Twist Rate Research Articles

Coupling of two helical circular waveguides.

Coupling between optical waveguides has always been an important topic. By using the finite element method (FEM) based on a helicoidal coordinate system, we present a detailed study of the couplings between two helical coupled circular waveguides, showing several important aspects that were not found in previous studies. Our numerical results show that for the two-fold rotationally symmetric cases, intersections will appear in the effective index curves of the two composite modes with increasing twist rate, and we have found that this is related to the different increases of the composite modes in the helical path and the emergence of high-order harmonics. Further, for the one-fold rotationally symmetric structures formed by the two waveguides with the same radical but different azimuthal positions, as the twist rate increases, we observe the emerging asymmetric modal distributions of the composite modes, indicating that couplings between the two waveguides are no longer equivalent.

Presence of Apical Aneurysm and Its Impact on Left Ventricular Mechanics and Mechano-Energetic Coupling in Patients With Apical Hypertrophic Cardiomyopathy.

Left ventricular (LV) apical aneurysms (ApAn+) occur in 10%-15% of apical hypertrophic cardiomyopathy (ApHCM) patients and confer considerable morbidity. We hypothesized that ApAn+ adversely impact ventricular mechanics and mechano-energetic coupling in ApHCM. Ninety-eight ApHCM patients were identified, of which nine (9%) had ApAn+ and were compared with 89 (91%) who did not (ApAn-). 2D speckle-tracking echocardiography assessed ventricular mechanics using LV global longitudinal strain (GLS) and torsion, and mechano-energetic coupling as myocardial work indices. Clinical events over follow-up were adjudicated. Mean age was 64±15 years, 46% were female, and 3% had an HCM family history, with similar clinical risk factors between groups. Of the nine ApAn+ patients, there were six small (<2cm) and three moderate-sized (2-4cm) aneurysms. There was no difference in LV ejection fraction (65±15vs. 67±11%, p = 0.51) or GLS (-9.6±3.3vs. -11.9±3.9%, p = 0.09) between ApAn+ versus ApAn-. ApAn+ patients had greater myocardial global wasted work (347±112vs. 221±165 mmHg%, p = 0.03) and lower global work efficiency (GWE, 75±5vs. 82±8%, p = 0.006). LV GLS (β = -0.67, p < 0.001), ApAn+ (β = -0.15, p = 0.04), and twist rate (β = -0.14, p = 0.04) were independently associated with GWE. At 3.9-year follow-up, cardiovascular mortality (4%) and heart failure hospitalization (14%) events were similar between groups. ApHCM patients with ApAn+ are characterized by more impaired LV mechano-energetic coupling when compared with ApAn-. ApAn+ is independently associated with worse GWE.

Sensitivity and Optimization Analysis of Torsional Behavior in Multicellular Thin-Walled Tubes

Multicellular thin-walled tubes are widely used due to their lightweight, economical design, and superior shear and torsional performance. Their design is sometimes governed by the available materials and the required dimensions. The current study uses advanced sensitivity analysis with meta-modeling tools to understand how different geometric and mechanical factors affect the torsional performance of multicellular thin-walled tubes. The geometric factors include the length, thickness, and width of the beams, while the mechanical properties involve the shear modulus. Variance-based sensitivity analysis is used to assess how variations in these factors impact the rate of twist, torsional stiffness, and shear stress. The interconnected relations between input parameters are exploited for optimal design and superior performance. The results revealed that for a three-celled tube, thick horizontal interior elements with thin deep vertical elements and thin exterior elements provide an optimal design when the cross-sectional area is constrained. This finding, combined with varying the geometrical and material properties, results in an optimal design using CFRP composites when constrained by minimizing the total weight and superior torsional performance. The analysis can be extended to include other constraint(s), but changing the design constraints might change the optimal design. Doi: 10.28991/CEJ-2024-010-09-09 Full Text: PDF

Phase preservation of orbital angular momentum of light in multiple scattering environment

Recent advancements in wavefront shaping techniques have facilitated the study of complex structured light’s propagation with orbital angular momentum (OAM) within various media. The introduction of spiral phase modulation to the Laguerre–Gaussian (LG) beam during its paraxial propagation is facilitated by the negative gradient of the medium’s refractive index change over time, leading to a notable increase in the rate of phase twist, effectively observed as phase retardation of the OAM. This approach attains remarkable sensitivity to even the slightest variations in the medium’s refractive index (∼10−6). The phase memory of OAM is revealed as the ability of twisted light to preserve the initial helical phase even propagating through the turbid tissue-like multiple scattering medium. The results confirm fascinating opportunities for exploiting OAM light in biomedical applications, e.g. such as non-invasive trans-cutaneous glucose diagnosis and optical communication through biological tissues and other optically dense media.

The characteristics of vortex modes in twisted fiber with dielectrically chiral ring core

A novel twisted ring core fiber incorporating chiral material into the ring core is proposed, which supports orbital angular momentum (OAM) modes. Results show that between chirality and twist rate there exist a cooperative effect in birefringence and a competitive effect in mode index bifurcation between OAM modes with different helicity. The cooperative effect between chirality and twist rate also breaks the degeneracy within OAM modes of the same or opposite helicity while preserving the vectorial nature of the modes. The OAM modes generated by twisted dielectrically chiral fiber are less likely to have crosstalk. The dependences of OAM modes birefringence on chirality and twist rate are investigated. Additionally, the mode effective index bifurcation as a function of wavelength is also discussed under both kind of chirality. Owing to high birefringence, good refractive index bifurcation, we believe that this kind of fiber can find applications in new kind of OAM mode generators, OAM mode filters, optical communication, and sensing.

Strain-insensitive micro torsion and temperature sensor based on a helical taper seven-core fiber structure.

We propose a multimode interference-based optical fiber NHTSN sensor with a helical taper for simultaneous measurement of micro torsion and temperature. The sensor consists of single mode fiber (SMF), no-core fiber (NCF), and seven-core fiber (SCF). A helical taper is fabricated in the SCF using a flame heater, forming the SMF-NCF-Helical Taper SCF-NCF-SMF (NHTSN) structure. Theoretical analysis and experimental results demonstrate that the introduction of helical taper not only imparts directionality to the torsion measurement, but also results in a significant improvement in torsion sensitivity due to the increased inter-mode optical path difference (OPD) and enhanced inter-mode coupling. In the experiment, the torsion sensitivity of the NHTSN sensor reaches -1.255 nm/(rad/m) in the twist rate (TR) range of -3.931 rad/m to 3.931 rad/m, which is a 9-fold improvement over the original structure. Further reduction of the helical taper diameter increases the sensitivity to -1.690 nm/(rad/m). In addition, the sensor has a temperature sensitivity of up to 97 pm/°C from 20 °C to 90 °C, and simultaneous measurement of torsion and temperature is attainable through a dual-parameter measurement matrix. The NHTSN sensor possesses advantages of compact size, high sensitivity, good linearity, and strain-independence, endowing it with potential applications in structural health monitoring (SHM) and engineering machinery.

Paradoxical increase in E/e' during severe central hypovolemia in healthy humans

Abstract Introduction The ratio of mitral blood inflow to mitral annular tissue velocity in early diastole (E/e') is widely used as an index of left ventricular (LV) diastolic dysfunction. Theoretically, it is considered that e’ can correct the effect of LV relaxation on E, and thus E/e’ can be applied for the prediction of LV filling pressures in patients with cardiac diseases. However, recent guidelines indicate that E/e’ may not provide a reliable estimate of filling pressures in healthy subjects. Indeed, previous studies have reported that E/e' did not decrease during acute central hypovolemia because both E and e’ are similarly reduced by low preload condtions. However, it is possible that E/e' did not decrease since central hypovolemia are not critical in the previous studies. Purpose The purpose of the present study was to clarify the change of E/e’ during severe central ypovolemia induced by lower body negative pressure. Methods Twelve healthy men (25±5 years old) underwent 2D Doppler and 3D echocardiography during graded lower body negative pressure (LBNP) up to presyncope. We measured LV diastolic function indices by 2D echocardiography including septal and lateral mitral annular early diastolic velocities (e’), and early (E) and late (A) mitral inflow velocities. In addition, we measured LV function indices by 3D echocardiography including end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), ejection fraction (EF), global longitudinal strain (GLS), global circumferential strain (GCS), twist and peak untwisting rate. We compared echocardiography indices before LBNP (Baseline) with those at maximal LBNP (LBNPmax) and at half of the maximal LBNP (LBNP1/2max). Results E/e’ (Baseline: 5.8±0.8, LBNP1/2max: 5.4±1.0, LBNPmax: 7.8±2.3, mean±SD, p&amp;lt;0.01, ANOVA) did not change at the LBNP1/2max but increased only at the LBNPmax. E (80±11, 59±10, 62±12 cm/sec, p&amp;lt;0.01) and E/A (2.2±0.8, 1.5±0.5, 1.0±0.3, p&amp;lt;0.01) decreased at the LBNP1/2max as compared to baseline but did not change from LBNP1/2max to LBNPmax. e’ (14.1±2.0, 11.1±1.5, 8.2±2.2 cm/sec, p&amp;lt;0.01) decreased in response to LBNP. LV EF (62±3, 55±5, 43±9 %, p&amp;lt;0.01), LV GLS (-20.5±2.8, -17.6±2.7, -13.6±4.7 %, p&amp;lt;0.01), and LV GCS (-31.2±3.7, -26.8±3.3, -19.4±5.3 %, p&amp;lt;0.01) decreased in response to LBNP. LV twist (15.2±5.1, 14.5±5.4, 20.9±7.7 °, p&amp;lt;0.01) and LV peak untwisting rate (-138±42, -164±50, -245±88 °/cm, p&amp;lt;0.01) increased only at the LBNPmax. Conclusion The present study for the first time showed that E/e’ paradoxically increased during acute severe hypovolemia in healthy humans. This paradox was likely caused by well-preserved E, while e’ decreased in response to acute severe central hypovolemia. The present finding also showed that peak untwisting rate was increased only at severe central hypovolemia, suggesting that the well-preserved E may be caused by high pressure gradient from left atrium to LV induced by enhanced LV untwisting suction function.Key results of this study①Key results of this study②

Effect of excitability on partially pinned scroll waves in excitable chemical media.

We present an investigation of excitability effects on the dynamics of scroll waves partially pinned to inert cylindrical obstacles in three-dimensional Belousov-Zhabotinsky excitable media. We also report on corresponding numerical simulations with the Oregonator model. The excitability varies according to the concentration of sulfuric acid [H_{2}SO_{4}] in the Belousov-Zhabotinsky (BZ) reaction and the parameter ɛ^{-1} in the Oregonator model. Initially, the freely rotating scroll segment rotates faster than the pinned one. The difference in the frequency of the two parts results in a transition from a straight pinned scroll wave to a twisted one, which helically wraps around the entire obstacle. The wave frequency in the whole volume is equal to that of the freely rotating scroll wave. When the excitability is increased, the time for the transition to the twisted wave structure decreases while the average speed s of the development increases. After the transition, the twisted wave remains stable. In media with higher excitability, the helical pitch is shorter but the twist rate ω is higher. Analysis presented in this study together with our previous findings of the effect of the cylindrical obstacle diameter on the wave dynamics results in common features: The average speed s and the twist rate ω of both studies fit well to functions of the difference in the initial frequency Δf of the freely rotating and untwisted pinned waves. We also demonstrate the robustness of the partially pinned scroll waves against perturbations from spontaneous waves emerging during the wave generation in the BZ medium with high [H_{2}SO_{4}]. Even though the scroll wave is partly disturbed at the beginning of the experiment, the spontaneous waves are gradually suppressed and the typical wave structure is finally developed.

General and Reliable Azimuthal Alignment Algorithm for Low Loss Multicore Fiber Fusion Splicing

Multicore fiber is a promising spatial division multiplexing technology to increase the transmission bandwidth of optical fiber links in any given available spatial cross section. To connect multicore fibers, similar to single-core fibers, fusion splicing is an indispensable tool. Since multicore fibers cannot be circularly symmetric, precise transverse and azimuthal alignment is crucial to minimize the insertion loss penalty that would originate from even small offsets in the core locations of the two fibers to be spliced together. In this paper, a novel azimuthal alignment algorithm for multicore fiber splicing is presented. Since it is based on side-view images, it can also determine the twist rates of both fibers to be spliced and take these twist rates into account when calculating the optimum azimuthal alignment angle at the very ends of the two fibers. In the case of fibers with markers, i.e., fibers that are not rotationally symmetric, the relative and absolute polarities of the two fiber ends are computed as well. We present the formulation of the azimuthal alignment algorithm and demonstrate its stability and versatility for a wide range of fibers with vastly different geometries, core numbers and twist rates, including an offset single-core fiber. In the case of 4-core fibers with markers, we achieve average splice losses of less than 0.03 dB regardless of the polarity, which is a substantial advantage in terms of real-world applicability in the field. For a twisted 7-core fiber, we demonstrate an accurate twist rate detection with standard deviation < 1.4/m (turns per meter).

Atomistic insight of torsional behavior of CNT-nanocrystalline Al nanocomposites

In this study, the deformation behavior of nanocrystalline (NC) Al and carbon nanotube (CNT) reinforced NC Al nanocomposite specimens (CNT-NC Al NCs) have been inspected under torsional loading using molecular dynamics (MD) simulations. Torsional loading on the specimens has been applied using a constant twist rate (2°/ps) relative to either end of the specimen. The evolution of grain structure at the nanoscale, the changes in crystal structure at the atomic scale, and their correlation with potential energy are investigated at different stages of torsional deformation. The fracture path for NC Al and CNT-NC Al NCs is seen along the grain boundary, and the CNT fracture process in torsion is similar to tension. The (30) CNT-NC Al NC specimen has unveiled higher torsional failure strength of 69.6 % than NC Al without the CNT specimen. The interaction of the activated slip planes, stacking faults, and dislocation motion with the Burger vector have been discussed in detail during torsion deformation. The correlation between defect evolution with strain contour has also been discussed in this paper.

OAM mode generation in helically twisted hollow-core antiresonant fiber.

We investigate the orbital angular momentum (OAM) mode-generating process of a long-period onefold chiral fiber grating (L-1-CFG) based on a helically twisted hollow-core antiresonant fiber (HC-ARF). Taking the right-handed L-1-CFG for an example, we theoretically and experimentally prove that the first-order OAM+1 mode can be generated by only inputting a Gaussian beam. We fabricated three right-handed L-1-CFG samples based on the helically twisted HC-ARF with twist rates (α) of -0.42, -0.50, and -0.60 rad/mm, where the twisted HC-ARF with α of -0.42 rad/mm can achieve high OAM+1 mode purity of 94%. Subsequently, we present simulated and experimental transmission spectra at the C-band, and sufficient modulation depths were obtained at wavelengths of 1550 nm and 1561.5 nm in the experiment.

Mode converter using bent and twisted coupled-multicore fibers for group delay spread reduction

A mode converter using bent and twisted coupled-multicore fiber for the reduction of the group delay spread is proposed. The bent and twisted fiber, which is one of the periodic structures, can work as a long-period grating mode converter by properly setting the twist rate. To investigate the mode conversion characteristics, a simple and effective eigenmode analysis for three-dimensional periodic structures is proposed. We found that to convert the specified modes, the core layout is also important as well as the twist rate. For example, the mode conversion behaviors of 4CFs with square lattice and triangular lattice layouts are greatly different although each 4CF enables the specified mode conversion. It is revealed that, by switching the higher and lower order modes, the group delay can be equalized, resulting in the suppression of the group delay spread. It leads to reducing the complexity of the multiple-input multiple-output receiver in the mode division multiplexing system.

Study of thermophoresis and Brownian motion phenomena in radial stagnation flow over a twisting cylinder

This article deals with the analysis of nanofluid flow and its thermal energy transport in the stagnation region, impinged radially on a rotating circular cylinder with magnetohydrodynamic (MHD) effect. The swirling flow is driven by the rotational motion of a circular cylinder along the z -direction. A two-phase nanofluid model, namely the Buongiorno model is utilized to determine the thermal characteristics of nanoparticles, which highlights the influence of Brownian diffusion and thermophoresis on temperature and concentration distributions. Numerical outcomes are computed by applying the built-in program bvp5c in MATLAB. The focus of this manuscript is to determine the numerical interpretations of wall stresses with their asymptotic behavior, Nusselt number, and Sherwood number against relevant parameters. The axial and azimuthal wall stress parameters are obtained as a function of twist rate at various values of Reynolds number. Furthermore, the asymptotic behavior for small Reynolds number is compared with their corresponding numerical solutions. The comparison of our result as a special case for non-electrically conducting flow is found in exact agreement with the ones in the literature. It is noticed that wall stresses are greatly affected due to an increment in Reynolds number. The thermal and mass transport phenomena is reduced due to increment in the twisting rate of the cylinder. However, the momentum of the system is inclined, and consequently, an increase in the axial and azimuthal velocities is observed. Moreover, the numerical values of heat and mass transfer rates deteriorate because of thermophoresis; however, owing to the Brownian diffusion, the former declines, and the latter progress significantly.

Torsional vibration of Timoshenko-Gere non-circular nano-bars

The displacement field and governing equation completely depend on the cross-section shape in the torsion of nano-bars. Due to the torsion of structure and warping of its cross-section, axial strain is created. A review of the literature demonstrates that the effect of the normal strain in the torsional analysis of nanostructures with non-circular cross-sections is ignored for the sake of simplicity and causes a computational error. While in the torsion of short nano-bars due to the great warping of the cross-section the normal strain appears and it shouldn’t be ignored. Therefore, for the first time, the effect of normal strain based on the torsion of Timoshenko-Gere theory is considered in this research. In this theory, the twist rate of non-circular sections in the axial direction is not considered constant, unlike studies in the literature. The governing equation of torsional vibration is extracted using the Hamilton principle, and the nonlocal strain gradient theory is used to show the size-dependent effects. The fundamental frequency is calculated for the arbitrary cross-section shape by using Galerkin’s method. The effect of parameters such as size effects, the thickness of nano-bar, mode number, and dimensions changes of cross-section versus natural frequency of nano-bar for both the Timoshenko-Gere and typical theories are investigated. Results indicate that neglecting normal strain due to warping the cross-section causes a significant error in the short nano-bars, especially at higher mode numbers. Also, a comparison is made between the obtained natural frequencies and those of the results reported in the literature.

Experimental and Numerical Analysis of Triply Coupled Vibration of Thin-Walled Beam with Arbitrary Closed Cross-Section

In this paper, a numerical experimental study about coupled vibration and natural frequency of thin-walled beams with an arbitrary closed cross-section is presented. A new thin-walled beam dynamic transfer matrix method, named TDTMM, is presented in the frequency domain for the thin-walled beam, which expands the advantages of the general dynamic transfer matrix method (GDTMM). The theory takes into account the influence of warping effect, that is, both the bimoment B and the rate of twist ϕ(x) of the beam are considered, and the TDTMM is derived by solving the governing differential equations of motion for coupled bending and torsional vibration of the thin-walled beam. Finally, two numerical examples and one experimental example are given and compared with the GDTMM and the finite element method (FEM) results to validate the developed theory.

Helically twisted double-cladding-three-core photonic crystal fiber for generation of orbital angular momentum

Aiming at the shortcomings of helically twisted single-cladding-few-core photonic crystal fibers in generating orbital angular momentum (OAM), the double-cladding and three-core structures with non-uniform inner and outer air holes are introduced into a photonic crystal fiber for the first time and the generation of high-order OAM modes through helical twisting is realized. The fiber is expected to reduce the losses of the generated OAM modes by introducing a specially designed double-cladding structure, while the three cores distributed in a regular triangle around the center are expected to increase the number of generated OAM modes. On the basis of optical transformation theory, the optical fiber is systematically analyzed by the finite element method. It is found that with the twist rate &lt;i&gt;α&lt;/i&gt; = 7853.98 rad/m, the generated OAM modes include “OAM&lt;sub&gt;–4,1&lt;/sub&gt;, OAM&lt;sub&gt;+9,1&lt;/sub&gt;, OAM&lt;sub&gt;+10,1&lt;/sub&gt;, OAM&lt;sub&gt;+11,1&lt;/sub&gt;, OAM&lt;sub&gt;+13,1&lt;/sub&gt;”, where +13 is the highest order in the OAM modes currently generated by using helically twisted fibers. And the losses of OAM modes are all less than 1.64×10&lt;sup&gt;–3&lt;/sup&gt; dB/m, which is at least two orders of magnitude lower than the lowest OAM mode loss reported in the existing references (Napiorkowski M, Urbanczyk W S 2018 &lt;i&gt;Opt. Express&lt;/i&gt; &lt;b&gt;26&lt;/b&gt; 12131), and their purity is greater than 93%. Further studies show that the generation of orbital angular momentum depends on the resonant coupling between the core supermode and the ring-core mode, and the parity of the order of the generated OAM modes is related to the polarization direction of the fiber core supermode and the ring-core mode.

S-52-3: ROLE OF NOVEL ECHOCARDIOGRAPHIC METHODS TO DETECT EARLY MYOCARDIAL DYSFUNCTION IN WOMEN WITH PREECLAMPSIA

Normal pregnancy is associated with reversible changes in both systolic and diastolic mechanics, consistent with an increase in preload and decrease in afterload and systemic vascular resistance. The aim of the study is to evaluate left ventricular cardiac mechanics via speckle tracking echocardiography in a population of pregnant women with per partum cardiomyopathy and preeclampsia(PE) after invitro fertilization (IVF) during different stages of pregnancy. The study population included 525 pregnant women with PE, after IVF, 100 of them with multiple pregnancy (46.5 ± 3 years) and 30 healthy nonpregnant women (33 ± 4years).Apical and basal short axis and apical view for three, two and four chamber for 2D images were acquired (65 ± 7 frames/s) during the first, second and third trimester of the pregnancy, as well as up to two months post partum. The curves of longitudinal(GLS), circumferential(GCS), radial strain(GRS) and LVT /LVUR were extracted using a commercial software. Results: Peak LVT and LVUR increased significantly in the 3rd trimester in both pregnancy groups (13.48 ± 2.90°,13.12 ± 3.30?,16.83 ± 3.61?,P &lt; 0.001; and -111.52 ± 23.54°/sec,-107.40 ± 26.58?/sec,-144.30 ± 45.14?/sec, P &lt; 0.001; in the 1st, 2nd, and 3rd trimester, respectively.The pregnants with twins have the highest value for LVT and LVUR compare with other pregnants (p &lt; 0.01), but in the last trimester, the time to peak LVUR is prolonged. An independent correlation was found between the change in LVT and LV end-systolic volume in 1st and 3rd trimester (r = 0,56). Peak LVUR at the 3rd trimester correlated significantly with LV end-diastolic volume. Multiple regression analysis indicates that only systolic blood pressure (r = 0.394, P = 0.005) was an independent predictor for increased LV torsion. Arterial hypertension (AH) and prevalence of preeclampsia (PE) are more often in IVF group. Longitudinal strain decreased significantly (p &lt; 0.001) during 3th trimester in women with AH and PE. Global longitudinal strain measures of the LV were non-significantly different between the different groups in first and second trimester (GLS-20.6 ± 3,14 vs.-19,29 ± 2,17).There are not found significant differences for GCS and GRS during pregnancy. Conclusions: During pregnancy LV twist and peak untwisting rate increase in the 3rd trimester and correlate with end-systolic and end-diastolic volume, respectively. Blood pressure and condition of multiple pregnancy are independently associated with increased torsion during pregnancy and may predict the new onset heart failure and perinatal cardiomyopathy. Global longitudinal strain is the main predictor of new onset peripartum cardiomyopathy

Twist Rate Measurement Method Based on Panoramic Imaging for Automatic Tracking Barrel Rifling

Twist Rate Measurement Method Based on Panoramic Imaging for Automatic Tracking Barrel Rifling

Refractive Index Sensing Using Helical Broken-Circular-Symmetry Core Microstructured Optical Fiber

Helical twist provides an additional degree of freedom for controlling light in optical waveguides, expanding their applications in sensing. In this paper, we propose a helical broken-circular-symmetry core microstructured optical fiber for refractive index sensing. The proposed fiber consists of pure silica and its noncircular helical core is formed by a broken air ring. By using finite element modeling combined with transformation optics, the modal characteristics of the fiber are investigated in detail. The results show that for the core located at the fiber center, the confinement loss of fundamental core modes increases with twist rate, whereas for a sufficiently large core offset the modes can be well confined owing to the twist-induced light guidance mechanism, showing decreases with rising twist rate in the loss spectra. Moreover, we have found that for large twist rates and core offsets, resonant peaks occur at different twist rates due to the couplings between the fundamental core modes and the highly leaky modes created by the helical structure. The refractive index sensing performance is also studied and the obtained results show that the proposed fiber has great potential in fiber sensing.

Expression of Twist 1 in bone marrow and extramedullary lesions of patients with myeloma and its prognostic significance

In patients with multiple myeloma (MM) extramedullary (EM) lesions could be a possible indicator of poor prognosis. Twist 1, an EMT related transcription factor, is known to play an important role in embryonic development and also in the process of tumor cell proliferation, apoptosis, metastasis etc. The Twist 1 protein expression hence has prognostic significance in MM. This study investigates expression of Twist-1 in MM patients with extramedullary lesions and its relationship with clinicopathological data and prognosis, so as to elucidate the clinical significance of Twist-1 expression. Patients with MM complicated with EM lesions were selected retrospectively, including 35 cases in the bone marrow group (MM complicated with extramedullary lesions) and 80 cases in the extramedullary group (MM combined with extramedullary lesions). The expression of Twist 1 protein was detected by immunohistochemistry. The relationship between Twist 1 protein expression and general clinicopathological data was analyzed by statistics. The relationship between Twist 1 protein expression and prognosis was analyzed by COX single factor and multivariate regression analysis. Immunohistochemical staining showed that the expression level of Twist-1 protein in the nucleus of myeloma cells in the extramedullary group was significantly higher than that of the bone marrow group. However, in the cytoplasm of myeloma cells, there was no significant difference in the expression level of Twist-1 protein between the extramedullary group and the bone marrow group. The expression level of Twist-1 protein in extramedullary tissue was not related to sex, age, D-S stage, ISS stage, immunoglobulin type, creatinine and hemoglobin. The expression level of β2-microglobulin in Twist-1 high expression group was significantly higher than that of Twist-1 low expression group. Follow-up findings discovered that overall survival (OS) of Twist 1 high expression group was significantly lower than that of Twist 1 low expression group. COX multivariate analysis showed that Twist 1 protein and International Staging System (ISS) stage were independent risk factors affecting OS for 3 years. The high expression rate of Twist 1 protein in extramedullary lesions of MM patients with extramedullary lesions is significantly higher than that in bone marrow tissues of patients with extramedullary lesions. The results suggest that high expression of Twist 1 protein is an independent risk factor affecting the prognosis of MM patients with extramedullary lesions.