Crossed Intralaminar Screws for Fusion of the Cervicothoracic Junction and the Thoracic Spine: The Experience in an Iberic Service with Case Series and Review of the Current Literature with Technique Description

The treatment of pathologies in the thoracic spine is a challenge. The periodic failure of pedicle screw insertion and anatomical variations make the search for an alternative to pedicle screws in thoracic spine surgery necessary. The interlaminar crossed screws is a well-known and secure method for fusion in cervical spine, and in thoracic spine there used to be insufficient clinical data to support this technique, until now. We demonstrate in an initial series of 10 cases treated with interlaminar fusion in association of other fusion techniques in the thoracic spine with good results. Objective: Intralaminar screws have been shown to be a biomechanical salvage technique in the thoracic spine, especially in long cervicothoracic, thoracic and thoracolumbar fixation. The goals of this article are to demonstrate our initial experience and the range of indications for thoracic crossed intralaminar screws. Methods: In this article we describe our initial series performed at S&#227o Teot&#243nio Hospital in Viseu, Portugal, and our results, and also provide a comprehensive review of the recent literature in the use of intralaminar crossed fixation.

Control of micro-wettability of pore-throat on shale oil occurrence:A case study of laminated shale of Permian Lucaogou Formation in Jimusar Sag,Junggar Basin,NW China

The control of micro-wettability of pore-throat on shale oil occurrence in different types of reservoir spaces remains unclear.Take the shale oil reservoir of the Permian Lucaogou Formation in the Jimusar Sag,Junggar Basin as an example,the reservoir space in laminated shale and the control of micro-wettability of pore-throat on shale oil occurrence were studied by using scanning electron microscope(SEM),multi-stage pyrolysis,quantitative fluorescence,nuclear magnetic resonance(NMR)and other techniques.The results show that there are mainly two types of laminated shale in the Lucaogou Formation,namely laminated shale rich in volcanic materials+terrigenous felsic,and laminated shale rich in volcanic materials+carbonate.The former type contains feldspar dissolution pores and intergranular pores,mainly with felsic mineral components around the pore-throats,which are water-wet and control the free shale oil.The latter type contains carbonate intercrystalline pores and organic pores,mainly with oil-wet mineral components around the pore-throats,which control the adsorbed shale oil.The oil-wet mineral components around the pore-throats are conducive to oil accumulation,but reduce the proportion of free oil.In the Lucaogou Formation,free oil,with high maturity and light quality,mainly occurs in the laminated shale rich in volcanic materials+terrigenous felsic.

核基质蛋白LaminA/C在正常乳腺和乳腺癌组织中的差异表达

目的:采用比较蛋白质组学方法研究正常乳腺和乳腺癌组织中的差异表达核基质蛋白(nuclear matrix protein,NMP),并在蛋白质水平对差异蛋白LaminA/C进一步地确证。方法:分别提取4例正常乳腺和乳腺癌组织的核基质蛋白,进行双向凝胶电泳。分离出的差异表达蛋白质点进行基质辅助激光解吸电离飞行时间质谱(MALDI-TOF-MS)分析,获得肽质量指纹图谱(Peptide Mass Fingerprinting,PMF),应用Mascot搜索引擎在NCBInr数据库中进行检索鉴定。最后用免疫组化和Western blotting方法验证差异蛋白LaminA/C在正常乳腺和乳腺癌组织的相对表达量。结果:经双向凝胶电泳和质谱鉴定,正常乳腺组含有(904±58)个蛋白质点,乳腺癌组检测出含有(944±70)个蛋白质点,共发现27个差异表达蛋白,成功鉴定出12种蛋白,其中包括LaminA/C。用免疫组化方法分析LaminA/C在正常乳腺和乳腺癌组织各20例中的表达,结果显示LaminA/C在正常乳腺和乳腺癌组织中的阳性率分别为15%(3/20)和40%(8/20),P<0.05。用Western blot方法观察LaminA/C在正常乳腺和乳腺癌组织各10例中的表达,结果显示乳腺癌组中LaminA/C/β-actin灰度值比值为0.40±0.13,是正常乳腺组LaminA/C/β-actin灰度值比值(0.21±0.13)的1.91倍(P<0.05)。结论:LaminA/C在乳腺癌组织中表达明显增高,LaminA/C蛋白在乳腺癌的发生和发展中可能起一定的作用。

核纤层蛋白LaminA/C负性调控ASCs增殖促进应力诱导脂肪再生的实验研究

目的探索核纤层蛋白LaminA/C对脂肪来源间充质干细胞(Adipose-derived stromal cells,ASCs)机械敏感性的调控作用,及其在应力诱导脂肪再生中的作用机制。方法构建大鼠预扩张脂肪瓣(Expanded Prefabricated Adipose Tissue,EPAT)负压吸引模型,于术后1、4、8周取材制备标本,行组织免疫印迹及免疫化学检测核纤层蛋白(Lamins)表达量变化,用以分析核纤层蛋白表达与应力诱导脂肪再生的相关性;构建体外LaminA/C过表达慢病毒载体并转染ASCs,行体外静态拉伸ASCs处理并采用细胞免疫印迹及免疫荧光检测ASCs增殖程度,用以明确LaminA/C对ASCs增殖的调控作用。结果体内实验发现,负压作用早期,大鼠EPAT内ASCs增殖增多,与此同时,脂肪瓣内LaminA/C表达量明显下降,LaminB1、LaminB2的表达则无明显差异;体外实验发现,过表达LaminA/C可显著抑制体外静态机械应力对ASCs增殖的促进作用。结论新型力学感受器核纤层蛋白通过负性调ASCs增殖参与应力诱导脂肪组织再生过程。

Clostridium butyricum alleviates intestinal low-grade inflammation in TNBS-induced irritable bowel syndrome in mice by regulating functional status of lamina propria dendritic cells

BACKGROUND Irritable bowel syndrome (IBS) is one of the most common functional gastroenterological diseases characterized by abnormal visceral sensitivity and lowgrade inflammation. The role of Clostridium butyricum (C. butyricum) in reducing intestinal low-grade inflammation via immune pathways has been well defined. However, the detailed mechanisms of the effects of C. butyricum on intestinal mucosal immunity, especially on immune cells of the lamina propria, remain unclear. Dendritic cells (DCs), which are important immune cells, secrete proinflammatory cytokines (IL-1β, IL-6, and others) and express T cell immunoglobulin and mucin domain-3 (TIM3), promoting proliferation and activation of DCs, and mediating Th1 and Th17 inflammatory responses. AIM To investigate the role of DCs in the development of IBS in a rat model and to understand the regulation of DCs after C. butyricum intervention. METHODS An IBS animal model was established using C57BL/6 mice, and C. butyricum was continuously administered via the intragastric route to simulate different intestinal immune states. Intestinal visceral hypersensitivity and histopathology were assessed using the abdominal withdrawal reflex (AWR) test and hematoxylin & eosin (H&E) staining, respectively. The expression of proinflammatory cytokines (IL-1β and IL-6) and TIM3 was analyzed by Western blot analysis and real-time PCR. Flow cytometry was applied to analyze the quantity, function, and membrane molecule TIM3 of the lamina propria dendritic cells (LPDCs). The regulatory effect of C. butyricum was verified in bone marrowderived dendritic cells by in vitro experiments. RESULTS The secretion of proinflammatory cytokines (IL-1β and IL-6) in mice with IBS was significantly increased compared with that of the control group, which suggested that the intestinal mucosa in mice with IBS was in a low-grade inflammatory state. The expression of CD11C+CD80+ and CD11c+TIM3+ in intestinal LPDCs in mice with IBS increased significantly. Meanwhile, the cytokines (IL-1β and IL-6) were significantly reduced after the intervention with probiotic C. butyricum. The amount and function of LPDCs and the TIM3 on the surface of the LPDCs were decreased with the alleviation of the intestinal inflammatory response. CONCLUSION The results suggest that C. butyricum regulates the amount and functional status of LPDCs in the intestinal mucosa of mice with IBS, and therefore modulates the local immune response in the intestine.

Lamina cribrosa thickness in children with hyperopic anisometropic amblyopia

AIM:To determine lamina cribrosa thickness(LCT)in the optic nerve head region of the eyes in children with hyperopic anisometropic amblyopia and to compare this thickness with that of fellow eyes,hyperopic nonamblyopia,and age-matched controls.METHODS:Thirty-two patients(12.0±1.8y,mean±standard deviation)with hyperopic anisometropic amblyopia,31 subjects with age-and refractive error-matched hyperopic non-amblyopia(10.7±2.2y),and 32 age-matched controls(11.2±2.0y)were included in this prospective,crosssectional study.LCT was measured using an enhanced depth-imaging program of a spectral domain optical coherence tomographic instrument in all participants,and the correlation between LCT and axial length was calculated.RESULTS:The mean LCT was 180.9±29.4μm in amblyopic eyes,247.7±19.0μm in fellow eyes,251.6±27.3μm in hyperopic non-amblyopic eyes,and 240.2±15.8μm in control eyes.Lamina cribrosa in amblyopic eyes was significantly thinner than fellow,hyperopic non-amblyopic,and control eyes(P<0.05).There was no significant correlation in LCT and axial length between amblyopic(P=0.16)and control(P=0.31)group.CONCLUSION:Lamina cribrosa of eyes with hyperopic anisometropic amblyopia is significantly thinner than that of fellow eyes,hyperopic non-amblyopia,and age-matched controls.The LCT profile in amblyopic eyes is different from that observed in fellow,hyperopic non-amblyopic,and control eyes.

Age related changes of the central lamina cribrosa thickness, depth and prelaminar tissue in healthy Chinese subjects

AIM: To investigate the variation in the central lamina cribrosa thickness(cLCT), and the central anterior lamina cribrosa surface depth(cALCSD), as well as the central prelaminar tissue thickness(cPLTT) related to age in healthy Chinese subjects.METHODS: A total of 96 eyes from 96 Chinese healthy subjects were recruited. According to age, the 96 cases were divided into three groups: the young group(YG, 18-39 y), middle-age group(MG, 40-59 y) and older-age group(OG, 60 y and above). Lamina cribrosa images were obtained from all participants using radial linear protocol by enhanced depth imaging spectral-domain optical coherence tomography. The cLCT, cALCSD and cPLTT were calculated from the average value of the lamina cribrosa thickness, anterior lamina cribrosa surface depth and prelaminar tissue thickness in the optic nerve head(ONH) centre point and paracentral points(150 μm from the centre point in the horizontal and vertical directions). RESULTS: For the total subjects, the mean cLCT, c ALCSD and cPLTT were 235.18±41.27, 358.02±93.80 and 182.02±92.11 μm, respectively. No statistically significant differences in cLCT, cALCSD or cPLTT were found between gender and different eyes(P=0.27-0.92). The cLCT of the OG was the thickest among the three groups, while the c PLTT of the YG was the thickest among the three groups(P<0.05). Age was positively correlated with cLCT(r=0.42, P<0.001), and negatively correlated with cPLTT(r=-0.24, P=0.02). No significant correlation was found between the age and cALCSD(r=-0.06, P=0.55). And no correlation has been found between axial length and cLCT, cALCSD and c PLTT(P=0.11-0.81).CONCLUSION: The impact of age on the cLCT and the cPLLTT should be taken into account when analysing glaucoma and other diseases related to lamina cribrosa.

The application of machine learning under supervision in identification of shale lamina combination types——A case study of Chang 7_(3)sub-member organic-rich shales in the Triassic Yanchang Formation,Ordos Basin,NW China

Organic rich laminated shale is one type of favorable reservoirs for exploration and development of continental shale oil in China.However,with limited geological data,it is difficult to predict the spatial distribution of laminated shale with great vertical heterogeneity.To solve this problem,taking Chang 73 sub-member in Yanchang Formation of Ordos Basin as an example,an idea of predicting lamina combinations by combining'conventional log data-mineral composition prediction-lamina combination type identification'has been worked out based on machine learning under supervision on the premise of adequate knowledge of characteristics of lamina mineral components.First,the main mineral components of the work area were figured out by analyzing core data,and the log data sensitive to changes of the mineral components was extracted;then machine learning was used to construct the mapping relationship between the two;based on the variations in mineral composition,the lamina combination types in typical wells of the research area were identified to verify the method.The results show the approach of'conventional log data-mineral composition prediction-lamina combination type identification'works well in identifying the types of shale lamina combinations.The approach was applied to Chang 73 sub-member in Yanchang Formation of Ordos Basin to find out planar distribution characteristics of the laminae.

Prediction of multiscale laminae structure and reservoir quality in fine-grained sedimentary rocks:The Permian Lucaogou Formation in Jimusar Sag,Junggar Basin

Fine-grained sedimentary rocks have become a research focus as important reservoirs and source rocks for tight and shale oil and gas.Laminae development determines the accumulation and production of tight and shale oil and gas in fine-grained rocks.However,due to the resolution limit of conventional logs,it is challenging to recognize the features of centimeter-scale laminae.To close this gap,complementary studies,including core observation,thin section,X-ray diffraction(XRD),conventional log analysis,and slabs of image logs,were conducted to unravel the centimeter-scale laminae.The laminae recognition models were built using well logs.The fine-grained rocks can be divided into laminated rocks(lamina thickness of<0.01 m),layered rocks(0.01-0.1 m),and massive rocks(no layer or layer spacing of>0.1 m)according to the laminae scale from core observations.According to the mineral superposition assemblages from thin-section observations,the laminated rocks can be further divided into binary,ternary,and multiple structures.The typical mineral components,slabs,and T2spectrum distributions of various lamina types are unraveled.The core can identify the centimeter-millimeter-scale laminae,and the thin section can identify the millimeter-micrometer-scale laminae.Furthermore,they can detect mineral types and their superposition sequence.Conventional logs can identify the meter-scale layers,whereas image logs and related slabs can identify the laminae variations at millimeter-centimeter scales.Therefore,the slab of image logs combined with thin sections can identify laminae assemblage characteristics,including the thickness and vertical assemblage.The identification and classification of lamina structure of various scales on a single well can be predicted using conventional logs,image logs,and slabs combined with thin sections.The layered rocks have better reservoir quality and oil-bearing potential than the massive and laminated rocks.The laminated rocks’binary lamina is better than the ternary and multiple layers due to the high content of felsic minerals.The abovementioned results build the prediction model for multiscale laminae structure using well logs,helping sweet spots prediction in the Permian Lucaogou Formation in the Jimusar Sag and fine-grained sedimentary rocks worldwide.

Ultrathin Wood Laminae–Thermoplastic Starch Biodegradable Composites

Novel fully biodegradable thermoplastic composite laminates reinforced with ultrathin wood laminae were prepared through a hot-pressing process by using two different thermoplastic starch(TPS)matrices.The microstructure and physical properties of the resulting unidirectional and bidirectional laminates were studied.The investigated materials presented a complex microstructure,in which the porosity of the wood laminae was almost entirely occluded by the polymer matrix.The mechanical behavior of the laminates was strongly affected by the obtained microstructure,and matrix penetration in wood pores led to biodegradable composites with elastic modulus and tensile strength higher than those of their constituents.Finally,thermal welding and thermoformability tests proved how these materials possess features typical of thermoplastic materials.

Guben Tongluo Formula Protects LPS-induced Damage in Lamina Propria B Lymphocytes Through TLR4/MyD88/NF-κB Pathway

Objective The main pathological feature of immunoglobulin A nephropathy(IgAN),an autoimmune kidney disease,is the deposition of IgA immune complexes,accompanied by mesangial cell proliferation and elevated urine protein.The Guben Tongluo formula(GTF)is a traditional Chinese medicine prescription,which has predominant protective effects on IgAN.However,the therapeutic mechanism of the GTF in IgAN remains elusive.The present study aimed to determine the effects of GTF in treating IgAN via regulating the TLR4/MyD88/NF-κB pathway.Methods In the present study,lamina propria B lymphocytes were treated with different concentrations of lipopolysaccharide(LPS)(0,1,5,10 and 20 ng/mL).Flow cytometry was used to define positive CD86+CD19+cells.CCK-8 assay was used to examine cell proliferation.RNAi was used to induce TLR4 silencing.qRT-PCR and Western blotting were used to determine gene expression.Results It was found that the LPS dose-dependently increased the content of IgA and galactose-deficient IgA1(Gd-IgA),the levels of TLR4,Cosmc,MyD88 and phosphorylated(p)-NF-κB,and the ratio of CD86+CD19+and IgA-producing B cells.However,the TLR4 knockdown reversed the role of LPS.This suggests that TLR4 mediates the effects of LPS on lamina propria B lymphocytes.Furthermore,the GTF could dose-dependently counteract the effects of LPS and TLR4 overexpression on lamina propria B lymphocytes through the TLR4/MyD88/NF-κB pathway.Conclusion Collectively,these results demonstrate that the GTF can regulate the TLR4/MyD88/NF-κB pathway to treat IgAN model lamina propria B lymphocytes stimulated by LPS.

Laminae combination and shale oil enrichment patterns of Chang 73 sub-member organic-rich shales in the Triassic Yanchang Formation, Ordos Basin, NW China

The Chang 73 sub-member of Triassic Yanchang Formation in the Ordos Basin was taken as an example and the lamina types and combinations,reservoir space features and shale oil enrichment patterns in organic-rich shale strata were investigated using core observation,thin section analysis,XRF element measurement,XRD analysis,SEM,high solution laser Raman spectroscopy analysis,and micro-FTIR spectroscopy analysis,etc.According to the mineral composition and thickness of the laminae,the Chang 73 organic-rich shales have four major types of laminae,tuff-rich lamina,organic-rich lamina,silt-grade feldspar-quartz lamina and clay lamina.They have two kinds of shale oil-bearing layers,"organic-rich lamina+silt-grade feldspar-quartz lamina"and"organic-rich lamina+tuff-rich lamina"layers.In the"organic-rich+silt-grade feldspar-quartz"laminae combination shale strata,oil was characterized by relative high maturation,and always filled in K-feldspar dissolution pores in the silt-grade feldspar-quartz laminae,forming oil generation,migration and accumulation process between laminae inside the organic shales.In the"organic-rich+tuff-rich lamina"binary laminae combination shale strata,however,the reservoir properties were poor in organic-rich shales,the oil maturation was relatively lower,and mainly accumulated in the intergranular pores of interbedded thin-layered sandstones.The oil generation,migration and accumulation mainly occurred between organic-rich shales and interbedded thin-layered sandstones.

Prevalence of focal lamina cribrosa defects in eyes with pachychoroid disease spectrum

AIM:To determine the prevalence of focal lamina cribrosa(LC)defect among patients with pachychoroid disease spectrum(PDS)in the absence of peripapillary retinoschisis.METHODS:This retrospective,cross-sectional study comprised of 180 patients with PDS,including polypoidal choroidal vasculopathy(PCV),central serous chorioretinopathy,and pachychoroidal neovasculopathy.Medical records and optic ner ve head evaluations conducted using spectral-domain optical coherence tomography with enhanced depth imaging were reviewed.As a control group,236 patients who underwent ophthalmologic evaluation for vitreous floaters,without obvious ocular disease,were also included.RESULTS:The mean age of the PDS group,which included 118 male patients(65.6%),was 57.4±11.1 y.There was no significant difference between the two groups in age(P=0.710)or sex(P=0.248).Six patients(3.3%)in the PDS group and none in the control group showed focal LC defect(P=0.318).Among the six patients with focal LC defect in the PDS group,four eyes had PCV,one eye was the fellow eye of a PCV eye,and one eye had pachychoroidal neovasculopathy.CONCLUSION:Focal LC defect can be defected in patients with PDS in the absence of peripapillar y retinoschisis.However,the prevalence of focal LC defect was not different significantly between PDS patients and those who did not have PDS.

Enhanced depth OCT imaging of the lamina cribrosa for 24 hours

The lamina cribrosa thickness(LCT) could be affected by dynamic changes in its structure.Using spectral-domainoptical coherence tomography(SD-OCT),we have studied the behaviour of the laminar region in 14 young subjects over 24 h.Significant changes in LCT were observed,depending on the time at which the measurement was taken,with the maximum thickness being observed at 7.30 p.m.,and the minimum at 7.30 a.m.This finding could suggests a circadian pattern in the LCT thickness in healthy subjects,which could have implications for the classification,diagnosis and prognosis of both normal and glaucomatous subjects.

Laminae characteristics of gas-bearing shale fine-grained sediment of the Silurian Longmaxi Formation of Well Wuxi 2 in Sichuan Basin,SW China

Based on various test data, the composition, texture, structure and lamina types of gas-bearing shale were determined based on Well Wuxi 2 of the Silurian Longmaxi Formation in the Sichuan Basin. Four types of lamina, namely organic-rich lamina, organic-bearing lamina, clay lamina and silty lamina, are developed in the Longmaxi Formation of Well Wuxi 2, and they form 2 kinds of lamina set and 5 kinds of beds. Because of increasing supply of terrigenous clasts and enhancing hydrodynamics and associated oxygen levels, the contents of TOC and brittle mineral reduce and content of clay mineral increases gradually as the depth becomes shallow. Organic-rich lamina, organic-rich + organic-bearing lamina set and organic-rich bed dominate the small layers 1-3 of Member 1 of the Longmaxi Formation, suggesting anoxic and weak hydraulic depositional setting. Organic-rich lamina, along with organic-bearing lamina and silty lamina, appear in small layer 4, suggesting increased oxygenated and hydraulic level. Small layers 1-3 are the best interval and drilling target of shale gas exploration and development.

Reservoir characteristics and genetic mechanisms of gas-bearing shales with different laminae and laminae combinations: A case study of Member 1 of the Lower Silurian Longmaxi shale in Sichuan Basin, SW China

Based on thin-section,argon-ion polished large-area imaging and nano-CT scanning data,the reservoir characteristics and genetic mechanisms of the Lower Silurian Longmaxi shale layers with different laminae and laminae combinations in the Sichuan Basin were examined.It is found that the shale has two kinds of laminae,clayey lamina and silty lamina,which are different in single lamina thickness,composition,pore type and structure,plane porosity and pore size distribution.The clayey laminae are about 100μm thick each,over 15%in organic matter content,over 70%in quartz content,and higher in organic pore ratio and plane porosity.They have abundant bedding fractures and organic matter and organic pores connecting with each other to form a network.In contrast,the silty laminae are about 50μm thick each,5%to 15%in organic matter content,over 50%in carbonate content,higher in inorganic pore ratio,undeveloped in bedding fracture,and have organic matter and organic pores disconnected from each other.The formation of mud lamina and silt lamina may be related to the flourish of silicon-rich organisms.The mud lamina is formed during the intermittent period,and silt lamina is formed during the bloom period of silicon-rich organisms.The mud laminae and silt laminae can combine into three types of assemblages:strip-shaped silt,gradating sand-mud and sand-mud thin interlayers.The strip-shaped silt assemblage has the highest porosity and horizontal/vertical permeability ratio,followed by the gradating sand-mud assemblage and sand-mud thin interlayer assemblage.The difference in the content ratio of the mud laminae to silt laminae results in the difference in the horizontal/vertical permeability ratio.

Numerical simulation of hydraulic fracture propagation in laminated shale reservoirs

The main area of the Jiaoshiba anticline of the Fuling shale gas field was taken as the research object,laboratory rock mechanical experiments and direct shear experiments were conducted to clarify the mechanical anisotropy characteristics and parameters of rock samples with rich beddings.Based on the experimental results,a 3D fracture propagation model of the target reservoir taking mechanical anisotropy,weak bedding plane and vertical stress difference into account was established by the discrete element method to analyze distribution patterns of hydraulic fractures under different bedding densities,mechanical properties,and fracturing engineering parameters(including perforation clusters,injection rates and fracturing fluid viscosity).The research results show that considering the influence of the weak bedding plane and longitudinal stress difference,the interlayer stress difference 3–4 MPa in the study area can control the fracture height within the zone of stress barrier,and the fracture height is less than 40 m.If the influence of the weak bedding plane is not considered,the simulation result of fracture height is obviously higher.Although the opening of high-density bedding fractures increases the complexity of hydraulic fractures,it significantly limited the propagation of fracture height.By reducing the number of clusters,increasing the injection rate,and increasing the volume and proportion of high-viscosity fracturing fluid in the pad stage,the restriction on fracture height due to the bedding plane and vertical stress difference can be reduced,and the longitudinal propagation of fractures can be promoted.The fracture propagation model was used to simulate one stage of Well A in Fuling shale gas field,and the simulation results were consistent with the micro-seismic monitoring results.

En bloc resection of semi-facet and lamina for thoracic ossification of ligamentum flavum with epidural adhesion

Objective To explore the strategy and outcomes of surgical treatment of thoracic ossification of ligamentum flavum(OLF),especially combined with ossification of posterior longitudinal ligament,thoracic kyphosis and epidural

Transpedicular osteotomy en bloc lamina resection for the treatment of thoracic spinal stenosis

Objective To study the safety and efficacy of transpedicular osteotomy en bloc lamina resection to treat thoracic spinal stenosis.Methods A retrospective study of 23 consecutive patients underwent transpedicular osteotomy en bloc lamina

Pseudo-elastic Hysteresis Damping Characteristics of SMA Hybrid Composite Lamina

The longitudinal mechanical behavior of shape memory alloy(SMA)composite lamina subjected to longitudinally strain or stress controlled cyclic loading is investigated.The SMA is under pseudo- elastic condition and the fibers are embedded(bonded)to the host material.The influences of temperature, volume fraction of SMA and longitudinal modulus of the host material on the stress-strain relation and energy dissipation of the SMA hybrid composite lamina are discussed.The results indicate that the stress-strain curve of the lamina per cycle shows a hysteresis loop.The hysteresis damping decreases with increasing temperature and with decreasing volume fractions of SMA.In addition,the hysteresis damping is nearly independent of the longitudinal modulus of the host material under strain controlled loading.However,it depends dramatically on the longitudinal modulus of the host material under stress controlled loading,which shows the SMA composite lamina has high pseudo-elastic hysteresis damping when the longitudinal modulus of the host material is low.