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Mar 2019 DOI 10.14302/issn.2642-9241.jrd-19-2689
A. S. Sardenberg RodrigoCorresponding author
Chief of Thoracic Surgery, Hospital Paulistano, Americas Serviços Médicos São Paulo, Brazil
Background The aim of this study is to evaluate the outcomes of patients submitted to diaphragmatic pacing, and the impact on quality of life of patients who chronically depend on mechanical ventilation, as well as the effectiveness of phrenic stimulation to eliminate the need for mechanical ventilation. Methods From 2010- 2014, 10 patients completely dependent on mechanical ventilation were operated upon, with the implantation of phrenic pacing device. The diagnoses were quadriplegia and congenital central hypoventilation syndrome (CCHS). All patients underwent bilateral approach to the phrenic nerves, by video-assisted thoracic surgery or mini-thoracotomy. Results All patientsstarted pacing 30-40 days post-operatively. The mean age of patients was 12.1 years (2-27 years range) with a median of ten years. Six patients (54.5%) were as old as ten years, and three (27.2%) were older than 20 years. Younger patients had CCHS and older ones were quadriplegic. All patients with CCHS (n = 4) were nine years old or younger while only two quadriplegic patients were in this age group. Conclusions Diaphragmatic pacing can provide improvement in the quality of life of patients who depend on mechanical ventilation, allowing freedom to conduct daily activities, lower respiratory infections, and tracheostomy decannulation.
Aug 2018 DOI 10.14302/issn.2377-2549.jndc-18-2187
Randjbaran EliasCorresponding author
Aerospace Manufacturing Research Centre (AMRC) Level 7, Tower Block, Faculty of Engineering 43400 UPM, Serdang, Selangor, Malaysia
Among the numerous potential uses of carbon nanotubes (CNT), its utilization to fortify polymers was given careful consideration. This reason can be because of the remarkable firmness, magnificent quality, and the low thickness of CNT. This has given various chances to the innovation of new material frameworks for applications requiring high quality and high modulus. Exact control over preparing factors, including safeguarding flawless CNT structure, uniform scattering of CNT inside the polymer grid, compelling filler– lattice interfacial communications, and arrangement/introduction of polymer chains/CNT, add to the composite strands' unrivalled properties. Consequently, manufacture techniques assume an imperative part in deciding the composite filaments' microstructure and extreme mechanical conduct. The present best in the class of polymer/CNT elite composite filaments, particularly concerning processing– structure– execution, were looked into in this commitment. Future requirements for material by configuration approaches for handling these nano-composite frameworks were likewise examined.
Sep 2017 DOI 10.14302/issn.2832-4048.jsm-17-1621
A. Koryak YuriCorresponding author
SSC of the Russian Federation − Institute of Biomedical Problems of the RAS
The effects of long-term space flight on human triceps surae (TS) muscle function and electromechanical delay (EMD) have been investigated. Voluntary and electrically evoked contractions of the TS were obtained from 7 male cosmonauts 30 days before and 3 days after landing. For all cosmonauts the isometric maximal voluntary contraction was reduced by 41.7 % (p < 0.01), whereas the electrically evoked maximal tetanic contraction force (Po) was found to decrease by 25.6 % (p < 0.05). Force deficit increased by 50 % (p < 0.001). This suggests that most of the force loss is due to a reduction in motor drive (motor control). The decrease in Po was associated with a significant increase of the corresponding maximal rates of tension development (43.7 %). The twitch tension (Pt) was not significantly changed and the Pt/Po ratio was increased by 46.7 % (p < 0.05) after space mission. The twitch time-to-peak tension of the TS increased by 7.7 %, but half-relaxation time decreased by 20.6 %. Force-velocity properties of the TS calculated according to a relative scale of voluntary contraction development significantly decreased. The calculations of the same properties of electrically evoked contraction development did not differ substantially from the initial physiological state. Total reaction time (TRT), pre-motor time (PMR) and motor time or EMD were determined. In response to a supramaximal single electrical pulses applied to the tibial nerve, the latent period between the M-wave and Рt beginning was determined. The voluntary contraction EMD increased by 34.1 %; but PMR and TRT decreased by 19.0 and 14.1 %, respectively. The EMD of electrically evoked contraction did not significantly change. Thus, the comparison of the mechanical alterations recorded during voluntary contractions and in contractions evoked by electrical stimulation of the motor nerve, suggests that weightlessness not only modifies the peripheral processes associated with contractions, but also changes central and/or neural command of the contraction.
Sep 2016 DOI 10.14302/issn.2377-2549.jndc-16-1119
Saleem H.Corresponding author
Department of Physics, Annamalai University, Annamalainagar-608 002, Tamil Nadu, India
The FT-IR, FT-Raman and UV-Vis spectra of E-[1-(3'-methylthienyl)-5-Phenyl-2,4-Pentadiene-3-one (MPPO) were recorded. The optimized molecular bond parameters, harmonic frequencies were calculated using B3LYP method with 6-311++G (d,p) basis set.The various normal modes were precisely assigned with thehelp ofTED calculation. The theoretical spectrograms for FT-IR, FT-Raman and Ultra Violet visible. Spectra of the title molecule had been constructed. The ICT was calculated by means of Natural Bond Orbital analysis. The Non Linear Optical properties related to polarizability and hyperpolarizability based on the finite-field approach were calculated.The band gap energy was calculated using HOMO-LUMO analysis. Furthermore, the Molecular Electrostatic Potential, Mulliken atomic charges and thermodynamic properties of MPPO were also calculated.
Jun 2026 DOI 10.14302/issn.2694-2283.jsem-26-6247
Quintero GabrielCorresponding author
Background Ankle sprains are among the most common injuries in sports, often characterized by high recurrence rates despite appropriate local treatment. Traditional approaches primarily focus on the injured joint, with limited attention to proximal biomechanical factors that may predispose athletes to injury. Objective To propose a functional, longitudinal kinetic chain model in which sacroiliac joint dysfunction may act as a predisposing factor for ankle sprain/strain injuries in athletes. Methods This paper presents a clinical hypothesis based on biomechanical reasoning and observational findings. The proposed model describes how sacroiliac joint dysfunction, particularly posterior innominate rotation (PI), may lead to pelvic obliquity and functional leg length discrepancy. These changes may induce compensatory femoral external rotation and foot toe-out, altering ground contact mechanics during gait and running. Results (Hypothesis) The altered alignment and loading pattern may increase the vertical impact force and modify the ground reaction vector on the functionally shorter limb, resulting in reduced mechanical stability at the ankle during heel strike or foot contact. Over time, this may increase susceptibility to inversion or eversion injuries, manifesting clinically as recurrent sprain/strain. Conclusion Ankle sprains in athletes may, in some cases, represent the distal expression of a proximal biomechanical imbalance. Incorporating assessment of the sacroiliac joint and the longitudinal kinetic chain into routine clinical evaluation may improve injury risk identification and contribute to more effective prevention strategies. Further research is needed to investigate this proposed relationship.
Oct 2023 DOI 10.14302/issn.2639-3166.jar-21-4033
Wole Damena AregaCorresponding author
Root is has great role for plant adaptation and productivity of the agricultural crops as well as other plants by exploiting the soil resource thus, important for plant growth and development or main growth factors. Root system architecture is made up of structural features which exhibits great role in response to environmental stress, and critical to plant growth and development with sufficient root growth. Root system architecture has a central role in crop plants’ response to abiotic (soil microorganisms) and abiotic stresses like water stress, mechanical impedance. Root morphology can be affected by nutrient availability, osmotic stress, salinity, and light. Phenotyping root is one of the drought management tools as roots are more prone to drought conditions and play a significant role in the plant’s life by extracting soil resources from deeper soil layers to carry on several metabolic functions in the plant’s body and its phenotyping helps to understand different root traits. Understanding interactions between roots and their surrounding soil environment is important to increase root growth, which can be improved through root phenotyping. In addition, knowing of the development and architecture of roots, as well its plasticity, holds thus great role for stabilizing the productivity under suboptimal conditions in the root environment
Mar 2023
Abdellatif ElaakiliCorresponding author
In the present document, the dynamic analysis of isotropic materials applied to the laminated composite beam has been studied to improve the simplification of the homogenization process of heterogeneous composite materials.12 This study is based on the conventional stratified theory of Von Karman's formulation and the kinetic energy of Euler Bernoulli developed through displacement relationships. The model used in this study to explain the problem of non-linear geometry in the free vibration applied of laminated beam is based on the Hamilton's principle for solving the motion equation and determining the frequency of the reaction of the rolled beam. The numerical of the symmetric an asymmetric material gives a good idea of the behaviour of the orthotropic materials, and to minimize the problem of many areas used these materials such as: dental medicine, aeronautical, aerospace, because they have a good strength, high rigidity.23 The comparison between the different lay up may give greater importance to this study and open the search to simplify the problem of non linear geometry and give a good result about the older other published. For instance the application of medicine,the researcher has to decode the compatibility of the human body with new materials,and to minimize the problem of deterioration,The comparison with different lay up give more interesting by the mechanical engineering and the researcher's to give the solution of no linear problem and optimize the composite material’s to adaptation with problem study.4
Jan 2022 DOI 10.14302/issn.2379-8572.joa-21-3964
Mohamed Bofares KhaledCorresponding author
Professor of otorhinolaryngology Omar Almoukhtar University, Elbyda, Libya
Back ground and Objectives The inferior conchae have important role in the maintenance of nasal airflow via providing the nasal valve mechanism but increase of inferior turbinate bulk may result in significant nasal obstruction. Therefore, this may need further surgical intervention to deal with these bulky conchae but it is very necessary to balance between the mechanical as well as the functional patency of the nose. Thus, through this surgery it become difficult to decide whether the patient is a candidate for surgery and which technique is suitable for that particular patient. Patients and Methods Two- thousands three- hundreds and six patients aged 3-65 years of hypertrophied inferior conchae, had been diagnosed as a cases of mechanical nasal obstruction due to hypertrophied inferior conchae (HIC). The patients operated by two techniques of inferior conchae surgery, which are sub-mucosal diathermy (SMD) and partial inferior turbinectomy (PIT). The outcomes were correlated to different factors to assess as much as possible the clear conclusion for this significant issue in rhinology. Results and Conclusion The proper selection of patient for this pattern of surgery is considered as one of main aspects of this issue and one of significant steps toward the resolving of this dilemma it is very necessary to select the most suitable candidate for this surgery. On the other hand, the type of the technique for this surgery is needed to be selected probably.
Jul 2021 DOI 10.14302/issn.2576-6694.jbbs-21-3819
Jana SnehasisCorresponding author
Trivedi Science Research Laboratory Pvt. Ltd., Thane (W), Maharashtra, India.
The present study aimed to evaluate the effect of the Trivedi Effect®- Biofield Energy Treated/Blessed Test formulation/item (TI) composed of minerals (magnesium, zinc, copper, calcium, selenium, and iron), vitamins (ascorbic acid, pyridoxine HCl, alpha tocopherol, cyanocobalamin, and cholecalciferol), Panax ginseng extract, CBD isolates, and β-carotene on elasticity of skin, heart, muscle, and neuronal cells in the H9C2 (rat cardiomyocytes), C2C12 (mouse myoblast cells), HaCaT (human keratinocytes), and SH-SY5Y (human neuroblastoma cells) cell line in DMEM medium. The test formulation constituents were divided into two parts; one section was defined as untreated test formulation (UT), while the other portion of test formulation received Biofield Energy Healing/Blessing Treatment (BT) by a renowned Biofield Energy Healer, Mr. Mahendra Kumar Trivedi. The test items were treated with Biofield Energy Healing/Blessing Treatment and divided as Biofield Energy Treated/Blessed (BT) and untreated (UT) test items. MTT data showed that the test formulation in various concentrations was found as safe and nontoxic in the tested concentrations with viability range from 73% to 307%. Young’s modulus (YM) is a measure of cell stiffness, a decrease in YM value indicates increase elasticity of the cells and vice-versa. YM in H9C2 cells were decreased by 9.6% and 66.1% in the BT-DMEM + UT-TI group at 0.1 and 1 µg/mL respectively, as compared with untreated test group. However, C2C21 cells showed increased YM by 443.9% at 1 µg/mL in the UT-DMEM + BT-TI group, while 869.6% increased YM in the BT-DMEM + UT-TI group at 1 µg/mL as compared with untreated test group. However, 314% increased YM was reported in the BT-DMEM + BT-TI group at 1 µg/mL as compared with the untreated test group. However, the value of YM was significantly decreased in the HaCaT cell line by 247.7% (at 1 µg/mL), 225.8% (at 0.1 µg/mL), and 97.9% (at 1 µg/mL) in the UT-DMEM + BT-TI, BT-DMEM + UT-TI, and BT-DMEM + BT-TI group respectively, as compared with the untreated group. In addition, YM was significantly decreased in the SH-SY5Y cell line by 92.6%, 18.1%, and 26.6% at 1 µg/mL in the UT-DMEM + BT-TI, BT-DMEM + UT-TI, and BT-DMEM + BT-TI group respectively, as compared with the untreated group. Overall, the results showed the significant decreased YM among the SH-SY5Y, HaCaT, and H9C2 cells, while it was increased in the C2C21 cell line. Thus, the mechanical properties of cells such as cellular function, including shape, motility, differentiation, division, and adhesion to its surrounding extracellular matrix were improved. Overall, it can be useful in many disease progressions with improved cellular elasticity and its associated complications/symptoms.
Sep 2020 DOI 10.14302/issn.2379-7835.ijn-20-3369
Kishan Gupta BalCorresponding author
Senior Professor, In-charge Medical ICU, Department. of Medicine, S.P.Medical College, Bikaner.
Background Since swine flu has been declared pandemic in 2009 it has become a major challenging public-health problem associated with high morbidity and mortality. 25(OH)D deficiency is also pandemic and has been reported to be clinically correlated with decreased immunity and respiratory infections. The possible role of vitamin D in infections is implied from its impact on the innate and adaptive immune responses. This study is planned to evaluate clinical significance of 25(OH)D status on course and outcome in hospitalized cases of swine flu and to compare it with normal healthy subjects living in the same vicinity to evaluate if vitamin D is having any protective effect. Material & Methods Present prospective cross-sectional study was conducted on 79 RT-PCR confirmed cases of swine flu admitted during recent epidemic. All patients were evaluated thoroughly by clinical history physical examination and laboratory investigations as per Performa and followed-up during hospital stay. 25-hydroxyvitamin D (25(OH)D) estimation was done by electro-chemiluminescent Assay in all the cases and it was also done in 36 normal healthy family members of study patients living in the same vicinity (control group). Results High prevalence (70.9%) of low (≤30ng/ml) status of 25(OH)D was observed in cases of swine flu as compared to control group. 25(OH)D status was associated with severity of illness. Mean value of 25(OH)D in mechanically ventilated patients was 9.81±6.43 while it was 22.76±11.35 ng/ml in patients who do not required ventilation (p<0.05). Mean 25(OH)D level in patients who stayed in hospital for <5 days was 28.60±8.79 ng/ml, 24.18±11.67 for 6-10 days and 8.23±2.12 for >10 days (p<0.01). Mean value of 25(OH)D in patients who died was 9.59±5.90 ng/ml as compared to 23.13±11.62 ng/ml who survived (p<0.01). Conclusion Our study suggests that 25(OH)D may have preventive role for swine flu infection. Low level of 25(OH)D is associated with high morbidity in terms of increase requirement for mechanical ventilation, multiorgan dysfunction and long duration of hospital stay. 25(OH)D deficiency is associated with high mortality in swine flu. 25(OH)D status should be given due consideration in high risk patients especially during winter season.
Jul 2020 DOI 10.14302/issn.2831-8846.j3dpa-20-3438
Shirbhate NimishaCorresponding author
Department of Mechanical Engineering, LT College of Engineering, Koparkhairne, Navi Mumbai, India
Bone Scaffold is a three-dimensional porous construction which provides support to promote natural cell growth in damaged or broken section of bone. In recent years researchers from various departments like biomedical, mechanical, orthopedics, have shown significant interest in adopting ‘Bone Scaffolds’ as a promising treatment for bone defects. ‘Bone Scaffold’ is a honeycomb-like architecture composes of bio-compatible material having grater advantages over current grafting solution. In this paper, the authors try to review the available e-articles in an organized way on the bone scaffold in the field of biomedical implants with 3D printing. The selected literature mainly focuses on the biocompatible material and various advanced manufacturing methods used for manufacturing / preparing of bone scaffolds. This article tries to padding the gap between theoretical and actual implementation of ‘Bone Scaffolds’ by properly analyzing selected research and allowing future opportunities for reinventing the new possibilities in the field of biomedical.
Apr 2020 DOI 10.14302/issn.2689-2855.jan-20-3244
Bendjemil BadisCorresponding author
DGM, FST, University of 8 Mai 1945 of Guelma, 24000 Guelma, Algeria
Nanocomposites are worn resistant materials used in cutting tool applications. The materials are composed of ultrafine powder hard phase grains surrounded by a tough binder phase carbon nanotubes (Mo2C)1-x–(TiC)x (2≤x≤4)//1Wt% SWCNTs. Composite bicarbide Mo2C-TiC was rapidly synthesised and simultaneously consolidated by field activated sintering technique (spark plasma sintering) at which the extensive volume expansion occurred as a function of the volumic fraction from 20 to 40 vol.% of TiC powders and 1 Wt.% of SWCNTs was reinforcement of the NCMC’s. The sintered powder mixture was examined by XRD patterns, the morphology of the obtained phase was observed by SEM and the phase compositions in different regions were analyzed by EDX. The composites were processed using Field Activated Sintering Technique, spark plasma sintering (SPS) at temperatures in the range of 1700-1800°C with addicting of SWCNTs. The effects of SWCNTs addition on phases morphology, microstructure hardness and fracture toughness of the nanocomposite were investigated. The best product contained 1.0 Wt% SWCNTs from (Mo2C)1-x–(TiC)x , x= 0.2 which was sintered at 1700°C, 70 MPa for 10 min, M0.8T0.2/ 1 Wt% SWCNTs exhibit a better density, highest hardness and good ductility. Relative densification was achieved 99.5 % from the theoretical and good mechanical properties like hardness and fracture toughness (KIC=5.6 Mpa m1/2) are improved. The results were confirmed using Raman scattering resonant spectroscopy.
Mar 2020 DOI 10.14302/issn.2689-2855.jan-20-3263
Bendjemil BadisCorresponding author
DGM, FST, University of 8 Mai 1945 of Guelma, 24000 Guelma, Algeria
Nanocomposites are worn resistant materials used in cutting tool applications. The materials are composed of ultrafine powder hard phase grains surrounded by a tough binder phase carbon nanotubes (Mo2C)1-x–(TiC)x (2≤x≤4)//1Wt% SWCNTs. Composite bicarbide Mo2C-TiC was rapidly synthesised and simultaneously consolidated by field activated sintering technique (spark plasma sintering) at which the extensive volume expansion occurred as a function of the volumic fraction from 20 to 40 vol.% of TiC powders and 1 Wt.% of SWCNTs was reinforcement of the NCMC’s. The sintered powder mixture was examined by XRD patterns, the morphology of the obtained phase was observed by SEM and the phase compositions in different regions were analyzed by EDX. The composites were processed using Field Activated Sintering Technique, spark plasma sintering (SPS) at temperatures in the range of 1700-1800°C with addicting of SWCNTs. The effects of SWCNTs addition on phases morphology, microstructure hardness and fracture toughness of the nanocomposite were investigated. The best product contained 1.0 Wt% SWCNTs from (Mo2C)1-x–(TiC)x , x= 0.2 which was sintered at 1700°C, 70 MPa for 10 min, M0.8T0.2/ 1 Wt% SWCNTs exhibit a better density, highest hardness and good ductility. Relative densification was achieved 99.5 % from the theoretical and good mechanical properties like hardness and fracture toughness (KIC=5.6 Mpa m1/2) are improved. The results were confirmed using Raman scattering resonant spectroscopy.
Mar 2020 DOI 10.14302/issn.2689-2855.jan-20-3243
Bendjemil BadisCorresponding author
DGM, FST, University of 8 Mai 1945 of Guelma, 24000 Guelma, Algeria
Cubic boron nitrid (cBN) bonded TiC and alloyed with single walled carbon nanotubes (SWCNTs or NC) ceramics matrix nanocomposites (CMNCs) tools were manufacturated by a field actived sparck plasma sintering processus (FASPS). The effects of cBN-TiC ratio, carbon nanotubes and optimisation of the sintering process on the microstructure, densification in addition mechanical and vibronic properties of NC-cBN-TiC nanocomposites were studied. The results showed that for the nanocomposite cBN-TiC vol. ratio of 8:2 with 0.1 wt% NC, it was found that microhardness incresses significantly with addition of carbon nanotubes exhibited the highest microhardness and fracture toughness. After sintering of the samples at 1800 °C, 10 mn, 75 MPa of cBN–TiC1-x, x=0.8 with and without addition of 0.1 wt% NC were characterized using field emission scanning electron microscopy (FESEM) and X-ray diffraction. The samples exhibited a dense polycrystalline structure. From the resonant Raman scattering we can locate the vibration frequency of the transformation cBN to hexagonal boron nitrid (hBN) and formation of secondary hard phase TiB2to consolid the (CMNCs) tools. The final product is hBN-TiC-TiB2-NC.The best product contained cBNx-TiC1-x (x=0.8)-0.1 wt % NC which was sintered at 1800 °C, 75 MPa for 10 mn. The Vickers hardness of cBN-TiC1-x (x=0.8) incresses with NC incorporation in the matrix The indentation fracture toughness was calculated to be 12.30 MPa m1/2 for cBNx-TiC1-x (x=0.8 -0.1 wt % NC ceramics matrix nanocomposite (CMNCs) tools with excellent wear resistant will be confirmed. The wear of cBN-TiC of the composites tools have shown that this is predominantly a chemical process involving the interaction of the tool with its environment and is restricted by the formation of protective layers on the exposed faces of the tool by the addition of carbon nanotubes (NC). The wear features of tools used in fine cutting tests under identical conditions will be compared and the results will be interpreted in terms of the existing models for the wear of cBN -based nanomaterials by the effects of the additives in the modified tools
Sep 2019 DOI 10.14302/issn.2474-3585.jpmc-19-3009
Konadu-Yeboah DominicCorresponding author
Orthopaedic and Trauma Surgeon, Komfo Anokye Teaching Hospital, Kumasi, Ghana, Part-Time Lecturer, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
Blount’s disease, also known as tibia vara, is a developmental disorder involving the posteromedial proximal tibial physis resulting in progressive varus, procurvatum and internal torsion of the affected tibia 1. The condition was first published by Blount in 1973 2. The aetiology of this disease is unkown. However, associations exist between blount’s disease and the Afro-Caribbean race, early age of walking and obesity 34. Furthermore, genetic predisposition has been postulated as well as mechanical loading of the physis 456. Affected children are usually overweight and start walking early. It is bilateral in 80% of cases 7.
Jul 2019 DOI 10.14302/issn.2694-2283.jsem-19-2938
Hinzpeter C JaimeCorresponding author
Medical Doctor, University of Chile, Clinical Hospital, Santiago Chile.
An anterior cruciate ligament (ACL) injury is an important cause of rest in athletes. In most cases, ACL injuries do not require external contact and they are associated with biomechanical risk factors that increase ACL tension. The increase of the hip flexion angle (HF) is included within these. The ACL requires cooperation of the periarticular musculature of the knee, muscle groups, hip stabilizers and CORE muscles; consequently, fatigue caused by exercise would alter the balance and put this ligament at risk. The objective of the study is to determine the angular behavior for HF before and after a physical load (a standardized training) in children between 11 and 12 years old. A non-randomized clinical study was carried out. The sample consisted of 50 soccer school students born between 11 and 12 years old. The angular behavior of HF was compared before and after performing a training session. The angular behavior was measured through the Drop Jump test (DJ), with data obtained by inertial sensors. After the exercise, there was a significant increase in HF. It was concluded that the angular behavior of HF increases significantly in both extremities after training and that preventive measures must be applied for neuromuscular control of the hip.
Jul 2019 DOI 10.14302/issn.2694-2283.jsem-19-2949
Hinzpeter JaimeCorresponding author
Department of Orthopaedic Surgery, Clinical Hospital, University of Chile, Santos Dumontt # 999, Independencia, Zip Code: 8380456, Santiago, Chile.
Background The Anterior Cruciate Ligament (ACL) injury is uncommon, but constitutes an important percentage of the lesions requiring more than 8 weeks of recovery in sports. Most ACL injuries do not require external contact and are associated with biomechanical risk factors that stress this ligament ACL: like an increase in knee valgus angle (KV) and hip flexion (HF) and a decreased in knee flexion (KF). The ACL requires muscle cooperation to resist the load; however, when there is fatigue, the protective capacity of the musculature would decrease. The objective of the study is to analyze the angular behavior before and after a physical load for HF in children of 14-15 years old. Hypothesis The physical load applied in a single training session is enough to change some biomechanical risk factors of ACL injury. Study Design Experimental study Level of Evidence 2b Methods The sample consisted of 50 students from different soccer schools between 14-15 years old. We analyzed the hip angular behavior of hip flexion before and after a training session. The angles where obtained from inertioal sensor while the students performed a Drop Jump test from a 30 centimeters drawer. Results Statistically significant differences were found in the differences between pre physical load HF / post-load HF (p = 0.00053), right pre physical load HF / right post- load HF (p = 0.0086) and left post- load (p = 0.0248206). Conclusions It was concluded that the angular behavior of HF increases significantly in both post-training limbs, after performing a physical load. Clinical Relevance This study analyzed the importance of using prevention injury programs since early stages, and give importance to the eccentric role of hamstring, gluteus and core exercises.
Jan 2019 DOI 10.14302/issn.2473-1005.jdoi-19-2577
Ricardo Kina JoséCorresponding author
DDS, MSc, PhD. Retired Associate Professor, Department of Surgery and Integrated Clinic, Araçatuba School of Dentistry, Sao Paulo State University – UNESP. Rua José Bonifácio, 1193. Zip code: 16015-050, Araçatuba, Brazil.
The article discusses biomechanical principles underlying tooth support and hydrodynamic equilibrium. It considers periodontal ligament behavior, load distribution, and fluid dynamics, linking basic science concepts to clinical implications.
Jul 2018 DOI 10.14302/issn.2831-8846.j3dpa-18-2207
Dehghanghadikolaei AmirCorresponding author
Oregon State University, USA
Additive manufacturing (AM) is reshaping fabrication in engineering and clinical settings. This editorial highlights metal AM routes—SLS, SLM, DMLS, and EBM—and their application to patient-specific NiTi implants, where biocompatibility and shape-memory behavior are compelling. We note the current gaps that matter in practice: process parameter tuning, post-processing (heat treatment, coating, machining/finishing), and their effects on mechanical performance and corrosion. We invite contributions that quantify these trade-offs and expand AM beyond metals into polymers and ceramics, with clear comparisons across processes and materials. Our goal is to surface actionable findings that improve part quality, reliability, and clinical/industrial readiness.
Jun 2018
Kendall KevinCorresponding author
University of Birmingham, B15 2TT, UK
Graphene-Ceramic Composites (GCCs) have been little studied compared to graphene-polymer composites 1. Recent reviews 23 indicate that both mechanical and electrical property ceramic improvements can be obtained by mixing small quantities, typically 1 to 15% of graphene material with a ceramic precursor, then compacting and sintering. The greatest effect is on the electrical properties. The electrical conductivity of a material was first shown to rise by several orders of magnitude for only a 1% volume addition of graphene as in polymer composites 4 but the stiffness, strength and toughness only increased by 20-160% or so at 5% addition, a rather minor improvement compared to significant increases caused by slight ceramic process changes. Some crack bridging and pull-out mechanism was observed by electron microscopy in graphene-alumina composites, though the effects were modest. Surface friction and wear improvements of around 100% were also notable. This paper seeks to show that much higher toughness increases might be produced using the method pioneered by Clegg et al 5, where the graphite interlayers are replaced with graphene to produce improved ordered interfaces with reliable coverage and consistent interface fracture energy, enabling an increase in the fracture resistance of the ceramic by two orders of magnitude.
Feb 2018 DOI 10.14302/issn.2329-9487.jhc-18-1932
Erne PaulCorresponding author
Faculty of Biomedical Sciences, Universita della Svizzera Italiana, Lugano, Switzerland
The aim of this study was to assess the use of ambulatory acoustic cardiography during the initial data collection of the longitudinal study of a rural population in Switzerland (n=297, mean age 48.9 ±16.5 years, 57% female). Ambulatory acoustic cardiography non-invasively can assess sleep disordered breathing (SDB) and provides markers of left ventricular systolic and diastolic dysfunction. The percentage of the third heart sound detected during sleep decreased significantly across age groups (age < 40 years, 40-60 years, > 60 years) for both genders (males, p=0.04; females, p=0.02). The percentage of a fourth heart sound detected exhibited an increasing trend for both genders with age suggesting increased diastolic dysfunction with aging. Mean electromechanical activation time (EMAT) during sleep was within the normal range across age groups and both genders (male 93.7 ± 11.6 ms, female 94.6 ± 13.0 ms), and did not vary significantly with age. A large proportion of subjects had a high likelihood of sleep disordered breathing (17.6%). Baseline characteristics categorized by SDB severity indicate increasing age, male gender and being overweight (BMI ≥ 25) to be associated with greater SDB severity. Acoustic cardiography findings categorized by SDB severity reveal increased nocturnal non-dipping heart rate, presence of atrial fibrillation, prolonged QRS duration and QTc interval, increased percentage of fourth heart sound detected, and longer EMAT to be significantly associated with greater SDB severity. Overall, acoustic cardiography detected a very low prevalence of systolic dysfunction, age-related increases in diastolic dysfunction and a moderate prevalence of sleep disordered breathing.
Jan 2018 DOI 10.14302/issn.2578-8590.ipj-17-1910
J Foster WilliamCorresponding author
Department of Physics, University of Houston, Houston, TX, USA
Following ocular trauma and retinal detachment, gliotic changes in the retina may develop over the subsequent month, a process known as PVR (proliferative vitreoretinopathy). There have been no successful therapeutic interventions to inhibit PVR. The protein CTGF (Connective Tissue Growth Factor) has been associated with retinal PVR and other fibrotic diseases of the retina in clinical studies but the mechanistic link between different pathologies and retinal gliosis has not been determined. In addition, CTGF has been previously noted to be associated, in some cases, with YAP/TAZ (Yes-associated protein and Tafazzin protein complex), transcriptional regulatory proteins that change subcellular localization in response to mechanical cues, such as the stiffness of the underlying material. We have previously shown that the mRNA for CTGF is markedly (100-fold) upregulated in retinal Müller cells grown on soft substrates. In order to evaluate if the mechanism by which mechanotransduction modulating CTGF production in retinal Müller cells involves the YAP/TAZ complex, this study tests the influence of substrate stiffness on the time dependence of CTGF protein expression, as well as subcellular localization of YAP/TAZ using a conditionally-immortalized mouse retinal Müller cell line plated on laminin-coated, polyacrylamide substrates of varying elastic modulus. Changes were assayed using immunohistochemistry and ELISA (Enzyme-Linked ImmunoSorbent Assay). In retinal Müller cells, the relationship between elastic modulus and the pattern of CTGF protein expression was bimodal, with CTGF levels rising more rapidly for cells on hard substrates and more slowly for cells grown on soft substrates. In addition, nuclear localization of YAP/TAZ corresponded directly to the maximum CTGF expression.
Dec 2017 DOI 10.14302/issn.2766-8630.jrnm-17-1770
Y. Moawad EmadCorresponding author
Independent researcher graduated from department of engineering, Ain Shams University
The aims of this study are to investigate the variation in the mechanical behaviour of the primary cancer from cancer relapse, and measuring the therapeutic resistance acquired by cancer relapse. A431-cultured cells were irradiated for 7 months until 85 Gy. Then, a selected single cell was left to grow as stable A431-R cell line. 106 cells of A431 cells and 106 of A431-R cells suspended in 100 μL of medium were injected into subcutaneous tissues on the right thigh of athymic mice to generate tumor xenografts models of primary cancer (A431-P) and cancer relapse (A431-R). Radiotherapy of a low-dose of 30Gy was applied on xenoimplanted tumors after one week from inoculation. A mock process was performed on untreated groups of mice for controls. Tumor size was monitored starting from inoculation and tumor growth was measured along 42 days. Rates of mitosis and apoptosis and the histologic grade (HG) that characterize the tumor response were determined as described in earlier studies. Alterations induced on tumor HG in the treated models were 100% identical to the energy of the applied doses. The differences in response energy between cancer relapse and primary cancer irrespectively of the treatment (untreated vs. treated) or origin of the cells (A431-P vs. A431-R) in all phases of tumor responses (growth, shrinkage or regrowth) were 100% identical to the total differences in the administered regimens applied on those groups during those phases. Cancer relapse is characterized by a delay in growth before second line therapy for its relatively lower rate of mitosis compared by the primary cancer inducing a corresponding delay in the early detection. The therapeutic resistance of the cancer relapse is equivalent to the energy of the doses which have been delivered in the prior therapies, and requires increasing the administered dose by an amount equivalent to that resistance.
Aug 2017 DOI 10.14302/issn.2470-5020.jnrt-17-1487
Alipour Ataabadi YasaminCorresponding author
Faculty of Physical Education and Sports Sciences, Department of Sports Biomechanics, kharazmi university, Tehran
The global popularity of soccer has led to widespread tendency towards this sport. Because of the convenience of using artificial surfaces, the rapid growth of using these surfaces led to concerns about the declining performance of the players. The aim of this comprehensive review is to study the difference between the performance of players on different playing surfaces and the risk factors for use of artificial turf compared to natural grass. A literature search of valid scientific databases such as Science Direct, PubMed and Jstor by searching keywords was performed. In total, more than 6,000 articles were retrieved. After the preliminary selection process, the final analysis was performed on a total of 76 articles. Results: Mechanical properties of artificial grass have a significant effect on the average time of sprinting, the best time of sprinting and maximum speed. The numbers of sliding tackles on artificial turf were lower compared to natural grass. Artificial turfs exposed hardness, elasticity and high friction. The characteristics of artificial grass have changed over time and increased the probability of injuries. There was no significant difference between the overall risks of acute injuries in soccer players performing on artificial turf compared to natural grass. The amateur, young and female soccer players had rated lower injuries on artificial grass. But the rate of injuries in elite soccer players were higher on artificial grass and hence they are not found of playing on such playing surfaces.