Effect of thickness on shrinkage stress and bottom-to-top hardness ratio of conventional and bulk-fill composites.

This study evaluated the effect of the material thickness on shrinkage stress and bottom-to-top hardness ratio of conventional and bulk-fill composites. Six commercial composites were selected based on their different technologies: Two conventional (C1, C2), two high-viscosity bulk-fill (HVB1, HVB2), and two low-viscosity bulk-fill (LVB1, LVB2). Shrinkage stress was analyzed for five specimens with 2 mm thickness (C-factor 0.75 and volume 24 mm3 ) and five specimens with 4 mm thickness (C-factor 0.375 and volume 48 mm3 ) for 300 s in a universal testing machine. Bottom-to-top hardness ratio values were obtained from Knoop microhardness measurements in specimens with 2- and 4-mm thickness (n = 5). Thickness increase resulted in significantly higher shrinkage stress for all materials with the exception of HVB2 and LVB1. C1, C2, HVB2, and LVB1 showed lower bottom-to-top hardness ratios at 4 mm than at 2 mm. Only LVB2 presented a bottom-to-top hardness ratio lower than 80% at 2 mm, while HVB1 surpassed this threshold at 4 mm of depth. The results suggest that the increase of composite thickness affected the shrinkage stress values. Also, thickness increase resulted in lower bottom-to-top hardness ratio. HVB1 showed better behavior than other bulk-fill materials, with low stress and adequate bottom-to-top hardness ratio at 4 mm thickness.

A case report of individualized ventilation in a COVID-19 patient - new possibilities and caveats to consider with flow-controlled ventilation.

BACKGROUND: Flow-controlled ventilation (FCV) is a novel ventilation method increasingly being used clinically, particularly during the current COVID-19 pandemic. However, the continuous flow pattern in FCV during inspiration and expiration has a significant impact on respiratory parameters and ventilatory settings compared to conventional ventilation modes. In addition, the constant flow combined with direct intratracheal pressure measurement allows determination of dynamic compliance and ventilation settings can be adjusted accordingly, reflecting a personalized ventilation approach. CASE PRESENTATION: A 50-year old women with confirmed SARS-CoV-2 infection suffering from acute respiratory distress syndrome (ARDS) was admitted to a tertiary medical center. Initial ventilation occurred with best standard of care pressure-controlled ventilation (PCV) and was then switched to FCV, by adopting PCV ventilator settings. This led to an increase in oxygenation by 30 %. Subsequently, to reduce invasiveness of mechanical ventilation, FCV was individualized by dynamic compliance guided adjustment of both, positive end-expiratory pressure and peak pressure; this intervention reduced driving pressure from 18 to 12 cm H2O. However, after several hours, compliance further deteriorated which resulted in a tidal volume of only 4.7 ml/kg. CONCLUSIONS: An individualized FCV approach increased oxygenation parameters in a patient suffering from severe COVID-19 related ARDS. Direct intratracheal pressure measurements allow for determination of dynamic compliance and thus optimization of ventilator settings, thereby reducing applied and dissipated energy. However, although desirable, this personalized ventilation strategy may reach its limits when lung function is so severely impaired that patient's oxygenation has to be ensured at the expense of lung protective ventilation concepts.

Individualized flow-controlled ventilation compared to best clinical practice pressure-controlled ventilation: a prospective randomized porcine study.

BACKGROUND: Flow-controlled ventilation is a novel ventilation method which allows to individualize ventilation according to dynamic lung mechanic limits based on direct tracheal pressure measurement at a stable constant gas flow during inspiration and expiration. The aim of this porcine study was to compare individualized flow-controlled ventilation (FCV) and current guideline-conform pressure-controlled ventilation (PCV) in long-term ventilation. METHODS: Anesthetized pigs were ventilated with either FCV or PCV over a period of 10 h with a fixed FiO2 of 0.3. FCV settings were individualized by compliance-guided positive end-expiratory pressure (PEEP) and peak pressure (Ppeak) titration. Flow was adjusted to maintain normocapnia and the inspiration to expiration ratio (I:E ratio) was set at 1:1. PCV was performed with a PEEP of 5 cm H2O and Ppeak was set to achieve a tidal volume (VT) of 7 ml/kg. The respiratory rate was adjusted to maintain normocapnia and the I:E ratio was set at 1:1.5. Repeated measurements during observation period were assessed by linear mixed-effects model. RESULTS: In FCV (n = 6), respiratory minute volume was significantly reduced (6.0 vs 12.7, MD - 6.8 (- 8.2 to - 5.4) l/min; p < 0.001) as compared to PCV (n = 6). Oxygenation was improved in the FCV group (paO2 119.8 vs 96.6, MD 23.2 (9.0 to 37.5) Torr; 15.97 vs 12.87, MD 3.10 (1.19 to 5.00) kPa; p = 0.010) and CO2 removal was more efficient (paCO2 40.1 vs 44.9, MD - 4.7 (- 7.4 to - 2.0) Torr; 5.35 vs 5.98, MD - 0.63 (- 0.99 to - 0.27) kPa; p = 0.006). Ppeak and driving pressure were comparable in both groups, whereas PEEP was significantly lower in FCV (p = 0.002). Computed tomography revealed a significant reduction in non-aerated lung tissue in individualized FCV (p = 0.026) and no significant difference in overdistended lung tissue, although a significantly higher VT was applied (8.2 vs 7.6, MD 0.7 (0.2 to 1.2) ml/kg; p = 0.025). CONCLUSION: Our long-term ventilation study demonstrates the applicability of a compliance-guided individualization of FCV settings, which resulted in significantly improved gas exchange and lung tissue aeration without signs of overinflation as compared to best clinical practice PCV.

Myocardial volume change during cardiac cycle derived from three orthogonal systolic strains: towards a quality assessment of strains.

BACKGROUND: The relative modification of the myocardial volume between end-systole and end-diastole ( Vs/d=Vend-systole/Vend-diastole ) has already been assessed with different methods and falls in a range of 0.9-0.97 (mean value = 0.93). PURPOSE: To estimate Vs/d from the three longitudinal ( ɛl) , circumferential ( ɛc ), and radial ( ɛr ) strains of the left ventricle using the formula: Vs/d=(1+ɛc)(1+ɛr)(1+ɛl) and to test whether this estimate of Vs/d can be used as a marker of the echocardiography quality. MATERIAL AND METHODS: Two hundred manuscripts, including a total of 34,690 patients or healthy volunteers, were identified in the Medline database containing values of ɛl , ɛc , and ɛr measured from echocardiography. RESULTS: The median value of was 0.93, in accordance with the literature, with no significant difference between patients or healthy volunteers ( P = 0.38). The proportion of studies with Vs/d=0.93±0.1 was 79%. When only considering groups of healthy volunteers, the studies failing this test had higher standard deviations for the three individual strains: 0.038 vs. 0.029 ( P = 0.02) for ɛl ; 0.060 vs. 0.034 ( P < 10-6) for ɛc , and 0.243 vs. 0.101 ( P < 10-14) for ɛr . CONCLUSION: The median ratio of the left ventricular myocardial volumes between end-systole and end-diastole in the investigated studies was Vs/d=0.93 . The formula (1+ɛc)(1+ɛr)(1+ɛl)∉[0.83;1.03] could be used to detect studies with inaccurate strain measurements.

Optimized Modeled Myofascial Release Enhances Wound Healing in 3-Dimensional Bioengineered Tendons: Key Roles for Fibroblast Proliferation and Collagen Remodeling.

OBJECTIVE: The purpose of this study was to evaluate the mechanisms of action of optimized myofascial release (MFR) on wound healing using a 3-dimensional human tissue construct. METHODS: Bioengineered tendons were cultured on a deformable matrix, wounded using a steel cutting tip, then strained in an acyclic manner with a modeled MFR paradigm at 103% magnitude for 5 minutes. Imaging and measurements of the width and wound size were performed daily, and the average tissue width of the entire bioengineered tendon was measured, and wound size and major and minor axes of the elliptical wound were additionally measured. Assessments of actin and collagen were performed by immunofluorescence, and Gomori's trichrome staining and fibroblast nuclei deposition was quantified using the CellProfiler analysis software. RESULTS: Optimized modeled MFR treatment significantly reduced the wound size and increased both collagen density and cell deposition at the wound site. All measures of wound healing improvements required the presence of proliferating fibroblasts. CONCLUSION: Myofascial release-induced cell deposition and collagen density at wound sites required actively proliferating fibroblasts. If clinically translatable, our results support a mechanism by which MFR improves patient wound healing.

Role of nifedipine and hydrochlorothiazide in MAPK activation and vascular smooth muscle cell proliferation and apoptosis.

BACKGROUND: Once hypertension is established, increased mechanical stretch stress becomes a leading cause of vascular remodeling. Clinical antihypertension guidelines demonstrate that antihypertension drugs prevent vascular remodeling in hypertensive patients mainly by lowering blood pressure, suggesting an indirect way of reducing the effects of stretch stress (hypertension). Whether these drugs can directly block the effects of the stretch stress on vascular remodeling has not been reported to date. This study was designed to answer this question and explore the underlying mechanisms. METHODS: Cultured quiescent vascular smooth muscle cells (VSMCs) were stimulated by stretch stress after pretreatment with nifedipine and hydrochlorothiazide. The phosphorylation levels of extracellular signal-regulated kinases (ERKs), c­Jun NH2-terminal protein kinases (JNKs), and p38 mitogen-activated protein kinase (MAPK) in VSMCs were detected via Western blotting. The treated cells were stained using triple-labeled immunofluorescence with Ki67 antibody and a TUNEL kit in the presence of DAPI for the detection of proliferative, apoptotic, and resting cells. RESULTS: Compared with the negative control, both nifedipine and hydrochlorothiazide had no influence on the phosphorylation of MAPKs and on the proliferation and apoptosis of VSMCs in resting state. Stretch stress could significantly induce increased phosphorylation of MAPKs as well as proliferation and apoptosis of VSMCs. Nifedipine inhibited the effects of stretch stress in a dose-dependent manner. Contrary to the effects of nifedipine, hydrochlorothiazide synergistically amplified the effects induced by stretch stress. CONCLUSION: Nifedipine and hydrochlorothiazide have opposing functions in the increased phosphorylation of MAPK and in the proliferation and apoptosis of VSMCs induced by stretch stress. The former plays a role as an inhibitor, while the latter functions as a promoter.

Effectiveness of Nerve Gliding Exercises on Carpal Tunnel Syndrome: A Systematic Review.

OBJECTIVE: The objective of this study was to review the literature regarding the effectiveness of neural gliding exercises for the management of carpal tunnel syndrome (CTS). METHODS: A computer-based search was completed through May 2014 in PubMed, Physiotherapy Evidence Database (PEDro), Web of Knowledge, Cochrane Plus, and CINAHL. The following key words were included: nerve tissue, gliding, exercises, carpal tunnel syndrome, neural mobilization, and neurodynamic mobilization. Thirteen clinical trials met the inclusion/exclusion criteria, which were: nerve gliding exercise management of participants aged 18 years or older; clinical or electrophysiological diagnostics of CTS; no prior surgical treatment; and absence of systemic diseases, degenerative joint diseases, musculoskeletal affectations in upper limbs or spine, or pregnancy. All studies were independently appraised using the PEDro scale. RESULTS: The majority of studies reported improvements in pain, pressure pain threshold, and function of CTS patients after nerve gliding, combined or not with additional therapies. When comparing nerve gliding with other therapies, 2 studies reported better results from standard care and 1 from use of a wrist splint, whereas 3 studies reported greater and earlier pain relief and function after nerve gliding in comparison with conservative techniques, such as ultrasound and wrist splint. However, 6 of the 13 studies had a quality of 5 of 11 or less according to the PEDro scale. CONCLUSION: Limited evidence is available on the effectiveness of neural gliding. Standard conservative care seems to be the most appropriate option for pain relief, although neural gliding might be a complementary option to accelerate recovery of function. More high-quality research is still necessary to determine its effectiveness and the subgroups of patients who may respond better to this treatment.

[Effects of low-frequency pulsed wave ultrasound on the shear properties of the interface of vancomycin-loaded acrylic bone cement-stem].

Objective: To investigate the effects of low-frequency pulsed wave ultrasound on the shear properties of interface of the vancomycin -loaded acrylic bone cement-stem. Methods: The interfaces of 1% vancomycin-loaded acrylic bone cement-stem specimences were successfully manufactured and randomly divided into three groups: the control group, 450 mW/cm(2) ultrasound group and 1 200 mW/cm(2) ultrasound group, each group consisted of eight samples.Two ultrasound groups were exposed to a local ultrasonic field for 7 d, then immersed in PBS for 23 d, and the control groups were immersed in PBS for 30 d. After curing in air for 24 h, the shear strength of the stem-cement interface was determined by push-out test.The specimens were then photographed using SEM and analysed using Image-Pro Plus 6.0 to determine the porosity at the stem-cement interface. Results: The mean shear strength of stem-cement interface additionally decreased by 9% (P>0.05) and 17% (P<0.05) in 450 mW/cm(2) ultrasound group and 1 200 mW/cm(2) group respectively comparing with the control group, but no significant difference was found between the two ultrasound groups.The porosity at the stem-cement interface additionally increased by 44% (P>0.05) and 110% (P<0.05) in 450 mW/cm(2) ultrasound group and 1 200 mW/cm(2) group respectively comparing with the control group, furthermore.The porosity in 1 200 mW/cm(2) ultrasound group increased by 46% (P<0.05) comparing with the 450 mW/cm(2) group. There are much more fluid penetration along the stem-cement interface in ultrasound group . Conclusion: Low-frequency pulsed wave ultrasound signifiantly enhanced porosity and fluid penetration interface, and reduced the interface shear strength and initial stability.

Segmental aortic stiffening contributes to experimental abdominal aortic aneurysm development.

BACKGROUND: Stiffening of the aortic wall is a phenomenon consistently observed in age and in abdominal aortic aneurysm (AAA). However, its role in AAA pathophysiology is largely undefined. METHODS AND RESULTS: Using an established murine elastase-induced AAA model, we demonstrate that segmental aortic stiffening precedes aneurysm growth. Finite-element analysis reveals that early stiffening of the aneurysm-prone aortic segment leads to axial (longitudinal) wall stress generated by cyclic (systolic) tethering of adjacent, more compliant wall segments. Interventional stiffening of AAA-adjacent aortic segments (via external application of surgical adhesive) significantly reduces aneurysm growth. These changes correlate with the reduced segmental stiffness of the AAA-prone aorta (attributable to equalized stiffness in adjacent segments), reduced axial wall stress, decreased production of reactive oxygen species, attenuated elastin breakdown, and decreased expression of inflammatory cytokines and macrophage infiltration, and attenuated apoptosis within the aortic wall, as well. Cyclic pressurization of segmentally stiffened aortic segments ex vivo increases the expression of genes related to inflammation and extracellular matrix remodeling. Finally, human ultrasound studies reveal that aging, a significant AAA risk factor, is accompanied by segmental infrarenal aortic stiffening. CONCLUSIONS: The present study introduces the novel concept of segmental aortic stiffening as an early pathomechanism generating aortic wall stress and triggering aneurysmal growth, thereby delineating potential underlying molecular mechanisms and therapeutic targets. In addition, monitoring segmental aortic stiffening may aid the identification of patients at risk for AAA.

Cortisol Reactivity to a physical stressor in Patients with Depression and Alzheimer's disease.

Some prevalent mental disorders in the elderly, such as Alzheimer's disease (AD) and major depression disorder (MDD), are associated with chronic stress and consequently with possible dysregulation of hypothalamic-pituitary-adrenal (HPA) axis and cortisol levels in basal conditions or in the reactivity of an acute stressor. However, evidence of cortisol behavior after a physical stressor in patients with AD and MDD is scarce. Objective: This study aimed to investigate the cortisol reactivity to a single session of physical exercise in patients with MDD and AD and compare it to healthy control (HC) older individuals. Methods: HC individuals (n=10) and elderly with clinical diagnostic of MDD (n=08) and AD (n=13) were submitted to a single bout of aerobic exercise in a treadmill during 30 minutes of moderate intensity. Salivary cortisol was collected before and after acute stressor. A repeated-measure analysis of variance (ANOVA), spearman correlation, and linear regression were performed. Results: The repeated-measure ANOVA revealed no interaction for cortisol on the moment×group [F(2.000, 28.000)=1.285; p=0.293] and no effect for group (F=0.323; p=0.727). However, a significant effect for moment [F(1.000, 28.000)=4.930; p=0.035] was found, with a decreased cortisol levels in postexercise for all groups. The effect size (ES) of cortisol reduction was small for patients with MDD (d=0.402) and trivial for patients with AD (d=0.166) and HC group (d=0.090). Conclusions: All participants show a decreased cortisol reactivity to a physical stressor, which can be associated with an impairment in coping with an acute stressor.

A doença de Alzheimer (DA) e o transtorno depressivo maior (TDM) são transtornos que acometem idosos e estão associadas ao estresse crônico e à desregulação do eixo hipotálamo-hipófise-adrenal (HPA), que repercute em alterações nos níveis de cortisol (basal e reatividade). Objetivo: Investigar a reatividade do cortisol em uma única sessão de exercício físico em pacientes com TDM e com DA e compará-la com a de idosos saudáveis. Métodos: Indivíduos controle saudáveis (n=10) e idosos com diagnóstico clínico de TDM (n=08) e DA (n=13) foram submetidos a uma única sessão de exercício aeróbio em esteira rolante, durante 30 minutos, em intensidade moderada. O cortisol salivar foi coletado antes e depois do estressor agudo. Na estatística, foram realizadas as análises de variância (ANOVA) de medidas repetidas, correlação de spearman e regressão linear. Resultados: Não foi encontrada interação para momento x grupo [F (2.000, 28.000)=1.285; p=0,293] e tampouco efeito para o grupo (F=0,323; p=0,727). Todavia, foi observado efeito significativo para o momento [F(1,000, 28,000)=4,930; p=0,035], mostrando diminuição dos níveis de cortisol no pós-exercício para todos os grupos. O tamanho do efeito (TE) foi considerado pequeno para o grupo TDM (d=0,402) e trivial para o DA (d=0,166) e o saudável (d=0,090). Conclusões: Todos os participantes apresentaram diminuição da reatividade do cortisol a um estressor físico, o que pode estar associado a um comprometimento no enfrentamento de um estressor agudo.

Speckle-Tracking Echocardiography in Cardio-Oncology and Beyond.

Speckle-tracking echocardiography has enabled clinicians to detect changes in myocardial function with more sensitivity than that afforded by traditional diastolic and systolic functional measurements, including left ventricular ejection fraction. Speckle-tracking echocardiography enables evaluation of myocardial strain in terms of strain (percent change in length of a myocardial segment relative to its length at baseline) and strain rate (strain per unit of time). Both measurements have potential for use in diagnosing and monitoring the cardiovascular side effects of cancer therapy. Regional and global strain measurements can independently predict outcomes not only in patients who experience cardiovascular complications of cancer and cancer therapy, but also in patients with a variety of other clinical conditions. This review and case series examine the clinical applications and overall usefulness of speckle-tracking echocardiography in cardio-oncology and, more broadly, in clinical cardiology.

Localization of Atypical Femoral Fracture on Straight and Bowed Femurs.

BACKGROUND: To elucidate the effect of anterolateral bowing on the fracture height of atypical femoral fractures (AFFs), we separated the AFFs into 2 groups according to the presence of anterolateral femoral bowing (straight group and bowing group) and analyzed the fracture height. The aims of this study were to evaluate the clinical and radiological features of AFFs in the straight group and bowing group, and to determine which factors were associated with the fracture height of AFFs in the total cohort and each subgroup. METHODS: Ninety-nine patients with AFFs were included in this study (43 patients in the bowing group and 56 patients in the straight group). Clinical and radiological characteristics were compared between the groups. Multivariable linear regression analysis was performed to determine the effect of factors on fracture height. RESULTS: Patients in the straight group were younger, heavier, and taller, and had a higher bone mineral density, smaller anterior and lateral bowing angles, and more proximal fracture height than those in the bowing group. Multivariable analysis showed that the presence of anterolateral bowing itself and height were associated with fracture height in the total cohort. In the subgroup analysis, the lateral bowing angle in the straight group and the estimated apex height in the bowing group were associated with fracture height. The lateral bowing angle was not significantly associated with fracture height in the total cohort and the bowing group. CONCLUSIONS: The presence of anterolateral bowing and the level of the apex of the bowed femur were important factors for the fracture height of AFFs.

[Design and finite element analysis of customized pelvic prosthesis].

OBJECTIVE: To introduce the design of customized pelvic prosthesis, to evaluate the biomechanical property under three load conditions of customized pelvic prosthesis under three load cinditions. METHODS: A titanium alloy prosthesis for reconstruction of pelvic tumors was designed by CAD software. The strength and stiffness of the custom prosthesis under static and slow gait conditions were analyzed and evaluated by finite element method. RESULTS: The results of the finite element analysis suggested that the maximum von Mises stress in the pelvic under three load conditions were 39.0, 202.8 and 42.4 MPa; the maximum displacement were 0.199, 0.766 and 0.847 mm. The maximum von Mises stress in the prosthesis under three load conditions were 62.3, 318 and 468 MPa. The maximum Von Mises stress in the Ti-alloy prosthesis and pelvic was far smaller than the yield strength of Ti-alloy. CONCLUSIONS: The study can design the size and shape of prosthesis accurately according to patient's condition. The finite element method can reduce the bone stress level and fracture risk, prolong the service life of prostheses, and ensure the safety and stability of the postoperative patients under normal gait.

[Three-dimensional finite element analysis of the stress distribution of bone tissue around porous titanium implant].

Objective: To analyze the stress distribution of different types of bone tissue around porous titanium implant in different mechanical loads and to further evaluate the biomechanical properties of porous titanium implant. Methods: Finite element (FE) models of implant restorations for the maxillary first premolar was established, and the diameter of implants in the models was 4.1 mm. Five models was constructed according to diameter of implant central pillar and the thickness of outer porosity: solid group (group A), central pillar 1.5 and 3.1 mm and outer porosity 30% (group B and C), central pillar 1.5 and 3.1 mm and outer porosity 40% (group D and E). Different loads (150 N vertical force, 50 N lateral force) were applied to the occlusal surface of implant restorations in type Ⅲ bone and maximal von Mises stress was evaluated. Meanwhile, a couple of simplified maxillary part models varied in four types of bone were constructed with the implants bearing load of simulation ultimate force to evaluate the stress distribution of different types of bone. Results: With different mechanical loading, the stress value of bone tissue around porous implant (group B-E) was greater than that in the solid structure (group A). Under the load of simulation ultimate force, the maximum stress of the bone rised with the increase of porosity and thickness of the porous implant. And the maximum stress value of the surrounding bone tissue changed with the change of bone. Under vertical loading, the maximal von Mises stress of the bone around solid implants of group A was 17.56 MPa, which was a little lower than that of group B and C. And the maximal equivalent von Mises stress of group D and E was 69.24 MPa. The results of lateral force and simulation ultimate force loading were similar. The stress of the bone tissue around implant increased with the decrease of bone quality. The maximum stress value of group D implant was 134.95 MPa. Conclusions: Porous structure of the implant is conducive to transmit stress to surrounding bone tissue and increases the mechanical stimulation of bone. However, if the value and direction of load are inappropriate or quality of bone is poor, pathological stress may be produced.

Shear-Sensitive lncRNA AF131217.1 Inhibits Inflammation in HUVECs via Regulation of KLF4.

Atherosclerosis is one of the most common vascular diseases, and inflammation participates in all stages of its progression. Laminar shear stress protects arteries from atherosclerosis and reduces endothelial inflammation. Long noncoding RNAs have emerged as critical regulators in many diseases, including atherosclerosis. However, the expression and functions of long noncoding RNAs subjected to laminar shear stress in endothelial cells remain unclear. This study aimed to reveal the mechanism by which shear stress-regulated long noncoding RNAs contribute to anti-inflammation. In this study, we identified a novel long noncoding RNA AF131217.1, which was upregulated after laminar shear stress treatment in human umbilical vein endothelial cells. Knockdown of AF131217.1 inhibited flow-mediated reduction of monocyte adhesion VCAM-1 (vascular cell adhesion molecule-1) and ICAM-1 (intercellular adhesion molecule-1) expression and inhibited flow-mediated enhancement of flow-responsive expression of KLF (Kruppel-like factor) 2 and eNOS (endothelial NO synthase). Furthermore, TNF-α (tumor necrosis factor-α) was used to induce an inflammatory response in human umbilical vein endothelial cells. Knockdown of AF131217.1 promoted ICAM-1 and VCAM-1 expression, as well as changes in monocyte adhesion and KLF2 and eNOS expression induced by TNF-α. Mechanistic investigations indicated that AF131217.1 acted as a competing endogenous RNA for miR-128-3p, leading to regulation of its target gene KLF4. In conclusion, our study demonstrates for the first time that laminar shear stress regulates the expression of AF131217.1 in human umbilical vein endothelial cells, and the AF131217.1/miR-128-3p/KLF4 axis plays a vital role in atherosclerosis development.

BIOMECHANICAL COMPARISON OF MEDIAL VERSUS LATERAL SIDED PLATING IN FEMORAL FRACTURES.

OBJECTIVE: The aim of the present study was to determine whether the side of application of the plate itself affects the mechanical stability of the fixation. The specific question addressed is whether or not a lateral or medial plate application is biomechanically better, for the treatment of distal diaphysis fractures of the femur. METHODS: Stability and stiffness of medial sided plating relative to the conventional lateral sided plating in distal diaphysis of the femur were measured by analyzing axial loading forces leading to implant failure. Sixty synthetic femurs were tested in physiological bending, to calculate the yield and ultimate load to displacement following fixation of distal diaphysis fractures of the femur by either medial or lateral sided plating. Axial loading was applied to samples using a uniaxial testing machine. RESULTS: There was more implant deformation in the lateral sided plating group - a difference with statistical significance. CONCLUSION: Medial sided plating was found to be as stiff as lateral plating. Medial plating may be a reasonable treatment option that can be used safely in selected cases. Level of Evidence I, Therapeutic Studies Investigating the Results of Treatment.

OBJETIVO: O objetivo deste estudo foi determinar se o lado de aplicação da placa em si afeta a estabilidade mecânica da fixação. A questão específica abordada é se a aplicação da placa lateral ou medial é melhor ou não em termos biomecânicos para o tratamento das fraturas da diáfise distal do fêmur. MÉTODOS: A estabilidade e a rigidez da placa medial com relação à lateral, convencional na diáfise distal do fêmur, foram medidas pela análise das forças de carga axial que levam à falha do implante. Sessenta fêmures sintéticos foram testados em flexão fisiológica, para calcular a tolerância e a carga final para o deslocamento após a fixação das fraturas diafisárias distais do fêmur com placa medial ou lateral. A carga axial foi aplicada às amostras usando máquina de teste uniaxial. RESULTADOS: Verificou-se maior deformação do implante no grupo de placa lateral ­ diferença com significância estatística. CONCLUSÃO: Constatou-se que a placa medial era tão rígida quanto a lateral. A placa medial pode ser uma opção de tratamento razoável e segura em casos selecionados. Nível de evidência I, Estudos terapêuticos - Investigação dos resultados do tratamento.

Deep Friction Massage and the Minimum Skin Pressure Required to Promote a Macroscopic Deformation of the Patellar Tendon.

OBJECTIVE: The purpose of this study was to determine the skin pressure needed to promote the macroscopic deformation of the asymptomatic patellar tendon and to verify if the pressure is associated with the individual's characteristics. METHODS: A descriptive laboratory study was performed with a convenience sample of 18 young, voluntary, and asymptomatic individuals of both sexes. A progressively increasing pressure was applied on the skin over the patellar tendon, through an instrument designed to perform and control the pressure upon an ultrasound probe; data were recorded and analyzed by 2 blind investigators. All statistical analyses were conducted considering α = 0.05. RESULTS: The average pressure needed to promote a macroscopic deformation of the patellar tendon was 1.12 ± 0.37 kg/cm2. Female sex and age were inversely but not significantly associated with the pressure performed. Sports practice, weight, height, body mass index, muscle mass, and subcutaneous thickness were positively but not significantly associated with the pressure executed. CONCLUSION: The average pressure needed to promote the macroscopic deformation of the patellar tendon was 1.12 ± 0.37 kg/cm2, which was not influenced by the characteristics of the participants.

Biomechanical analysis of narrow dental implants for maxillary anterior rehabilitation / Análise biomecânica de implantes de diâmetro reduzido para reabilitação da região anterior da maxila

Introdução: O conhecimento da biomecânica de implantes de diâmetro reduzido indica dimensões seguras para uso clínico. Objetivo: O objetivo do presente estudo foi comparar biomecanicamente implantes de diâmetro regular e reduzido para suporte de próteses implantossuportadas unitárias na região anterior da maxila por meio de análise de elementos finitos 3D (3D-FEA). Material e método: Quatro modelos 3D-FEA foram desenvolvidos a partir de recomposição de tomografia computadorizada e dados da literatura: um bloco ósseo na região incisiva lateral superior direita com implante e coroa. M1: 3,75 x 13 mm, M2: 3,75 x 8,5 mm, M3: 2,9 x 13 mm e M4: 2,9 x 8,5 mm. Foi aplicada carga de 178 N nos ângulos 0, 30 e 60 graus em relação ao longo eixo do implante. Foram avaliados mapas de tensão de Von Mises, tensão principal máxima e microdeformação. Resultado: M3 e M4 apresentaram maiores valores de tensão e microdeformação que M1 e M2, principalmente quando foram aplicadas forças inclinadas. Porém, M3 apresentou comportamento biomecânico melhor do que M4. Conclusão: Pode-se concluir que reduzir o diâmetro dos implantes pode prejudicar a biomecânica durante a aplicação de forças, mas a distribuição e intensidade das tensões, bem como os valores de microdeformação podem ser melhorados se o comprimento do implante for aumentado

Introduction: Narrow diameter implants biomechanics knowledge indicates safe dimensions for clinical use. Objective: Purpose of the present study was biomechanically to compare regular and narrow diameter implants to support single implant-supported prosthesis in the anterior region of the maxilla by 3D finite element analysis (3D-FEA). Material and method: Four 3D-FEA models were developed form CT scan recompositing and literature data: a bone block in the right upper lateral incisive region with implant and crown. M1: 3.75 x 13 mm, M2: 3.75 x 8.5 mm, M3: 2.9 x 13 mm and M4: 2.9 x 8.5 mm. It was applied load was of 178 N at 0, 30 and 60 degrees in relation to implant long axis. Von Mises stress, maximum principal stress and microdeformation maps were evaluated. Result: M3 and M4 did show higher tension and higher microdeformation values than M1 and M2, especially when inclined forces were applied. However, M3 presented enhanced biomechanical behavior than M4. Conclusion: It can be concluded that reduce the diameter of the implants can disadvantage to the biomechanics during the application of forces, but the distribution and intensity of the stresses, as well as the micro deformation values can be improved if the length of the implant is increased

Low-Stress Mechanical Property Study of Various Functional Fabrics for Tactile Property Evaluation.

Functional finishing brings an alteration on the mechanical and surface properties of textile materials and henceforth influences the tactile properties. In this work, Kawabata evaluation systems (KES) for fabrics were utilized to notice the changes in the tactile properties of fabrics resulting from different finishing types such as inkjet printing, screen printing, and coating. The effects of functional finishing on the fabric's tactile property were inconsistent with reference to the course of decrease or increase being dependent on the types of finishes. The findings showed that KES can be employed as a promising tool to sort out the suitable functional finishing types in terms of tactile properties. Amongst the implemented finishing types, inkjet printing offered superior tactile properties with respect to tensile energy (softness), shear rigidity, compressional softness, bending stiffness (drapability), and surface properties. The KES results confirmed that low-stress mechanical properties are strongly associated with the tactile property and might assist as a quality profile data source for guaranteeing the production and development of a virtuous quality product. The result encourages further utilization of the KES for functional fabric tactile property evaluation.