesis of Mn0.8Zn0.2Fe2O4 ferrite. 3 wt.% of mechanically milled ferrite was mixed with Fe3Si powder alloy. Mixed micro-nano powder system was homogenized by the Resonant Acoustic Mixing using ResodynLabRAM Mixer. This non-invasive homogenization technique was used to preserve spherical morphology of Fe3Si powder particles. Uniaxial cold pressing in the closed die at pressure 600 MPa was applied to obtain a compact sample. Microwave sintering of green compact was realized at 800°C, 20 minutes, in air. Density of the powders and composite was measured by Hepycnometry. Impulse excitation method was used to measure elastic properties of sintered composite. Mechanical properties were evaluated by measurement of transverse rupture strength (TRS) and Vickers hardness (HV). Resistivity was measured by 4 point probe method. Ferrite phase distribution in volume of the composite was documented by metallographic analysis. It has been found that nano-ferrite particle distributed among micro- particles of Fe3Si powder alloy led to high relative density (~93%) and suitable mechanical properties (TRS >100 MPa, HV ~1GPa, E-modulus ~140 GPa) of the composite. High electric resistivity (R~6.7 ohm.cm) of prepared composite indicate their potential application as soft magnetic material at medium and high frequencies.

Keywords: micro- and nano-composite, soft magnetic materials, microwave sintering, mechanical and electric properties

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1682 Law, Regulatory Transformations and Evolving Paradigm: The Case of Corporate Social Responsibility in India

Authors: Shuchi Bharti

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This article intends to analyse the transforming nature of state and corporate sector relationship in the light of evolving regulatory and institutional aspects pertaining to Corporate Social Responsibility (CSR) in India. The focus is on evaluating the accounts of law and decentred discourses, relevant within the changing regulatory and institutional paradigm that substantially goes ahead of formal legal control of state towards corporate actors. At this vantage point, it is important to understand the state’s posture towards a changing scenario particularly as the tone is set by regulatory parameters pertaining to CSR to drive process of engagement with the stakeholders. The tripartite framework of the article intends to focus on finding on the vital interconnected aspects of the CSR provisions (Section 135) of The Companies Act 2013 (The Act), rise of new institutions and the emergence of the decentred regulatory space. Thus is earmarked in a neo-liberal paradigm; state is witnessed to perform a responsive function in engendering enhanced public role for the corporate sector. In this overarching framework the aim is to undertake a causal, exploratory and relational analysis of aspects pertaining law, regulation and institutional transformations. Firstly, focus is drawn on to investigate the relational facets of the advent of law and regulatory framework of CSR. Secondly, in the light of the historical evolution, a causal connection is attempted between globalization, emergence of international soft law framework and the Indian case of CSR. Finally, I look into how the new Companies Act mandates CSR expenditure vis- a -vis multiple parameters and guidelines.

Keywords: corporate social responsibility, stakeholders, soft law, decentred regulation

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1681 Prediction of Changes in Optical Quality by Tissue Redness after Pterygium Surgery

Authors: Mohd Radzi Hilmi, Mohd Zulfaezal Che Azemin, Khairidzan Mohd Kamal, Azrin Esmady Ariffin, Mohd Izzuddin Mohd Tamrin, Norfazrina Abdul Gaffur, Tengku Mohd Tengku Sembok

Abstract:

Purpose: The purpose of this study is to predict optical quality changes after pterygium surgery using tissue redness grading. Methods: Sixty-eight primary pterygium participants were selected from patients who visited an ophthalmology clinic. We developed a semi-automated computer program to measure the pterygium fibrovascular redness from digital pterygium images. The outcome of this software is a continuous scale grading of 1 (minimum redness) to 3 (maximum redness). The region of interest (ROI) was selected manually using the software. Reliability was determined by repeat grading of all 68 images and its association with contrast sensitivity function (CSF) and visual acuity (VA) was examined. Results: The mean and standard deviation of redness of the pterygium fibrovascular images was 1.88 ± 0.55. Intra- and inter-grader reliability estimates were high with intraclass correlation ranging from 0.97 to 0.98. The new grading was positively associated with CSF (p<0.01) and VA (p<0.01). The redness grading was able to predict 25% and 23% of the variance in the CSF and the VA respectively. Conclusions: The new grading of pterygium fibrovascular redness can be reliably measured from digital images and show a good correlation with CSF and VA. The redness grading can be used in addition to the existing pterygium grading.

Keywords: contrast sensitivity, pterygium, redness, visual acuity

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1680 Molecular Study of P53- and Rb-Tumor Suppressor Genes in Human Papilloma Virus-Infected Breast Cancers

Authors: Shakir H. Mohammed Al-Alwany, Saad Hasan M. Ali, Ibrahim Mohammed S. Shnawa

Abstract:

The study was aimed to define the percentage of detection of high-oncogenic risk types of HPV and their genotyping in archival tissue specimens that ranged from apparently healthy tissue to invasive breast cancer by using one of the recent versions of In Situ Hybridization(ISH) 0.2. To find out rational significance of such genotypes as well as over expressed products of mutants P53 and RB genes on the severity of underlying breast cancers. The DNA of HPV was detected in 46.5 % of tissues from breast cancers while HPV DNA in the tissues from benign breast tumours was detected in 12.5%. No HPV positive–ISH reaction was detected in healthy breast tissues of the control group. HPV DNA of genotypes (16, 18, 31 and 33) was detected in malignant group in frequency of 25.6%, 27.1%, 30.2% and 12.4%, respectively. Over expression of p53 was detected by IHC in 51.2% breast cancer cases and in 50% benign breast tumour group, while none of control group showed P53- over expression. Retinoblastoma protein was detected by IHC test in 49.7% of malignant breast tumours, 54.2% of benign breast tumours but no signal was reported in the tissues of control group. The significance prevalence of expression of mutated p53 & Rb genes as well as detection of high-oncogenic HPV genotypes in patients with breast cancer supports the hypothesis of an etiologic role for the virus in breast cancer development.

Keywords: human papilloma virus, P53, RB, breast cancer

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1679 Development of a Vacuum System for Orthopedic Drilling Processes and Determination of Optimal Processing Parameters for Temperature Control

Authors: Kadir Gök

Abstract:

In this study, a vacuum system was developed for orthopedic drilling processes, and the most efficient processing parameters were determined using statistical analysis of temperature rise. A reverse engineering technique was used to obtain a 3D model of the chip vacuum system, and the obtained point cloud data was transferred to Solidworks software in STL format. An experimental design method was performed by selecting different parameters and their levels, such as RPM, feed rate, and drill bit diameter, to determine the most efficient processing parameters in temperature rise using ANOVA. Additionally, the bone chip-vacuum device was developed and performed successfully to collect the whole chips and fragments in the bone drilling experimental tests, and the chip-collecting device was found to be useful in removing overheating from the drilling zone. The effects of processing parameters on the temperature levels during the chip-vacuuming were determined, and it was found that bone chips and fractures can be used as autograft and allograft for tissue engineering. Overall, this study provides significant insights into the development of a vacuum system for orthopedic drilling processes and the use of bone chips and fractures in tissue engineering applications.

Keywords: vacuum system, orthopedic drilling, temperature rise, bone chips

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1678 Synthesize And Physicochemical Characterization Of Biomimetic Scaffold Of Gelatin/zn-incorporated 58s Bioactive Glass

Authors: SeyedMohammad Hosseini, Amirhossein Moghanian

Abstract:

The main purpose of this research was to design a biomimetic system by freeze-drying method for evaluating the effect of adding 5 and 10 mol. % of zinc (Zn)in 58S bioactive glass and gelatin (5ZnBG/G and 10ZnBG/G) in terms of structural and biological changes. The structural analyses of samples were performed by X-Ray Diffraction (XRD), scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FTIR). Also, 3-(4,5dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide(MTT) and alkaline phosphate (ALP) activity test were carried out for investigation of MC3T3-E1cell behaviors. The SEM results demonstrated the spherical shape of the formed hydroxyapatite (HA) phases, and also HA characteristic peaks were detected by X-ray diffraction spectroscopy (XRD)after 3 days of immersion in the simulated body fluid (SBF) solution. Meanwhile, FTIR spectra proved that the intensity of P–O peaks for 5ZnBG/G was more than 10ZnBG/G and control samples. Moreover, the results of alkaline phosphatase activity (ALP) test illustrated that the optimal amount of Zn (5ZnBG/G) caused a considerable enhancement in bone cell growth. Taken together, the scaffold with 5 mol.% Zn was introduced as an optimal sample because of its higher biocompatibility, in vitro bioactivity, and growth of MC3T3-E1cellsin in comparison with other samples in bone tissue engineering.

Keywords: scaffold, gelatin, modified bioactive glass, alp, bone tissue engineering

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1677 A Rural Journey of Integrating Interprofessional Education to Foster Trust

Authors: Julia Wimmers Klick

Abstract:

Interprofessional Education (IPE) is widely recognized as a valuable approach in healthcare education, despite the challenges it presents. This study explores IP surface anatomy lab sessions, with a focus on fostering trust and collaboration among healthcare students. The research is conducted within the context of rural healthcare settings in British Columbia (BC), where a medical school and a physical therapy (PT) program operate under the Faculty of Medicine at the University of British Columbia (UBC). While IPE sessions addressing soft skills have been implemented, the integration of hard skills, such as Anatomy, remains limited. To address this gap, a pilot feasibility study was conducted with a positive outcome, a follow-up study involved these IPE sessions aimed at exploring the influence of bonding and trust between medical and PT students. Data were collected through focus groups comprising participating students and faculty members, and a structured SWOC (Strengths, Weaknesses, Opportunities, and Challenges) analysis was conducted. The IPE sessions, 3 in total, consisted of a 2.5-hour lab on surface anatomy, where PT students took on the teaching role, and medical students were newly exposed to surface anatomy. The focus of the study was on the relationship-building process and trust development between the two student groups, rather than assessing the acquisition of surface anatomy skills. Results indicated that the surface anatomy lab served as a suitable tool for the application and learning of soft skills. Faculty members observed positive outcomes, including productive interaction between students, reversed hierarchy with PT students teaching medical students, practicing active listening skills, and using a mutual language of anatomy. Notably, there was no grade assessment or external pressure to perform. The students also reported an overall positive experience; however, the specific impact on the development of soft skill competencies could not be definitively determined. Participants expressed a sense of feeling respected, welcomed, and included, all of which contributed to feeling safe. Within the small group environment, students experienced becoming a part of a community of healthcare providers that bonded over a shared interest in health professions education. They enjoyed sharing diverse experiences related to learning across their varied contexts, without fear of judgment and reprisal that were often intimidating in single professional contexts. During a joint Christmas party for both cohorts, faculty members observed students mingling, laughing, and forming bonds. This emphasized the importance of early bonding and trust development among healthcare colleagues, particularly in rural settings. In conclusion, the findings emphasize the potential of IPE sessions to enhance trust and collaboration among healthcare students, with implications for their future professional lives in rural settings. Early bonding and trust development are crucial in rural settings, where healthcare professionals often rely on each other. Future research should continue to explore the impact of content-concentrated IPE on the development of soft skill competencies.

Keywords: interprofessional education, rural healthcare settings, trust, surface anatomy

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1676 Development and Characterization of Hydroxyapatite Based Nanocomposites for Local Drug Delivery to Periodontal Pockets

Authors: Indu Lata Kanwar, Preeti K. Suresh

Abstract:

The aim of this study is to fabricate hydroxyapatite based nanocomposites for local drug delivery in periodontal pockets. Hydroxyapatite is chemically similar to the mineral component of bones and hard tissues in mammals. Synthetic biocompatibility and bioactivity with human teeth and bone, making it very attractive for biomedical applications. Nanocomposite is a multiphase solid material where one of the phases has one, two or three dimensions of less than 100 nanometres (nm), or structures having nano­scale repeat distances between the different phases that make up the material. Nanostructured calcium phosphate materials play an important role in the formation of hard tissues in nature. It is reported that calcium phosphates materials in nano-size can mimic the dimensions of constituent components of calcified tissues. Nano-sized materials offer improved performances compared with conventional materials due to their large surface-to-volume ratios. The specific biological properties of the nanocomposites, as well as their interaction with cells, include the use of bioactive molecules. The approach of periodontal tissue engineering is considered promising to restore bone defect through the use of engineered materials with the aim that they will prohibit the invasion of fibrous connective tissue and help repair the function during bone regeneration.

Keywords: bioactive, hydroxyapatite, nanocomposities, periondontal

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1675 Study of Phase Separation Behavior in Flexible Polyurethane Foam

Authors: El Hatka Hicham, Hafidi Youssef, Saghiri Khalid, Ittobane Najim

Abstract:

Flexible polyurethane foam (FPUF) is a low-density cellular material generally used as a cushioning material in many applications such as furniture, bedding, packaging, etc. It is commercially produced during a continuous process, where a reactive mixture of foam chemicals is poured onto a moving conveyor. FPUFs are produced by the catalytic balancing of two reactions involved, the blowing reaction (isocyanate-water) and the gelation reaction (isocyanate-polyol). The microstructure of FPUF is generally composed of soft phases (polyol phases) and rigid domains that separate into two domains of different sizes: the rigid polyurea microdomains and the macrodomains (larger aggregates). The morphological features of FPUF are strongly influenced by the phase separation morphology that plays a key role in determining the global FPUF properties. This phase-separated morphology results from a thermodynamic incompatibility between soft segments derived from aliphatic polyether and hard segments derived from the commonly used aromatic isocyanate. In order to improve the properties of FPUF against the different stresses faced by this material during its use, we report in this work a study of the phase separation phenomenon in FPUF that has been examined using SAXS WAXS and FTIR. Indeed, we have studied with these techniques the effect of water, isocyanates, and alkaline chlorides on the phase separation behavior. SAXS was used to study the morphology of the microphase separated, WAXS to examine the nature of the hard segment packing, and FTIR to investigate the hydrogen bonding characteristics of the materials studied. The prepared foams were shown to have different levels of urea phase connectivity; the increase in water content in the FPUF formulation leads to an increase in the amount of urea formed and consequently the increase of the size of urea aggregates formed. Alkali chlorides (NaCl, KCl, and LiCl) incorporated into FPUF formulations show that is the ability to prevent hydrogen bond formation and subsequently alter the rigid domains. FPUFs prepared by different isocyanate structures showed that urea aggregates are difficult to be formed in foams prepared by asymmetric diisocyanate, while are more easily formed in foams prepared by symmetric and aliphatic diisocyanate.

Keywords: flexible polyurethane foam, hard segments, phase separation, soft segments

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1674 The Effect of Three-Dimensional Morphology on Vulnerability Assessment of Atherosclerotic Plaque

Authors: M. Zareh, H. Mohammadi, B. Naser

Abstract:

Atherosclerotic plaque rupture is the main trigger of heart attack and brain stroke which are the leading cause of death in developed countries. Better understanding of rupture-prone plaque can help clinicians detect vulnerable plaques- rupture prone or instable plaques- and apply immediate medical treatment to prevent these life-threatening cardiovascular events. Therefore, there are plenty of studies addressing disclosure of vulnerable plaques properties. Necrotic core and fibrous tissue are two major tissues constituting atherosclerotic plaque; using histopathological and numerical approaches, many studies have demonstrated that plaque rupture is strongly associated with a large necrotic core and a thin fibrous cap, two morphological characteristic which can be acquired by two-dimensional imaging of atherosclerotic plaque present in coronary and carotid arteries. Plaque rupture is widely considered as a mechanical failure inside plaque tissue; this failure occurs when the stress within plaque excesses the strength of tissue material; hence, finite element method, a strong numerical approach, has been extensively applied to estimate stress distribution within plaques with different compositions which is then used for assessment of various vulnerability characteristics including plaque morphology, material properties and blood pressure. This study aims to evaluate significance of three-dimensional morphology on vulnerability degree of atherosclerotic plaque. To reach this end, different two-dimensional geometrical models of atherosclerotic plaques are considered based on available data and named Main 2D Models (M2M). Then, for each of these M2Ms, two three-dimensional idealistic models are created. These two 3D models represent two possible three-dimensional morphologies which might exist for a plaque with similar 2D morphology to one of M2Ms. Finite element method is employed to estimate stress, von-Mises stress, within each 3D models. Results indicate that for each M2Ms stress can significantly varies due to possible 3D morphological changes in that plaque. Also, our results show that an atherosclerotic plaque with thick cap may experience rupture if it has a critical 3D morphology. This study highlights the effect of 3D geometry of plaque on its instability degree and suggests that 3D morphology of plaque might be necessary to more effectively and accurately assess atherosclerotic plaque vulnerability.

Keywords: atherosclerotic plaque, plaque rupture, finite element method, 3D model

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1673 Effect of Dietary Supplementation of Allium Hookeri Root and Processed Sulfur on the Growth Performance of Guinea Pigs

Authors: Nayeon, Lee, Won-Young, Cho, Hyun Joo, Jang, Chi-Ho, Lee

Abstract:

This study investigated the effects of the dietary supplementation of the Allium hookeri root, and processed sulfur, on the growth performance of guinea pigs. The guinea pigs were fed a control diet (CON), as well as the control diet including 1% freeze-dried Allium hookeri root (AH), or 0.1% processed sulfur (S), or including both the freeze-dried Allium hookeri root and the processed sulfur (AHS). The weight of perirenal adipose tissue (PAT) and the epididymal adipose tissue (EAT) in the AH were significantly lower than CON (p < 0.05). The serum cholesterols levels of the AH and the AHS were significantly lower than the S (p < 0.05). While the total saturated fatty acid content in the serum of the AH and AHS groups showed a tendency to decrease, the total monounsaturated fatty acid increased. The results of this study suggested that dietary consumption of Allium hookeri root may help to decrease fat accumulation, lower serum cholesterol levels, and control serum free fatty acid contents in the guinea pigs.

Keywords: Allium hookeri, dietary supplementation, growth performance, processed sulfur, Guinea pig

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1672 Tuning of Indirect Exchange Coupling in FePt/Al₂O₃/Fe₃Pt System

Authors: Rajan Goyal, S. Lamba, S. Annapoorni

Abstract:

The indirect exchange coupled system consists of two ferromagnetic layers separated by non-magnetic spacer layer. The type of exchange coupling may be either ferro or anti-ferro depending on the thickness of the spacer layer. In the present work, the strength of exchange coupling in FePt/Al₂O₃/Fe₃Pt has been investigated by varying the thickness of the spacer layer Al₂O₃. The FePt/Al₂O₃/Fe₃Pt trilayer structure is fabricated on Si <100> single crystal substrate using sputtering technique. The thickness of FePt and Fe₃Pt is fixed at 60 nm and 2 nm respectively. The thickness of spacer layer Al₂O₃ was varied from 0 to 16 nm. The normalized hysteresis loops recorded at room temperature both in the in-plane and out of plane configuration reveals that the orientation of easy axis lies along the plane of the film. It is observed that the hysteresis loop for ts=0 nm does not exhibit any knee around H=0 indicating that the hard FePt layer and soft Fe₃Pt layer are strongly exchange coupled. However, the insertion of Al₂O₃ spacer layer of thickness ts = 0.7 nm results in appearance of a minor knee around H=0 suggesting the weakening of exchange coupling between FePt and Fe₃Pt. The disappearance of knee in hysteresis loop with further increase in thickness of the spacer layer up to 8 nm predicts the co-existence of ferromagnetic (FM) and antiferromagnetic (AFM) exchange interaction between FePt and Fe₃Pt. In addition to this, the out of plane hysteresis loop also shows an asymmetry around H=0. The exchange field Hex = (Hc↑-HC↓)/2, where Hc↑ and Hc↓ are the coercivity estimated from lower and upper branch of hysteresis loop, increases from ~ 150 Oe to ~ 700 Oe respectively. This behavior may be attributed to the uncompensated moments in the hard FePt layer and soft Fe₃Pt layer at the interface. A better insight into the variation in indirect exchange coupling has been investigated using recoil curves. It is observed that the almost closed recoil curves are obtained for ts= 0 nm up to a reverse field of ~ 5 kOe. On the other hand, the appearance of appreciable open recoil curves at lower reverse field ~ 4 kOe for ts = 0.7 nm indicates that uncoupled soft phase undergoes irreversible magnetization reversal at lower reverse field suggesting the weakening of exchange coupling. The openness of recoil curves decreases with increase in thickness of the spacer layer up to 8 nm. This behavior may be attributed to the competition between FM and AFM exchange interactions. The FM exchange coupling between FePt and Fe₃Pt due to porous nature of Al₂O₃ decreases much slower than the weak AFM coupling due to interaction between Fe ions of FePt and Fe₃Pt via O ions of Al₂O₃. The hysteresis loop has been simulated using Monte Carlo based on Metropolis algorithm to investigate the variation in strength of exchange coupling in FePt/Al₂O₃/Fe₃Pt trilayer system.

Keywords: indirect exchange coupling, MH loop, Monte Carlo simulation, recoil curve

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1671 Integrated Geotechnical and Geophysical Investigation of a Proposed Construction Site at Mowe, Southwestern Nigeria

Authors: Kayode Festus Oyedele, Sunday Oladele, Adaora Chibundu Nduka

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The subsurface of a proposed site for building development in Mowe, Nigeria, using Standard Penetration Test (SPT) and Cone Penetrometer Test (CPT) supplemented with Horizontal Electrical Profiling (HEP) was investigated with the aim of evaluating the suitability of the strata for foundation materials. Four SPT and CPT were implemented using 10 tonnes hammer. HEP utilizing Wenner array were performed with inter-electrode spacing of 10 – 60 m along four traverses coincident with each of the SPT and CPT. The HEP data were processed using DIPRO software and textural filtering of the resulting resistivity sections was implemented to enable delineation of hidden layers. Sandy lateritic clay, silty lateritic clay, clay, clayey sand and sand horizons were delineated. The SPT “N” value defined very soft to soft sandy lateritic (<4), stiff silty lateritic clay (7 – 12), very stiff silty clay (12 - 15), clayey sand (15- 20) and sand (27 – 37). Sandy lateritic clay (5-40 kg/cm2) and silty lateritic clay (25 - 65 kg/cm2) were defined from the CPT response. Sandy lateritic clay (220-750 Ωm), clay (< 50 Ωm) and sand (415-5359 Ωm) were delineated from the resistivity sections with two thin layers of silty lateritic clay and clayey sand defined in the texturally filtered resistivity sections. This study concluded that the presence of incompetent thick clayey materials (18 m) beneath the study area makes it unsuitable for shallow foundation. Deep foundation involving piling through the clayey layers to the competent sand at 20 m depth was recommended.

Keywords: cone penetrometer, foundation, lithologic texture, resistivity section, standard penetration test

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1670 Experimental Lead Toxicity in Lohi Sheep: Risks and Impact on Edible Tissues

Authors: Muhammad Younus, Muhammad Sajid, Muti-ur-Rehman Khan, Aftab Ahmad Anjum, Muhammad Asif Idrees, Iahtasham Khan, Aman Ullah Khan, Sajid Umar, Raheela Akhtar

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The present study was conducted to investigate the hazardous effects of lead on health and edible organs of Lohi sheep. The adult Lohi sheep (n=48) were randomly divided into two equal groups. The first group was administered lead acetate at dose of 70 mg/kg live body weight daily as 10% solution by oral route for a period of 90 days and the second group served as a negative control. Blood and tissue samples were collected at day 0, 30, 60 and 90 and analyzed for lead concentration by atomic absorption spectrophotometry. The kidney showed the highest lead concentration (p < 0.05) followed by liver and then muscle. Lead acetate treated sheep showed structural and behavioral changes during the last month of trial. Liver showed necrosis, hemorrhages and hyperactivation of macrophages. Kidney showed degenerative and necrotic changes in glomeruli and tubules and the characteristic intranuclear inclusion bodies in tubular epithelial cells on H and E staining. It was concluded that Lohi sheep is affected by lead intoxication at low dose for longer period and hence exhibits lead accumulation in edible tissues.

Keywords: Lohi sheep, lead acetate, edible tissue, histopathology

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1669 Literature Review of Rare Synchronous Tumours

Authors: Diwei Lin, Amanda Tan, Rajinder Singh-Rai

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We present the first reported case of a concomitant Leydig cell tumor (LCT) and paratesticular leiomyoma in an adult male with a known history of bilateral cryptorchidism. An 80-year-old male presented with a 2-month history of a left testicular lump associated with mild discomfort and a gradual increase in size on a background of bilateral cryptorchidism requiring multiple orchidopexy procedures as a child. Ultrasound confirmed a lesion suspicious for malignancy and he proceeded to a left radical orchidectomy. Histopathological assessment of the left testis revealed a concomitant testicular LCT with malignant features and paratesticular leiomyoma. Leydig cell tumors (LCTs) are the most common pure testicular sex cord-stromal tumors, accounting for up to 3% of all testicular tumors. They can occur at almost any age, but are noted to have a bi-modal distribution, with a peak incidence at 6 to 10 and at 20 to 50 years of age. LCT’s are often hormonally active and can lead to feminizing or virilizing syndromes. LCT’s are usually regarded as benign but can rarely exhibit malignant traits. Paratesticular tumours are uncommon and their reported prevalence varies between 3% and 16%. They occur in a complex anatomical area which includes the contents of the spermatic cord, testicular tunics, epididymis and vestigial remnants. Up to 90% of paratesticular tumours are believed to originate from the spermatic cord, though it is often difficult to definitively ascertain the exact site of origin. Although any type of soft-tissue neoplasm can be found in the paratesticular region, the most common benign tumors reported are lipomas of the spermatic cord, adenomatoid tumours of the epididymis and leiomyomas of the testis. Genetic studies have identified potential mutations that could potentially cause LCTs, but there are no known associations between concomitant LCTs and paratesticular tumors. The presence of cryptorchidism in adults with both LCTs and paratesticular neoplasms individually has been previously reported and it appears intuitive that cryptorchidism is likely to be associated with the concomitant presentation in this case report. This report represents the first documented case in the literature of a unilateral concomitant LCT and paratesticular leiomyoma on a background of bilateral cryptorchidism.

Keywords: testicular cancer, leydig cell tumour, leiomyoma, paratesticular neoplasms

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1668 Inhibitory Effect of Coumaroyl Lupendioic Acid on Inflammation Mediator Generation in Complete Freund’s Adjuvant-Induced Arthritis

Authors: Rayhana Begum, Manju Sharma

Abstract:

Careya arborea Roxb. belongs to the Lecythidaceae family, is traditionally used in tumors, anthelmintic, bronchitis, epileptic fits, astringents, inflammation, an antidote to snake-venom, skin disease, diarrhea, dysentery with bloody stools, dyspepsia, ulcer, toothache, and ear pain. The present study was focused on investigating the anti-arthritic effect of coumaroyl lupendioic acid, a new lupane-type triterpene from Careya arborea stem bark in the chronic inflammatory model and further assessing its possible mechanism on the modulation of inflammatory biomarkers. Arthritis was induced by injecting 0.1 ml of Complete Freund’s Adjuvant (5 mg/ml of heat killed Mycobacterium tuberculosis) into the subplantar region of the left hind paw. Treatment with coumaroyl lupendioic acid (10 and 20 mg/kg, p.o.) and reference drugs (indomethacin and dexamethasone at the dose of 5 mg/kg, p.o.) were started on the day of induction and continued up to 28 days. The progression of arthritis was evaluated by measuring paw volume, tibio tarsal joint diameters, and arthritic index. The effect of coumaroyl lupendioic acid (CLA) on the production PGE₂, NO, MPO, NF-κB, TNF-α, IL-1β, and IL-6 on serum level as well as inflamed paw tissue were also assessed. In addition, ankle joints and spleen were collected and prepared for histological examination. CLA in inflamed rats resulted in significant amelioration of paw edema, tibio-tarsal joint swelling and arthritic score as compared to CFA control group. The results indicated that CLA treated groups markedly decreased the levels of inflammatory mediators (PGE₂, NO, MPO and NF-κB levels) and down-regulated the production of pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) in paw tissue homogenates as well as in serum. However, the more pronounced effect was observed in the inflamed paw tissue homogenates. CLA also revealed a protective effect to the tibio-tarsal joint cartilage and spleen. These results suggest that coumaroyl lupendioic acid inhibits inflammation may be through the suppression of the cascade of proinflammatory mediators via the down-regulation of NF-ҡB.

Keywords: complete Freund’s adjuvant , Coumaroyl lupendioic acid, pro-inflammatory cytokines, prostaglandin E2

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1667 Half Dose Tissue Plasminogen Activator for Intermediate-Risk Pulmonary Embolism

Authors: Macie Matta, Ahmad Jabri, Stephanie Jackson

Abstract:

Introduction: In the absence of hypotension, pulmonary embolism (PE) causing right ventricular dysfunction or strain, whether confirmed by imaging or cardiac biomarkers, is deemed to be an intermediate-risk category. Urgent treatment of intermediate-risk PE can prevent progression to hemodynamic instability and death. Management options include thrombolysis, thrombectomy, or systemic anticoagulation. We aim to evaluate the short-term outcomes of a half-dose tissue plasminogen activator (tPA) for the management of intermediate-risk PE. Methods: We retrospectively identified adult patients diagnosed with intermediate-risk PE between the years 2000 and 2021. Demographic data, lab values, imaging, treatment choice, and outcomes were all obtained through chart review. Primary outcomes measured include major bleeding events and in-hospital mortality. Patients on standard systemic anticoagulation without receiving thrombolysis or thrombectomy served as controls. Patient data were analyzed using SAS®️ Software (version 9.4; Cary, NC) to compare individuals that received half-dose tPA with controls, and statistical significance was set at a p-value of 0.05. Results: We included 57 patients in our final analysis, with 19 receiving tPA. Patient characteristics and comorbidities were comparable between both groups. There was a significant difference between PE location, presence of acute deep vein thrombosis, and peak troponin level between both groups. The thrombolytic cohort was more likely to demonstrate a 60/60 sign and thrombus in transit finding on echocardiography than controls. The thrombolytic group was more likely to have major bleeding (17% vs 7.9%, p= 0.4) and in-hospital mortality (5.3% vs 0%, p=0.3); however, this was not statistically significant. Patients who received half-dose tPA had non-significantly higher rates of major bleeding and in-hospital mortality. Larger scale, randomized control trials are needed to establish the benefit and safety of thrombolytics in patients with intermediate-risk PE.

Keywords: pulmonary embolism, half dose thrombolysis, tissue plasminogen activator, cardiac biomarkers, echocardiographic findings, major bleeding event

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1666 Molecular Pathogenesis of NASH through the Dysregulation of Metabolic Organ Network in the NASH-HCC Model Mouse Treated with Streptozotocin-High Fat Diet

Authors: Bui Phuong Linh, Yuki Sakakibara, Ryuto Tanaka, Elizabeth H. Pigney, Taishi Hashiguchi

Abstract:

NASH is an increasingly prevalent chronic liver disease that can progress to hepatocellular carcinoma and now is attracting interest worldwide. The STAM™ model is a clinically-correlated murine NASH model which shows the same pathological progression as NASH patients and has been widely used for pharmacological and basic research. The multiple parallel hits hypothesis suggests abnormalities in adipocytokines, intestinal microflora, and endotoxins are intertwined and could contribute to the development of NASH. In fact, NASH patients often exhibit gut dysbiosis and dysfunction in adipose tissue and metabolism. However, the analysis of the STAM™ model has only focused on the liver. To clarify whether the STAM™ model can also mimic multiple pathways of NASH progression, we analyzed the organ crosstalk interactions between the liver and the gut and the phenotype of adipose tissue in the STAM™ model. NASH was induced in male mice by a single subcutaneous injection of 200 µg streptozotocin 2 days after birth and feeding with high-fat diet after 4 weeks of age. The mice were sacrificed at NASH stage. Colon samples were snap-frozen in liquid nitrogen and stored at -80˚C for tight junction-related protein analysis. Adipose tissue was prepared into paraffin blocks for HE staining. Blood adiponectin was analyzed to confirm changes in the adipocytokine profile. Tight junction-related proteins in the intestine showed that expression of ZO-1 decreased with the progression of the disease. Increased expression of endotoxin in the blood and decreased expression of Adiponectin were also observed. HE staining revealed hypertrophy of adipocytes. Decreased expression of ZO-1 in the intestine of STAM™ mice suggests the occurrence of leaky gut, and abnormalities in adipocytokine secretion were also observed. Together with the liver, phenotypes in these organs are highly similar to human NASH patients and might be involved in the pathogenesis of NASH.

Keywords: Non-alcoholic steatohepatitis, hepatocellular carcinoma, fibrosis, organ crosstalk, leaky gut

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1665 Cold Stunned Sea Turtle Diet Analysis In Cape Cod Bay from 2015-2020

Authors: Lucille McWilliams

Abstract:

As water temperatures drop in November, Kemp’s Ridley, Loggerhead, and Green sea turtles cold-stun in Cape Cod Bay. The foraging ecology of these sea turtles remains an understudied area of research. In this study, we aim to assess the diet of these turtles using a multi-tissue stable isotope analysis of cold-stunned kemp’s ridley, loggerhead, and green sea turtles stranded from 2015 to 2020. Stable isotope ratios of carbon and nitrogen were measured in blood, front and rear flipper, liver, muscle, skin, and scute tissue samples. We predict an elevated level of Nitrogen isotope ratios in kemp’s ridley and loggerhead turtles compared to green turtles due to the carnivorous loggerheads and kemp ridleys’ carnivorous diet and the greens herbivorous diet. We anticipate empty stomachs due to starvation while stranded, and a variety of foraging strategies, migration patterns, and trophic positions between these species. Data collected from this study will add to the knowledge of these turtles’ prey species and aid managers in the preservation of these species as a mitigation strategy for these turtles' extinction.

Keywords: sea turtles, kemp's ridleys, greens, loggerheads, cold-stunning, diet analysis, stable isotope analysis, environmental science, marine biology

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1664 Biocompatible Porous Titanium Scaffolds Produced Using a Novel Space Holder Technique

Authors: Yunhui Chen, Damon Kent, Matthew Dargusch

Abstract:

Synthetic scaffolds are a highly promising new approach to replace both autografts and allografts to repair and remodel damaged bone tissue. Biocompatible porous titanium scaffold was manufactured through a powder metallurgy approach. Magnesium powder was used as space holder material which was compacted with titanium powder and removed during sintering. Evaluation of the porosity and mechanical properties showed a high level of compatibility with human bone. Interconnectivity between pores is higher than 95% for porosity as low as 30%. The elastic moduli are 39 GPa, 16 GPa and 9 GPa for 30%, 40% and 50% porosity samples which match well to that of natural bone (4-30 GPa). The yield strengths for 30% and 40% porosity samples of 315 MPa and 175 MPa are superior to that of human bone (130-180 MPa). In-vitro cell culture tests on the scaffold samples using Human Mesenchymal Stem Cells (hMSCs) demonstrated their biocompatibility and indicated osseointegration potential. The scaffolds allowed cells to adhere and spread both on the surface and inside the pore structures. With increasing levels of porosity/interconnectivity, improved cell proliferation is obtained within the pores. It is concluded that samples with 30% porosity exhibit the best biocompatibility. The results suggest that porous titanium scaffolds generated using this manufacturing route have excellent potential for hard tissue engineering applications.

Keywords: scaffolds, MG-63 cell culture, titanium, space holder

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1663 Evaluation of Pile Performance in Different Layers of Soil

Authors: Orod Zarrin, Mohesn Ramezan Shirazi, Hassan Moniri

Abstract:

The use of pile foundations technique is developed to support structures and buildings on soft soil. The most important dynamic load that can affect the pile structure is earthquake vibrations. Pile foundations during earthquake excitation indicate that piles are subject to damage by affecting the superstructure integrity and serviceability. During an earthquake, two types of stresses can damage the pile head, inertial load that is caused by superstructure and deformation which caused by the surrounding soil. Soil deformation and inertial load are associated with the acceleration developed in an earthquake. The acceleration amplitude at the ground surface depends on the magnitude of earthquakes, soil properties and seismic source distance. According to the investigation, the damage is between the liquefiable and non-liquefiable layers and also soft and stiff layers. This damage crushes the pile head by increasing the inertial load which is applied by the superstructure. On the other hand, the cracks on the piles due to the surrounding soil are directly related to the soil profile and causes cracks from small to large. However, the large cracks reason have been listed such as liquefaction, lateral spreading, and inertial load. In the field of designing, elastic response of piles is always a challenge for designer in liquefaction soil, by allowing deflection at top of piles. Moreover, absence of plastic hinges in piles should be insured, because the damage in the piles is not observed directly. In this study, the performance and behavior of pile foundations during liquefaction and lateral spreading are investigated. In addition, emphasize on the soil behavior in the liquefiable and non-liquefiable layers by different aspect of piles damage such as ranking, location and degree of damage are going to discuss.

Keywords: pile, earthquake, liquefaction, non-liquefiable, damage

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1662 Rheometer Enabled Study of Tissue/biomaterial Frequency-Dependent Properties

Authors: Polina Prokopovich

Abstract:

Despite the well-established dependence of cartilage mechanical properties on the frequency of the applied load, most research in the field is carried out in either load-free or constant load conditions because of the complexity of the equipment required for the determination of time-dependent properties. These simpler analyses provide a limited representation of cartilage properties thus greatly reducing the impact of the information gathered hindering the understanding of the mechanisms involved in this tissue replacement, development and pathology. More complex techniques could represent better investigative methods, but their uptake in cartilage research is limited by the highly specialised training required and cost of the equipment. There is, therefore, a clear need for alternative experimental approaches to cartilage testing to be deployed in research and clinical settings using more user-friendly and financial accessible devices. Frequency dependent material properties can be determined through rheometry that is an easy to use requiring a relatively inexpensive device; we present how a commercial rheometer can be adapted to determine the viscoelastic properties of articular cartilage. Frequency-sweep tests were run at various applied normal loads on immature, mature and trypsinased (as model of osteoarthritis) cartilage samples to determine the dynamic shear moduli (G*, G′ G″) of the tissues. Moduli increased with increasing frequency and applied load; mature cartilage had generally the highest moduli and GAG depleted samples the lowest. Hydraulic permeability (KH) was estimated from the rheological data and decreased with applied load; GAG depleted cartilage exhibited higher hydraulic permeability than either immature or mature tissues. The rheometer-based methodology developed was validated by the close comparison of the rheometer-obtained cartilage characteristics (G*, G′, G″, KH) with results obtained with more complex testing techniques available in literature. Rheometry is relatively simpler and does not require highly capital intensive machinery and staff training is more accessible; thus the use of a rheometer would represent a cost-effective approach for the determination of frequency-dependent properties of cartilage for more comprehensive and impactful results for both healthcare professional and R&D.

Keywords: tissue, rheometer, biomaterial, cartilage

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1661 The Impact of Electrospinning Parameters on Surface Morphology and Chemistry of PHBV Fibers

Authors: Lukasz Kaniuk, Mateusz M. Marzec, Andrzej Bernasik, Urszula Stachewicz

Abstract:

Electrospinning is one of the commonly used methods to produce micro- or nano-fibers. The properties of electrospun fibers allow them to be used to produce tissue scaffolds, biodegradable bandages, or purification membranes. The morphology of the obtained fibers depends on the composition of the polymer solution as well as the processing parameters. Interesting properties such as high fiber porosity can be achieved by changing humidity during electrospinning. Moreover, by changing voltage polarity in electrospinning, we are able to alternate functional groups at the surface of fibers. In this study, electrospun fibers were made of natural, thermoplastic polyester – PHBV (poly(3-hydroxybutyric acid-co-3-hydrovaleric acid). The fibrous mats were obtained using both positive and negative voltage polarities, and their surface was characterized using X-ray photoelectron spectroscopy (XPS, Ulvac-Phi, Chigasaki, Japan). Furthermore, the effect of the humidity on surface morphology was investigated using scanning electron microscopy (SEM, Merlin Gemini II, Zeiss, Germany). Electrospun PHBV fibers produced with positive and negative voltage polarity had similar morphology and the average fiber diameter, 2.47 ± 0.21 µm and 2.44 ± 0.15 µm, respectively. The change of the voltage polarity had a significant impact on the reorientation of the carbonyl groups what consequently changed the surface potential of the electrospun PHBV fibers. The increase of humidity during electrospinning causes porosity in the surface structure of the fibers. In conclusion, we showed within our studies that the process parameters such as humidity and voltage polarity have a great influence on fiber morphology and chemistry, changing their functionality. Surface properties of polymer fiber have a significant impact on cell integration and attachment, which is very important in tissue engineering. The possibility of changing surface porosity allows the use of fibers in various tissue engineering and drug delivery systems. Acknowledgment: This study was conducted within 'Nanofiber-based sponges for atopic skin treatment' project., carried out within the First TEAM programme of the Foundation for Polish Science co-financed by the European Union under the European Regional Development Fund, project no POIR.04.04.00-00- 4571/18-00.

Keywords: cells integration, electrospun fiber, PHBV, surface characterization

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1660 Protein Quality of Game Meat Hunted in Latvia

Authors: Vita Strazdina, Aleksandrs Jemeljanovs, Vita Sterna

Abstract:

Not all proteins have the same nutritional value, since protein quality strongly depends on its amino acid composition and digestibility. The meat of game animals could be a high protein source because of its well-balanced essential amino acids composition. Investigations about biochemical composition of game meat such as wild boar (Sus scrofa scrofa), roe deer (Capreolus capreolus) and beaver (Castor fiber) are not very much. Therefore, the aim of the investigation was evaluate protein composition of game meat hunted in Latvia. The biochemical analysis, evaluation of connective tissue and essential amino acids in meat samples were done, the amino acids score were calculate. Results of analysis showed that protein content 20.88-22.05% of all types of meat samples is not different statistically. The content of connective tissue from 1.3% in roe deer till 1.5% in beaver meat allowed classified game animal as high quality meat. The sum of essential amino acids in game meat samples were determined 7.05–8.26g100g-1. Roe deer meat has highest protein content and lowest content of connective tissues among game meat hunted in Latvia. Concluded that amino acid score for limiting amino acids phenylalanine and tyrosine is high and shows high biological value of game meat.

Keywords: dietic product, game meat, amino acids, scores

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1659 The 6Rs of Radiobiology in Photodynamic Therapy: Review

Authors: Kave Moloudi, Heidi Abrahamse, Blassan P. George

Abstract:

Radiotherapy (RT) and photodynamic therapy (PDT) are both forms of cancer treatment that aim to kill cancer cells while minimizing damage to healthy tissue. The similarity between RT and PDT lies in their mechanism of action. Both treatments use energy to damage cancer cells. RT uses high-energy radiation to damage the DNA of cancer cells, while PDT uses light energy to activate a photosensitizing agent, which produces reactive oxygen species (ROS) that damage the cancer cells. Both treatments require careful planning and monitoring to ensure the correct dose is delivered to the tumor while minimizing damage to surrounding healthy tissue. They are also often used in combination with other treatments, such as surgery or chemotherapy, to improve overall outcomes. However, there are also significant differences between RT and PDT. For example, RT is a non-invasive treatment that can be delivered externally or internally, while PDT requires the injection of a photosensitizing agent and the use of a specialized light source to activate it. Additionally, the side effects and risks associated with each treatment can vary. In this review, we focus on generalizing the 6Rs of radiobiology in PDT, which can open a window for the clinical application of Radio-photodynamic therapy with minimum side effects. Furthermore, this review can open new insight to work on and design new radio-photosensitizer agents in Radio-photodynamic therapy.

Keywords: radiobiology, photodynamic therapy, radiotherapy, 6Rs in radiobiology, ROS, DNA damages, cellular and molecular mechanism, clinical application.

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1658 Effects of Polydispersity on the Glass Transition Dynamics of Aqueous Suspensions of Soft Spherical Colloidal Particles

Authors: Sanjay K. Behera, Debasish Saha, Paramesh Gadige, Ranjini Bandyopadhyay

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The zero shear viscosity (η₀) of a suspension of hard sphere colloids characterized by a significant polydispersity (≈10%) increases with increase in volume fraction (ϕ) and shows a dramatic increase at ϕ=ϕg with the system entering a colloidal glassy state. Fragility which is the measure of the rapidity of approach of these suspensions towards the glassy state is sensitive to its size polydispersity and stiffness of the particles. Soft poly(N-isopropylacrylamide) (PNIPAM) particles deform in the presence of neighboring particles at volume fraction above the random close packing volume fraction of undeformed monodisperse spheres. Softness, therefore, enhances the packing efficiency of these particles. In this study PNIPAM particles of a nearly constant swelling ratio and with polydispersities varying over a wide range (7.4%-48.9%) are synthesized to study the effects of polydispersity on the dynamics of suspensions of soft PNIPAM colloidal particles. The size and polydispersity of these particles are characterized using dynamic light scattering (DLS) and scanning electron microscopy (SEM). As these particles are deformable, their packing in aqueous suspensions is quantified in terms of effective volume fraction (ϕeff). The zero shear viscosity (η₀) data of these colloidal suspensions, estimated from rheometric experiments as a function of the effective volume fraction ϕeff of the suspensions, increases with increase in ϕeff and shows a dramatic increase at ϕeff = ϕ₀. The data for η₀ as a function of ϕeff fits well to the Vogel-Fulcher-Tammann equation. It is observed that increasing polydispersity results in increasingly fragile supercooled liquid-like behavior, with the parameter ϕ₀, extracted from the fits to the VFT equation shifting towards higher ϕeff. The observed increase in fragility is attributed to the prevalence of dynamical heterogeneities (DHs) in these polydisperse suspensions, while the simultaneous shift in ϕ₀ is ascribed to the decoupling of the dynamics of the smallest and largest particles. Finally, it is observed that the intrinsic nonlinearity of these suspensions, estimated at the third harmonic near ϕ₀ in Fourier transform oscillatory rheological experiments, increases with increase in polydispersity. These results are in agreement with theoretical predictions and simulation results for polydisperse hard sphere colloidal glasses and clearly demonstrate that jammed suspensions of polydisperse colloidal particles can be effectively fluidized with increasing polydispersity. Suspensions of these particles are therefore excellent candidates for detailed experimental studies of the effects of polydispersity on the dynamics of glass formation.

Keywords: dynamical heterogeneity, effective volume fraction, fragility, intrinsic nonlinearity

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1657 Experimental-Numerical Inverse Approaches in the Characterization and Damage Detection of Soft Viscoelastic Layers from Vibration Test Data

Authors: Alaa Fezai, Anuj Sharma, Wolfgang Mueller-Hirsch, André Zimmermann

Abstract:

Viscoelastic materials have been widely used in the automotive industry over the last few decades with different functionalities. Besides their main application as a simple and efficient surface damping treatment, they may ensure optimal operating conditions for on-board electronics as thermal interface or sealing layers. The dynamic behavior of viscoelastic materials is generally dependent on many environmental factors, the most important being temperature and strain rate or frequency. Prior to the reliability analysis of systems including viscoelastic layers, it is, therefore, crucial to accurately predict the dynamic and lifetime behavior of these materials. This includes the identification of the dynamic material parameters under critical temperature and frequency conditions along with a precise damage localization and identification methodology. The goal of this work is twofold. The first part aims at applying an inverse viscoelastic material-characterization approach for a wide frequency range and under different temperature conditions. For this sake, dynamic measurements are carried on a single lap joint specimen using an electrodynamic shaker and an environmental chamber. The specimen consists of aluminum beams assembled to adapter plates through a viscoelastic adhesive layer. The experimental setup is reproduced in finite element (FE) simulations, and frequency response functions (FRF) are calculated. The parameters of both the generalized Maxwell model and the fractional derivatives model are identified through an optimization algorithm minimizing the difference between the simulated and the measured FRFs. The second goal of the current work is to guarantee an on-line detection of the damage, i.e., delamination in the viscoelastic bonding of the described specimen during frequency monitored end-of-life testing. For this purpose, an inverse technique, which determines the damage location and size based on the modal frequency shift and on the change of the mode shapes, is presented. This includes a preliminary FE model-based study correlating the delamination location and size to the change in the modal parameters and a subsequent experimental validation achieved through dynamic measurements of specimen with different, pre-generated crack scenarios and comparing it to the virgin specimen. The main advantage of the inverse characterization approach presented in the first part resides in the ability of adequately identifying the material damping and stiffness behavior of soft viscoelastic materials over a wide frequency range and under critical temperature conditions. Classic forward characterization techniques such as dynamic mechanical analysis are usually linked to limitations under critical temperature and frequency conditions due to the material behavior of soft viscoelastic materials. Furthermore, the inverse damage detection described in the second part guarantees an accurate prediction of not only the damage size but also its location using a simple test setup and outlines; therefore, the significance of inverse numerical-experimental approaches in predicting the dynamic behavior of soft bonding layers applied in automotive electronics.

Keywords: damage detection, dynamic characterization, inverse approaches, vibration testing, viscoelastic layers

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1656 Properties of Adipose Tissue Derived Mesenchymal Stem Cells with Long-Term Cryopreservation

Authors: Jienny Lee, In-Soo Cho, Sang-Ho Cha

Abstract:

Adult mesenchymal stem cells (MSCs) have been investigated using preclinical approaches for tissue regeneration. Porcine MSCs (pMSCs) are capable of growing and attaching to plastic with a fibroblast-like morphology and then differentiating into bone, adipose, and cartilage tissues in vitro. This study was conducted to investigate the proliferating abilities, differentiation potentials, and multipotency of miniature pig adipose tissue-derived MSCs (mpAD-MSCs) with or without long-term cryopreservation, considering that cryostorage has the potential for use in clinical applications. After confirming the characteristics of the mpAD-MSCs, we examined the effect of long-term cryopreservation (> 2 years) on expression of cell surface markers (CD34, CD90 and CD105), proliferating abilities (cumulative population doubling level, doubling time, colony-forming unit, and MTT assay) and differentiation potentials into mesodermal cell lineages. As a result, the expression of cell surface markers is similar between thawed and fresh mpAD-MSCs. However, long-term cryopreservation significantly lowered the differentiation potentials (adipogenic, chondrogenic, and osteogenic) of mpAD-MSCs. When compared with fresh mpAD-MSCs, thawed mpAD-MSCs exhibited lower expression of mesodermal cell lineage-related genes such as peroxisome proliferator-activated receptor-g2, lipoprotein lipase, collagen Type II alpha 1, osteonectin, and osteocalcin. Interestingly, long-term cryostoraged mpAD-MSCs exhibited significantly higher cell viability than the fresh mpAD-MSCs. Long-term cryopreservation induced a 30% increase in the cell viability of mpAD-MSCs when compared with the fresh mpAD-MSCs at 5 days after thawing. However, long-term cryopreservation significantly lowered expression of stemness markers such as Oct3/4, Sox2, and Nanog. Furthermore, long-term cryopreservation negatively affected expression of senescence-associated genes such as telomerase reverse transcriptase and heat shock protein 90 of mpAD-MSCs when compared with the fresh mpAD-MSCs. The results from this study might be important for the successful application of MSCs in clinical trials after long-term cryopreservation.

Keywords: mesenchymal stem cells, cryopreservation, stemness, senescence

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1655 The Effects of Periostin in a Rat Model of Isoproterenol-Mediated Cardiotoxicity

Authors: Mahmut Sozmen, Alparslan Kadir Devrim, Yonca Betil Kabak, Tuba Devrim

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Acute myocardial infarction is the leading cause of deaths in the worldwide. Mature cardiomyocytes do not have the ability to regenerate instead fibrous tissue proliferate and granulation tissue to fill out. Periostin is an extracellular matrix protein from fasciclin family and it plays an important role in the cell adhesion, migration, and growth of the organism. Periostin prevents apoptosis while stimulating cardiomyocytes. The main objective of this project is to investigate the effects of the recombinant murine periostin peptide administration for the cardiomyocyte regeneration in a rat model of acute myocardial infarction. The experiment was performed on 84 male rats (6 months old) in 4 group each contains 21 rats. Saline applied subcutaneously (1 ml/kg) two times with 24 hours intervals to the rats in control group (Group 1). Recombinant periostin peptide (1 μg/kg) dissolved in saline applied intraperitoneally in group 2 on 1, 3, 7, 14 and 21. days on same dates in group 4. Isoproterenol dissolved in saline applied intraperitoneally (85mg/kg/day) two times with 24 hours intervals to the groups 3 and 4. Rats in group 4 further received recombinant periostin peptide (1 μg/kg) dissolved in saline intraperitoneally starting one day after the final isoproterenol administration on days 1, 3, 7, 14 and 21. Following the final application of periostin rats continued to feed routinely with pelleted chow and water ad libitum for further seven days. At the end of 7th day rats sacrificed, blood and heart tissue samples collected for the immunohistochemical and biochemical analysis. Angiogenesis in response to tissue damage, is a highly dynamic process regulated by signals from the surrounding extracellular matrix and blood serum. In this project, VEGF, ANGPT, bFGF, TGFβ are the key factors that contribute to cardiomyocyte regeneration were investigated. Additionally, the relationship between mitosis and apoptosis (Bcl-2, Bax, PCNA, Ki-67, Phopho-Histone H3), cell cycle activators and inhibitors (Cyclin D1, D2, A2, Cdc2), the origin of regenerating cells (cKit and CD45) were examined. Present results revealed that periostin stimulated cardiomyocye cell-cycle re-entry in both normal and MCA damaged cardiomyocytes and increased angiogenesis. Thus, periostin contributes to cardiomyocyte regeneration during the healing period following myocardial infarction which provides a better understanding of its role of this mechanism, improving recovery rates and it is expected to contribute the lack of literature on this subject. Acknowledgement: This project was financially supported by Turkish Scientific Research Council- Agriculture, Forestry and Veterinary Research Support Group (TUBİTAK-TOVAG; Project No: 114O734), Ankara, TURKEY.

Keywords: cardiotoxicity, immunohistochemistry, isoproterenol, periostin

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