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Department of Orthopedics, Yang Pu Hospital Affiliated to Tongji University,
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Objective To explore the effects of osmotic pressure on biomechanical properties and immune function of immature dendritic cells (imDCs) from mechanobiological viewpoint. Methods After treated with different osmotic pressures, the cell viability of imDCs was detected using cell counting kit-8 (CCK-8). The changes in morphology of imDCs were observed under laser scanning confocal microscope. Cell electrophoresis was applied to detect the changes in cell electrophoresis mobility. The membrane fluidity of the cells was detected by fluorescence polarization method, and the expression changes of immune-related molecules were detected by real-time fluorescent quantitative PCR (qPCR). The phagocytic ability of the cell was detected by flow cytometry. ResultsBoth hyperosmosis and hypoosmosis could remodel the cyoskeletonof cells, even induce apoptosis. The electrophoresis mobility of the hypoosmosis group was significantly higher than that of the normal osmolarity group, while that of the hyperosmosis group was lower than that of the normal osmolarity group (P<0-05). Fluorescence polarization results showed that both hyperosmosis and hypoosmosis could significantly decrease the membrane fluidity of cells (P<0-05). The results of qPCR detection showed that both hyperosmosis and hypoosmosis could significantly increase the expression of CCR7, CD40, CD205, CD11a, CD11c on the surface of DCs, and the phagocytosis of cell was increased (P<0-05). Conclusions Hypertonic and hypotonic stress can influence biomechanical properties of imDCs and expression of immune-related molecules. The research findings are important for further understanding the immune regulation function of DCs.
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@#【Objective】 To examine a potential correlation between corneal biomechanical properties with lamina cribrosa thickness.【Methods】Thirty-two patients with POAG，20 with NTG，15 with OHT and 26 healthy controls were included in the cross- sectional study. The parameters of corneal biomechanical properties and lamina cribrosa thickness were compared among POAG，NTG，OHT and healthy subjects by mixed-model analysis of variance（ANOVA）. Spearman′ s coefficient of rank correlation analysis was used to assess the association between parameters of deformation response and clinical factors. 【Results】 The Cronbach′ s α of lamina cribrosa thickness was 0.911，and ICC was more than 0.8. Laminar thickness was thinner in the POAG and NTG groups than in the OHT group and Normal group（P < 0.05）. There were no significant differences between OHT and normal groups（P = 0.653）. Correlation analysis showed that LCT and some important corneal biomechanical properties had significant correlation （P = 0.000）. 【Conclusions】 LCT showed different characteristic in glaucoma，and it may be an important factor for glaucoma progression. LCT and corneal biomechanical properties showed significant correlation ，and corneal biomechanical properties may be used to evaluate the biomechanical properties of optic nerve.
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Objective To compare the differences of corneal biomechanics in different types of glaucoma and its related influence factors,and to investigate the change trends of cornea biomechanics after the operations.Methods In a prospective comparative case series,61 eyes of 61 acute primary angle-closure glaucoma (APACG)(remission or chronic phase)patients,94 eyes of 94 chronic primary angle-closure glaucoma (CPACG) patients,70 eyes of 70 primary open angle glaucoma (POAG) patients and 64 eyes of 64 age-related cataract (ARC) patients were recruited in Tianjin Eye Hospital from January to July,2017.Corneal biomechanical properties were measured by using Corvis ST.The differences of corneal biomechanics in different types of glaucoma and the change trends after surgeries were assessed;the association between parameters and the age,intraocular pressure after correction (IOPcc),central cornea thickness (CCT),axial length (AL),average corneal diopter (K) were assessed by multiple linear regression analysis.This study followed the Declaration of Helsinki.This study protocol was approved by Ethic Committee of Tianjin Eye Hospital (TJYYLL-2016-17).Written informed consent was obtained from each subject prior to any medical examination.Results Compared with the ARC group,the first applanation velocity (A1V)and second applanation time (A2T) were both smaller in preoperative CPACG,POAG groups (all at P＜0.05);compared with the ARC group and APACG group,second applanation velocity (A2V) was larger in preoperative CPACG,POAG groups,the differences were all statistically significant (all at P＜0.05).A1V,A2T,deformation amplitude (DA) and peak distance (PD) were negatively correlated with IOPcc (r =-0.494,-0.612,-0.652,-0.277;all at P＜0.05),A2V,first applanation time (A1T) and central curvature radius (CCR) were positively correlated with IOPcc (r =0.508,0.960,0.249;all at P ＜ 0.05);first applanation length (A1 L) and second applanation length (A2L) were negatively correlated with K (r =-0.323,-0.227;both at P＜0.05);A 1 V,A2T and DA were positively correlated with K (r =0.214,0.256,0.242;all at P＜0.05).Compared with preoperative,the A1T and A2V were reduced,A1V,A2T and DA were increased in one month after surgery in CPACG group;the A1T and A2V were reduced,the A2T and DA were increased in one month after surgery in POAG group,and the differences were all statistically significant (all at P＜0.05).Compared with preoperative,there were no statistically significant differences between the parameters in one month after surgery in APACG group and ARC group (all at P ＞0.05).Conclusions CPACG and POAG have poorer ability of corneal deformation,which gradually returns to normal after surgery;because the intraocular pressure of APACG (remission or chronic stage) return to normal after transient elevated stage,the corneal biomechanics is basically similar to ARC,which has no difference between pre-and pos-operation.The parameters of corneal biomechanics are affected by IOPcc and K.
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A novel testing system is designed to simulate the mechanical performance and evaluate the biomechanical properties of the bone and the corresponding bone fixator. It is mainly composed of movement platform and servo motor system, sensors and hardware circuit system and software system. In order to prove the feasibility of the design, on the basis of the calibration for the force sensor, the fatigue experiment is carried out using the tibia of the sheep. It is concluded from the result that under the condition of 1 Hz in frequency, 50 kg in loading force and 18 000 cycles, the bone fixator can be still in good condition, which proves the feasibility of the design.
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Animals , Biomechanical Phenomena , Bone Screws , Mechanical Phenomena , Sheep , Stress, Mechanical , Tibia , PhysiologyABSTRACT
Objective To investigate the correlations between corneal biomechanical properties and corneal high-order aberrations (HOAs) in myopic eyes.Methods In this retrospective study,263 right eyes with myopia or myopic astigmatism were enrolled from January to October 2015 in Tianjin Eye Hospital.The values of first applanation time (A1T),first applanation length (A1L),first applanation velocity (A1V),second applanation time (A2T),second applanation length (A2L),second applanation velocity (A2V),highest concavity time (HCT),highest concavity deformation amplitude (HCDA),highest concavity peak distance (HCPD),highest concavity radius (HCR) and non-contact intraocular pressure (IOPnct) were measured using the corneal visualization Scheimpflug technology (Corvis ST).The central corneal thickness (CCT) and wavefront aberrations of the anterior,posterior surface,and the total cornea were measured with Pentacam.Pearson correlation and stepwise multivariate linear regression analysis were applied to analyze the correlations between biomechanical properties and corneal HOAs.This study follows the Helsinki declaration.The experiment was approved by the Ethic Committee of Tianjin Eye Hospital.Informed consent was signed from each patient.Results There was a correlation between biomechanical properties and corneal HOAs.Negative correlations were found between A1L and the spherical aberration,HOAs RMS of anterior surface,total RMS and HOAs RMS of the posterior surface and HOAs RMS of the total cornea (P＜0.05).HCRs were negatively correlated with total RMS of the total cornea and the anterior surface (P＜0.05).The A2V was correlated with various aberrations.Multiple stepwise linear regression model analysis showed that,the correlation between the aberrations of anterior surface and biomechanical parameters,and the correlations between the total corneal aberration and biomechanical parameters were weak,the correlations between the aberrations of posterior surface and biomechanical parameters were strong.Conclusions There is a correlation between the biomechanical properties and corneal HOAs.The changes of the corneal biomechanical properties are mainly associated with the posterior corneal aberrations,which may contribute to the early diagnosis of subclinical keratoconus or dilated corneal disease.
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Objective To measure biomechanical parameters of the cornea after keratoconus and laser corneal refractive surgery by Scheimpflug noncontact tonometry (Corvis ST),and analyze the changes and differences in these parameters.Methods From April 2011 to November 2016,63 patients (96 eyes) with clinically diagnosed as keratoconus were selected as the keratoconus group,and 60 patients (120 eyes) underwent laser corneal refractive surgery between November 2016 to March 2017 were selected as postoperative cornea group,and totally 51 healthy person (102 eyes) who received physical examination during the same period were selected as healthy cornea group.Scheimpflug noncontact tonometry (Corvis ST) was performed to measure the length of appl 1,length of appl 2,velocity of appl 1,velocity of appl 2,maximum deformation amplitude,apex distance and radius of curvature in the three groups.Total comparison of biomechanical parameters was performed using ANOVA test among the three groups,while pairwise comparison was performed to analyze the difference of these parameters by SNK methods.Pearson or Spearman correlation analysis was applied to assess the differences in corneal morphological and biomechanical parameters.Results There was no significant difference in length of appl 1,length of appl 2 of the three groups (all P ＞ 0.05).And velocity of appl 1 in the keratoconus group was significantly higher than that of the healthy cornea group [(0.189 ± 0.230) m · s-1 vs.(0.151 ± 0.017)m · s-1] (P ＜ 0.05).As for velocity of appl 2,the keratoconus group was larger than the healthy cornea group,both which were larger than the postoperative cornea group,and the differences were significant (all P ＜ 0.05).And this was true of maximum deformation amplitude in the three groups,with the significant differences(all P ＜ 0.05).The apex distance in the keratoconus group was significantly longer than that in the healthy cornea group (P ＜ 0.05).The radius of curvature of the keratoconus group,postoperative cornea group and healthy cornea group were (5.696 ± 0.881) mm,(7.129 ± 0.681) mm and (7.012 ± 0.728) ram,respectively,which approached significant differences(all P ＜ 0.05).There was significant correlation between the anterior surface refractive power (Km) and apex distance and radius of curvature in the keratoconus group (r =-0.205,0.1 84;P =0.023,0.041),and maximum posterior surface elevation had a statistically significant correlation with velocity of appl 2,maximum deformation amplitude and radius of curvature (r =-0.579,-0.307,0.256,P =0.022,0.002,0.000).For the eyes in the postoperative cornea group,there were no significance correlation between the anterior surface refractive power (Km) and biomechanical properties (P ＞ 0.05),but significant correlation with length of appl 2 (r =-0.297,P =0.026).There were no significant correlation between maximum posterior surface elevation and biomechanical properties (P ＞ 0.05).Conclusion The corneal biomechanical parameters are decreased in eyes after keratoconus and laser corneal refractive surgery,and Corvis ST can become an auxiliary examination tool for earlier diagnosis of secondary keratoconus after corneal refractive surgery.
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Este trabajo tiene como objetivo conocer los avances más novedosos relacionados con el estudio de las características biomecánicas de la córnea y su posible relación en el diagnóstico del glaucoma. Se realizó una búsqueda en la plataforma Infomed, específicamente en la Biblioteca Virtual de Salud, con el objetivo de conocer los avances más novedosos relacionados con el estudio de las características biomecánicas de la córnea y su posible relación en el diagnóstico del glaucoma. La biomecánica corneal es la facultad de resistencia y flexión simultánea de las moléculas de colágeno en las diferentes capas de la córnea. Trata del equilibrio y de la deformación del tejido corneal sometido a cualquier acción exterior. La histéresis corneal, junto con el factor de resistencia corneal, son medidas que pueden ser proporcionadas por el analizador de respuesta ocular. La existencia de un bajo valor de estas dos medidas pudiera considerarse como un factor de riesgo de progresión en el glaucoma(AU)
The purpose of this work is to know the more novel advances related with the study of the biomechanic characteristic of the cornea and its possible relationship in the diagnosis of the glaucoma. A search was made in Infomed platform, particularly in the Virtual Library of Health, to find out the most advanced in the study of the corneal biomechanical properties and its possible relation with the diagnose of glaucoma. Corneal biomechanical is the power of the resistance and flexion simultaneity of collagen molecules of the different corneal layer. It is the balance and deformity of the corneal tissue submitted to an external action. Corneal hysteresis and corneal resistance factor are two corneal biomechanical properties measured by the Ocular Response Analyzer. The existence of a low value of these two properties may be considered as progression factors in glaucoma(AU)
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Humans , Cornea/physiopathology , Glaucoma/diagnosis , Review Literature as Topic , Technological Development/adverse effectsABSTRACT
Objective:To research the effect of lumbar spinal nerve block combined with ultrashort wave on the pain and biomechanics of lumbar back muscle of patients biomechanics with lumbar disc.Methods:98 patients with lumbar disc herniation in our hospital from February 2014 to August 2016,according to the lottery method divided into control group and research group.The control group was treated with Lumbar spinal nerve block.The research group was based on the control group treated with ultrashort wave,clinical curative effect,changes of the visual analogue scale (VAS),60 ° /s angular velocity,120° /s average apical power (AP),peak torque (PT),lumbar dorsiflexion / dorsal flexion (F/E),serum levels of substance P (SP),β-endorphin (β-EP),interleukin-6 (IL-6),tumor necrosis factor-α (TNF-α) before and after treatment,and adverse reactions were compared between two groups.Results:The total effective rate of research group was95.91％,which was significant higher than that of the control group,the difference was statistically significant (P＜0.05).After treatment,The VAS,F/E,serum levels of SP,IL-6 and TNF-α of two groups were significantly lower than those before treatment,the above indicators of research group were significantly lower than those of the control group.The AP,PT and serum levels of β-EP between two groups were significantly higher than those before treatment,the above indicators of research group were significantly higher than those of the control group (P＜0.05).No statistical difference was found in the incidence of adverse effects between the two groups (P＞0.05).Conclusion:Umbar spinal nerve block combined with ultrashort wave was more effective than lumbar paravertebral nerve block treatment alone in the treatment of lumbar disc herniation,it could effectively relieve the pain and improve the low back muscle biological mechanics performance and reduce the inflammatory response.
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Aim To investigate the skeletal effects of ginseng flower bud(GF)on osteopenia induced by D-galactose using histomorphometry and biomechanical properties.Methods Fifty three-month-old male Sprague-Dawley rats were randomly divided into five groups.Rats in NS group(NS)were treated with NS(5 mL·kg-1·d-1)by subcutaneous injection and daily oral gavage with vehicle as control.Rats in the other four groups were given D-galactose at the dose of 100 mg·kg-1·d-1 by subcutaneous injection.Solvent control was performed between NS and DG: gastric irrigation with distilled water of 10 mL·kg-1·d-1.Other groups were: CP was gastric irrigated with integrated medicine(stanozolol 0.54 mg·kg-1·d-1+piracetam 432 mg·kg-1·d-1),GF(L)with ginseng flower bud of 0.486 g·kg-1·d-1 and GF(H)with ginseng flower bud of 2.43 g·kg-1·d-1 for 14 weeks.The longitudinal proximal tibial metaphyseal(PTM),the fifth lumbar vertebral body(LVB)and tibial shaft(Tx)sections were performed undecalcifiedly and used for bone histomorphometric analysis.858 Mini Bionix materials testing system was used to analyze the biomechanic properties of right femur via three-point bending test.The left femur was dried and assimilated,whose bone calcium(Ca),phosphate(P)content and bone hydroxyproline content were tested.Results Compared with D-glagatose group,in PTM of D-galactose treated rats,the％Tb.Ar was increased both in GF(L)and GF(H)treated groups.While the Tb.Sp was decreased.％Oc.S.Pm and Oc.N/mm decreased in GF(L),and those in GF(H)were decreased as well.In Tx,％Ct.Ar was raised,while％Ma.Ar was decreased in GF(L)and GF(H).The elastic load of femur was increased.Conclusions Compared with DG group,there are significant differences in bone histomorphometry of Tx and PTM in all doses of GF,but no significant changes are detected in hydroxyproline,Ca,and P content of femur.
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Background Keratoconus is a chronic and progressive non-inflammatory ectatic disorder characterized by corneal thinning and irregular corneal topography,and its pathgenesis is a hot topic.A suitable animal model of keratoconus is still lacking,which limits the progress of relevant research.Corneal ectasia is a main anatomical basis of keratoconus,so we assume that keratoconus model could be constructed by simulating corneal ectasia.Objective This study was to investigate the influence of collagenase type Ⅱ on biomechanical responses detected by corneal visualization Scheimpflug technology (Corvis ST) and the feasibility of construction of rabbit model of corneal ectasia using coliagenase type Ⅱ.Methods This study protocol was approved by Ethic Committee of Peking University First Hospital and followed the Statement about experimental animal use and care from Association for Research in Vision and Ophthalmology (ARVO).Keratectasia models were established in 10 right eyes of 10 New Zealand white rabbits by soaking 8 mm-diameter central cornea using collagenase type Ⅱ solution prepared by PBS solution containing 15％ dextran (200 μl of 5 mg/ml) for 30 minutes after epithelial debridement,and only 200 μl PBS solution containing 15％ dextran was used in the same way in the left eyes as controls.The average corneal curvature (Km) and central corneal thickness (CCT) were measured with hand-held electronic corneal curvature meter and corneal ultra-sonic pachymetry respectively before modeling and 14 days after modeling.Corneal biomechanical parameters and intraocular pressure were measured in vivo by using Corvis ST at day 14 after modeling.The rabbits were sacrificed at day 14 after modeling,and corneal sections were prepared for hematoxylineosin staining and transmission electron microscopic examination.Results There were no significant differences in Km and C CT between model group and control group before modeling (Km:[48.28±2.29] D vs.[48.82± 1.63] D;CCT:[356.50± 19.13] μm vs.[356.20±21.66] μm;both at P＞0.05).The Km increased to (48.87±2.27) D and CCT decreased to (340.40±19.84)μm at day 14 after modeling,which were significantly different from (46.86±1.47) D and (367.80±23.38)μm (both at P＜0.01).The maximal deformation amplitude of model group and control group was (1.25±0.07) mm and (1.15 ±0.13) mm,respectively,showing a considerable difference between them (t=2.65,P＜0.05).No significant differences were found in applanation 1/2 time,applanation 1/2 length,applanation velocity,radius of curvature and peak distance between the two groups (all at P＞0.05).The morphology and ultrastructure examinations revealed that the arrangement of collagen fibers was loose and disorder and the interfiber space was enlarged in comparison with control group.Conclusions Collagenase type Ⅱ can lower corneal biomechanical properties.Soaking of cornea with collagenase type Ⅱ may be a potential way to establish a keratectasia animal model.
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Tissue engineering as a high technology solution for treating disc's problem has been the focus of some researches recently; however, the upcoming successful results in this area depends on understanding the complexities of biology and engineering interface. Whereas the major responsibility of the nucleus pulposus is to provide a sustainable hydrated environment within the disc, the function of the annulus fibrosus (AF) is more mechanical, facilitating joint mobility and preventing radial bulging by confining of the central part, which makes the AF reconstruction important. Although the body of knowledge regarding the AF tissue engineering has grown rapidly, the opportunities to improve current understanding of how artificial scaffolds are able to mimic the AF concentric structure—including inter-lamellar matrix and cross-bridges—addressed unresolved research questions. The aim of this literature review was to collect and discuss, from the international scientific literature, information about tissue engineering of the AF based on scaffold fabrication and material properties, useful for developing new strategies in disc tissue engineering. The key parameter of this research was understanding if role of cross-bridges and inter-lamellar matrix has been considered on tissue engineering of the AF.
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Biology , Intervertebral Disc , Joints , Tissue EngineeringABSTRACT
ABSTRACT Background Stretching exercises are able to promote adaptations in the muscle-tendon unit (MTU), which can be tested through physiological and biomechanical variables. Identifying the key variables in MTU adaptations is crucial to improvements in training. Objective To perform an exploratory factor analysis (EFA) involving the variables often used to evaluate the response of the MTU to stretching exercises. Method Maximum joint range of motion (ROMMAX), ROM at first sensation of stretching (FSTROM), peak torque (torqueMAX), passive stiffness, normalized stiffness, passive energy, and normalized energy were investigated in 36 participants during passive knee extension on an isokinetic dynamometer. Stiffness and energy values were normalized by the muscle cross-sectional area and their passive mode assured by monitoring the EMG activity. Results EFA revealed two major factors that explained 89.68% of the total variance: 53.13% was explained by the variables torqueMAX, passive stiffness, normalized stiffness, passive energy, and normalized energy, whereas the remaining 36.55% was explained by the variables ROMMAX and FSTROM. Conclusion This result supports the literature wherein two main hypotheses (mechanical and sensory theories) have been suggested to describe the adaptations of the MTU to stretching exercises. Contrary to some studies, in the present investigation torqueMAX was significantly correlated with the variables of the mechanical theory rather than those of the sensory theory. Therefore, a new approach was proposed to explain the behavior of the torqueMAX during stretching exercises.
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Humans , Tendons/physiology , Range of Motion, Articular/physiology , Muscle, Skeletal/physiology , Muscle Stretching Exercises , Muscle Contraction/physiology , Factor Analysis, Statistical , Torque , Electromyography , Muscle Stretching Exercises/standardsABSTRACT
Objective To study biomechanical properties such as range of motion (ROM), intervertebral disc stress, ligament tension of inferior cervical spinal segment after the treatment of Discover, Prodisc-C artificial intervertebral disc replacement, and anterior cervical discectomy and fusion (ACDF), as well as mechanical property changes of the prosthesis after implantation. Methods Three kinds of operation plan on C5-6 cervical disc degeneration were established: Discover model, Prodisc-C model and ACDF model, as well as C4-7 segment original model of cervical vertebra. Biomechanical property changes after operation in cervical spine C4-7 segment in sagittal, coronal and transverse section were analyzed. Results ROM changes of cervical segment C5-C6 were as following: in Discover model it increased by 12.7%-73.1%, Prodisc-C model increased by 74%-98%, ACDF decreased by 55.8%-71.8%. The stress of C4-5 intervertebral disc after Discover artificial disc replacement showed no obvious increase, while the stress of C6-7 intervertebral disc decreased by 33.2%-54.2% under flexion, extension and axial rotation conditions. The amplification of ligament tension in Discover model decreased by 30%-40% as compared to that in Prodisc-C model. The maximum stress of Discover model (36.72 MPa) appeared under flexion condition, which was smaller than that in Prodisc-C model. Conclusions Artificial disc replacement can help to keep movement performance for segment after surgery. As a newly developed artificial intervertebral disc prosthesis, Discover makes some progress in the aspect of decreasing ligament stress and maintaining spinal stability. The research findings will provide theoretical basis for the clinical study on ACDF and artificial cervical intervertebral disc replacement surgeries.
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Objective To explore the effect of ultra-early hyperbaric oxygenation (HBO) on bone calcium, biomechanical properties and bone collagen of femur in rats with complete spinal cord transaction. Methods A total of 75 Sprague-Dawley rats were randomly divided in-to sham group (n=15), model group (n=20) and HBO group (n=40). HBO group was divided into three hours group (HBO1 group, n=20) and twelve hours group (HBO2 group, n=20). All groups underwent laminectomy at T10, while the model group, HBO1 group and HBO2 group underwent complete spinal cord transection at the same level. Three hours and twelve hours after surgery, HBO1 group and HBO2 group received HBO, respectively, for three courses with ten days in a course. After treatment, the femoral biomechanical properties, bone calcium and hydroxyproline (Hyp) were determined. The morphology of bone trabecula and the bone collagen was observed with HE stain-ing and Masson triad color staining, respectively. Results After treatment, compared with the sham group, the femoral biomechanical proper-ties, the content of bone calcium and Hyp decreased in the model group (P<0.05);compared with the model group and HBO2 group, they in-creased in HBO1 group (P<0.05). The number of bone trabecula and the bone collagen decreased, and derangement and sparseness were ob-served in the model group;however, the changes were substantially mild in HBO1 group. Conclusion Ultra-early HBO could increase the content of bone calcium and Hyp of femur, improve the morphology of the femur bone collagen, and improve the femoral biomechanical properties in rats with complete spinal cord transection.
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Background Corneal biomechanical properties is important in the safety assessment of corneal refractive surgery.Corvis is a new device for measuring corneal biomechanics properties.Objective This study was to observe the correlation among corneal thickness, Corvis intraocular pressure and corneal biomechanical properties with Corvis.Methods A prospective observational study was performed.One hundred and fifty eyes of 75 patients with corneal thickness from 501 μm to 590 μm were divided into three groups according to the corneal thickness:low corneal thickness group (corneal thickness range from 501 μm to 530 μm), middle corneal thickness group (corneal thickness range from 531 μm to 560 μm) ,and high corneal thickness group (corneal thickness range from 561 μm to 590 μm);and 50 eyes of 25 patients for each group.The difference of intraocular pressure, corneal thickness and deformation amplitude (DA) among the three groups were analyzed by one-way ANOVA and the correlation among the groups were analyzed by liner regression.Results The DA in the low corneal thickness group and middle corneal thickness group were significantly higher than that in the high corneal thickness group (P ＜ 0.05).The intraocular pressure was statistically different among the 3 groups (F =9.98, P＜0.05).DA was negatively correlated with intraocular pressure and corneal thickness (r=-0.84,-0.33;both at P＜0.01), with the linear regression DA =1.69-0.04×IOP (F=366.19, t=-19.14,P＜0.01).Conclusions Corneal thickness cannot simply represent the corneal biomechanical properties in the safety assessment of corneal refractive surgery,IOP should be considered.
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Background Recent studies have demonstrated that glaucoma progression had great relationship with corneal biomechanical properties.However,there are not enough studies about corneal biomechanical properties in different types of glaucoma.Objective This study was to evaluate the corneal biomechanical properties in chronic primary angle-closure glaucoma (CPACG) and primary open angle glaucoma (POAG).Methods Prospective observational study was adopted.Sixty-eight cases (68 eyes) with CPACG and 69 POAG patients (69 eyes) from Zhongshan Ophthalmic Center were investigated by a novel technique named Corvis-ST which can measure corneal deformation.The Cronbach's αt coefficient and intraclass correlation coefficient (ICC) were used to evaluate the repeatability of the parameters from Corvis-ST.The differences of corneal biomechanical properties between POAG and CPACG were evaluated by independent-samples t test.Multiple regression analysis was used to assess the association between parameters of deformation response and clinical factors.This study protocol was approved by Ethic Committee of Zhongshan Ophthalmic Center and complied with Helsinki Declaration.Written informed consent was obtained from each patient prior to any medical examination.Results There were no statistic differences about age,sex and intraocular pressure (IOP) between CPACG and POAG patients (all at P＞0.05).However,differences existed in the number of anti-glaucoma medications (t =-2.388,P =0.020).Measurements of central corneal thickness (CCT),deformation amplitude (DA),and peak distance (PD) demonstrated excellent repeatability (ICC≥ 0.8).There were no statistic differences about CCT,first applanation time/length/velocity (A1 T,A1 L,A1V),second applanation time/length/velocity (A2T,A2L,A2V),DA between CPACG and POAG patients (all at P＞ 0.05).The highest concavity time was shorter (t =2.920,P =0.005),PD was bigger (t =-2.453,P =0.017),and central curvature radius (CCR) was smaller (t =1.997,P =0.050) in POAG than those in the CPACG patients.DA,A1V,A2T and PD were negatively associated with IOP (r =-0.709,-0.531,-0.645,-0.554;all at P＜0.001).However,A1T and A2V were positively associated with IOP (r=0.744,0.546;both at P＜0.001).And CCR was positively associated with CCT (r =0.181,P =0.039).Conclusions It is useable to evaluate corneal biomechanical properties of glaucoma by Corvis ST.Under the same level of IOP,the corneal concavity of POAG is easier than that of CPACG,which indicates that cornea in POAG patients is more deformable.
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Objective To prepare 3D printed tracheal graft and investigate its cellular biocompatibility and biomechanical properties.Methods Bone marrow was isolated from tibial plateau of young New Zealand white rabbit,and bone mesenchymal stem cells (BMSCs) were obtained by whole bone marrow culture method and adherent purification method.Biomechanical test was performed for 3D printed trachea graft.After co-cultured of 3D printed trachea graft and BMSCs,cell morphology was observed and the proliferation index of the cells on 3D printed trachea graft was quantified using sulforhodamine B (SRB) assay.Results 3D printed trachea graft showed excellent biomechanical properties.Cell morphology was normal and cells grew well after co-culture with 3D printed trachea graft.The SRB assay indicated good proliferation of BMSCs on 3D printed trachea graft.Conclusions 3D printed trachea graft shows favorable cellular biocompatibility and biomechanical properties,and therefore can be used as a scaffold material for tissue-engineered trachea.
ABSTRACT
Clay mineral facial masks are used to treat some dermatological diseases, just for cleansing or reduce the amount of oil secreted by sebaceous glands. There are several types of clays, which vary in mineralogical and chemical composition, color and origin. However, the literature lacks studies involving clay facial masks, in particular regarding their inï¬uence on skin´s biomechanical properties. Thus, this work aimed to characterize colored clays and evaluate its inï¬uence on skin frmness and elasticity by a short-term clinical study. Diï¬erent clays (named in this study magnesium aluminum silicate - MAS, white, pink and green) were chemically characterized, and facial mask formulations were prepared. The short-term clinical study was performed through the application of formulations on the skin. The skin frmness and elasticity were assessed before treatment and after mask removal. The statistical analysis showed no signifcant inï¬uence of time or formulations in those parameters, although volunteers reported the sensation of mechanical tension after the removal of the clay facial masks. Thus, the composition of the diï¬erent clays did not aï¬ect the skin viscoelasticity behavior in the short-term clinical study, and a long-term use of this type of formulation must be indicated to observe all the expected benefts.(AU)
Máscaras faciais argilosas são utilizadas para tratar algumas doenças dermatológicas, apenas para a limpeza ou reduzir a quantidade de óleo secretado pelas glândulas sebáceas. Existem vários tipos de argilas, que variam em composição mineral, química, cor e origem. No entanto, a literatura carece de estudos envolvendo máscaras faciais argilosas, em particular em relação a sua inï¬uência nas propriedades biomecânicas da pele. Assim, este trabalho teve como objetivo caracterizar argilas coloridas e avaliar sua inï¬uência sobre a frmeza e elasticidade da pele por meio de um estudo clínico de curto prazo. Diferentes argilas (chamadas neste estudo de silicato de alumínio e magnésio - MAS, branca, rosa e verde) foram caracterizadas quimicamente, e formulações de máscaras faciais foram preparadas. O estudo clínico de curto prazo foi realizado por meio da aplicação das formulações na pele. A frmeza e elasticidade da pele foram avaliadas antes do tratamento e após a remoção da máscara. A análise estatística mostrou nenhuma inï¬uência signifcativa do tempo ou das formulações nesses parâmetros, embora os voluntários tenham reportado sensação de tensão mecânica, após a remoção das máscaras faciais argilosas. Assim, a composição das diferentes argilas não afetou o comportamento visco-elástico da pele no estudo clínico de curto prazo, e uma utilização de longa duração poderia ser indicada com a fnalidade de se observar todos os benefícios esperados.(AU)
Subject(s)
Humans , Female , Adult , Young Adult , Clay , Skin Care , Facial Masks , Clinical Study , Skin Care/methods , Magnesium Silicates/chemistry , Color , Aluminum Silicates/chemistryABSTRACT
PURPOSE: To evaluate the effects of short-term prostaglandin analogues treatment on the corneal biomechanics of patients with normal tension glaucoma. METHODS: This study included 52 eyes of 52 patients who were diagnosed with normal tension glaucoma. All patients were divided into two groups; one group (27 eyes) received tafluprost while the other group (25 eyes) received travoprost. Intraocular pressure, Biomechanical properties were measured by using goldmann applanation tonometer, ocular response analyzer before treatment and at 8-week after treatment. RESULTS: The mean decrease in intraocular pressure, Goldmann-correlated IOP (IOPg), corneal-compensated intraocular pressure by using Goldmann applanation tonometer, and Ocular response analyzer were statistically significant in total patients, tafluprost, and travoprost group after using prostaglandin analogues (p < 0.001, p < 0.001, p < 0.001, respectively). Corneal hysteresis showed no statistical differences after treatment in total, tafluprost and travoprost group but corneal resistance factor (CRF) showed statistically significant decrease after using prostaglandin analogues in total, tafluprost, and travoprost group (p < 0.001, p = 0.025, p < 0.001). Upon multivariate analysis, the higher initial IOPg and the lower initial CRF checked, the variation of CRF (CRF in baseline – CRF at 8 weeks) got higher (β = 0.134, p = 0.017). CONCLUSIONS: It is needed to carefully monitor and evaluate the effects of prostaglandin analogues on intraocular pressure associated with initial intraocular pressure and the changes of CRF after prostaglandin treatment in normal tension glaucoma patients. CRF is sensitive factor to short-term changes of intraocular pressure after prostaglandin analogues treatment, and it is required to consider the properties of CRF when we evaluate between progression of glaucoma and corneal biomechanical properties.